An Active Harmonic Grid-Connecting Current Suppression Strategy for Hierarchical Control Based Microgrid
Feng Wei1, Sun Kai1, Guan Yajuan2, Josep M. Guerrero2, Xiao Xi1
1. State Key Lab of Security Control and Simulation of Power Systems and Generation Equipments Tsinghua University Beijing 100084 China; 2. Department of Energy Technology Aalborg University Aalborg 9000 Denmark
Abstract：Given that the droop controlled inverters based grid-connected microgrid (DCIGC-MG) presents low equivalent output impedance when connecting to the grid, the grid-connecting current (GCC) is distorted easily by the harmonic voltage components at the point of common coupling (PCC), and results in the increase of THDn of GCC. An active harmonic GCC suppression strategy for DCGC-MG based on hierarchical theory was proposed in this paper. Firstly, the voltage error between bus of DCGC-MG and PCC of grid was transferred to dq frame by the Park transformation. Then, an additional compensator consisting of multiple resonant voltage regulators was added into the secondary control to generate the harmonic voltage reference for inverters in the primary level. PI and multiple resonant controllers were adopted as voltage controller in the original primary level to improve the voltage tracking performance of inverter. As a result, the voltage difference between the PCC and system bus decreased, and the GCC is purified. The proposed control strategy not only reduces the steady-state hormonic current injected into the grid by the microgrid, but also suppressed the harmonic inrush currents when the microgrid connects to the distorted grid for protecting inverter. Finally, the simulation and experimental results from scaled-down laboratory prototype have verified the proposed control strategy.
冯伟, 孙凯, 关雅娟, JosepM.Guerrero, 肖曦. 基于分层控制的微电网并网谐波电流主动抑制控制策略[J]. 电工技术学报, 2018, 33(6): 1400-1409.
Feng Wei, Sun Kai, Guan Yajuan, Josep M. Guerrero, Xiao Xi. An Active Harmonic Grid-Connecting Current Suppression Strategy for Hierarchical Control Based Microgrid. Transactions of China Electrotechnical Society, 2018, 33(6): 1400-1409.
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2018, Vol. 33 
