JP2005304138A - Motor driving unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor driving unit which can localize a leakage point. <P>SOLUTION: Differential voltage detectors 11 and 12 severally detect voltages Vp and Vm and output them to a controller 40. A leakage detector 30 detects a voltage value Vk which shows the peak of an AC signal V<SB>N1</SB>at a node N1, and outputs it to the controller 40. The controller 40 judges that leakage has occurred in a motor driver MDRV when the voltage value Vk is smaller than the value at nonoccurrence of leakage. Then, on the basis of the voltages Vp and Vm and their absolute values ¾Vp¾ and ¾Vm¾, the controller 40 judges which leakage has occurred in out of the side of a positive bus LN1, the side of a negative bus LN2, and a battery 10 or three-phase wiring 15. Furthermore, the controller 40 permits or inhibits the drive of an AC motor M1, according to the leakage point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor drive device that drives a motor, and more particularly, to a motor drive device that can identify a leakage portion.

  Patent Document 1 discloses a leakage detection device. This leakage detection device includes protective resistors A to D, detection resistors E and F, and switches SA and SB. The protection resistor A, the protection resistor B, the detection resistor E, the detection resistor F, the protection resistor C, and the protection resistor D are connected in series between the positive electrode and the negative electrode of the high-voltage DC power supply in this order. The switch SA is connected to both ends of the protective resistor B, and the switch SB is connected to both ends of the protective resistor C. The switch SA opens or short-circuits both ends of the protective resistor B, and the switch SB opens or short-circuits both ends of the protective resistor C.

  In the leakage detection device, the two switches SA and SB are opened and closed in three types as follows.

(A) Both switches SA and SB are open. (B) Switch SA is closed and switch SB is open. (C) Switch SA is open and switch SB is closed. When two switches SA and SB are opened and closed. The voltage at both ends of the detection resistors E and F is detected, and the leakage site is specified based on the detected voltage.
JP-A-6-308185 JP 2003-66090 A JP-A-6-46502 JP-A-8-163704 Japanese Patent Laid-Open No. 7-20185

  However, since the leakage detection device disclosed in Patent Document 1 specifies a leakage portion in a high-voltage DC power supply, a DC power supply, a positive bus and a negative bus connected to the DC power supply, and a positive bus and a negative bus In a motor drive device including an inverter that drives a motor by receiving a direct-current voltage through a pin, there is a problem that it is difficult to specify a leakage site.

  Moreover, since patent document 1 does not disclose a coping method when a leak is detected, there is a problem that when a leak is detected in the motor drive device, the leak cannot be dealt with.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a motor drive device capable of specifying a leakage site.

  Another object of the present invention is to provide a motor drive device having a countermeasure against electric leakage.

  According to this invention, the motor drive device includes a motor drive unit, a leakage detection unit, a leakage site identification unit, and a control unit. The motor driving unit drives the motor. The electric leakage detection means detects electric leakage in the motor drive unit. The leakage part specifying means specifies a leakage part in the motor drive unit when leakage in the motor drive unit is detected. The control means controls the motor driving unit so as to permit or prohibit the driving of the motor based on the result of specifying the leakage site. The motor driving unit includes a power source, a motor driving device that drives the motor, a three-phase wiring that connects the motor driving device to the motor, a positive bus that connects the motor driving device to the positive electrode of the power source, and a motor driving device. A negative bus connected to the negative electrode of the power supply. In addition, the leakage site specifying means detects a first voltage between the positive bus and the ground node and a second voltage between the ground node and the negative bus when a leakage in the motor driving unit is detected. Then, the leakage site is specified based on the detected first and second voltages. The control means is that when the earth leakage site specified by the earth leakage site identification means is a positive bus or a negative bus, and the insulation resistance is reduced in the negative bus or the positive bus opposite to the positive bus or the negative bus as the earth leakage site The motor driving unit is controlled so as to prohibit the driving of the motor.

  Preferably, the voltage between the positive bus and the ground node when no leakage occurs is the first reference voltage, and the voltage between the ground node and the negative bus when no leakage is generated is the first reference voltage. When the reference voltage of 2 is used, the leakage site characteristic means sets the positive bus to the leakage site when the first voltage is lower than the first reference voltage or when the second voltage is lower than the second reference voltage. When the first voltage is higher than the first reference voltage or when the second voltage is higher than the second reference voltage, the negative bus is specified as the leakage site.

  Preferably, the control unit controls the motor driving unit so as to drive the motor when the leakage site specified by the leakage site specifying unit is other than the positive bus and the negative bus.

  Preferably, the leakage site characteristic means specifies that the leakage site is other than the positive bus and the negative bus when the first absolute value of the first voltage is substantially equal to the second absolute value of the second voltage. .

  Preferably, the leakage site characteristic means identifies the battery or the three-phase wiring as the leakage site when the first absolute value is substantially equal to the second absolute value.

  Moreover, according to this invention, a motor drive device is provided with a motor drive part, an electrical leakage detection means, and an electrical leakage site | part identification means. The motor driving unit drives the motor. The electric leakage detection means detects electric leakage in the motor drive unit. The leakage part specifying means specifies a leakage part in the motor drive unit when leakage in the motor drive unit is detected. The motor driving unit includes a power source, a motor driving device that drives the motor, a three-phase wiring that connects the motor driving device to the motor, a positive bus that connects the motor driving device to the positive electrode of the power source, and a motor driving device. A negative bus connected to the negative electrode of the power supply, and a relay connected to the positive bus and the negative bus to connect / negatively connect the power supply and the motor drive device. The leakage site specifying means detects a first voltage between the positive bus and the ground node and a second voltage between the ground node and the negative bus when the leakage in the motor drive unit is detected, An electrical leakage site is identified based on the detected first and second voltages and the presence or absence of electrical leakage when the motor drive device and the relay are turned on / off.

