Vol. 1, Issue 4 (2017)
Sliding mode control technique to regulate DC/DC buck converters in systems exploiting photovoltaic power generation
Author(s): Le Tien Phong, Nguyen Thi Thanh Thuy
Abstract: This paper introduces a new method, called IB-SMC method, to control DC/DC buck converters in systems exploiting photovoltaic power generation. This method combines the iterative-bisectional technique in the maximum power point tracker and the sliding mode control technique to adjust operational modes of photovoltaic power generation. The IB-SMC controller uses a voltage sliding surface to evaluate the relation between the value of instantaneous voltage at the input terminal of the DC/DC converter and the value of instantaneous voltage at the maximum power point. Using information about the power of electromagnetic radiation from a pyranometer and temperature from a temperature sensor, the sliding surface and hyteresis band are modified by practically operational conditions that help improve energy efficiency of the process exploiting photovoltaic power generation. Simulations are carried out by Matlab/Simulink that show the ability to ensure dynamic stability by tracking instaneous maximum power point at any time whenever having any change of the operational condition, static stability by maintaining the operational point at maximum power point whenever not having any change of the operational condition and help bring out approximately absolute energy efficiency.