Secondary control circuit diagram of isolation switch and ground switch in 110kV combined electric

Substations designed for voltage levels ranging from 55 kV to 765 kV are known as outdoor substations. This type of substation requires less construction time but occupies more space. Outdoor substations are mainly divided into pole-mounted substations and foundation-mounted substations.Pole-Mounted SubstationsThis type of substation is used to support distribution transformers with capacities up to 250 kVA. Such transformers represent the cheapest, simplest, and smallest form of distribution. A

(1) Generator Protection:Generator protection covers: phase-to-phase short circuits in stator windings, stator ground faults, inter-turn short circuits in stator windings, external short circuits, symmetrical overload, stator overvoltage, single- and double-point grounding in the excitation circuit, and loss of excitation. Tripping actions include shutdown, islanding, limiting fault impact, and alarm signaling.(2) Transformer Protection:Power transformer protection includes: phase-to-phase short

Analysis and Handling of Fault Tripping in 35kV Substation Operation1. Analysis of Tripping Faults1.1 Line-Related Tripping FaultsIn power systems, the coverage area is extensive. To meet power supply demands, numerous transmission lines must be installed—posing significant management challenges. Especially for special-purpose lines, installations are often located in remote areas such as suburbs to minimize impact on residential life. However, these remote areas have complex environments, makin

1. Methods for Detecting Busbar Discharge1.1 Insulation Resistance TestThe insulation resistance test is a simple and commonly used method in electrical insulation testing. It is highly sensitive to through-type insulation defects, overall moisture absorption, and surface contamination—conditions that typically result in significantly reduced resistance values. However, it is less effective in detecting localized aging or partial discharge faults.Depending on the equipment’s insulation class and