Abstract: A method for managing power quality events in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one intelligent electronic device (IED) to identify at least one power quality event associated with one or more loads monitored by the at least one IED. The method also includes determining at least one means for mitigating or eliminating an impact (and/or reducing a recovery time) of the at least one identified power quality event on the electrical system based, at least in part, on an evaluation of a dynamic tolerance curve associated with one or more loads in the electrical system. The method further includes applying one or more of the at least one means for mitigating or eliminating the impact (and/or reducing the recovery time) to selected portions or zones of the electrical system.

Abstract: A method for characterizing power quality events in an electrical system includes deriving electrical measurement data for at least one first virtual meter in an electrical system from (a) electrical measurement data from or derived from energy-related signals captured by at least one first IED in the electrical system, and (b) electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system. In embodiments, the at least one first IED is installed at a first metering point in the electrical system, the at least one second IED is installed at a second metering point in the electrical system, and the at least one first virtual meter is derived or located at a third metering point in the electrical system. The derived electrical measurement data may be used to generate or update a dynamic tolerance curve associated with the third metering point.

Abstract: A method for quantifying power quality events in an electrical system including a plurality of intelligent electronic devices (IEDs) includes processing electrical measurement data from or derived from energy-related signals captured by at least one first IED of the plurality of IEDs to identify a power quality event at a first point of installation of the at least one first IED in the electrical system. An impact of the power quality event at a second point of installation in the electrical system is determined based on an evaluation of electrical measurement data from or derived from energy-related signals captured by at least one second IED of the plurality of IEDs at the second point of installation proximate to a determined time of occurrence of the power quality event at the first point of installation.

Abstract: A method for analyzing power quality events in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one of a plurality of metering devices in the electrical system to generate or update a plurality of dynamic tolerance curves. Each of the plurality of dynamic tolerance curves characterizes a response characteristic of the electrical system at a respective metering point of a plurality of metering points in the electrical system. Power quality data from the plurality of dynamic tolerance curves is selectively aggregated to analyze power quality events in the electrical system.

Abstract: A method for managing voltage event alarms in an electrical system includes processing electrical measurement data from energy-related signals captured by at least one intelligent electronic device (IED) of a plurality of IEDs to identify an anomalous voltage condition at a point of installation of a respective one of the plurality of IEDs in the electrical system. In embodiments, the anomalous voltage condition corresponds to a measured IED voltage being above one or more upper alarm thresholds or below one or more lower alarm thresholds. The method also includes determining if the electrical system is affected by the identified anomalous voltage condition. In response to determining that the electrical system is not affected by the identified anomalous voltage condition, at least one of the one or more upper alarm thresholds or at least one of the one or more lower alarm thresholds may be adjusted to the measured IED voltage.

Abstract: A method for managing power quality events in an electrical system includes processing electrical measurement data captured by an intelligent electronic device (IED) to identify at least one power quality event associated with one or more loads monitored by the IED. The IED and the loads are installed at respective locations in the electrical system. The method also includes determining an impact of the at least one identified power quality event on one or more of the loads, and using the at least one identified power quality event and the determined impact to generate a tolerance curve associated with the one or more of the loads. The tolerance curve characterizes a tolerance level of the loads to certain power quality events. The loads can include one or more loads “downstream” from the IED in the electrical system and/or one or more loads “upstream” from IED in the electrical system.

Abstract: A method and program for minimizing objectionable currents while still providing neutral-to-ground voltage measurements by controlling a switch to determine when the neutral-to-ground impedance is placed in an electrical circuit.

Abstract: A method for automatically aligning measured power-related data in a power monitoring system to a common reference point. A conductor in a power delivery system is modeled according to an equivalent pi model of a transmission line that is characterized by model parameters. The conductor is monitored on both ends by a reference monitoring device and a second monitoring device. The voltage and current are measured in either the reference monitoring device or the second monitoring device and a phase shift offset between the voltages or currents at the two devices is calculated. The calculated phase shift offset corresponds to a temporal delay between events observed at the pair of devices, and calculating and storing the phase shift offset allows a power monitoring system controller to more accurately align data received from monitoring devices.

Abstract: Systems and methods for evaluating the stability of an islanded electrical system (off-grid) using high-speed frequency measurements of the electrical signal supplied by an alternate power source in the islanded electrical system. Additional inputs may include status signals from an automatic transfer switch, a generator, and loads within the islanded electrical system. The high-speed frequency measurements have a resolution sufficient to enable analysis of any combination of the frequency magnitude (e.g., sudden increase), frequency slew rate (e.g., frequency rate of change), frequency rate of recovery (e.g., frequency recovery time), or frequency oscillations (e.g., frequency ringing around the nominal value before settling) to indicate the presence of an actual or impending instability of the islanded electrical system. The frequency referred to herein corresponds to the frequency at which an alternating current supplied by the alternate power source is cycling.

Abstract: A method of automatically identifying an anomalous condition of an induction motor by normalizing the voltage measured across its terminals relative to the power flow to the motor or the motor's impedance. The starting and/or run current and associated voltage of the motor is measured, and a voltage variation between the measured voltage and the motor's rated voltage is determined. The power flow or impedance at the voltage variation is calculated to determine an expected power flow or impedance at the measured voltage variation. The actual power flow or impedance is compared against a nominal or expected power flow or impedance or a statistical comparison is carried out on a historical set of power flow or impedance values within an expected range at the voltage variation. When the measured values deviate from the expected ones, an alarm is triggered to indicate a potential anomaly with the motor or external thereto.

