WO2023047468A1

WO2023047468A1 - Motor drive device having dynamic braking circuit

Info

Publication number: WO2023047468A1
Application number: PCT/JP2021/034637
Authority: WO
Inventors: 総齊藤; 力鹿川
Original assignee: ファナック株式会社
Priority date: 2021-09-21
Filing date: 2021-09-21
Publication date: 2023-03-30
Also published as: JP7640725B2; JPWO2023047468A1

Abstract

This motor drive device comprises: a storage unit for storing the prespecified parameters of a registered motor; a dynamic braking circuit; a calculation unit for calculating, using the rotational speed per unit time of a driven motor when the dynamic braking circuit starts braking and the parameters stored in the storage unit, information about an estimated value of dynamic braking current flowing while the dynamic braking circuit is braking; a measurement unit for obtaining information about the measured value of the dynamic braking current during braking by the dynamic braking circuit; and a determination unit for determining, on the basis of the result of the comparison between the information about the estimated value of the dynamic braking current and the information about the measured value of the dynamic braking current, whether the driven motor is consistent with the registered motor or not.

Description

MOTOR DRIVE WITH DYNAMIC BRAKE CIRCUIT

The present invention relates to a motor drive device having a dynamic braking circuit.

Dynamic braking, which short-circuits the input terminals of the motor and applies dynamic braking, is widely used in motor drive devices that drive motors that power machines such as machine tools and robots.

For example, a power semiconductor module in which electronic components are mounted on an insulating substrate inside a housing and controls a three-phase AC motor provided outside the housing, the upper stage connected to each other in series on the insulating substrate A plurality of sets of switching elements each having a pair of a side element and a lower side element, a diode element connected in anti-parallel to the switching elements, and dynamic brake switching provided between any two phases of the three-phase AC motor. There is known a power semiconductor module characterized by comprising an element and (see, for example, Patent Literature 1).

For example, power conversion means for converting DC power into three-phase AC power, current detection means for detecting the current flowing in the output line of the power conversion means for each phase, and a motor driven by the current flowing in the output line. a speed detecting means for detecting the rotation speed of the motor; a relay for short-circuiting each of the output lines by a back contact directly or via a current limiting means when the motor is in a non-driving state; a failure detection means for detecting a failure of the relay or the current limiting means based on the detection output of the current detection means and the detection output of the speed detection means when the motor is in the non-driving state, is known (see, for example, Patent Document 2).

For example, in a motor drive device having a dynamic brake circuit that generates a deceleration torque in a motor, the torque flowing to the dynamic brake circuit is based on the motor rotation speed and the parameters defined in advance for the motor and the dynamic brake circuit. a dynamic braking current calculator for calculating a value of the dynamic braking current; and a dynamic braking current applied to the contacts of the relay during the dynamic braking period based on the value of the dynamic braking current obtained by the dynamic braking current calculator. a Joule heat calculation unit for calculating Joule heat by a dynamic braking current value at the start of dynamic braking; and the dynamic brake current value obtained by the dynamic brake current calculation unit at the start of the dynamic brake each time the dynamic brake is started. Joule heat due to the arc obtained from the table, Joule heat due to the dynamic braking current obtained by the Joule heat calculation unit during the dynamic braking period, or the sum of the Joule heat due to these arcs and the Joule heat due to the dynamic braking current and a comparison unit that compares the integrated value obtained by the integration unit with a preset reference value and outputs a comparison result. (See Patent Document 3, for example).

JP 2010-098919 A JP-A-2000-253687 JP 2017-022940 A

For machines such as machine tools and robots, the optimum motor is selected according to the operation of the machine, and the motor drive device is designed according to the selected motor. Machines such as machine tools and robots are used for many years while being repaired. When repairing a machine, use of the machine even if the motor that powers the machine is different from the motor that was originally selected, such as a third-party motor instead of the manufacturer's genuine motor, or a manufacturer's genuine motor. The motor may be replaced with a motor that is not suitable for If a motor with specifications different from the selected motor is replaced and the motor is connected to a motor drive device and operated, the motor will operate unexpectedly and damage the machine, the motor incorporated in the machine, and the motor. The motor driving device that drives the motor breaks down, or the surroundings of the machine are adversely affected. For example, it is conceivable to determine whether or not the motor is a manufacturer-genuine motor suitable for use in the machine based on the ID information given to the motor, but it is necessary to provide the motor with a storage unit for storing the ID information , which is a factor of high cost. In addition, a complicated design such as processing for passing ID information between the motor and the motor driving device is required, and moreover, it takes time and effort to write the ID information in the storage unit. Therefore, it is desired to realize a low-cost and easy-to-manufacture motor drive device that can determine whether or not an expected motor is attached.

