目前我国电力系统中载波通道(又称高频通道)是用得很普遍的一种通道类型。在继电保护中使用时有专用通道和复用通道2种,其中专用通道用相-地耦合通道,一般用在闭锁式中,收发讯机用继电保护专用收发讯机;复用通道采用相-相耦合通道,一般用在允许式(或闭锁式)中,收发讯机用载波机。为解决长距离、高电压电力线载波通道传输衰减大的矛盾,国内外均采用相-相耦合方 At present, China’s power system carrier channel (also known as high-frequency channel) is a very common use of a channel type. When used in relay protection, there are two types of dedicated channels and multiplexed channels, of which the dedicated channels are phase-to-ground coupling channels, commonly used in the latching type, and the transceivers use relay protection special transceivers; the multiplex channels are used Phase - phase coupling channel, generally used in the allowable (or lock), transceiver transceiver. In order to solve the long-distance, high voltage power line carrier attenuation attenuation of the channel, both at home and abroad are used phase-phase coupling side