CN108562782B - Stray current acquisition method and stray current detection system - Google Patents
Stray current acquisition method and stray current detection system Download PDFInfo
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Abstract
The invention discloses a stray current acquisition method and a stray current detection system, which comprise the following steps of 1: collecting detection data of each stray current detection device; step 2: calculating the polarization potential of the stray current detection device and carrying out normalization processing to obtain a reduced polarization potential; and step 3: calculating the track potential of the stray current detection device, and calculating the track current of the stray current detection device; and 4, step 4: acquiring the traction current of the current train, and calculating the stray current of the stray current detection device; and 5: acquiring the running environment of the current train and constructing a fitting data set; step 6: and performing one-dimensional polynomial curve fitting on the data in each fitting data set by adopting a least square method to obtain a distribution function of the stray current. The invention provides a method for acquiring stray current in a power supply interval at the current moment, which can acquire specific numerical values and can monitor the stray current more timely and effectively.
Description
Technical Field
The invention belongs to the technical field of rail transit, and particularly relates to a stray current acquisition method and a stray current detection system.
Background
Urban rail transit plays a great economic and social role in solving the traffic problem of large and medium cities. However, rail transit brings convenience to people's life, and meanwhile, some problems which cannot be ignored occur, because subway rails are difficult to completely insulate the ground, a part of current leaks to the underground through the rails, and the part of current is called stray current or stray current. Stray current is distributed in each region extended by a subway line, the stray current not only causes serious electrochemical corrosion to metal components and buildings under the ground of an urban rail system (the metal weight loss caused by the stray current 1A in one year can reach 9.13kg), for example, the gas leakage accident caused by the corrosion perforation of a gas pipeline caused by the stray current of the subway in hong Kong, and the corrosion perforation of water pipes near Beijing and Tianjin subways often occur; meanwhile, the method can also have extremely adverse effects on the surrounding power grid, for example, stray current causes a power transformer to generate direct current magnetic bias, which leads to serious consequences such as increase of running noise of the transformer, increase of system harmonic waves, misoperation of relay protection and the like.
The stray current of the existing subway is monitored by a system for monitoring the polarization potential, and the size of the stray current is indirectly considered. The long-acting reference electrode is used as a measuring sensor to measure the potential difference between the surface of the metal pipeline and the reference electrode, namely the reference potential. Under the condition of no stray current disturbance, the measured potential distribution presents a stable value, and the stable potential is the natural body potential. The buried metal structure is affected by stray current interference, and compared with the voltage of a reference electrode, namely the reference potential, the buried metal structure can deviate from the natural body potential. The average value of the offset natural body potential in a certain time is measured and calculated to be the polarization potential. The track potential is the voltage measured between the track and the side wall structural steel. Subway stray current corrosion protection technical regulation CJJ49-1992 specifies: for the steel bars of the main structure of the reinforced concrete subway, the forward offset of the polarization potential should not exceed 0.5V of dangerous voltage. However, for field applications, the skilled person indicates that the polarisation potential should preferably not exceed 0.3V. Therefore, the existing polarization potential monitoring method for reflecting the distribution condition of the stray current cannot know the specific value of the distribution of the stray current in the interval, is difficult to estimate the corrosion condition of the buried metal at the critical dangerous voltage for a long time, and has potential safety hazard; meanwhile, as the polarization potential is the offset obtained for different reference electrodes, the diversity presented by the polarization potential is difficult to establish direct numerical relation with the corrosion characteristic quantity and the transformer direct-current magnetic bias characteristic quantity.
To sum up, subway stray current aggravates to burying ground metallic corrosion, electric wire netting's influence on every side day, and prior art can only indirectly reflect stray current distribution, can't directly calculate stray current numerical value, leads to unable timely effectual realization stray current's protection and monitoring.
Disclosure of Invention
The invention aims to provide a stray current acquisition method and a stray current detection system, which convert the traditional monitoring method of indirectly reflecting the distribution of stray current by polarization potential into directly calculating the value of the stray current and have guiding significance for quantitatively analyzing and predicting the corrosion of buried metal and evaluating the influence degree of a surrounding power grid.
In one aspect, the present invention provides a method for obtaining a stray current, including the following steps:
step 1: collecting detection data of a stray current detection device in a power supply interval of a train traction substation;
the stray current detection device is arranged in the power supply interval, and detection data of each stray current detection device comprises a natural body potential, a reference potential and a track structure potential;
step 2: calculating the polarization potential of the stray current detection device, and performing normalization processing on each polarization potential to obtain a reduced polarization potential;
wherein the polarization potential of each stray current detection device is equal to the difference between the reference potential and the natural body potential of the same stray current detection device;
and step 3: calculating the track potential of the stray current detection device, and calculating the track current corresponding to the stray current detection device based on ohm's law and the track potential;
the track potential of each stray current detection device is equal to the sum of the track structure potential and the reduced polarization potential of the same stray current detection device;
the stray current detection device for calculating the track current is a non-last stray current detection device in the power supply interval;
and 4, step 4: acquiring the traction current of the current train, and calculating the stray current corresponding to the stray current detection device;
wherein, the stray current corresponding to the stray current detection device is equal to the difference between the traction current and the track current corresponding to the same stray current detection device;
and 5: acquiring the current running environment of the train, and constructing a fitting data set based on the current running environment, the stray current corresponding to the stray current detection device obtained in the step 4 and the track position coordinates corresponding to the stray current detection device;
taking the stray current detection device which calculates the stray current in the step 4 as a fitting sampling point, wherein the fitting data set consists of track position coordinates of the fitting sampling point and the corresponding stray current;
the operation environments are divided into single-end power supply supplied by a single traction substation and double-end power supply supplied by two traction substations, and if the current operation environment is single-end power supply, a fitting data set is constructed in the step 5; if the double-end power supply is carried out, step 5 is carried out to construct two fitting data sets, and fitting sampling points in the two fitting data sets are set as boundary points by the position of the current train;
step 6: performing one-dimensional polynomial curve fitting on the data in each fitting data set by adopting a least square method to obtain a distribution function of the stray current;
the stray current of the stray current detection device is obtained by calculating and processing detection data of the existing stray current detection device, then fitting is carried out by utilizing a fitting data set formed by the stray current of the stray current detection device and track position coordinates to obtain a function with the track position as an independent variable and the stray current fitting value as a dependent variable, so that a calculation formula of the stray current at the current moment is obtained, namely if the stray current at any track position is to be obtained, the track position coordinates to be obtained are substituted into a distribution function of the stray current to obtain the stray current fitting value, and the stray current fitting value is used as the stray current at the track position to be obtained. Meanwhile, the method considers the difference of stray current distribution under single-end power supply and double-end power supply, adds the characteristics of the stray current distribution under the single-end power supply and the double-end power supply into the fitting process, and improves the reliability of the fitting result. Wherein, the stray current distribution characteristic that single-ended power supply corresponds is: the stray current is distributed in a parabola shape, and the zero crossing point is the position of a traction substation and the position of a train; the stray current distribution characteristics corresponding to the double-end power supply are as follows: stray current is distributed in two continuous parabolas, zero crossing points are two traction substation positions and train positions, therefore, only one fitting data set is obtained under single-ended power supply, a one-dimensional polynomial curve is obtained through fitting, two fitting data sets are obtained under double-ended power supply, two one-dimensional polynomial curves are obtained through fitting, and the distribution function of the stray current is a piecewise function.
