Electric Energy Meter Dynamic Error Measurement Device and System

Abstract

The present application discloses an electric energy meter dynamic error measurement device and system. The measurement device includes a test signal generation unit for generating a voltage test signal and two current test signals, outputting the voltage test signal to the measurement unit, and outputting the two current test signals to the measurement unit and the current addition unit; the measurement unit is used for determining the electric energy value according to the voltage test signal and the two current test signals, and outputting the electric energy value to the calculation and control unit; the current addition unit is used for determining the combined current signal according to the two current test signals; the calculation and control unit is used for determining the total electric energy value according to the electric energy value. The system includes a standard meter and the measurement device, and using this measurement system to calibrate the dynamic error of the measurement device achieves the shortest time theoretically, and solves the problem of lack of a high-dynamic-accuracy standard meter. The system includes the meter under test and the measurement device, and using this measurement system to measure the dynamic error of the meter under test greatly reduces the uncertain factors affecting the test results.

Description

Technical Field

[0001] This application relates to the technical field of electricity meter detection, and particularly to a dynamic error measurement device and system for electricity meters. Background Art

[0002] To detect the dynamic error of the meter under test, it is usually necessary for the measurement device to output an AC current signal with a changing amplitude, and then measure the metering error of the meter under test under the changing current signal (or power signal). To accurately measure the dynamic error of the meter under test, generally, the dynamic accuracy of the measurement device itself is required to be higher than that of the meter under test by two grades. To obtain the dynamic error index of the measurement device itself, it is usually necessary to carry out dynamic traceability tests on the measurement device. The general method of the test is to use a standard meter with a dynamic accuracy higher than that of the measurement device by two grades, and measure electrical energy simultaneously with the measurement device under the dynamic test signal output by the measurement device, and then obtain the dynamic error of the measurement device by comparing the difference in the electrical energy measured by the two. It can be seen that to carry out the dynamic traceability test of the measurement device according to the conventional method, it is necessary to use a standard meter with high dynamic accuracy. However, for the existing standard meters currently, all their basic error indexes are steady-state indexes obtained by using an electricity meter calibration device and testing under a steady-state sine signal, and do not include dynamic indexes. Therefore, there is currently no available standard meter with high dynamic accuracy. Summary of the Invention

[0003] To solve the above problems, the embodiments of this application provide a dynamic error measurement device and system for electricity meters, aiming to overcome or partially overcome the above technical problems.

[0004] The embodiments of this application adopt the following technical solutions:

[0005] In the first aspect, a dynamic error measurement device for electricity meters is provided, including a test signal generation unit, a measurement unit, a current addition unit, and a calculation and control unit; wherein,

[0006] The test signal generation unit is configured to generate a voltage test signal and two current test signals according to the control of the calculation and control unit, output the voltage test signal to the measurement unit, and output the two current test signals to the current addition unit and the measurement unit;

[0007] The measurement unit is configured to determine the electrical energy value according to the received voltage test signal and two current test signals, and output the electrical energy value to the calculation and control unit;

[0008] The current addition unit is configured to determine a combined current signal according to the two current test signals;

[0009] The calculation and control unit is configured to determine the total electrical energy value according to the electrical energy value.

[0010] Optionally, the test signal generation unit is configured to generate a single-phase voltage test signal and two single-phase current test signals according to the control of the calculation and control unit, output the single-phase voltage test signal to the measurement unit, and output the two single-phase current test signals to the current addition unit and the measurement unit;

[0011] The measurement unit is configured to determine a single-phase electric energy value according to the received single-phase voltage test signal and two single-phase current test signals, and output the single-phase electric energy value to the calculation and control unit;

[0012] The current addition unit is configured to determine a single-phase combined current signal according to the two single-phase current test signals;

[0013] The calculation and control unit is configured to determine a single-phase total electric energy value according to the single-phase electric energy value.

[0014] Optionally, the test signal generation unit is configured to generate a three-phase voltage test signal and two three-phase current test signals according to the control of the calculation and control unit, output the three-phase voltage test signal to the measurement unit, and output the two three-phase current test signals to the current addition unit and the measurement unit;

[0015] The measurement unit is configured to determine a three-phase electric energy value according to the received three-phase voltage test signal and two three-phase current test signals, and output the three-phase electric energy value to the calculation and control unit;

[0016] The current addition unit is configured to determine a three-phase combined current signal according to the two three-phase current test signals;

[0017] The calculation and control unit is configured to determine a three-phase total electric energy value according to the three-phase electric energy value.

[0018] Optionally, the measurement unit is configured to determine a first-loop electric energy value according to the voltage test signal and the first-loop current test signal, and determine a second-loop electric energy value according to the voltage test signal and the second-loop current test signal; output the first-loop electric energy value and the second-loop electric energy value to the calculation and control unit;

[0019] The calculation and control unit is configured to determine the total electric energy value according to the sum of the first-loop electric energy value and the second-loop electric energy value.

