Processing device

Abstract

A processing device is provided that can appropriately suppress voltage fluctuations in a power supply path for supplying power to a motor control device. The processing device suppresses voltage fluctuations in a power supply path for supplying power from a DC power supply to the motor control device, and includes: a filter circuit including a plurality of specified units, each specified unit having a circuit element including one or more specified passive elements and a semiconductor switch for controlling current supply to the circuit element, the filter circuit being connected to the power supply path; and a control unit that controls the switching of the semiconductor switches of the plurality of specified units included in the filter circuit to suppress voltage fluctuations or current fluctuations in the direct current in the power supply path.

Description

Technical Field

[0001] The present invention relates to a processing device for suppressing voltage fluctuations in a power supply path that supplies power from a DC power supply to a motor control device. Background Art

[0002] In factories and the like, there is a system in which multiple electric motors are PWM-driven by multiple servo drives arranged in separate locations (such as a system composed of a robot and its control device). In such a system, there are problems as follows: In order to reduce the radiation noise from the long cables between the motors and servo drives, the switching operation speed cannot be increased, and a large amount of cables are required for the connection between the motors and servo drives.

[0003] If a structure is adopted in which a device obtained by removing a converter from a servo drive (hereinafter referred to as a motor control device) is arranged near each motor, and power is supplied from one DC power supply device to each motor control device via a DC bus, the above problems can be avoided. However, in a system adopting this structure, there is a case where the LC circuit on the DC bus side interferes with the motor control device side and the voltage of the DC bus fluctuates (vibrates) (for example, refer to Non-Patent Document 1).

[0004] Non-Patent Document 1: Shinji Yokoo, Keiichiro Kondo, "Design method of damping control system for induction motor drive system vector-controlled in DC electric railway vehicle", Transactions of the Institute of Electrical Engineers of Japan, D, Vol. 135 No. 6 pp. 622-631 (2015) Summary of the Invention

[0005] Problems to be Solved by the Invention

[0006] The reasons for voltage fluctuations in the power supply path (such as the above-mentioned DC bus) from the DC power supply device to the motor control device are various. For example, due to the operation of the motor to which the drive current is supplied by the motor control device, resonance sometimes occurs in the power supply path, resulting in voltage fluctuations. The present invention has been completed in view of such problems, and its object is to provide a technique capable of appropriately suppressing voltage fluctuations in the power supply path that supplies power to the motor control device.

[0007] Means for Solving the Problems

[0008] A processing device according to an aspect of the present invention is a processing device that suppresses voltage fluctuations in a power supply path for supplying power from a DC power supply to a motor control device, and includes: a filter circuit including a plurality of specified units, each of the specified units having a circuit element including one or more specified passive elements and a semiconductor switch that controls current supply to the circuit element, the filter circuit being connected to the power supply path; and a control unit that controls switching operations of the semiconductor switches of the plurality of specified units included in the filter circuit to suppress voltage fluctuations or current fluctuations in the DC power in the power supply path.

[0009] In addition, in the above processing device, it may be that the filter circuit is configured to be able to adjust the resonance characteristics of the entire circuit by the switching operations of the semiconductor switches in the specified units, and the control unit controls the switching operations of the semiconductor switches based on the rotational speed of the motor to which a drive current is supplied by the motor control device or the PWM frequency in the motor control device to suppress voltage fluctuations or current fluctuations in the DC power in the power supply path.

[0010] As one of the causes of voltage fluctuations in the power supply path for supplying power to the motor control device, the rotational speed of the motor associated with the frequency of the drive current generated by the motor control device and the PWM frequency in the motor control device can be cited. If the frequency of the drive current accompanying the change in the rotational speed of the motor or the PWM frequency in the motor control device becomes a value near the resonance frequency of the power supply path, voltage fluctuations may occur due to electrical resonance. Therefore, the above processing device has a filter circuit connected to the power supply path, and the control unit controls the switching operations of the semiconductor switches of the plurality of specified units included in the filter circuit.

