JPH0851799A - Inverter and power source using the same - Google Patents

Abstract

PURPOSE:To protect an inverter used to drive a power generator and electric motor by automatically turning off an IGBT of the inverter when no or insufficient power source is provided for an inverter gate drive circuit. CONSTITUTION:An FET 141 is provided to short-circuit between a gate and source of an IGBT 50 when no power is supplied. The IGBT 50 can be kept off when its gate is short-circuited to its source. When the negative voltage of a drive power source 102 is lower than the Zener voltage of a Zener diode, the gate potential of the FET 141 becomes equal to the Zener potential, and the FET 141 is turned on. Thus, the gate of the IGBT 50 can be short-circuited to the source with the FET 141 even when the supply voltage to the gate drive circuit has not reached a specified value. If a drive power source 102 is defective, the IGBT 50 cannot be turned on in error.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for driving a generator by an internal combustion engine, and more particularly, energization by an IGBT (voltage drive type element) for driving the generator as an electric motor when starting the internal combustion engine. The present invention relates to one having an inverter circuit for controlling.

[0002]

2. Description of the Related Art In a mobile power supply device, an internal combustion engine (engine) is used to drive a generator, but the load on a starter for starting the internal combustion engine is reduced, and the entire device is reduced in size. In order to achieve this, it is considered that the generator is energized and driven to operate as an electric motor. As described above, in the device for energizing and driving the generator, as shown in FIG.
As shown in FIG. 3, the generator 3 includes, in addition to the diode D for rectifying the AC power generated by the power generation, an inverter circuit that generates a rotating magnetic field for rotating the generator 3, specifically, a high voltage. Transistor (I
An inverter circuit in which a switching circuit is configured by a GBT (voltage-driven energization element) T is provided.

Further, in the drive circuit for controlling the gate of the IGBT, a complementary circuit forming a current booster is used in order to rapidly discharge the electric charge of the gate when the IGBT is turned off. Further, since a high voltage resulting from power generation is divided by the inter-electrode capacitance of the IGBT and applied to the output side of the drive circuit, the drive circuit outputs a gate control signal to the drive circuit. An insulating element such as a photocoupler is provided between the circuit and the drive circuit. As a power source of the drive circuit, for example, a positive / negative dual power source drive power source for a gate control circuit is provided by a converter insulated by a transformer. It is provided separately from the power source.

[0004]

As described above, in the case of driving the internal combustion engine by the generator at the time of starting the internal combustion engine, since the generator starts power generation after the internal combustion engine is started, the generator Electric drive is no longer necessary. Therefore, the IGBT of the inverter for energizing and driving the generator needs to be always kept in the OFF state, but there is interelectrode capacitance Cd, Cs between the electrodes of the IGBT as shown in FIG.
As shown in FIG. 6, when the voltage appearing in each phase accompanying power generation is applied between the drain and source of the IGBT in the phase of the diode D that is off, the gate-source capacitance C of the IGBT is generated.
Since the impedance of s is high, electric charge is easily charged and accumulated in the gate-source capacitance Cs of the IGBT, and when the electric charge becomes large, the IGBT may turn on. Therefore, in order to reliably turn off the IGBT, it is necessary to maintain the gate-source voltage at 0 volt or less so that the gate potential of the IGBT does not become higher than the source.

However, in order to maintain the potential of the gate of the IGBT at 0 volt or less, it is necessary to operate the above drive circuit and apply a bias voltage. However, the drive power source is supplied by the starter signal at the time of starting the internal combustion engine, and therefore the drive power source is lost with the completion of the start. It is possible to make new wiring to supply power, but IGB
There is a problem in that the drive power source must be operated in order to control the T to be off, and the power consumption during power generation increases. Further, if the drive power supply is cut off due to disconnection or the like, the gate of the IGBT cannot be stably biased, and the operation cannot be guaranteed.

When the internal combustion engine is started at a low temperature, the voltage of the auxiliary battery (also serving as the power supply for the control circuit) is likely to drop due to the large current generated by the starter, which lowers the voltage of the drive power supply. Therefore, IGB
The gate drive voltage of T drops,
The source-to-source voltage rises. That is, since the forward voltage drop of the IGBT increases, the conduction loss due to the current increases and the IGBT
The heat generation amount of T increases and the possibility of causing a defect increases.

