KR102421851B1 - Motor assembly and method for controlling same - Google Patents

Abstract

The present invention relates to a motor assembly comprising a three-phase double winding. The present invention, a stator having a plurality of slots; a first coil wound so that a three-phase alternating current is applied to each of the plurality of slots of the stator, and a second coil separated from the first coil and having a predetermined phase difference from the first coil; a rotor rotating by a rotating magnetic field generated by the first coil and the second coil; a first inverter unit generating a three-phase alternating current applied to the first coil to generate a rotating magnetic field; a second inverter unit generating a three-phase alternating current applied to the second coil to generate a rotating magnetic field; and a control unit configured to drive the first inverter unit and the second inverter unit by setting the first coil as a reference phase and setting the second coil as the predetermined phase difference from the reference phase.

Description

Double winding motor assembly and method for controlling the same

The present invention relates to a motor assembly comprising a three-phase double winding.

The use of a rotating magnetic field created by using three coils and three-phase alternating current is called a three-phase rotating field, and it is used in three-phase induction motors and three-phase synchronous motors. A three-phase rotating magnetic field is formed by arranging three coils with equal performance, such as number of turns and size, at an interval of 120 degrees from the central position and allowing each phase of three-phase alternating current to flow through each coil.

Similarly, a land motor can be used through a land winding, but in general, a dual-winding system using a dual-inverter system to control one three-phase three-phase alternating current using a dual-winding system. of the motor is used.

It is used in high-speed elevators, submarines, aircraft, and automobiles that require high stable operation. This is because if one inverter fails, it can be driven by the other inverter, so it can be driven even in an emergency such as a failure. That is, a three-phase double-winding type motor is used where there is a need for stable operation.

The three-phase double winding type motor may include two windings, that is, a first coil and a second coil. In terms of driving the motor, when a three-phase current flows through the first coil, a first combined torque is formed therein. However, when a three-phase current flows through the other three-phase winding, that is, the second coil, the resulting second combined torque is formed.

Accordingly, the combined torque of the three-phase double winding synchronous motor may be determined as the vector sum (final combined torque) of the first combined torque and the second combined torque.

In order to generate the maximum combined torque, two pairs of three-phase currents must flow to match the physical shape of the motor for this combined torque.

However, the current applied to the first coil and the second coil and the physical shape of the first coil and the second coil do not match each other (especially the phase difference), so the vector of the first combined torque and the second combined torque is For example, when the magnitude is the same and the direction is opposite, the instantaneous torque of the motor may be continuously '0'.

As such, if the combined torque does not become the maximum combined torque, more current must flow in the same load. Such a case may correspond to a misconnection.

Accordingly, there is a need to detect such misconnection and, in some cases, correct such misconnection to normal wiring.
A technique for detecting such a misconnection is disclosed in the following prior art document as an example.

1. Patent Publication No. 2000-0021116 (published on April 15, 2000)

An object of the present invention is to provide a dual winding motor assembly capable of detecting miswiring of a double winding when driving a three-phase double winding type motor, and a method for controlling the same.

Another object of the present invention is to provide a dual winding motor assembly and a control method thereof, capable of driving a motor in a normally connected state by detecting an erroneous wiring of the double windings.

In order to solve the above problem, in the three-phase double winding type motor, the physical phase between the two windings and the phase difference between the output of the two inverter units are detected to determine whether there is an erroneous connection, and then the physical phase between the two windings and the two windings are detected. A desired inverter output can be secured by matching the phase difference between the inverter outputs.

For example, in a motor including a first coil wound so that a three-phase alternating current is applied and a second coil separated from the first coil and having a predetermined phase difference with the first coil, generating a rotating magnetic field with the first coil A first inverter unit generating a three-phase alternating current applied to the second coil and a second inverter unit generating a three-phase alternating current applied to generate a rotating magnetic field to the second coil may be connected.

At this time, the first coil and the first inverter are connected and the second coil and the second inverter are connected by comparing calculated values including the maximum values of the respective output voltages of the first and second inverters. At least one misconnection may be determined.

As a specific example, the present invention, a stator having a plurality of slots; a first coil wound so that a three-phase alternating current is applied to each of the plurality of slots of the stator, and a second coil separated from the first coil and having a predetermined phase difference from the first coil; a rotor rotating by a rotating magnetic field generated by the first coil and the second coil; a first inverter unit generating a three-phase alternating current applied to the first coil to generate a rotating magnetic field; a second inverter unit generating a three-phase alternating current applied to the second coil to generate a rotating magnetic field; and a control unit configured to drive the first inverter unit and the second inverter unit by setting the first coil as a reference phase and setting the second coil as the predetermined phase difference from the reference phase.

In this case, the control unit compares the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit to connect the first coil and the first inverter unit, and to connect the second coil and the second inverter unit. At least one misconnection of the inverter unit may be determined.

In addition, the control unit may determine that the calculated value including the maximum value of each of the output voltages of the first inverter unit and the second inverter unit is normal within a predetermined range.

In addition, the control unit may correct the misconnection when the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit do not match within a predetermined range.

In addition, the operation of correcting the misconnection may reset the phase difference of the second coil.

Also, the reset phase difference may be one of ±integer multiples of the predetermined phase difference.

In addition, the predetermined phase difference may be 30 degrees or -30 degrees, and the reset phase difference may be any one of ±30, ±150, and ±270.

In addition, the reset phase difference may include a value such that the combined torque by the first coil and the second coil represents a maximum value.

In addition, the calculated value including the maximum value of the output voltage may be an output ratio of the maximum value of the output voltage to the torque component voltage.

In addition, the calculated value including the maximum value of the output voltage may be an output ratio of the q-axis voltage when the three-phase AC component is converted into a two-phase AC component including the d-axis and the q-axis compared to the maximum value of the output voltage.

In addition, the first inverter unit and the second inverter unit generate a control signal for turning on/off each three-phase alternating current applied to the first coil and the second coil symmetrically during a preset switching period. can do it

As another specific example, the present invention provides a stator having a plurality of slots; a first coil wound so that a three-phase alternating current is applied to each of the plurality of slots of the stator, and a second coil separated from the first coil and having a predetermined phase difference from the first coil; a rotor rotating by a rotating magnetic field generated by the first coil and the second coil; a first inverter unit generating a three-phase alternating current applied to the first coil to generate a rotating magnetic field; and a second inverter unit generating a three-phase alternating current applied to the second coil to generate a rotating magnetic field, wherein the first coil is set as a reference phase and the second coil is set to the second coil. driving the first inverter unit and the second inverter unit by setting the predetermined phase difference from a reference phase; and comparing the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit, among the connection of the first coil and the first inverter unit and the connection of the second coil and the second inverter unit. The method may include determining at least one misconnection.

In addition, when the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit coincide within a predetermined range, it may be determined that the operation is normal.

In addition, when the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit do not match within a predetermined range, the misconnection may be corrected.

In addition, the calculated value including the maximum value of the output voltage may be an output ratio of the q-axis voltage when the three-phase AC component is converted into a two-phase AC component including the d-axis and the q-axis compared to the maximum value of the output voltage.

In addition, the first inverter unit and the second inverter unit generate a control signal for turning on/off each three-phase alternating current applied to the first coil and the second coil symmetrically during a preset switching period. can do it

On the other hand, an embodiment of the control method of the present invention includes the steps of applying a command voltage vector according to the pulse width modulation control using a space vector; determining the magnitude and angle of the command voltage vector on a d-q plane; Among the 12 sectors divided by the first space voltage vector by the first inverter unit and the second space voltage vector by the second inverter unit on the d-q plane, the command voltage vector is determined according to the angle of the command voltage vector. determining a location; calculating an application time of an effective voltage vector and a zero voltage vector necessary for rotation of the rotor among a first space voltage vector and a second space voltage vector according to a sector in which the command voltage vector is located; and turning on/off a switching unit of the first inverter unit and a switching unit of the second inverter unit to generate a space voltage vector required for the calculated application time.

In this case, when the command voltage vector is located in the 3n-1 th sector (n=1,2,3,4), the effective voltage vector and the necessary first space voltage vector through Equation 1 below The application time of the effective voltage vector among the second space voltage vectors may be calculated.

When the command voltage vector is located at a location corresponding to the 3n-2th sector (n=1,2,3,4), the effective voltage vector and the second space among the first space voltage vectors required through Equation 2 below The application time of the effective voltage vector among the voltage vectors can be calculated.

In addition, when the command voltage vector is located at a location corresponding to the 3n-th sector (n=1,2,3,4), the application time of the effective voltage vector among the space voltage vectors required can be calculated through Equation 3 below. .

[Equation 1]

[Equation 2]

[Equation 3]

According to the present invention, there are the following effects.

First, according to the present invention, in a three-phase dual winding type motor, it is possible to determine whether a erroneous connection is made by detecting a phase difference between the physical phase between the two windings and the output of the two inverter units.

Accordingly, it is possible to prevent a decrease in driving efficiency and a decrease in the efficiency of the motor due to an increase in the loss of the inverter unit due to miswiring.

In addition, a desired inverter output can be secured by matching the physical phase between the two windings and the phase difference between the outputs of the two inverters.

1 is a schematic circuit diagram showing a power conversion device for driving a three-phase double-winding motor that can be applied to the present invention.
2 is a view showing the appearance of two coils wound on the motor and terminals respectively connected thereto.
3 is a diagram illustrating a modeling of the winding arrangement of a three-phase double-winding motor.
4 is a schematic diagram illustrating a part of a state in which the first coil and the second coil of the motor are wound in a distributed winding manner.
5(a) to 5(c) are diagrams illustrating a method of decomposing a voltage reference vector using five inverter vectors.
5(d) to 5(f) are diagrams illustrating a method of decomposing a voltage command vector using four inverter vectors.
6 is a diagram illustrating a switching pattern in the case of using four composite vectors adjacent to a sector to which a voltage command vector belongs.
7(a) and 7(b) are diagrams for explaining a method of calculating an application time using a space vector pulse width modulation (SVPWM) in a three-phase alternating current.
8(a) to 8(c) are diagrams illustrating a method of calculating a voltage vector application time by dividing all 12 sectors into three cases.
9 is a flowchart illustrating a method for controlling a motor assembly according to an embodiment of the present invention.
10 is a flowchart illustrating a method of controlling a motor assembly according to another embodiment of the present invention.
11 is a schematic diagram illustrating a phase relationship reset by a motor assembly control method according to an embodiment of the present invention.
12 to 14 are diagrams illustrating current waveforms of the first coil and the second coil due to different phase differences, respectively.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical spirit disclosed in the present specification by the accompanying drawings.

