JP2010245910A - Electric power conversion apparatus and on-vehicle electric system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease detection errors of a short-circuit protection circuit. <P>SOLUTION: An electric power conversion apparatus includes a power module having a plurality of switching elements for converting direct current supplied from a battery into alternating current, a drive circuit for controlling switching operations of the plurality of switching elements, an electric current sense switching element for sensing currents of the switching elements, a sense resistor for converting an electric current of the electric current sense switching element into a sense voltage, a detection permission circuit for inputting the sense voltage to output the sense voltage for a predetermined time period, a threshold adjusting circuit for adjusting a threshold for the detection permission circuit using a drive signal voltage of the switching elements for adjusting the predetermined time period, and a short-circuit protection circuit for protecting the switching elements from short-circuit for the predetermined time period. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power conversion device that converts DC power into AC power or converts AC power into DC power.

  The power converter is a function for converting DC power supplied from a DC power source into AC power for supplying an AC electric load such as a rotating electrical machine, or for supplying AC power generated by the rotating electrical machine to a DC power source. It has a function to convert to DC power. In order to perform the conversion function, the power conversion device includes an inverter circuit having a plurality of switching elements, and the switching elements repeat conduction operation and interruption operation, thereby switching from DC power to AC power or from AC power to DC power. Power conversion to.

  In the circuit for driving the switching element, if there is no protection circuit in the event of an abnormality such as a power supply short circuit, an excessive current flows through the switching element, and the element is destroyed due to heat generation or switching surge voltage. A technique for suppressing this short-circuit overcurrent is described in Patent Document 1 (Japanese Patent Laid-Open No. 8-316808). According to Patent Document 1, it is described that when a switching element exceeds a predetermined threshold value, a gate voltage value is held at a predetermined voltage and an overcurrent is limited.

  In particular, in a power conversion device configured with a switching element with current sense, a surge voltage enters the current sense circuit during switching, and erroneous detection of the short-circuit protection circuit is likely to occur. For this reason, it is desirable to reduce false detection as much as possible.

JP-A-8-316808

  Then, the objective of this invention is providing the power converter device which reduces the misdetection of a short circuit protection circuit.

  A power conversion device according to the present invention includes a power module that converts a direct current supplied from a battery into an alternating current and has a plurality of switching elements each including at least one current sensing switching element, and the plurality of switching A drive circuit for controlling the switching operation of the element, a sense resistor that converts the current of the current sensing switching element into a sense voltage, and the sense voltage and the drive signal voltage of the switching element are input for sensing for a predetermined period. A detection permission circuit that outputs a voltage; and a short-circuit protection circuit that short-circuits the switching element during the predetermined period.

  According to the present invention, since the surge voltage generated at the time of switching does not enter the short circuit protection circuit, it is possible to reduce false detection of the short circuit protection circuit.

It is a figure which shows the control block of a hybrid vehicle. 1 shows an inverter device including a series circuit of upper and lower arms and a control unit, a power conversion device including a capacitor connected to the DC side of the inverter device, a battery, and a motor drive generator circuit configuration including a motor generator. FIG. It is an appearance perspective view of the whole composition of the power converter concerning the embodiment of the present invention. It is the perspective view which decomposed | disassembled the whole structure of the power converter device which concerns on embodiment of this invention into each component. It is a figure which shows the housing | casing regarding embodiment of this invention, and the cooling water flow in a cooling water flow path. It is a perspective view from the upper part of the power module regarding this embodiment. It is the perspective view which decomposed | disassembled the power module and drive circuit board | substrate 22 which concern on this embodiment into each component. It is sectional drawing of the power module regarding this embodiment. It is a perspective view when the heat sink 700 is assembled | attached to the power module regarding this embodiment. It is a top view of the drive circuit board concerning this embodiment. It is a circuit block diagram of the short circuit protection regarding this embodiment. It is a circuit diagram of the short circuit protection regarding this embodiment. It is a time chart at the time of operation | movement of the short circuit protection circuit regarding this embodiment.

  A power converter according to an embodiment of the present invention will be described below in detail with reference to the drawings. The power conversion device according to the embodiment of the present invention can be applied to a hybrid vehicle or a pure electric vehicle. As a representative example, control when the power conversion device according to the embodiment of the present invention is applied to a hybrid vehicle. A structure and the circuit structure of a power converter device are demonstrated using FIG. 1 and FIG. FIG. 1 is a diagram showing a control block of a hybrid vehicle. FIG. 2 shows an inverter device including a series circuit of upper and lower arms and a control unit, a power conversion device including a capacitor module connected to the DC side of the inverter device, a battery, and a motor drive electric machine system including a motor generator. FIG.

  The power conversion device according to the embodiment of the present invention is used in a vehicle-mounted power conversion device for a vehicle-mounted electrical system mounted on an automobile, in particular, a vehicle drive electrical system, and has a very severe mounting environment and operational environment. The inverter device will be described as an example. A vehicle drive inverter device is provided in a vehicle drive electrical system as a control device for controlling the drive of a vehicle drive motor, and a DC power supplied from an onboard battery or an onboard power generator constituting an onboard power source is a predetermined AC power. Then, the AC power obtained is supplied to the vehicle drive motor to control the drive of the vehicle drive motor. Further, since the vehicle drive motor also has a function as a generator, the vehicle drive inverter device also has a function of converting the AC power generated by the vehicle drive motor into DC power according to the operation mode. Yes. The converted DC power is supplied to the on-vehicle battery.

  The configuration of the present embodiment is optimal as a power conversion device for driving a vehicle such as an automobile or a truck. However, other power conversion devices such as a power conversion device such as a train, a ship, and an aircraft, and a factory facility are also included. Applicable to industrial power converters used as drive motor control devices, or household power conversion devices used in home solar power generation systems and motor control devices that drive household appliances It is.

  In FIG. 1, a hybrid electric vehicle (hereinafter referred to as “HEV”) 110 is one electric vehicle and includes two vehicle drive systems. One of them is an engine system that uses an engine 120 that is an internal combustion engine as a power source. The engine system is mainly used as a drive source for HEV. The other is an in-vehicle electric system using motor generators 192 and 194 as a power source. The in-vehicle electric system is mainly used as an HEV drive source and an HEV power generation source. The motor generators 192 and 194 are, for example, synchronous machines or induction machines, and operate as both a motor and a generator depending on the operation method.

  A front wheel axle 114 is rotatably supported at the front portion of the vehicle body. A pair of front wheels 112 are provided at both ends of the front wheel axle 114. A rear wheel axle (not shown) is rotatably supported on the rear portion of the vehicle body. A pair of rear wheels are provided at both ends of the rear wheel axle. The HEV of this embodiment employs a so-called front wheel drive system in which the main wheel driven by power is the front wheel 112 and the driven wheel to be driven is the rear wheel. You may adopt.

  A front wheel side differential gear (hereinafter referred to as “front wheel side DEF”) 116 is provided at the center of the front wheel axle 114. The front wheel axle 114 is mechanically connected to the output side of the front wheel side DEF 116. The output shaft of the transmission 118 is mechanically connected to the input side of the front wheel side DEF 116. The front wheel side DEF 116 is a differential power distribution mechanism that distributes the rotational driving force that is shifted and transmitted by the transmission 118 to the left and right front wheel axles 114. The output side of the motor generator 192 is mechanically connected to the input side of the transmission 118. The output side of the engine 120 and the output side of the motor generator 194 are mechanically connected to the input side of the motor generator 192 via the power distribution mechanism 122. Motor generators 192 and 194 and power distribution mechanism 122 are housed inside the casing of transmission 118.

