阅读说明：本技术 电流测量装置 (Current measuring device ) 是由 梅红伟 王黎明 曹洪铭 苏宇 于昕哲 周军 邱刚 于 2021-06-18 设计创作，主要内容包括：本申请提供一种电流测量装置,包括：罗氏线圈,所述罗氏线圈设置在特高压线路外围,用于测量特高压直流电路的短路电流；采集模块,连接所述罗氏线圈,用于采集所述罗氏线圈测量的电流；传输模块,连接所述采集模块,用于传输所述采集模块采集的电流；信号处理模块,连接所述传输模块,用于获取来自所述传输模块的电流；所述信号处理模块还用于分析所述电流,以获取所述特高压直流电路的短路电流测量结果。该电流测量装置能够通过光电转换进行远端测量,实现电气隔离、且将电信号转化成光信号使用光信号传输,具有良好的抗电磁干扰性。(The application provides a current measurement device, includes: the Rogowski coil is arranged on the periphery of the extra-high voltage circuit and used for measuring the short-circuit current of the extra-high voltage direct current circuit; the acquisition module is connected with the Rogowski coil and is used for acquiring the current measured by the Rogowski coil; the transmission module is connected with the acquisition module and is used for transmitting the current acquired by the acquisition module; the signal processing module is connected with the transmission module and used for acquiring the current from the transmission module; the signal processing module is also used for analyzing the current to obtain a short-circuit current measurement result of the extra-high voltage direct current circuit. The current measuring device can carry out remote measurement through photoelectric conversion, realize electrical isolation, convert an electric signal into an optical signal and use optical signal transmission, and has good electromagnetic interference resistance.)

1. A current measuring device, comprising:

the Rogowski coil is arranged on the periphery of the extra-high voltage direct current transmission line and used for measuring the short-circuit current of the extra-high voltage direct current circuit and converting the short-circuit current into output voltage;

the acquisition module is connected with the Rogowski coil and used for acquiring the output voltage and converting the output voltage into current variation;

the transmission module is connected with the acquisition module and is used for transmitting the current variable quantity acquired by the acquisition module;

and the signal processing module is connected with the transmission module and used for acquiring the current variation from the transmission module and analyzing the current variation so as to acquire the short-circuit current value of the extra-high voltage direct current circuit.

2. The current measurement device of claim 1, wherein the transmission module comprises an optoelectronic transmission module and an optoelectronic reception module;

the photoelectric sending module is connected with the acquisition module and used for converting the current variation acquired by the acquisition module to generate an optical signal;

the photoelectric receiving module is connected with the photoelectric sending module and the signal processing module, and is used for converting the optical signal generated by the photoelectric sending module to form an electric signal and transmitting the electric signal to the signal processing module.

3. The current measurement device of claim 2, further comprising an electromagnetic shielding cavity;

the electromagnetic shielding cavity is arranged on the periphery of the acquisition module and the photoelectric transmission module and is used for shielding an electromagnetic field generated by the ultra-high voltage direct current transmission line during short circuit.

4. The current measurement device of claim 3, wherein the electromagnetically shielded cavity further comprises a first shield layer, a second shield layer, and a third shield layer;

the third shielding layer is arranged at the periphery of the acquisition module and the photoelectric transmission module and is used for shielding a low-frequency magnetic field in the electromagnetic field;

the second shielding layer is arranged at the periphery of the third shielding layer and is used for shielding a high-frequency magnetic field in the electromagnetic field;

the first shielding layer is arranged at the periphery of the second shielding layer and used for shielding a low-frequency electric field in the electromagnetic field.

5. The current measurement device of claim 4, wherein the material of the third shield layer is permalloy.

6. The current measuring device of claim 4, wherein the material of the second shielding layer is iron.

7. The current measuring device of claim 1, further comprising an insulator;

the inside chamber that holds of insulating part, hold the chamber and be used for holding extra-high voltage direct current circuit.

8. The current measuring device of claim 7, wherein the insulator further comprises at least two insulating branches;

the insulating branch knots are arranged at the edge of the insulating piece, and an air gap is formed between the at least two insulating branch knots so as to improve the insulating property of the insulating piece.

9. The current measuring device of claim 8, wherein said rogowski coil is wound around the periphery of said insulating member.

10. The current measurement device of claim 3, further comprising a power module;

the power module is arranged in the electromagnetic shielding cavity and connected with the photoelectric transmission module, and the power module is used for supplying power to the photoelectric transmission module and the acquisition module.

Technical Field

The application relates to the technical field of electric power, in particular to a current measuring device.

