Abstract: Techniques for monitoring the health of a three-phase induction motor are provided. An expected threshold value is calculated as a function of an expected ratio of current unbalance to voltage unbalance for the three-phase motor. Embodiments determine whether a measured current unbalance exceeds the expected threshold value. Responsive to the measured current unbalance exceeding the expected threshold value, a remedial action may be taken, such as generating diagnostic information or activating one or more protection operations for the three-phase induction motor.

Abstract: Systems, methods, and apparatus embodiments for electric power grid and network registration and management of active grid elements. Grid elements are transformed into active grid elements following initial registration of each grid element with the system, preferably through network-based communication between the grid elements and a coordinator, either in coordination with or outside of an IP-based communications network router. A multiplicity of active grid elements function in the grid for supply capacity, supply and/or load curtailment as supply or capacity. Also preferably, messaging is managed through a network by a Coordinator using IP messaging for communication with the grid elements, with the energy management system (EMS), and with the utilities, market participants, and/or grid operators.

Abstract: An equipment control device has: a reception unit for receiving desired time information indicating a desired operation start time or a desired operation termination time, operation period information and electrical power information; a time-shift period setting unit for setting a time-shift period indicating a period which has a time range including the desired time information and during which the operation start time or the operation termination time of a household appliance is shiftable; an electrical power charge information acquisition unit for acquiring electrical power charge information; an operation time computing unit for computing the operation start time or the operation termination time, on the basis of which the electricity charge that is billed when the household appliance is operated within the time-shift period falls to or below a predetermined charge; and a transmission unit for transmitting the operation start time or the operation termination time to the household appliance.

Abstract: Systems, methods, and messages of the present invention provides IP-based messages associated with the grid elements, wherein each IP-based message includes an internet protocol (IP) packet that is generated autonomously and/or automatically by the grid elements, intelligent messaging hardware associated with the grid elements, at least one coordinator, and/or a server associated with the electric power grid and its operation, energy settlement, and/or financial settlement for electricity provided or consumed, transmitted, and/or curtailed or reduced. The IP packet preferably includes a content including raw data and/or transformed data, a priority associated with the IP-based message, a security associated with the IP packet, and/or a transport route for communicating the IP-based message via the network.

Abstract: Aspects of a multi-level electrical distribution control system associated with an electrical distribution grid are disclosed. Data access and processing across the multi-level control system and the electrical distribution grid can provide improved utilization of energy within the electrical distribution grid. Further, dynamic reconfiguration of the electric distribution grid can be based distributed processing and access to information relating to the electrical distribution control system or electrical distribution grid. An encapsulated DNNC data element is disclosed as an efficient and secure means of accessing data across the multi-level electrical distribution control system or the associated electrical distribution grid.

Abstract: A method, system and computer software for detecting an incipient failure of a generator in a power system including the steps of ascertaining one or more generator reference parameter of the generator for use as a baseline reference; measuring one or more operating parameter values of the generator; using the one or more operating parameter values to solve for an estimated present value of the one or more of the generator's current performance parameters using particle swarm optimization technique; and determining whether the estimated present values of the one or more of the generator's current performance parameters are outside of an acceptable limit.

Abstract: Systems for reducing power usage and/or wastage use sensors to gather information about a circuit and its usage. Triggers are identified based on the information from the sensors, and subsequently used to control power delivery by reversibly effectuating energization and deactivation of particular circuits through smart nodes.

Abstract: Embodiments of the invention relate generally to power management and the like, and more particularly, to an apparatus, a system, a method, and a computer-readable medium for providing power controlling functionality to generate configurable power signals and to deliver power during fault conditions. In at least some embodiments, a power control unit can generate power signals having configurable attributes as a function of a mode of operation, a fault type, and the like.

Abstract: The objective of this patent is to describe novel methods and device systems for detecting the fault-cleared state in a shunt compensated transmission line. The methods are applicable in all types of transmission line types and faults, in any type of reclosure mechanism, and can be implemented in existing devices such as relays and not need sophisticated equipment. One application of detecting the fault-cleared state is adaptive reclosure in which case, substantial improvement in transmission system reliability and benefits in protection can be achieved.