Further preferably, the above further includes screening and processing of abnormal data, and the execution process is as follows:
and 7: calculating a stray current fitting value of the stray current detection device of the stray current obtained in the step 4 according to the distribution function of the stray current obtained in the step 6;
and 8: respectively calculating potential energy of the stray current detection device of the stray current obtained in the step 4, respectively judging whether the potential energy is greater than or equal to 0.02, if the potential energy of the stray current detection device is greater than or equal to 0.02, rejecting data of a fitting sampling point at the stray current detection device, and re-executing the step 6; otherwise, the distribution function of the stray current is a required stray current calculation formula;
the potential energy calculation formula of the stray current detection device is as follows:
in the formula, Ek、
IskRespectively calculating potential energy, a stray current fitting value and a stray current of a kth stray current detection device in the stray current detection device of the stray current in the step 4, wherein S-1 is the number of the stray current detection devices calculating the stray current in the step 4.
According to the method, the abnormal data are screened out and removed, and then are fitted again, so that the reliability of the fitting effect is improved. The existing subway stray current monitoring system mostly adopts distributed sensors, data transmission depends on a test cable, and due to the particularity of the subway environment, the cable is inevitably influenced by factors such as moisture, water seepage, high ground stress action and electromagnetic interference caused by stray current, so that the problems of data loss, data distortion and the like in the data transmission process are easily caused, and therefore the stray current monitoring system can mistakenly send an early warning signal or miss sending the early warning signal. Therefore, the invention reduces the error caused by the difficult avoidance of error data in the prior art.
Further preferably, if the current running environment of the train is single-ended power supply, the fitting sampling point in the fitting data set constructed in the step 5 further comprises a stray current zero crossing point under the single-ended power supply;
the stray current zero crossing point under the single-end power supply is the position of a traction substation and the position of a train;
if the current running environment of the train is double-end power supply, the track position coordinates of the fitting sampling points in the first fitting data set and the second fitting data set in the two fitting data sets are respectively less than or equal to, greater than or equal to the track position coordinates of the train;
wherein, the fitting sampling point in the first fitting data set is a stray current zero crossing point of which the track position coordinate is less than or equal to the train track position coordinate under double-end power supply, and the track position coordinate in the stray current detection device for calculating the stray current in the step 4 is less than or equal to the stray current detection device of which the track position coordinate is less than or equal to the train track position coordinate;
the fitting sampling points in the second fitting data are stray current zero-crossing points of which the track position coordinates are greater than or equal to the train track position coordinates under double-end power supply, and stray current detection devices of which the track position coordinates are greater than or equal to the train track position coordinates in the stray current detection devices for calculating the stray currents in the step 4;
the stray current zero crossing point under double-end power supply is the position of two traction substations and the position of a train.
The zero-crossing point under single-ended power supply and the zero-crossing point under double-ended power supply are added into the fitting data set, so that the reliability of the fitting result can be improved, and the stray current distribution function is more consistent with the theoretical distribution characteristic.
Preferably, if the current running environment of the train is double-end power supply, the track position coordinates of the fitting sampling points in the first fitting data set and the second fitting data set in the two fitting data sets constructed in the step 5 are respectively less than or equal to, greater than or equal to the track position coordinates of the train;
wherein, the fitting sampling point in the first fitting data set is the position of the stray current detection device of which the track position coordinate is less than or equal to the train track position coordinate in the stray current detection device for calculating the stray current in the step 4;
and the fitting sampling point in the second fitting data is the position of the stray current detection device of which the track position coordinate is greater than or equal to the train track position coordinate in the stray current detection device for calculating the stray current in the step 4.
And 6, performing one-dimensional polynomial fitting on the data in each fitting data set by adopting a least square method to obtain a one-dimensional polynomial curve, wherein the fitting process of each one-dimensional polynomial curve is as follows:
first, an intermediate parameter R is calculated by fitting the data in the data set according to the following formula2；
In the formula IsjStray current, x, for the jth fitting sample point in the fitting data setjThe track position coordinate of the jth fitting sampling point in the fitting data set is obtained, M is the number of the fitting sampling points in the fitting data set, a0、a1、anAll coefficients are one-dimensional polynomial curves, and n is a non-negative integer;
if single-ended power supply is available, the value range of the number M of the fitting sampling points is as follows: s-1 is more than or equal to M and is less than or equal to S +1
If the power is supplied from both ends and the fitting data set is a first fitting data set, the value range of the number M is as follows: n is a radical of1≤M≤N1+2；
If the power is supplied from both ends and the fitting data set is a second fitting data set, the value range of the number M is as follows: n is a radical of2≤M≤N2+2；
N1、N2The number of fitting sampling points corresponding to the stray current detection device in the first fitting data set and the second fitting data set respectively supplies power to two ends, and the number is N1、N2The sum of the values is equal to S-1, and S-1 is the number of stray current detection devices for calculating the stray current in the step 4;
then, an intermediate parameter R is calculated2Partial derivatives of the coefficients of the one-dimensional polynomial;
in the formula, aiCoefficients that are one-dimensional polynomial curves;
finally, according to the intermediate parameter R2Calculating all coefficients of the one-dimensional polynomial curve to obtain the one-dimensional polynomial curve of the stray current distribution according to the extreme value condition of partial derivatives of the coefficients of the one-dimensional polynomial;
the extreme conditions are as follows:
the calculation formula for all the coefficients of the one-dimensional polynomial curve is as follows:
according to the method, a one-dimensional polynomial curve is fitted by using least squares, only one fitting data set is provided under single-ended power supply, and then the one-dimensional polynomial curve is fitted; two fitting data sets are provided under double-end power supply, and then two one-dimensional polynomial curves are obtained through fitting, namely, piecewise fitting.
