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

1. Structure Forms and Classification of BushingsThe structure forms and classification of bushings are shown in the table below: Serial No. Classification Feature Category 1 Main insulation structure Capacitive Type Resin-impregnated paperOil-impregnated paper Non-capacitive Type Gas insulationLiquid insulationCasting resinComposite insulation 2 External Insulation Material PorcelainSilicone Rubber 3 Filling Material Between Capacitor Core and Exte

On May 7, China's first large-scale integrated wind-solar-thermal-storage comprehensive energy base UHV transmission project—the Longdong~Shandong ±800kV UHV DC transmission project—was officially energized and put into operation. The project has an annual transmission capacity exceeding 36 billion kilowatt-hours, with new energy sources accounting for more than 50% of the total. After commissioning, it will reduce carbon dioxide emissions by approximately 14.9 million tons annually, contributin

On August 10, a self-developed 750 kV single-column, high-capacity autotransformer manufactured by China Transformer Manufacturing Company successfully passed the national-level technical appraisal for new products. Experts at the appraisal meeting unanimously concluded that the product’s key technical specifications have reached an internationally leading level among similar products, marking a significant advancement for China in the design and manufacturing of extra-high-voltage (EHV) transfo

(1) The contact gap is primarily determined by insulation coordination parameters, interruption parameters, contact material of the high-voltage SF₆-free ring main unit, and the design of the magnetic blowout chamber. In practical application, a larger contact gap is not necessarily better; instead, the contact gap should be adjusted as close as possible to its lower limit to reduce operating energy consumption and extend service life.(2) The determination of contact overtravel is related to fac

Recently, the world’s first 500kV/90kA cost-effective high-voltage AC current limiter, jointly led by Guangzhou Power Supply Bureau of Guangdong Power Grid and developed by China High-Voltage AC Current Limiter Manufacturer, successfully completed artificial short-circuit tests and has been officially connected to the grid for trial operation on the Shunguang Jia Line at the 500kV Guangnan Substation. As a key project under China’s National Key R&D Program, the successful completion of the “

First, the installation of 10 kV high-voltage disconnect switches must meet the following requirements. The first step is to select an appropriate installation location, typically near the switchgear power supply in the power system to facilitate operation and maintenance. At the same time, sufficient space must be ensured at the installation site to accommodate equipment placement and wiring.Secondly, equipment safety must be fully considered—for example, lightning protection and explosion-proo

1.Blocking Principle of Ultra-High-Voltage Converter Valves1.1 Working Principle of Converter ValvesUltra-high-voltage (UHV) converter valves typically employ thyristor valves or insulated-gate bipolar transistor (IGBT) valves to convert alternating current (AC) to direct current (DC) and vice versa. Taking the thyristor valve as an example, it consists of multiple thyristors connected in series and parallel. By controlling the triggering (turn-on) and turn-off of thyristors, the valve regulates

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

In power systems, high-voltage disconnectors in substations have suffered from aging infrastructure, severe corrosion, increasing defects, and insufficient current-carrying capacity of the main conductive circuit, significantly compromising power supply reliability. There is an urgent need to carry out technical retrofits on these long-in-service disconnectors. During such retrofits, to avoid interrupting customer power supply, the common practice is to place only the retrofit bay under maintena

High-voltage disconnectors are extremely widely used, and therefore people pay great attention to potential problems that may arise with them. Among various faults, corrosion of high-voltage disconnectors is a major concern. In light of this situation, this article analyzes the composition of high-voltage disconnectors, types of corrosion, and faults caused by corrosion. It also investigates the causes of disconnector corrosion and studies theoretical foundations and practical techniques for cor