Abstract: A system for monitoring a power transmission line includes at least one monitoring device located along the power transmission line configured to provide power transmission line data. A wide area situational awareness module is configured to receive the power transmission line data and an adaptation module is configured to receive output from the wide area situational awareness module and further configured to calculate control actions for the power transmission line based on the power transmission line data.

Abstract: A method and apparatus for high-speed fault detection of circuits in power distribution networks utilizing protective relay devices (14) segmenting a distribution line (11) having Intelligent Electronic Devices (IED) (22) associated with switching devices (20) communicating peer-to-peer via a communication system (30) to provide fast and accurate fault location information in distribution systems.

Abstract: The invention provides a power supply system for a data storage system, the power supply system comprising: a first power supply unit for supplying power to the storage system; a second power supply unit independent from the first power supply unit for supplying power to the storage system; an auxiliary power supply; a power redundancy controller, arranged to monitor the region of an efficiency curve within which the first and/or second power supplies are operating in and control the first and second power supplies accordingly such that the either or both of the first and second power supplies are providing power at any one time, wherein in the event of failure of a power supply unit when only one of the power supply units is operating, the power redundancy controller is arranged to provide power supply to the data storage system from the auxiliary power supply.

Abstract: A method and apparatus for controlling electric power supplied to one or more electrical devices from a power source are disclosed. Measurements of the supplied electricity are detected. Estimated deviant voltage levels that the supplied electricity will not drop below or exceed as a result of varying electrical consumption by the one or more electrical devices is computed based on a predetermined confidence level and the detected measurements. A voltage level output of the electricity supplied to the electrical device is adjusted based on the computed deviant voltage level.

Abstract: Methods and apparatuses for providing a solution for incompatibility between nonsinusoidal waveform uninterruptible power supply (UPS) systems and active power factor correction (PFC) loads are disclosed. An embodiment of the invention includes generating a nonsinusoidal signal waveform (e.g., a voltage waveform), to be delivered to the load, with a pulse width modulation (PWM) duty width, sampling the nonsinusoidal signal waveform to collect output signal samples, and adjusting the duty width to control the nonsinusoidal signal waveform as a function of the output signal samples to deliver a desired signal characteristic (e.g., RMS signal level) to the load. In embodiments of the invention, the output duty width is adjusted differently in cases of rising and falling power consumption, respectively, by the load. Techniques disclosed herein find broad applicability in UPS systems and inverters and improve efficiency and reliability for end users and utility providers.

Abstract: An active load management system (ALMS) controllably restarts electrical service to service points in a utility service area after a power outage. The ALMS includes client devices installed at the service points and a central controller. In one embodiment, the controller associates numbers with the service points and stores the associations. Each service point may be associated with a unique number or a group of service points may share a number. After receiving notification that power is available, the controller determines a number and communicates the number to one or more of the client devices. Where the number was determined randomly, the client devices associated with the number may restart electrical service upon receipt of the number. Where the number was determined sequentially, a client device may determine its own random number and compare it to the received number. If a match occurs, electrical service can be restarted.

Abstract: A method for aggregate load management includes determining whether a load capacity limit within a utility power network will be exceeded, selecting an aggregated demand reduction target to remain within capacity bounds if the load capacity limit is to be exceeded, selecting a demand reduction strategy, and sending a control signal that includes a randomized PWM level, based on the strategy, to a controller in a load component of the utility system based on the reduction target. A method for component load management includes receiving a control signal from a utility system based on a utility demand reduction strategy, converting the signal into randomized PWM control of the load component in accordance therewith, receiving an updated control signal based on utility system monitoring of an aggregate load of a component of the utility system, and converting the updated signal into randomized PWM control of the load component in accordance therewith.

Abstract: Systems configured to analyze and/or respond to faults detected during the operation of a power transmission system are disclosed. In one embodiment, a system includes: at least one computing device adapted to monitor operation of a power transmission system by performing actions comprising: processing operational data from a set of line phases in the power transmission system to detect a faulted line phase; opening a circuit breaker for the faulted line phase in response to detecting the fault; determining whether the fault is transient or permanent; and determining if an arc associated with the fault has been extinguished.

