JP2017118814A - Control system of power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize a control system capable of transmitting a signal showing temperature information and a signal showing abnormality information while decreasing the number of insulative elements in a power conversion device having a plurality of semiconductor switching elements.SOLUTION: A control system of a power conversion device comprises: a first drive circuit Da including a temperature information transmit part 21 which transmits temperature information of a switch SW in synchronization with a synchronizing signal, and an abnormality information transmit part 22 which transmits abnormality information of the switch SW in synchronization with the synchronizing signal; and a second drive circuit Db including an abnormality information transmit part 22. Output signals from the drive circuits Da, Db are output to a controller 40 through a common route after the logical sum thereof is taken. The abnormality information transmit part 22 starts outputting abnormality information in a period during which no temperature information is output according to the synchronizing signal. The controller 40 determines whether or not abnormality occurs on the switch SW in the period during which no temperature information is output.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a control system for a power conversion device that is applied to a power conversion device including a plurality of semiconductor switching elements and includes a control device that controls an open / close state of the plurality of semiconductor switching elements.

  The inverter device that drives the in-vehicle motor constitutes a high voltage system, and the control device that controls the inverter device constitutes a low voltage system insulated from the high voltage system. When a signal representing temperature information of the semiconductor switching elements constituting the inverter device or abnormality information notifying the abnormality of the semiconductor switching elements is transmitted from the inverter device to the control device, the signal is transmitted from the high voltage system to the low voltage system. . Since the high-voltage system and the low-voltage system are insulated, signal transmission from the inverter device to the control device is performed via an insulating element.

  Patent Document 1 describes a configuration for transmitting a signal representing temperature information and a signal representing abnormality information through a common insulating element for the purpose of reducing the number of insulating elements to be used. Further, in the configuration of Patent Document 1, the temperature information of the semiconductor switching element is represented by the time ratio of the pulse signal. Further, the abnormal information of the semiconductor switching element having a higher degree of urgency than the temperature information is represented by a pulse signal shorter than the signal representing the temperature information. Then, a signal representing temperature information and a signal representing abnormality information are superimposed, and the abnormality information is represented by comparing a signal obtained by applying a low-pass filter to the superimposed signal and a signal obtained by applying a delay circuit to the superimposed signal. The signal is restored.

JP 2009-136115 A

  Japanese Patent Laid-Open No. 2004-228561 has a configuration in which the occurrence of an abnormality in the semiconductor switching element and the end of the abnormality are transmitted with a short pulse signal. However, Patent Document 1 discloses how to transmit a signal indicating temperature information and a signal indicating abnormality information while reducing the number of insulating elements in a configuration including a plurality of semiconductor switching elements. Absent.

  The present invention has been made in view of the above problems, and transmits a signal representing temperature information and a signal representing abnormality information while reducing the number of insulating elements in a power conversion device including a plurality of semiconductor switching elements. The main purpose is to realize a possible control system.

  This configuration is applied to a power converter (INV) including a plurality of semiconductor switching elements (SW, SWp1 to SWp3, SWn1 to SWn3) connected to different reference potentials, and the open / close states of the plurality of semiconductor switching elements A control system for a power conversion device comprising a control device (40) for controlling a plurality of drives connected to the reference potential corresponding to the semiconductor switching elements and driving the corresponding semiconductor switching elements, respectively. Circuit (Da, Db, Dp1 to Dp3, Dn1 to Dn3), the control device and the plurality of drive circuits are insulated from each other, and the control device and the plurality of drive circuits are respectively Connected via first insulating elements (Ma, Mb, Mp1 to Mp3, Mn1 to Mn3) The plurality of drive circuits are synchronized by a predetermined synchronization signal via second insulating elements (Mc, Md, Mp1 to Mp3, Mn1 to Mn3), and the semiconductor switching corresponding to each of the plurality of drive circuits A first transmission unit (21) for driving each element, and transmitting a signal representing temperature information of the corresponding semiconductor switching element to the control device in synchronization with the synchronization signal as the plurality of drive circuits; and A first driving circuit (Da) including a second transmission unit (22) that transmits a signal representing abnormality information of the corresponding semiconductor switching element to the control device in synchronization with the synchronization signal; A second drive circuit (Db) including a transmission unit, the first transmission unit of the first drive circuit, the second transmission unit of the first drive circuit, and the second drive circuit. The output signal of the second transmitter is logically ORed and output to the control device via the same path, and the second transmitter receives the temperature information according to the synchronization signal. The control device starts outputting the signal representing the abnormality information during a period when the signal representing the temperature information is not output, and the control device includes the first drive circuit and the second circuit during the period when the signal representing the temperature information is not output. Based on a signal input from the drive circuit, it is determined whether or not an abnormality has occurred in the semiconductor switching element.

  In the plurality of semiconductor switching elements used in the power conversion device, the temperatures of the semiconductor switching elements can be regarded as substantially the same. In addition, for example, if a detection value of the semiconductor switching element used in the power conversion device that has the highest temperature is obtained and control is performed so that the detection value becomes a predetermined value or less, all the semiconductor switching elements An excessive increase in the temperature of can be suppressed.

  Therefore, the control device is configured to acquire only the temperature of the semiconductor switching element connected to the same reference potential as that of the first drive circuit. Further, in the above configuration, the signal representing the temperature information of the semiconductor switching element corresponding to the first drive circuit and the signal representing the abnormality information of the semiconductor switching element corresponding to the first drive circuit and the second drive circuit are logically After being summed, it is output via the same route. By adopting a configuration for outputting a plurality of signals through the same path, the circuit configuration can be simplified.

