电阻型超导故障电流限制器应用于VSC-HVDC系统的位置优选研究

Optimal Location Selection of Resistive-Type Superconducting Fault Current Limiter in VSC-HVDC System

由于能独立控制有功、无功功率,无换相失败等优点,基于电压源换流器的高压直流输电系统(voltage source converter based high-voltage direct current,VSC-HVDC)系统被认为是未来电网的发展方向。但是,直流故障与交流故障快速有效隔离,成为影响VSC-HVDC系统发展的重要技术难题之一。为了解决VSC-HVDC系统故障隔离问题和限制故障线路过大的短路电流,应用超导故障限流器逐渐被人们重视。提出基于电阻型超导限流器的故障限流方法,并用所设计的两端双极性VSC-HVDC系统,分别在直流线间短路、直流线路接地短路和三相交流短路情况下,比较电阻型超导限流器可行的安装位置并证明所提限流方法的有效性。最后,利用PSCAD/EMTDC仿真提出在VSC-HVDC系统中电阻型超导限流器的最优安装位置。

Due to the independent control of active and reactive pow er and no commutation failure,etc.,voltage source converter based high-voltage direct current（ VSC-HVDC） system is considered to be the development direction of the future pow er grid. How ever,the problem w hich quickly and efficiently isolates DC fault or AC fault becomes one of the important technical problems of VSC-HVDC system. In order to solve the problem of fault isolation and limit short-circuit current in VSC-HVDC system,the application of superconducting fault current limiter is considered seriously by people gradually. This paper proposes fault current limiting technique based on the resistive-type superconducting fault current limiter（ R-SFCL）.Then,w ith utilizing the designed bipolar VSC-HVDC systems,this paper compares the feasible locations of R-SFCLs,w hen DC line-to-line,DC line-to-ground and three-phase AC faults are occurred,and proves the effectiveness of the proposed current limiting method. Finally,based on the simulation tests in PSCAD / EM TDC,this paper suggests the optimum locations of SFCLs in VSC-HVDC transmission systems.