JP2007159289A - Motor drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the deterioration of the insulation resistance of a motor simply and accurately. <P>SOLUTION: The drive of the motor 10 is stopped and a contact point 5 of a magnetic contactor is turned off. Contact points a1, a2 are turned on and a charging voltage of a smoothing capacitor C of a power supply portion 6 of a motor drive main unit 1 is boosted by a power supply circuit 2a to supply the voltage between a motor coil and ground. A leakage current flows from a rectifier circuit 23 to an closed circuit of the contact a2, a resistor R2, a detection resistor R1, the motor coil, grounds G2, G1, the contact point a1, and the rectifier circuit 23. If a potential difference at both ends of the detection resistor R1 exceeds a prescribed value, a photocoupler 29 indicates the deterioration of the motor insulation resistance. The detected potential difference (a leakage current value) and temperature/humidity detected by a temperature/humidity detector 2d are displayed in a display circuit 31. Also, its history is displayed graphically. Simple and accurate detection can be achieved because the accumulated energy of the smoothing capacitor, an element provided on the motor drive unit, is used as a power source and the deterioration of the motor insulation is detected after boosting the voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor driving device capable of detecting deterioration of insulation resistance of a motor.

  If the motor is used for many years, the insulation of the motor will deteriorate depending on the usage environment. The leakage breaker is activated by the leakage current due to the deterioration of the insulation, and the device using the motor suddenly stops operating. In such a case, it is unclear whether there is a problem with the motor or a problem with the drive device, it takes time to investigate the cause of the sudden stop, and the stoppage of the equipment or production line that uses this motor is long. It tends to become.

  As a method for detecting the deterioration of the insulation resistance of the motor, a method for detecting the leakage current as described above has been common. However, the leakage detectors such as the leakage detector and the leakage protection relay cannot be detected unless the leakage current is large to a certain extent (3 mA to 15 mA), and can only be detected when the insulation resistance of the motor has deteriorated. there were. In addition, because of a sudden stop due to electric leakage, whether the cause of the stop is due to the motor itself or the motor drive unit or other peripheral devices, or the entire system work such as the device and the production line is stopped. And have to investigate. Furthermore, this leakage detector cannot be used for prediction of motor insulation resistance deterioration and preventive maintenance.

In addition, as a method of detecting a ground fault of a motor coil without using a leakage detector, a motor control device that drives a motor by using an inverter as a DC power source obtained by rectifying an AC power source with a rectifier circuit, An invention is known in which a smoothing capacitor provided in the rectifier circuit is used, and the voltage of the smoothing capacitor is applied between the motor coil and the counter, and the insulation deterioration of the motor is detected by the current flowing at that time. (See Patent Document 1).
Further, in the inverter device for driving and controlling the motor, one phase of the motor and one of the DC buses are connected via a resistor, a comparator is connected in the middle of the resistor, and the inverter device is turned on. While the inverter is stopped, the voltage of the resistor by the current flowing in the motor coil, the resistor, the diode of the rectifier circuit, the power supply, and the closed circuit of the motor coil is compared with the reference value by the comparator, and the inverter output side An invention that detects a ground fault is also known (Patent Document 2).

JP 2005-110400 A JP 2001-218474 A

In the method described in Patent Documents 1 and 2 that detects deterioration of the insulation resistance of the motor by using the components of the motor drive device without using the leakage detector, the power supply voltage of the circuit that detects the deterioration of the insulation resistance However, it is limited to the power supply voltage supplied to the motor drive device.
The power supply voltage supplied to the motor drive device is generally a three-phase AC voltage having a line voltage of 200 Vrms in Japan, and is 400 Vrms (380 V to 415 V) in Europe. Therefore, if the insulation resistance deterioration of the motor is detected and used by the power supply voltage supplied to the motor drive device, the insulation resistance deterioration is adapted to the size of the DC power supply applied to the insulation resistance deterioration detection circuit for domestic and European use. It is necessary to have two detection standards for detection, and even if a single standard is used, it is necessary to change the detection constant and the like.

