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Study of the choice of DC voltage level within a photovoltaic power station

You can contact the CAPSIM's specialist of this activity:
   - By email
   - By phone: +33 (0)4 42 63 61 18
Customer: CEA INES

voltage-power characteristic of a set of photovoltaic array
voltage-power characteristic of a set of photovoltaic array
The breakthroughs in the field of power electronics regarding on one hand photovoltaic panels and on the other hand enable to consider higher levels of DC distribution voltage within PV power stations. Indeed, for a given photovoltaic power, the increase in distribution voltage allows decreasing the current to be delivered to the network, and therefore to limit the cable distances required and distribution losses. These advantages must however be compared to technical-economic issues that an increase in distribution voltage may represent: availability of equipment from manufacturers, higher purchase costs, technical uncertainties).
Our client requested us for quantifying the technical-economic impact of increasing the DC voltage to 1500V, and then to 3000V (initially planned to be at 1000V) of their several MWs PV power station.

Capsim firstly did the sizing calculation of cables, junction boxes and conversion stations of the whole power station in the 1500V and 3000V configurations. This sizing is accompanied by an analysis of existing technologies and an estimation of corresponding costs.
Capsim next did a modeling of the power station under PSIM software in the 1000V, 1500V and 3000V configurations and simulated these cases for a period of 1 year in considering archives of meteorological evolutions (sunlight intensity and temperature), but also exact voltage/current characteristics of the PV panels.
The model has thus allowed to compare the evolutions obtained in the various configurations in terms of:
  • Voltage drops within DC cables,
  • Loss by Joules effect during power distribution,
  • Power transmitted to the grid.

Finally, the study allowed performing a comparison in economic terms of the various configurations:
  • Acquisition costs (cables, converters, junction boxes),
  • Production revenues on the basis of the performed simulations.

The study has allowed our client to acquire the necessary technical and economical knowledge in order to choose the voltage level for their PV power station.

PSIM model of the power station in the 1000V configuration
PSIM model of the power station in the 1000V configuration

CAPSIM - Les Grandes Terres - 13650 MEYRARGUES - France
Tel : +33 (0)4 42 63 61 18 - Fax : +33 (0)4 42 63 61 19