CN105850029B - Power inverter - Google Patents

Abstract

The problem to be solved by the present invention is: when obtaining the induced voltage coefficient of a motor whose motor constant is unknown, if the information related to the motor is insufficient and it is difficult to estimate the approximate value of the induced voltage coefficient, etc., if the input approximate value is consistent with the motor's If the true values are significantly different, the control of the sensorless control unit becomes unstable, resulting in abnormal rotation of the motor, and the induced voltage coefficient cannot be obtained. The power conversion device provided by the present invention includes: an AC conversion unit that converts DC power into required AC power; a current detection unit that detects the current of a connected synchronous motor; coordinate conversion of the current detected by the current detection unit a current conversion unit; a voltage calculation unit that provides instructions to the above-mentioned AC conversion unit; a control calculation unit that provides instructions to the above-mentioned voltage calculation unit; and an abnormality detection unit that judges the abnormality of the current detected by the above-mentioned current detection unit. The unit performs speed control of the synchronous motor based on the abnormality determination determined by the abnormality detection unit, thereby performing control to accelerate or decelerate the synchronous motor, and starts acquisition of an induced voltage coefficient of the synchronous motor.

Description

power conversion device

technical field

The present invention relates to power conversion devices.

Background technique

As the background art of this technical field, there is Japanese Patent No. 4300730 (Patent Document 1). This publication describes a permanent magnet motor device, which has "a device provided in the above-mentioned inverter control unit to recognize (identify) the above-mentioned permanent magnet motor before and during the operation of the above-mentioned permanent magnet motor. The constant identification unit of the motor constant composed of the resistance component, the d-axis inductance component, the q-axis inductance component, and the angular velocity proportional coefficient of the induced voltage when the permanent magnet rotates, that is, the back electromotive force constant."

In the above-mentioned constant recognition unit, the back electromotive force constant is determined by "forced operation of separate excitation controlled by an inverter without the sensorless control unit 3 estimating the position, or by inputting a certain approximate value as the back electromotive force constant and driving the motor by a certain method." 1", "after rising to a predetermined speed provided in advance, maintain a stable rotation state at this speed" for identification.

Patent Document 1: Japanese Patent No. 4300730

Contents of the invention

The above-mentioned Patent Document 1 discloses a method of measuring the induced voltage coefficient of the permanent magnet induction of the permanent magnet motor before starting the operation. However, in this method, in a state where the motor constant such as the induction voltage coefficient is unknown, a certain approximate value is input and the motor is forcibly rotated by a certain method. Therefore, when there is insufficient information about the motor and it is difficult to estimate the approximate value of the motor constant, if the input approximate value differs greatly from the true value of the motor, the control of the sensorless control unit becomes unstable, and there is a possibility of motor rotation. An error may occur and the induced voltage coefficient may not be acquired.

Therefore, the present invention provides a power conversion device that can obtain an induced voltage coefficient by rotating a motor whose motor constant is unknown.

In order to solve the above-mentioned problems, for example, the configuration described in the claims is adopted.

The present application includes various means for solving the above-mentioned problems, and an example of a power conversion device is given, which is characterized in that it includes: an AC conversion unit that converts DC power into required AC power; a current detection unit that detects the synchronization of the connection electric current of the motor; a current conversion unit that performs coordinate conversion on the current detected by the current detection unit; a voltage calculation unit that provides instructions to the AC conversion unit; a control calculation unit that provides instructions to the voltage calculation unit; and an abnormality detection unit that judges an abnormality of the current detected by the current detection unit, and the control calculation unit performs speed control of the synchronous motor based on the abnormality judgment judged by the abnormality detection unit, thereby accelerating the synchronous motor or deceleration control, start acquiring the induced voltage coefficient of the synchronous motor mentioned above.

According to the present invention, there is provided a power conversion device capable of obtaining an induced voltage coefficient by rotating a motor whose motor constant is unknown.

Problems, configurations, and effects other than those described above will be described through the description of the following embodiments.

Description of drawings

FIG. 1 is an example of a configuration diagram of a power conversion device in Embodiment 1. FIG.

FIG. 2 is a flow chart up to the start of acquisition of the induced voltage coefficient in Embodiment 1. FIG.

FIG. 3 shows the status of the rotational speed ω, the d-axis current Id, and the q-axis current Iq of the synchronous motor when an abnormal state is judged in the first embodiment.

