【摘要】 分析单级式光伏并网发电系统中光伏组件、滤波电容及并网逆变器之间的能量耦合关系,把光伏组件的P-V曲线划分为非稳定区、稳定区和滑模变结构区,并给出判别区域的方法。通过理论分析和计算推导,利用其三者之间的耦合关系,可仅根据滤波电容电压的变化,精确给出并网逆变器下一个功率周期的输出功率给定值,在一个功率周期内解除滤波电容与并网逆变器和光伏组件之间的能量耦合关系,优化MPPT的动态过程。提出的方法在系统启动及光伏组件输出功率发生剧烈变化的动态过程尤其适用。通过一台180W的单级并网逆变器样机实验验证理论分析的正确性。更多还原

【Abstract】 The power coupling relationship amongst PV array,filtering capacitor,and grid-connected PV inverter was investigated.The P-V curve was categorized into 3 sections,i.e the unstable area,the stable area,and the sliding-mode stable area.Through theoretical analysis and mathematical reasoning,the periodic power coupling can be reflected by the capacitor voltage and its change in monotony.Based on the power de-coupling of the capacitor in a power cycle by calculating out precisely the required power reference for the inverter in the coming cycle,MPPT process was optimized.The proposed method is especially efficient during MPPT dynamic process,for example during start-up and sharp change in solar radiation.An experimental 180W prototype is designed for verification of theorectical analysis.更多还原