107results about How to "Improve fault location accuracy" patented technology

The invention belongs to the electrical power system domain, specially relates to the line single end fault distance measuring method of the anti- distributed capacity electric current and the transition resistance influence. Including: surveys the transformer substation protection installment place fault phase voltage, the phase current, the zero sequence voltage, the zero sequence electric current and the negative sequence electric current as the input value; using the fault voltage cross zero time to measure the resistance characteristic which is not influence by transition resistance, from the protected line begin end start, computing the measure voltage real part computed value of the fault point voltage cross zero point time, compared with the measured value of the measure voltage real part, computing the error; and taking the delta-S as the step size, in turn computing the setting range which is protected by the send tripping signal, if cannot obtain the protect tripping signal, searching the total track length which is protected, taking the minimum point as the fault point. The invention method is not influenced by the distributed capacity electric current and transition resistance, does not have the false root problem of solving equation method and non convergence question of the iterative method, and has the very high practical value.

The invention relates to an automatic monitoring method and system for long distance pipeline safety. It uses the monomode optical fiber laid near the distant pipeline, or the backup monomode optical fiber in the measured cable as sensing element; when the pipeline has leakage or the pipeline is damaged, the transmission character of the optical fiber will be changed, the light path difference of the laser in the two fibers will be changed; the change can be acquired with light interference method; at the same time, uses the affection of exterior force to the monomode optical fiber, and locating the position of the exterior on the pipeline. The several monitoring systems can be assembled into a network, thus the high sensitive, remote, real-time and automatic monitor to the long distance pipeline can be realized.

The multiple-terminal signal process of positioning fault in power transmission line includes the following steps: realizing sync sampling of multiple-terminal voltage and current signals of power transmission line with GPS; recording and exchanging the electric quantities before and after fault to obtain required data for positioning fault; obtaining the accurate position of the fault point via judging the sort of the fault and precise positioning. The fault positioning device for power transmission line includes voltage converter, current converter, GPS signal receiver board, data acquisition card and industrial control computer. The present invention can position fault in power transmission line precisely and in high robustness.

The invention discloses a single-terminal distance measurement method for line single-phase earth faults based on distributed parameter measurement impedance amplitude characteristics. The method includes adopting a distributed parameter model, selecting an initial value of fault distance as 1x, successively increasing the fault distance by the step length of delta1, sequentially calculating distributed parameter measurement impedance amplitude z(1x) until the amplitude z(1x) from every point on the transmission line to a single-phase earth fault point is calculated and selecting the distance between a minimum corresponding point of the distributed parameter measurement impedance amplitude z(1x) to a protection installation position of the transmission line as the fault distance. The method has the advantages that a principle that the distributed parameter measurement impedance amplitude corresponding to the single-phase earth fault point reaches the minimum is utilized for achieving single-terminal distance measurement of the single-phase earth faults of the transmission line, influences of transition resistance and load current on accuracy of single-terminal fault distance measurement are eliminated, and particularly when used for distance measurement of single-phase high-impedance earth faults of the transmission lines, the method is capable of accurately measuring fault distance and has quite high fault distance measurement accuracy.

The present invention relates to a method for location of a fault utilizing unsynchronized measurements of three phase voltages and currents acquired at the line terminals without synchronization. Phasors for symmetrical components of the measured quantities are determined and used in the fault location algorithm. According to one embodiment, positive sequence phasors of post-fault quantities are used for estimation of the distance to fault and it is distinctive that such an estimation of a distance to fault is performed without essentially involving iterative techniques. In this embodiment, the fault location algorithm step is performed regardless of the fault type. In later steps, the type of fault may be obtained. According to another embodiment of the invention, at the occurrence of a fault, the type of fault is determined. If it is determined that it is not a three-phase balanced fault, negative sequence phasors are used for the estimation of the distance to fault. On the other hand, if it is a three-phase balanced fault, the incremental positive sequence phasors are used.

