Three-phase electric energy meter false wiring on-line detection device

Abstract

The invention discloses an online detection device for false wiring of a three-phase electric energy meter, relates to the technical field of three-phase electric energy meters, and solves the problem that a group of complete analysis processing logic is not set to comprehensively evaluate abnormal conditions. Through comprehensive functions, an accurate detection means, a reliable judgment mechanism, an effective evaluation method, deep load analysis and flexible operation, the detection efficiency and accuracy of the three-phase electric energy meter can be greatly improved, the problems of wiring errors, power errors, load imbalance and the like of the three-phase electric energy meter can be found and solved in time, and the detection accuracy of the three-phase electric energy meter is improved. Safe, stable and accurate metering of a power system is guaranteed, economic losses and safety risks caused by electric energy meter faults or inaccurate metering are reduced, and a powerful guarantee is provided for reliable operation of the power system.

Description

Technical Field

[0001] The invention relates to the technical field of three-phase electric energy meters, in particular to an online detection device for incorrect wiring of a three-phase electric energy meter. Background Art

[0002] The three-phase energy meter mainly works based on the principle of electromagnetic induction. In a three-phase AC circuit, the current coil and voltage coil are respectively fed with three-phase current and voltage, which will generate an alternating magnetic field. These magnetic fields interact with each other, generating induced eddy currents on the aluminum disk. The interaction between the eddy currents and the magnetic field generates an electromagnetic torque, which drives the aluminum disk to rotate. The rotation speed of the aluminum disk is proportional to the power of the three-phase circuit. By counting the number of revolutions of the aluminum disk, the energy consumption can be measured.

[0003] With the rapid development of the power system, the accuracy and reliability of the energy meter as an important device for power measurement are crucial to the stable operation of the power system. However, due to incorrect wiring or equipment failure of the energy meter, inaccurate energy measurement may occur, causing economic losses to power companies and users.

[0004] The application with publication number CN106990384B discloses a three-phase electric energy meter wrong wiring detection device and detection method, which relate to the technical field of electric energy metering detection; the three-phase electric energy meter wrong wiring detection device includes a control management unit, a communication unit, a signal generating unit, a signal processing unit, a signal detection unit and a protection and alarm unit; compared with the traditional electrical test, it avoids the shortcomings of large operation volume and cumbersome wiring, and can realize the combination of single or multiple wrong wiring types, simulate various electric energy meter wiring errors, and make the test more flexible; the control management platform based on Labview is simple to operate, and the visual interface design makes the test process more intuitive, concise and clear; the theoretical vector diagram is automatically generated according to the error type and parameter setting, so that the output signal control is more precise and the parameter accuracy is higher.

[0005] When the three-phase electricity meter is conducting wiring detection, if there is a wiring abnormality, it can be confirmed based on the corresponding power parameter performance. However, when the corresponding parameter is abnormal but there is no wiring abnormality, a complete set of analysis and processing logic is not set up to comprehensively evaluate such abnormal situations, making the corresponding three-phase electricity meter's comprehensive detection method more comprehensive, and it is impossible to achieve a better comprehensive detection effect. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides an online detection device for incorrect wiring of a three-phase electric energy meter, which solves the problem of not providing a set of complete analysis and processing logic to comprehensively evaluate such abnormal conditions.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A three-phase electric energy meter wrong wiring online detection device, comprising:

[0008] The phase parameter monitoring terminal monitors the power parameters associated with different phases of the three-phase electric energy meter in real time, and transmits the real-time monitored power parameters to the phase angle confirmation terminal or the power parameter confirmation terminal;

[0009] The phase angle confirmation terminal confirms the voltage waveform and current waveform of the same phase based on the power parameters monitored in real time at the corresponding phase, determines the characteristic time difference and the change cycle from the two sets of power waveforms of the corresponding phase, locks the phase angle associated with the corresponding phase, and determines the abnormal phase. The specific method is as follows:

