Inverters are important electric devices for the access of the renewable distributed generation.However,when multiple parallel inverters operating together,it is easy to produce resonance phenomenon in the multi-inverter system because of the influence of the LCL filters and the system circuit.In this paper,the physical model of the multi-inverter system is built and the mathematical model is derived as well.Based on the analysis of the mathematical model,the theory of the resonance is studied.Bode diagrams are constructed to show the resonance of the system with multiple parallel inverters.On the basis of method of virtual resistance,a control strategy is also proposed to achieve harmonic compensation and resonance damping.Finally,the effectiveness of the proposed control strategy is verified on the platform of Matlab/Simulink.%逆变器是新能源分布式发电接入电力系统的重要装置.多逆变器并联运行时,由于LCL滤波器与系统电路的交互影响,极有可能产生谐振问题.文章通过建立多逆变器并联运行时的物理模型与数学模型,分析得出多逆变器并联谐振的基本原理,同时利用波特图综合分析了多逆变器并联谐振现象.之后,基于谐振机理的分析结论,提出了一种不含微分控制环节虚拟电阻的谐振抑制方法,并对虚拟电阻参数的影响和取值进行了分析.最后,通过Matlab/Simulink仿真测试,验证了多逆变器并联谐振及虚拟电阻控制策略的正确性和有效性.
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