On-site Measurement Method for the No-load and Load Loss of Transformer

Summary

The power transformer is the core equipment in the power grid, which reliability directly affects the safety of the power system. The no-load loss and load loss are important parameters of the transformers, because the transformer losses reflect not only the operating efficiency but also the status of equipment. Generally, these parameters are measured through off-line no-load and load tests. But it is difficult to be carried out in field. As for the large capacity transformers, the operating efficiency is high. Limited to the accuracy of the measuring instruments, the online measurement is infeasible. This paper presents a more effective on-site measurement method for transformer losses. The implementation is also discussed. It directly performs the no-load test by using power grid as the experiment power source. A customized current sensor unit is designed to measure the no-load current. The current sensor unit can work under the high potential and be operated with wireless communication. The current and the voltage are triggered synchronously by the signal of the GPS module. Besides, the on-line measurement system for transformers load loss is developed based on transformer equivalent circuit. In addition, interpolation algorithm with Blackman-Harris window is applied to increase the precision of the system. The accuracy requirements for voltage and current measurements are also analysed.

Additional informations

Authors

Raulf Tobias, Ketel Daniel, Haas Bruno, Singh Shailendra, Serdyuk Yuriy