JP2012175881A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion apparatus in which a substrate size is reduced by reducing the number of components of a power-supply unit that supplies driving power to a gate driving circuit for semiconductor switching elements such as IGBTs or FETs.SOLUTION: A power conditioner 1 comprises: a plurality of semiconductor switching elements 6 and 7; a plurality of gate driving circuits 8 and 9 that drive the semiconductor switching elements 6 and 7, respectively; and a power-supply unit 10 that supplies driving power to the gate driving circuits 8 and 9. The power-supply unit 10 is constituted from a high-frequency AC power supply. The power conditioner 1 is further provided, at the input sides of the gate driving circuits 8 and 9, with pulse transformers 13 and 14 that convert a high-frequency alternating current output from the power-supply unit 10 into a direct current.

Description

  The present invention relates to a power conversion device that converts DC power into AC power, and more particularly to a power conversion device that is used in a power conditioner or the like that connects a distributed power source to a system.

  For example, as shown in a solar power conditioner, a power conditioner boosts DC power generated by a distributed power source that is a solar cell, and uses a PWM-controlled inverter to provide a single-phase three-wire system or a three-phase system. It converts into AC power according to the frequency and voltage of a commercial system such as a three-wire system, and outputs power to the commercial system. That is, the power conditioner includes a boosting unit and an inverter unit, the boosting unit boosts the voltage of the solar cell to a voltage required to connect to the system, and the inverter unit is composed of four switching elements. PWM switching is performed so that the output current has a phase synchronized with the system voltage, and AC power is output to the system.

  By the way, in general, a plurality of semiconductor switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and FETs (Field Effect Transistors) are used in the boosting unit and the inverter unit of the power conditioner. When a plurality of elements are used, the semiconductor switching element and its gate drive circuit must be insulated from each other.

  For example, Japanese Patent Laying-Open No. 2009-284562 (Patent Document 1) discloses a plurality of semiconductor switching elements that switch DC voltage at high speed, a plurality of gate drive circuits that respectively drive these semiconductor switching elements, and gates thereof. There is disclosed a high-frequency AC power supply apparatus configured with a gate power supply that supplies drive power to a drive circuit via a rectifier circuit.

  The gate power supply is provided with a plurality of transformer cores that form closed magnetic paths, a common primary winding that passes through these transformer cores, and a spatial distance from the primary winding. And a plurality of secondary windings connected to the respective gate drive circuits, and a transformer drive circuit for switching a DC voltage and supplying an AC voltage to a common primary winding.

JP 2009-284562 A (summary column, FIGS. 3 and 4)

  In order to realize advanced control by the power conditioner, it is necessary to increase the number of semiconductor switching elements such as IGBTs and FETs in the boosting unit and the inverter unit. However, when the number of semiconductor switching elements is increased, as described above, the semiconductor The switching element and its gate drive circuit must be insulated from each other. In the power supply device disclosed in Patent Document 1, the output of the secondary winding wound around the transformer core is set to DC via the rectifier circuit and supplied to the gate drive circuit as DC drive power. There are problems in that the number of components of the power supply device that supplies driving power to the gate drive circuit increases, the substrate size increases, and the total wiring length from the power supply device to the semiconductor switching element increases.

An object of the present invention is to provide a power conversion device in which the number of parts of a power supply device that supplies driving power to a gate drive circuit of a semiconductor switching element such as an IGBT or FET is reduced to reduce the substrate size.

  A power conversion device according to the present invention is a power conversion device that converts DC power of a DC power source into AC power, a plurality of semiconductor switching elements, and a plurality of gate drive circuits that respectively drive these semiconductor switching elements, A power conversion device including a power supply device that supplies driving power to each of the gate drive circuits, wherein the power supply device is configured with a high-frequency AC power supply, and is output from the power supply device to an input side of the gate drive circuit. It comprises a pulse transformer that converts high frequency alternating current to direct current.

  According to the present invention, since the power source of the gate drive circuit of the semiconductor switching element such as IGBT or FET is a high-frequency AC power supply device, it is not necessary to insulate the output terminals, reducing the number of parts of the power supply device, and the substrate size. Can be reduced.

It is a block diagram explaining the power converter device which concerns on Embodiment 1 of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a power conversion device according to the invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and includes various design changes.

Embodiment 1 FIG.
FIG. 1 is a block diagram illustrating a power conversion apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, a power converter (hereinafter referred to as a power conditioner) 1 includes a booster unit 2 and an inverter unit 3, and converts DC power generated by a distributed power source 4 that is a solar cell into a booster unit 2. The voltage is boosted by the inverter unit 3 and PWM controlled using the inverter unit 3 to convert the power into AC power according to the frequency and voltage of a commercial system such as a single-phase three-wire system or a three-phase three-wire system by an electric power company. Then, power is output to the commercial power supply 5.

  The step-up unit 2 and the inverter unit 3 are each composed of four semiconductor switching elements 6 and 7 such as IGBTs or FETs, and the inverter unit 3 outputs an output current having a phase synchronized with the system voltage as described above. PWM switching is performed and AC power is output to the system. The semiconductor switching elements 6 and 7 of the booster unit 2 and the inverter unit 3 are driven by gate drive circuits 8 and 9 that are insulated from each other.

  A power supply device 10 that supplies driving power to the gate drive circuits 8 and 9 includes a power supply input unit 11 that inputs DC power generated by the distributed power supply 4 that is a solar battery, and a power supply AC output unit 12 that outputs high-frequency AC. I have. On the input side of the gate drive circuits 8 and 9, pulse transformers 13 and 14 that convert high-frequency AC output from the power supply AC output unit 12 of the power supply device 10 into DC are provided. Note that the wiring 15 from the power supply AC output unit 12 to the gate drive circuit 8 of the booster unit 2 connects the pulse transformers 13 in a chain shape, and the power supply AC output unit 12 to the gate drive circuit of the inverter unit 3. The wiring 16 to 9 is similarly configured.

As described above, the power conditioner 1 according to the first embodiment is a power supply device that supplies driving power to the gate drive circuits 8 and 9 that drive the semiconductor switching elements 6 and 7 of the booster unit 2 or the inverter unit 3. 10 is composed of a high-frequency AC power supply device,
It is not necessary to insulate each of the power supply AC output units 12. Therefore, the number of parts can be reduced, and the board size is reduced.

  In addition, the wirings 15 and 16 from the power supply device 10 to the gate drive circuits 8 and 9 are connected in a chain shape, and the power supply to the semiconductor switching elements 6 and 7 such as IGBTs or FETs used in the power conditioner 1 is the same. Therefore, there is an effect that the total number of wirings can be reduced and the total wiring length can be shortened.

1 Power conditioner 2 Booster 3 Inverter 4 Distributed power supply (solar cell)
5 Commercial system power supply 6 and 7 Semiconductor switching element 8 and 9 Gate drive circuit 10 Power supply device 11 Power supply input part 12 Power supply AC output part 13 and 14 Pulse transformer 15 and 16

Claims (2)

A power conversion device that converts DC power of a DC power source into AC power, a plurality of semiconductor switching elements, a plurality of gate drive circuits that respectively drive these semiconductor switching elements, and a drive for each of these gate drive circuits In a power conversion device comprising a power supply device for supplying power,
A power converter comprising: a power transformer configured with a high-frequency alternating current power supply; and a pulse transformer for converting high-frequency alternating current output from the power supply into direct current on an input side of the gate drive circuit.   The power converter according to claim 1, wherein wiring from the power supply device to the gate drive circuit is connected in a chain shape.

Images