The present invention is an apparatus that performs an inverter operation only when it is operated as an electric motor, such as an inverter of a generator driven by an internal combustion engine, even when power is not supplied to the gate drive circuit of the inverter.
The purpose is to reliably keep the IGBT in the off state. When the power supply voltage of the gate drive circuit drops,
In order to prevent failure due to increase in heat generation of IGBT, IGBT
The purpose is to automatically keep T off.

[0008]

According to the present invention, claim 1
In an inverter device that rotationally drives an electric motor, a voltage-driven energization element that is composed of a transistor and supplies a current from a battery to the electric motor, and the voltage-driven energization element is connected in parallel, and when the electric motor performs a power generation operation, A rectifying element that rectifies the current from the electric motor, a gate drive circuit that controls the gate of the voltage-driven energization element, and a gate of the voltage-driven energization element when power is not supplied to the gate drive circuit. The technical means is to include a short-circuiting means for short-circuiting between the sources.

According to a second aspect of the present invention, in the inverter device according to the first aspect, the short-circuiting means is opened when the power supply voltage of the gate drive circuit is higher than a predetermined voltage, and the voltage drive is performed when the power supply voltage is lower than the predetermined voltage. It is a technical means to provide a short-circuit control means for short-circuiting the gate and source of the die energization element. According to a third aspect of the present invention, in the inverter device according to the first aspect, the circuit for setting the gate potential of the voltage-driven energization element to zero potential when the gate-source of the voltage-driven energization element is short-circuited by the short-circuit means. Is provided as a technical means.

According to a fourth aspect of the present invention, in a power supply device, a battery for driving a generator by an internal combustion engine to charge an output of the generator, and a voltage-driven energizing element for supplying a current of the battery to the generator. An inverter circuit consisting of
A gate drive power source for supplying electric power to a gate drive circuit of the inverter circuit; a control circuit for operating the gate drive power source and the gate drive circuit at the time of starting the internal combustion engine to rotationally drive the generator; The technical means comprises a short-circuit means for short-circuiting the gate and the source of the voltage-driven energization element when power is not supplied to the gate drive circuit.

[0011]

According to the present invention, when power is not supplied to the gate drive circuit, the gate of the voltage-driven energization element of the inverter circuit is short-circuited with the source by the short-circuiting means. As a result, the drain-source of the voltage-driven energization element is maintained in the off state. Therefore, the voltage-driven energization element does not accidentally turn on while the electric motor is generating electricity.

According to a second aspect of the present invention, the short circuit control means is provided, and when the voltage of the driving power source is higher than a predetermined voltage,
Since the gate and source of the voltage-driven energization element are opened, the voltage-driven energization element must be reliably switched according to the output of the gate drive circuit when the drive power supply is operating normally. You can If the voltage is lower than the predetermined voltage, the gate and source of the voltage-driven energization element are short-circuited. Therefore, when the voltage of the driving power supply is not normal, even if a signal for turning on the voltage-driven energization element is given to the gate, the voltage-driven energization element is maintained in the off state. Therefore, even when the voltage for the driving power supply is not normal and the signal for turning on the voltage-driven energization element is erroneously and continuously sent from the gate drive circuit, the voltage-driven energization element continues to operate. And never turn on. As a result, the switching loss of the voltage-driven energization element does not increase and heat is not generated, and the voltage-driven energization element and the generator can be protected. According to the third aspect, when the gate and the source of the voltage-driven energization element are short-circuited, the gate potential of the voltage-driven energization element is set to zero potential. Therefore, the potential of the gate is maintained at a potential at which the voltage-driven energization element is surely turned off.