  FIG. 5 is an explanatory diagram of an experimental circuit for obtaining the relationship between the motor insulation resistance, current, and applied voltage. FIG. 6 shows the DC power supply voltage applied to the experimental circuit as 280 V or 500 V, and the motor insulation resistance is changed. FIG. 6 is a graph of experimental results obtained by measuring the voltage across the detection resistor (constant value) and detecting the flowing current.

As is apparent from the graph shown in FIG. 6, the deterioration of the insulation resistance can be detected more accurately when the voltage of the DC power source E is set to 500V. For example, assuming that the detection voltage for detecting the insulation resistance deterioration is 2V, when the voltage of the DC power source E is 280V, the detection voltage 2V is detected at about 14 MegΩ, and at 500V, it is 26 MegΩ.
If the value of the detection resistor Rs is increased, the detection voltage can be increased. However, since the current flowing through the circuit for detecting this insulation deterioration is reduced and this current flows through the ground, various noises are generated. It becomes easy to pick up and becomes a source of erroneous detection, and it is not preferable to increase the detection resistance.

In addition, the reduction in the insulation resistance of the motor is affected by the environment such as the temperature and humidity around the motor. In particular, the influence of humidity is large, and the degree of insulation resistance increases when the humidity is high. Therefore, it is desirable to consider the ambient temperature and humidity when detecting the insulation resistance deterioration of the motor.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the above-described problems of the prior art, and to detect a decrease in the insulation resistance of a motor simply and more accurately by using elements provided in the motor drive device.

  A power supply unit that rectifies power supplied from an AC power supply via a switch with a rectifier circuit and smoothes it with a capacitor, and a motor drive amplifier that converts the DC voltage from the power supply unit into AC and drives the motor In the motor driving apparatus according to the first aspect of the present invention, the boosting means for boosting the charging voltage of the capacitor and the output of the boosting means are applied between the motor coil and the ground based on a signal for turning off the switch. And when the output of the boosting means is applied between the motor coil and the ground, the output of the boosting means and the current flowing in a closed circuit formed by the motor coil and the ground are detected, and the motor Insulation resistance deterioration detection means for detecting insulation resistance deterioration is provided. According to a second aspect of the present invention, the boosting means includes a switching circuit that switches the voltage of the capacitor to convert it into an alternating current, a transformer that boosts the output of the switching circuit, and a rectifier circuit that rectifies the output of the transformer. It is composed.

  According to a third aspect of the present invention, there is provided a DC power source for insulative deterioration inspection rectified from a secondary output of a transformer used as a power source of a control circuit of a motor drive device, and the above-mentioned signal is based on a signal for turning off the switch. Means for applying an output of a DC power source for inspection of insulation lowering between the motor coil and the ground, and when the output of the DC power source for inspecting insulation lowering is applied between the motor coil and the ground, Insulation resistance deterioration detection means for detecting the insulation resistance deterioration of the motor by detecting the current flowing in the closed circuit formed by the output of the DC power supply and the motor coil and the ground. is there.

  According to a fourth aspect of the present invention, the insulation resistance deterioration detecting means is provided with a resistor in the closed circuit, detects a potential difference generated at both ends of the resistor, and detects a magnitude of a flowing current, or The magnitude of the current flowing by the current sensor provided in the closed circuit is detected to detect the insulation resistance deterioration of the motor. According to a fifth aspect of the present invention, the insulation resistance deterioration detecting means detects the deterioration of the insulation resistance of the motor based on the magnitude of the output from a current detector provided in the motor drive device for motor control. Further, the invention according to claim 6 is provided with a comparator for comparing the insulation resistance deterioration detection means with the current detection value and the reference value, and when the current detection value exceeds the reference value, the display means is notified of the abnormality. To do. In the invention according to claim 7, the insulation resistance deterioration detecting means converts the detected current value into a digital signal by an A / D converter and displays the converted value on the display means. The invention according to claim 8 comprises storage means for storing a value obtained by converting the detected current value into a digital signal by an A / D converter, and means for displaying the stored value in a graph on the display means. The invention according to claim 9 is provided with an interface means with a temperature / humidity detector provided with an external temperature / humidity detector, and the temperature / humidity detected by the temperature / humidity detector is also provided in the display means. Displayed.