  Further, in the above configuration, the signal representing the temperature information and the signal representing the abnormality information are output in synchronization with the speed information, and the signal representing the abnormality information is output during a period in which the signal representing the temperature information is not output. The configuration was started. Thus, the control device can determine whether the signal transmitted from the drive circuit is information representing temperature information or information representing abnormality information. That is, it is possible to realize a control system capable of transmitting a signal representing temperature information and a signal representing abnormality information while reducing the number of insulating elements.

The figure showing the electric constitution of an inverter apparatus. Schematic showing the circuit board in which an inverter apparatus is mounted. Schematic showing the structure of a power card (semiconductor switching element). The electrical block diagram showing the connection of the drive circuit of 1st Embodiment and a control apparatus. The timing chart showing the speed signal of 1st Embodiment, a temperature information signal, an abnormality information signal, and the input signal to a control apparatus. A truth table showing the state of each signal according to the normality and abnormality of the switch. The timing chart showing the speed signal of 2nd Embodiment, a temperature information signal, an abnormality information signal, and the input signal to a control apparatus. The electrical block diagram showing the connection of the drive circuit and control apparatus of 3rd Embodiment.

(First embodiment)
Hereinafter, an embodiment in which a power conversion device is applied to a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows an electrical configuration of the power converter according to the present embodiment. The motor generator 10 is mechanically coupled to drive wheels and an internal combustion engine. The motor generator 10 is connected to the inverter device INV. The inverter device INV (power conversion circuit) converts the DC power into AC power using the output voltage of the DC power supply 12 as an input voltage. Here, DC power supply 12 is a high voltage battery whose terminal voltage is a high voltage of, for example, 100 V or higher. The DC power source may be a buck-boost converter or the like.

  The inverter device INV is configured by connecting three series-connected bodies of switching elements SWp1 to SWp3 (upper arm switches) on the high voltage side and switching elements SWn1 to SWn3 (lower arm switches) on the low voltage side in parallel. Connection points of these switching elements SWp <b> 1 to SWp <b> 3 and switching elements SWn <b> 1 to SWn <b> 3 are connected to respective phases of the motor generator 10.

  Further, between the input / output terminals (between the collector and the emitter) of the switching elements SWp1 to SWp3 on the high voltage side and the switching elements SWn1 to SWn3 on the low voltage side, free wheel diodes FDp1 to 3 on the high voltage side and low The cathodes and anodes of the voltage-side freewheel diodes FDn1 to FDn1 are connected.

  The capacitor CA is connected to the collectors (high voltage side terminals) of the upper arm switches SWp1 to SWp3 and the emitters (low voltage side terminals) of the lower arm switches SWn1 to SWn3, and smoothes the voltage between both terminals. It is a capacitor.

  The semiconductor switches SW (SWp1 to SWp3, SWn1 to SWn3) constituting the inverter device INV are all power semiconductors, and more specifically, insulated gate bipolar transistors (IGBTs).

  The control device 40 is a microcomputer and is digital processing means for controlling the control amount of the motor generator 10 by operating the inverter device INV. Specifically, the control device 40 outputs an operation signal to each switch SW of the inverter device INV via an interface 42 including magnetic couplers Mp1 to Mp3 and Mn1 to Mn3 as insulating means to be described later, whereby the inverter device INV is output. To operate.

  More specifically, the control device 40 outputs operation signals to the drive circuits Dp1 to Dp3 and Dn1 to Dn3 that input drive signals to the control terminals (gates) of the switches SW via the interface 42. Here, the reason why the interface 42 is provided with an insulating means is to insulate the high voltage system including the inverter device INV and the DC power supply 12 from the low voltage system including the control device 40.

  The emitters of the switches SWp1 to SWp3 and SWn1 to SWn3 are insulated and connected to different reference potentials. The drive circuits Dp1 to Dp3 and Dn1 to Dn3 are connected to the emitters of the switches SWp1 to SWp3 and SWn1 to SWn3 to be driven. The drive circuits Dp1 to Dp3 and Dn1 to Dn3 apply voltages to the gates of the switches SWp1 to SWp3 and SWn1 to SWn3 to be driven using the potentials of the emitters of the switches SWp1 to SWp3 and SWn1 to SWn3 to be driven as reference potentials.

  FIG. 2 shows a circuit board 50 on which the inverter device INV according to the present embodiment is mounted. The illustrated circuit board 50 has both a high voltage circuit region HV connected to the inverter device INV and a low voltage circuit region LV. Here, basically, in the drawing, the region on the right side (the direction opposite to the direction in which the upper arm switch SWp2 is provided with respect to the upper arm switch SWp3) is the low voltage circuit region LV, and the The region in the direction in which the upper arm switch SWp2 is provided with respect to the upper arm switch SWp3 is the high voltage circuit region HV. However, in the high voltage circuit area HV, there are also components that constitute both the low voltage system and the high voltage system, such as magnetic couplers Mp1 to Mp3 and Mn1 to Mn3.

  Further, an electrolytic capacitor (not shown) for a flyback converter that constitutes a power supply circuit of the drive circuits Dp1 to Dp3 and Dn1 to Dn3 of each switch SW that constitutes the inverter device INV is assumed to constitute a low voltage system. It is arranged in the low voltage circuit region LV on the middle right side. Further, the primary winding side of the transformer (not shown) for the flyback converter constituting the power supply circuit of the drive circuits Dp1 to Dp3, Dn1 to Dn3 is arranged in the low voltage circuit region LV as constituting the low voltage system. The secondary winding side is arranged in the high voltage circuit area HV as a component of the high voltage system.

