高壓直流轉換開關點火失敗引起之現象及其對渦輪發電機之影響

Phenomena Caused by a Misfire Fault in an HVDC Converter Valve and the Impact on a Turbine Generator

本文對高壓直流鏈兩種故障狀況加以比較，一為整流器開關點火失敗，另一為換流器開關點火失敗。經由動態模擬分析，本文發現兩故障導致之現象不同，對整流器開關點火失敗而言，這會引起一個具有整流側系統頻率之功率干擾，如果侵犯到換流側鄰近之渦輪發電機組的任何自然扭轉振模，將會引起嚴重的扭轉轉矩。對換流器開關點火失敗而言，這會導致轉換器之換向失敗，進而使高壓直流鏈崩潰，一旦高壓直流鏈崩潰，整流及換流兩側之渦輪發電機組都將遭受相當嚴重的衝擊。

In this paper, we make a comparison between two faults in an HVDC link. One is a misfire fault in the rectifier valve. The other is a misfire fault ill the inverter valve. It is found by a dynamic simulation analysis that the resulting phenomena are different. For a misfire fault ill a rectifier valve, a power disturbance on the rectifier side of system frequency will be induced, which will induce, in a turbine generator neighboring the inverter station, a significant torsional torque if any of the natural torsional modes were invaded. As to a misfire fault in an inverter valve, it tends to cause commutation failure in converters and to collapse the HVDC link. Once there is a collapse ill the HVDC link, a relatively serious impact will be made on both the rectifier and inverter sides of a generator.