The Development of Instrument Transformer Comprehensive Characteristics Tester Based on the Principle of Low Frequency and Frequency Conversion

As the increase of current transformer knee point voltage, the conventional test method can not meet the requirements. In response to this situation, a prototype of instrument transformer tester based on low frequency source and compensation algorithm is developed. When using this device, it is possible to achieve testing at lower voltage. Due to the application of this tester, the flexibility and measurement capability are improved, at the same time the test intensity effectively reduced and the efficiency enhanced. The comprehensive performance of this tester is high, as a result of adopting SPWM, power factor correction (PFC), soft-switching and other advanced technologies. The principles of its main components and functions are described, and following the performance and comparison test indicate that the performance of this tester basically can meet the application requirements.