CN211263701U - High-precision direct current electric energy metering standard source - Google Patents
High-precision direct current electric energy metering standard source Download PDFInfo
- Publication number
- CN211263701U CN211263701U CN201922226567.1U CN201922226567U CN211263701U CN 211263701 U CN211263701 U CN 211263701U CN 201922226567 U CN201922226567 U CN 201922226567U CN 211263701 U CN211263701 U CN 211263701U
- Authority
- CN
- China
- Prior art keywords
- module
- direct current
- electric energy
- current
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Measurement Of Current Or Voltage (AREA)
Abstract
The utility model relates to a high-precision direct current electric energy metering standard source, which mainly comprises a direct current constant voltage source, a constant current source, an electric energy error calculation module, an electric energy pulse sampling module, an error display module, computer automatic calibration software and the like; the direct current component and the alternating current component are respectively measured by adopting a ripple superposition and precise electric energy measurement technology, so that the problem that high-precision alternating current components with frequency bands of 100 Hz-1000 Hz and adjustable amplitudes and phases are superposed in a direct current large voltage source and a current source is solved, the precise measurement of the direct current energy under the ripple superposition can be realized, and the energy consumption evaluation of a direct current charger is realized; the direct current comparator technology is adopted, the magnetic flux detection module is adopted to convert current to be detected into a voltage signal, and the power amplifier is controlled to control output, so that the iron core is finally enabled to achieve magnetic balance, and accurate measurement of large current is achieved.
Description
Technical Field
The utility model belongs to the technical field of the direct current electric energy measurement, concretely relates to direct current electric energy measurement standard source of high accuracy.
Background
At present, direct current electric energy metering standard source equipment for energy efficiency evaluation of a direct current charger needs to realize accurate measurement of direct current heavy current and superpose high-precision alternating current components on a direct current source and a voltage source to carry out energy efficiency evaluation and on-site verification work; aiming at direct current heavy current measurement, a four-terminal resistance method, a Hall method, a magneto-optical effect measurement method and a direct current comparator method are mainly adopted in the prior art; when the four-terminal resistance method is used for measuring current, the precision is reduced due to self-heating of the resistor, and the power consumption and the equipment volume are large; the Hall method is greatly influenced by the external temperature when measuring the current, so the precision is difficult to improve; the magneto-optical effect measuring method is simple to operate and can prevent electromagnetic interference, but the measuring precision is low; at present, there is no mature application technology for high-precision output and measurement under direct current ripple superposition.
SUMMERY OF THE UTILITY MODEL
The utility model aims at overcoming the not enough of prior art, and provide a direct current electric energy measurement standard source of high accuracy swift, convenient, simple structure, fixed effectual, the flexibility is fixed.
The purpose of the utility model is realized like this: a high-precision direct current electric energy metering standard source comprises a direct current comparator, wherein the high-precision direct current electric energy metering standard source comprises a constant voltage source, a constant current source, an electric energy error calculation module, an electric energy pulse acquisition module, an error display module and an FPGA; the FPGA is connected with the DAC module, a user is connected with the microprocessor through a computer interface, the microprocessor is connected with the direct current constant voltage source and the constant current source, the direct current constant voltage source and the constant current source are connected with the tester, the tester is connected with the pulse acquisition module of the calibration system, and the electric energy error calculation module is connected with the tester, the calibration system and the display module; the FPGA is connected with a ripple superposition unit, and the ripple superposition unit consists of a DAC module, an ADC module, a conditioning circuit, a sampling module, a high-voltage output operational amplifier module and an adder; the adder, the high-voltage output operational amplifier module and the sampling module are sequentially connected in series.
The utility model provides a direct current electric energy measurement standard source of high accuracy still has following technical characteristic:
furthermore, the FPGA adopts a large-capacity field programmable gate array module, the model number of which is 10M50SCE144C 8G.
Further, the DAC module is a 16-bit AD 5622A.