  As shown in FIG. 3, each switch SW constituting the inverter device INV is inserted and connected to the circuit board 50 from the back side of the circuit board 50 (the back side of the surface shown in FIG. 2). Here, each switch SW is covered with an insulating material together with other elements to constitute a power card PWC (module). The power card PWC also stores a freewheel diode FD and a temperature sensitive diode SD, but the description of the freewheel diode FD is omitted in FIG.

  The power card PWC has the same structure as that in which the switch SWp on the high voltage side is accommodated and that in which the switch SWn on the low voltage side is accommodated. The power card PWC has a plurality of signal terminals exposed to the outside from the insulating material. Specifically, the gate terminal G of the switch SW, the emitter detection terminal KE, the sense terminal SE, and the anode A and cathode K terminals of the temperature-sensitive diode SD are inserted and connected to the circuit board 50. Here, the emitter detection terminal KE is an electrode connected to the emitter E of the switch SW and having the same voltage as the emitter E. The collector detection terminal KC is connected to the collector of the switch SW and is an electrode having the same voltage as the collector. The sense terminal SE is a terminal for outputting a minute current having a correlation with the current flowing through the switch SW.

  As shown in FIG. 2, since the switch SW constitutes a high voltage system, an insulating region IA is provided on the circuit board 50 in order to insulate each switch SW from other circuits. The insulating region IA is a region where a circuit (element, wiring, power supply pattern) is not arranged.

  In the upper row in the figure, terminals of the power card PWC including the upper arm switches SWp1 to SWp3 are shown, which are separated from each other by an insulating region IA. Then, driving circuits Dp1 to Dp3 for driving the upper arm switches SWp1 to SWp3 are mounted in a region surrounded by the insulating region IA. This is because the voltage at the emitter detection terminal KE between the upper arm switches SWp1 to SWp3 varies greatly depending on whether the corresponding lower arm switches SWn1 to SWn3 are in the on state or the off state. For this reason, it is necessary to insulate the drive circuits Dp1 to Dp3 from each other even though the operation voltages of these drive circuits Dp1 to Dp3 are small. The width of the insulating region IA is determined from the viewpoint of avoiding legal requirements, dielectric breakdown, and the like.

  In the lower column of the figure, terminals of the power card PWC including the lower arm switches SWn1 to SWn3 are shown. Since the voltages of the emitter detection terminals KE corresponding to these lower arm switches SWn1 to SWn3 are close, the insulating region IA is not provided between them. The operating voltages of the components of the drive circuits Dn1 to Dn3 are not necessarily higher than those of the components in the low voltage circuit region LV. For this reason, the drive circuits Dn1 to Dn3 of the lower arm switches SWn1 to SWn3 do not necessarily need to be provided with the insulating region IA on the circuit board 50.

  However, the reference potentials of the drive circuits Dn1 to Dn3 (the potentials of the emitters of the corresponding switches SWn1 to SWn3) are different from each other depending on the resistance component and the induction component between the emitters of the switches SWn1 to SWn3 during the operation of the inverter device INV. is there. For this reason, although the insulating region IA is not provided between the drive circuits Dn1 to Dn3, the drive circuits Dn1 to Dn3 are insulated from each other.

  The drive circuits Dp1 to Dp3, Dn1 to Dn3 (hereinafter also referred to as drive circuit D) are connected to the gate terminal G and the emitter detection terminal KE of the corresponding switch SW, and apply a voltage to the gate terminal G of the switch SW. As a result, the switch SW is driven.

  Furthermore, the drive circuit D of this embodiment is connected to the sense terminal SE of the corresponding switch SW and the anode A and cathode K of the temperature sensitive diode SD. Then, the drive circuit D detects the current flowing through the switch SW based on the voltage value of the sense terminal SE. Further, the drive circuit D detects the temperature of the switch SW based on the voltage between the anode A and the cathode K of the temperature sensitive diode SD. Further, the drive circuit D determines the abnormality of the switch SW based on the detected value of the current flowing through the switch SW and the detected value of the temperature of the switch SW. Then, the drive circuit D transmits the temperature information and abnormality information of the switch SW to the control device 40.

  FIG. 4 is a schematic diagram showing the connection between the drive circuits Da and Db and the control device 40 in the present embodiment. Here, the first drive circuit Da is any one of the drive circuits Dp1 to Dp3, Dn1 to Dn3, and is, for example, the drive circuit Dp1. The second drive circuit Db is any one of the drive circuits Dp1 to Dp3 and Dn1 to Dn3 other than the first drive circuit Da, for example, the drive circuit Dp2.

  Each of the drive circuits Da and Db includes a temperature information transmission unit 21 (first transmission unit) and an abnormality information transmission unit 22 (second transmission unit). Here, in the switches SWp1 to SWp3 and SWn1 to SWn3 used in the inverter device INV, the temperatures of the switches SWp1 to SWp3 and SWn1 to SWn3 can be regarded as substantially the same. Therefore, the control device 40 is configured to acquire only the temperature information of the switch SW connected to the same reference potential as that of the first drive circuit Da (first transmission circuit). For this reason, the temperature information transmission unit 21 of the second drive circuit Db (second transmission circuit) is invalidated. Specifically, the output terminal P1 of the temperature information transmission unit 21 of the drive circuit Db is not connected to other elements and is in a floating state.

