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

Recently, three IEC standards on insulators, led by China for the first time, have been officially published. These standards primarily address the coupling markings, dimensions, and tests of insulator end fittings, specifically including IEC 60120:2020, IEC 60372:2020, and IEC 60471:2020. These three standards were jointly completed under the leadership and coordination of numerous experts from the National Technical Committee on Insulators of China (SAC/TC80). The publication of these standard

The selection principles and precautions for fuse-switch disconnectors are crucial to ensuring the safe and stable operation of power systems.Selection Principles for Fuse-Switch Disconnectors Rated Voltage:The rated voltage of the fuse-switch disconnector shall be equal to or greater than the rated voltage of the electrical system to ensure the equipment operates normally without damage. Rated Current:The selection of rated current should be based on the load conditions of the electrical system

I. Fuse Structure and Root Cause AnalysisSlow Fuse Blowing:From the design principle of fuses, when a large fault current passes through the fuse element, due to the metal effect (certain refractory metals become fusible under specific alloy conditions), the fuse first melts at the soldered tin ball. The arc then rapidly vaporizes the entire fuse element. The resulting arc is quickly extinguished by quartz sand.However, due to harsh operating environments, the fuse element may age under the comb

Common Causes of Fuse BlowingCommon reasons for fuse blowing include voltage fluctuations, short circuits, lightning strikes during storms, and current overloads. These conditions can easily cause the fuse element to melt.A fuse is an electrical device that interrupts the circuit by melting its fusible element due to heat generated when current exceeds a specified value. It operates on the principle that, after an overcurrent persists for a certain period, the heat produced by the current melts

1. Fuse MaintenanceFuses in service should be regularly inspected. The inspection includes the following items: Load current should be compatible with the rated current of the fuse element. For fuses equipped with a fuse blown indicator, check whether the indicator has actuated. Check the conductors, connection points, and the fuse itself for overheating; ensure connections are tight and making good contact. Inspect the fuse exterior for cracks, contamination, or signs of arcing/discharge. Liste

1. Current Status and Shortcomings of Online MonitorsCurrently, online monitors are the most commonly used tools for surge arrester monitoring. While they can detect potential defects, they have significant limitations: manual on - site data recording is required, precluding real - time monitoring; and post - collection data analysis adds to operational complexity. IoT - based intelligent monitoring overcomes these issues—collected data is uploaded via the IoT to processing platforms,

1. Overview of Surge Arrester Handover Test Technology1.1 Necessity of Handover TestThe handover test is a crucial step in ensuring the performance and safe operation of surge arresters within power systems. For power systems with voltage levels at 220 kV and below, surge arresters play a core role in protecting electrical equipment from damage caused by overvoltages and lightning strikes. However, during the process from the arrester leaving the factory to its actual operation after installatio

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