Background

With the continuous development of economy and the continuous increase of power consumption requirements, the ultra-high voltage direct current transmission line is becoming more and more popular. In the debugging process of the extra-high voltage direct current transmission line and the extra-high voltage test site, the short circuit grounding test is a very important test, and the detected short circuit current of the extra-high voltage direct current transmission line can be used for measuring and calculating the direct current restart remaining time of the extra-high voltage direct current transmission line. However, the extra-high voltage dc transmission line may generate an impulse rising current with a high current amplitude at the moment of a short circuit to ground, which has a high risk.

Disclosure of Invention

In view of the above, it is desirable to provide a current measuring device. The impact rising current generated by the extra-high voltage direct current transmission line at the moment of ground short circuit can be accurately detected, the detected current can be analyzed at a far end, and the safety in current detection is improved.

An embodiment of the present application provides a current measuring apparatus, including:

the Rogowski coil is arranged on the periphery of the extra-high voltage direct current transmission line and used for measuring the short-circuit current of the extra-high voltage direct current circuit and converting the short-circuit current into output voltage;

the acquisition module is connected with the Rogowski coil and used for acquiring the output voltage and converting the output voltage into current variation;

the transmission module is connected with the acquisition module and is used for transmitting the current variable quantity acquired by the acquisition module;

and the signal processing module is connected with the transmission module and used for acquiring the current variation from the transmission module and analyzing the current variation so as to acquire the short-circuit current value of the extra-high voltage direct current circuit.

In the embodiment of the application, the transmission module comprises a photoelectric transmission module and a photoelectric receiving module;

the photoelectric sending module is connected with the acquisition module and used for converting the current variation acquired by the acquisition module to generate an optical signal;

the photoelectric receiving module is connected with the photoelectric sending module and the signal processing module, and is used for converting the optical signal generated by the photoelectric sending module to form an electric signal and transmitting the electric signal to the signal processing module.

In an embodiment of the present application, the current measuring device further includes an electromagnetic shielding cavity;

the electromagnetic shielding cavity is arranged on the periphery of the acquisition module and the photoelectric transmission module and is used for shielding an electromagnetic field generated by the ultra-high voltage direct current transmission line during short circuit.

In an embodiment of the present application, the electromagnetic shielding cavity further comprises

The electromagnetic shielding cavity further comprises a first shielding layer, a second shielding layer and a third shielding layer;

the third shielding layer is arranged at the periphery of the acquisition module and the photoelectric transmission module and is used for shielding a low-frequency magnetic field in the electromagnetic field;

the second shielding layer is arranged at the periphery of the third shielding layer and is used for shielding a high-frequency magnetic field in the electromagnetic field;

the first shielding layer is arranged at the periphery of the second shielding layer and used for shielding a low-frequency electric field in the electromagnetic field.

In the embodiment of the present application, the material of the third shielding layer is permalloy.

In the embodiment of the application, the material of the second shielding layer is iron.

In an embodiment of the present application, the current measuring device further comprises an insulating member;

the inside chamber that holds of insulating part, hold the chamber and be used for holding extra-high voltage direct current circuit.

In an embodiment of the present application, the insulation member further comprises at least two insulation branches;

the insulating branch knots are arranged at the edge of the insulating piece, and an air gap is formed between the at least two insulating branch knots so as to improve the insulating property of the insulating piece.

In the embodiment of the application, the Rogowski coil is wound on the periphery of the insulating part.

In an embodiment of the present application, the current measuring apparatus further includes a power supply module;

the power module is arranged in the electromagnetic shielding cavity and connected with the photoelectric transmission module, and the power module is used for supplying power to the photoelectric transmission module and the acquisition module.

The current measuring device that this application embodiment provided can carry out the distal end through photoelectric conversion and measure, realizes electrical isolation, and changes the signal of telecommunication into light signal and use optical signal transmission, has good anti-electromagnetic interference.

Drawings

Fig. 1 is a block diagram of a current measuring device according to an embodiment of the present disclosure.

Fig. 2 is a block diagram of a current measuring device according to another embodiment of the present disclosure.

Fig. 3 is a schematic view of the electromagnetic shielding cavity of fig. 2.

Fig. 4 is a schematic view of an insulator according to an embodiment of the present application.

Fig. 5 is a schematic diagram of test results provided by an embodiment of the present application.

Description of the main elements

Current measuring device 10

Rogowski coil 100

Acquisition module 200

Transmission module 300

Photoelectric transmission module 310

Photoelectric receiving module 320

Signal processing module 400

Power supply 500

Electromagnetic shielding cavity 600

First shielding layer 610

First ground point 611

Second ground point 612

First capacitor C1

Second shielding layer 620

Third shield layer 630

Insulating member 700

Insulating branch 710

Accommodating chamber 720

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application.

In the present embodiment, "at least one" means one or more, and a plurality means two or more. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It should be noted that in the embodiments of the present application, the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or order. The features defined as "first", "second" may explicitly or implicitly include one or more of the features described. In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

All other embodiments that can be obtained by a person skilled in the art without inventive step based on the embodiments in this application are within the scope of protection of this application.

