新型的单相光伏并网发电装置

Novel Single Phase Photovoltaic Grid-connected Power Generation Device

针对光伏并网发电过程中电能转换效率低、输出电压总谐波失真偏大等特点,设计了基于STC12C5410AD单片机的单相发电装置。采用电压型全桥逆变电路为核心,运用查表算法,由单片机生成正弦波脉宽调制开关信号,并通过实时采样输出电压与电流,实现了最大功率点跟踪与过压、过流保护,通过降低开关管频率与适当加大回路电流容量等方式降低了能量损耗;同时通过差值比较算法实现了频率跟踪和实时相位跟踪。最后,通过实验进一步完善了系统的设计目标和指定功能。

Aiming at the features of photovoltaic grid-connected generation process,e.g.low power conversion efficiency and large total harmonic distortion in output voltage,the single phase generation device based on STC12C5410AD single chip computer has been designed.In the design,by using voltage full-bridge inverting circuit as the kernel,with table look-up algorithm,the sinusoidal pulse width modulation switching signal is generated by single chip computer,and the maximum power point tracking,over-voltage and over-current protections are implemented through real-time sampling output voltage and current,the energy loss is reduced by decreasing frequency of switching transistor and properly increase loop current rate,and the frequency tracking and real-time phase tracking are realized with difference comparison algorithm.The design target and specific functions of the system are verified and perfected by experiments finally.