Schweitzer Engineering Laboratories, Inc.

Gary W Scheer

James R Kesler

Douglas M Trout

Edmund O Schweitzer, Iii

Veselin Skendzic

Dhruba P Das

Mark L Zeller

Angelo D'Aversa

An method for automatically testing an arc flash detection system by periodically or continually transmitting electro-optical (EO) radiation through one or more transmission cables electro-optically coupled to respective EO radiation collectors. A test EO signal may pass through the EO radiation collector to be received by an EO sensor. An attenuation of the EO signal may be determined by comparing the intensity of the transmitted EO signal to an intensity of the received EO signal. A self-test failure may be detected if the attenuation exceeds a threshold. EO signals may be transmitted according to a particular pattern (e.g., a coded signal) to allow an arc flash detection system to distinguish the test EO radiation from EO radiation indicative of an arc flash event.

Arc flash protection system with self-test

An electro-optical (EO) radiation collector for collecting and/or transmitting EO radiation (which may include EO radiation in the visible wavelengths) for transmission to an EO sensor. The EO radiation collector may be used with an arc flash detection device or other protective system, such as an intelligent electronic device (IED). The arc flash detection device may detect an arc flash event based upon EO radiation collected by and/or transmitted from the EO radiation collector. The EO radiation collector may receive an EO conductor cable, an end of which may be configured to receive EO radiation. A portion of the EO radiation received by the EO radiation collector may be transmitted into the EO conductor cable and transmitted to the arc flash detection device. The EO radiation collector may be adapted to receive a second EO conductor cable, which may be used to provide redundant EO transmission and/or self-test capabilities.

Electro-optical radiation collector for arc flash detection

An arc flash validation unit may generate stimulus to be received by an arc flash detection unit (AFDU) and observe the response of the AFDU thereto. The response of the AFDU to the stimulus may allow for validation of the AFDU (e.g., validation that the AFDU is operating as expected). In addition, the arc flash validation unit may determine the response time of the AFDU. Different types of stimulus may be provided to the AFDU, including electro-optical (EO) stimulus (e.g., visible light), current stimulus, and the like. Results of the validation may be displayed on a human-machine interface, which may display an estimate of the total energy that would be released in an actual arc flash event. The estimate may be used to define appropriate safety parameters for the equipment monitored by the AFDU.

Validation of arc flash detection systems

Arc flash protection with self-test

The communication system includes transmitting output status bits indicative of a function of the relay directly from one microprocessor-based protective relay in a power system to a second companion microprocessor-based relay. Each relay has transmit and receive modules connected by a communications link, with the transmit and receive modules using the logic output and input bits produced by the respective relays in their respective relay calculations.

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Pullman, WA, United States of America

Gary W Scheer