FIG. 4 is a flow chart of obtaining the induced voltage coefficient in Embodiment 2.

FIG. 5 shows the status of the synchronous motor's rotation speed ω, d-axis current Id, q-axis current Iq, and q-axis voltage Vq when the induced voltage coefficient is obtained in the second embodiment.

FIG. 6 is a flow chart of obtaining the induced voltage coefficient in Embodiment 3. FIG.

Fig. 7 shows the status of the synchronous motor's rotation speed ω, d-axis current Id, q-axis current Iq, and q-axis voltage Vq when detecting the induced voltage coefficient in the third embodiment.

FIG. 8 is a flow chart of obtaining the induced voltage coefficient in Embodiment 4. FIG.

FIG. 9 is an example of a configuration diagram of a power conversion device in Embodiment 5. FIG.

FIG. 10 is a flowchart up to the start of acquisition of the induced voltage coefficient in Embodiment 5. FIG.

Symbol Description

101...Three-phase AC voltage; 102...DC conversion unit; 103...Smoothing capacitor; 104...AC conversion unit; 105...Synchronous motor; 106...Current detector; 107...Current conversion unit; 108... …control calculation unit; 109…voltage conversion unit; 110…storage unit; 111…abnormality detection unit; 112…display/operation unit; 901…induced voltage detector; 902…induced voltage detection unit

Detailed ways

Hereinafter, an embodiment will be described with reference to the drawings.

Example 1

In this embodiment, an example in which the induced voltage coefficient is acquired in a steady state when the induced voltage coefficient due to the rotation of the permanent magnet of the synchronous motor is unknown will be described.

FIG. 1 is an example of a configuration diagram of a power conversion device and a synchronous motor 105 according to the present embodiment.

In this embodiment, a three-phase AC power supply 101, a DC conversion unit 102, a smoothing capacitor 103, an AC conversion unit 104, a synchronous motor 105, a current detector 106, a current conversion unit 107, a control calculation unit 108, and a voltage conversion unit 109 are provided. , a storage unit 110 , an abnormality detection unit 111 , and a display/operation unit 112 .

The three-phase AC power supply 101 is, for example, a three-phase AC voltage supplied from a power company or an AC voltage supplied from a generator, and outputs it to the DC conversion unit 102 .

The DC conversion unit 102 is constituted by, for example, a DC conversion circuit composed of diodes or a DC conversion circuit using IGBTs and freewheeling diodes, and converts the AC voltage input from the three-phase AC power supply 101 into a DC voltage, and outputs it to the smoothing capacitor 103 . FIG. 1 shows a DC converter composed of diodes.

Smoothing capacitor 103 smoothes the DC voltage input from DC conversion unit 102 and outputs the DC voltage to AC conversion unit 104 . For example, when the output of the generator is a DC voltage, the smoothing capacitor 103 may directly input the DC voltage from the generator without passing through the DC conversion unit 102 .

The AC conversion unit 104 is composed of an AC conversion circuit using, for example, an IGBT and a flywheel diode, and receives the DC voltage of the smoothing capacitor 103 and an output command from the voltage conversion unit 109 as input, converts the DC voltage into an AC voltage, and outputs it to the synchronous motor 105 .

The current detector 106 is constituted by, for example, a Hall CT or a shunt resistor, and is disposed at the output unit of the power conversion device to detect the current flowing through the synchronous motor 105 and output it to the current detection unit 107 as a current detection value. The current detector 106 may be arranged at any position as long as it is arranged in a place where the three-phase output current can be estimated or directly detected. In FIG. 1 , an example of detecting the current flowing through the AC motor 105 is shown.

The current conversion unit 107 converts the current detection value input from the current detector 106 into current data Id and Iq of a two-axis coordinate system, for example, with the magnet axis as the d-axis and the axis perpendicular thereto as the q-axis, to the control calculation unit 108. , the storage unit 110 and the abnormality detection unit 111 outputs. Regardless of whether the data output by the current detector 107 is a three-phase current or a converted DC current, as long as the increase of the current can be determined.

The control computing unit 108 takes the current information output from the current conversion unit 107 , the current information stored in the storage unit 110 , the abnormality judgment command output from the abnormality detection unit 111 , and the operation command from the display/operation unit 112 as inputs. Then, based on the input information, the control computing unit 108 performs a control operation on the resistance R of the synchronous motor, the d-axis inductance Ld, the q-axis inductance Lq, the induced voltage coefficient Ke, the speed command ω*, and the current commands Id* and Iq* of the two-axis coordinate system. Computation is performed with the voltage commands Vd*, Vq*, and the command speed ω* and the voltage commands Vd*, Vq* are output to the voltage conversion unit 109 . In addition, the control calculation unit 108 calculates the induced voltage coefficient based on the input information.

