A dynamic DC traceability system and traceability method

Abstract

The present invention discloses a dynamic DC traceability system and a traceability method, which relate to the technical field of electric energy metering traceability and solve the problem of traceability of dynamic DC electric energy. The key points of the solution include: a dynamic DC power source for modulating and generating a dynamic DC signal; a measured dynamic DC watt-hour meter for measuring the dynamic DC signal to obtain a first measurement result; a 0.02-level dynamic DC standard meter for measuring the dynamic DC signal to obtain a second measurement result and comparing the first measurement result with the second measurement result to obtain the measurement traceability result of the measured dynamic DC watt-hour meter; a 0.01-level traceability system for generating a dynamic DC signal according to a known DC signal and a dynamic AC signal, and measuring and tracing the 0.02-level dynamic DC standard meter according to the dynamic DC signal to obtain the measurement traceability result of the 0.02-level dynamic DC standard meter. The solution solves the problem of traceability of dynamic DC measurement by converting the dynamic DC signal into separate traceability for single AC and DC respectively.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy metering traceability, and more specifically, to a dynamic DC traceability system and a traceability method. Background Art

[0002] With the vigorous promotion of the construction of a new power system in China, the proportion of DC power supply and distribution in the power grid in the industrial and transportation fields is increasing. Such as: new energy rail transit, electric vehicles, photovoltaic systems, urban rail transit systems, etc. At present, the AC and DC electric energy metering technologies in China are relatively mature. However, in actual DC power supply and distribution scenarios, DC signals contain a large number of random ripple AC components. The strong randomness of the amplitude and frequency of these ripple components contains a large number of high-frequency harmonics, which will pose challenges to the accuracy of DC electric energy metering and lead to errors. Compared with the AC electric energy traceability system, the DC electric energy metering traceability system has not been perfected.

[0003] At present, there is no recognized traceability method for DC electric energy (dynamic DC) containing non-specific ripples, and a complete DC electric energy metering traceability system has not been established; although DC electric energy meters under the existing national standards reach 0.01 level, they only consider the precise metering of DC components under steady-state conditions. Some manufacturers' standard DC electric energy meters consider the influence of ripple voltage or ripple current, but cannot measure power and electric energy, and do not consider the influence of ripple power. In addition, at present, high-grade DC electric energy meter calibration devices adopt a distributed traceability method, which traces upward to national voltage, current, time frequency and other references and standards respectively. The voltage and current measurements have cumbersome wiring, complex operations, are prone to misoperations, increase the calibration time, reduce the work efficiency, and may introduce more measurement uncertainty components during the separate traceability process, which is not conducive to the transfer and traceability of DC electric energy values.

[0004] Therefore, the present application provides a dynamic DC traceability system and a traceability method to solve the above problems. Summary of the Invention

[0005] The purpose of the present application is to provide a dynamic DC traceability system and a traceability method to solve the problems that there is currently no traceability method for dynamic DC electric energy, a complete DC electric energy metering traceability system has not been established, and at the same time, the existing traceability methods require the cooperation of multiple devices, with cumbersome wiring and complex operations; through the design of a dynamic DC traceability system and a traceability method, the present application can perform national reference detection at the 0.01 level on the metering accuracy of 0.05-level dynamic DC electric energy meters and its own 0.02-level dynamic DC standard meters, provide an effective traceability method for the metering traceability of dynamic DC, improve the DC electric energy metering traceability system, and at the same time, through the integrated design of the system, simplify the wiring and make the operation simpler.

[0006] The present application first provides a dynamic DC traceability system, including: a dynamic DC power source for modulating and generating a dynamic DC signal; a dynamic DC watt-hour meter under test for measuring the dynamic DC signal to obtain a first measurement result; a 0.02-level dynamic DC standard meter for measuring the dynamic DC signal to obtain a second measurement result, and comparing the first measurement result and the second measurement result to obtain the measurement traceability result of the dynamic DC watt-hour meter under test; a 0.01-level traceability system for generating a dynamic DC signal according to a known DC signal and a dynamic AC signal, and performing measurement traceability on the 0.02-level dynamic DC standard meter according to the dynamic DC signal to obtain the measurement traceability result of the 0.02-level dynamic DC standard meter.

[0007] Adopting the above technical solution, aiming at the characteristic that the dynamic DC signal can actually be decomposed into a dynamic AC signal and a DC signal, the traceability of the dynamic DC signal is transformed into the separate traceability of a single AC and DC, and the indirect traceability of the dynamic DC signal is jointly realized by combining the existing mature DC power traceability system and AC power traceability system to solve the traceability problem of dynamic DC measurement.

[0008] In a possible implementation manner, the 0.01-level traceability system includes: a dynamic AC power source for modulating and generating a dynamic AC voltage and a dynamic AC current, the dynamic AC voltage and the dynamic AC current being a combination of half-cycles of the AC power frequency, and having the same waveform and phase; a 0.01-level AC traceability system for measuring the dynamic AC voltage and the dynamic AC current; a 0.01-level DC traceability system for providing a measured DC voltage and a DC current; wherein, the dynamic AC voltage and the DC voltage are connected in series to provide a dynamic DC voltage, the dynamic AC current and the DC current are coupled to provide a dynamic DC current, and the dynamic DC voltage and the dynamic DC current are dynamic DC signals.

[0009] In a possible implementation manner, the dynamic AC power source includes: a signal generator, a dynamic AC voltage amplifier, and a dynamic AC current amplifier; the signal generator is connected to the dynamic AC voltage amplifier and outputs an amplified dynamic AC voltage; the signal generator is connected to the dynamic AC current amplifier and outputs an amplified dynamic AC current.