  The power distribution mechanism 122 is a differential mechanism composed of gears 123 to 130. The gears 125 to 128 are bevel gears. The gears 123, 124, 129, and 130 are spur gears. The power of motor generator 192 is directly transmitted to transmission 118. The shaft of the motor generator 192 is coaxial with the gear 129. With this configuration, when no driving power is supplied to the motor generator 192, the power transmitted to the gear 129 is directly transmitted to the input side of the transmission 118.

  When the gear 123 is driven by the operation of the engine 120, the power of the engine 120 is transferred from the gear 123 to the gear 124, then from the gear 124 to the gear 126 and the gear 128, and then from the gear 126 and the gear 128 to the gear 130. Each is transmitted and finally transmitted to the gear 129. When the gear 125 is driven by the operation of the motor generator 194, the rotation of the motor generator 194 is transmitted from the gear 125 to the gear 126 and the gear 128, and then from the gear 126 and the gear 128 to the gear 130, respectively. Is transmitted to the gear 129. As the power distribution mechanism 122, other mechanisms such as a planetary gear mechanism may be used instead of the above-described differential mechanism.

  The motor generators 192 and 194 are synchronous machines having a permanent magnet on the rotor, and the AC power supplied to the armature windings of the stator is controlled by the inverter devices 140 and 142, thereby the motor generators 192 and 194. Is controlled. A battery 136 is electrically connected to the inverter devices 140 and 142, and power can be exchanged between the battery 136 and the inverter devices 140 and 142.

  In the present embodiment, the first motor generator unit composed of the motor generator 192 and the inverter device 140 and the second motor generator unit composed of the motor generator 194 and the inverter device 142 are provided. ing. That is, in the case where the vehicle is driven by the power from the engine 120, when assisting the driving torque of the vehicle, the second motor generator unit is operated as the power generation unit by the power of the engine 120 to generate power. The first electric power generation unit is operated as an electric unit by the obtained electric power. Further, in the same case, when assisting the vehicle speed of the vehicle, the first motor generator unit is operated by the power of the engine 120 as a power generation unit to generate power, and the second motor generator unit is generated by the electric power obtained by the power generation. Operate as an electric unit.

  In the present embodiment, the vehicle can be driven only by the power of the motor generator 192 by operating the first motor generator unit as an electric unit by the electric power of the battery 136. Furthermore, in the present embodiment, the battery 136 can be charged by generating power by operating the first motor generator unit or the second motor generator unit as the power generation unit by the power of the engine 120 or the power from the wheels.

  The battery 136 is also used as a power source for driving an auxiliary motor 195. The auxiliary machine is, for example, a motor that drives a compressor of an air conditioner or a motor that drives a hydraulic pump for control. DC power is supplied from the battery 136 to the auxiliary machine inverter unit 43, and the auxiliary machine inverter unit 43 It is converted into AC power and supplied to the motor 195. The auxiliary inverter device 43 has the same function as the inverter devices 140 and 142 and controls the phase, frequency, and power of the alternating current supplied to the motor 195. For example, the motor 195 generates torque by supplying AC power having a leading phase with respect to the rotation of the rotor of the motor 195. On the other hand, by generating the delayed phase AC power, the motor 195 acts as a generator, and the motor 195 is operated in a regenerative braking state. The control function of the auxiliary inverter device 43 is the same as the control function of the inverter devices 140 and 142. Since the capacity of the motor 195 is smaller than that of the motor generators 192 and 194, the maximum conversion power of the auxiliary inverter device 43 is smaller than the inverter devices 140 and 142, but the circuit configuration of the auxiliary inverter device 43 is basically an inverter. The circuit configuration of the devices 140 and 142 is the same.

  The inverter devices 140 and 142, the auxiliary inverter device 43, and the capacitor module 500 are in an electrical close relationship. Furthermore, there is a common point that measures against heat generation are necessary. It is also desired to make the volume of the device as small as possible. From these points, the power conversion device described in detail below includes the inverter devices 140 and 142, the auxiliary inverter device 43, and the capacitor module 500 in the casing of the power conversion device. With this configuration, a small and highly reliable device can be realized.

  Further, by incorporating the inverter devices 140 and 142, the auxiliary inverter device 43, and the capacitor module 500 in one housing, it is effective in simplifying wiring and taking measures against noise. Further, the inductance of the connection circuit between the capacitor module 500, the inverter devices 140 and 142, and the auxiliary inverter device 43 can be reduced, the spike voltage can be reduced, the heat generation can be reduced, and the heat radiation efficiency can be improved.

  Next, the electric circuit configuration of the inverter devices 140 and 142 or the auxiliary inverter device 43 will be described with reference to FIG. In the embodiment shown in FIGS. 1 and 2, the case where the inverter devices 140 and 142 or the auxiliary inverter device 43 are individually configured will be described as an example. Since the inverter devices 140 and 142 or the auxiliary inverter device 43 have the same function and the same function, the inverter device 140 will be described here as a representative example.

  The power conversion device 200 according to the present embodiment includes an inverter device 140 and a capacitor module 500, and the inverter device 140 includes an inverter circuit 144 and a control unit 170. The inverter circuit 144 includes a plurality of upper and lower arm series circuits 150 including an IGBT 328 (insulated gate bipolar transistor) and a diode 156 that operate as an upper arm, and an IGBT 330 and a diode 166 that operate as a lower arm (FIG. 2). In this example, three upper and lower arm series circuits 150, 150, 150), an AC power line (AC bus bar) 186 from the middle point (intermediate electrode 169) of each upper and lower arm series circuit 150 to the motor generator 192 through the AC terminal 159, It is a configuration to connect. In addition, the control unit 170 includes a driver circuit 174 that drives and controls the inverter circuit 144 and a control circuit 172 that supplies a control signal to the driver circuit 174 via the signal line 176.

  The IGBTs 328 and 330 of the upper arm and the lower arm are switching power semiconductor elements, operate in response to a drive signal output from the control unit 170, and convert DC power supplied from the battery 136 into three-phase AC power. . The converted electric power is supplied to the armature winding of the motor generator 192. As described above, the inverter device 140 can also convert the three-phase AC power generated by the motor generator 192 into DC power.

  As shown in FIG. 1, the power conversion device 200 according to the present embodiment includes the inverter devices 140 and 142 and the auxiliary inverter device 43 and the capacitor module 500. As described above, the inverter devices 140 and 142 and the auxiliary device are included. Since the inverter device 43 has the same circuit configuration, the inverter device 140 is described as a representative, and the inverter device 142 and the auxiliary inverter device 43 are omitted as described above.

  The inverter circuit 144 is configured by a three-phase bridge circuit, and a DC positive terminal 314 to which upper and lower arm series circuits 150, 150, 150 for three phases are electrically connected to the positive side and the negative side of the battery 136, respectively. And DC negative electrode terminal 316 are electrically connected in parallel. Here, the upper and lower arm series circuit 150 is called an arm, and includes an upper arm switching power semiconductor element 328 and a diode 156, and a lower arm switching power semiconductor element 330 and a diode 166.

