改进的光伏发电最大功率间歇式扰动跟踪算法研究

Research on Improved Intermittent Perturb & Observe Algorithms of MPPT in PV System

针对扰动跟踪法实现最大功率跟踪(MPPT)时,存在的跟踪速度慢和功率振荡等问题,提出了一种改进的光伏发电最大功率间歇式扰动跟踪算法。根据输出功率的变化对外界环境进行实时判断,若外界环境变化较大,则采用常规的变步长扰动跟踪搜索,提高跟踪的动态响应速度;若外界环境变化较小,则通过恒定的占空比控制维持输出功率不变。仿真结果表明,该算法提高了光伏电池的输出功率,并消除了最大功率点附近的功率振荡。

An improved intermittent perturb ＆ observe algorithms of MPPT in PV system was proposed to solve the problem on the tracking speed low and power fluctuation in the P＆O method for PV cell. The change of environment was judged by the variable quantity of PV cell output power. When the environment changes strongly, the varied step search is implemented, dynamic response speed is also improved. On the contrary, constant duty ratio is utilized to avoid the continuOus perturbation for the P＆O method. Based on the simulation. This algorithm highlights the PV cell power output and climinates the power fluctuation near the max power point.