基于锁相放大器的最大功率点跟踪方法

Maximum Power Point Tracking Method Based on Lock-in Amplifier

为了保证光伏电池组件向负载传输最大功率,光伏发电系统需要快速且精度较高的最大功率点跟踪方法。提出一种基于锁相放大器的最大功率点跟踪方法,采用锁相放大器提取开关纹波的振幅,得到小信号导纳,应用闭环控制使直流工作点的负载导纳与小信号导纳相等,此时即实现最大功率点跟踪。该算法能够在稳态和环境条件改变时快速跟踪最大功率点,追踪精度较高。在Matlab/Simulink环境下将所提出的方法与传统的电导增量法进行仿真对比,结果验证了所提出方法的正确性和有效性。

In order to ensure that the photovoltaic cells transmit the maximum power to the load,the photovoltaic power generation system requires a maximum power point tracking method with quickness and high precision.A new method based on phase-locked amplifier was proposed which could achieve the maximum power point tracking through extracting the amplitude of the ripple by adopting the lock-in amplifier to obtain the small signal admittance and applying the closed-loop control to make the load admittance of the DC operating point equal to the small signal admittance.This algorithm,with relatively high tracking accuracy,could quickly track the maximum power point during the steady state and the changing circumstance.In addition,the method proposed was compared with the traditional conductance increment methods through using Matlab/Simulink simulation,the results verify the correctness and validity of the proposed method.