According to a fourth aspect of the present invention, when the internal combustion engine is started, the internal combustion engine start control means operates the drive power source to supply power to the gate drive circuit, and the gate drive circuit drives the inverter circuit in the voltage drive type. The energization element performs a switching operation, the generator is energized and rotationally driven, and an operation for starting the internal combustion engine is performed. When the internal combustion engine is started, the generator starts power generation, and the operation of the drive power source and the gate drive circuit is stopped. When power is no longer supplied from the driving power supply to the gate drive circuit, the gate of the voltage-driven energization element of the inverter circuit is short-circuited with the source by the short-circuiting means. As a result, the drain-source of the voltage-driven energization element is maintained in the off state. Therefore, the voltage-driven energization element does not accidentally turn on while the generator is operating.

[0014]

According to the first aspect of the present invention, when no power is supplied from the driving power source for supplying power to the gate drive circuit for controlling the gate of the voltage-driven energization element, the voltage-driven energization element is provided. Since the gate-source is short-circuited and the voltage-driven energization element is turned off, it is not necessary to operate the gate drive circuit during the power generation operation by the electric motor. Therefore, the wiring for supplying electric power to the gate drive circuit during power generation is unnecessary, and since it is not necessary to operate the driving power supply, power consumption during power generation can be suppressed.

According to the second aspect of the present invention, the gate-source of the voltage-driven energizing element is controlled according to the voltage of the driving power source. Therefore, when the voltage of the driving power source is normal, the voltage-driving element is gate-driven. Since the switching operation can be performed according to the control of the circuit, the generator can be surely driven to rotate at the time of starting the internal combustion engine. When the voltage of the driving power source becomes abnormal and does not reach the predetermined voltage, the gate and source of the voltage-driven energization element are short-circuited and the voltage-driven energization element is kept off. For this reason,
When the voltage of the driving power supply drops during the start of the internal combustion engine, the voltage-driven energization element generates power even if a signal for turning on the voltage-driven energization element is given to the gate. Since the energization of the machine is once interrupted and the voltage-driven energization element loses its loss and does not generate heat, the voltage-driven energization element and the generator can be protected.

According to another aspect of the present invention, when the gate and source of the voltage-driven energization element are short-circuited, the gate potential of the voltage-driven energization element is set to zero potential. Therefore, even if the ON control signal to the voltage-driven energization element is generated, the voltage-driven energization element can be reliably turned off, and the voltage-driving-type energization element can be protected. According to another aspect of the present invention, when no power is supplied from the driving power supply that supplies power to the gate drive circuit that controls the gate of the voltage-driven energization element, the gate and source of the voltage-driven energization element are short-circuited. Since the voltage-driven energization element is turned off, it is not necessary to operate the gate drive circuit after the internal combustion engine is started and while power is being generated by the generator. Therefore, power consumption during power generation can be suppressed, wiring for supplying power to the gate drive circuit during power generation is unnecessary, and it is not necessary to operate the driving power supply.

[0017]

EXAMPLE An example of the present invention will be described below with reference to FIG. In FIG. 1, the output shaft of the engine 1 is connected to the input shaft of the speed increaser 2, and the output shaft of the speed increaser 2 and the rotor of the generator 3 are connected. It is connected to the engine 1 via. Further, the engine 1 is provided with a starter 4, and the output shaft of the starter 4 is connected to the output shaft of the engine 1 via a mechanical reduction mechanism such as a pulley and a belt or a gear.

The generator 3 is a three-phase AC generator, the stator coil is Y-connected, and the rectifying six diodes D are connected to the output of the Y-connected stator coil. Six IGBTs (voltage-driven transistors) 50 are connected in parallel to each diode D to form an inverter circuit 5, and a smoothing capacitor 6 and a generator 3 are provided on the output side of the rectifier circuit formed by the diodes D.
A battery 7 and an electric load (not shown) for accumulating the output power of the are connected. The output of the Y-connected stator coil is connected to an induced voltage detection circuit 8 for detecting the electromotive force of each phase. A position signal generator 9 is provided for detecting the rotational position of the rotor of the generator 3 based on the output signal and transmitting the position signal.

Each IGBT 50 of the inverter circuit 5 is for driving the generator 3 as an electric motor, and the gate of each IGBT 50 of the inverter circuit 5 has a gate of each IGBT 50.
Is connected to a gate drive circuit 100 for controlling the drive current of the.

