Abstract
In a proton exchange membrane (PEM) fuel cell/battery hybrid vehicle, a fuel cell system fulfills the stationary power demand, and a traction battery provides the accelerating power and recycles braking energy. The entire system is coordinated by a distributed control system, incorporating three key strategies: 1) vehicle control, 2) fuel cell control and 3) battery management. They make up a hierarchical control system. This paper introduces a hierarchical control strategy for a fuel cell / battery hybrid powertrain applied in a city bus. The vehicle control strategy comprises three parts: an energy management strategy, a brake regeneration strategy and an active tolerant control strategy. The entire powertrain power is split between the fuel cell system and the battery in such a way that the fuel cell system works in a quasi-steady state and the battery can keep charge sustaining. The braking energy is recycled on the basis of the pedal position and the rotational speed of the electric motor. An active tolerance control strategy is developed to guarantee the work of the entire system in case of malfunctions. A fuel cell system consists of a water and heat management system, an air system, a humidifier system and a hydrogen in-out let system. Control strategies are designed to regulate air supply and water cooling temperature. Primary tasks of a battery management system are to estimate the state of charge (SOC), and to keep the temperature in safety range. A real-time applicable strategy for SOC is developed. The temperature of the battery is controlled by some air fans with on-off strategy. The hierarchical control system was applied on a fuel cell city bus. Experimental results show the effectiveness of the proposed strategy.
Highlights
In order to avoid climate change and to reduce dependency on fossil fuels as the predominant primary energy source, novel energy technologies are strongly required in automotive industry
A controller area network (CAN) based distributed system is necessary to coordinate the work of the entire system
Because of the complexity of the hybrid fuel cell powertrain, a networked hierarchical control system is necessary to coordinate the work of the entire system, to communicate with the remote monitoring system and to evaluate the status of components
Summary
In order to avoid climate change and to reduce dependency on fossil fuels as the predominant primary energy source, novel energy technologies are strongly required in automotive industry. As results of collaboration among Tsinghua University, Beijing SinoHytec Company, Foton Automotive Company and SAIC motor, several fuel cell city buses are developed for Beijing Olympic Games and Shanghai EXPO It has a range of 300km and can speed up to 80kmph [6]. Answers to these three questions correspond to three key technologies, 1) vehicle control, 2) fuel cell control and 3) battery management They make up a hierarchical control strategy. This paper proposes the hierarchical control strategy of the fuel cell / battery hybrid powertrain.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