According to one aspect of the present disclosure, a motor drive device short-circuits a storage unit that stores predetermined parameters for a registered motor and an input terminal of the motor that is being driven through a dynamic brake resistance, thereby using a dynamic brake circuit that brakes the driving motor by generating a deceleration torque at a constant speed, the number of revolutions per unit time of the driving motor at the start of braking by the dynamic brake circuit, and the parameters stored in the storage unit, a calculation unit for calculating information about an estimated value of the dynamic braking current flowing between the motor being driven and the dynamic braking circuit during braking by the dynamic braking circuit; a measuring unit that acquires information about the measured value of the dynamic braking current flowing between the motor and the registered motor based on the result of comparison between the information about the estimated value of the dynamic braking current and the information about the measured value of the dynamic braking current; a determination unit that determines whether or not they match.

According to one aspect of the present disclosure, it is possible to realize a low-cost and easy-to-manufacture motor drive device that can determine whether or not an expected motor is attached.

1 illustrates a motor drive device according to an embodiment of the present disclosure; FIG. 4 is a flow chart showing the operation flow of the motor driving device according to the embodiment of the present disclosure; FIG. 5 is a diagram illustrating a current waveform of an estimated value of dynamic brake current calculated by a calculator in the motor drive device according to the embodiment of the present disclosure;

A motor drive device having a dynamic brake circuit will be described below with reference to the drawings. In each drawing, similar parts are provided with similar reference numerals. Also, to facilitate understanding, the scales of these drawings are appropriately changed. The illustrated forms are examples of implementations and are not limited to these forms.

FIG. 1 is a diagram showing a motor drive device according to one embodiment of the present disclosure.

A motor driven by the motor driving device 1 according to one embodiment of the present disclosure is called a "driving motor". A motor that is registered in advance as being permitted to be connected to the motor drive device 1 is referred to as a "registered motor". The driving and registration motors may be, for example, induction motors or synchronous motors. For example, the registered motor may be a motor that is selected at the time of design as a power source for a machine such as a machine tool or a robot and is permitted to be connected to the motor drive device 1 provided in the machine, or a motor manufactured by a genuine manufacturer. can be Motors that are different from registered motors include, for example, motors manufactured by a genuine manufacturer whose specifications are different from those originally designed, and motors manufactured by third parties.

In one embodiment of the present disclosure, a motor permitted to be connected to the motor drive device 1 is registered in advance as a registered motor, and the motor being driven is the registered motor when the dynamic braking circuit 12 brakes the motor being driven. Determine whether or not If it is determined that the driving motor does not match the registered motor, the driving motor is the registered motor (for example, a motor that was selected in advance as a power source for a machine such as a machine tool or a robot at the time of design, or a motor manufactured by a genuine manufacturer. (e.g., motors made by a genuine manufacturer but different from the original design specifications, motors made by a third party, etc.), notify workers to that effect. do.

A motor drive device 1 according to an embodiment of the present disclosure includes a converter 101, an inverter 102, a DC link capacitor 103, a motor control unit 10, a storage unit 11, a dynamic brake circuit 12, a calculation unit 13, a measurement A unit 14 , a determination unit 15 , a position detector 16 , and a brake control unit 17 are provided.

The converter 101 converts the AC power supplied from the AC power supply 2 into DC power and outputs it to the DC link. Examples of the converter 101 include a diode rectifier circuit, a 120-degree conduction rectifier circuit, and a PWM switching control type rectifier circuit. For example, if the converter 101 is a PWM switching control rectifier circuit, it consists of a switching element and a bridge circuit of diodes connected in inverse parallel to the switching element. Each switching element is on/off-controlled to perform power conversion in both AC and DC directions. Examples of semiconductor switching elements include unipolar transistors such as FETs, bipolar transistors, IGBTs, thyristors, and GTOs. There may be.

A "DC link" refers to a circuit portion that electrically connects the DC output side of the converter 101 and the DC input side of the inverter 102. , ``DC bus'' or ``DC intermediate circuit''. A DC link capacitor 103 is provided in the DC link. The DC link capacitor 103 has a function of accumulating energy (DC power) in the DC link and a function of suppressing pulsation of the DC side output of the converter 101 . As the DC link capacitor 103 is charged, DC power is accumulated in the DC link.

