基于半正定松弛最优潮流的主动配电网多源协调优化控制

Distribution System Optimal Power Flow With Various Controllable Sources Based on Semi-Definite Relaxation

在负荷持续增长、分布式电源接入条件下,配电网可能遇到复杂的容量阻塞、电压越限问题,需要采用适当的调控方式进行缓解。提出综合多种可控设备对配电网中的电压、容量问题进行多源协调控制。具体包括有载调压变压器分接头、分组投切电容器、分布式电源、电动汽车充电站充电功率以及中压柔性直流互联。首先建立了半正定松弛最优潮流模型,保证最优潮流模型的最优性和求解复杂度;随后讨论了松弛模型的适用条件,指出所采用的松弛方法对一般配电网具有较强的适用性;最后通过算例验证所提出方法能够有效消除电压越限、弃光以及容量越限等情况。

Under background of steady load growth and more distributed generation, distribution systems would face complicated voltage and load problems. Therefore an advanced control method is needed to ensure system safety. This paper proposes a control method integrating different kinds of controllable sources, including on-load tap changing transformers, shunt capacitors, photovoltaic, electric vehicle and DC interconnection. Firstly, an optimization model is proposed based on positive semi-definite relaxation to ensure global optimality and computation efficiency. Then capability of the method, especially why the relaxation is safe, is discussed. Case studies demonstrate effectiveness of the proposed method on relieving voltage violation, solar power curtailment and overload.