电流预测的电导增量法在光伏MPPT中的应用

Application of Current Prediction-based Incremental Conductance Method in PV MPPT

在太阳能最大功率点跟踪(MPPT)控制中,传统的扰动观察法(P&O)和电导增量法(INC)在跟踪精度和跟踪速度之间存在矛盾。当外界条件剧烈变化时,还可能产生误判而使跟踪失败。在简要论述误判发生的原因、电流预测的原理和变步长扰动特点的基础上,提出了一种基于电流预测和变步长相结合的INC,通过对传统的INC判据和变步长算法的改进,使MPPT控制的速度和精度均得到提升,并能有效避免系统的误判。仿真和试验证明,该方法较传统P&O和INC有明显优势。

In solar energy MPPT control, there are contradictions between tracking accuracy and tracking speed in traditional perturbation observation （ P＆amp;O ） method and incremental conductance （ INC ） method. Furthermore, when external conditions dramatically change, misjudgement may occur and lead to tracking fails. On the basis of brief description of the reasons of misjudgement, the principle of current prediction, and the features of disturbance with variable step lengths, the INC based on combination of current prediction and variable step length is proposed. Through improving the traditional INC criterion and variable step length algorithm, the control speed and accuracy of MPPT are upgraded, and misjudgement of the system can be avoided. The experimental simulation shows that the method proposed is obviously better than P＆O and INC.