The voltage conversion unit 109 receives the speed command ω* and the voltage commands Vd*, Vq* output from the control operation unit 108 as input, converts them into PWM output commands, and outputs them to the AC conversion unit 104 .

The storage unit 110 receives the current data output from the current conversion unit 107 as input, stores the current data in time, and outputs the data to the control calculation unit 108 .

For example, the abnormality detection unit 111 takes the current data output by the current conversion unit 107 as input, compares the rated current of the synchronous motor 102 with the current data output by the current conversion unit 107, and if it exceeds the above-mentioned rated current, determines that the driving state is abnormal. , an abnormality determination command is output to the control calculation unit 108 . The value to be compared with the current data acquired by the current conversion unit 107 may be data arbitrarily specified by the user. In addition, the abnormality detection unit 111 may also detect abnormalities in the driving of the synchronous motor, such as monitoring the DC voltage data of the smoothing capacitor 103 and judging an increase in the DC voltage data as an abnormal state, an increase in the temperature inside the power conversion device, etc. It is judged as an abnormality when it is high, when the input/output power increases, when the synchronous motor is out of step, and the like.

The display/operation unit 112 represents, for example, an operation panel or a user interface that is an analog input/output terminal, and outputs information input by a user, such as various setting values and operation commands, to the control calculation unit 108 .

FIG. 2 is a flow chart until the control computing unit 108 issues an instruction to start acquiring the induced voltage coefficient in the first embodiment. The flowchart in FIG. 2 is a flowchart at the time of auto-tuning for acquiring various motor constants as a preparation for operation.

FIG. 3 is a diagram showing the state of operation of the rotational speed ω and the currents Id and Iq in the first embodiment.

The control calculation unit 108 receives an induction voltage coefficient acquisition command input by the user through the display/operation unit 112 ( S201 ), starts acceleration of the synchronous motor ( S202 ), and issues a voltage command to the voltage conversion unit 109 . At this time, in order to make the calculation of the induced voltage coefficient described later more efficient, the higher the speed, the greater the influence of the unknown motor constant, and the higher the possibility that the rotation of the motor will become unstable. The induction voltage coefficient detection speed of the induction voltage coefficient calculation may be set in advance to 10% of the basic rotational speed of the synchronous motor.

Since the induced voltage coefficient is not known, the control calculation unit 108 determines a voltage command using the resistance component and inductance component of the synchronous motor acquired in advance and the current data input from the current conversion unit 107 , and outputs it to the voltage conversion unit 108 . The resistance component and the inductance component of the synchronous motor used in the control calculation unit 108 can be measured by manually applying a voltage using existing known techniques, and can also be measured through other process measurement actions. As long as the above-mentioned resistance component and inductance component can be obtained, can be any method.

In the model of the permanent magnet synchronous motor in a steady state, the following (Number 1) holds.

[number 1]

Here, R: resistance value, Ld: d-axis inductance value, Lq: q-axis inductance value, ω: rotational speed, Id: d-axis current, Iq: q-axis current, Ke: induced voltage coefficient, Vd: d-axis voltage, Vq: q-axis voltage.

Since the induced voltage coefficient is unknown, the control computing unit 108 considers the term of the rotational speed or the term of the product of the rotational speed ω and the induced voltage coefficient Ke to be sufficiently small to approximate (1) when the speed is relatively slow, using the following (Number 2) calculates the voltage command.

[number 2]

Here, ω*: command speed, Id*: d-axis current command, Iq*: q-axis current command, Vd*: d-axis voltage command, Vq*: q-axis voltage command. Also, if the induced voltage coefficient Ke can be estimated from the rated voltage of the synchronous motor, etc., a value other than 0 may be substituted into (1) as a fixed value for driving. Hereinafter, a case where the control calculation unit 108 outputs a voltage command to the voltage conversion unit by using (2) will be described.