Abstract: A power limiter system is described. The power limiter system is configured to receive a phase locked loop (PLL) error signal; analyze the PLL error signal to identify an occurrence of a grid contingency event; generate a first power command signal corresponding to an occurrence of the grid contingency event; and, transmit the first command signal to a converter interface controller. The system further includes a memory configured to store at least one variable that corresponds to the PLL error signal upon identification of an occurrence of the grid contingency event.

Abstract: According to one embodiment, there is provided a substation automatic control system. An automatic power adjusting apparatus activates an automatic voltage adjusting apparatus when a phase tap is controlled. The automatic voltage adjusting apparatus activates the automatic power adjusting apparatus when a voltage tap is controlled. The automatic power adjusting apparatus suppresses the effective power on a transmission line to the value smaller than the prescribed value while the automatic voltage adjusting apparatus is performing an automatic control, thereby maintaining transmission-side system voltage within a tolerant system voltage range.

Abstract: Systems and methods for monitoring power generation are provided. For example, such a system may include a gas turbine, an electrical generator coupled to the drive, a controller coupled to the gas turbine, and a compliance monitor. The gas turbine may generate a torque, and the electrical generator may provide power to a power grid based on the torque. The controller may cause the gas turbine to vary the torque in response to a frequency disturbance occurring on the power grid. The compliance monitor may determine whether the response to the frequency disturbance complies with a specification for the response.

Abstract: An arrangement for protecting equipment of an AC electrical power system comprises first means configured to measure the frequency of the current and voltage at at least one location in the electrical power system along an interconnection between two theoretical electric machines of an equivalent two machine system. Fourth means are configured to use the values of the frequency of the current and voltage measured to determine whether a power swing has occurred and if an occurrence of a power swing has been determined determine whether the measuring location is located on a motor side or a generator side of a potential pole slip electrical centre along said interconnection, the electrical centre being defined as the location where the voltage becomes zero during a pole slip, and send this information further to third means for use in a control for protecting equipment of the electrical power system.

Abstract: Discussed is a method and device for increasing the operational flexibility of a current-generating system with a turboset, comprising a turbine coupled to an electrical generator, a power set point value being predefined, and a future target time at which the turboset is supposed to be at the power set point value, so that a power curve is determined via the power set point value and the target time, the turboset being operated starting from a actual power value at an actual time along the power curve such that the predefined power set point value is reached at the predefined target time. Also discussed is a gas turbine and to a steam turbine in accordance with the above description.

Abstract: Var optimization (VARO) is a subsystem of a voltage and var optimization (VVO) system that processes a capacitor switching optimization problem. The VARO is a self contained process that may work stand alone or in conjunction with a Voltage Regulation Optimization (VRO) system to provide integrated VVO solutions. The VARO system takes network inputs and calculates optimal settings for distribution network capacitor banks.

Abstract: A sensor-less technique is described for detecting the status of an AC contactor of a power inverter. In one embodiment, a method is provided of sensing an unexpected condition of an AC contactor used to couple to a power distribution system a power inverter having at least one power conductor. The method includes determining a voltage value for the conductor; determining a current value for the conductor; determining a phase difference using the voltage value and the current value; and monitoring successive values of the phase difference to produce a monitoring result. Depending on the monitoring result, a determination is made whether or not to issue an alert signal. Control routines embodying such technique may be stored on computer-readable media. A power inverter using such technique is described.

Abstract: Data from a digitizing unit is stored in a time-series data buffer, via a data receiving circuit. The data on which a digital filtering process is performed by a digital filtering processing circuit is stored in time series in a time-series instantaneous-value data storing circuit. A digital computing unit sets a time of temporally oldest data from among a group of latest time data stored in a latest time-data storing circuit as a reference time, extracts time data having the same time as the reference time from the time-series instantaneous-value data storing circuit, and then performs a digital computation.

Abstract: A method of managing an electric utility grid includes geographically grouping a set of customer electric usage meters to create a set of fine sensors on a power grid. Each usage meter in the grouped set is capable of being remotely monitored, and each usage meter is at a different location along the power line. If a power anomaly is detected at the subset of meters, then power to the electric utility grid is adjusted to correct the anomaly.