  Preferably, when the leakage is detected by the leakage detection means when the relay is turned off, and the first absolute value of the first voltage is different from the second absolute value of the second voltage. The battery is identified as a leakage site.

  Preferably, when the first absolute value is smaller than the second absolute value, the leakage site specifying unit specifies the positive electrode side of the battery as the leakage site.

  Preferably, when the first absolute value is larger than the second absolute value, the leakage site specifying unit specifies the negative electrode side of the battery as the leakage site.

  Preferably, the leakage site specifying means detects the leakage by the leakage detection means when the relay is turned off, and the first absolute value of the first voltage is substantially equal to the second absolute value of the second voltage. Then, the middle part of the battery is specified as a leakage site.

  Preferably, the earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor driving device is turned on, the earth leakage detecting means is not detected when the motor driving device is turned off, and the first voltage When the first absolute value of is substantially equal to the second absolute value of the second voltage, the three-phase wiring is specified as the leakage site.

  Preferably, the earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor driving device is turned on, the earth leakage detecting means is not detected when the motor driving device is turned off, and the first voltage When the first absolute value of is different from the second absolute value of the second voltage, the three-phase wiring is specified as the leakage site.

  Preferably, the motor drive device further includes a control unit. The control means controls the motor driving unit so as to drive the motor when the leakage site specified by the leakage site specifying means is a battery or a three-phase wiring.

  Preferably, the earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor drive device is turned off, and the first absolute value of the first voltage is changed to the second absolute value of the second voltage. When they are approximately equal, the positive bus and the negative bus are specified as the leakage site.

  Preferably, the leakage detecting unit is not detected by the leakage detection means when the relay is turned off, the leakage detection is detected by the leakage detection means when the motor drive device is turned off, and the leakage of the first voltage is further detected. When the absolute value of 1 is different from the second absolute value of the second voltage, the positive bus or the negative bus is specified as the leakage site.

  Preferably, when the first absolute value is smaller than the second absolute value, the leakage portion specifying means specifies the positive bus as the leakage portion.

  Preferably, when the first absolute value is larger than the second absolute value, the leakage portion specifying means specifies the negative bus as the leakage portion.

  Preferably, the motor drive device further includes a control unit. In the control means, the earth leakage site specified by the earth leakage site specifying means is a positive bus and / or a negative bus, and the insulation resistance decreases in the negative bus or the positive bus opposite to the positive bus or the negative bus as the earth leakage site. The motor drive unit is controlled so as to prohibit the drive of the motor.

  Preferably, the leakage site specifying means includes a first resistor connected between the positive bus and the ground node, a second resistor connected between the ground node and the negative bus, and a first resistor. Based on the first and second voltages, first voltage detecting means for detecting the first voltage across the first resistor, second voltage detecting means for detecting the second voltage across the second resistor, and the first and second voltages. And a specifying means for specifying a leakage site.

  Preferably, the motor drives a drive wheel of the vehicle.

  In the present invention, when the leakage detection means detects a leakage in the motor drive unit that drives the motor, the leakage site specifying means specifies the leakage site in the motor drive unit. In this case, the leakage site specifying means specifies the positive bus side, the negative bus side, and the power source or the three-phase wiring of the motor drive unit as the leakage site. In addition, the earth leakage site specifying means uses any one of a positive side, an intermediate unit, a negative side, a positive bus side, a negative bus side, a positive bus and a negative bus side, and a three-phase wiring of the power source as a leakage site in the motor drive unit. Identify. And, when the leakage site is the positive bus side and / or the negative bus side, and a decrease in insulation resistance is detected on the negative bus side or the positive bus side opposite to the positive bus side or the negative bus side as the leakage site, Driving of the motor is prohibited, otherwise driving of the motor is permitted.

  Therefore, according to this invention, the electrical leakage site | part in a motor drive part can be specified. Further, according to the present invention, when a leakage occurs, it is possible to cope with the leakage.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram of a motor drive device according to an embodiment of the present invention. Referring to FIG. 1, motor drive device 100 according to the embodiment of the present invention includes a battery 10, system main relays SMR1, SMR2, a positive bus LN1, a negative bus LN2, resistors R1, R2, and a differential. Voltage detectors 11 and 12, a voltage sensor 13, a current sensor 14, a three-phase wiring 15, an inverter 20, a leakage detector 30, and a control device 40 are provided.

  Battery 10, system main relays SMR1 and SMR2, positive bus LN1, negative bus LN2, voltage sensor 13, current sensor 14, three-phase wiring 15 and inverter 20 constitute motor drive unit MDRV.

  The motor drive device 100 is mounted on a hybrid vehicle or an electric vehicle. AC motor M1 is a motor for driving drive wheels of a hybrid vehicle or an electric vehicle. AC motor M1 may be mounted on the hybrid vehicle as a motor generator that is coupled to the engine of the hybrid vehicle and has both the function of a generator that generates electric power by the rotational force of the engine and the function of an electric motor that starts the engine.