Further preferably, the process of normalizing each polarization potential in step 2 to obtain the reduced polarization potential is as follows:
firstly, selecting one from natural body potentials of all stray current detection devices as a standard natural body potential;
then, calculating the voltage difference between the natural body potential of the stray current detection device of the non-standard natural body potential and the standard natural body potential, and then calculating the reduced polarization potential of the stray current detection device of the non-standard natural body potential; the reduced polarization potential of the stray current detection device of the standard natural body potential is equal to the polarization potential;
the calculation formula of the voltage difference corresponding to the non-standard natural body potential and the reduced polarization potential is as follows:
ΔUbt(k-i)＝Ubtk-UBT
Ujhk'＝Ujhk+ΔUbt(k-i)
in the formula, Δ Ubt(k-i)、UbtkRespectively is the voltage difference between the natural local potential of the kth stray current detection device in the power supply interval and the standard natural body potential, the natural local potential, UBTThe normal body potential is the normal body potential and the natural body potential of the selected i-th stray current detection device;
Ujhk'、Ujhkare respectively the kth spurThe reduced polarization potential and the polarization potential, k and i of the current detection device are positive integers.
Further preferably, the calculation formula for calculating the track current corresponding to the stray current detection device in step 3 is as follows:
in the formula IkA track current U corresponding to the kth stray current detection device in the power supply intervalgg(k+1)、UggkThe track structure potentials of the k +1 th and k-th stray current detection devices, Ujh(k+1)'、Ujhk' reduced polarization potential, R, of the k +1 th and k-th stray current detecting devices, respectivelygIs the track longitudinal resistance, and k is a positive integer.
Preferably, S stray current detection devices are arranged in the power supply interval, and step 3 and step 4 are respectively used for calculating the track current and the stray current corresponding to the first S-1 stray current detection devices in the power supply interval;
wherein S is a positive integer.
On the other hand, the invention provides a stray current detection system, which comprises an upper computer and a stray current detection device which are mutually connected, wherein the stray current detection device is arranged in a power supply interval of a train traction substation, and different stray current detection devices correspond to different positions of a track in the power supply interval;
the stray current detection device is provided with three lead-in wires which are respectively a reference electrode lead-in wire, a structural steel lead-out terminal wire and a track potential measurement lead-in wire; the upper computer fits a stray current distribution function by using detection data acquired by each stray current detection device;
the upper computer is used for calculating the distribution function of the stray current by adopting the method from the step 2 to the step 6 in the claim 1.
The stray current detection device used in the invention is the existing stray current detection device.
Further preferably, the stray current detection devices in the power supply section are distributed at equal intervals.
Advantageous effects
The invention has the advantages that:
1. according to the invention, the stray current corresponding to the stray current detection device is calculated by using the detection data of the stray current detection device, and then the least square method is used for carrying out polynomial fitting on the data of the stray current and the position coordinates to obtain the distribution function of the stray current, the residual error is small, and the calculation result precision is high. Meanwhile, the stray current distribution characteristics under the condition of single-end power supply and double-end power supply are considered in the fitting process, and the reliability of the fitting result is further improved.
2. In view of the fact that polarization potential is offset data recorded aiming at different reference electrodes in an actual field, the polarization potential is reduced into the offset data of the same reference electrode, and the calculation result is more accurate.
3. The invention introduces the potential energy function to calculate the square of the corresponding difference between the data point and the fitting function, can effectively eliminate error points and ensure the accuracy of fitting.
Drawings
FIG. 1 is a schematic diagram of a stray current detection device.
FIG. 2 is a schematic diagram of potential measurement of the stray current detecting apparatus.
Fig. 3 is an equivalent circuit diagram of potential measurement of the stray current detection device during subway operation.
Fig. 4 subway operation traction current curve.
Fig. 5 is a potential measurement equivalent circuit diagram of the stray current detection device during subway operation under single-ended power supply.
FIG. 6 is a potential measurement equivalent circuit diagram of the stray current detection device during subway operation under double-end power supply.
FIG. 7 shows the distribution profile of stray currents in different power supply environments.
FIG. 8 shows the calculated distribution function of the stray current of the present invention (containing erroneous data) with single-ended power supply.
FIG. 9 shows the calculation result of the distribution function of the stray current according to the present invention (eliminating the error data) under single-ended power supply.
Fig. 10 CDEGS simulates single-ended supply stray current distribution results.
FIG. 11 shows the calculated distribution function of the stray current of the present invention with both ends powered.
Fig. 12 CDEGS simulates double-ended supply stray current distribution results.
Fig. 13 is a schematic flow chart of a method for calculating a stray current according to the present invention.
Detailed Description
The present invention will be further described with reference to the following examples.
The invention will be further explained and explained with reference to the drawings. As shown in fig. 13, the stray current obtaining method provided by the present invention includes the following steps:
step 1: and collecting the detection data of each stray current detection device in the power supply interval of the train traction substation.
As shown in fig. 1, a stray current detection device is installed in a power supply section of two traction substations of a subway. The number of the stray current detection devices is determined according to the interval length, if 6 or 8 stray current detection devices are arranged, each stray current detection device is connected through a communication cable, and detection data (natural body potential, reference potential and track potential) are transmitted to an upper computer for background recording and calculation. Wherein, stray current detection device can be evenly distributed in the power supply interval, also can set for according to actual conditions, for example set up multiple spot stray current detection device in the area that humidity is great, underground piping is comparatively dense.
In this embodiment, S stray current detection devices are sequentially arranged in the power supply interval, where detection data of each stray current detection device is applied, that is, the first S-1 stray current detection devices are selected as fitting sampling points in the fitting data set in step 5. In other feasible embodiments, the stray current detection device in the power supply interval can be selected as a fitting sampling point according to actual requirements, and corresponding detection data can be further acquired.
As shown in FIG. 2, the measurement point of the stray current detection device is to embed a long-acting reference electrode on the side wall of the tunnel for measuring the voltage U of the structural steel and the side wall reference electrodecb. Track structure potential UggIs to measure the voltage between the rail and the structural steel. Therefore, 3 lead-in stray current detection devices are provided, namely 1 reference electrode lead-in wire, 1 structural steel lead-out terminal wire and 1 track potential measurement lead-in wire. It will be appreciated that each measurement point of the stray current detection means requires a reference electrode which is long lasting, meaning that it remains potential stable for a long period of time. The stray current detection device can simultaneously measure the instantaneous voltage between the structural steel and the reference electrode, namely the reference potential Ucb(ii) a The instantaneous voltage between the rail and the structural steel is the rail potential UggAnd automatically measuring the natural body potential U of the structural steel when the subway train stops at nightbt. In this embodiment, S stray current detection devices are provided, and the reference potential, the track structure potential, and the natural body potential corresponding to the kth stray current detection device are represented as Ucbk、Uggk、Ubtk。
Step 2: and calculating the polarization potential of each stray current detection device, and performing normalization processing on each polarization potential to obtain a reduced polarization potential.
