Development of an adaptive control strategy for the three‐phase grid side converter with wide range of parametric and load uncertainties

Abstract

A new approach is proposed here to control the two-level three-phase grid side converter. The proposed control strategy is an extended state observer (ESO)-based adaptive control, consists of two cascaded control loops. The adaptive-multi-input multi-output controller is employed in the inner control loop, which is used to regulate the active and reactive component of the grid currents. The outer-loop consists of an adaptive controller augmented with an ESO to regulate the DC bus voltage. The goal of the proposed control strategy is to maintain a unity power factor while keeping the DC bus voltage constant under a sudden change in load demand at DC side, i.e. change in the resistive load connected across the DC bus. The proposed adaptive controller in the inner control loop does not require any information about the parameters associated with the grid filter (L-filter), and hence, it is found to be more robust towards parametric variations. The ESO-based adaptive controller is compared with the classical proportional–integral control in real-time, and the comparison indicates that the proposed controller not only accomplishes a nearly flawless tracking performance but also delivers a complete robust performance against resistive load variation across the DC bus.