CN112379156A - Method for rapidly measuring kA-level direct current sudden change - Google Patents
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Abstract
本发明公开了一种快速测量kA级直流电流突变的方法。本发明先使用电流互感器将直流大电流信号转换为小电流信号，通过采样电阻得到电压信号和小电流信号，通过调理电路对电压信号和小电流信号进行滤波整流和放大后进入交直流拟合测量模块，交直流拟合测量模块输出交流电压测量结果信号、直流电流测量结果信号和突变信号；直流电流测量结果信号输入直流大电流比较电路中；然后，将直流大电流比较电路的输出信号和交流电压测量结果信号经A/D转换器转化为计算机可处理的数字信号，突变信号和直流大电流比较电路的输出信号采用电流突变量算法在计算机中得出全部直流大电流测量结果和电流突变测量结果。本发明优化了直流大电流动态测量方法。
The invention discloses a method for rapidly measuring the sudden change of kA level direct current current. In the present invention, a current transformer is used to convert a DC large current signal into a small current signal, a voltage signal and a small current signal are obtained through a sampling resistor, and the voltage signal and the small current signal are filtered, rectified and amplified by a conditioning circuit, and then entered into AC and DC fitting. The measurement module, the AC/DC fitting measurement module outputs the AC voltage measurement result signal, the DC current measurement result signal and the mutation signal; the DC current measurement result signal is input into the DC high current comparison circuit; then, the output signal of the DC high current comparison circuit is combined with The AC voltage measurement result signal is converted into a digital signal that can be processed by the computer through the A/D converter. The sudden change signal and the output signal of the DC high current comparison circuit use the current sudden change algorithm to obtain all the DC high current measurement results and current sudden changes in the computer. measurement results. The invention optimizes the dynamic measurement method of direct current and large current.
Description
Technical Field
The invention belongs to the field of metrological verification, relates to heavy current measurement, and particularly relates to a method for rapidly measuring kA-level direct current sudden change.
Background
In the rapid propelling process of industrialization and urbanization, the direct current large current is widely applied in various industrial fields, and the direct current large current above kA level is applied in the fields of rail transit, shipbuilding, aviation and various heavy equipment manufacturing. The requirements for the stability, reliability and accuracy of the direct current large current precise calibration work are more and more strict. In the application of the direct current large current in various fields, the quality problem that the direct current large current application is affected by sudden change of the current and current adjustment fluctuation after the sudden change when the control is started and stopped often needs to be faced, dynamic metering research on the direct current large current is needed, and then the measurement of the sudden change of the direct current large current also becomes an aspect of intensive research on large current measurement. The technical advancement of direct current large current mutation measurement plays a crucial role in safety and economic benefit of enterprise manufacturing.
Domestic measurement of large current is mostly carried out in a mode of a shunt or a direct current transformer, as shown in fig. 1-2, the accuracy is not high, the measurement is not sensitive to loop parameters, and rapid and accurate measurement of direct current large current mutation cannot be realized.
The current divider measurement is to put a known pure resistor in a measured current circuit, the current in a loop is obtained by measuring the voltage on the resistor, and the measurement is carried out by using an ohm theorem, and the resistance value of the current divider is in the level of m omega or mu omega in practical application.
The current divider principle is used for measuring large current by measuring voltage on a resistor, but the current divider usually has smaller inductance, so that the heat productivity of the current divider is greatly increased when the frequency and the amplitude are high, the measurement precision of the current divider is seriously influenced, and the current divider is only suitable for occasions insensitive to main loop parameters and cannot finish the measurement of current mutation.
The traditional direct current transformer principle measures the mutual inductance of the large current converted by the magnitude of the direct current, and the direct current large current passing through a coil is converted into the direct current small current in the inverse ratio of the number of turns through a rectifying circuit, so that the large current is measured, but the measurement result of the direct current transformer is easily influenced by an external magnetic field, so that a great error is generated, for example, when the exciting current of the measured current is smaller than that of the direct current transformer, no matter which soft magnetic material has an imperfect magnetization characteristic curve, a defect exists. Therefore, the accuracy of direct current large current measurement is greatly influenced, and the optimization development of the traditional direct current transformer measurement technology for measuring the current mutation is limited.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects in the prior art and provide a method for rapidly measuring kA-level direct current sudden change, which adopts a high-speed direct current large current data acquisition technology, a precise direct current large current measurement technology, an alternating current and direct current fitting measurement module and a current sudden change algorithm, after rapidly acquiring direct current large current data signals, precisely measuring the direct current large current signals, and measuring the current sudden change in the direct current large current through the alternating current and direct current fitting measurement module and the current sudden change algorithm; by adopting the mode, the value mutation in the direct current large current can be sensitively measured on the basis of precisely measuring the large current, and the kA-level direct current mutation can be quickly measured, so that the reliable guarantee is provided for the research of the dynamic metering characteristics of the direct current large current.
