253results about How to "Accurate fault location" patented technology

The invention relates to a cable-overhead joint line failure travelling wave range count method, particularly performing the effective fusion based on the failure range count method of the fundamental frequency and the travelling wave aiming at the particularity and the complexity of the cable joint line, belonging to the technical field of the power system relay protection. The invention judges the failure generating places firstly based on the cable-overhead junction derivated through the electric quantity at the two ends of the system attached with the negative sequence net after the failure, then performs the correct range count by the range count method of the single end; on the basis of considering the line zero modulus component couple, through comparing the performance of the current travelling wave line zero modulus component, the performance of each reflected wave is judged, to find out the fault point reflected wave, and then perform the correct range count.

The invention discloses an online fault diagnosis method for a hydraulic system. A sensor network (2) and an industrial personal computer (3) are used for acquiring a signal of a key position of the hydraulic system (1). Meanwhile, a system model is established for the hydraulic system (1), and fault injection simulation is carried out to obtain a simulation result serving as fault simulation data in a fault simulation module (6). The key characteristic information of the data provided by a data reading module (4) is found by a data characteristic extraction module (5), and fault diagnosis is carried out through a fault diagnosis module (7). A fault positioning module (8) can be used for positioning the fault according to fault information obtained by the fault diagnosis module (7), and providing a fault diagnosis result, fault causes, a detection flow and fault elimination measures, which are all displayed on a human-computer interface (9). According to the method, the false fault alarm rate is reduced, the capacities such as early warning are improved, and the method plays an important role in improvement of the reliability of the hydraulic system of product equipment.

The invention discloses a server fault automatic detection system and a detection method based on a decision tree, which combines an expert system and an IPMI management unit to generate a historicaldata set. The server running state data, i.e. Abnormal data stream, is obtained by IPMI management unit. According to the abnormal data stream, the new fault feature vector is extracted, and the new feature vector and the fault cause relation pair are formed into a fault data set, and the fault data set is trained into a self-diagnosing decision tree model. When the server fails while running, thecorresponding fault feature vectors are extracted, the fault types are automatically judged by the self-diagnostic decision tree model, After the fault is cleared, the fault feature vector and the fault cause relation are updated and the self-diagnosing fault tree model is updated. Therefore, the fault diagnosis system will be more accurate and reliable with the improvement of the history fault set.

The invention relates to a two-end distance measuring method of transmission line fault under a dynamic condition, comprising the following steps of: acquiring two-end voltage and current signals through two-end phasor measurement units of the transmission line; then acquiring dynamic positive sequence impedance, admittance, wave impedance and propagation coefficients according to line parameter estimation and a dynamic line parameter method; and finally solving a nonlinear equation related to a fault distance according to the fact that positive sequence voltages derived from two ends to a fault point are equal by applying a Newton iteration method so as to obtain a dynamic distance measuring result of the transmission line fault. The two-end distance measuring method can more effectivelysolve the problem of line parameter and fault distance estimation under the dynamic condition and has accurate and reliable fault distance measuring result.

The invention discloses a fault localization method suitable for a three-terminal T connection electric transmission line, comprising the following steps: firstly, judging the running state of the three-terminal electric transmission line: if the line is in a three-terminal running mode, firstly identifying a fault branch line, and calculating the fault distance according to the electric quantityof both ends of a T connection point and the endpoint of the fault branch line; if the line is in a two-terminal running mode or one side branch line is in a three-terminal running mode in a hot standby state, firstly determining if a fault point is at a switch cut-off branch line or not, if so, adopting a single-terminal localization method to calculate the distance from the T connection point tothe fault point, thereby obtaining the fault distance from the endpoint of the branch line to the fault point; but if the fault point is not at the switch cut-off branch line, respectively carrying out fault localization calculation under the two-terminal running mode or the three-terminal running mode. The invention provides a fault localization method before/after converting the running mode ofthe three-terminal electric transmission line and a fault localization method when the line is in the two-terminal running mode or one side branch line is in the three-terminal running mode under thehot standby condition.

