含分布式电源的三相不平衡配电网连续潮流计算

Continuation Power Flow Calculation for Unbalanced Three-phase Distribution Networks with Distributed Generators

连续潮流是电力系统电压稳定分析的重要工具。针对含不同类型分布式电源的配电网及其三相线路参数和负荷不平衡的情况,提出了一种三相配电网连续潮流方法,由切线预测环节和牛顿法校正环节组成,并采用局部几何参数化策略处理三相不平衡系统PV曲线的斜锐角现象。考虑了PV和PQ节点类型分布式电源的限值约束,给出了新的节点类型双向转换逻辑和分岔点类型识别方法。通过对IEEE 33节点配电系统进行算例仿真,表明所述算法可以有效追踪三相配电系统的PV曲线,准确计算电压稳定临界点并识别分岔点类型。

Continuation power flow is an important tool for assessing power system voltage stability.A continuation power flow calculation method for three-phase distribution networks is proposed for the unbalanced three-phase lines and loads existing in distribution networks with distributed generators(DGs).Composed of the tangent predictor and the Newton corrector,the proposed method uses local geometric parameterization technique for the characteristics of the PV curves of three-phase unbalanced systems.And a double-switching logic is proposed for handling the operation constraints of DGs modeled as PVand PQnodes.A scheme for identifying the type of bifurcation is also given.Simulation results on an IEEE 33-bus distribution system show that the proposed method is effective in tracing the PVcurves of three-phase distribution systems and calculating the voltage stability critical point as well as identifying the type of bifurcation.