High performance triggered lightning current arresters for international power supply systems

Triggered spark-gap lightning current arresters with low protection voltage level and high follow-current interrupt capabilities have been in existence for the last 3 years and are used throughout the world to protect sensitive power supply equipment (<600VAC) from the direct effects of lightning while maintaining small space requirements. The coordination of these powerful arrestors with metal oxide varistor components is known as active energy control (AEC) and allows very compact protection systems that contain energetically coordinated class I and class II (IEC 61643) surge protection devices (SPDs). This paper will discuss in detail the AEC concept and additionally introduce a new spark-gap ignition electronic circuit. This technology is based on an ignition current which flows through a special ignition element to produce an initial electrical arc. There is no need for further ignition electronics to produce the high voltage impulse required to ignite the spark gap thus making a more robust design. The results are a very powerful lightning arrestor with low voltage protection level and limited follow-current. The technical function of this special spark gap lightning arrestor will be discussed in detail. Finally this work will discuss performance advantages of the AEC protection concept when installed in a telecommunication power application.