When the generator 3 is used as an electric motor, the gate drive circuit 100 sends to each IGBT 50 a switching signal corresponding to the rotational position of the rotor of the generator 3 according to the output signal of the position signal generator 9. It sends out sequentially,
As shown in FIG. 2, a control power supply 101 including a gate control circuit 110, six photocouplers 120, and six drive circuits 130, which supplies a predetermined DC voltage for control to the gate control circuit 110, A drive power supply 102 that supplies a DC voltage for driving a drive circuit 130 that requires a large amount of power.

The control power supply 101 comprises a stabilizing power supply such as a self-exciting chopper, and when the power of the control battery 12 is supplied by driving a relay 13, which will be described later, a predetermined direct current is generated by an oscillating operation of the self-exciting chopper. Voltage (eg 5
[V]) is output.

The drive power supply 102 is a transformer 10 driven by a transformer drive circuit 103 formed by an oscillator circuit.
An AC signal is generated via 4 to convert the secondary voltage of the transformer 104 to rectifier diodes d1 and d2 and a power supply capacitor c.
It rectifies and converts it into a predetermined DC voltage by means of 1 and c2, and here it is a dual power supply having two kinds of positive and negative polarities. This drive power supply 102 is also the control power supply 10
As in the case of No. 1, when the power of the control battery 12 is supplied by driving the relay 13, the transformer drive circuit 10
3 oscillates to generate an AC voltage on the secondary side of the transformer 104, thereby supplying the positive and negative two types of DC voltages.

The gate control circuit 110 outputs the gate control signal of each IGBT 50 to each IGBT according to the output signal of the position signal generator 9 corresponding to the rotational position of the rotor of the generator 3.
The light emitting diodes are sequentially sent to the respective photocouplers 120 corresponding to 50 to drive the light emitting diodes for lighting. The photocoupler 120 is for transmitting the control signal of the gate control circuit 110 to the drive circuit 130 to which the induced voltage of the generator 3 is applied in an insulated state.

As shown in FIG. 3, the drive circuit 130 is provided corresponding to each IGBT 50 similarly to the photocoupler 120, and the transistor T for inputting the output of the phototransistor on the light receiving side of the photocoupler 120 is input.
1. A main circuit including transistors T2, T3 and resistors r1, r2, r3 forming a complementary circuit provided in the subsequent stage of the transistor T1 is formed, and each drive circuit 130 is a phototransistor of the corresponding photocoupler 120. A switching signal is sent to the gate G of each IGBT 50 in accordance with the received light signal. Each drive circuit 130 surely turns off each IGBT 50 when the engine 1 is started and the generator 3 is performing a power generation operation, and each IGBT 50 is also turned on when the drive power source 102 starts up or is momentarily disconnected. A protection circuit 140 is provided for each protection circuit.

The protection circuit 140 ensures that the drain and source of the IGBT 50 are in the off state when the drive power supply 102 is in the non-operating state due to the power generation operation of the generator 3. Is a circuit for discharging the electric charge between the gate and the source charged by the electromotive force of the generator 3 by turning on the gate and the source between the source and the low voltage that appears when the drive power source 102 rises. It is a circuit for protecting each element of the IGBT 50 and the drive circuit 130 when applied to the drive circuit 130.

Specifically, the IGBT is generated when the generator 3 is generating power.
As a configuration for turning off 50, the drain and source of the FET 141 are connected between the gate and source of the IGBT 50 through the resistor r4 and the diode d3, and the FET1
The gate and source of 41 are short-circuited by a resistor r5. With this configuration, when the voltage of the drive power source 102 is not applied to the drive circuit 130, the FET1
The gate and source of 41 are short-circuited by the resistor r5,
Since the drain-source of the FET 141 is turned on, the gate-source of the IGBT 50 is short-circuited, and as a result, the IGBT 50 is maintained in the off-state. Further, in order to turn off the IGBT 50 even when a voltage lower than the normal predetermined voltage of the drive power supply 102 is applied at the time of the rise of the drive power supply 102, the FET 50 is turned off.
The cathode of the Zener diode Zd is connected to the gate of the resistor 141, and the anode of the Zener diode Zd is connected to the resistor r6.
The negative power source of the drive power source 102 is connected via. As a result, the potential of the gate of the FET 141 does not become a negative potential when a voltage smaller than the regular voltage set higher than the Zener voltage of the Zener diode Zd is applied at the time of rising of the drive power supply 102. , The gate and source are short-circuited, and the drain and source are always on. By this, IG
The BT 50 is maintained in the off state.

