JP2022062861A - Power conversion device - Google Patents

Abstract

To provide a power conversion device that can make communication less frequent than before and detect an abnormal place earlier than before when a power circuit board and a control circuit board perform wireless communication with each other.SOLUTION: A power conversion device includes a power circuit board on which a power conversion circuit and a drive circuit that directly drives the power conversion circuit are mounted and a control circuit board on which a control circuit that controls the drive circuit is mounted. The power circuit board and the control circuit board perform wireless communication with each other. The power conversion device includes: an abnormality detection unit that is mounted on the power circuit board and at least determines abnormality of the power conversion circuit; a power-side communication unit that is mounted on the power circuit board and wirelessly transmits abnormality detection information output by the abnormality detection unit to the control circuit board; and a control-side communication unit that is mounted on the control circuit board, receives the abnormality detection information, and outputs it to the control circuit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power conversion device.

The following Patent Document 1 discloses a switch circuit capable of reducing the size of a control board and reducing the risk of wiring failure. This switch circuit includes a first board, a plurality of switching elements provided on the first board, and a plurality of drives provided on the first board to generate a drive signal for driving each of the plurality of switching elements. A gap is provided between the circuit and the plurality of power receiving side coils provided on the first board corresponding to each of the plurality of drive circuits and supplying power to the corresponding drive circuits, and the first board. A second board arranged to face the first board and a plurality of feeding side coils provided at positions of the second board overlapping with each of the plurality of power receiving side coils are provided.

Japanese Unexamined Patent Publication No. 2018-16432

By the way, in the above background technology, a drive circuit of a power circuit is arranged on a first board (power circuit board), and the drive circuit and a control circuit provided on the second board (control circuit board) communicate wirelessly. However, when an abnormality is determined for the first board (power circuit board) in the control circuit, communication is performed each time wireless communication is performed for each abnormality item (overcurrent, overvoltage, circuit failure, etc.), so the communication frequency There is a risk that abnormalities cannot be detected at an early stage.

The present invention has been made in view of the above-mentioned circumstances, and when the power circuit board and the control circuit board perform wireless communication, the communication frequency can be reduced as compared with the conventional case, and the abnormal portion can be set earlier than before. It is an object of the present invention to provide a power conversion device capable of detecting.

In order to achieve the above object, in the present invention, as a first solution for a power conversion device, a power circuit board on which a power conversion circuit and a drive circuit for directly driving the power conversion circuit are mounted, and the drive thereof. In a power conversion device having a control circuit board on which a control circuit for controlling a circuit is mounted and the power circuit board and the control circuit board perform wireless communication, the power circuit board is mounted on the power circuit board and an abnormality in the power conversion circuit is provided. An abnormality detection unit that detects at least the above, a power supply side communication unit that is mounted on the power circuit board and wirelessly transmits abnormality detection information output by the abnormality detection unit to the control circuit board, and a power supply side communication unit that is mounted on the control circuit board. A means of including a control-side communication unit that receives the abnormality detection information and outputs the abnormality detection information to the control circuit is adopted.

In the present invention, as a second solution relating to the power conversion device, in the first solution, the power side communication unit transmits a PWM signal having a different duty ratio according to the content of the abnormality detection information as a wireless transmission signal. The means of generating as is adopted.

In the present invention, as a third solution relating to the power conversion device, in the second solution, the power side communication unit includes a signal conversion circuit that outputs signals of different levels according to the abnormality detection information. A means of including a triangular wave generator that outputs a triangular wave having a predetermined period and a PWM signal generator that sets the duty ratio based on the output signal of the signal conversion circuit and the triangular wave is adopted.

In the present invention, as the fourth solution means for the power conversion device, in any one of the first to third solutions, the power circuit board is received by the power side communication unit from the control side communication unit. A means of providing a rectifier circuit that rectifies a pulse to generate a power source for the drive circuit is adopted.

In the present invention, as a fifth solution relating to the power conversion device, in any one of the first to fourth solutions, the power side communication unit and the control side communication unit are described from the control side communication unit to the control side communication unit. A means of including a first non-contact transformer for downlink communication to the power-side communication unit and a second non-contact transformer for uplink communication from the power-side communication unit to the control-side communication unit is adopted.

According to the present invention, when the power circuit board and the control circuit board perform wireless communication, a power conversion device capable of reducing the communication frequency as compared with the conventional one and detecting an abnormal part earlier than the conventional one can be provided. It is possible to provide.