  In the present embodiment, the use of IGBTs 328 and 330 as switching power semiconductor elements is exemplified. The IGBTs 328 and 330 include collector electrodes 153 and 163, emitter electrodes (signal emitter electrode terminals 155 and 165), and gate electrodes (gate electrode terminals 154 and 164). Diodes 156 and 166 are electrically connected between the collector electrodes 153 and 163 of the IGBTs 328 and 330 and the emitter electrode as shown. The diodes 156 and 166 have two electrodes, a cathode electrode and an anode electrode, and the cathode electrode serves as the collector electrode of the IGBTs 328 and 330 so that the direction from the emitter electrode to the collector electrode of the IGBTs 328 and 330 is the forward direction. The anode electrodes are electrically connected to the emitter electrodes of the IGBTs 328 and 330, respectively. A MOSFET (metal oxide semiconductor field effect transistor) may be used as the power semiconductor element for switching. In this case, the upper arm diode 156 and the lower arm diode 166 are not required.

Upper and lower arm series circuit 150 is provided for three phases corresponding to each phase winding of the armature winding of motor generator 192. The three upper and lower arm series circuits 150, 150, and 150 are respectively connected to the U-phase and V-phase to the motor generator 192 via the intermediate electrode 169 that connects the emitter electrode of the IGBT 328 and the collector electrode 163 of the lower arm of the IGBT 330 and the AC terminal 159. , W phase is formed. The upper and lower arm series circuits are electrically connected in parallel.
The collector electrode 153 of the upper arm IGBT 328 is connected to the positive capacitor electrode of the capacitor module 500 via the positive terminal (P terminal) 157, and the emitter electrode of the lower arm IGBT 330 is connected to the capacitor module 500 via the negative terminal (N terminal) 158. Are respectively electrically connected (connected by a DC bus bar) to the negative electrode capacitor electrode. The intermediate electrode 169 corresponding to the middle point portion of each arm (the connection portion between the emitter electrode of the IGBT 328 of the upper arm and the collector electrode of the IGBT 330 of the lower arm) is connected to the corresponding phase winding of the armature winding of the motor generator 192 with an AC connector. It is electrically connected via 188.

  Capacitor module 500 is for configuring a smoothing circuit that suppresses fluctuations in DC voltage caused by the switching operation of IGBTs 328 and 330. The positive electrode side of the battery 136 is electrically connected to the positive electrode side capacitor electrode of the capacitor module 500, and the negative electrode side of the battery 136 is electrically connected to the negative electrode side capacitor electrode of the capacitor module 500 via the DC connector 138. Thus, the capacitor module 500 is connected between the collector electrode 153 of the upper arm IGBT 328 and the positive electrode side of the battery 136, and between the emitter electrode of the lower arm IGBT 330 and the negative electrode side of the battery 136. Electrically connected in parallel to the series circuit 150.

  The control unit 170 is for operating the IGBTs 328 and 330, and generates a timing signal for controlling the switching timing of the IGBTs 328 and 330 based on input information from other control devices or sensors. And a drive circuit 174 that generates a drive signal for switching the IGBTs 328 and 330 based on the timing signal output from the control circuit 172.

  The control circuit 172 includes a microcomputer (hereinafter referred to as “microcomputer”) for calculating the switching timing of the IGBTs 328 and 330. The microcomputer receives as input information a target torque value required for the motor generator 192, a current value supplied to the armature winding of the motor generator 192 from the upper and lower arm series circuit 150, and a magnetic pole of the rotor of the motor generator 192. The position has been entered. The target torque value is based on a command signal output from a host controller (not shown). The current value is detected based on the detection signal output from the current detection unit 180. The magnetic pole position is detected based on a detection signal output from a rotating magnetic pole sensor (not shown) provided in the motor generator 192. In the present embodiment, the case where the current values of three phases are detected will be described as an example, but the current values for two phases may be detected.

  The microcomputer in the control circuit 172 calculates the d and q axis current command values of the motor generator 192 based on the target torque value, and the calculated d and q axis current command values and the detected d and q The voltage command values for the d and q axes are calculated based on the difference from the current value of the shaft, and the calculated voltage command values for the d and q axes are calculated based on the detected magnetic pole position. Convert to W phase voltage command value. Then, the microcomputer generates a pulse-like modulated wave based on the comparison between the fundamental wave (sine wave) and the carrier wave (triangular wave) based on the voltage command values of the U-phase, V-phase, and W-phase, and the generated modulation The wave is output to the driver circuit 174 as a PWM (pulse width modulation) signal.

  When driving the lower arm, the driver circuit 174 amplifies the PWM signal, and when the driver circuit 174 drives the upper arm to the gate electrode of the corresponding IGBT 330 of the lower arm, the driver circuit 174 sets the level of the reference potential of the PWM signal. After shifting to the level of the reference potential of the upper arm, the PWM signal is amplified and output as a drive signal to the gate electrode of the corresponding IGBT 328 of the upper arm. As a result, each IGBT 328, 330 performs a switching operation based on the input drive signal.

  In addition, the control unit 170 performs abnormality detection (overcurrent, overvoltage, overtemperature, etc.) to protect the upper and lower arm series circuit 150. For this reason, sensing information is input to the control unit 170. For example, information on the current flowing through the emitter electrodes of the IGBTs 328 and 330 is input to the corresponding drive units (ICs) from the signal emitter electrode terminals 155 and 165 of each arm. Thereby, each drive part (IC) detects overcurrent, and when overcurrent is detected, the switching operation of corresponding IGBT328,330 is stopped, and corresponding IGBT328,330 is protected from overcurrent. Information on the temperature of the upper and lower arm series circuit 150 is input to the microcomputer from a temperature sensor (not shown) provided in the upper and lower arm series circuit 150. In addition, voltage information on the DC positive side of the upper and lower arm series circuit 150 is input to the microcomputer. The microcomputer performs over-temperature detection and over-voltage detection based on the information, and when an over-temperature or over-voltage is detected, it stops the switching operation of all the IGBTs 328 and 330, and the upper and lower arm series circuit 150 (subtract) The semiconductor module portion including the circuit 150 is protected from overtemperature or overvoltage.

  In FIG. 2, an upper and lower arm series circuit 150 is a series circuit of an upper arm IGBT 328 and an upper arm diode 156, and a lower arm IGBT 330 and a lower arm diode 166, and the IGBTs 328 and 330 are switching semiconductor elements. . The conduction and cut-off operations of the IGBTs 328 and 330 of the upper and lower arms of the inverter circuit 144 are switched in a fixed order, and the current of the stator winding of the motor generator 192 at this switching flows through a circuit formed by the diodes 156 and 166.

  As shown in the figure, the upper and lower arm series circuit 150 includes a positive terminal (P terminal, positive terminal) 157, a negative terminal (N terminal 158, negative terminal), an AC terminal 159 from the intermediate electrode 169 of the upper and lower arms, and an upper arm signal. A terminal 155 for the signal (signal emitter electrode terminal), a gate electrode terminal 154 for the upper arm, a signal terminal (signal emitter electrode terminal for signal 165) for the lower arm, and a gate electrode terminal 164 for the lower arm. The power conversion device 200 has a DC connector 138 on the input side and an AC connector 188 on the output side, and is connected to the battery 136 and the motor generator 192 through the connectors 138 and 188, respectively. Further, as a circuit for generating an output of each phase of the three-phase alternating current to be output to the motor generator, a power conversion device having a circuit configuration in which two upper and lower arm series circuits are connected in parallel to each phase may be used.

  Next, the overall configuration of the power conversion device 200 described in FIGS. 1 and 2 will be described below with reference to FIGS. 3 to 5 and FIG. 6. The same reference numerals as those in FIGS. The description of the contents already shown is omitted. FIG. 3 is an external perspective view of the overall configuration of the power conversion device 200.