  The output (output terminal P1) of the temperature information transmission unit 21 of the first drive circuit Da and the output (output terminal P2) of the abnormality information transmission unit 22 of the first drive circuit Da are logically summed, It is connected to the magnetic coupler Ma. Here, since the output terminal P1 of the temperature information transmission unit 21 and the output terminal P2 of the abnormality information transmission unit 22 are both open drain outputs, they are connected at the connection point P3 and connected to the pull-up resistor R1. It is considered wired or The output terminal P2 of the abnormality information transmission unit of the second drive circuit Db is connected to the magnetic coupler Mb after being connected to the pull-up resistor R2.

  Here, the magnetic couplers Ma and Mb are a kind of insulating elements. An insulating element is an element that transmits a signal received from a receiving-side element to a transmitting-side element after insulating the receiving side and the transmitting side of the insulating element. Specifically, when the magnetic coupler Ma transmits a signal received from the first drive circuit Da to the control device 40, the magnetic coupler Ma corresponds to an element on the reception side, and the control device 40 corresponds to an element on the transmission side. It corresponds to. The magnetic coupler magnetically couples the receiving side and the transmitting side to insulate the receiving side and the transmitting side of the insulating element and transmit a signal received from the receiving side element to the transmitting side element. . For example, the magnetic coupler includes a reception coil provided on the reception side and a transmission coil provided on the transmission side as elements for magnetically coupling the reception side and the transmission side. The magnetic coupler changes the magnetic field by passing a current (signal) through the receiving coil, and changes the current or voltage flowing through the transmitting coil. Thereby, the signal received from the receiving element is transmitted to the transmitting element. Further, for example, the magnetic coupler includes a receiving coil provided on the receiving side and a magnetoresistive effect element provided on the transmitting side as elements for magnetically coupling the receiving side and the transmitting side. The magnetic coupler changes the magnetic field by passing a current (signal) through the receiving coil, and changes the resistance or resistance of the magnetoresistive element to change the current or voltage on the transmission side. Thereby, the signal received from the receiving element is transmitted to the transmitting element.

  The magnetic couplers Ma and Mb (first insulating elements) are open drain output insulating elements. The magnetic coupler Ma outputs a signal input from the first drive circuit Da from the output terminal P4, and the magnetic coupler Mb outputs a signal input from the second drive circuit Db from the output terminal P5. The output signal of the magnetic coupler Ma and the output signal of the magnetic coupler Mb are logically summed and input to the control device 40. Specifically, the output terminal P4 of the magnetic coupler Ma and the output terminal P5 of the magnetic coupler Mb are both connected to the connection point P6 and connected to the pull-up resistor R3, so that a logical OR is performed by wired OR. Is input to the control device 40.

  Further, the output signal of the magnetic coupler Ma and the output signal of the magnetic coupler Mb are logically summed and input to the buffer 43 which is a high impedance element. The output signal of the buffer 43 is input to the control device 40 via the low pass filter 44.

  The control device 40 of the present embodiment detects the output voltage Vout of the inverter device INV and changes the drive speed (switching speed) of the switch SW by the drive circuit D based on the detected value. Thereby, it is possible to suppress power loss in the switch SW while suppressing application of an excessive voltage to the switch SW.

  The control device 40 outputs a speed signal for instructing a switching speed to the drive circuits Da and Db via the magnetic couplers Mc and Md (second insulating elements). The speed signals input to the drive circuits Da and Db are common. The speed signal output from the control device 40 is input to the terminal P7 of the magnetic coupler Mc, and is input from the terminal P8 of the magnetic coupler Mc to the terminal CLK of the first drive circuit Da as an open drain output. The speed signal output from the control device 40 is input to the terminal P9 of the magnetic coupler Md, and is input from the terminal P10 of the magnetic coupler Mc to the terminal CLK of the second drive circuit Db as an open drain output. The terminals CLK of the drive circuits Da and Db are pulled up by pull-up resistors R4 and R5. In addition to the speed signal, the drive circuits Da and Db receive a signal for commanding the switch SW to be turned on / off (not shown).

  In FIG. 4, for convenience of explanation, the magnetic couplers Ma and Mc are illustrated as separate bodies, but the magnetic couplers Ma and Mc are sealed in the same package. Similarly, the magnetic couplers Mb and Md are sealed in the same package. Note that the package in which the magnetic couplers Ma and Mc shown in FIG. 4 are sealed corresponds to one of the magnetic couplers Mp1 to Mp3 and Mn1 to Mn3 shown in FIG.

  Here, the drive circuit D of the present embodiment is configured to output a signal representing temperature information and a signal representing abnormality information in synchronization with the speed signal. Further, the control device 40 and the plurality of drive circuits D are configured to communicate in synchronization with a speed signal (clock signal). That is, the drive circuit D uses the speed signal as a synchronization signal. For example, communication using an SPI protocol (Serial Peripheral Interface) can be performed (SPI is a registered trademark).

  FIG. 5 is a timing chart showing time changes of the speed signal, the temperature information signal, the abnormality information signal, and the input signal of the control device 40.

  As a speed signal, a pulse shorter than the predetermined period is output for each predetermined period. Times T10 to T12 in FIG. 5 correspond to a predetermined cycle. The control device 40 generates the speed signal so that the reciprocal of the period of the speed signal becomes the switching speed of the switch SW. Note that the control device 40 may generate the speed signal so that a constant multiple of the reciprocal of the period of the speed signal becomes the switching speed. The drive circuits Da and Db drive the switch SW at a switching speed corresponding to the speed signal.

  The temperature information transmission unit 21 of the drive circuit D transmits a pulse representing temperature information in synchronization with the speed signal. Further, the temperature information transmission unit 21 transmits the temperature information of the switch SW at a pulse time ratio (Duty) with respect to the period of the speed signal. Specifically, as shown in FIG. 5, a pulse is output over a period (time T10 to T11) corresponding to the temperature of the switch SW. Further, the temperature information transmission unit 21 outputs one pulse every two cycles of the speed signal.

