Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

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 inn

Open - Circuit Fault on the Secondary SideOpen - circuit in the secondary side is a typical fault of low - voltage voltage transformers, showing abnormal voltmeter readings (zero/fluctuation), faulty power meters, buzzing noises, and core overheating. When open - circuited, the secondary voltage spikes (no secondary current to balance the primary EMF), causing core saturation, flux distortion, and potential overheating/damage.Causes include loose terminals, poor contact, or human error. In low

1 IntroductionLow - voltage current transformers for metering, with a through - core type epoxy resin structure, are widely used in distribution transformer areas and for small - to - medium - sized industrial and commercial electricity consumption. As a range expander for electric energy metering, their performance directly relates to electricity consumption safety and the accuracy of users' trade calculations. Studying long - term immersion's impact on these transformers is practically signifi

Low-voltage current transformers, as indispensable measurement and protection devices in power systems, often encounter various faults when used in combination with other power equipment due to environmental factors, equipment linkage issues, and improper installation and maintenance. These faults not only affect the normal operation of power equipment but may also endanger personal safety. Therefore, it is necessary to gain an in-depth understanding of fault types, judgment methods, and prevent

1. Selection of Low - Voltage Current Transformer ConfigurationThere are many factors leading to wrong selection of low - voltage current transformers in civil construction projects. For example, common factors include design problems: the calculated coefficient designed for the load of electrical equipment is relatively large, or the transformation ratio of the current transformer is selected incorrectly. Such a series of reasons will affect the use of electrical equipment. Therefore, in the co

To ensure safe operation of the power system, power equipment operation must be monitored/measured. General devices can’t connect to primary high - voltage equipment directly; instead, large primary currents are scaled down for current transformation, electrical isolation, and use by measurement/protection devices. For AC large - current measurement, conversion to a unified current eases secondary instrument use.Current transformers split into measurement - and protection - type, with

1. Overview of Components and IssuesTA (low-voltage current transformer) and electric energy meters are key components of low-voltage electric energy metering. The load current of such meters is no less than 60A. Electric energy meters vary in type, model, and anti-DC performance, and are connected in series in the metering device. Due to the lack of anti-DC capability, they suffer from metering errors under DC component loads, usually caused by non-linear loads. With the increasing use of DC or