Abstract: A soft PLC technology based computer-implemented method includes updating a system configuration incidence matrix for an electric power distribution system based on both a depth-first search of a connectivity matrix for the electric power distribution system and information about the electric power distribution system, wherein the information includes at least status information about one or more switches of the electric power distribution system. The method further includes detecting a fault in the system based on the incidence matrix. The method further includes generating isolation control logic based on the incidence matrix and isolating the fault based on isolation control logic. The method further includes generating restoration control logic based on a breadth-first search of the incidence matrix and restoring the system based on the restoration control logic.

Abstract: Disclosed are a power management system and associated method that not only initiate a “greenout” to avoid the negative impact of high loads (i.e., to avoid high power cost, negative environmental impact, brownouts, and ultimately blackouts), but can also predict the initiation of such a “greenout”. Predicting the initiation of a “greenout” and communicating the prediction to one or more of the various electronic devices connected to the power grid allows the electronic device(s) to take preparatory action to avoid and/or limit any negative impact that may be caused by the “greenout”.

Abstract: A method of power factor correction without using current sensing or a multiplier is disclosed. A generated predictive pulse is used to charge and discharge a power factor correction (PFC) inductor so that the current in the PFC inductor has a similar phase angle as the input AC voltage. Each ON portion of the pulse is used for charging while each OFF portion is used for discharging. As the input voltage increases in phase, the predictive pulse gradually increases in ON time duty and the PFC inductor is charged in increasing amount and discharged in decreasing amount per pulse. When peak is reached the duty ratio is reduced each pulse and the PFC inductor current is reduced along with the input AC voltage source until phase angle reaches 180 degrees and the ON time becomes zero.

Abstract: A method and system for a power distribution system are provided. The method includes determining at a central controller normal mode configuration settings for a plurality of circuit breakers of the power distribution system and determining at the central controller alternate mode configuration settings for the plurality of circuit breakers of the power distribution system. The method further includes controlling with the central controller the operation of the plurality of circuit breakers based on the normal mode configuration settings and the alternate mode configuration settings.

Abstract: The present invention relates generally to a partial discharge counter for the diagnosis of a GIS. The partial discharge counter includes a partial discharge detection sensor for detecting a partial discharge. A first surge inflow prevention circuit separates a surge signal from an output terminal of the partial discharge detection sensor. A channel 1 frequency conversion module forms a low-frequency signal. A noise detection sensor detects noise. A second surge inflow prevention circuit separates a surge signal from an output terminal of the noise detection sensor. A channel 2 frequency conversion module forms a low-frequency signal. An ADC circuit generates partial discharge data and noise data. A synchronization device enables the partial discharge data and the noise data to be output in synchronization with frequency of the phase voltage. A digital signal processing unit counts a number of times the partial discharge occurs. Counting units display a count value.

Abstract: A power system oscillation detection device is provided for use in an electric power system. A plurality of sample signals are acquired from the electrical power system via a plurality of intelligent electronic devices (IEDs) in communication with the power system. The power system oscillation detection device includes a real-time modal analysis module, a real-time mode identification module, and real-time decision and control logic. The real-time modal analysis module calculates modes of at least one of the signals, each mode including mode information. The real-time mode identification module together with the real-time decision and control logic determines, from the mode information, whether there is an undesirable oscillation in the electric power system and activates a remedial action.

Abstract: A system for detecting and locating a disturbance event within a power grid includes a series of frequency disturbance recorders (FDRs) taking measurements in the power grid at dispersed points of the power grid, an information management system, configured to receive data from the series of FDRs and analyze the received data and a communications network interconnecting the series of FDRs and the information management system. The information management system is configured to examine orders and patterns of receipt of frequency changes at the FDRs in the data caused by the disturbance event and to triangulate a location of the disturbance event based on the orders and patterns of receipt of the frequency changes. Example methods of detection and location of disturbance events are also described.

Abstract: A cable fault detection component (168) receives input data indicative of a fault in an electrical power system. The component (168) analyzes the input data to determine if the fault is indicative of a temporary or self-clearing cable fault and generates corresponding output data (276). In one implementation, the cable fault detection component (168) is implemented as a software module which operates on a computer (105) of a substation intelligence system (104).