The invention belongs to the structural health monitoring field and relates to a system monitoring whether a pipeline leaks or is blocked or not in real time. An intelligent monitoring system comprises pipeline state monitoring devices, signal acquisition modules, signal transmission modules, power supply modules and data analysis display modules, wherein sensors in the pipeline state monitoring devices are buried in the inner walls of the monitoring devices, and three or more pipeline monitoring systems are buried in the pipelines between pump stations and used for monitoring the pressure of fluid conveyed by the pipelines to the pipeline walls, the fluid temperature and the flow state in real time. An information analysis system carries out analysis operation according to acquired sensor signals, judges whether the signals are abnormal or not, judges whether leakage or blockage occurs in the pipelines or not, and feeds analysis results and warning information to monitoring personnel of the pump stations, thereby achieving intelligent monitoring of pipeline health states, positioning breakdown areas more quickly and more accurately and realizing precise maintenance.

The invention relates to a fault positioning method for power system automation, and especially relates to an area power network fault positioning method based on an optimal wave velocity. The method, based on a genetic algorithm and a signal spectrum analysis, carries out fault positioning by use of branch line refracted waves correlated with fault lines in a power network. The method comprises the following steps: (1), analyzing a power grid structure and carrying out data pairing; (2), constructing a target function, and generating variable constraining conditions; (3), carrying out the signal spectrum analysis on the branch line refracted waves, and determining frequency components of signals and a frequency correction coefficient scope; (4), solving an optimal solution of the target function by use of the genetic algorithm to obtain the optimal wave velocity; and (5), according to the optimal wave velocity, obtaining a fault point position and outputting a result. The method provided by the invention takes the influences of the frequency and the path of each branch line into full consideration, and compared to a conventional area power network fault positioning algorithm, obviously improves the precision.

The invention discloses a double-circuit on the same tower double-circuit line fault distance measurement method which includes the following steps: (S1) using double-circuit three-phase transient currents which are obtained by sampling as original current signals for denoising; (S2) conducting six-phase phase-mode transformation to denoised current processing signals and extracting one mode of components to be used as fault analysis signals; (S3) conducting matching pursuit to the fault analysis signals which are obtained by applying a matching pursuit algorithm by using pulse signal atoms, comparing peak time of three optimum matching pulse atom signals with the largest energy, and taking the time which reaches a peak value at the earliest to be used as the time when a traveling-wave head reaches a measurement point; and (4) calculating and obtaining the distances respectively from measurement points at two ends and a fault point according to the obtained time during which the traveling-wave head can reach the measurement points at the two ends. By means of the double-circuit on the same tower double-circuit line fault distance measurement method, the characteristics of the traveling-wave head can be extracted accurately and reliably, and precision and reliability are achieved in the double-circuit on the same tower double-circuit line fault distance measurement.

The invention discloses a mixed modulus time domain fault positioning method for an identical-tower double-loop direct current line. The method comprises the following steps that 1, a phase-mode transformation matrix is constructed through an impedance matrix and an admittance matrix, and a voltage decoupling matrix and a current decoupling matrix are built; 2, according to the obtained voltage decoupling matrix and the current decoupling matrix, the voltage and the current obtained at the two ends of the line are subjected to decoupling conversion, each modulus voltage and modulus current of the identical-tower double-loop direct current line are worked out, and the line modulus voltage component and the line modulus current component are extracted; 3, the way-side voltage distribution at the two ends of the line is calculated; 4, the fault positioning criterion based on the mixed modulus is constructed. The mixed modulus time domain fault positioning method has the advantages that the fault positioning precision is high, the reliability is high, the calculation quantity is small, the realization is easy, and the like.

The present invention discloses an electric railway AT traction network fault positioning method, and relates to the electric railway traction power supply technology field. The electric railway AT traction network fault positioning method can automatically determine the fault types and the fault positions, and the principle of the method comprises the steps of separately hypothesizing that the short circuit faults happen between an overhead line system T and a steel rail R and between a positive feeder line F and the steel rail R, and according to a calculation model of an AT traction network, taking the minimum error of the theoretical value and the actual value of the AT suck current distribution as an optimization target to optimize; comparing the current distribution error minimum values on the two short circuit fault conditions, and defining the fault type corresponding to the smaller numerical value as the fault type of the faults this time and the corresponding positions as the fault positions of the faults this time. Compared with an AT suck current, the method enables the fault positioning errors brought by the AT suck current errors at the two ends of a fault section tobe reduced, is simple in structure and less in investment, is convenient to construct, can be used for the new line construction, and is also suitable for the old line reconstruction.