When the drive circuit 130 is applied with a regular predetermined voltage of the drive power source 102, the FE
Since the Zener diode Zd is connected between the gate of T141 and the negative power source of the driving power source 102, the driving power source 102 operates and the Zener diode Zd operates.
If a regular negative voltage higher than the Zener voltage of d is applied, the drain-source of the FET 141 is surely turned off, and the short-circuit state between the gate and source of the IGBT 50 is released. As a result, by the gate drive output circuit including the complementary circuit of the transistors T2 and T3,
A signal corresponding to the output of the photocoupler 120 is transmitted, and I
The GBT 50 is controlled.

In the gate drive circuit 100 of the present embodiment having the above configuration, when the voltage of the drive power source 102 is not operating, when the normally-on type FET 141 is used, the gate rsource is connected by the resistor r5. Is short-circuited, and the drain-source of the FET 141 is turned on. As a result, the gate and source of the IGBT 50 are short-circuited, and the IGBT 50 is set to the off state. When the drive power supply 102 is operating and a regular predetermined voltage appears, a negative voltage higher than the Zener voltage is applied to the gate of the FET 141 by the negative power supply of the drive power supply 102. With a negative potential, the FET 141 is turned off, and the gate of the IGBT 50 is controlled according to the output of the photocoupler 130.

When a voltage smaller than the regular predetermined voltage appears when the drive power source 102 starts up,
While the voltage is lower than the Zener voltage, FET141
Between the gate and source of the
Is turned on, the voltage appearing at the gate of the IGBT 50 is discharged by the FET 141 and the IGBT 50
Since the gate-source of is turned on, the IGBT5
0 remains off.

As described above, when the gate and source of the IGBT 50 are short-circuited, it is necessary to rapidly discharge the amount of charge between the gate and source, and the current capacity of the discharge circuit becomes a problem. The present invention uses the transistors T2 and T3 of the gate output drive circuit to provide the IGBT5
The current capacity of the FET 141 that short-circuits the gate and source of 0 is realized with a small one. That is, in this embodiment,
The drain of the FET 141 is connected to the resistor r4 with respect to the gate potential of the IGBT 50 and the emitters of the transistors T2 and T3.
And a diode d3. Therefore, IGB
The gate potential of T50 is higher than that of the short-circuited FET 141 by the voltage drop of the diode d3. But,
Since the drain of the FET 141 is connected to the collector of the transistor T1 via the diode 4 and further connected to the bases of the transistors T2 and T3 via the resistor r3, if the voltage drops of the diode d3 and the diode d4 are the same. , The base potentials of the transistors T2 and T3 are equal to the gate potential of the IGBT 50. That is, since the emitters and the bases of the transistors T2 and T3 have the same potential, the transistors T2 and T3 are turned off.
Even if the gate and source of T50 are short-circuited, power is not supplied from the drive power supply 102, so the short-circuit FET 14
The current capacity of 1 may be small. Next, a case where the amount of electric charge accumulated between the gate and the source is rapidly discharged will be described. When the FET 141 is short-circuited, the anode potentials of the diodes d3 and d4 become equal as described above. At this time, when the gate potential is high due to the charge accumulated between the gate and the source, the resistance r4 causes a voltage drop, so that the anode potential of the diode d3 becomes substantially equal to the source potential, and the base potential of the transistor T3 also becomes equal to the source potential. . On the other hand, the emitter of the transistor T3 is the IGB
Since it is equal to the gate potential of T50, the emitter and base of the transistor T3 are negatively biased and a base current flows. As a result, the transistor T3 causes the IGBT
Since the gate of 50 is connected to the negative power source, the electric charge accumulated between the gate and the source is rapidly discharged via the transistor T3 and hardly flows to the FET 141. Gate·
When the charge between the sources is released, the gate potential of the IGBT 50 is lowered to the zero potential as described above, and the transistor T3 is automatically turned off. Thus, the current capacity of the FET 141 for short-circuiting the gate and the source can be reduced.