According to the monitoring data, the upper computer can calculate the polarization potential Ujh. Polarization potential UjhIs a reference potential UcbCompared with the natural body potential UbtBy an amount of voltage offset, i.e. Ujh＝Ucb-UbtFrom this, it can be seen that the polarization potential U of the kth stray current detecting apparatusjhk＝Ucbk-Ubtk。
As shown in fig. 3, an equivalent circuit diagram is made according to the measurement principle of the stray current detection apparatus. Due to the polarization potential U in the actual fieldjhk(k is the sensor number) is the offset data recorded for different reference electrodes, i.e. the referenceThe polarization potential U is different from the potential of the electrodesjhkThe data is arranged into offset data of the same reference electrode, namely different reference electrodes are reduced according to a certain natural body potential. In this embodiment, the natural body potential U of the 1 st stray current detection device is selectedbt1As a standard natural body potential UBT. The reduction principle and the process are as follows:
Ujh1＝Ucb1-Ubt1(1)
Ujh2＝Ucb2-Ubt2(2)
Ujhk＝Ucbk-Ubtk(3)
the reduced polarization potential after reduction is:
Ujh2'＝Ucb2-UBT＝Ucb2-Ubt1(4)
Ujhk'＝Ucbk-UBT＝Ucbk-Ubt1(5)
the sum of formula (1) and formula (2) and the sum of formula (1) and formula (3) can be obtained
Ucb2-Ubt1＝Ubt2-Ucb1+Ujh1+Ujh2＝Ubt2-Ubt1+Ujh2(6)
Ucbk-Ubt1＝Ubtk-Ucb1+Ujh1+Ujhk＝Ubtk-Ubt1+Ujhk(7)
Note delta Ubt(2-1)＝Ubt2-Ubt1，ΔUbt(k-1)＝Ubtk-Ubt1The polarization potential is reduced by the formula
Ujh2'＝Ucb2-Ubt1＝Ujh2+ΔUbt(2-1)(8)
Ujhk'＝Ucbk-Ubt1＝Ujhk+ΔUbt(k-1)(9)
Therefore, the polarization potential U of any stray current detection devicejhkReduced polarization potential U of reduced stray current detection devicejhk' is:
Ujhk'＝Ujhk+ΔUbt(k-i)，ΔUbt(k-i)＝Ubtk-UBT(10)
in other possible embodiments, the natural body potential of any one of the stray current detection devices may be selected as the standard natural body potential UBT。
And step 3: and calculating the track potential corresponding to each stray current detection device, and calculating the track current corresponding to the previous S-1 stray current detection devices based on ohm' S law and the track potential.
And the track potential corresponding to each stray current detection device is equal to the sum of the track structure potential and the reduced polarization potential of the same stray current detection device. The following equation:
Ug1＝Ujh1'+Ugg1(11)
Ugk＝Ujhk'+Uggk(12)
in the formula of Ug1、UgkThe track potentials of the first and kth stray current detection means. The track potential corresponding to each stray current detecting device can be calculated by the above equation 12.
Calculating the track current I based on ohm's lawkThe calculation formula is as follows:
in the formula I1、IkTrack currents, R, corresponding to the first and k-th stray current detecting means, respectivelygIs a track longitudinal resistance. As can be seen from the above equation, the track current corresponding to the kth stray current detection is the ratio of the difference between the track potentials of the kth stray current detection device and the kth +1 th stray current detection device to the track longitudinal resistance. As can be seen from the above formula, S stray current detections are provided in this example in sequenceAnd the device acquires S-1 track current values, and the track current of the last stray current detection device cannot be acquired. It should be understood that if some of the S stray current detection devices are selected as fitting sampling points in other embodiments, the detection data of the next stray current detection device adjacent to each fitting sampling point also needs to be acquired, so that the track current of each fitting sampling point can be calculated.
And 4, step 4: and acquiring the traction current of the current train, and calculating the stray current corresponding to the previous S-1 stray current detection devices.
Wherein, stray current I is calculated according to traction current I measured in real time of the subwayskIs composed of
Is1＝I-I1(15)
Isk＝I-Ik(16)
In the formula Is1、IskThe stray currents corresponding to the first and kth stray current detection means, respectively. The stray current corresponding to the first S-1 stray current detection devices can be calculated according to the above formula 16.
As shown in FIG. 4, the traction current I is determined according to the working condition of the subway, and is divided into IAcceleration，IAt uniform speed，ISpeed reduction. However, the traction currents I corresponding to all the stray current detection devices at the same time are equal, and the same subway train is based on the fact that the traction currents are supplied with power.
In summary, by the methods of the above steps 2 to 4, the stray current is specifically calculated according to the detection data obtained in the step 1. In this embodiment, S stray current detection devices obtain S-1 stray currents Isk(k＝1,2，...，S-1)。
And 5: and (4) acquiring the current running environment of the train, and constructing a fitting data set based on the current running environment, the stray current corresponding to the stray current detection device obtained in the step (4) and the track position coordinates corresponding to the stray current detection device.
Specifically, as shown in fig. 5, the distribution rule of stray current i (x) during subway operation under single-ended power supply is as follows:
in the formula, RgIs a track longitudinal resistance, RsFor the ground transition resistance, L is the distance of the power supply section, and x is the position coordinate of any point on the section track. The function represents that under single-end power supply, stray current distribution is parabolic, and stray current at the positions of a traction substation and a subway train is 0.
As shown in fig. 6, the distribution rule of stray current during subway operation under double-end power supply is as follows:
in the formula, L represents the distance between the subway train and the left traction substation at the current moment, L is the distance of the power supply section, and x is the position coordinate of any point on the section track. Under the characteristic of double-end power supply, the stray current distribution is in two continuous parabolas, and the stray currents at the positions of two traction substations and the position of a subway train are 0. The length of the train is still small compared with the power supply interval, the middle position of the train is selected as the position coordinate point of the train in the embodiment, and other positions of the train can be selected as the position coordinate point in other feasible embodiments. It should be understood that the serial numbers of the stray current detection devices are sequentially overlapped from left to right, and the track position coordinates in the corresponding power supply interval are sequentially increased from left to right.
