Electric power conversion device

Abstract

An abnormality selection circuit according to the present invention comprises: a plurality of signal output circuits that are connected on the respective input lines of a plurality of abnormality signals, the plurality of signal output circuits switching an output possibility in accordance with a signal inputted from a switching terminal; and a plurality of prescribed terminals that are provided between the switching terminals of the plurality of signal output circuits and the input unit of another abnormal signal. The abnormality selection circuit is configured to be capable of transmitting the other abnormality signal to the switching terminal between the plurality of prescribed terminals connected to the switching terminals of the plurality of signal output circuits and an input unit of another abnormal signal having a higher priority.

Description

Power Conversion Device

[0001] The present invention relates to a power conversion device, and is suitable for application to a power conversion device relating to a technology for outputting an abnormality signal by prioritizing multiple abnormal states that may occur simultaneously, for example.

[0002] In a typical power conversion device, a predetermined protective action is taken when an abnormal state is detected. For example, the power conversion device disclosed in Patent Document 1 includes a first abnormality detection unit that detects overvoltage, overcurrent, and temperatures of the upper and lower arms to detect an abnormality in the inverter unit, and a second abnormality detection unit that detects abnormalities in each of the semiconductor switching elements constituting the upper arm and the lower arm to detect an abnormality in the inverter unit. When an abnormal signal is detected by the first abnormality detection unit or the second abnormality detection unit, a drive control unit takes a predetermined protective action (e.g., a three-phase short or a six-phase open) for the arms. Furthermore, in the power conversion device disclosed in Patent Document 1, a switch for changing the priority of the upper arm three-phase short and the lower arm three-phase short can be provided in an arm selection circuit of the three-phase short drive signal control logic, thereby changing the priority of the upper arm three-phase short signal and the lower arm three-phase short signal.

[0003] Republished Patent No. 2012 / 077187

[0004] However, while the technology disclosed in Patent Document 1 can set the priority of short-circuit signals for performing the above-mentioned predetermined protective operation, it cannot specify the priority of which abnormality among multiple abnormal conditions that may occur simultaneously should be prioritized. Recently, such priorities have been changed at the customer's request, which requires large-scale circuit design changes. Furthermore, in circuit configurations using large-scale integrated circuits (ICs) such as complex programmable logic devices (CPLDs), large-scale specification changes are required when replacement of ICs is required due to end-of-production (EOP) or semiconductor shortages, making it difficult to change the above-mentioned priorities inexpensively.

[0005] The present invention has been made in consideration of the above points, and aims to propose a power conversion device that can change the priority of abnormality signals output in response to multiple abnormal conditions at low cost without requiring any changes to the circuit pattern.

[0006] In order to solve this problem, the present invention provides a power conversion device that converts power by switching a plurality of switching elements and includes a protection circuit that causes the plurality of switching elements to perform a predetermined protection operation based on an abnormal state, wherein the protection circuit includes an abnormality selection circuit that, when a plurality of abnormality signals that represent the abnormal state are input, selectively outputs an abnormality signal that represents one of the abnormal states in accordance with a predetermined priority, and a signal switching circuit that switches drive control signals for the plurality of switching elements so as to perform the predetermined protection operation based on the abnormality signal that represents the one abnormal state output by the abnormality selection circuit, wherein the abnormality selection circuit has a plurality of signal output circuits that are connected to input lines of the plurality of abnormal signals and switch whether to output or not in accordance with a signal input from a switching terminal, and a plurality of predetermined terminals that are provided between the switching terminals of the plurality of signal output circuits and an input unit for another abnormal signal, and is configured so that the other abnormal signal can be transmitted to the switching terminal between the plurality of predetermined terminals connected to the switching terminals of the plurality of signal output circuits and the input unit for the other abnormal signal having a higher priority.

[0007] According to the present invention, changing the priority of abnormality signals output in response to a plurality of abnormal states can be achieved at low cost without requiring any change to the circuit pattern.

[0008] 1 is a block diagram showing an example of the configuration of a power conversion device according to the present embodiment. FIG. 2 is a block diagram showing an example of the configuration of a protection circuit which is a part of the safety logic circuit shown in FIG. 1. FIG. 3 is a diagram showing an example of the priority of abnormality signals which can be set according to the attachment / detachment state of a jumper to a signal switching unit. FIG. 4 is a diagram showing an example of the relationship between two output signals of a signal switching circuit and statuses.

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] FIG. 1 is a block diagram showing an example of the configuration of a power conversion device 100 according to this embodiment. In the illustrated example, characters (e.g., "LV Lost") shown near signal lines mainly indicate the names of signals. In this embodiment, a motor drive device for a hybrid vehicle (hereinafter abbreviated as "vehicle") will be described as an example of the power conversion device (hereinafter also referred to as "inverter") 100. Note that this embodiment can also be applied to power conversion devices other than the motor drive device for a hybrid vehicle. First, the schematic configuration of the inverter 100 will be described.

