Electric energy meter calibrating device capable of rapidly and stably switching current and control method

Abstract

The invention discloses an electric energy meter calibrating device capable of rapidly and stably switching current and a control method, and relates to the technical field of electric measuring instruments, the electric energy meter calibrating device comprises a high-speed current switching circuit, a synchronous control circuit, a signal conditioning circuit, a standard signal acquisition and error analysis module and a core control module; the core control module initializes parameters and predicts a current change trend, the synchronous control circuit calibrates a switching phase, the high-speed current switching circuit realizes rapid current switching and inhibits overshoot and hysteresis, the signal conditioning circuit acquires current and environmental parameter feedback, and the standard signal acquisition and error analysis module performs error calculation and compensation. And closed-loop control is formed. According to the invention, the current switching time can be shortened, the switching peak and overshoot can be suppressed, the phase stability and the detection accuracy can be improved, and the dynamic test defect of the existing device can be effectively solved.

Description

Technical Field

[0001] This invention relates to the field of electrical measuring instrument technology, and more specifically to a device and control method for calibrating an energy meter with a fast and stable switching current. Background Technology

[0002] With the rapid development of smart grids, electricity meters, as the core equipment for electricity metering, directly affect the stable operation of the power system and the interests of users through their accuracy and reliability. Currently, although domestic electricity meter calibration devices have achieved partial automation, significant technical bottlenecks still exist in the dynamic testing stage, specifically manifested as follows:

[0003] 1) Low current switching efficiency: Traditional devices rely on mechanical relays or analog switches to achieve current switching, which is slow and frequent switching can easily lead to contact oxidation and increased contact resistance, further aggravating the switching delay.

[0004] 2) Overshoot and hysteresis problems are prominent: During the switching process, the presence of energy storage components such as inductors and capacitors in the circuit can easily cause current overshoot or hysteresis, resulting in the verification error exceeding the allowable range.

[0005] 3) Poor phase stability: The phase difference characteristic of the current transformer in the energy meter will cause phase shift with the magnitude of current and load changes. The existing device lacks a dynamic phase compensation mechanism, resulting in large fluctuations in phase measurement error and affecting the accuracy of energy metering.

[0006] 4) Limited testing capabilities: Most devices can only calibrate standard electricity meters or a few types of smart meters, and cannot meet the rapid testing needs of multiple types (such as three-phase four-wire, multi-rate meters) and multiple parameters (such as harmonics, instantaneous power), resulting in insufficient scalability.

[0007] The aforementioned problems result in low efficiency and difficulty in guaranteeing measurement accuracy for electricity meters, failing to meet the high-precision metering requirements of modern power systems. Therefore, developing an electricity meter calibration device and control method capable of rapid and stable current switching, good phase stability, and strong detection capabilities is of significant practical importance and a technical problem urgently needing to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the present invention provides a power meter calibration device and control method for rapidly and stably switching current, which solves the problems existing in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A fast and stable current switching energy meter calibration device includes: a high-speed current switching circuit, a synchronous control circuit, a signal conditioning circuit, a standard signal acquisition and error analysis module, and a core control module;

[0011] The input terminal of the high-speed current switching circuit is connected to the power supply module, the first output terminal is connected to the current interface of the energy meter under test, and the second output terminal is connected to the signal conditioning circuit and the standard signal acquisition and error analysis module respectively. The other input terminal of the standard signal acquisition and error analysis module is connected to the signal output terminal of the energy meter under test. The synchronous control circuit is connected to the control terminal of the high-speed current switching circuit, and the core control module is connected to the synchronous control circuit, the signal conditioning circuit and the high-speed current switching circuit respectively.

[0012] Optionally, the high-speed current switching circuit includes: a multi-stage current path, a high-speed power switch array, a waveform modulation unit, a drive unit, and a buffer damping network;

[0013] The multi-range current path includes at least three parallel branches with different ranges, and each branch is connected in series with a high-speed power switch array consisting of at least two high-speed power switching devices.

[0014] The input of the waveform modulation unit receives waveform control commands from the core control module, and the output is connected to a multi-level current path through an analog front-end circuit.

[0015] A buffer damping network is connected across the high-speed power switching device, and the drive unit integrates overcurrent protection and temperature monitoring functions.