[0020] In a second aspect, there is provided an electric energy meter dynamic error measurement system, including: a standard meter and the above-mentioned electric energy meter dynamic error measurement device; wherein,

[0021] The standard meter is configured to receive the voltage test signal and the combined current signal output by the electric energy meter dynamic error measurement device, and determine a standard electric energy value according to the voltage test signal and the combined current signal; the steady-state accuracy of the standard meter is higher than the dynamic accuracy of the electric energy meter dynamic error measurement device;

[0022] The calculation and control unit is further configured to calibrate the dynamic error of the electric energy meter dynamic error measurement device according to the standard electric energy value and the total electric energy value.

[0023] In a third aspect, a method for calibrating the dynamic error of an electric energy meter dynamic error measurement device is provided, which is implemented by the above-mentioned electric energy meter dynamic error measurement system. The method includes:

[0024] Generating a voltage test signal and a second-loop current test signal according to the control of the calculation and control unit;

[0025] Outputting the voltage test signal and the second-loop current test signal to the measurement unit, so that the measurement unit determines the electric energy value according to the voltage test signal and the second-loop current test signal;

[0026] Outputting the second-loop current test signal to the current summing unit, so that the current summing unit determines the combined current signal according to the second-loop current test signal;

[0027] Outputting the electric energy value to the calculation and control unit, so that the calculation and control unit determines the total electric energy value according to the electric energy value;

[0028] Outputting the voltage test signal and the combined current signal to the standard meter, so that the standard meter determines the standard electric energy value according to the voltage test signal and the combined current signal;

[0029] Calibrating the dynamic error of the electric energy meter dynamic error measurement device according to the total electric energy value and the standard electric energy value.

[0030] Optionally, the first-loop current test signal and the second-loop current test signal in the second-loop current test signal form a mirror change pair. For the two current test signals forming the mirror change pair, taking a power frequency steady-state signal as the reference signal, the waveforms of the two current test signals change continuously relative to the reference signal, and the ratio of the sum of the instantaneous values of the two signals at any moment to the instantaneous value of the reference signal at that moment remains unchanged.

[0031] In a fourth aspect, an electric energy meter dynamic error measurement system is provided, including: the meter under test and the above-mentioned electric energy meter dynamic error measurement device; wherein,

[0032] The meter under test is configured to receive the voltage test signal and the combined current signal output by the electric energy meter dynamic error measurement device, and determine the electric energy value to be tested according to the voltage test signal and the combined current signal;

[0033] The calculation and control unit is further configured to determine the dynamic error of the meter under test according to the electric energy value to be tested and the total electric energy value.

[0034] In a fifth aspect, a method for testing the dynamic error of an electric energy meter dynamic error measurement device is provided, which is implemented by the above-mentioned electric energy meter dynamic error measurement system. The method includes:

[0035] Generate a voltage test signal and a second current test signal according to the control of the calculation control unit;

[0036] Output the voltage test signal and the second current test signal to the measurement unit, so that the measurement unit determines the electrical energy value according to the voltage test signal and the second current test signal;

[0037] Output the second current test signal to the current addition unit, so that the current addition unit determines the combined current signal according to the second current test signal;

[0038] Output the electrical energy value to the calculation control unit, so that the calculation control unit determines the total electrical energy value according to the electrical energy value;

[0039] Output the voltage test signal and the combined current signal to the meter under test, so that the meter under test determines the electrical energy value to be tested according to the voltage test signal and the combined current signal;

[0040] Determine the dynamic error of the meter under test according to the total electrical energy value and the electrical energy value to be tested.

[0041] Optionally, the first current test signal and the second current test signal in the second current test signal form a same-image change pair. The two current test signals forming the same-image change pair are both power frequency signals. The power frequency effective values of the two current test signals change with time, and the waveforms always remain consistent.

[0042] The above at least one technical solution adopted in the embodiments of the present application can achieve the following beneficial effects:

[0043] The present application provides an electrical energy meter dynamic error measurement device and system. First, when calibrating the dynamic error of the measurement device using this measurement device and system, a conventional electrical energy meter that only guarantees steady-state indicators can be used as the standard meter, solving the problem of the current lack of a high-dynamic-accuracy standard meter; second, when calibrating the dynamic error of the measurement device, the standard electrical energy value measured by the standard meter and the total electrical energy value determined by the measurement device are theoretically equal at any time period, making the dynamic error calibration achievable with the shortest theoretical time; third, when performing the dynamic error test of the meter under test and the dynamic error calibration of the measurement device, their hardware configurations and wiring methods are the same, which can greatly reduce the uncertain factors affecting the test results. Description of the Drawings

[0044] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0045] Figure 1Shows a schematic structural diagram of an electric energy meter dynamic error measurement device according to an embodiment of the present application;

[0046] Figure 2 Shows a schematic structural diagram of a current addition unit of an electric energy meter dynamic error measurement device according to an embodiment of the present application;

[0047] Figure 3 Shows a schematic structural diagram of an electric energy meter dynamic error measurement system according to an embodiment of the present application;

[0048] Figure 4 Shows a schematic flow diagram of a dynamic error calibration method of an electric energy meter dynamic error measurement device according to an embodiment of the present application;

[0049] Figure 5 Shows waveforms of the a-phase voltage test signal, the first return current test signal, and the second return current test signal during dynamic error calibration of an electric energy meter dynamic error measurement device according to an embodiment of the present application;

[0050] Figure 6 Shows a schematic structural diagram of an electric energy meter dynamic error measurement system according to another embodiment of the present application;

[0051] Figure 7 Shows a schematic flow diagram of a method for testing dynamic error of an electric energy meter dynamic error measurement device according to another embodiment of the present application. Detailed implementation manners

[0052] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0053] The following will detail the technical solutions provided by each embodiment of the present application in conjunction with the drawings.

