Friedrich K Schaeffer

US Patent:

56044232, Feb 18, 1997

Filed:

Apr 6, 1995

Appl. No.:

8/223900

Inventors:

Robert C. Degeneff - Niskayuna NY
Friedrich K. Schaeffer - Goldsboro NC
Robert H. Frazer - Goldsboro NC
David A. Torrey - Ballston Lake NY
Osman Demirci - Troy NY

Assignee:

Utility Systems Technologies, Inc. - Niskayuna NY

International Classification:

G05F 116

US Classification:

323258

Abstract:

A tap changing system for operation with a transformer and featuring a special group of gate-controlled electronic devices that operate as a circuit breaker and recloser such that, after half-cycle of short-circuit current, said special group is transferred to the OFF-state, whereby the tap changer winding is open circuited; the advantage being that only the special group of devices need be rated to sustain short-circuit conditions; a further feature is the concept of Discrete-Cycle Modulation (DCM) whereby tap voltage magnitudes are obtainable in increments intermediate the physical tap winding voltage magnitudes.