[0010] Based on the real-time monitored power parameters, the power waveform associated with the corresponding power parameters is confirmed by an oscilloscope, and the first group of zero-crossing points associated with the corresponding power waveform with the same phase are confirmed and calibrated as limited characteristic points;

[0011] Confirm the characteristic moments associated with the corresponding limited characteristic points from the two groups of power waveforms, and confirm the time difference associated with the two groups of characteristic moments, recorded as SC, and then confirm the waveform association period from the confirmed power waveforms: randomly select a group of waveforms from the current waveform and the voltage waveform associated with the power waveform, and confirm the time difference between adjacent peak points from the selected waveforms, recorded as the waveform association period ZT;

[0012] Use: X i =(SC÷ZT)×100%Confirm the phase angle X associated with the corresponding phase i , where i represents the different phases monitored;

[0013] Confirm the direction of current transmission. If the current is in the positive flow direction, identify whether there is X i ∈[95°, 265°], if any, the corresponding phase is marked as an abnormal phase;

[0014] If the current is in the reverse direction, identify whether there is X i ∈[275°, 85°], if any, the corresponding phase is marked as an abnormal phase;

[0015] The relevant phase synchronization processing end performs voltage phase angle processing on the abnormal phase and other phases based on the calibrated abnormal phase to identify whether there is an error wiring signal. The specific method is as follows:

[0016] Based on the determined abnormal phase, the voltage waveform associated with the abnormal phase is recorded as the waveform to be checked, and the voltage waveform associated with another group of phases is randomly selected and recorded as the waveform to be determined;

[0017] Determine the limited characteristic points existing in the waveform to be checked and the waveform to be determined, and lock the time difference based on the determined limited characteristic points, then confirm the waveform correlation period of the waveform to be checked, and confirm the phase angle XW between the abnormal phase and the selected phase based on the confirmed time difference and waveform correlation period. If XW∈[115°, 120°] or [235°, 245°], it means that there is a wrong wiring situation between the abnormal phase and the selected phase, and directly generate and display the wrong wiring signal;

[0018] like or [235°, 245°], then perform waveform analysis on the phases that are not selected to identify whether an error wiring signal needs to be generated and displayed;

[0019] If there is no relevant judgment condition for generating an error wiring signal, the power parameter confirmation terminal is directly executed;

[0020] The power parameter confirmation end analyzes and processes the power error associated with the abnormal phase based on the determined abnormal phase and the power parameter associated with the corresponding abnormal phase, and confirms whether the power error associated with the corresponding abnormal phase meets the standard. The specific method is as follows:

[0021] The voltage measurement value U associated with the abnormal phase corresponding to the moment i , current measurement value D i and the phase angle X between voltage and current i Confirm and simultaneously confirm the measured power P associated with the corresponding time i ;

[0022] Based on the real-time data monitored at the corresponding time, the following is adopted: WC=(U i ×D i ×CosX i -P i ) / P i ×100% confirmation of the power error WC associated with the abnormal phase;

[0023] And evaluate whether the confirmed power error WC meets: WC ≥ ± 10%. If it does, generate a power error signal for display;

[0024] If not met, the load analysis assessment end is executed;

[0025] The load analysis and evaluation end confirms the neutral current in the three-phase electric energy meter, and first identifies whether the confirmed neutral current exceeds the standard. If it exceeds the standard, the three-phase electric energy meter is processed for imbalance to assess whether there is load imbalance. If it does not exceed the standard, an abnormal phase signal is generated for display. The specific method is as follows:

[0026] Define a set of processing cycles T, where T is a preset value;

[0027] The neutral current confirmed in real time within the processing cycle T is calibrated as L t , where t represents different moments, if L t If ≥1A, an over-limit signal is generated, otherwise, monitoring continues;

[0028] Based on the generated over-limit signal, the maximum current value associated with the corresponding time t is selected from the different power parameters associated with the three phases and calibrated as D t max, using: (L t -|D t max|) / L t ×100%=PD t Lock the rating value PD associated with the corresponding moment t , the evaluation value PD associated with the corresponding moment t Check with the preset value Y1. If PD t >Y1, the current moment is recorded as the load moment, where Y1 is the preset value;

[0029] Based on the determined load moments, confirm whether the subsequent moments are all load moments. If 36 groups of load moments appear continuously, a load imbalance signal is generated and displayed. If 36 groups do not appear continuously, continue monitoring. If no load imbalance signal is generated within the processing cycle T, an abnormal phase signal is directly generated for display. If PD t ≤Y1, no calibration is performed.