Further, the ADC module is a 20-bit SAR-type LTC 2378.
Further, the GPS clock checking module comprises a TDC-GPX chip.
Furthermore, the sampling module is mainly divided into a voltage sampling module and a current sampling module, wherein the voltage sampling module is connected in series through a plurality of resistors and then connected in parallel to a red and black terminal of voltage output; the current sampling module is connected in series in a loop of which the output black end is connected back to the system reference ground through a sampling resistor.
Further, the adder adopts a general-purpose precision operational amplifier OPA 189.
Furthermore, the FPGA converts the preset voltage/current value into analog quantity through the DAC module, and the analog voltage outputs the voltage value of the corresponding range after passing through the power amplification and transformer boosting module; a user sets a calibration point through a computer interface and transmits the calibration point to a microprocessor, the microprocessor calculates the selected voltage and current, controls the direct current constant voltage source and the constant current source to switch to the optimal range, and simultaneously outputs the required voltage and current to the tester to be calibrated; the tester generates standard pulses and outputs the standard pulses to a pulse acquisition module of the calibration system; the electric energy error calculation module compares the pulse number of the tester with the pulse number of the calibration system to calculate the electric energy error, and transmits a data value to the display module to be displayed; the FPGA is connected with the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module through the DAC module, the sampling module is connected with the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module through the conditioning circuit, and the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module adder are connected in parallel.
Further, a direct current comparator technology is adopted, a magnetic flux detection module is adopted to convert current to be detected into a voltage signal, and a power amplifier is controlled to control output, so that the iron core is finally in magnetic balance, and accurate measurement of large current is realized; clock checking: integrates the receiving function of the absolute clock of the high-precision GPS
Furthermore, the main source of system errors during verification is that the rising edges of the detected pulse are inconsistent with the rising edges of the standard pulse, and the solution of the tester is to adopt a TDC chip by a pulse delay digital compensation technology.
Further, the overall structure of the ripple superposition module is described as follows: the ripple (i.e. alternating current) signal which needs to be superimposed and the direct current signal of the ripple (i.e. alternating current) signal have similar processing methods in the system; from the view of ripple waves, the device mainly comprises an independent digital-to-analog converter, an alternating current signal processing circuit, an adder, a power output circuit, a high-voltage sampling circuit, a DC blocking circuit, a feedback circuit, an analog-to-digital converter shared with direct current and the like.
Furthermore, the FPGA adopts a large-capacity field programmable gate array module with the model number of 10M50SCE144C8G, the maximum frequency reaches 450MHz, the programmable logic resource is 50k, the available memory 1677312bits is provided, flash storage is arranged on the chip, powerful logic programming and data processing can be independently realized without peripheral configuration chips, the FPGA has the functions of relay switching, receipt acquisition and the like, and the system processing efficiency can be improved.
Further, a direct current constant voltage source feeds back the voltage division sampling through a resistor so as to ensure the stable operation of the whole system; the U1 is responsible for preprocessing signals, is of an OPA189 type, has extremely small offset voltage of 3 muV and noise performance of 5.2nV/√ Hz, and can perfectly amplify and preprocess the signals from the DAC, namely adjusting the amplitude and providing driving capability; u2 is responsible for power amplification, and its model is LM 3886; the maximum output of 1150V is amplified by a transformer, and feedback is performed by resistance sampling.
Further, the constant current source performs feedback through resistance sampling so as to ensure the stable operation of the whole system; the U1 is responsible for preprocessing signals, is of an OPA189 type, has extremely small offset voltage of 3 muV and noise performance of 5.2nV/√ Hz, and can perfectly amplify and preprocess the signals from the DAC, namely adjusting the amplitude and providing driving capability; the U2 is responsible for power amplification, the model is LM3886, and 600A can be output to the maximum extent after the amplification is carried out through a transformer; and outputting current resistance sampling for feedback.