The invention discloses a power distribution grid fault positioning method with high precision and low cost. According to the fault positioning method, a small amount of traveling wave detection devices with GPS time comparison functions are mounted at two ends of different overhead lines and cable lines of a power distribution grid; when the power distribution grid has faults, the wave speeds of traveling wave line mode component and floor mold component in different lines are calculated by using detection devices of a non-fault line, subsequently the distance of a fault point to one detection device is calculated according to the time difference of the traveling wave line mode component and the floor mold component reaching the detection device, and finally the position of the fault point is confirmed according to the ranging result of a plurality of detection devices. The power distribution grid fault positioning method can achieve accurate fault positioning, shortens the time for troubleshooting, improves the power supply reliability, is small in mounting equipment quantity and good in economy, and has very good practicability.

The invention provides an asset positioning method and system. The asset positioning method includes the steps that collection points are arranged on an equipment cabinet per U unit, and all the collection points are provided with asset collection sensors; asset equipment is bound to serial numbers of asset labels attached to the asset equipment in an adhesive mode; the asset collection sensors are connected with the asset labels, and physical connection states of the asset equipment are obtained; the physical connection states of the asset equipment are transmitted to a server and are matched with the network connection states of the asset equipment, and asset positioning is achieved. The positioning system comprises the equipment cabinet, the asset collection sensors and the asset labels. The asset collection sensors are arranged on the collection points, and the asset collection sensors are connected with the asset labels. By means of the asset positioning method and system, the spatial utilization rate of a data center is increased, and using of free space is improved; the failure positioning accuracy of IT equipment of the data center is improved, and the time spent in failure positioning is lowered; the risks brought in the data center change process are lowered.

The invention provides a fault detection method and apparatus. The method comprises the steps of obtaining a physical Rank address corresponding to Rank where a to-be-detected circuit is; converting the physical Rank address into a system physical address; writing data into the system physical address and reading the data from the system physical address; and by utilizing the data written in the system physical address and the data read from the system physical address, determining whether the to-be-detected circuit has a fault or not. Through the technical scheme provided by the invention, a central processor can detect whether faults such as a short circuit, an open circuit, fixed logic and the like exist or not by adopting a walking method, higher fault positioning precision is provided, and the fault detection time is shortened.

A single / double-circuit power-transmission-line whole-line high-precision fault range finding method is disclosed. Range finding precision of many existing range finding schemes of a general long-distance power transmission line middle section fault is not easy to control because the fault is far away from a measurement apparatus and there are a plurality of range finding influence factors. In the invention, through listing a two-end calculation voltage amplitude ratio under a fault line equivalence network, a proportion function of a distance from a fault point to a line end in a whole length of the line is derived so as to realize accurate range finding to the power transmission line fault. In addition, in order to widen an application scope of the fault range finding method, through considering electrical characteristic differences of a double-circuit line and a single-circuit line, according to a network structure characteristic of a double-circuit power transmission line, and from an aspect of equivalent transformation, a terminal voltage amplitude comparison range finding method adapting to the double-circuit power transmission line is provided. By using the method, range finding operation is simple; a range finding result is not influenced by a transition impedance; a whole line range finding precision is high and a suitable scope is wide. A problem that power transmission line middle section range finding precision is poor can be well solved.

