S&c Electric Company

Yoav Sharon

Michael Quinlan

Alejandro Montenegro

Boris Marendic

Qing Guo

Michael Meisinger

John Seuss

Michael G Ennis

Michael John Meisinger, Sr

Daniel Desmond

Adam Gardner

Peter S Curtiss

Amy Overmyer

James Rarick

Michael Ennis

A system and method for representing the topology of a power distribution network, where the network includes at least one power source, a feeder and a plurality of switching devices positioned along the feeder. The method includes providing a device list in each switching device that includes a local device index of each of the switching devices, a local team index of the team on an X-side of each of the switching devices, the local team index of the team on a Y-side of each of the switching devices and device specific data, where the X and Y-sides of the switching device is the physical orientation of the device when it is installed, and providing a team list in each switching device that includes the local team index of each of the teams, the local device indices of the switching devices on each team and team specific data.

Dynamic graph for data propagation

A system and method for estimating fault current using a sliding observation window that is shorter than one cycle. The method may also include providing a pickup level that defines a current threshold for opening a switch in response to detecting the fault current; estimating the fault current from current measurement signals; accumulating time from a reset zero position during the time that the estimation of the fault current is greater than the pickup level; subtracting time from the accumulated time during the time that the estimation of the fault current is less than the pickup level after time has been accumulated from when the estimation of the fault current is greater than the pickup level; detecting the fault current if the accumulated time reaches a predetermined accumulation time; and opening the switch if the fault current is detected.

Fast fault detector

A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

Fault location system using voltage or current measurement from diverse locations on a distribution network

A system and method for controlling an operation of devices in a power distribution network. The method determines that there is a power loss in the network as a result of a fault and one or more teams is not receiving power and performs a switching process in switching devices to prevent fault current from flowing to the fault. The method initiates a power restoration process to control the open and closed status of switching devices to isolate the fault and performs the power restoration process by the leader device in a division that the fault is occurring that includes opening and closing switching devices so that power is provided to all of the teams except the team that the fault is in. The method reconfigures the divisions based on which switching devices are now open and selects new leader devices based on the reconfiguration of the divisions.

Restoration management

A switching device for controlling power flow on a power line. The device includes a current sensor for measuring primary current on the line, a first voltage sensor for measuring primary voltage on the line at one side of the switching device, and a second voltage sensor for measuring primary voltage on the line at another side of the switching device. An ADC converts measurement signals from the current sensor and the voltage sensors to digital signals, and a PMU calculates magnitude and phase angle synchrophasor data using the current and voltage measurement digital signals and calibration data.

Accuracy for phasor measurement units (synchrophasors) in utility distribution applications

A method for fault location and isolation in a power distribution network, where the network includes a plurality of switching devices provided along a feeder, and at least one of the switching devices does not have voltage sensing capabilities. The method includes detecting an overcurrent event in the network from the fault and interrupting the overcurrent event by opening and then immediately locking out or subsequently reclosing and testing the fault. A count value is increased in each switching device that detected the overcurrent event. A message is sent from each of the switching devices that detected the overcurrent event and then detected the loss of voltage upstream to an upstream neighbor switching device. Current measurements in the messages, measured current by the devices and the counts values in the devices determine what devices are opened to isolate the fault.

Method for locating and isolating a fault in a power distribution network

A system and method for restoring power in a closed-loop power distribution network. The network includes at least two power sources, at least one feeder and a plurality of switching devices positioned along the at least one feeder and being in communications with each other. The method performs a radial restoration process for restoring power and then determines that at least one of the sections is not receiving power after the radial restoration process has been performed. The method estimates power flow through each switching device and determines an available power capacity from each switching device. The method then determines if the unpowered sections can be powered by any of their neighbor and non-neighbor devices. The method virtually closes the switching devices to power the unpowered sections and updates the estimation of power flow through each switching device and determination of available power capacity from each switching device.

