Load Test Method Using Two Power Supplies for High-Frequency Transformers

This paper proposes a load test method for high-frequency transformers using two power supplies. In this method, the two power supplies need to supply only the power losses of the transformer because the power is circulated between the primary and secondary sides. Hence, this load test can be performed on high-frequency transformers with capacity higher than that of the power supply without requiring a high-frequency load. The experimental results show that the load test method can be applied to a transformer under a 100 kHz sinusoidal voltage/current using two power supplies with a capacity of 50 VA/unit, which is much smaller than the rated capacity of the transformer, i.e., 900 VA. Furthermore, the load test can be performed at all power factors from 0 to 1. In addition, the experimental results show that using the proposed method, the accuracy of power loss measurement is improved compared with the existing method that obtains the power loss by subtracting the output power from the input power of the transformer.