Hybrid Electric Vehicles (HEVs) combine combustion and electric propulsion means to achieve key objectives, such as: reducing fuel consumption, minimizing pollutant emissions, and enhancing the overall energy efficiency of the Powertrain System. The series hybrid electric vehicles, in special, have a topology compound by four Subsystems, which are: Traction, Storage, Energy Generation, and Energy Management. The Energy Generation Subsystem is responsible for the power supply of the electric traction motors and batteries, depending on the control strategy promoted by the Energy Management Subsystem. The Energy Generation Subsystem is essentially made by an Internal Combustion Engine (ICE) and a Generator. Effective control of the power output from the Energy Generation Subsystem necessitates precise regulation of the engine speed. Thus, it is necessary to control the engine speed because this is directly related to the power demand of the consumers of other subsystem components.
This study presents a preliminary speed control approach for a four-stroke engine utilized in the Energy Generation Subsystem of a series hybrid-flex vehicle. This work is a component of the larger project “Desenvolvimento de um Veículo Urbano Leve Híbrido Flex (VHF-Urbano)” from the ROTA 2030/MOVER program. To allow the engine speed control, a throttle-by-wire system was designed. Notably, at this stage, the physical system to be controlled is a Single Input and a Single Output (SISO) system, where the desired engine speed is solely achieved by varying the angular position of the throttle valve. A model-based control was developed to achieve the desired engine speed. It is expected to use this first control strategy as a groundwork to develop a more sophisticated strategy, involving other sensors and actuators of the ICE utilized in this work.