An insulator is a critical component in power systems that serves the key functions of electrical insulation and mechanical support. Its primary role is to electrically isolate energized conductors from grounded components (such as towers, poles, and equipment enclosures), preventing current leakage or short circuits, and ensuring the safe and stable operation of power equipment and transmission/distribution lines.
Modern insulators are increasingly made from advanced composite materials (such as silicone rubber and high polymer compounds) to enhance insulation performance, resistance to pollution flashover, and anti-aging capabilities. Some insulators are evolving into smart insulators by integrating sensors that enable real-time monitoring of parameters such as temperature, humidity, voltage, leakage current, and mechanical stress, thereby improving the intelligence level of the power grid.
Insulators effectively prevent high-voltage current leakage, tripping, short circuits, fires, and electric shock accidents, making them the first line of defense for the safe operation of power systems. They are also widely used in electrified railway systems, including subways, light rail, and high-speed rail, particularly in traction power supply systems—for example, as support insulators for overhead contact lines—to ensure the safe transmission of traction current while preventing ground faults.