  The abnormality information transmission unit 22 of the drive circuit D starts outputting a signal representing abnormality information in a period in which a pulse representing temperature information is not output in accordance with the speed signal. Specifically, as shown in FIG. 5, when the abnormality information transmitting unit 22 determines that an abnormality has occurred in the switch SW in a period (time T12 to T14) in which a pulse representing temperature information is not output. Output of a signal representing the abnormality information is started (time T13 in FIG. 5). If it is determined that an abnormality has occurred in the switch SW, the abnormality information transmission unit 22 continues to output a signal indicating the abnormality information even during a period (after time T14) in which a pulse indicating the temperature information is output.

  The control device 40 determines whether or not an abnormality has occurred in the switch SW based on a signal input from the drive circuit D during a period (time T12 to T14) in which a signal indicating temperature information is not output. Specifically, the control device 40 sets the input signal to the control device 40 to low (true) over a period longer than the period of the speed signal based on the voltage value of the signal input from the low pass filter 44. In this case, it is determined that an abnormality has occurred in the switch SW.

  Hereinafter, the duty ratio set by the temperature information transmission unit 21 of the drive circuit D will be described. A constant current circuit is connected to the temperature sensitive diode SD (FIG. 3) so that a constant current flows. The drive circuit D acquires the voltage between the anode A and the cathode K of the temperature sensitive diode SD, that is, the forward voltage drop (analog value) of the temperature sensitive diode SD. The temperature information transmission unit 21 performs PWM modulation on the forward voltage drop of the temperature sensitive diode SD to convert it into a temperature information signal that is a digital signal, and outputs this to the control device 40. The temperature information signal has a predetermined time ratio corresponding to the forward voltage drop of the temperature sensitive diode SD. Since the forward voltage drop of the temperature sensing diode SD is a value corresponding to the temperature of the temperature sensing diode SD, that is, the switch SW, the time ratio of the temperature information signal is a value corresponding to the temperature of the switch SW.

  For example, the temperature information transmission unit 21 converts the forward drop voltage of the temperature-sensitive diode SD when the switch SW is lower than the minimum temperature A ° C. (eg, −50 ° C.) and A ° C. into a signal with a time ratio of 0%. Convert. Further, the temperature information transmission unit 21 is a signal having a time ratio of 100% for the forward voltage drop of the temperature-sensitive diode SD when the switch SW is at a maximum temperature B ° C. (for example, 200 ° C.) and higher than B ° C. Convert to Then, the temperature information transmitting unit 21 sets the forward voltage drop of the temperature sensitive diode SD when the temperature T of the switch SW is between A ° C. and B ° C. as (TA) / (BA)%. Convert to a time ratio signal. The minimum temperature A ° C and the maximum temperature B ° C of the switch SW are set according to the environment in which the switch SW is used. In the above description, the duty ratio is linearly changed according to the temperature T of the switch SW. However, the duty ratio may be changed and changed non-linearly.

  FIG. 6 shows a truth representing a signal state in each part of the circuit when the switching element SWa corresponding to the first drive circuit Da and the switching element SWb corresponding to the second drive circuit Db are normal or abnormal. A value table is shown.

  When the switching element SWa is normal, the state of the terminal P1 of the first drive circuit Da changes at a time ratio corresponding to the temperature of the switching element SWa, and the terminal P2 of the first drive circuit Da is set to a high impedance state. Therefore, when the switching element SWa is normal, the state of the connection point P3 corresponding to the first drive circuit Da changes at a time ratio according to the temperature of the switching element SWa, and the output signal of the first magnetic coupler Ma is The state changes at a time ratio corresponding to the temperature of the switching element SWa.

  When the switching element SWa is abnormal, the state of the terminal P1 of the first drive circuit Da changes at a time ratio corresponding to the temperature of the switching element SWa, and the terminal P2 of the first drive circuit Da is set to the low state. Therefore, when the switching element SWa is abnormal, the connection point P3 corresponding to the first drive circuit Da is set to the low state, and the output signal of the first magnetic coupler Ma is set to the low state.

  When the switching element SWb is normal, the terminal P2 of the second drive circuit Db is in a high impedance state. For this reason, the output signal of the second magnetic coupler Mb is in a high impedance state.

  When the switching element SWb is abnormal, the terminal P2 of the second drive circuit Db is set to a low state. For this reason, the output signal of the second magnetic coupler Mb is set to the low state.

  Therefore, when both of the switching elements SWa and SWb are normal, the signal input to the control device 40 (the signal at the connection point P6) is a signal that changes state with the time ratio output from the magnetic coupler Ma, and the second Since the high-impedance state signal output from the magnetic coupler Mb is logically ORed with a wired OR, the signal changes state at a time ratio.

  When the switching element SWa is abnormal and the switching element SWb is normal, the state of the signal input to the control device 40 (the signal at the connection point P6) changes at the time ratio output from the magnetic coupler Ma. Since the signal and the low-state signal output from the second magnetic coupler Mb are logically ORed by wired OR, the signal becomes a low-state signal.

  In addition, when the switching element SWa is normal and the switching element SWb is abnormal, the signal input to the control device 40 (the signal at the connection point P6) is the low state signal output from the magnetic coupler Ma, The signal in the high impedance state output from the two magnetic coupler Mb is logically ORed by wired OR, so that it becomes a signal in the low state.

