变步长扰动法在光伏最大功率点跟踪中的应用

The Application of Variable Step Size Disturbance Method inPhotovoltaic Maximum Power Point Tracking

由于光伏组件参数的离散性、太阳辐射的差异以及光伏电池部分遮挡等情况,会使光伏组件并联情况下发电效率严重降低。为了提高光伏并网系统的发电效率,提出了分布式的变步长占空比扰动法进行MPP(最大功率点)跟踪方法,克服了由于部分组件发电量下降,连累其他并联组件都同时下降的缺点。变步长占空比扰动法跟踪精度高、运算速度快,更适合大规模光伏发电系统;硬件采用了DC/DC升压电路调节PWM占空比的方法,软件程序采用DSP2812编写。对此方法进行了实际验证,证明此方法运算速度快,准确率高,系统具有较高的稳定性。

Because of the discrete parameters of photovoltaic module,the difference of solar radiation and the partial occlusion of photovoltaic cells,the power generation effi ciency of photovoltaic module in parallel will be seriously reduced.In order to improve the conversion effi ciency of photovoltaic grid-connected system,a distributed variable step duty cycle disturbance method is proposed to track the maximum power point,which overcomes the disadvantage that some components lose power and even other parallel components decrease at the same time.The variable step length duty cycle disturbance method has high tracking accuracy and fast operation speed,so it is more suitable for large-scale photovoltaic power generation system.