灵活电源的协调运行策略与配电网潮流计算

协调确定储能与灵活电源的出力,提高可再生能源的接纳能力,从而获得较高质量的潮流分布方案,是含可再生能源、储能、灵活调节电源配电网规划和运行的基础性工作。针对此提出了一种协调储能、灵活电源出力的实用策略。该策略计算简单、使用方便,在获得收敛的潮流方案的同时,有效提升了配电网对可再生能源的接纳能力。首先给出了所研究配网系统的拓扑结构,针对该结构建立了配电网潮流计算的数学模型,并基于模型分析了以可再生能源电源为主的配电网潮流计算的特点以及存在问题;随后,分别针对潮流模型解算之前以及当出现潮流越限之后两个阶段,提出了协调确定储能与其他灵活机组出力的实用策略,并给出了基于前推回代法解算配网潮流的详细过程;最后,采用改造后的IEEE33节点配网系统作为算例,对所提方法的有效性进行了验证。本研究工作可为以光伏、风电为主的配电网制定潮流分布方案提供一种实用可行的策略。

Coordinated Operation Strategy for Flexible Sources and Power Flow Calculation in Distribution Network

The coordinative determination of output from energy storages and flexible sources can enhance the capability of consuming renewable energy, and thus obtain a high-quality power flow distribution scheme. Therefore, it is fundamental work in the planning and operation of distribution network that contains renewable energy, energy storages, and flexible resources. In this paper, a practical strategy for the coordination of energy storages and flexible sources is proposed, which is simple and convenient to use, and can enhance the distribution network''s capability of consuming renewable energy while obtaining a convergent power flow scheme. First, the topological structure of the distribution system is given, based on which a mathematical model of power flow calculation in distribution network is established, and the characteristics and the existing problem of power flow calculation in distribution network dominated by renewable energy sources are analyzed. Second, aiming at two stages, i.e., before the power flow calculation and after the power flow overload, a practical strategy for coordinatively determining the output from energy storages and other flexible units is proposed, and the detailed process of power flow calculation in distribution network is given based on forward and backward substitution method. At last, the effectiveness of the proposed method is verified with a modified IEEE 33-node distribution system as an example. The research work in this paper can provide a practical and feasible strategy for formulating a better power flow distribution scheme in distribution network that mainly contains photovoltaic and wind power.