  Positive bus LN1 connects the high voltage side of inverter 20 to positive electrode 10P of battery 10. Negative bus LN2 connects the low voltage side of inverter 20 to negative electrode 10N of battery 10. System main relay SMR1 is connected to positive bus LN1, and system main relay SMR2 is connected to negative bus LN2.

  Resistors R1 and R2 are connected in series between positive bus LN1 and negative bus LN2, and have the same resistance value. An intermediate point MP between the resistors R1 and R2 is grounded, for example, to the chassis of the vehicle. The differential voltage detector 11 is connected to both ends of the resistor R1, and the differential voltage detector 12 is connected to both ends of the resistor R2.

  The capacitor C <b> 1 is connected in parallel to the inverter 20 on the input side of the inverter 20. Three-phase wiring 15 connects inverter 20 to AC motor M1.

  Inverter 20 includes a U-phase arm 21, a V-phase arm 22, and a W-phase arm 23. U-phase arm 21, V-phase arm 22 and W-phase arm 23 are provided in parallel between positive bus LN1 and negative bus LN2. The U-phase arm 21 includes NPN transistors Q1 and Q2 connected in series, the V-phase arm 22 includes NPN transistors Q3 and Q4 connected in series, and the W-phase arm 23 includes NPN transistors connected in series. It consists of transistors Q5 and Q6. Between the collectors and emitters of the NPN transistors Q1 to Q6, diodes D1 to D6 that flow current from the emitter side to the collector side are respectively connected.

  An intermediate point of each phase arm is connected to each phase end of each phase coil of AC motor M1. That is, AC motor M1 is a three-phase permanent magnet motor, and is configured such that one end of three coils of U, V, and W phases are connected in common to the middle point, and the other end of the U-phase coil is NPN transistor Q1, The other end of the V-phase coil is connected to the intermediate point of NPN transistors Q3 and Q4, and the other end of the W-phase coil is connected to the intermediate point of NPN transistors Q5 and Q6, respectively.

  Leakage detector 30 is connected to negative bus LN2 on the battery 10 side of system main relay SMR2. Leakage detector 30 includes an AC power supply 31, a resistor 32, a capacitor 33, a bandpass filter 34, and a peak hold circuit 35.

  AC power supply 31 and resistor 32 are connected in series between node N1 and ground node GND (vehicle chassis). Capacitor 33 is connected between node N1 and negative bus LN2.

  The battery 10 is a secondary battery such as nickel metal hydride and lithium ion, and outputs a power supply voltage Vb. System main relays SMR1 and SMR2 are turned on / off by signals SE1 and SE2 from control device 40, respectively. More specifically, system main relays SMR1 and SMR2 are turned on by H (logic high) level signals SE1 and SE2, and are turned off by L (logic low) level signals SE1 and SE2, respectively. Therefore, system main relays SMR1 and SMR2 connect / disconnect battery 10 to inverter 20 by signals SE1 and SE2.

  The differential voltage detector 11 detects the voltage Vp across the resistor R1 and outputs the detected voltage Vp to the control device 40. The differential voltage detector 12 detects the voltage Vm across the resistor R2 and outputs the detected voltage Vm to the control device 40.

  Capacitor C1 smoothes power supply voltage Vb received from battery 10 via system main relays SMR1 and SMR2, and supplies the smoothed power supply voltage Vb to inverter 20. The voltage sensor 13 detects the voltage Vc across the capacitor C1 and outputs the detected voltage Vc to the control device 40.

  The inverter 20 converts the power supply voltage Vb supplied from the capacitor C1 into an AC voltage by a signal PWM from the control device 40, and supplies the converted AC voltage to the AC motor M1 via the three-phase wiring 15. Drive M1. Further, the inverter 20 receives the AC voltage generated by the AC motor M1 through the three-phase wiring 15, converts the received AC voltage into a DC voltage by the signal PWM from the control device 40, and supplies the DC voltage to the capacitor C1.

  Current sensor 14 detects motor current MCRT flowing through AC motor M1, and outputs the detected motor current MCRT to control device 40.

In the leakage detector 30, the AC power supply 31 outputs a low-frequency AC signal, for example, an AC signal of 2.5 Hz. The band-pass filter 34 receives the AC signal _{V N1} on the node N1, and outputs the extracted only components 2.5Hz from the AC signal _{V N1} thereof received into the peak hold circuit 35.

  The peak hold circuit 35 holds the peak of the 2.5 Hz AC signal received from the band pass filter 34 and outputs the held voltage value Vk to the control device 40.

  Control device 40 receives motor current MCRT from current sensor 14, receives voltage Vc from voltage sensor 13, receives a torque command value TR from an ECU (Electrical Control Unit) provided outside motor drive device 100, and performs differential operation. The voltage detectors 11 and 12 receive the voltages Vp and Vm, respectively, and the leakage detector 30 receives the voltage value Vk.

  Then, control device 40 calculates a voltage to be applied to each phase coil of AC motor M1 based on voltage Vc, motor current MCRT and torque command value TR, and based on the calculated result, inverter 20 is actually used. A signal PWM for turning on / off each of the NPN transistors Q1 to Q6 is generated, and the generated signal PWM is output to each of the NPN transistors Q1 to Q6 of the inverter 20.

  Thereby, each NPN transistor Q1-Q6 is switching-controlled, and controls the electric current sent through each phase of AC motor M1 so that AC motor M1 may output the commanded torque. In this way, the motor drive current is controlled, and a motor torque corresponding to the torque command value TR is output.

