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

In a certain region, after maintenance of ultra-high-voltage (UHV) transmission lines, the following issues were identified: existing drones lack sufficient performance to meet the current large-scale and extensive inspection and maintenance demands of UHV lines. In practical operations, drones exhibit inadequate endurance, limited image acquisition capability, and poor electromagnetic interference (EMI) resistance, which negatively impacts inspection effectiveness and prevents accurate identifi

Currently, traditional-type breathers are widely used in transformers. The moisture-absorbing capability of silica gel is still judged by operation and maintenance personnel through visual observation of the color change of silica gel beads. Subjective judgment by personnel plays a decisive role. Although it has been clearly stipulated that silica gel in transformer breathers should be replaced when more than two-thirds of it changes color, there is still no accurate quantitative method to deter

High-voltage vacuum circuit breakers are widely used across China’s power industry—in urban and rural power grid upgrades, chemical plants, metallurgy, railway electrification, mining, and other sectors—thanks to their excellent arc-quenching characteristics, suitability for frequent operations, and long maintenance-free intervals. They have received widespread acclaim from users.The primary advantage of vacuum circuit breakers lies in the vacuum interrupter; however, a long maintenance-free int

Recently, Chinese GIS manufacturers announced exciting news: the first ZF11C-252(L) mixed-gas double-break GIS product developed by a Chinese GIS manufacturer successfully passed its on-site power frequency withstand voltage test on the first attempt at a project site. This achievement marks another milestone for Chinese GIS manufacturers in advancing green and high-quality development of power grids.The ZF11C-252(L) mixed-gas double-break GIS that passed the test represents the culmination of t

With the advancement of smart grid technologies, sequential control (SCADA-based automated switching) in substations has become a core technique for ensuring stable power system operation. Although existing sequential control technologies have been widely deployed, challenges related to system stability under complex operating conditions and equipment interoperability remain significant. Unmanned Aerial Vehicle (UAV) technology—characterized by its agility, mobility, and non-contact inspection c

GIS (Gas-Insulated Switchgear) offers advantages such as compact structure, flexible operation, reliable interlocking, long service life, maintenance-free operation, and small footprint. It also possesses many irreplaceable advantages in insulation performance, environmental friendliness, and energy saving, and is increasingly applied in industrial and mining enterprises, airports, railways, subways, wind power stations, and other fields.A certain enterprise’s 35 kV indoor substation was origina

Intelligentization has become an important development direction for power systems. As a critical component of the power system, the stability and safety of 10 kV distribution network lines are vital to the overall operation of the power grid. The fully enclosed disconnector, as one of the key devices in distribution networks, plays a significant role; thus, achieving its intelligent control and optimized design is of great importance for enhancing the performance of distribution lines.This pape

1.Analysis of the Structure and Working Principle of GN30 DisconnectorThe GN30 disconnector is a high-voltage switching device primarily used in indoor power systems to open and close circuits under voltage but no-load conditions. It is suitable for power systems with a rated voltage of 12 kV and AC frequency of 50 Hz or lower. The GN30 disconnector can be used either in conjunction with high-voltage switchgear or as a standalone unit. Featuring a compact structure, simple operation, and high re

1.Working Principle and Structural Features of GW4-126 DisconnectorThe GW4-126 disconnector is suitable for AC 50/60 Hz power lines with a rated voltage of 110 kV. It is used to disconnect or connect high-voltage circuits under no-load conditions, enabling circuit switching, operational mode changes, and safe electrical isolation of busbars, circuit breakers, and other high-voltage equipment during maintenance. Disconnectors typically feature a clearly visible open point to ensure safe current i

1.Description of the Fault PhenomenonThe disconnector fault in a 550 kV GIS equipment occurred at 13:25 on August 15, 2024, while the equipment was operating under full load with a load current of 2500 A. At the moment of failure, the associated protection devices acted promptly, tripping the corresponding circuit breaker and isolating the faulty line. System operating parameters changed significantly: the line current dropped abruptly from 2500 A to 0 A, and the bus voltage instantly decreased