Further, the DC DAC adopts 16-bit AD5622A, the offset voltage is extremely low and is only 10mV, and the amplitude of the DC output can be controlled; the ripple is handled in a dual DAC mode, where 1 block is a 12bit AD7845J responsible for generating ac waveforms of different frequencies, and the other DAC block is AD5622A responsible for amplitude modulating the ac waveform.
Furthermore, the ADC module adopts a 20-bit SAR type LTC2378, the module has a sampling rate of 1000kSPS, and has excellent sampling effect on the frequency bands involved in the project; the voltage signal and the current signal are fed back and sampled to be digital type, and the digital type is sent to the FPGA for operation processing.
Furthermore, the GPS clock check module adopts a TDC-GPX chip for measurement, the chip is a digital converter based on internal propagation time delay, and comprises 3 paths of LVPECL differential inputs and 8 paths of LVTTL single-ended test channels, the starting edges of the LVPECL differential inputs and the LVTTL single-ended test channels can be configured, and the measurement precision reaches 27 ps.
Further, the conditioning circuit is introduced as follows, interference such as high-frequency noise and the like can not be avoided in the voltage feedback and current feedback transmission processes, the interference is suppressed by designing a low-pass filter, and signal conditioning is performed by designing a second-order Butterworth low-pass filter.
Furthermore, the sampling module is mainly divided into voltage sampling and current sampling; voltage sampling is performed through a plurality of resistors in series connection, then the voltage sampling is connected to a red and black terminal of voltage output in parallel, the high voltage of 1000V is divided into 1V low-voltage sampling signals, the resistors adopt inlet precision resistors, and the temperature drift is only +/-10 ppm; the total resistance value of the divider resistor is high by 10 MOmega, so that the current output capability is not reduced due to shunting; the current sampling is realized by connecting a sampling resistor in series in a loop of which the output black end is connected back to the reference ground of the system, and different current measuring ranges adopt different sampling resistors to correspond to the current measuring ranges.
Further, regarding the adder, the parameters of the adder are: the output signal is a direct current signal +0.2 alternating current signal, and the requirement that the ripple content is 20% of direct current can be met under the condition that the ripple signal is not attenuated; the adder adopts a general precision operational amplifier OPA 189; meanwhile, the design of a relay is added, so that the adder can control different bandwidths to meet the requirement of the output frequency band of the signal.
The traditional method and the defects thereof are as follows: the traditional scheme is for realizing adding the ripple component on direct current electric quantity, directly with DA output mixed waveform (direct current adds the ripple), then power amplification output carries out AC feedback with the waveform at the output, guarantees entire system's steady operation, and this method mainly has following three not enough:
first, the adjustment resolution of the waveform is low. In the interval of the original DA, not only the dc full scale needs to be realized, but also ripple components of up to 20% need to be superimposed. In the most ideal case, after 20% of ripple component is added, the full value of the dc value is 78% of the original full value, so the adjustment resolution is greatly reduced.
② the accuracy of the direct current is low. Because the direct current and the ripple adopt the same output and feedback hardware structures, and the ripple is an alternating current signal, the requirement range for the bandwidth is large, a large amount of noise components exist in the direct current signal, and the direct current parameter precision is directly reduced.
And thirdly, the adjusting mechanism is unstable, and because the operational amplifier has different processing effects on the direct current and the ripple waves, the adjustment of the direct current and the alternating current components cannot be synchronous in the direct current waveform with the aliasing ripple waves, which can cause the unstable phenomenon of the feedback system and further influence the stability of the operation of the whole system.
The invention creates an improved method and an idea: separating direct current and ripples on hardware and software, specifically as follows:
firstly, separating direct current and ripples at a generating and feedback position, superposing the direct current and the ripples at a power amplifying and output position, and sampling by using an ADC (analog-to-digital converter) at the rear end; the DC and the ripple waves are provided with independent DACs and different hardware amplifying and feedback circuits, and the independent DACs can ensure higher adjustment resolution and output precision of the DC and the AC.