The invention provides a hierarchical location method for locating the fault of an active power distribution network by utilizing multi-source data. The method comprises two levels of initial region layer positioning and accurate line layer positioning. According to the method, firstly, the information of a circuit breaker, a section switch and an interconnection switch monitoring terminal FTU, which is uploaded at a fault moment, is comprehensively utilized. The information is subjected to fault section area layer positioning, and then a line layer is positioned in the determined range of a fault section. The calculation is carried out by utilizing the electric quantity information of nodes at the two ends of the fault section and then an accurate fault position is obtained. The result ofthe verification shows that, the method is not influenced by the fault type and the position, and the fault positioning is rapidly realized. The adopted fault positioning principle is simple and reliable. The method is strong in anti-transition resistance capability and the sampling frequency requirement of the method is not high. Meanwhile, the fault positioning precision can be improved by increasing the sampling frequency, so that the method has higher practical application value.

The invention discloses a time-domain fault range finding method for a co-tower double-loop DC power transmission line based on the single-loop electrical quantity. The method comprises the following steps that an impedance matrix and an admittance matrix are extracted; 2) a voltage decoupling matrix and a current decoupling matrix are obtained; 3) a single-loop voltage phase-mode transformation matrix from which a ground mode component is eliminated is constructed according to the obtained voltage decoupling matrix, and a single-loop voltage differential-mode component from which the ground mode component is eliminated is obtained; 4) a single-loop current phase-mode transformation matrix from which the ground mode component is eliminated is constructed according to the obtained current decoupling matrix, and a single-loop current differential-mode component from which the ground mode component is eliminated is obtained; 5) a most prominent component is selected according to distribution characteristics of different modulus in different pole wire faults, and modulus parameters corresponding to the modulus are selected; 6) voltage distribution along the line is calculated; 7) a fault positioning criterion based on mixed modulus is calculated; 8) fault time is calculated; and 9) a redundant data window is selected. The time-domain fault range finding method has advantages including that the calculating precision and the reliability are high, the needed data time window is short and realization is easy.

The invention discloses a method and device for managing sensors. The method comprises the steps that storage lists of various states in a BMC store sensor identifications of corresponding states, and when a user has access to the sensor identifications stored in the BMC, if the state corresponding to the accessed sensor identification is an activated state, a page table comprising the accessed sensor identification is changed into a preferred state from the activated state. By means of the technical scheme, the sensors are classified according to the states corresponding to the sensors, the sensor identifications of different states are stored in the different storage lists, and due to the fact that all page tables in the storage lists can store not more than 255 sensor identifications, the number of the sensors managed by the BMC does not need to be limited, the corresponding sensors can be allocated for each module to be monitored, the managing granularity of the sensors is guaranteed, and the fault positioning precision is effectively improved.

The invention discloses a method utilizing lumped parameters to realize line interphase fault single-terminal location. According to the method, the lumped parameters are adopted to describe the physical properties of voltage and current transmission of a transmission line; the fault interphase negative sequence current phase angle of a relay location of the transmission line is adopted to calculate the voltage phase angle of an interphase short circuit fault point; and the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the interphase short circuit fault point and the fault location. According to the invention, as the fault location is calculated according to the linear relationship between the voltage drop from the relay location of the transmission line to the interphase short circuit fault point and the fault location, the influences of the transitional resistance and the load current to the location precision are avoided, the location precision is high, the location principle is simple and the practicability is strong. The method can directly calculate the fault distance without adopting the search algorithm, and is high in location speed and strong in real-time performance.

The invention discloses a power distribution network fault locating method based on incomplete marketing and distribution information fusion, comprising dividing all power supply users of a distribution network into a plurality of power supply regions, and reading alarm information; layering devices in dependence on the alarm device in each power supply link and the alarm information; reading a first fault maintenance telephone call message as a current fault maintenance telephone call; finding a power supply link corresponding with the current fault maintenance telephone call, and calculating the fault membership degree of each layer of devices in handling the current fault maintenance telephone call; calculating the final fault membership degree of each device after handling the current fault maintenance telephone call; and determining the fault section of a current power supply link in dependence on the final fault membership degree of each device. The power distribution network fault locating method meets the fault locating requirements of fault tolerance and rapidity, and has the advantages of high fault locating accuracy, sound fault tolerance, and fast positioning speed.