The control calculation unit 108 calculates the voltage command using (2) to gradually increase the speed. However, since (Number 2) is not a complete model, as shown in Fig. 3, when the rotation speed gradually increases, the approximation of the term of the induced voltage coefficient is incorrect, so the control fails and the current increases. At this time, the control computing unit 108 sets the rated current of the synchronous motor as an abnormality occurrence level for the current data output from the current conversion unit 107, and judges whether an abnormality has occurred when the level exceeds this level (S203). When it is judged that an abnormality has occurred, it immediately decelerates to a steady state (S204), and starts detection of an induced voltage coefficient at a speed that becomes stable (S205).

On the other hand, when it is determined that no abnormality has occurred, the control computing unit 108 compares whether the speed command has reached the set induced voltage coefficient detection speed (S206), and starts detecting the induced voltage coefficient if it has reached it. On the other hand, when it has not reached, the control computing unit continues the acceleration of the synchronous motor (S207), and judges again whether or not an abnormality has occurred (S203). This driving method is an example, and any method may be used as long as the synchronous motor can be rotationally driven.

To obtain the induced voltage coefficient, the induced voltage coefficient may be calculated by the following (Expression 3) obtained by transforming (Expression 1). The control calculation unit 108 obtains the induced voltage coefficient Ke using the current data Id and Iq output from the current conversion unit 107 , the command speed ω*, the command voltage Vq*, the resistance value R obtained in advance, and the d-axis inductance Ld.

[number 3]

If there is rotational speed feedback from the synchronous motor, the actual rotational speed ω after feedback can also be used for the command speed ω*. If there is voltage feedback of the synchronous motor, the voltage command Vq* may use Vq obtained based on the actual voltage conversion after the feedback. In addition, if the current data Id, Iq becomes unstable due to external disturbances, etc., current commands Id*, Iq* may be used.

According to the method described above, by rotating a synchronous motor whose motor constant is unknown and obtaining the induced voltage coefficient in a stable driving state, the induced voltage coefficient can be obtained with high accuracy.

Example 2

In the present embodiment, the parts common to the first embodiment are described with the same symbols, and the different parts are described in detail.

The structure of this embodiment is the same as that of Embodiment 1, using FIG. 1 as an example of the structure diagram.

In Example 2, by performing control so that both the steady-state values of Id and Iq output from the current conversion unit 107 become near 0, Id and Iq in (Expression 3) are approximated to 0, and calculated by the following (Expression 4) Induction voltage coefficient. As a result, when the resistance component R and the inductance component Ld calculated before starting to obtain the induced voltage coefficient include errors, the induced voltage coefficient Ke can be obtained with high accuracy without being affected by the errors.

[number 4]

If there is rotational speed feedback from the synchronous motor, the actual rotational speed ω after feedback can also be used for the command speed ω*. If there is voltage feedback of the synchronous motor, the voltage command Vq* may use Vq obtained based on the actual voltage conversion after the feedback.

In addition, if it is difficult to control the steady-state values of both the output Id and Iq to 0, it is also possible to perform control to make only one of the steady-state values of Id or Iq 0, and use the modification of (Equation 3) as a method to obtain The formula for the induced voltage coefficient.

FIG. 4 is a diagram showing a flowchart of acquiring an induced voltage coefficient in Embodiment 2. FIG.

5 is a graph showing the rotational speed ω, currents Id and Iq, and voltage Vq in Embodiment 2. FIG.

The control computation unit 108 drives the synchronous motor to a stable driving state in the same manner as in the first embodiment, and starts detection of the induced voltage coefficient. First, the control computing unit 108 performs control so as to oscillate at a cycle that is a multiple of the frequency of the rotational speed of the synchronous motor and around zero current ( S401 ). By controlling in this way, the average value of Id becomes 0. In addition, when the output of Id is visually observed through the display/operation unit 112 or the like, it can be clearly confirmed that the Id is gradually controlled to become 0.

Next, the control computing unit 108 performs deceleration control of the synchronous motor as shown in FIG. 4 ( S402 ), and controls so that Iq becomes near zero current. In this example, Iq is a current related to the torque of the synchronous motor, and is controlled by utilizing the fact that it is positive during power running torque and negative during regenerative torque.

The control calculation unit 108, for example, uses ±1% of the rated current as the allowable detection range, and judges whether Iq is within the range (S403). If Iq is outside the range, the deceleration control of the synchronous motor will continue, and if it is within the range, Vq* and ω * is stored in the storage unit 110 (S404).

