Three-level integrated gate commutation thyristor voltage source inverter bridge arm through protector

Abstract

The invention discloses a three-level integrated gate commutation thyristor voltage source frequency converter bridge arm through protector. The bridge arm through protector is arranged in parallel in a rectifier, a DC filter capacitor and an inverter which are sequentially connected in parallel. In the DC circuit of the three-level integrated gate-commutated thyristor voltage source inverter, the bridge arm through protector includes a protection unit, a bridge arm through protection control unit connected to the protection unit, and a bridge arm through protection control unit connected to the protection unit. A plurality of bridge arms connected to the unit are directly connected to the signal detection unit. The present invention can quickly bypass and reduce the short-circuit current of the through bridge arm; bypass the reverse surge current generated by the inductance of the through loop; consume the energy of the DC bus and accelerate the attenuation process of the surge current; after detecting the through-through of the bridge arm, it can Trigger the bypass thyristor to bypass the discharge of DC energy, and send an alarm signal to the system, so that the system is interlocked for protection. It can effectively protect the three-level IGCT voltage source medium-voltage inverter in the event of a bridge arm through fault.

Description

technical field [0001] The invention belongs to a bridge arm straight-through protector in a high-power medium-voltage variable-frequency AC speed regulating device, in particular to a medium-voltage frequency conversion that can effectively protect a three-level integrated gate commutation thyristor voltage source when a bridge arm straight-through fault occurs Three-level integrated gate-commutated thyristor voltage source inverter bridge arm through protector. Background technique [0002] Integrated gate commutated thyristor (IGCT) is an advanced high-power semiconductor switching device currently used for power conversion. The main power switching device of the three-level medium voltage inverter. [0003] figure 1 Shown is an active front-end type three-level IGCT voltage source type three-phase medium voltage frequency converter. Due to the failure of the IGCT device, or the reverse breakdown of the anti-parallel fast recovery freewheeling diode, or the hardware fa...

AI Technical Summary

Problems solved by technology

[0004] The fatal shortcoming of IGCT is that once the current flowing through it exceeds its shutdown current, it will not be able to shut down

However, this method has limitations. It is suitable for the case where the IGCT component used in the inverter has a small current (lower output power). If the IGCT used in the inverter has already reached the maximum current specification, this method is not suitable.

In addition, due to the high price of IGCT itself, the cost of using this method is relatively high

[0008] Another disadvantage of open circuit protection is that the protection components are connected in series in the DC circuit, and DC current flows during normal operation, which increases the conduction loss. If IGCT is used, a radiator needs to be added

[0009] The bypass shunt method overcomes the shortcomings of the above-mentioned open circuit protection, and is a more suitable and effective direct short-circuit protection method for high-power three-level IGCT voltage source medium-voltage inverters

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