The inverter 102 performs power conversion between DC power in the DC link and AC power, which is drive power or regenerative power for the motor 3 being driven. Examples of the inverter 102 include a PWM inverter including semiconductor switching elements therein. The semiconductor switching element is composed of, for example, a unipolar transistor such as an FET, a bipolar transistor, an IGBT, a thyristor, a GTO, or the like. may be

The motor control unit 10 generates a drive command for on/off controlling each semiconductor switching element of the inverter 102 and outputs it to the inverter 102 . The motor control unit 10 detects the rotation speed (speed feedback) of the driving motor 3 detected by the position detector 16, and the current flowing in the power line between the inverter 102 and the driving motor 3 detected by the measuring unit 14 ( It controls the power conversion operation of the inverter 102 based on current feedback), a predetermined torque command, an operation program of the motor 3 during driving, and the like. The speed, torque, or position of the rotor of the motor 3 being driven is controlled based on the AC power supplied from the inverter 102 . Note that the configuration of the motor control unit 10 described here is merely an example, and terms such as a position command generation unit, a position control unit, a speed control unit, a current control unit, and a torque command generation unit are included in the motor control unit. A configuration of the unit 10 may be defined.

The storage unit 11 stores parameters defined in advance for registered motors. The storage unit 11 is composed of an electrically erasable/recordable nonvolatile memory such as EEPROM (registered trademark), or a random access memory such as DRAM or SRAM that can be read and written at high speed. good too. Even after the parameters are stored in the storage unit 11, the parameters may be rewritten as necessary. The parameters for the registered motor include mechanical friction T _f [kgm ² ], back electromotive force coefficient K _v [Vsec/rad], motor winding resistance value R _m [Ω], motor pole number p, motor At least one of inductance L _m [H] and rotor inertia moment J [kgm ² ] is included. The storage unit 11 also stores the value R _DB [Ω] of the dynamic brake resistor 21 as a dynamic brake circuit parameter related to the dynamic brake circuit 12 .

The dynamic brake (DB) circuit 12 has a dynamic brake resistor 21 and a switch 22 connected in series with the dynamic brake resistor 21 . As shown, a series circuit consisting of a dynamic brake resistor 21 and a switch 22 is provided between the input terminals of the motor 3 during driving (between the winding phases of the motor 3 during driving). The switch 22 is composed of a relay, a semiconductor switching element, or the like, and is controlled to be turned on/off by a brake command (on/off command) generated by the brake control unit 17, which will be described later. When the dynamic brake circuit 12 brakes the driving motor 3, the drive power supply to the driving motor 3 by the inverter 102 is cut off, and then the brake control unit 17 outputs an ON command as a brake command to perform dynamic braking. In the circuit 12, the switch 22 is turned on to short-circuit the input terminals of the motor 3 through the dynamic brake resistor 21 during driving. At that time, even if the driving motor 3 is electrically disconnected from the power supply, the field magnetic flux exists, and the driving motor 3 rotating by inertia works as a generator, so the dynamic brake current generated by this is turned on. The heat flows into the dynamic brake resistor 21 through the switch 22 and is converted into Joule heat by the dynamic brake resistor 21 and consumed. As a result, deceleration torque is generated in the motor 3 during driving. This deceleration torque brakes the driving motor 3, and finally the driving motor 3 stops.

The calculation unit 13 uses the number of revolutions per unit time of the driving motor 3 detected by the position detector 16 when the dynamic brake circuit 12 starts braking, and the parameter stored in the storage unit 11, to calculate the dynamic brake circuit. Information about the estimated value of the dynamic braking current flowing between the motor 3 and the dynamic braking circuit 12 during driving by 12 is calculated.

As a calculation formula used when calculating information about the estimated value of the dynamic brake current, for example, a formula derived as follows can be used.

When the switch 22 is turned on to apply braking to the motor 3 being driven by the dynamic brake circuit 12, the value R [Ω] of the energy consumption contribution resistance that contributes to the energy consumption for braking the motor 3 being driven is: Assuming that the value of the motor winding resistance is R _m [Ω] and the value of the dynamic brake resistance 21 is R _DB [Ω], it is expressed as Equation 1.

Assuming that the back electromotive force constant of the motor 3 being driven is _Kv [Vsec/rad], the rotational angular velocity is ω [rad/sec], and the number of motor poles is p, the stator voltage of the first phase of the three phases of the motor 3 being driven is and e _I [V] are expressed as in Equation 2.

When the current of the first phase of the three phases of the motor 3 being driven is i _I [A], the circuit equation of Equation 3 holds.

If D is a differential operator, Equation 3 can be expressed as Equation 4.

　Formula 5 is defined as a cofunction with C as a constant.