[0011] The inverter 100 has the function of converting DC voltage into AC voltage by switching six-phase switching elements as an example of a plurality of switching elements, specifically, three-phase switching elements on the upper arm side and three-phase switching elements on the lower arm side.

[0012] The inverter 100 is connected to a control device 108, an LV battery 109, an HV battery 102, and a motor 101. The control device 108 has a function of performing vehicle communication (corresponding to "vehicle communication" shown in the figure) with a CAN circuit 209 of the inverter 100. The HV battery 102 is a DC voltage power source for driving the motor 101. The motor 101 is driven by the inverter 100.

[0013] The inverter 100 includes at least a safety logic circuit 200, a microcontroller 201, a gate driver 202, a three-phase power module (hereinafter abbreviated as "power module") 203, an AC (Alternating Current) sensor 204, an HVAC current monitor 205, and an HVDC voltage monitor 206, as well as a power supply 211, an LV monitor 208, an IGN (Ignition) monitor 210, a CAN circuit 209, etc. The gate driver may also be abbreviated as "GD." The following description will focus on the main parts of this embodiment.

[0014] The microcontroller 201 receives as inputs the detected value of the output of the LV battery 109 by the LV monitor 208, an IGN (Ignition) signal detected by the IGN monitor 210, a vehicle communication signal with the CAN circuit 209, an FOV signal as an example of an output signal and an abnormality signal from the HVDC voltage monitor 206, a GD Fault signal from the gate driver 202, an FOC signal as an example of an output signal and an abnormality signal from the HVAC current monitor 205, the temperature value of the motor 101 by the motor temperature monitor 213, and a rotor position signal indicating the rotational position of the motor 101 by the rotor position monitor 212.

[0015] The microcontroller 201 outputs a μc fail signal indicating its own abnormal state to the safety logic circuit 200 as an example of an abnormality signal, and outputs a PWM (Pulse Width Modulation) control signal for controlling the motor 101 to the gate driver 202. The gate driver 202 has a gate driver (Upper) for the upper arm switching elements and a gate driver (Lower) for the lower arm switching elements. Hereinafter, when there is no need to distinguish between the two gate drivers, they will be collectively referred to as the gate driver 202.

[0016] The microcontroller 201 outputs PWM commands to the safety logic circuit 200. The microcontroller 201 outputs, for example, PWM commands for a plurality of switching elements on the upper arm side and PWM commands for a plurality of switching elements on the lower arm side. These PWM commands are used by the safety logic circuit 200 to transition the inverter 100 to a safe state in response to a command from the microcontroller 201.

[0017] The gate driver 202 outputs a gate drive signal to the power module 203 in response to a PWM control signal input from the microcontroller 201. The gate driver 202 converts the DC voltage input from the HV battery 102 into a three-phase AC voltage consisting of U-phase, V-phase, and W-phase by switching the power module 203 in accordance with this gate drive signal. The gate driver 202 controls the motor 101 by inputting this three-phase AC voltage to the motor 101. An AC sensor 204 is provided between the gate driver 202 and the motor 101. The AC sensor 204 detects each of the three-phase HVAC currents flowing between the gate driver 202 and the motor 101.

[0018] Furthermore, the gate driver 202 monitors the current value of the current flowing through the power module 203 and the voltage of the HV battery 102. When the gate driver 202 detects an abnormality in any of these, it outputs, for example, a GD (Gate Driver) Fault signal as an example of an abnormality signal to the microcontroller 201 and the safety logic circuit 200.

[0019] The HVAC current monitor 205 monitors each of the three-phase HVAC currents detected by the AC sensor 204 and outputs the results to the microcontroller 201. If the HVAC current monitor 205 detects an abnormality in the HVAC current, it outputs an abnormality signal to the microcontroller 201 and the safety logic circuit 200. Such an abnormality may be, for example, an overcurrent (corresponding to the "FOC" signal in the illustrated example).

[0020] The HVDC voltage monitor 206 monitors the voltage of the HV battery 102 and outputs the voltage value to the microcontroller 201. If an abnormality in the HV battery 102 is detected, an abnormality signal indicating the type of abnormal state (for example, an FOV signal indicating an overvoltage in the illustrated example) is output to the microcontroller 201 and the safety logic circuit 200.

[0021] The LV monitor 208 monitors the output voltage of the LV battery 109 and outputs the value of the output voltage to the microcontroller 201. When the LV monitor 208 detects an abnormal state indicating loss of the LV battery 109, for example, when the vehicle equipped with the inverter 100 is involved in a collision, the LV monitor 208 outputs an LV Lost signal, which is an example of an abnormality signal, to the safety logic circuit 200.

[0022] The safety logic circuit 200 is a group of circuits that determine the results of an abnormal state based on each abnormal signal and a command from the microcontroller 201, output a three-phase short (AKS) or six-phase open (FW) signal (corresponding to the "3-phase short Freewheel Signal" shown in the figure) to the gate driver 202, and transition the inverter 100 to a safe state. "PWM" indicates that PWM control continues. That is, the state includes the following four states: PWM, which indicates a normal state; AKS-H (safe state), which indicates a short in the three-phase switching elements on the upper arm; AKS-L (safe state), which indicates a short in the three-phase switching elements on the lower arm; and FW (safe state), which indicates an open in the six-phase switching elements.

