Grid-forming inverters (GFMs) are increasingly popular for integrating renewable energy into the power grid, offering features such as inertia emulation that enhance the stability of inverter-dominated grids. Traditionally, GFMs utilize battery energy storage systems (BSS) or hybrid battery-photovoltaic (HBP) systems to enable full functionality, particularly for grid frequency support. However, the high costs and maintenance requirements associated with BSS pose challenges for widespread adoption. This paper explores potential solutions for using photovoltaic (PV) systems as a sole source for grid-interactive GFMs. While operating PV systems at maximum power point (MPP) presents challenges for maintaining full GFM functionality, this study examines methods to leverage PV systems for inertia support, traditionally provided by BSS. The provided case studies demonstrate the feasibility and effectiveness of using PV systems alone as a source for grid-interactive GFMs.

This paper presents a detail dynamic modeling, small-signal analysis, controller design and its stability assessment of non-ideal Sheppard-Taylor DC-DC converters. This class of DC-DC converter provides non-pulsing input and output current via two inductors at the input and output sides with improved current ripple. This paper provides the detail small-signal analysis that can be used as a systematic guideline for designing a robust control system for this class of DC-DC converters, which is a missing piece of the puzzle within the literature. The state space model and the canonical model of the system are also provided. Furthermore, the open loop line-to-output transfer function and control-to-output (open loop and closed loop) for non-ideal Sheppard-Taylor DC-DC converter are derived and used for developing a PID-based compensator to validate the derived models. The provided analysis is supported with simulation studies to validate the theoretical derivations.

This paper presents a high-performance finite-set model predictive control for an efficient power electronics interface for photovoltaic (PV) system. The proposed control scheme is able to harvest the maximum available power from the PV panel without the requirement of complex modulation scheme with multi-nested loop classical controllers for the considered efficient power electronic interface. Two-stage back-to-back dc/dc and dc/ac converter architecture is a common power conversion unit for PV systems. The back-to-back stages requires multi-loop controller to harvest the maximum power. In this paper, an efficient multilevel dc/ac converter is used, which is challenging to control by classical modulation schemes. Furthermore, this adds more complexity to the back-to-back power conversion system under study. The goal of this paper is to mitigate the control complexity while maximizing the benefits of the efficient topology. Thus, realizing a high-performance power conversion for PV systems with straight forward control scheme. Several case studies are presented that validates the functionality of the proposed architecture.

This paper presents an optimized single phase DC-AC converter with RCD snubber circuit. The proposed converter has an optimized number of levels per number of switches (nL/nS) which is by far the best relationship among the converters proposed in literature. The most important characteristics of the proposed configuration are: (i) reduced number of semiconductor devices, while keeping a high number of levels at the output converter side, (ii) only one DC source without any need to balance capacitor voltages, and (in) reduced semiconductor losses and as a result higher efficiency. The principle of operation, RCD snubber design, modulation technique, and modeling of the proposed converter are presented in this paper. The proposed multilevel DC-AC converter topology is simulated and validated experimentally.

In this paper, a single-phase rectifier topology based on a five-level four-switch converter is proposed. Such topology will be called as 5L-4S Rectifier, which presents some advantages over the traditional ones, such as lower THD of the grid current due to high number of levels generated at the grid side and lower power switching losses. The complete analysis presented in this paper includes the rectifier model, its operation, the PWM strategy, dc-link capacitor voltage and grid current controls. A comprehensive comparison between the proposed and conventional rectifiers is also presented. Simulated and experimental results corroborate the theoretical study.