However, since Equation 6 holds, i _I is a periodic function and C=0.

A special solution represented by Equation 7 with X and Y as constants is obtained.

Equations 8 and 9 are obtained by comparing equations obtained by substituting the above special solution into equation 3 with equation 2.

Here, X and Y are expressed as in

Equations

10 and 11.

By arranging the above formula, the first phase current i _I [A] can be expressed as shown in Equation 12.

Here, θ _α is expressed as in Equation 13.

The stator voltage e _II and current i _II of the second phase, the stator voltage e _III and current i _III of the third phase, and the stator voltage e _I and current i _I of the first phase are 2/3π and -2/3π respectively. Since there is a deviation, the stator power P[W] can be expressed as shown in Equation 14.

Here, the torque constant K _t [N·m/Ap] is represented by Equation 15.

cos θ _α can be expressed as in Equation 16.

By substituting

Equations

15 and 16 into Equation 14, the power P [W] of the stator of the driving motor 3 as expressed by Equation 17 is obtained.

Since the energy applied to the stator of the motor 3 during driving is equal to the energy of the rotor (torque x angle = power x time), Equation 18 holds. In Equation 18, the torque of the rotor of the motor 3 being driven is T [N], and the rotation angle of the rotor is θ [rad].

　　Formula 19 is obtained by substituting formula 17 into formula 18 and arranging it. Let ω [rad/sec] be the rotational angular velocity of the rotor.

The equation of motion of the rotor of the driving motor 3 is expressed by Equation 20.

By substituting the torque T[N] represented by Equation 19 into Equation 20 and solving, Equation 21 is obtained.

Here, A, B, α, β, δ, and γ are expressed as in Equation 22.

From the above, the equation of formula 23 is obtained.

Equation 24 is obtained by integrating both sides of Equation 23 with C ₁ as the integration constant.

In Equation 24, assuming that the time at which the dynamic brake circuit 12 starts braking is t=0 and the rotational angular velocity at this time is ω ₀ [rad/sec], the initial condition t=0 and ω=ω ₀ are integrated. A constant C ₁ is expressed as in Equation 25.

The rotational angular velocity ω ₀ [rad/sec] of the driving motor 3 when the dynamic braking circuit 12 starts braking is the rotation speed N ₀ [rotation/sec] of the driving motor 3 per unit time when the dynamic braking circuit 12 starts braking. sec] is expressed as in Equation 26.

By substituting Equation 25 into Equation 24 and rearranging, Equation 27 is obtained.

In summary, assuming that the time when the dynamic brake circuit 12 starts braking is t=0, the estimated value of the dynamic brake current i _DB (ωt )[A] can be expressed as Equation 28 based on Equation 12. In Equation 28, θ _α is represented by Equation 29.

Also, the relationship between the rotational angular velocity ω [rad/sec] of the driving motor 3 after the start of braking by the dynamic brake circuit 12 and the time t can be expressed as in Equation 30 based on Equation 27.

In Equation 30, each constant is represented by Equation 31.

Based on Equation 28, the current peak value i _DBpeak [A] of the estimated value of the dynamic braking current shown in Equation 32 is obtained.

Estimated static time t _set [sec], which is the time required for the number of rotations per unit time of the motor 3 being driven to become equal to or less than a predetermined threshold value from the start of braking by the dynamic brake circuit 12 (t=0). can be expressed as Equation 33 by substituting ω=0 in Equation 30. Here, the predetermined threshold is set to a minute value close to zero. When the number of revolutions per unit time of the motor 3 being driven becomes equal to or less than a predetermined threshold value (becomes close to 0), it may be considered equivalent to that the dynamic brake current becomes close to 0.

The calculation unit 13 uses the number of revolutions per unit time of the driving motor 3 detected by the position detector 16 when the dynamic brake circuit 12 starts braking, and the parameter stored in the storage unit 11, to calculate the dynamic brake circuit. 12, the current peak value i _DBpeak [A] of the estimated value shown in Equation 32, the estimated static time t _set [sec] shown in Equation 33, or , or the estimated value i _DB (ωt) [A] of the dynamic braking current shown in Equation 28 representing the current waveform of the estimated value of the dynamic braking current at each time t. FIG. 3 is a diagram illustrating a current waveform of an estimated value of dynamic braking current calculated by a calculator in the motor drive device according to the embodiment of the present disclosure. In the illustrated example, the estimated value of the dynamic brake current becomes zero after 0.668 [sec] from time t=0, which is _the time when the dynamic brake circuit 12 starts braking. ] is 0.668 [sec].