Furthermore, although each drawing is described for convenience of description, it is also within the scope of the present invention that those skilled in the art implement other embodiments by combining at least two or more drawings.

It is also understood that when an element, such as a layer, region, or module, is referred to as being “on” another element, it may be directly on the other element or intervening elements in between. There will be.

1 is a schematic circuit diagram showing a power conversion device for driving a three-phase double-winding motor that can be applied to the present invention. 2 is a view showing the appearance of two coils wound on the motor and terminals respectively connected thereto. 3 is a diagram illustrating a modeling of the winding arrangement of a three-phase double-winding motor.

Here, FIG. 1 schematically shows a circuit diagram in which two inverters are connected to a three-phase double-winding motor.

Conventional AC motors include an induction motor and a synchronous motor, and both motors are based on the principle that the stator rotates a magnetic field to influence the rotor to rotate. This rotating magnetic field is called a rotating magnetic field. There are two types of motors using a rotating magnetic field: induction motors and synchronous motors. An induction motor is a motor that generates an induced current in the rotor by the rotating magnetic field of the stator and rotates by the electromagnetic force of the induced current. On the other hand, in the synchronous motor, the rotor rotates by magnetic attraction and repulsion by the rotating magnetic field of the stator.

AC motors use three-phase (three-phase) AC as a power source, and there are those that use single-phase AC. In general, expressions such as three-phase induction motor and three-phase synchronous motor are used, including the principle of rotation.

In particular, a rotating magnetic field created using three-phase alternating current is called a three-phase rotating magnetic field. In the case of an AC motor, a rotating magnetic field is generated by a fixed electromagnet. At this time, using three coils and three-phase alternating current is called a three-phase rotating magnetic field, and is used in three-phase induction motors and three-phase synchronous motors.

A three-phase rotating magnetic field is generated when three coils with equal performance, such as number of turns and size, are arranged at intervals of 120° from the central position and each phase of three-phase alternating current flows through each coil. The magnetic field of each coil becomes the same phase as a single-phase alternating current and draws a sinusoidal curve.

Each coil only repeats the reversal of strength and weakness, but the arrangement of each coil is out of phase by 120°, and the flowing three-phase alternating current is also out of phase by 120°. The composite magnetic field can change direction sequentially.

In an induction motor, AC power is supplied only to the three-phase stator windings. Three-phase windings made of insulated copper wire are placed at intervals of 120 degrees (electrical degrees) in several slots of the stator core. In general, the three-phase winding is connected by Y-Connection at high voltage and Δ-Connection at voltage. However, this is only an example and is not necessarily followed.

FIG. 1 is a partial circuit diagram of inverter units 15 and 25 for converting DC power into AC power and supplying it to a land (6-phase) motor and a land motor. Specifically, the land motor represents a three-phase double-winding motor assembly 30 (hereinafter referred to as a motor) controlled by the first inverter unit 15 and the second inverter unit 25 respectively supplying three-phase alternating current. That is, this is a form in which inverter units 15 and 25 including two three-phase inverters respectively controlling two three-phase winding coils are connected.

The first inverter unit 15 and the second inverter unit 25 include a three-phase inverter, which is a power conversion device for generating AC power of a voltage and frequency of an arbitrary size from the constant or variable DC power supply unit 10 . Each three-phase inverter arrangement may be arranged in any way as long as it can control the three-phase double-winding motor 30 or a motor having a total of six phases. That is, the first inverter unit 15 and the second inverter unit 25 may be connected independently and separately, or the first inverter unit 15 and the second inverter unit 25 may be integrated and connected to each other. .

In addition, the first inverter unit 15 and the second inverter unit 25 may be built-in to the motor 30 , but alternatively, the motor 30 may be controlled from the outside of the motor 30 . . Therefore, it is collectively referred to as a motor assembly in this specification. That is, the motor assembly is a concept including a motor composed of a coil, a stator, and a rotor, and a first inverter unit 15 and a second inverter unit 25 that control the motor. Therefore, even if the inverter part is built in the motor, it is only referred to as a motor assembly.

In FIG. 1 , the first inverter unit 15 and the second inverter unit 25 (hereinafter, the two inverters 15 and 25 will be collectively referred to as an inverter unit) have a direct current in order to maintain a constant DC power supply voltage. It shows that a capacitor 7 is connected in parallel between the power supply unit 10 and the inputs of the first inverter unit 15 and the second inverter unit 25 . The power supply unit 10 input to the first inverter unit 15 and the second inverter unit 25 may include a rectifier (not shown). That is, the power supply unit 10 may include at least one of a connection unit connected to commercial AC power, a rectifier, and a DC-DC converter that converts a DC voltage and improves a power factor. As another example, the power supply unit 10 may use a distributed power source such as a battery.

In addition, a control unit 100 called a motor control unit (MCU) may be connected to the inverter unit. In this case, the control unit detects the current or position of the motor 30, or after performing a calculation necessary for a pulse width modulation (PWM) method (eg, a space vector pulse width modulation (SVPWM) method), Through this, the switching elements Q101 to Q106 and Q201 to Q206 of the inverter can be turned on/off.

Such a control unit 100 may be built in the inverter unit. On the other hand, unlike this, the control unit may be located outside the inverter unit to control the motor 30 through a micro-controller or the like. On the other hand, the control unit 100 may be a concept including a driver (driver) for driving the switching elements (Q101 to Q106, Q201 to Q206).

In addition, the control method of the present invention can be applied regardless of whether it has a current sensor, a speed sensor, or a position sensor for detecting the speed or position of the motor. In addition, the present invention can be applied regardless of whether it is a synchronous motor or an asynchronous motor.

Looking specifically at the inverter units 15 and 25, as shown in FIG. 1 , two switching devices are required for each single phase in order to generate and control one single-phase AC. Since it is a three-phase alternating current, there are three single phases, and if they are referred to as first phase alternating current, second phase alternating current, and third phase alternating current, each single phase may have a phase difference of 120 degrees.

The first phase AC of the first inverter unit 15, for example, the U phase of the three-phase AC (U, V, W phase) of the first inverter unit 15 is the first phase of the first inverter unit 15 composed of two switching elements. 1It may be generated by the switching unit (or element) Q101 and Q104. The second phase AC of the first inverter unit 15, for example, the V phase of the three-phase AC (U, V, W phase) of the first inverter unit 15 is the second phase of the first inverter unit 15 composed of two switching elements. 2 may be generated by the switching units (or elements) Q103 and Q106. W-phase of the three-phase alternating current (U, V, W phase) of the first inverter unit 15, for example, of the three-phase alternating current (U, V, W phase) of the first inverter unit 15 is the second of the first inverter unit 15 composed of two switching elements. 3 may be generated by the switching unit (or element) Q105, Q102.

In addition, the X phase of the first phase alternating current of the second inverter unit 25, for example, the three-phase alternating current (X, Y, Z phase) of the second inverter unit 25 is the second inverter unit 25 composed of two switching elements. may be generated by the first switching unit (or element) Q201 and Q204 of The second phase alternating current of the second inverter unit 25, for example, the Y phase of the three-phase alternating current (X, Y, Z phase) of the second inverter unit 25 is the second of the second inverter unit 25 composed of two switching elements. 2 may be generated by the switching units (or elements) Q203 and Q206. The Z-phase of the three-phase alternating current (X, Y, Z phase) of the second inverter unit 25, for example, of the three-phase alternating current (X, Y, Z phase) of the second inverter unit 25 is the second inverter unit 25 composed of two switching elements. 3 may be generated by the switching unit (or element) Q205 and Q202.

For example, the first switching units Q101 and Q104 have a structure in which two switching elements Q101 and Q104 are connected in series, which is generally referred to as a pole, a leg, or an arm. The switching elements perform complementary switching of on/off alternately with each other. A DC power is input to both ends of the first switching units Q101 and Q104, and an AC voltage is output between the two switching units. This AC output voltage is called pole voltage. Since these two switching elements control one phase, all three switching units or six switching elements are required to control the three-phase alternating current.

1 shows six switching elements Q101 to Q106 in the first inverter unit 15 and six other switching elements Q201 to Q206 in the second inverter unit 25 .

Switching devices used in such basic circuits include a gate turn-off (GTO) thyristor, an insulated gate commutated transistor (IGCT), an insulated gate bipolar transistor (IGBT), and a metal oxide semiconductor field effect (MOSFET), which are semiconductor devices for power. Transistor) is typically used, and may be selected according to the power capacity and switching frequency required for the application field.

For example, GTO thyristors and IGBTs are the devices that can handle the largest capacity and are used in inverters of 10MVA or higher, but the possible switching frequencies are as low as 1kHz or less. The IGBT is the most widely used device and is used in the medium-capacity class of 10 MVA or less, and it can achieve a switching frequency of up to several tens of kHz. MOSFET is a small-capacity class and is used in low-voltage inverters of 600V or less.

In addition, diodes D101 to D106 and D201 to Q206 may be connected to each switching element in anti-parallel to the switch to protect the switching element.

In general, three-phase AC motors are widely used in motors using AC. A three-phase motor or three-phase induction motor refers to a device that obtains power by generating a rotating magnetic field using three single-phase alternating currents having different phases. In other words, it refers to a motor that rotates at each frequency of the applied power when AC is passed by connecting it to the windings arranged at 120° intervals.

A three-phase inverter circuit that controls a three-phase motor consists of three poles. Each pole switches independently of each other, each responsible for the output of one phase voltage.

