Hi everyone, I'm James, and I've been working with current transformers (CTs) for 10 years. Today, I’ll talk about what you need to watch out for when selecting and installing GIS current transformers.Part 1: Key Considerations During Selection1. Accuracy ClassProtection-grade CTs: Used for relay protection — focus on overload capacity and transient response.Metering-grade CTs: Used for billing purposes — require high accuracy, usually 0.2S or 0.5S class.2. Rated Primary Curren

In UHV GIS, current transformers are key to electric energy metering. Their accuracy determines power trade settlements, so on - site error verification perJJG1021 - 2007is needed. On - site, use power supplies, voltage regulators, and current boosters. Due to encapsulation in GIS, build test circuits via exposed grounding knives, bushings, and return conductors; right circuits simplify wiring and boost accuracy.Challenges like large test current, long circuits, and high impedance exist, but rea

I’m Oliver, an 8 - year current transformer testing pro. Today, let’s break down new and old polarity test methods for GIS current transformers—how they work and their pros/cons.1.Testing Methods1.1New MethodPre - test ops: Open FDS21/FDS22 fast disconnectors + DS23 disconnector. Close CB21 breaker, then ES21/ES22 grounding disconnectors. Disconnect ES21’s SF6 - shell ground.Wiring: Connect battery between ES21’s moving contact (negative grounded) + ground electrode

1.Design and Application Example of Photoelectric Current Transformer in GISThis article takes a 126kV GIS project as a specific example to deeply explore the design ideas and practical application of photoelectric current transformers in the GIS system. Since this GIS project was officially put into operation, the power system has remained stable, with no major failures occurring, and the operation status is relatively ideal.1.1 Design and Application Ideas of Photoelectric Current TransformerI

I'm Oliver, with 8 years of experience in current transformer testing. These are all practical experiences, shared with you1 Maintenance of Current TransformersHaving been in the business of current transformer testing for 8 years, I know a thing or two about their maintenance! The maintenance of current transformers is divided into minor repairs, intermediate repairs, and major overhauls.Minor repairs mainly involve opening the cover (if necessary) and changing the oil, usually carried out once

Gas - insulated switchgear (GIS) , often called “SF6 combined electrical apparatus”, is widely used in power systems for its high reliability, small footprint, low noise, and low loss. It encloses high - voltage devices like circuit breakers, fast grounding switches, current transformers, and busbars in a grounded metal shell filled withSF6gas. Each device sits in a separate gas chamber with different pressures. The CT terminal block divides gas chambers, connects components, and eas