SOLUTION

• The amount of power a transformer can transfer depends primarily on the magnetic properties and the volume of its core.
• This power is frequency-dependent and it scales essentially with P ∝ V ∝ F.
• For a given core size and core material (which also depends on the application), the number of turns then determines the inductance and the capacitance of the primary and secondary coils.
• The capacity of a transformer is in KVA or MVA. Its voltage and current ratings are fixed for a particular transformer.
• The kVA capacity of a transformer is the output that it can deliver for a specified period of time, at the rated secondary voltage and rated frequency, without exceeding a specified temperature rise based on insulation life and ambient temperature.
• Transformers can be loaded above their kVA ratings with no loss of life expectancy only when operated within the manufacturer’s stated limits. Select the transformer based on its kVA capacity and temperature rating.
• The rated kVA capacity is based on the maximum current delivered at rated voltage.
• The real limit in the transformer’s capability is the amount of current that it can provide without exceeding a defined temperature rise.