[0010] In a possible implementation, the signal generator includes: an embedded single-chip microcomputer, a first digital isolator, a second digital isolator, a first DAC converter, and a second DAC converter; on the one hand, the embedded single-chip microcomputer generates dynamic AC voltage waveform fitting data, the dynamic AC voltage waveform fitting data is connected to the first digital isolator, the first digital isolator is connected to the first DAC converter, and the first DAC converter outputs a dynamic AC voltage signal; on the other hand, the embedded single-chip microcomputer generates dynamic AC current waveform fitting data, the dynamic AC current waveform fitting data is connected to the second digital isolator, the second digital isolator is connected to the second DAC converter, and the second DAC converter outputs a dynamic AC current signal.

[0011] In a possible implementation, the dynamic AC voltage amplifier includes: a plurality of signal isolators and a plurality of voltage amplifiers. One end of the plurality of signal isolators is connected to the signal generator, and the other end is connected to the corresponding voltage amplifier. All the voltage amplifiers are connected in series and stacked to output the amplified dynamic AC voltage.

[0012] In a possible implementation, the voltage amplifier adopts an in-phase proportional amplification circuit.

[0013] In a possible implementation, the dynamic AC current amplifier includes: an error amplifier, a driving transistor, a high-power transistor group, and a zero-flux mutual inductor sampling circuit. One end of the error amplifier is connected to the signal generator, the other end is connected to the driving transistor, the driving transistor is connected to the high-power transistor group, the output of the high-power transistor group is connected to the error amplifier through the zero-flux mutual inductor sampling circuit, and the high-power transistor group outputs the amplified dynamic AC current.

[0014] In a possible implementation, the 0.02-class dynamic DC standard meter includes: a precision resistor voltage division circuit, a zero-flux mutual inductor sampling circuit, a synchronous sampling ADC, a microprocessor, a pulse input / output unit, and an amplitude / power / electric energy calculation and display unit; the voltage input is connected to the precision resistor voltage division circuit, the precision resistor voltage division circuit is connected to the synchronous sampling ADC, the current input is connected to the zero-flux mutual inductor sampling circuit, the zero-flux mutual inductor sampling circuit is connected to the synchronous sampling ADC, the synchronous sampling ADC is connected to the microprocessor, and the microprocessor is connected to the pulse input / output unit and the amplitude / power / electric energy calculation and display unit.

[0015] In a possible implementation, the zero-flux mutual inductor sampling circuit includes: a mutual inductor and two coils passing through the mutual inductor and isolated from each other. The two coils respectively lead out a DC current input terminal and an AC current input terminal.

[0016] The present application also provides a dynamic DC traceability method, which is executed based on a dynamic DC traceability system as described above, and includes: tracing the 0.02-level dynamic DC standard meter through the 0.01-level traceability system: sending dynamic DC voltage and dynamic DC current to the 0.02-level dynamic DC standard meter through the 0.01-level traceability system, calculating the standard values of the dynamic DC voltage and dynamic DC current according to the DC voltage, dynamic AC voltage, DC current and dynamic AC current measured by the 0.01-level traceability system, comparing the standard values of the dynamic DC voltage and dynamic DC current with the measurement results of the 0.02-level dynamic DC standard meter, and obtaining the measurement traceability result of the 0.02-level dynamic DC standard meter; when the measurement error of the 0.02-level dynamic DC standard meter is within the specified error range, tracing the measured dynamic DC watt-hour meter through the 0.02-level dynamic DC standard meter: sending dynamic DC voltage and dynamic DC current to the measured dynamic DC watt-hour meter and the 0.02-level dynamic DC standard meter through the dynamic DC power source, and comparing the measurement result of the measured dynamic DC watt-hour meter with the measurement result of the 0.02-level dynamic DC standard meter to obtain the measurement traceability result of the measured dynamic DC watt-hour meter.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] First, the dynamic DC traceability system and the traceability method are built-in with a dynamic DC power source and a 0.02-level dynamic DC standard meter, and adopt an integrated design. There is no need for cumbersome wiring, and the operation is simple. It can detect the measurement accuracy of a 0.05-level dynamic DC watt-hour meter, can generate and measure dynamic DC signals, and fills the blank of existing dynamic DC traceability.

[0019] Second, the dynamic DC traceability system and the traceability method rely on the existing 0.01-level DC / AC traceability system, and trace the dynamic DC standard meter from three aspects of DC, AC, and AC-DC signals, providing a feasible method for dynamic DC traceability.

[0020] Third, the dynamic DC traceability system and the traceability method can generate and measure dynamic DC signals with high precision, and the types of dynamic DC signals can be expanded according to actual needs, greatly saving costs and having strong social and economic benefits. Description of the Drawings

[0021] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0022] Figure 1 is a structural diagram of the dynamic DC traceability system provided by the embodiment of the present application;

[0023] Figure 2It is a schematic diagram of the dynamic DC traceability system for tracing the measured dynamic DC watt-hour meter;

[0024] Figure 3 It is a schematic diagram of the dynamic DC traceability system for tracing the 0.02-class dynamic DC standard meter;

[0025] Figure 4 It is a schematic diagram of the connection between the 0.01-class traceability system and the 0.02-class dynamic DC standard meter;

[0026] Figure 5 It is a modulation schematic diagram of the dynamic AC voltage and the dynamic AC current;

[0027] Figure 6 It is a structural diagram of the 0.01-class DC traceability system

[0028] Figure 7 It is a structural diagram of the dynamic AC power source;

[0029] Figure 8 It is a structural diagram of the signal generator;

[0030] Figure 9 It is a structural diagram of the dynamic AC voltage amplifier;

[0031] Figure 10 It is a structural diagram of the voltage amplifier;

[0032] Figure 11 It is a structural diagram of the dynamic AC current amplifier;

[0033] Figure 12 It is a structural diagram of the 0.02-class dynamic DC standard meter;

[0034] Figure 13 It is a flowchart of the dynamic DC traceability method provided by the embodiment of the present application. Specific embodiments

[0035] In the following, the term "comprising" or "may comprise" that can be used in various embodiments of the present application indicates the presence of the claimed function, operation, or element, and does not limit the addition of one or more functions, operations, or elements. In addition, as used in various embodiments of the present application, the terms "comprising", "having" and their cognates are only intended to mean the presence of a specific feature, number, step, operation, element, component, or combination of the foregoing items, and should not be construed as precluding the existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items first.