  Further, when both of the switching elements SWa and SWb are abnormal, a signal input to the control device 40 (a signal at the connection point P6) is a low-state signal output from the magnetic coupler Ma and a second magnetic coupler Mb. Since the low state signal to be output is logically ORed with wired OR, it becomes a low state signal.

  The effects of this embodiment will be described below.

  In the plurality of semiconductor switching elements used in the power supply circuit, the temperatures of the semiconductor switching elements can be regarded as substantially the same. Therefore, in order to simplify the circuit configuration, the control device 40 may acquire only the temperature information of one semiconductor switching element. Further, when the control device 40 acquires the abnormality information of a plurality of semiconductor switching elements, in order to simplify the circuit configuration, the logical sum of each signal representing the abnormality information of the semiconductor switching elements is taken and the logic A configuration in which the sum is input to the control device 40 is conceivable.

  In such a configuration, a configuration to which the method described in Patent Document 1 is applied is assumed. Japanese Patent Laid-Open No. 2004-228561 has a configuration in which the occurrence of an abnormality in the semiconductor switching element and the end of the abnormality are transmitted with a short pulse signal. For example, if an abnormality occurs at different timings in two semiconductor switching elements, a short pulse signal is input twice to the control device 40. In this case, the first short pulse signal indicating an abnormality in the first semiconductor switching element is determined to be abnormal, and the second short pulse signal indicating an abnormality in the second semiconductor switching element is determined to be the end of the abnormality. The For this reason, it is erroneously determined that the abnormality has ended although the abnormality has continued in the two semiconductor switching elements.

  In the plurality of switches SW used in the inverter device INV, the temperature of each switch SW can be regarded as substantially the same. Further, for example, if a detection value of a switch having the highest temperature among a plurality of switches SW used in the inverter device INV is acquired and control is performed so that the detection value becomes a predetermined value or less, for all the switches SW, An excessive increase in temperature can be suppressed.

  Therefore, the control device 40 is configured to acquire only the temperature of the switch SW connected to the same reference potential as that of the first drive circuit Da. Further, in the above configuration, a signal indicating the temperature information of the switch SW corresponding to the first drive circuit Da and a signal indicating the abnormality information of the switch SW corresponding to the first drive circuit Da and the second drive circuit Db are provided. It is output via the same route (connection point P6). By adopting a configuration for outputting a plurality of signals through the same path, the circuit configuration can be simplified.

  Moreover, according to the said structure, switch SW will be driven at the switching speed according to each speed signal. For this reason, for example, it is possible to suppress power loss in the switch SW while suppressing application of an excessive voltage to the switch SW. Furthermore, the number of insulating elements used for connection between the control device 40 and the drive circuit D can be reduced by using the speed signal as the synchronization signal. That is, erroneous determination of abnormality information can be suppressed while simplifying the circuit configuration.

  Further, in the above configuration, the signal representing the temperature information and the signal representing the abnormality information are output in synchronization with the speed information, and the signal representing the abnormality information is output during a period in which the signal representing the temperature information is not output. The configuration was started. Thereby, the control device 40 can determine whether the signal transmitted from the drive circuits Da and Db is information representing temperature information or information representing abnormality information. Further, by using the speed signal as the synchronization signal, the number of magnetic couplers M used for connection between the control device 40 and the drive circuits Da and Db can be reduced. That is, erroneous determination of abnormality information can be suppressed while simplifying the circuit configuration.

  The output signal of the temperature information transmitter 21 of the first drive circuit Da and the output signal of the abnormality information transmitter 22 of the first drive circuit Da are ORed on the first drive circuit Da side with respect to the magnetic coupler Ma. In addition, it is output to the magnetic coupler Ma. As a result, the number of magnetic couplers Ma used between the first drive circuit Da and the control device 40 can be reduced.

  The magnetic couplers Ma and Mb are open drain outputs, and the output signal of the first drive circuit Da and the output signal of the second drive circuit Db are wired OR more on the control device 40 side than the magnetic couplers Ma and Mb. As a result of the logical sum being taken, the result is output to the control device 40. By connecting the outputs of the open drain magnetic couplers Ma and Mb, a logical sum (wired OR) can be obtained with a simple configuration.

(Second Embodiment)
The electrical configuration of this embodiment is the same as that of the first embodiment. The drive circuits Da and Db in the present embodiment output a signal representing abnormality information so as not to interfere with a signal representing temperature information. Specifically, as shown in FIG. 7, the period from time T20 to T22 and time T24 to T26 is a period for outputting a pulse representing temperature information, and the period from time T22 to T24 in which a pulse representing temperature information is not output. Is a period during which a pulse representing abnormality information is output. Thereby, the control device 40 can acquire both the temperature information and the abnormality information while outputting the signal representing the temperature information and the signal representing the abnormality information through the same path.

(Third embodiment)
The drive circuit D in the first and second embodiments outputs a signal representing temperature information and a signal representing abnormality information in synchronization with the speed signal received from the control device 40. In the present embodiment, each of the drive circuits D has a clock circuit DC (internal oscillation circuit) instead of the configuration. The clock circuit DC is a circuit that outputs a pulse signal (clock signal) output at a predetermined cycle by applying a voltage to a vibrator (for example, a crystal vibrator or a ceramic vibrator).

  When there is no periodic pulse signal input to the terminal CLK (clock signal input terminal) of the drive circuit D, the drive circuit D is synchronized with the clock signal output from the clock circuit DC of the drive circuit D. Then, a signal representing temperature information and a signal representing abnormality information are output. In addition, when a periodic pulse signal is input to the terminal CLK, the drive circuit D outputs a signal representing temperature information and a signal representing abnormality information in synchronization with the periodic pulse signal. Do. Specifically, when a periodic pulse signal is input to the terminal CLK, the drive circuit D of the present embodiment is synchronized with the rising edge of the periodic pulse signal and a signal indicating temperature information and an abnormality A signal representing information is output.