The control operation unit 108 calculates the average value of Vq* when it is vibrating, and calculates the induced voltage based on (Equation 4) using the speed command ω* and the averaged value of Vq* at at least one rotational speed Coefficient Ke (S405).

According to the above method, when the resistance component R and the inductance component Ld calculated before starting to obtain the induced voltage coefficient include errors, the induced voltage coefficient Ke can be obtained with higher accuracy without being affected by the errors.

Example 3

In the present embodiment, the parts common to the first embodiment are described with the same symbols, and the different parts are described in detail.

The structure of this embodiment is the same as that of Embodiment 1, using FIG. 1 as an example of the structure diagram.

Embodiment 3 is a modified example of Embodiment 2. Regarding both Id and Iq output by the control current conversion unit 107, the formula obtained by modifying (Numerical 3) or (Numerical 3) is used as the formula for calculating the induced voltage coefficient This point is the same as in Embodiment 2, and thus detailed description thereof will be omitted.

FIG. 6 is a diagram showing a flowchart of acquiring an induced voltage coefficient in Embodiment 3. FIG.

7 is a graph showing the rotational speed ω, currents Id and Iq, and voltage Vq in Embodiment 3. FIG.

The control computation unit 108 drives the synchronous motor to a stable driving state in the same manner as in the first embodiment, and starts detection of the induced voltage coefficient. The current conversion unit 107 outputs the current data Ida, Iqa, voltage data Vqa, and rotational speed ωa at the time ta when the steady state is achieved, and stores them in the storage unit 110 (S601). Next, the control calculation unit 108 reduces the current command Id* and Iq* at intervals of 0 at the same time (S602), decreases Id and Iq, and judges whether or not the values of Ida and Iqa stored initially are half or less (S603 ). If it is not judged to be less than half, the current commands Id* and Iq* are continuously decreased at intervals when they become 0 at the same time ( S602 ), and Id and Iq are decreased. On the other hand, when it is determined that the value of Ida or Iqa stored initially is less than half of the value, the current conversion unit outputs the current data Idb and Iqb, the voltage data Vqb, and the rotational speed ωb at the time tb, and stores them in the storage unit 110. (S604). Next, as shown in FIG. 7 , the control calculation unit 108 obtains the rotational speed ω0 and the voltage data Vq0 at the time t0 when the current Iq becomes 0 by extrapolation (S605). Specifically, it is calculated as follows.

First, time t0 at which Iq becomes 0 is obtained. Between the current Iq and the time t, the following (Equation 5) holds true.

[number 5]

Arranging (equation 5) for t0 yields the following (equation 6).

[number 6]

ω0 and Vq0 at time t0 when Iq becomes 0 can be obtained by the following (Expression 7) (Expression 8).

[number 7]

[number 8]

The control computing unit 108 substitutes the above result into (Expression 4), and calculates the induced voltage coefficient (S606).

According to the above method, when the resistance component R and the inductance component Ld calculated before starting to obtain the induced voltage coefficient include errors, the induced voltage coefficient Ke can be obtained with higher accuracy without being affected by the errors.

Example 4

In the present embodiment, the parts common to the first embodiment are described with the same symbols, and the different parts are described in detail.

The structure of this embodiment is the same as that of Embodiment 1, using FIG. 1 as an example of the structure diagram.

Embodiment 4 is an application example of Embodiment 1, Embodiment 2 and Embodiment 3. That is, the control calculation unit 108 uses the induced voltage coefficient acquired after the completion of any one of the first to third embodiments as an internal coefficient for the voltage command calculation, drives the synchronous motor, and performs the calculation of the induced voltage coefficient again. As a result, the induced voltage coefficient can be measured in a form closer to actual driving, and further, detection can be performed with a synchronous motor in a more stable driving state. In the calculation of the induced voltage coefficient, the higher the frequency, the higher the resolving power of the calculated induced voltage coefficient, so the higher the detection speed, the better.

FIG. 8 shows a flowchart up to the acquisition of the induced voltage coefficient by the control computing unit 108 in the fourth embodiment.

The control calculation unit 108 receives a command from the user to start acquiring the induced voltage coefficient from the display/operation unit 112 ( S801 ), starts acceleration of the synchronous motor ( S802 ), and issues a voltage command to the voltage conversion unit 109 . At this time, since the state of the induced voltage is not known, the control calculation unit 108 determines the voltage command using the previously obtained resistance component and inductance component of the synchronous motor and the current input from the current conversion unit 107 . The resistance component and inductance component of the synchronous motor used by the control calculation unit 108 can be measured by manually applying a voltage using known techniques, or can be measured by other process measurement operations, as long as the data can be obtained, it can be arbitrary. method.