[0011] Each specified unit has a combination of a circuit element and a semiconductor switch, and controls the supply current to the circuit element by switching the semiconductor switch. As the circuit element, passive elements such as capacitors, inductors, and resistors can be exemplified, including any one of capacitors, inductors, and resistors, or can appropriately combine and include capacitors, inductors, and resistors. As a result, the filter circuit having a plurality of such specified units can adjust the resonance characteristics of the entire filter circuit by switching the semiconductor switches. As the resonance characteristics, the resonance frequency and the Q value can be exemplified. Therefore, by controlling the switching operations of the semiconductor switches by the control unit as described above, for example, the resonance frequency of the filter circuit can be set to a frequency sufficiently far from the frequency of the drive current associated with the rotational speed of the motor and the PWM frequency in the motor control device, thereby suppressing voltage fluctuations or current fluctuations in the DC power in the power supply path.

[0012] Here, in the above processing device, it is also possible that the control unit is configured to control the switching operation of the semiconductor switch in the plurality of specified units so that the resonance frequency of the power supply path including the filter circuit deviates from a specified frequency range, which is a specified frequency range centered on the frequency of the drive current based on the rotational speed of the motor or the PWM frequency of the motor control device. According to this structure, it is possible to more appropriately suppress voltage fluctuations or current fluctuations of direct current in the power supply path.

[0013] In addition, as another method, in the above processing device, it is also possible that the control unit detects voltage fluctuations or current fluctuations of direct current in the power supply path, and based on the result of this detection, controls the switching operation of the semiconductor switch to adjust the impedance of the power supply path including the filter circuit to suppress voltage fluctuations or current fluctuations of direct current in the power supply path. Voltage fluctuations in the power supply path sometimes occur when the impedance on the motor side (for example, the part composed of an inverter circuit and a motor body) controlled by the motor control device is smaller than the impedance on the power supply path side. Therefore, by the switching control of the semiconductor switch, it is possible to reduce the peak value of the impedance on the power supply path side, and thus suppress voltage fluctuations in the power supply path.

[0014] Here, in the processing device up to the above, the specific structure of the plurality of specified units in the filter circuit is not limited to a specific structure. For example, the plurality of specified units may be configured to be respectively arranged between the wiring on the positive electrode side and the wiring on the negative electrode side forming the power supply path. For example, according to the circuit elements and the form of the semiconductor switch in the specified unit, the plurality of specified units may be respectively arranged in parallel or in series between the wiring on the positive electrode side and the wiring on the negative electrode side. In addition, as another method, it is also possible that the plurality of specified units are configured to be respectively arranged on one of the wirings on the positive electrode side and the negative electrode side forming the power supply path. For example, according to the circuit elements and the form of the semiconductor switch in the specified unit, the plurality of specified units may be respectively arranged in parallel or in series with one of the wirings on the positive electrode side and the negative electrode side. In addition, the specified units included in the filter circuit may all be composed of a combination of the same type of circuit elements and semiconductor switches. As another method, they may also be composed of a combination of two or more types of circuit elements and semiconductor switches.

[0015] Here, in the processing device described above, it is also possible that a plurality of the motor control devices are connected to the power supply path, and the power from the DC power supply is distributed and supplied to the plurality of motor control devices. That is, the processing device of the present application can also be applied to a structure in which DC power is supplied to a plurality of motor control devices via a power supply path. By controlling the switching operation of the semiconductor switch on this basis, voltage fluctuations or current fluctuations of the direct current in the power supply path can be suppressed.

[0016] Here, a specific embodiment of the processing device described above is illustrated. As a first embodiment, the processing device may be a connector that includes a pair of input terminals and a pair of output terminals electrically connected to the pair of input terminals respectively, and the pair of input terminals and the pair of output terminals are connected to the wiring on the positive electrode side and the wiring on the negative electrode side that form the power supply path. As a second embodiment, the processing device may be configured to be assembled to the DC power supply, and the output of the filter circuit is output to the power supply path. As a third embodiment, when the motor control device has an inverter circuit for converting the supplied DC into AC for driving a servo motor, the processing device is assembled to the motor control device, and the output of the filter circuit is output to the inverter circuit. In addition, the processing device of the present application may also be specifically configured by means other than the above three embodiments.

[0017] Advantages of the Invention

[0018] It is possible to appropriately suppress voltage fluctuations in the power supply path that supplies power to the motor control device. Description of the Drawings

[0019] Figure 1 It is an explanatory diagram of the schematic structure of a servo DC power supply system according to an embodiment of the present invention.

[0020] Figure 2 It is an explanatory diagram of the schematic structure of a motor control device in a servo DC power supply system.

[0021] Figure 3 It is a first diagram showing the schematic structure of a DC power supply device used in a servo DC power supply system.

