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

(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 “

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

High-voltage disconnectors, also known as isolator switches or knife switches, feature a simple working principle and convenient operation. As commonly used high-voltage switching equipment, they significantly impact the operational safety of substations, demanding stringent reliability in practical applications. The remote online defect-elimination system for high-voltage disconnector contacts offers advantages such as ease of operation, low operating costs, and high stability, making it well-s

Traditional switches have become increasingly inadequate for the operational demands of modern traction power supply systems. The emergence of high-voltage disconnectors has effectively filled this gap. High-voltage disconnector systems optimize the structure of conventional switches, broaden their applicability, and place greater emphasis on fine details, thereby enhancing the safety and reliability of power systems during actual operation. Therefore, it is essential to analyze and study the ap

According to relevant regulations, high-voltage disconnectors are permitted to perform the following operations: Switching (opening/closing) normally operating potential transformers (PTs) and surge arresters; Switching the neutral grounding disconnector of a main transformer under normal operating conditions; Switching small-current loops to balance circulating currents.A high-voltage disconnector is an electrical component without arc-quenching capability. Therefore, it may only be operated wh