A high power calibration device

Abstract

The application discloses a high-power calibration device, and belongs to the technical field of power electronic equipment test and measurement, which comprises the following: a high-voltage calibration unit for calibrating a high-voltage output signal, comprising a standard high-voltage voltage divider, a standard high-voltage sensor, a first voltage acquisition module and a second voltage acquisition module; a large-current calibration unit for calibrating a large-current output signal, comprising a large-current fiber sensor, a large-current Rogowski coil, a third voltage acquisition module and a fourth voltage acquisition module; a timing synchronization unit for realizing the synchronization of high-voltage calibration and large-current calibration, comprising a timing source module, a clock processing module, a phase-locked loop module and a synchronization signal generation module; and a data processing unit for realizing data acquisition and data processing calculation of high power, comprising a communication card, an optoelectronic conversion interface, a central control machine and a data processing module. The application realizes the parameter traceability of high-power energy equipment and guarantees the accurate and reliable high-power parameter values.

Description

Technical Field

[0001] This application belongs to the field of power electronic equipment testing and measurement technology, specifically relating to a high-power calibration device. Background Technology

[0002] High-power energy equipment such as electric arc furnace steelmaking equipment, large motor drive equipment, and energy storage system charging and discharging equipment generates power reaching hundreds of megawatts. The power generated by such high-power energy equipment includes DC, low-frequency, and high-frequency components. Accurate measurement of this power in practical work presents the following challenges:

[0003] large value

[0004] Transient current amplitudes in high-power applications typically reach hundreds of kiloamperes; the peak-to-peak recording voltage of modern digital high-speed oscilloscopes is generally around 80V; for high-current testing, the commonly used shunt resistor values ​​range from 0.1mΩ to 100mΩ, requiring good response characteristics while also being able to withstand currents up to 10... 6 For instantaneous power exceeding a certain level, it is difficult to use standard components, and their manufacturing is also quite challenging.

[0005] Broadband

[0006] The frequency bands of high-power transient voltages and currents can reach tens of thousands of hertz, and there are abundant DC, low-frequency and AC signals, which places high demands on the performance of the sensor's measurement frequency band.

[0007] steep rising edge

[0008] Typically, the rise time of nanosecond-level high-voltage and high-current transient measurement systems is required to be in the range of sub-nanosecond to ten nanoseconds. The rise time of the square wave transient used to calibrate the measurement system should be comparable to or smaller than the response time of the measurement system. With such a rise time requirement, even very small stray parameters in the measurement and calibration system may have a significant impact on the measurement and calibration results, thus causing many sensors to fail to meet the measurement requirements.

[0009] Large electromagnetic interference

[0010] Because the transient front is fast, the corresponding short-wavelength components have high energy and strong spatial electromagnetic interference. Electromagnetic waves generated during the switching process, as well as electromagnetic waves radiated from the high-voltage measurement circuit, can easily cause interference in the low-voltage measurement circuit. Although the amplitude of this interference is not high, it has not been attenuated by the measurement system, so it can significantly reduce the signal-to-noise ratio of the recorded signal. Sometimes the amplitude of the interference is even much greater than the amplitude of the real signal.

[0011] Long transient current and voltage measurement

[0012] Due to the extremely high energy of high-amplitude transient currents and voltages with long durations in the microsecond / millisecond range, the effect of temperature rise on transient shunts and voltage dividers on the measurement uncertainty of transient currents and voltages cannot be ignored.

[0013] The aforementioned problems severely restrict the accurate measurement of high-power energy equipment such as electric arc furnace steelmaking equipment, large motor drive equipment, and energy storage system charging and discharging equipment. Therefore, it is urgent to carry out research on high-power calibration technology and develop high-power calibration devices to ensure the accuracy and reliability of power parameter values ​​for electric arc furnace steelmaking equipment, large motor drive equipment, and energy storage systems. Summary of the Invention

[0014] To address the technical problems encountered in the background, this application discloses a high-power calibration device, comprising: a high-voltage calibration unit, a high-current calibration unit, a timing synchronization unit, and a data processing unit;

[0015] The high-voltage calibration unit includes: a standard high-voltage divider, a standard high-voltage sensor, a first voltage acquisition module, and a second voltage acquisition module, used to calibrate the high-voltage output signal;

[0016] The high-current calibration unit includes: a high-current fiber optic sensor, a high-current Rogowski coil, a third voltage acquisition module, and a fourth voltage acquisition module, used to calibrate the high-current output signal;

[0017] The timing synchronization unit includes a timing source module, a clock processing module, a phase-locked loop module, and a synchronization signal generation module, which are used to realize the synchronization of high-voltage calibration and high-current calibration.

