JP2571963Y2 - Inverter device - Google Patents

Description

[Detailed description of the invention]

 [Purpose of the invention]

[0001]

The present invention relates to IGBT, MOSFE
The present invention relates to an inverter device having a main circuit including a switching element such as T.

[0002]

2. Description of the Related Art In recent years, a main circuit element has a low driving power.
Inverters using switching elements such as GBTs and MOSFETs are increasing. In general, positive and negative power supplies are required to drive these elements. In the case of an n-phase inverter, the power supply on the negative side of the inverter arm can be shared, so it is necessary to prepare n + 1 individually insulated power supplies. General. Next, a conventional three-phase inverter using an IGBT as a switching element will be described with reference to FIG. FIG.
1 shows a main circuit and a drive circuit of a conventional inverter device.

In FIG. 1, reference numerals 1 to 4 denote power transformers for driving inverter main circuit elements, which are insulated from each other. Reference numeral 1 denotes a power transformer for driving the negative element of each arm of the inverter. It is a power transformer for driving the positive side element of each phase of V and W. 5 to 12 are rectifying diodes of the power transformers 1 to 4 and 13 to 20.
Are composed of two positive and negative power supplies by the smoothing capacitors of the outputs of the rectifying diodes 5 to 12. Also, 21 to 2
Reference numeral 6 denotes a gate drive circuit of the IGBTs 27 to 32. Here, the capacitors 13, 15, 17, and 19 are power sources for positive bias for turning on the IGBTs 27 to 32, and the capacitors 14, 16, 18, and 20 are IGBT 27s.
It is a power source for reverse bias that turns off the switches 32 through 32.

[0004]

However, in the above-described conventional inverter device, the individually insulated transformer requires four outputs in the three-phase inverter, so that even if a multi-output transformer is used, the number of outputs is large. Also, there is a problem that the transformer becomes large because insulation between the windings is required.

Accordingly, the present invention has been made to solve the above-mentioned problems, and provides a small-sized inverter device by sharing a predetermined positive / negative drive power source as another drive power source. The purpose is to: [Structure of device]

[0006]

In order to achieve the above-mentioned object, the present invention has a main circuit having a switching element in a bridge connection, a positive and negative drive power source, and a negative side of the main circuit. A first drive circuit for driving the switching element; and a second drive circuit having positive and negative capacitors and driving the positive-side switching element of the main circuit, wherein a positive drive power supply for the first drive circuit is provided. Are connected to the positive capacitor of the second drive circuit via a diode, and the negative capacitor of the second drive circuit is connected to the negative drive circuit of the first drive circuit via a diode and a resistor. By connecting a voltage fixing zener diode in parallel to the negative capacitor of the second drive circuit, the positive and negative drive power supplies of the first drive circuit can be used as drive power supplies of the first and second drive circuits. Characterized by comprising Nba - the other apparatus.

[0007]

In the present invention configured as described above, the positive and negative drive power supplies are used in place of other drive power supplies.
The drive power supply can be reduced, and the device itself can be downsized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 1, 33 is a resistor,
Reference numerals 34 to 36 denote Zener diodes. Next, the U phase in this embodiment will be described. IGBT2
Since neither 7 nor 28 is turned on, the other three cases will be described.

First, both IGBTs 27 and 28 are turned off.
At this time, the power supply capacitors 15 and 16 of the IGBT 28 are connected to the diode 7, the capacitor 15, the capacitor 16, and the diode 8 from the positive power supply capacitor 13 among the positive and negative power supply capacitors 13 and 14 generated from the output of the transformer 1. , Resistor 33 and capacitor 14 for negative power supply. Here, the Zener diode 34 is an IGB
The voltage of the reverse bias negative power supply capacitor 16 at T28 is fixed, and the voltage of the positive bias power supply capacitor 15 is calculated from the sum of the voltages of the capacitors 13 and 14 by the Zener diode 34.
Minus the Zener voltage of

Next, the IGBT 27 is turned on and the IGBT 28 is turned on.
Is OFF, the positive bias power supply capacitor 15 of the IGBT 28 is charged through the path from the capacitor 13 to the diode 7, the capacitor 15, and the IGBT 27, and the capacitor 1
The voltage is the same as that of the voltage 3.

Finally, the IGBT 27 is turned off and the IGBT
When 28 is ON, the positive pole P of the main circuit DC power supply of the inverter
From the IGBT 28, the capacitor 16, the diode 8, the resistor 33, the capacitor 14, and the negative bias power supply capacitor 16 of the IGBT 28 through the path of the negative electrode N of the main circuit DC power supply.
Is charged, and the voltage becomes the Zener voltage of the Zener diode 34.

At this time, a current flows in the capacitor 14 in the discharging direction. However, if the power supply capability from the transformer 1 is large, the voltage of the capacitor 14 remains at the output voltage of the transformer 1. The resistor 33 is used for limiting the current at this time. Further, diodes 7 and 8 are capacitors 15 and 16
, But also to prevent backflow from other phases,
Insulation from power supply of other phases.

Since the other V and W phases are charged through the same charging path, the IGBT 2 on the negative side of the inverter arm is
7, 29, 31 Only one transformer output for the drive power supply is required, and the device can be downsized.

[0014]

As described above, according to the present invention, the power supply structure can be simplified by sharing a predetermined drive power supply as another drive power supply, so that the inverter device itself can be downsized. Can be.

[Brief description of the drawings]

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

FIG. 2 is a circuit configuration diagram showing a conventional inverter device.

[Explanation of symbols]

1 to 4 Power transformer, 5 to 12 Rectifier diode, 13 to 20 Capacitor, 21 to 26
... gate drive circuits, 27 to 32 ... IGBTs.

Claims (1)

(57) [Scope of request for utility model registration] A first drive circuit having a positive and a negative drive power source for driving a negative switching element of the main circuit; a first drive circuit having a positive and a negative drive power source; And a second drive circuit for driving the positive-side switching element of the main circuit, wherein a positive drive power supply of the first drive circuit is connected to a positive capacitor of the second drive circuit by a diode. together are connected via a de, diode the negative capacitor of the second driving circuit to the negative drive circuit of the first driving circuit - connected via a de and a resistor, the negative capacitor of the second driving circuit A voltage fixing Zener diode is connected in parallel to the first and second driving circuits so that the positive and negative driving power sources of the first driving circuit are configured as driving power sources of the first and second driving circuits. Inverter device.