It is a schematic diagram which shows the whole structure of the power conversion apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the functional structure of the power circuit board B in one Embodiment of this invention. In one embodiment of the present invention, there is a circuit diagram (a) showing the detailed configuration of the state signal generation circuit 6 in the power circuit board B, and a timing chart (b) showing the generation of the state signal J in the drive circuit b5. In one embodiment of the present invention, there is a characteristic table (a) showing the relationship between the state signal J and the duty ratio in the power circuit board B, and a characteristic table (b) showing the relationship between the gate pulse and the duty ratio.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The power conversion device according to the present embodiment is a device mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle, and supplies drive power (AC power) to, for example, a motor (travel motor) that generates traveling power. That is, this power conversion device converts DC power supplied from an assembled battery (not shown) such as a lithium ion battery into driving power (AC power) and supplies it to the traveling motor.

Such a power conversion device generates the above-mentioned drive power (AC power) under the control of a vehicle ECU (Electronic Control Unit) which is a higher-level control device, and as shown in FIG. 1, the control circuit board A and the power. A circuit board B is provided. The control circuit board A and the power circuit board B are housed in a predetermined metal casing, and drive power (AC power) is generated as a whole by performing bidirectional wireless communication.

The control circuit board A is a printed circuit board that functions as a control main body with respect to the power circuit board B that functions as a control target. As shown in the figure, the control circuit board A has a gate signal generation circuit a2, a pair of communication coils a3, a4, and a control circuit a5 mounted on the control wiring board a1. Such a control circuit board A has a flat plate shape as a whole, and faces the power circuit board B having a flat plate shape in a substantially parallel state.

On the other hand, the power circuit board B is a printed circuit board that functions as a control target of the control circuit board A. As shown in the figure, the power circuit board B has a pair of communication coils b2, b3, a rectifier circuit b4, a drive circuit b5, and a power conversion circuit b6 mounted on the power wiring board b1 at least. Such a power circuit board B has a flat plate shape as a whole, and faces the flat plate-shaped control circuit board A in a substantially parallel state.

Explaining the control circuit board A first, the control wiring board a1 is a printed wiring board provided with printed wiring for connecting various electronic components to each other. That is, the control wiring board a1 is a printed wiring that interconnects various electronic components constituting the gate signal generation circuit a2, the pair of communication coils a3, a4, and the control circuit a5. Such a control wiring board a1 is a multilayer board in which printed wiring is formed in multiple layers with an insulating layer interposed therebetween.

The gate signal generation circuit a2 generates a plurality of gate pulse signals that control the generation of drive power (AC power) in the power circuit board B. The power conversion circuit b6 of the power circuit board B is provided with a plurality of semiconductor switching elements (power elements) for generating drive power (AC power), and the gate signal generation circuit a2 is provided in each semiconductor switching element. Corresponds to generate multiple gate pulse signals.

The details will be described later, but if the power conversion circuit b6 is a full-bridge three-phase inverter, the power conversion circuit b6 has a total of six semiconductor switching elements for the upper arm and the lower arm of each phase. Be prepared. In the case of such a power conversion circuit b6, a total of six gate signal generation circuits a2 are provided corresponding to each of the six semiconductor switching elements.

This gate pulse signal is a PWM (Pulse Width Modulation) signal having a predetermined repetition period and having a duty ratio adjusted as necessary. By outputting such a gate pulse signal to the communication coil a3, the gate signal generation circuit a2 wirelessly transmits the gate pulse signal to the power circuit board B via the communication coil a3.

The pair of communication coils a3 and a4 are coils for performing wireless communication with the power circuit board B. Of these communication coils a3 and a4, one of the communication coils a3 is arranged close to the communication coil b2 of the power circuit board B as shown in the figure. The coil a3 is electromagnetically coupled to the communication coil b2 of the power circuit board B with a predetermined coupling coefficient, and the gate pulse signal input from the gate signal generation circuit a2 is not connected to the communication coil b2 of the power circuit board B. Contact transmission.

On the other hand, the other communication coil a4 is arranged close to the communication coil b3 of the power circuit board B. The communication coil a4 is electromagnetically coupled to the communication coil b3 of the power circuit board B with a predetermined coupling coefficient, and outputs a state signal non-contact transmitted from the communication coil b3 to the control circuit a5. Such a communication coil a4 corresponds to the control side communication unit of the present invention.