[0023] In this embodiment, as described above, there are a plurality of abnormality signals, but as shown below, priorities are set so that a plurality of abnormality signals can be output. Specific explanations are given below.

[0024] 2 is a block diagram showing an example of the configuration of a protection circuit that is a part of the safety logic circuit 200 shown in FIG. This embodiment is characterized by a configuration that allows the priority of an abnormality signal that triggers a predetermined protection operation to be easily switched by switching a switching unit (a jumper resistor or switching element, described later). In the illustrated example, "R" represents a resistor and indicates, for example, a high impedance state, and "0Ω" represents a resistor and indicates, for example, a low impedance state (including 0Ω). Also in the illustrated example, "OE" represents an output enable signal that is input to an output enable terminal, as an example of a switching terminal, to switch the output of a three-state buffer, as an example of a signal output circuit, described later. " / (OE)" represents an inverted signal (of the output enable signal).

[0025] This embodiment is characterized in that a protection circuit having the following configuration and operation is provided as part of the safety logic circuit 200. The safety logic circuit 200 mainly includes at least an abnormality selection circuit 301 and a signal switching circuit 401. First, an overview of the power conversion device 100 will be described.

[0026] The abnormality selection circuit 301 is a circuit that determines the priority of the abnormality signals A, B, and C using the signal switching unit 302. Note that the abnormality signals A, B, and C represent the respective abnormality signals output from the HVAC current monitor 205 and the like, but the abnormality signals A, B, and C may also be abnormality signals input from, for example, the HVDC voltage monitor 206. The abnormality selection circuit 301 is provided with jumper terminals, and by switching these terminals, the priority of the abnormality signals can be changed. That is, in this embodiment, by switching the jumper resistors of the abnormality selection circuit 301, the ON / OFF states of the multiple switching elements (power modules 203) on the upper arm side and the ON / OFF states of the multiple switching elements (power modules 203) on the lower arm side can be switched to patterns corresponding to predetermined safe operation.

[0027] The signal switching circuit 401 is a circuit for executing a predetermined protective operation (transition to a safe state) based on the abnormality signal indicating an abnormal state output by the abnormality selection circuit 301. The signal switching circuit 401 receives the PWM command (Upper) and the PWM command (Lower), and may also receive the abnormality signals A, B, and C output from the abnormality selection circuit 301 as described above.

[0028] The signal switching circuit 401 includes three-state buffers 470 , 460 , and 450 , and three-state buffers 471 , 461 , and 451 .

[0029] The three-state buffer 470 receives the PWM command (Upper) and also receives the abnormality signal C as an output enable signal. Therefore, the three-state buffer 470 can output the PWM command (Upper) to the input side of the three-state buffer 460 only when the abnormality signal C is a Lo signal.

[0030] The three-state buffer 460 receives the output of the three-state buffer 470 and also receives the abnormality signal B as an output enable signal. Therefore, the three-state buffer 460 can output the PWM command (Upper) to the input side of the three-state buffer 450 only when the abnormality signal B is a Lo signal.

[0031] The three-state buffer 450 receives the output of the three-state buffer 460 and also receives the abnormality signal A as an output enable signal. Therefore, the three-state buffer 450 can output the PWM command (Upper) as the output abnormality signal CTR_1 to the Upper side of the gate driver 202 only when the abnormality signal A is a Low signal.

[0032] The three-state buffer 471 receives the PWM command (Lower) and also receives the abnormality signal C as an output enable signal. Therefore, the three-state buffer 471 can output the PWM command (Lower) to the input side of the three-state buffer 461 only when the abnormality signal C is a Lo signal.

[0033] The three-state buffer 461 receives the output of the three-state buffer 470 and also receives the abnormality signal B as an output enable signal. Therefore, the three-state buffer 461 can output the PWM command (Lower) to the input side of the three-state buffer 451 only when the abnormality signal B is a Lo signal.

[0034] The three-state buffer 451 receives the output of the three-state buffer 460 and also receives the abnormality signal A as an output enable signal. Therefore, the three-state buffer 451 can output a PWM command (Lower) to the lower side of the gate driver 202 as the output abnormality signal CTRL_2 only when the abnormality signal A is a Lo signal.

[0035] The power conversion device 100 according to this embodiment converts power by switching a plurality of switching elements, and includes a protection circuit that causes the plurality of switching elements to perform a predetermined protection operation based on an abnormal state. The protection circuit includes an abnormality selection circuit 301 that, when a plurality of abnormality signals indicating abnormal states are input, selectively outputs an abnormality signal indicating one of the abnormal states in accordance with a predetermined priority, and a signal switching circuit 401 that switches the drive control signals of the plurality of switching elements so as to perform the predetermined protection operation based on the abnormality signal indicating one of the abnormal states output by the abnormality selection circuit 301.

