Dynamic Programming Optimized Constrained Engine on and off Control Strategy for Parallel HEV

This paper presents a new control strategy to optimize the fuel economy of parallel configured charge sustained hybrid electric vehicles. This new approach is a constrained engine on-off strategy, which has been developed from the two extreme control strategies of maximum SOC and engine on-off, by taking their advantages and overcoming their disadvantages. A system optimization program using dynamic programming algorithm has been developed to calibrate the control parameters used in the developed control strategy, so that its performance can be as close to the optimal solution as possible. For this paper, a passenger car is simulated on a typical highway driving cycle to illustrate the strategy. The methodology developed can be used on other types of vehicles operating in different environments, such as cities, suburban areas, and their combinations.