An Instantaneous Optimization Based Power Management Strategy to Reduce Fuel Consumption in Hydraulic Hybrids

An instantaneous optimization based power management strategy for output-coupled power-split based hydraulic hybrids has been described in this work. Design considerations for a hydraulic accumulator based regenerative system for hybrids have been outlined. Optimal operation of the non-hybrid version of the power-split transmission provides useful insight into the system optimization and its result has been utilized later. Instantaneous optimization based control combines the efficient system operation with the braking energy regeneration to achieve fuel savings with the hydraulic hybrids in this work. Fuel mileage for a hybrid passenger car has been simulated for standard drive cycles under the instantaneous optimization based control. An output-coupled power-split transmission prototype built on the Hardware-In-the-Loop (HIL) principle has been described briefly. Proposed instantaneous optimization based control has been implemented on the test-rig. The proposed management strategy is compared through measurements and simulations to validate its effectiveness in improving fuel economy.