By Oliver, 8 Years in the Electrical IndustryHi everyone, I'm Oliver, and I've been working in the electrical industry for 8 years.From early days doing substation equipment commissioning to now managing protection and metering configurations for entire distribution systems, one of the most frequently used devices in my work has been the Current Transformer (CT).Recently, a friend who's just starting out asked me: “How do you test current transformers? Is there a simple and effective w

Fellow electric power calibration workers, you must have encountered this situation: The nameplate of an outdoor current transformer has been tormented by wind, sun, rain, and freezing, to the point where the transformation ratio is indistinguishable! Don't panic, we have a solution - use a current transformer calibrator and through the “transformation ratio trial calibration method”, we can figure out the actual transformation ratio and errors clearly. Here, taking the SHGQ

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

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 Method Pre - 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 ground

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

Hey everyone, I'm Oliver, and I've been working with current transformers (CTs) and voltage transformers (VTs) for 8 years.From assisting my mentor on site to leading high-voltage testing teams and conducting error calibrations independently, I’ve dealt with all kinds of instrument transformers — especially those used in GIS systems. The error test for voltage transformers is something I perform regularly.A few days ago, a friend asked me: “Oliver, how exactly do yo

Hey everyone, I’m Oliver, and I’ve been working in current transformer (CT) testing for 8 years.From running around with test equipment on site to now leading full inspection teams, I’ve seen how thousands of outdoor CTs go through a whole series of tests — like going through a military training camp — before they can finally be put into service.A few days ago, a friend asked me: “Oliver, our factory just produced a new batch of outdoor

1. IntroductionOutdoor voltage transformers are key equipment for ensuring the safety of electrical apparatus. Scientific and comprehensive test analysis is required to avoid hazards and property losses caused by improper operation. Test analysis can guide the formulation of operation strategies and precautions, ensure the stable operation of equipment, and maximize economic and social benefits.2. Concept of Outdoor Voltage TransformersAn outdoor voltage transformer is essentially an outdoor ste

1.Gas Generation and Analysis Principle of High - Voltage ReactorsHigh - voltage reactors use oil and insulating paper for insulation. Normal operation may see local overheating or discharges (e.g., iron core/winding issues, inter - turn short circuits), causing insulation cracking and producing gases like hydrocarbons (methane, etc.), CO, CO2, H2). These gases reflect internal insulation status, enabling real - time monitoring.For closed oil - filled reactors, insulation aging and oil oxidation

Hey everyone, I’m Oliver, a 10-year veteran in the power system industry. Today we’re going to talk about a very practical topic — how do you know if a current transformer (CT) used in Air Insulated Switchgear (AIS) is truly qualified? This isn’t just about meeting technical specs; it’s directly tied to equipment safety, grid stability, and accurate metering.Let’s dive in — based on my real-world experience.IntroductionIn subs