[0054] The concept of the present application is to provide an electric energy meter dynamic error measurement device and system. When calibrating the dynamic error of the electric energy meter dynamic error measurement device, a conventional electric energy meter that only guarantees steady-state indicators can be used as the standard meter; when testing the dynamic error of the meter under test using the electric energy meter dynamic error measurement device and system, the same hardware configuration and wiring method as those in the dynamic error calibration of the measurement device are continued. Thus, the problem of lacking a high-dynamic-accuracy standard meter when calibrating the dynamic error of the measurement device is solved, and at the same time, it is ensured that there are fewer uncertainty factors affecting the test results and the dynamic error calibration time is shorter.

[0055] An electric energy meter dynamic error measurement device 100 provided by an embodiment of the present application includes a test signal generation unit 101, a measurement unit 102, a current addition unit 103, and a calculation and control unit 104. The test signal generation unit 101 is configured to generate a voltage test signal and two-channel current test signals according to the control of the calculation and control unit 104, output the voltage test signal to the measurement unit 102, and output the two-channel current test signals to the current addition unit 103 and the measurement unit 102. The measurement unit 102 is configured to determine an electric energy value according to the received voltage test signal and two-channel current test signals, and output the electric energy value to the calculation and control unit 104. The current addition unit 103 is configured to determine a combined current signal according to the two-channel current test signals. The calculation and control unit 104 is configured to determine a total electric energy value according to the electric energy value.

[0056] The calculation and control unit 104 plays the following roles in the electric energy meter dynamic error measurement device 100: First, the calculation and control unit 104 can achieve human-computer interaction, that is, the user sends instructions to the calculation and control unit 104 to make the calculation and control unit 104 control the test signal generation unit 101 to generate and output a voltage test signal and two-channel current test signals. Second, the calculation and control unit 104 can achieve the function of data transmission, including receiving the electric energy value output by the measurement unit 102 in the form of electric energy pulses. Third, the calculation and control unit 104 can achieve the function of data calculation, including determining the total electric energy value according to the electric energy value.

[0057] The electric energy meter dynamic error measurement device 100 may be a single-phase measurement device. The test signal generation unit 101 is configured to generate a single-phase voltage test signal and two-channel single-phase current test signals according to the control of the calculation and control unit 104, output the single-phase voltage test signal to the measurement unit 102, and output the two-channel single-phase current test signals to the current addition unit 103 and the measurement unit 102; the measurement unit 102 determines a single-phase electric energy value according to the received single-phase voltage test signal and two-channel single-phase current test signals, and outputs the single-phase electric energy value to the calculation and control unit 104; the current addition unit 103 determines a single-phase combined current signal according to the two-channel single-phase current test signals; the calculation and control unit 104 determines a single-phase total electric energy value according to the single-phase electric energy value.

[0058] The dynamic error measurement device 100 of the electric energy meter can also be a three-phase measurement device. The test signal generation unit 101 is used to generate a three-phase voltage test signal and two sets of three-phase current test signals according to the control of the calculation and control unit 104, output the three-phase voltage test signal to the measurement unit 102, and output the two sets of three-phase current test signals to the current addition unit 103 and the measurement unit 102; the measurement unit 102 determines the three-phase electric energy value according to the received three-phase voltage test signal and two sets of three-phase current test signals, and outputs the three-phase electric energy value to the calculation and control unit 104; the current addition unit 103 determines the three-phase combined current signal according to the two sets of three-phase current test signals; the calculation and control unit 104 determines the total three-phase electric energy value according to the three-phase electric energy value.

[0059] As an alternative embodiment, regardless of whether the dynamic error measurement device 100 of the electric energy meter is a single-phase measurement device or a three-phase measurement device, the measurement unit 102 determines the first-loop electric energy value according to the voltage test signal and the first-loop current test signal, determines the second-loop electric energy value according to the voltage test signal and the second-loop current test signal, and outputs the first-loop electric energy value and the second-loop electric energy value to the calculation and control unit 104, so that the calculation and control unit 104 determines the total electric energy value according to the sum of the first-loop electric energy value and the second-loop electric energy value.

[0060] Figure 1 The figure shows a dynamic error measurement device of an electric energy meter according to an embodiment of the present application. Figure 2 The figure shows a schematic structural diagram of the current addition unit of the dynamic error measurement device of the electric energy meter according to an embodiment of the present application. Combining Figure 1 and Figure 2 below, the three-phase dynamic error measurement device 100 of the electric energy meter will be taken as an example for detailed description.