The invention provides a method for positioning a travelling wave fault of an A type overhead line-cable joint line, comprising the following steps of: (1) by using a connection point of the overhead line and the cable as a boundary, respectively expressing lengths of a cable section and an overhead line section by using LC and LO, respectively expressing transmission speeds of transient travelling waves in the overhead line and the cable by using vO and vC, computing the time difference of achieving both ends (M, N) of the line by an initial travelling wave surge generated by the fault of the connection point P of the overhead line and the cable to be used as a setting valve; (2) measuring the absolute time of achieving both ends (M, N) of the line by the initial travelling wave surge generated by the fault of a certain point of the line, and expressing by using tM and tN; (3) determining the position of a fault point, wherein when tM-tN equal to delta TP, a fault point is the connection point P of the overhead line and the cable; when tM-tN is less than delta TP, the fault point is positioned a line MP section, and the distances between the fault point and the N end and the M end are respectively DNF=LC+LO-DMF; and when tM-tN is more than delta TP, the fault point is positioned a line MP section, and the distances between the fault point and the N end and the M end are respectively DMF=LC+LO-DNF. The method realizes the on-line fault sectioning and the fault distance measurement of the A type overhead line-cable joint line.

The invention belongs to the technical field of power system relay protection, and discloses a circuit single-end ranging method based on phase aberration characteristic of positioning function. The method deduces an operating voltage of reference positions and a fault point voltage based on distribution parameters by using electric quantity of a single end, and constructs a positioning function. When the reference positions are positioned on the left side and the right side of fault point, the positioning function has different phase characteristics; and when the reference positions are changed in front and back of the fault point, the phase of the positioning function has a unique stepped aberration. A circuit is subjected to N equal distribution, the equal distribution area containing the fault point is determined by using the phase characteristics, the step length is further reduced to determine the phase aberration position in the area, and then quick fault positioning of the single end can be realized. The method overcomes the defects of the traditional single-end ranging method, and theoretically is not affected by the factors such as distributed capacitance, transition resistance, opposite side running mode, communication facilities, load current and the like. The algorithm is simple, reliable and easy to realize, and the use value of the method is strong.

The invention discloses an accurate measurement and calculation method for parameters of a power transmission line. In the method, the parameters of the power transmission line are accurately calculated according to short-circuit impedance ZS and open-circuit impedance ZO of the power transmission line. The method comprises the following steps of: measuring the short-circuit impedance ZS and the open-circuit impedance ZO of the power transmission line with length of D; acculate calculating characteristic impedance zc and propagation coefficient gamma of the power transmission line according to a calculation formula provided by the invention; further, calculating impedance z and admittance y under the condition of unit length of the line through the formulas of z=zc gamma and y=gamma/zc; and accurately calculating impedance Z' and admittance Y' of an equivalent pi circuit of the power transmission line according to the calculation formula provided by the invention. By adopting the measurement and calculation method provided by the invention, the accuracy for the parameters of the power transmission line can be greatly improved, manpower and material resources are saved, tide current of a power system is stably analyzed; protection setting is performed; and fault positioning is more accurate.

The invention discloses a failure message integrated device based on FPGA and ARM hardware platform, which comprises a PT/CT board, an ARM board, a network switch board, a serial port board, a GPS board and a high speed acquisition board composed of an A/D sampling chip and an FPGA; the FPGA has a DDR2 controller, an DMA controller, an FIFO memory and an FIR low-pass filter; and the FPGA is also provided with a starting algorithm module and a fault recorder module. The device organically combines the functions of the fault recorder, a travelling wave distance measuring device and a failure message management sub-station by using parallel processing capability of the high speed AD chip and the FPGA, for realizing accurate localization of fault points when a power transmission line in an electric power system has a fault, and obtaining a complete fault report, thereby complying with intelligentization and miniaturization needs of secondary device of power grid.

The invention provides a B-type overhead line-cable hybrid line traveling wave fault positioning method, which comprises the following steps of: (1) using connecting points P1 and P2 of an overhead line and a cable as boundaries, representing lengths of an overhead segment MP1, a cable segment P1P2 and an overhead segment MP P2N by using LO1, LC and LO2 respectively, representing the propagation speed of a transient state travelling wave in the overhead line and the cable by using vO and vC respectively, and calculating the time difference from an initial travelling wave surge generated at a P1 point fault to two ends of M and N of the line and the time difference from an initial travelling wave surge generated at a P2 point fault to the two ends of M and N of the line, which serve as setting values; (2) measuring an absolute moment from an initial travelling wave surge generated at a certain fault to the two ends of M and N of the line, and representing the absolute moment by using tM and tN; and (3) determining the fault point position.

