Improvement of energy efficiency and environmental safety indicators of a hybrid vehicle through rational selection of its control parameters

Abstract

In the article, based on power balance equations and using the results of experimental studies, a mathematical model of the Toyota Prius II hybrid vehicle has been developed, which makes it possible to determine its energy efficiency and environmental safety indicators under specified driving conditions.

An algorithm for selecting the operating mode of a hybrid vehicle has been developed, which is achieved depending on driving conditions, power unit parameters, and the fulfillment of control and boundary conditions. This algorithm enables the implementation of a specific control strategy and influences the vehicle’s energy efficiency and environmental safety indicators.

To evaluate the influence of the hybrid vehicle power unit parameters and its control on energy efficiency and environmental safety indicators, coefficients of maximum capacity and power of the traction battery, as well as the threshold speed for switching to hybrid mode, are proposed. Depending on these parameters, mathematical modeling of the energy efficiency and environmental performance of the Toyota Prius II hybrid vehicle was carried out in a driving cycle according to UNECE Regulation No. 83.

Based on the simulation results, it was established that, from the standpoint of improving energy efficiency and environmental safety indicators, the most effective approach is to use a control strategy with switching to hybrid mode at speeds above 40 km/h, ensuring that the electric power drawn from the traction battery does not exceed 50% of its nominal value, provided that the battery maximum capacity is within 50-100% of nominal capacity. This makes it possible to reduce the fuel consumption of the hybrid vehicle compared to a conventional ICE vehicle by up to 42%, CO emissions by up to 29%, C_mH_n by up to 52%, and CO₂ by up to 46%, while NO_x emissions increase by up to 33%.