The present invention relates to a three-phase double winding motor. Accordingly, the three-phase double winding motor refers to a motor in which two three-phase coils are controlled by the first inverter unit 15 and the second inverter unit 25, respectively, as shown in FIG. 1 .

That is, each of the first inverter unit 15 and the second inverter unit 25 for switching three phases has six switching elements. The first inverter unit 15 may include six switching elements Q101 to Q106 and may include six diodes D101 to D106 connected to each of the switching elements. The second inverter unit 25 may also include six switching elements Q201 to Q206 and may include six diodes D201 to D206 connected to each of the switching elements.

The present invention relates to a motor assembly including a three-phase double winding motor and two inverter units and a method for controlling the same. The reason for using a dual three-phase motor is to use a dual-winding three-phase AC in which each inverter controls one three-phase using a dual inverter system in a system requiring more stable driving. can

This is because, even if one inverter part fails, the other inverter part can be driven, so that it can be driven even in an emergency such as a failure.

2 shows an example of an AC motor having a coil for supplying two three-phase AC. The first terminal 311 for connecting the first coil 321 including the three-phase windings controlled by the first inverter unit 15 as a set, and the three-phase windings controlled by the second inverter unit 25 are connected to each other. The second terminal 312 for connecting the second coils 322 as a set is shown.

The first terminal 311 includes a first winding 321a (see FIG. 4(a)), a second winding 321b (see FIG. 4(a)) to which an alternating current of three phases U-phase, V-phase, and W-phase is applied, respectively; It is connected to the third winding 321c (refer to FIG. 4(a)). The second terminal 312 is a first winding 322a (refer to FIG. 4(a)), a second winding 322b (refer to FIG. 4(a)) to which three-phase X-phase, Y-phase, and Z-phase alternating current is applied, respectively; It is connected to the third winding 322c (refer to FIG. 4(a)). Here, it is illustrated as being connected to each other by different metal bars, but otherwise, any shape such as a shape of a bus bar may be used as long as it can be connected to each phase.

3 is a diagram schematically illustrating the arrangement of windings of the first coil 321 and the second coil 322 of the motor. In the first coil 321, U, V, and W-phase alternating current having a phase difference of 120° respectively flows to the windings arranged at intervals of 120°, and the second coil 322 is 120° to the windings arranged at intervals of 120°, respectively. X, Y, and Z-phase alternating current with a phase difference of can flow.

4 is a schematic diagram illustrating a part of a state in which the first coil and the second coil of the motor are wound in a distributed winding manner.

Figure 4 (a) shows a part of the motor 30 in which the first coil 321 and the second coil 322 are wound in a distributed winding method, and Figure 4 (b) shows the first coil 321 and the first coil 321 and The phase difference of each phase by the arrangement of the second coil 322 is shown.

The motor 30 also includes a stator 330 having a cylindrical structure and a rotor 350 including a rotating shaft, and an air gap between the stator and the rotor, as in a general motor. The stator and rotor can be made of an iron core of a ferromagnetic material to obtain a large magnetic flux density. As such an iron core, in order to reduce core loss, that is, hysteresis loss and eddy current loss caused by time-varying magnetic flux, thin silicon-alloy sheet steels are laminated and insulated between them. can

The first coil 321 and the second coil 322, which are three-phase windings composed of insulated copper wires or conductors, are inserted into several slots 315 formed by the iron core 316 of the stator 330 at intervals of 120 degrees (°). can be concentrated.

However, alternatively, as shown in FIG. 4 , copper wires or conductors of each phase may be distributed in several slots. That is, the conductors of each phase may be distributed in a sinusoidal number in several slots so that the air gap magnetic flux generated when a current flows in the first coil 321 or the second coil 322 has a sinusoidal waveform. This winding arrangement method is called the distributed winding method. Compared to the concentrated winding method in which all conductors are placed in a pair of slots, the utilization rate of the iron core structure is increased, and the harmonics of the air gap magnetic flux are reduced. Torque ripple can be reduced, so the distribution sphere is used more.

Referring to FIG. 4A , windings 321a, 321b, and 321c through which three-phase, that is, U-phase, V-phase, and W-phase alternating current of the first coil 321 flow in a distributed winding method are sequentially disposed, and between each In a distributed winding method, the windings 322a, 322b, and 322c through which three-phase, that is, X-phase, Y-phase, and Z-phase alternating current of the second coil 322 flow are sequentially arranged.

Fig. 4(a) shows an example of a stator having a total of 36 slots. Therefore, 9 slots corresponding to a quarter of them are shown. That is, according to the slot, the U-phase winding 321a, the X-phase winding 322a, the V-phase winding 321b, the Y-phase winding 322b, the W-phase winding 321c, and the Z-phase winding 322c are in six slots. It shows how they enter and are arranged alternately.

The first coil 321 and the second coil 322 are physically arranged to have a phase difference of 30 degrees (°) or -30 degrees. Hereinafter, a -30° phase difference is described as having a -30° phase difference because there is no difference in description with a 30° phase difference. Also, unlike U-phase AC and W-phase AC, V phase is marked with -V, which is only indicated by changing the direction of current flow depending on the winding method. For the same reason, Y-phase alternating current is indicated by -Y.

The rotor 350 may also have a structure in which a conductor of a thinly stacked ferromagnetic iron core is inserted similarly to the stator 330 . The rotor 350 may have various types of rotors depending on the induction motor or the synchronous motor.

Figure 4(b) shows that the U-phase and X-phase AC, V-phase and Y-phase AC, and the W-phase and Z-phase have a phase difference of 30°. When dealing with a three-phase system such as a three-phase motor or a three-phase AC motor, a, b, and c phase variables having a phase difference of 120°, which are commonly used, can be expressed as rotation vectors as shown in FIG. 4(b) . At this time, since the first coil 321 and the second coil 322 have a phase difference of 30°, the X, Y, and Z phases having a phase difference of 30° from the U, V, W phases can be displayed using a rotation vector. can

In addition, in order to match the structure of the motor 30 , a desired output can be obtained only when a current flows from the first inverter 15 and the second inverter 25 . If each winding of the first coil 321 and the second coil 322 is erroneously arranged, the physical phase does not match and the power factor of the first inverter 15 and the second inverter 25 is not matched. ) is degraded and the desired output cannot be obtained.

On the other hand, as shown in Fig. 4(a), the biggest characteristic of the motor structure using the three-phase alternating current is that the gap between the stator and the rotor, that is, the air gap is small. If the gap is small, the power factor can be improved by reducing the exciting current. On the other hand, when the gap is small, the harmonic effect of the magnetic field is strongly influenced, and the loss increases and the performance may be deteriorated.

If harmonics are generated, the motor may not start, not accelerate, or an abnormal sound may be generated during startup. Therefore, it is necessary to control the motor in the direction of predicting and reducing the occurrence of harmonics. Harmonics refers to a frequency that is an integer multiple of the fundamental wave. Harmonics cause mechanical vibration during operation, noise and reduced efficiency due to the increase in harmonic current, and ultimately shorten the life of the motor due to insulation breakdown. , because there is a risk of causing deformation and destruction.

5(a) to 5(c) relate to a method of decomposing a voltage reference vector using five inverter vectors in a conventional manner. 5(d) to 5(f) relate to a method of decomposing a voltage command vector using four inverter vectors.

In order to explain FIGS. 5(a) to 5(f), first, a space vector pulse width modulation (SVPWM) method using d-q-axis coordinate transformation and vector space decomposition. to explain about Since this is a well-known theory to those skilled in the art, it will be briefly described within the necessary scope. In other words, in the present specification, the space vector pulse width modulation method is briefly described with one three-phase alternating current, and then an embodiment of the present invention has been described using two three-phase alternating currents.

When dealing with a three-phase system such as a three-phase motor, variables on the Orthogonal Coordinates consisting of the d-axis, q-axis, and z-axis rather than using a, b, c phase variables as shown in Fig. 4(b). It is used after being transformed into a Cartesian coordinate system through Reference Frame Transformation. This is because it can be controlled more efficiently.

The d-axis (Direct axis) or the orthogonal axis of the converted Cartesian coordinate system is an axis in which the field flux of an electric motor is generated. The d-axis is a reference axis in vector control of an AC motor.

The q-axis (Quadrature Axis) or the abscissa axis of the converted Cartesian coordinate system is an axis that is perpendicular to the d-axis, which is the reference axis. do. The q-axis is the axis of current or counter electromotive force that generates torque in vector control.

The z-axis (Neutral Axis, or n-axis) or the neutral axis (or the image segment axis) of the transformed Cartesian coordinate system is an axis in which the d and q axes are orthogonal to each other in a three-dimensional space. This represents a loss component. The terms contributing to the generation of mechanical output in the motor are the d and q-axis components.

In general, in the case of a three-phase square wave inverter (Six step inverter or three-phase square wave inverters), the magnitude of the output voltage is fixed to the maximum, and only the frequency is controllable. In an inverter that drives an AC motor, it is necessary to modulate not only the frequency of the output voltage but also its magnitude. For this purpose, PWM (Pulse Width Modulation) technique is used.

These PWM methods include an optimal modulation method (Optimal/Programmed PWM), a triangular wave comparison modulation method (Carrier Based PWM), and a space vector pulse width modulation method (Space Vector PWM).

Among them, the space vector pulse width modulation method (SVPWM), unlike other PWM methods, uses three-phase voltage references as one space vector (Space It is a technique to modulate it by expressing it as a vector). This technique is currently the most widely used due to the fact that when a voltage modulated by this technique is applied to a motor through an inverter, there are fewer harmonics included in current and torque than other techniques.

In the space vector pulse width modulation (SVPWM) technique, since the voltage reference for the phase voltage is given as a space vector, the output voltage of the inverter of the inverter units 15 and 25 that will generate it is also converted to a space voltage vector. is expressed This is because the phase voltage depends not only on the switching state of the corresponding pole, but also on the switching state of the other two poles. Accordingly, the phase voltage refers to a voltage determined by the states of all switches of the inverter.