Meanwhile, the bandwidth of the direct current loop is low, high-frequency noise can be effectively removed, and the stability of output is improved; the ripple circuit can perform DC blocking operation to eliminate DC noise such as offset voltage generated by the operational amplifier; the modular design ensures the accuracy of the direct current and ripple signals.
And secondly, the electrical isolation between the digital circuit and the analog circuit is increased. Because the DAC can output different noises under different frequency working states, the direct current output performance of the equipment can be influenced; according to the relevant standards, the frequency of the ripple wave needs to be adjusted between 100Hz and 1kHz, so that the accuracy of the direct current electric quantity is influenced by different degrees when the ripple wave is output under different frequencies; by isolating the digital circuit from the analog circuit, the interference of the DAC on the DC power can be effectively eliminated.
Introduction of the FPGA used in connection with the creation of the present invention: the FPGA device belongs to a semi-custom circuit in an application-specific integrated circuit, is a programmable logic array, and can effectively solve the problem that the number of gate circuits of the original device is small; the FPGA chip is not only limited to research and design chips, but also can be optimally designed by means of a specific chip model aiming at products in more fields; from the viewpoint of chip devices, the FPGA itself constitutes a typical integrated circuit in a semi-custom circuit, which includes a digital management module, an embedded unit, an output unit, an input unit, and the like.
For the convenience of understanding the invention, the standard voltage/current output, ripple superposition and difference verification principles related to the invention are introduced as follows:
(1) standard voltage/current output: the FPGA converts the preset voltage/current value into analog quantity through a DAC module, analog voltage is output to a voltage value of a corresponding range after passing through a power amplification and transformer boosting module, the maximum output voltage reaches 1150V, and the maximum output current is 600A: the device adopts the direct current comparator technology to realize the accurate feedback measurement of the direct current heavy current, and the voltage/current accuracy level can reach 0.02 level.
(2) And (3) ripple superposition: the ripple superposition and precise electric energy metering technology is adopted to respectively meter the direct current component and the alternating current component, so that the problem of superposing high-precision alternating current components with frequency bands of 100 Hz-1000 Hz and adjustable amplitudes and phases in a direct current large voltage source and a current source is solved, precise metering of direct current electric energy under ripple superposition can be realized, and the ripple accuracy can reach 0.05 level.
(3) The principle of differential detection: the main source of the system error during the detection is the inconsistency between the rising edges of the detected pulse and the standard pulse, and the solution of the tester is that the delay of the rising edges of the standard pulse and the detected pulse is measured by adopting a pulse delay digital compensation technology and a TDC chip with the resolution of 55ps, and the delay is digitally compensated, so that higher measurement precision is realized.
The microprocessor and the FPGA control the DAC module to generate preset alternating current and direct current electric quantity, and the preset alternating current and direct current electric quantity is output as required electric quantity through the pre-operational amplifier module, the adder and the high-voltage output operational amplifier; meanwhile, the sampling and conditioning module feeds back and outputs the power to the pre-operational amplifier module for adjustment, so that the accuracy of the output power is ensured; for the electric energy measurement superposed with the specific ripple quantity, the electric energy E of N sampling points at the preset time of t is calculated as shown in the following formula:
in the formula (I), the compound is shown in the specification,
averaging direct current voltage and direct current;
θ: phase angle between ripple voltage and ripple current.
The utility model has the advantages that: the invention specifically has the following beneficial effects in terms of specific technical means:
(1) electric energy verification: the direct current voltage/current of 1150V/600A at maximum can be output, the electric energy accuracy reaches 0.05 level, and tests such as voltage/current, power/electric energy and the like can be performed on an electric vehicle charger;
(2) and (3) ripple superposition: high-precision alternating current components with the frequency band of 100 Hz-1000 Hz can be superposed in a direct current large voltage source and a current source, and the amplitude and the phase of the high-precision alternating current components can be adjusted so as to carry out a ripple influence test of a tester.