  Control device 40 also stores voltages Vp and Vm received from differential voltage detectors 11 and 12, respectively. Then, control device 40 determines whether or not a leakage has occurred in motor drive unit MDRV based on voltage value Vk received from leakage detector 30.

FIG. 2 is a waveform diagram of the AC signal V _N1 output from the bandpass filter 34 shown in FIG. Referring to FIG. 2, AC signal V _N1 has a waveform WV1 when there is no leakage in motor drive unit MDRV, and has a waveform WV2 when a leakage occurs in motor drive unit MDRV. The peak hall circuit 35 outputs a voltage value Vk1 based on the waveform WV1, and outputs a voltage value Vk2 based on the waveform WV2.

  FIG. 3 is a timing chart of the voltages Vp and Vm output from the differential voltage detectors 11 and 12 shown in FIG. Referring to FIG. 3, voltage Vp is a voltage across resistor R1, ie, a voltage between positive bus LN1 and ground node GND, and voltage Vm is a voltage across resistor R2, ie, a negative bus. This is a voltage between LN2 and the ground node GND. A power supply voltage Vb is applied between the positive bus LN1 and the negative bus LN2. The resistors R1 and R2 have the same resistance value. Therefore, when there is no leakage in the motor drive unit MDRV, the voltage Vp is equal to the voltage Vm, and the voltages Vp and Vm are the voltage Vb / 2 (see (a) of FIG. 3).

  When a leakage occurs in the positive bus LN1, the voltages Vp and Vm decrease (see (b) in FIG. 3). That is, assuming that the voltages Vp and Vm when no leakage occurs in the motor drive unit MDRV are the reference values Vstd1 and Vstd2, respectively, when the leakage occurs in the positive bus LN1, the voltages Vp and Vm are respectively the reference It falls below the values Vstd1 and Vstd2.

  Further, when a leakage occurs in the negative bus LN2, the voltages Vp and Vm are higher than the reference values Vstd1 and Vstd2, respectively (see (c) in FIG. 3).

  Referring again to FIG. 1, control device 40 determines whether or not electric leakage has occurred in motor drive unit MDRV based on voltage value Vk received from peak hold circuit 35 of electric leakage detector 30. More specifically, control device 40 holds voltage value Vk1 when there is no leakage in motor drive unit MDRV, and compares voltage value Vk received from peak hold circuit 35 with voltage value Vk1. Thus, it is determined whether or not electric leakage has occurred in the motor drive unit MDRV. If the voltage value Vk is not lower than the voltage value Vk1, the control device 40 determines that there is no leakage in the motor drive unit MDRV, and the voltage value Vk is lower than the voltage value Vk1. For example, it is determined that electric leakage has occurred in the motor drive unit MDRV.

  When it is determined that a leakage has occurred in the motor drive unit MDRV based on the voltage value Vk, the control device 40 determines whether the polarity can be determined based on the stored voltages Vp and Vm. That is, the control device 40 determines whether the polarity can be determined by determining whether the absolute value | Vp | of the voltage Vp is different from the absolute value | Vm | of the voltage Vm. In the present invention, “polarity discrimination is possible” means that when a leakage occurs in the motor drive unit MDRV, it is determined whether the leakage portion is on the positive bus LN1 side or the negative bus LN2 side.

  As described above, when the leakage occurs in the positive bus LN1, the voltages Vp and Vm are lower than the reference values Vstd1 and Vstd2, respectively, and the absolute value | Vp | of the voltage Vp is equal to the voltage Vm. It is smaller than the absolute pair | Vm |. When leakage occurs in the negative bus LN2, the voltages Vp and Vm rise above the reference values Vstd1 and Vstd2, respectively, and the absolute value | Vp | of the voltage Vp is the absolute value | Vm | Bigger than.

  Therefore, by determining whether or not the absolute value | Vp | of the voltage Vp is different from the absolute value | Vm | of the voltage Vm, it is possible to determine whether or not polarity determination is possible. When the absolute value | Vp | is different from the absolute value | Vm |, the control device 40 determines that the polarity can be determined. When the absolute value | Vp | is substantially equal to the absolute value | Vm | Is determined to be impossible.

  Then, when the absolute value | Vp | is different from the absolute value | Vm |, the control device 40 further determines whether or not the absolute value | Vp | is smaller than the absolute value | Vm |, and the absolute value | Vp | When the absolute value | Vm | is smaller than the absolute value | Vm |, it is determined that a leakage has occurred on the positive bus LN1 side, and the absolute value | Vp | is larger than the absolute value | Vm | If it is smaller than Vp |), it is determined that a leakage has occurred on the negative bus LN2 side.

  In this case, detecting that the absolute value | Vp | is smaller than the absolute value | Vm | is detecting that the voltage Vp is lower than the reference value Vstd1 or that the voltage Vm is lower than the reference value Vstd2. It corresponds to. Further, detecting that the absolute value | Vp | is larger than the absolute value | Vm | means that the voltage Vp is higher than the reference value vstd1 or that the voltage Vm is higher than the reference value Vstd2. Equivalent to.