Through this, the switching functions of three phases, for example, a, b, and c phases, are called S _a , S _b , and S _c , respectively, and the switching function can be expressed as 1 when the above switch is on, and 0 when it is off. . In this way, the eight different switching states that can be output by the three switching parts of each inverter part of the switching function are expressed using six active voltage vectors and two zero voltage vectors. Since the switching unit of each phase has 0 or 1, a total of 8 switching states may exist in the case of 3 phases.

If this is expressed in the complex space of the d-q plane, it can be expressed as shown in Fig. 7(a). The superscript #1 denotes the first inverter unit 15, and the subscript denotes six effective voltage vectors. Two zero voltage vectors are indicated at the origin. A plane divided by each effective voltage vector is called a sector, and as shown in the figure, it can be divided into 6 sectors.

When the three-phase voltage reference changes with time, the voltage reference vector (V*) rotates counterclockwise in the complex space as above. At this time, the command voltage vector is a command voltage vector during a constant voltage modulation period T _s using two adjacent effective voltage vectors, V _n , V _{n +1} (n=1 to 5) and a zero voltage vector (V ₀ , V ₇ ). can produce the same voltage on average as In three-phase, the process of synthesizing voltage is repeated every voltage modulation period T _s determined by the switching frequency. In order to display the voltage modulation period and the command voltage vector, it may refer to the period in which the space voltage vector is modulated within one switching period. This is because there is an on-sequence voltage modulation cycle to turn on each switching unit and an off-sequence voltage modulation cycle to turn off each switching unit again. Here, both cases are referred to as a voltage modulation period (T _s ).

Referring to FIG. 7(b), one vector V ₁ among the effective voltage vectors adjacent to the command voltage vector V* is first applied for a time T _a . Then, a voltage with a magnitude of V ₁ ·(T _a /T _s ) is generated in the direction of V ₁ . The next step is to apply the remaining adjacent vector V ₂ for T _b time to match the phase and magnitude of the command voltage vector V*. Then, the zero voltage vector is applied for the time T ₀ = T _s -(T ₁ +T ₂ ) so that no more voltage is generated.

On the other hand, no matter what order the effective voltage and the zero voltage vector are applied within the voltage modulation period T _s , the average output voltage of the same magnitude can be obtained. However, various voltage modulation performance such as harmonic characteristics, switching frequency, and voltage utilization ratio may vary according to the application order. In particular, the magnitude of the ripple and the ripple frequency of the load current may vary according to the application position of the effective voltage vector. Therefore, in general, it is known that harmonic characteristics are best when the effective voltage vector is located at the center within the voltage modulation period T _s . In this case, the switching frequency may also be reduced. This is called Symmetrical Space Vector Pulse Width Modulation (SVPWM).

At this time, the sum of the voltage modulation period for turning on the inverter (On sequence) and the voltage modulation period for turning off the switch of the inverter (Off sequence) is referred to as a switching period. However, in general, if the effective voltage vector is placed in the center within the voltage modulation period T _s , the left and right patterns become symmetrical, so that one switching period is twice the two voltage modulation periods. That is, T _sw = 2·T _s . In addition, the number of switching is also minimized at this time, and the influence by harmonics can be minimized. In addition, the normal voltage modulation period is used the same as the current control period.

In other words, using 6 active voltage vectors and 2 zero vectors that can be output from _one inverter, the command voltage vector ( Reference voltage vector) can be generated, and through this, the on/off time of each switching element can be determined. That is, the switching function can be determined.

In the three-phase, the application time of the effective voltage vector and the zero voltage vector can be calculated by using Equation 4 below (Equations 1 to 3 are shown in FIG. 8, and referring to FIG. 8 below) explain).

In addition, the switching functions S _a , S _b , and S _c determined in this way have an on sequence and an off sequence in a symmetrical pattern during the switching period T _sw . In other words, a switching pattern can be referred to as a schematic diagram of the switching function of each phase according to the on sequence and the off sequence during one switching cycle. can make

That is, the switching pattern refers to a picture showing the three switching states of each inverter unit within one switching cycle according to the applied time according to the applied voltage command vector. Alternatively, according to the applied voltage command vector, it may refer to a picture showing the space voltage vector (two effective voltage vectors and zero voltage vector adjacent to the voltage command vector) according to the application time within one period of switching.

In three-phase AC, the switching pattern can always be a symmetrical pattern, which is the order of turning on and off the two effective voltage vectors and zero voltage vectors, respectively, in two voltage modulation cycles within one switching cycle. ) because the order is applied in reverse. This means that the control signal that turns on/off the three-phase by the inverter during the switching period is symmetrical.

Specifically, a signal for turning on/off the first switching unit Q101, Q104/Q201, Q104, the second switching unit Q102, Q105/Q202, Q205, and the third switching unit Q103, Q106/Q203, Q206 may be expressed symmetrically within the switching period. In addition, according to the on/off of the first switching unit Q101, Q104/Q201, Q104, the second switching unit Q102, Q105/Q202, Q205, and the third switching unit Q103, Q106/Q203, Q206 The voltages applied to the respective phase windings of the first coil and the second coil are symmetrical during the switching period.

For example, if you look at only the upper three of the switching patterns of FIG. 7(c), the patterns of three switching functions (S _a ^#1 , S _a ^{# 2} , S _a ^{# 3} ) are all symmetrical about half of T _sw . it can be seen that Also, this can be known by checking the output of the inverter terminal with a waveform analyzer, for example, an oscilloscope or a spectrum analyzer. Of course, the sampling time of the waveform analyzer may be affected by noise, but it can be seen that it is mathematically symmetrical.

So far, it has been about space vector pulse width modulation (SVPWM) in three-phase alternating current. If this is applied to a land motor or a three-phase double winding motor, one inverter that can control the land at the same time can be used, but two conventional three-phase inverters are used for more stable control. In this case, six sectors are generated by the inverters of the two inverter units 15 and 25, respectively, and each has a phase difference of 30 degrees.

FIG. 5(b) shows an inverter output voltage vector by the first inverter unit 15, and FIG. 5(c) shows an inverter output voltage vector having a phase difference of 30 degrees by the second inverter unit 25. Voltage Vectors) are shown in the complex space of the dq plane. A figure combining these two is shown in Fig. 5(a). Accordingly, the first effective voltage vectors V ₁ ^#1 to V ₆ ^{# 1} of the first inverter unit 15 are displayed in FIG. 5( b ), and the second inverter unit 25 in FIG. 5( c ). The second effective voltage vectors V ₁ ^#2 to V ₆ ^{# 2} are indicated. In addition, the second effective voltage vectors V ₁ ^#2 to V ₆ ^#2 of the second inverter unit 15 are displayed by rotating 30 degrees in consideration of the phase difference.

Fig. 5(a) shows a picture in which two hexagons are combined and shown on one plane. In addition, the first effective voltage vectors (V ₁ ^#1 to V ₆ ^#1 ) and the second effective voltage vectors (V ₁ ^#2 to V ₆ ^#2 ) are added to adjacent vectors to form 12 composite vectors (V ₁ to V). ₁₂ ) is expressed.

Specifically, the first effective voltage vectors (V ₁ ^#1 to V ₆ ^#1 ) and the second effective voltage vectors (V ₁ ^#2 to V ₆ ^#2 ) rotated by 30 degrees are synthesized between adjacent effective voltage vectors. can do. For example, V 1 #2 which is the first effective voltage vector of the second inverter unit 25 is V ₁ ^{#1 which} is the first effective voltage vector of the first inverter unit 15 and V ₂ which is the _second effective voltage vector. Since it is located between ^#1 , adjacent vectors of V ₁ # ² are V ₁ ^#1 and V ₂ ^#1 . When these two are synthesized separately, V ₂ and V ₃ can be synthesized. Similarly, when the rest are synthesized, all 12 synthesis vectors (V ₁ to V ₁₂ ) can be obtained. A region divided on the dq plane by the 12 composite vectors thus obtained is called a sector, and a total of 12 sectors can be obtained.

When the synthesized vector thus obtained is expressed as V ₁ to V ₁₂ , a total of 12 sectors are displayed in a counterclockwise direction using the area between the synthesis vectors V ₂ and V ₃ as sector 1 .

In this case, the z1-z2 plane may be represented as shown as the z1-z2 plane in the conventional method of Table 1 below.

On the other hand, the prior art generates two independent planes from which the vector interference component is removed by modeling through the winding of the land in this way. The three sub-spaces or planes are decomposed into the d-q plane, the z1-z2 plane and the o1-o2 plane. However, in the o1-o2 plane, since the first coil 321 and the second coil 322 are neutrally wound, they are always mapped to the origin, and only the d-q plane and the z1-z2 plane need to be considered. That is, a plane in which energy conversion is substantially performed is called a d-q plane, and a subspace representing harmonic components or energy loss is called a z1-z2 plane. As described above, the d-q plane is represented by 12 composite vectors, and a z plane can be obtained through a total of two z1 and z2 of three phases each. This is called Vector Space Decomposition.

In this case, the prior art requires four composite vectors to calculate four independent values from the coordinate axes on each plane. And the time (turn on time) for which the corresponding four composite vectors are applied must be calculated through the inverse matrix by calculating the size of each coordinate axis.

In this case, since the four composite vectors use a total of five effective voltage vectors, one inverter uses two effective voltage vectors, but the other inverter uses three effective voltage vectors, making it impossible to create a symmetrical pattern. In addition, since it is necessary to calculate the inverse matrix through the selected synthesis vector each time, the amount of computation increases, and the switching period increases to secure the computation time by the increased amount of computation.

For example, in order to display the voltage indicated by the voltage command vector A (Ref. A) in Fig. 5(a), a total of four synthesis vectors V ₁ , V ₂ , V ₃ and V ₄ are required (Fig. 5( In a), mark V ₁ , V ₂ , V ₃ and V ₄ in squares). This is because there are 4 variables in both the dq plane and the z1-z2 plane (see the first row of Table 1). Also, since the dq plane relates to the electromechanical energy, while the z1-z2 plane relates to the energy loss, the average voltage value for every sampling time should satisfy zero. In order to display each composite vector as an effective voltage vector again, five effective voltage vectors represented by V ₆ ^#2 , V ₁ ^#1 , V ₁ ^#2 , V ₂ ^#1 and V ₂ ^{# 2} are required ( In Fig. 5(a), V ₆ ^#2 , V ₁ ^#1 , V ₁ ^#2 , V ₂ ^#1 and V ₂ ^#2 are indicated in a rectangle). In one inverter unit, V ₁ ^#1 and V ₂ ^{# 1} indicated by a rectangle are used as in FIG. 5(b), whereas in the other inverter unit, a rectangle is used as in FIG. 5(c). Since we will use three V ₆ ^#2 , V ₁ ^#2 and V ₂ ^{# 2} marked with , it is impossible to make the switching pattern symmetrical.