[0016] Optionally, the synchronization control circuit includes: a prediction signal interface, a multi-phase phase detection unit, an intelligent delay compensation unit, an inter-phase equalization regulator, and a synchronization trigger generator;

[0017] The prediction signal interface is connected to the core control module, the multiphase phase detection unit is connected to the output of the high-speed current switching circuit and the external reference signal source, the phase equalization regulator is connected to the multiphase phase detection unit, and the synchronous trigger generator is connected to the intelligent delay compensation unit and the high-speed current switching circuit.

[0018] Optionally, the signal conditioning circuit includes: a dual-channel signal acquisition unit, an isolation unit, a multi-stage filtering network, and a signal calibration unit;

[0019] The dual-channel signal acquisition unit includes a current signal acquisition channel and an environmental parameter acquisition channel; the input of the isolation unit is connected to the dual-channel signal acquisition unit, and the output is connected to the multi-stage filtering network; the multi-stage filtering network includes an RC low-pass filter circuit and an active band-pass filter circuit, and the signal calibration unit is connected to the core control module.

[0020] Optionally, the standard signal acquisition and error analysis module includes: a high-precision standard acquisition unit, an energy meter signal interface, an error analysis and calculation unit, and an environmental compensation unit;

[0021] The high-precision standard acquisition unit is connected to the second output terminal of the high-speed current switching circuit, and the energy meter signal interface is connected to the signal output terminal of the energy meter under test; the error analysis and calculation unit is based on the FPGA+ARM architecture and is connected to the high-precision standard acquisition unit and the energy meter signal interface respectively, with a built-in dynamic error algorithm; the environmental compensation unit is connected to the error analysis and calculation unit and the signal conditioning circuit respectively, and pre-stores the temperature-error compensation curve and humidity-error correction coefficient.

[0022] Optionally, the core control module includes: a main control unit, a parameter storage unit, a prediction algorithm unit, a communication interface unit, and a closed-loop regulation unit;

[0023] The main control unit adopts an FPGA+DSP heterogeneous architecture, and the parameter storage unit is a non-volatile memory; the prediction algorithm unit has built-in algorithms based on neural networks or model predictive control, and outputs prediction signals to the synchronization control circuit; the communication interface unit includes SPI, I2C and Ethernet interfaces, which are used to interact with the synchronization control circuit, signal conditioning circuit and high-speed current switching circuit; the closed-loop adjustment unit is used to generate control commands based on the deviation between the signal fed back by the signal conditioning circuit and the predicted value, combined with the preset lag interval, and at the same time receives the compensation results from the standard signal acquisition and error analysis module to correct the control signal, so as to realize closed-loop control.

[0024] A control method for a fast and stable switching current energy meter calibration device according to any one of the above claims includes the following steps:

[0025] Initialization steps: Configure the reference parameters of the high-speed current switching circuit, synchronous control circuit, signal conditioning circuit and standard signal acquisition and error analysis module through the core control module, and set the threshold range and response time standard for current switching;

[0026] Current trend prediction steps: The core control module predicts the current change trend based on dynamic test requirements, generates a prediction signal, and sends it to the synchronous control circuit.

[0027] Phase synchronization calibration steps: Based on the predicted signal, the synchronization control circuit performs phase calibration between the current signal and the reference signal to ensure the stability of the switching phase;

[0028] Current switching execution steps: The core control module sends control commands to the high-speed current switching circuit to drive the high-speed current switching circuit to achieve rapid current switching, while suppressing amplitude overshoot and hysteresis during the switching process.

[0029] Signal feedback and deviation calculation steps: The signal conditioning circuit acquires the current signal output by the high-speed current switching circuit and environmental parameters, and feeds it back to the core control module after conditioning. The core control module calculates the deviation between the predicted value and the actual sampled value.

[0030] Closed-loop adjustment steps: The core control module corrects the control command according to the deviation value, avoids frequent switching by setting the lag interval, and adjusts the phase calibration parameters of the synchronous control circuit synchronously.

[0031] Error detection and compensation steps: The standard signal acquisition and error analysis module acquires the standard current signal and the metering results of the tested energy meter, compares and analyzes them to generate error data, performs dynamic compensation in combination with environmental parameters, and feeds the compensation results back to the core control module to correct the control signal, thus completing the dynamic verification of the energy meter.

[0032] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a device and control method for rapidly and stably switching current in energy meters, which has the following beneficial effects:

[0033] (1) Improve current switching performance: The high-speed current switching circuit adopts a multi-stage current path and a high-speed switching device, combined with a buffer damping network, which can realize the rapid switching of current and significantly shorten the switching response time. At the same time, it effectively suppresses the amplitude overshoot and hysteresis during the switching process, meeting the requirements of rapid and stable current changes in dynamic testing.