  In other words, the drive circuit D outputs a signal in synchronization with the synchronization signal output from the clock circuit DC (internal oscillation state) depending on whether or not a periodic pulse signal is input to the terminal CLK, and inputs to the terminal CLK. The state of outputting a signal (clock input state) is switched in synchronization with the received signal. Further, the switching between the internal oscillation state and the clock input state of the drive circuit D may be performed, for example, by pulling up or pulling down a predetermined terminal included in the drive circuit D.

  FIG. 8 is a schematic diagram showing the connection between the drive circuits Da and Db and the control device 40 in the present embodiment. The same components as those shown in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. Among the plurality of drive circuits D, one first drive circuit Da is in an internal oscillation state, and a second drive circuit Db different from the first drive circuit Da is in a clock input state. The control system includes a plurality of second drive circuits Db. In FIG. 8, only one of the second drive circuits Db is shown, and the other second drive circuits Db are omitted.

  The first drive circuit Da outputs a temperature information signal and an abnormality information signal in synchronization with the clock circuit DC included in the first drive circuit Da. When the first drive circuit Da is normal, the abnormality information signal output from the abnormality information transmission unit 22 is in a high impedance state, so that the signal at the connection point P3 is the same as the temperature information signal output from the temperature information transmission unit 21. become.

  The signal of the connection point P6 is input to the clock signal input terminal CLK of the second drive circuit Db via the magnetic coupler Md. When the drive circuits Da and Db are both normal, the signals output from the drive circuits Da and Db are both in a high impedance state. Therefore, the temperature information transmitting unit 21 of the first drive circuit Da receives the signal at the connection point P6. It becomes the same as the temperature information signal to be output. That is, when both the drive circuits Da and Db are normal, the temperature information signal output from the temperature information transmission unit 21 of the first drive circuit Da is input to the clock signal input terminal CLK of the second drive circuit Db. From the temperature information transmission unit 21 of the first drive circuit Da, a pulse signal representing temperature information is output every two cycles of the clock signal output from the clock circuit DC. Thereby, the abnormality information transmission part 22 of the 2nd drive circuit Db outputs abnormality information synchronizing with the temperature information signal which the temperature information transmission part 21 of the 1st drive circuit Da outputs.

  More specifically, the second drive circuit Db is synchronized with the rise of the temperature information signal output from the temperature information transmission unit 21 of the first drive circuit Da (corresponding to times T10 and T14 in FIG. 5). Then, the second drive circuit Db divides the period in which the temperature information signal rises into the first period and the latter period, and the abnormality information transmission unit 22 of the second drive circuit Db is in a later period, which is a period in which a signal representing temperature information is not output Then, the output of the signal representing the abnormality information is started. When the period in which the temperature information signal rises is divided into the first and second periods, the first period corresponds to times T10 to T12 in FIG. 5, and the second period corresponds to T12 to T14 in FIG. The first and second periods correspond to one cycle of the clock signal output from the clock circuit DC.

  In the configuration of the present embodiment, a signal for synchronizing with a second drive circuit Db different from the first drive circuit Da in synchronization with the clock signal of the clock circuit DC included in one of the drive circuits D. Can be output. Further, since the temperature information signal output from the first drive circuit Da is also used as a signal for synchronization with the other second drive circuit Db, the number of magnetic couplers provided corresponding to the first drive circuit Da is reduced. be able to.

  Further, when the abnormality information signal output from the abnormality information transmission unit 22 of the second drive circuit Db is low (true), the signal at the connection point P6 is low. As a result, there is a concern that the abnormality information signal output from the abnormality information transmitter 22 of the second drive circuit Db is handled as a synchronization signal by the second drive circuit Db. Therefore, as in the first embodiment, the abnormality information transmission unit 22 of the present embodiment outputs a pulse indicating temperature information (after time T14) when it is determined that an abnormality has occurred in the switch SW. Also, the output of the signal representing the abnormality information is continued. Thereby, it can suppress that the abnormal information signal output from the abnormal information transmission part 22 of 2nd drive circuit Db is handled as a signal for a synchronization by 2nd drive circuit Db.

  The clock signal of the clock circuit DC included in the first drive circuit Da may be output to the clock signal input terminal CLK of another second drive circuit Db via a magnetic coupler. When the clock signal of the clock circuit DC included in the first drive circuit Da is output to the clock signal input terminal CLK of the other second drive circuit Db via the magnetic coupler, as in the second embodiment, the drive circuits Da, Db may be configured to output a signal representing abnormality information so as not to interfere with a signal representing temperature information. The drive circuit D that outputs the temperature information signal may be different from the drive circuit D that outputs the clock signal.

(Other embodiments)
-Although the temperature information transmission part 21 of 1st Embodiment and 2nd Embodiment was set as the structure which outputs the pulse showing temperature information for every 2 periods of a speed signal, you may change this. The temperature information transmission part 21 is good also as a structure which outputs the pulse showing temperature information for every n period of a speed signal (n is arbitrary natural numbers). By setting n large, the period during which the abnormality information can be transmitted becomes longer, so that a signal representing the abnormality information can be transmitted from the drive circuits Da and Db to the control device 40 more quickly.