It should be noted that the calculation formula used for calculating the information regarding the estimated value of the dynamic braking current described above is an example, and the information regarding the estimated value of the dynamic braking current may be calculated using a calculation formula other than this.

The measuring unit 14 acquires information about the measured value of the dynamic braking current flowing between the motor 3 and the dynamic braking circuit 12 during braking by the dynamic braking circuit 12 . A current sensor provided in the power line connecting the motor 3 and the dynamic brake circuit 12 during driving sequentially measures the dynamic brake current at minute intervals from the start of braking by the dynamic brake circuit 12, and the current waveform is are sequentially stored in a memory (not shown). The measurement unit 14 determines from the current waveform stored in the memory, the current peak value of the measured value of the dynamic brake current, and the rotation speed per unit time of the motor 3 being driven from the start of braking by the dynamic brake circuit 12 is equal to or less than a predetermined threshold value. Either the measured settling time, which is the time required to reach , or the measured value (current waveform) of the dynamic brake current at each time t is acquired. Acquisition of information on the measured value of the dynamic brake current by the measuring unit 14 is performed by measuring the measured value of the dynamic brake current flowing between the motor 3 and the dynamic brake circuit 12 during driving from t=0 when the dynamic brake circuit 12 starts braking. This is done until the amplitude is below a predetermined amplitude threshold. By setting the amplitude threshold value to a minute value close to 0 (zero), it is detected that the motor 3 being driven is stopped by the braking of the motor 3 being driven by the dynamic brake circuit 12 and the dynamic brake current becomes 0. be able to.

The determination unit 15 determines whether the driving motor 3 is registered based on the result of comparison between the information regarding the estimated value of the dynamic braking current calculated by the calculating unit 13 and the information regarding the measured value of the dynamic braking current obtained by the measuring unit 14. Determine whether or not it matches the motor. That is, when the information about the estimated value of the dynamic braking current and the information about the measured value of the dynamic braking current match, the determination unit 15 determines that the motor 3 being driven matches the registered motor, and the estimated value of the dynamic braking current and the information about the measured value of the dynamic brake current do not match, it is determined that the motor 3 being driven does not match the registered motor.

The determination result by the determination unit 15 is sent to a display unit (not shown), and the display unit displays, as the determination result, "the motor being driven does not match the registered motor" or "the motor being driven matches the registered motor". to display Examples of the display unit include a single display device, a display device attached to the motor drive device 1, a display device attached to a host controller (not shown), a display device attached to a personal computer and a mobile terminal, an LED, There are light-emitting devices such as lamps. Also, for example, if the display unit is composed of a light-emitting device such as an LED or a lamp, the light-emitting device emits light when an alarm is received. It notifies the operator that it matches the motor. Further, for example, the determination result by the determination unit 15 is sent to, for example, an acoustic device (not shown), and the acoustic device emits a sound such as voice, speaker, buzzer, chime, etc., so that "the driving motor is registered. The operator is informed that "the motor does not match" or "the motor being driven matches the registered motor". Based on the determination result by the determination unit 15, the operator can easily grasp whether or not the motor 3 being driven matches the registered motor.

Further, the determination result by the determination unit 15 is sent to the motor control unit 10, and the motor control unit 10 stops the inverter 102 when the determination unit 15 determines that the motor 3 being driven does not match the registered motor. You may make it control so that it may carry out.

Thus, according to an embodiment of the present disclosure, the driving motor 3 is a registered motor (for example, a motor that has been selected in advance as a power source for a machine such as a machine tool or a robot at the time of design, a motor manufactured by a genuine manufacturer, or the like). ) (for example, a motor manufactured by a genuine manufacturer but different from the specifications at the time of design, a motor manufactured by a third party, etc.). According to one embodiment of the present disclosure, whether or not the motor 3 being driven matches the registered motor is associated with the function of the dynamic braking circuit 12 provided in the motor driving device 1 that drives the motor 3 being driven. is determined, manufacturing is easier and the cost is lower than when determination processing is performed based on the ID information assigned to the motor.

Here, some forms of determination processing by the determination unit 15 are listed.