A method and apparatus for determining a location of a phase-to-earth fault on a three-phase electric line of an electric network, comprising determining, when the ratio of a fault current and load current has a first value, a first fault distance line which indicates an estimate of a distance of the fault from the measuring point in relation to an equivalent load distance, determining, when the ratio of the fault current and load current has a second value which differs from the first value, at least one second fault distance line, determining a distance at which the determined fault distance lines intersect when superimposed and determining the distance between the measuring point and the point of fault on the basis of the determined distance or distances of intersection.

The invention discloses an intelligent overhead line fault positioning and monitoring system. The system is precise in fault positioning, high in precision and capable of quickly isolating faults, avoids long-time outage and improves operation reliability of a power grid. The intelligent overhead line fault positioning and monitoring system comprises a background server, a data collecting communication terminal, multiple fault indicators, a geographic information system and a distribution network automated system, wherein the background server, the data collecting communication terminal, the fault indicators, the geographic information system and the distribution network automated system are sequentially connected in a communication mode, and the geographic information system and the distribution network automated system are respectively connected with the background server. After a fault positioning and monitoring platform receives motion messages of the fault indicators, the geographic information system is accessed, all fault indicators which work and do not work on the same line are defined as upstream fault indicators and downstream fault indicators respectively, and a fault area is reduced to obtain a precisely positioned fault area by analyzing and determining the upstream fault indicators of a positioned fault area and the downstream fault indicators in the positioned fault area.

The invention provides a wind power monitoring and fault diagnosis system which comprises a station-control-level computer monitoring network, a bay-level data communication network, a power grid EMS (electronic management system), a data collection system, a transformer substation measuring and control protecting system, a remote working station and units (1...n). The station-control-level computer monitoring network respectively performs data interaction with the power grid EMS, the data collection system and the transformer substation measuring and control protecting system through the bay-level data communication network and controls the remote working station, the data collection system respectively collects data of each collection unit (1...n), and the station-control-level computer monitoring network receives meteorological information of a wind power plant. The wind power monitoring and fault diagnosis system can simultaneously realize functions of monitoring of electrical quantity of wind power and state monitoring and fault diagnosis of a wind power unit, precognition and alarming of fault states of the wind power unit can be realized while wind power monitoring is realized.

The present invention relates to a method for locating single-phase ground fault of a low current grounding system power distribution network, including determining a total length L[total] and a total impedance Z[total] between two lines of M and N, and injecting signals when occurring a fault, when a P point between the M and N positions occurring a single-phase ground fault, systems of the two positions inject signals at the M and N position, and measures the amplitude of a return current signal as well as a phase difference between the return current signal and the injection voltage signal, after a line selection device has selected the fault phase; calculating a loop total impedance Z[M] grounded through the P point from the M and N ends, the modulo of the Z[N], and a phase angle Phi[M] of the Z[M] and the Z[N], according to |Z| = |U| / |I|, the measured injection voltage, the amplitude of the return current signal and the phase difference, a distance from the fault point P to the M position is further calculated through the following formula. By the method of the invention, it is easy to detect when the signal amplitude is strong, the attrition in the power distribution network is low, the algorithm is high, and the accuracy is high.

The invention discloses a network fault positioning method and a device. The method comprises steps of: dividing an original network domain into multiple sub network domains according to occurrence probability of different types of faults to a network node; acquiring history fault data in the network and obtaining a network fault positioning model through the neural network training; and acquiring information network fault data in the current network, inputting the information network fault data into the network fault positioning model and calculating to obtain communication network fault data so as to obtain a positioning result of the network faults. According to the invention, by considering dependency, between different layers, of the faults, the network domain with complex structure, high volume and many faults is divided into sub network domains with simplified structures, so more precise fault positioning can be performed; parallel positioning based on multiple sub network domains is performed, so fault positioning efficiency is improved; and by use of the neural network, the correlation between the network nodes is considered in the fault positioning, so accuracy of the network fault positioning is improved.

The invention provides an array substrate and a display device, and belongs to the technical field of display. The array substrate can solve the problems that an existing array substrate cannot detect leads independently, and the fault positioning is inaccurate. The array substrate comprises an expanding area, an edge area and a display area for performing displaying, and the expanding area and the edge area are connected with the display area and located on the two non-adjacent sides of the display area respectively. A plurality of leads are arranged on the array substrate and penetrate through the display area into the edge area. One end of each lead is an input end for connecting a drive chip, and the input end of each lead is located in the expanding area. The array substrate further comprises connectors which are located on the sides, far away from the input ends, of the leads and used for detecting probe contact, and the connectors are located in the edge area.

