Effective Control of Speed and Regenerative Braking in Electric Vehicles Utilizing Fractional Order PI Controller

In the automotive industry, a significant application of the Proportional Integral (PI) controller is in electric motors, specifically Brushless Direct Current (BLDC) motors used in Electric Vehicles (EVs). The accuracy of speed regulation in BLDC motors, acclaimed for their effectiveness and dependability, is crucial for enhancing vehicle performance and ensuring energy efficiency. On the other hand, regenerative braking is also important for energy recovery during vehicle navigation. In this paper, fractional order PI controller (FOPI) is implemented for smooth and precise control of speed and energy recovery during regenerative braking. Conventional Ziegler-Nichols method is used to tune the gains of the controller and for better controlling $\lambda$ value for fractional order PI is predicted using trial and error method over extensive simulations on Simulink environment. The simulation results show accurate control of speed by variation of desired speed from 1500 rpm to 2800 rpm with fast transient response and without any delay. Energy recovery has been implemented through regenerative braking and show the battery charging and reverse flow of current during deceleration and applied braking in the EV.