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

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 impa

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) a

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 Effic

1 Research BackgroundMetal - oxide surge arresters, sealed in cabinets, bear system voltage continuously, risking aging failures, even breakdowns/explosions causing electrical fires. Thus, regular inspection/maintenance is needed. Traditional 3–5 - year - cycle detection (power cut, arrester removal for tests; reinstallation if replaced) poses safety risks and faces space/environment - based standard - grasping difficulties.2 Monitoring Principle of 10kV GIS Cabinet Surge ArresterTo en

Can a 50Hz-Designed Power Transformer Operate on 60Hz Grid?If a power transformer is designed and built for 50Hz, can it run on a 60Hz grid? If so, how do its key performance parameters change?Key Parameter Changes Short-Circuit Impedance:For a given transformer (same voltage and capacity), short-circuit impedance is proportional to frequency. Thus, a 50Hz-designed unit operating at 60Hz sees a 20% increase—higher frequency intensifies alternating leakage field opposition to current. N

Overhead cables, due to their exposure to external environments, are subject to various influences that can lead to different types of faults. Below are some common types of faults in overhead cables and their causes:1. Mechanical Damage Caused by external forces such as falling trees, vehicle collisions, or construction accidents. Prolonged vibrations or swinging can also cause material fatigue in cables.2. Weather-Related Faults Lightning Strikes: Direct hits or nearby lightning strikes can ca

A core challenge in online cable eccentricity measurement is the cable’s high - speed motion. This requires non - contact measurement equipment that can handle cable jitter. X - ray cable eccentricimeters, based on optical transmission imaging, measure multi - layer contour dimensions to calculate the geometric center of conductors relative to insulation eccentricity. However, they have drawbacks: slow measurement speed (only a few times per second), increased errors from cable jitter,

1. Current Situation and ProblemsLow - voltage overhead cables often suffer insulation damage. Urbanization and infrastructure construction expose them to complex environments (construction, severe weather like strong winds/rains causing scratches or impacts, animal damage), easily breaking insulation layers. Long - term operation also degrades insulation due to aging, corrosion, and prolonged sunlight—e.g., cables in old communities age and crack, raising failure risks.Existing restor

1 Research on Cable Laying and Wiring Construction Technology of Photovoltaic Power Station1.1 Data CollectionBefore constructing the BIM model for cable laying, it is necessary to deeply master the detailed parameters of the involved equipment specifications, materials used in construction, and site conditions, aiming to improve the accuracy of model construction. To ensure that the BIM model can accurately reflect the actual situation of the construction site, the core lies in accurately colle