[0036] The abnormality selection circuit 301 includes three-state buffers 350, 360, and 370 as an example of a plurality of signal output circuits that are connected to input lines 350z, 360z, and 370z of the plurality of abnormal signals, and that switch whether to output or not in response to output enable signals that are an example of signals input from output enable terminals 350a, 360a, and 370a that are an example of switching terminals, and a plurality of predetermined terminals provided between the output enable terminals 350a, 360a, and 370a of the three-state buffers 350, 360, and 370 and the input section of another abnormal signal (for example, the input section of the abnormality signal BorC), and is configured so that the other abnormal signal can be transmitted to the output enable terminals 350a, 360a, and 370a between the plurality of predetermined terminals (for example, jumper terminals, described later) connected to the output enable terminals 350a, 360a, and 370a of the three-state buffers 350, 360, and 370a and the input section of the other abnormal signal having a higher priority.

[0037] More specifically, the abnormality selection circuit 301 has, as the plurality of specified terminals described above, a plurality of jumper terminals into which jumpers, as an example of connecting members, can be inserted, and at least one jumper is inserted between the plurality of jumper terminals connected to the output enable terminals 350 a, 360 a, 370 a of the three-state buffers 350, 360, 370 and the input section for another abnormality signal having a higher priority, so that the other abnormality signal can be transmitted to the output enable terminals 350 a, 360 a, 370 a.

[0038] That is, in this embodiment, the priority of the abnormal signal can be changed by switching the jumper resistor by inserting a jumper. In order to enable transmission of the abnormal signal to the output enable terminals 350 a, 360 a, and 370 a of the three-state buffers 350, 360, and 370 between the inputs of other abnormal signals with higher priorities, jumpers are inserted, and the output of the abnormal signal that is desired to have a lower priority is disabled, so that the abnormal signal that is desired to have a higher priority can be output preferentially.

[0039] In this embodiment, among the multiple jumper terminals connected to the output enable terminals 350 a, 360 a, and 370 a of the three-state buffers 350, 360, and 370, no jumpers are inserted between the input terminals of other abnormal signals with lower priorities. In other words, by not inserting jumpers between the inputs of other abnormal signals with lower priorities, the influence of low-priority abnormal signals input to the output enable signal of an abnormal signal whose priority is desired to be high is nullified, and the priority order of the abnormal signals is determined. In this way, even if the priorities of multiple abnormal signals are changed, the priority of some of the abnormal signals can be lowered by not inserting jumpers as described above, making it possible to change the priority at low cost without changing the circuit pattern.

[0040] In this embodiment, a jumper or the like having a predetermined resistance value or more is inserted between the input of another abnormal signal having a lower priority among the multiple jumper terminals connected to each output enable terminal 350 a, 360 a, 370 a of the multiple three-state buffers 350, 360, 370 a, so that the other abnormal signal cannot be substantially transmitted to each output enable terminal 350 a, 360 a, 370 a.

[0041] In the following embodiments, "mounting" refers to attaching a jumper across multiple jumper terminals to short-circuit the multiple jumper terminals, while "not mounting" refers to removing a jumper from the multiple jumper terminals to insulate the multiple jumper terminals.

[0042] In this embodiment, instead of using the jumper described above, the following may be adopted. For example, taking the jumper resistor R_B1 as an example, even if the abnormal signal B at the input section of the abnormal signal B indicates an abnormal state (e.g., a 5V output state), instead of leaving the jumper resistor R_B1 "unmounted," the resistance ratio between the jumper resistor R_B1 and the resistor R is set to, for example, a resistance ratio that is equal to or lower than the threshold voltage at which the output enable terminal 350a of the three-state buffer 350 is enabled. For example, if the threshold voltage at which the output enable terminal 350a of the three-state buffer 350 is enabled is 0.9V or lower, the output voltage of the abnormal signal B in the abnormal state is 5V, and the resistance ratio between the jumper resistor R_B1 and the resistor R is 100:1, the voltage at the output enable terminal 350a of the three-state buffer 350 is approximately 0V, and the output enable terminal 350a remains enabled. In other words, when the jumper resistor R_B1 is "unmounted," i.e., when the output enable terminal 350a of the three-state buffer 350 is in an enabled state, the same effect can be obtained. The same is true for the other jumper resistors R_A1, R_A2, R_B2, R_C1, and R_C2. In this way, even without using the jumpers described above, the same effect can be obtained as when the jumpers are used.

[0043] In the present embodiment, the signal switching circuit 401 includes three-state buffers 470, 460, 450 and three-state buffers 471, 461, 451 as an example of a pair of three-state buffers, each of which includes output enable terminals 470 a, 460 a, 450 a, 471 a, 461 a, 451 a that are provided in plurality corresponding to each of the plurality of abnormal signals and to which a corresponding abnormal signal from among the plurality of abnormal signals is input, and a state switching circuit that switches the ON / OFF state of a plurality of switching elements on an upper arm side and the ON / OFF state of a plurality of switching elements on a lower arm side among the plurality of switching elements to a three-phase short or a six-phase open as an example of a pattern corresponding to a predetermined protection operation when each output of the pair of three-state buffers 470, 460, 450, 471, 461, 451 is in a high impedance state.

