Patent application number | Description | Published |
20090125158 | STATE AND TOPOLOGY PROCESSOR - A State and Topology Processor (STP) may be communicatively coupled to one or more intelligent electronic devices (IEDs) communicatively coupled to a electrical power system to obtain one or more current measurements, voltage measurements, and dynamic topology data therefrom. The STP may receive the measurement data and may determine a current topology and a voltage topology therefrom. A current processor may use the current topology and the current measurements to refine the measurements, perform KCL, unbalance, symmetrical component, and consistency checks on the electrical power system. The voltage processor may use the voltage topology and the voltage measurements to perform similar checks on the electrical power system. One or more alarms may be generated responsive to the checks. The data may be displayed to a user in a display of a human machine interface and/or may be transmitted to a user programmable task module, and/or an external control unit. | 05-14-2009 |
20100002348 | DISTRIBUTED BUS DIFFERENTIAL PROTECTION USING TIME-STAMPED DATA - A distributed busbar protection system using time-stamped data gathered from measurement devices in an electrical power system bus arrangement by respective intelligent electronic devices (IEDs). The IEDs may derive the timestamp information from a clock or other time source, which may be synchronized to a common time source and/or an absolute time. The time-stamped measurement data may be used by a protection device to monitor and/or protect the electrical power system. The protection device may include a real-time vector processor, which may time-align the time-stamped data, determine one or more bus differential protection zones, and implement a differential protection function within each of the protection zones. One or more protective control signals may be transmitted to the IEDs to trip the corresponding breakers and clear the bus fault. | 01-07-2010 |
20100286838 | ISLANDING DETECTION IN AN ELECTRICAL POWER DELIVERY SYSTEM - An intelligent electronic device is operable to use a signal derived from an electrical power delivery system to effectively detect an islanding condition. The intelligent electronic device is configured to compare a frequency deviation (from nominal frequency) and a rate-of-change of frequency of the electrical power delivery system to a protection characteristic of the intelligent electronic device to quickly and securely detect islanding conditions thereby enhancing power protection, automation, control, and monitoring performance. The intelligent electronic device uses local measurements of the electrical power deliver system to provide reliable and economical means to properly separate a generation site from the remainder of the electrical power delivery system. Such may be useful to prevent reclosing out of synchronism. | 11-11-2010 |
20110004425 | STATE AND TOPOLOGY PROCESSOR - A State and Topology Processor (STP) may be communicatively coupled to one or more intelligent electronic devices (IEDs) communicatively coupled to a electrical power system to obtain one or more current measurements, voltage measurements, and dynamic topology data therefrom. The STP may receive the measurement data and may determine a current topology and a voltage topology therefrom. A current processor may use the current topology and the current measurements to refine the measurements, perform KCL, unbalance, symmetrical component, and consistency checks on the electrical power system. The voltage processor may use the voltage topology and the voltage measurements to perform similar checks on the electrical power system. One or more alarms may be generated responsive to the checks. The data may be displayed to a user in a display of a human machine interface and/or may be transmitted to a user programmable task module, and/or an external control unit. | 01-06-2011 |
20110066301 | SYSTEMS AND METHODS FOR MONITORING AND CONTROLLING ELECTRICAL SYSTEM STABILITY - Disclosed herein are systems and methods for monitoring and controlling an electric power delivery system to mitigate against voltage instability. According to various embodiments, one or more stability thresholds may be compared to one or more stability estimates. Stability estimates may be generated based on electrical conditions in an electric power delivery system. Upon the occurrence of the contingency, one or more control actions specified by a contingency index may be executed in order to mitigate against voltage instability. A plurality of stability estimates may be generated, each of which may be compared to a respective stability threshold. According to various embodiments, stability estimates and stability thresholds may be based on a reactive power to voltage margin, an incremental reactive power cost, an incremental load cost, and a power import margin. | 03-17-2011 |
20110251732 | SYSTEMS AND METHOD FOR OBTAINING A LOAD MODEL AND RELATED PARAMETERS BASED ON LOAD DYNAMICS - Disclosed are systems and methods for calculating load models and associated tunable parameters that may be used to describe the behavior of loads connected to an electric power distribution system. The load models may be utilized to predict variations in demand caused by changes in the supply voltage, and may be utilized in determining an optimized control strategy based on load dynamics. Any action which causes a disruption to the electric power distribution system may provide information regarding the composition or dynamics of connected loads. Such actions may be referred to as modeling events. Modeling events may occur with some frequency in electric power distribution systems, and accordingly, a number of data sets may be acquired under a variety of conditions and at a variety of times. Load models may include static load models, dynamic load models, or a combination of static and dynamic load models. | 10-13-2011 |
20120265457 | SYSTEMS AND METHODS FOR DETECTING MOTOR ROTOR FAULTS - Systems and methods for detecting fault conditions in a rotor of an electric induction motor are disclosed. In certain embodiments, a method for detecting fault conditions may include sampling a plurality of currents from an electric induction motor to obtain a plurality of current data points, calculating a global maximum magnitude of the plurality of current data points in the frequency domain over a range of predetermined frequencies, calculating an average magnitude of the plurality of current data points in the frequency domain over the range of predetermined frequencies, and declaring a motor rotor fault condition based on a comparison between the average magnitude and a first predetermined threshold, a comparison between a difference between the global maximum magnitude and the average magnitude and a second predetermined threshold, and a comparison between the global maximum magnitude and at least a third predetermined threshold. | 10-18-2012 |
20150088444 | Monitoring Synchronization of a Motor Using Stator Current Measurements - Monitoring synchronization of an electric motor using current signals from power supplied to the motor is disclosed herein. The current signals may be used to calculate representative current values which may be used to calculate a rotational frequency of the rotor of the motor. The rotational frequency may be used to determine synchronization, such as slip. Monitoring may be during startup of a synchronous motor in induction mode. Upon reaching a predetermined synchronization threshold, the motor may be configured from induction mode to synchronous mode. | 03-26-2015 |