  Since the reduction in the insulation resistance between the motor and the ground is measured using the elements of the motor drive device, the reduction in insulation can be detected at low cost, simply and with high accuracy. Furthermore, even if the voltage of the AC power supply of the motor drive device is different, it is possible to reliably detect the deterioration of the insulation resistance of the motor. Further, the temperature and humidity when the insulation resistance is detected can also be detected and displayed, so that the deterioration of the insulation resistance of the motor can be detected more accurately.

FIG. 1 is an explanatory diagram of a first embodiment of the motor drive device of the present invention.
Reference numeral 1 denotes a motor drive device main body for driving the motor 10, a power supply unit 6 for converting a three-phase AC power source into a DC power source by a rectifier circuit, and a motor for driving the motor 10 by converting the DC power source to an arbitrary AC power source. The drive amplifier 8 is used.
The power supply unit 6 of the motor drive device body 1 includes a rectifier circuit composed of diodes D1 to D6 that rectify power input from a three-phase AC power supply via the magnetic contactor contact 5 and convert the power into a DC power supply, and each diode. In parallel with D1 to D6, switching elements Q1 to Q6 configured by IGBTs or the like for returning a regenerative current to an AC power supply are provided, and a controller 7 for controlling the switching elements Q1 to Q6 is provided. Further, a smoothing capacitor C that smoothes the DC output rectified by the rectifier circuit of the diodes D1 to D6 is provided, and further, a discharge resistor R13 that discharges the energy of the smoothing capacitor C is provided. Further, resistors R11 and R12 are provided as voltage detecting means for detecting the charging voltage of the smoothing capacitor C.

Further, the motor drive amplifier 8 is composed of an inverter circuit composed of switching elements Q11 to Q16 composed of IGBT or the like, and diodes D11 to D16 connected in parallel with the switching elements Q11 to Q16, respectively, and a controller 9. The output of the inverter circuit is connected to the motor 10.
Output lines (DC link units) 12 and 13 of the rectifier circuit of the power supply unit 6 are connected to the motor drive amplifier 8 and supply a DC voltage to the motor drive amplifier 8.
The controllers 7 and 9 of the power supply unit 6 and the motor drive amplifier 8 are connected to a control device 30 that controls the motor drive device constituted by a numerical control device or the like, and based on an instruction from the control device 30, the controller 9 The driving of the motor 10 is controlled by turning on / off the switching elements Q11 to Q16. The electromagnetic contactor contact 5 is controlled to be turned on / off based on a command from the control device 30. The connection between the control device 30, the controller 2c of the detection device 2, and the controllers 7 and 9 in the motor drive device main body 1 is simply indicated by a single broken line.

  The motor drive device main body 1 described above is the same as a conventional motor drive device. In the motor drive device main body 1 and the motor as described above, in order to detect the insulation resistance deterioration of the motor 10, the present embodiment is provided with a detection device 2 for detecting the insulation resistance deterioration of the motor. The detection device 2 is connected to the positive and negative lines 12 and 13 of the DC link unit, and the voltage across the capacitor C is input. The power supply circuit 2a boosts this voltage, and the detection circuit 2b detects the insulation resistance deterioration of the motor. It comprises a temperature / humidity detector 2d for detecting ambient temperature and humidity, and a controller 2c. The power supply circuit 2a includes a switching circuit 21 that switches the charging voltage (DC link voltage) of the capacitor C to convert it into alternating current, a transformer 22 that boosts the voltage converted into alternating current by the switching circuit 21, and a secondary side output of the transformer Is composed of a rectifying circuit 23 for obtaining a DC voltage and an output stabilizing circuit 24 for stabilizing the DC output. One output terminal of the rectifier circuit 23 is connected to the ground via a contact a1 of a relay built in the controller 2c. The other output terminal of the rectifier circuit 23 is connected to the detection circuit 2b.