(3) Clock checking: the device integrates the function of receiving the absolute clock of the high-precision GPS, can display the Beijing time in real time, and completes the verification of the clock indication error of the field detection device of the charger.
Drawings
Fig. 1 is a schematic diagram of a system of a high-precision dc power measurement standard source of the present invention.
Fig. 2 is the utility model relates to a ripple superposition unit schematic diagram of direct current electric energy measurement standard source of high accuracy.
Fig. 3 is a schematic diagram of a ripple superposition module of a high-precision dc power measurement standard source.
Fig. 4 is a schematic view of a constant voltage source of a high-precision dc power measuring standard source of the present invention.
Fig. 5 is a schematic diagram of a constant current source of a high-precision dc power measuring standard source of the present invention.
Fig. 6 is a schematic diagram of a conditioning circuit of a high-precision dc power measurement standard source of the present invention.
Fig. 7 is a schematic diagram of an adder of a high-precision dc power measurement standard source according to the present invention.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings in conjunction with embodiments; it should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.
As shown in fig. 1 to 7, a high-precision dc power measurement standard source includes a dc comparator, and the high-precision dc power measurement standard source includes a constant voltage source, a constant current source, a power error calculation module, a power pulse acquisition module, an error display module, and an FPGA; the FPGA is connected with the DAC module, a user is connected with the microprocessor through a computer interface, the microprocessor is connected with the direct current constant voltage source and the constant current source, the direct current constant voltage source and the constant current source are connected with the tester, the tester is connected with the pulse acquisition module of the calibration system, and the electric energy error calculation module is connected with the tester, the calibration system and the display module; the FPGA is connected with a ripple superposition unit, and the ripple superposition unit consists of a DAC module, an ADC module, a conditioning circuit, a sampling module, a high-voltage output operational amplifier module and an adder; the adder, the high-voltage output operational amplifier module and the sampling module are sequentially connected in series.
In an embodiment of the present application, as shown in fig. 1-2, the FPGA is connected to a ripple superposition unit, and the ripple superposition unit is composed of a DAC module, an ADC module, a dc pre-operational amplifier module, a conditioning circuit, a ripple pre-operational amplifier module, a sampling module, a high-voltage output operational amplifier module, and an adder; the adder, the high-voltage output operational amplifier module and the sampling module are sequentially connected in series; the FPGA is connected with the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module through the DAC module, the sampling module is connected with the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module through the conditioning circuit, and the direct-current pre-operational amplifier module and the ripple pre-operational amplifier module adder are connected in parallel.
In an embodiment of the present application, as shown in fig. 1-2, the FPGA converts the preset voltage/current value into an analog quantity through the DAC module, and the analog voltage outputs a voltage value of a corresponding range after passing through the power amplification and transformer boosting module; a user sets a calibration point through a computer interface and transmits the calibration point to a microprocessor, the microprocessor calculates the selected voltage and current, controls the direct current constant voltage source and the constant current source to switch to the optimal range, and simultaneously outputs the required voltage and current to the tester to be calibrated; the tester generates standard pulses and outputs the standard pulses to a pulse acquisition module of the calibration system; the electric energy error calculation module compares the pulse number of the tester with the pulse number of the calibration system to calculate the electric energy error, and transmits a data value to the display module to be displayed.
When the embodiment is implemented, the following technical effects (1) of electric energy verification can be achieved: the direct current voltage/current of 1150V/600A at maximum can be output, the electric energy accuracy reaches 0.05 level, and tests such as voltage/current, power/electric energy and the like can be performed on an electric vehicle charger; (2) and (3) ripple superposition: high-precision alternating current components with the frequency band of 100 Hz-1000 Hz can be superposed in a direct current large voltage source and a current source, and the amplitude and the phase of the high-precision alternating current components are adjustable so as to carry out a ripple influence test of a tester; (3) clock checking: the device integrates the function of receiving the absolute clock of the high-precision GPS, can display the Beijing time in real time, and completes the verification of the clock indication error of the field detection device of the charger.
