基于粒子群优化算法的交流不对称故障下HVDC谐波计算

Particle Swarm Optimization Based HVDC Harmonic Calculation under Asymmetric Faults in AC System

将基于调制理论的谐波分析计算方法与粒子群优化算法相结合,提出了一种基于粒子群优化算法的HVDC谐波计算方法。首先建立改进的换流器动态相量模型,解决了交直流系统的接口问题;然后,利用调制理论对频域下谐波相互作用进行分析,把交直流系统的谐波计算转化为对换流母线电压的优化;最后,应用粒子群优化算法,求解不对称故障情况下换流母线电压最优值,同时得到交直流系统的谐波分布。为验证算法,以CIGRE HVDC模型为例,采用该方法对交流系统各种不对称故障情况编制程序并计算,并与PSCAD/EMTDC软件得到的电磁暂态仿真结果相比较,证明了该算法准确有效。

The paper proposes an optimization algorithm of HVDC harmonic distribution under asymmetric faults in the AC by combining system particle swarm optimization with modulation theory based harmonic analysis.Based on advanced dynamic phasor model of converter,a DC system model which can directly interface with AC systems is established for AC/DC system steady state analysis.The interaction of harmonic through the converter is analyzed by modulation theory.The harmonic calculation of AC / DC system is transformed into the optimization of the converter bus voltage.Finally,the optimized converter bus voltage is achieved by using particle swarm algorithm,and the harmonic distribution of AC / DC system with different asymmetric fault conditions is acquired at the same time.To verify the correctness and effectiveness of the algorithm,the method is used to analyze and calculate the harmonic of CIGRE HVDC system.Compared the results with those obtained by simulation using PSCAD/EMTDC software,it is found that the proposed method is accurate and effective.