基于最优分割法的含DG配电网动态无功优化

Dynamic Reactive Power Optimization in Distribution Network With DG Based on Optimal Partition

为解决有载调压变压器分接头(on-load tap changer,OLTC)、电容器组和分布式电源(distributed generation,DG)的协调优化问题,提出一种配电网动态无功优化方法。该方法采用最优分割法分别对OLTC和电容器组的静态最优投切序列进行有序聚类,在满足最大动作次数约束的前提下实现控制设备在时间上的解耦。分析了常见DG无功出力极限的影响因素,考虑OLTC、电容器组和DG在电压无功调节中的控制能力,提出三者的协调优化方法。由于OLTC的档位调节直接影响整个线路的电压无功分布,首先根据各时刻的静态优化结果和最优分割法确定OLTC的动作时刻及档位;然后,采用最优分割法确定电容器组的动作时刻,并将电容器组的投切容量和DG无功出力联合优化,得到最终的控制方案。最后,通过某实际电网算例验证了所提方法的合理性和有效性。

This paper proposed a dynamic reactive power optimization method in distribution network to solve coordinated optimization problem of on-load tap changer （OLTC）, capacitor bank and distributed generation （DG）. In this method, optimal partition method is used to cluster static optimal switching sequence of OLTC and capacitor bank in order. Optimal partition result can meet constrains of maximum number of switching times and realize time decoupling of control devices. Influencing factors of common DG reactive power output limit is analyzed, and a coordinated optimization method is proposed with consideration of control ability of OLTC, capacitor bank and DG in voltage and reactive power dispatching. Firstly, switching time and position of OLTC is optimized because it affects voltage and reactive power distribution of whole feeder. It is optimized based on static optimization results at each moment and the optimal partition method. Then, capacitor operating time is determined with the optimal partition method. After that, switching capacity of capacitor bank is optimized with DG reactive power output, and final optimal schedule is obtained. At last, rationality and effectiveness of the method proposed is verified with case simulation of a practical power grid.