Adaptive sliding mode predictive power control of three-phase AC/DC converters

Abstract

This article presents a new adaptive sliding mode–based model predictive controller for AC/DC three-phase converters achieving better dynamic performance and stability. In the classical model predictive controller available in the literature, the model-based approach, for example, proportional–integral controller is employed for producing the active power reference for the three-phase converters. The traditional proportional–integral–based model predictive controllers consist of steady-state error and slow transient response characteristics. As a result, the DC-link voltage contains uncertainties due to variations in the load demand and output voltage. To overcome these limitations, this article suggests an adaptive sliding mode controller for generating the active power reference value from the DC-link voltage which then combines with the model predictive controller in order to minimize the cost function. The proposed controller minimizes the effects of uncertainties and variations in the output voltage by adaptively regulating the gain of sliding mode controller and modifying the control law online. The cost function is then minimized using the model predictive controller in order to control the active and reactive power flow. The stability analysis of the designed controller is performed using Lyapunov theorem. The effectiveness of the designed control scheme is proved by comparing its performance with the proportional–integral model predictive controller and fixed gain sliding mode–based model predictive controller control schemes. Simulation and experimental system results are obtained for validating the presented control approach.