Integrated Optimization of Power Split, Engine Thermal Management, and Cabin Heating for Hybrid Electric Vehicles

TL;DR

This paper introduces an integrated management scheme for hybrid electric vehicles that optimizes power split, engine thermal control, and cabin heating to reduce fuel consumption, especially in cold and congested conditions.

Contribution

It develops a control-oriented model validated with real data and uses dynamic programming to optimize multiple thermal and power parameters for fuel efficiency.

Findings

Significant fuel savings potential identified with the integrated scheme.

Engine thermal effects and cabin heating greatly influence optimal power management.

Simulation shows improved fuel efficiency over conventional strategies.

Abstract

Cabin heating demand and engine efficiency degradation in cold weather lead to considerable increase in fuel consumption of hybrid electric vehicles (HEVs), especially in congested traffic conditions. This paper presents an integrated power and thermal management (i-PTM) scheme for the optimization of power split, engine thermal management, and cabin heating of HEVs. A control-oriented model of a power split HEV, including power and thermal loops, is developed and experimentally validated against data collected from a 2017 Toyota Prius HEV. Based on this model, the dynamic programming (DP) technique is adopted to derive a bench-mark for minimal fuel consumption, using 2-dimensional (power split and engine thermal management) and 3-dimensional (power split, engine thermal management, and cabin heating) formulations. Simulation results for a real-world congested driving cycle show that the engine thermal effect and the cabin heating requirement can significantly influence the optimal behavior for the power management, and substantial potential on fuel saving can be achieved by the i-PTM optimization as compared to conventional power and thermal management strategies.