Clyde G. Dewey

One-Cycle Fault Interruption at 500 kV: System Benefits and Breaker Design

The need for ultra-rapid fault interruption is identified on the basis of improvements to generator stability and the power transmission capability of the BPA 500 kV system. The development of a modified 500 kV air blast circuit breaker and a special fault sensor, which in combination should reduce total fault duration to essentially one cycle, is then described.

Static Mho Distance and Pilot Relaying

Design principles and typical circuits are described for new directional-comparison static-relaying equipment for transmission-line protection. Mho distance units, with offset-impedance supervision, are used for phase faults. The equipment is designed for use with either carrier-current or microwave communications channels, uses semiconductor circuitry throughout, and features high speed: less than 1/2 cycle for 3-phase faults and less than 1 cycle for unbalanced faults.

Development of Experimental 20-kY, 36-MW Solid-State Converters for HVDC Systems

Two 20-kV, 36-MW converters, one used as a rectifier and the other as an inverter in a pump-back configuration, have been operated successfully demonstrating the feasibility of SCRs for high-voltage high-current applications. Effects of commutation transients within the converters and on other apparatus have been thoroughly explored and analyzed.