[0034] (2) Enhance phase stability and phase balance: The synchronous control circuit receives the current change trend prediction signal through the prediction signal interface. It can use the multi-phase phase detection unit and intelligent delay compensation unit to calibrate the switching phase of each phase current in real time, thereby improving the phase stability and phase balance of the output current of the calibration device.

[0035] (3) Improve signal acquisition accuracy and anti-interference capability: The dual-channel design of the signal conditioning circuit can simultaneously and accurately acquire current signals and environmental parameters. The multi-level filtering network and isolation unit can effectively suppress high-frequency noise, harmonic interference and electromagnetic interference. The signal calibration unit dynamically adjusts the gain and zero point, providing a reliable basis for the closed-loop control of the core control module.

[0036] (4) Improve the accuracy of dynamic error detection of electricity meters: The standard signal acquisition and error analysis module uses a high-precision acquisition unit to acquire standard current signals, combines the measurement results of the tested electricity meters to calculate errors, and eliminates the influence of environmental factors on the test results through the environmental compensation unit. It can accurately evaluate the dynamic metering performance of different types and different accuracy levels of electricity meters.

[0037] (5) Achieve efficient and coordinated closed-loop control: The core control module acts as the central hub, coordinating the collaborative work of each module. Combined with the setting of the lag interval, it avoids frequent current switching, improves the control efficiency and stability of the entire device, and ensures the efficient and accurate dynamic verification process of the electricity meter. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0039] Figure 1 A structural diagram of the energy meter calibration device for rapid and stable current switching provided by the present invention;

[0040] Figure 2 A flowchart of the control method for the energy meter calibration device with fast and stable current switching provided by the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Existing electricity meter calibration devices suffer from problems such as slow current switching speed, overshoot or hysteresis at switching points, poor phase stability, and insufficient detection capability during dynamic testing, severely affecting the accuracy and reliability of electricity meter calibration and failing to meet the high-precision metering requirements of modern power systems. Therefore, this invention discloses an electricity meter calibration device with rapid and stable current switching, such as... Figure 1 As shown, it includes: a high-speed current switching circuit, a synchronous control circuit, a signal conditioning circuit, a standard signal acquisition and error analysis module, and a core control module;

[0043] The input terminal of the high-speed current switching circuit is connected to the power supply module, the first output terminal is connected to the current interface of the tested energy meter, and the second output terminal is connected to the signal conditioning circuit and the standard signal acquisition and error analysis module, respectively, to realize the rapid switching of current, suppress the amplitude overshoot and hysteresis during the switching process, and adjust the current output waveform according to the control command.

[0044] The synchronous control circuit is connected to the control terminal of the high-speed current switching circuit. It is used to realize the synchronous control of the current signal and the reference signal according to the prediction signal, dynamically calibrate the switching phase of each phase current, and improve the phase stability and phase balance of the current output.

[0045] The signal conditioning circuit is used to acquire and condition the current signal and environmental parameter signal output by the high-speed current switching circuit and feed the conditioned signal back to the core control module.

[0046] The other input terminal of the standard signal acquisition and error analysis module is connected to the signal output terminal of the energy meter under test. It is used to acquire the standard current signal output by the high-speed current switching circuit and compare it with the sampled signal to calculate the error. Combined with environmental parameters, dynamic compensation analysis is performed.

[0047] The core control module is connected to the synchronous control circuit, signal conditioning circuit, and high-speed current switching circuit, respectively. It is used to initialize the reference parameters of each circuit module, establish the threshold range and response time standard for current switching, predict the current change trend through predictive control logic and output the predicted signal to the synchronous control circuit. Based on the deviation between the signal fed back by the signal conditioning circuit and the predicted value, it generates control commands to drive the action of the high-speed current switching circuit. Frequent switching is avoided by setting the hysteresis range. The control signal is corrected by combining the compensation results of the standard signal acquisition and error analysis module to form a closed-loop control.

[0048] (I) High-speed current switching circuit

[0049] In this embodiment, the high-speed current switching circuit is the core execution unit of the energy meter calibration device. Its core functions are: 1) to quickly switch the amplitude, frequency, or phase of the output current according to the instructions of the core control module to simulate dynamic load scenarios; 2) to suppress current amplitude overshoot and hysteresis during the switching process to ensure the stability of the output current; 3) to provide a standard current signal for the energy meter under test, and at the same time to provide the original current signal for feedback and calibration to the signal conditioning circuit and the standard signal acquisition and error analysis module.