[0018] The data processing unit includes: a communication card, a photoelectric conversion interface, a central control unit, and a data processing module, used to achieve high-power data acquisition and data processing calculations.

[0019] Optionally, the standard high-voltage divider, standard high-voltage sensor, first voltage acquisition module, and second voltage acquisition module are connected as follows: the input terminal of the standard high-voltage divider and the input terminal of the standard high-voltage sensor are connected in parallel to the high-voltage output terminal of the device being calibrated; the output terminal of the standard high-voltage divider is connected to the first voltage acquisition module; and the output terminal of the standard high-voltage sensor is connected to the second voltage acquisition module.

[0020] Optionally, the high-current fiber optic sensor, the high-current Rogowski coil, the third voltage acquisition module, and the fourth voltage acquisition module are connected in series with the input end of the high-current fiber optic sensor and the input end of the high-current Rogowski coil and the high-current output end of the calibrated device, respectively. The output end of the high-current fiber optic sensor is connected to the third voltage acquisition module, and the output end of the high-current Rogowski coil is connected to the fourth voltage acquisition module.

[0021] Optionally, the standard high-voltage sensor is a closed-loop Hall sensor.

[0022] Optionally, the high-current fiber optic sensor employs an interferometric digital closed-loop fiber optic current sensor based on the Faraday effect.

[0023] Optionally, the high-current Rogowski coil is a rigid Rogowski coil.

[0024] Optionally, the calculation formula for the calibration high voltage of the high voltage calibration unit is as follows:

[0025]

[0026] Where V0 is the high-voltage calibration value, V1 is the measured value of the first voltage acquisition module, and V 01 V is the high-voltage calibration value obtained through a standard high-voltage divider. 02 U1 represents the high-voltage calibration value obtained through a standard high-voltage sensor, U2 represents the measurement uncertainty of the standard high-voltage divider, and U3 represents the measurement uncertainty of the standard high-voltage sensor.

[0027] Optionally, the calculation formula for the calibration current of the high-current calibration unit is as follows:

[0028]

[0029] Where I0 is the high current calibration value, I 01 For the high-current calibration value obtained through a high-current fiber optic sensor, I 02 U3 represents the high-current calibration value obtained through the high-current Rogowski coil, U4 represents the measurement uncertainty of the high-current fiber optic sensor, and U5 represents the measurement uncertainty of the high-current Rogowski coil.

[0030] Optionally, the standard high-voltage divider is a coaxial resistive-capacitive voltage divider with a double-shielded coaxial cable structure.

[0031] Optionally, the high-power data processing calculation is performed using the following formula:

[0032]

[0033] Where W0 is the calibration value for high power; t is the preset time for acquiring low voltage signals; V0 is the high current calibration value; V0 is the high voltage calibration value.

[0034] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following:

[0035] This application provides a high-power calibration device. It converts high-voltage signals into low-voltage signals for acquisition using standard high-voltage dividers and standard high-voltage sensors with the same precision but different principles. It also converts high-current signals into low-voltage signals for acquisition using high-current fiber optic sensors and high-current Rogowski coils with the same precision but different principles. The low-voltage data is then transmitted from the central control unit to the data processing module, where it is converted into high-voltage calibration signals, high-current calibration signals, and high-power signals. Finally, the high-power calibration results are displayed on the central control unit interface. This solution addresses the problems of large amplitude, wide bandwidth, steep rise time, high electromagnetic interference, and long transient current and voltage measurement in existing high-power energy equipment power measurements. It enables parameter traceability for high-power energy equipment, ensuring accurate and reliable high-power parameter values. Attached Figure Description

[0036] Figure 1 This is a schematic block diagram of the high-power calibration device shown in the embodiment of this application. Detailed Implementation

[0037] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] Reference Figure 1 This application discloses a power calibration device, including a high-voltage calibration unit, a high-current calibration unit, a timing synchronization unit, and a data processing unit.

