Measurement of transformer and shunt reactor load losses using a Poynting vector probe

The authors describe a novel method for the direct measurement of load losses in high-voltage transformers and shunt reactors using a Poynting vector probe. The probe measures the rate of flow of electromagnetic energy from the source supply to the load by sensing the electric and magnetic fields in a well-defined region. Unlike the complex bridge methods which are currently being used, the proposed method does not require any current or potential transformers, high-voltage capacitors, or current comparators. The integrated nature of the probe together with its light weight provides a simple and inexpensive method for measuring power losses in transformers, shunt reactors, and power capacitors in an industrial environment. Also, the very small number of components used in the probe and its electronic circuit ensures a minimum overall error and a high measurement accuracy. Design details and performance results are presented