[0044] That is, in this embodiment, by inputting individual abnormality signals to output enable terminals 470 a, 460 a, 450 a, 471 a, 461 a, and 451 a of three-state buffers 470, 460, 450, 471, 461, and 451 of signal switching circuit 401, when the output of abnormality selection circuit 301 transitions to an abnormal state, the output of the three-state buffer of signal switching circuit 401 becomes a high impedance state, and as a result, it is possible to disable the output of the state buffer circuit in the preceding stage (for example, the output of three-state buffer 450 with respect to three-state buffer 460). Also, by switching jumper resistors in signal switching circuit 401, it is possible to switch the ON / OFF states of the multiple switching elements on the upper arm side by power module 203 and the ON / OFF states of the multiple switching elements on the lower arm side by power module 203 to a predetermined protective operation, i.e., a safe operation pattern, based on the output signal of abnormality selection circuit 301.

[0045] In this way, the state switching circuit can switch the ON / OFF state of the multiple switching elements on the upper arm side and the ON / OFF state of the multiple switching elements on the lower arm side based on the output signal of the abnormality selection circuit 301, and perform a specified protective operation to transition to a safe state.

[0046] In the signal switching circuit 401, the above-mentioned state switching circuit is configured to be able to switch the outputs of three-state buffers 470, 460, 450 and three-state buffers 471, 461, 451 (e.g., corresponding to CTRL_1 and CTRL_2 in FIG. 4) as examples of a pair of three-state buffers to either a high state or a low state depending on whether a jumper as an example of a connecting member is inserted (i.e., "presence / absence").

[0047] In this embodiment, for example, three types of abnormalities can occur, and the signals indicating these three types of abnormalities are illustrated as abnormality signals A to C. Note that the number of types of abnormality signals may be greater or less than this.

[0048] The above-mentioned abnormality selection circuit 301 includes at least a signal switching unit 302 for switching whether or not to transmit a plurality of abnormality signals, and preferably includes a resistor (corresponding to "R" in the figure) and three-state buffers 350, 360, and 370.

[0049] The abnormality selection circuit 301 receives an LV Lost signal as an example of abnormality signal A, a μc fail signal as an example of abnormality signal B, and an FOV signal / FOC signal as an example of abnormality signal C. The above-mentioned LV Lost signal, μc fail signal, and FOV signal / FOC signal each become a Hi signal or a Lo signal. A Hi signal indicates an abnormality, and a Lo signal indicates normality. Note that in this embodiment, the abnormality signals are not limited to these, and may be abnormality signals indicating other abnormal states.

[0050] The output of the abnormality selection circuit 301 is connected to the signal switching circuit 401. Specifically, in the abnormality selection circuit 301, the output of the three-state buffer 350 is connected to output enable terminals 450a and 451a of the three-state buffers 450 and 451 of the signal switching circuit 401. The output of the three-state buffer 360 is connected to output enable terminals 460a and 461a of the three-state buffers 460 and 461 of the signal switching circuit 401. The output of the three-state buffer 370 is connected to output enable terminals 470a and 471a of the three-state buffers 470 and 471 of the signal switching circuit 401.

[0051] When the output of each three-state buffer 350, 360, 370 in the abnormality selection circuit 301 transitions to an abnormal state, the output of each corresponding three-state buffer 450, 451, 460, 461, 470, 471 in the signal switching circuit 401 becomes a high impedance state, and the voltage level of the output signal CTL_1 / CTL_2 becomes a signal level state corresponding to a predetermined safe operation.

[0052] The signal switching unit 302 has a jumper resistor R_B1 as an example of a switching unit 302B1, a jumper resistor R_C1 as an example of a switching unit 302C1, a jumper resistor R_A1 as an example of a switching unit 302A1, a jumper resistor R_C2 as an example of a switching unit 302C2, a jumper resistor R_A2 as an example of a switching unit 302A2, and a jumper resistor R_B2 as an example of a switching unit 302B2.

[0053] These switching units 302B1 and the like have the same configuration and function, and include, for example, an input-side jumper terminal, an output-side jumper terminal, and a jumper that can be attached or detached to both jumper terminals to short-circuit the two jumper terminals. That is, when jumpers are attached to both jumper terminals, these switching units 302B1 and the like can short-circuit the input-side and output-side jumper terminals to establish electrical continuity, while when jumpers are not attached to both jumper terminals, they can insulate the input-side and output-side jumper terminals to prevent electrical continuity. In the illustrated example, switching units marked with an "x" have their jumpers removed, and switching units not marked with an "x" have jumpers attached.

[0054] The abnormality signal A is input to the input side of the three-state buffer 350 and also input to jumper terminals on the input sides of jumper resistors R_A1 and R_A2. The abnormality signal B is input to the input side of the three-state buffer 360 and also input to jumper terminals on the input sides of jumper resistors R_B1 and R_B2. The abnormality signal C is input to the input side of the three-state buffer 370 and also input to jumper terminals on the input sides of jumper resistors R_C1 and R_C2.

