Comparison between unipolar and bipolar single phase grid-connected inverters for PV applications

Bowtell, Les and Ahfock, Tony (2007) Comparison between unipolar and bipolar single phase grid-connected inverters for PV applications. In: AUPEC 2007: 17th Australasian Universities Power Engineering Conference, 9-12 Dec 2007, Perth, Australia.

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An inverter is essential for the interfacing of photovoltaic panels with the AC network. There are many possible inverter topologies and inverter switching schemes and each one will have its own relative advantages and disadvantages. Efficiency and output current distortion are two important factors governing the choice of inverter system. In this paper, it is argued that current controlled inverters offer significant advantages from the point of view of minimisation of current distortion. Two inverter switching strategies are explored in detail. These are the unipolar current controlled inverter and the bipolar current controlled inverter. With respect to low frequency distortion, previously published works provide theoretical arguments in favour of bipolar switching. On the other hand it has also been argued that the unipolar switched inverter offers reduced switching losses and generates less EMI. On efficiency grounds, it appears that the unipolar switched inverter has an advantage. However, experimental results presented in this paper show that the level of low frequency current distortion in the unipolar switched inverter is such that it can only comply with Australian Standard 4777.2 above a minimum output current. On the other hand it is shown that at the same current levels bipolar switching results in reduced low frequency harmonics.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: No evidence of copyright restrictions.
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Electrical, Electronic and Computer Engineering
Date Deposited: 17 Aug 2008 23:59
Last Modified: 14 Jun 2016 04:19
Uncontrolled Keywords: inverter switching; current controlled inverters
Fields of Research : 09 Engineering > 0913 Mechanical Engineering > 091305 Energy Generation, Conversion and Storage Engineering
01 Mathematical Sciences > 0101 Pure Mathematics > 010106 Lie Groups, Harmonic and Fourier Analysis
09 Engineering > 0906 Electrical and Electronic Engineering > 090601 Circuits and Systems
Socio-Economic Objective: B Economic Development > 85 Energy > 8505 Renewable Energy > 850504 Solar-Photovoltaic Energy
Identification Number or DOI: 10.1109/AUPEC.2007.4548098

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