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

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

According to statistics, the vast majority of faults on overhead power lines are transient, with permanent faults accounting for less than 10%. Currently, medium-voltage (MV) distribution networks commonly employ 15 kV outdoor vacuum automatic circuit reclosers in coordination with sectionalizers. This setup enables rapid restoration of power supply after transient faults and isolates faulty line segments in the event of permanent faults. Therefore, it is essential to monitor the operational sta

1 Current Grid StatusWith the continuous deepening of rural power grid transformation, the health level of rural grid equipment is constantly improving, and power supply reliability basically meets user needs. However, regarding the current grid status, due to funding constraints, ring networks have not been implemented, dual power supplies are unavailable, and lines adopt a single radial tree-like power supply method. This resembles a tree trunk with many branches—meaning the lines have numerou

With the improvement of social productivity and people's quality of life, the demand for electricity is continuously increasing. To ensure the effectiveness of power grid system configuration, it is necessary to reasonably construct distribution networks based on actual conditions. However, during the operation of distribution network systems, 17.5kV ring main units play a very important role, so the impact caused by failures is extremely significant. At this point, it is essential to adopt reas

DTU (Distribution Terminal Unit), a substation terminal in distribution automation systems, is secondary equipment installed in switching stations, distribution rooms, N2 Insulation ring main units (RMUs), and box-type substations. It bridges primary equipment and the distribution automation master station. Older N2 Insulation RMUs without DTUs cannot communicate with the master station, failing to meet automation requirements. While replacing entire RMUs with new DTU-integrated models would sol

1. Specific Design1.1 Design ConceptState Grid Corporation of China actively promotes grid energy conservation and low-carbon development to achieve national carbon peak (2030) and neutrality (2060) goals. Environmentally friendly gas-insulated ring main units represent this trend. A new 12kV integrated environmentally friendly gas-insulated ring main unit was designed combining vacuum interrupter technology with three-position disconnectors and vacuum circuit breakers. The design utilized Solid

On December 2nd, the South Cairo distribution network loss reduction pilot project in Egypt, led and implemented by a Chinese power grid company, officially passed the acceptance inspection by the South Cairo Electricity Distribution Company of Egypt. The comprehensive line loss rate in the pilot area decreased from 17.6% to 6%, achieving an average daily reduction of lost electricity of approximately 15,000 kilowatt-hours. This project is the first overseas distribution network loss reduction p

In the rational application of intelligent technologies, the integrated intelligent ring main unit in 10kV distribution automation construction is more conducive to improving the construction level of 10kV distribution automation and ensuring the stability of 10kV distribution automation construction.1 Research Background Integrated intelligent ring main unit.(1) The integrated intelligent ring main unit adopts more advanced technologies, including but not limited to network technology, communic

This article introduces a case of 35kV ring main unit busbar insulation breakdown failure, analyzes the failure causes and proposes solutions [3], providing reference for the construction and operation of new energy power stations.1 Accident OverviewOn March 17, 2023, a photovoltaic desertification control project site reported a ground fault trip accident in the 35kV ring main unit [4]. The equipment manufacturer arranged a team of technical experts to rush to the site to investigate the cause

Gas-insulated ring main units are compact and expandable switchgear suitable for medium-voltage power distribution automation systems. These devices are used for 12~40.5 kV ring network power supply, dual radial power supply systems, and terminal power supply applications, serving as control and protection devices for electrical energy. They are also suitable for installation in pad-mounted substations.By distributing and scheduling electrical energy, they ensure the stable operation of power sy