🔍 What is MVA Loading?
Transformer MVA loading is the ratio of the transformer's operating apparent power (S = √3 × V × I) to its rated MVA capacity. It provides a combined measure of how much real and reactive power a transformer is transferring.
🔌 What is Current Loading?
Current loading looks only at the magnitude of current flowing through the transformer winding compared to its rated current. It's important when assessing thermal limits and relay settings.
Example:
A 100 MVA transformer rated at 132 kV side and drawing 400 A:
- MVA Loading = √3 × 132 × 0.4 / 100 = ~91.5%
- Current Loading = 400 A / Rated Current
🎞️ MVA Loading Animation (S = √3 × V × I)
🎞️ Current Loading Animation (I / Irated)
🧠 Summary
- MVA Loading reflects power throughput (used in planning/operations).
- Current Loading is critical for protection and thermal design.
- Both are needed to fully assess transformer utilization.