Exhibition Video

Essential Transformer Protection Knowledge You Must Know!

Internal faults refer to failures occurring within the tank enclosure, including phase-to-phase short circuits in windings, turn-to-turn short circuits within a single phase winding, short circuits between windings and the core, and broken wires in windings. External faults encompass various phase-to-phase short circuits between the transformer's external leads, as well as single-phase ground faults caused by flashover through the insulation bushings of the leads to the tank enclosure.

What is zero-sequence overcurrent protection?

What is Zero-Sequence Overcurrent Protection In power systems, zero-sequence protection refers to an electrical protection measure designed to guard against zero-sequence currents caused by ground faults or short-circuit faults. When leakage occurs in a line (below the transformer), the vector sum of currents passing through the transformer is no longer zero, resulting in an output current on the transformer's secondary winding. This principle enables zero-sequence overcurrent protection.

Working Principle and Fundamentals of Instrument Transformers

Voltage Transformer A voltage transformer (abbreviated as PT), similar to a transformer, is an instrument used to transform voltage. The primary purpose of a voltage transformer's voltage transformation is to supply power to measuring instruments and relay protection devices.

Participating in the Vietnam Exhibition in 2024

Participating in the Vietnam Exhibition in 2024

Inner Mongolia completes full-area transmission of 35 kV voltage transformer metrology comparison

The 2025 35 kV voltage transformer metrology comparison project, led by the Standard Instrument Transformer Laboratory of the Electric Energy Measurement Supervision Center of the Inner Mongolia Electric Power Research Institute, completed full-region on-site transmission and testing over a two-month period. The comparison, covering 11 power supply units under the Inner Mongolia Electric Power Group, employed a "petal-shaped" dual-route transmission scheme. The goal was to establish a unified measurement value transmission system across the region and provide technical support for fair settlement of electricity trade. Final data processing and report generation will be completed in September.

What is the working principle of current transformer?

Current transformers are important devices used for measurement and protection in power systems. Their working principle is based on the law of electromagnetic induction. The core is to achieve the conversion of large current on the primary side to small current on the secondary side through electromagnetic coupling, which facilitates measurement, protection and monitoring.

How to choose a suitable current transformer?

Selecting a suitable current transformer requires comprehensive consideration of multiple factors such as power system parameters, application scenarios, and accuracy requirements to ensure its safe and reliable operation and meet functional requirements such as measurement and protection.

What are the accuracy levels of current transformers?

The accuracy grade of a current transformer is a key indicator of the accuracy of its measurement or protection performance. Different grades correspond to different tolerances, and the selection should be based on the specific application (metering, measurement, protection). The following is a classification of common accuracy grades and detailed descriptions:

Is there a big price difference between current transformers of different accuracy levels?

Current transformers of different accuracy grades vary in price. Generally speaking, higher accuracy grades increase prices, but the extent of this difference varies depending on factors such as product specifications and type.

Advantages of power transformers

Power instrument transformers (including current transformers and voltage transformers) are essential, critical equipment in power systems. Their core function is to safely convert high voltages and high currents to the low voltages and low currents required by measurement and protection equipment. They offer several significant advantages