基于配电网馈线首端电压追踪的分布式光伏变斜率下垂控制策略

分析了分布式光伏电站无功出力与并网点电压之间的关系,研究了光伏电站无功功率吸收量对配电网线路损耗的影响。在传统下垂控制策略的基础上,提出了一种基于馈线首端母线电压追踪的分布式光伏变斜率下垂控制策略,并介绍了控制系统的架构与软件控制逻辑。在所提改进控制策略下,线路电压水平略高于传统下垂控制策略下的线路电压水平,但线损率指标则更接近线损最优控制策略下的线损率。以IEEE 33节点配电网系统为算例,在OpenDSS上进行时序仿真,并与传统下垂控制策略和线损最优控制策略进行对比,仿真结果表明,所提改进控制策略可以牺牲较少的降压效果来换取更多的降损收益,验证了所提控制策略的正确性和实用性。

Variable slope droop control strategy of distributed photovoltaic based on feeder head-end voltage tracking of distribution network

The relationship between the reactive power output of distributed PV(PhotoVoltaic) power stations and the voltage of interconnection point is analyzed, and the effect of reactive power absorption of PV power station on line loss of distribution network is studied. Based on the traditional droop control strategy, a variable slope droop control strategy of distributed PV based on feeder head-end voltage tracking of distribution network is proposed, and the architecture and software control logic of the control system are introduced. Based on the improved control strategy, the line voltage level is slightly higher than that under the traditional droop control strategy, but the line loss ratio is closer to that under the optimal line loss control strategy. Taking IEEE 33-bus distribution network system as an example, time series simulation is carried out on OpenDSS, and the proposed control strategy is compared with the traditional droop control strategy and the optimal line loss control strategy. Simulative results show that the improved control strategy can sacrifice less voltage reduction effect to gain more loss reduction benefits, which verifies the correctness and practicability of the proposed control strategy.