Inverter drive device and semiconductor module

Abstract

The invention provides an inverter drive device capable of suppressing loss of a semiconductor switching element arranged at an output stage and controlling an output current output to a load during normal operation and preventing overvoltage damage to the semiconductor switching element in an abnormal state. The inverter drive device includes a main drive circuit configured to apply a drive voltage to the semiconductor switching element (such as an IGBT), to thereby turn on and off the semiconductor switching element, a clamping diode configured to clamp a voltage of a counter electromotive force applied to the semiconductor switching element during operation stop of the main drive circuit, a voltage dividing resistor configured to perform resistance voltage dividing and detect a voltage that is proportional to a current flowing through the clamping diode, and an auxiliary drive circuit configured to generate a control voltage in accordance with the voltage detected by the voltage dividing resistor, and to apply the control voltage to the semiconductor switching element, to thereby turn on the semiconductor switching element.

Description

technical field [0001] The present invention relates to an inverter driving device provided at an output stage of an inverter to turn on and off a semiconductor switching element that controls a current output to a load, and an inverter driving device integrally equipped with the inverter driving device and A semiconductor module of the semiconductor switching element. Background technique [0002] The inverter 10 for driving a single-phase motor or a three-phase motor has a semiconductor switching element SW for controlling the current output to the load at its output stage, and an inverter for turning the semiconductor switching element SW on and off. drive unit 1. image 3 It is a diagram showing a schematic configuration of an inverter 10 that drives a three-phase motor M as a load. As a semiconductor switching element SW, an upper arm that is connected to a U-phase, a V-phase, and a W-phase in a totem-pole manner and is driven to conduct in a complementary manner is pro...

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Problems solved by technology

[0025] In this way, if the internal impedance of the upper arm drive circuit 6 (6u, 6v, 6w) is increased, the switching loss in the upper arm IGBT 2u (2v, 2w) will increase when the inverter 10 is operating normally.

In addition, as the heat generated by the conduction operation of the upper arm IGBT 2u (2v, 2w) increases, the switching operation becomes difficult when the general switching frequency of the inverter 10 is 10 Hz or higher.

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