  FIG. 4 is a perspective view in which the entire configuration of the power conversion device 200 according to the present embodiment is disassembled into components. FIG. 5 is an explanatory view showing a casing which is a housing of the power conversion apparatus shown in FIGS. 3 and 4 and a cooling water flow path provided in the casing. FIG. 6 is a perspective view of the power module as viewed from above.

  3 to 5 and 6, 200 is a power converter, 10 is an upper case, 11 is a metal base plate, 12 is a housing, 13 is a cooling water inlet pipe, 14 is a cooling water outlet pipe, 420 is a cover, Reference numeral 16 denotes a lower case, 17 denotes an AC terminal case, 19 denotes a cooling water flow path, and 20 denotes a control circuit board, which holds the control circuit 172 shown in FIG. 21 is a connector for connection with the outside, and 22 is a drive circuit board which holds the driver circuit 174 shown in FIG. An inter-board connector 23 is provided to be electrically connected to the control circuit 172 provided on the control circuit board 20, and is used to connect the signal line 176 shown in FIG. Illustration is omitted. 300 is a power module case, 302 is a power module case, 304 is a metal base, 314 is a DC positive terminal, 316 is a DC negative terminal, 49 is a cast meat stealer, 500 is a capacitor module , 502 denotes a capacitor case, 504 denotes a negative side capacitor terminal, 506 denotes a positive side capacitor terminal, and 514 denotes a capacitor cell.

  The power conversion device 200 according to the present embodiment is roughly divided into components, a power module (semiconductor module unit) 300 that performs conversion between DC power and AC power, a capacitor module 500 for voltage smoothing of a DC power source, The cooling water channel 19 is used to cool the power module 300 and the like. As shown in FIG. 3, the external appearance of the power conversion device 200 according to the present embodiment is that the top surface or the bottom surface of the casing 12 is substantially rectangular and the cooling provided on one of the outer circumferences on the short side of the casing 12. The water inlet pipe 13 and the cooling water outlet pipe 14, the upper case 10 for closing the upper opening of the casing 12, and the lower case 16 for closing the lower opening of the casing 12 are fixedly formed. Is. Three sets of AC terminal cases 17 for assisting the connection with the motor generators 192 and 194 shown in FIG. 1 are provided on the outer periphery of the long side of the power converter 200. Since the shape of the bottom view or the top view of the housing 12 is substantially rectangular, it is easy to attach to the vehicle and to produce easily.

  As shown in FIG. 4, a cooling water flow path 19 is provided in the middle of the housing 12, and two sets of openings 400 and 402 are formed in the upper part of the cooling water flow path 19 side by side in the flow direction. . Two power modules 300 are fixed to the upper surface of the cooling water passage 19 so that the two sets of openings 400 and 402 are respectively closed by the power module 300. Each power module 300 is provided with fins (FIG. 7) for heat dissipation, and the fins 305 of each power module 300 protrude into the cooling water flow from the openings 400 and 402 of the cooling water flow path 19, respectively. ing.

  An opening 404 for facilitating aluminum casting is formed below the cooling water channel 19, and the opening 404 (FIG. 5B) is closed by a cover 420. An auxiliary inverter device 43 is attached below the cooling water channel 19. The auxiliary inverter device 43 includes a circuit similar to the inverter circuit 144 shown in FIG. 2, and includes a power module including a power semiconductor element that constitutes the inverter circuit 144. The auxiliary inverter device 43 (FIG. 1) is fixed to the lower surface of the cooling water channel 19 such that the heat dissipation metal surface of the built-in power module faces the lower surface of the cooling water channel 19. .

  In addition, a lower case 16 is provided in the lower part of the cooling water flow path 19 so as to dissipate heat. It is fixed to the surface of the lower case 16 so as to face the surface. With this structure, cooling can be efficiently performed using the upper surface and the lower surface of the cooling water channel 19, which leads to downsizing of the entire power conversion device.

  When the cooling water from the inlet / outlet pipes 13 and 14 flows through the cooling water flow path 19, the heat radiation fins of the two power modules 300 provided side by side are cooled, and the entire two power modules 300 are cooled. . The auxiliary inverter device 43 provided on the lower surface of the cooling water passage 19 is also cooled at the same time.

  Further, the casing 12 provided with the cooling water flow path 19 is cooled, whereby the lower case 16 provided at the lower portion of the casing 12 is cooled, and by this cooling, the heat of the capacitor module 500 is transferred to the lower case 16 and the casing. The capacitor module 500 is cooled by being thermally conducted to the cooling water through the body 12.

  Although details will be described later, in this embodiment, the DC positive terminal 314 and the DC negative terminal 316 of the power module 300 are directly electrically and mechanically connected to the negative capacitor terminal 504 and the positive capacitor terminal 506 of the capacitor module 500, respectively. Is connected in the housing 12.

  A control circuit board 20 and a drive circuit board 22 are arranged above the power module 300 so as to cover the two power modules 300, and the driver circuit 174 shown in FIG. A control circuit 172 having a CPU shown in FIG. Further, a metal base plate 11 is disposed between the drive circuit board 22 and the control circuit board 20, and the metal base plate 11 functions as an electromagnetic shield for a circuit group mounted on both the boards 22 and 20, and also the drive circuit board. The heat generated by the control circuit board 20 and the control circuit board 20 is released and cooled.

  As described above, the cooling water flow path 19 is provided in the central portion of the housing 12, the vehicle driving power module 300 is disposed on one side thereof, and the auxiliary power module 43 is disposed on the other side. Thus, cooling can be efficiently performed in a small space, and the entire power conversion device can be downsized. Further, by making the main structure of the cooling water channel 19 at the center of the casing by casting an aluminum material integrally with the casing 12, the cooling water channel 19 has the effect of increasing the mechanical strength in addition to the cooling effect. Further, by making the aluminum casting, the housing 12 and the cooling water flow path 19 are integrated with each other, heat conduction is improved, and cooling efficiency is improved.

  The drive circuit board 22 is provided with an inter-board connector 712 that passes through the metal base plate 11 and is connected to a circuit group of the control circuit board 20. The control circuit board 20 is provided with a connector 21 for electrical connection with the outside. The connector 21 transmits a signal to, for example, a lithium battery module mounted on the vehicle as a battery 136 (FIG. 1) outside the power conversion device, and a signal indicating the state of the battery or a lithium battery is transmitted from the lithium battery module. Signals such as charge status are sent. The board-to-board connector 712 is provided to send and receive signals to and from the control circuit 172 held on the control circuit board 20, and the signal line 176 shown in FIG. The signal of the switching timing of the inverter circuit is transmitted from the control circuit board 20 to the drive circuit board 22 through the signal line 176 and the board-to-board connector 712, and the drive circuit board 22 generates a gate drive signal as a drive signal. Each is applied to the gate electrode of the power module.

  Openings are formed in the upper part and the lower part of the housing 12, and these openings are closed by fixing the upper case 10 and the lower case 16 to the housing 12 with, for example, screws. A cooling water channel 19 is provided in the center of the housing 12, and the power module 300 and the cover 420 are fixed to the cooling water channel 19. In this way, the cooling water channel 19 is completed, and a water leak test of the water channel is performed. When the water leakage test is passed, the operation of attaching the substrate and the capacitor module 500 from the upper and lower openings of the housing 12 can be performed next. In this way, the cooling water flow path 19 is arranged in the center, and then the structure for performing the work of fixing the necessary parts from the upper and lower openings of the housing 12 is made, and the productivity is improved. Moreover, it becomes possible to complete the cooling water flow path 19 first and to attach other parts after the water leak test, which improves both productivity and reliability.