[0050] To achieve the dual goals of "fast switching" and "overshoot / hysteresis suppression", the high-speed current switching circuit of this embodiment includes: a multi-level current path, a high-speed power switch array, a waveform modulation unit, a drive unit, and a buffer damping network.

[0051] The multi-range current path includes at least three parallel branches with different ranges. Each branch is connected in series with a high-speed power switch array consisting of at least two high-speed power switching devices, which is used to achieve a wide range of current output through range switching. The three different ranges are: small current range, 0-10A; medium current range, 10-50A; and large current range, 50-100A.

[0052] The high-speed power switching device adopts an enhanced GaN HEMT, which, together with the gate drive signal output by the drive unit, achieves a current switching response time of ≤10μs.

[0053] The input of the waveform modulation unit receives waveform control commands (such as sine waves, square waves, sharp pulses, and other dynamic waveforms) from the core control module, and the output is connected to a multi-level current path through an analog front-end circuit to adjust the harmonic content of the current output waveform to ≤0.1%. The waveform modulation unit includes a digital waveform synthesizer and a D / A converter.

[0054] A buffer damping network is connected across the high-speed power switching device to suppress the current overshoot during switching to within ±0.5% of the target value, with a peak duration ≤2μs; the buffer damping network consists of an RC snubber circuit and a TVS diode connected in parallel.

[0055] The drive unit integrates overcurrent protection and temperature monitoring functions. When the junction temperature of the switching device is ≥125℃ or the branch current exceeds 120% of the rated value, a lockout signal is output to the core control module, and the buffer damping network is triggered to force braking.

[0056] (II) Synchronization Control Circuit

[0057] In this embodiment, the synchronization control circuit is a key module for ensuring the phase stability of the energy meter calibration device. Its core functions are: 1) receiving the current change prediction signal output by the core control module, adjusting the phase reference of the high-speed current switching circuit in advance, ensuring that the current switching action is synchronized with the predicted trend, and reducing phase lag; 2) eliminating the phase imbalance caused by differences in device parameters or load fluctuations by real-time monitoring of the phase difference of each phase current through closed-loop regulation, so that the phase deviation of each phase is controlled within a very small range; 3) using an external standard voltage or high-precision clock as a reference, dynamically compensating for phase shifts caused by circuit delay, temperature drift and other factors, and ensuring phase stability during long-term operation.

[0058] To achieve "phase synchronization" and "stability improvement", the synchronization control circuit in this embodiment includes: a prediction signal interface, a multi-phase phase detection unit, an intelligent delay compensation unit, an inter-phase equalization regulator, and a synchronization trigger generator;

[0059] The prediction signal interface is connected to the core control module and is used to receive current change trend prediction signals;

[0060] The multiphase phase detection unit is connected to the output of the high-speed current switching circuit and the external reference signal source, respectively. It integrates a phase detector and a multi-channel sampling circuit to detect the phase difference between each phase current and the reference signal in real time.

[0061] The intelligent delay compensation unit includes a programmable digital phase shifter and a temperature compensation circuit, which are used to dynamically adjust the phase delay based on the phase detection results and the ambient temperature.

[0062] The phase-to-phase equalization regulator is connected to the multi-phase phase detection unit. By comparing the phase detection values ​​of each phase, it generates equalization adjustment commands and controls the intelligent delay compensation unit of the corresponding phase to make the phase difference between phases ≤0.02°.

[0063] The synchronous trigger generator is connected to the intelligent delay compensation unit and the high-speed current switching circuit respectively. It is used to generate trigger pulses that are synchronized with the zero-crossing point of the reference signal to drive the switching action of the high-speed current switching circuit.

[0064] (III) Signal Conditioning Circuit

[0065] In this embodiment, the signal conditioning circuit needs to process both current signals and environmental parameter signals simultaneously to provide high-precision feedback for the closed-loop control of the core control module. Its core functions are: 1) to isolate, amplify, and filter the current signal output by the high-speed current switching circuit, converting it into a standard electrical signal that the core control module can recognize, ensuring that the sampling accuracy meets the dynamic testing requirements; 2) to collect environmental parameters such as temperature and humidity, providing environmental compensation basis for the core control module and the standard signal acquisition and error analysis module, and offsetting the impact of environmental factors on the verification accuracy; 3) to suppress electromagnetic interference and common-mode noise through filtering and isolation design, ensuring the signal-to-noise ratio of the feedback signal and avoiding control errors caused by noise.