[0030] Preferably, if the current is in the positive flow direction, there is no X i ∈[95°, 265°], no calibration is performed;

[0031] If the current is in the reverse direction, there is no X i ∈[275°, 85°], without any calibration.

[0032] The present invention provides an online detection device for incorrect wiring of a three-phase electric energy meter. Compared with the prior art, it has the following beneficial effects:

[0033] The present invention analyzes the power parameters associated with each phase, evaluates whether there is a wrong wiring between the corresponding phases, and confirms the specific problems of each phase one by one based on a step-by-step evaluation process, and generates a corresponding confirmation signal based on the confirmation result for display, so that external personnel can view it and take timely response measures to ensure the comprehensiveness of the corresponding electric energy meter detection;

[0034] The three-phase electric energy meter wrong wiring online detection device can greatly improve the detection efficiency and accuracy of the three-phase electric energy meter through its comprehensive functions, accurate detection means, reliable judgment mechanism, effective evaluation method, in-depth load analysis and flexible operation, timely discover and solve the wiring errors, power errors and load imbalance problems of the three-phase electric energy meter, ensure the safety, stability and accurate measurement of the power system, reduce the economic losses and safety risks caused by electric energy meter failures or inaccurate measurement, and provide a strong guarantee for the reliable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the principle framework of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] First embodiment

[0038] See also Figure 1 , the present application provides an online detection device for incorrect wiring of a three-phase electric energy meter, comprising a phase parameter monitoring terminal, a phase angle confirmation terminal, a related phase synchronization processing terminal, a power parameter confirmation terminal and a load analysis and evaluation terminal, wherein the phase parameter monitoring terminal is electrically connected to the input node of the phase angle confirmation terminal or the power parameter confirmation terminal, respectively, and the phase angle confirmation terminal is electrically connected to the input node of the related phase synchronization processing terminal, wherein the power parameter confirmation terminal is electrically connected to the input node of the load analysis and evaluation terminal;

[0039] The phase parameter monitoring terminal monitors the power parameters associated with different phases of the three-phase electric energy meter in real time, and transmits the real-time monitored power parameters to the phase angle confirmation terminal or the power parameter confirmation terminal, wherein the power parameters include current parameters and voltage parameters;

[0040] Among them, the phase angle confirmation end confirms the voltage waveform and current waveform belonging to the same phase based on the power parameters monitored in real time in the corresponding phase, determines the characteristic time difference and the change cycle from the two sets of power waveforms of the corresponding phase, locks the phase angle associated with the corresponding phase, and determines the abnormal phase. The specific method for determination is:

[0041] Based on the real-time monitored power parameters, the power waveform associated with the corresponding power parameters is confirmed by an oscilloscope, and the first group of zero-crossing points associated with the corresponding power waveform with the same phase are confirmed and calibrated as limited characteristic points;

[0042] Confirm the characteristic moments associated with the corresponding limited characteristic points from the two groups of power waveforms, and confirm the time difference associated with the two groups of characteristic moments, recorded as SC, and then confirm the waveform association period from the confirmed power waveforms: randomly select a group of waveforms from the current waveform and the voltage waveform associated with the power waveform, and confirm the time difference between adjacent peak points from the selected waveforms, recorded as the waveform association period ZT;

[0043] Use: X i =(SC÷ZT)×100%Confirm the phase angle X associated with the corresponding phase i , where i represents the different phases monitored;

[0044] Confirm the direction of current transmission. If the current is in the positive flow direction (the normal power transmission direction of electric energy flowing from the power supply side to the load side), identify whether there is X i ∈[95°, 265°], if the relevant phase exists, the corresponding phase will be calibrated as an abnormal phase, otherwise, no calibration will be performed;

[0045] If the current is in the reverse direction (opposite to the forward direction), identify whether there is X i ∈[275°, 85°], if any, the corresponding phase is calibrated as an abnormal phase, otherwise no calibration is performed.

