多端直流架构的交直流混合配电网三相不平衡潮流计算

在配电网向交直流混合供电的方向发展的新形势下,提出一种能够计及交流三相不平衡的交直流配电网潮流计算方法。首先建立了电压源型换流器的三相稳态潮流模型,推导了换流器的三相潮流以及直流配电网潮流计算方程,并对不平衡系统进行了补偿。考虑了不同的控制方式及适用于配电网的多端直流控制策略,在此基础上,提出了适合配电网的三相不平衡交直流交替迭代潮流计算方法,该方法采用了模块化思想,不需要全局迭代,可以从交、直流侧任意方向开始潮流计算,自动修正越限变量并调用控制策略,实现了交直流潮流计算的解耦。最后,对修改的IEEE 37节点配电系统进行仿真计算,仿真结果证明了算法的有效性、快速性和准确性。

VSC-MTDC Based Three-phase Unbalanced Power Flow Calculation Algorithm for AC/DC Hybrid Distribution Network

Under the new situation where distribution network is developing into AC/DC hybrid distribution network, a three-phase unbalanced AC/DC power flow calculation algorithm considering interconnection from AC unbalanced networks with DC systems is proposed. Firstly, the three-phase steady-state power flow model of voltage source converter (VSC) is established. The power flow calculation equation of a three-phase VSC and DC distribution network is deduced in detail and the unbalanced system is compensated. Furthermore, considering different control methods and control strategies for multi-terminal DC system with voltage source converters (VSC-MTDC) in distribution network, a three-phase unbalanced AC/DC sequential iteration power flow calculation algorithm for distribution network is proposed. Based on the modularization idea, global iteration is not required, and the algorithm calculation could start from any direction of AC or DC side. As a result, the AC/DC power flow calculation is decoupled, and the over-limit variables can be corrected automatically. Finally, the simulation results on the modified IEEE 37-bus test feeder system demonstrate the effectiveness, rapidity and accuracy of the proposed algorithm.