A new power-type fast discrete-time terminal sliding mode controller of buck converter

In order to improve the convergence rate and robustness of the current fast terminal sliding control and based on the requirement of digital control and engineering application, a new power-type fast discrete-time terminal sliding mode control is put forward by choosing a logarithmic function and a power function for constructing a piecewise sliding mode surface. It is proved that the convergence speed is faster than fast discrete-time terminal sliding mode control in arbitrary points. And then, power-type fast discrete-time terminal sliding mode control law is designed and the stability of the system state is proved. At last, the discrete-time control strategy is applied to Buck converter and compared with the traditional fast discrete-time terminal sliding mode control. Theoretical analysis and simulation results show that the system performance under power-type fast discrete-time terminal sliding mode control is significantly improved in accelerating system error track convergence speed, enhancing the robustness and decreasing steady-state error.