The present application provides an application-level disaster tolerant method and an application-level disaster tolerant system. The application-level disaster tolerant method is deployed at each data center, and comprises the steps of: determining that an abnormal connection of an application cluster occurs and pushes a notification that the abnormal connection of the application cluster occurs when a main control terminal of a HAProxy clustered system judges that number of application terminals having abnormal connection in the application cluster is greater than a first preset number; and determining that an abnormal connection of a database cluster occurs and pushes a notification that the abnormal connection of the database cluster occurs when a main control terminal of the application cluster judges that number of databases having abnormal connection in the database cluster is greater than a second preset number. The application-level disaster tolerant method and the application-level disaster tolerant system can achieve the purpose of accurately determining a fault position. Since the application-level disaster tolerant method and the application-level disaster tolerant system can accurately determine the fault position, the switching can be carried out at the fault position when switching the data center without switching the overall data center.

Aspects of the present disclosure aim at configuring an optical time domain reflectometry (OTDR) in a central office such that the OTDR is configured to be operatively coupled with and also configured to periodically poll each fiber at defined intervals and compute/store a reflection signature that can be used to compare with future signatures received from subsequent polls of the fiber to determine a fault (e.g., a fiber cut or breakage) between the central office (CO) and one or more optical network unit (ONU) over GIS.

The invention discloses a full-parallel AT traction network fault location t method, which comprises the following steps that: when a fault occurs, synchronously acquiring the states of uplink and downlink bipolar feeder circuit breakers of each kiosk and the current flowing through the circuit breakers, and constructing a traction network parallel state matrix and a feeder current matrix; constructing a current state matrix and a fault state matrix; and judging whether the fault section is an uplink and downlink parallel section post-ranging section, or judging whether the fault section is asingle-line AT section post-ranging section, or judging the fault type post-ranging section. The invention has the following beneficial effects: the operation mode of the traction network is characterized by the switch state matrix, the fault section is identified by the current state matrix and the fault state matrix, and finally the fault distance calculation is realized by three classified fault location methods, which can realize the fault location in normal power supply operation mode and various abnormal power supply operation modes. The method has the characteristics of accurate distance measurement, high applicability and the like.

The invention discloses a wireless communication device testability design method. The method includes performing functional unit division on a wireless communication device, including a voice and panel unit, a processor unit, a baseband signal processing unit, a radio frequency unit, a power amplifier unit, a filter unit and a backboard unit, wherein the voice and panel unit, the baseband signal processing unit, the radio frequency unit, the power amplifier unit and the filter unit are connected with the processor unit through respective control interfaces and data communication interfaces via the backboard unit, and the voice and panel unit provides a device internal unit program upgrade interface and maintenance interface to the outside. Main faults of each unit are automatically diagnosed when the device is powered on, a test command is input through the maintenance interface when a fault occurs, a test signal passes through each unit inside and realizes loopback gradually, and the faults of each unit are diagnosed automatically. The wireless communication device testability design method has the beneficial effects of utilizing hardware resources of the device itself, increasing test software to realize testability design of the device itself, accurately positioning the faults inside the device, and greatly reducing debugging and testing and maintenance guarantee cost of the device.

The invention discloses a fault range finding method of a power distribution network based on an equivalent positive and negative sequence impedance principle. According to the method, a PMU is used to obtain line state information in real time, and a fault line is determined by calculating and comparing the head-end line voltages in the same branch point; normal line information is used to calculate the head-end voltage and current of the fault line; and on the basis that electrical quantity of the two ends of the fault line is known, accurate fault locating is realized on the basis of the equivalent positive and negative sequence impedance principle. The difficulty that too many branch lines are included in fault location in the power distribution network via the limited PMU, and accurate fault locating is realized; fault range finding is realized by measurement in the two ends, it is not required to determine the fault type, the method is avoided from influence of transitional resistors or opposite-end feed-in current, and it is not required to consider the change of fault boundary condition or system operation manner, and compared with the single-end measurement method, the range finding precision is higher, fault range finding can be realized rapidly and accurately, the operational reliability, safety and flexibility of the system are improved greatly, and the applicationprospects are better.