S&c Electric Company

John French

Alejandro Montenegro

Michael Quinlan

Konstantin Lakirovich

Daniel Desmond

Gabrielle Madden

David G Porter

Goran Djogo

Thomas J Dyer

Keith W Benson

Joseph W Milton

Nicholas Seng

Boris Marendic

William Yadusky

Thomas S Kelley

Robert E Sroka

Christopher De Young

Farnaz Harirchi

Oleg Nazarov

A system and method for adaptive impedance protection in a power network. The method includes determining a measured impedance in an upstream interrupting device, determining an impedance set point in the upstream interrupting device, and identifying a predetermined percentage of the impedance set point. The method also includes determining if the measured impedance falls below the predetermined percentage, determining whether a change in a measured current value on the power line is less than a threshold change value in a downstream interrupting device, and sending the determination of whether the change in the measured current value is less than the threshold change value from the downstream interrupting device to the upstream interrupting device. The upstream interrupting device is opened if the measured impedance falls below the predetermined percentage of the impedance set point and the change in the measured current value is less than the threshold change value.

Adaptive impedance protection

A series Z-source circuit breaker including a semiconductor switch that breaks source power being provided to a load in response to overcurrent. An electromechanical switch is electrically coupled in parallel with the semiconductor switch, a first capacitor is electrically coupled to an output side of the semiconductor switch, a second capacitor is electrically coupled in parallel with the semiconductor switch, and a delay circuit is electrically coupled in series with the first capacitor. The semiconductor switch is in an open position and the electromechanical switch is in a closed position when overcurrent is not present. Upon detection of overcurrent the semiconductor switch is closed, the electromechanical switch is opened and the delay circuit is controlled to delay when reverse bias current is provided from the first capacitor to the semiconductor switch to prevent source power from being provided to the load to give the electromechanical switch time to open.

Series Z-source circuit breaker with pulse-testing capability

An actuator assembly including a first actuator having a first magnetically actuated plunger and a first latching plate, where the first plunger is operable to be magnetically latched to the first latching plate. The actuator assembly further includes a second actuator coupled to and axially aligned with the first actuator. The second actuator includes a second magnetically actuated plunger, a second latching plate, a sleeve positioned within and extending from the second plunger and being rigidly secured to the first plunger, and a tolerance spring wrapped around the sleeve. The second plunger is operable to be magnetically latched to the second latching plate, where latching of the second plunger causes the tolerance spring to compress and provide additional latching force of the first plunger to the first latching plate.

Magnetic latching actuator

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.

Loop restoration switching device assembly including multiple switches with common control

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first recloser connected to one end of the power line and a second recloser connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where power is provided to both ends of the power line through the first and second reclosers and one of the switching devices is a normally open switching device. The method includes detecting overcurrent by some of the switching devices, detecting loss of voltage by some of the switching devices and sending clear to close messages to some of the switching devices to open and close certain ones of the switching devices to isolate the fault.

Method for restoring power in an underground radial loop network

A system and method for detecting a high impedance fault in an electrical line strung along and between utility poles, where the line is part of an electrical power distribution network. A current sensor is provided on each line segment between the utility poles, where each current sensor harvests power therefrom and continuously monitors the current flow on the line segment. An observer/repeater device is provided on a number of the poles and each is in communication with certain select ones of the current sensors to receive the current measurements therefrom. One of the observer/repeater devices compares the current readings transmitted to it from the subordinate current sensors, and if a violation of Kirchhoff's current law exists, an indication of a high impedance fault occurs, where the observer/repeater device relays the current irregularity to an upstream recloser to take appropriate action.

Method of wire break detection

Growing community of inventors

Chicago, IL, United States of America

John French