Common 35~110kV substation main wiring（Double bus line)

The arrangement of neutral point grounding operation modes for 110kV～220kV power grid transformers shall meet the insulation withstand requirements of transformer neutral points, and shall also strive to keep the zero-sequence impedance of substations basically unchanged, while ensuring that the zero-sequence comprehensive impedance at any short-circuit point in the system does not exceed three times the positive-sequence comprehensive impedance.For 220kV and 110kV transformers in new constructi

Why Do Substations Use Stones, Gravel, Pebbles, and Crushed Rock?In substations, equipment such as power and distribution transformers, transmission lines, voltage transformers, current transformers, and disconnect switches all require grounding. Beyond grounding, we will now explore in depth why gravel and crushed stone are commonly used in substations. Though they appear ordinary, these stones play a critical safety and functional role.In substation grounding design—especially when multiple gr

According to the "Eighteen Major Anti-Accident Measures for Power Grid of State Grid Corporation of China (Revised Edition)" promulgated in 2018, operation and maintenance units should improve the on-site operation regulations for intelligent substations, refine the usage instructions and abnormal handling methods for various messages, signals, hard pressure plates, and soft pressure plates of intelligent equipment, standardize the operation sequence of pressure plates, strictly follow the seque

In China's power system, the 6 kV, 10 kV, and 35 kV grids generally adopt a neutral-point ungrounded operation mode. The distribution voltage side of the main transformer in the grid is usually connected in delta configuration, which provides no neutral point for connecting a grounding resistor.When a single-phase ground fault occurs in a neutral-point ungrounded system, the line-to-line voltage triangle remains symmetrical, causing minimal impact on user operations. Moreover, when the capacitiv