[0036] Expressions (such as "first", "second", etc.) used in various embodiments of the present application may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only for the purpose of distinguishing one element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of the present application, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0037] It should be noted that: If it is described that a constituent element is "connected" to another constituent element or "linked" to another constituent element, the first constituent element may be directly connected to the second constituent element, and a third constituent element may be "connected" between the first constituent element and the second constituent element. On the contrary, when a constituent element is "directly connected" to another constituent element or "directly linked" to another constituent element, it can be understood that there is no third constituent element between the first constituent element and the second constituent element.

[0038] The terms used in the various embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the various embodiments of the present application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the various embodiments of the present application belong. Terms (such as those defined in a commonly used dictionary) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in the various embodiments of the present application.

[0039] To make the purpose, technical solutions, and advantages of the present application clearer and more understandable, the present application will be further described in detail below in conjunction with embodiments and drawings. The illustrative embodiments and descriptions of the present application are only for explaining the present application and do not serve as a limitation to the present application.

[0040] Currently, there is no recognized traceability method for direct current electrical energy (i.e., dynamic direct current electrical energy) superimposed with non-specific frequency / amplitude ripple components. The direct current electrical energy metering traceability system is incomplete, and although the direct current electrical energy meter meets the 0.01 level according to the existing national standard, the precise metering of the direct current component under dynamic conditions is not considered.

[0041] Therefore, the present application provides a dynamic DC traceability system and a traceability method, the purpose of which is to realize the verification and traceability of the measured dynamic DC watt-hour meter, and at the same time realize the traceability of the dynamic DC standard meter built in the dynamic DC traceability system itself, and trace it back to the national standard of 0.01 level; the principle is based on the characteristic that the dynamic DC signal can actually be decomposed into an AC signal and a DC signal, and the AC and DC are traced separately. By using the existing mature DC power traceability system and AC power traceability system to trace the AC and DC respectively, the indirect traceability of the dynamic DC traceability system is realized, the problem that the dynamic DC measurement cannot be traced at present is solved, the DC power metering traceability system is improved, and the precise metering of the DC component under dynamic conditions is realized.

[0042] Please refer to Figure 1 as shown in Figure 1 FIG. is the structural diagram of the dynamic DC traceability system provided by the embodiment of the present application. The system includes: a dynamic DC power source for modulating and generating a dynamic DC signal; a measured dynamic DC watt-hour meter for measuring the dynamic DC signal to obtain a first measurement result; a 0.02-level dynamic DC standard meter for measuring the dynamic DC signal to obtain a second measurement result, and comparing the first measurement result and the second measurement result to obtain the measurement traceability result of the measured dynamic DC watt-hour meter; a 0.01-level traceability system for generating a dynamic DC signal according to the known DC signal and dynamic AC signal, and measuring and tracing the 0.02-level dynamic DC standard meter according to the dynamic DC signal to obtain the measurement traceability result of the 0.02-level dynamic DC standard meter.

[0043] Specifically, please refer to Figure 2 as shown in Figure 2 FIG. is the schematic diagram of the dynamic DC traceability system tracing the measured dynamic DC watt-hour meter. The measured dynamic DC watt-hour meter performs dynamic DC voltage, dynamic DC current, dynamic DC power, and dynamic DC energy value traceability through a 0.02-level dynamic DC traceability system to realize the verification of the measured DC watt-hour meter. The dynamic DC power source is respectively connected to the 0.02-level dynamic DC standard meter and the measured dynamic DC watt-hour meter. The dynamic DC power source can output a dynamic DC signal. The measured dynamic DC watt-hour meter and the 0.02-level dynamic DC watt-hour meter simultaneously measure the dynamic DC signal output by the dynamic DC power source to realize dynamic DC voltage, dynamic DC current, and dynamic DC power and energy tests; the 0.02-level dynamic DC standard meter is connected to the measured dynamic DC watt-hour meter to receive the power pulse output by the measured dynamic DC watt-hour meter to realize the power detection of the measured dynamic DC watt-hour meter.

[0044] Please refer to Figure 3 as shown in Figure 3This is the schematic diagram of the dynamic DC traceability system for traceability of a 0.02-class dynamic DC standard meter. The dynamic DC traceability method relies on the existing traceability chain to separately trace the DC power and AC power of the 0.02-class dynamic DC watt-hour meter. In terms of AC traceability, the 0.01-class AC traceability system is connected to the 0.02-class dynamic DC standard meter, and the AC traceability of the 0.02-class dynamic DC standard meter is realized through the existing 0.01-class AC traceability system. The 0.01-class AC traceability system can be traced back to the national reference. In terms of DC traceability, the 0.01-class DC traceability system is connected to the 0.02-class dynamic DC standard meter, and the AC traceability of the 0.02-class dynamic DC standard meter is realized through the existing 0.01-class DC traceability system. The 0.01-class DC traceability system can be traced back to the national reference.

[0045] Compared with the existing technology, the present application decomposes the dynamic DC into a dynamic AC component and a DC component, and performs traceability through the existing 0.01-class AC traceability system and 0.01-class DC traceability system respectively, so as to solve the traceability problem of dynamic DC measurement; it can accurately trace the dynamic DC with a wide frequency range (40Hz - 2400Hz), random speed change, and pseudo-period.