Therefore, the invention adopts the following technical scheme: a method for rapidly measuring kA-level direct current sudden change comprises the steps of firstly converting a direct current large current signal into a small current signal by using a current transformer, obtaining a voltage signal and a small current signal by using a sampling resistor, filtering, rectifying and amplifying the voltage signal and the small current signal by using a conditioning circuit, and then enabling the voltage signal and the small current signal to enter an alternating current and direct current fitting measurement module, wherein the voltage signal and the small current signal comprise an alternating current voltage signal and a direct current signal, and the alternating current and direct current fitting measurement module outputs an alternating current voltage measurement result signal, a direct current measurement result signal and a sudden change signal;
the direct current measurement result signal is input into a direct current heavy current comparison circuit, pulse modulation and amplitude modulation are carried out through PWM, and then the direct current measurement result signal is converted into a voltage value capable of being precisely measured through magnetic modulation;
then, the output signal of the DC large current comparison circuit and the AC voltage measurement result signal are converted into digital signals which can be processed by a computer through an A/D converter, and the sudden change signal and the output signal of the DC large current comparison circuit adopt a current sudden change algorithm to obtain all DC large current measurement results and current sudden change measurement results in the computer.
As a further complement to the above method, the specific processing procedure of the conditioning circuit is as follows:
the voltage signal and the small current signal are subjected to filtering rectification and operational amplifier amplification processing, converted into signals meeting the accuracy requirement of an alternating current/direct current fitting measurement module, and enter the alternating current/direct current fitting measurement module; meanwhile, a weak current signal is adopted for synchronous tracking processing and serves as a source for the computer MCU to interrupt the INTO signal action.
As a further supplement of the method, before entering the conditioning circuit, sampling and holding are carried out, namely, the sampling precision and speed are kept after the voltage signal is sampled by the analog switch and the MOS field effect transistor.
As a further supplement to the above method, the specific processing procedure of the ac/dc fitting measurement module is as follows:
shaping and filtering the voltage signal and the small current signal processed by the conditioning circuit, and then entering a direct current large current comparison circuit to accurately measure direct current large current; meanwhile, the direct current signal after shaping and filtering and the alternating current voltage signal after processing by the conditioning circuit are operated by a logic operator, then width and amplitude modulation processing is carried out by PWM after cutting by a triangular wave generator, the alternating current signal is converted into a square wave signal, namely a sudden change signal, and the sudden change quantity is recorded.
As a further complement to the above method, the specific processing procedure of the dc large current comparison circuit is as follows:
the direct current measurement result signals shaped and filtered by the alternating current and direct current fitting measurement module are subjected to pulse modulation output through PWM, meanwhile, the signals in the PWM are transmitted to the FPGA through SPI, a D/A converter is controlled to convert a voltage reference signal to an integrator, the integrator outputs a stable voltage signal to control the PWM to generate square wave signal amplitude, and the square wave signals are subjected to direct current accurate processing on the large current signals shaped and filtered by the alternating current and direct current fitting measurement module through a power amplifier; and then, the processed high-current signal is used as a primary signal to be converted through magnetic modulation, voltage drop is generated on a secondary side standard resistor through a winding, a voltage value is accurately measured, and accurate measurement of the direct-current high current is realized after conversion.