6 shows a switching pattern in the case of using the prior art, that is, four composite vectors adjacent to the sector to which the voltage command vector belongs. The time for applying a voltage to the four adjacent synthesis vectors is calculated using four synthesis vectors in the d-q plane and the z1-z2 plane as in the conventional method shown in Table 1, It can be calculated only by finding the inverse matrix.

However, in Equation 5, V _d ^k denotes the magnitude on the d-axis of the k-th effective voltage vector, and V _q ^k denotes the magnitude on the q-axis of the k-th effective voltage vector. V _z1 ^k means the magnitude on the z1-axis of the k-th effective voltage vector, and V _z2 ^k means the magnitude on the z2-axis of the k-th effective voltage vector. And, V _d ^* and V _q ^* mean the d-axis and q-axis magnitude of the voltage command vector. T _s is the voltage modulation period, and T _k is the dwell time of the vector. However, T ₅ is the application time of the synthesis vector selected from the zero voltage vector on the dq plane.

By calculating T ₁ to T ₄ , which are effective synthesis vector application times, an example of a switching pattern of (R1) to (R12) for each sector of 12 can be represented as shown in FIG. 6 . Looking at the case of (R1), where the voltage command vector is in one sector, the switching functions of the three phases of the first inverter part are expressed as S _a ^#1 _, S _b ^{#1 ,} S _c ^#1 , and the three phases of the second inverter part are shown. The switching functions are denoted as S _a ^#2 _, S _b ^{#2 , and} S _c ^#2 . At this time, the pattern of the switching function per switching period is not formed symmetrically with respect to the center T ₀ . Similarly, it can be seen that all sectors are asymmetrically formed. Here, each time is displayed at the same interval, but this is only a display expression, and in reality, the interval may be different depending on the time of application.

In order to observe the pattern of the switch function of each phase, the output terminal of each inverter can be grasped through a waveform analyzer, for example, an oscilloscope or a spectrum analyzer.

In contrast, the control method of the present invention uses two adjacent effective voltage vectors for each inverter unit 15 and 25 instead of four composite vectors, and as in the above-described space vector pulse width modulation (SVPWM) method in the three-phase inverter, a switching pattern to make it symmetrical.

5(d) to 5(f) show the voltage command vector (Ref. B) in the two inverter units 15 and 25 according to the present invention for a total of four inverter effective voltage vectors by two adjacent effective voltage vectors. An example of making the switching pattern symmetrical using

Referring to FIG. 8A , the first effective voltage vectors V ₁ ^#1 to V ₆ ^#1 and the second effective voltage vectors V ₁ ^#2 to V ₆ ^{# 2} of the second inverter unit 25 are is displayed in the counterclockwise direction as above, whereas the effective voltage vector can be displayed in the z1-z2 plane representing harmonics as shown in the figure. Unlike the dq plane, V ₁ ^{# 1} and V ₁ ^{# 2} are not contiguous, which means that the dq plane shows the fundamental and harmonic components of 12m ± 1 (however, m=1,2,3…), whereas This is because z1-z2 represents a harmonic component of 6m±1 (however, m=1, 3, 5...).

FIG. 5(e) shows an inverter output voltage vector by the first inverter unit 15, and FIG. 5(f) shows an inverter output voltage vector having a phase difference of 30 degrees by the second inverter unit 25. Voltage Vectors) are shown in the complex space of the dq plane. A figure combining these two is shown in Fig. 5(d). Accordingly, the first effective voltage vectors V ₁ ^#1 to V ₆ ^{# 1} of the first inverter unit 15 are displayed in FIG. 5(e), and the second inverter unit 25 in FIG. 5(f). The second effective voltage vectors V ₁ ^#2 to V ₆ ^{# 2} are indicated. In addition, the second effective voltage vectors V ₁ ^#2 to V ₆ ^{# 2} of the second inverter unit 15 are displayed by rotating 30 degrees counterclockwise in consideration of the phase difference.

Specifically, the first effective voltage vectors (V ₁ ^#1 to V ₆ ^#1 ) and the second effective voltage vectors (V ₁ ^#2 to V ₆ ^#2 ) rotated counterclockwise by 30 degrees are shown in FIG. 5 ( When combined as in d), a total of 12 sectors can be distinguished. In FIG. 5(a), a sector is divided between each composite vector, whereas in FIG. 5(d), a region between which effective voltage vectors of each inverter are alternately arranged is divided into sectors. That is, the region or space between V ₁ ^#1 and V ₁ ^#2 may be distinguished as the twelfth sector, and the region or space between V ₁ ^#2 and V ₂ ^#1 may be distinguished as the first sector. In this case, each effective voltage vector can be expressed as in the first case of Table 1 in the z1-z2 space.

Fig. 5(d) shows a picture in which two hexagons are combined on a single plane by adding these two. However, unlike FIG. 5( a ), the effective voltage vector of each inverter is used as it is, rather than using a composite vector obtained by adding the effective voltage vectors of each inverter. Therefore, it is possible to make the switching pattern symmetrical like the three-phase SVPWM method by using the two effective voltage vectors selected in each inverter.

7(a) and 7(b) illustrate a method of calculating an application time using a space vector pulse width modulation (SVPWM) in a three-phase alternating current. This is the same method as obtaining the application time respectively performed in one inverter among the two inverter units 15 and 25 in the three-phase double winding motor. This is because two effective voltage vectors selected in each inverter are used. Therefore, it is the same as the three-phase AC method described in Arthur.

7( c ) shows the three-phase switching functions of the inverter unit S _a ^#1 _, S _b ^{#1 and} S _c ^{# 1} in each inverter unit 15 , 25 , and represents the three-phase operation of the second inverter unit 25 . When the switching functions of S _a ^#2 _, S _b ^{#2 , and} S _c ^#2 are expressed, an example of a pattern that can be generated during one switching period (T _sw ) is shown. It can be seen that the pattern is symmetric with respect to the time T _o ^#1 or T _o ^#2 for which the zero voltage vector is applied, respectively.

In addition, as described above, one switching period (T _sw ) is twice the aforementioned voltage modulation period (T _s ), and the switching function for applying each voltage vector during one T _sw is calculated after the time Ts elapses, i.e. , it can be seen that it is symmetrical about T _sw /2.

In addition, this may make the switching pattern symmetrical by placing the effective voltage vector at the center during one switching period (T _sw ).

The time for applying two effective voltage vectors and two zero voltage vectors adjacent to the command voltage vector applied by the first inverter unit 15 is the first application time T _a , the second application time T _b , and the third application time T _o It is denoted as ^#1 , and the time for applying two effective voltage vectors and two zero voltage vectors adjacent to the command voltage vector applied from the second inverter unit 25 is the fourth application time T _c , and the fifth application time T _d , represented by the sixth application time T _o ^{# 2} , the voltage modulation cycle of turning on and turning off the three switching units of each inverter during the switching period (T _sw ) is repeated, which is as soon as FIG. 7(c) appear in a symmetrical pattern. That is, since each inverter independently controls using two effective voltage vectors, the pattern can always have a symmetrical pattern with respect to the center of T _sw /2 just like the three-phase alternating current has a symmetrical pattern.

Here, the third application time T _o ^{# 1} is indicated to represent the remaining time obtained by subtracting the first application time T _a and the second application time T _b from one switching cycle (T _sw ) for convenience. The third application time T _o ^#1 appears at both ends and in the middle within one switching period T _sw of the first inverter unit 15 , but may be arbitrarily divided according to the command voltage vector. That is, it is not necessary to divide the time size of both ends and the middle by half. Even so, since the voltage modulation period is half of one switching period, the sum of the third application time, twice the first application time, and twice the second application time is equal to twice the switching period or voltage modulation period.

Similarly, the sixth application time T _o ^#2 is displayed to represent the remaining time after subtracting the fourth application time T _c and the fifth application time T _d from one switching cycle (T _sw ) for convenience. The sixth application time T _o ^#2 appears at both ends and in the middle within one switching period T _sw of the second inverter unit 25 , but may be arbitrarily divided according to the command voltage vector. That is, it is not necessary to divide the time size of both ends and the middle by half. Even so, since the voltage modulation period is half of one switching period, the sum of the sixth application time, the double fourth application time, and the double fifth application time is equal to twice the switching period or voltage modulation period.

Here, the squared part means a 1 that the switching part of each phase is turned on, and the unscaled part means a 0 that is not turned on. Therefore, when the space voltage vector of the first inverter unit 15 is checked in FIG. 5(c) for each, (0, 0, 0) → Ta _a during the first T _o ^#1 while (1, 0, 0) → T _b During (1, 1 ,0) → middle T _o ^#1 goes through a voltage modulation cycle that switches on (1, 1, 1 ) for half of the time, and again during the other half of center T _o ^{# 1} (1, 1, 1) → T _b while (1, 1, 0) → T _a During (1, 0,0) → During T _o ^#1 , it goes through a voltage modulation cycle that turns off the switch as (0, 0, 0). That is, when voltage vectors are applied in this order, a switching pattern in which the left and right sides are symmetrical during one switching period can be obtained.

Therefore, when the switching pattern is symmetrical, it means that the order of voltage vectors applied during the switching period T _sw appears symmetrically. Alternatively, it may mean that the switching function of each switching unit is symmetrical during the switching period T _sw . Alternatively, each single-phase alternating current applied to the first coil 321 and the second coil 322 by the first inverter unit 15 and the second inverter unit 25 according to the switching function is applied during the switching period T _sw . It can mean left-right symmetry.