  5A and 5B are diagrams showing an aluminum cast product of the housing 12 having the cooling water flow path 19, FIG. 5A is a perspective view of the housing 12, FIG. 5B is a top view of the housing 12, and FIG. (C) is a bottom view of the housing 12. As shown in FIG. 5, the casing 12 and a cooling water flow path 19 provided in the casing 12 are integrally cast. The upper surface or the lower surface of the housing 12 has a substantially rectangular shape, and an inlet hole 401 for taking in cooling water is provided on the side surface of one side of the rectangular short side, and an outlet hole 403 is provided on the same side surface. Yes.

The cooling water that has flowed into the cooling water flow path 19 from the inlet hole 401 flows along the long side of the rectangle in the direction of the arrow 418, and is folded back as shown by the arrow 421 in the vicinity of the front side of the other side surface of the short side of the rectangle. It flows again in the direction of the arrow 422 along the long side of the rectangle and flows out from the outlet hole 403. Two openings 400 and 402 are formed on the outgoing side and the return side of the cooling water channel 19, respectively. A power module 300 shown in FIG. 13 to be described later is fixed to each of the openings, and fins for radiating heat of each power module 300 protrude from the respective openings into the flow of cooling water. The power modules 300 are fixed side by side in the flow direction of the casing 12, that is, along the long side, and the fixing is supported so that the opening of the cooling water flow path 19 can be completely closed by the power modules 300. Part 410 is formed integrally with the housing. The support portion 410 is located substantially at the center, and one power module 300 is fixed to the support portion 410 on the cooling water entrance / exit side, and also on the cooling water return side with respect to the support portion 410. Another one power module 300 is fixed.
A screw hole 412 shown in FIG. 5B is used to fix the power module 300 on the entrance / exit side to the cooling water flow path 19, and the opening 400 is sealed by this fixing. The screw hole 414 is used to fix the folded-back power module 300 to the cooling water passage 19, and the opening 402 is sealed by this fixing.

  Since the power module 300 on the entrance / exit side is close to the cold coolant from the entrance hole 401 and the exit side, it is cooled by the warmed coolant. On the other hand, the folded power module 300 is cooled by the slightly warmed cooling water, but the temperature is lower than that of the cooling water near the outlet hole 403. As a result, the arrangement relationship between the folded cooling passage and the two power modules 300 has an advantage that the cooling efficiency of the two power modules 300 is balanced.

  The support 410 is used for fixing the power module 300 and is necessary for sealing the openings 400 and 402. Further, the support portion 410 has a great effect on strengthening the strength of the housing 12. The cooling water channel 19 has a folded shape as described above, and is provided with a partition 408 that separates the going-side channel and the returning-side channel, and the partition 408 is formed integrally with the support portion 410. The partition wall 408 not only simply separates the going-side flow path and the return-side flow path but also acts to increase the mechanical strength of the housing. Also, it acts as a heat transfer passage between the turn-back passages and makes the temperature of the cooling water uniform. If the temperature difference between the inlet side and the outlet side of the cooling water is large, uneven cooling efficiency increases. Although the temperature difference to some extent is unavoidable, the partition wall 408 is integrally formed with the support portion 410, so that there is an effect of suppressing the temperature difference of the cooling water.

  FIG. 5C shows the back surface of the cooling water channel 19, and an opening 404 is formed on the back surface corresponding to the support portion 410. The opening 404 is for improving the yield of the support unit 410 and the housing 12 integrated structure formed by casting the housing. The formation of the opening 404 eliminates the double structure of the support 410 and the bottom of the cooling water channel 19 in the cast product, facilitating casting and improving productivity.

  A through-hole 406 is formed between the side of the cooling water passage 19 and the long side of the rectangle to penetrate the upper and lower sides of the passage. Since electrical components are attached to both sides of the cooling water channel 19, the electrical components on both sides must be electrically connected. The through hole 406 is a hole for electrically connecting the electrical components on both sides of the cooling water channel 19.

The housing structure shown in FIG. 5 is suitable for casting production, particularly aluminum die casting production.
That is, there is an effect that an integrated structure of the cooling water channel 19 and the housing 12 can be manufactured in a shape close to completion. Since the folded portion of the water channel indicated by the arrow 421 is a part of the opening 402, the folded portion can be integrally cast. That is, the folding path is completed by fixing the power module 300 to the opening 402. Furthermore, since the return path can be used for cooling, good miniaturization is possible. The periphery of the cooling water channel 19 is substantially perpendicular to the opening surface, and the side surface of the partition wall 408 is also substantially perpendicular. By adopting such a shape, the water channel is completed by fixing the power module 300 to the openings 400 and 402 on the upper surface and the cover 420 to the rear surface. At this point, water leakage is inspected in the water channel, and then the parts are attached, so that defective products can be quickly removed and productivity can be improved.

  FIG. 6 shows a state where the power module 300 is fixed to the upper surface opening of the cooling water passage 19 and the cover 420 is fixed to the rear surface opening. On one long side of the rectangle of the housing 12, an AC power line 186 and an AC connector 188 protrude from the housing 12. 7 shows a state in which an AC terminal case 17 for connecting the AC terminals of the motor generators 192 and 194 and the AC connector 188 is attached to the AC connector 188 side of the power conversion device 200.

  Next, the detailed structure of the power module 300 in the power conversion device according to the present embodiment will be described below with reference to FIGS.

FIG. 6 is a perspective view from above of the power module according to the present embodiment. FIG. 7 is a perspective view in which the power module and the drive circuit board 22 according to this embodiment are disassembled into components.
FIG. 8 is a cross-sectional view of the power module according to this embodiment. FIG. 9 is a perspective view when the heat radiating plate 700 is assembled to the power module according to the present embodiment.

  The structure of the power module 300 will be described with reference to FIGS.

  In the above figure, 300 is a power module (semiconductor module part), 302 is a power module case, 304 is a metal base, 305 is a fin (see FIG. 8), 186 is an AC power line having a substantially rectangular cross section, 314 is a DC positive terminal, 316 is a DC negative electrode terminal, 318 is a thin insulating material (insulating paper), 326 is an IGBT, 334 is an insulating substrate, 327 is a diode, 320 is a control terminal, 342 is a power module case protrusion, 350 is a stay, 700 is a heat sink , 702 represents a heat sink opening, and 704 represents a heat conductive sheet.

  The power module 300 is roughly divided into, for example, a semiconductor module portion including wiring in a power module case 302 made of a resin material, a metal base 304 made of a metal material such as Cu, Al, AlSiC, and the like, and connection to the outside. Terminals (DC positive terminal 314, control terminal 320, etc.). As terminals to be connected to the outside, the power module 300 has a U, V, W phase AC terminal 159 for connection to the motor, and a DC positive terminal 314 and a DC negative terminal 316 to be connected to the capacitor module 500. is doing.

  In the semiconductor module section, upper and lower arms IGBTs 326 and diodes 327 are provided on an insulating substrate 334. The insulating substrate 334 may be a ceramic substrate or a thinner insulating sheet. The metal base 304 has fins 305 on the opposite side of the insulating substrate 334 in order to efficiently radiate heat to the cooling water by being immersed in the cooling water flow path.

  The shape of the fin 305 shown in FIG. 8 is a pin type, but as another embodiment, a straight type formed along the flow direction of the cooling water may be used. When the straight type is used as the shape of the fin 305, the pressure for flowing the cooling water can be reduced. On the other hand, when the pin type is used, the cooling efficiency can be improved.

