Discrete Wavelet Transform Based Power Management System for HESS for EV Applications

Recent developments in Electric Vehicles technologies have resulted in considerable advancement in Hybrid Energy Storage System (HESS) technology. Due to the modern driving style, the load demands are stochastic and contain high peak transients. These high peaks are responsible for degrading the health of the battery. A HESS which consists of a battery and an Ultracapacitor (UC) is suggested to overcome this disadvantage. This paper proposes a Power Management System which controls the flow of current between the ultracapacitor and battery by using a Discrete Wavelet Transform (DWT) to separate the high and low frequency components of current demand and optimally reducing the stress on the battery, hence, leading to better performance and longer life of the battery.