Adaptive Control of Grid-Connected Solar PV System Under Stochastic Operational Environments

Abstract

This paper introduces an Adaline-based control approach for a two-stage grid-integrated solar photovoltaic system (SPVS) in stochastic operating conditions. The Adaline algorithm is capable of estimating the fundamental component necessary to determine reference grid currents from harmonically distorted load currents at the point of common coupling. The Adaline algorithm is more adaptable than conventional methods for the fundamental frequency of the system, and it enables the H-bridge voltage source inverter (VSI) to inject precise currents for harmonic correction. Additionally, the H-bridge VSI injects the active power generated by the integrated SPVS at a unity power factor. Moreover, for the optimal gate drive signals, a model predictive controller (MPC) is implemented, which considers the nonlinear switching dynamics of the H-bridge VSI and the DC-DC converter of the SPVS. To assess the Adaline-based MPC approach in stochastic operating conditions, the two-stage grid-integrated SPVS is developed, and its operation is simulated in MATLAB/Simulink. The results obtained from MATLAB/Simulink and the real-time simulator (OP4512) in both grid- supplying and grid-injecting modes with source and load variations. Also, the observed total harmonic distortion of source current has been improved to align with the IEEE 1547-2018 standard.