Improvement in fuel economy of hybrid hydraulic powertrain by conducting a comparative study of two different optimization strategies

This contribution investigates two different power management optimization techniques to optimally split the power between the engine and accumulator of a parallel hybrid hydraulic vehicle (HHV). The goal is to operate the engine at its most efficient region, keep the accumulator charge within bounds, and reduce the fuel consumption while maintaining the vehicle performance. After deriving the mathematical model of the HHV, a local optimization technique is used to solve the problem in each time step for an urban European drive cycle. Then for the same cycle, the results are compared with a global optimization technique. The global optimization shows a distinct improvement in terms of fuel consumption.