That is, the communication coil a3 of the control circuit board A and the communication coil b2 of the power circuit board B constitute a first non-contact transformer T1 that non-contactly transmits a gate pulse from the control circuit board A to the power circuit board B. .. On the other hand, the communication coil a4 of the control circuit board A and the communication coil b3 of the power circuit board B constitute a second non-contact transformer T1 that non-contactly transmits the state signal J from the power circuit board B to the control circuit board A. There is.

Here, FIG. 1 shows a pair of non-contact transformers T1 and T2, but the number of non-contact transformers T1 and T2 is equal to the number of gate pulse signals, that is, the number of semiconductor switching elements (power elements) in the power circuit board B. It is provided. That is, the communication coils a3 and a4 in the control circuit board A are provided for the number of semiconductor switching elements (power elements) in the power circuit board B, and the communication coils b2 and b3 in the power circuit board B are also provided in the power circuit board B. It is provided as many as the number of semiconductor switching elements (power elements).

The control circuit a5 controls the generation of the gate pulse signal in the gate signal generation circuit a2, and determines the operating state of the power circuit board B based on the state signal that the communication coil a4 wirelessly receives from the communication coil b3 of the power circuit board B. evaluate. The operation of such a control circuit a5 is monitored and controlled by the vehicle ECU (upper control device) described above.

The power wiring board b1 is a printed wiring board including printed wiring for connecting various electronic components to each other. That is, the power wiring plate b1 interconnects various electronic components constituting the pair of communication coils b2, b3, the drive circuit b5, and the power conversion circuit b5. Such a power wiring board b1 is a multilayer board in which printed wiring is formed in multiple layers with an insulating layer interposed therebetween.

The pair of communication coils b2 and b3 are coils for performing wireless communication with the control circuit board A. Of these communication coils b2 and b3, one of the communication coils b2 is arranged close to the communication coil a3 of the control circuit board A as shown in the figure. The communication coil b2 is electromagnetically coupled to the communication coil a3 of the control circuit board A with a predetermined coupling coefficient, and the gate pulse signal transmitted non-contactly from the communication coil a3 is rectified circuit b4 and the drive circuit b5. Output to.

On the other hand, the other communication coil b3 is arranged close to the communication coil a4 of the control circuit board A. The communication coil b3 is electromagnetically coupled to the communication coil a4 of the control circuit board A with a predetermined coupling coefficient, and the state signal input from the drive circuit b5 is non-contact transmitted to the communication coil a4 of the control circuit board A. do.

The rectifier circuit b4 is a power supply circuit that generates a power supply (DC voltage) for the drive circuit b5 based on the gate pulse signal. As shown in FIG. 2, the rectifier circuit b4 has an input end connected to one end of the communication coil b2 and an output end connected to the power supply terminal Vcc of the drive circuit b5. Such a rectifier circuit b4 includes a rectifier diode and a smoothing capacitor as shown in the figure.

In the rectifier diode, the anode terminal is the input end of the rectifier circuit b4 and is connected to one end of the communication coil b2, and the cathode terminal is the output end of the rectifier circuit b4 and is connected to one end of the smoothing capacitor and the power supply terminal Vcc. There is. One end of the smoothing capacitor is connected to the cathode terminal of the rectifier diode and the power supply terminal Vcc, and the other end is connected to the other end of the communication coil b2. Such a rectifier circuit b4 generates a DC voltage by rectifying a gate pulse signal input from the communication coil b2, and supplies the DC voltage to the power supply terminal Vcc of the drive circuit b5 as a power source.

The drive circuit b5 is a drive circuit that directly drives the power conversion circuit b5 based on the gate pulse signal input from the communication coil b2. As shown in FIG. 2, the drive circuit b5 includes a level conversion circuit 1, a clock generation circuit 2, a multiplication circuit 3, an error detection circuit 4, a D / A converter 5, and a state signal generation circuit 6.

Here, the rectifier circuit b4 and the drive circuit b5 described above are provided as many as the number of semiconductor switching elements (power elements) constituting the power conversion circuit b6, similarly to the pair of communication coils b2 and b3. FIG. 2 shows one rectifier circuit b4 and a drive circuit b5 for one semiconductor switching element S for convenience. As shown in FIG. 2, the semiconductor switching element S is, for example, an IGBT (Insulated Gate Bipolar Transistor).

Further, as shown in FIG. 2, one end of one of the pair of communication coils b2 and b3 described above is the input end of the level conversion circuit 1, the input end of the clock generation circuit 2, and the rectifying circuit b4. Each is connected to the input end. Further, as shown in FIG. 2, one end of the other communication coil b2 is connected to the output end of the state signal generation circuit 6.

