Известия Томского политехнического университета: Инжиниринг георесурсов (Aug 2016)
Study of algorithms for tracking maximum power point for boost DC-DC converter of solar inverter
Abstract
The relevance of the discussed issue is caused by the need to improve energy efficiency of DC-DC power converting devices for needs of alternative power engineering. Nowadays the increasing attention is paid to alternative energy sources such as solar power. This is caused by increase in price for non-renewable energy sources. However, generation of solar energy has a number of problems related to the cost of photovoltaic panels, their utilization and imperfections of devices of energy conversion of these systems. All these issues demand the development of power supplies on modern element base and their control systems which allow reaching high rates of energy efficiency. To achieve these aims the authors have used the known methods of tracking maximum power point. The main aim of the study is to research various maximum power point tracking algorithms for photovoltaic systems; to develop the system with the best efficiency and high-speed performance and physical model of the final device and to estimate its efficiency. The methods used in the study: reviewing of technical publications concerning maximum power point tracking algorithms; simulation modeling using Matlab/Simulink and certain experiments with a prototype of two-phase DC-DC boost converter. The experiments and modeling includes: setup of PI-regulator, imitation of various levels of blackout of a solar battery, assessment of efficiency of the converter. The results. The authors developed the simulation models for adaptive and non-adaptive perturbation and the observation and incremental conductance method and studied their application for different levels of illumination. The software for a microprocessor control system was designed. The authors carried out the experiments in simulation of different levels of illumination of the solar battery to estimate the efficiency of the device. The research demonstrates high value of maximum power point tracking efficiency (99 %) for option with adaptive algorithm of a step change. At the experiment the similar indicators of accuracy (95-96 %) were obtained, at quantization time of 10 ms (for not adaptive algorithm of pertrubation and observation).
