防止过电压对电力系统的危害而采取的措施。主要有： 在输电线路和变电所设置避雷线和避雷针，防止直接雷击;对重要的旋转电机采取电缆进 (出) 线并设置避雷器以防止雷电波的侵入; 采用并联电抗器限制工频过电压; 对断路器加装并联电阻以限制操作过电压。特别是正确地选用避雷器可以有效地限制最常见的大气过电压和操作过电压。近年来出现的金属氧化物压敏电阻，为380伏/220伏低压配电线路及设备提供了有效的过电压保护器件。
Measures taken to prevent the harm of overvoltage to power system. The main points are as follows: setting lightning arresters and lightning rods in transmission lines and substations to prevent direct lightning strikes; adopting cable-in (out) lines and lightning arresters for important rotary motors to shiyany.89ix.com diandongmen.89ix.comtongmen.89ix.comqingxijii.89ix.comgangmumen.89ix.comerliu.89ix.comprevent the intrusion of lightning waves; adopting shunt reactors to limit power frequency overvoltage; and adding shunt resistors to circuit breakers to limit operating overvoltage. In particular, the correct selection of arresters can effectively limit the most common atmospheric and operational overvoltages. In recent years, metal oxide varistors have emerged, which provide effective over-voltage protection devices for 380 V/220 V low-voltage distribution lines and equipment.