Study on reverse recovery characteristics of thyristor used in HVDC converter valve

Abstract

As the core component of the HVDC transmission converter valve, thyristors' reverse recovery characteristics have important influence on electromagnetic transient characteristics of the converter valve, and are also the theoretical foundation for the converter valve design, manufacture, operation and maintenance. The effects of forward current, absorption circuit parameters and current change rate on the thyristors' reverse recovery characteristics are studied, and the influence mechanism has been analyzed by experiments. The results shows that the change of the forward current and the current change rate can lead to the reverse recovery charge change, which can change the reverse recovery voltage stress of thyristors. The greater the absorption capacity, the smaller the reverse recovery voltage press of thyristor, and when the absorption capacity is constant, there is the only absorption resistor of the thyristor which can lead to the minimal reverse recovery voltage overshoot of the thyristor.