[0040] The high-voltage calibration unit includes a standard high-voltage divider, a standard high-voltage sensor, a first voltage acquisition module, and a second voltage acquisition module. The high-current calibration unit includes a high-current fiber optic sensor, a high-current Rogowski coil, a third voltage acquisition module, and a fourth voltage acquisition module. The timing synchronization unit includes a timing source module, clock processing, a phase-locked loop module, and a synchronization signal generation module. The data processing unit includes a communication card, a photoelectric conversion interface, a central control unit, and a data processing module.

[0041] Calibration Process: First, the central control unit sends a calibration signal to the timing synchronization unit. After detecting the calibration signal, the timing synchronization unit generates a timing synchronization signal and collects the low voltage signals measured by the first, second, third, and fourth voltage acquisition modules in real time. When the preset time t is reached, the central control unit sends a stop calibration signal to the timing synchronization unit. After detecting the stop calibration signal, the timing synchronization unit stops generating timing synchronization signals and stops receiving the collected low voltage signals. The low voltage signals collected within time t are transmitted to the data processing module through the communication card, photoelectric conversion interface, and central control unit. The data is converted into high voltage calibration signals, high current calibration signals, and high power signals. Finally, the high power calibration results are displayed on the central control unit interface.

[0042] In specific implementation, the high-power calibration device disclosed in this embodiment calibrates high power ranges of 1MVA to 600MVA, high voltage ranges of 1kV to 10kV, and high current ranges of 1kA to 600kA. It has the characteristics of high power and high current. Electromagnetic compatibility during the calibration process should be considered during the development of the high-power calibration device.

[0043] As a preferred option, the high-voltage calibration unit consists of a standard high-voltage divider, a standard high-voltage sensor, a first voltage acquisition module, and a second voltage acquisition module. The connection method is that the input terminal of the standard high-voltage divider and the input terminal of the standard high-voltage sensor are connected in parallel to the high-voltage output terminal of the device being calibrated, the output terminal of the standard high-voltage divider is connected to the first voltage acquisition module, and the output terminal of the standard high-voltage sensor is connected to the second voltage acquisition module.

[0044] As a more preferred solution, the high-current calibration unit consists of a high-current fiber optic sensor, a high-current Rogowski coil, a third voltage acquisition module, and a fourth voltage acquisition module. The connection method is that the input end of the high-current fiber optic sensor and the input end of the high-current Rogowski coil are connected in series with the high-current output end of the device being calibrated, the output end of the high-current fiber optic sensor is connected to the third voltage acquisition module, and the output end of the high-current Rogowski coil is connected to the fourth voltage acquisition module.

[0045] As a more preferred solution, the standard high-voltage divider has a voltage division factor of k1, the standard high-voltage sensor has a turns ratio of k2, the measured value of the first voltage acquisition module is V1, the measured value of the second voltage acquisition module is V2, and the high-voltage calibration value obtained through the standard high-voltage divider is V. 01 =V1×k1, measurement uncertainty is U1 (coverage factor k=2), and the high-voltage calibration value obtained through a standard high-voltage sensor is V. 02 =V2×k2, measurement uncertainty is U2 (coverage factor k=2), which must satisfy the following conditions: ,

[0046] The high voltage calibration value is .

[0047] As a more preferred solution, the proportional coefficient of the high-current fiber optic sensor is k3, the proportional coefficient of the high-current Rogowski coil is k4, the measured value of the third voltage acquisition module is V3, the measured value of the fourth voltage acquisition module is V4, and the high-current calibration value obtained through the high-current fiber optic sensor is I. 01 =V3×k3, measurement uncertainty is U3 (coverage factor k=2), and the high-current calibration value obtained through a high-current Rogowski coil is I. 02 =V4×k4, measurement uncertainty is U4 (coverage factor k=2), which must satisfy the following conditions: The high current calibration value is .

[0048] As a more preferred option, the calibration value for high power is... The high-current calibration value I0 and the high-voltage calibration value V0 are converted into a low-voltage signal (0.1V~40V) that can be accurately measured by two devices based on different principles, ensuring the accuracy and reliability of the high-power calibration results.

[0049] As a preferred option, the standard high-voltage divider adopts a coaxial type resistive-capacitive structure with a double-shielded coaxial cable, which has the advantages of simple principle, fast response, high power, low measurement distortion, strong environmental adaptability and short rise time.