Depending on the application time of the space voltage vector ^, the switching unit ^of each phase _is turned on or off during ^the switching period _{( T sw )} . As shown in FIG. 5( c ), it can be seen that each of the switching functions is also symmetrical.

Here, T _o ^#1 or T _o ^#2 is T _s twice in one switching cycle (T _sw ) Since there is , it comes out twice each, so the amount of time is T _o ^#1 = T _sw -2(T _a +T _b ) or T _o ^#2 =T _sw -2(T _c +T _d ) is satisfied. Here, in order to emphasize that the pattern appears symmetrically, T _o ^#1 or T _o ^#2 , which is the time for applying the zero voltage, is indicated to appear at the front, center, and rear of the switching function, but not the overall size. The size of the front and the back is the same because it is symmetrical, and the ratio of the center and the front can be different depending on the calculation.

FIG. 7( d ) shows a pattern form that can be produced for each of 12 sectors. That is, the pattern of each switching function per switching period in the first sector P1 to the twelfth sector P12 is shown. Depending on the magnitude of the application time, T _a and T _b or T _c and T _d may be changed, but the patterns are all symmetric about the center T _o ^#1 or T _o ^#2 . Also, it is symmetric with respect to T _sw /2. In each sector, T _a and T _b or T _c and T _d can be applied by analogy based on those indicated in the first sector P1 to the third sector P3 , and thus repeated expressions are omitted.

In the case of using the space vector or the symmetrical pattern of the switching function as described above, T _a and T _b , which are the application times required to decompose the command voltage vector in each inverter unit 15 , 25 and display it as two adjacent effective voltage vectors, respectively. Alternatively, looking at the method of calculating T _c and T _d , there are advantages as follows. That is, in the case of using the composite vector in the conventional method, an asymmetric pattern occurs, and instead of calculating the inverse matrix of all 5 rows and 5 columns each time, when the effective voltage vector of each inverter unit 15, 25 is rotated and used, According to the distribution, a total of three cases can be classified. Therefore, if the inverse matrix for the three cases is calculated in advance and stored and used according to the three cases, the amount of calculation in the inverter units 15 and 25 can be reduced by that much. That is, instead of the inverse matrix to be calculated for every operation, the calculation amount is reduced because it is calculated according to the table entered in advance with three patterns.

In addition, unlike the prior art, it may not be necessary to give up control of the z1-z2 plane for a symmetric pattern. This is because all three cases are classified into three cases according to how they are represented on the z1-z2 plane, and the application time can be calculated using different equations accordingly.

8(a) to 8(c) show equations for calculating the application time of the voltage vector by dividing all 12 sectors into three cases. In addition, Table 1 summarizes the d-q plane, z1-z2 plane, and inverse matrix equations in the prior art, and three cases classified in the present invention are also shown for comparison.

As described above, when the switching function within the switching period becomes symmetrical, harmonics are reduced and the number of switching can be minimized. Find the application times T _a and T _b or T _c and T _d for the switching function, and through this, T _o ^#1 = T _s -(T _a +T _b ) or T _o ^#2 = By calculating T _s -(T _c +T _d ), the application time of the zero voltage vector can be calculated. Also, here T _s = T _sw /2, that is, the voltage modulation period is equal to half of one switching period.

However, if the voltage command vector is moved after fixing the entire coordinate system in the d-q plane and the z1-z2 plane, the inverse matrix must be calculated every time the voltage command vector crosses a sector. Instead, when the voltage command vector crosses a sector, the entire coordinate system is rotated and four effective voltage vectors representing the voltage command vector can always be positioned in the first quadrant on the d-q plane. At this time, according to the distribution pattern of the corresponding effective voltage vector on the z1-z2 plane, it can be divided into three as shown in FIGS. 8(a) to 8(c).

8( a ) is a case in which the sector in which the voltage command vector is currently located is 3n-2 (where n=1,2,3,4). That is, the sector is the first sector, the fourth sector, the seventh sector, and the tenth sector. 8(b) is a case in which the sector in which the voltage command vector is currently located is 3n-1 (where n=1,2,3,4). That is, the sector is the second sector, the fifth sector, the eighth sector, and the eleventh sector. 8( c ) is a case in which the sector in which the voltage command vector is currently located is 3n (where n=1,2,3,4). That is, the sector is the third sector, the sixth sector, the ninth sector, and the twelfth sector. This is also summarized in Table 1.

In the first case of Table 1, that is, when the sector where the voltage command vector is currently located is 3n-2 (however, n=1, 2, 3, 4), display the voltage command vector located in the first sector on the dq plane For this, a total of 4 effective voltage vectors including V ₁ ^#1 , V ₂ ^#1 , V ₁ ^#2 , and V ₂ ^#2 are required. The fourth sector, the seventh sector, and the tenth sector correspond to the case of the first sector since they are all positioned in the first sector when rotated by 90 degrees, 180 degrees and 270 degrees. At this time, the distribution of four effective voltage vectors for V ₁ ^#1 , V ₂ ^#1 , V ₁ ^#2 , and V ₂ ^{# 2} in the z1-z2 plane is also shown. (See Table 1 or FIG. 8(a)) At this time, the formula to obtain T _a and T _b or T _c and T _d that are the application times of V ₁ ^#1 , V ₂ ^#1 , V ₁ ^#2 , and V ₂ ^#2 is It can be expressed as Equation 1. Here, V _mi means the magnitude of the voltage command vector, and θ means the angle between the voltage command vector and the d-axis in the counterclockwise direction.

In the second case of Table 1, that is, when the sector where the voltage command vector is currently located is 3n-2 (however, n=1, 2, 3, 4), in order to display the voltage command vector in the fourth sector on the dq plane A total of 4 effective voltage vectors including V ₂ ^#1 , V ₃ ^#1 , V ₁ ^#2 , and V ₂ ^#2 are required. The fourth sector, the seventh sector, and the tenth sector correspond to the case of the second sector since they are all positioned in the second sector when rotated by 90 degrees, 180 degrees and 270 degrees. At this time, if all of the effective voltage vectors are rotated by 30 degrees, the effective voltage vectors V ₂ ^#1 , V ₃ ^#1 , V ₁ ^#2 , and V ₂ ^{# 2} can all be displayed to be located in the first quadrant, which is the first same as case However, only the distribution of a total of four effective voltage vectors including V ₂ ^#1 , V ₃ ^#1 , V ₁ ^#2 , and V ₂ ^#2 is different in the z1-z2 plane (Table 1 or FIG. 8(b) ) Reference). Accordingly, the equations for obtaining T _a and T _b or T _c and T _d which are the application times of V ₂ ^#1 , V ₃ ^#1 , V ₁ ^#2 , and V ₂ ^#2 can be expressed as Equation 2 .

In the third case of Table 1, that is, when the sector where the voltage command vector is currently located is 3n (however, n=1, 2, 3, 4), V ₂ to display the voltage command vector in the third sector on the dq plane A total of 4 effective voltage vectors including ^#1 , V ₃ ^#1 , V ₂ ^#2 , and V ₃ ^#2 are required. When the 6th, 9th, and 12th sectors are rotated by 90 degrees, 180 degrees and 270 degrees, they are all the same as they are located in the third sector, so it corresponds to the case of the third sector. At this time, if all of the effective voltage vectors are rotated by 60 degrees, the effective voltage vectors V ₂ ^#1 , V ₃ ^#1 , V ₂ ^#2 , and V ₃ ^# can all be displayed to be located in the first quadrant. However, only the distribution of a total of four effective voltage vectors is different for V ₂ ^#1 , V ₃ ^#1 , V ₂ ^#2 , and V ₃ ^# in the z1-z2 plane (see Table 1 or FIG. 6(c)). In addition, an equation for obtaining T _a and T _b or T _c and T _d , which are the application times of V ₂ ^#1 , V ₃ ^#1 , V ₂ ^#2 , and V ₃ ^{# 2} , can be expressed as in Equation 3 .

Since the second case and the third case are eventually at the same position on the d-q plane through rotation, columns 1 and 2 of the matrices shown in Equations 1 to 3 are the same, and only the values of the z1-z2 plane are different. It can be seen that only the values in columns 3 and 4 change.

Since voltage command vectors of 12 sectors can be represented by classifying them into three cases, simply store three determinants in the inverter unit's storage unit (not shown), e.g., ROM, in advance, without the hassle of calculating the inverse matrix every time. It has the advantage of being able to calculate the application time. This leads to a reduction in the amount of computation, and thus the computation time can be reduced.

On the other hand, as mentioned above, in the winding structure of the motor 30, U-phase and X-phase AC, V-phase and Y-phase AC, and W-phase and Z-phase may have a phase difference of 30°. When dealing with a three-phase system such as a three-phase motor or a three-phase AC motor, a, b, and c phase variables having a phase difference of 120°, which are commonly used, can be expressed as rotation vectors as shown in FIG. 2(b) . At this time, since the first coil 321 and the second coil 322 have a phase difference of 30°, the X, Y, and Z phases having a phase difference of 30° from the U, V, W phases can be displayed using a rotation vector. can

In addition, in order to match the structure of the motor 30 , a desired output can be obtained only when a current flows from the first inverter 15 and the second inverter 25 . If each winding of the first coil 321 and the second coil 322 is erroneously arranged, the physical phase does not match and the power factor of the first inverter 15 and the second inverter 25 is not matched. ) is degraded and the desired output cannot be obtained.

In general, U-phase, V-phase, W-phase and the order of these phases in a three-phase motor are not determined, but each U-phase, V-phase, and W-phase set the award

At this time, according to the U-phase, V-phase, and W-phase standards arbitrarily set on the motor based on the rotation direction of the desired motor, connect the inverter and the motor to U-phase, V-phase and W-phase, or V-phase, W-phase and U-phase, or W-phase. , U-phase, and V-phase are connected in order, and there is no problem in controlling if only the input current value is exactly matched.

