Photovoltaic System with a Battery-Assisted Quasi-Z-Source Inverter: Improved Control System Design Based on a Novel Small-Signal Model

Ivan Grgić, Dinko Vukadinović, Mateo Bašić and Matija Bubalo
Additional contact information
Ivan Grgić: Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Department of Power Engineering, University of Split, 21000 Split, Croatia
Dinko Vukadinović: Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Department of Power Engineering, University of Split, 21000 Split, Croatia
Mateo Bašić: Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Department of Power Engineering, University of Split, 21000 Split, Croatia
Matija Bubalo: Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Department of Power Engineering, University of Split, 21000 Split, Croatia

Energies, 2022, vol. 15, issue 3, 1-29

Abstract: This paper deals with a photovoltaic (PV) system containing a quasi-Z-source inverter (qZSI) and batteries connected in parallel with the qZSI’s lower-voltage capacitor. The control system design is based on knowledge of three transfer functions which are obtained from the novel small-signal model of the considered system. The transfer function from the d -axis grid current to the battery current has been identified for the first time in this study for the considered system configuration and has been utilized for the design of the battery current control loop for the grid-tied operation. The transfer function from the duty cycle to the PV source voltage has been utilized for the design of the PV source voltage control loop. The PV source voltage is controlled so as to ensure the desired power production of the PV source. For the maximum power point tracking, a perturb-and-observe algorithm is utilized that does not require the measurement of the PV source current, but it instead utilizes the battery current during the stand-alone operation and the d -axis reference current during the grid-tied operation. The corresponding tracking period was determined by using the transfer function from the duty cycle to the battery current and in accordance with the longest settling time noted in the corresponding step response. The proposed control algorithm also has integrated protection against battery overcharging during the stand-alone operation. The considered system has been experimentally tested over wide ranges of irradiance and PV panel temperature.

Keywords: battery; maximum power point; photovoltaic source; small-signal model; transfer functions; quasi-Z-source inverter (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
https://www.mdpi.com/1996-1073/15/3/850/pdf (application/pdf)
https://www.mdpi.com/1996-1073/15/3/850/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:15:y:2022:i:3:p:850-:d:732494

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().