Abstract: A system and method for operating a transferable feeder system on an electrical distribution system is provided. The system includes a controller that is disposed in communication with switches associated with feeders of a first substation and circuit breakers associated with a second substation. The first substation and second substation are electrically coupled in a manner to allow load transfer from the first substation to the second substation. The system is arranged to disconnect a first pair of circuits from the first substation before connecting the pair of circuits to the second substation while leaving a third circuit coupled to the first substation. During the entire process of transferring load from one substation to the second substation, customer load does not experience any interruption in electrical service.

Abstract: A system for a wind energy installation. The wind energy installation feeds electrical power into a power supply system. A phase control device can include a power supply system fault detector, a phase angle detector, and a signal processing module. When a power supply system fault is detected, a phase error signal can be determined. A preset angle signal can be determined based on the phase error signal. The preset angle signal can be provided to a converter which can emit electrical power having a phase angle corresponding to the preset angle signal into the power supply system. Accordingly, an undesirable sudden surge in power output resulting from a phase change occurring at the end of the power supply system disturbance can be avoided.

Abstract: The invention relates to a method for determining the chance of a disturbance-free operation of a frequency converter (2) connected to a feeding network (18). According to the invention, during the operation of said frequency converter (2), an intermediate circuit voltage (UZK) is continuously measured and a network-side intermediate circuit current (iZKmains) is continuously determined; these measuring quantities are compared with pre-determined operating values of the frequency converter (2), and quantities which are higher or lower than said values are respectively stored; and the frequency (Hij) of said higher and lower measuring quantities is determined and converted into a characteristic number for the quality of the feeding network (18). As said characteristic number decreases, the chance of a disturbance-free operation of the frequency converter (2) increases.

Abstract: A method of voltage instability load shedding, that includes the steps of measuring current and voltage waveforms of an electrical system at a local bus estimating the Thevenin equivalent admittance based on Kalman Filter techniques, then a voltage stability margin index is calculated using the voltage magnitude. The determined Thevenin admittance and the load at the local system bus and the calculated voltage stability margin index is compared with a predetermined threshold value to determine whether to initiate a load shedding action.

Abstract: Discussed is a method and device for increasing the operational flexibility of a current-generating system with a turboset, comprising a turbine coupled to an electrical generator, a power set point value being predefined, and a future target time at which the turboset is supposed to be at the power set point value, so that a power curve is determined via the power set point value and the target time, the turboset being operated starting from a actual power value at an actual time along the power curve such that the predefined power set point value is reached at the predefined target time. Also discussed is a gas turbine and to a steam turbine in accordance with the above description.

Abstract: There is disclosed a protection system for a power distribution system having a plurality of breakers arranged in a hierarchy. The protection system has a network and a breaker coupled to the power distribution system. A module is coupled to the network and the breaker is at a first level in the hierarchy. The module samples an electrical condition of the power distribution system at the breaker and monitors the electrical condition for a predetermined trip condition. The module, upon detection of the predetermined trip condition, trips said breaker if the first level is a lowest level of the hierarchy, but monitors the network for a notification message if the first level is not the lowest level of the hierarchy.

Abstract: A system for detecting and locating a disturbance event within a power grid includes a series of frequency disturbance recorders (FDRs) taking measurements in the power grid at dispersed points of the power grid, an information management system, configured to receive data from the series of FDRs and analyze the received data and a communications network interconnecting the series of FDRs and the information management system. The information management system is configured to examine orders and patterns of receipt of frequency changes at the FDRs in the data caused by the disturbance event and to triangulate a location of the disturbance event based on the orders and patterns of receipt of the frequency changes. Example methods of detection and location of disturbance events are also described.

Abstract: The present invention provides an electric power system for stably supplying power while suppressing corona discharge generating ultraviolet radiation which may cause health problems in human beings. The corona discharge start voltage varies with the weather. Data on weather forecasts is inputted for each district at certain times so as to calculate the corona discharge estimated start voltage for each transmission line with a computer. If the calculation result predicts start of corona discharge at normal transmission voltage, the transmission voltage of the line is lowered or power transmission through the transmission line is stopped.