[0050] As a preferred option, the standard high-voltage sensor is a closed-loop Hall sensor; the closed-loop Hall sensor has a small air gap, which can reduce magnetic leakage, and has good insulation between the measured signal and the output signal, good linearity, and high measurement accuracy.

[0051] As a preferred solution, the high-current fiber optic sensor employs an interferometric digital closed-loop fiber optic current sensing method based on the Faraday effect. Light emitted from the source passes through a circulator, is converted to linear polarization by a polarizer, and then enters the fast and slow axes of the polarization-maintaining fiber via the 45° fiber melting point. The two orthogonal linearly polarized beams are modulated by a phase modulator and propagate along the polarization-maintaining delay fiber. They are then converted to left-handed and right-handed circularly polarized light by a quarter-wave plate. Under the influence of the measured current, a phase difference proportional to the measured current is generated between the two orthogonal circularly polarized beams. This phase difference is doubled after reflection by a mirror at the end of the sensing fiber, returning along the original path.

[0052] As a preferred option, the high-current Rogowski coil uses a rigid Rogowski coil with a circular iron casing to ensure its safety and prevent damage from external pressure. The coil frame uses a toroidal iron core with a low coefficient of thermal expansion, reducing measurement errors caused by temperature. The winding material is selected from copper core enameled wire with low resistivity, reducing the coil's internal resistance. During coil winding, a return-turn method is used to reduce the influence of distributed capacitance and improve measurement accuracy.

[0053] As a preferred approach, in practical applications, the internal resistance R and self-inductance L of a high-current Rogowski coil can be obtained through bridge measurements. Then, the mutual inductance M of the coil can be indirectly calculated using the formula L=nM, where n is the number of turns. The stray capacitance C is obtained by determining the resonant frequency using the resonance method. Considering that stray capacitance C can suppress the response speed of the Rogowski coil and introduce stability errors, a purely resistive damping resistor is connected in series at the end of the coil to minimize its adverse effects on the coil's dynamic characteristics.

[0054] As a preferred approach, the high-voltage calibration waveform is acquired by converting the high-voltage signal into a low-voltage signal using a standard high-voltage divider and a standard high-voltage sensor connected in parallel. This acquisition is specifically performed by a first voltage acquisition module and a second voltage acquisition module. It is required that the standard high-voltage divider and the standard high-voltage sensor have the same accuracy, and that the first and second voltage acquisition modules also have the same accuracy.

[0055] As a preferred approach, the high-current calibration waveform is acquired by converting the high-current signal into a low-voltage signal using a high-current fiber optic sensor and a high-current Rogowski coil connected in series. This is specifically achieved through a second voltage acquisition module and a third voltage acquisition module. It is required that the high-current fiber optic sensor and the high-current Rogowski coil have the same accuracy, and that the second and third voltage acquisition modules also have the same accuracy.

[0056] As a preferred solution, a single central control unit simultaneously performs both control and measurement functions. The central control unit communicates wirelessly with the data acquisition units (including the first, second, third, and fourth data acquisition modules). The network ports of the data acquisition units are connected to a wireless router via RJ45 cables, forming a small wireless local area network (WLAN). The central control unit accesses the WLAN via a wireless network card and then uses software to acquire and process the waveforms displayed on the data acquisition units.

[0057] As a more preferred option, the calibration results of high power are obtained through the formula Calculations show that the acquired high-voltage and high-current signals must be synchronized. A timing synchronization unit ensures this synchronization, guaranteeing the accuracy and reliability of the high-power calibration results.

[0058] In summary, the high-power calibration device disclosed in this application, through the implementation of the above scheme, has several advantages, mainly manifested in the following aspects:

[0059] 1. The calibration device is designed to calibrate high-voltage signals using standard high-voltage dividers and standard high-voltage sensors with the same accuracy but different principles. By comparing the amplitude and waveform of the high-voltage signal obtained through the standard high-voltage divider and the high-voltage signal obtained through the standard high-voltage sensor, it is easier to find problems in the high-voltage output value of the calibrated equipment, thus ensuring the accuracy and reliability of the high-voltage output value of the calibrated equipment.

[0060] 2. The calibration device is designed to calibrate high-current signals using high-current fiber optic sensors and high-current Rogowski coils with the same accuracy but different principles. By comparing the amplitude and waveform of the high-current signal obtained by the high-current fiber optic sensor and the high-current signal obtained by the high-current Rogowski coil, it is easier to find problems in the output value of the high-current Rogowski coil in the calibrated equipment, thus ensuring the accuracy and reliability of the high-voltage output value in the calibrated equipment.

