Abstract: Aiming at the deficiency in boost capacity of the traditional booster circuit，a new type of coupledinductance high-gain DC-DC converter（Fibonacci switch capacitor-Y sources DC-DC converter，FSCYS）was proposed. Using sliding mode variable structure control with superior dynamic response performance and robust performance，the design of a DC closed-loop sliding mode controller superior to PID control was realized. The dynamic performance of two control methods of input voltage and load disturbance was compared by Matlab/

Simulink software simulation and experiment. Simulations and experiments show that the sliding mode variable

structure control is suitable for closed-loop control of high-order DC-DC converters due to its simple modeling

method，ultra-fast dynamic response and strong robustness.

      Key words: DC-DC converter；sliding mode control；chattering；robustness