基于序电流注入模型的三相潮流计算方法

Three phase power flow solution based on node injection sequence currents

针对三相潮流计算中,不对称输电线路间弱耦合关系处理难的问题,引入不对称输电线路的补偿注入电流模型,并提出基于节点注入序电流的牛顿-拉夫逊法。这种方法使PQ节点对应的Jacobian矩阵成为一个常系数矩阵,避免了迭代过程中对Jacobian矩阵的更新。在迭代中通过逐次更新序电流实现潮流求解,克服了序电压变化对方程求解速度的影响。仿真结果表明,该方法较其他算法对不平衡功率、R/X比值敏感度低,能够大幅度地减少迭代次数,缩短不对称输电线路三相潮流的计算时间。

According to the weak mutual coupling of the sequence coupled line in calculating the three phase power flow, three phase sequence deeoupling-eompensation models of unsymmetrical transmission lines were described. The Newton-Raphson method based on node injection sequence currents was applied on the PQ busbars, and the coefficient matrices of updating equations was set to be constant which reduced the time of updating the Jaeobian matricx. Updating the specified sequence currents in every iteration has overcome the influence of the changed sequence voltage on the speed of solving the equation. The results presented show that the proposed method has low sensitivity for power unbalance and R/X ratio compared with the previous methods. The method in this paper can substantially reduce the iteration number and time of calculating the three phase power flow.