As a low-speed induction voltage coefficient detection speed, the control calculation unit 108 is preset to 10% of the base rotation speed as a range that can be driven by (Expression 2), for example, and after it is determined that the detection speed has been reached (S803), the induction voltage is started. Coefficient detection (S804). The detection method of the induced voltage coefficient may be any method in Embodiments 1, 2, and 3. After detecting the induced voltage coefficient, the control calculation unit 108 reflects the data to the control calculation unit, and switches to perform the voltage command calculation using (number 1) (S805). The control operation part 108 accelerates again (S806), and as a high-speed induction voltage coefficient detection speed, presets 50% of the basic rotation speed as a range that can be driven by (number 1), for example, after it is determined that the detection speed has been reached (S807), start to acquire the induced voltage coefficient (S808). The method for obtaining the induced voltage coefficient may be any of the methods in Embodiments 1, 2 and 3. The control calculation unit 108 adopts the recalculated induced voltage coefficient as final data for driving the synchronous motor (S809).

According to the above method, the induced voltage coefficient can be measured in a form closer to actual driving, and further, detection can be performed with a synchronous motor in a more stable driving state.

Example 5

In the present embodiment, the parts common to the first embodiment are described with the same symbols, and the different parts are described in detail.

FIG. 9 is an example of a configuration diagram of the power conversion device and the synchronous motor 105 of this embodiment.

In this embodiment, a three-phase AC power supply 101, a DC conversion unit 102, a smoothing capacitor 103, an AC conversion unit 104, a synchronous motor 105, a current detector 106, a current conversion unit 107, a control calculation unit 108, and a voltage conversion unit 109 are provided. , the storage unit 110 , the abnormality detection unit 111 , the display/operation unit 112 , the induced voltage detector 901 , and the induced voltage detection unit 902 .

The induced voltage detector 901 detects the induced voltage generated in the synchronous motor 105 by being disposed in the output unit of the power conversion device or the synchronous motor, and outputs the induced voltage detection value to the induced voltage detection unit 902 as an induced voltage detection value. The induced voltage detector 901 detects, for example, a voltage between two phases among three phases as an inter-terminal voltage generated in a synchronous motor. The phase selection may be any phase among the three phases as long as it is between two phases.

The induced voltage detection unit 902 takes the induced voltage detection value output by the induced voltage detector 901 as an input, calculates the rotation speed ω of the synchronous motor according to the fluctuation cycle of the induced voltage detection value, calculates the induced voltage acquisition value Ve according to the induced voltage detection value, and performs control calculation The unit 108 and the storage unit 110 output the rotation speed ω and the induced voltage acquisition value Ve. When converted into the induced voltage acquisition value Ve, a peak value or an effective value may be used as long as it is converted in accordance with the unit calculated by the control calculation unit 108 .

The control calculation unit 108 uses the current information output by the current conversion unit 107, or the current information, rotational speed information, and induced voltage value information stored in the storage unit 110, the abnormality judgment command output by the abnormality detection unit 111, and the operation from the display/operation unit 112. command, and the rotational speed ω output by the induced voltage detection unit 902 and the acquired value Ve of the induced voltage are used as input, and the resistance R of the synchronous motor, the d-axis inductance Ld, the q-axis inductance Lq, the induced voltage coefficient Ke, the speed command ω*, and the two-axis The current commands Id*, Iq* and voltage commands Vd*, Vq* of the coordinate system are calculated, and the command speed ω* and voltage commands Vd*, Vq* are output to the voltage conversion unit 109 . In addition, the control calculation unit 108 calculates the induced voltage coefficient based on the input information.

The storage unit 110 receives the current data output from the current conversion unit 107 as input, stores the current data in time, and outputs the data to the control calculation unit 108 . Also, the storage unit 110 receives the rotational speed data and the induced voltage data output from the induced voltage detection unit 902 as input, stores each data in time when the induced voltage detection starts, and outputs the respective data to the control calculation unit 108 .

FIG. 10 is a flow chart until an instruction to start acquiring the induced voltage coefficient is issued in Embodiment 5. FIG.