  The detection circuit 2b includes a contact a2 of a relay built in the controller 2c, resistors R1 to R6, capacitors C1 and C2, a Zener diode 25, a comparator 26, a transistor 27, a diode 28, and a photocoupler 29, and supplies power via the contact a2. Motor drive via a protective resistor R2 and a detection resistor R1 connected in series with a contact a2 connected to the rectifier circuit 23, connected to one output (plus side output) of the rectifier circuit 23 of the circuit 2a The amplifier 8 and the motor 10 are connected to a connection line that connects one phase coil. The controller 2c is connected to a control device 30 such as a numerical control device for controlling the motor drive device main body 1.

  When the motor 10 is driven, the electromagnetic contactor contact 5 is turned on based on a command from a control device 30 such as a numerical control device that controls the motor drive device main body 1, and the power supply unit 6 of the motor drive device main body 1 is turned on. Is connected to a three-phase AC power source. The electric power from the three-phase power supply is rectified by the diodes D1 to D6 and the smoothing capacitor C is charged. The rectified DC power is supplied to the motor drive amplifier 8 via the DC link unit, and the controller 9 controls the driving of the motor 10 by controlling the switching elements Q11 to Q16 on / off.

  When the operation of the motor 10 is stopped and the power supply of the three-phase power supply is stopped, the control device 30 outputs a signal for turning off the switching elements Q11 to Q16 and turning off the electromagnetic contactor contact 5 via the controller 9. The electromagnetic contactor contact 5 is turned off. This signal is also input to the controller 2c of the detection device 2 for detecting the insulation resistance deterioration of the motor. When the controller 2c receives the signal for turning off the magnetic contactor contact 5, the controller 2c may operate the relay to turn on the contacts a1 and a2. However, in this embodiment, the charging voltage of the smoothing capacitor C is set as a resistance. The voltage divided by R11 and R12 is detected by the controller 7, and when reaching a preset voltage, an insulation resistance measurement start command signal is output to the controller 2c. Upon receipt of this signal, the controller 2c is connected to the contacts a1 and a2. I try to turn it on. When the magnetic contactor contact 5 is turned off and the supply of power to the power supply unit 6 is stopped, the energy of the smoothing capacitor C is discharged through the resistor R13 and its charging voltage is lowered, but this charging voltage is reduced to the resistors R11 and R12. When the voltage reaches a preset voltage, the contacts a1 and a2 are turned on.

  The charging voltage of the smoothing capacitor C is input to the switching circuit 21 of the power supply circuit 2a of the detection device 2, and the voltage is switched to become an AC voltage, boosted by the transformer 22, and rectified by the rectifier circuit 23 and boosted. Is output.

  Since the contacts a1 and a2 are on, the voltage output from the rectifier circuit 23 is applied between the coil of the motor 10 and the ground. That is, from one output terminal (plus side terminal) of the rectifier circuit 23, the relay contact a2, the protective resistor R2, the detection resistor R1, the one-phase winding of the motor, the insulation resistance of the motor 10 (including the parasitic capacitor of the motor). ), A closed circuit connected to the ground G2, G1, the contact a1, and the other output side terminal (minus side terminal) of the rectifier circuit 23 is formed. A current (leakage current) flows through this closed circuit. Since the potential difference between both ends of the detection resistor R1 varies depending on the magnitude of this current, the insulation resistance between the motor and the ground is measured based on the magnitude of this potential difference. If the insulation resistance between the motor and the ground decreases, the current (leakage current) increases and the potential difference across the detection resistor R1 increases.

  If the potential difference between both ends of the detection resistor R1 does not exceed the reference voltage determined by the Zener diode 25, no signal is output from the comparator 26, but if the reference voltage exceeds the reference voltage (the insulation resistance of the motor 10 deteriorates and grounds) When the insulation resistance decreases and the flowing current increases, an output signal is output from the comparator 26, the transistor 27 is turned on, a current flows through the light emitting element of the photocoupler 29, and the output signal from the photocoupler 29 Is input to the control device 30 via the controller 2c, and a display of a reduction in the insulation resistance of the motor is displayed on the display circuit 31 provided in the control device 30. At this time, the temperature and humidity detected by the temperature / humidity detector 2d are displayed together with a display of a decrease in insulation resistance.

