8323results about "Fault location by conductor types" patented technology

The present invention includes a fault indicator for an electrical transmission line comprising: a fault indicator circuit; and a remote communicator operatively coupled to the fault indicator circuit to transmit condition data to a remote location, where such condition data includes current load data. The invention also includes a method of monitoring and responding to current faults and load variations across an electrical transmission network, the method comprising: installing two fault indicators in electrical communication with an electrical transmission network and including two-way communication capability; generating, by the two fault indicators, condition data specific to a respective location of each of the two fault indicators, where such condition data includes current load data; transmitting the condition data from the two fault indicators to a remote location; receiving, at the remote location, the condition data transmitted from the two fault indicators; and, monitoring and processing the condition data received.

A system and method is provided for detecting an island condition using active detection. The active detection involves biasing the voltage, frequency, current or phase of a distributed resource connected to a utility network. Biasing the distributed resource involves inducing a change of voltage, frequency, current or phases above or below the normal operating values. The impact of this biasing on the system operating parameters can then be measure to determine if an island condition exists. Once an island condition has been detected, the system can initiate an anti-islanding procedure to remove the distributed resource from the utility network such as opening a breaker connecting the distributed resource to the network. Additionally, the system and method can include a passive element for detecting frequency and voltage (or other parameters) shifts above certain points.

A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

A system and method for detecting, identifying, and fixing the location of the source of an acoustic event. The inventive system includes: a plurality of sensors dispersed at somewhat regular intervals throughout a monitored area; a communication network adapted to deliver information from the sensors to a host processor; and a process within the host processor for determining, from the absolute times of arrival of an event at two or more sensors, a position of the source of the event. Acoustic events are detected and analyzed at each sensor so that the sensor transmits over the network: an identifier for the sensor; an identifier for the type of event; and a precise absolute time of arrival of the event at the sensor. In a preferred embodiment, the system also identifies the type of weapon firing a gunshot.

System for monitoring an electrical system of a facility includes one or more local sensing devices, each of which is adapted to be connected to the electrical system of the facility in proximity to a respective load that receives power from the electrical system so as to make local measurements of a voltage across the load continuity measurements of electrical-power presence at one or more points in the electrical system of said facility. A processing unit is adapted to receive and compare the local measurements to reference measurements of the voltage supplied to the facility, in order to detect a fault in the electrical system.

A method and system for detecting and locating a single-phase ground fault on a low current grounded power-distribution network, comprising: respectively testing and picking up the voltage signals and current signals at multiple positions on each phase feeder (61), and determining the corresponding transient voltage signals and transient current signals according to the extraction of the voltage signals and the current signals (62); when the change in the transient voltage signals and the transient current signals exceeds a preset threshold (63), synchronously picking up the voltage signals and current signals at multiple positions on a three-phase feeder (64); calculating corresponding zero-sequence voltages and zero-sequence currents according to the voltage signals and current signals synchronously picked up at multiple positions on the three-phase feeder (65), and then extracting the steady-state signal and transient signal of the zero-sequence voltage and zero-sequence current at each position on the three-phase feeder (66); and determining a specific fault location on a faulty line according to the steady-state signal and the transient signal (67). The method effectively detects and displays a single-phase ground fault on a low current grounded power-distribution network.

A physical layer device that communicates over a cable comprises a cable tester that determines a cable status, which includes an open status, a short status, and a normal status. The cable tester includes a pretest module that senses activity on the cable and selectively enables testing based on the sensed activity. A test module is enabled by the pretest module, transmits a test pulse on the cable, measures a reflection amplitude, calculates a cable length, and determines the cable status based on the measured amplitude and the calculated cable length. An insertion loss estimator communicates with the cable tester and estimates insertion loss of the cable. A return loss estimator communicates with the cable tester and estimates return loss of the cable based on gain parameters of the physical layer device.

