Basic Principle of Lightning Arrester
Lightning arrester is a kind of overvoltage protector mainly applied for the protection of various electrical appliances (such as transformer, switch,capacitor,trap.mutual inductor,generator,motor and power cable etc.) in power system, railway electrification system and overvoltage etc. The arrester is the basis of insulation coordination in power system. The core elements of metal oxide arrester (resistor disc) applies an advanced formulate with zinc oxide as the main material and has an outstanding nonlinear properties (voltage-ampere). That is, under the normal operating voltage, the current passing through is only on microampere level. When overvoltage is incurred, the current passing through can be thousands of amperes instantly and the arrester is switched into conduction to release the energy of overvoltage. By this means the damage caused by overvoltage on the electric transmission and transformation equipments can be effectively restrained. The traditional silicon carbide arrester has high steep wave discharging voltage caused by steep wave discharging and the operation wave discharging voltage is high caused by discharging decentrality. While the zinc oxide arrester has good steep wave response properties and make no delay on steep wave voltage and provide low residual voltage during operation; and also the advantage of no discharging decentrality. The arrester can greatly improve the protective margin of the steep wave and operation wave. And on insulation coordination, the proactive margins of steep wave, lightning wave and operation wave are nearly consistent and best protection can be provided for the power equipments. Composite coating metal oxide arrester applies integrated extruding shaping and both-end envelopment techniques and can provide high performances of sealing and anti-explosion, pollution resistance, free of cleaning and reducing the wet flashover in foggy conditions. The product is also featured by electrical erosion resistance, aging resistance, small volume, light weight and easy installation and maintenance, and is the upgraded new generation product of porcelain sheath arrester.
