基于HEM灵敏度的配电网分层分区电压调节策略

针对光伏接入后潮流倒送和出力波动带来的电压越限问题,提出一种基于全纯嵌入法(holomorphic embedding method, HEM)灵敏度分析的光储参与配电网分层分区电压调节方法。首先,建立储能和光伏的无功出力模型,并推导出基于HEM的配电网电压灵敏度矩阵,根据灵敏度矩阵运用聚类对配电网进行分区。然后,建立上层电压优化模型,通过全局和分区优化协调调度并网储能、光伏电站与无功调压设备对节点电压和网损进行优化;下层电压调节模型进一步挖掘并网小型分布式光伏及储能的无功能力,基于所得电压灵敏度对各区内越限节点的电压进行调节。最后,应用于某省35 kV的配电网实际系统,验证了所提灵敏度计算方法能够提高电压灵敏度的计算效率以及所提分层分区调压策略能够较好地改善光伏并网后电压越限问题。

Divisional and Hierarchical Voltage Regulation Strategy Based on HEM Sensitivity for Distribution Network

With the increasing integration of PV, the peak and valley of the source and the load are inconsistent in the distribution networks, and the PV generation is intermittent and fluctuating. These characteristics have brought about the problem of overvoltage. This paper proposes a divisional and hierarchical voltage regulation model based on the sensitivity analysis of holomorphic embedding method (HEM). First, the reactive-power output model for energy storage and PV are established, and the voltage sensitivity matrix of distribution network based on HEM is derived. A network partition method is further studied using sensitivity matrix. Then, a two-layer voltage optimization strategy is proposed. The upper-level model dispatches the grid-connected energy storage, PV and volt-var regulating equipment to regulate the voltage in the entire network. The lower-level voltage regulation model further explores the reactive power potential of small grid-connected distributed PV and energy storage to adjust the voltage in each region according to the voltage sensitivity. Finally, the proposed strategy is simulated on a 35kV distribution network. The simulation verified that the proposed sensitivity calculation method is applicable and the voltage regulation strategy is efficient in solving the voltage problem.