Research for Maximum Power Point Tracking Method of Solar cell Based on Load Current Control Combined with Improved Hysteresis Comparison

• Main Authors: Tai-Wei Tseng, 曾台偉
• Other Authors: Horng-Ching Hsiao
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/45124738990293461154

碩士 === 國立臺灣科技大學 === 電機工程系 === 101 === Solar energy is an inexhaustible supply of green energy, but power output of the solar cell can not keep at the maximum power output due to various factors such as sunlight intensity, temperature and load changes, causing energy loss. It is necessary to track the maximum power output with the appropriate hardware circuit and software control techniques so that the solar cells can be responsible to external environment changes at any time, and adjusted to maintain maximum power outputthe state. The thesis presents a maximum power point tracking method of solar cell based on combining load current control and improved hysteresis comparison technique to track the maximum power output. Without detecting voltage and calculating the power, we monitor the output current of DC/DC converter only to simplify the control circuitry and reduce costs. The traditional hysteresis comparison method was revised by adjusting the disturbance direction automatically to improve the tracking performance, meanwhile the time control aogorithm reduced the oscillation loss during working at the maximum power point. The commercial software of Matlab/simulink were used to simulate performances of solar cells, DC/DC converter and the maximum power point tracking technique, to test and compare the power output differences among proposed method and various conventional methods for fixed and variable sunlight. Finally, the microcontroller PIC18F4520, built-in A/D converter and PWM signal generator, was used to construct hardware circuitry, 2W single crystalline silicon solar cell and a 60W tungsten lamp as the sunlight, to simulate power output for different illuminance and verify the effectiveness of the maximum power point tracking proposed.