Abstract: A system and method are presented to detect and account for regenerated voltage in a three phase power source failures. The method involves monitoring a power source for phase voltage unbalances to determine the presence of a single phase failure. If the voltage unbalance caused by the single phase failure is restored before a sensing timer expires, a regenerated voltage condition is detected and retransfer to the power source is inhibited. Retransfer to the power source may be delayed by a period determined by a retransfer time value, in order to prevent transfer cycling between the preferred power source and an alternate power source. In addition, retransfer inhibiting may be terminated due to user interaction, power source voltage readings indicating a repair state, or by failure of an alternate source.

Abstract: For the control of an electric power transmission network, where local protection functions are implemented by a plurality of local protection devices (3,3a,3b,3b?,3c) located at a plurality of locations throughout the network, the following steps are executed measuring phasor data for voltages and currents at a plurality of locations (A,B) of the network, transmitting said phasor data to a central processing device (2), emulating, in the central processing device (2), protection functions that are implemented in the local protection devices (3,3a,3b,3b?,3c), and executing, in accordance with a given redundancy strategy, control commands that are issued redundantly by the local protection devices (3,3a,3b,3b?,3c) and by the central processing device (2). In a preferred variant of the invention, values of predetermined parameters that are used in the protection function, in particular protection threshold values, are adapted to measured values.

Abstract: A revision to a Power Management Control System includes an improved waveform client/waveform server communication interface based on a first inter-process communication protocol, preferably DCOM. The first inter-process communication protocol preferably resides in the waveform application alongside an existing second inter-process communication protocol, i.e. DDE, for backwards compatibility. The improvement allows the application to operate across network segments in a more robust, reliable manner than through the first inter-process communication protocol, thus enabling the waveform server to operate effectively as an NT service and providing independent third party client software access to the waveform server waveform capture functions.

Abstract: A disturbance locating system deployed within a power grid to estimate a location of a disturbance in a power system includes a voltage transducer, a current transducer and disturbance energy determination circuitry. The system may also include disturbance power determination circuitry. The voltage transducer couples to an output of a voltage transformer, the output of the voltage transformer representative of a voltage on a line within the power grid. The current transducer couples to an output of a current transformer, the output of the current transformer representative of the current flowing through the line, the output having a forward reference direction and a behind reference direction. The voltage and current transformers may be hard wired to the line. The disturbance energy determination circuitry couples to the voltage transducer and the current transducer.

Abstract: The present invention is a system and method for variable base load demand-side energy management. The system of the present invention includes a power reduction device receiving electrical power from an electrical power source and outputting electrical power to a load. The system of the present invention can control the power delivered to one or more devices in a single facility or to multiple facilities. The system of the present invention can control the power delivered to one or more devices located in one or more facilities by sending control signals over various kinds of networks using various communication methods simultaneously, such as a modem, a LAN, or a WAN such as the Internet.

Abstract: A method of monitoring variations is carried out within an electrical energy meter containing means therein for metering a quantity of electrical energy generated by a supplier and transferred via a power supply line to a load. The method includes a first step of sensing a line voltage transferred via the power supply line to the load during the energy measurement time interval. The method also includes the step of detecting a variation in a magnitude of the sensed line voltage relative to an acceptable voltage level, wherein the variation exceeds a first variation threshold. The method then includes the step of capturing a first waveform of the sensed line voltage corresponding to the time when the variation is detected.

Abstract: A mimic filter which can be implemented in analog or digital circuitry, and which removes dc offset or other noise from an input signal using a pseudo-differentiation technique. The input signal is adjusted by a feedback value, and the adjusted signal is amplified by a proportional gain factor to generate an output signal. The feedback value is determined by integrating the output signal and multiplying the integration by an integration gain factor. The mimic filter avoids the generation of false signal spikes.

Abstract: In systems embodying the invention, a “downed” power line is detected by sensing whether there is an open circuit along the power line and producing an indication that an open circuit condition exists. In response to an indication that an open circuit condition exists, the system compares the nature of the voltage and/or current signals present on the power line at the time an open circuit condition is indicated to exist, with a preprogrammed stored condition which includes typical signals to be expected when a “break” occurs along a power line. When a downed power line is detected, power is then removed from the affected line.