Wavelet-transform based energy and power decoupling strategy for a novel ultracapacitor-battery hybrid power-split gear powertrain

Electrification of performance vehicles brings several challenges such as the necessity of high-power sources, which can satisfy the power requirements during acceleration and efficiently retrieve energy during deceleration, without performance and lifecycle deterioration of such sources. In addition, the limited space under the hood for these vehicles exterminates the possibility of utilizing large volume high-power propulsion machines. This manuscript proposes an efficient wavelet-transform based energy/power decoupling strategy implemented on a unique power-split gear (PSG) based powertrain deploying two propulsion machines with a hybrid battery/ultra-capacitor (UC) energy storage system (ESS) to overcome the limitations associated with electrified performance vehicles. The proposed control and management strategy guarantees that battery provides the base, transient-free power while transients are compensated by ultra-capacitor. With the proposed hybrid ESS and energy/power decoupling strategy, power density of the ESS can be increased, vehicle performance can be improved and battery lifetime can be prolonged.