Abstract: An automated hierarchy classification algorithm that searches for a child monitoring device's parent in a utility monitoring system by segmenting the device data measured by a given device pair and calculating a segment correlation coefficient for each data segment. Devices to be placed in the hierarchy are filtered by calculating the variance of their device data and eliminating devices with a low variance. Devices are ranked by computing the sum of squares of their device data and ordering the devices accordingly from highest to lowest. The device data is segmented and segment correlation coefficients are averaged to produce an overall correlation coefficient. Criteria are evaluated to determine whether a device pair is linked. A correlation coefficient is calculated using the complete data series of a device pair, and the solution produced by this approach is compared with the solution produced by segmenting the device data.

Abstract: Systems and methods for evaluating the stability of an islanded electrical system (off-grid) using high-speed frequency measurements of the electrical signal supplied by an alternate power source in the islanded electrical system. Additional inputs may include status signals from an automatic transfer switch, a generator, and loads within the islanded electrical system. The high-speed frequency measurements have a resolution sufficient to enable analysis of any combination of the frequency magnitude (e.g., sudden increase), frequency slew rate (e.g., frequency rate of change), frequency rate of recovery (e.g., frequency recovery time), or frequency oscillations (e.g., frequency ringing around the nominal value before settling) to indicate the presence of an actual or impending instability of the islanded electrical system. The frequency referred to herein corresponds to the frequency at which an alternating current supplied by the alternate power source is cycling.

Abstract: A method and program for minimizing objectionable currents while still providing neutral-to-ground voltage measurements by controlling a switch to determine when the neutral-to-ground impedance is placed in an electrical circuit.

Abstract: A method and system of automatically correlating data measured by monitoring devices that monitor first and second electrical grids. The second electrical grid producing alternating current signals that are electrically isolated from alternating current signals produced by the first electrical grid. An example power monitoring device includes a controller, a first monitoring device interface and a second monitoring device interface. The first monitoring device interface is coupled to a first monitoring device in the first electrical grid and the second monitoring device interface is coupled to a second monitoring device in the second electrical grid. A first counter stores data counts of occurrences from the first electrical grid. A second counter stores data counts of occurrences from the second electrical grid.

Abstract: A method of automatically learning how multiple devices are directly or indirectly linked in a monitoring system, comprises determining configuration parameters for the multiple devices in said system, receiving data measured by the devices, and grouping the devices into multiple segments according to at least one type of information selected from the group consisting of configuration parameters and data measured by said devices. Potential relationships of the devices in each segment are determined according to at least one type of information selected from the group consisting of configuration parameters and data measured by the devices, the hierarchies of the devices within individual segments are determined, and the hierarchies of the top-most device or devices in the segments are determined.

Abstract: A method and system of converting numerical infrastructure data relating to a utility monitoring system having elements arranged in a hierarchy to a graphic compatible storage data format. Numerical infrastructure data relating to the elements of the utility monitoring system is obtained. The numerical infrastructure data relating to the elements of the utility monitoring system is converted to the graphic compatible storage data format. The graphic compatible storage data format may be System Specification Description (SSD). The converted data is stored in a storage file. A user interface may access the storage file to generate a graphic display showing the elements of the utility monitoring system arranged in the hierarchy.

Abstract: A method of automatically identifying whether intelligent electronic devices (IEDs) in a power monitoring system are in multiple electrical grids. A controller sends an instruction to each IED in a predetermined time sequence such that each IED receives the instruction at a different time, commanding each IED to begin logging frequency variation data in a current/voltage signal monitored by the IED and to send the data to the controller and an associated cycle count. The controller receives the variation data and associated cycle count and determines a peak correlation using a data alignment algorithm on IED pair combinations. If the IEDs are on the same electrical grid, the peak correlations should occur at cycle count offsets that match the order that the IEDs received the instruction. Any discrepancies in the expected order of peak correlations are flagged, and the corresponding IEDs are determined to be on different grids.

Abstract: A method for automatically aligning measured power-related data in a power monitoring system to a common reference point. A conductor in a power delivery system is modeled according to an equivalent pi model of a transmission line that is characterized by model parameters. The conductor is monitored on both ends by a reference monitoring device and a second monitoring device. The voltage and current are measured in either the reference monitoring device or the second monitoring device and a phase shift offset between the voltages or currents at the two devices is calculated. The calculated phase shift offset corresponds to a temporal delay between events observed at the pair of devices, and calculating and storing the phase shift offset allows a power monitoring system controller to more accurately align data received from monitoring devices.

Abstract: A method of graphically representing values of at least one selected parameter at multiple monitoring points in a utility system, comprises receiving data measured at the multiple monitoring points; determining the values of the selected parameter at the multiple monitoring points, based on the received data, and using the values to generate a graphical representation of the values of the selected parameter at the multiple monitoring points, the graphical representation including shapes having (1) sizes representative of the magnitudes of the values and (2) locations representative of the hierarchy of the monitoring points. In one application, the selected parameter is at least one of electrical power and energy consumed in portions of an electrical power distribution system that correspond to the multiple monitoring points.

Abstract: An auto-discovery algorithm attempts a scattered-read of register addresses of a device in a utility monitoring system whose identity is unknown to a computer system. If the scattered read is successful, and data from the device includes a device ID code that is matched against a lookup table of devices. If unsuccessful, the algorithm attempts a block-read, and if unsuccessful, iteratively checks each register against the lookup table to determine whether a match exists until either one is found or the device reports an illegal data address exception, whereupon the algorithm stops attempting to read from subsequent addresses. The algorithm analyzes the response from the communications driver of the computer system to determine whether the response is valid, and if not, what type of exception is reported. If a timeout occurs, the algorithm flags the device for a later retry scan, and moves on to attempt to discover the next device.