[0022] Figure 4 It is a diagram showing the control flow for suppressing voltage fluctuations performed in a processing device assembled to a DC power supply device.

[0023] Figure 5 It is a second diagram showing the schematic structure of a DC power supply device used in a servo DC power supply system.

[0024] Figure 6It is an explanatory diagram of the equivalent circuit of a servo DC power supply system.

[0025] Figure 7 It is used to explain Figure 6 the region where the equivalent circuit shown becomes unstable.

[0026] Figure 8 It is a diagram for explaining the function of the filter circuit.

[0027] Figure 9 It is the first diagram showing another schematic structure of the motor control device within the servo DC power supply system.

[0028] Figure 10 It is the second diagram showing another schematic structure of the motor control device within the servo DC power supply system.

[0029] Figure 11 It is the first diagram of the schematic structure of the servo DC power supply system according to another embodiment of the present invention.

[0030] Figure 12 It is the second diagram of the schematic structure of the servo DC power supply system according to another embodiment of the present invention.

[0031] Reference numeral description

[0032] 10: Motor control device; 20: Connector; 21: Control circuit; 23: Capacitor; 24: Transistor; 25: Inductor; 30: DC power supply device; 32, 32A: Filter circuit; 35: Power supply path; 81, 82 Stabilization unit. Detailed implementation mode

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 It shows the schematic structure of a servo DC power supply system according to an embodiment of the present invention, Figure 2 and shows the schematic structure of the motor control device 10 included in the servo DC power supply system.

[0034] <First Embodiment>

[0035] As Figure 1 shown, the servo DC power supply system of this embodiment is a system in which a DC power supply device 30 and a plurality of motor control devices 10 are connected through a power supply path 35. The DC power supply device 30 is a power supply that outputs a specified DC voltage and has a power supply unit 31 inside (refer to the following Figure 6)。The power supply unit 31 is a unit that outputs a specified DC voltage. As the power supply unit 31, it can be a unit that converts three-phase alternating current from the three-phase AC power supply 50 into a DC voltage, or the power supply unit 31 can also be a unit that converts single-phase alternating current into a DC voltage. Additionally, the power supply unit 31 can be a rectifier circuit (such as a full-wave rectifier circuit) combined with diodes, or it can be an AC-DC converter (such as a power regeneration converter) using switching elements. Moreover, the power supply unit 31 can also be a secondary battery. The motor control device 10 is a device that controls the servo motor 40 (hereinafter, also simply referred to as the motor 40) according to instructions (position instructions, speed instructions, etc.) from a superior device such as a PLC (Programmable Logic Controller). As Figure 2 shown, the motor control device 10 includes an inverter circuit 11 and a control unit 12.

[0036] The inverter circuit 11 is a circuit for converting the DC voltage from the DC power supply device 30 input via the power supply path 35 into three-phase alternating current. The inverter circuit 11 has a structure in which an arm for the U phase, an arm for the V phase, and an arm for the W phase are connected in parallel between the power line on the positive side and the power line on the negative side. In the motor control device 10, current sensors 28 are provided for measuring the output current of each arm of the inverter circuit 11.

[0037] The control unit 12 is a unit that performs PWM (Pulse Width Modulation) control on the inverter circuit 11 according to instructions from a superior device (such as a PLC). The control unit 12 is composed of a processor (microcontroller, CPU, etc.) and its peripheral circuits. The control unit 12 is input with signals from each current sensor 28, signals from an encoder 41 (absolute encoder, incremental encoder) installed on the motor 40, etc.

[0038] As Figure 1 shown, the power supply path 35 is a power supply path that combines multiple power cables in such a way that the power (current) from the DC power supply device 30 can be distributed and supplied to each motor control device 10 within the servo DC power supply system. A smoothing capacitor 18 is usually provided at the connection portion of the power supply path 35 to each motor control device 10 (between the power terminals of each motor control device 10).

[0039] Figure 3Shows the schematic structure of the motor control device 10 used in the servo DC power supply system of this embodiment. As shown in the figure, the motor control device 10 includes an inverter circuit 11 and a filter circuit 32. The filter circuit 32 is arranged at a position in the motor control device 10 that is connected to the power supply path 35, and has a structure in which the DC power supplied from the power supply path 35 is output to the inverter circuit 11 through the filter circuit 32.

