MPPT Controller Design of PV Module Based on Improved Beta Method for Adaptive Tracking and Zero Oscillation

• Main Authors: Wu, Po-Hsiang, 吳伯祥
• Other Authors: Chen, Yon-Ping
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/qkzcb9

碩士 === 國立交通大學 === 電控工程研究所 === 107 === Maximum Power Point Tracking is an important technique for photovoltaic systems to obtain the maximum power output of a PV module under any environmental conditions. The commonly used methods are the perturb and observe method and Beta method. The perturb and observe method uses a fixed step size to change the duty cycle, which may reduce the tracking speed of the operating point or cause oscillation near the maximum power point. The Beta method first estimates the β values of the maximum power points under various environmental conditions, and then based on the β range to separate the tracking process into transient and steady state. However, the steady state covers a large β range and adopts a fixed step size, so that it faces the same shortcomings as the perturb and observe method. In order to solve this problem, this thesis analyzes the influence of irradiance and temperature change on the β value, and finds that the β value is mainly related to temperature, but only little affected by irradiance. As a result, an improved Beta method is proposed by reducing the β range of steady state, which can increase the tracking speed, achieve zero oscillation and reduce the error between output power and maximum power.