Abraham V Nieves

6799125, Sep 28, 2004

Sep 19, 2002

10/247111

James Frederick Lau - Orlando FL
Abraham Nieves - Orlando FL

Siemens Westinghouse Power Corporation - Orlando FL

G01B 528

702 38

The present invention monitors an electrical generator ( ) to provide an indication of a problem in the generators bearing insulation ( ), such as insulation damage or insulation bridging, and sets an alarm to warn an operator of the problem, thereby avoiding damage to the electrical generator ( ). Methods and systems consistent with the present invention identify problems with bearing insulation ( ) by monitoring the naturally occurring shaft voltage on the generator rotor ( ) and by setting an alarm if the shaft voltage drops below a predetermined value.

6882173, Apr 19, 2005

Sep 26, 2003

10/672770

Robert John Nelson - Orlando FL, US
Aleksandar Prole - Winter Springs FL, US
Stephen W. Cates - Oviedo FL, US
Abraham Nieves - Orlando FL, US

Siemens Westinghouse Power Corporation - Orlando FL

G01R031/06
G01R031/34

324772, 324546

Methods and systems consistent with the present invention provide improved online detection of one or more shorts in rotor turns () of a field winding () of an electric generator. An initial reference inductance Lis determined by an impedance-measuring circuit (). A subsequent inductance L is determined by the impedance measuring circuit (). A data processing system () compares Lto L to determine whether they differ by a predetermined amount. If Land L differ by the predetermined amount, an alarm is provided to operators to indicate the presence of one or more shorted rotor turns.

53230795, Jun 21, 1994

Apr 15, 1992

7/870009

Abraham Nieves - Orlando FL
Charles Senic - Casselberry FL
Robert W. Ramsay - Oviedo FL

Westinghouse Electric Corp. - Pittsburgh PA

H02K 314

310213

A half-coil for the stator winding of an electrodynamic system such as an electrical generator or motor includes an improved tube stack arrangement and a roebelling configuration which is designed to minimize power loss. The tube stack arrangement includes, in the disclosed embodiment, two central tube stacks and two roebel bars, one on each side of the tube stacks. By this arrangement, the individual strands in the roebel bars do not need to be transposed around the tube stacks, as was the case in prior art configurations utilizing more than one tube stack. The improved roebelling arrangement includes, in the disclosed embodiment, a total 720. degree. transposition, including a 90. degree. transposition in each of the two involute portions. To accomplish the 720. degree.