  When it is determined that leakage has occurred on the positive bus LN1 side or the negative bus LN2 side, the control device 40 further determines whether or not the insulation resistance is reduced at the opposite pole. That is, when it is determined that leakage has occurred on the positive bus LN1 side, the control device 40 determines whether the absolute value | Vm | of the voltage Vm is smaller than the voltage Vb / 2, thereby determining the negative bus LN2 When it is further determined whether or not the insulation resistance has decreased on the side (reverse pole), and it is determined that leakage has occurred on the negative bus LN2 side, the absolute value | Vp | of the voltage Vp becomes the voltage Vb / 2 It is further determined whether or not the insulation resistance is reduced on the positive bus LN1 side (reverse pole) by determining whether or not the resistance is smaller than the above.

  Then, when leakage occurs on the positive bus LN1 side or the negative bus LN2 side and the insulation resistance is reduced at the opposite pole, the control device 40 outputs L level signals SE1 and SE2 and outputs the system mains. Relays SMR1 and SMR2 are turned off, and inverter 20 is disconnected from battery 10. If leakage occurs in the positive bus LN1 or the negative bus LN2 and the insulation resistance is reduced at the opposite pole, it is difficult to drive the vehicle by driving the AC motor M1, so the system main Relays SMR1 and SMR2 are turned off to stop driving AC motor M1.

  On the other hand, when the leakage occurs on the positive bus LN1 side or the negative bus LN2 side but the insulation resistance does not decrease at the opposite pole, the control device 40 drives the motor so as to continue driving the AC motor M1. Control part MDRV.

  In addition, when the polarity cannot be determined, the control device 40 determines that a leakage has occurred in the intermediate portion 10 </ b> C or the three-phase wiring 15 of the battery 10. Then, when it is determined that leakage has occurred in the intermediate portion 10C or the three-phase wiring 15 of the battery 10, the control device 40 controls the motor drive unit MDRV so as to continue driving the AC motor M1.

FIG. 4 is a flowchart for explaining an operation of detecting leakage in motor drive device 100 shown in FIG. Referring to FIG. 4, when a series of operations is started, leakage detector 30 detects AC signal V _N1 at node _N1, and detects voltage value Vk indicating the peak of detected AC signal V _N1. To the control device 40. The differential voltage detectors 11 and 12 detect the voltages Vp and Vm, respectively, and output them to the control device 40. Then, control device 40 determines whether or not electric leakage has occurred in motor drive unit MDRV by the above-described method based on voltage value Vk (step S1).

  If control device 40 determines that leakage has occurred in motor drive unit MDRV (in the case of “No” in step S1), whether or not absolute value | Vp | of voltage Vp differs from absolute value | Vm | of voltage Vm. Determine. That is, the control device 40 determines whether or not polarity determination is possible (step S2).

  When the polarity can be discriminated, the control device 40 determines whether the insulation resistance has decreased at the opposite pole by the above-described method based on the absolute value | Vp | or the absolute value | Vm | Step S3). When the insulation resistance decreases at the opposite pole, control device 40 outputs L level signals SE1, SE2 to turn off system main relays SMR1, SMR2, and disconnects inverter 20 from battery 10 (step S4). . And the control apparatus 40 controls the inverter 20 to stop, and stops the driving | operation of the vehicle by which the motor drive device 100 is mounted (step S5).

  On the other hand, when the polarity cannot be determined in step S2, the control device 40 determines that a leakage has occurred in the intermediate portion 10C or the two-phase wiring 15 of the battery 10 (step S6). If the insulation resistance does not decrease at the opposite pole in step S3 (if “No” in step S3), or after step S6, control device 40 drives the motor to continue driving AC motor M1. The unit MDRV is controlled to permit normal operation (step S7).

  Then, a series of operation | movement is complete | finished after step S5 or step S7.

  As described above, the control device 40 determines whether or not a leak has occurred in the motor drive unit MDRV based on the voltage value Vk detected by the leak detector 30, and a leak has occurred in the motor drive unit MDRV. By determining whether or not the absolute value | Vp | is smaller than the absolute value | Vm |, it is specified whether the leakage portion is on the positive bus LN1 side or the negative bus side LN2. When the positive bus LN1 side or the negative bus side LN2 is specified as the leakage site, the control device 40 determines whether or not the insulation resistance is reduced at the opposite pole, and the insulation resistance is lowered at the opposite pole. If so, the motor drive unit MDRV is controlled so as to prohibit the drive of the AC motor M1.

  Further, when absolute value | Vp | is substantially equal to absolute value | Vm |, control device 40 specifies intermediate portion 10C or three-phase wiring 15 of battery 10 as a leakage site. Then, the control device 40 has a leakage occurring in the middle portion 10C or the three-phase wiring 15 of the battery 10 or in either the positive bus LN1 side or the negative bus side LN2, but the reverse pole If the insulation resistance is not reduced, the motor drive unit MDRV is controlled so as to continue the driving of the AC motor M1.

  Therefore, according to the present invention, it is possible to specify a leakage site in the motor drive unit MDRV. Further, when a leakage occurs in the motor drive unit MDRV, it is possible to take measures against the leakage.

  In the above description, the method for specifying whether the leakage site is the positive bus LN1, the negative bus LN2, the intermediate portion 10C of the battery 10 or the three-phase wiring 15 has been described. However, the present invention is not limited to this. First, the positive bus LN1 and / or the negative bus LN2 on the positive electrode 10P side of the battery 10, the negative electrode 10N side of the battery 10, and the input side of the inverter 20 are added as identifiable leakage current sites, and leakage occurs in the battery 10. It is also possible to distinguish between the case where there is a leak and the case where leakage occurs in the three-phase wiring 15.