As a further supplement to the above method, the architecture of the current mutation algorithm includes a data source, an acquisition layer, a data layer, a capability layer, and an application layer;
a data source: collecting corresponding original electric quantity data of the sample, wherein the data comprises voltage value data, current value data, time value data, frequency data, accuracy data and interface data; the data is an original data value required to be measured and a corresponding mutation signal characteristic value, and is a basic value for finally measuring large current data and mutation data;
obtaining a layer: the method mainly solves the problem of managing data through ETL and content analysis, ensures the quality of the data, ensures the correctness, integrity, consistency, completeness, effectiveness, timeliness and acquirability of the data, and realizes the integration of the data mainly through null value processing, normalization of data format, data splitting, verification of data correctness and data replacement; the part of data can be simply processed, and the correctness, integrity, consistency and effectiveness of the required values corresponding to the data are analyzed through software control, so that the data acquired by a data source are ensured to be the required data;
and (3) a data layer: after the original electric quantity data is subjected to analog-digital processing, the data is subjected to resource comparison, data records are collected and integrated and then are analyzed in a unified mode, the data deep analysis and data mining capacity is supported, and key index data and highly-collected data are output to a main data warehouse; the alternating current and the direct current are separately processed after the data pass through the alternating current and direct current fitting measurement module, the direct current data are directly recorded as a measurement result, and the alternating current data are matched into a dynamic event of corresponding mutation through a basic analysis capability and a multidimensional analysis capability through an analysis algorithm to be recorded; constructing a WEB resource pool according to the statistical basic data and the data of different detected devices; the data is summarized and analyzed, the data is compared with the content of a database, direct current measurement data is directly used as a final measurement result, and alternating current data needs to be matched with corresponding current mutation characteristics, so that the current mutation condition is obtained;
a capacity layer: original electric quantity data are integrated and summarized to form an upper-layer available data mining tool, basic analysis capability, multi-dimensional analysis capability, data mining capability, real-time analysis capability, self-service analysis capability and data sharing capability are provided, and FTP transmission, API (application program interface) and SQL \ MDX statement use capability are provided; summarizing the data, and performing classification analysis and data distribution storage on the processed data to serve as a final calling database of a verification report;
an application layer: various flexible verification report tasks and data trend arrangement are realized according to business requirements, so that the requirement of the whole dynamic metering is met; this section subjects the data to final data processing and collating to form a report of the required certification metrics.
The invention has the following beneficial effects: according to the invention, after the direct current large current data signals are rapidly collected, the direct current large current signals are precisely measured, the current mutation quantity in the direct current large current is measured through the alternating current-direct current fitting measurement module and the current mutation algorithm, and the dynamic measurement method for the direct current large current is optimized.
Drawings
FIG. 1 is a schematic diagram of an equivalent circuit of a shunt in the prior art;
FIG. 2 is a schematic diagram of a DC transformer in the prior art;
FIG. 3 is a schematic block diagram of the method for rapidly measuring kA level DC current mutation according to the present invention;
FIG. 4 is a block diagram of the conditioning circuit of the present invention;
FIG. 5 is a schematic block diagram of an AC/DC fitting measurement module according to the present invention;
FIG. 6 is a block diagram of a DC high current comparison circuit according to the present invention;
fig. 7 is an architecture diagram of the current step change algorithm of the present invention.
Detailed Description
The invention will be further described with reference to the accompanying drawings, but the scope of the invention is not limited to the following description. Any modification and variation made within the spirit of the present invention and the scope of the claims fall within the scope of the present invention.
The embodiment provides a method for rapidly measuring kA-level direct current sudden change, as shown in fig. 3, a current transformer is used for converting a direct current large current signal into a small current signal, a voltage signal and a small current signal are obtained through a sampling resistor, the voltage signal and the small current signal are filtered, rectified and amplified through a conditioning circuit and then enter an alternating current and direct current fitting measurement module, the voltage signal and the small current signal comprise an alternating current voltage signal and a direct current signal, and the alternating current and direct current fitting measurement module outputs an alternating current voltage measurement result signal, a direct current measurement result signal and a sudden change signal;
the direct current measurement result signal is input into a direct current heavy current comparison circuit, pulse modulation and amplitude modulation are carried out through PWM, and then the direct current measurement result signal is converted into a voltage value capable of being precisely measured through magnetic modulation;
then, the output signal of the DC large current comparison circuit and the AC voltage measurement result signal are converted into digital signals which can be processed by a computer through an A/D converter, and the sudden change signal and the output signal of the DC large current comparison circuit adopt a current sudden change algorithm to obtain all DC large current measurement results and current sudden change measurement results in the computer.
As shown in fig. 4, the processing procedure of the conditioning circuit is as follows:
the voltage signal and the small current signal are subjected to filtering rectification and operational amplifier amplification processing, converted into signals meeting the accuracy requirement of an alternating current/direct current fitting measurement module, and enter the alternating current/direct current fitting measurement module; meanwhile, a weak current signal is adopted for synchronous tracking processing and serves as a source for the computer MCU to interrupt the INTO signal action.
Before entering the conditioning circuit, sampling and holding are carried out, namely, the sampling precision and speed are kept after the voltage signal is sampled by the analog switch and the MOS field effect transistor.