[0040] The filter circuit 32 is a circuit for stabilizing the DC in the power supply path 35. As shown in the figure, the filter circuit 32 includes a control circuit 21 and a plurality of stabilization units 81 arranged between the power line on the positive side and the power line on the negative side (including 3 stabilization units 81 in the Figure 3 example shown). Each of these stabilization units has a series connection of a capacitor 23 and a transistor 24 that functions as a semiconductor switch, and a drive circuit 22 for the transistor 24. The drive circuit 22 is a circuit that applies a voltage to the gate of the transistor 24 according to a control signal from the control circuit 21, thereby causing the transistor 24 to function as a semiconductor switch.

[0041] Information related to the rotational speed of the motor 40 included in the instructions given to the control unit 12 of the motor control device 10 is input from the upper-level device to the control circuit 21. Based on the information related to the rotational speed, the control circuit 21 applies a voltage to the drive circuit 22 of each of the plurality of stabilization units 81 to control the switching of the corresponding transistor 24.

[0042] Here, in the power supply path 35, let L1 be the inductance of the power supply path 35, and C1 be the combined capacitance of the capacitance of the power supply path 35 and the smoothing capacitor 18. Also, let the capacitance of the capacitor 23, which is a passive element included in each stabilization unit 81 in the filter circuit 32, be C2. As a result, in the case where the transistor 24 is turned on in only 1 stabilization unit 81 by the control circuit 21 (Case 1), in the case where the transistor 24 is turned on in only 2 stabilization units 81 by the control circuit 21 (Case 2), and in the case where the transistor 24 is turned on in all the stabilization units 81 by the control circuit 21 (Case 3), the resonance frequencies of the power supply path 35 are as follows.

[0043] (Case 1)

[0044]

[0045] (Case 2)

[0046]

[0047] (Case 3)

[0048]

[0049] At this time, f3 < f2 < f1.

[0050] By controlling the switching of the transistor 24 by the control circuit 21 in this way, the resonance frequency of the power supply path 35 can be controlled. Here, based on Figure 4 The switching control of the transistor 24 by the control circuit 21 in each motor control device 10 will be described. Figure 4 The processing shown is achieved by repeatedly executing a prescribed control program at prescribed intervals in the control circuit 21. First, in S101, in Figure 1 the servo DC power supply system shown, speed information (information associated with the rotational speed) of the motor 40 corresponding to each motor control device 10 is obtained.

[0051] Next, in S102, it is determined whether the resonance frequency of the filter circuit 32 needs to be adjusted. Specifically, when the resonance frequency of the power supply path 35 derived from the switching state (either the on state or the off state) of the transistor 24 of each stabilization unit 81 at the current time belongs to a prescribed frequency range centered on the frequency of the drive current of the motor 40, it is determined that the resonance frequency of the filter circuit 32 needs to be adjusted. If an affirmative determination is made in S102, the process proceeds to S103, and if a negative determination is made, it proceeds to S104. Then, in S103, the switching state of the transistor 24 of each stabilization unit 81 in the filter circuit 32 is changed so that the resonance frequency of the power supply path 35 deviates from the prescribed frequency range centered on the frequency of the drive current of the motor 40. In addition, in S104, since the possibility of voltage fluctuation in the power supply path 35 due to resonance is low, the switching state of the transistor 24 of each stabilization unit 81 in the filter circuit 32 is maintained as it is.

[0052] As described above, according to Figure 4 the control shown, the control circuit 21 controls the switching of the transistor 24 so that the resonance frequency of the power supply path 35 deviates from the prescribed frequency range centered on the frequency of the drive current based on the rotational speed of the motor 40, thereby effectively avoiding voltage fluctuations in the power supply path 35 caused by resonance of the DC voltage generated in association with the driving of the motor.

[0053] In addition, in the case where even if the switching state of the transistor 24 of each stabilization unit 81 in the filter circuit 32 is adjusted, the resonance frequency of the power supply path 35 cannot be avoided from being included in the prescribed frequency range centered on the frequency of the drive current of the motor 40, it is only necessary to adjust the switching state of the transistor 24 so that the frequency of the drive current of the motor 40 and the resonance frequency of the power supply path 35 are in a state of being as deviated as possible.