Based on the above stray current distribution rules under single-ended power supply and double-ended power supply, the fitting data set constructed in step 5 in this embodiment is as follows:
if the current train operation environment is single-ended power supply, the fitting sampling points in the constructed fitting data set comprise stray current zero-crossing points under the single-ended power supply and the stray current detection device for calculating the stray current in step 4Here, that is, the stray current detection device that calculates the stray current in step 4 in this embodiment is the first S-1 stray current detection devices, the stray current zero crossing point under the single-ended power supply is the traction substation position (0,0) and the train position (l,0), and the data of the stray current detection device is (x)k，Isk)(k＝1,2，...，S-1)；
If the current running environment of the train is double-end power supply, the track position coordinates of the fitting sampling points in the first fitting data set and the second fitting data set in the two fitting data sets are respectively less than or equal to, greater than or equal to the track position coordinates of the train;
wherein, the fitting sampling points in the first fitting data set are stray current zero-crossing points under the condition that the track position coordinate is less than or equal to the double-end power supply of the train track position coordinate, and stray current detection devices of which the track position coordinate is less than or equal to the train track position coordinate in the first S-1 stray current detection devices; the zero crossings added to the first fitting data set at this time are (0,0), (l, 0).
The fitting sampling points in the second fitting data are stray current zero-crossing points under the condition that the track position coordinate is larger than or equal to the double-end power supply of the train track position coordinate, and stray current detection devices of which the track position coordinate is larger than or equal to the train track position coordinate in the first S-1 stray current detection devices; the zero crossings added to the second fitting data set at this time are (L,0), (L, 0).
In other possible embodiments, if the number of the stray current detection devices serving as the fitting sampling points is sufficient, the fitting may be performed directly by using only the data of the stray current detection devices, where whether the number is sufficient is determined according to an empirical value or whether the fitting effect meets the requirement after the fitting.
Step 6: and performing one-dimensional polynomial curve fitting on the data in each fitting data set by adopting a least square method to obtain a distribution function of the stray current.
It should be noted that, if the power is supplied at a single end, the data of the fitting data set is fitted by the following steps to obtain a one-dimensional polynomial curve; and if the power is supplied from both ends, fitting the data in the two fitting data sets respectively, and obtaining a one-dimensional polynomial curve correspondingly for each fitting data set. Wherein the fitting process of each one-dimensional polynomial curve is as follows:
a: first, an intermediate parameter R is calculated by fitting the data in the data set according to the following formula2；
In the formula IsjStray current, x, for the jth fitting sample point in the fitting data setjThe track position coordinate of the jth fitting sampling point in the fitting data set is obtained, M is the number of the fitting sampling points in the fitting data set, a0、a1、anAre coefficients of a one-dimensional polynomial curve, and n is a non-negative integer.
Wherein, if single-ended power supply, the value range of M is: m is more than or equal to S-1 and less than or equal to S + 1; in this embodiment, if the track position coordinate corresponding to the stray current detection device does not coincide with the zero crossing point, the number M is S +1, and if there is coincidence, the number M is smaller than S + 1; in other possible embodiments, M equals S-1 if zero crossings are not added to the fit data set.
If the power is supplied by two ends, wherein the value range of the number M in the first data set is as follows: n is a radical of1≤M≤N1+2, the value range of the number M of the second fitting data set is: n is a radical of2≤M≤N2+2，N1、N2The number of fitting sampling points corresponding to the stray current detection device in the first fitting data set and the second fitting data set respectively supplies power to two ends, and the number is N1、N2The sum of which is equal to S-1. Similarly, if the track position coordinate corresponding to the stray current detection device is not coincident with the zero crossing point, then N is added1、N2And 2 is added on the basis.
B: then, an intermediate parameter R is calculated2Partial derivatives of the coefficients of the one-dimensional polynomial;
in the formula, aiFor the fitted curve coefficients, i ═ 0,1, 2.
C: finally, according to the intermediate parameter R2Calculating all coefficients of the one-dimensional polynomial curve to obtain the one-dimensional polynomial curve of the stray current distribution according to the extreme value condition of partial derivatives of the coefficients of the one-dimensional polynomial;
the extreme conditions are as follows:
the linear fit equation from the extreme condition is:
all coefficients of the one-dimensional polynomial curve are calculated to have a coefficient0,a1,...,anThe calculation formula of (a) is as follows:
it should be understood that the distribution function of the stray currents with the coordinate position x of each point of the track as an unknown is a piecewise function in the case of double-ended supply, and a functional expression in the case of single-ended supply. For example, a distribution function of the stray current in single-ended power supply is obtained as follows: i iss(x)＝a0+a1x+a2x2+...+anxn。
And 7: calculating the stray current fitting value at the track position corresponding to the previous S-1 stray current detection devices according to the distribution function of the stray current obtained in the step 6;
and 8: respectively calculating the potential energy of the first S-1 stray current detection devices, respectively judging whether the potential energy is greater than or equal to 0.02, if the potential energy of the stray current detection devices is greater than or equal to 0.02, rejecting the data of the fitting sampling points corresponding to the stray current detection devices, and re-executing the step 6, namely re-fitting until the potential energy is less than 0.02; otherwise, outputting a distribution function of the stray current, wherein the output distribution function of the stray current is the required stray current calculation function;
the potential energy calculation formula of the stray current detection device is as follows:
Ek＝(Is(xk)-Isk)2,k＝1,2，...，S-1
in the formula, EkIs the potential of the kth stray current detection means,
is the stray current fitting value, I, of the kth stray current detection deviceskIs the stray current of the kth stray current detection device.
Simulation and verification
In order to verify the invention, a subway operation model is built in CDEGS software. The CDEGS software can simulate and build metal pipes, closed pipelines, cable systems and various complex soil structures with exposed and externally coated insulating layers, analyze and calculate current distribution and conductor potential distribution in a network topological structure consisting of electrified conductors at any positions on the ground or underground and conductors, and is commonly used for modeling simulation of subway rails and transformer substation grounding grids.
A subway three-dimensional tunnel model is established by using CDEGS software, the operation environment is set to be single-ended power supply, the interval length L is 2km, the injected traction current I is 1000A, and the train operation position L is 2 km. The relevant parameter is set as the soil resistivity ρ0500 Ω · m, longitudinal direction R of the trackg0.03 Ω/km, and the track insulation resistivity ρ 706500 Ω · m. 8 observation points were set in the model, and the monitoring data are shown in Table 1. Due to the particularity of the subway operation environment and the complexity of the operation working condition, data are lost or distorted, and in order to verify the abnormal data screening function of the invention, the detection data of the stray current detection device 5 are artificially set to be wrong.
