LCL并网逆变器一阶自抗扰控制及基于粒子群优化的控制参数整定方法

在实际并网现场,电网时常包含未知、时变的扰动,故LCL并网逆变器运行工况复杂、恶劣,经常面临频繁脱网的问题.基于此,首先针对LCL并网逆变器设计了结构简单的一阶自抗扰控制器;其次,针对自抗扰控制器参数难以整定的问题,构建了包含控制误差和系统调节时间在内的多目标优化函数,并结合粒子群优化算法实现了一阶自抗扰控制器的参数整定,提高了自抗扰控制器参数设计的效率和合理性;最后,在频域中对系统性能进行分析,并通过仿真和实验验证了所设计控制器的可行性及所设计参数的优越性.结果表明,相比传统带宽法所得控制参数,带所提方法所得控制参数的一阶自抗扰控制能够使LCL并网系统获得更好的跟踪性、抗扰性和入网电流质量,且能够保证LCL并网逆变器在复杂工况下不脱网.

First-order active disturbance rejection control and parameter tuning method based on particle swarm optimization for LCL grid-connected inverter

In the actual grid-connected field, the grid often contains unknown and time-varying disturbances, so the LCL grid-connected inverter operates in complex and harsh conditions, and often faces the problem of frequent off-grid. Firstly, a simple first-order active disturbance rejection controller for LCL grid-connected inverter is designed. Secondly, considering the problem that the parameters of active disturbance rejection controller are difficult to be tuned, a multi-objective optimization function including tracking error and settling time is constructed, and the parameters of the first-order active disturbance rejection controller are tuned by PSO(Particle Swarm Optimization) algorithm, which improves the efficiency and rationality of parameter design for active disturbance rejection controller. Finally, the system performance is analyzed in frequency domain, the feasibility of the designed controller and the superiority of the designed parameters are verified by simulation and experiment. The results show that, compared with the control parameters obtained by the traditional bandwidth method, the first-order active disturbance rejection control with the control parameters obtained by the proposed method can make the LCL grid-connected system obtain better traceability, immunity and quality of grid-connected current, and ensure that the LCL grid-connected inverter will not be off-grid under complex conditions.