Abstract: 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.

Abstract: 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.

Abstract: A system and method for generating phasors having a phase angle and magnitude from a sinusoidal power signal, and using the phasors to generate a frequency and RoCoF of the power signal. The system and method provide improvements over known systems and methods by correcting the frequency of sensor signals, providing a simplified phasor correction equation, reducing errors in a non-recursive DFT algorithm, improving frequency estimation by spacing out DFTs, correcting the sampling rate, providing linear interpolation of frequency and/or providing a variable DFT window length.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A system and method for determining the optimal time to perform a pulse test to determine the presence of a fault after a switch opens to clear the fault to prevent generator instability. The method includes detecting the fault, opening a switch to clear the fault, determining an optimal time for performing the pulse test for determining the continued presence of the fault based on predetermined system data and parameters after the switch is opened so as to prevent the pulse test from occurring too early that could cause generator instability, and performing the pulse test at the optimal time to determine if the fault is still present. Determining the optimal time can use available system data and information, such as a priori knowledge or real-time behaviour. If the fault is not present, then the method determines a desired time to perform a reclose operation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A system and method for maintaining electrical stability of a high-voltage transmission power system in response to a fault. The method includes detecting the fault, opening a switch to clear the fault, performing a first pulse test for a predetermined duration of time to determine if the fault is still present, preventing a reclosing operation from occurring if the pulse test indicates that the fault is still present, and allowing the reclosing operation to occur if the first pulse test indicates that the fault is not present. One or more subsequent pulse tests can be performed if the first pulse test is inclusive about the persistence of the fault, where the reclosing operation is prevented from occurring if the pulse tests indicate that the fault is still present and the reclosing operation is allowed if the pulse tests indicate that the fault is no longer present.

Abstract: 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.

Abstract: 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.

Abstract: A system and method for determining loads throughout a power distribution network having a plurality of switching devices provided along a feeder. The method includes measuring the current and/or voltage on one or both sides of the switching devices and calculating a power flowing through each of the switching devices and a load in each section using the current and/or voltage measurements at predetermined sample times. The method further includes storing a plurality of recorded current/voltage measurements or calculated powers flowing through each device for consecutive sample times. The method then determines a median load from the measurements and power flows and calculates a load in each of network sections.

Abstract: 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.

Abstract: A system and method for disseminating information and data throughout a power distribution network. A timer is set in each of the network endpoint switching devices that expire at the same time. A message is sent from each endpoint device to its neighbor switching device(s) when the timer expires that includes data about the endpoint switching device, and the message is received from the endpoint switching device at a receiving side of the neighbor switching devices. A message is sent from the neighbor switching devices to their neighbor switching devices at a sending side of the neighbor switching devices that includes data about the endpoint switching device and the neighbor switching device of the endpoint switching device. The messages are continually sent through the switching devices in this manner until all of the switching devices have the data about all of the other switching devices in a division or feeder.

Abstract: 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.

Abstract: 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.

Abstract: 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.