  In the illustrated example, the DC terminals 314 and 316 connected to the capacitor module 500 are fixed by soldering or ultrasonic bonding at a portion to be connected in the central portion of the insulating substrate 334, and a thin insulating material 318 is provided between the DC terminals 314 and 316. Is used to insulate both.

  The insulating substrate 334 is formed by forming a Cu or Al film on both sides of a ceramic, and a metal base 304 (Cu, Al or AlSiC) with fins or pins is fixed to the lower side of the insulating substrate 334 by solder. On the upper side, the IGBT 326 and the diode 327 are fixed by solder, and the DC terminals 314 and 316 are fixed by solder or ultrasonic bonding. 6 shows the power module control terminal 320, which are the upper and lower arm gate electrode terminals 154 and 164 and the emitter electrode terminals 155 and 165 described in FIG. A signal for controlling the switching operation is applied.

  A plurality of power module case protrusions 342 are formed on the power module case 302, and a stay 350 is inserted into the protrusion 342. The stay 350 supports the drive circuit board 22 and simultaneously conducts heat generated by the drive circuit board 22 to the metal base via the power module case 302. The stay 350 and the drive circuit board 22 are fixed by fixing means 721 such as screws. The stay 350 is preferably made of a metal having good thermal conductivity such as brass, iron, or aluminum.

  In FIG. 7, a heat radiating plate 700 and a heat conductive sheet 704 are sandwiched between the power module 300 and the drive circuit board 22. The heat conductive sheet 704 is in close contact with the drive circuit board 22, and the heat conductive sheet 704 is also in close contact with the heat sink 700. The heat radiating plate 700 is in close contact with the housing 12 and has a structure in which heat flows to the housing 12 side. The heat radiating plate 700 is preferably made of a metal having good thermal conductivity such as aluminum or copper.

  8 is a cross-sectional view taken along one-dot chain line AA in FIG. The stay 350 is inserted into the module case protrusion 342 and the module case 302. The stay 350 may be in contact with the metal base 304, but it is desirable that the stay 350 and the metal base are not in contact as much as possible as shown in FIG.

  For safety reasons, the power converter is connected to the metal base and the earth. When the stay 350 and the metal base are in contact with each other, the stay 350 becomes the ground potential and is close to the high voltage control terminal 320 of the drive circuit board 22 so that the insulation can be maintained. Disappear. Therefore, the stay 350 and the metal base 304 are separated by a certain distance to maintain insulation. Also, from the viewpoint of EMC (Electro Magnetic Compatibility), there are cases where the fixing means 721 of the drive circuit board 22 is grounded, and when the stay 350 and the metal base are in contact, a plurality of ground loop currents flow, and the EMC characteristics deteriorate. There is also a reason to avoid this.

  In other words, the lower portion of the stay 350 and the stay lower region 352 of the metal base 304 are preferably as close as possible in terms of releasing the heat of the drive circuit board 22 to the metal base 304, but in terms of insulation, a certain distance (for example, several Mm) is desirable.

  There are two types of heat dissipation paths for the heat generated by the drive circuit board 22. One is a first heat dissipation path 730 that flows from the drive circuit board 22 through the heat conductive sheet 704 and the heat dissipation plate 700 to the housing 12. The other is a second heat radiation path 731 that flows from the drive circuit board 22 to the metal base 304 via the stay 350 and the stay lower region 352. Naturally, only the first heat radiation path 730 or the second heat radiation path 731 has a heat radiation effect, but it is most effective to have both heat radiation paths as in this embodiment.

  FIG. 9 is a perspective view of the power module when the heat radiating plate 700 and the heat conductive sheet 704 are assembled to the two power modules. Reference numeral 702 denotes a radiator plate opening for preventing interference with the power module protrusion 342. When one of the two power modules performs a switching operation and the other does not operate, the heat dissipation effect by the heat dissipation plate 700 is further improved. In addition, there are a plurality of power module protrusions 342 and stays 350, and the module case 302 may be arranged evenly at regular intervals or according to the heat distribution of the drive circuit board 22. For example, when heat generating components such as a power circuit transformer 706 and a driver IC 708 are mounted in a certain area of the drive circuit board 22, the heat radiation effect can be improved by arranging a plurality of heat radiation stays 350 in the vicinity of this area. The Furthermore, if a heat conductive sheet 704 and a heat radiating plate 700 are added immediately below this region, a further heat radiating effect can be expected. Details of the heat distribution of the drive circuit board 22 will be described with reference to FIG.

  FIG. 10 is a plan view of the drive circuit board 22 on which electronic components are mounted. 706 is a power circuit transformer, 708 is a driver IC for driving the gate of the IGBT 326 of the power module 300, 710 is a smoothing electrolytic capacitor for the power circuit, and 712 is an inter-board connector between the control circuit board 20 and the drive circuit board 22. , 714 is a power transistor of the primary side switching element for the power supply circuit, 718 is an AC terminal notch for avoiding interference with the AC terminal 159, and 722 is for penetrating the control terminal 320 of the power module 300 into the drive circuit board. A control terminal hole 724 is a notch for avoiding interference between the negative-side capacitor terminal 504 and the positive-side capacitor terminal 506 of the capacitor module 500, and 721 is a fixing means for fixing the drive circuit board 22 and the stay 350. .

  Among the electronic components mounted on the drive circuit board 22, the power circuit transformer 706, the driver IC 708, the power transistor 714, and the like are components that generate heat compared to other electronic components, and the board area in the vicinity of these components is also included. Fever. In particular, in order to reduce the size of the drive circuit board 22 and to reduce the size of the power circuit transformer 706, the power transistor 714 is switched at a high speed, so that the heat generation becomes more intense. Further, when the element area of the IGBT 326 is increased in order to make the power conversion device 200 output a large current, the drive current of the driver IC 708 increases and the heat generation of the driver IC 708 increases. Further, when the carrier frequency is increased in order to increase the accuracy of control of the power conversion device 200, the drive current of the driver IC further increases and heat generation increases. In order to effectively dissipate heat in the board area in the vicinity of these heat-generating components, a heat conductive sheet is closely attached directly under the board on which the heat-generating parts are mounted, or a metal stay 350 is disposed in the vicinity of the board on which the heat-generating parts are mounted. Thus, the heat generation of the substrate can be effectively suppressed.

  Next, the short circuit protection operation of the drive circuit board according to the present invention will be described with reference to FIGS.

  FIG. 11 is a circuit block diagram of short circuit protection according to the present embodiment. FIG. 12 is a circuit diagram of short circuit protection according to this embodiment. FIG. 13 is a time chart during operation of the short circuit protection circuit according to the present embodiment.

  In FIG. 11, 330 is a lower arm IGBT, 166 is a lower arm diode, 800 is a sense IGBT that shunts a part of the current of the IGBT 330, 801 is a sense resistor, 802 is a gate voltage of the IGBT 330, and is adjusted to a predetermined threshold value. 803 is a detection permission circuit that receives the voltage of the sense resistor 801 and the output voltage of the threshold adjustment circuit 802 and outputs the voltage of the sense resistor 801 only during a predetermined turn period of the IGBT 330, and 804 is a detection permission circuit. A short-circuit protection circuit that holds the gate voltage of the IGBT 330 at a predetermined voltage when an output is input and a predetermined threshold value is exceeded, and 708 is a driver IC that drives the gate of the IGBT 330. The circuit operation of FIG. 11 will be described below.

