JP2000102288A - Inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter device with which input DC supply voltage can be detected at a low cost by simple constitution without deteriorating reliability. SOLUTION: A DC supply voltage detector 15 is mounted on the same circuit board as a pair of switching-element driver circuits 13 which discretely drive power switching elements 40 that constitute arms for inverter circuits 4a or controlled power circuits 14 supplying the driver circuits 13 with a controlled supply voltage. The DC supply voltage detector 15 detects DC supply voltage, on the basis of the potential of the lower main electrode terminals of the power switching elements 40 input to the switching-element driver circuits 13. The DC supply voltage detector 15 can input at least one of the higher or lower supply power-supply potential of DC supply voltage to be detected to the switching-element driver circuits 13 or the controlled power circuit 14 mounted on the same board from the lower main electrode terminals of the power switching elements 40 through a wiring pattern 16 or 17, and the conventional lead-in cables of voltage and terminal connection with the lead-in cables can be omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inverter device for driving a motor for an electric vehicle.

[0002]

2. Description of the Related Art In an electric vehicle using an AC motor as a traction motor, an inverter circuit for controlling the traction motor converts a DC power of an on-vehicle battery into AC power and supplies the AC power to the traction motor. And a regenerative mode in which regenerative power generated by the motor for use is converted into DC power and returned to the on-vehicle battery.

However, the inverter circuit performs a regenerative operation in the regenerative mode at a power higher than the power that can be absorbed by the vehicle-mounted battery, or the DC power supply line between the vehicle-mounted battery and the motor control circuit is disconnected due to, for example, a blown fuse. Then, since the electromagnetic energy accumulated in the inductance of the traveling motor rapidly increases the main engine input voltage (terminal voltage of the traveling motor) of the inverter circuit against the current decrease, a switching element constituting the inverter circuit or In addition, a smoothing capacitor or the like that suppresses a change in the input DC voltage of the inverter circuit has an adverse effect such as a shortened life.

In order to solve this problem, a DC power supply voltage detection circuit for monitoring the input voltage of the main engine and detecting a sudden increase thereof is provided, and a voltage abnormality protection device for stopping the regenerative mode operation of the inverter circuit when the sudden increase is detected is known. More adopted. FIG. 3 shows a conventional example of a conventional inverter device for driving a traveling motor for an electric vehicle (including a hybrid vehicle).

[0005] 1 is a main battery, 2 is a DC power supply voltage detection circuit, 3 is a smoothing capacitor, 4 is a three-phase inverter circuit, 5
Is a controller, 6 is an auxiliary battery, 7 is a flyback diode, 8 is a traveling motor for an electric vehicle, 9 is a high-level DC power supply line connecting the positive terminal of the main battery 1 and the high-level DC voltage terminal of the three-phase inverter circuit 4. Reference numeral 10 denotes a low-level DC power supply line for connecting the negative terminal of the main battery 1 to the low-level DC voltage terminal of the three-phase inverter circuit 4. Reference numeral 11 denotes a DC power supply voltage to the DC power supply lines 9, 10 and the DC power supply voltage detection circuit 2. The lead-in cable 12 is a gate control unit that applies a control voltage to the gate electrode of the IGBT 40 configuring each arm of the three-phase inverter circuit 4.

[0006] The controller 5 includes a three-phase inverter circuit 4 based on a signal voltage from the DC power supply voltage detection circuit 2 and the like.
Control. The gate control unit 12 amplifies a gate control signal of the controller 5 and applies it to the gate electrode of the IGBT 40, and a control that supplies power from the auxiliary battery 6 and supplies a control power supply voltage to the switching element drive circuit. Power circuit and built-in.

[0007]

However, since the traveling motor 8 for an electric vehicle has a large output and a high voltage specification of 300 V or more for miniaturization and reduction of wiring loss, a DC power supply voltage detection circuit is required. 2 needs to detect a very high overvoltage in the regenerative mode. For this reason, an expensive lead-in cable 11 for connecting the main battery 1 and the three-phase inverter circuit 4 to the DC power supply voltage detection circuit 2 from the high and low DC power supply lines 9 and 10 having a busbar configuration is expensive. It is necessary to adopt a high withstand voltage type. Further, a DC power supply line 9,
10, terminal connection between lead-in cable 11 and DC power supply line, lead-in cable 11 and DC power supply voltage detection circuit 2
In this case, there is a problem that such high-voltage cable wiring and terminal connection are troublesome and costly from the viewpoint of securing insulation and preventing short circuit.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an inverter device capable of detecting an input DC power supply voltage with a simple configuration at a low cost without reducing reliability. That is the purpose.

[0009]

According to a first aspect of the present invention, a DC power supply voltage detecting circuit for an inverter device is mounted on the same circuit board as a switching element driving circuit for individually driving a power switching element constituting an arm of the inverter circuit. Further, the DC power supply voltage detection circuit detects the DC power supply voltage based on the potential of the lower main electrode terminal of the power switching element input to the switching element drive circuit.

With this configuration, at least the DC power supply voltage detection circuit mounts at least one of the high and low power supply potentials of the DC power supply voltage to be detected on the same substrate from the lower main electrode terminal of the power switching element. The input from the wiring pattern on the board that is input to the switching element drive circuit can be input, and the conventional high-voltage pull-in cable and terminal connection with it can be omitted, so the DC power supply voltage can be detected with a simple configuration and at low cost. it can.

The details will be described below. Each switching element drive circuit that individually controls the power switching elements constituting each arm of the inverter circuit generates a control voltage based on the lower main electrode terminal of the power switching element. Therefore, the potential of the lower main electrode terminal of the power switching element controlled by the circuit board on which the switching element drive circuit is mounted is always input.

Therefore, by mounting the DC power supply voltage detection circuit on the circuit board, at least one of the high and low power supply potentials of the DC power supply voltage to be detected can be transferred from the switching element drive circuit through the wiring pattern on the circuit board. You can receive it directly. When the power switching element constitutes the upper arm of the inverter circuit, the potential of the lower main electrode terminal changes between the higher potential and the lower potential of the DC power supply voltage due to the intermittent operation of the power switching element on the upper arm side. However, there is no problem because either of them may be selected. According to the configuration of claim 2, in the inverter device of claim 1, the DC power supply voltage detection circuit is further mounted on the same circuit board as a pair of switching element drive circuits that intermittently connect both power switching elements of the same phase, A DC power supply voltage is detected based on a voltage between the lower main electrode terminals of both power switching elements input to both switching element drive circuits.

With this configuration, both the high and low potentials of the DC power supply voltage can be input to the DC power supply voltage detection circuit through the wiring pattern of the circuit board without connecting the high-voltage lead-in cable or the terminal to the high-voltage power supply cable. A simple configuration can be detected at low cost. The inverter device according to claim 3 is mounted on the same circuit board as a control power supply circuit that supplies a control power supply voltage to a switching element drive circuit that individually drives a power switching element that constitutes an arm of the inverter circuit. The power supply voltage detection circuit detects the DC power supply voltage based on the potential of the lower main electrode terminal of the power switching element input to the control power supply circuit.

With this configuration, at least the DC power supply voltage detection circuit mounts at least one of the high and low power supply potentials of the DC power supply voltage to be detected on the same substrate from the lower main electrode terminal of the power switching element. Can be input from the wiring pattern on this board, which is input to the control power supply circuit, and the conventional high-voltage pull-in cable and terminal connection with it can be omitted, so that the DC power supply voltage can be detected with a simple configuration and at low cost. .

The details will be described below. Each switching element drive circuit that individually controls the power switching elements constituting each arm of the inverter circuit generates a control voltage based on the lower main electrode terminal of the power switching element. For this reason, the circuit board on which the control power supply circuit that supplies the control power supply voltage to the switching element drive circuit is necessarily mounted on a circuit board on which the low-level power switching element that is controlled by the switching element drive circuit that supplies the control power supply voltage. The potential of the electrode terminal is input.

Therefore, by mounting the DC power supply voltage detection circuit on this circuit board, at least one of the high and low power supply potentials of the DC power supply voltage to be detected is directly transmitted from the control power supply circuit through the wiring pattern on the circuit board. You can receive. When the power switching element constitutes the upper arm of the inverter circuit, the potential of the lower main electrode terminal changes between the higher potential and the lower potential of the DC power supply voltage due to the intermittent operation of the power switching element on the upper arm side. However, there is no problem because either of them may be selected. According to the configuration described in claim 2, in the inverter device according to claim 1, the DC power supply voltage detection circuit further supplies a control power supply voltage to each of a pair of switching element driving circuits that intermittently connect both power switching elements of the same phase. A DC power supply voltage is mounted on the same circuit board as the pair of control power supply circuits, and a DC power supply voltage is detected based on a voltage between the lower main electrode terminals input to the pair of control power supply circuits.

With this arrangement, both the high and low potentials of the DC power supply voltage can be input to the DC power supply voltage detection circuit through the wiring pattern of the circuit board without connecting the high-voltage lead-in cable or the terminal to the high-voltage lead-in cable. A simple configuration can be detected at low cost. According to the configuration of claim 5, in the inverter device according to any one of claims 1 to 4, the DC power supply voltage detection circuit further includes a DC power supply voltage exceeding a predetermined threshold value in a regenerative mode of the electric vehicle traveling motor. In the case of the high-voltage electric vehicle traveling motor, the configuration is used to notify the main battery when it is in the regenerative mode. .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the inverter device according to the present invention will be described with reference to the following embodiments.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the inverter device of the present invention is applied to a driving motor drive circuit for an electric vehicle will be described with reference to FIGS. The overall configuration of the traveling motor drive circuit for an electric vehicle is the same as that of the conventional one shown in FIG. 3 except that the DC power supply voltage detection circuit 2 and the lead-in cable 11 are omitted, and a DC power supply voltage detection circuit is newly added to the gate control unit 12. The only difference is that it is built in.

FIG. 1 is a circuit diagram showing a block diagram of the three-phase inverter circuit 4 and the gate control unit 12, and FIG.
FIG. 2 is a circuit diagram of an inverter circuit for one phase and a gate control unit 12 that controls a pair of IGBTs 40; (Configuration) The three-phase inverter circuit 4 is configured by connecting high and low DC power supply terminals of a U-phase inverter circuit 4a, a V-phase inverter circuit 4b, and a W-phase inverter circuit 4c to a high-order DC power supply line 9 and a low-order DC power supply line 10, respectively. , Their AC output terminals U to W
Supplies power to a three-phase AC motor, which is a driving motor for electric vehicles.

Each phase inverter circuit 4a, 4b, 4c
Upper arm side IGBT (power switching element) 40
(Lower main electrode terminal) and lower arm side IGBT
40 collectors (higher main electrode terminals) are AC output terminals U
To the W, the upper arm side IGBT
The collector (higher main electrode terminal) of the (power switching element) 40 connects the higher DC power supply line 9 to the lower arm I
The emitter (lower main electrode terminal) of the GBT 40 is connected to the positive and negative terminals of the main battery 1 through the lower DC power supply line 10 as shown in FIG.

Each phase inverter circuit 4a, 4b, 4c
It is controlled by a gate control unit 12 having the same circuit configuration including a pair of switching element drive circuits 13, a pair of control power supply circuits 14, and one DC power supply voltage detection circuit 15. In this embodiment, the pair of switching element driving circuits 1 constituting a phase inverter circuit of the same phase.
3. The pair of control power supply circuits 14 and one DC power supply voltage detection circuit 15 are mounted on the same circuit board, but the mounting form can be variously changed as described later.

The gate controller 12 for controlling the U-phase inverter circuit 4a will be described in detail with reference to FIG. The control power supply circuit 14 includes a DC-D
An inverter 141 for converting a low-voltage DC power supply voltage input from the auxiliary battery 6 into a predetermined AC voltage; an insulation for boosting the AC voltage applied from the inverter 141 to the primary coil at a predetermined ratio; Transformer 1
42, a rectifier circuit 143 for rectifying the AC voltage output from the secondary coil of the insulating transformer 142. The primary coil and the secondary coil of the insulating transformer 142 are electrically insulated.

Upper-arm switching element drive circuit 1
One end of the secondary coil of the insulating transformer 142 of the control power supply circuit 14 for supplying power to the IGBT 40 is connected to the emitter electrode of the IGBT 40 on the upper arm side through the wiring pattern 16 on the circuit board (not shown). The potential of the lower output terminal of the control power supply circuit 14 becomes the emitter potential of the IGBT 40 on the upper arm side.

Similarly, one end of a secondary coil of an insulating transformer (not shown) of a control power supply circuit 14 for supplying power to the switching element drive circuit 13 on the lower arm side is connected to a phase inverter circuit through a wiring pattern 17 on a circuit board (not shown). 4a
Is connected to the emitter electrode of the IGBT 40 on the lower arm side, whereby the potential of the lower output terminal of the control power supply circuit 14 on the lower arm side becomes the emitter potential of the IGBT 40 on the lower arm side.

The switching element drive circuit 13 includes a photocoupler circuit 131 for electrical insulation between input and output lines to which a gate control signal is input from the controller 5, and a gate control signal output from the photocoupler circuit 131 for converting voltage and current. And an amplifier 132 for amplifying and applying the amplified voltage to the gate electrode of the IGBT 40. As described above, the control power supply voltage is supplied to the photocoupler circuit 131 and the amplifying unit 132 from the control power supply circuit 14 through the pair of wiring patterns 18 and 19 forming the internal power supply line, and the switching element drive circuit 13 The lower internal power supply line 19 is connected to the upper arm IG through the wiring pattern 16.
It has the same potential as the emitter electrode of BT40,
The switching device drive circuit 13 on the upper arm side can apply a control voltage based on the emitter electrode to the gate electrode of the IGBT 40 on the upper arm side. Similarly,
The switching element drive circuit 13 on the lower arm side can apply a control voltage based on the emitter electrode to the gate electrode of the IGBT 40 on the lower arm side. The DC power supply voltage detection circuit 2 includes a voltage dividing circuit 21 and the voltage dividing circuit 2.
A low-pass filter 22 for cutting the high-frequency component of the divided voltage output from the amplifier 1, an amplifying circuit 23 for amplifying the DC voltage (including the low-frequency component) output from the low-pass filter 22 at a predetermined gain, and an amplifying circuit 23 And a comparator 24 for comparing the amplified voltage output from the comparator with a predetermined reference voltage Vref.

The voltage dividing circuit 21 includes wiring patterns 16 and 17
Between the resistors r1 and r2 connected in series with each other,
The connection point of these resistors r1 and r2 forms an output terminal for the divided voltage output. The low-pass filter 22 is formed by a well-known resistance integration circuit including a resistor r3 and a capacitor c, and the amplification circuit 23 is formed by a well-known operational amplifier voltage amplification circuit. Reference voltage Vref input to comparator 24
Are formed by inputting a control power supply voltage supplied from the switching element drive circuit 13 on the lower arm side to a constant voltage circuit (not shown).

(Description of Operation) As is well known, six gate control signals are output from the controller 5 to each switching element driving circuit 13 in a predetermined order, and each switching element driving circuit 13 is input. Each IGBT 40 is intermittently controlled according to the gate signal, and a three-phase AC voltage is output to the AC output terminals U to W. Note that the pair of upper and lower IGBTs 40 of the same phase are not conducted at the same time.
In accordance with the intermittent operation of the GBT 40, the higher DC power supply voltage of the DC power supply line 9 and the lower DC power supply voltage of the DC power supply line 10 are alternately applied, and the lower DC power supply voltage of the DC power supply line 10 is constantly applied to the wiring pattern 17. Has been applied.

Therefore, the maximum value of the potential difference between the wiring patterns 16 and 17 becomes equal to the potential difference between the DC power supply lines 9 and 10, so that the amplified voltage V of the DC component of the divided voltage is obtained.
When x becomes larger than the reference voltage Vref, it is determined that the voltage is excessive in the regenerative mode of the electric vehicle traveling motor 8, and an overvoltage detection signal is output from the comparator 24 to the controller 5. The controller 5 is requested to stop the regeneration mode.

As described above, in this embodiment, since the DC power supply voltage detection circuit 2 is mounted on the same substrate as the switching element drive circuit 13 and the control power supply circuit 14,
The DC power supply voltage input to the three-phase inverter circuit 4 can be detected without requiring an expensive lead-in cable and complicated terminal connection as in the related art.

[0031]

[Modification] Another modification of the inverter device of the present invention will be described below. First, in the above embodiment, the DC power supply voltage detection circuit 2 is mounted on the same substrate as the pair of switching element drive circuits 13 and the pair of control power supply circuits 14. The circuit 14 may be provided separately.

Conversely, the DC power supply voltage detection circuit 2 may be mounted together with the pair of control power supply circuits 14 and the switching element drive circuit 13 may be provided separately. Further, the DC power supply voltage detection circuit 2 is connected to the switching element drive circuit 13 on the upper arm side or the control power supply circuit 1 on the upper arm side.
4, the control power supply circuit 14 on the lower arm side and / or the switching element drive circuit 13 on the lower arm side can be mounted on another board.

In this case, however, the lower control power supply line of the DC power supply voltage detection circuit 2 is connected to the upper arm IGB.
The DC power supply voltage detection circuit 2 is connected to the emitter electrode of T40, and it is necessary to draw the potential of the DC power supply line 10 from the lower DC power supply line 10 with a single lead-in cable. Nevertheless, according to this aspect, the number of lead-in cables and the number of terminal connections can be reduced.

Similarly, the DC power supply voltage detection circuit 2 is mounted together with the switching element drive circuit 13 on the lower arm side or the control power supply circuit 14 on the lower arm side, and the control power supply circuit 14 on the upper arm side and / or the upper arm side. The switching element driving circuit 13 can be mounted on another substrate. However, in this case, it is necessary to pull in the potential from the high-order DC power supply line 9 input to the DC power supply voltage detection circuit 2 with one lead-in cable. Nevertheless, according to this aspect, the number of lead-in cables and the number of terminal connections can be reduced.

In addition, in the above embodiment, each of the six IGBs
The T40 and the flyback diode 7 connected in anti-parallel with each other are individually modularized. However, one pair of IGBTs 40 and one pair of flyback diodes for each phase may be used as one module, or six IGBTs 40 and flyback diodes 7 may be used. Into one module,
Furthermore, the switching element driving circuit 1 is added to the module including the IGBT 40 and the flyback diode 7.
3 and the DC power supply voltage detection circuit 2 can be built in, and the control power supply circuit 14 can be built in this intelligent module.

Further, the switching element driving circuit 13
A detection circuit for detecting an excessive current or an excessive temperature of the IGBT 40 may be incorporated therein. Further, an alarm signal when the excessive current or the excessive temperature is detected and an excessive voltage alarm signal output from the DC power supply voltage detection circuit 2 By outputting the logical sum output of the above on one alarm signal line, the number of alarm signal lines may be reduced.

Further, in this embodiment, the DC power supply voltage detection circuit 2 is provided for each phase, but may be provided for only one phase.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an inverter device according to the present invention.

FIG. 2 is a circuit diagram of an inverter circuit for one phase of the inverter device shown in FIG. 1 and a gate control unit 12 that controls a pair of IGBTs 40;

FIG. 3 is a circuit diagram showing a conventional drive circuit device for driving a traveling motor for an electric vehicle.

[Explanation of symbols]

4 is a three-phase inverter circuit (inverter circuit), 4a, 4
b, 4c are phase inverter circuits, 40 is an IGBT (power switching element), 13 is a switching element drive circuit, 14 is a control power supply circuit, and 15 is a DC power supply voltage detection circuit

Continued on the front page F-term (reference) JJ26 LL22 LL24 LL34 MM02 MM03 MM11 PP02 PP03

Claims (5)

[Claims] A plurality of phase inverter circuits each having a lower main electrode terminal of an upper arm power switching element and a higher main electrode terminal of a lower arm power switching element connected to an AC output terminal; An inverter circuit to which a DC power supply voltage is applied between a high-order main electrode terminal of the power switching element and a low-order main electrode terminal of the power switching element on the lower arm side; The same number of switching element drive circuits as the power switching elements for forming the control voltage for intermittent power switching elements for each of the power switching elements, and power based on the potential of the lower main electrode terminal of each power switching element. The control power supply voltage for switching the switching element And a DC power supply voltage detection circuit for detecting the DC power supply voltage, wherein the DC power supply voltage detection circuit is a lower arm side power switching element or an upper arm side. The DC power supply voltage is detected based on the potential of the lower main electrode terminal of the power switching element which is mounted on the same circuit board as the switching element drive circuit that drives the power switching element. An inverter device characterized by the above-mentioned. 2. The inverter device according to claim 1, wherein the DC power supply voltage detection circuit is mounted on a same circuit board as a pair of switching element driving circuits intermittently connecting the power switching elements of the same phase. An inverter device, wherein the DC power supply voltage is detected based on a voltage between the low-order main electrode terminals of the two power switching elements input to an element driving circuit. A plurality of phase inverter circuits each having a lower main electrode terminal of a power switching element on an upper arm side and a higher main electrode terminal of a power switching element on a lower arm side connected to an AC output terminal; An inverter circuit to which a DC power supply voltage is applied between a high-order main electrode terminal of the power switching element and a low-order main electrode terminal of the power switching element on the lower arm side; The same number of switching element drive circuits as the power switching elements for forming the control voltage for intermittent power switching elements for each of the power switching elements, and power based on the potential of the lower main electrode terminal of each power switching element. The control power supply voltage for switching the switching element And a DC power supply voltage detection circuit for detecting the DC power supply voltage, wherein the DC power supply voltage detection circuit is for driving a power switching element on a lower arm side. Switching element drive circuit,
Alternatively, the power switching element is mounted on the same circuit board as the control power supply circuit that supplies a power supply voltage to the switching element drive circuit for driving the power switching element on the upper arm side, and the power switching element is input to the control power supply circuit. An inverter device for detecting the DC power supply voltage based on a potential of a lower main electrode terminal. 4. The control power supply according to claim 3, wherein the DC power supply voltage detection circuit applies a control power supply voltage to each of a pair of switching element driving circuits intermittently connecting the power switching elements of the same phase. An inverter device mounted on the same circuit board as a circuit, wherein the DC power supply voltage is detected based on a voltage between the lower main electrode terminals of the power switching elements input to the control power supply circuits. 5. The inverter device according to claim 1, wherein the inverter circuit drives a traction motor for an electric vehicle, and the DC power supply voltage detection circuit is configured to control the DC power supply voltage in a regenerative mode of the motor. An inverter device is provided for notifying when a predetermined threshold value is exceeded.