The invention discloses a direct current system line fault positioning method. The method includes steps: firstly, deducing a voltage and current transient characteristic equation of lines with different fault types based on a VSC direct current system, and calculating a current differential initial value during the fault; performing fault discrimination by employing catastrophes of a positive electrode and a negative electrode in different fault types, and determining the fault type and the fault electrode after occurrence of the fault; then calculating a post-fault current and voltage characteristic equation, and calculating the transition resistance of a fault circuit; and finally deducing a fault positioning value by employing the current differential initial value during the fault, and realizing accuracy positioning of the line faults. According to the method, the fault positioning precision is high for a direct current system with high transition resistance and long distance, and the method can be applied to single-end radiation type direct current distribution networks, marine direct current distribution systems, and direct current systems whose transmission power is disperse, small, and random.

The invention discloses a DC single-ended fault positioning system and a DC single-ended fault positioning method based on active detection. The DC single-ended fault positioning method comprises thesteps of: determining a fault ride-through strategy of a converter, and enabling an MMC system to detect the change of a direct voltage or a direct current when a DC line fails; injecting an active detection signal, and discriminating faults through active fault control and disturbance application; filtering fault information, and processing the fault information by considering the coupling influence between positive and negative direct-current lines; and realizing fault positioning by using a least square method and a data sliding window method according to the voltage and current informationof a set point. The DC single-ended fault positioning system and the DC single-ended fault positioning method can precisely identify the fault region, are suitable for long DC lines, are not affectedby transition resistance, have low requirements for the sampling rate, and have relatively high reliability and precision in fault positioning.

The invention discloses a frequency domain method for double-end traveling wave fault location of a power transmission line, which comprises the following steps of: 1) when the power transmission linehas a fault, detecting and recording three-phase fault transient current by measuring elements at two ends of the line through a full-cycle method; 2) obtaining a current line mode component and a ground mode component by utilizing Karenbayer transformation; and 3) wavelet packet transformation is performed on the traveling wave line mode and ground mode components, the frequency band where the natural frequency is located is determined through the wavelet coefficient energy maximization principle, the line mode and ground mode natural frequency is calculated, and a distance measurement formula is constructed to calculate the fault distance. According to the method, wave velocity information and data synchronization are not needed, the problem that reflection of a time domain wave head isnot easy to extract is avoided, the error influence caused by uncertain parameters is reduced, a large number of experimental simulations show that the distance measurement precision based on the traveling wave natural frequency can be effectively improved, and therefore the fault positioning precision of the power transmission line is effectively improved.

The invention relates to an on-line fault distance measurement method for a high-voltage cable, and the method comprises the steps: (1) collecting transient traveling wave current signals at the head and tail ends of a cable; (2) enabling the current signals obtained at step (1) to be converted into independent analog current signals i1-i6 through phase-mode transformation; (3) selecting the analog current signal i4 at step (2) for wavelet packet decomposition, solving an energy ratio of all frequency bands through employing a wavelet packet decomposition coefficient, then extracting the frequency band with the high energy ratio, and reconfiguring a transient traveling wave; (4) carrying out the wavelet analysis of the configured transient traveling wave at step (3), and determining the time t1 and T1 when the configured transient traveling wave arrives at the head and tail ends of the cable; (5) judging a fault region according to the time t1 and T1 at step (4), and solving a geographic distance from a fault point to the head end of the cable. Compared with the prior art, the method is high in distance measurement precision, and is few in interference.

The invention discloses a distance measurement method for a transmission line fault based on the TT transform and the wave velocity optimization. The method is characterized by comprising the following steps of: 1) extraction of fault signals; 2) signal decoupling; 3) detection of mutation points of a traveling wave in a fault 1 mode; 4) optimization of a wave velocity; 5) determination of a faultsection; 6) distance measurement for faults. According to the distance measurement method for the transmission line fault based on the TT transform and the wave velocity optimization, the method canimproves the detection precision of the mutation points of the traveling wave, thereby improving the precision of the distance measurement for the transmission line fault; and the application range iswide.

