微电网低压接口变换器的参数寻优自抗扰控制

Active Disturbance Rejection Control with Automatic Optimization for Low-Voltage Interface Converter in Microgrid

混合储能微电网的并、离网模式灵活切换可较好地容纳分布式能源,但在复杂的工况下,其用电端降压接口的电能质量会受到影响。为此,该文提出一种带有参数自寻优的模糊自抗扰控制(FLADRC)策略对传统双闭环PI控制方式的外环进行改造。首先,根据需求对变换器模型进行分析与化简,并通过状态空间平均法进行建模;然后,依据状态方程包含的模型信息设计了FLADRC的线性扩张状态观测器(LESO)矩阵;之后,在频域分析部分,探究应用FLADRC时的系统性能,从理论上分析FLADRC的跟踪性、收敛性和抗扰性,并基于分析结果给出参数自寻优的模糊逻辑规则;此外,运用李雅普诺夫稳定性理论证明了应用FLADRC时微电网接口变换器的稳定性;最后,在40kW的实验平台上进行实验测试,得到了在多种工况下不同控制策略的动态曲线。实验结果验证了该文所提FLADRC方法的可行性和有效性。

Hybrid energy storage microgrid can accommodate distributed energy well with flexible switching of parallel and off-grid modes, but the power quality of its step-down interface will be affected under complex working conditions. Therefore, an active disturbance rejection control strategy with parameter optimization(FLADRC) is proposed to transform the outer loop of the traditional double closed loop PI control mode in this paper. Firstly, the converter model is analyzed and simplified according to the requirements, and the model is established by the state space averaging method. Then, the linear extended state observer(LESO) matrix of FLADRC is designed according to the model information contained in the state equation. In the frequency domain analysis part, the system performance of FLADRC is explored, and the tracking, convergence and disturbance immunity of FLADRC are theoretically analyzed. Based on the analysis results, the fuzzy logic rules of parameter optimization are given. In addition, Lyapunov theory is used to prove the stability of the microgrid interface converter when FLADRC is applied. Finally, the dynamic curves of different control strategies under various working conditions were obtained by tests on a 40KW experimental platform,which verifies the feasibility and effectiveness of the proposed FLADRC method.