Further, as shown in FIG. 2, the other ends of the pair of communication coils b2 and b3 are interconnected, and are commonly connected to the GND terminal of the drive circuit b5 and the emitter terminal of the semiconductor switching element S. Further, the other end of the smoothing capacitor of the rectifier circuit b4 is connected to the other ends of the communication coils b2 and b3.

The level conversion circuit 1 is a circuit that converts the gate pulse signal input from the communication coil b2 into a voltage level at which the semiconductor switching element S can be sufficiently turned ON / OFF. The level conversion circuit 1 outputs the gate pulse signal after voltage level voltage conversion to the control terminal (gate terminal in the case of an IGBT or MOS transistor) of the semiconductor switching element S.

The clock generation circuit 2 is a circuit that generates a clock pulse having a repetition period synchronized with the gate pulse signal input from the communication coil b2. The clock generation circuit 2 outputs a clock pulse to the multiplication circuit 3.

The multiplication circuit 3 is a circuit that converts a clock pulse input from the clock generation circuit 2 into a multiplication clock pulse having a repetition period of 1/2, that is, a frequency of twice. The multiplication circuit 3 outputs a multiplication clock pulse to the state signal generation circuit 6.

The error detection circuit 4 is a circuit that detects an operating state of the power conversion circuit b6 and the like and various abnormal states. As shown in FIG. 3, the error detection circuit 4 detects an operating state or an abnormal state over, for example, nine items as state items, and outputs the detection result, that is, the abnormality detection information indicating the content of the state, to the AC signal W of a predetermined frequency. Is output to the D / A converter 5. Such an error detection circuit 4 corresponds to the abnormality detection unit of the present invention.

That is, the state items in this embodiment are "stopped", "standby", "standby completed", "overcurrent 1", "overheat 1", "gate power supply error 1", "overcurrent 2", and "overheat". 2 ”and“ Gate power supply error 2 ”. Frequencies F1 to F10 are pre-assigned to these nine state items as the frequencies of the AC signals W output by the error detection circuit 4 as the detection result.

For example, "stop" is a state item indicating a stop state of the semiconductor switching element S, and the frequency F1 is assigned as the AC signal W. This frequency F1 is a frequency corresponding to 5% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Standby” is a state item indicating that the semiconductor switching element S is preparing for operation, and the frequency F2 is assigned as the AC signal W. This frequency F2 is a frequency corresponding to 15% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Standby complete” is a state item indicating that the semiconductor switching element S is ready for operation, and the frequency F3 is assigned as the AC signal W. This frequency F3 is a frequency corresponding to 25% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Overcurrent 1” is a state item indicating that the output current of the semiconductor switching element S is in the first overcurrent state, and the frequency F4 is assigned as the AC signal W. This frequency F4 is a frequency corresponding to 35% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Superheat 1” is a state item indicating that the semiconductor switching element S is in the first superheat state, and the frequency F5 is assigned as the AC signal W. This frequency F5 is a frequency corresponding to 45% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Gate power supply abnormality 1” is a state item indicating that the gate power supply of the semiconductor switching element S is in the first abnormal state, and the frequency F6 is assigned as the AC signal W. This frequency F6 is a frequency corresponding to 55% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Overcurrent 2” is a state item indicating that the output current of the semiconductor switching element S is in the second overcurrent state, and the frequency F7 is assigned as the AC signal W. This frequency F7 is a frequency corresponding to 65% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Superheat 2” is a state item indicating that the semiconductor switching element S is in the second superheat state, and the frequency F8 is assigned as the AC signal W. This frequency F8 is a frequency corresponding to 75% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

“Gate power supply abnormality 2” is a state item indicating that the gate power supply of the semiconductor switching element S is in the second abnormal state, and the frequency F9 is assigned as the AC signal W. This frequency F9 is a frequency corresponding to 85% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 based on the AC signal W output by the error detection circuit 4.

Here, as shown in FIG. 3, a state item is not assigned to the frequency F10. This frequency F10 corresponds to 95% as the duty ratio of the state signal (PWM signal), but when a new state item to be detected occurs, it is separately assigned to the new state item.

The D / A converter 5 is a signal converter that converts an AC signal W indicating the state of such a semiconductor switching element S as a frequency into a DC voltage E. The D / A converter 5 converts the AC signals W having frequencies F1 to F10 into voltage values V1 to V10, and outputs the voltage values V1 to V10 to the state signal generation circuit 6.

