基于粒子群优化算法的孤岛微电网电压不平衡补偿协调控制

微电网系统孤岛运行条件下,其系统电压完全由网内众微电网逆变器协调运行提供支撑,微电网逆变器控制性能将决定网内供电电压质量的优劣。考虑到微电网中大量单相负荷的存在,系统负荷实则通常表征为不平衡,容易引起系统电压的不平衡。针对这一问题,以同时兼顾微电网逆变器端口电压及公共连接点(PCC)电压不平衡度控制为目标,从分析电压不平衡机理入手,提出一种基于粒子群优化算法的负序电压补偿算法。补偿算法以逆变器端口电压和PCC电压不平衡度作为约束条件建立目标函数,同时考虑逆变器间的环流问题,在实现逆变器端口及PCC电压不平衡控制的同时减小逆变器间的环流。最后,分别基于MATLAB及某电力电子实时仿真平台搭建了系统仿真模型和半实物实时仿真模型,仿真及实验结果验证了所提方法的正确性和有效性。

Coordinated Control of Voltage Unbalance Compensation in Islanded Microgrid Based on Particle Swarm Optimization Algorithm

The system voltage of microgrid in the islanded operation mode is fully supported by the coordinated operation of all microgrid inverters in the network. Thus, the supply voltage quality of the microgrid is highly dependent on the control performance of microgrid inverters. Due to the existence of a large number of single-phase loads, the system load is usually unbalanced, which causes system voltage unbalance. In solve this problem, aiming at controlling the unbalance degrees of voltages both at the inverter port and the point of common coupling (PCC), this paper proposes a compensation algorithm for negative voltage based on the particle swarm optimization (PSO) algorithm, which starts from analysis on unbalance mechanism. The unbalance degrees of voltages at inverter port and PCC are taken as the constraint conditions to establish the objective function. At the same time, the problem of circulating current between inverters is also taken into account. Consequently, the circulating current among microgrid inverters is suppressed while the voltage unbalance degree is controlled. Finally, based on MATLAB and a power electronic real-time simulation platform, the system simulation model and the semi-physical real-time simulation model are built. The simulation and experimental results verify the correctness and effectiveness of the proposed method.