[0061] As Figure 1 shown, the test signal generation unit 101 is connected to the calculation and control unit 104 through the data line A, and generates and outputs a three-phase voltage test signal and two sets of three-phase current test signals under the control of the calculation and control unit 104. The four terminals Ua, Ub, Uc, and Un of the voltage output interface of the test signal generation unit 101 respectively output the voltage test signals of the a-phase, b-phase, c-phase, and neutral point; the Ia1 + , Ia1 - terminals are used to output the first-loop a-phase current test signal, and the Ia2 + , Ia2 - terminals are used to output the second-loop a-phase current test signal, the Ib1 + , Ib1 - terminals are used to output the first-loop b-phase current test signal, and the Ib2 + , Ib2 -The terminal is used to output the second loop b-phase current test signal, Ic1 + 、Ic1 - The terminal is used to output the first loop c-phase current test signal, Ic2 + 、Ic2 - The terminal is used to output the second loop a-phase current test signal.

[0062] The output three-phase voltage test signals are connected in parallel and output to the corresponding terminals of the voltage input interface of the measurement unit 102. The output two-loop three-phase current test signals are connected in series and output to the corresponding terminals of the current input interface of the current summing unit 103 and the corresponding terminals of the current input interface of the measurement unit 102.

[0063] Combined Figure 2 As shown, the current summing unit 103 receives two-loop three-phase current test signals, and performs in-phase summation on each phase of the two-loop current test signals to obtain three-phase combined current signals. Among them, the first loop a-phase current test signal received by the current input interface Ia1 + 、Ia1 - terminals of the current summing unit 103 and the second loop a-phase current test signal received by the Ia2 + 、Ia2 - terminals are combined into Ia + 、Ia - terminals through a precision current transformer to output the a-phase combined current signal; the first loop b-phase current test signal received by the current input interface Ib1 + 、Ib1 - terminals of the current summing unit 103 and the second loop b-phase current test signal received by the Ib2 + 、Ib2 - terminals are combined into Ib + 、Ib - terminals through a precision current transformer to output the b-phase combined current signal; the first loop c-phase current test signal received by the current input interface Ic1 + 、Ic1 - terminals of the current summing unit 103 and the second loop c-phase current test signal received by the Ic2 + 、Ic2 - terminals are combined into Ic + 、Ic - terminals through a precision current transformer to output the c-phase combined current signal.

[0064] The measurement unit 102 is connected to the calculation and control unit 104 via the data line B. The measurement unit 102 measures the first return electrical energy value based on the voltage test signal and the first return current test signal, and outputs the first return electrical energy value to the calculation and control unit 104 in the form of electrical energy pulses via the electrical energy pulse 1 signal line; it measures the second return electrical energy value based on the voltage test signal and the second return current test signal, and outputs the second return electrical energy value to the calculation and control unit 104 in the form of electrical energy pulses via the electrical energy pulse 2 signal line.

[0065] The calculation and control unit 104 receives the first return electrical energy value and the second return electrical energy value respectively in the form of received electrical energy pulses, and adds the first return electrical energy value and the second return electrical energy value to obtain the total electrical energy value.

[0066] Figure 3 The figure shows an electrical energy meter dynamic error measurement system according to an embodiment of the present application. This system can be used to implement the dynamic error calibration method of the electrical energy meter dynamic error measurement device, including: a standard meter 300 and the above-mentioned electrical energy meter dynamic error measurement device 100. The standard meter 300 is used to receive the voltage test signal and the combined current signal output by the electrical energy meter dynamic error measurement device 100, and determine the standard electrical energy value based on the voltage test signal and the combined current signal; the steady-state accuracy of the standard meter 300 is higher than the dynamic accuracy of the electrical energy meter dynamic error measurement device 100. The calculation and control unit 104 of the electrical energy meter dynamic error measurement device 100 is also used to calibrate the dynamic error of the electrical energy meter dynamic error measurement device 100 according to the standard electrical energy value and the total electrical energy value.

[0067] In this system, the voltage test signal generated by the test signal generation unit 101 is output to the corresponding terminal of the voltage input interface of the standard meter 300 in addition to being output to the measurement unit 102. The current test signal output by the current addition unit 103 is output to the corresponding terminal of the current input interface of the standard meter 300.

[0068] When the electrical energy meter dynamic error measurement device 100 is a three-phase measurement device, the four terminals Ua, Ub, Uc, and Un of the voltage output interface of the test signal generation unit 101 respectively output the voltage test signals of phase a, phase b, phase c, and the neutral point, and are connected in parallel and output to the corresponding terminals of the voltage input interface of the standard meter 300; the current addition unit 103 outputs the combined current signal of phase a to the corresponding terminal of the current input interface of the standard meter 300 through the Ia + 、Ia - terminals, outputs the combined current signal of phase b to the corresponding terminal of the current input interface of the standard meter 300 through the Ib + 、Ib - terminals, and outputs the combined current signal of phase c to the corresponding terminal of the current input interface of the standard meter 300 through the Ic + 、Ic -The terminal outputs the combined current signal of phase c to the corresponding terminal of the current input interface of the standard meter 300.

