Multi-Resonant Third-Order Generalized Integrator Based PLL for Seamless Control of Solar-Battery Fed Grid Synchronized Water Pumping System

Abstract

The solar photovoltaic array and battery energy storage fed grid interfaced water pumping system operates in islanding mode under grid outage. There is a need to synchronize such system to grid on recovery of grid to facilitate interconnection and interoperability between the two. Thus, a multi-resonant third-order generalized integrator (MR-TOGI) based phase-locked loop (PLL) to realize seamless control for grid synchronization of solar-battery fed water pumping system is presented in this paper. The presented MR-TOGI-PLL rejects lower-order harmonics and DC-offset by using developed MR-TOGI based quadrature signal generation (QSG). Besides, MR-TOGI-QSG based current control is realized under grid-connected mode to improve power quality at grid in accordance to the IEEE-519 standard. This current control even operates photovoltaic array at its peak power, thereby enabling its direct connection to DC-link. While MR-TOGI-QSG based voltage control is realized for islanding mode to ensure uninterrupted operation of system under grid outage. Meanwhile, power management system is also developed to manage power flow among different system components. The detailed analysis of MR-TOGI-PLL is performed to illustrate its advantages. Test performances of system are obtained for various operating scenarios including MR-TOGI-PLL based synchronization to demonstrate effective operation of the system.