基于接口修正方程的含柔性直流大电网解耦潮流算法

含柔性直流的大电网潮流计算是深入研究柔性直流运行特性的基础。潮流算法主要包括交直流联立求解算法和交直流交替求解算法两类。前者无法利用已有的交流计算程序,扩展性差;后者存在收敛性差、有交替误差等缺点。基于接口修正方程技术,构建了含柔性直流的大电网解耦潮流算法。通过把换流器交流侧和直流侧的节点分裂开,形成换流器、交流网络和直流网络三部分,利用交流网络、直流网络各自与换流器之间的接口修正方程,实现交流电网和柔性直流的潮流计算解耦。该算法可弥补常规算法的不足,同时具备扩展方便和收敛性好的优势。实际的柔性直流工程算例结果验证了方法的正确性及上述优点。

Decoupled Power Flow Algorithm for Large Power Grid with Flexible DC Based on Interface Correction Equation

The power flow calculation of large power grid containing voltage source converter based(VSC-based)high voltage direct current(HVDC)is the foundation for in-depth study of the operation characteristics. Power flow calculation can be divided into two types which are alternative algorithm and simultaneous algorithm. The simultaneous algorithm cannot reuse existing AC power flow calculation while the alternative algorithm has such drawbacks as weak convergence and inherent error. Based on interface correction equation technology, this paper devises a decoupled power flow algorithm with VSC-based HVDC. The nodes of AC and DC side of converter are split and the whole system is divided into the converter, AC network and DC network. With the help of interface modification equation, AC grid and VSC-based HVDC power flow calculations are able to proceed separately. This algorithm has the advantages of high extensibility and good convergence. The validity and superiority of the algorithm is verified by actual power system data with VSC-based HVDC.