Discontinuous PWM Operation of a Single-Phase PV Generator With Low-Voltage Energy Storage

Identifier:  imarina:9433303

Handle: https://hdl.handle.net/20.500.11797/imarina9433303

Authors:  Ramos, ER; Leyva, R; Liu, QX; Vazquez, S; Farivar, GG; Townsend, CD; Tafti, HD; Pou, J

Abstract:
Using energy storage (ES) in grid-connected photovoltaic (PV) generators is an efficient solution to deliver regulated power to the grid despite fluctuations in solar irradiance. The article analyses a single-phase grid-connected PV generators with ES, where the ES has a low voltage, namely without too many series-connected storing cells. The PV generator consists of three subsystems connected by a common dc-link capacitor: a PV unit, an ES unit, and an inverter. Furthermore, in the proposed solution, the inverter does not switch for a significant portion of the grid period, resulting in lower switching losses. The single-phase inverter discontinuous operation implies the need of an appropriate control strategy in the boost dc-dc converter of the ES unit. The proposed control employs an augmented state model that accounts for resonant variables. The proposed PV solution with low-voltage ES, including its control, is validated in a 350-VA experimental prototype to verify the novel approach.