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

CIS (Gas Insulated Switchgear) refers to a gas - insulated enclosed switchgear assembly. A busbar is a common pathway to which multiple devices are connected in parallel. In a CIS, the internal space of the busbar is relatively small, yet it operates under high voltage and current. Local discharge, if it occurs, can severely affect the inter - phase insulation and pose a significant threat to the safe and stable operation of the equipment. This article presents an analysis and solution of a loca

Overview of the SituationDuring the AC commissioning period of a certain substation, a flashover discharge fault of the post insulator occurred. The specific fault situation is as follows:When closing the 500 kV AC switchyard switch to charge the busbar, the dual - set busbar differential protection of the busbar operated, and the switch tripped. The fault phase was phase B, and the fault current was 5,760 A. The gas composition analysis of the SF₆ gas in the gas chamber was carried out, and the

As a key component of circuit breakers, the insulating pull - rod is an important insulating and transmission part of Gas - Insulated Switchgear (GIS) equipment. It is required to have high reliability in terms of mechanical and electrical properties. Generally, insulating pull - rods rarely malfunction, but once a failure occurs, it can have serious consequences for the circuit breaker.The 550kV circuit breaker in a certain power station has a single - break horizontal arrangement, with the mod

IntroductionThe LW12 - 500 tank - type SF₆ circuit breaker is a domestic high - voltage circuit breaker. As the operation time increases continuously, frequent failures of the main body and operating mechanism have had a significant impact on the safe and stable operation of the power grid, affecting the power supply reliability and causing the maintenance cost of the circuit breaker to rise year by year. Aiming at the common defects and faults of the LW12 - 500 tank - type SF₆ circuit breaker,

IntroductionIn the context of the African market, especially in Nigeria, the reliable operation of electrical equipment is of utmost importance for the stable development of the power industry. Tank - type SF₆ circuit breakers play a crucial role in power systems due to their excellent arc - extinguishing and insulating properties. However, like any electrical equipment, they are prone to failures. This paper presents a detailed case analysis of a tank - type SF₆ circuit breaker failure in Niger

Failure PhenomenonFailure Information and Operational Mode Before FailureAt 17:53:50 on May 16, 2016, the protection devices of two sets on Jingchuan II Line operated successively. Phase B was selected for tripping, and the B - phase of circuit breakers 7522 and 7520 was opened. The protection of circuit breaker 7522 detected a permanent fault on the two - circuit line protection device, with a delay of 0.6s. Subsequently, the ABC three - phase of circuit breaker 7522 tripped. During this proces

1. IntroductionDue to long - term operation, faults and accidents of distribution transformers in rural power grids cannot be completely avoided. These faults and accidents are caused by a multitude of factors, such as external forces like damage and impact, and irresistible natural disasters such as lightning strikes. Meanwhile, in some rural areas, the low - voltage lines are inadequately maintained, frequently resulting in overloading and short - circuits, which cause distribution transformer

Introduction to Fuses of American-style Box TransformersAmerican-style box transformers generally use a combination of plug-in fuses and backup protection fuses in series to provide protection. The protection principle is advanced and reliable, and the operation is simple. The backup protection fuse is an oil-immersed current-limiting fuse, usually installed inside the box transformer. It will operate only when a fault occurs inside the box transformer, and it is used to protect the high-voltage

Fault Causes of Distribution TransformersFaults Caused by Temperature RiseImpact on Metal MaterialsWhen a transformer is in operation, if the current is too large, causing the customer load to exceed the rated capacity of the transformer, the temperature of the transformer will rise, which in turn softens the metal materials and significantly reduces their mechanical strength. Take copper as an example. If it is exposed to a high - temperature environment above 200 °C for a long time, it

In an SF₆ circuit breaker, the SF₆ gas can decompose into toxic and corrosive gases and water in a high-temperature environment, which can damage the insulating layer. To prevent this situation, while effectively strengthening the protection of electrical components, the insulation level should also be improved. In addition, faults should be analyzed, and corresponding measures should be taken for treatment.1 Case AnalysisA 110 kV switch in a substation was struck by lightning, causing a reclosi