A Review on Recent Advances and Future Trends of Transformerless Inverter Structures for Single-Phase Grid-Connected Photovoltaic Systems

Abstract

Abstract:The research significance of various scientific aspects of photovoltaic (PV) systems has increased over the past decade. Grid-tied inverters the vital elements for the effective interface of Renewable Energy Resources (RER) and utility in the distributed generation system. Currently, Single-Phase Transformerless Grid-Connected Photovoltaic (SPTG-CPV) inverters (1-10 kW) are undergoing further developments, with new designs, and interest of the solar market. In comparison to the transformer (TR) Galvanic Isolation (GI)-based inverters, its advantageous features are lower cost, lighter weight, smaller volume, higher efficiency, and less complexity. In this paper, a review of SPTG-CPV inverters has been carried out. The basic operational principles of all SPTG-CPV inverters are presented in details for positive, negative, and zero cycles. A comprehensive analysis of each topology has been deliberated. A comparative assessment is also performed based on weaknesses, strengths, component ratings, efficiency, total harmonic distortion (THD), semiconductor device losses, and leakage current of various SPTG-CPV inverters schemes. Typical PV inverter structures and control schemes for grid connected three-phase system and single-phase systems are also discussed, described, and reviewed. Comparison of various industrial grids-connected PV inverters is also performed. Loss analysis is also performed for various topologies at 1 kW. Selection of appropriate topologies for their particular application is thoroughly presented. Then, discussion and forthcoming progress are emphasized. Lastly, the conclusions are presented. More than 100 research publications on the topic of SPTG-CPV inverter topologies, configurations, and control schematics along with the recent developments are thoroughly reviewed and classified for quick reference.

Design of a Proportional Resonant Controller with Resonant Harmonic Compensator and Fault Ride Trough Strategies for a Grid-Connected Photovoltaic System

“…However, in the proposed system, two-stage topology is employed, because when the PV voltage is low the boost converter will boost it for the use of an inverter, and the cost is reduced. Figure 2 illustrates the DC-DC boost converter circuit having input voltage Vin, switch SW, boost inductor L, diode D, filtering capacitor C, and resistive load R. A capacitor is used between the PVS and the DC-DC circuit to minimize harmonics in frequency (CPV) which is given in Equation 4 [23]. To calculate the value of boost inductor [24],…”

A Comprehensive Review of DC–DC Converter Topologies and Modulation Strategies with Recent Advances in Solar Photovoltaic Systems

“…In 2016, the cumulative global PV capacity was found to be 303 GW. The global trend in the advancement of installed PV capacity can be observed in Figure 2a [32], and Figure 2b depicts the actuals and the forecast of both the wind and solar energy sources [33].…”

Dynamic Modeling and Robust Controllers Design for Doubly Fed Induction Generator-Based Wind Turbines under Unbalanced Grid Fault Conditions

“…The stator and grid voltage are directly linked to each other while the rotor and back-to-back converter are interfaced, comprising a GSC common DC-link and a RSC [28]. The generator output power is controlled by the RSC while GSC ensures the stability of the DC-link voltage irrespective of the direction and magnitude of the rotor power [29]. At the wind turbine the terminal grid active power P O is equal to the sum of the stator active power P s and the grid active power P g .…”