However, as described above, in the case of the motor 30 including the three-phase double winding according to the embodiment of the present invention, physically the first coil 321 (refer to FIG. 2 ) (U-phase, V-phase and W-phase) compared to the second The phases of the coil 322 (refer to FIG. 2 ) (X-phase, Y-phase, and Z-phase) may be determined with a predetermined phase difference.

For example, the first coil 321 may be wound with a reference phase, and the second coil 322 may be wound with a predetermined phase difference such as 30 degrees or -30 degrees from the reference phase. Hereinafter, a case in which the second coil 322 has a phase of -30 degrees with respect to the first coil 321 will be described as an example.

In this case, if the U-phase, V-phase, and W-phase are arbitrarily set in the first coil 321 , the X-phase, Y-phase, and Z-phase having a -30 degree phase difference may be determined in the second coil 322 .

In this way, in the state in which the first coil 321 and the second coil 322 are wound, as described above, when the inverter and the motor are connected, the first coil 321 and the first inverter 15 are connected, The second coil 322 and the second inverter 25 may be connected.

At this time, the connection between the first coil 321 and the first inverter 15 and the connection between the second coil 322 and the second inverter 25 are the U phase, V phase and W phase, and X phase and Y phase set above. and the first terminal 311 and the second terminal 312 in the Z-phase order.

In such a state, when three-phase current flows from the first inverter 15 and the second inverter 25 , the rotation direction and the phase order may be determined according to the order of the three-phase current.

Then, the three-phase combined torque may be instantaneously changed in the same direction as the rotation direction inside the motor 30 by the three-phase current.

As such, a desired output can be obtained only when current flows from the first inverter 15 and the second inverter 25 to match the winding structure of the motor 30 .

However, when the respective windings of the first coil 321 and the second coil 322 are erroneously arranged, the driving current output from the first inverter 15 and the second inverter 25 is the first coil 321 and the second coil 321 . Since the physical phase of the second coil 322 is not matched, the power factor of the first inverter 15 and the second inverter 25 is lowered, and thus a desired output may occur. This case is commonly referred to as 'misconnection'.

Such miswiring may occur during manufacturing or maintenance of the motor assembly. That is, it may occur when the motor assembly is initially manufactured, and may also occur during maintenance of the motor assembly thereafter.

When misconnection occurs in this way, according to the embodiment of the present invention, whether or not misconnection is determined using a calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 . can judge

That is, by comparing the calculated values including the maximum values of the respective output voltages of the first inverter unit 15 and the second inverter unit 25 , the first coil 321 and the first inverter 15 are connected and the first At least one misconnection of the two coils 322 and the second inverter 25 may be determined.

In terms of driving the motor 30 , when a three-phase current flows through the first coil 321 , a first combined torque is formed therein. However, when a three-phase current flows through the other three-phase winding, that is, the second coil 322, the resulting second combined torque is formed.

Accordingly, the combined torque of the three-phase double winding synchronous motor may be determined as the vector sum (final combined torque) of the first combined torque and the second combined torque.

In this combined torque, two pairs of three-phase currents must flow to match the physical shape of the motor 30 so that the maximum combined torque can be generated.

However, the current applied to the first coil 321 and the second coil 322 and the physical shape of the first coil 321 and the second coil 322 do not match each other (in particular, the phase difference), When the vectors of the first combined torque and the second combined torque have the same magnitude and opposite directions, for example, the instantaneous torque of the motor 30 may continue to be '0'.

Therefore, if this combined torque does not become the maximum combined torque, more current must flow in the same load. Such a case may correspond to a misconnection.

The determination of such a misconnection may be made by the control unit 100 (refer to FIG. 1 ) that controls the driving of the first inverter unit 15 and the second inverter unit 25 . Specific details of the control unit 100 are as described above. Hereinafter, a situation performed in the control unit 100 will be described as an example for the determination of misconnection and an operation resulting therefrom.

As such, the control unit 100 may determine that the calculated values including the maximum values of the respective output voltages of the first inverter unit 15 and the second inverter unit 25 match within a certain range, and thus determine that it is normal.

The predetermined range may be in consideration of impedance errors of the first coil 321 and the second coil 322 . Therefore, this range may be experimentally determined according to the motor 30 . For example, the predetermined range of the calculated value may be 90% or more. That is, if the calculated values including the maximum values of the respective output voltages of the first inverter unit 15 and the second inverter unit 25 coincide with each other by about 90% or more, it can be determined as a normal connection.

On the other hand, the control unit 100, if the calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 does not match within the predetermined range described above, correct the misconnection. to drive the motor 30 .

Correcting such a misconnection may include resetting the phase difference of the second coil 322 applied to the second inverter 25 .

The reset phase difference of the second coil 322 may be one of ±integer multiples of the above-described constant phase difference (-30 degrees). That is, when the predetermined phase difference is -30 degrees (or +30 degrees), the reset phase difference may be any one of ±30, ±150, and ±270.

That is, while changing the phase difference of the second coil 322 applied to the second inverter 25 as ±30, ±150, or ±270, it is possible to determine again whether the wrong connection is made.

Through this process, if the calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 is determined to be within the predetermined range described above, the case is determined as a normal connection, and the corresponding The motor 30 may be driven according to the connection.

At this time, the calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 is specifically each of the first inverter unit 15 and the second inverter unit 25 . It may be an output ratio of the torque component voltage to the maximum value of the output voltage.

More specifically, the calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 is the value of each of the first inverter unit 15 and the second inverter unit 25 . It may be an output ratio of the q-axis voltage when the three-phase AC component is converted into a two-phase AC component including the d-axis and the q-axis compared to the maximum value of the output voltage.

A specific example of determining the misconnection using a calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 will be described later in detail.

In this way, when the normal connection is determined, the first inverter unit 15 and the second inverter unit 25 turn on/off each three-phase alternating current applied to the first coil 321 and the second coil 322. The motor 30 may be driven by generating a control signal for turning on/off) symmetrically during a preset switching period.

9 is a flowchart illustrating a method for controlling a motor assembly according to an embodiment of the present invention. Also, FIG. 10 is a flowchart illustrating a method of controlling a motor assembly according to another exemplary embodiment of the present invention.

Hereinafter, a method of controlling a motor assembly according to an embodiment of the present invention will be described with reference to FIG. 9 . As described above, this method of controlling the motor assembly may be performed by the controller 100 described above.

First, different phase angles (phase differences) may be set between the first coil 321 (winding 1) and the second coil 322 (winding 2) ( S10 ).

As described above, this phase difference may be -30 degrees. That is, physically, the second coil 322 may be wound with a phase difference of -30 degrees compared to the first coil 321 . Accordingly, a phase angle of -30 degrees may be set between the first coil 321 and the second coil 322 in order to drive the motor 30 .

Thereafter, a current command may be applied to the first coil 321 (winding 1) and the second coil 322 (winding 2) (S20).

That is, according to the current command of the two windings of the first coil 321 and the second coil 322 , a current required for starting the motor may be applied.

At this time, at least one of the same starting current and speed command may be set and applied to the first coil 321 and the second coil 322 .

For driving the motor 30, a speed control unit that receives a speed command value input inside and outside the control unit 100 and outputs a current corresponding thereto, a current control unit that generates a voltage using the current of the speed control unit, and the output current of the motor A sensorless estimator for estimating the position/speed of the motor may be provided. Since these matters are general matters, a detailed description thereof will be omitted.

On the other hand, in order to apply a current to the first coil 321 and the second coil 322, only the current control unit may be used among the above-mentioned configurations. That is, only the current command can be set. Alternatively, in some cases, both the speed and the current command may be set.

Thereafter, the motor 30 is driven according to a current command to the first coil 321 (winding 1) and the second coil 322 (winding 2), and the first inverter unit 15 and the second inverter unit 25 are A calculated value including the maximum value of each output voltage may be calculated.

An error may occur in the output voltage of the first inverter unit 15 and the second inverter unit 25 according to a difference in impedance between the first coil 321 and the second coil 322 . However, in the three-phase winding, if the impedances of the first coil 321 and the second coil 322 are similar, the ratio of the maximum value of the inverter output voltage to the q-axis voltage is similar.

In addition, as described above, it can be controlled by mathematically vector-converting the three-phase AC component into the two-phase DC component (d-axis and q-axis). In this case, the phase information of the motor 30 may be used. In general, the d-axis means the magnetic flux component and the q-axis means the torque component.

Such phase information may be estimated by using a measuring device such as an encoder, a resolver, a hall sensor, etc. installed in the motor 30 or by using a sensorless estimator.

In general, when controlling the torque component of the motor 30 using the q-axis voltage, the q-axis voltage component may be relatively larger than the d-axis voltage.

Therefore, if the impedances of the first coil 321 and the second coil 322 are similar, the ratio of the maximum value of the inverter output voltage to the q-axis voltage can be obtained, respectively (S30).

와 같이 나타낼 수 있다. 따라서, 위에서 설명한 제1인버터부(15) 및 제2인버터부(25)의 각각의 출력 전압의 최대치를 포함하는 계산값은

를 포함할 수 있다.Here, the maximum value of the inverter output voltage is

can be expressed as Therefore, the calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 described above is

may include.

(#1) 및

(#2)와 같이 나타낼 수 있다. 이하, 제1인버터부(15) 및 제2인버터부(25)의 각각의 출력 전압의 최대치를 포함하는 계산값은 제1코일(321) 및 제2코일(322)의 임피던스가 유사하다면 인버터 출력 전압의 최대치와　q축 전압의 비를 의미하는 것으로 설명한다.Specifically, if the impedances of the first coil 321 and the second coil 322 are similar, the ratio of the maximum value of the inverter output voltage to the q-axis voltage is each

(#1) and

It can be expressed as (#2). Hereinafter, a calculated value including the maximum value of each output voltage of the first inverter unit 15 and the second inverter unit 25 is the inverter output if the impedances of the first coil 321 and the second coil 322 are similar. It will be explained as meaning the ratio of the maximum voltage to the q-axis voltage.

Therefore, it is possible to determine whether a misconnection is made using these two values (#1 and #2).

At this time, as described above, if the impedances of the first coil 321 and the second coil 322 are similar and the ratio of the maximum value of the inverter output voltage to the q-axis voltage matches within a certain range, it may be determined as normal.

