Title:	The Desert Knowledge Australia Solar Centre: High Voltage Effects on Inverter Performance
Author(s):	P. Rodden, G.R. Lee, L. Frearson
Keywords:	Photovoltaic PV, Inverter Performance, High AC Grid Voltage, DKA Solar Centre
Topic:	PV Systems
Subtopic:	Large PV Power Plants and Distributed PV: System Aspects and Grid Connection
Event:	26th European Photovoltaic Solar Energy Conference and Exhibition
Session:	5BV.2.46
Pages:	4334 - 4338
ISBN:	3-936338-27-2
Paper DOI:	10.4229/26thEUPVSEC2011-5BV.2.46
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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The significant increase in the penetration of PV into local electricity grids can lead to an elevation of AC grid voltage. This effect is particularly evident in mini grids operating in hot climates with long spur lines which, due to network requirements, already operate at relatively high AC grid voltages. The Desert Knowledge Australia Solar Centre (DKASC) was developed as a site where competing photovoltaic technologies could be installed, operated and monitored under the same conditions. Data from the DKASC has provided the basis for studying the impact of high grid voltage on the performance of inverters across the site. Assessment of the site data identified one system whose underperformance could be directly related to high AC grid voltage which was in turn linked to high local PV penetration. By reducing AC voltage to this array this issue was effectively resolved. The problems experienced by this one system at the DKASC was found to be the result of a combination of high AC grid voltage and low DC array voltage; which saw the inverter MPPT being forced to move beyond its effective working parameters and lead to a marked reduction in system performance. It can be demonstrated that high AC grid voltages can have a detrimental impact on the performance of PV systems. In locations with a combination of high AC grid voltage and high PV penetration this risk is accentuated and particular attention must be paid to ensure that the DC array voltage is significantly above the minimum recommended MPPT DC operating voltage.