一种基于回路电流法的有源配电网潮流算法

Loop-current method based power flow algorithm for active distribution network

提出一种基于回路电流法的主动配电网三相潮流算法,并提出风机等多种分布式电源在该算法中的计算模型。首先建立配电网络对应的图,然后将基本回路电流、变压器原边支路电压、非恒阻抗负荷支路电压、分布式电源支路电压、异步电机正序负序电压、转差率作为未知量,列写回路KVL方程、变压器原副边电流方程、负荷功率平衡方程以及分布式电源相关方程,推导Jacobian矩阵,并利用牛顿法求解方程。该方法不需要PV节点转化为PQ节点的过程,也不需要将环路解列及复杂的节点编号,没有对Jacobian矩阵进行简化和近似,具有二阶收敛性。算例表明,所提方法计算速度快,能够处理所有常见的分布式电源,具有较强环路处理能力,且比前推回推法有更好的收敛性。

A three-phase power flow algorithm for active distribution network based on loop-current method is proposed, in which, the calculation models of various distributed generations, such as wind turbines, etc. are built. The graph of distribution network is constructed, while the loop KVL equations, transformer winding current equations, load power balance equations, and distributed generation relevant equations are formulated, which take the funda- mental loop current, transformer primary winding voltage, branch voltage of non-constant impedance load, branch voltage of dispersed generation, positive and negative voltages of induction motor, and slip as unknown quantities. The Jacobian matrix is derived and Newton method is adopted to solve the equations. The process of PV node trans- ferring to PQ node, loop splitting and complex node numbering ; and simplification and approximation of Jacobian matrix are not needed in the proposed method, and it is of quadratic convergence. Cases show that, the proposed method can handle all common distributed generations and loop circuits with fast calculation speed, and has better convergence than the forward-backward sweep method.