Eaton Corporation

Lawrence B Farr

Irving Albert Gibbs

Joe M Kellis

Charles Allan Morse

Robert Yanniello

Charles Richard Mummert

Bruce R Quayle

Cathleen M Clausen

John M Tillman

A protection relay for an electrical switching apparatus for a load includes a number of voltage sensors structured to sense voltage applied to the load, a number of current sensors structured to sense current flowing to the load, and a processor cooperating with the number of voltage sensors and the number of current sensors. The processor determines a fault current available at the load. An output cooperates with the processor. The output is structured to output the determined fault current and a number of: incident energy at the electrical switching apparatus, and a personal protective equipment level operatively associated with the electrical switching apparatus. The processor determines from the determined fault current the number of: the incident energy at the electrical switching apparatus, and the personal protective equipment level operatively associated with the electrical switching apparatus.

Protection relay, electrical switching apparatus, and system for determining and outputting fault current available at a load and incident energy or personal protective equipment level operatively associated therewith

An electrical switching apparatus is for another apparatus including a number of insulators, a number of temperature sensors operatively associated with the number of insulators, and a number of conductors operatively associated with the number of insulators. The electrical switching apparatus includes a number of separable contacts, an operating mechanism structured to open and close the separable contacts, a number of sensors structured to sense a number of currents flowing through the separable contacts and through the conductors, a processor structured to input the sensed currents from the sensors, and an output. The processor calculates at least one of: (a) a thermal age of the other apparatus from a number of sensed temperatures from the temperature sensors, and (b) the thermal age of the other apparatus from the sensed currents. The output includes the thermal age of the other apparatus.

Electrical switching apparatus and protection apparatus determining thermal age of another apparatus or a number of insulators

An electrical switching apparatus includes a plurality of poles each having a Rogowski coil and a conductor passing through an opening thereof, and a processor circuit including a sensor circuit including a plurality of inputs each electrically interconnected with an output of the Rogowski coil of a corresponding pole. The sensor circuit further includes a number of outputs having values each corresponding to current flowing through the conductor, a memory including for each corresponding pole an offset value and a gain correction factor for the sensor circuit, and a gain correction factor for the Rogowski coil, a number of routines, and a processor cooperating with the sensor circuit and the routines to provide for each pole a corrected current value as a function of a corresponding one of the values, the sensor circuit offset value and gain correction factor, and the Rogowski coil gain correction factor.

Electrical switching apparatus including a plurality of Rogowski coils and method of calibrating the same

An electrical switching apparatus includes a number of separable contacts, an operating mechanism structured to open and close the separable contacts, a number of sensors structured to sense at least current flowing through the separable contacts, and a processor structured to cooperate with the operating mechanism to open and close the separable contacts. The processor determines a fault from the sensed current flowing through the separable contacts. The processor further responsively opens the separable contacts if the sensed current associated with the fault is less than the interrupting rating of the electrical switching apparatus. The processor keeps the separable contacts closed and waits for another circuit interrupter to interrupt the fault if the sensed current associated with the fault is greater than the interrupting rating.

Electrical switching apparatus providing coordinated opening with a circuit interrupter and method of operating the same

Hot spots in power conductors are monitored by apparatus comprising a temperature probe embedded in an electrically insulative thermally conductive material in surface-to-surface contact with the power conductor, typically at a joint being monitored. The temperature probe is spaced from the power conductor by the electrically insulative thermally conductive material a distance sufficient to provide electrical isolation, while the material has sufficient thermal conductivity that the temperature probe is able to substantiate trends in temperature changes at the joint. The invention can be incorporated into existing electrically insulative supports for the power conductors.

Apparatus and method for detecting hot spots in an electric power conductor

An isolation system is provided for generating a control voltage in a low voltage control system that is representative of the input voltage in a high voltage power system of an excitation system, such as in a rotating electrical apparatus. The control voltage isolation system includes a voltage-controlled oscillator for converting the input voltage into a first frequency signal corresponding to the input voltage. Fiber optic conversion and receiving devices are employed in conjunction with a fiber optic cable to transmit the first frequency signal from the high voltage power system to the low voltage control system. Utilizing a fiber optic device provides voltage isolation between the power system and the control system. The use of a fiber optic device for voltage isolation also resists the damaging effects of relatively high transient currents and voltages from affecting sensitive semiconductor components and the like in the control system. A microprocessor and counter device can also be utilized in association with the isolation system to reconstruct the input voltage by integrating the frequency signal received from the power system into a control voltage representative of the input voltage. A method associated with the isolation system is also disclosed.

Control voltage isolation system for electrical rotating apparatus utilizing fiber optics and associated method

An excitation control system for a generator includes an SCR bridge for providing an excitation voltage to the input of the generator; a regulator for regulating the excitation voltage; and a sensing sub-system for providing an electrical signal, such a generator current or generator watts, which is related to the output of the generator. The generator includes a circuit breaker for the one or more alternating current phases output by the generator. An output of the circuit breaker has a signal with a true state when the circuit breaker is closed and the generator is on-line and with a false state when the circuit breaker is open and the generator is off-line. A comparator provides a validation signal when the generator electrical signal is greater than a predetermined signal, such as minimum generator current or minimum generator watts, respectively. An OR gate qualifies the signal of the output of the circuit breaker with the validation signal and provides a qualified signal therefrom. Trip and protection logic employs the qualified signal for protecting or tripping the generator.

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Asheville, NC, United States of America

Lawrence B Farr