单相LCL型光伏并网逆变器的控制技术

Study on Control Technology of Single-phase Grid-connected Inverter Using LCL Filter

采用并网电流和电容电流双闭环控制策略对并网电流进行直接控制,与传统的并网电流单环控制相比,相当于引入了虚拟阻抗来增加系统阻尼,从而抑制了谐振,增加了系统的稳定性.对提出的策略进行系统建模,深入分析了所提策略的控制器参数对系统稳定性的影响.仿真结果表明,该策略可有效抑制进网电流谐振,并且具有较高的入网电流功率因数和良好的稳态性能.

Dual-loop control strategy with grid current and capacitor current feedback is proposed,which is similar to introducing virtual impedance to increase the system damping eliminating resonance and improving system stability. The system modeling based on proposed control strategy is presented to analyze the influence of controller parameters on its stability. Finally the simulation result illustrates that the strategy can effectively restrain the resonance of grid current,a high in-grid power factor and good steady-state performance are also achieved.