JPH06178529A - Gate power supply circuit - Google Patents

Abstract

PURPOSE:To provide an effective gate power supply circuit for realizing size reduction of an inverter or the like, except for a high voltage resistance insulating transformer which feeds a gate power supply voltage to a high voltage region from a low voltage control circuit. CONSTITUTION:A gate power supply circuit comprises a series circuit of capacitors 5, 13 connected in parallel with a self arc-extinguishing type element and resistors 3, 14 and a transformer 15 having an input coil and an output coil connecting the input coil in parallel to the resistors 3, 14 and supplies gate energy to the gate circuit of the self arc-extinguishing type element from the output coil side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate power supply circuit for supplying gate power to a gate circuit of a self-extinguishing type element (hereinafter referred to as GTO) which constitutes an inverter device or the like. Regarding

[0002]

2. Description of the Related Art In an inverter device or the like using a GTO, when the device has a large capacity and a high voltage, a plurality of GTOs are connected in series. Here, as an example, one GTO among a plurality of GTOs that constitute the inverter device is used.
And a circuit accompanying it will be described as an example. FIG. 3 is a block diagram showing a gate power supply circuit which has been conventionally used. For the sake of explanation, the voltage dividing resistors and the like provided at both ends of the GTO are omitted. When using the GTO, a snubber circuit is provided to suppress an overvoltage applied to both ends of the GTO. The snubber circuit is composed of a capacitor 5, a diode 4 and a resistor 3, and when a rapid forward voltage (dv / dt) is applied to the GTO, it is mitigated by a series circuit composed of the capacitor 5 and the diode 4. The resistor 3 is provided to suppress the discharge current from the capacitor 5 at the moment when the GTO 6 is turned on. Diode 7 is a freewheeling diode. The low potential control circuit 2 is provided with an ON signal generation circuit and an OFF signal generation circuit, and each of the light guides 10 and 11 is provided.
ON / OFF signals are transmitted to the gate circuit 8 provided in the high potential stage 1 via the. Gate power is supplied as high frequency power by the gate power supply 12 provided in the low potential control circuit 2 to the high potential stage 1 through the insulating transformer 9 provided in the high potential stage 1. It is supplied to the gate circuit 8. The gate circuit 8 is configured to supply gate power to the GTO 6, and is insulated from the low potential control circuit 2 by an insulating transformer 9.

[0003]

As described above, in the gate circuit of the self-extinguishing element such as the GTO, the insulating transformer 9 is used to supply the gate power of higher potential stage than that of the low voltage control circuit. Are being supplied.

In recent years, with the high frequency of GTO switching, it is necessary to supply a large amount of gate power, and a high-insulation large-capacity insulating transformer becomes large in size, which hinders miniaturization of the device. It was. Also, since a large capacity, high voltage inverter device requires a large number of GTOs to be connected in series, a large number of insulation transformers for high-voltage insulation are also required for the gate power supply, which also reduces the size of the device. It is an obstacle to doing.

An object of the present invention is to omit a high withstand voltage insulating transformer for feeding gate power from a low potential control circuit to a high potential part,
An object of the present invention is to provide an effective gate power supply circuit capable of downsizing an inverter device or the like.

[0006]

In order to achieve the above object, the present invention has a series circuit of a capacitor and a resistor connected in parallel with a self-extinguishing element, an input winding and an output winding. A transformer having an input winding connected in parallel with the resistor;
Gate energy is supplied from the output winding side to the gate circuit of the self-extinguishing element.

[0007]

With the above structure, the capacitor is charged during the off period of the GTO, and when the GTO is turned on, the charge of the capacitor is discharged through the path of the GTO, the transformer and the resistor. That is, the charging energy of the capacitor is taken out as the GTO gate power from the secondary side of the transformer and supplied to the GTO gate circuit.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
The same reference numerals as those in FIG. 3 used in the description of the prior art have the same functions, and the description thereof will be omitted.

In FIG. 1, a capacitor 13 and a resistor 14 are provided.
The series circuit of is connected in parallel to GTO6. Further, the input winding of the transformer 15 having an input winding and an output winding is connected to the resistor 1
4 is connected in parallel, and the output winding and the gate circuit 8 are connected so that the gate electric power is supplied from the output winding to the GTO gate circuit 8. Next, the operation of the present invention will be described with reference to the operation explanatory diagrams of FIGS.

When the GTO 6 is turned off at time t0 = 0, the capacitor 13 is charged to the same value as the voltage applied between the anode and cathode of the GTO 6. G at time t1
When TO6 is turned on, the charging charge of the capacitor 13 is GTO.
6 → The path of the resistor 14 and the path of the GTO 6 → the transformer 15 are discharged. At time t2, the electric charge of the capacitor 13 becomes zero, and the capacitor 13 is charged in the opposite direction between time t2 and t3. Time t4
Then, when the GTO 6 is turned off, the capacitor 13 is recharged to the voltage applied between the anode and cathode of the GTO 6. Thereafter, this operation is repeated, and the charge stored in the capacitor 13, that is, the stored energy is transmitted from the secondary side of the transformer 15 to the gate circuit 8 and used as the gate power of the GTO 6. If such a circuit is used, the power of the gate circuit can be directly supplied from the high voltage section, and it is not necessary to use the insulating transformer 9 used in the prior art.

In the above description, the case where one GTO is used is taken as an example. However, even when a large number of GTOs are connected in series, by adding the circuit of the present invention to each GTO, it is possible to directly obtain the voltage from the high voltage section. -It is clear that the electric power can be obtained.

[0012]

As described above, according to the present invention, since the gate electric power is directly supplied from the high voltage portion, the high withstand voltage insulating transformer can be omitted and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the present invention.

FIG. 3 is a configuration diagram of a conventional gate power supply circuit.

[Explanation of symbols]

1 ... High potential stage 2
... Low potential control circuit 3,14 ... Resistance 4,7
… Diodes 5, 13… Capacitor 6
… GTO 8… Gate circuit 9
… Insulation transformer 10,11… Light guide 12C
… Gate power supply 15… Transformer

Claims (1)

[Claims] 1. A self-extinguishing element, comprising a series circuit of a capacitor and a resistor connected in parallel, a transformer having an input winding and an output winding, and the input winding connected in parallel to the resistor. A gate power supply circuit, wherein gate energy is supplied from the output winding side to the gate circuit of the self-extinguishing element.