FIG. 5 is another flowchart for explaining the operation of detecting leakage in motor drive device 100 shown in FIG. Referring to FIG. 5, when a series of operations is started, leakage detector 30 detects AC signal V _N1 at node _N1, and detects voltage value Vk indicating the peak of detected AC signal V _N1. To the control device 40. The differential voltage detectors 11 and 12 detect the voltages Vp and Vm, respectively, and output them to the control device 40. Then, control device 40 determines whether or not electric leakage has occurred in motor drive unit MDRV by the above-described method based on voltage value Vk (step S11).

  If control device 40 determines that electric leakage has occurred in motor drive unit MDRV (“No” in step S11), it stores voltages Vp and Vm received from differential voltage detectors 11 and 12, respectively (step S12). ), It is determined whether the polarity can be determined by determining whether the absolute value | Vp | of the voltage Vp is different from the absolute value | Vm | of the voltage Vm (step S13).

  When it is determined that the polarity can be determined, control device 40 outputs L level signals SE1 and SE2 to turn off system main relays SMR1 and SMR2 (step S14), and system main relays SMR1 and SMR2 Whether or not a leakage has occurred is determined based on the voltage value Vk received from the leakage detector 30 after the power is turned off (step S15).

  When it is determined in step S15 that leakage has occurred (in the case of “No” in step S15), control device 40 further determines whether absolute value | Vp | is smaller than absolute value | Vm |. Determination is made (step S16). Then, when the absolute value | Vp | is smaller than the absolute value | Vm |, the control device 40 determines that a leakage has occurred on the positive electrode 10P side of the battery 10 (step S17), and the absolute value | Vp | When it is larger than the absolute value | Vm |, it is determined that a leakage has occurred on the negative electrode 10N side of the battery 10 (step S18).

  In step S15, determining that the insulation resistance is not normal corresponds to determining that a leakage has occurred in the battery 10.

  On the other hand, when it is determined in step S15 that the insulation resistance is normal, control device 40 outputs H level signals SE1 and SE2 to turn on system main relays SMR1 and SMR2 (step S19). Is output to NPN transistors Q1 to Q6 to turn off inverter 20 (step S20).

  Then, control device 40 determines whether or not a leakage has occurred based on voltage value Vk received from leakage detector 30 after turning off inverter 20 (step S21), and determines that a leakage has occurred. ("No" in step S21), it is further determined whether or not the absolute value | Vp | is smaller than the absolute value | Vm | (step S22). When the absolute value | Vp | is smaller than the absolute value | Vm |, the control device 40 determines that a leakage has occurred on the positive bus LN1 side on the input side of the inverter 20 (step S23), and the absolute value. When | Vp | is larger than the absolute value | Vm |, it is determined that a leakage has occurred on the negative bus LN2 side on the input side of the inverter 20 (step S24).

  In step S21, determining that the insulation resistance is not normal corresponds to determining that a leakage has occurred in the positive bus LN1 or the negative bus LN2 on the input side of the inverter 20.

  On the other hand, when it is determined in step S13 that the polarity cannot be determined, control device 40 outputs L level signals SE1 and SE2 to turn off system main relays SMR1 and SMR2 (step S25). It is determined whether or not a leakage has occurred based on voltage value Vk received from leakage detector 30 after main relays SMR1 and SMR2 are turned off (step S26).

  When it is determined that a leak has occurred (in the case of “No” in step S26), the control device 40 determines that a leak has occurred in the intermediate portion 10C of the battery 10 (step S27). If it is determined in step S26 that a leakage has occurred, it is determined in step S13 that the polarity cannot be determined in order to determine that a leakage has occurred in the intermediate portion 10C of the battery 10. This is because, when the absolute value | Vp | is substantially equal to the absolute value | Vm |, it is determined that the polarity cannot be determined.

  On the other hand, when it is determined in step S26 that no leakage has occurred (in the case of "Yes" in step S26), control device 40 outputs H level signals SE1 and SE2 to turn on system main relays SMR1 and SMR2. Turns on (step S28), outputs a signal PWM having an on-duty value of zero to the NPN transistors Q1 to Q6, and turns off the inverter 20 (step S29).

  Then, control device 40 determines whether or not a leakage has occurred based on voltage value Vk received from leakage detector 30 after turning off inverter 20 (step S30), and determines that a leakage has occurred. ("No" in step S30), it is determined that leakage has occurred on the positive bus LN1 side and the negative bus LN2 side on the input side of the inverter 20 (step S31).

  If it is determined in step S30 that a leakage has occurred, it is not possible to determine the polarity in step S13 because it is determined that a leakage has occurred in the positive bus LN1 and the negative bus LN2 on the input side of the inverter 20. This is because it is determined that the polarity cannot be determined when the absolute value | Vp | is substantially equal to the absolute value | Vm |. That is, when the absolute value | Vp | is substantially equal to the absolute value | Vm |, no leakage is detected if the system main relays SMR1 and SMR2 are turned off (in the case of “Yes” in step S26), and the inverter 20 is stopped. In this case, leakage is detected (in the case of “No” in step S30) because it is limited to when leakage occurs on the positive bus LN1 side and the negative bus LN2 side.

  In this case, in order to detect the leakage on the positive bus LN1 side and the negative bus LN2 side more accurately, after detecting that the absolute values | Vp | and | Vm | are smaller than the reference values Vstd1 and Vstd2, respectively, It may be determined that leakage has occurred on the LN1 side and the negative bus LN2 side.

