Number and localisation of MV/LV transformer substations

Main characteristics to consider to determine the transformation substations:

• Surface area of building or site
• Power demand, (to be compared with standardized transformer power),
• Load distribution

The preferred basic configuration comprises one single substation.Certain factors contribute to increasing the number of substations (>1):

• A large surface area (> 25000m²),
• The site configuration: several buildings,
• Total power > 2500kVA,
• Sensitivity to interruption: need for redundancy in the case of a fire.
  

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	Configuration
Characteristic to consider	1 substation with N transformers	N substations N transformers (identical substations)	N substations M transformers (different powers)
Building configuration	< 25000m²	≥ 25000m² 1 building with several floors	≥ 25000m² several buildings
Power demand	< 2500kVA	≥ 2500kVA	≥ 2500kVA
Load distribution	Localized loads	Uniform distribution	Medium density

Fig. D11: Typical characteristics of the different configurations

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