That is, the D / A converter 5 converts the AC signal W of the frequency F1 into the DC voltage E of the voltage value V1 and outputs it to the state signal generation circuit 6. This voltage value V1 is a voltage value corresponding to 5% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F1.

Further, the D / A converter 5 converts the AC signal W of the frequency F2 into the DC voltage E of the voltage value V2 and outputs it to the state signal generation circuit 6. This voltage value V2 is a voltage value corresponding to 15% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F2.

The D / A converter 5 converts the AC signal W having a frequency F3 into a DC voltage E having a voltage value V3 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V3 is a voltage value corresponding to 25% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F3.

The D / A converter 5 converts the AC signal W having a frequency F4 into a DC voltage E having a voltage value V4 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V4 is a voltage value corresponding to 35% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F4.

The D / A converter 5 converts the AC signal W having a frequency F5 into a DC voltage E having a voltage value V5 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V5 is a voltage value corresponding to 45% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F5.

The D / A converter 5 converts the AC signal W having a frequency F6 into a DC voltage E having a voltage value V6 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V6 is a voltage value corresponding to 55% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F6.

The D / A converter 5 converts the AC signal W having a frequency F7 into a DC voltage E having a voltage value V7 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V7 is a voltage value corresponding to 65% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F7.

The D / A converter 5 converts the AC signal W having a frequency F8 into a DC voltage E having a voltage value V8 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V8 is a voltage value corresponding to 75% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F8.

The D / A converter 5 converts the AC signal W having a frequency F9 into a DC voltage E having a voltage value V9 and outputs the AC signal W to the state signal generation circuit 6. This voltage value V9 is a voltage value corresponding to 85% as the duty ratio of the state signal (PWM signal) finally output by the state signal generation circuit 6 like the frequency F9.

As with the frequency F10 described above, no state item is assigned to the voltage value V10. This voltage value V10 corresponds to 95% as the duty ratio of the state signal (PWM signal), but when a new state item to be detected occurs, it is separately assigned to the new state item.

The state signal generation circuit 6 is a signal converter that converts a DC voltage E indicating the state of such a semiconductor switching element S as a voltage value into a state signal (PWM signal) having a predetermined duty ratio. The state signal generation circuit 6 converts the DC voltage E having voltage values V1 to V10 into a state signal (PWM signal) having a duty ratio corresponding to the voltage values V1 to V10 and outputs the DC voltage E to one end of the communication coil b3.

That is, the state signal generation circuit 6 converts the DC voltage E of the voltage value V1 into a state signal (PWM signal) having a duty ratio of 5% and outputs the DC voltage E to the communication coil b3. Further, the state signal generation circuit 6 converts the DC voltage E of the voltage value V2 into a state signal (PWM signal) having a duty ratio of 15% and outputs the DC voltage E to the communication coil b3.

The state signal generation circuit 6 converts the DC voltage E of the voltage value V3 into a state signal (PWM signal) having a duty ratio of 25% and outputs the DC voltage E to the communication coil b3. Further, the state signal generation circuit 6 converts the DC voltage E of the voltage value V4 into a state signal (PWM signal) having a duty ratio of 35% and outputs the DC voltage E to the communication coil b3.

The state signal generation circuit 6 converts the DC voltage E of the voltage value V5 into a state signal (PWM signal) having a duty ratio of 45% and outputs the DC voltage E to the communication coil b3. Further, the state signal generation circuit 6 converts the DC voltage E of the voltage value V6 into a state signal (PWM signal) having a duty ratio of 55% and outputs the DC voltage E to the communication coil b3.

The state signal generation circuit 6 converts the DC voltage E of the voltage value V7 into a state signal (PWM signal) having a duty ratio of 65% and outputs the DC voltage E to the communication coil b3. Further, the state signal generation circuit 6 converts the DC voltage E of the voltage value V8 into a state signal (PWM signal) having a duty ratio of 75% and outputs the DC voltage E to the communication coil b3. Further, the state signal generation circuit 6 converts the DC voltage E of the voltage value V9 into a state signal (PWM signal) having a duty ratio of 85% and outputs the DC voltage E to the communication coil b3.

Such a state signal generation circuit 6 includes, for example, the circuit configuration shown in FIG. 4A. That is, the state signal generation circuit 6 includes a triangular wave generator 6a, a comparator 6b, and a pull-up resistor 6c. The triangular wave generator 6a synchronizes with the clock pulse based on the multiplication pulse input from the multiplication circuit 3, generates a triangle wave having the same period, and outputs the triangle wave to the negative electrode input end of the comparator 6b.

