Abstract:The current on inductive branch on the DC side of the energy storage system in the DC microgrid contains a secondary harmonic component, which will increase the current stress and through-state loss of the switching tube in the converter. The traditional dual-loop control method shows that the secondary harmonic current is not suppressed obviously and the dynamic characteristics of the system is inferior during load hopping. Aiming at these two problems, a control method of introducing notch filter (NF), quasi-proportional resonator (QPR) and load power feedforward (LPF) based on dual-loop control is proposed. The method increases the amplitude of the equivalent impedance of the DC-side inductance branch at twice the output frequency without reducing the amplitude-frequency gain of the voltage regulator or changing the frequency adaptability of the equivalent impedance, and has a excellent suppression effect of the second harmonic current. Meanwhile, the equivalent impedance of the DC side inductance branch outside the double output frequency amplitude is reduced under this control method, which improves the system's ability to resist sudden changes in load. Finally, the experimental results demonstrate the effectiveness of the proposed control method.
徐卿瀚, 蒙显辉, 杨苓, 叶美婷, 何江伦. 直流微电网储能系统的NF+QPR+LPF双闭环2次谐波电流抑制方法[J]. 电工技术学报, 2022, 37(20): 5188-5200.
Xu Qinghan, Meng Xianhui, Yang Ling, Ye Meiting, He Jianglun. NF+QPR+LPF Dual-Loop Secondary Harmonic Current Suppression Method for Energy Storage System in DC Microgrid. Transactions of China Electrotechnical Society, 2022, 37(20): 5188-5200.
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