[0046] Please refer to Figure 4 as shown in Figure 4 This is the schematic diagram of the connection between the 0.01-class traceability system and the 0.02-class dynamic DC standard meter. In a possible implementation manner, the 0.01-class traceability system includes: a dynamic AC power source for modulating and generating a dynamic AC voltage and a dynamic AC current, where the dynamic AC voltage and the dynamic AC current are a combination of AC power frequency half-cycles, and the waveforms and phases are consistent; a 0.01-class AC traceability system for measuring the dynamic AC voltage and the dynamic AC current; a 0.01-class DC traceability system for providing the measured DC voltage and DC current; wherein, the dynamic AC voltage and the DC voltage are connected in series to provide a dynamic DC voltage, the dynamic AC current and the DC current are coupled to provide a dynamic DC current, and the dynamic DC voltage and the dynamic DC current are dynamic DC signals.

[0047] Specifically, since the current 0.01-class AC traceability system is based on power frequency power measurement and cannot directly realize the measurement of dynamic AC, during the signal modulation process, if there is a step change in the signal, the output waveform spectrum will be broadened, generating a large number of harmonics, which has a serious impact on the measurement. Therefore, the present application uses the zero-crossing switching method for modulation. There is no step change in the signal modulation process, and the original signal is completely retained without generating additional harmonic signals; at the same time, the power frequency half-cycle is used as the minimum modulation unit, and the voltage and current waveforms have the same phase, so the 0.01-class standard meter of the existing 0.01-class AC traceability system can directly measure the voltage, current, and power of the dynamic AC. As Figure 5 shown in Figure 5It is a schematic diagram of the modulation of dynamic AC voltage and dynamic AC current. The minimum modulation unit is a half-cycle, so the modulation outputs of dynamic AC voltage and dynamic AC current in this scheme are based on the half-cycle power frequency. The modulation principles of voltage and current are the same, and the waveforms and phases of dynamic AC voltage and dynamic AC current are exactly the same. Therefore, the dynamic AC voltage, dynamic AC current, dynamic AC power, and dynamic AC electric energy are as follows:

[0048] U = A1 * sin(2π * f * t) * modulation pulse

[0049] I = A2 * sin(2π * f * t) * modulation pulse

[0050] P = U * I = A1 * A2 * modulation pulse / 2

[0051] W = P * T = A1 * A2 * T * modulation pulse / 2

[0052] In the formula, U is the output of dynamic AC voltage, I is the output of dynamic AC current, P is the dynamic AC power, W is the dynamic AC electric energy, A1 is the amplitude of the dynamic AC voltage output, A2 is the amplitude of the dynamic AC current output, f is the output frequency, t represents time, T is the cumulative duration of dynamic AC electric energy, and based on the existing 0.01-level AC traceability system, f = 50Hz. The modulation pulse can be compiled as needed. As Figure 5 shown, the modulation of the output waveform is realized. The modulation pulse can be arbitrarily compiled as needed, which is convenient for the modulation of the output waveform. The dynamic AC output under various modulation waveforms can be realized, and finally the dynamic DC test under various modulation waveforms can be realized, and the indirect traceability of the 0.02-level dynamic DC standard meter can be achieved. According to the formulas of dynamic AC voltage, dynamic AC current, dynamic AC power, and electric energy, the output waveform is still a complete power-frequency half-cycle unit combination, and the waveforms and phases of dynamic AC voltage and dynamic AC current are the same. The 0.01-level standard meter of the existing 0.01-level AC traceability system can be directly used to measure the values of dynamic AC voltage, dynamic AC current, dynamic AC power, and electric energy.

[0053] The 0.02-level dynamic DC standard meter needs to measure the dynamic DC. In this application, through the method of separate traceability for AC and DC, the dynamic DC is split into dynamic AC and DC for separate traceability, and the dynamic DC test performance of the 0.02-level dynamic DC standard meter is indirectly traced. As Figure 4 shown, the dynamic DC traceability method relies on the existing traceability chain and realizes the dynamic DC measurement traceability of the 0.02-level dynamic DC standard meter through the existing 0.01-level DC traceability system and 0.01-level AC traceability system. It is mainly divided into dynamic DC voltage traceability, dynamic DC current traceability, and dynamic DC power and electric energy traceability.

[0054] For dynamic DC voltage traceability, the dynamic AC power source outputs a dynamic AC voltage based on half-cycle modulation. The 0.01-level DC traceability system outputs a DC voltage based on the built-in high-stability DC standard voltage source. A dynamic DC voltage is formed by connecting the dynamic AC voltage and the DC voltage in series. The dynamic DC voltage is input into a 0.02-level dynamic DC standard meter to obtain the measurement result. At the same time, the dynamic AC voltage output by the dynamic AC power source is connected to the 0.01-level AC traceability system for traceability, and the DC voltage output by the 0.01-level DC traceability system is directly traced through the 0.01-level DC traceability system. Therefore, the dynamic DC voltage measured by the 0.02-level dynamic DC standard meter can be jointly traced by the 0.01-level AC traceability system and the 0.01-level DC traceability system.

[0055] For dynamic DC current traceability, the dynamic AC power source outputs a dynamic AC current based on half-cycle modulation. The 0.01-level DC traceability system outputs a DC current based on the built-in high-stability DC standard current source. The dynamic AC current and the DC current are input into the zero-flux current transformer built in the 0.02-level dynamic DC standard meter through different wires. The dynamic AC current and the DC current are measured independently and isolated from each other, and the measurement results are superimposed to obtain the measurement result of the dynamic DC current. At the same time, the dynamic AC current output by the dynamic AC power source is connected to the 0.01-level AC traceability system for traceability, and the DC current output by the 0.01-level DC traceability system is directly traced through the 0.01-level DC traceability system. Therefore, the dynamic DC current measured by the 0.02-level dynamic DC standard meter can be jointly traced by the 0.01-level AC traceability system and the 0.01-level DC traceability system.