The operator sees this display and replaces the motor 10 or the like. In the initial stage when the contacts a1 and a2 are closed, the voltage detected by the detection resistor R1 fluctuates while charging the parasitic capacitor between the motor and the ground. However, after the contacts a1 and a2 are closed and slightly delayed, What is necessary is just to discriminate | determine the insulation resistance fall between grounds in the stable state after charge to the parasitic capacitor between grounds.
As described above, the insulation resistance between the motor and the ground can be easily measured, and the deterioration of the insulation resistance and the insulation drop of the motor can be easily detected. Therefore, the preventive maintenance of the deterioration of the insulation resistance of the motor can be performed.

Note that when the motor drive amplifier 8 is driven to operate the motor 10, the relay contacts a1 and a2 are held off.
In the embodiment described above, an example in which the temperature / humidity detector 2d is provided in the detection device 2 has been described. However, as indicated by a broken line 2'd in FIG. An interface (terminal T) for connecting the device 2'd may be provided to connect the external temperature / humidity detector 2'd to the controller 2c.

  FIG. 2 is a block circuit diagram of a detection device for detecting motor insulation resistance deterioration in the second embodiment of the motor drive device of the present invention. In the second embodiment, the insulation resistance deterioration can be detected in accordance with the specification (type) of the motor drive amplifier of the motor drive device main body 1, that is, the specification (type) of the motor. The second embodiment is different from the detection circuit 2′b and the controller 2′c in the detection device 2 ′ that detects deterioration of the insulation resistance of the motor, and is provided with a display means 2e. Since this embodiment is different from the embodiment of the detection device 2 and the others are the same as those of the first embodiment, only the detection device 2 ′ is shown.

The detection circuit 2'b is the same as that of the first embodiment in that it includes a relay contact a2, a detection resistor R1, a protection resistor R2, a filter resistor R3, and a capacitor C1, but the voltage across the detection resistor R1 is determined. It is different from the detection circuit 2b of the first embodiment in that it is input to an A / D converter (converter that converts an analog signal into a digital signal) 40, and also includes a microcomputer 41, a memory 42, and a data input means 43. The second embodiment is different from the first embodiment in that the controller 2′c is provided with a display means 2e.
In the second embodiment, a display means 2e is connected to the microcomputer 41 of the controller 2'c, and a temperature / humidity detector 2d for detecting ambient temperature and humidity is further connected. The memory 42 stores in advance a reference value for displaying the deterioration (insulation resistance deterioration) of the motor according to the specifications (types) of the various motor drive amplifiers 8 used in the motor drive device main body 1 or the motor specifications (types). .

  Therefore, the type (specification) of the motor drive amplifier is set in advance from the data input means 43, and the reference value is determined. When an off command for the magnetic contactor contact 5 is output from the control device 30, the magnetic contactor contact 5 is turned off. The microcomputer 41 receives this off signal (or receives a signal when the charging voltage of the smoothing capacitor reaches the set voltage as in the first embodiment), and the microcomputer 41 operates the relay to The contacts a1 and a2 are turned on. As a result, the charging voltage of the smoothing capacitor C is boosted by the power supply circuit 2a as described above. From the power supply circuit 2a, the contact a2, the protection resistor R2, the detection resistor R1, the coil of the motor 10, and the ground G2, G1, and the contact The boosted voltage is applied to the closed circuit of a1 and the power supply circuit 2a, and a leakage current flows. A potential difference between the detection resistors R1 caused by this leakage current is converted into a digital signal by the A / D converter 40. The microcomputer 41 reads and stores this detected potential difference, and also stores the temperature and humidity detected by the temperature / humidity detector 2d at this time. Further, the detected potential difference is compared with a reference value corresponding to the set motor type, and if the detected potential difference exceeds the reference value, a signal indicating a decrease in insulation resistance is sent to the display means 2e to display a decrease in insulation resistance. The value of the detected potential difference at this time, the temperature detected by the temperature / humidity detector 2d, and the humidity are also displayed.

  Further, by inputting a history display command from the data input means 43, the microcomputer 41 displays the value of the detected potential difference stored in the memory 42, the history of the ambient temperature and humidity corresponding thereto as a numerical value, or a graph display process. And display it as a graph.

