Line loss checking analyzer for low-voltage transformer area

Abstract

The invention discloses a line loss checking analyzer for a low-voltage transformer area, which comprises an acquisition module, a metering module and an analysis module, and is characterized in that the acquisition module acquires electrical quantity information of an installation node; the metering module is used for metering electric quantity data of the installation node, including split-phase metering data, and carrying out time freezing; and the analysis module obtains lower-level ammeter data of the acquisition module, and compares, analyzes and calculates the data of the acquisition module to obtain line loss reasons. The application of the system well solves the last kilometer problem of line loss investigation of the low-voltage transformer area, only simple operation of equipment hanging and recovery is needed on site, the line loss reason system automatically judges, a large amount of site investigation work during line loss investigation is overcome, the workload of operators is greatly reduced, manpower and material resources are saved, and the working efficiency is improved. The working efficiency is improved, and the line loss management level is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power monitoring, and particularly relates to a low-voltage substation line loss troubleshooting analyzer. Background Art

[0002] The power loss of the power grid, simply referred to as line loss, is an important comprehensive indicator of power enterprises. It reflects the planning and design, production technology, and operation management level of a power grid, and has been valued by power enterprises at all levels for a long time.

[0003] With the development of the economy and the deepening of power marketization, in order to reduce the operating cost of the power grid, power grid companies have gradually introduced and promoted the assessment indicators for energy conservation and loss reduction, from "simultaneous line loss assessment" to "one index per substation assessment", and from "user information acquisition system" to "State Grid integrated index assessment system", aiming to promote energy conservation and loss reduction work reasonably and efficiently.

[0004] There are many factors affecting the line loss index of the substation. The most common ones are: inaccurate public transformer metering terminals, unreasonable or out-of-tolerance current transformer settings, inaccurate user metering, meter shunt, and pre-metering power consumption, etc.

[0005] Problems with public transformer metering terminals and current transformers belong to upper-layer problems of the substation. There are many methods to find such problems, and the testing methods are relatively simple. Some conventional means can also be used for judgment. For example, a clamp-on ammeter can be used to measure the currents on the primary and secondary sides of the current transformer to determine whether the current transformer ratio is correct and whether it is out of tolerance, and the current on the secondary side of the current transformer can be compared with the indicated current of the public transformer metering terminal to determine whether the public transformer metering terminal is inaccurate.

[0006] Inaccurate user metering, meter shunt, pre-metering power consumption, etc. mostly occur at the end of the substation. However, the power consumption environment at the end of the substation is complex and there are many users. The existing troubleshooting means are roughly divided into 3 types.

[0007] Manpower-intensive approach, using traditional tools to troubleshoot all meters and all lines, with a large workload and poor results.

[0008] Segmented metering, similar to the troubleshooting method of the patent with the publication number "CN112114172A" and the patent name "A low-voltage substation abnormal line loss testing system and method with automatic topology function". This method can narrow the troubleshooting scope to a certain extent, but there is no way to finally locate the line loss point. It can only locate the line loss in a certain branch line, and the specific line loss point still needs to be manually troubleshot.

[0009] With the development of Internet of Things technology and the application of HPLC technology, various software for analyzing line losses using big data have emerged. However, they all boil down to a few common methods. One is to read the power outage events or cover opening records of electricity meters, and use these records to judge possible electricity theft motors and abnormal operations on the meters, marking them as objects for line loss investigation. Another is to use algorithms to compare the electricity consumption of all individual meters in a substation area to find the correlation between the meters and line losses. Meters with a high correlation are marked as objects for line loss investigation, similar to the method in the article numbered "1009 - 1831(2014)02 - 0052 - 03 Using the Pearson correlation coefficient algorithm to find abnormal electricity meter users". In addition to the above methods, there are also methods such as sudden current drop judgment and line loss feature modeling, which are all based on the fuzzy calculation method of the entire substation area. They use a large amount of data, have many similar meters, and the results obtained are not very reliable. On-site, it is still necessary to check each meter one by one and each line one by one. The workload of the staff is still very large. If the problem is not within these similar meters, it will result in ineffective work, wasting time, manpower, and material resources, and it cannot adapt to the unpredictable electricity theft behaviors in complex on-site situations. Summary of the Invention

[0010] To solve the above problems, the present invention provides a low-voltage substation area line loss investigation analyzer, which can quickly, effectively, and accurately judge the reasons for the last-stage line loss in the substation area, solve the problem of the last mile of line loss investigation in the substation area, and the system can judge the specific line loss points, greatly reducing the on-site verification work of the staff.