[0056] For dynamic DC power and energy traceability, as can be seen from the previous dynamic DC voltage traceability and dynamic DC current traceability, the dynamic AC signals (dynamic AC voltage, dynamic AC current) in the dynamic DC signals (dynamic DC voltage, dynamic DC current) input into the 0.02-level dynamic DC standard meter all come from the 0.01-level AC traceability system, and the DC signals (DC voltage, DC current) all come from the 0.01-level DC traceability system. Therefore, the dynamic DC power and energy measured by the 0.02-level dynamic DC standard meter can be jointly traced by the AC power and energy of the 0.01-level AC traceability system and the DC power and energy of the 0.01-level DC traceability system.

[0057] Please refer to Figure 6 as shown in Figure 6 the structure diagram of the existing 0.01-level DC traceability system. The existing DC traceability system still realizes DC detection and traceability through the method of separately detecting voltage, current, power and energy. As above Figure 6As shown in the figure, the 0.01-level DC traceability system includes: a 7.5-digit high-stability DC standard voltage source, a high-stability DC standard current source, three eight-and-a-half-digit digital multimeters, and a 0.005-level DC standard conversion module; the 7.5-digit high-stability DC standard voltage source is connected to the eight-and-a-half-digit digital multimeter 1, and the 7.5-digit high-stability DC standard voltage source is connected to the DC watt-hour meter under test. By outputting different voltage values through the 7.5-digit high-stability DC standard voltage source, the voltage indication values of the eight-and-a-half-digit digital multimeter 1 and the DC watt-hour meter under test are compared to realize the voltage detection of the DC watt-hour meter under test; the high-stability DC standard current source is connected to the 0.005-level DC standard conversion module. The high-stability DC standard current source is converted into a proportional 0-1V voltage signal through the 0.005-level DC standard conversion module. The 0.005-level DC standard conversion module is connected to the eight-and-a-half-digit digital multimeter 2. The voltage signal after conversion by the 0.005-level DC standard conversion module is tested through the eight-and-a-half-digit digital multimeter 2. High-precision current measurement is achieved through proportional conversion. The high-stability DC standard current source is connected to the DC watt-hour meter under test. By outputting different current values through the high-stability DC standard current source, the current indication value after conversion by the eight-and-a-half-digit digital multimeter 2 and the current indication value of the DC watt-hour meter under test are compared to realize the current detection of the DC watt-hour meter under test; the eight-and-a-half-digit digital multimeter 3 is connected to the power pulse output of the DC watt-hour meter under test. The pulse output frequency of the DC watt-hour meter under test is tested through the digital multimeter of the eight-and-a-half-digit digital multimeter 3. According to the definition of the power pulse constant, the output frequency of the power pulse and the output power of the watt-hour meter under test are in a proportional relationship. Therefore, power and energy detection can be realized by testing the power pulse frequency. However, this method has a reading error problem of unstable frequency measurement due to insufficient power stability. Therefore, according to the relevant standard requirements, it is necessary to ensure that the output stability of the power source is higher than 1 / 5 of the test accuracy. For the 0.01-level DC traceability system, the required power stability is 0.002 level, and the required voltage and current stability are better than 0.002 level. Therefore, a 7.5-digit high-stability DC standard voltage source and a high-stability DC standard current source are required.

[0058] Please refer to Figure 7 as shown in the figure Figure 7 Shown is the structural diagram of a dynamic AC power source. In a possible implementation, the dynamic AC power source includes: a signal generator, a dynamic AC voltage amplifier, and a dynamic AC current amplifier; the signal generator is connected to the dynamic AC voltage amplifier to output an amplified dynamic AC voltage; the signal generator is connected to the dynamic AC current amplifier to output an amplified dynamic AC current.

[0059] Specifically, the dynamic AC power source of the present application adopts a virtual power source design scheme. According to the technical principle of calibrating power and electric energy with a virtual power source, the voltage and current will adopt an isolated output method. The dynamic AC voltage signal output by the signal generator is amplified and output through a dynamic AC voltage amplifier, and the dynamic AC current signal output by the signal generator is output through a dynamic AC current amplifier.

[0060] As Figure 8 shown, Figure 8 Figure 1 is the structural diagram of the signal generator. Further, the signal generator includes: an embedded single-chip microcomputer, a first digital isolator, a second digital isolator, a first DAC converter, and a second DAC converter; on the one hand, the embedded single-chip microcomputer generates dynamic AC voltage waveform fitting data, the dynamic AC voltage waveform fitting data is connected to the first digital isolator, the first digital isolator is connected to the first DAC converter, and the first DAC converter outputs a dynamic AC voltage signal; on the other hand, the embedded single-chip microcomputer generates dynamic AC current waveform fitting data, the dynamic AC current waveform fitting data is connected to the second digital isolator, the second digital isolator is connected to the second DAC converter, and the second DAC converter outputs a dynamic AC current signal.

[0061] Specifically, the embedded single-chip microcomputer outputs dynamic AC voltage waveform fitting data, which is isolated by the first digital isolator and then converted into a dynamic AC voltage signal through the first DAC converter; the embedded single-chip microcomputer outputs dynamic AC current waveform fitting data, which is isolated by the second digital isolator and then converted into a dynamic AC current signal through the second DAC converter.

