Analysis and mitigation of common mode voltages in photovoltaic power systems

Somasundaram Essakiappan, Prasad Enjeti, Robert S. Balog, Shehab Ahmed

Research output: Chapter in Book/Report/Conference proceedingConference contribution

20 Citations (Scopus)

Abstract

A typical photovoltaic (PV) power system is composed of multiple strings of PV arrays with one central inverter or a combination of PV modules with micro-inverters. Per-module DC-DC converter and series connected multilevel inverter topologies are possible candidates. In this paper, the analyses of common mode voltages and currents in the afore-mentioned PV topologies are detailed. The grid integration of PV power employs a combination of pulse width modulation (PWM) DC-DC converters and inverters. Due to their fast switching nature a common mode voltage is generated with respect to the ground, inducing a circulating current through the ground capacitance. Common mode voltages lead to increased voltage stress, electromagnetic interference and malfunctioning of ground fault protection systems. This paper analyzes the common mode voltages and current present in high and low power PV systems with different topologies. Mitigation strategies such as common mode filter and transformer shielding are proposed to minimize common mode voltages and currents. A practical rooftop PV system rated at 2.76 kW per string is used in the analysis.

Original languageEnglish
Title of host publicationIEEE Energy Conversion Congress and Exposition
Subtitle of host publicationEnergy Conversion Innovation for a Clean Energy Future, ECCE 2011, Proceedings
PublisherIEEE Computer Society
Pages28-35
Number of pages8
ISBN (Print)9781457705427
DOIs
Publication statusPublished - 1 Jan 2011
Event3rd Annual IEEE Energy Conversion Congress and Exposition, ECCE 2011 - Phoenix, AZ, United States
Duration: 17 Sep 201122 Sep 2011

Publication series

NameIEEE Energy Conversion Congress and Exposition: Energy Conversion Innovation for a Clean Energy Future, ECCE 2011, Proceedings

Other

Other3rd Annual IEEE Energy Conversion Congress and Exposition, ECCE 2011
CountryUnited States
CityPhoenix, AZ
Period17/9/1122/9/11

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Keywords

  • Common Mode Filter
  • Common Mode Voltage
  • Photovoltaic
  • Power Converters
  • Transformer Shielding

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Renewable Energy, Sustainability and the Environment

Cite this

Essakiappan, S., Enjeti, P., Balog, R. S., & Ahmed, S. (2011). Analysis and mitigation of common mode voltages in photovoltaic power systems. In IEEE Energy Conversion Congress and Exposition: Energy Conversion Innovation for a Clean Energy Future, ECCE 2011, Proceedings (pp. 28-35). [6063745] (IEEE Energy Conversion Congress and Exposition: Energy Conversion Innovation for a Clean Energy Future, ECCE 2011, Proceedings). IEEE Computer Society. https://doi.org/10.1109/ECCE.2011.6063745