Double-integral sliding mode control of the switched-inductor quasi-Z source boost converter

Abstract

Compared with the traditional converter, the switching inductance quasi-Z source DC-DC boost converter has the characteristics of wide output voltage, small capacitor size and more reliable circuit. However, in the process of DC voltage boost, the system is prone to high startup impulse voltage, output voltage fluctuation, and other problems. Therefore, a double integral sliding mode control (DISMC) method is proposed. The control method takes the capacitance voltage error, the inductance current error and their sum of single integral and double integral as state variables, and derives the equivalent control law from the sliding mode surface. A Lyapunov function is constructed to analyze the existence conditions of DISMC method. And the effects of abrupt changes of input voltage, negative reference voltage and load power on transient oscillation, steady state error and overshoot of the system are analyzed. This control method solves the non-minimum phase problem of capacitor voltage, so as to improve the start-up performance of the controller and speed up the response of the system. Finally, the superiority and effectiveness of the control method are verified by simulation.