Research On Active Electronic Current Transformer For Protection

Electronic Current Transformer, ECT for short, is the kind of equipment measuring current directly or indirectly by utilizing electronic and optical technology. And the research on it has good achievement in recent years.However, there is still a long distance for the ECT to be practical. It is a new theme that applying the ECT in microprocessor relay protection in Power System, which is also the extension of the ECT application. In this paper, the working principle of the ECT is researched deeply, and the design requirements and detecting criterion of the national criterion to ECT are inquired. Meanwhile, the design scheme of the protecting ECT is discussed, and the directing idea and designing method of its corresponding signal processing circuit. Finally, the experimental circuit's designing, manufacturing and debugging processes are completed, and then the device sample has been sent to the national transformer detecting center.Some data and conclusion with practical directing meaning have been obtained by experimental testing and detecting, which has important signification in the areas of theory and engineering practice for the ECT technology applied in microprocessor relay protection system.