  After any of step S23, step S24, and step S31, control device 40 determines whether the insulation resistance has decreased at the opposite pole based on absolute value | Vp | or absolute value | Vm | In step S32), if the insulation resistance is reduced at the opposite pole, the L level signals SE1 and SE2 are output to turn off the system main relays SMR1 and SMR2 (step S33). Thereby, the inverter 20 is disconnected from the battery 10. Then, the control device 40 controls the inverter 20 to be turned off, and the operation of the vehicle is stopped (step S34).

  Further, when it is determined in step S21 that no leakage has occurred ("Yes" in step S21), or when it is determined in step S30 that no leakage has occurred ("Yes" in step S30). ), The control device 40 determines that a leakage has occurred in the three-phase wiring 15 (step S35).

  And after any of step S17, step S18, step S27, and step S35, the control apparatus 40 controls the motor drive part MDRV so that the alternating current motor M1 may be driven continuously, and driving | operation of a vehicle is permitted. (Step S36).

  And a series of operation | movement is complete | finished after step S34 or step S36.

  As described above, according to the flowchart shown in FIG. 5, the positive electrode 10P side of the battery 10, the negative electrode 10N side of the battery 10, the intermediate part 10C of the battery 10, the positive bus LN1 side, the negative bus LN2 side, the positive bus LN1 and the negative It is possible to specify which of the bus line LN2 side and the three-phase wiring 15 is causing the electric leakage, and when electric leakage occurs, it is possible to take measures against the electric leakage according to the result of specifying the electric leakage portion.

  The detection of electric leakage in the motor drive device 100 is actually executed by a CPU (Central Processing Unit), and the CPU stores a program including each step of the flowchart shown in FIG. 4 or FIG. 5 in a ROM (Read Only Memory). Is read and executed, and leakage in the motor drive device 100 is detected according to the flowchart shown in FIG.

  Therefore, the ROM corresponds to a computer-readable recording medium that records a program for causing a computer (CPU) to execute detection of electric leakage in the motor drive device.

  In the present invention, leakage detector 30 and control device 40 that detects leakage in motor drive unit MDRV based on voltage value Vk constitute “leakage detection means”.

  Furthermore, the differential voltage detectors 11 and 12, the system main relays SMR1 and SMR2, and the inverter 20 are turned on / off, and the control device 40 that specifies a leakage portion in the motor drive unit MDRV based on the voltages Vp and Vm is: "Electrical leakage site specifying means" is configured.

  Further, when leakage occurs in battery 10 or three-phase wiring 15, motor drive unit MDRV is controlled to drive AC motor M1, and when leakage occurs in positive bus LN1 and / or negative bus LN2, AC motor The control device 40 that controls the motor drive unit MDRV so as to prohibit the driving of M1 controls the motor drive unit so as to permit or prohibit the driving of the motor based on the result of specifying the leakage portion of the leakage portion specifying means. "Control means" is configured.

  Furthermore, the inverter 20 constitutes a “motor drive device”.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a motor driving device capable of specifying a leakage site. Further, the present invention is applied to a motor drive device having a countermeasure against electric leakage.

1 is a schematic diagram of a motor drive device according to an embodiment of the present invention. It is a wave form diagram of the alternating current signal which the band pass filter shown in FIG. 1 outputs. 3 is a timing chart of voltages output from the differential voltage detector shown in FIG. 1. It is a flowchart for demonstrating the operation | movement which detects the leak in the motor drive device shown in FIG. FIG. 6 is another flowchart for explaining an operation of detecting electric leakage in the motor drive device shown in FIG. 1. FIG.

Explanation of symbols

  10 batteries, 10P positive electrode, 10N negative electrode, 10C intermediate part, 11, 12 differential voltage detector, 13 voltage sensor, 14 current sensor, 15 three-phase wiring, 20 inverter, 30 leakage detector, 31 AC power supply, 32, R1 , R2 resistance, 33, C1 capacitor, 34 band pass filter, 35 peak hold circuit, 40 control device, 100 motor drive device, SMR1, SMR2 system main relay, MDRV motor drive unit, N1 node, M1 AC motor, MP intermediate point , Q1-Q6 NPN transistor, D1-D6 diode, LN1 positive bus, LN2 negative bus.

Claims (20)