[0011] The technical solution of the present invention is: a low-voltage substation area line loss investigation analyzer, including a collection module, a metering module, and an analysis module.

[0012] Collection module: Collect the electrical quantity information of the installation node, including data such as the voltage, current, and power factor of each phase.

[0013] Metering module: Meter the electricity quantity data of the installation node, including split-phase metering data, that is, separately meter the electricity quantities of phases A, B, and C, and perform time freezing. The electricity quantity can be frozen in units of minutes, hours, or days. The split-phase electricity quantities can be summarized into the total line electricity quantity at the same time of this node.

[0014] Analysis module: Obtain the electricity meter data at the lower level of the collection module, and analyze it with the data of the collection module to obtain the final line loss point and the reason for the line loss. Here, the frozen electricity quantity data is preferably used as a reference.

[0015] The analysis steps of the analysis module are as follows.

[0016] S1. Piecewise calculation: The analysis module compares the frozen power consumption data of the acquisition module installation nodes measured by the metering module with the aggregated power consumption of the corresponding lower-level electric meters at the same time respectively, and obtains the acquisition modules with end-line losses. That is, the aggregated power consumption of phases A, B, and C at the installation nodes of the acquisition module is compared with the aggregated power consumption of all lower-level electric meters at the same time. If the aggregated power consumption of the acquisition module is not equal to the aggregated power consumption of the lower-level electric meters, it is determined that there is a line loss under this acquisition module.

[0017] S2. Phase-by-phase calculation: The analysis module compares the acquisition modules with end-line losses with the same-phase electric meters at the lower level according to the phase-by-phase frozen power consumption at the same time, and obtains the phases with end-line losses. That is, the frozen power consumption of phase A is compared with the aggregated power consumption of all phase A electric meters under this acquisition module at the same time, the frozen power consumption of phase B is compared with the aggregated power consumption of all phase B electric meters under this acquisition module at the same time, and the frozen power consumption of phase C is compared with the aggregated power consumption of all phase C electric meters under this acquisition module at the same time. The phase with line loss is confirmed through comparison.

[0018] S3. Phase determination calculation: The analysis module analyzes and calculates the frozen power consumption at multiple time points of the phases with end-line losses respectively with each electric meter of the same phase at the lower level according to the frozen power consumption of this phase, and obtains the reasons for end-line losses. That is, assuming that the line loss is under phase C of this acquisition module, then the phase C electric meters under this acquisition module are used to analyze and calculate the frozen power consumption with phase C of the acquisition module at multiple same times to obtain the final line loss point and the reasons for line loss, including meter over-allowance, meter shunt, pre-meter power consumption, etc.

[0019] Furthermore, the low-voltage substation area line loss detection analyzer further includes a cloud platform and a PDA. The cloud platform performs data interaction with the analysis module and the PDA through remote communication.

[0020] Furthermore, the installation nodes of the acquisition module include the main outgoing line, branch lines, and nodes in front of multiple electric meters or centralized meter boxes. The electrical quantity data of the installation nodes are collected phase by phase through current collectors and voltage sampling clamps.

[0021] Furthermore, the metering module is connected to the acquisition module and also connected to the transmission module. The frozen power consumption data of the installation nodes are uploaded to the analysis module through mainstream methods such as carrier communication, small wireless communication, or 4G and 5G. The metering module can be separately connected to the acquisition module and the transmission module. In order to save materials and costs, one metering module can also be connected to multiple acquisition modules for separate metering and then upload data through one transmission module.

[0022] Furthermore, the analysis module is also connected to the communication module and accesses the cloud platform through the communication module to obtain electric meter data, including the phase of the affiliated electric meter, frozen power consumption data, and meter number information.

[0023] Further, the PDA bundles the acquisition module with the subordinate electric meters. The bundling method can be by scanning barcodes or inputting meter numbers. After bundling, the information is uploaded to the cloud platform and then sent by the cloud platform to the analysis module to establish the correspondence between the acquisition module and the electric meters within the analysis module, which is used for sectional differentiation during line loss analysis.

[0024] Section 1 is all the electric meters subordinate to the No. 1 acquisition module, section 2 is all the electric meters subordinate to the No. 2 acquisition module, and so on; during analysis, the No. 1 acquisition module is analyzed corresponding to its subordinate electric meters, the No. 2 acquisition module is analyzed corresponding to its subordinate electric meters, and so on.

