Laboratory and Field Testing of a Production-Type Current-Limiting Protector. Final Report

摘要

A fully operational current limiter system has been developed, laboratory and field tested. It is rated 15 kV, 1000 Ampere, 15 kA peak let-thru current on a 40 kA (RMS sym) prospective fault. The underlying principle is the current limiting protector (CLP) consisting of a pyrotechnically operated current limiting interrupter and a fault current level sensing and triggering circuit per phase. The development effort resulted in consistent manufacturing processes for reliable CLP systems. Thus an epoxy cast body was produced with tight tolerances necessary to match the precisely machined main conductor of the CLP, to locate the pyrotechnic charges, and to accept the parallel current limiting fusible elements. Various fault current sensing schemes were explored. A level sensor including an isolation/current transformer was developed and hardened under severe simulated utility conditions. Numerous mechanical, dielectric and short circuit tests were conducted to prove the CLP system. A station type and an overhead CLP system were designed, built and installed in the circuits of Boston Edison Co. and of Consolidated Edison Co. of New York, respectively. Energization and control problems were encountered and largely resolved. General application criteria for CLP's were derived and are included. (ERA citation 08:009762)