The determination process according to the first form determines whether or not the motor 3 being driven matches the registered motor based on the current peak value of the dynamic brake current. The calculating unit 13 calculates the current peak value of the estimated value of the dynamic braking current according to the equation 32, for example, as information related to the estimated value of the dynamic braking current. The measurement unit 14 acquires the current peak value of the measured value of the dynamic braking current as information about the measured value of the dynamic braking current. If the difference between the current peak value of the estimated value of the dynamic braking current and the current peak value of the measured value of the dynamic braking current is outside a predetermined range, the determination unit 15 determines that the motor 3 being driven does not match the registered motor. If it is within a predetermined range, it is determined that the driving motor 3 matches the registered motor. Here, the predetermined range may be set to, for example, about ±30% of the current peak value of the dynamic brake current. Note that the predetermined range may be stored in a rewritable storage unit (not shown) and rewritable by an external device. It can be changed to an appropriate value depending on the situation.

The determination process according to the second mode is a settling time, which is the time required from the start of braking by the dynamic brake circuit 12 (t=0) until the number of revolutions per unit time of the driven motor 3 becomes equal to or less than a predetermined threshold value. , it is determined whether or not the driving motor 3 matches the registered motor. The calculation unit 13 calculates the estimated value of the dynamic brake current as information related to the estimated value of the dynamic brake current, for example, according to Equation 33, from the start of braking by the dynamic brake circuit 12 until the number of rotations per unit time of the motor 3 being driven becomes equal to or less than a predetermined threshold value. Calculate the static time estimate, which is time. The measuring unit 14, as information on the measured value of the dynamic braking current, measures the time required from the start of braking by the dynamic braking circuit 12 until the number of revolutions per unit time of the motor 3 being driven becomes equal to or less than a predetermined threshold value. Get time measurements. If the difference between the estimated settling time value and the measured settling time value is outside the predetermined range, the determining unit 15 determines that the driving motor 3 does not match the registered motor, and if the difference is within the predetermined range. determines that the driving motor 3 matches the registered motor. Here, the predetermined range may be set to, for example, about ±30% of the settling time estimated value, but the numerical values given here are only examples, and other numerical values may be used. Note that the predetermined range may be stored in a rewritable storage unit (not shown) and rewritable by an external device. It can be changed to an appropriate value depending on the situation.

The determination process according to the third mode determines whether or not the driving motor 3 matches the registered motor based on the current waveform of the dynamic brake current during braking by the dynamic brake circuit 12 . The calculation unit 13 calculates the current waveform of the estimated value of the dynamic braking current according to, for example, Equation 28 as information about the estimated value of the dynamic braking current. The measuring unit 14 acquires the current waveform of the measured value of the dynamic braking current as information about the measured value of the dynamic braking current. The determination unit 15 compares the difference between the current waveform of the estimated value of the dynamic braking current and the current waveform of the measured value of the dynamic braking current at minute intervals. It is determined that the driving motor 3 does not match the registered motor. For example, if it is within a predetermined range for several milliseconds, it is determined that the driving motor 3 matches the registered motor. Here, the predetermined range may be set to, for example, about ±30% of the amplitude of the dynamic brake current, but the numerical values given here are only examples and other numerical values may be used. Note that the predetermined range may be stored in a rewritable storage unit (not shown) and rewritable by an external device. It can be changed to an appropriate value depending on the situation.

FIG. 2 is a flow chart showing the operation flow of the motor drive device according to one embodiment of the present disclosure.

While the motor 3 is being driven by the alternating current supplied from the inverter 102 under the control of the motor control unit 10 (step S101), in step S102, the calculation unit 13 and the measurement unit 14 operate the dynamic brake circuit 12 determines whether or not braking of the motor 3 during driving has started. The fact that the dynamic brake circuit 12 has started braking the motor 3 during driving can be determined by the fact that the brake command output from the brake control unit has been switched from the OFF command to the ON command. When the dynamic brake circuit 12 starts braking the motor 3 during driving, the motor control unit 10 controls the inverter 102 to cut off the supply of driving power to the motor 3 during driving. turns on the switch 22 to short-circuit the input terminals of the motor 3 through the dynamic brake resistor 21 during driving. The dynamic brake current generated thereby flows into the dynamic brake resistor 21 via the switch 22 that is turned on, where it is converted into Joule heat and consumed, resulting in the generation of deceleration torque in the motor 3 during driving. This deceleration torque brakes the motor 3 during driving.

If it is determined in step S102 that the dynamic brake circuit 12 has started braking the motor 3 during driving, the process proceeds to steps S103 and S105, and it is determined that the dynamic brake circuit 12 has not started braking the motor 3 during driving. If so, the process returns to step S101.