[0055] The jumper terminals on the output side of jumper resistors R_B1 and R_C1 are connected to the input side of the output enable element of the three-state buffer 350, and the output signals of the jumper terminals on the output side of jumper resistors R_B1 and R_C1 are input as output enable signals of the three-state buffer 350.

[0056] Therefore, the three-state buffer 350 outputs an abnormality signal A when neither jumper resistor R_B1 nor jumper resistor R_C1 has a jumper installed, but does not output an abnormality signal A otherwise (when a jumper is installed in at least one of jumper resistor R_B1 and jumper resistor R_C1, or when jumpers are installed in both).

[0057] The jumper terminals on the output side of jumper resistors R_A1 and R_C2 are connected to the input side of the output enable element of the three-state buffer 360, and the output signals of the jumper terminals on the output side of jumper resistors R_A1 and R_C2 are input as output enable signals of the three-state buffer 360.

[0058] Therefore, the three-state buffer 360 outputs an abnormality signal B when neither jumper resistor R_A1 nor jumper resistor R_C2 has a jumper installed, but does not output an abnormality signal B otherwise (when a jumper is installed in at least one of jumper resistor R_A1 and jumper resistor R_C2, or when jumpers are installed in both).

[0059] The jumper terminals on the output side of jumper resistors R_A2 and R_B2 are connected to the input side of the output enable element of the three-state buffer 370, and the output signals of the jumper terminals on the output side of jumper resistors R_A2 and R_B2 are input as output enable signals of the three-state buffer 370.

[0060] Therefore, the three-state buffer 370 outputs an abnormality signal C when neither jumper resistor R_A2 nor jumper resistor R_B2 has a jumper installed, but does not output an abnormality signal C otherwise (when a jumper is installed in at least one of jumper resistor R_A2 and jumper resistor R_B2, or when jumpers are installed in both).

[0061] The three-state buffer 350 receives an abnormality signal A, and may also receive abnormality signals B and C as output enable signals. The three-state buffer 360 receives an abnormality signal B, and may also receive abnormality signals A and C as output enable signals. The three-state buffer 370 receives an abnormality signal C, and may also receive abnormality signals A and B as output enable signals.

[0062] FIG. 3 is a diagram showing an example of the priority order of abnormal signals that can be set depending on whether a jumper is attached to or detached from the signal switching unit 302. In FIG.

[0063] Pattern 1: When the priority of abnormal signals A, B, and C is A>B>C, jumper resistors R_A1, R_A2, and R_B2 are set to "implemented," and jumper resistors R_B1, R_C1, and R_C2 are set to "not implemented."

[0064] In this case, if the abnormality signal A transitions to a Hi signal (abnormal state), the output signals of the three-state buffers 360, 370 go into a high impedance state (Hi-Z), and the outputs of the three-state buffers 360, 370 are cut off.

[0065] When abnormality signal A is a Lo signal (normal state) and abnormality signal B transitions to a Hi signal (abnormal state), the output signal of three-state buffer 370 becomes a high impedance state (Hi-Z), and the output of three-state buffer 370 is blocked.

[0066] When abnormality signals A and B are Lo signals (normal state) and abnormality signal C transitions to Hi signal (abnormal state), the abnormality signal C is input as is to the signal switching circuit 401. In other words, by setting jumper resistors R_A1, R_A2, and R_B2 to "mounted" and jumper resistors R_B1, R_C1, and R_C2 to "not mounted," the priority order of abnormality signals A, B, and C can be A>B>C.

[0067] Pattern 2: When the priority of the abnormal signals A, B, and C is C>B>A, the jumper resistors R_B1, R_C1, and R_C2 are set to "implemented" and the jumper resistors R_A1, R_A2, and R_B2 are set to "not implemented."

[0068] In this case, if the abnormality signal C transitions to a Hi signal (abnormal state), the output signals of the three-state buffers 350 and 360 go into a high impedance state (Hi-Z) and are cut off.

[0069] When abnormality signal C is a Lo signal (normal state) and abnormality signal B transitions to a Hi signal (abnormal state), the output signal of three-state buffer 350 becomes a high impedance state (Hi-Z), and the output of three-state buffer 350 is blocked.

[0070] When the abnormality signals C and B are Lo signals (normal state) and the abnormality signal A transitions to Hi signal (abnormal state), the abnormality signal A is input as is to the signal switching circuit 401. In other words, by setting the jumper resistors R_B1, R_C1, and R_C2 to "mounted" and the jumper resistors R_A1, R_A2, and R_B2 to "not mounted," the priority order of the abnormality signals A, B, and C can be C>B>A.

[0071] As described above, by switching the jumper resistors as shown in FIG. 3, the priority of the abnormality signals A, B, and C can be easily changed without changing the design of the circuit pattern.

[0072] 4 is a diagram showing an example of the relationship between the two output abnormality signals CTRL_1 and CTRL_2 and the status (corresponding to "status" in the figure) of the signal switching circuit 401. The output abnormality signal CTRL_1 is input to the gate driver 202 (upper side) shown in FIG. 1, while the output abnormality signal CTRL_2 is input to the gate driver 202 (lower side) described above.