[0025] Further, the analysis module also uploads the analysis results to the cloud platform through the communication module. The mainstream communications such as 4G and 5G are preferably used. The cloud platform provides a window for result display and can synchronously send the result information to the PDA for synchronous display.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The present invention first obtains the final line loss area through automatic sectional calculation, secondly obtains the final line loss phase through phase-by-phase calculation, and then obtains the final line loss cause through phase determination calculation. It effectively solves the problems of high investment and low output with a large amount of equipment investment and a large amount of manpower investment in line loss investigation work, the accuracy problem of the results of theoretical analysis, and the ineffective investigation problem caused by analysis errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the system in the present invention.

[0029] Figure 2 It is an application diagram of the system in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] As Figure 1 shown, a low-voltage substation area line loss investigation analyzer includes an acquisition module, a metering module, and an analysis module.

[0031] Acquisition module: It acquires the electrical quantity information of the installation node, including data such as the voltage, current, and power factor of each phase;

[0032] Metering module: According to the data such as voltage, current, and power factor acquired by the acquisition module, it performs the electricity metering of the installation node, including phase-by-phase metering data, that is, separately measures the electricity of phase A, phase B, and phase C, and performs time freezing, which can freeze electricity in units of minutes, hours, and days. The phase-by-phase electricity can be summarized into the total line electricity of the node at the same time, that is, the sum of the electricity of phase A, phase B, and phase C;

[0033] Analysis module: It obtains the electricity meter data at the lower level of the acquisition module by accessing the cloud platform, analyzes it with the data of the acquisition module, and obtains the final line loss points and reasons for line loss. Here, the frozen electricity quantity data is preferably used as a reference.

[0034] The bundling relationship between the acquisition module and its lower-level electricity meters is pre-stored inside the analysis module. The bundling relationship is established by scanning the electricity meter barcode with a PDA or inputting the electricity meter number to bundle the acquisition module with its lower-level electricity meters and uploading them to the cloud platform, and then the cloud platform distributes them to the analysis module. For each bundling relationship, a segment is established. After the segmentation is completed, the analysis of the final-stage line loss is carried out as follows.

[0035] S1. Segment calculation: The analysis module respectively compares the frozen electricity quantity of the acquisition module in each segment with the aggregated electricity quantity of the lower-level electricity meters at the same time. Each segment is calculated to obtain the acquisition modules with final-stage line loss. That is, the aggregated electricity quantity of phases A, B, and C at the installation node of the acquisition module is compared with the aggregated electricity quantity of all the lower-level electricity meters of the acquisition module at the same time. If the aggregated electricity quantity of the acquisition module is not equal to the aggregated electricity quantity of the lower-level electricity meters, it is determined that there is a line loss under the acquisition module.

[0036] S2. Phase-by-phase calculation: The analysis module compares the acquisition modules with final-stage line loss with the electricity meters of the same phase at the lower level according to the phase-by-phase frozen electricity quantity at the same time to obtain the phases with final-stage line loss. That is, the frozen electricity quantity of phase A is compared with the aggregated electricity quantity of all the phase-A electricity meters under the acquisition module at the same time, the frozen electricity quantity of phase B is compared with the aggregated electricity quantity of all the phase-B electricity meters under the acquisition module at the same time, and the frozen electricity quantity of phase C is compared with the aggregated electricity quantity of all the phase-C electricity meters under the acquisition module at the same time. The phases with confirmed line loss are obtained through the comparison.

[0037] S3. Phase determination calculation: The analysis module analyzes and calculates the frozen electricity quantity at multiple time points of the phases with final-stage line loss with each electricity meter of the same phase at the lower level according to the frozen electricity quantity of this phase to obtain the reasons for the final-stage line loss. That is, assuming that the line loss is under phase C of the acquisition module, the phase-C electricity meters under the acquisition module are respectively used to perform multiple frozen electricity quantity analyses and calculations with phase C of the acquisition module at the same time points to obtain the final line loss points and reasons for line loss, including meter over-allowance, meter shunt, electricity consumption before the meter, etc.

[0038] There are many calculation methods for the final reasons for line loss after line loss phase determination. What the present invention claims to protect is the overall system and the design principles of segmentation, phase-by-phase, and phase determination. Therefore, any method for calculating line loss through big data should be applicable to this system. Various methods are not listed one by one here, but in order to more clearly express the feasibility of the present invention, the following calculation methods are exemplified.

[0039]

[0040] Where: x is the user's power consumption; y is the line loss power consumption; t is the same time point; r is the correlation coefficient

[0041] In the calculation, the values of x and y must be based on the same t point. After calculation, the closer the r value is to 1, the higher the correlation. That is, for each electric meter under the line loss of the acquisition module with end-stage line loss, the above formula is respectively substituted for calculation. Taking multiple t points, each electric meter is calculated once. The higher the correlation of an electric meter indicates that the line loss of the phase is caused by this electric meter, and the line loss point is at this electric meter.

[0042] To further illustrate the innovation and practicality of the present invention, the following is combined with Figure 2 to make a more detailed composition and elaborate in combination with the actual application environment.

[0043] The acquisition module is connected to the metering module, and the metering module is also connected to the transmission module for transmitting the acquired and metered data to the analysis module. The acquisition module, the metering module, and the transmission module can be set in the same housing. In order to save materials and costs, one metering module can also be connected to multiple acquisition modules for separate metering, and then the data is uploaded through one transmission module. Here, for a clearer description, this solution is described by taking a single connection as an example, and the above connection is called Combination 1.

[0044] The analysis module is connected to the communication module and can be set in the same housing, hereinafter referred to as Combination 2. It receives the data uploaded by Combination 1 below and connects to the cloud platform above to obtain the electric meter data and upload the analysis data.

[0045] Furthermore, Combination 1 is installed on each main outgoing line and each branch line. By scanning the bar code of the electric meter or inputting the meter number through a PDA, the Combination 1 on each branch line is bundled with the subordinate electric meters below. That is, the Combination 1 on Branch Line 1 is bundled with the subordinate electric meters 1.1~1.6, the Combination 1 on Branch Line 2 is bundled with the subordinate electric meters 2.1~2.9, the Combination 1 on Branch Line 3 is bundled with the subordinate electric meters 3.1~3.n, and the Combination 1 on Branch Line 4 is bundled with the subordinate electric meters 4.1~4.n.

[0046] Furthermore, after the bundling is completed, the PDA uploads the bundling information to the cloud platform, and the cloud platform issues this bundling relationship to the analysis module of Combination 2, and establishes the bundling relationship between each Combination 1 and the subordinate electric meters inside the analysis module. One bundling relationship is a segment, such as Figure 2It is divided into four segments. Segment 1 corresponds to Branch 1, Segment 2 corresponds to Branch 2, Segment 3 corresponds to Branch 3, and Segment 4 corresponds to Branch 4. The analysis module also needs to classify the subordinate electric meters in each segment by phase. It can obtain the phase types of the electric meters in each segment by accessing the cloud platform, and classify them respectively with the corresponding metering phase types of the metering modules in the upper-level combination 1. That is, the A-phase electric meters in Segment 1 are classified into the A phase of the metering module of combination 1, and so on.

[0047] Further, after the combination 1 on each hanging node has worked for a period of time, the corresponding metering modules have respectively measured the phase-separated power and node power at multiple time points, and uploaded them to the analysis module of combination 2 through the transmission module.

[0048] At this time, the analysis module of combination 2 can first calculate the upper-level line loss of each segment, and enter the calculation of the final-level line loss after giving priority to excluding the upper-level line loss. It can be done by comparing the metering power of combination 1 on the main outgoing line with the metering power of combination 1 on the subordinate branch lines at the same time. For example Figure 2 Compare the metering power of combination 1 on the main outgoing line 1 with the sum of the metering powers of combination 1 on the subordinate branch lines 1 and 2 at the same time. If the power of the main outgoing line 1 is greater than the sum of the powers of the subordinate branch lines 1 and 2, it means that the line loss is on this section of the line. If they are equal, but greater than or less than the power of the subordinate electric meters, it means that the line loss is at the final level, and enter the calculation scheme of the final-level line loss of the present invention.

[0049] Segment calculation: For example Figure 2 , the analysis module compares the node power of combination 1 in Segment 1 with the sum of the powers of the subordinate electric meters 1.1 to 1.6 at the same time. If the node power of combination 1 is greater than or less than the sum of the powers of the subordinate electric meters 1.1 to 1.6, it means that there is a line loss in Segment 1. The same applies to Segments 2, 3, and 4.

[0050] Phase-separated calculation: For example Figure 2 , combining the results of the segment calculation, assuming that the line loss is in Segment 1, at this time, the analysis module calculates the power of each phase according to the phase classification relationship of Segment 1, and compares the phase-separated power of phase A with the sum of the powers of the subordinate electric meters 1.1 and 1.2 of the same phase at the same time. If the power of phase-separated A is greater than or less than the sum of the powers of the subordinate electric meters 1.1 to 1.2, it means that there is a line loss in phase A. The same applies to phases B and C.

[0051] Phase determination calculation: Combining the above calculations, after determining the phase type of the line loss, the analysis module starts the phase-determined line loss calculation method. For example Figure 2 , assuming that the phase determination of the line loss is in phase A of Segment 1, the final line loss point calculation is started. The frozen power and line loss power of electric meters 1.1 and 1.2 under phase A at multiple time points obtained are as shown in Table 1 below. The line loss power is the power of phase A minus the power of the subordinate electric meters.

[0052] Table 1. Power consumption at multiple time points of electricity meters 1.1 and 1.2

[0053]

[0054] The calculation example is as follows:

[0055]

[0056] Obtained according to the data in Table 1

[0057] Substitute the data of electricity meter 1 into the calculation

[0058]

[0059] Substitute the data of electricity meter 2 into the calculation

[0060]

[0061] It can be clearly seen from the above calculations that the last-stage line loss point is electricity meter 1, and the reasons for line loss are meter over-allowance or meter shunt. Specifically, it can be judged through the line loss rate. The line loss rate is small for meter over-allowance and large for meter shunt, which can be defined by a threshold; if there is no correlation through the above calculations, it can be clearly judged that the line loss point is the A-phase line connecting electricity meters 1.1 and 1.2 in combination 1 of section 1, and it can be judged that the reason is electricity consumption before the meter.

[0062] Due to the previous calculations of sectioning and phase separation, the line loss range has been greatly reduced, and the final directional calculation makes the line loss calculation more accurate. In practical applications, the number of electricity meters under a branch is limited, generally not exceeding 12, and at most 4 for each phase after phase separation. The directional calculation only targets 4 electricity meters, compared with the calculation of hundreds of electricity meters in the entire substation area, which greatly reduces the calculation difficulty, effectively improves the calculation accuracy, and substantially solves the problems of repeated on-site verification and ineffective verification during line loss investigation.

[0063] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A low voltage area line loss investigation and analysis instrument, comprising a collection module, a metering module and an analysis module, characterized in that: The acquisition module collects the electrical quantity (interchange acquisition) information of the installation node; Metering module, which measures the electricity data of the installation node, including phase metering data, and freezes the data in time; The analysis module obtains the meter data of the lower level of the acquisition module and analyzes it with the data of the acquisition module to obtain the final line loss point and the cause of the line loss. The steps are as follows: S1. Segmented calculation: The analysis module compares the frozen power data of the collection module installation node measured by the metering module with the summary power of the corresponding lower-level electric meters at the same time, and obtains the collection module with the final line loss; S2. Phase calculation: The analysis module compares the acquisition module with the final line loss with the same-phase electric meter of the lower level at the same time according to the phase-frozen power, and obtains the phase difference with the final line loss; S3. Phase calculation: The analysis module separates the phases with final line loss and, based on the frozen electricity of the phase, analyzes and calculates the frozen electricity at multiple time points with each electric meter of the same phase at the lower level to obtain the specific final line loss point and the cause of the line loss.

2. According to the low-voltage substation line loss investigation and analysis instrument according to claim 1, it is also characterized by a cloud platform and a PDA, and the cloud platform exchanges data with the analysis module and the PDA through remote communication.

3. A low voltage area line loss troubleshooting and analyzing instrument according to claim 1, characterized in that: The installation nodes of the acquisition module include main outgoing lines, branch lines and nodes at the front end of multiple electric meters or centralized meter boxes, and the electrical quantity data of the installation nodes are collected in phases through current collectors and voltage sampling clamps.

4. A low voltage area line loss troubleshooting and analyzing instrument according to claim 1, characterized in that: The metering module is connected to the collection module and also connected to the transmission module, and the frozen power data of the installation node is uploaded to the analysis module through the transmission module.

5. A low voltage area line loss troubleshooting and analyzing instrument according to claim 1 or 2, characterized in that: The analysis module is also connected to the communication module, and accesses the cloud platform through the communication module to obtain the meter data, including the phase difference, frozen electricity data, and meter number information of the meter.

6. A low voltage area line loss troubleshooting and analyzing instrument according to claim 1 or 2, characterized in that: The PDA bundles the acquisition module with the lower-level electric meter, uploads the bundled information to the cloud platform, and sends it to the analysis module through the cloud platform to establish a corresponding relationship between the acquisition module and the electric meter inside the analysis module.

7. A low voltage area line loss troubleshooting and analyzing instrument according to claim 1 or 2, characterized in that: The analysis module also uploads the analysis results to the cloud platform through the communication module. The cloud platform provides a window to display the results and can synchronously send the result information to the PDA for synchronous display.

Images