[0062] It should be noted that the signal generator of the present application outputs a dynamic AC voltage signal and a dynamic AC current signal of two-channel small signals, and then outputs the signals required for dynamic DC traceability through a dynamic AC voltage amplifier and a dynamic AC current amplifier respectively. The two-channel programmable dynamic digital signal generation technology of the present application decomposes and quantifies the complex dynamic waveforms in the DC signal feature library, stores the waveform amplitudes in the time domain as digital information in the register, and realizes the modal fitting output of the characteristic waveforms through DAC conversion. The difficulty of this technology is that the more the number of decomposition points and the amplitude quantization levels, the smaller the waveform distortion, but it will also cause the problem of large storage data volume; therefore, preferably, a high-resolution DAC chip AD5780 with more than 18 bits of ADI can be selected to achieve a high amplitude quantization level and a low waveform distortion problem, and an STM32 embedded single-chip microcomputer can be used to build an embedded single-chip microcomputer system with a large data storage capacity, and 64M memory can be externally expanded to solve the problem of large storage data volume.

[0063] Please refer to Figure 9 shown, Figure 9This is the structural diagram of a dynamic AC voltage amplifier. Further, the dynamic AC voltage amplifier includes: a plurality of signal isolators and a plurality of voltage amplifiers. One end of the plurality of signal isolators is connected to a signal generator, and the other end is connected to the corresponding voltage amplifier. All the voltage amplifiers are connected in series and stacked to output the amplified dynamic AC voltage.

[0064] Specifically, transformers are usually applied to AC voltage amplification. However, the signal generated by the signal generator in this application has a DC ratio of not less than 80%, so the transformer scheme is not suitable; the commonly used DC-DC conversion in DC power supplies is also not applicable due to the disadvantage of high high-frequency ripple in the output. Therefore, this application uses operational amplifiers and precision resistors to design a high-gain and low-distortion dynamic AC voltage amplifier. The high-voltage amplification of the dynamic AC voltage is achieved by connecting multiple modules in series. The signal distortion is reduced by reducing the magnification of a single voltage amplifier, and the overall bandwidth is provided to solve the contradictions among the amplification factor, distortion degree, and passband. In terms of circuit implementation, devices such as ultra-low-noise and low-offset-voltage operational amplifiers and precision resistors with low temperature drift are used for design to ensure the high linearity and stability of the voltage output.

[0065] The dynamic AC voltage amplifier adopts a voltage series stacking boost technology solution. Optionally, by stacking 20 voltage amplifiers of 50V, an output voltage of 20 * 50V = 1000V can be achieved; to realize multi-module series boosting, it is necessary to ensure isolation between each voltage amplifier, that is, isolation of the input signals of the voltage amplifiers and isolation of the power supplies of the voltage amplifiers. Therefore, the dynamic AC voltage signal generated by the signal generator is connected to the signal isolator, and after being transformed by the signal isolator 1:1, it becomes an isolated voltage signal to realize the subsequent stacking of voltage power amplifiers. The principle is the same for 20 channels of power amplifiers and will not be elaborated further; a signal isolator is connected to a 50V voltage amplifier, and the voltage signal output by the signal isolator is amplified according to a fixed ratio by the 50V voltage amplifier to realize the amplification of the input signal. The principle is the same for 20 channels of power amplifiers and will not be elaborated further; the 50V voltage amplifiers are connected to each other to realize the series connection of the voltage amplifiers, and finally, a dynamic DC voltage output of 1000V high voltage is realized.

[0066] Preferably, the signal isolator can adopt the signal isolation module TF5554N, which has high precision, high linearity, an isolation voltage of 2KV, a ripple noise lower than 30mV, and a temperature drift less than 50ppm / °C in the full working range, meeting the design requirements of this application.

[0067] Please refer to Figure 10 as shown in Figure 10 This is the structural diagram of the voltage amplifier. Further, the voltage amplifier adopts an in-phase proportional amplification circuit.

[0068] Specifically, as Figure 10As shown in the figure, a 50V voltage amplifier can adopt a non-inverting proportional amplifier circuit. The amplification factor of the amplifier can be set by adjusting the resistance values of R3 and R4. The power supply of the amplifier can be selected as ±80V power supply to achieve a 50V voltage output; the AMP amplifier uses the high-voltage, high-current, and high-precision operational amplifier OPA462 of TI, which supports a maximum power supply of ±90V, a maximum output current of 45mA, a gain-bandwidth product of 6.5MHz, and has output overheat and overload protection, meeting the requirements of amplification.

[0069] Please refer to Figure 11 as shown in the figure Figure 11 As shown in the figure, it is the structure diagram of a dynamic AC current amplifier. Further, the dynamic AC current amplifier includes: an error amplifier, a driving transistor, a high-power transistor group, and a zero-flux current transformer sampling circuit. One end of the error amplifier is connected to the signal generator, and the other end is connected to the driving transistor. The driving transistor is connected to the high-power transistor group. The output of the high-power transistor group is connected to the error amplifier through the zero-flux current transformer sampling circuit. The high-power transistor group outputs the amplified dynamic AC current.

[0070] Specifically, the dynamic AC current amplifier is essentially a voltage-controlled constant current source, which can convert a differential small voltage signal into a large current signal output. Since there is only a voltage-current change stage and a current transmission stage inside and no voltage gain stage, the transconductance amplifier does not have a large swing voltage signal and the Miller capacitance multiplication effect, and has good high-frequency performance and a high conversion rate under large signals. Since the output current and input voltage that determine the gain are measured at two nodes respectively, the bandwidth and gain of the circuit are independent of each other, overcoming the limitation of the gain-bandwidth product, enabling the constant current source to have excellent broadband performance and large current output ability. Then, through the series zero-flux current transformer sampling circuit for current negative feedback and comparison with the reference voltage, the difference signal is amplified and then drives the high-power transistor group to adjust and compensate for the change of the output current to achieve a high-stability constant current output.