The comparator 6b compares the triangular wave input from the triangular wave generator 6a to the negative electrode input end with the DC voltage E input from the D / A converter 5 to the positive electrode input end, and obtains a signal indicating the comparison result, that is, a state signal J. Output to the communication coil b3. That is, the output end of the comparator 6b is the output end of the state signal generation circuit 6.

One end of the pull-up resistor 6c is connected to the power supply Vcc, and the other end is connected to the output end of the comparator 6b. The pull-up resistor 6c is a resistor that sets the output current of the state signal generation circuit 6, that is, the energization current of the communication coil b3, according to the resistance value.

In such a drive circuit b5, as shown in FIG. 4B, the clock generation circuit 2 synchronizes with the gate pulse and generates a clock pulse having the same repetition period based on the gate pulse input from the communication coil b2. Generate. Then, the multiplication circuit 3 generates a multiplication pulse based on this clock pulse, which is synchronized with the clock pulse and whose same repetition period is ½ of the clock pulse.

Then, the state signal generation circuit 6 compares the triangular wave generated by the triangular wave generator 6a based on the multiplication pulse with the DC voltage E input from the D / A converter 5, so that the voltage value V of the DC voltage E is V. A state signal J (PWM signal) whose duty ratio is determined according to the above is generated and output to the communication coil b3.

Here, among the components of the drive circuit b5, the communication coil b3, the D / A converter 5, and the state signal generation circuit 6 constitute the power-side communication unit of the present invention. That is, the communication coil b3, the D / A converter 5, and the state signal generation circuit 6 are mounted on the power circuit board B, and the contents of the AC signal W (abnormality detection information) output by the error detection circuit 4 (abnormality detection unit). A state signal J (wireless transmission signal) having a different duty ratio is generated according to the above, and wirelessly transmitted to the control circuit board A.

On the other hand, the power conversion circuit b6 shown in FIG. 1 is a power circuit including a plurality of the above-mentioned semiconductor switching elements S and bidirectionally converting power based on a plurality of gate pulses input from the drive circuit b5. That is, in this power conversion circuit b6, the operation mode is selectively set to the power running mode or the regeneration mode by setting each semiconductor switching element S to the ON state or the OFF state based on the gate pulse signal. It is a power converter.

The power running mode is an operation mode in which DC power (battery power) of a predetermined voltage supplied from an assembled battery is converted into drive power (AC power) having a predetermined amplitude and output to a traveling motor. On the other hand, the regenerative mode is an operation mode in which regenerative power (AC power) having a predetermined amplitude supplied from the traveling motor is converted into DC power having a predetermined voltage and output to the assembled battery.

Such a power conversion circuit b6 converts, for example, a bidirectional buck-boost circuit for boosting battery power / stepping down regenerative power and boosting power (DC power) input from the bidirectional buck-boost circuit into three-phase AC power. It is provided with a three-phase inverter circuit that supplies the drive power to the traveling motor and converts the regenerative power (AC power) supplied from the traveling motor into DC power and outputs it to the bidirectional buck-boost circuit.

Next, the operation of the power conversion device according to the present embodiment will be described in detail with reference to FIGS. 1 to 4.

In this power conversion device, immediately after startup, that is, when power is supplied to the control circuit board A from the outside, the control circuit a5 of the control circuit board A sends a control signal having a constant duty ratio to the communication coil b2 over a predetermined time. Output. This control signal is an initial control signal for starting up the power supply Vcc of the drive circuit b5 in the power circuit board B.

That is, in the power circuit board B, the voltage of the power supply Vcc gradually rises as the rectifier circuit b4 rectifies the initial control signal, and finally reaches the voltage at which the drive circuit b5 can operate. Then, when the error detection circuit 4 in the drive circuit b5 starts normal operation, it generates an AC signal W having a frequency F3 indicating “standby completion” in FIG. 3A and outputs the AC signal W to the D / A converter 5. This frequency F3 is a frequency corresponding to 25% when converted into the duty ratio of the state signal J output by the state signal generation circuit 6.

The D / A converter 5 converts the AC signal W having a frequency F3 into a DC voltage E having a voltage value V3 corresponding to 25% when converted to the duty ratio of the state signal J, and outputs the AC signal W to the state signal generation circuit 6. do. Then, the state signal generation circuit 6 generates a state signal J (PWM signal) having a duty ratio of 25% based on the DC voltage E of the voltage value V3 and outputs the state signal J (PWM signal) to the communication coil b3.