[0066] To achieve the above objectives, the signal conditioning circuit of this embodiment includes: a dual-channel signal acquisition unit, an isolation unit, a multi-level filtering network, and a signal calibration unit;

[0067] The dual-channel signal acquisition unit includes a current signal acquisition channel and an environmental parameter acquisition channel. The current signal acquisition channel uses a Hall sensor and an AD converter, while the environmental parameter acquisition channel integrates a temperature and humidity sensor.

[0068] The input of the isolation unit is connected to the dual-channel signal acquisition unit, and the output is connected to the multi-stage filtering network to achieve electrical isolation; the isolation unit uses a magnetic isolation chip.

[0069] The multi-stage filtering network includes an RC low-pass filter circuit and an active band-pass filter circuit, which are used to suppress high-frequency noise and harmonic interference, so that the signal-to-noise ratio is ≥80dB.

[0070] The signal calibration unit is connected to the core control module and is used to dynamically adjust the signal gain and zero point according to the instructions of the core control module to ensure annual drift ≤0.05%; the signal calibration unit includes a programmable gain amplifier and a zero point calibration circuit.

[0071] (iv) Standard Signal Acquisition and Error Analysis Module

[0072] In this embodiment, the standard signal acquisition and error analysis module is the core unit for realizing the error detection of the electricity meter. It needs to accurately acquire the standard signal and perform error analysis in combination with environmental parameters. Its core functions are: 1) to acquire the standard current signal from the high-speed current switching circuit as the benchmark parameter for the metering error of the electricity meter, providing accurate raw data for error calculation; 2) to receive the metering result of the electricity meter under test, compare it with the standard signal in real time, calculate the dynamic error value, and evaluate the metering performance of the electricity meter under test; 3) to dynamically compensate for the error result in combination with the environmental parameters provided by the signal conditioning circuit, eliminate the influence of environmental factors on the detection accuracy, and ensure the accuracy of the verification result.

[0073] To achieve the above objectives, the standard signal acquisition and error analysis module of this embodiment includes: a high-precision standard acquisition unit, an energy meter signal interface, an error analysis and calculation unit, and an environmental compensation unit;

[0074] The high-precision standard acquisition unit is connected to the second output terminal of the high-speed current switching circuit, and uses a current sensor and an AD converter to acquire standard current signals.

[0075] The energy meter signal interface is connected to the signal output terminal of the energy meter under test and is used to receive the metering data of the energy meter under test; the energy meter signal interface includes an RS485 interface and a pulse output interface;

[0076] The error analysis and calculation unit is based on the FPGA+ARM architecture and is connected to the high-precision standard acquisition unit and the energy meter signal interface respectively. It has a built-in dynamic error algorithm for real-time calculation of the ratio difference and angle difference during the current switching process and buffering detection data.

[0077] The environmental compensation unit is connected to the error analysis and calculation unit and the signal conditioning circuit respectively. It pre-stores the temperature-error compensation curve and the humidity-error correction coefficient, which are used to compensate for the error results in combination with environmental parameters, so that the error correction amount caused by environmental factors is ≤0.01%.

[0078] (V) Core Control Module

[0079] In this embodiment, the core control module is the central hub of the entire device, responsible for coordinating the collaborative work of various modules to achieve rapid and stable current switching and accurate calibration. Its core functions are: 1) Initializing the reference parameters of all modules at startup, setting key parameters such as the threshold range for current switching and the response time standard, laying the foundation for system operation; 2) Analyzing the current change pattern through predictive control algorithms, generating predictive signals in advance and sending them to the synchronous control circuit, so that each module can prepare for switching in advance and improve the response speed; 3) Adjusting the control commands to the high-speed current switching circuit and the synchronous control circuit in real time based on the deviation between the actual sampled value and the predicted value fed back by the signal conditioning circuit, avoiding frequent current switching by setting a lag range, and ensuring system stability; 4) Receiving the error calculation results and environmental compensation information from the standard signal acquisition and error analysis module, correcting the control signals to the power switching unit of the high-speed current switching circuit, and further improving the control accuracy.