  When the driver IC 708 outputs a gate voltage pulse of the IGBT 303, the IGBT 303 is turned on, and a collector current Ic flows through the IGBT 303. At the same time, a shunt current Is of Ic flows through the sense IGBT 800 and flows into the sense resistor 801. A sense voltage Vs is generated in the sense resistor 801 and input to the detection permission circuit 803. The detection permission circuit 803 has a circuit function of cutting off the sense voltage Vs when the gate voltage is equal to or lower than a predetermined threshold voltage Vg1, and outputting the sense voltage Vs when the gate voltage is higher than Vg1. The threshold adjustment circuit 802 is a circuit that adjusts the threshold voltage Vg1, and can change Vg1 by adjusting the resistance value, for example. The short-circuit protection circuit 804 receives the sense voltage Vs. When the sense voltage Vs exceeds the first predetermined threshold value Vs1 in the event of an abnormality such as a short circuit, the gate voltage is held at a predetermined voltage value and the saturation current of the IGBT 303 is suppressed. Has a circuit function. Further, when the sense voltage Vs is equal to or lower than the first predetermined threshold Vs1, the short circuit protection circuit 804 does not operate.

  Furthermore, as another embodiment, the circuit function of the short-circuit protection circuit 804 may be used in combination with the soft interruption function at the time of abnormality of the driver IC 708. In that case, the sense voltage Vs is also input to the driver IC 708. When the sense voltage Vs exceeds the second threshold value Vs2, the driver IC 708 starts a soft shut-off operation of the IGBT 303. When the sense voltage Vs is equal to or lower than the second threshold value Vs2, the driver IC 708 maintains a normal switching operation.

  FIG. 12 is an example of a specific circuit diagram for short-circuit protection according to the present embodiment, and other circuit diagrams may be used with the same circuit function. The threshold adjustment circuit 802 includes a first resistor 810 and a second resistor 811, and a divided voltage value of the gate voltage is input to the detection permission circuit 803. The detection permission circuit 803 includes a voltage inverting circuit 808 and a first nMOS switch 809, and the divided voltage value of the gate voltage is input to the voltage inverting circuit 808, and the output of the voltage inverting circuit 808 is the output of the first nMOS switch 809. Input to the gate, the drain of the first nMOS switch 809 is connected to the sense resistor 801. The short-circuit protection circuit 804 includes a second nMOS switch 807 and a constant voltage diode (Zener diode) 806, the gate of the second nMOS switch 807 is connected to the sense resistor 801, and the drain of the second nMOS switch 807 is constant. The anode of a voltage diode (Zener diode) 806 is connected, and the cathode of the constant voltage diode (Zener diode) 806 is connected to the gate of the IGBT 303. Hereinafter, the circuit operation of FIG. 12 will be described.

  When the driver IC 708 outputs a gate voltage pulse of the IGBT 303, the IGBT 303 is turned on, and a collector current Ic flows through the IGBT 303. At the same time, a shunt current Is of Ic flows through the sense IGBT 800, flows into the sense resistor 801, and a sense voltage Vs is generated at the sense resistor 801. The threshold adjustment circuit 802 is a circuit that divides the gate voltage, and the divided value enters the voltage inverting circuit 808 of the detection permission circuit 803. When the gate voltage is equal to or lower than the predetermined threshold voltage Vg1, the voltage inverting circuit 808 outputs a high level, the first nMOS switch 809 is turned on, and the sense voltage Vs is approximately 0 volts. That is, when the gate voltage is equal to or lower than the predetermined threshold voltage Vg1, detection of the sense voltage Vs is not permitted. On the other hand, when the gate voltage is larger than Vg1, the voltage inverting circuit 808 outputs a low level, the first nMOS switch 809 is turned off (the drain of the nMOS switch 809 is opened), and the sense voltage Vs remains as it is. The gate of switch 807 is entered. That is, when the gate voltage is higher than the predetermined threshold voltage Vg1, detection of the sense voltage Vs is permitted. In order to adjust the threshold voltage Vg1, the resistance value of the first resistor 810 or the second resistor 811 is changed. When the detection permission circuit 803 is in the permitted state, that is, when the gate voltage is larger than Vg1, the second nMOS switch 807 is turned on when the sense voltage Vs exceeds the first predetermined threshold Vs1 due to an abnormality such as a power supply short circuit. The anode of the constant voltage diode (Zener diode) 806 is approximately 0 volts. A voltage higher than the Zener voltage Vz is applied to the cathode side of the constant voltage diode (Zener diode) 806, the gate voltage is held at a predetermined voltage value (Zener voltage Vz), and the saturation current of the IGBT 303 is suppressed. When the sense voltage Vs is equal to or lower than the first predetermined threshold Vs1, the second nMOS switch 807 is turned off, the anode of the constant voltage diode (Zener diode) 806 is opened, and the short circuit protection circuit 804 does not operate. Even when the threshold adjustment circuit 802 is not provided, the effect of the present invention can be realized. That is, the gate voltage of the IGBT 303 may be directly input to the voltage inverting circuit 808. In this case, since the normal gate voltage is about 15V, the voltage inverting circuit 808 needs to be a circuit capable of 15V operation.

  Furthermore, as another embodiment, the circuit function of the short-circuit protection circuit 804 may be used in combination with the soft interruption function at the time of abnormality of the driver IC 708. In that case, the sense voltage Vs is also input to the driver IC 708. When the sense voltage Vs exceeds the second threshold value Vs2, the driver IC 708 starts a soft shut-off operation of the IGBT 303. When the sense voltage Vs is equal to or lower than the second threshold value Vs2, the driver IC 708 maintains a normal switching operation. The magnitude relationship between the first threshold value Vs1 and the second threshold value Vs2 of the sense voltage Vs depends on the short-circuit tolerance of the IGBT 303, the delay time until the driver IC 708 performs a soft shut-off operation, and the like. For example, when the first threshold value Vs1 is larger than the second threshold value Vs2, the short circuit protection circuit 804 operates after the soft shut-off operation of the driver IC 708 is first started at the time of abnormality such as a short circuit. However, when the delay time until the driver IC 708 performs the software shut-off operation is long, this operation is reversed. Finally, it is necessary to determine the magnitude relationship between the threshold values Vs1 and Vs2 in consideration of the short-circuit withstand capability of the IGBT 303.

  FIG. 13 is a time chart during operation of the short circuit protection circuit according to the present embodiment.

  In FIG. 13, reference numeral 812 denotes a voltage waveform of the sense resistor 801 carrying the surge voltage, 813 denotes a first permission period of the detection permission circuit 803, 814 denotes a second permission period of the detection permission circuit 803, and 815 denotes a first sense. Voltage threshold levels Vs1 and 816 are detection timings when a short circuit is abnormal, 817 is a gate voltage waveform of the IGBT 303, 818 is a gate voltage threshold level Vg1 and 819 that determines the first permission period and the second permission period, and the IGBT 303 is the first one. The first turn-on surge voltage generated in the sense voltage waveform when the IGBT is turned on, 820 is the first turn-off surge voltage generated in the sense voltage waveform when the IGBT 303 is turned off, and 821 is the sense voltage waveform when the IGBT 303 is turned on the second time. The second turn-on surge voltage generated at the second time, The second turn-off surge voltage generated at the sense voltage waveforms at turn-off, 823 output voltage waveform of the detection permission circuit 803, 824 is a second sense voltage threshold level Vs2. In this figure, the second sense voltage threshold level Vs2 is smaller than the first sense voltage threshold level Vs1, but it may be the same or larger.

  When the detection permission circuit 803 is not provided, the second turn-on surge voltage 821 exceeds the first sense voltage threshold level Vs1, and thus the short circuit protection circuit 804 erroneously detects here. When the detection permission circuit 803 is provided, the first turn-on surge voltage 819, the first turn-off surge voltage 820, the second turn-on surge voltage, and the second turn-off surge voltage are removed, and erroneous detection due to these surge voltages is eliminated.

