Thermal-Aware Control of Power Converters in High-Efficiency Renewable Energy Systems

Abstract

Renewable power generation systems like photovoltaic (PV) arrays and wind energy conversion systems demand very efficient power electronic converters to provide proper energy conversion and good grid connexion. Nevertheless, conduction and switching losses ensure that semiconductor devices including MOSFETs and IGBTs produce a lot of heat during the operation of these converters. Over temperature and cyclic thermal operation may hasten device wear and tear, efficiency, and operational life of power converters, and hence have a direct impact on the overall reliability of the renewable energy system. As a way of overcoming this challenge, this paper suggests a thermal-sensitive approach to power converter that introduces thermal real-time monitoring into the converter controller. The offered method makes use of an electro-thermal model to determine an approximate temperature of junction of semiconductor devices and adjust the critical control parameters (switching frequency and modulation strategy) depending on the temperature. A combination of the temperature feedback and adaptive control algorithms allows the system to maintain device operation within safe thermal constraints and in the process maintain operation with high energy conversion efficiency. The efficiency of the suggested approach is assessed by means of the simulation of a system of energy converters that runs on different loads and at different environmental conditions with renewable energy. According to the results of simulating, it has been shown that the thermal-sensitive control strategy can reduce the maximum junction temperature, decrease thermal stress and converter efficiency by significant margins when compared to the finite-parameter control strategies used traditionally. Moreover, the suggested approach will allow improving the reliability of the existing systems and prolong the life of the essential electronic components in the power sources through overheating avoidance. The results prove that a possible solution to the issues associated with high-efficiency conversion systems of renewable energy power sources is to combine thermal control and intelligent control methods, thus, enhancing their functioning, their durability, and their sustainability.