In step S103, the calculation unit 13 acquires the parameters stored in the storage unit 11, and acquires from the position detector 16 the number of rotations per unit time at the start of braking the motor 3 being driven by the dynamic brake circuit 12. . Next, in step S104, the calculation unit 13 calculates the number of revolutions per unit time of the driving motor 3 detected by the position detector 16 at the start of braking by the dynamic brake circuit 12 and the parameters stored in the storage unit 11. is used to compute information about an estimate of the dynamic braking current that flows between the motor 3 and the dynamic braking circuit 12 during braking by the dynamic braking circuit 12 . After that, the process proceeds to step S107.

On the other hand, in step S105, the measuring unit 14 acquires information about the measured value of the dynamic braking current flowing between the driving motor 3 and the dynamic braking circuit 12 during braking by the dynamic braking circuit 12 . Next, in step S106, the measurement unit 14 determines whether or not the amplitude of the measured value of the dynamic braking current has become equal to or less than a predetermined amplitude threshold. If it is determined that the amplitude of the measured value of the dynamic braking current is equal to or less than the predetermined amplitude threshold value, the process proceeds to step S107.If it is not determined that the amplitude of the measured value of the dynamic braking current is equal to or less than the predetermined amplitude threshold value Return to step S105. Through steps S105 and S106, the amplitude of the measured value of the dynamic brake current flowing between the driving motor 3 and the dynamic brake circuit 12 is less than or equal to a predetermined amplitude threshold from the time t=0 when the dynamic brake circuit 12 starts braking. Until , acquisition of information on the measured value of the dynamic brake current by the measurement unit 14 is executed.

In step S107, the determining unit 15 determines whether or not the information regarding the estimated value of the dynamic braking current calculated by the calculating unit 13 and the information regarding the measured value of the dynamic braking current obtained by the measuring unit 14 match. . If it is determined in step S107 that the information regarding the estimated value of the dynamic braking current and the information regarding the measured value of the dynamic braking current match, the determination unit 15 determines that the motor being driven matches the registered motor in step S108. . If it is determined in step S107 that the information regarding the estimated value of the dynamic braking current and the information regarding the measured value of the dynamic braking current do not match, then in step S108 the determination unit 15 determines that the motor being driven does not match the registered motor. judge. The determination result by the determination unit 15 is sent to a display unit (not shown), and the display unit displays, as the determination result, "the motor being driven does not match the registered motor" or "the motor being driven matches the registered motor". to display Also, for example, if the display unit is composed of a light-emitting device such as an LED or a lamp, the light-emitting device emits light when an alarm is received. It notifies the operator that it matches the motor. Further, for example, the determination result by the determination unit 15 is sent to, for example, an acoustic device (not shown), and the acoustic device emits a sound such as a voice, a speaker, a buzzer, a chime, or the like to indicate that "the driving motor is registered. The operator is informed that "the motor does not match" or "the motor being driven matches the registered motor". Thereby, the operator can easily grasp whether or not the motor 3 being driven matches the registered motor.

When the number of revolutions per unit time of the motor 3 being driven at the start of braking by the dynamic brake circuit 12 is low, the amplitudes of the estimated value and the measured value of the dynamic brake current become small, and the estimated value of the settling time and the settling time Since the time measurement value is also shortened, there is a possibility that the accuracy of the determination processing by the determination unit 15 is lowered. Therefore, after it is determined in step S102 that the dynamic braking circuit 12 has started braking the driving motor 3, whether the number of rotations of the driving motor 3 at the start of braking by the dynamic braking circuit 12 is equal to or greater than a predetermined rotation number threshold. If it is determined that the number of revolutions of the motor being driven at the start of braking by the dynamic brake circuit 12 is equal to or greater than a predetermined number of revolutions threshold value, the process proceeds to steps S103 and S105, and the dynamic brake circuit 12 If it is not determined that the rotation speed of the driving motor at the start of braking by the dynamic brake circuit 12 is equal to or greater than a predetermined rotation speed threshold value, only the braking process by the dynamic brake circuit 12 may be executed as it is, and the process may end.

Among the motor parameters, the rotor moment of inertia J [kgm ² ] has a different value depending on the load applied to the motor. Therefore, after it is determined in step S102 that the dynamic brake circuit 12 has started braking the motor 3 during driving, the operator is notified of the rotor inertia moment J [kgm ² ] via a display unit (not shown). A process for requesting input may be provided. When the operator is requested to input the rotor inertia moment J [kgm ² ], the operator inputs the rotor inertia moment J [kgm ² ] via an input unit (not shown), writes it in the storage unit 11, and then The process proceeds to steps S103 and S105. Thereby, the determination accuracy by the determination unit 15 can be further improved.