  Furthermore, as another embodiment, when used in combination with the circuit function of the short circuit protection circuit 804 and the soft interruption function at the time of abnormality of the driver IC 708, if the detection permission circuit 803 is not provided, the first turn-off surge voltage 820 is Since the sense voltage threshold level Vs2 is exceeded, the soft cutoff circuit of the driver IC 708 erroneously detects here. However, when the detection permission circuit 803 is provided, the first turn-on surge voltage 819, the first turn-off surge voltage 820, the second turn-on surge voltage, and the second turn-off surge voltage are removed, and false detection due to these surge voltages is prevented. Disappear.

9 Cooling unit 10 Upper case
11 Metal base plate 12 Housing 13 Cooling water inlet pipe 14 Cooling water outlet pipe 16 Lower case 17 AC terminal case 18 AC terminal 19 Cooling water flow path 20 Control circuit board 21 Connector 22 Drive circuit boards 23 and 712 Inter-board connector 43 Auxiliary machine Inverter device (including power module)
49 Cast Meat Stealing 110 Hybrid Electric Vehicle 112 Front Wheel 114 Front Wheel Axle 116 Front Wheel Side DEF
118 Transmission 120 Engine 122 Power distribution mechanism 123, 124, 125, 126, 127, 128, 129, 130 Gear 136 Battery 138 DC connector 140, 142 Inverter device 144 Inverter circuit 150 Upper and lower arm series circuit 153 Upper arm collector electrode 154 Upper arm gate electrode terminal 155 Upper arm signal emitter electrode terminal 156 Upper arm diode 157 Positive electrode (P) terminal 158 Negative electrode (N) terminal 159 AC terminal 163 Lower arm collector electrode 164 Lower arm gate electrode terminal 165 Lower arm signal emitter electrode terminal 166 Lower arm diode 169 Intermediate electrode 170 Control unit 172 Control circuit 174 Driver circuits 176 and 182 Signal line 180 Current detection unit 186 AC power line 188 AC connector 192 , 194 Motor generator 195 Motor (auxiliary equipment = air conditioner, oil pump, cooling pump)
200 Power converter 300 Power module (semiconductor module part)
302 Power module case 304 Metal base 305 Fin 308 U-phase AC bus bar 310 V-phase AC bus bar 312 W-phase AC bus bar 314 DC positive terminal 315, 507 Positive conductor plate 316 DC negative terminal 317, 505 Negative conductor plate 318 Insulating paper 320 Power module Control terminal 326 IGBT
327 Diode 334 Insulating substrate 341 Junction (for DC negative bus bar)
342 Power module case protrusion 350 Stay 352 Stay lower region 400, 402, 404 Opening 401 Inlet hole 403 Outlet hole 406 Through hole 408 Separator 410 Support part 412, 414 Screw hole (for power module fixing)
416 Screw hole (for fixing the water channel cover)
418 Flow of refrigerant (inflow direction)
420 Cover 421 Flow of refrigerant (U-turn part)
422 Flow of refrigerant (outflow direction)
500 Capacitor module 502 Capacitor case 504 Negative electrode side capacitor terminal 506 Positive electrode side capacitor terminal 508 Conductive material 509, 511 Opening (for terminal fixing)
700 Heat sink 702 Heat sink opening
704 Thermal conductive sheet 706 Power supply circuit transformer 708 Driver IC
710 Electrolytic capacitor 714 Power transistor 718 Notch for AC terminal 720, 721 Fixing means 722 Control terminal hole 724 Notch
730 First heat dissipation path 731 Second heat dissipation path 800 Sense IGBT
801 Sense resistor 802 Threshold adjustment circuit 803 Detection permission circuit 804 Short circuit protection circuit 806 Constant voltage diode (Zener diode)
807 Second nMOS switch 808 Voltage inversion circuit 809 First nMOS switch 810 First resistor 811 Second resistor 812 Voltage waveform 813 of the sense resistor when there is no detection permission circuit First permission period 814 Second permission Period 815 First sense voltage threshold level Vs1
816 Detection timing at the time of short circuit abnormality 817 Gate voltage waveform 818 of IGBT 303 Gate voltage threshold level Vg1
819 First turn-on surge voltage 820 First turn-off surge voltage 821 Second turn-on surge voltage 822 Second turn-off surge voltage 823 Voltage waveform 824 of the sense resistor when there is a detection enabling circuit 824 Second sense voltage threshold level Vs2

Claims (9)

A power module having a plurality of switching elements configured to convert a direct current supplied from a battery into an alternating current and configured with at least one current sensing switching element;
A drive circuit for controlling a switching operation of the plurality of switching elements;
A sense resistor for converting a current of the current sensing switching element into a sense voltage;
A detection permission circuit for inputting the sense voltage and the drive signal voltage of the switching element and outputting the sense voltage for a predetermined period;
The power converter device which has a short circuit protection circuit which carries out the short circuit protection of the said switching element in the said predetermined period. The power conversion device according to claim 1,
A threshold adjustment circuit for adjusting a threshold of the detection permission circuit using a drive signal voltage of the switching element to adjust the predetermined period;
The power converter device which has a short circuit protection circuit which carries out the short circuit protection of the said switching element in the said predetermined period. The power conversion device according to claim 1 or 2,
The drive circuit has a short-circuit protection function, and is a power conversion device that performs a short-circuit protection operation in combination with the short-circuit protection circuit. The power conversion device according to any one of claims 1 to 3,
The detection permission circuit includes a switch element that short-circuits both ends of the sense resistor;
A power conversion device having a voltage inversion circuit for inputting and logically inverting the output voltage of the threshold adjustment circuit. The power conversion device according to claim 2,
The threshold value adjustment circuit divides a gate voltage of the switching element, and outputs a divided value to the detection permission circuit, and includes a first resistor and a second resistor. An in-vehicle electric system that converts electric power supplied from an in-vehicle power source into electric power,
An electric motor that generates the electric force;
A power conversion device that is electrically connected between the in-vehicle power source and the electric motor, and controls the transfer of electric power between the in-vehicle power source and the electric motor;
The power converter is
A power module having a plurality of switching elements configured to convert a direct current supplied from a battery into an alternating current and configured with at least one current sensing switching element;
A capacitor module electrically connected in parallel to the in-vehicle power supply side of the power module;
A drive circuit for controlling a switching operation of the plurality of switching elements;
A sense resistor for converting a current of the current sensing switching element into a sense voltage;
A detection enabling circuit for inputting the sense voltage and outputting the sense voltage for a predetermined period;
A threshold adjustment circuit for adjusting a threshold of the detection permission circuit using a drive signal voltage of the switching element to adjust the predetermined period;
A vehicle-mounted electrical system having a short-circuit protection circuit that short-circuit protects the switching element during the predetermined period. The in-vehicle electric system according to claim 6,
The drive circuit has a short circuit protection function, and is used in combination with the short circuit protection circuit to perform a short circuit protection operation. The on-vehicle electric system according to claim 6 or 7,
The detection permission circuit includes a switch element that short-circuits both ends of the sense resistor;
An in-vehicle electric system having a voltage inverting circuit for inputting and logically inverting the output voltage of the threshold adjustment circuit. The on-vehicle electric system according to any one of claims 6 to 8,
The threshold adjustment circuit divides the gate voltage of the switching element, and outputs a divided value to the detection permission circuit, and includes a first resistor and a second resistor.

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