Abstract: Provided is a system, a tool and a method for communicating with a faulted circuit indicator (FCI), the faulted circuit indicator including a detection circuit for monitoring an electrical conductor of a power system. The system includes a display and a first light emitting diode associated with the display. The first light emitting diode generates an optical FCI status signal in response to an occurrence of a fault in the electrical conductor. The system also includes a first microcontroller operatively coupled to the display and the detection circuit, and a handheld user command tool adapted to optically signal the display. The handheld user command tool may be also adapted to generate an optical serial communication. The optical serial communication may provide data and/or commands for operation of the faulted circuit indicator. The display may be integrated into the FCI. The FCI may be an overhead FCI.

Abstract: A faulted circuit indicator (FCI) for providing an indication of a fault on a monitored conductor, determining whether the FCI is near the end of its useful life (or entered into an end-of-life mode) and altering an operation of the FCI if the useful life of the FCI has reached a select threshold. The operation alteration may include an alteration of the display and/or deactivation of certain features and/or functions of the FCI. Thus, the useful life of the FCI will be increased. Further, utility personnel will be more likely to notice that the FCI is in end-of-life mode. The FCI may also include a battery discharge module and a thyristor for discharging the battery for disposal upon decommissioning of the FCI.

Abstract: A system and method for monitoring the rotation of a generator rotor and calculating a power angle using an optical rotor displacement monitor. The monitor uses a light beam directed toward the rotor to detect a marking thereon, and generates an electrical pulse when the marking is detected. The time between the pulse and a reference point (such as a zero crossing) of the signal waveform from the terminals of the generator is used to calculate the power angle of the generator. The system is adaptive in that it can account for new markings on the rotor. The system may be connected to a network so that power angles from various generators on the electrical network may be compared. The system may further be connected to a common time source such that a time stamp may be applied to the power angles from various generators, allowing for more accurate comparison of the power angles.

Abstract: A system and method for monitoring the rotation of a generator rotor and calculating a power angle using an optical rotor displacement monitor. The monitor uses a light beam directed toward the rotor to detect a marking thereon, and generates an electrical pulse when the marking is detected. The time between the pulse and a reference point (such as a zero crossing) of the signal waveform from the terminals of the generator is used to calculate the power angle of the generator. The system is adaptive in that it can account for new markings on the rotor. The system may be connected to a network so that power angles from various generators on the electrical network may be compared. The system may further be connected to a common time source such that a time stamp may be applied to the power angles from various generators, allowing for more accurate comparison of the power angles.

Abstract: Independent frequency measurement and tracking of a signal using a measurement interval where the frequency of the signal is measured and a sampling rate is calculated, and a settling interval where the frequency of the signal is not measured. The sampling rate is calculated to correspond with the frequency of the signal and updated only after the calculation of the sampling rate in the measuring interval. The signal may be a signal of an electric power system such as a voltage waveform or a current waveform. The frequency calculation may include determination of a rate of rotation of a positive-sequence phasor of the signal.

Abstract: A system and method for acquiring phasors outside of the frequency tracking range for power protective relays. As the frequency of a power system varies from the rated frequency, phasors calculated from such samples include errors. A frequency tracking range is used to sample the signal waveform at a rate corresponding to the frequency when the frequency is within the frequency tracking range. When the frequency is outside of the frequency tracking range, the signal waveform is sampled at a rate corresponding with the maximum or minimum of the frequency tracking range depending on whether the frequency exceeds or falls below the frequency tracking range. The difference between the frequency and the minimum or maximum of the frequency tracking range is used to correct the measured phasors to result in accurate phasors.

Abstract: An apparatus and method detects an open condition of a grounding path provided by a rotor grounding brush electrically connecting a rotor body of a rotor to electrical ground. The rotor includes an insulated field winding wrapped around the rotor body and is configured to generate a magnetic field upon receipt of an exciter voltage across lower and upper extremities of the insulated field winding. The method includes applying a square wave voltage signal to a second end of each of a first and a second buffer resistor, where a first end of each of the buffer resistors is operatively connected to respective upper and lower leads of the exciter voltage source, and calculating the total capacitance between the insulated field winding and electrical ground. The total capacitance when compared to a pre-selected capacitance value is determinative of the absence of the grounding path.

Abstract: Provided is a system, a tool and a method for communicating with a faulted circuit indicator (FCI), the faulted circuit indicator including a detection circuit for monitoring an electrical conductor of a power system. The system includes a display and a first light emitting diode associated with the display. The first light emitting diode generates an optical FCI status signal in response to an occurrence of a fault in the electrical conductor. The system also includes a first microcontroller operatively coupled to the display and the detection circuit, and a handheld user command tool adapted to optically couple with the display. The handheld user command tool is also adapted to generate an optical serial communication. The optical serial communication provides data and commands for operation of the faulted circuit indicator. The display may be remote or integrated into the FCI.

Abstract: An accurate slip calculation for providing monitoring and protection to an electric motor. The slip calculation is made using a minimum value of stator resistance as the initial stator resistance, where the minimum value of stator resistance is the minimum value of stator resistance calculated during an initiation period of the motor. The initiation period may be a predetermined time period or a predetermined number of cycles during the motor startup. The initiation period may start after a predetermined settling time or after a predetermined condition is met.