Optimal Control of Zero Voltage Soft‐Switching Synchronous Buck Converter Using Linear Quadratic Regulator Control Strategy for Electric Vehicle Applications

ABSTRACT Effective control of DC‐DC converters is essential in Electric Vehicles (EVs) to enhance battery efficiency and motor performance. Traditional controllers often struggle with the complex dynamics of fourth‐order converters. To overcome these challenges, this paper proposes an optimal Linear Quadratic Regulator (LQR) to control a soft‐switching synchronous buck converter. By minimising a cost function that balances state variables and control efforts, the LQR enhances both stability and dynamic response. The controller achieves notable improvements, such as, reducing overshoot to less than 2% and achieving a settling time of approximately 70 S. Bode plot and root locus analysis confirm the converter's robust operation, with a phase margin of 66° and a gain margin of 64.2 dB, ensuring adaptability to varying loads. Experimental tests further demonstrate that soft switching is achieved without performance degradation, even under dynamic conditions, proving the controller's practicality for real‐time EV applications. Overall, the proposed control method provides a reliable and efficient solution for high‐performance EV power converters under changing load and input conditions.