The state signal J (PWM signal) having a duty ratio of 25% is input from the communication coil b3 to the control circuit a5. Then, the control circuit a5 evaluates which of the determination ranges (determination criteria) shown in FIG. 3A the 25% state signal J (PWM signal) belongs to. Since the 25% state signal J (PWM signal) belongs to the determination range of 20 to 30%, the control circuit a5 recognizes that the drive circuit b5 is in the operating state where the standby is completed.

When the drive circuit b5 of the power circuit board B starts up normally in this way, each circuit of the control circuit board A and the power circuit board B shifts to the normal control operation. That is, in the power circuit board B, the error detection circuit 4 in the drive circuit b5 sequentially determines the state of each semiconductor switching element S constituting the power conversion circuit b6 at a predetermined time interval.

Then, the AC signal W indicating the determination result is converted into the DC voltage E in the D / A converter 5 and input to the state signal generation circuit 6. Then, a state signal J (PWM signal) is generated based on this DC voltage E, and is wirelessly transmitted to the communication coil a4 of the control circuit board A via the communication coil b3.

Then, in the control circuit board A, the state signal J (PWM signal) is input from the communication coil a4 to the control circuit a5. The control circuit a5 recognizes the state of the semiconductor switching element S by evaluating the duty ratio of the state signal J (PWM signal) based on the determination criteria as shown in FIG.

For example, when the error detection circuit 4 detects the “overcurrent 1” of the semiconductor switching element S as shown in FIG. 3A, it outputs the AC signal W of the frequency F4 to the D / A converter 5. This frequency F4 is a frequency corresponding to 35% when converted into the duty ratio of the state signal J output by the state signal generation circuit 6.

The D / A converter 5 converts the AC signal W having a frequency F4 into a DC voltage E having a voltage value V4 corresponding to 35% when converted to the duty ratio of the state signal J, and outputs the AC signal W to the state signal generation circuit 6. do. Then, the state signal generation circuit 6 generates a state signal J (PWM signal) having a duty ratio of 35% based on the DC voltage E of the voltage value V4 and outputs the state signal J (PWM signal) to the communication coil b3.

The state signal J (PWM signal) having a duty ratio of 35% is input from the communication coil b3 to the control circuit a5. Then, the control circuit a5 evaluates which of the determination ranges (determination criteria) shown in FIG. 3A the 35% state signal J (PWM signal) belongs to. Since the 35% state signal J (PWM signal) belongs to the determination range of 30 to 40%, the control circuit a5 recognizes that the semiconductor switching element S is in the operating state of “overcurrent 1”.

Then, the control circuit a5 reports such a recognition result to the vehicle ECU as necessary and takes necessary measures. For example, the control circuit a5 generates a control signal related to “power save” for the operating state of “overcurrent 1” and outputs it to the communication coil b2. That is, the control circuit a5 generates a control signal (PWM signal) having a duty ratio of 45% and outputs it to the communication coil b2.

According to this embodiment, since the power circuit board B is provided with the error detection circuit 4 for detecting the state of the power conversion circuit b6 (power circuit) instead of the control circuit board A, the control circuit board A and the power circuit board are provided. When the B communicates wirelessly, the communication frequency can be reduced as compared with the conventional case. For example, according to the present embodiment, since the communication frequency is reduced as compared with the conventional case, it is possible to detect the abnormal portion of the power conversion circuit b6 earlier than the conventional one.

Further, according to the present embodiment, the state signal J and the state of the power circuit board B to the control circuit board A using the duty ratio which is the characteristic attribute value of the PWM signal generated as the control signal J. The report and the control of the power circuit board B are realized. That is, according to the present embodiment, the state signal J and the control signal can be generated by a simple circuit.

Further, according to the present embodiment, the D / A converter 5 (DC signal) that outputs a DC voltage E (DC signal) having a different voltage level according to the frequency F (abnormality detection information) of the AC signal W output by the error detection circuit 4. (Signal conversion circuit), a triangular wave generator 6a that outputs a triangular wave having a predetermined period, and a state signal J (PWM signal) based on the output signal (DC voltage E) and the triangular wave of the D / A converter 5 (signal conversion circuit). Since the state signal generation circuit 6 (PWM signal generator) for setting the duty ratio of the above is provided, it is possible to generate the state signal J (PWM signal) by a relatively simple circuit.

