用短路发电机进行换流阀故障电流试验

Valve Fault Current Tests of Thyristor Valves by Short-circuit Generator System

阀故障电流试验作为考核换流阀短路电流耐受能力的运行型式试验项目,必须在与实际运行工况最为等价的试验回路上进行。短路发电机系统既能提供阀故障电流试验要求的短路电流,同时又能够在短路电流过零时刻立即提供预期恢复电压,具有较高的等价性,是进行阀故障电流试验的一种理想回路。短路发电机系统进行阀故障电流试验时,先利用阀运行试验合成回路提供换流阀正常工况下的运行条件,在换流阀结温及运行参数满足要求时,通过短路发电机系统模拟实际运行中的突发短路故障,使换流阀流过标准规定的短路故障电流,并承受恢复电压,以考核其故障电流耐受能力。

As an important operation test item, valve fault current tests must prove that the proper design of the valve to withstand the maximum current, voltage and temperature stresses arising from short-circuit current. And the characteristics of the test circuit should be high equivalent to the condition of real operation states. As a power source, the short-circuit generator system supplies the fault current and the prospective recovery voltage exactly at the time when the fault current reaches its zero. It is an ideal test circuit for the valve fault current tests with high equivalence. During the test, the synthetic test circuit for the operational type test supplies normal operation condition of the valve, and the short-circuit generator system suddenly makes a short-circuit fault while the temperature of the thyristor junction and operation parameters reach the required values. So the valve conducts fault current and undertakes prospective voltage to check its ability to withstand the stresses arising from the fault.