基于改进接口算法的移频分析与电磁暂态混合多速率实时仿真

SFA-EMTP Multi-rate Real-time Simulation Based on Improved Interface Algorithm

“双高”电力系统对实时仿真算法的计算效率提出了更高的要求,采用单一的仿真算法往往难以兼顾计算效率与仿真精度。为解决这一问题,提出了一种混合使用移频分析(shifted frequency analysis,SFA)与传统电磁暂态(electromagnetic transients program,EMTP)方法的多速率实时仿真方案,并对子系统的接口算法进行了改进。首先,充分发挥SFA方法的高效性优势,建立了在移频相量下联立子系统诺顿等效电路的SFA-EMTP混合仿真框架。随后,从减少计算量的角度出发,提出了一种滑窗离散傅里叶变换与三相坐标变换相结合的解析信号构造方法。进而,为兼顾计算的实时性与仿真精度,提出了一种开关状态更新时刻与仿真节点错位的多速率仿真计算时序。最后,对含分布式电源接入的配电网算例采用所提算法与其他多种算法进行仿真,并将仿真结果与PSCAD(Power Systems Computer Aided Design)的离线仿真结果进行对比,验证了所提算法的正确性和有效性。

Power systems with high shares of renewables and power electronics put forward higher requirements for the computational efficiency of real-time simulation algorithms.However,it is challenging to consider both computational efficiency and accuracy by using only a single simulation algorithm.A multi-rate real-time simulation scheme is proposed to solve this problem,combining shifted frequency analysis and traditional electro-magnetic transient method.The sub-system's interface algorithm was improved in this scheme.Firstly,taking full advantage of the high efficiency of the SFA method,an SFA-EMTP hybrid simulation framework is established to simultaneously solve the sub-system Norton equivalent circuit under the shifted frequency phasor.Then,an analytical signal construction method combining sliding window discrete Fourier transform and three-phase coordinate transformation is proposed to reduce the amount of calculation.Furthermore,a multi-rate simulation calculation order with different switch state update times and simulation start times is proposed to balance the real-time performance and simulation accuracy.Finally,the proposed algorithm and others simulate the distribution network with distributed power access.Compared with the offline simulation results of PSCAD,the correctness and effectiveness of the proposed algorithm are verified.