Schweitzer Engineering Laboratories, Inc.

Mark W Feltis

Tony J Lee

Kei Hao

Luther S Anderson

Robert E Morris

Naresh Malla

The present disclosure relates to controlling a capacitor bank using current measurements from different current sensors depending on the power flow direction. For example, the system may perform capacitor bank control operations using current measurements from a first current sensor coupled to the power line between an initial source and the capacitor bank when power is flowing in a first power flow direction on the power line. The system may determine that power flow on the power line has changed from flowing in the first power flow direction to flowing in a second power flow direction from an updated source, different from the initial source. The system may, upon detecting the change in the power flow direction perform control operations of the capacitor bank using current measurements from a second current sensor between an updated source and the capacitor bank.

Bidirectional capacitor bank control

A power system device-to-device direct communication system comprises a first intelligent electronic device with a processor and a transmit module. Software within the processor maintains a list of 'virtual outputs,' which correspond to a number of data channels maintained within the transmit module. The second intelligent electronic device receives the data channels from the first intelligent electronic device and extracts the virtual output bits. The second intelligent electronic device then adjusts a group of its own output contacts in accordance with the received virtual output bits.

Apparatus, system, and method for sharing output contacts across multiple relays

A breaker failure relay circuit is responsive to either a trip signal from a protective relay or a manual trip signal, as well as the current through a circuit breaker protecting a transmission line. The trip signal is applied to an edge triggered timer (28) having selected pickup and dropout times, and is also applied as one input to one OR gate (24). The circuit breaker current is applied to an overcurrent element (34), the output of which is applied to a reset input of the edge triggered timer (28) to reset and disable the timer and also as one input to another OR gate (30). The other input to OR gate (30) is the output of the edge triggered timer (28). The outputs of OR gates (24, 30) are applied to an AND gate (26), the output of which is applied to a second timer (32) and as another input to the one OR gate (24). The output of the timer (32), if and when it occurs, is used as a trip signal for a backup circuit breaker.

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Pullman, WA, United States of America

Mark W Feltis