Handling of Minor Action of Transformer Gas RelayImmediately check and record the protective relay action signals, and report to the dispatcher and station manager.Closely monitor the transformer’s voltage, current, temperature, oil level, oil color, sound, and cooler operation, and assign personnel to conduct an external inspection of the transformer.If significant abnormalities are found during the inspection, report to the dispatcher and take the faulty transformer offline. If no obviou

What Is a Voltage Class?Definition of Voltage Class:Voltage classes (or voltage levels) refer to a set of standardized rated voltages used in power systems and electrical equipment. A rated voltage is the nominal voltage at which equipment is designed to operate under normal conditions; essentially, a voltage class defines the intended working voltage range for a system or device.Analogy to Consumer Appliances:Household appliances (e.g., refrigerators, TVs) operate at a nominal voltage—typ

Verification of Insulation IntegrityWhen a new or overhauled transformer is energized under open-circuit (no-load) conditions, switching surges—caused by operations such as opening or closing the no-load transformer circuit—can generate overvoltages. These reach 4.0–4.5 times the phase voltage if the neutral point is isolated or earthed through a Petersen coil, and up to 3.0 times the phase voltage when the neutral is solidly grounded. The full-voltage, no-load impact test deli

1. IntroductionDuring power system operation, main equipment faces threats from internal and atmospheric overvoltages. Surge arresters, especially metal oxide arresters (MOAs) with excellent nonlinear volt - ampere characteristics, are key for protection due to their good performance, large current - carrying capacity, and strong pollution resistance. However, long - term exposure to power frequency voltages, along with component quality, manufacturing processes, and external environments, makes

1 Architecture of the Online Monitoring System for Zinc Oxide Surge ArrestersThe online monitoring system for zinc oxide surge arresters comprises three layers: the station control layer, bay layer, and process layer.Station Control Layer: Includes a monitoring center, a Global Positioning System (GPS) clock, and a B - code clock source.Bay Layer: Consists of online monitoring Intelligent Electronic Devices (IEDs).Process Layer: Features monitoring terminals for Potential Transformers (PTs) and

1 Significance of Surge Arrester Online Monitors1.1 Enhance Power System Safety, Reduce Lightning DamageDuring lightning strikes, surge arresters play a core role in discharging overvoltage. Online monitors ensure arrester stability, detect potential faults in real - time, and trigger alarms for timely intervention—effectively reducing lightning - induced damage to power equipment and systems, and maintaining stable operation.1.2 Real - Time Status Monitoring, Improve Maintenance Efficienc