Here, the triangular wave generator 6a outputs a triangular wave synchronized with the gate pulse. Therefore, according to the present embodiment, the downlink communication signal (gate pulse) from the control circuit board A to the power circuit board B and the uplink communication signal (state signal J) from the power circuit board B to the control circuit board A. It is possible to establish communication synchronization.

Further, according to the present embodiment, since the power circuit board B includes a rectifier circuit b4 that generates the power supply Vcc of the drive circuit b5 based on the gate pulse, the power supply Vcc is generated by a relatively simple circuit called the rectifier circuit b4. It is possible. Therefore, according to the present embodiment, it is possible to simplify the power supply circuit of the drive circuit b5, and thus it is possible to reduce the mounting area of the power supply circuit on the power circuit board B.

Further, according to the present embodiment, the first non-contact transformer T1 for downlink communication for non-contact transmission of the gate pulse from the control circuit board A to the power circuit board B and the state signal J are transmitted from the power circuit board B to the control circuit board B. Since the second non-contact transformer T1 for uplink communication that is non-contact transmitted to A is provided, the configuration of the communication circuit can be configured as compared with the case where the gate pulse and the state signal J are wirelessly transmitted using a single non-contact transformer. It can be simplified.

The present invention is not limited to the above embodiment, and for example, the following modifications can be considered.
(1) In the above embodiment, the PWM signal whose duty ratio indicates abnormality detection information is adopted as the state signal J, but the present invention is not limited to this. A signal indicating abnormality detection information using attribute information other than the duty ratio may be used for the state signal J.

(2) In the above embodiment, the allocation of the state signal J and the control item of the gate pulse to the duty ratio is set as shown in FIG. 3, but the present invention is not limited thereto.

(3) In the above embodiment, the first non-contact transformer T1 for downlink communication and the second non-contact transformer T1 for uplink communication are provided, but the present invention is not limited thereto. For example, by setting a frequency band different from the frequency band of the downlink communication signal and the frequency band of the uplink communication signal, wireless communication of the downlink communication signal and the uplink communication signal may be realized by using a single non-contact transformer. ..

A control circuit board a1 control wiring board a2 gate signal generation circuit a3 communication coil a4 communication coil (control side communication unit)
a5 Control circuit B Power circuit board b1 Power wiring board b2 Communication coil b3 Communication coil (Power side communication unit)
b4 Rectifier circuit b5 Drive circuit b6 Power conversion circuit S Semiconductor switching element T1 First non-contact transformer T2 Second non-contact transformer 1 Level conversion circuit 2 Clock generation circuit 3 Multiplying circuit 4 Error detection circuit (abnormality detection unit)
5 D / A converter (power side communication unit)
6 Status signal generation circuit (power side communication unit)

Claims (5)

A power circuit board on which a power conversion circuit and a drive circuit for directly driving the power conversion circuit are mounted, and a control circuit board on which a control circuit for controlling the drive circuit is mounted, the power circuit board and the control In a power conversion device in which the circuit board performs wireless communication
An abnormality detection unit mounted on the power circuit board and detecting at least an abnormality in the power conversion circuit,
A power-side communication unit mounted on the power circuit board and wirelessly transmitting abnormality detection information output by the abnormality detection unit to the control circuit board.
A power conversion device mounted on the control circuit board and provided with a control-side communication unit that receives the abnormality detection information and outputs the abnormality detection information to the control circuit. The power conversion device according to claim 1, wherein the power-side communication unit generates a PWM signal having a different duty ratio according to the content of the abnormality detection information as a wireless transmission signal. The power side communication unit is
A signal conversion circuit that outputs signals of different levels according to the abnormality detection information, and
A triangular wave generator that outputs a triangular wave with a predetermined period,
The power conversion device according to claim 2, further comprising a PWM signal generator that sets the duty ratio based on the output signal of the signal conversion circuit and the triangular wave. One of claims 1 to 3, wherein the power circuit board includes a rectifying circuit in which the power-side communication unit rectifies a pulse received from the control-side communication unit to generate a power supply for the drive circuit. The power conversion device according to paragraph 1. The power side communication unit and the control side communication unit
A first non-contact transformer for downlink communication from the control side communication unit to the power side communication unit,
The power conversion device according to any one of claims 1 to 4, further comprising a second non-contact transformer for uplink communication from the power side communication unit to the control side communication unit.

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