TABLE 1
| Device number k | Device position xk(m) | Natural body potential Ujh(V) | Polarization potential Ujh(V) | Track structure potential Ugg(V) |
| 1 | 300 | 0.0594 | 0.0098 | 23.79 |
| 2 | 500 | 0.0269 | 0.034 | 17.8 |
| 3 | 600 | 0.1177 | -0.0544 | 11.8 |
| 4 | 650 | -0.2186 | 0.2846 | 5.8 |
| 5 | 1000 | 0.0933 | -0.0289 | -0.19 |
| 6 | 1600 | -0.0467 | 0.1133 | -6.18 |
| 7 | 1850 | 0.1161 | -0.0516 | -12.18 |
| 8 | 1950 | 0.1203 | -0.0567 | -18.18 |
According to the stray current calculation method, the natural body potential of the stray current detection device 1 is selected as the standard natural body potential, and the calculation result is shown in table 2.
TABLE 2
Based on the distribution profile characteristics of the single-end power supply stray current, the stray current I is subjected to least square methodsk( k 1,2, 3.., 7) is subjected to one-dimensional polynomial curve fitting, and data (x) is subjected to one-dimensional polynomial curve fittingk，Isk) Substituting linear fitting equation (21) to obtain coefficient a0＝0.27,a1＝-0.0018,a2＝8.9*10-7The stray current distribution curve is obtained as follows, and the fitting result is shown in fig. 8:
Is(x)＝8.9*10-7*x2-0.0018*x+0.27
introducing potential energy function EkScreening abnormal data, and calculating the square difference between the data points and the fitting function
Respectively is, E1＝0.0081，E2＝0.0000，E3＝0.0016，E4＝0.0019，E5＝0.0441，E6＝0.0002，E70.0185, wherein E5＝0.0441>And 0.02, accurately identifying abnormal data of the stray current detection device 5 and rejecting the abnormal data. Using least square method to the rest data Isk(k ≠ 5) one-dimensional polynomial fitting is performed to the data (x)k，Isk) Substituting linear fitting equation (21) to obtain coefficient a0＝-0.0064,a1＝-0.0011,a2＝5.4*10-7Obtaining the stray current distribution curve as y-5.4 x 10-7*x2-0.0011 x-0.0064. The corresponding difference squared E of the data points and the fitting function is calculated againk＝(Is(xk)-Isk)2Respectively is, E1＝0.0001，E2＝0.0003，E3＝0.0005，E4＝0.0002，E6＝0.0015，E7All satisfy E0.0019k<0.02, the stray current distribution curve y is 5.4 x 10-7*x2The results were found to be-0.0011 × x-0.0064, and the fitting results are shown in fig. 9.
The distribution function of the stray current calculated by the method is compared with a stray current simulation result of a subway tunnel model built by CDEGS software (as shown in FIG. 10, a plurality of curves are provided because a plurality of conductors are placed in the building process of the simulation software, but each curve is not required to be subdivided for solving the distribution situation of the stray current).
In order to verify the present invention, it is,a subway operation model is built in CDEGS software, the operation environment is double-end power supply, the interval length L is 2km, the injected traction current I is 1000A, and the train operation position L is 1.5 km. The relevant parameter is set as the soil resistivity ρ0500 Ω · m, longitudinal direction R of the trackg0.03 Ω/km, and the track insulation resistivity ρ 706500 Ω · m. Observation points were set in the model and the monitoring data are shown in table 3.
TABLE 3
| Device number k | Device position xk(m) | Natural body potential Ujh(V) | Polarization potential Ujh(V) | Track structure potential Ugg(V) |
| 1 | 200 | 0.005 | -0.007 | -10.67 |
| 2 | 400 | -0.167 | 0.1639 | -9.17 |
| 3 | 600 | 0.1235 | -0.1186 | -7.68 |
| 4 | 800 | 0.0641 | -0.0617 | -6.18 |
| 5 | 1000 | -0.164 | 0.0639 | -4.68 |
| 6 | 1600 | 0.0761 | -0.0733 | -0.19 |
| 7 | 1700 | 0.1367 | -0.1242 | -2.44 |
| 8 | 1900 | 0.2001 | -0.1886 | -6.94 |
According to the stray current calculation method, the natural body potential of the stray current detection device 1 is selected as the standard natural body potential, and the calculation result is shown in table 4.
TABLE 4
Based on the distribution profile characteristics of the stray current with double-end power supply, the stray current I is subjected to least square methodsk( k 1,2, 3.., 7) is subjected to one-dimensional polynomial curve fitting, and data (x) is subjected to one-dimensional polynomial curve fittingk，Isk) Substituting linear fitting equation (21) to obtain coefficient, and obtaining stray current distribution curve in a segmented manner
The fitting results are shown in fig. 11.
Introducing potential energy function EkScreening abnormal data, and calculating the square difference between the data points and the fitting function
Respectively is, E1＝0.0000，E2＝0.0002，E3＝0.0004，E4＝0.0008，E5＝0.0012，E6＝0.0000，，E7All satisfy E of 0.0000k<0.02, then stray current distribution curve
The result is obtained.
The calculation result of the method provided by the invention is contrasted with the CDEGS stray current simulation result (as shown in FIG. 12, a plurality of curves are because a plurality of conductors are placed in the simulation software building process, but the stray current distribution situation is solved, so that each curve does not need to be subdivided), and the stray current calculation method provided by the invention has the advantages of high accuracy and higher precision.
It should be emphasized that the examples described herein are illustrative and not restrictive, and thus the invention is not to be limited to the examples described herein, but rather to other embodiments that may be devised by those skilled in the art based on the teachings herein, and that various modifications, alterations, and substitutions are possible without departing from the spirit and scope of the present invention.
Claims (10)
1. A method of obtaining a stray current, comprising: the method comprises the following steps:
step 1: collecting detection data of a stray current detection device in a power supply interval of a train traction substation;
the stray current detection device is arranged in the power supply interval, and detection data of each stray current detection device comprises a natural body potential, a reference potential and a track structure potential;
step 2: calculating the polarization potential of the stray current detection device, and performing normalization processing on each polarization potential to obtain a reduced polarization potential;
the polarization potential of each stray current detection device is equal to the difference between the reference potential and the natural body potential of the same stray current detection device, the reduced polarization potential of the stray current detection device serving as the standard natural body potential is equal to the polarization potential, the reduced polarization potential of the stray current detection device at the non-standard natural local potential is equal to the sum of the voltage difference between the natural body potential and the standard natural body potential and the polarization potential of the same stray current detection device, and the standard natural body potential is the randomly selected natural body potential of one stray current detection device;
and step 3: calculating the track potential of the stray current detection device, and calculating the track current corresponding to the stray current detection device based on ohm's law and the track potential;
the track potential of each stray current detection device is equal to the sum of the track structure potential and the reduced polarization potential of the same stray current detection device;
the stray current detection device for calculating the track current is a non-last stray current detection device in the power supply interval;
and 4, step 4: acquiring the traction current of the current train, and calculating the stray current corresponding to the stray current detection device;
wherein, the stray current corresponding to the stray current detection device is equal to the difference between the traction current and the track current corresponding to the same stray current detection device;
and 5: acquiring the current running environment of the train, and constructing a fitting data set based on the current running environment, the stray current corresponding to the stray current detection device obtained in the step 4 and the track position coordinates corresponding to the stray current detection device;
taking the stray current detection device which calculates the stray current in the step 4 as a fitting sampling point, wherein the fitting data set consists of track position coordinates of the fitting sampling point and the corresponding stray current;
the operation environments are divided into single-end power supply supplied by a single traction substation and double-end power supply supplied by two traction substations, and if the current operation environment is single-end power supply, a fitting data set is constructed in the step 5; if the double-end power supply is carried out, step 5 is carried out to construct two fitting data sets, and fitting sampling points in the two fitting data sets are set as boundary points by the position of the current train;
step 6: performing one-dimensional polynomial curve fitting on the data in each fitting data set by adopting a least square method to obtain a distribution function of the stray current;
the distribution function of the stray current is a function which takes the track position coordinate as an independent variable and takes the stray current fitting value as a dependent variable, and the distribution function of the stray current is a calculation formula of the stray current in the power supply interval at the current moment.
2. The method of claim 1, wherein: the method also comprises screening and processing abnormal data, and the execution process is as follows:
and 7: calculating a stray current fitting value of the stray current detection device of the stray current obtained in the step 4 according to the distribution function of the stray current obtained in the step 6;
and 8: respectively calculating potential energy of the stray current detection device of the stray current obtained in the step 4, respectively judging whether the potential energy is greater than or equal to 0.02, if the potential energy of the stray current detection device is greater than or equal to 0.02, rejecting data of a fitting sampling point at the stray current detection device, and re-executing the step 6; otherwise, the distribution function of the stray current is a required stray current calculation formula;
the potential energy calculation formula of the stray current detection device is as follows:
in the formula, Ek、
IskRespectively calculating potential energy, a stray current fitting value and a stray current of a kth stray current detection device in the stray current detection device of the stray current in the step 4, wherein S-1 is the number of the stray current detection devices calculating the stray current in the step 4.
3. The method of claim 1, wherein: if the current running environment of the train is single-ended power supply, the fitting sampling point in the fitting data set constructed in the step 5 also comprises a stray current zero crossing point under the single-ended power supply;
the stray current zero crossing point under the single-end power supply is the position of a traction substation and the position of a train;
if the current running environment of the train is double-end power supply, the track position coordinates of the fitting sampling points in the first fitting data set and the second fitting data set in the two fitting data sets are respectively less than or equal to, greater than or equal to the track position coordinates of the train;
wherein, the fitting sampling point in the first fitting data set is a stray current zero crossing point of which the track position coordinate is less than or equal to the train track position coordinate under double-end power supply, and the track position coordinate in the stray current detection device for calculating the stray current in the step 4 is less than or equal to the stray current detection device of which the track position coordinate is less than or equal to the train track position coordinate;
the fitting sampling points in the second fitting data are stray current zero-crossing points of which the track position coordinates are greater than or equal to the train track position coordinates under double-end power supply, and stray current detection devices of which the track position coordinates are greater than or equal to the train track position coordinates in the stray current detection devices for calculating the stray currents in the step 4;
the stray current zero crossing point under double-end power supply is the position of two traction substations and the position of a train.
4. The method of claim 1, wherein: if the current running environment of the train is double-end power supply, the track position coordinates of the fitting sampling points in the first fitting data set and the second fitting data set in the two fitting data sets constructed in the step 5 are respectively less than or equal to, greater than or equal to the track position coordinates of the train;
wherein, the fitting sampling point in the first fitting data set is the position of the stray current detection device of which the track position coordinate is less than or equal to the train track position coordinate in the stray current detection device for calculating the stray current in the step 4;
and the fitting sampling point in the second fitting data is the position of the stray current detection device of which the track position coordinate is greater than or equal to the train track position coordinate in the stray current detection device for calculating the stray current in the step 4.
5. The method according to claim 3 or 4, characterized in that: and 6, performing one-dimensional polynomial fitting on the data in each fitting data set by adopting a least square method to respectively obtain a one-dimensional polynomial curve, wherein the fitting process of each one-dimensional polynomial curve is as follows:
first, an intermediate parameter R is calculated by fitting the data in the data set according to the following formula2；
In the formula IsjStray current, x, for the jth fitting sample point in the fitting data setjFor fitting the jth in the data setThe track position coordinates of the fitting sampling points, M is the number of the fitting sampling points in the fitting data set, a0、a1、anAll coefficients are one-dimensional polynomial curves, and n is a non-negative integer;
if single-ended power supply is available, the value range of the number M of the fitting sampling points is as follows: m is more than or equal to S-1 and less than or equal to S + 1;
if the power is supplied from both ends and the fitting data set is a first fitting data set, the value range of the number M is as follows: n is a radical of1≤M≤N1+2；
If the power is supplied from both ends and the fitting data set is a second fitting data set, the value range of the number M is as follows: n is a radical of2≤M≤N2+2；
N1、N2The number of fitting sampling points corresponding to the stray current detection device in the first fitting data set and the second fitting data set respectively supplies power to two ends, and the number is N1、N2The sum of the values is equal to S-1, and S-1 is the number of stray current detection devices for calculating the stray current in the step 4;
then, an intermediate parameter R is calculated2Partial derivatives of the coefficients of the one-dimensional polynomial;
in the formula, aiCoefficients that are one-dimensional polynomial curves;
finally, according to the intermediate parameter R2Calculating all coefficients of the one-dimensional polynomial curve to obtain the one-dimensional polynomial curve of the stray current distribution according to the extreme value condition of partial derivatives of the coefficients of the one-dimensional polynomial;
the extreme conditions are as follows:
the calculation formula for all the coefficients of the one-dimensional polynomial curve is as follows:
6. the method of claim 1, wherein: the process of normalizing each polarization potential in the step 2 to obtain the reduced polarization potential is as follows:
firstly, selecting one from natural body potentials of all stray current detection devices as a standard natural body potential;
then, calculating the voltage difference between the natural body potential of the stray current detection device of the non-standard natural body potential and the standard natural body potential, and then calculating the reduced polarization potential of the stray current detection device of the non-standard natural body potential; the reduced polarization potential of the stray current detection device of the standard natural body potential is equal to the polarization potential;
the calculation formula of the voltage difference corresponding to the non-standard natural body potential and the reduced polarization potential is as follows:
ΔUbt(k-i)＝Ubtk-UBT
Ujhk'＝Ujhk+ΔUbt(k-i)
in the formula, Δ Ubt(k-i)、UbtkRespectively is the voltage difference between the natural local potential of the kth stray current detection device in the power supply interval and the standard natural body potential, the natural local potential, UBTThe normal body potential is the normal body potential and the natural body potential of the selected i-th stray current detection device;
Ujhk'、Ujhkrespectively is the reduced polarization potential and the polarization potential of the kth stray current detection device, and k and i are positive integers.
7. The method of claim 1, wherein: the calculation formula for calculating the track current corresponding to the stray current detection device in step 3 is as follows:
in the formula IkA track current U corresponding to the kth stray current detection device in the power supply intervalgg(k+1)、UggkThe track structure potentials of the k +1 th and k-th stray current detection devices, Ujh(k+1)'、Ujhk' reduced polarization potential, R, of the k +1 th and k-th stray current detecting devices, respectivelygIs the track longitudinal resistance, and k is a positive integer.
8. The method of claim 1, wherein: s stray current detection devices are arranged in the power supply interval, and the step 3 and the step 4 are respectively used for calculating the track current and the stray current corresponding to the first S-1 stray current detection devices in the power supply interval;
wherein S is a positive integer.
9. A stray current detection system, comprising: the system comprises an upper computer and a stray current detection device which are mutually connected, wherein the stray current detection device is arranged in a power supply section of a train traction substation, and different stray current detection devices correspond to different positions of a track in the power supply section;
the stray current detection device is provided with three lead-in wires which are respectively a reference electrode lead-in wire, a structural steel lead-out terminal wire and a track potential measurement lead-in wire; the upper computer fits a stray current distribution function by using detection data acquired by each stray current detection device;
the upper computer is used for calculating the distribution function of the stray current by adopting the method from the step 2 to the step 6 in the claim 1.
10. The detection system of claim 9, wherein: the stray current detection devices in the power supply interval are distributed at equal intervals.
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Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN111324966B (en) * | 2020-03-04 | 2021-03-16 | 西南交通大学 | CDEGS-based urban rail transit stray current simulation calculation method |
| CN112632740B (en) * | 2020-09-30 | 2024-02-13 | 南方电网科学研究院有限责任公司 | Surface potential measurement method based on stray current model |
| CN112230040B (en) * | 2020-10-13 | 2022-05-17 | 广州市扬新技术研究有限责任公司 | Stray current evaluation method for calculating direct current traction power supply system |
| CN112505390B (en) * | 2020-12-17 | 2022-12-16 | 广州市扬新技术研究有限责任公司 | Distributed rail potential and stray current real-time monitoring method |
| CN112904110B (en) * | 2021-01-18 | 2022-08-02 | 中车青岛四方机车车辆股份有限公司 | Rail vehicle electrical performance measuring method |
| CN112989660B (en) * | 2021-03-15 | 2021-09-17 | 广州地铁设计研究院股份有限公司 | Method for predicting corrosion of pipeline under subway stray current based on partial least square method |
| CN114966216B (en) * | 2022-08-01 | 2022-11-29 | 中铁电气化勘测设计研究院有限公司 | Steel rail longitudinal resistance and transition resistance measuring system |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101477146A (en) * | 2009-01-23 | 2009-07-08 | 电子科技大学 | Stray current tester and stray current analysis method |
| CN102175597A (en) * | 2011-01-21 | 2011-09-07 | 中国矿业大学 | On-line monitoring method of metro stray current corrosion on-line monitoring system |
| CN102262173A (en) * | 2011-04-19 | 2011-11-30 | 天津市嘉信技术工程公司 | Method for measuring buried depth of buried pipeline, size and direction of stray current and geomagnetic azimuth angle |
| CN103439562A (en) * | 2013-08-28 | 2013-12-11 | 徐州润泽电气有限公司 | Portable stray current tester |
| US8854070B2 (en) * | 2012-01-26 | 2014-10-07 | General Electric Company | Charging device, detection system, and method of testing a detection system |
| CN204613279U (en) * | 2015-02-26 | 2015-09-02 | 北京煜能电仪自动化技术有限公司 | A kind of stray current comprehensive detection device |
| CN206339595U (en) * | 2016-12-29 | 2017-07-18 | 北京太格时代自动化系统设备有限公司 | Metro stray current composite monitoring device |
| CN107657072A (en) * | 2017-08-02 | 2018-02-02 | 中国电力科学研究院 | Computational methods and device of the buried metal pipeline by DC influence |
| CN107991873A (en) * | 2017-12-11 | 2018-05-04 | 中国矿业大学 | A kind of metro stray current leakage class Forecasting Methodology based on convolutional neural networks and BP neural network |
| CN108120887A (en) * | 2017-11-07 | 2018-06-05 | 北京交通大学 | Flow field simulation system is confused in track traffic |
-
2018
- 2018-07-17 CN CN201810784749.8A patent/CN108562782B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101477146A (en) * | 2009-01-23 | 2009-07-08 | 电子科技大学 | Stray current tester and stray current analysis method |
| CN102175597A (en) * | 2011-01-21 | 2011-09-07 | 中国矿业大学 | On-line monitoring method of metro stray current corrosion on-line monitoring system |
| CN102262173A (en) * | 2011-04-19 | 2011-11-30 | 天津市嘉信技术工程公司 | Method for measuring buried depth of buried pipeline, size and direction of stray current and geomagnetic azimuth angle |
| US8854070B2 (en) * | 2012-01-26 | 2014-10-07 | General Electric Company | Charging device, detection system, and method of testing a detection system |
| CN103439562A (en) * | 2013-08-28 | 2013-12-11 | 徐州润泽电气有限公司 | Portable stray current tester |
| CN204613279U (en) * | 2015-02-26 | 2015-09-02 | 北京煜能电仪自动化技术有限公司 | A kind of stray current comprehensive detection device |
| CN206339595U (en) * | 2016-12-29 | 2017-07-18 | 北京太格时代自动化系统设备有限公司 | Metro stray current composite monitoring device |
| CN107657072A (en) * | 2017-08-02 | 2018-02-02 | 中国电力科学研究院 | Computational methods and device of the buried metal pipeline by DC influence |
| CN108120887A (en) * | 2017-11-07 | 2018-06-05 | 北京交通大学 | Flow field simulation system is confused in track traffic |
| CN107991873A (en) * | 2017-12-11 | 2018-05-04 | 中国矿业大学 | A kind of metro stray current leakage class Forecasting Methodology based on convolutional neural networks and BP neural network |
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