In one embodiment of the present application, the FPGA employs a large-capacity field programmable gate array module, model 10M50SCE144C 8G.
In one embodiment of the present application, the DAC module is a 16-bit AD 5622A.
In one embodiment of the present application, the ADC block is a 20-bit SAR-type LTC 2378.
In one embodiment of the present application, the GPS clock calibration module comprises a TDC-GPX chip.
In one embodiment of the present application, the sampling module is mainly divided into a voltage sampling module and a current sampling module, wherein the voltage sampling module is connected in series through a plurality of resistors and then connected in parallel to a red and black terminal of a voltage output; the current sampling module is connected in series in a loop of which the output black end is connected back to the system reference ground through a sampling resistor.
In one embodiment of the present application, the adder employs a general purpose precision op-amp 189.
In an embodiment of the present application, a main source of the system error during verification is inconsistency between the detected pulse and the rising edge of the standard pulse, and the solution of the tester is to use a TDC chip by a pulse delay digital compensation technique.
As shown in fig. 3, in one embodiment of the present application, the overall structure of the ripple superposition module is described as follows: the ripple (i.e. alternating current) signal which needs to be superimposed and the direct current signal of the ripple (i.e. alternating current) signal have similar processing methods in the system; from the view of ripple waves, the device mainly comprises an independent digital-to-analog converter, an alternating current signal processing circuit, an adder, a power output circuit, a high-voltage sampling circuit, a DC blocking circuit, a feedback circuit, an analog-to-digital converter shared with direct current and the like.
In an embodiment of the application, the FPGA adopts a large-capacity field programmable gate array module, the model is 10M50SCE144C8G, the maximum frequency reaches 450MHz, the programmable logic resource is 50k, the available memory is 1677312bits, flash storage is arranged on a chip, powerful logic programming and data processing can be independently realized without a peripheral configuration chip, the FPGA has the functions of relay switching, receipt acquisition and the like, and the system processing efficiency can be improved.
As shown in fig. 4, in an embodiment of the present application, a dc constant voltage source, which performs feedback by sampling through a resistor to ensure stable operation of the whole system; the U1 is responsible for preprocessing signals, is of an OPA189 type, has extremely small offset voltage of 3 muV and noise performance of 5.2nV/√ Hz, and can perfectly amplify and preprocess the signals from the DAC, namely adjusting the amplitude and providing driving capability; u2 is responsible for power amplification, and its model is LM 3886; the maximum output of 1150V is amplified by a transformer, and feedback is performed by resistance sampling.
As shown in fig. 5, in an embodiment of the present application, the constant current source performs feedback by resistance sampling to ensure stable operation of the whole system; the U1 is responsible for preprocessing signals, is of an OPA189 type, has extremely small offset voltage of 3 muV and noise performance of 5.2nV/√ Hz, and can perfectly amplify and preprocess the signals from the DAC, namely adjusting the amplitude and providing driving capability; the U2 is responsible for power amplification, and model is LM3886, can export 600A at most after enlargiing through the transformer, and output current resistance sampling feedbacks.
In one embodiment of the application, the DC DAC adopts 16 bits AD5622A, the offset voltage is extremely low, only 10mV, and the amplitude of the DC output can be controlled; the ripple is handled in a dual DAC mode, where 1 block is a 12bit AD7845J responsible for generating ac waveforms of different frequencies, and the other DAC block is AD5622A responsible for amplitude modulating the ac waveform.
In one embodiment of the application, the ADC module adopts a 20-bit SAR type LTC2378, the module has a sampling rate of 1000kSPS, and has excellent sampling effect on the frequency bands involved in the project; the voltage signal and the current signal are fed back and sampled to be digital type, and the digital type is sent to the FPGA for operation processing.
