基于频率调整策略的微电网多目标优化自愈控制

Multi-Objective Optimization for Microgrid Self-Healing Control Based on Frequency Regulation Strategy

针对微电网由并网转孤岛运行时自愈控制过程中的电能质量、经济性、负荷支撑和快速响应等多方面的需求,考虑负荷、分布式电源的随机性特点,以微电网频率控制为主线,提出了基于频率调整的多目标优化自愈控制策略。该策略中,将微电网由并网转孤岛运行的优化自愈控制分为2个主要阶段:第1阶段为一次和二次调频阶段,一次调频通过分布式电源的下垂控制实现,在二次调频中使用了按成本大小依次投退分布式电源的优化控制策略,实现微电网功率平衡及经济运行下的频率、功率稳定;第2阶段为三次调频阶段,以经济运行和最大负荷支撑为目标,综合考虑负荷、分布式电源的随机性,引进机会约束规划算法将不确定量转化为确定量,实现微电网最大负荷支撑下的经济运行。

This paper is concerned with various needs for electricity quality, economy, load support and fast response during self-healing control when microgrid switches from grid-connected to isolated operation. Random features of load and distributed power are also considered. Focusing on microgrid frequency control, multi-objective optimized self-healing control strategy based on frequency regulation is proposed. In this strategy, optimized self-healing control is divided into two stages. The first stage consists of primary and secondary frequency regulations. The primary frequency regulation is realized with droop control of distributed power. For the secondary frequency regulation, optimized control strategy featured with in-service and out-of-service distributed power according to generation cost is adopted. Hence, power equilibrium of microgrid and stability of frequency and power in economical operation is also realized. The second stage is the tertiary frequency regulation with purpose of economical operation and maximal load support. Random features of load and distributed power are taken into consideration. Chance constrained programming algorithm is introduced to transform uncertainty into certainty, thus realizing economical operation of microgrid with maximal load support.