A Fuzzy Incremental Proportional Integral Derivative Control Strategy for Flywheel Energy Storage Machines in Autonomous Vehicles

In energy storage systems for autonomous vehicles, flywheel energy storage machines still suffer from high rotating iron consumption, a weak rotor structure, and poor robustness. As a flywheel energy storage device, this study employs a homopolar machine with a doubly salient solid rotor to address these issues. It has a simple design, a strong rotor, and reduced rotational loss at high speeds. It is given a fuzzy incremental proportional integral derivative (FIPID) intelligent control strategy. A simulation experiment is used to implement the novel optimization method. The constant speed sensitivity is enhanced by a factor of 20, and the torque variation is reduced by a factor of 6. The modeling and testing data show that the simulation and experimental results are reasonable. This shows that the proposed improved FIPID controller system and the considered intelligent homopolar machine system are effective, precise, stable, and respond in a dynamic way. It will be considered for applications in flywheel energy storage systems for autonomous vehicles with stored energy up to 500 MJ and power ranges from KW to GW. Its application will enhance the energy storage capacity of autonomous vehicles. Note to Practitioners —In this research we considered the urgent need of flywheel energy-storage machine system of new-energy autonomous vehicle for high-speed machine and found out energy-efficient, environment-friendly and high-efficiency automatic control algorithm. Previous researches on energy-storage machine were mainly focused on heteropolar machines which tend to have defects such as large iron loss in rotation, low rotor structural strength and poor robustness, etc., resulting in limited energy conversion efficiency of the flywheel energy-storage machine of autonomous vehicle during high-speed operation. Very few people ever chose homopolar machine from high-speed machines for energy storage control. In this paper, we chose a new type of homopolar machine with topology structure to minimize the machine's iron loss in high-speed rotation and to enhance the rotor's structural strength. We also put forward a new control algorithm matching with this machine, in order to further improve the system control performances including control precision and reliability. The simulation experiment of fuzzy incremental PID control system of homopolar machine for flywheel energy storage of autonomous vehicle and the actual data-driven simulation result showed that this algorithm realized more precise speed regulation and better reduced faults like torque ripple than the classical PID control algorithm, and further improved the machine efficiency within the whole operating speed and power ranges, and realized the dual purposes of quick charge and stable and safe operation of the flywheel energy storage machine. This algorithm provides theoretical and data validation support for the application of the flywheel energy storage into the autonomous vehicle system. And it can be readily implemented and incorporated into large-scale industrial computing systems.