University of Tasmania, Australia

Power Smoothing of a Variable Speed Wind Turbine with Controlled Hybrid Energy Storage

The main problem of wind energy system is its intermittent nature. As wind is fluctuating in nature, power variations may occur that can reduce the system reliability and power quality. Energy storage can play a vital role to smooth the fast wind-induced power variations. This storage device can also be used to reinforce the dc bus during transients, thereby enhancing its low voltage ride through (LVRT) capability. There are several alternatives available for energy storage devices, such as battery, super-capacitor, hydrogen, flywheel, pumped hydro, compressed air and hybrid storage. In this project, hybrid supercapacitor-battery energy storage is considered. The supercapacitor contains a higher power density than the battery, which allows the supercapacitor to provide more power over a short period of time which is vital in wind energy system. For a corresponding high-efficiency discharge, batteries would have a much lower power capability. On the other hand, the battery has a higher energy density to store more energy and release that over a longer period of time. The supercapacitor-battery hybrid energy storage system will integrate the advantages of both technologies.

This project aims to develop a power electronic converters and their control strategies for hybrid supercapacitor-battery energy storage system to improve the reliability and power quality of wind power generation system. The project works include: development of control strategies, computer modeling and simulation, and hardware implementation using DSP/microcontroller.