The present invention relates to a method of generating fault indication in a feeder remote terminal unit for a power distribution automation system. The method is performed in a distribution system that includes a plurality of feeder remote terminal units, which are installed in respective sections of a line and are configured to measure voltage, current and a phase difference of the line, and a central control unit for determining whether a fault occurs and controlling operation of the feeder remote terminal units. In the method, phases are measured by each of the feeder remote terminal units. The phase of a zero-sequence current is compared with that of a zero-sequence voltage. A direction of a fault current is calculated, and fault indication information is generated in the calculated direction of the fault current.

A fault is located in a power distribution system having a line frequency. The power distribution system includes a plurality of phases, at least one feeder, and each feeder includes at least one segment. The fault is located by detecting a faulted phase from the plurality of phases of the power distribution system. A measurement signal having a measurement frequency is injected into the detected faulted phase, the measurement frequency being a different frequency than the line frequency. The fault location is determined for a selected segment based on at least one measured residual current corresponding to the injected signal and a predetermined relative impedance of the power distribution system.

A method for testing an installed wiring harness is provided. The method comprises providing a signal source testing module at a first node in the wiring harness and a measurement termination testing module at a second node in the wiring harness. A central management module for controlling the testing modules coordinates the testing modules to send testing signals for performing tests and recording test measurements of the installed wiring harness. The testing modules send the test measurements to the management module.

An isolation monitor is disclosed in which a switchable bias voltage is imposed on a chassis ground. An isolation voltage is measured when a bias voltage is applied. When there are no electrical faults, the isolation voltage swings up and down to known values. When a fault occurs, the isolation voltage will not to swing to the known values, and thus the isolation resistance can be measured and alarm generated if the isolation resistance falls below a threshold value.

The present invention provides methods for using time domain analysis of NEXT, Return Loss and the like, in conjunction with the application of time or distance referenced limits to verify and determine compliance of the performance requirements of connections in a typical link. Time domain analysis of NEXT, Return Loss data and the like, suitably provides the performance characteristics of a link as a function of time or distance. When coupled with time or distance performance curves for connections, it can be determined if the transmission fault is at a connection or in the cable. The time limit curves for connections can be generated based on the frequency domain performance requirements for connecting hardware of a specific level of performance. The connection time limit curves thus provide an interpretation means to determine if the connection is within performance standards, allowing improved isolation of the fault condition.

A method for locating a ground fault in an electrical power distribution system includes providing a plurality of current sensors at a plurality of locations in the electrical power distribution system. The method further includes detecting a ground fault in the electrical power distribution system. Current is monitored at a plurality of locations in the electrical power distribution system via the current sensors and a test signal is introduced into the electrical power distribution system via a test signal generating device. The plurality of locations are monitored to locate the ground fault between a location at which the test signal is detected and a downstream location at which the test signal is not detected.

When a disturbance (for example, lightning strike) occurs on a high-voltage overhead transmission line, the line must be checked for any possible damage. If the distance-to-fault is known, line crews can be quickly dispatched for any necessary repair. The present invention is a fault location method and system that uses filtered, time-synchronized positive- or negative-sequence voltage and current measurements from both ends of the overhead transmission line to determine the exact distance to the fault with respect to either end.

The present invention relates to a real time dynamic physics simulation device of flexible DC transmission system. The device includes simulated converter transformer, simulated AC field, simulated DC field, simulated converter reactor, simulated converter, and measurement and control cabinet chassis; the simulated AC field includes the vacuum switch I, the contactor I, resistors and the vacuum switch II connected orderly; the simulated DC field includes successively connected the vacuum switch contactor III and II; the simulated AC field is connected with said measurement and control cabinet chassis; Said converter transformer is set between said resistors and said vacuum switch II; Said simulated converter reactors and said simulated converter connected are set between the vacuum switch II and the vacuum switch III. The present invention can accurately simulate different voltage level flexible DC transmission system based on modular multilevel converter (MMC-HVDC), able to accurately understand the operation characteristics of MMC-HVDC and the dynamic responds to the instruction of the control system.