[0069] The standard meter 300 determines the standard electric energy value according to the received voltage test signal and the combined current signal, and outputs it to the calculation and control unit 104 through the electric energy pulse 3 signal line. The calculation and control unit 104 calibrates the dynamic error of the electric energy meter dynamic error measuring device 100 according to the standard electric energy value and the total electric energy value.

[0070] As a preferred embodiment, the steady-state accuracy of the standard meter 300 is two grades higher than the dynamic accuracy of the electric energy meter dynamic error measuring device 100.

[0071] As an alternative embodiment, the calibration of the dynamic error of the electric energy meter dynamic error measuring device 100 can also be realized by the error calculator of the standard meter. When the error calculator of the standard meter is adopted, the calculation and control unit 104 no longer undertakes the function of calibrating the dynamic error of the electric energy meter dynamic error measuring device 100, but outputs the total electric energy value to the error calculator of the standard meter. The standard meter also no longer outputs the standard electric energy value to the calculation and control unit 104 (inside the standard meter, the standard electric energy value must be output to the error calculator of the standard meter). The error calculator of the standard meter compares the difference between the total electric energy value and the standard electric energy value, so as to calibrate the dynamic error of the electric energy meter dynamic error measuring device 100.

[0072] Figure 4 shows a schematic flowchart of a method for calibrating the dynamic error of an electric energy meter dynamic error measuring device according to an embodiment of the present application. The dynamic error calibration method is implemented by Figure 3 the shown electric energy meter dynamic error measurement system. The method includes:

[0073] Step S401, generating a voltage test signal and a two-circuit current test signal according to the control of the calculation and control unit.

[0074] Step S402, outputting the voltage test signal and the two-circuit current test signal to the measurement unit, so that the measurement unit determines the electric energy value according to the voltage test signal and the two-circuit current test signal.

[0075] Step S403, outputting the two-circuit current test signal to the current adding unit, so that the current adding unit determines the combined current signal according to the two-circuit current test signal.

[0076] Step S404, outputting the electric energy value to the calculation and control unit, so that the calculation and control unit determines the total electric energy value according to the electric energy value.

[0077] Step S405: Output the voltage test signal and the combined current signal to a standard meter, so that the standard meter determines the standard electrical energy value according to the voltage test signal and the combined current signal.

[0078] Step S406: Calibrate the dynamic error of the electric energy meter dynamic error measurement device according to the total electrical energy value and the standard electrical energy value.

[0079] As an optional implementation manner, the first loop current test signal and the second loop current test signal in the two-loop current test signals form a mirror change pair. For the two current test signals forming the mirror change pair, a power frequency steady-state signal is used as a reference signal. The waveforms of the two current test signals change continuously relative to the reference signal, and the ratio of the sum of the instantaneous values of the two signals at any moment to the instantaneous value of the reference signal at that moment remains unchanged. The power frequency steady-state signal refers to a power frequency sine wave signal or a power frequency steady-state distortion signal whose amplitude, frequency, and phase all remain unchanged. The power frequency steady-state distortion signal contains a power frequency fundamental wave signal and its finite number of harmonic signals.

[0080] Hereinafter, taking the electric energy meter dynamic error measurement device as a three-phase measurement device as an example, the signals generated by the test signal generation unit will be described in detail.

[0081] The following formulas (1), (2), and (3) are the mathematical expressions of the phase-a voltage test signal, the first loop phase-a current test signal, and the second loop phase-a current test signal respectively; the following formulas (4), (5), and (6) are the mathematical expressions of the phase-b voltage test signal, the first loop phase-b current test signal, and the second loop phase-b current test signal respectively; the following formulas (7), (8), and (9) are the mathematical expressions of the phase-c voltage test signal, the first loop phase-c current test signal, and the second loop phase-c current test signal respectively.

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091] Taking the second - order a - phase current test signal as an example, the requirements for mirror - image variation it satisfies are described. i a 1(t) current test signal and i a 2(t) current test signal form a pair of mirror - image variations for the a - phase. These two current test signals use the power - frequency steady - state signal as the reference signal. Therefore, these two current test signals have the following characteristics:

[0092] First, as can be seen from Equations (2) and (3), these two current test signals are actually two modulation signals formed after the reference signal is amplitude - modulated by two amplitude - modulation functions 0.25·sin(2π·5·t + 0) and - 0.25·sin(2π·5·t + 0) respectively. Therefore, the waveforms of these two current test signals are constantly changing relative to the waveform of the reference signal.

[0093] Second, since Therefore, at any moment, the ratio of the sum of the instantaneous values of these two current test signals to the instantaneous value of the reference signal is always 2 and remains unchanged.

[0094] Figure 5 The waveform diagrams of the a - phase voltage test signal, the first - order current test signal, and the second - order current test signal during the dynamic error calibration of the electric energy meter dynamic error measurement device are shown. Compared with the waveform diagram of the a - phase, the corresponding waveform diagrams of the b - phase are the same except that the initial phase difference is - 120°; compared with the waveform diagram of the a - phase, the corresponding waveform diagrams of the c - phase are the same except that the initial phase difference is 120°. The requirements for mirror - image variation satisfied by the b - phase and c - phase current test signals are similar to those of the a - phase and will not be elaborated here.

