CAJ | 학술논문

针对一种在整流侧和逆变侧分别采用电网换相型换流器和模块化多电平换流器(MMC )的混合直流输电系统，提出了直流侧谐波电流频率计算方法和完整流程。在整流侧采用三脉动谐波电压源，等效了12脉动换流器的谐波输出特性；在逆变侧使用电容串联电感的无源结构，作为MMC直流侧等效电路；线路参数计算中采用了全相非解耦模型的改进算法。与基于 PSCAD/EMTDC搭建数字仿真模型进行直流侧谐波电流计算结果的比较，验证了提出方法的准确性。
침대일충재정류측화역변측분별채용전망환상형환류기화모괴화다전평환류기(MMC )적혼합직류수전계통，제출료직류측해파전류빈솔계산방법화완정류정。재정류측채용삼맥동해파전압원，등효료12맥동환류기적해파수출특성；재역변측사용전용천련전감적무원결구，작위MMC직류측등효전로；선로삼수계산중채용료전상비해우모형적개진산법。여기우 PSCAD/EMTDC탑건수자방진모형진행직류측해파전류계산결과적비교，험증료제출방법적준학성。
For a hybrid high-voltage direct current(HVDC)transmission system using the line commutated converter(LCC)at the rectifier side and the modular multilevel converter (MMC) at the inverter side,a calculation method and the complete process of harmonic current at the DC side are proposed.Firstly,the LCC at the rectifier side is replaced by the three-pulse harmonic voltage source,whose harmonic output characteristic is equivalent to a twelve-pulse converter.Secondly,the MMC is represented by a passive electric network,with an improved calculating method for the coupled line model introduced for calculating the admittance matrix of DC transmission lines.Finally,by comparing with harmonic current calculation results at the DC side of a digital simulation model based on PSCAD/EMTDC,the accuracy of the proposed method is verified. This work is supported by National High Technology Research and Development Program of China (863 Program) (No.2012AA051704).