In an embodiment of the application, the GPS clock calibration module performs measurement by using a TDC-GPX chip, which is a digitizer based on internal propagation time delay, and includes 3 channels of LVPECL differential inputs and 8 channels of LVTTL single-ended test channels, where the starting edge of the channel can be configured, and the measurement precision reaches 27 ps.
As shown in fig. 6, in an embodiment of the present application, a conditioning circuit is introduced as follows, interference such as high-frequency noise is inevitably received in the voltage feedback and current feedback transmission processes, the interference is suppressed by designing a low-pass filter, and signal conditioning is performed by designing a second-order butterworth low-pass filter.
In one embodiment of the present application, the sampling module is mainly divided into voltage sampling and current sampling; voltage sampling is performed through a plurality of resistors in series connection, then the voltage sampling is connected to a red and black terminal of voltage output in parallel, the high voltage of 1000V is divided into 1V low-voltage sampling signals, the resistors adopt gate-entering precision resistors, and the temperature drift is only +/-10 ppm; the total resistance value of the divider resistor is high by 10 MOmega, so that the current output capability is not reduced due to shunting; the current sampling is realized by connecting a sampling resistor in series in a loop of which the output black end is connected back to the reference ground of the system, and different current measuring ranges adopt different sampling resistors to correspond to the current measuring ranges.
As shown in fig. 7, in one embodiment of the present application, regarding the adder, the parameters of the adder used in the invention are: the output signal is a direct current signal +0.2 alternating current signal, and the requirement that the ripple content is 20% of direct current can be met under the condition that the ripple signal is not attenuated; the adder adopts a general precision operational amplifier OPA 189; meanwhile, the design of a relay is added, so that the adder can control different bandwidths to meet the requirement of the output frequency band of the signal.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (7)
1. The utility model provides a direct current electric energy measurement standard source of high accuracy, contains direct current comparator which characterized in that: the high-precision direct current electric energy metering standard source comprises a constant voltage source, a constant current source, an electric energy error calculation module, an electric energy pulse acquisition module, an error display module and an FPGA; the FPGA is connected with the DAC module, a user is connected with the microprocessor through a computer interface, the microprocessor is connected with the direct current constant voltage source and the constant current source, the direct current constant voltage source and the constant current source are connected with the tester, the tester is connected with the pulse acquisition module of the calibration system, and the electric energy error calculation module is connected with the tester, the calibration system and the display module; the FPGA is connected with a ripple superposition unit, and the ripple superposition unit consists of a DAC module, an ADC module, a conditioning circuit, a sampling module, a high-voltage output operational amplifier module and an adder; the adder, the high-voltage output operational amplifier module and the sampling module are sequentially connected in series.
2. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the FPGA adopts a large-capacity field programmable gate array module, the model number of which is 10M50SCE144C 8G.
3. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the DAC block is a 16-bit AD 5622A.
4. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the ADC module is a 20-bit SAR type LTC 2378.
5. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the GPS clock checking module comprises a TDC-GPX chip.
6. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the sampling module is mainly divided into a voltage sampling module and a current sampling module, wherein the voltage sampling module is connected in series through a plurality of resistors and then connected in parallel to a red and black terminal of voltage output; the current sampling module is connected in series in a loop of which the output black end is connected back to the system reference ground through a sampling resistor.
