Multiport Isolated link with Current-Fed Z-Source Converters to Manage Power Imbalance in PV Applications

Abstract

In order to address power imbalance in large-scale PV systems, this paper presents a multiport isolated medium-frequency (MF) link to process different power levels from PV arrays, using current-fed Z-source inverters (CZSI) modules to drive the energy from the PV array to the MF link in a single power stage. The MF link provides the galvanic isolation required by many codes and standards to integrate a system to the grid. The multiport configuration of the MF link allows the system to process different power levels on each primary port and, being all ports magnetically coupled, provide balanced power levels on secondary ports which can be used for multilevel converters applications. Additionally, the current-fed version of the Z-source topology offers natural protection against short-circuit damage enhancing reliability of the system. The analysis of CZSI cells and the study of asymmetrical power levels transference, as well as simulation and experimental results are presented.

Optimal Robust LQI Controller Design for Z-Source Inverters

“…By ignoring the parasitic resistances of inductors, i.e., r = 0, the first row of (4) in the steady-state, ẋ = 0, gives (5).…”

“…The Impedance Source Inverters (also called Z-Source Inverters or ZSIs) form a class of high-performance, highly reliable, and highly efficient yet low-cost inverters equipped with an X-shaped impedance circuit that enables shoot-through state [2,3]. Hence, they can overcome the limitations of traditional inverters and fulfill both buck and boost capability in a single-stage topology without the necessity for any kind of delays [4,5]. Therefore, the output voltage can be adjusted freely to provide a wider voltage gain range without any additional cost or distortion [6].…”

Power Converters in Power Electronics: Current Research Trends

“…In order to increase the voltage gain, a multiplier cell technique is applied to the quasi-switched boost inverter with low input current ripple [5]. The applications of the ISI for grid connection [6] and photovoltaic [7] are presented.…”

A Photovoltaic-Powered Modified Multiport Converter for an EV Charger with Bidirectional and Grid Connected Capability Assist PV2V, G2V, and V2G

“…These three constraints including (i) multiport charging option [21,22], (ii) bidirectional power flow from G2V and V2G [23,24], and (iii) fast charging [25] are components of the research gap. In [26], a multiport converter with a medium-frequency link is presented, utilizing current-fed Z-source inverter (CZSI) modules. The presentation includes an analysis of CZSI cells and a study of the transference of asymmetrical power levels.…”