[0054] In addition, in Figure 4 the control shown, information associated with the rotational speed of the motor 40 is input to the control circuit 21, and the control circuit 21 controls the switching of the transistor 24 based on the information associated with the rotational speed. However, instead of this method, information associated with the PWM frequency in the inverter circuit 11 can be transmitted to the control circuit 21. Moreover, the control circuit 21 controls the switching of the transistor 24 based on the information associated with the PWM frequency, thereby being able to suppress voltage fluctuations in the power supply path 35 caused by the switching operation in the inverter circuit 11.

[0055] <Modification Example>

[0056] Based on Figure 5 a modification example of the filter circuit assembled in the DC power supply device 32 will be described. The filter circuit 32A of this modification example is arranged on either the positive power line or the negative power line. In Figure 5 this case, the filter circuit 32A is arranged on the positive power line from the power supply unit 31. The filter circuit 32A includes a control circuit 21 and a plurality of stabilization units 82 (including 2 stabilization units 82 in the Figure 5 example shown), and each of the stabilization units has a parallel connection body of an inductor 25 as a passive element and a transistor 24 that functions as a semiconductor switch, and a drive circuit 22 for the transistor 24. In the filter circuit 32A, the stabilization units 82 are connected in parallel with each other. Regarding the control circuit 21 and the drive circuit 22, since they are substantially the same as those in the above-described first embodiment, detailed description thereof is omitted.

[0057] In this modification example, it is also configured to input information related to the rotational speed of the motor 40 to the control circuit 21, and based on the information related to the rotational speed, voltage is applied to the drive circuits 22 of the plurality of stabilization units 82 respectively to control the switching of the corresponding transistors 24. According to such a configuration, the resonance frequency of the power supply path 35 can also be controlled.

[0058] In addition, as the passive elements included in the stabilization unit 82, as described above, not only capacitors and inductors can be included, but also resistors can be included. In addition, capacitors, inductors, and resistors can be appropriately combined and used as the passive elements for the stabilization unit 82.

[0059] <Second Embodiment>

[0060] In the above-described embodiment, the resonance frequency of the power supply path 35 is controlled by the switching control of the transistor 24 to suppress its voltage variation. However, in the present embodiment, the DC voltage variation or current variation in the power supply path 35 is detected, and based on the detection result, the switching control of the transistor 24 is performed to adjust the impedance of the power supply path 35 including the filter circuits 32 and 32A, thereby suppressing the voltage variation or current variation in the power supply path.

[0061] Specifically, for the servo DC power supply system disclosed in the present application (i.e., the conventional servo DC power supply system), if the impedance of the motor side ( Figure 1 the part composed of the plurality of motor control devices 10 and the plurality of motors 40) is denoted as Zm, it can be represented by the Figure 6 equivalent circuit shown. In this Figure 6 equivalent circuit, L1 is the inductance of the power supply path 35, and rL is the series resistance of L1. In addition, C1 is the combined capacitance of the capacitance of the power supply path 35 and the capacitance of the smoothing capacitor 18, and rC is the series resistance of C1.

[0062] The peak value Z Figure 6 of the output impedance on the power supply side in this equivalent circuit ( o-peak ) is represented by the following formula.

[0063]

[0064] Moreover, as Figure 7 schematically shown, when "Z o-peak > Zm" holds, the voltage of the power supply path 35 becomes unstable. Therefore, if the value of Z o-peak is reduced, the instability (variation) of the voltage of the power supply path 35 can be suppressed.

[0065] The stabilization units 81 and 82 including the transistor 24 in the filter circuits 32 and 32A can change the impedance of the power supply path 35 to which the filter circuits 32 and 32A are connected by the switching control of the transistor 24. Therefore, the control circuit 21 detects the voltage variation or current variation of the power supply path 35, and as Figure 8 shown, based on the detection result, performs the switching control of the transistor 24 so that the value of Z o-peak is lower than Zm. Thereby, the instability (variation) of the voltage of the power supply path 35 is suppressed.

[0066] <Third Embodiment>

[0067] In the first embodiment, the filter circuits 32 and 32A are assembled in the motor control device 10, but in the present embodiment, as Figure 9 , Figure 10As shown, the filter circuits 32 and 32A are assembled in the DC power supply device 30. Regarding the filter circuits 32 and 32A, as shown in the first embodiment. In Figure 9 , the filter circuit 32 is assembled in the DC power supply device 30. The filter circuit 32 is arranged at a position connected to the power supply path 35, and has a structure in which the DC power output from the power supply unit 31 is output to the power supply path 35 through the filter circuit 32. In addition, in Figure 10 , the filter circuit 32A is assembled on the positive power line 33p inside the DC power supply device 30. The filter circuit 32A is arranged at a position connected to the positive wiring 33p of the power supply path 35, and has a structure in which the DC power output from the power supply unit 31 is output to the power supply path 35 through the filter circuit 32A. In addition, the filter circuit 32A may also be assembled on the negative wiring 33m of the DC power supply device 30.