7. The high-precision direct current electric energy metering standard source according to claim 1, characterized in that: the adder adopts a general precision operational amplifier OPA 189.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922226567.1U CN211263701U (en) | 2019-12-12 | 2019-12-12 | High-precision direct current electric energy metering standard source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922226567.1U CN211263701U (en) | 2019-12-12 | 2019-12-12 | High-precision direct current electric energy metering standard source |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211263701U true CN211263701U (en) | 2020-08-14 |
Family
ID=71960285
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922226567.1U Active CN211263701U (en) | 2019-12-12 | 2019-12-12 | High-precision direct current electric energy metering standard source |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211263701U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113253188A (en) * | 2021-03-30 | 2021-08-13 | 中国电力科学研究院有限公司 | Digital power quality detection method and device |
| CN113267743A (en) * | 2021-06-30 | 2021-08-17 | 广东电网有限责任公司 | Method and instrument for checking DC voltage transformer |
| CN113325233A (en) * | 2021-06-02 | 2021-08-31 | 云南电网有限责任公司电力科学研究院 | System and method for modulating and measuring ripple electric energy in direct current electric energy |
| CN116593757A (en) * | 2023-07-17 | 2023-08-15 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
-
2019
- 2019-12-12 CN CN201922226567.1U patent/CN211263701U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113253188A (en) * | 2021-03-30 | 2021-08-13 | 中国电力科学研究院有限公司 | Digital power quality detection method and device |
| CN113325233A (en) * | 2021-06-02 | 2021-08-31 | 云南电网有限责任公司电力科学研究院 | System and method for modulating and measuring ripple electric energy in direct current electric energy |
| CN113325233B (en) * | 2021-06-02 | 2024-04-09 | 云南电网有限责任公司电力科学研究院 | System and method for modulating and measuring ripple electric energy in direct-current electric energy |
| CN113267743A (en) * | 2021-06-30 | 2021-08-17 | 广东电网有限责任公司 | Method and instrument for checking DC voltage transformer |
| CN116593757A (en) * | 2023-07-17 | 2023-08-15 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
| CN116593757B (en) * | 2023-07-17 | 2023-11-03 | 济南巧步思仪器仪表有限公司 | Alternating current ratio measuring method, system and digital alternating current comparator |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN211263701U (en) | High-precision direct current electric energy metering standard source | |
| CN101655544B (en) | Device for measuring and checking errors of digital mutual inductor | |
| CN103941211B (en) | A kind of analog input merge cells automatic Verification method | |
| CN109655776B (en) | Broadband characteristic test system and method of direct current transformer for grounding polar line | |
| CN203909138U (en) | General three-phase AC signal synchronous sampling device | |
| Djokic et al. | Phase measurement of distorted periodic signals based on nonsynchronous digital filtering | |
| Hagen et al. | Development of a precision resistive voltage divider for frequencies up to 100 kHz | |
| CN104155545A (en) | Multichannel analog quantity acquisition module based on GPS signals | |
| CN112098916A (en) | System and method for superposing ripples on direct current loop in direct current electric energy detection device | |
| CN104155521A (en) | Method and apparatus for determining phase difference | |
| EP3884285B1 (en) | Mutual inductance-type current sensing | |
| CN102707153A (en) | Contact resistance measuring system and method based on voltage-frequency conversion method | |
| CN102445608B (en) | Monitoring device and calibration method for electric energy quality | |
| Ugur et al. | Field programmable gate array based data digitisation with commercial elements | |
| CN103884888B (en) | Oscillograph with function of multimeter | |
| CN203249967U (en) | Nonlinear load electric energy metering device | |
| CN210982602U (en) | High-accuracy three-phase standard electric energy meter with harmonic measurement function | |
| CN112557732A (en) | Magnitude tracing method and system of impulse current measuring device based on induction coil | |
| CN202204872U (en) | Three-phase electric energy meter measurement component based on manganese-copper current divider sampling | |
| CN216387349U (en) | Charger electric energy metering error calibration and source tracing device | |
| CN208224473U (en) | A kind of capacitance type equipment tests measuring device with electricity with respect to dielectric loss | |
| CN114415099A (en) | Electric energy meter phase correction circuit based on analog-to-digital conversion delay and electric energy meter | |
| CN212693881U (en) | Low-voltage switch cabinet power signal phase difference monitoring device | |
| CN102857307A (en) | Calibration method and calibration device for digital mobile communication general-purpose tester | |
| WO2019076166A1 (en) | Nonlinear load power output device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |