阅读说明：本技术 一种多维度识别电压互感器计量性能在线监测平台 (Multidimensional identification voltage transformer metering performance online monitoring platform ) 是由 陈艳 左淑平 于 2020-05-29 设计创作，主要内容包括：本发明提供一种多维度识别电压互感器计量性能在线监测平台,数据分析处理模块包括相对偏差处理模块、数据离散性处理模块和统计学规律模块；相对偏差处理模块用于通过对数据采集模块采集的信号,采用相对偏差分析方法,计算电压互感器之间运行的最大比值差和最大相位差,当实际采集的电压互感器之间运行的比值差大于最大比值差、且相位差大于最大相位差,则判断计量性能异常；数据离散性处理模块用于采用狄克逊准则进行数据异常化判断；统计学规律模块用于采用正态分布求取置信水平和置信区间的方法,判断计量性能是否异常。本平台采用相对偏差、数据离散性、统计学规律三种计算过程相互独立的数据分析方法,大大提高了计量性能评估的准确性。(The invention provides a multidimensional identification voltage transformer metering performance online monitoring platform.A data analysis processing module comprises a relative deviation processing module, a data discreteness processing module and a statistical rule module; the relative deviation processing module is used for calculating the maximum ratio difference and the maximum phase difference of operation between the voltage transformers by adopting a relative deviation analysis method according to the signals acquired by the data acquisition module, and judging that the metering performance is abnormal when the actually acquired ratio difference of operation between the voltage transformers is greater than the maximum ratio difference and the phase difference is greater than the maximum phase difference; the data discreteness processing module is used for judging data abnormality by adopting a Dixon criterion; the statistical rule module is used for judging whether the metering performance is abnormal or not by adopting a method of solving the confidence level and the confidence interval by normal distribution. The platform adopts a data analysis method with three independent calculation processes of relative deviation, data discreteness and statistical regularity, so that the accuracy of measurement performance evaluation is greatly improved.)

1. The utility model provides a multidimension degree discernment voltage transformer measurement performance on-line monitoring platform which characterized in that: the platform comprises a data acquisition module, a data analysis processing module and a communication module; wherein the content of the first and second substances,

the data acquisition module comprises an analog quantity acquisition module and a digital quantity acquisition module, and the analog quantity acquisition module comprises a voltage sensor and a voltage isolation protection unit and is used for acquiring the amplitude and the phase of the secondary output voltage of the voltage transformer; the digital quantity acquisition module is used for reading a digital signal of the voltage transformer in the whole station from the station control layer, and then unpacking the digital signal to obtain the amplitude, the phase and the frequency of the secondary output voltage of the voltage transformer to be monitored;

the data analysis processing module comprises a relative deviation processing module, a data discreteness processing module and a statistical rule module; the relative deviation processing module is used for calculating the maximum ratio difference and the maximum phase difference of operation between the voltage transformers by adopting a relative deviation analysis method according to the signals acquired by the data acquisition module, and judging that the metering performance is abnormal when the actually acquired ratio difference of operation between the voltage transformers is greater than the maximum ratio difference and the phase difference is greater than the maximum phase difference; the data discreteness processing module is used for judging data abnormality by adopting a Dixon criterion; the statistical rule module is used for judging whether the metering performance is abnormal by adopting a method of solving a confidence level and a confidence interval by normal distribution;

the communication module is used for remotely sending the result processed by the data analysis processing module to the background system.

2. The platform of claim 1, wherein: the data analysis processing module also comprises a data judgment module which is used for summarizing three judgment results of the relative deviation processing module, the data discreteness processing module and the statistical rule module, and judging that the metering performance of the detected voltage transformer is normal when the three judgment results judge that the metering performance is normal; when the three judgment results all judge that the metering performance is abnormal, judging that the metering performance of the detected voltage transformer is abnormal; and other judgment results are continuously observed.

3. The platform of claim 1, wherein: the synchronous signal of the platform adopts GPS time synchronization.

4. The platform of claim 1, wherein: the platform also comprises a local storage and display module which is used for storing and displaying the judgment result of the data separation processing module.

Technical Field

The invention belongs to the technical field of power grid operation and maintenance, and particularly relates to a multidimensional identification voltage transformer metering performance online monitoring platform.

Background

The accuracy of gateway metering is always a weak link of marketing work, the accuracy of gateway metering is directly related to a metering device, the metering device consists of an electric energy meter and a mutual inductor, the stability of the gateway meter and the electromagnetic mutual inductor is high, and the accuracy and the reliability of a capacitance type mutual inductor (CVT) are weak links of the metering device. According to 2015-plus-energy 2018 known data statistics, negative line loss occurs 31 times in a certain 500kV trans-provincial power transmission line, according to on-site power failure maintenance, the electric energy meter is found to be normal, the error of the A-phase CVT in the I loop of the line is + 0.395%, the error exceeds 2 times of the requirement of the 0.2% limit value, and the error of the A-phase CVT and the B-phase CVT in the II loop exceeds the limit value. These practical cases are still very many, and the direct disadvantage is that the loss of electricity charge is huge.

According to the verification regulation of JJG 1021-. However, the number of voltage level transformers of 110kV and above in operation in China exceeds 30 thousands, and except for error characteristic detection in a handover test of a newly built station, most of the voltage transformers cannot be periodically detected according to the rules of jjjg 1021-: 1) the transformer substation has power failure difficulty, and only the insulation performance of the equipment is tested even if a power failure maintenance plan exists; 2) with the improvement of the voltage grade, the volume and the weight of equipment for the measurement performance test of the voltage transformer are increased, and the labor intensity, the implementation cost and the working risk are greatly improved; 3) the power grid extension speed is far higher than the personnel increase speed, so that the working strength of related personnel is continuously increased, and the working mode of the traditional mutual inductor metering performance test is difficult to continuously implement.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the on-line monitoring platform for the metering performance of the multi-dimensional identification voltage transformer is provided, and the metering performance of the voltage transformer can be accurately evaluated.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a multidimension degree discernment voltage transformer measurement performance on-line monitoring platform which characterized in that: the platform comprises a data acquisition module, a data analysis processing module and a communication module; wherein the content of the first and second substances,

the data acquisition module comprises an analog quantity acquisition module and a digital quantity acquisition module, and the analog quantity acquisition module comprises a voltage sensor and a voltage isolation protection unit and is used for acquiring the amplitude and the phase of the secondary output voltage of the voltage transformer; the digital quantity acquisition module is used for reading a digital signal of the voltage transformer in the whole station from the station control layer, and then unpacking the digital signal to obtain the amplitude, the phase and the frequency of the secondary output voltage of the voltage transformer to be monitored;

the data analysis processing module comprises a relative deviation processing module, a data discreteness processing module and a statistical rule module; the relative deviation processing module is used for calculating the maximum ratio difference and the maximum phase difference of operation between the voltage transformers by adopting a relative deviation analysis method according to the signals acquired by the data acquisition module, and judging that the metering performance is abnormal when the actually acquired ratio difference of operation between the voltage transformers is greater than the maximum ratio difference and the phase difference is greater than the maximum phase difference; the data discreteness processing module is used for judging data abnormality by adopting a Dixon criterion; the statistical rule module is used for judging whether the metering performance is abnormal by adopting a method of solving a confidence level and a confidence interval by normal distribution;

the communication module is used for remotely sending the result processed by the data analysis processing module to the background system.

According to the platform, the data analysis processing module further comprises a data judgment module for summarizing three judgment results of the relative deviation processing module, the data discreteness processing module and the statistical rule module, and when the three judgment results all judge that the metering performance is normal, the metering performance of the detected voltage transformer is judged to be normal; when the three judgment results all judge that the metering performance is abnormal, judging that the metering performance of the detected voltage transformer is abnormal; and other judgment results are continuously observed.

According to the platform, the synchronous signal of the platform adopts GPS time synchronization.

According to the platform, the platform also comprises a local storage and display module which is used for storing and displaying the judgment result of the data separation processing module.

The invention has the beneficial effects that: the platform adopts three data analysis methods of relative deviation, data discreteness and statistical regularity, the calculation processes of the three algorithms are mutually independent, each algorithm can independently obtain whether the metering performance of the monitored voltage transformer is abnormal or not, and the accuracy of the metering performance evaluation is greatly improved.

Drawings

Fig. 1 is a schematic structural diagram according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the determination according to an embodiment of the present invention.

Detailed Description

The invention is further illustrated by the following specific examples and figures.

The invention provides a multidimensional identification voltage transformer metering performance online monitoring platform, which comprises a data acquisition module, a data analysis processing module and a communication module, as shown in figure 1.

The data acquisition module comprises an analog quantity acquisition module and a digital quantity acquisition module, and the analog quantity acquisition module comprises a voltage sensor and a voltage isolation protection unit and is used for acquiring the amplitude and the phase of the secondary output voltage of the voltage transformer; the overall accuracy rating is better than 0.01. And the digital quantity acquisition module is used for reading the digital signals of the voltage transformer in the whole station from the station control layer, and then unpacking the digital signals to obtain the amplitude, the phase and the frequency of the secondary output voltage of the voltage transformer to be monitored.

The data analysis processing module comprises a relative deviation processing module, a data discreteness processing module and a statistical law module. As shown in fig. 2, the relative deviation processing module is configured to calculate a maximum ratio difference and a maximum phase difference between the voltage transformers by using a relative deviation analysis method according to the signals acquired by the data acquisition module, and determine that the measurement performance is abnormal when the ratio difference between the voltage transformers that are actually acquired is greater than the maximum ratio difference and the phase difference is greater than the maximum phase difference; the data discreteness processing module is used for judging data abnormality by adopting a Dixon criterion; the statistical rule module is used for judging whether the metering performance is abnormal or not by adopting a method of solving the confidence level and the confidence interval by normal distribution.

The communication module is used for remotely sending the result processed by the data analysis processing module to the background system. The communication module adopts a chip encrypted by national security, and can realize the safe remote transmission of data

The data analysis processing module further comprises a data judgment module which comprises a multi-measurement-result uncertainty analysis function and is used for summarizing three judgment results of the relative deviation processing module, the data discreteness processing module and the statistical rule module, and when the three judgment results judge that the metering performance is normal, the measured voltage transformer is judged to be normal; when the three judgment results all judge that the metering performance is abnormal, judging that the metering performance of the detected voltage transformer is abnormal; and other judgment results are continuously observed.

When the GPS is adopted as the synchronous signal of the platform, the accuracy of the synchronous signal is 1 us.

Still further, the platform further comprises a local storage and display module, which is used for storing and displaying the judgment result of the data separation processing module.

The invention can monitor the metering performance of the running voltage transformer in real time under the uninterrupted state, and realize the accurate judgment of the rapid metering performance; the three data analysis methods of relative deviation, data discreteness and statistical regularity are adopted, the calculation processes of the three algorithms are mutually independent, but the conclusions are mutually restricted, each algorithm can independently obtain whether the metering performance of the monitored voltage transformer is abnormal or not, the weights obtained by each algorithm are the same, and the accuracy of the metering performance judgment is greatly improved; the platform can realize the uncertainty evaluation function of the measured data; the accuracy of the signal acquisition part of the platform is superior to 0.01 level, the signal synchronization adopts a GPS (global positioning system), the accuracy is 1us, and the accuracy of the whole hardware of the platform is superior to 0.05 level.

A multidimensional identification voltage transformer metering performance on-line monitoring platform example:

the method is used for carrying out online monitoring on a 220kV voltage class I mother voltage transformer and a 220kV voltage class II mother voltage transformer in a certain transformer substation. Firstly, finding out the metering windings of the voltage transformers of the I parent and the II parent in a control room of the transformer substation, and connecting the signals of the metering windings of the voltage transformers of the I parent and the II parent into a signal acquisition part of the platform; then, a GPS signal in the transformer substation is connected into the platform, the platform is powered on, the offline data of the monitored voltage transformer is input, an analysis program is started, the platform can automatically acquire the data of the operating voltage transformer in real time, and data analysis, result display and storage are carried out. And if the remote transmission is needed, starting the remote transmission function.

The data analysis portion of the present platform is described below for three data methods.

The first method comprises the following steps: relative deviation of

1. The monitored voltage transformer offline error data were obtained as shown in table 1.

TABLE 1 offline error data of 220kV voltage transformer of certain transformer substation

The ratio difference is: when the transformer offline error detection is carried out, the ratio difference of the detected voltage transformer relative to the standard voltage transformer is obtained. In the off-line error test, the accuracy grade of the adopted standard instrument is higher than the 2 grades of the detected voltage transformer, so that the error of the standard transformer can be ignored and is considered as 0, and the detected data is the error of the detected voltage transformer.

2. The error deviation data obtained by the system in the operation of the two voltage transformers is shown in the table 2.

TABLE 2 electrified error data of 220kV voltage transformer of certain transformer substation

3. And carrying out data analysis. Firstly, the data of the live monitoring system shows that the relative deviation of the two groups of voltage transformers is within +/-0.4% and +/-20', namely, the two groups of transformers have no out-of-tolerance phenomenon. And further analyzing the relative operation stability of the two groups of transformers. The deviations of the two during off-line and on-line are compared to obtain the data in table 3.

TABLE 3 comparison of error relative deviations of voltage transformers

As can be seen from table 3, the relative error between the two voltage transformers in the off-line state is very close to the deviation between the two voltage transformers in the operation, the deviation of the ratio between the two voltage transformers is in ten-thousandth, and the deviation of the phase difference is in individual decimals. According to the maximum operation variation of the voltage transformer in operation in the JJG1021-2007 table 5, it can be known that the maximum operation deviation of two CVTs installed in the same substation is 0.1% and 5.4' when the operating environment temperature is consistent and the operating power supply frequency is consistent, and the data in table 3 is far less than the threshold value, it is determined that the CVT with 220kV voltage class operated in the station has good operation stability and the metering performance is "normal". If the relative operation data of the two voltage transformers is greater than +/-0.4% and +/-20 'or the calculated maximum deviation is greater than 0.1% and 5.4', the metering performance is abnormal. The other data is "warning".

And the second method comprises the following steps: data discreteness

And calculating by taking the amplitude of the running voltage transformer between the same voltage grade and different phase sequences in the transformer substation as an example. The 10 measurement point data for obtaining the amplitude of the mother phase A of the 220kV voltage class I are respectively as follows: 57.68V, 57.69V, 57.68V, 57.70V, 57.71V, 57.68V, 57.69V, 57.70V, 57.68V; the data of 10 measurement points of the B-phase amplitude are respectively: 57.70V, 57.69V, 57.72V, 57.70V, 57.69V, 57.69V, 57.70V, 57.68V; the data of 10 measurement points of the C-phase amplitude are respectively as follows: 57.68V, 57.68V, 57.68V, 57.69V, 57.70V, 57.73V, 57.69V, 57.68V, 57.70V, 57.69V. All the measured values are arranged according to a rule from small to large as follows: x is the number of₁、x₂、┄、x₃₀. Collecting data n as 30 groups, selecting Dixon criterion according to formulaCalculating according to the formula when gamma is_ij＞γ′_ij,γ_ij> D (a, n), then x_nIs an abnormal value when γ is_ij＜γ′_ij,γ′_ij> D (a, n), then x₁Is an abnormal value. Using this criterion, outliers can be removed multiple times, but only one at a time.

After all data are arranged from small to large: 57.68V, 57.68V, 57.68V, 57.68V, 57.68V, 57.68V, 57.68V, 57.68V, 57.68V, 57.69V, 57.69V, 57.69V, 57.69V, 57.69V, 57.69V, 57.69V, 57.69V, 57.70V, 57.71V, 57.72V, 57.73V. n is 30, the significance level a is 0.05, and the critical value D (0.05, 30) is 0.412 by table look-up.

γ₁₁＞γ′₁₁，γ₁₁0.2 < D, so there is no anomaly. And judging whether the monitored data has abnormal values.

And the third is that: statistical law

The data of the voltage transformers in the transformer substation are normally distributed, and the amplitude and the phase positions which are all collected in the transformer substation are used as analysis data to establish a normal distribution curve of the amplitude values and the phase positions. Taking the amplitude as an example, if the normal distribution value is μ ═ 57.70 and σ ═ 0.1, then the probability of P (57.7 < x < 57.75) is calculated.

If the probability that the mean value of the measurement points is (mu-a, mu + a) is not less than 0.95, then a is calculated as:

according to the empirical value of the error offline weekly inspection of the voltage transformer developed on site, the metering performance of the voltage transformer is abnormal with a probability of 10 percent after operation. Then, when the probability of the occurrence of the measurement point X is not more than 10%, that is, the probability of the occurrence is less than 0.1, the measurement performance of the voltage transformer is considered to be "warning", otherwise, the measurement performance is "normal".

The three calculation methods are relatively independent, and when the three calculation results point to a certain voltage transformer, the probability that the metering performance of the voltage transformer is abnormal is high; when only one or two algorithms show that the metering performance of a certain voltage transformer has 'warning' or 'abnormity', the observation is continued; and when all algorithms display that the voltage transformers are normal, the metering performance of the monitored voltage transformer is proved to be normal.

The data analysis processing part in the platform comprises three data analysis methods, namely: the relative deviation is suitable for monitoring the metering performance of the running voltage transformer with the same voltage grade and the same phase sequence in the transformer substation; and the second method comprises the following steps: the data discreteness can monitor the operating voltage transformers with the same voltage grade and the same phase sequence, and also can monitor the metering performance of the operating voltage transformers with the same voltage grade and different phase sequences in a transformer substation; thirdly, the statistical law is applicable to the methods of the same phase sequence of the same voltage grade, the different phase sequences of the same voltage grade and the different phase sequences of different voltage grades and the participation of the total station operation voltage transformer in the calculation;

three algorithms of a data analysis processing part in the platform are relatively independent, a judgment result can be iterated, namely, each voltage transformer obtains a conclusion after passing through three different algorithms, and when the three algorithms all point to the abnormal metering performance of a certain voltage transformer, the abnormal metering performance probability of the voltage transformer is considered to be very high.

The above embodiments are only used for illustrating the design idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention accordingly, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.