Cable diagnostic test methods, systems and apparatus are disclosed that utilize “standing wave” principles to facilitate identification and location of insulation defect(s) along a power cable. The methods/systems measure dissipation factors and dielectric constants associated with the power cable insulation and the impedance of the power cable conductor at any number of points or sections along the axial length of the cable. In an exemplary embodiment, the disclosed method involves (i) connecting an alternating voltage source to a cable at a “sending end” thereof; (ii) applying a voltage to the cable at a first frequency to set up a traveling wave along the cable that is reflected at the “receiving end” thereof; (iii) permitting a standing wave pattern to be established along the cable by the traveling wave and the reflection thereof; (iv) measuring the total complex power loss (S_in) at the sending end of the cable; (v) calculating the standing wave voltage at any point/section of the cable based on the load impedance (Z_L) connected at the receiving end of the cable, and the characteristic impedance (Z_O) of the cable, or the measured/calculated cable parameters for the first frequency of the voltage source, (vi) repeating the foregoing steps while one of: (1) varying at least one of: the load impedance (Z_L) connected at the receiving end of the cable, the first frequency of the voltage source; the output impedance of the voltage source, a combination of the load impedance (Z_L), the output impedance of the voltage source and the first frequency of the voltage source, and combinations thereof; (2) interchanging sending and receiving cable ends; and (3) a combination thereof, and (vii) determining a dissipation factor (tan δ) and a dielectric constant (∈′), for the insulation, and an impedance, for the conductor at predetermined points/sections along the axis of the cable.

A system and method of detecting changes in the impedance of a segment of medium voltage power line is provided. In one embodiment, the method comprises receiving voltage data comprising data of the voltage of the power lines at locations at a plurality of different points in time, receiving current data that comprises data of the current flowing between adjacent locations at the plurality of points in time, intermittently determining an impedance of the power lines between adjacent locations based on the voltage data and current data, monitoring the impedance of the power lines between adjacent locations over time, and providing a notification of a change in the impedance of a power line between adjacent locations upon detection of a change in the impedance beyond a threshold change.

The invention discloses a multi-terminal flexible DC grid DC line quick protection method and system based on single-terminal voltage. The method comprises the following steps: collecting the voltagesignals on the two sides of DC positive and negative line current limiting reactors in real time; forming a low voltage starting criterion; performing wavelet transform on the calculated line mode voltage on the current limiting reactors and calculating the wavelet transform modulus maximum; performing the data validity test and recording the size and the symbol of the first wavelet transform modulus maximum meeting the data validity condition; establishing the fault identification criterion to identify the fault based on the symbol and amplitude difference of the single-terminal voltage traveling wave wavelet transform modulus maximum; and constructing the fault pole identification criterion to identify the fault pole based on the size difference of the voltage traveling wave transient energy. According to the line protection method, the fault direction can be reliably and quickly identified under various initial fault conditions, and the transition resistance, the fault location andthe fault of the AC system and other factors have little influence on the protection criterion so as to have high reliability and sensitivity.

The invention discloses a pole tower model matching and visual navigation-based power unmanned aerial vehicle and an inspection method. In an unmanned aerial vehicle, a depth image of a front end of the unmanned aerial vehicle is acquired by a dual-eye visual sensor, distance between the unmanned aerial vehicle and a front object is further measured, a surrounding image is acquired by a cloud deckand a camera, the object is further identified, and the flight gesture of the unmanned aerial vehicle is controlled by flight control of unmanned aerial vehicle. The method comprises the steps of performing pole tower model building on different types of power transmission line pole towers; automatically identifying the power transmission line pole towers and pole tower types by the unmanned aerial vehicle during the flight process, matching and loading a pre-built pole tower model; performing visual positioning on the power transmission line pole towers by the unmanned aerial vehicle, and acquiring relative positions of the unmanned aerial vehicle and the pole towers; and performing flight inspection by the unmanned aerial vehicle according to optimal flight path. By the unmanned aerialvehicle, the modeling workload is greatly reduced, and the model universality is improved; and the inspection method does not dependent on absolute coordinate flight, the flexibility is greatly improved, the cost is reduced, and the power facility safety is improved.