[0046] Specifically, during the current output process of each phase, the internal voltage and current have corresponding phase time difference conditions. Based on the existing specific time analysis and processing conditions, the specific abnormal conditions of the corresponding phase are locked. Based on the determined abnormal conditions, it is assessed whether there are abnormal wiring or incorrect wiring conditions in the future.

[0047] Among them, the relevant phase synchronization processing end performs voltage phase angle processing on the abnormal phase and other phases based on the calibrated abnormal phase to identify whether there is an error wiring signal. The specific method of identifying is:

[0048] Based on the determined abnormal phase, the voltage waveform associated with the abnormal phase is recorded as the waveform to be checked, and the voltage waveform associated with another group of phases is randomly selected and recorded as the waveform to be determined;

[0049] Determine the limited characteristic points existing in the waveform to be checked and the waveform to be determined, and lock the time difference based on the determined limited characteristic points, then confirm the waveform correlation period of the waveform to be checked, and confirm the phase angle XW between the abnormal phase and the selected phase based on the confirmed time difference and waveform correlation period. If XW∈[115°, 120°] or [235°, 245°], it means that there is a wrong wiring situation between the abnormal phase and the selected phase, and directly generate and display the wrong wiring signal;

[0050] like or [235°, 245°], then perform waveform analysis on the phases that are not selected to identify whether an error wiring signal needs to be generated and displayed;

[0051] If there is no relevant judgment condition for generating an error wiring signal, the power parameter confirmation terminal is directly executed;

[0052] Specifically, when there is a numerical angle abnormality in the corresponding phase, the specific confirmation between the phase angles is performed based on the specific numerical fluctuations of the corresponding phase and the related phases, and a comprehensive assessment is performed based on the confirmed specific values ​​to identify whether there is incorrect wiring between the corresponding phases. The abnormal phase is selected based on the numerical performance of the corresponding phase, and then the angle analysis of the selected abnormal phase and other phases is performed to assess whether there is incorrect wiring, and a signal display is performed to make the assessed numerical signal more accurate and achieve a more precise processing effect.

[0053] Second embodiment

[0054] Among them, the power parameter confirmation end analyzes and processes the power error associated with the abnormal phase based on the determined abnormal phase and the power parameter associated with the corresponding abnormal phase, and confirms whether the power error associated with the corresponding abnormal phase meets the standard. Specifically, when the power data error associated with the corresponding phase is large, it will cause the corresponding phase to have a phase angle abnormality, so it is necessary to determine the power error of the abnormal phase, and the specific method of confirmation is:

[0055] The voltage measurement value U associated with the abnormal phase corresponding to the moment i , current measurement value D i and the phase angle X between voltage and current i Confirm and simultaneously confirm the measured power P associated with the corresponding time i ;

[0056] Based on the real-time data monitored at the corresponding time, the following is adopted: WC=(U i ×D i ×CosX i -P i ) / Pi ×100% confirmation of the power error WC associated with the abnormal phase;

[0057] And evaluate whether the confirmed power error WC meets: WC ≥ ± 10%. If it does, generate a power error signal for display;

[0058] If not, the load analysis and assessment end is executed to assess whether there is a phase load situation.

[0059] Specifically, based on the specific parameters monitored, it is evaluated whether there is a large error between the power parameter monitored by the corresponding phase and the specific parameters monitored. If there is a large error, it means that the corresponding phase angle of the corresponding phase is abnormal, which is basically caused by the corresponding power error. Therefore, it is necessary to specifically confirm the power error signal.