[0068] Here, based on the above Figure 4 , the switching control of the transistor 24 performed on the control circuit 21 in the third embodiment will be described. First, in S101, in Figure 1 the shown servo DC power supply system, the speed information (information related to the rotational speed) of all the motors 40 to be driven is obtained. Specifically, the speed information of each motor 40 is transmitted from the motor control devices 10 corresponding to the three motors 40 to the control circuit 21 respectively.

[0069] Next, in S102, it is determined whether it is necessary to adjust the resonance frequency of the filter circuit 32. If an affirmative determination is made in S102, the process proceeds to S103, and if a negative determination is made, it proceeds to S104. Then, in S103, the switching state of the transistor 24 of each stabilization unit 81 in the filter circuit 32 is changed so that the resonance frequency of the power supply path 35 deviates from a specified frequency range centered on the frequencies of the drive currents of the three motors 40. In addition, in S104, since the possibility of voltage fluctuation in the power supply path 35 due to resonance is low, the switching state of the transistor 24 of each stabilization unit 81 in the filter circuit 32 is maintained as it is.

[0070] In this way, the control circuit 21 controls the switching of the transistor 24 so that the resonance frequency of the power supply path 35 deviates from a specified frequency range centered on the frequency of the drive current based on the rotational speed of the motor 40, thereby effectively avoiding voltage fluctuations in the power supply path 35 caused by resonance of the DC voltage generated in association with the driving of the motor. In addition, in the case where the resonance frequency of the power supply path 35 cannot be avoided from being included in the specified frequency range centered on the frequencies of the drive currents of the three motors 40 even when adjusting the switching states of the transistors 24 of the respective stabilization units 81 in the filter circuit 32, it is only necessary to adjust the switching state of the transistor 24 so that the frequencies of the drive currents of the three motors 40 and the resonance frequency of the power supply path 35 are in a state of being as deviated as possible. Further, in the case where there is a motor among the three motors 40 that has a dominant influence on the voltage fluctuation of the DC voltage in the power supply path 35 (for example, the drive current of one motor 40 is larger than the drive currents of the other motors 40, etc.), the control as Figure 4 shown can also be performed only based on the speed information of this motor 40.

[0071] In addition, in the present embodiment, the information input to the control circuit 21 may be information related to the PWM frequency in the inverter circuit 11 instead of the information related to the rotational speed of the motor 40. Then, the control circuit 21 controls the switching of the transistor 24 based on the information related to this PWM frequency, thereby being able to suppress the voltage fluctuation of the power supply path 35 caused by the switching operation in the inverter circuit 11.

[0072] <Fourth Embodiment>

[0073] In the first embodiment, the filter circuits 32 and 32A are assembled in the DC power supply device 30, but in the present embodiment, as Figure 11 、 Figure 12 shown, they are assembled in the connector 20 that constitutes the power supply path 35. Regarding the filter circuits 32 and 32A, as in the first embodiment.

[0074] In Figure 11In [the device], a filter circuit 32 is assembled in a connector 20 provided in a power supply path 35. The connector 20 includes a pair of input terminals 21p and 21m for connecting a power cable on the upstream side (DC power supply device 30 side). Further, the input terminal 21p is a positive-side input terminal, and the input terminal 21m is a negative-side input terminal. Furthermore, the connector 20 also includes a pair of output terminals 22p and 22m for connecting a power cable on the downstream side. The output terminals 22p and 22m are respectively connected to the input terminals 21p and 21m through wirings inside the connector. In addition, the connector 20 is provided with terminals such that the internal wiring is branched, and a power supply path 35 for another motor control device 10 can be connected. And in the connector 20, the filter circuit 32 is arranged at a position connected to the power supply path 35, and DC power in the power supply path 35 is supplied from the DC power supply device 30 to the motor control device 10 via the filter circuit 32.

