光伏并网逆变器的仿真研究

为了提高光伏发电效率和电能质量，对光伏并网逆变器进行了相关研究，针对光伏最大功率点跟踪问题，对传统的电导增量法进行融合和改进．提出一种改进的电导增量控制算法。该控制算法能够快速精准地跟踪最大功率点；有效改善系统在最大功率点附近的震荡现象；提高了光伏电池的发电效率。在逆变控制方面，采用电压外环、电流内环的双PI环控制，电压外环实现中间直流母线电压的稳定控制。电流内环用于控制输出电流的稳定，两者通过中间直流母线耦合，匹配简单，系统控制具有较好的快速性和稳定性；减少了谐波含量，输出电流具有良好的正弦度，且与电网电压同频同相．因而提高了电能质量。最后用matlab对光伏并网逆变器进行建模仿真，实验结果表明该系统工作稳定．性能良好。达到了预定的设计效果。

Photovoltaic inverter simulation study

In order to improve the efficiency of photovoltaic power generation and power quality, grid-connected inverter for photovohaic research was carried out for photovohaic maximum power point tracking problem, and After integration improvement to the traditional incremental conductance method, an improved incremental conductance control algorithm was proposed, the control algorithm can track maximum power point fast and accurately, effectively improve the system at maximum power point in the vicinity of the shock phenomenon, and improve the efficiency of photovohaie cells generate electricity. In the inverter control, the outer voltage and inner current double PI loop control were used, voltage outer loop achieved stability of the intermediate DC bus voltage control, current inner loop controled the output current stability, both through the intermediate DC link coupling , simple matched system control has good speed and stability; reduced harmonic content, output current has a good sinusoidal degree, and has same frequency an phase with the grid voltage, thus improved power quality. Finally, use matlab to photovoltaic inverter for modeling and simulation, experiment results show that the system was stable, good performance, and achieved clesigned purpose.