[0071] As Figure 11 shown in the figure, the signal generator generates a dynamic AC current signal, the zero-flux current transformer sampling circuit generates a voltage signal proportional to the output current, the error amplifier realizes error amplification by comparing the dynamic AC current signal and the voltage signal proportional to the output current, and controls the conduction and amplification of the driving transistor, and finally drives the high-power transistor group to achieve the amplified output of the dynamic AC current, realizing the closed-loop amplified output of the dynamic AC current.

[0072] Please refer to Figure 12 as shown in the figure Figure 12It is the structural diagram of a 0.02 - level dynamic DC standard meter. In a possible implementation, the 0.02 - level dynamic DC standard meter includes: a precision resistor voltage - dividing circuit, a zero - flux mutual - inductor sampling circuit, a synchronous sampling ADC, a microprocessor, a pulse input / output unit, and an amplitude / power / electric - energy calculation and display unit; the voltage input is connected to the precision resistor voltage - dividing circuit, the precision resistor voltage - dividing circuit is connected to the synchronous sampling ADC, the current input is connected to the zero - flux mutual - inductor sampling circuit, the zero - flux mutual - inductor sampling circuit is connected to the synchronous sampling ADC, the synchronous sampling ADC is connected to the microprocessor, and the microprocessor is connected to the pulse input / output unit and the amplitude / power / electric - energy calculation and display unit.

[0073] Furthermore, the zero - flux mutual - inductor sampling circuit includes: a mutual - inductor and two coils that pass through the mutual - inductor and are isolated from each other. The two coils respectively lead out a DC current input terminal and an AC current input terminal.

[0074] Specifically, as Figure 12 shown, the dynamic DC voltage is input to the precision resistor voltage - dividing circuit. After being divided by the precision voltage - dividing circuit, it is collected by the synchronous sampling ADC; the dynamic DC current (dynamic AC current and DC current) is input to the zero - flux mutual - inductor sampling circuit. After passing through the zero - flux mutual - inductor sampling circuit, it is collected by the synchronous sampling ADC; the microprocessor reads the sampling data of the synchronous sampling ADC through the SPI interface; the microprocessor is connected to the pulse input / output unit, calculates the power and electric - energy values through the microprocessor, outputs electric - energy pulses, or calculates the electric - energy error according to the input electric - energy pulses; the microprocessor is connected to the amplitude / power / electric - energy calculation and display unit. The microprocessor reads the data sampled by the ADC, calculates the amplitude, power, and electric - energy values and displays them.

[0075] Preferably, the precision resistor voltage - dividing circuit can adopt a standard voltage divider of Fluke, supporting an input range of 0V - 1000V, with a linearity of ±0.1ppm, a temperature - drift coefficient of 0.1ppm, and having a self - calibration ability, which is very suitable for measuring high - precision dynamic DC voltage ranges. The zero - flux mutual - inductor sampling circuit can adopt a zero - flux mutual - inductor of LEM and a standard resistor of Fluke to achieve high - precision I / V conversion of the input current, facilitating subsequent ADC acquisition. The synchronous sampling ADC can adopt a 24 - bit ADC of TI to achieve high - precision analog - to - digital conversion, and can achieve synchronous sampling between voltage and current to achieve precise measurement of dynamic DC power and electric energy. The microprocessor can adopt an STM32 series embedded single - chip microcomputer, having an SPI interface, capable of reading ADC data, adopting a Cortex series kernel, having extremely strong data - processing capabilities, capable of realizing amplitude, power, and electric - energy analysis and calculation, with a built - in 32 - bit timer, supporting input / output pulse measurement, and having an LCD display interface, capable of realizing amplitude, power, and electric - energy display.

[0076] In summary, the dynamic DC traceability system provided by this application has the following advantages: First, it is built-in with a dynamic DC power source and a 0.02-level dynamic DC standard meter, adopting an integrated design, eliminating the need for cumbersome wiring, with simple operation. It can detect the measurement accuracy of a 0.05-level dynamic DC watt-hour meter, realize the generation and measurement of dynamic DC signals, filling the gap in existing dynamic DC traceability. Second, relying on the existing 0.01-level DC / AC traceability system, it traces the 0.02-level dynamic DC standard meter from three aspects: DC, AC, and AC-DC signals, providing a feasible method for dynamic DC traceability. Third, it can generate and measure dynamic DC signals with high precision, and the types of dynamic DC signals can be expanded according to actual needs, greatly saving costs and having strong social and economic benefits.

[0077] Please refer to Figure 13 as shown Figure 13 which is a flowchart of the dynamic DC traceability method provided by an embodiment of this application. The method is executed based on the above dynamic DC traceability system. The method includes: tracing the 0.02-level dynamic DC standard meter through the 0.01-level traceability system: sending dynamic DC voltage and dynamic DC current to the 0.02-level dynamic DC standard meter through the 0.01-level traceability system, calculating the standard values of the dynamic DC voltage and dynamic DC current according to the DC voltage, dynamic AC voltage, DC current, and dynamic AC current measured by the 0.01-level traceability system, comparing the standard values of the dynamic DC voltage and dynamic DC current with the measurement results of the 0.02-level dynamic DC standard meter to obtain the measurement traceability result of the 0.02-level dynamic DC standard meter; when the measurement error of the 0.02-level dynamic DC standard meter is within the specified error range, tracing the measured dynamic DC watt-hour meter through the 0.02-level dynamic DC standard meter: sending dynamic DC voltage and dynamic DC current to the measured dynamic DC watt-hour meter and the 0.02-level dynamic DC standard meter through the dynamic DC power source, and comparing the measurement result of the measured dynamic DC watt-hour meter with the measurement result of the 0.02-level dynamic DC standard meter to obtain the measurement traceability result of the measured dynamic DC watt-hour meter.

[0078] It should be noted that the dynamic DC traceability method provided by the embodiment of this application is executed based on the above dynamic DC traceability system and has corresponding technical effects, so it will not be elaborated here.