The invention discloses a power distribution network fault intelligent searching and positioning method based on multi-source data fusion, and relates to the field of the power distribution network fault diagnosis. The method comprises the following steps: determining a fault occurrence high-probability region, establishing a fault data matrix related to the fault occurrence high-probability region and a network topological node according to the multi-source data of the power distribution network for fault region positioning; constructing a fault description matrix by utilizing the uploaded information of monitoring terminals of a circuit breaker, a section switch and an interconnection switch at the fault moment by the fault data matrix, then performing fault region layer positioning; performing line layer positioning in the determined fault section range, and calculating by utilizing electric quantity information of the nodes at two ends of the fault section, thereby obtaining the precise fault location. Under the support of a judgment result of the region layer, the precise positioning of the fault can be quickly realized, the adopted fault positioning principle is simple and reliable, and the strong anti-transition resistance capacity is provided; a sampling frequency requirement is low, and the fault positioning precision can be improved by improving the sampling frequency.

The invention relates to a dynamic-real-time-parameter-based along-line voltage cross correction fault ranging method of a T type line. On the basis of electrical information of a T type line under the normal operating condition, real-time parameters of three-terminal lines are calculated dynamically in real time and calculation errors of the real-time parameters of the lines are corrected based on a genetic algorithm; after a fault occurs at one line, voltages of T nodes are calculated respectively based on a line distribution parameter line model under the modified parameters and a fault branch is determined by voltage comparison; two non-fault branches are equivalent to T terminals and form, together with one end of the fault branch, a two-terminal power transmission line model; and then two straight lines are formed by measuring voltages at two sides and calculating opposite-side voltages and an intersection point is calculated based on intersection of the straight lines, so that afault ranging method is formed. Therefore, the line parameter error can be adjusted dynamically in real time; the fault ranging precision is improved; and the engineering practicability is high.

The present invention discloses an overhead contact system single-ended traveling wave fault positioning device, and relates to an overhead contact system fault positioning technology. The overhead contact system single-ended traveling wave fault positioning device is equipped with an overhead contact system access current, an overhead contact system access voltage, a backflow perfect information data acquisition unit, an event trigger fault information preserving unit, a short circuit fault identification unit, a short circuit fault positioning unit and a fault display and alarm unit. A current transformer and a voltage transformer are accessed in a connection line of a traction station and an overhead contact system, and by real-timely detecting and analyzing the instantaneous waveforms of a current and a voltage, the fault types are identified, and the fault occurrence places are determined. The overhead contact system single-ended traveling wave fault positioning device of the present invention is used for the electrified railway overhead contact system short circuit fault positioning, and has the characteristics of simple structure, high precision and reliability and few investment.

The invention discloses an integrated transmission line protection and traveling wave distance measurement method. Through a protection DSP unit starting criterion and traveling wave DSP unit starting combination, the frequent false starting of traveling wave distance measurement is effectively reduced, through dividing a high speed cache unit into four cache sub units to store traveling wave distance measurement data in a circulated way and timely storing the traveling wave distance measurement data of each time to a data storage device, thus the multiple times of traveling wave distance measurement data with near initiation intervals are not covered, a problem of data coverage or loss caused by frequent starting is effectively solved, through a mode of setting two types of extraction sampling units, the precision of protecting DSP sampling is improved, the fault distance measurement precision of a transmission line is improved, at the same time station resources are saved, and the method has a good application prospect.

The invention provides a fault monitoring system for a railway signal machine, and relates to the technical field of railway signals. The fault monitoring system comprises an intelligent lighting unitand a machine room terminal; one end of the intelligent lighting unit is connected with a dual-filament bulb of the railway signal machine, and the other end of the intelligent lighting unit is connected with the machine room terminal through a power supply cable line of the railway signal machine; the intelligent lighting unit comprises a filament conversion relay, a signal transformer, a load switching relay and a resistive load; and the machine room terminal determines whether the railway signal machine is faulted or not by monitoring the current change on the power supply cable line and gives an alarm. Compared with the prior art, a special alarm line does not need to be laid on a railway site, fault positioning and alarming functions of the railway signal machine can be realized by using the existing power supply cable line, the construction complexity is lowered, the cost is saved, and the fault positioning precision is improved.