In modern power systems, DC electronic current transformers play a crucial role. They are not only used for high-precision current measurement but also serve as key tools for grid optimization, fault detection, and energy management. With the rapid development of high-voltage direct current (HVDC) transmission technology and its widespread deployment globally, the performance requirements for DC current transformers have become increasingly stringent, especially in terms of measurement accuracy

1 Performance AdvantagesIn recent years, electronic current transformers (ECTs) have emerged as a key industry trend. National standards classify them into two types: Active Optical Current Transformers (AOCTs, active hybrid type) and Optical Current Transformers (OCTs, passive optical type). Active hybrid ECTs use low-power electromagnetic transformers and Rogowski coils as core sensing elements (Figure 1).Rogowski coils outperform traditional sensors with non-saturation and wide dynamic ranges

1 Principle and Role of Electronic Current Transformers1.1 Working Principle of ECTAn Electronic Current Transformer (ECT) is a key device for managing safe power system operations, converting large currents into manageable small-current signals for measurement and control. Unlike traditional transformers (relying on direct magnetic field interaction between primary and secondary windings), ECTs use sensors (e.g., Hall effect sensors) to detect magnetic field changes from the primary winding. Th

Traditional power transformers face inherent issues due to their sensors. Critically, they are vital for power plant monitoring, control, and protection (e.g., fault recording, safety control). However, large electrical energy transmission via information carriers and the lack of digital signal output from digital systems complicate secondary communication. Complex secondary wiring compensates for microcomputers’ high reliability, streamlining protection and secondary devices. This innovat