[0073] In the illustrated example, the signal switching circuit 401 outputs two output abnormality signals CTRL_1 and CTRL_2, and the protection circuit determines whether to activate a predetermined protection operation based on the status (corresponding to "status" in the figure) determined by these two output abnormality signals CTRL_1 and CTRL_2. Examples of such statuses include AKS-H, AKS-L, FW, and PWM. As described above, AKS-H and AKS-L indicate a three-phase short (AKS) command to the gate driver 202, and FW indicates a six-phase open (FW) command. PWM indicates that there is no abnormality and that PWM control will continue.

[0074] The power conversion device 100 according to this embodiment converts power by switching a plurality of switching elements, and includes a protection circuit that causes the plurality of switching elements to perform a predetermined protection operation based on an abnormal state. The protection circuit includes an abnormality selection circuit 301 that selectively outputs an abnormality signal that indicates one of the abnormal states in accordance with a predetermined priority when a plurality of abnormality signals that indicate abnormal states are input, and a signal switching circuit 401 that switches drive control signals for the plurality of switching elements so as to perform the predetermined protection operation based on the abnormality signal that indicates one of the abnormal states output by the abnormality selection circuit 301. The abnormality selection circuit 301 is connected to input lines 350z, 360z, and 370z of the plurality of abnormality signals, and determines whether to enable or disable output in accordance with an output enable signal that is an example of a signal that is input from output enable terminals 350a, 360a, and 370a that are examples of switching terminals. The circuit has three-state buffers 350, 360, 370 as an example of a plurality of signal output circuits to be switched, and a plurality of predetermined terminals provided between output enable terminals 350a, 360a, 370a of the three-state buffers 350, 360, 370 and an input section for another abnormal signal (for example, an input section for abnormal signal B or abnormal signal C), and is configured so that the other abnormal signal can be transmitted to the output enable terminals 350a, 360a, 370a between the plurality of predetermined terminals connected to the output enable terminals 350a, 360a, 370a of the three-state buffers 350, 360, 370 and the input section for the other abnormal signal having a higher priority.

[0075] More specifically, the abnormality selection circuit 301 has, as the plurality of specified terminals described above, a plurality of jumper terminals into which jumpers, as an example of connecting members, can be inserted, and at least one jumper is inserted between the plurality of jumper terminals connected to the output enable terminals 350 a, 360 a, 370 a of the three-state buffers 350, 360, 370 and the input section for another abnormality signal having a higher priority, so that the other abnormality signal can be transmitted to the output enable terminals 350 a, 360 a, 370 a.

[0076] In this way, even if the priorities of multiple abnormal signals change, the priorities of some of the abnormal signals can be raised without changing the circuit pattern, making it possible to change the priorities easily and inexpensively. This allows a vehicle in which multiple abnormalities may occur simultaneously to be stopped safely while taking into account the priorities of the abnormal conditions.

[0077] In this embodiment, no jumpers are inserted between the input terminals for other abnormal signals with lower priorities among the multiple jumper terminals connected to the output enable terminals 350 a, 360 a, and 370 a of the three-state buffers 350, 360, and 370. In this way, even if the priorities of multiple abnormal signals are changed, the priorities of some of the abnormal signals can be lowered by not inserting jumpers as described above, so that the priorities can be changed inexpensively without changing the circuit pattern.

[0078] In this embodiment, the connecting member having a predetermined resistance value or more that substantially prevents the transmission of the other abnormal signal to the switching terminal is inserted between the input of the other abnormal signal having a lower priority among the plurality of jumper terminals connected to the output enable terminals 350 a, 360 a, 370 a of the plurality of three-state buffers 350, 360, 370. In this way, the same effect as when the jumper is used can be achieved without using the above-mentioned jumper.

[0079] In this embodiment, the signal switching circuit 401 includes a pair of three-state buffers (three-state buffers 470, 460, 450 and three-state buffers 471, 461, 451) each including an output enable terminal to which a corresponding one of the plurality of abnormal signals is input, and a state switching circuit that switches the ON / OFF states of the upper-arm switching elements and the lower-arm switching elements among the plurality of switching elements to a three-phase short or a six-phase open circuit as an example of a pattern corresponding to a predetermined protective operation when the outputs of the pair of three-state buffers 470, 460, 450 and 471, 461, 451 are in a high impedance state. In this manner, the state switching circuit can switch the ON / OFF states of the upper-arm switching elements and the lower-arm switching elements among the plurality of switching elements based on the output signal of the abnormality selection circuit 301, thereby performing a predetermined protective operation involving a transition to a safe state.

[0080] In this embodiment, the state switching circuit of the signal switching circuit 401 is configured to switch the output abnormality signals CTRL_1 and CTRL_2 of the pair of three-state buffers 470, 460, 450 and 471, 461, 451 between a high state and a low state depending on whether or not a jumper, which is an example of a connecting member, is inserted (i.e., "presence or absence"). In this way, the voltage level can be set to a level required to perform a predetermined protective operation, thereby ensuring a transition to a safe state.