  In addition, a signal indicating a decrease in insulation resistance, a value of the detected potential difference, temperature, and humidity at that time are transmitted to the control device 30 so that the display circuit 31 of the control device 30 displays the decrease in ground insulation resistance and the temperature and humidity. To do. Further, on the control device 30 side, the history of the detected potential, temperature, and humidity stored in the memory 42 is displayed as a numerical value, or is displayed by graph display processing.

  In the first and second embodiments described above, the voltage applied between the motor coil and the ground is applied to the smoothing capacitor C of the power supply unit 6 of the motor drive device main body 1 in order to detect a decrease in the insulation resistance of the motor. Although the accumulated charging energy is used, the motor driving device main body 1 has a switching element Q1 for feeding back the regenerative current to the AC power supply in the rectifier circuit of the power supply unit 6 included in the motor driving device main body 1. The power supply for the control circuit of the motor drive device comprising the controller 7 for controlling .about.Q6 and the controller 9 for controlling the switching elements Q11 to Q16 of the inverter circuit of the motor drive amplifier 8 is provided. The power supply for the control circuit of the motor drive device may be used as a power supply for detecting a decrease in insulation resistance of the motor.

FIG. 3 shows the configuration of the power source of the detection device 2 for detecting the insulation resistance deterioration of the motor by using the power source for the control circuit of the motor driving device. In the first embodiment shown in FIG. The only difference is that the power source circuit 2a is not provided and the power source for detecting the insulation resistance drop is taken from the power source circuit 50 for the control circuit of the motor drive device. Therefore, elements common to the first embodiment are denoted by the same reference numerals.
In FIG. 3, reference numeral 50 denotes a power supply circuit for the control circuit of the motor drive device, which is different from the conventional power supply circuit in that a rectifier circuit 55 that constitutes a power supply for detecting a decrease in insulation resistance is provided on the secondary side of the transformer. It is a connected point.

  This power supply circuit 50 inputs the voltage between the two phases of the three-phase AC power supply to the rectifier circuit 51 and rectifies and converts it to DC, converts this DC voltage into AC by the switching circuit 52, and converts the DC voltage to the secondary side by the transformer 53. The voltage is adjusted, rectified by a rectifier circuit 54, converted into a DC voltage, and supplied to each control circuit such as the controllers 7 and 9 of the motor drive device. The power supply circuit 50 including the rectifier circuit 51, the switching circuit 52, the transformer 53, and the rectifier circuit 54 is the same as the conventional one, but in this embodiment, for the detection device 2 for detecting the insulation resistance deterioration of the motor, A rectifier circuit 55 is provided on the secondary side of the transformer 53. The rectifier circuit 55 is supplied with a voltage boosted or stepped down by the transformer 53 (usually a boosted voltage), and the output of the rectifier circuit 55 turns on the contacts a1 and a2 as described above. At this time, it is applied between the winding of the motor and the ground, and the leakage current is detected by the detection circuit 2b as in the first embodiment.

  In the third embodiment, the detection circuit 2'b shown in FIG. 2 may be used instead of the detection circuit 2b. Further, as a configuration of the power supply circuit 50 in the third embodiment, a transformer 56 is newly provided as a power supply of a detection device for detecting the insulation resistance deterioration of the motor as shown in FIG. May be boosted and input to the rectifier circuit 55.

  In each of the above-described embodiments, the leakage current is detected by the potential difference between both ends of the detection resistor R1, but the current flowing in the above-described closed circuit may be detected using a Hall element. is there.

Furthermore, the motor drive device normally performs current loop control by detecting current flowing through each phase (at least two phases) with a current detector that feeds back the detected current.
You may use this current detector as a current detector in this embodiment. That is, the outputs of the rectifier circuits 23 and 55 boosted by the power supply circuit 2a or the power supply circuit 50 are applied between the motor coil and the ground by turning on the contacts a1 and a2, and the current flowing at that time is detected by this current detector. Then, a decrease in the insulation resistance of the motor may be detected.