An arithmetic processing unit (processor) is provided in the motor driving device 1 described above. Examples of arithmetic processing units include ICs, LSIs, CPUs, MPUs, and DSPs. This arithmetic processing unit has a motor control section 10 , a calculation section 13 , a measurement section 14 , a determination section 15 and a brake control section 17 . Each of these units of the arithmetic processing unit is, for example, a functional module realized by a computer program executed on the processor. For example, when the motor control unit 10, the calculation unit 13, the measurement unit 14, the determination unit 15, and the brake control unit 17 are constructed in a computer program format, by operating the arithmetic processing unit according to this computer program, the functions of each unit can be realized. A computer program for executing each process of the motor control unit 10, the calculation unit 13, the measurement unit 14, the determination unit 15, and the brake control unit 17 is stored in a computer-readable medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. It may be provided in a form recorded on a recording medium. Alternatively, the motor control unit 10, the calculation unit 13, the measurement unit 14, the determination unit 15, and the brake control unit 17 may be realized as semiconductor integrated circuits in which computer programs for realizing the functions of each unit are written. The storage unit 11 is an electrically erasable and recordable nonvolatile memory such as EEPROM (registered trademark), or a random access memory such as DRAM or SRAM that can be read and written at high speed. may be configured.

Reference Signs List 1 motor drive device 2 AC power supply 3 driving motor 10 motor control unit 11 storage unit 12 dynamic brake circuit 13 calculation unit 14 measurement unit 15 determination unit 16 position detector 17 brake control unit 21 dynamic brake resistance 22 switch 101 converter 102 inverter 103 DC link capacitor

Claims

a storage unit that stores predetermined parameters for registered motors;
a dynamic brake circuit that short-circuits input terminals of a motor that is being driven through a dynamic brake resistor to generate deceleration torque in the motor that is being driven to brake the motor that is being driven;
Using the number of rotations per unit time of the motor being driven at the start of braking by the dynamic brake circuit and the parameters stored in the storage unit, the motor being driven and the motor being driven are controlled during braking by the dynamic brake circuit. a calculation unit for calculating information about an estimated value of the dynamic braking current flowing to and from the dynamic braking circuit;
a measuring unit that obtains information about a measured value of a dynamic braking current that flows between the driving motor and the dynamic braking circuit during braking by the dynamic braking circuit;
a determination unit that determines whether the motor being driven matches the registered motor based on a comparison result between the information regarding the estimated value of the dynamic braking current and the information regarding the measured value of the dynamic braking current;
A motor drive device.
The measuring unit measures the amplitude of the measured value of the dynamic braking current flowing between the driving motor and the dynamic braking circuit from when the dynamic braking circuit starts braking until the amplitude of a measured value of the dynamic braking current flowing between the motor being driven and the dynamic braking circuit becomes equal to or less than a predetermined amplitude threshold. 2. The motor drive device of claim 1, wherein the information regarding the measured value of the dynamic braking current is obtained.
The calculation unit calculates a current peak value of the estimated value as information related to the estimated value of the dynamic brake current,
The measuring unit acquires a current peak value of the measured value as information related to the measured value of the dynamic brake current,
2. When a difference between the current peak value of the estimated value and the current peak value of the measured value is outside a predetermined range, the determination unit determines that the motor being driven does not match the registered motor. 3. or the motor drive device according to 2.
The calculation unit calculates, as information related to the estimated value of the dynamic brake current, a static time, which is the time required for the number of revolutions per unit time of the motor being driven to become equal to or less than a predetermined threshold value after the start of braking by the dynamic brake circuit. compute a constant-time estimate,
The measuring unit measures, as information about the measured value of the dynamic brake current, a static time that is the time required for the number of revolutions per unit time of the motor being driven to become equal to or less than a predetermined threshold value after the start of braking by the dynamic brake circuit. take timed measurements,
3. The judging unit judges that the motor being driven does not match the registered motor when a difference between the estimated stationary time value and the measured stationary time value is outside a predetermined range. The motor drive device according to .
The calculation unit calculates a current waveform of the estimated value as information related to the estimated value of the dynamic brake current,
The measurement unit acquires a current waveform of the measured value as information on the measured value of the dynamic brake current,
3. When a difference between the current waveform of the estimated value and the current waveform of the measured value is outside a predetermined range, the determination unit determines that the motor being driven does not match the registered motor. The motor drive device according to .
6. The parameter includes at least one of mechanical friction, back electromotive force coefficient, motor resistance value, motor pole number, motor inductance, and rotor moment of inertia for the registered motor. The motor drive device according to .
The motor driving device according to any one of claims 1 to 6, wherein said registered motor is a motor registered in advance as being permitted to be connected to said motor driving device.