Design of Single-Stage Management System for Grid-Connected Photovoltaic Sustainable Power Generation and Its HVRT Technology with Energy Storage Coordination

Abstract

With the rapid development of sustainable photovoltaic power generation, energy-storage-coordinated grid-connected photovoltaic systems have been widely adopted to stabilize power output and enhance grid adaptability. Aiming at the low fault tolerance of conventional photovoltaic grid-connected systems under grid voltage swell disturbances, this paper designs a single-stage power management system for grid-connected photovoltaic generation and studies its energy-storage-coordinated high-voltage ride-through (HVRT) technology. The single-stage topology boasts simple structure, low cost and high conversion efficiency, yet faces prominent stability risks under voltage swell faults. The system integrates photovoltaic units, energy storage modules and grid-connected interfaces to implement flexible bidirectional power dispatching. A three-phase AC/DC converter realizes photovoltaic maximum power point tracking (MPPT), and the energy storage module connects to the DC bus via a dual half-bridge (DHB) converter to restrain power fluctuations. Under HVRT faults, the energy storage coordination strategy elevates DC bus voltage to maintain stable grid-tied operation without disconnection. Different from schemes requiring extra hardware or complicated control optimization, the proposed method realizes stable bus voltage regulation and flexible energy scheduling with zero additional hardware cost. Simulations and experiments validate the rationality, feasibility and outstanding fault-ride-through performance of the designed system.