The control calculation unit 108 receives a command from the user to start acquiring the induced voltage coefficient from the display/operation unit 112 (S1001), starts acceleration of the synchronous motor (S1002), and issues a voltage command to the voltage conversion unit 109. In this case, it is preferable that the induction voltage coefficient detection speed at which the user starts the induction voltage coefficient calculation be set in advance to, for example, 10% of the base rotational speed of the synchronous motor. Since the state of the induced voltage is unknown, the control calculation unit 108 determines the voltage command using the resistance component and the inductance component of the synchronous motor acquired in advance and the current input from the current conversion unit 107 . The resistance component and inductance component of the synchronous motor used by the control calculation unit 108 can be measured by manually applying a voltage using known techniques, or can be measured by other process measurement operations, as long as the data can be obtained, it can be arbitrary. method.

The control calculation unit 108 calculates the voltage command using (2) to gradually increase the speed. However, since (Number 2) is not a complete model, as shown in Fig. 3, when the rotation speed gradually increases, the approximation of the term of the induced voltage coefficient becomes incorrect, and the control fails, and the current increases. At this time, the control calculation unit 108 judges whether the current data output by the current conversion unit 107 is abnormal (S1003), and if it is judged that an abnormality occurs, the voltage command is cut off to allow the synchronous motor to run freely (S1004), and the induction motor starts to be acquired. Voltage coefficient (S1005).

On the other hand, when it is judged that no abnormality has occurred, the control calculation unit 108 compares whether the speed command has reached the set induced voltage coefficient detection speed (S1006), and if it has reached the speed command, cuts off the voltage command to make The synchronous motor becomes a free-running state to obtain an induced voltage coefficient. If not, the control calculation unit continues the acceleration of the synchronous motor (S1007), and judges again whether an abnormality has occurred (S1003). This driving method is an example, and any method may be used as long as the synchronous motor can be rotationally driven.

The control computing unit 108 performs computation using (Number 9) obtained by substituting (Number 4) for the actual induced voltage Ve and the rotational speed ω when the free running state is reached.

[Number 9]

If there is speed feedback from the synchronous motor, the speed ω can also use the speed after feedback. The induced voltage Ve at the time of free running of the synchronous motor is only a voltage generated by the permanent magnet, so Vq* of (Expression 4) can be substituted with the induced voltage Ve.

According to the above method, the induced voltage coefficient in a stable state can be acquired.

In addition, this invention is not limited to the said Example, Various modification examples are included. In addition, the present invention is not limited to the time of automatic tuning, but can also be applied to the time of normal operation of a synchronous motor and the like. For example, the above-mentioned embodiments have been described in detail for the purpose of explaining the present invention in an easy-to-understand manner, and are not necessarily limited to all the configurations described. In addition, it is possible to replace part of the structure of a certain example with the structure of another example, or to add the structure of another example to the structure of a certain example. In addition, other configurations can be added, deleted, or substituted for some of the configurations of the respective embodiments.

In addition, a part or all of the above-mentioned configurations, functions, processing units, processing units, etc. may be realized by hardware, for example, by designing with an integrated circuit or the like. In addition, each of the above-mentioned configurations, functions, and the like can also be realized by software by interpreting and executing a program for realizing each function by a processor. Information such as programs, tables, and files for realizing various functions can be stored in recording devices such as memory, hard disks, and SSDs (Solid State Drives), or recording media such as IC cards, SD cards, and DVDs.

In addition, the control lines and information lines show what are considered to be necessary for illustration, and do not necessarily show all the control lines and information lines on the product. In fact, it can also be considered that almost all structures are connected to each other.

Claims (15)

1. a kind of power inverter, which is characterized in that including：

Converter section is exchanged, direct current power is converted into required AC power；

Current detecting part detects the electric current of the synchronous motor of connection；

Electric current converter section carries out coordinate conversion to the electric current detected by the current detecting part；

Voltage operational portion provides instruction to the exchange converter section；

Operational part is controlled, instruction is provided to the voltage operational portion；With

Abnormity detection portion judges the exception of the electric current detected by the current detecting part,

It is described control operational part based on the synchronous motor without using induced voltage coefficient model or used prediction The model of induced voltage coefficient to provide instruction to the voltage operational portion, and according to the exception carried out by the abnormity detection portion Judge to carry out the speed control of the synchronous motor, thus into the control for exercising the synchronous motor acceleration or deceleration, Start to obtain the induced voltage coefficient of the synchronous motor.

