PWM-Based Double Integral Sliding Mode Control for Current Control Loop of DC-DC Boost Converter

Abstract

The use of dc-dc boost converters is common for increasing output voltage and supplying power. These converters, being time-varying nonlinear circuits, encounter uncertainties in load and variations in input voltage and current over a wide range. Nonlinear sliding mode control (SMC) has emerged as a promising strategy, offering advantages in terms of stability and robustness against parameter and load fluctuations. To address switching frequency variations in conventional hysteresis-based SMC, the indirect SMC or pulse-width modulation (PWM)-based SMC has been adopted. However, the adoption of PWM-based SMC raised concerns regarding steady-state error in power converters. Despite incorporating the integral of the state variable into the sliding surface of PWM-based SMC, the steady-state error still exists. Focusing on the current control loop of a dc-dc boost converter with the goal of reducing steady-state error, this study proposes double integral sliding mode control (DISMC), which employs a sliding surface that includes the double integral term of the current error. Simulation and experimental results demonstrate that the proposed approach effectively mitigates the steady-state error of the inductor current.