A new overcurrent test equipment for TSC valve

Rough test must be done before the TSC (Thyristor switched capacitor) is put into service, to demonstrate the proper design of the valve during over-current conditions, caused by valve firing at instants with non-zero voltage between its terminals. However, modern TSC thyristor valves have a high power rating and are difficult to test directly. The core to design TSC over-current test equipment is to correctly reproduce the stresses on the thyristor under fault conditions. The overcurrent fault conditions of TSC and the corresponding current, voltage and heating stresses on the thyristor valves during over-current are studied. The existing test equipments are appraised. New overcurrent test equipment for TSC valve is proposed. The heating current of the new test equipment is supplied by large current source; the over-current and corresponding reapplied voltage are produced by LC resonant circuit. The schematic diagram of the test equipment is given. The working principles are introduced, and the real test waveforms are analyzed. It is proved that the proposed new over-current test equipment is more flexible, whose test ability is also improved evidently, and the most important is that the new equipment can fully meet the IEC standard so is more equivalence to the real fault, which make it override all the existing TSC over-current test equipment.