[0075] In addition, in the power supply path 35, a connector 55 for branching the supply path is also arranged on the downstream side of the connector 20. However, the connector 55 is a conventional connector for branching the supply path, and no filter circuit 32 is provided inside it. As another method, a filter circuit 32 can also be provided on the connector 55.

[0076] In Figure 12 [the device], a filter circuit 32 is assembled in a connector 20 provided in a power supply path 35. The connector 20 includes a pair of input terminals 21p and 21m for connecting a power cable on the upstream side (DC power supply device 30 side) and a pair of output terminals 22p and 22m for connecting a power cable on the downstream side, and the output terminals 22p and 22m are respectively connected to the input terminals 21p and 21m through wirings inside the connector. And in the connector 20, the filter circuit 32A is arranged on the positive-side power line inside the connector, and DC power in the power supply path 35 is supplied from the DC power supply device 30 to the motor control device 10 via the filter circuit 32A. In addition, Figure 12 The branching method of the supply path in the connectors 20 and 55 in Figure 11 is the same as the method shown in

[0077] According to such a method, by controlling the switching of the transistor 24 through the control circuit 21 in the filter circuits 32 and 32A, it is also possible to effectively avoid voltage fluctuations in the power supply path 35 caused by resonance of the DC voltage associated with the driving of the motor.

[0078] <Supplementary Note 1>

[0079] A processing device suppresses voltage fluctuations in a power supply path (35) that supplies power from a DC power supply (30) to a motor control device (10), and the processing device includes:

[0080] Filter circuits (32, 32A) each including a plurality of specified units (81, 82) each having a circuit element (23, 25) and a semiconductor switch (24), the circuit element (23, 25) having at least one of a specified capacitance and a specified inductance, the semiconductor switch (24) controlling current supply to the circuit element (23, 25), the filter circuits (32, 32A) being connected to the power supply path (35); and

[0081] A control unit (21) that controls switching operations of the semiconductor switches of the plurality of specified units (81, 82) included in the filter circuits (32, 32A) to suppress voltage fluctuations or current fluctuations of direct current in the power supply path (35).

Claims

1. A processing device that suppresses voltage fluctuations in a power supply path for supplying power from a DC power supply to a motor control device, the processing device comprising: A filter circuit including a plurality of specified units, each of the specified units having a circuit element including one or more specified passive elements and a semiconductor switch that controls current supply to the circuit element, the filter circuit being connected to the power supply path; and A control unit that controls the switching operation of the semiconductor switches of the plurality of specified units included in the filter circuit to suppress voltage fluctuations or current fluctuations in the direct current in the power supply path, The processing device is a connector having a pair of input terminals and a pair of output terminals electrically connected to the pair of input terminals respectively, the pair of input terminals and the pair of output terminals being connected to a wiring on the positive side and a wiring on the negative side forming the power supply path.

2. The processing device according to claim 1, wherein The filter circuit is configured to be able to adjust the resonance characteristics of the entire circuit by the switching operation of the semiconductor switches in the specified units, The control unit controls the switching operation of the semiconductor switches based on the rotational speed of a motor to which a drive current is supplied by the motor control device or the PWM frequency in the motor control device to suppress voltage fluctuations or current fluctuations in the direct current in the power supply path.

3. The processing device according to claim 2, wherein The control unit controls the switching operation of the semiconductor switches in the plurality of specified units so that the resonance frequency of the power supply path including the filter circuit deviates from a specified frequency range, the specified frequency range being a specified frequency range centered on the frequency of the drive current based on the rotational speed of the motor or the PWM frequency of the motor control device.

4. The processing device according to claim 1, wherein The control unit detects voltage fluctuations or current fluctuations in the direct current in the power supply path, and based on the result of the detection, controls the switching operation of the semiconductor switches to adjust the impedance of the power supply path including the filter circuit to suppress voltage fluctuations or current fluctuations in the direct current in the power supply path.

5. The processing device according to claim 1, wherein The plurality of specified units are configured such that each of the plurality of specified units is disposed between a wiring on the positive side and a wiring on the negative side forming the power supply path.

6. The processing device according to claim 1, wherein The plurality of specified units are configured such that each of the plurality of specified units is disposed on one of a wiring on the positive side and a wiring on the negative side forming the power supply path.

7. The processing device according to claim 1, wherein A plurality of the motor control devices are connected to the power supply path, and power from the DC power supply is distributed and supplied to the plurality of motor control devices.

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