Filter-Based Approach for EV Applications to Share Power between Battery and Ultracapacitor

Electric vehicles demand energy sources that possess both high power and energy density, which cannot be met by individual sources like batteries, fuel cells, or ultra-capacitors (UCs). Therefore, the integration of battery and UC can provide significant benefits to the management of power flow of an EV, as they allow for both large energy storage and the ability to handle rapid load variations. In this paper both the sources (battery and UC) are linked to the DC circuit via converters. The proposed filter based control algorithm will split the demanded current into high and low frequencies components based on time constant. UC will deliver high frequency component during transient loading, while the low frequency component is supplied by the battery during steady-state power demand. DC link voltage profile is maintained constant during transient state. In order to prove the effectiveness of the filter control approach, a simulation is carried out with different time constants (T = 5 sec and 20 sec).