[0095] When using the above - mentioned electric energy meter dynamic error measurement system to calibrate the dynamic error of the measurement device, a conventional electric energy meter that only guarantees steady - state indicators can be used as the standard meter, which solves the problem of the current lack of a high - dynamic - accuracy standard meter; the standard electrical energy value measured by the standard meter and the total electrical energy value determined by the measurement device are theoretically equal at any time period, making the dynamic error calibration achieve the shortest theoretical time.

[0096] Figure 6The figure shows an electric energy meter dynamic error measurement system according to another embodiment of the present application. This system can be used to implement a method for testing the dynamic error of an electric energy meter dynamic error measurement device, including: a meter under test 600 and the above-mentioned electric energy meter dynamic error measurement device 100. The meter under test 600 is configured to receive a voltage test signal and a combined current signal output by the electric energy meter dynamic error measurement device 100, and determine the electric energy value to be tested according to the voltage test signal and the combined current signal. The calculation and control unit 104 of the electric energy meter dynamic error measurement device 100 is further configured to determine the dynamic error of the meter under test 600 according to the electric energy value to be tested and the total electric energy value.

[0097] In this system, the voltage test signal generated by the test signal generation unit 101 is output not only to the measurement unit 102 but also to the corresponding terminal of the voltage input interface of the meter under test 600. The current test signal output by the current addition unit 103 is output to the corresponding terminal of the current input interface of the meter under test 600.

[0098] When the electric energy meter dynamic error measurement device 100 is a three-phase measurement device, the four terminals Ua, Ub, Uc, and Un of the voltage output interface of the test signal generation unit 101 respectively output voltage test signals of phase a, phase b, phase c, and the neutral point, and are connected in parallel and output to the corresponding terminals of the voltage input interface of the meter under test 600; the current addition unit 103 outputs the combined current signal of phase a to the corresponding terminal of the current input interface of the meter under test 600 through the Ia + 、Ia - terminal, outputs the combined current signal of phase b to the corresponding terminal of the current input interface of the meter under test 600 through the Ib + 、Ib - terminal, and outputs the combined current signal of phase c to the corresponding terminal of the current input interface of the meter under test 600 through the Ic + 、Ic - terminal.

[0099] The meter under test 600 determines the electric energy value to be tested according to the received voltage test signal and the combined current signal, and outputs it to the calculation and control unit 104 through the electric energy pulse 4 signal line. The calculation and control unit 104 determines the dynamic error of the meter under test according to the electric energy value to be tested and the total electric energy value.

[0100] Figure 7 The figure shows a schematic flowchart of a method for testing the dynamic error of an electric energy meter dynamic error measurement device according to another embodiment of the present application. This method for testing the dynamic error is implemented by the Figure 6 shown electric energy meter dynamic error measurement system. This method includes:

[0101] Step S701, generating a voltage test signal and a two-loop current test signal according to the control of the calculation and control unit.

[0102] Step S702: Output a voltage test signal and a second-loop current test signal to a measurement unit, so that the measurement unit determines an electrical energy value according to the voltage test signal and the second-loop current test signal.

[0103] Step S703: Output the second-loop current test signal to a current summing unit, so that the current summing unit determines a combined current signal according to the second-loop current test signal.

[0104] Step S704: Output the electrical energy value to a calculation and control unit, so that the calculation and control unit determines a total electrical energy value according to the electrical energy value.

[0105] Step S705: Output the voltage test signal and the combined current signal to a meter under test, so that the meter under test determines a to-be-tested electrical energy value according to the voltage test signal and the combined current signal.

[0106] Step S706: Determine the dynamic error of the meter under test according to the total electrical energy value and the to-be-tested electrical energy value.

[0107] As an optional implementation manner, the first-loop current test signal and the second-loop current test signal in the second-loop current test signal form a homomorphic change pair. Both of the two current test signals forming the homomorphic change pair are power frequency signals. The power frequency effective values of the two current test signals change with time continuously, and the waveforms always remain consistent.

[0108] Hereinafter, taking the electrical energy meter dynamic error measurement device as a three-phase measurement device as an example, the signals generated by the test signal generation unit are described in detail.

[0109] The following formulas (10), (11), and (12) are the mathematical expressions of the a-phase voltage test signal, the first-loop a-phase current test signal, and the second-loop a-phase current test signal respectively; the following formulas (13), (14), and (15) are the mathematical expressions of the b-phase voltage test signal, the first-loop b-phase current test signal, and the second-loop b-phase current test signal respectively; the following formulas (16), (17), and (18) are the mathematical expressions of the c-phase voltage test signal, the first-loop c-phase current test signal, and the second-loop c-phase current test signal respectively.

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] Taking the two - cycle a - phase current test signal as an example, the requirements for the same - image change it satisfies are described. i a 1(t) current test signal and i a 2(t) current test signal form a pair of signals with the same - image change for the a - phase. It can be seen from Equation (11) and Equation (12) that these two current test signals are actually the same signal, both of which are formed by the power - frequency carrier signal with a frequency of 50 Hz after amplitude - modulation by the amplitude - modulation function 0.25·sin(2π·5·t + 0). Therefore, these two current test signals are both power - frequency signals, whose power - frequency effective values change with time continuously, and the waveforms of these two current test signals always remain consistent.

