李国庆,刘宇超,王鹤.MMC-HVDC站内交流母线故障特性和保护策略[J].电测与仪表,2017,54(16):. LI Guoqing,Liu Yuchao,Wang He.Characteristic Investigation and Protection strategy Modular Multilevel Converter Based HVDC System under Internal AC Bus Fault Conditions[J].Electrical Measurement & Instrumentation,2017,54(16):.
MMC-HVDC站内交流母线故障特性和保护策略
Characteristic Investigation and Protection strategy Modular Multilevel Converter Based HVDC System under Internal AC Bus Fault Conditions
In order to ensure the efficient and stable operation of the modular multilevel converter HVDC transmission system, it is necessary to analyze the failure mode and failure mechanism of MMC-HVDC in detail. The theory of relay protection and the protection criterion of MMC-HVDC are needed to be further studied. This paper briefly introduces the protection zone of the MMC-HVDC protection system, the different ways of action and the measurement methods of the data required for the protection system. Furthermore, we deeply analysis characteristic investigation under internal AC bus fault(including grounding short circuit and phase to phase short circuit).And the protection strategy after the failure of the AC bus in the station is studied. This paper puts forward a current differential protection by using the percentage restraint. It can reliably avoid the unbalanced current caused by the saturation of the current transformer when an external fault occurs., and it can reliably guarantee the sensitivity of internal fault of AC bus at the same time. In the RT-LAB real-time simulation platform, analysis and the proposed protection strategy is validated.
