A Fault Operation Test Device for a Flexible DC Transmission Valve

Abstract

The invention relates to a fault operation test device of a flexible direct current transmission valve. The fault operation test device comprises a decay current injection loop, a sinusoidal current injection loop and a high voltage injection loop. The high-voltage side of a tested valve is respectively connected with a control valve S1 in the decay current injection loop, a bidirectional control valve S3 in the sinusoidal current injection loop and a bidirectional control valve S4 in the high voltage injection loop. The low-voltage side of the decay current injection loop, the low-voltage side of the sinusoidal current injection loop and the low-voltage side of the high voltage injection loop are respectively connected with the low-voltage side of the tested valve and are earthed. The fault operation test device enables the tested valve to withstand a transient current, transient heat and loss strength similar to real fault working conditions, achieves the test and evaluation to the valve under the fault operation working conditions, and meanwhile, provides a basis for a main circuit parameter design and a protective design. By the adoption of the test device, amplitude, rise time and a decaying process of the decay current can be adjusted according to real working conditions, and the requirement of testing versatility can be achieved.

Description

technical field [0001] The invention relates to a test device for a valve of a flexible direct current transmission system. Background technique [0002] Modular multilevel converter (MMC) has attracted extensive attention since it was proposed in 2003 due to its easy scalability and redundancy under fault conditions. Flexible) is one of the engineered converter topologies. The bridge arm of the MMC is not only a valve for performing switching actions, but also a controllable voltage source connected between the AC output terminal of a certain phase of the converter and the DC bus. Each phase bridge arm unit is composed of several valve towers and a valve reactor. Each valve tower is composed of several valve assemblies, which are independent support parts. Each valve assembly is composed of several sub-modules connected in series. The core device of the sub-module is a high-power high-voltage insulated gate bipolar transistor (IGBT), also known as a modular multilevel con...

AI Technical Summary

Problems solved by technology

In order to make the current have a faster rise rate at the beginning of the test while maintaining a slower decay rate of the subsequent decay current, it is difficult to select the inductance L and the resistance R

At the same time, the instantaneous power and total energy consumed by the resistor R in this circuit are very large, and the system needs to be equipped with a strong heat dissipation system

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