[0120] Since Equation (10) is the same as Equation (1), Equation (11) and Equation (12) are the same as Equation (2), and the waveform diagrams corresponding to Equation (1) and Equation (2) have been shown Figure 5 previously, so they will not be shown again. Compared with the waveform diagram of the a - phase, the corresponding waveform diagram of the b - phase is the same except that the initial phase difference is - 120°; compared with the waveform diagram of the a - phase, the corresponding waveform diagram of the c - phase is the same except that the initial phase difference is 120°. The requirements for the same - image change satisfied by the b - phase and c - phase current test signals are similar to those of the a - phase, and will not be elaborated here.

[0121] Using the above - mentioned dynamic error measurement system for electric energy meters to conduct the dynamic error test of the meter under test, its hardware configuration and wiring method for calibrating the dynamic error of the electric energy meter dynamic error measurement system are the same, which can greatly reduce the uncertain factors affecting the test results.

[0122] It should also be noted that the term "including", "comprising" or any other variant thereof is intended to cover non - exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such a process, method, commodity or device. Without further limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity or device including the said element.

[0123] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0124] The above are only the embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A dynamic error measurement system for an electric energy meter, characterized in that, It includes a standard meter and a dynamic error measuring device for watt-hour meters; the dynamic error measuring device for watt-hour meters includes a test signal generation unit, a measurement unit, a current addition unit, and a calculation and control unit; wherein, The test signal generation unit is configured to generate a voltage test signal and two sets of current test signals according to the control of the calculation and control unit, output the voltage test signal to the measurement unit, and output the two sets of current test signals to the current addition unit and the measurement unit; the two sets of current test signals include a first set of current test signals and a second set of current test signals; The measurement unit is configured to determine an electric energy value according to the received voltage test signal and the two sets of current test signals, and output the electric energy value to the calculation and control unit; The current addition unit is configured to determine a combined current signal according to the two sets of current test signals; The calculation and control unit is configured to determine a total electric energy value according to the electric energy value; The standard meter is configured to receive the voltage test signal and the combined current signal output by the dynamic error measuring device for watt-hour meters, and determine a standard electric energy value according to the voltage test signal and the combined current signal; the steady-state accuracy of the standard meter is higher than the dynamic accuracy of the dynamic error measuring device for watt-hour meters; The calculation and control unit is further configured to calibrate the dynamic error of the dynamic error measuring device for watt-hour meters according to the standard electric energy value and the total electric energy value.

2. The electric energy meter dynamic error measurement system according to claim 1, characterized in that The test signal generation unit is configured to generate a single-phase voltage test signal and two sets of single-phase current test signals according to the control of the calculation and control unit, output the single-phase voltage test signal to the measurement unit, and output the two sets of single-phase current test signals to the current addition unit and the measurement unit; The measurement unit is configured to determine a single-phase electric energy value according to the received single-phase voltage test signal and the two sets of single-phase current test signals, and output the single-phase electric energy value to the calculation and control unit; The current addition unit is configured to determine a single-phase combined current signal according to the two sets of single-phase current test signals; The calculation and control unit is configured to determine a single-phase total electric energy value according to the single-phase electric energy value.

3. The electric energy meter dynamic error measurement system according to claim 1, characterized in that The test signal generation unit is configured to generate a three-phase voltage test signal and two sets of three-phase current test signals according to the control of the calculation and control unit, output the three-phase voltage test signal to the measurement unit, and output the two sets of three-phase current test signals to the current addition unit and the measurement unit; The measurement unit is configured to determine a three-phase electric energy value according to the received three-phase voltage test signal and the two sets of three-phase current test signals, and output the three-phase electric energy value to the calculation and control unit; The current addition unit is configured to determine a three-phase combined current signal according to the two sets of three-phase current test signals; The calculation and control unit is configured to determine a three-phase total electric energy value according to the three-phase electric energy value.

4. The electric energy meter dynamic error measurement system according to any one of claims 1-3, characterized in that The measurement unit is used to determine the first return electrical energy value according to the voltage test signal and the first return current test signal, and determine the second return electrical energy value according to the voltage test signal and the second return current test signal; output the first return electrical energy value and the second return electrical energy value to the calculation and control unit; The calculation and control unit is used to determine the total electrical energy value according to the sum of the first return electrical energy value and the second return electrical energy value.

5. A dynamic error calibration method for a dynamic error measurement device of an electric energy meter, characterized in that, Implemented by the electric energy meter dynamic error measurement system according to any one of claims 1-4, the method includes: Generate a voltage test signal and a second return current test signal according to the control of the calculation and control unit; Output the voltage test signal and the second return current test signal to the measurement unit, so that the measurement unit determines the electrical energy value according to the voltage test signal and the second return current test signal; Output the second return current test signal to the current addition unit, so that the current addition unit determines the combined current signal according to the second return current test signal; Output the electrical energy value to the calculation and control unit, so that the calculation and control unit determines the total electrical energy value according to the electrical energy value; Output the voltage test signal and the combined current signal to the standard meter, so that the standard meter determines the standard electrical energy value according to the voltage test signal and the combined current signal; Calibrate the dynamic error of the electric energy meter dynamic error measurement device according to the total electrical energy value and the standard electrical energy value.