[0080] To achieve the above objectives, the core control module of this embodiment includes: a main control unit, a parameter storage unit, a prediction algorithm unit, a communication interface unit, and a closed-loop adjustment unit;

[0081] The main control unit adopts an FPGA+DSP heterogeneous architecture, which is responsible for high-speed logic control and complex algorithm operation, respectively.

[0082] The parameter storage unit is a non-volatile memory used to store the reference parameters of each module, the threshold range of current switching, and the response time standard. It supports online modification and power-off saving.

[0083] The prediction algorithm unit has a built-in algorithm based on neural network or model predictive control, which is used to analyze the current change trend and predict the current change in the next 5-10ms, and output the prediction signal to the synchronous control circuit.

[0084] The communication interface unit includes SPI, I2C and Ethernet interfaces, which are used to interact with the synchronous control circuit, signal conditioning circuit and high-speed current switching circuit.

[0085] The closed-loop control unit is used to generate control commands based on the deviation between the signal fed back by the signal conditioning circuit and the predicted value, combined with the preset lag interval. At the same time, it receives the compensation results from the standard signal acquisition and error analysis module to correct the control signal, thereby realizing closed-loop control.

[0086] This embodiment also discloses a control method for a power meter calibration device that rapidly and stably switches currents, such as... Figure 2 As shown, it includes the following steps:

[0087] Initialization steps: Configure the reference parameters of the high-speed current switching circuit, synchronous control circuit, signal conditioning circuit and standard signal acquisition and error analysis module through the core control module, and set the threshold range and response time standard for current switching;

[0088] Current trend prediction steps: The core control module predicts the current change trend based on dynamic test requirements, generates a prediction signal, and sends it to the synchronous control circuit.

[0089] Phase synchronization calibration steps: Based on the predicted signal, the synchronization control circuit performs phase calibration between the current signal and the reference signal to ensure the stability of the switching phase;

[0090] Current switching execution steps: The core control module sends control commands to the high-speed current switching circuit to drive the high-speed current switching circuit to achieve rapid current switching, while suppressing amplitude overshoot and hysteresis during the switching process.

[0091] Signal feedback and deviation calculation steps: The signal conditioning circuit acquires the current signal output by the high-speed current switching circuit and environmental parameters, and feeds it back to the core control module after conditioning. The core control module calculates the deviation between the predicted value and the actual sampled value.

[0092] Closed-loop adjustment steps: The core control module corrects the control command according to the deviation value, avoids frequent switching by setting the lag interval, and adjusts the phase calibration parameters of the synchronous control circuit synchronously.

[0093] Error detection and compensation steps: The standard signal acquisition and error analysis module acquires the standard current signal and the metering results of the tested energy meter, compares and analyzes them to generate error data, performs dynamic compensation in combination with environmental parameters, and feeds the compensation results back to the core control module to correct the control signal, thus completing the dynamic verification of the energy meter.

[0094] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The methods disclosed in the embodiments are described simply because they correspond to the apparatus disclosed in the embodiments; relevant details can be found in the method section.

[0095] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for calibrating an energy meter with rapid and stable current switching, characterized in that, include: High-speed current switching circuit, synchronous control circuit, signal conditioning circuit, standard signal acquisition and error analysis module, core control module; The input terminal of the high-speed current switching circuit is connected to the power supply module, the first output terminal is connected to the current interface of the tested energy meter, and the second output terminal is connected to the signal conditioning circuit and the standard signal acquisition and error analysis module, respectively. The other input terminal of the standard signal acquisition and error analysis module is connected to the signal output terminal of the tested energy meter. The control terminal of the synchronous control circuit is connected to the control terminal of the high-speed current switching circuit. The core control module is connected to the synchronous control circuit, the signal conditioning circuit and the high-speed current switching circuit respectively.

2. The energy meter calibration device for rapid and stable current switching according to claim 1, characterized in that, The high-speed current switching circuit includes: a multi-stage current path, a high-speed power switch array, a waveform modulation unit, a drive unit, and a buffer damping network; The multi-range current path includes at least three parallel branches with different ranges, and each branch is connected in series with a high-speed power switch array consisting of at least two high-speed power switching devices. The input of the waveform modulation unit receives waveform control commands from the core control module, and the output is connected to a multi-level current path through an analog front-end circuit. A buffer damping network is connected across the high-speed power switching device, and the drive unit integrates overcurrent protection and temperature monitoring functions.

