基于主动脉冲的MMC-HVDC单极接地故障测距

Single Terminal Fault Location for MMC-HVDC Transmission Line Using Active Pulse

准确可靠的故障测距技术对模块化多电平柔性直流输电系统(MMC-HVDC)故障恢复至关重要。通过分析MMC子模块控制特性,提出基于子模块控制的MMC主动式脉冲产生原理,进而通过检测脉冲发出时间和反射脉冲到达监测点的时间,提出基于主动式脉冲的MMC-HVDC单极接地故障测距方法。针对脉冲到达时刻的精确检测问题,采用基于二分递推奇异值分解(SVD)的脉冲到达时刻检测方法;进一步利用主动式脉冲方法进行在线波速的测定,最后给出了MMC-HVDC主动式脉冲故障测距的流程。该主动式脉冲单端测距方法利用换流器子模块产生脉冲,不需要额外增加设备,并且不受过渡电阻影响,可多次进行测量,提高了故障检测的准确度和可靠性。仿真结果表明单端主动式脉冲测距方法能够对MMC-HVDC线路的单极接地故障进行准确定位,提高了单端测距的可靠性和准确度。

Fault location technology plays an important role in fault recovery of modular multilevel converter high voltage direct current （MMC-HVDC） system. Active pulse generation principle based on submodule control is proposed by analyzing the characteristics of MMC submodule. And then a single terminal fault location method using active pulse is proposed in this paper. Meanwhile dichotomizing recursion singular value decomposition （SVD） is used to detect the accurate arrival time of active pulse. In order to reduce the impact of the active pulse traveling speed on fault location, active pulse method is utilized to detect the travelling speed of the active pulse. The proposed active pulse method does not require additional equipment and the method is not influenced by transition resistance. Fault location can be repeated since the pulse can be sent repeatedly. The simulation results show that the proposed method can locate the grounding point of MMC-HVDC and the reliability and accuracy are improved.