[0079] The above specific implementation manners further elaborate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific implementation manners of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dynamic DC source tracing system, characterized in that: include: A dynamic DC power source, used for modulating and generating a dynamic DC signal; The dynamic DC electric energy meter to be measured is used to measure the dynamic DC signal to obtain a first measurement result; A 0.02-level dynamic DC standard meter is used to measure a dynamic DC signal to obtain a second measurement result, and compare the first measurement result with the second measurement result to obtain a measurement traceability result of the dynamic DC electric energy meter being measured; A 0.01-level traceability system is used to generate a dynamic DC signal according to a known DC signal and a dynamic AC signal, and to perform measurement traceability on the 0.02-level dynamic DC standard meter according to the dynamic DC signal to obtain a measurement traceability result of the 0.02-level dynamic DC standard meter; The 0.01-level traceability system includes: a dynamic AC power source, used for modulating and generating a dynamic AC voltage and a dynamic AC current, wherein the dynamic AC voltage and the dynamic AC current are a combination of half cycles of the AC power frequency, and have consistent waveforms and phases; a 0.01-level AC traceability system, used for measuring the dynamic AC voltage and the dynamic AC current; a 0.01-level DC traceability system, used for providing measured DC voltage and DC current; wherein the dynamic AC voltage and the DC voltage are connected in series to provide a dynamic DC voltage, the dynamic AC current and the DC current are coupled to provide a dynamic DC current, and the dynamic DC voltage and the dynamic DC current are dynamic DC signals; The 0.02-level dynamic DC standard meter includes: a precision resistor voltage divider circuit, a zero-flux mutual inductor sampling circuit, a synchronous sampling ADC, a microprocessor, a pulse input and output unit, and an amplitude / power / electric energy calculation and display unit; the voltage input is connected to the precision resistor voltage divider circuit, the precision resistor voltage divider circuit is connected to the synchronous sampling ADC, the current input is connected to the zero-flux mutual inductor sampling circuit, the zero-flux mutual inductor sampling circuit is connected to the synchronous sampling ADC, the synchronous sampling ADC is connected to the microprocessor, and the microprocessor is connected to the pulse input and output unit and the amplitude / power / electric energy calculation and display unit.

2. A dynamic DC source tracing system according to claim 1, characterized in that: The dynamic AC power source includes: a signal generator, a dynamic AC voltage amplifier, and a dynamic AC current amplifier; The signal generator is connected to the dynamic AC voltage amplifier to output the amplified dynamic AC voltage; The signal generator is connected to the dynamic alternating current amplifier and outputs the amplified dynamic alternating current.

3. A dynamic DC source tracing system according to claim 2, characterized in that: The signal generator comprises: An embedded single-chip microcomputer, a first digital isolator, a second digital isolator, a first DAC converter, and a second DAC converter; On the one hand, the embedded single-chip computer generates dynamic AC voltage waveform fitting data, the dynamic AC voltage waveform fitting data is connected to the first digital isolator, the first digital isolator is connected to the first DAC converter, and the first DAC converter outputs a dynamic AC voltage signal; On the other hand, the embedded single chip microcomputer generates dynamic AC current waveform fitting data, the dynamic AC current waveform fitting data is connected to the second digital isolator, the second digital isolator is connected to the second DAC converter, and the second DAC converter outputs a dynamic AC current signal.

4. A dynamic DC source tracing system according to claim 2, characterized in that: The dynamic AC voltage amplifier includes: multiple signal isolators and multiple voltage amplifiers, one end of the multiple signal isolators is connected to the signal generator, and the other end is connected to the corresponding voltage amplifier, all the voltage amplifiers are stacked in series to output the amplified dynamic AC voltage.

5. A dynamic DC source tracing system according to claim 4, characterized in that: The voltage amplifier adopts a common-phase proportional amplifier circuit.

6. A dynamic DC source tracing system according to claim 2, characterized in that: The dynamic AC current amplifier includes: an error amplifier, a driving tube, a high-power triode group and a zero-flux mutual inductor sampling circuit. One end of the error amplifier is connected to the signal generator, and the other end is connected to the driving tube. The driving tube is connected to the high-power triode group. The output of the high-power triode group is connected to the error amplifier through the zero-flux mutual inductor sampling circuit. The high-power triode group outputs the amplified dynamic AC current.

7. A dynamic DC source tracing system according to claim 1, characterized in that: The zero-flux transformer sampling circuit comprises: a transformer and two coils passing through the transformer and isolated from each other, wherein the two coils lead to a direct current input terminal and an alternating current input terminal respectively.

8. A dynamic DC source tracing method, characterized in that: The method is performed based on a dynamic DC source tracing system according to any one of claims 1 to 7, comprising: Trace the 0.02-level dynamic DC standard meter through the 0.01-level traceability system: send the dynamic DC voltage and dynamic DC current to the 0.02-level dynamic DC standard meter through the 0.01-level traceability system, calculate the standard values ​​of the dynamic DC voltage and dynamic DC current according to the DC voltage, dynamic AC voltage, DC current and dynamic AC current measured by the 0.01-level traceability system, compare the standard values ​​of the dynamic DC voltage and dynamic DC current with the measurement results of the 0.02-level dynamic DC standard meter, and obtain the measurement traceability results of the 0.02-level dynamic DC standard meter; When the measurement error of the 0.02-level dynamic DC standard meter is within the specified error range, the dynamic DC electric energy meter under test is traced through the 0.02-level dynamic DC standard meter: the dynamic DC voltage and dynamic DC current are sent to the dynamic DC electric energy meter under test and the 0.02-level dynamic DC standard meter through the dynamic DC power source, and the measurement result of the dynamic DC electric energy meter under test is compared with the measurement result of the 0.02-level dynamic DC standard meter to obtain the measurement traceability result of the dynamic DC electric energy meter under test.

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