3. The energy meter calibration device for rapid and stable current switching according to claim 1, characterized in that, The synchronization control circuit includes: a prediction signal interface, a multi-phase phase detection unit, an intelligent delay compensation unit, an inter-phase equalization regulator, and a synchronization trigger generator; The prediction signal interface is connected to the core control module, the multiphase phase detection unit is connected to the output of the high-speed current switching circuit and the external reference signal source, the phase equalization regulator is connected to the multiphase phase detection unit, and the synchronous trigger generator is connected to the intelligent delay compensation unit and the high-speed current switching circuit.

4. The energy meter calibration device for rapid and stable current switching according to claim 1, characterized in that, The signal conditioning circuit includes: a dual-channel signal acquisition unit, an isolation unit, a multi-stage filtering network, and a signal calibration unit; The dual-channel signal acquisition unit includes a current signal acquisition channel and an environmental parameter acquisition channel; the input of the isolation unit is connected to the dual-channel signal acquisition unit, and the output is connected to the multi-stage filtering network; the multi-stage filtering network includes an RC low-pass filter circuit and an active band-pass filter circuit, and the signal calibration unit is connected to the core control module.

5. The energy meter calibration device for rapid and stable current switching according to claim 1, characterized in that, The standard signal acquisition and error analysis module includes: a high-precision standard acquisition unit, an energy meter signal interface, an error analysis and calculation unit, and an environmental compensation unit; The high-precision standard acquisition unit is connected to the second output terminal of the high-speed current switching circuit, and the energy meter signal interface is connected to the signal output terminal of the energy meter under test; the error analysis and calculation unit is based on the FPGA+ARM architecture and is connected to the high-precision standard acquisition unit and the energy meter signal interface respectively, with a built-in dynamic error algorithm; the environmental compensation unit is connected to the error analysis and calculation unit and the signal conditioning circuit respectively, and pre-stores the temperature-error compensation curve and humidity-error correction coefficient.

6. The energy meter calibration device for rapid and stable current switching according to claim 1, characterized in that, The core control module includes: a main control unit, a parameter storage unit, a prediction algorithm unit, a communication interface unit, and a closed-loop regulation unit; The main control unit adopts an FPGA+DSP heterogeneous architecture, and the parameter storage unit is a non-volatile memory; the prediction algorithm unit has built-in algorithms based on neural networks or model predictive control, and outputs prediction signals to the synchronization control circuit; the communication interface unit includes SPI, I2C and Ethernet interfaces, which are used to interact with the synchronization control circuit, signal conditioning circuit and high-speed current switching circuit; the closed-loop adjustment unit is used to generate control commands based on the deviation between the signal fed back by the signal conditioning circuit and the predicted value, combined with the preset lag interval, and at the same time receives the compensation results from the standard signal acquisition and error analysis module to correct the control signal, so as to realize closed-loop control.

7. A control method for a power meter calibration device with fast and stable current switching according to any one of claims 1-6, characterized in that, Includes the following steps: Initialization steps: Configure the reference parameters of the high-speed current switching circuit, synchronous control circuit, signal conditioning circuit and standard signal acquisition and error analysis module through the core control module, and set the threshold range and response time standard for current switching; Current trend prediction steps: The core control module predicts the current change trend based on dynamic test requirements, generates a prediction signal, and sends it to the synchronous control circuit. Phase synchronization calibration steps: Based on the predicted signal, the synchronization control circuit performs phase calibration between the current signal and the reference signal to ensure the stability of the switching phase; Current switching execution steps: The core control module sends control commands to the high-speed current switching circuit to drive the high-speed current switching circuit to achieve rapid current switching, while suppressing amplitude overshoot and hysteresis during the switching process. Signal feedback and deviation calculation steps: The signal conditioning circuit acquires the current signal output by the high-speed current switching circuit and environmental parameters, and feeds it back to the core control module after conditioning. The core control module calculates the deviation between the predicted value and the actual sampled value. Closed-loop adjustment steps: The core control module corrects the control command according to the deviation value, avoids frequent switching by setting the lag interval, and adjusts the phase calibration parameters of the synchronous control circuit synchronously. Error detection and compensation steps: The standard signal acquisition and error analysis module acquires the standard current signal and the metering results of the tested energy meter, compares and analyzes them to generate error data, performs dynamic compensation in combination with environmental parameters, and feeds the compensation results back to the core control module to correct the control signal, thus completing the dynamic verification of the energy meter.

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