A motor drive unit for driving the motor;
A leakage detecting means for detecting a leakage in the motor drive unit;
When a leakage in the motor drive unit is detected, a leakage site specifying means for specifying a leakage site in the motor drive unit;
Control means for controlling the motor drive unit so as to permit or prohibit the drive of the motor based on the result of specifying the leakage portion;
The motor drive unit is
Power supply,
A motor drive device for driving the motor;
Three-phase wiring connecting the motor drive device to the motor;
A positive bus connecting the motor drive device to the positive electrode of the power source;
A negative bus connecting the motor drive device to the negative electrode of the power source,
The leakage portion specifying means is configured to detect a first voltage between the positive bus and the ground node and a second voltage between the ground node and the negative bus when a leakage in the motor driving unit is detected. And identifying the leakage site based on the detected first and second voltages,
In the control unit, the leakage site specified by the leakage site specifying unit is the positive bus or the negative bus, and the insulation resistance in the negative bus or the positive bus opposite to the positive bus or the negative bus as the leakage site A motor drive device that controls the motor drive unit so as to prohibit the drive of the motor when the motor is lowered. The voltage between the positive bus and the ground node when there is no leakage is the first reference voltage, and the voltage between the ground node and the negative bus when there is no leakage is the first reference voltage. When the reference voltage is 2,
When the first voltage is lower than the first reference voltage, or when the second voltage is lower than the second reference voltage, the leakage portion characteristic means uses the positive bus as the leakage portion. Identifying and identifying the negative bus as the leakage site when the first voltage is higher than the first reference voltage or when the second voltage is higher than the second reference voltage. Item 2. The motor drive device according to Item 1.   The said control means controls the said motor drive part so that the said motor may be driven, when the electrical leakage site | part specified by the said electrical leakage site | part specification means is other than the said positive bus and the said negative bus. 2. The motor drive device according to 2.   When the first absolute value of the first voltage is substantially equal to the second absolute value of the second voltage, the leakage site characteristic means is other than the positive bus and the negative bus when the first absolute value of the first voltage is substantially equal to the second absolute value of the second voltage. The motor drive device according to claim 3, which is specified as follows.   5. The motor drive device according to claim 4, wherein when the first absolute value is substantially equal to the second absolute value, the leakage portion characteristic means specifies the battery or the three-phase wiring as the leakage portion. A motor drive unit for driving the motor;
A leakage detecting means for detecting a leakage in the motor drive unit;
When a leakage current is detected in the motor drive unit, a leakage site specifying means for specifying a leakage site in the motor drive unit, and
The motor drive unit is
Power supply,
A motor drive device for driving the motor;
Three-phase wiring connecting the motor drive device to the motor;
A positive bus connecting the motor drive device to the positive electrode of the power source;
A negative bus connecting the motor drive device to the negative electrode of the power source;
A relay connected in the positive bus and the negative bus, and connecting / negatively connecting the power source and the motor drive device;
When the leakage in the motor driving unit is detected, the leakage portion specifying means includes a first voltage between the positive bus and the ground node, and a second voltage between the ground node and the negative bus. A motor drive device that identifies the leakage site based on the detected first and second voltages and the presence or absence of leakage when the motor drive device and the relay are turned on / off.   The leakage part specifying means detects a leakage by the leakage detection means when the relay is turned off, and the first absolute value of the first voltage is the second absolute value of the second voltage. The motor driving device according to claim 6, wherein when different, the battery is specified as the leakage portion.   The motor drive device according to claim 7, wherein when the first absolute value is smaller than the second absolute value, the leakage portion specifying means specifies the positive electrode side of the battery as the leakage portion.   The motor drive device according to claim 7, wherein when the first absolute value is larger than the second absolute value, the leakage portion specifying means specifies the negative electrode side of the battery as the leakage portion.   The earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the relay is turned off, and the first absolute value of the first voltage is changed to the second absolute value of the second voltage. The motor drive device according to claim 6, wherein when substantially equal, an intermediate portion of the battery is specified as the leakage portion.   The earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor driving device is turned on, the earth leakage detecting means is not detected when the motor driving device is turned off, and The motor driving device according to claim 6, wherein when the first absolute value of the voltage of 1 is substantially equal to the second absolute value of the second voltage, the three-phase wiring is specified as the leakage portion.   The earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor driving device is turned on, the earth leakage detecting means is not detected when the motor driving device is turned off, and The motor drive device according to claim 6, wherein when the first absolute value of the voltage of 1 is different from the second absolute value of the second voltage, the three-phase wiring is specified as the leakage portion.   13. The control device for controlling the motor driving unit to drive the motor when the leakage site specified by the leakage site specifying unit is the battery or the three-phase wiring. The motor drive device of any one of these.   The earth leakage site specifying means detects the earth leakage by the earth leakage detecting means when the motor drive device is turned off, and the first absolute value of the first voltage is the second absolute value of the second voltage. The motor drive device according to claim 6, wherein when the value is substantially equal to the value, the positive bus and the negative bus are specified as the leakage portion.   When the relay is turned off, the leakage detection means is not detected by the leakage detection means. When the motor drive device is turned off, the leakage detection means is detected by the leakage detection means. The motor drive device according to claim 6, wherein when the first absolute value of the voltage is different from the second absolute value of the second voltage, the positive bus or the negative bus is specified as the leakage portion.   The motor drive device according to claim 15, wherein when the first absolute value is smaller than the second absolute value, the leakage part specifying unit specifies the positive bus as the leakage part when the first absolute value is smaller than the second absolute value.   The motor drive device according to claim 15, wherein when the first absolute value is larger than the second absolute value, the leakage portion specifying means specifies the negative bus as the leakage portion.   The earth leakage site specified by the earth leakage site specifying means is the positive bus and / or the negative bus, and the insulation resistance decreases in the negative bus or the positive bus opposite to the positive bus or the negative bus as the electric leakage site. The motor drive device according to any one of claims 14 to 17, further comprising control means for controlling the motor drive unit so as to prohibit the drive of the motor when the motor is driven. The leakage site specifying means includes
A first resistor connected between the positive bus and a ground node;
A second resistor connected between the ground node and the negative bus;
First voltage detecting means for detecting a first voltage across the first resistor;
Second voltage detection means for detecting a second voltage across the second resistor;
The motor drive device according to claim 1, further comprising: a specifying unit that specifies the leakage portion based on the first and second voltages.   The motor driving device according to any one of claims 1 to 19, wherein the motor drives driving wheels of a vehicle.

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