[0060] Among them, the load analysis and evaluation end confirms the neutral current in the three-phase electric energy meter, and first identifies whether the confirmed neutral current exceeds the standard. If it exceeds the standard, the three-phase electric energy meter is processed for imbalance to evaluate whether there is load imbalance. If it does not exceed the standard, an abnormal phase signal is generated for display. The specific method of evaluation is as follows:

[0061] Define a set of processing cycles T, where T is a preset value, which is set by the operator based on experience and is generally 10 minutes;

[0062] The neutral current confirmed in real time within the processing cycle T is calibrated as L t , where t represents different moments, if L t If ≥1A, an over-limit signal is generated, otherwise, monitoring continues;

[0063] Based on the generated over-limit signal, the maximum current value associated with the corresponding time t is selected from the different power parameters associated with the three phases and calibrated as D t max, using: (L t -|D t max|) / L t ×100%=PD t Lock the rating value PD associated with the corresponding moment t , the evaluation value PD associated with the corresponding moment t Check with the preset value Y1. If PD t > Y1, the current moment is recorded as the load moment, where Y1 is a preset value, which is prepared in advance by the operator and is generally 30%. t≤Y1, no calibration is performed; based on the determined load moment, confirm whether the subsequent consecutive moments are all load moments. If 36 groups of load moments appear continuously, a load imbalance signal is generated and displayed. If 36 groups do not appear continuously, continuous monitoring is performed. If no load imbalance signal is generated within the processing cycle T, an abnormal phase signal is directly generated for display. Specifically, for the specific situation of such phase abnormality, it is necessary to perform relevant maintenance detection on such abnormal phase, and by dispatching relevant maintenance personnel, identify whether such abnormal phase actually has abnormal conditions or fault conditions, and promptly perform relevant processing on such abnormal conditions or fault conditions to ensure the specific maintenance processing effect;

[0064] Specifically, in a three-phase power system, under normal circumstances, the neutral current is theoretically zero under an ideal three-phase balanced load state, but in actual situations, its value is usually small; when L t When it is ≥1A, it indicates that there may be an abnormal situation. This method can quickly capture this excessive signal, thus providing a basis for subsequent in-depth analysis; this helps to promptly discover problems that may cause an increase in neutral current, such as three-phase load imbalance, single-phase grounding fault, harmonic current, etc., and avoid safety hazards caused by long-term excessive neutral current, such as wire overheating, electrical fires, etc.

[0065] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0066] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A three-phase electric energy meter wrong wiring online detection device, characterized in that: include: The phase parameter monitoring terminal monitors the power parameters associated with different phases of the three-phase electric energy meter in real time, and transmits the real-time monitored power parameters to the phase angle confirmation terminal or the power parameter confirmation terminal; The phase angle confirmation terminal confirms the voltage waveform and current waveform belonging to the same phase based on the power parameters monitored in real time at the corresponding phase, determines the characteristic time difference and the change cycle from the two sets of power waveforms at the corresponding phase, locks the phase angle associated with the corresponding phase, and determines the abnormal phase; The related phase synchronization processing end performs voltage phase angle processing on the abnormal phase and other phases based on the calibrated abnormal phase to identify whether there is an erroneous wiring signal; The power parameter confirmation end analyzes and processes the power error associated with the abnormal phase based on the determined abnormal phase and the power parameter associated with the corresponding abnormal phase, and confirms whether the power error associated with the corresponding abnormal phase meets the standard; At the load analysis and assessment end, the neutral current in the three-phase electric energy meter is confirmed, and priority is given to identifying whether the confirmed neutral current exceeds the standard. If it exceeds the standard, the three-phase electric energy meter is processed for imbalance to assess whether there is a load imbalance. If it does not exceed the standard, an abnormal phase signal is generated for display.

2. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 1, characterized in that: The specific method of determining the abnormal phase at the phase angle confirmation end is: Based on the real-time monitored power parameters, the power waveform associated with the corresponding power parameters is confirmed by an oscilloscope, and the first group of zero-crossing points associated with the corresponding power waveform with the same phase are confirmed and calibrated as limited characteristic points; Confirm the characteristic moments associated with the corresponding limited characteristic points from the two groups of power waveforms, and confirm the time difference associated with the two groups of characteristic moments, recorded as SC, and then confirm the waveform association period from the confirmed power waveforms: randomly select a group of waveforms from the current waveform and the voltage waveform associated with the power waveform, and confirm the time difference between adjacent peak points from the selected waveforms, recorded as the waveform association period ZT; Use: X i =(SC÷ZT)×100%Confirm the phase angle X associated with the corresponding phase i , where i represents the different phases monitored; Confirm the direction of current transmission. If the current is in the positive flow direction, identify whether there is X i ∈[95°, 265°], if any, the corresponding phase is marked as an abnormal phase; If the current is in the reverse direction, identify whether there is X i ∈[275°, 85°], if any, the corresponding phase is marked as an abnormal phase.

3. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 2, characterized in that: If the current is in the positive direction, there is no X i ∈[95°, 265°], no calibration is performed; If the current is in the reverse direction, there is no X i ∈[275°, 85°], without any calibration.

4. The three-phase electric energy meter wrong wiring online detection device according to claim 1 is characterized in that: The specific method of the related phase synchronization processing end to identify whether there is an error wiring signal is: Based on the determined abnormal phase, the voltage waveform associated with the abnormal phase is recorded as the waveform to be checked, and the voltage waveform associated with another group of phases is randomly selected and recorded as the waveform to be determined; The limited feature points existing in the waveform to be checked and the waveform to be determined are determined, and the time difference is locked based on the determined limited feature points, and then the waveform correlation period of the waveform to be checked is confirmed. Based on the confirmed time difference and waveform correlation period, the phase angle XW between this abnormal phase and the selected phase is confirmed. If XW∈[115°, 120°] or [235°, 245°], it means that there is an incorrect wiring situation between this abnormal phase and the selected phase, and the incorrect wiring signal is directly generated and displayed.

5. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 4, characterized in that: like or [235°, 245°], then perform waveform analysis on the phases that are not selected to identify whether an error wiring signal needs to be generated and displayed; If there is no relevant determination condition for generating an error wiring signal, the power parameter confirmation terminal is directly executed.

6. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 1, characterized in that: The specific method of the power parameter confirmation end to confirm whether the power error associated with the corresponding abnormal phase meets the standard is: The voltage measurement value U associated with the abnormal phase corresponding to the moment i , current measurement value D i and the phase angle X between voltage and current i Confirm and simultaneously confirm the measured power P associated with the corresponding time i ; Based on the real-time data monitored at the corresponding time, the following is adopted: WC=(U i ×D i ×CosX i -P i ) / P i ×100% confirmation of the power error WC associated with the abnormal phase; And evaluate whether the confirmed power error WC meets: WC ≥ ± 10%. If it does, generate a power error signal for display; If not met, the load analysis assessment end is executed.

7. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 6, characterized in that: The load analysis and assessment end evaluates whether there is a load imbalance in the following specific manner: Define a set of processing cycles T, where T is a preset value; The neutral current confirmed in real time within the processing cycle T is calibrated as L t , where t represents different moments, if L t If ≥1A, an over-limit signal is generated, otherwise, monitoring continues; Based on the generated over-limit signal, the maximum current value associated with the corresponding time t is selected from the different power parameters associated with the three phases and calibrated as D t max, using: (L t -|D t max|) / L t ×100%=PD t Lock the rating value PD associated with the corresponding moment t , the evaluation value PD associated with the corresponding moment t Check with the preset value Y1. If PD t >Y1, the current moment is recorded as the load moment, where Y1 is the preset value; Based on the determined load moments, confirm whether the subsequent consecutive moments are all load moments. If 36 groups of load moments appear consecutively, a load imbalance signal is generated and displayed. If 36 groups do not appear consecutively, continue monitoring. If no load imbalance signal is generated within the current processing cycle T, an abnormal phase signal is directly generated for display.

8. The device for online detection of incorrect wiring of a three-phase electric energy meter according to claim 7, characterized in that: If PD t ≤Y1, no calibration is performed.

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