2. power inverter as described in claim 1, it is characterised in that：

In the case where the abnormity detection portion is judged as exception, the control operational part makes the speed of the synchronous motor subtract It is small, start to obtain the induced voltage coefficient after deceleration.

3. power inverter as described in claim 1, it is characterised in that：

In the case where the abnormity detection portion is not judged as exception, the control operational part continues to make the synchronous motor Accelerate, after having reached the rotating speed that can obtain the induced voltage coefficient, starts to obtain the induced voltage coefficient.

4. power inverter as claimed in claim 2, it is characterised in that：

The current data obtained from the current detecting part is converted into the d shaft current values on two axial coordinates by the electric current converter section With orthogonal to that q shaft current values,

The control operational part detects the dynamic value of the d shaft currents value and the q shaft currents value to predict steady-state value, obtains The induced voltage coefficient.

5. power inverter as described in claim 1, it is characterised in that：

After obtaining the first induced voltage coefficient, the control operational part is anti-by the first induced voltage coefficient of acquisition It reflects to the voltage operational portion, the synchronous motor is made to again speed up, at least carry out the second induced voltage of primary acquisition The operation of coefficient.

6. power inverter as claimed in claim 5, it is characterised in that：

The second induced voltage coefficient, than obtain the first induced voltage coefficient when it is described synchronize it is electronic It is obtained under the fast rotating speed of the rotating speed of machine.

7. power inverter as claimed in claim 4, which is characterized in that have：

Storage part stores the d shaft currents value and the q shaft currents value,

The voltage operational portion is controlled will be stored in multiple d shaft currents values and the q axis in the storage part At least one of current value current value is average and becomes steady-state value.

8. power inverter as claimed in claim 4, it is characterised in that：

The voltage operational portion extrapolates to the variation of at least one of current value current value, is controlled such that it As steady-state value.

9. power inverter as claimed in claim 4, it is characterised in that：

The voltage operational portion controls at least one of current value current value, and steady-state value is made to become near 0.

10. power inverter as described in claim 1, which is characterized in that have：

Induced voltage detector, the induced voltage that the connected synchronous motor of detection generates,

It is judged as that abnormal situation or reached can detect the speed of the induced voltage coefficient in the abnormity detection portion In the case of, the control operational part cuts off the output order in the voltage operational portion, and the synchronous motor is made to become freely Operating condition starts the induced voltage coefficient for obtaining the synchronous motor.

11. a kind of power transferring method, which is characterized in that including：

Direct current power is converted into the exchange switch process of required AC power；

Detect the current detection step of the electric current of the synchronous motor of connection；

The electric current switch process of coordinate conversion is carried out to the electric current detected in the current detection step；

The voltage operational step of instruction is provided the exchange switch process；

The control calculation step of instruction is provided the voltage operational step；With

Judge that the electric current detected in the current detection step has anomalies detecting step without exception,

It is described control calculation step based on the synchronous motor without using induced voltage coefficient model or used prediction The model of induced voltage coefficient to provide instruction to the voltage operational step, and judge according to by the anomalies detecting step The presence or absence of it is abnormal into the control for exercising the synchronous motor acceleration or deceleration, start the induced electricity for obtaining the synchronous motor Press coefficient.

12. power transferring method as claimed in claim 11, it is characterised in that：

The control calculation step is judged as depositing in an exceptional case, inhibits described and synchronize electricity in the anomalies detecting step The speed of motivation starts to obtain the induced voltage coefficient after speed reduction.

13. power transferring method as claimed in claim 11, it is characterised in that：

The control calculation step is judged as, there is no in the case of exception, continuing to make the synchronization in the abnormity detection portion Motor accelerates, and after having reached the rotating speed that can obtain the induced voltage coefficient, obtains the induced voltage coefficient.

14. power transferring method as claimed in claim 12, it is characterised in that：

The current data obtained from the current detecting part is converted into the d shaft currents on two axial coordinates by the electric current switch process Value and orthogonal to that q shaft current values,

The control calculation step detection with when the time change, synchronous motor slows down the d shaft currents value and The q shaft currents value predicts steady-state value, obtains the induced voltage coefficient.

15. power transferring method as claimed in claim 11, it is characterised in that：

The control calculation step, after obtaining the first induced voltage coefficient, by first induced voltage system of acquisition Number is reflected into the voltage operational step, and the synchronous motor is made to again speed up, and obtains the second induced electricity at least once Press coefficient.