光伏发电并网逆变器建模及电能质量评估

Modeling of Photovoltaic Grid Connected Inverters and Electric Power Quality Evaluation

鉴于光伏发电并网逆变器的建模对于光伏大规模接入、保障系统稳定运行具有重要意义,提出了系统仿真方案,利用Hammerstein-Wiener(HW)非线性模型对光伏并网逆变器的运行进行仿真。通过试验获得直流逆变器电压电流波形、交流逆变器电压电流波形、电压公共耦合点、电网和负荷电流;利用编程确定各种模拟波形并搜索与实际波形相比最准确的模型,同时将该方法运用到电能质量分析中,进而完成对系统的分析和建模。模拟结果表明,该模型效果较好,可以为系统规划、防止系统故障和改善电能质量等方面提供理论依据。

PV grid-connected inverter modeling is important to photovoltaic large-scale access to grid and keep safestability of the system. System simulation scheme is proposed, which Hammerstein-Wiener （HW） nonlinear model isused to simulate the operation of PV grid-connected inverter. DC inverter voltage and current waveforms, AC invertervoltage and current waveforms, voltage point of common coupling, power grid and load current are obtained by experi-ments. It determines a variety of analog waveform and searches the most accurate model matching with the actual wave-form. And then this approach is applied to analyze the power quality. Finally, the system analysis and modeling is com-pleted. The simulation results show that the model has good effect and it can provide a theoretical basis for system plan-ning, preventing system failures and improving power quality.