IGBT (insulated gate bipolar transistor) parallel drive and drive protection circuit in high-power high-voltage frequency converter

Abstract

The invention discloses an IGBT (insulated gate bipolar transistor) parallel drive and drive protection circuit in a high-power high-voltage frequency converter. The circuit comprises a drive adapter board, a PWM (pulse width modulation) primary amplifying circuit, an auxiliary power source power-down protection circuit, a drive push-pull circuit, a drive short-out protection circuit, a drive disconnection protection circuit, an IGBT soft turn-off circuit and a drive fault output circuit, the auxiliary power source power-down protection circuit comprises a power source monitoring circuit and a drive resetting circuit, and the power source monitoring circuit sends a drive power source resetting signal to the drive resetting circuit which is connected with the PWM primary amplifying circuit; the drive push-pull circuit is connected with the auxiliary power source power-down protection circuit and connected with the drive adapter board through a drive cable, the drive short-out protection circuit is respectively connected with the drive push-pull circuit and the drive adapter board, an input end of the drive disconnection protection circuit is connected with the drive cable, the IGBT soft turn-off circuit is in signal connection with the drive short-out protection circuit, and an input end of the drive fault output circuit is connected with the drive short-out protection circuit and the drive disconnection protection circuit respectively. The IGBT parallel drive and drive protection circuit has functions of detecting short-out, power-down of a drive power source, soft turn-off and disconnection of the drive cable.

Description

technical field [0001] The invention relates to the field of high-power frequency converter speed regulating equipment, in particular to an IGBT parallel drive and drive protection circuit in a high-power high-voltage frequency converter. Background technique [0002] In high-power high-voltage inverters, the power level of the device is often increased by connecting insulated gate bipolar transistors IGBTs in parallel. Due to the high cost of directly using IGBTs with high power levels, IGBTs with lower power levels are generally used in parallel. In IGBT parallel drive and protection, when IGBT is used in parallel, because there are many drive cables, it is especially important when the drive cable terminal connection is unreliable. In the prior art, the drive cable terminal connection reliability is measured by a multimeter or other manual inspection methods. It is actually operable The performance is poor, and the normal operation of the IGBT cannot be guaranteed when th...

AI Technical Summary

Problems solved by technology

In IGBT parallel drive and protection, when IGBT is used in parallel, because there are many drive cables, it is especially important when the drive cable terminal connection is unreliable. In the prior art, the drive cable terminal connection reliability is measured by a multimeter or other manual inspection methods. It is actually operable Poor performance, when the cable is disconnected, the normal operation of the IGBT cannot be guaranteed

[0003] like figure 2 As shown, the three IGBTs of the lower bridge arm of the U phase are used in parallel. Each IGBT is equipped with a driver adapter board on the surface. If the driving cable corresponding to IGBTL1 is disconnected, the corresponding drivers of IGBTL2 and IGBTL3 are normal. When IGBTL2 and IGBTL3 are turned off, the U phase The upper bridge arm IGBT is turned on, and the UN voltage rises rapidly to the bus voltage. Due to the existence of the Miller capacitance between the IGBT gate and the collector, the rapid change of the UN voltage will induce a voltage at the gate of IGBTL1. When the voltage reaches the IGBTL1 When the voltage is turned on, IGBTL1 will also be turned on. Since the U-phase upper bridge arm IGBT is also in the on-state at this time, the U-phase bridge arm will appear in a short-circuit through state. If the short-circuit protection is not timely enough, a tube explosion will occur.

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