基于改进变步长爬山法的潮流能发电MPPT算法

MPPT Algorithm for Power Flow Generation Based on Improved Variable Step Mountain Climbing Method

针对传统变步长爬山法在潮流能发电系统中对潮流流速突变和随机性波动的适应能力较差,易出现扰动方向判断错误和速度追踪过快的问题,在变步长爬山法的基础上提出一种改进变步长最大功率追踪(MPPT)算法。该方法能够准确判断多种最大功率跟踪的情况并采用两次采样点下的功率和转速的变化程度确定下一时刻步长的大小,自动根据获能系数大小进行分阶段调节,实现对潮流流速突变情况的应对,从而实现最大功率的跟踪。在MATLAB/Simulink环境下搭建基于PID控制与自抗扰控制的仿真系统进行仿真试验,结果表明,改进的变步长爬山法不仅能够实现最大功率的跟踪,而且对潮流流速的随机性波动和突变情况的适应能力更强,具有良好的稳态特性。

Aiming at the problems that the traditional variable step size climbing method has poor adaptability to the sudden change and random fluctuation of tidal current velocity in tidal power generation system,and is prone to disturbance direction judgment error and speed tracking too fast,an improved variable step size maximum power point tracking(MPPT) algorithm is proposed based on the variable step size climbing method.The method can accurately judge a variety of maximum power tracking conditions and use the change degree of power and speed under two sampling points to determine the size of the next step,and automatically adjust the size of the step according to the size of the energy acquisition coefficient in stages to deal with the sudden change of tidal current velocity,so as to achieve maximum power tracking.A simulation system based on PID control and active disturbance rejection control is built in MATLAB/Simulink environment for simulation experiments.The results show that the improved variable step size climbing method not only can achieve maximum power tracking,but also has stronger adaptability to the random fluctuation and sudden change of tidal current velocity,and has good steady-state characteristics.