This paper presents a Lyapunov-based model reference controller for Buck converter operating under harmful disturbances. This strategy is an advanced version of the tuning method utilising Lyapunov stability function to reach a higher stability and a better disturbance rejection behavior in the practical applications. In addition, to reduce the computational burden and increase ease of implantation, Black-box technique is considered assuming no accurate mathematical model for the system. Lyapunov stability theory is used to enhance and tune the PID gain of this method with an adaptive mechanism while taking into account the real-time condition of a converter with regular changes. For this gain-based controller, an adaptive mechanism based on the Lyapunov concept is proposed, which can improve the stability and resilience of the system under various disturbances, particularly noise. Moreover, a Fuzzy-based PID controller and a PID technique with Particle swarm Optimization (PSO) algorithm are designed and compared with the presented Lyapunov-based technique. MATLAB\Simulink is utilized to examine the results of this improved controller. Additionally, this method produces better results in real-time contexts with faster dynamics and better frequency adaptation.