  Moreover, the temperature information transmission part 21 is good also as a structure which outputs the pulse showing temperature information in a predetermined period among one period of a speed signal. For example, a predetermined period (for example, the first X% period, X is an arbitrary value above 0% and less than 100%) in one period of the speed signal is set as a period for transmitting temperature information It is good also as composition to do. In this configuration, output of a signal representing abnormality information is started in a period other than a predetermined period in which temperature information is transmitted in one cycle of the speed signal.

  The temperature information transmission part 21 is good also as a structure which transmits temperature information other than a time ratio. For example, the temperature information may be transmitted by a digital signal representing a binary value of 0 and 1.

  -The above-mentioned composition may be applied to power converters other than an inverter device. For example, it may be applied to a DCDC converter device.

  As the insulating element, a photo coupler or a transformer may be used instead of the magnetic coupler. Further, a capacitive coupler may be used instead of the magnetic coupler. The capacitive coupler capacitively couples the receiving side and the transmitting side to insulate the receiving side and the transmitting side of the insulating element and transmit a signal received from the receiving side element to the transmitting side element. . The capacitive coupler has, for example, a capacitor as an element that capacitively couples the reception side and the transmission side.

  As the semiconductor switching element, a MOS-FET may be used instead of the IGBT.

  In the above configuration, the output signals of the temperature information transmission unit 21 and the abnormality information transmission unit 22 of the first drive circuit Da are configured to perform a logical OR by wired OR, but this is changed and a logical OR is performed by the logic circuit. It is good also as a structure to take. Similarly, the output signals of the magnetic couplers Ma and Mb are configured to take a logical sum by wired OR, but this may be changed and a logical sum may be obtained by a logic circuit.

  The magnetic coupler and the temperature information transmission unit and abnormality information transmission unit of the drive circuit may be open collector outputs instead of open drain outputs. Further, it may be a totem pole output.

  DESCRIPTION OF SYMBOLS 21 ... Temperature information transmission part (1st transmission part), 22 ... Abnormal information transmission part (2nd transmission part), 40 ... Control apparatus, D ... Drive circuit, Da ... 1st drive circuit, Db ... 2nd drive circuit, INV... Inverter device, SW, SWp1 to SWp3, SWn1 to SWn3... Switching element, Ma, Mb, Mc, Md, Mp1 to Mp3, Mn1 to Mn3.

Claims (9)

Control applied to a power conversion device (INV) including a plurality of semiconductor switching elements (SW, SWp1 to SWp3, SWn1 to SWn3) connected to different reference potentials, and controls open / close states of the plurality of semiconductor switching elements A control system for a power converter comprising the device (40),
A plurality of drive circuits (Da, Db, Dp1 to Dp3, Dn1 to Dn3) respectively connected to the reference potential corresponding to the semiconductor switching elements and driving the corresponding semiconductor switching elements;
The control device and the plurality of drive circuits are insulated from each other, and the control device and the plurality of drive circuits are respectively separated from first insulating elements (Ma, Mb, Mp1 to Mp3, Mn1 to Mn3). Connected through
The plurality of drive circuits are synchronized by a predetermined synchronization signal via second insulating elements (Mc, Md, Mp1 to Mp3, Mn1 to Mn3), and the semiconductor switching corresponding to each of the plurality of drive circuits Drive each element,
As the plurality of drive circuits, in synchronization with the synchronization signal, a first transmission unit (21) that transmits a signal representing temperature information of the corresponding semiconductor switching element to the control device, and in synchronization with the synchronization signal A first driving circuit (Da) including a second transmission unit (22) for transmitting a signal representing abnormality information of the corresponding semiconductor switching element to the control device, and a second including the second transmission unit. A drive circuit (Db),
The output signals of the first transmission unit of the first drive circuit, the second transmission unit of the first drive circuit, and the second transmission unit of the second drive circuit are ORed. , Output to the control device via the same path,
The second transmission unit starts outputting a signal representing the abnormality information in a period in which the signal representing the temperature information is not output in response to the synchronization signal,
The control device determines whether an abnormality has occurred in the semiconductor switching element based on signals input from the first drive circuit and the second drive circuit in a period in which a signal representing the temperature information is not output. A control system for a power conversion device to judge.   The said 2nd transmission part transmits the signal showing the said abnormality information to the said control apparatus in the period when the signal showing the said temperature information transmitted to the said control apparatus from the said 1st transmission part is not output. Power converter control system.   The output signal of the first transmission unit of the first drive circuit and the output signal of the second transmission unit of the first drive circuit are logically ORed on the first drive circuit side with respect to the first insulating element. The control system for the power conversion device according to claim 1, wherein the control system outputs the power to the insulating element. The insulating element is an open collector output or an open drain output,
The output signal of the first drive circuit and the output signal of the second drive circuit are logically ORed by taking wired or more on the control device side than the first insulating element, The control system for a power converter according to any one of claims 1 to 3, wherein the control system is output to the controller.   5. The power according to claim 1, wherein the first transmission unit transmits temperature information of the semiconductor switching element to the control device at a time ratio at which an output signal is high or low in a predetermined cycle. Control system for conversion equipment.   The control system of a power converter according to any one of claims 1 to 5, wherein the control device and the plurality of drive circuits communicate in synchronization with the synchronization signal.   The control system for a power converter according to any one of claims 1 to 6, wherein a pulsed speed signal representing a switching speed of the semiconductor switching element is used as the synchronization signal.   The control system of a power converter according to any one of claims 1 to 7, wherein the control device transmits the synchronization signal to the plurality of drive circuits via the second insulating element.   One drive circuit among the plurality of drive circuits transmits the synchronization signal to the drive circuit different from the one drive circuit through the second insulating element. The control system of the power converter device as described in the item.

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