±800 kV换流站交流滤波器绝缘配合影响因素

Influencing Factors of Insulation Coordination of AC Filter in±800 kV Converter Station

交流滤波器作为换流站内的重要设备,其绝缘配合方案对换流站安全稳定运行及设备造价至关重要。针对交流滤波器的绝缘配合方法,以侨乡换流站为例,首先基于PSCAD/EMTDC建立完整的±800 kV直流输电系统仿真模型,即考虑滤波器杂散参数、母线π型等效电路及保护策略的等效模型。其次,仿真分析滤波器投入、交流母线单/三相接地故障、交流滤波器母线单/三相接地故障等5种工况下各交流滤波器避雷器的最大电气应力,提出绝缘配合的决定性故障工况,分析避雷器频繁动作的原因,以及避雷器额定电压选取的影响因素,为交流滤波器的绝缘配合方法提供新的设计思路。最后,在不改变设备绝缘水平的前提下,通过串联避雷器阀片的方式提高避雷器的保护水平至临界值,有效减少避雷器的动作次数。

As an important equipment in the converter station,the insulation coordination scheme of the AC filter is very important to the safe and stable operation of the converter station and the cost of the equipment.In view of the method for insulation coordination of the AC filter,this paper firstly takes Qiaoxiang converter station as an example,building a complete±800 kV DC transmission system simulation model based on PSCAD/EMTDC,which is a detailed equivalent model considering filter spurious parameters,busπ-typed equivalent circuit and protection strategy.Secondly,it carries out the simulation analysis of the maximum electrical stress of each AC filter under five working conditions such as filter input,AC bus single/three-phase grounding faults,AC filter bus single/three-phase grounding faults.In addition,it puts forward the decisive fault condition of insulation coordination and analyzes the reasons for frequent actions of the arrester and the factors affecting the selection of the rated voltage of the arrester,which provides a new design idea for the insulation coordination method of the AC filter.Finally,without changing the insulation level of the equipment,the paper adopts a way of installing the arrester valves in series to increase the protection level of the arrester to a critical value,so as to effectively reduce the action numbers of the arrester.