Leakage current and energy efficiency analyses of single phase grid connected multi-kva transformerless photovoltaic inverters

Download
2012
Özkan, Ziya
In order to inject solar power to the utility grid, among various types of inverters, Grid Connected Transformerless Solar Inverters (GCTSI) are mostly preferred for residential or commercial applications. This preference is because of the high energy efficiency and low cost due to the absence of a line frequency or a high frequency transformer. Peak value of the efficiency characteristics of GCTSIs can reach 98%, which are selected topology, component optimization, switching strategy and operating condition dependent. In spite of the attractive energy efficiency characteristics of GCTSIs, due to the lack of galvanic isolation, these inverters are vulnerable to leakage currents, which are prohibitive for the safety and the maintenance reasons. The purpose of this research is to analyze GCTSIs in terms of their leakage current and energy efficiency characteristics. In the research, the leakage current mechanisms of GCTSIs are identified and grid connected solar inverters are classified in terms of their leakage current characteristics including the GCTSIs. In addition to the existing ones, several novel topologies are proposed enriching the family of GCTSIs. The leakage current and the inductor current ripple performances of GCTSI topologies are analyzed and evaluated by detailed simulations for 3 kVA and 10 kVA single-phase systems. In addition, the energy efficiency characteristics of GCTSIs are investigated in these power levels by making use of Calculated Average Power Per Switching Cycle (CAPPSC) method. The efficiency studies with CAPPSC method provide design guidelines and comparison of the GCTSI topologies in terms of their energy efficiency characteristics.

Suggestions

Sizing of Photovoltaic-Wind-Battery Hybrid System for a Mediterranean Island Community Based on Estimated and Measured Meteorological Data
Sadati, S. M. Sajed; Jahani, Elham; Taylan, Onur; Baker, Derek Keıth (2018-02-01)
Deploying renewable energy systems (RES) to supply electricity faces many challenges related to cost and the variability of the renewable resources. One possible solution to these challenges is to hybridize RES with conventional power systems and include energy storage units. In this study, the feasibility analysis of a grid-connected photovoltaic (PV)wind-battery hybrid system is presented as a microgrid for a university campus-scale community on a Mediterranean island. Models for PV and wind turbine syste...
Statistical analysis of solar radiation data
Yilmaz, E.; Cancino, B.; Parra, W. R. (Informa UK Limited, 2007-01-01)
Solar radiation is the most important parameter in the design and study of solar energy conversion devices. The present work is based on statistical analysis of solar radiation data for the city of Valparaiso in the coast region of Chile. Experimental data were obtained from the Santa Maria University in Valparaiso over a five-year period measured by the actinograph and the pyranometer. The error between the actinography values in relation to the pyranometer ones was determined. The most frequent error perc...
Sizing methodology of a PV/wind hybrid system: Case study in cyprus
Al-Ghussain, Loiy; Taylan, Onur (Wiley, 2019-05-01)
This study aims to suggest a method for sizing of a photovoltaic (PV)/wind hybrid system based on maximizing the annual renewable energy system (RES) fraction with levelized cost of electricity (LCOE) being equal to the grid tariff. The novelty of this article is the idea of maximizing the energy security, energy localization, and environmental benefits from the hybrid system and at the same time ensures the economic feasibility of the system where Middle East Technical University Northern Cyprus Campus (ME...
Cloud-based Optimal Energy Scheduling of Photovoltaics and Electric Vehicle-integrated Community Microgrids
Zehir, Mustafa Alparslan; Tufan Dogan, Osman; Merdanoglu, Hakan; Yakici, Ertan; Duran, Serhan; Can Akyildirim, Hayri (2022-01-01)
© 2022 IEEE.Community microgrid is one of the promising pathways to achieve higher levels of penetration of distributed generation from intermittent renewables and energy storage, further electrify heat and transport and enable active energy customers. Optimal energy scheduling of wide range and large number of flexible asset, using operational information from stakeholders (such dynamic pricing rates) and relying on customer preferences has been a processing power intensive major challenge. The inconsisten...
Seasonal variation of the monthly efficiencies of thin film PV modules
Özden, Talat; Turan, Raşit; Akınoğlu, Bülent Gültekin (null; 2017-12-04)
Outdoor testing of solar photovoltaic (PV) modules must be carried out at different climates as PV power plants nowadays are installed and continues to be installed in many countries. Present study is outdoor testing results and analyses of 5 thin film modules in Ankara, Turkey. The analyses are carried out using monthly efficiencies of the modules that are derived using the energy yield and input. The average efficiencies of the CIS, CIGS and μc-Si/a-Si thin film modules are. We present the monthly and ave...
Citation Formats
Z. Özkan, “Leakage current and energy efficiency analyses of single phase grid connected multi-kva transformerless photovoltaic inverters,” M.S. - Master of Science, Middle East Technical University, 2012.