基于新型趋近律的光伏MPPT控制策略

为了进一步提高光伏发电系统的最大功率跟踪性能，提出一种基于新型趋近律的滑模控制策略。同时，针对普遍采用的非线性滑动流形易出现判断误区的情况，提出一种应用于光伏发电系统最大功率跟踪的可切换线性滑动流形，使得系统在受干扰后具有更快的响应速度。采用Boost电路作为控制对象，利用双曲正切函数的连续性和快速性，设计一种基于指数函数的快速性和幂函数的平滑性的多幂次趋近律的滑模控制策略，并在Matlab/Simulink仿真平台中进行验证。结果表明：当光照强度、温度、负载和参数发生变化时，采用新型趋近律和可切换线性滑动流形的滑模控制策略能够实现对最大功率点的精确追踪，具有更好的动态响应速度和抗振性能。

MPPT control strategy based on a new reaching law for a photovoltaic power system

To further improve the maximum power tracking performance of a photovoltaic power generation system, a sliding-mode control strategy is proposed based on a novel reaching law. A switchable linear sliding manifold applied to the maximum power tracking of the PV is proposed for the commonly used nonlinear sliding manifold which is prone to judgment error. This makes the system have faster response after disturbance. This paper adopts the Boost circuit as the controlled object, and by using the continuity and rapidity of the hyperbolic tangent function, designs a sliding-mode control strategy based on multiple power convergence laws with the speed of the exponential function and the smoothness of the power function, and verifies it on the Matlab/Simulink simulation platform. The results show that the sliding-mode control strategy with the new convergence law and switchable linear sliding-mold surface can achieve accurate tracking of the maximum power point when the light intensity, temperature, load and parameters change, and has quicker dynamic response and better anti-buffeting performance.

This work is supported by the National Natural Science Foundation of China (No. 51867007).