It is a block circuit diagram of a 1st embodiment of the present invention. It is a principal part block circuit diagram of the 2nd Embodiment of this invention. It is a block circuit diagram of a 3rd embodiment of the present invention. It is a figure which shows another aspect of the power supply circuit in the 3rd Embodiment of this invention. It is explanatory drawing of the experimental circuit which calculates | requires the relationship between the insulation resistance of a motor, an electric current, and an applied voltage. It is an example of the graph display of the experimental result by the same experimental circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor drive device body 2,2 'Detection device for detecting insulation resistance deterioration of motor 2a Power supply circuit 2b, 2'b detection circuit 2c, 2'c Controller of motor insulation resistance deterioration detection device 2d Temperature / humidity detection Device 2'd External temperature / humidity detector 2e Display means 5 Magnetic contactor contact 6 Power supply unit 7 Power supply unit controller 8 Motor drive amplifier 9 Motor drive amplifier controller 10 Motor 21, 52 Switching circuit 22, 53 Transformer 23 , 54, 55 Rectifier circuit 24 Output stabilization circuit 25 Zener diode 26 Comparator 27 Transistor 29 Photocoupler 30 Controller 31 Display circuit a1, a2 Contact Q1-Q6, Q11-Q16 Switching element D1-D6, D11-D16 Diode

Claims (9)

A power supply unit that rectifies power supplied from an AC power supply via a switch with a rectifier circuit and smoothes it with a capacitor, and a motor drive amplifier that converts the DC voltage from the power supply unit into AC and drives the motor Motor drive device
Boosting means for boosting the charging voltage of the capacitor;
Means for applying the output of the boosting means between the motor coil and the ground based on a signal for turning off the switch;
When the output of the boosting means is applied between the motor coil and the ground, the current flowing in the closed circuit formed by the output of the boosting means and the motor coil and the ground is detected, and the insulation resistance of the motor is deteriorated. A motor drive device comprising: insulation resistance deterioration detection means for detecting   2. The motor according to claim 1, wherein the boosting unit includes a switching circuit that switches the voltage of the capacitor and converts the voltage into an alternating current, a transformer that boosts the output of the switching circuit, and a rectifier circuit that rectifies the output of the transformer. Drive device. A power supply unit that rectifies power supplied from an AC power supply via a switch with a rectifier circuit and smoothes it with a capacitor, and a motor drive amplifier that converts the DC voltage from the power supply unit into AC and drives the motor Motor drive device
A DC power source for insulative degradation inspection, which is rectified from a secondary output boosted by a transformer used as a power source for a control circuit of the motor driving device;
Means for applying an output of the DC power source for the insulation lowering inspection between the motor coil and the ground based on a signal for turning off the switch;
When the output of the DC power supply for inspection of insulation degradation is applied between the motor coil and the ground, the current flowing in the closed circuit formed by the output of the DC power supply for inspection of insulation degradation and the motor coil A motor drive device comprising: insulation resistance deterioration detecting means for detecting insulation resistance deterioration of the motor.   The insulation resistance deterioration detecting means provides a resistor in the closed circuit, detects a potential difference generated at both ends of the resistor, and detects a magnitude of a flowing current, or a current sensor provided in the closed circuit 4. The motor driving device according to claim 1, wherein the magnitude of the flowing current is detected to detect insulation resistance deterioration of the motor.   4. The insulation resistance deterioration detecting means according to claim 1, wherein the insulation resistance deterioration detecting means detects the deterioration of the insulation resistance of the motor based on a magnitude of an output from a current detector provided for motor control in the motor driving device. The motor drive device according to item.   6. The insulation resistance deterioration detection unit includes a comparator that compares a current detection value with a reference value, and notifies the display unit of an abnormality when the current detection value exceeds the reference value. 2. The motor drive device according to item 1.   6. The insulation resistance deterioration detection unit according to claim 1, wherein the current detection value is converted into a digital signal by an A / D converter, and the converted value is displayed on a display unit. Motor drive device.   8. The motor driving apparatus according to claim 7, further comprising storage means for storing a value obtained by converting a current detection value into a digital signal by an A / D converter, and means for displaying the stored value in a graph on the display means. 7. A temperature / humidity detector is provided or an interface means with a temperature / humidity detector provided outside is provided, and the temperature / humidity detected by the temperature / humidity detector is also displayed on the display means. The motor drive device according to any one of 1 to 8.

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