摘要
Abstract
To meet the comprehensive requirements of low cost,high efficiency,and strong stability for a household 5 kW single-phase grid-connected inverter,and to address the shortcomings of existing technologies in dynamic re-sponse,harmonic suppression,and scenario adaptability,a design scheme considering both performance and engineering feasibility is proposed.The operating principles of the full-bridge topology,LCL filter circuit,and the PR control+PLL control strategy are systematically analyzed,and the adaptive regulation mechanism under sudden irradiance changes and grid voltage fluctuations is clarified.A quantitative design method for the DC-side capacitor,IGBT,LCL filter,and control parameters is presented.A simulation model was estab-lished using MATLAB/Simulink,and three operating conditions were set for verification:rated steady state,sudden irradiance change(4 kW → 2.5 kW),and grid voltage fluctuation(±10%).Under rated conditions,the grid-connected current THD is 2.8%,the power factor is 0.992,and the efficiency reaches 94.6%.Under sudden irradiance change,the dynamic response time is 7 ms with an overshoot of 5%.Under grid voltage fluctuation,the PLL locking time is 8 ms,and the system maintains stable grid connection.All performance indicators comply with the requirements of GB/T 37408-2019 Technical Requirements for Grid-Connected In-verters for Photovoltaic Power Generation.The proposed parameter design and control strategy effectively achieve a balanced optimization of efficiency,power quality,and dynamic response performance for house-hold single-phase grid-connected inverters.关键词
光伏并网系统/单相并网逆变器/电网电压Key words
photovoltaic grid-connected system/single-phase grid-connected inverter/grid voltage分类
信息技术与安全科学
