Dynamic Behavior of a 220-Kv Dead-End Suspension Bus during Short Circuit

A full-size 220-kv dead-end twin-bundled conductor suspension bus was subjected to short-circuit currents of various magnitudes and durations. Transducers and instruments available allowed the measurement and recording of many physical variables during these tests. Maximum short-circuit magnitude was 30,000 rms amperes. Short-circuit currents cause dynamic forces to be applied to the bus conductors, hardware, and towers. The major shock force is a result of the twin conductors being pulled together between spreaders by the short-circuit magnetic forces. The number and location of twin conductor spreaders have considerable influence on the peak magnitude of the dynamic forces. Electrical and mechanical damage to conductors as a result of a short circuit was negligible. This suspension bus design proved to be adequate for a shortcircuit duty of 10 million kva (kilovoltamperes) at 220 kv, and with minor modifications it may be adequate for 20 million kva at 220 kv.