The predetermined range may be in consideration of impedance errors of the first coil 321 and the second coil 322 . Therefore, this range may be experimentally determined according to the motor 30 . For example, the predetermined range of the calculated value may be 90% or more. That is, if the impedances of the first coil 321 and the second coil 322 are similar, if the ratio of the maximum value of the inverter output voltage to the q-axis voltage matches each other by about 90% or more, it can be determined as a normal connection.

That is, if the two values (#1, #2) match 90% or more (or more), it can be determined as a normal connection (S40).

At this time, if the impedance of the first coil 321 and the second coil 322 is similar, if the ratio of the maximum value of the inverter output voltage to the q-axis voltage is less than 90%, it may be determined as a misconnection ( S40 ).

Accordingly, the motor 30 can be driven by correcting (compensating) the erroneous wiring (S50).

In the operation of correcting such a misconnection, as described above, the above calculated value may be obtained by resetting the phase of the second coil 322 as ±30, ±150, and ±270 (S30).

Thereafter, by comparing the calculated values obtained using the reset phase, it is possible to repeatedly determine whether there is a misconnection.

On the other hand, when it is determined that the wiring is erroneous according to the requirements of the system including the motor 30 and the inverter units 15 and 25 , the phase is reset after stopping the system, and the motor 30 can be driven again.

In addition, even when it is determined that the wiring is erroneous, continuous operation may be possible by resetting the phase without stopping the motor 30 .

In the case of FIG. 9 , even when it is determined that the wiring is erroneous, the phase may be reset without stopping the motor 30 to perform continuous operation and may correspond to a process of determining whether or not the wiring is erroneous.

On the other hand, in the case of FIG. 10 , when it is determined that the wiring is erroneous, the current command applied to the first coil 321 and the second coil 322 may be stopped ( S45 ). Thereafter, as described above, after resetting the phase ( S50 ), a current command is applied to the first coil 321 and the second coil 322 again ( S20 ), and the subsequent process may be performed.

In the case of FIG. 10, when it is determined that the wiring is erroneous, it is the same as the embodiment of FIG. 9 except for the process of stopping (S45) the current command applied to the first coil 321 and the second coil 322. omit

11 is a schematic diagram illustrating a phase relationship reset by a motor assembly control method according to an embodiment of the present invention.

As described above, the operation by the motor assembly control method according to an embodiment of the present invention resets the phase of the second coil 322 as ±30, ±150 and ±270 to obtain the above calculated value. There is (S30).

If the current connection is a normal connection, the inverter output when the U phase, V phase, and W phase of the first coil 312 and the X phase, Y phase and Z phase of the second coil 322 are set to a difference of -30 degrees The ratio of the maximum value of the voltage to the q-axis voltage will be calculated as the maximum value. That is, in the above example, it will match within 90% of the range.

However, in the process of comparing the calculated values by obtaining the above calculated values by resetting the phase of the second coil 322 as ±30, ±150 and ±270 as it is determined to be a misconnection, as shown in FIG. 10, ± A calculated value by any one of 30, ±150, and ±270 may be calculated as the maximum value. That is, in the above example, it can match within 90% of the range, and the connection due to the phase difference at this time can be determined as the normal connection.

Then, thereafter, the motor 30 can be driven by the phase difference set in the normal connection as described above.

12 to 14 are diagrams illustrating current waveforms of the first coil and the second coil due to different phase differences, respectively.

As described above, the phase change (reset) is possible during operation of the motor 30 (in the case of FIG. 9 ), and may also be detected by restarting the motor 30 after stopping and changing the phase (in the case of FIG. 10 ). ).

12 to 14 show waveforms for changing (resetting) the phase from -30 degrees to +30 degrees. That is, in FIG. 12, when the phase difference between the first coil 321 and the second coil 322 is -30 degrees, in FIG. 13, when the phases of the first coil 321 and the second coil 322 are the same, and in FIG. 14 shows a case where the phase difference between the first coil 321 and the second coil 322 is +30 degrees.

As in the embodiment shown in FIG. 9 , when changing the phases of the first coil 321 and the second coil 322 during operation of the motor 30, it is preferable to gradually change the phases to avoid system instability. can

At this time, the gradient of the change gradually changing may be experimentally obtained according to the gain of the current controller and the load of the system.

As described above, according to the present invention, in a three-phase double winding type motor, it is possible to determine whether a erroneous connection is made by detecting a physical phase between the two windings and a phase difference between the outputs of the two inverter units.

Accordingly, it is possible to prevent a decrease in driving efficiency and a decrease in the efficiency of the motor due to an increase in the loss of the inverter unit due to miswiring.

In addition, a desired inverter output can be secured by matching the physical phase between the two windings and the phase difference between the outputs of the two inverters.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments.

The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

15: first inverter unit 25: second inverter unit
7: capacitor 30: motor
100: control unit
311: Terminal 1 312: Terminal 2
321: first coil 322: second coil
330: stator 350: rotor

Claims (20)

a stator having a plurality of slots;
a first coil wound so that a three-phase alternating current is applied to each of the plurality of slots of the stator, and a second coil separated from the first coil and having a predetermined phase difference from the first coil;
a rotor rotating by a rotating magnetic field generated by the first coil and the second coil;
a first inverter unit generating a three-phase alternating current applied to the first coil to generate a rotating magnetic field;
a second inverter unit generating a three-phase alternating current applied to the second coil to generate a rotating magnetic field; and
a control unit configured to drive the first inverter unit and the second inverter unit by setting the first coil as a reference phase and setting the second coil to the predetermined phase difference from the reference phase;
The control unit compares a calculated value including the maximum value of each output voltage of the first inverter unit and the second inverter unit, and connects the first coil and the first inverter unit, and the second coil and the second inverter unit. Determining a misconnection of at least one of the connections,
The control unit is
When it is determined that the normal connection is made, the motor is driven by the phase difference set in the normal connection,
When it is determined as a misconnection, the misconnection is corrected by resetting the phase difference of the second coil with respect to the reference phase applied to the second inverter to match the actual arrangement of the first coil and the second coil. motor assembly. The method according to claim 1, wherein the control unit determines that it is normal if the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit match within a predetermined range,
The predetermined range is set in consideration of impedance errors of the first coil and the second coil. The method of claim 1, wherein the control unit corrects the misconnection when the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit do not match within a certain range,
The predetermined range is set in consideration of impedance errors of the first coil and the second coil. delete The motor assembly according to claim 1, wherein the reset phase difference is one of ±integer multiples of the predetermined phase difference. The motor assembly according to claim 5, wherein the predetermined phase difference is 30 degrees or -30 degrees, and the reset phase difference is any one of ±30, ±150, and ±270. The motor assembly according to claim 1, wherein the reset phase difference includes a value such that the combined torque by the first coil and the second coil exhibits a maximum value. The motor assembly according to claim 1, wherein the calculated value including the maximum value of the output voltage is an output ratio of the maximum value of the output voltage to the torque component voltage. The method according to claim 1, wherein the calculated value including the maximum value of the output voltage is an output ratio of the q-axis voltage when the three-phase AC component is converted into a two-phase AC component including the d-axis and the q-axis compared to the maximum value of the output voltage. Motor assembly, characterized in that. The method according to claim 1, wherein the first inverter unit and the second inverter unit apply a control signal for turning on/off each three-phase alternating current applied to the first coil and the second coil during a preset switching period. A motor assembly, characterized in that it is generated symmetrically. a stator having a plurality of slots; a first coil wound so that a three-phase alternating current is applied to each of the plurality of slots of the stator, and a second coil separated from the first coil and having a predetermined phase difference from the first coil; a rotor rotating by a rotating magnetic field generated by the first coil and the second coil; a first inverter unit generating a three-phase alternating current applied to the first coil to generate a rotating magnetic field; and a second inverter unit for generating a three-phase alternating current applied to generate a rotating magnetic field with the second coil,
driving the first inverter unit and the second inverter unit by setting the first coil as a reference phase and setting the second coil as the predetermined phase difference from the reference phase;
At least among the connection of the first coil and the first inverter part and the connection of the second coil and the second inverter part by comparing a calculated value including the maximum value of each output voltage of the first inverter part and the second inverter part determining any one of the misconnections;
driving the motor according to the phase difference set in the normal connection when it is determined that the normal connection is made; and
If it is determined that the wiring is misconnected, correcting the misconnection by resetting the phase difference of the second coil with respect to the reference phase applied to the second inverter to match the actual arrangement of the first coil and the second coil. Control method of the motor assembly, characterized in that. The method according to claim 11, wherein if the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit coincide within a predetermined range, it is determined as normal,
The control method of the motor assembly, characterized in that the predetermined range is set in consideration of the impedance error of the first coil and the second coil. The method according to claim 11, wherein if the calculated values including the maximum values of the respective output voltages of the first inverter unit and the second inverter unit do not match within a certain range, the misconnection is corrected,
The control method of the motor assembly, characterized in that the predetermined range is set in consideration of the impedance error of the first coil and the second coil. delete The method of claim 11 , wherein the reset phase difference is one of ±integer multiples of the predetermined phase difference. The method of claim 15, wherein the predetermined phase difference is 30 degrees or -30 degrees, and the reset phase difference is any one of ±30, ±150, and ±270. The control method of a motor assembly according to claim 11, wherein the reset phase difference includes a value such that the combined torque by the first coil and the second coil exhibits a maximum value. The method of claim 11 , wherein the calculated value including the maximum value of the output voltage is an output ratio of the maximum value of the output voltage to the torque component voltage. The method of claim 11 , wherein the calculated value including the maximum value of the output voltage is an output ratio of the q-axis voltage when the three-phase AC component is converted into a two-phase AC component including the d-axis and the q-axis compared to the maximum value of the output voltage. Control method of the motor assembly, characterized in that. The method of claim 11 , wherein the first inverter unit and the second inverter unit apply a control signal for turning on/off each three-phase alternating current applied to the first coil and the second coil during a preset switching period. A control method of a motor assembly, characterized in that it is generated symmetrically.

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