6. The dynamic error calibration method of the dynamic error measurement device of the electric energy meter according to claim 5, characterized in that, The first return current test signal and the second return current test signal in the second return current test signals form a mirror change pair. For the two current test signals forming the mirror change pair, with a power frequency steady-state signal as the reference signal, the waveforms of the two current test signals change continuously relative to the reference signal, and the ratio of the sum of the instantaneous values of the two signals at any moment to the instantaneous value of the reference signal at that moment remains unchanged.

7. A dynamic error measurement system for an electric energy meter, characterized in that, Including: The meter under test and the electric energy meter dynamic error measurement device; the electric energy meter dynamic error measurement device includes a test signal generation unit, a measurement unit, a current addition unit and a calculation and control unit; wherein, The test signal generation unit is used to generate a voltage test signal and a second return current test signal according to the control of the calculation and control unit, output the voltage test signal to the measurement unit, and output the second return current test signal to the current addition unit and the measurement unit; the second return current test signals include a first return current test signal and a second return current test signal; The measurement unit is used to determine the electrical energy value according to the received voltage test signal and the second return current test signal, and output the electrical energy value to the calculation and control unit; The current addition unit is used to determine the combined current signal according to the second return current test signal; The calculation and control unit is used to determine the total electrical energy value according to the electrical energy value; The meter under test is used to receive the voltage test signal and the combined current signal output by the electric energy meter dynamic error measurement device, and determine the electrical energy value to be tested according to the voltage test signal and the combined current signal; The calculation and control unit is further configured to determine the dynamic error of the meter under test according to the electricity energy value to be detected and the total electricity energy value.

8. The electric energy meter dynamic error measurement system according to claim 7, wherein, The test signal generation unit is configured to generate a single-phase voltage test signal and two single-phase current test signals according to the control of the calculation and control unit, output the single-phase voltage test signal to the measurement unit, and output the two single-phase current test signals to the current addition unit and the measurement unit; The measurement unit is configured to determine a single-phase electricity energy value according to the received single-phase voltage test signal and the two single-phase current test signals, and output the single-phase electricity energy value to the calculation and control unit; The current addition unit is configured to determine a single-phase combined current signal according to the two single-phase current test signals; The calculation and control unit is configured to determine a single-phase total electricity energy value according to the single-phase electricity energy value.

9. The electric energy meter dynamic error measurement system according to claim 7, characterized in that, The test signal generation unit is configured to generate a three-phase voltage test signal and two three-phase current test signals according to the control of the calculation and control unit, output the three-phase voltage test signal to the measurement unit, and output the two three-phase current test signals to the current addition unit and the measurement unit; The measurement unit is configured to determine a three-phase electricity energy value according to the received three-phase voltage test signal and the two three-phase current test signals, and output the three-phase electricity energy value to the calculation and control unit; The current addition unit is configured to determine a three-phase combined current signal according to the two three-phase current test signals; The calculation and control unit is configured to determine a three-phase total electricity energy value according to the three-phase electricity energy value.

10. The electric energy meter dynamic error measurement system according to any one of claims 7-9, characterized in that The measurement unit is configured to determine a first-loop electricity energy value according to the voltage test signal and the first-loop current test signal, and determine a second-loop electricity energy value according to the voltage test signal and the second-loop current test signal; output the first-loop electricity energy value and the second-loop electricity energy value to the calculation and control unit; The calculation and control unit is configured to determine the total electricity energy value according to the sum of the first-loop electricity energy value and the second-loop electricity energy value.

11. A method for measuring the dynamic error of an electric energy meter dynamic error measurement system, characterized in that Implemented by the electricity meter dynamic error measurement system according to any one of claims 7-10, the method includes: Generating a voltage test signal and two current test signals according to the control of the calculation and control unit; Outputting the voltage test signal and the two current test signals to the measurement unit, so that the measurement unit determines an electricity energy value according to the voltage test signal and the two current test signals; Outputting the two current test signals to the current addition unit, so that the current addition unit determines a combined current signal according to the two current test signals; Outputting the electricity energy value to the calculation and control unit, so that the calculation and control unit determines the total electricity energy value according to the electricity energy value; Outputting the voltage test signal and the combined current signal to the meter under test, so that the meter under test determines the electricity energy value to be detected according to the voltage test signal and the combined current signal; Determining the dynamic error of the meter under test according to the total electricity energy value and the electricity energy value to be detected.

12. The method for testing the dynamic error of the electric energy meter dynamic error measurement system according to claim 11, wherein, The first return current test signal and the second return current test signal in the double-return current test signal form an image-variant pair. Both current test signals forming the image-variant pair are power frequency signals. The power frequency effective values of the two current test signals change continuously with time, and the waveforms always remain consistent.

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