考虑直流固态断路器通态压降的低压直流配电网最优潮流

在直流固态断路器的实际应用中发现,其通态压降将对低压直流配电网的系统潮流产生不可忽略的影响。因此,文中对考虑直流固态断路器通态压降的低压直流配电网最优潮流(OPF)问题进行研究,建立了只包含连续变量的直流固态断路器稳态模型,从而可以方便地使用现有方法对该问题进行求解。通过RT-Lab仿真实验和对不同电压等级直流配电网的潮流分析可知,对于低压直流配电网而言,直流固态断路器的通态压降不可忽略,否则将导致较大的电压、功率计算误差,严重时将影响系统运行安全。此外,基于RT-Lab仿真平台,分别在考虑和不考虑断路器通态压降的情况下,对低压直流配电网OPF指令的控制效果给予验证。仿真结果表明,在低压直流配电网OPF中,考虑直流固态断路器的通态压降是必要的,并且所得到的指令可较为可靠地控制系统状态使其维持在可行域范围内。

Optimal Power Flow of Low-voltage DC Distribution Network Considering On-state Voltage Drop of DC Solid-state Breaker

In actual application of DC solid-state breaker, it is found that its on-state voltage drop cannot be ignored in the power flow of low-voltage DC distribution network. Therefore, in order to deal with the optimal power flow(OPF)with this problem in consideration, this paper proposes a steady-state model of DC solid-state breaker which contains only continuous variables. This model makes it possible to solve an OPF problem with existing methods conveniently. Based on the RT-Lab simulation results and an analysis of the DC distribution power flow calculations of different voltage levels, it is proved that the voltage drop of DC solid-state breakers cannot be ignored for the low-voltage DC distribution network. Otherwise, it will lead to large errors in voltage profile and power calculations, which will affect system operation safety if it gets serious. What''s more, based on the RT-Lab simulation platform, the control effect of OPF in low-voltage DC distribution network is verified by two cases, i. e. one with and one without the consideration of the voltage drop of DC solid-state breaker. Simulation results show that in the OPF of DC low-voltage distribution network, considering the on-state voltage drop of a DC solid-state breaker is necessary, and the OPF command obtained can reliably control system to maintain it within the feasible region.