Closed loop restoration

A system and method for fault location and isolation in an electrical power distribution network, where the network includes a plurality of switching devices provided along a feeder. The method includes detecting an overcurrent event in the network from the fault and interrupting the overcurrent event by opening and then immediately locking out or subsequently reclosing and testing the fault. A count value is increased in each switching device that detected the overcurrent event. A count and current (C&I) message is sent from each of the switching devices that detected the overcurrent event and then detected the loss of voltage upstream to an upstream neighbor switching device. Current measurements in the C&I messages, measured current by the devices and the counts values in the devices determine what devices are opened to isolate the fault.

Fault isolation

A control system and method for a group of interconnected feeders which enables fault location, isolation and service restoration without requiring each switch to have topology knowledge of devices in adjacent feeders. The method defines, for each switch, connectivity and X/Y directional information about its neighboring switches and propagates this information throughout each feeder. A leader device is also determined for each feeder. Information about topology of adjacent feeders is not needed by all devices. Only normally-open tie switches which define a boundary between two adjacent feeders have knowledge of the devices in both feeders. Switches which open during fault isolation automatically find open tie switches in a direction opposite the fault, and request service restoration downstream of the fault by providing power from an adjacent feeder. Leader devices ensure an overload condition is not created before initiating opening and closing operations of switches downstream of the fault.

Tie switch restoration

A communication-based permissive protection method for protecting an electrical power distribution network from a fault. The network includes a power source, an electrical line and a plurality of fault interrupters, where the fault interrupters are operable to prevent current flow in response to the fault. The method includes detecting the fault by each fault interrupter that is between the fault and the power source, and sending a drop of voltage message from each fault interrupter that doesn't detect the fault, but does detect a drop of voltage as a result of the fault to its immediate upstream fault interrupter. The method opens the fault interrupter that both detects the fault and receives a drop of voltage message from all of the fault interrupters immediately downstream of that fault interrupter.

Communication-based permissive protection scheme for power distribution networks

A method of determining the topology of a portion of the electrical distribution grid such as a feeder based on voltage and current measurements. The method employs Bayesian-based topology detection, where voltage and current data is measured at switches in the feeder at numerous sample times. A voltage variance is calculated for each switch, along with a voltage correlation coefficient for each pair of switches. Voltage variance is used to establish a preliminary position of a switch in the feeder, where switches closest to the substation source are expected to exhibit the least variance, and vice versa. The voltage correlation coefficient is used to provide a first determination of whether two switches are in series with each other in a parent-child relationship, and a current magnitude comparison is used to confirm or refute the preliminary parent-child relationship between the two nodes.

Topology detection

A method for controlling multiple switching devices in an electrical power distribution network in response to detecting a fault. The method determines that a fault current is present, and opens a switch in each of the switching devices in response thereto. The method then initiates a current pulse in the switch in a farthest upstream switching device for a first pulse duration time, closes the switch in the farthest upstream recloser if no fault current is detected during the first pulse duration temporarily changes the TCC curve of the farthest upstream recloser to a second TCC curve that is an instantaneous or near instantaneous TCC curve, and initiates a current pulse in the switch in a next farthest upstream switching device that is downstream of the farthest upstream switching device after the switch in a farthest upstream switching device is closed.

Method for coordinating switches in multiple reclosers in a distribution feeder line in response to detection of a fault

Detection of faults in an electrical power distribution network that includes measuring current flowing through a recloser in a feeder line, detecting a fault current indicating a fault is present in the feeder line, and opening a switch in the recloser in response to detecting the fault current. A first pulse having a first pulse duration time is generated, and the current flow in the recloser during the first pulse duration time is analyzed. A second pulse having a second duration time that is longer than the first pulse duration time is generated if it is determined that no fault current exists during the first pulse duration time, and the system voltages and the current flowing through the recloser after the second pulse duration time is analyzed for the presence of the fault.

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Evanston, IL, United States of America

Yoav Sharon