Lawson-Norm Adaptive Filter-Based Control Scheme for Self-Reliant Grid-Interfaced Solar Energy System

This article presents a smart control scheme for a grid-interfaced solar PV-battery energy storage system with seamless auto-transition capability for critical load applications. Majority of critical loads, connected at point of common coupling, are nonlinear and henceforth tend to deteriorate power quality of utility mains. Various adaptive filter-based grid current control strategies have been developed for performance improvement of such a system. To minimise oscillations, mean square error, computational burden and enhance convergence rate of extracted active weight component of load current, Lawson-norm-adaptive filter (LNAF) is put to use in this investigation. LNAF based model predictive control strategy is developed to regulate grid current, improve power quality at the utility side, reduce computational burden and ensure that only active power is exchanged with utility mains under surplus and deficit power modes. In addition, Model predictive voltage control scheme also regulates load voltage amplitude, frequency and power quality when system operates in standalone mode. This paper presents mathematical modelling, step-by-step design and stability analysis for the entire system. The system response is also validated through experimental investigations using an OPAL RT-5600 processor under various operating conditions. A comprehensive experimental investigation demonstrates superiority of the presented control technique over conventional existing schemes.