[0061] 3. During the calibration of high-power equipment, there are electromagnetic compatibility issues caused by high voltage and high current in the surrounding environment. The calibration device disclosed in this application reduces the impact of electromagnetic compatibility caused by high voltage and high current through the design of the above-mentioned components, especially the design of core components such as the standard high voltage divider, standard high voltage sensor, high current fiber optic sensor and high current Rogowski coil.

[0062] 4. High-power equipment calibration involves high voltage and high current. The calibration device in this application is designed with safety measures such as safe grounding and remote control to ensure the safety of personnel and equipment.

[0063] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-power calibration device, characterized in that, include: High voltage calibration unit, high current calibration unit, timing synchronization unit and data processing unit; The high-voltage calibration unit includes: a standard high-voltage divider, a standard high-voltage sensor, a first voltage acquisition module, and a second voltage acquisition module, used to calibrate the high-voltage output signal; The high-current calibration unit includes: a high-current fiber optic sensor, a high-current Rogowski coil, a third voltage acquisition module, and a fourth voltage acquisition module, used to calibrate the high-current output signal; The timing synchronization unit includes a timing source module, a clock processing module, a phase-locked loop module, and a synchronization signal generation module, which are used to realize the synchronization of high-voltage calibration and high-current calibration. The data processing unit includes: a communication card, a photoelectric conversion interface, a central control unit, and a data processing module, used to realize high-power data acquisition and data processing calculation; The standard high-voltage divider, standard high-voltage sensor, first voltage acquisition module, and second voltage acquisition module are connected as follows: the input terminals of the standard high-voltage divider and the standard high-voltage sensor are connected in parallel to the high-voltage output terminal of the device being calibrated; the output terminal of the standard high-voltage divider is connected to the first voltage acquisition module; and the output terminal of the standard high-voltage sensor is connected to the second voltage acquisition module. The high-current fiber optic sensor, high-current Rogowski coil, third voltage acquisition module, and fourth voltage acquisition module are connected as follows: the input terminals of the high-current fiber optic sensor and the high-current Rogowski coil are connected in series to the high-current output terminal of the device being calibrated; the output terminal of the high-current fiber optic sensor is connected to the third voltage acquisition module; and the output terminal of the high-current Rogowski coil is connected to the fourth voltage acquisition module.

2. The high-power calibration device according to claim 1, characterized in that, The standard high-voltage sensor is a closed-loop Hall sensor.

3. The high-power calibration device according to claim 1, characterized in that, The high-current fiber optic sensor employs an interferometric digital closed-loop fiber optic current sensing method based on the Faraday effect.

4. The high-power calibration device according to claim 1, characterized in that, The high-current Rogowski coil is a rigid Rogowski coil.

5. The high-power calibration device according to claim 1, characterized in that, The formula for calculating the calibration high voltage of the high voltage calibration unit is as follows: Where V0 is the high-voltage calibration value, V1 is the measured value of the first voltage acquisition module, and V 01 V is the high-voltage calibration value obtained through a standard high-voltage divider. 02 U1 represents the high-voltage calibration value obtained through a standard high-voltage sensor, U2 represents the measurement uncertainty of the standard high-voltage divider, and U3 represents the measurement uncertainty of the standard high-voltage sensor.

6. The high-power calibration device according to claim 1, characterized in that, The formula for calculating the calibration current of the high-current calibration unit is as follows: Where I0 is the high current calibration value, I 01 For the high-current calibration value obtained through a high-current fiber optic sensor, I 02 U3 represents the high-current calibration value obtained through the high-current Rogowski coil, U4 represents the measurement uncertainty of the high-current fiber optic sensor, and U5 represents the measurement uncertainty of the high-current Rogowski coil.

7. The high-power calibration device according to claim 1, characterized in that, The standard high-voltage divider is a coaxial resistive-capacitive voltage divider with a double-shielded coaxial cable structure.

8. The high-power calibration device according to claim 1, characterized in that, The high-power data processing calculation is performed using the following formula: Where W0 is the calibration value for high power; t is the preset time for acquiring low voltage signals; V0 is the high current calibration value; V0 is the high voltage calibration value.

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