The control device 11 is equipped with a control battery 12, which starts the engine 1 in response to the operation of a key switch (not shown) and, after the engine 1 is started, in response to an electric load such as the battery 7. It controls the exciting current of the exciting winding 3a of the generator 3 and also controls the throttle opening of the engine 1. Reference numeral 13 is a relay for energizing the starter 4 and the gate drive circuit 100.

Next, the operation of this embodiment having the above construction will be described. When the key switch is turned to the on position at time t ₀ and further to the starting position of the engine ₁ at time t ₁ , the relay 13 is driven and the power of the control battery 12 is supplied to the starter 4 by the relay 13. The engine 1 is started by the operation of the starter 4. Further, when current is also supplied to the control power supply 101 and the drive power supply 102 and a voltage higher than a predetermined voltage is supplied from each power supply to the gate drive circuit 100, the FET 141 is turned off and the outputs of the transistors T2 and T3 are output. Accordingly, the gate of the IGBT 50 becomes controllable.

It is induced that the rotational speed of the engine 1 gradually rises and the induced voltage of the generator 3 is generated, and the rotational speed Ne of the engine 1 reaches a predetermined rotational speed ns lower than the idle rotational speed ni at time t _2. When detected by the detection signal of the voltage detection circuit 8, the rotation signal of the rotor of the generator 3 is sent from the position signal generator 9 to the gate drive circuit 100, and the gate drive circuit 100 responds to the rotation position signal of each IGBT 50.
A switching signal is sent to the gate of the generator, and the generator 3 is inverter-controlled. As a result, the IGBT 50 of the inverter circuit 5 operates the generator 3 as an electric motor, so that the generator 3 itself starts rotating and drives the engine 1 via the speed increaser 2. Since the engine 1 is rotationally driven by the rotational force of the starter 4 and the rotational force of the generator 3,
The rotation speed increases, reaches the idle rotation speed ni at time t ₃ , and the start is completed.

When it is detected by the detection signal of the induced voltage detection circuit 8 that the engine speed Ne of the engine 1 has reached the idle engine speed ni, the drive of the inverter circuit 5 by the gate drive circuit 100 is stopped. When the start of the engine 1 is confirmed and the key switch is returned from the starting position to the on position, the relay 13 is turned off, and the starter 4, the control power supply 101, and the drive power supply 102 are deenergized to operate. Therefore, the power supply to the gate drive circuit 100 is stopped.

In the gate drive circuit 100, in the drive circuit 130, the FET is turned off when the supply voltage drops as the drive power supply 102 stops operating and becomes lower than a predetermined voltage.
Since 141 is turned on and the transistor T3 is turned on, the charge of the gate of the IGBT 50 is discharged by the transistor T3 and the potential of the gate of the IGBT 50 becomes 0 volt. As a result, the IGBT 50 is turned off. Further, when the voltage of the drive power source 102 becomes 0 volt, the FET 141 maintains the ON state, and the IGBT 50
In order to maintain the short circuit between the gate and source of
T50 is maintained in the off state. As a result, the induced voltage generated in each phase of the generator 3 turns on only the diode D of the inverter circuit 5 and does not flow to the IGBT 50.

On the other hand, when the engine 1 is started at a low temperature, the voltage of the control battery 12 is lowered by the relay 13, and the output voltage of the drive power source 102 is lowered to be lower than the predetermined voltage. In case of FET
Since the gate potential of 141 rises and the FET 141 is turned on, thereby short-circuiting the gate and source of the IGBT 50, the IGBT 50 is kept off even when the gate control signal is sent from the gate control circuit 110. To be done. Therefore, the generator circuit 3 is not energized by the inverter circuit 5. After that, when the voltage of the control battery 12 is recovered and the voltage of the drive power supply 102 reaches a normal predetermined voltage, the FET 141 is turned off again,
The gate of the IGBT 50 is controlled according to the control signal of the gate control circuit 110, and the generator 3 can be driven to rotate, whereby the engine 1 can be started.

As described above, according to the present invention, since the short-circuit means for short-circuiting the gate and the source of the IGBT 50 when the electric power is not supplied is provided, the generator 3 is driven by the inverter to operate as the electric motor to drive the engine 1. Even if the gate drive circuit 100 is not supplied with electric power after the start-up, the IGBT 50 of the inverter circuit 5 can be maintained in the OFF state. Therefore, it is not necessary to supply power to the gate drive circuit during power generation.

Further, even when the supply voltage is lower than the predetermined voltage, the gate and source of the IGBT 50 are short-circuited. Therefore, when the voltage of the power supply for supplying power to the gate drive circuit is low, the gate drive circuit operates. The IGBT 50 does not continue to be in the ON state even if
The GBT 50 and the generator 3 can be protected. Further, since the FET used as the short-circuit means is used for a signal with a small current, it is easy to form an IC as a gate drive circuit,
It is also possible to mount it on an IGBT. Although the FE is used as the short-circuit means in the above-described embodiment, the function can be realized by a switching element that is short-circuited when the power is not turned on and is opened when the power is turned on. For example, a normally-on type relay can be used. Further, in the above embodiment, the timing of starting the driving of the inverter circuit 5 is
This is performed when the rotation speed of the generator 3 reaches or exceeds the predetermined rotation speed. However, after starting the engine 1 by the starter 4, the rotation speed of the generator 3 is assumed to reach the rotation speed at which the induced voltage can be detected. A timer means for generating time may be provided and the driving of the inverter circuit 5 may be started by the timer.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of a mobile power supply device showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an outline of a gate drive circuit according to an embodiment of the present invention.

FIG. 3 is a circuit diagram showing details of a gate drive circuit according to an embodiment of the present invention.

FIG. 4 is a partial circuit diagram showing the relationship between the generator and the inverter circuit according to the embodiment of the present invention.

FIG. 5 is a circuit diagram of an IGBT for explaining the problem of the present invention.

FIG. 6 is a waveform diagram showing the output of the generator of the present invention.

[Explanation of symbols]

 1 Engine (Internal Combustion Engine) 3 Generator (Generator) 5 Inverter Circuit 50 IGBT (Voltage Driven Energization Element) 10 Gate Drive Circuit 11 Control Device (Internal Combustion Engine Start Control Circuit) 12 Battery 102 Drive Power Supply (Drive Power Supply) 141 FET (short-circuit means) Zd Zener diode (short-circuit control means)

Claims (4)

[Claims] 1. An inverter device for rotationally driving an electric motor, comprising a voltage-driven energization element comprising a transistor for supplying a current from a battery to the electric motor, and the voltage-driven energization element connected in parallel to generate electric power from the electric motor. A rectifying element that rectifies the current from the electric motor during operation, a gate drive circuit that controls the gate of the voltage-driven energization element, and a case where power is not supplied to the gate drive circuit,
An inverter device comprising: a short-circuit means for short-circuiting the gate and source of the voltage-driven energization element. 2. The gate-source connection of the voltage-driven energization element is opened when the power supply voltage of the gate drive circuit of the inverter device is higher than a predetermined voltage, and is opened when the power supply voltage is lower than the predetermined voltage. The inverter device according to claim 1, further comprising a short-circuit control means for short-circuiting the inverter. 3. A circuit for setting the gate potential of the voltage-driven energization element to zero when the gate-source of the voltage-driven energization element is short-circuited by the short-circuit means. The inverter device according to 1. 4. A battery for driving a generator by an internal combustion engine to charge an output of the generator, an inverter circuit including a voltage-driven energizing element for supplying a current of the battery to the generator, A gate drive power source for supplying electric power to a gate drive circuit of an inverter circuit; a control circuit for operating the gate drive power source and the gate drive circuit at the time of starting the internal combustion engine to rotationally drive the generator; A power supply device comprising: short-circuit means for short-circuiting the gate and source of the voltage-driven energization element when power is not supplied to the drive circuit.