[0081] It should be noted that the present invention is not limited to the above-described embodiments, and includes various modifications and equivalent configurations within the spirit and scope of the appended claims. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations.

[0082] The power conversion device 100 according to the present embodiment may be configured such that switching elements are provided between a plurality of predetermined terminals connected to output enable terminals 350 a, 360 a, and 370 a (each of which is an example of a switching terminal of three-state buffers 350, 360, and 370) (each of which is an example of a plurality of signal output circuits) and an input unit for receiving other abnormal signals having higher priority, thereby enabling transmission of the other abnormal signals to the output enable terminals 350 a, 360 a, and 370 a by controlling the ON / OFF of the plurality of predetermined terminals. Specifically, the switching units 302B1, 302C1, 302A1, 302C2, 302A2, and 302B2 in the signal switching unit 302 described above are configured as the switching elements instead of jumper resistors. Even with this configuration, the same effect as that achieved by inserting a jumper can be achieved without physically inserting a jumper, as described above.

[0083] In the above-described embodiment, a three-phase power conversion device has been described as an example, but it is not necessarily three-phase, and can be applied to any power conversion device having multiple phases or more.

[0084] The present invention can be applied to a power conversion device relating to a technology for outputting an abnormality signal by prioritizing multiple abnormal states that may occur simultaneously.

[0085] 100...power conversion device, 301...abnormality selection circuit, 350, 360, 370...three-state buffer, 350a, 360a, 370a...output enable terminal of abnormality selection circuit, 350z, 360z, 370z...input line, 401...signal switching circuit, 450, 460, 470...three-state buffer, 450a, 460a, 470a...output enable terminal of signal switching circuit, 451, 461, 471...three-state buffer of signal switching circuit, 451a, 461a, 471a...output enable terminal, A, B, C...signal

Claims

1. A power conversion device that converts power by switching a plurality of switching elements and includes a protection circuit that causes the plurality of switching elements to perform a predetermined protection operation based on an abnormal state, wherein the protection circuit includes: an abnormality selection circuit that, when a plurality of abnormality signals that represent the abnormal state are input, selectively outputs an abnormality signal that represents one of the abnormal states in accordance with a predetermined priority; and a signal switching circuit that switches drive control signals for the plurality of switching elements so as to perform the predetermined protection operation based on the abnormality signal that represents the one abnormal state output by the abnormality selection circuit, wherein the abnormality selection circuit has: a plurality of signal output circuits that are connected to input lines of the plurality of abnormal signals and that switch output enable / disable in accordance with a signal input from a switching terminal; and a plurality of predetermined terminals that are provided between the switching terminals of the plurality of signal output circuits and an input unit for another abnormal signal, wherein the power conversion device is configured so that the other abnormal signal with a higher priority can be transmitted to the switching terminal between the plurality of predetermined terminals connected to the switching terminals of the plurality of signal output circuits and the input unit for the other abnormal signal with a higher priority.

2. The power conversion device according to claim 1, characterized in that the abnormality selection circuit has a plurality of jumper terminals into which connecting members can be inserted as the plurality of specified terminals, and the connecting members are inserted between the plurality of jumper terminals connected to each of the switching terminals of the plurality of signal output circuits and the input section of the other abnormal signal having a higher priority so as to enable the other abnormal signal to be transmitted to the switching terminal.

3. The power conversion device according to claim 2, characterized in that the connecting member is not inserted between the input section of another abnormal signal having a lower priority among the plurality of jumper terminals connected to the switching terminal of the plurality of signal output circuits.

4. The power conversion device according to claim 2, characterized in that the connecting member having a predetermined resistance value or more is inserted between the input of another abnormal signal having a lower priority among the plurality of jumper terminals connected to the switching terminal of the plurality of signal output circuits, so that the other abnormal signal cannot be substantially transmitted to the switching terminal.

5. The power conversion device according to claim 2, characterized in that the signal switching circuit comprises: a pair of three-state buffers, each provided in a corresponding one of the plurality of abnormality signals, and each including an output enable terminal to which a corresponding one of the plurality of abnormality signals is input; and a state switching circuit, when each output of the pair of three-state buffers is in a high impedance state, for switching the ON / OFF state of a plurality of switching elements on an upper arm side of the plurality of switching elements and the ON / OFF state of a plurality of switching elements on a lower arm side to a pattern corresponding to the predetermined protection operation.

6. The power conversion device according to claim 5, characterized in that the state switching circuit of the signal switching circuit is configured to be able to switch the output of the pair of three-state buffers to either a high state or a low state depending on whether the connecting member is inserted or not.

7. The power conversion device according to claim 1, characterized in that a switching element is provided between the plurality of predetermined terminals connected to the respective switching terminals of the plurality of signal output circuits and an input section for the other abnormal signal having a higher priority, which controls ON / OFF of the plurality of predetermined terminals to enable the other abnormal signal to be transmitted to the switching terminal.

Images