Electrical Power Transformer Short-Circuit Impedance and Load Loss Testing

‌Short-Circuit Impedance‌ is the impedance value of a distribution transformer under short-circuit conditions, reflecting its resistance and reactance characteristics, and is used to evaluate its ability to withstand short-circuit currents‌.

‌‌This test evaluates the ‌short-circuit characteristics‌ and ‌load capacity‌ of distribution and power transformer transformers by measuring key parameters under standardized conditions‌.

‌Equipment and Procedure‌

‌Instrument‌: Power analyzer‌ voltage/current sensors, and temperature monitoring tools‌

‌Steps‌:

1.Apply voltage to the ‌low-voltage side‌ while measuring current and losses on the ‌high-voltage side‌‌

2.Gradually increase voltage to the ‌rated value‌ to ensure measurement accuracy‌

3.For oil-immersed transformers, conduct tests at ‌50°C oil temperature‌ to simulate operational conditions‌

‌Evaluation Criteria‌

‌Short-circuit impedance‌ and ‌load loss‌ must comply with technical specifications, typically within ‌±5% tolerance‌‌

Load loss includes ‌resistive losses‌ and ‌stray losses‌ (e.g., eddy currents, magnetic leakage)‌