摘要
对基于模块化多电平换流器(modular multilevel converter,MMC)的配电网电力电子变压器在发生交流输入侧单相接地故障、中压直流侧单极接地故障、低压直流侧单极接地故障以及交流输出侧单相接地故障下的故障特性进行了分析。参考MMC-UPFC、MMC-HVDC以及低压交流配电网现有的接地方案,提出适用于配电网电力电子变压器的接地方式:交流输入侧接地变压器接地、交流输入侧大电抗接地、中压直流侧大电阻接地、低压直流侧电容中点接地以及交流输出侧接地变压器接地。对上述接地故障在不同接地方式下的故障特性进行了对比分析,并通过PSCAD仿真平台对所分析接地方式及故障特性进行了仿真验证。最后,基于故障特性分析结果并考虑目前的制造技术,提出了输入侧、输出侧分别采用接地变压器接地作为目前配电网电力电子变压器接地方式的建议。
Fault characteristics of single-phase grounding fault in AC input/output side and single-pole grounding fault in MV/LV DC side of modular multilevel converter（MMC） based power electronic transformer in distribution network were analyzed.Based on existing grounding schemes of MMC-UPFC,MMC-HVDC and LV AC distribution network,different kinds of grounding modes suitable for power electronic transformers were presented in this paper,including AC input side zig-zag transformer grounding,AC input side large inductance grounding,MV DC side large resistance grounding,LV DC side capacitor midpoint grounding and AC output side zig-zag transformer grounding.Characteristics of above different grounding faults in different kinds of grounding modes were compared and analyzed.The grounding modes and fault characteristics were verified with PSCAD simulation.Finally,combined with analysis results of fault characteristics and current manufacturing technology,the conclusion was derived that AC input and output side zig-zag transformer grounding is more advantageous in power electronic transformer.
出处
《电网技术》
EI
CSCD
北大核心
2017年第12期4077-4085,共9页
Power System Technology
基金
北京市自然科学基金资助项目(3172036)~~
关键词
电力电子变压器
接地故障
接地设计
故障特性
power electronic transformer
grounding fault
grounding design
fault characteristics