As shown in fig. 5, the processing procedure of the ac/dc fitting measurement module is as follows:
shaping and filtering the voltage signal and the small current signal processed by the conditioning circuit, and then entering a direct current large current comparison circuit to accurately measure direct current large current; meanwhile, the direct current signal after shaping and filtering and the alternating current voltage signal after processing by the conditioning circuit are operated by a logic operator, then width and amplitude modulation processing is carried out by PWM after cutting by a triangular wave generator, the alternating current signal is converted into a square wave signal, namely a sudden change signal, and the sudden change quantity is recorded.
As shown in fig. 6, the processing procedure of the dc large current comparison circuit is as follows:
the direct current measurement result signals shaped and filtered by the alternating current and direct current fitting measurement module are subjected to pulse modulation output through PWM, meanwhile, the signals in the PWM are transmitted to the FPGA through SPI, a D/A converter is controlled to convert a voltage reference signal to an integrator, the integrator outputs a stable voltage signal to control the PWM to generate square wave signal amplitude, and the square wave signals are subjected to direct current accurate processing on the large current signals shaped and filtered by the alternating current and direct current fitting measurement module through a power amplifier; and then, the processed high-current signal is used as a primary signal to be converted through magnetic modulation, voltage drop is generated on a secondary side standard resistor through a winding, a voltage value is accurately measured, and accurate measurement of the direct-current high current is realized after conversion.
As shown in fig. 7, the architecture of the current mutation algorithm includes a data source, an acquisition layer, a data layer, a capability layer, and an application layer;
a data source: collecting corresponding original electric quantity data of the sample, wherein the data comprises voltage value data, current value data, time value data, frequency data, accuracy data and interface data; the data is an original data value required to be measured and a corresponding mutation signal characteristic value, and is a basic value for finally measuring large current data and mutation data;
obtaining a layer: the method mainly solves the problem of managing data through ETL and content analysis, ensures the quality of the data, ensures the correctness, integrity, consistency, completeness, effectiveness, timeliness and acquirability of the data, and realizes the integration of the data mainly through null value processing, normalization of data format, data splitting, verification of data correctness and data replacement; the part of data can be simply processed, and the correctness, integrity, consistency and effectiveness of the required values corresponding to the data are analyzed through software control, so that the data acquired by a data source are ensured to be the required data;
and (3) a data layer: after the original electric quantity data is subjected to analog-digital processing, the data is subjected to resource comparison, data records are collected and integrated and then are analyzed in a unified mode, the data deep analysis and data mining capacity is supported, and key index data and highly-collected data are output to a main data warehouse; the alternating current and the direct current are separately processed after the data pass through the alternating current and direct current fitting measurement module, the direct current data are directly recorded as a measurement result, and the alternating current data are matched into a dynamic event of corresponding mutation through a basic analysis capability and a multidimensional analysis capability through an analysis algorithm to be recorded; constructing a WEB resource pool according to the statistical basic data and the data of different detected devices; the data is summarized and analyzed, the data is compared with the content of a database, direct current measurement data is directly used as a final measurement result, and alternating current data needs to be matched with corresponding current mutation characteristics, so that the current mutation condition is obtained;
a capacity layer: original electric quantity data are integrated and summarized to form an upper-layer available data mining tool, basic analysis capability, multi-dimensional analysis capability, data mining capability, real-time analysis capability, self-service analysis capability and data sharing capability are provided, and FTP transmission, API (application program interface) and SQL \ MDX statement use capability are provided; summarizing the data, and performing classification analysis and data distribution storage on the processed data to serve as a final calling database of a verification report;
an application layer: various flexible verification report tasks and data trend arrangement are realized according to business requirements, so that the requirement of the whole dynamic metering is met; this section subjects the data to final data processing and collating to form a report of the required certification metrics.
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Patent Citations (5)
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| JP2000065867A (en) * | 1998-08-20 | 2000-03-03 | Inoue Denki Seisakusho:Kk | Current measuring device |
| CN103472282A (en) * | 2013-09-23 | 2013-12-25 | 东南大学 | Improved FBD harmonic current detection method based on adaptive principle |
| EP2884288A1 (en) * | 2013-12-16 | 2015-06-17 | Valeo Systèmes de Contrôle Moteur | Device for measuring a chopped current |
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| CN110672913A (en) * | 2019-10-09 | 2020-01-10 | 青岛鼎信通讯股份有限公司 | Complex waveform signal processing method suitable for alternating current and direct current leakage detection |
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