Ultra High Voltage Direct Current (UHVDC) transmission refers to direct current transmission of voltage class of ± 800kV and above. The extra-high voltage direct current transmission has the characteristics of high voltage, large transmission capacity, narrow line corridor and the like, and can meet the requirements of large-scale, long-distance and high-efficiency power transmission.

With the continuous development of economy and the continuous increase of power consumption requirements, the ultra-high voltage direct current transmission line is becoming more and more popular. In the debugging process of the extra-high voltage direct current transmission line, a short circuit grounding test is a very important test. The extra-high voltage direct current transmission line can generate an impact rising current with a high current amplitude at the moment of ground short circuit, and has higher risk. When the parameters are set during the restarting of the transmission line, the size and the dimension time of the impact rising current during the short circuit need to be accurately measured.

At present, due to the special waveform of the impact rising current, including a section of microsecond-level rapid rise, a 10 kA-level high current amplitude and a 10 millisecond-level duration current, the current measuring device has high requirements, and the current measuring device in the related technology cannot meet the requirement of measuring the short-circuit current of the ultra-high voltage direct current transmission line.

Some embodiments of the application are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Fig. 1 is a block diagram of a current measuring device 10 according to an embodiment of the present disclosure. The current measuring device 10 shown in fig. 1 comprises at least the following parts: rogowski coil 100, acquisition module 200, transmission module 300, and signal processing module 400. The rogowski coil 100 is sequentially connected to the acquisition module 200, the transmission module 300 and the signal processing module 400.

In the present embodiment, the Rogowski Coil 100 is a Rogowski Coil (Rogowski Coil). The rogowski coil 100 is arranged on the periphery of the extra-high voltage line and is used for measuring the short-circuit current I (namely the impact rising current) of the extra-high voltage direct current circuit. It will be appreciated that according to faraday's law of electromagnetic induction and ampere-loop law, when the surge current I passes through the center of the rogowski coil 100 along the axis, a correspondingly varying magnetic field is generated, and the rogowski coil 100 outputs an output voltage V proportional to the surge current I to the acquisition module 200.

In the embodiment of the application, the rogowski coil 100 can be used for measuring the short-circuit current I of an extra-high voltage direct current circuit with the current range of 0-300kA, the bandwidth of 0.1Hz-16MHz and the maximum current rising speed of 40 kA/mus. The rogowski coil 100 is a flexible coil having high ductility.

In the embodiment of the present application, the acquisition module 200 is electrically connected to the rogowski coil 100. The acquisition module 200 is configured to acquire the output voltage V from the rogowski coil 100, and calculate the impulse rising current I and the waveform of the impulse rising current I according to the output voltage V. It is understood that the calculated relationship between the output voltage V and the surge current I can be derived by equation (1).

Where M is the mutual inductance of the rogowski coil 100.For the rate of change of the rush-up current I with time

It will be appreciated that, according to equation (1), the rate of change of the surge current I with time can be obtainedNamely, equation (2).

In the embodiment of the present application, the change rate of the surge current I with time is integrated to obtain the surge current I.

It is understood that the integration operation to obtain the inrush rising current I may be performed by the rogowski coil 100, and the acquisition module 200 transmits the calculated result to the signal processing module 400. The acquisition module 200 is configured to transmit the change rate of the impact rising current I with time to the signal processing module 400 through the transmission module 300, and then the signal processing module 400 performs an integration operation, which is not limited herein.

In the embodiment of the present application, the acquisition module 200 may be an oscilloscope with a model number of USB-5133. The sampling frequency of the acquisition module 200 may be up to 100 Mb/s. The acquisition module 200 may indirectly measure the impulse rising current I acquired by the rogowski coil 100 by measuring the output voltage V.

In the embodiment of the present application, the transmission module 300 may be a photoelectric module for converting the electrical signal output by the collection module 200 into an optical signal. Since the optical signal has a lower attenuation rate than the electrical signal during transmission, the transmission module 300 transmits the short-circuit current of the extra-high voltage dc circuit acquired by the acquisition module 200 to realize long-distance transmission.

Specifically, referring to fig. 2, the transmission module 300 includes an optoelectronic transmitting module 310 and an optoelectronic receiving module 320. The current measuring device 10 further comprises a power supply 500. The optoelectronic transmitting module 310 is electrically connected to the collecting module 200 and the power supply 500. The optoelectronic transmitting module 310 is connected to the optoelectronic receiving module 320. The photoelectric receiving module 320 is electrically connected to the signal processing module 400.

In the embodiment of the present application, the transmission module 300 may be a photoelectric converter with model number usblanger 2344. The optical-electrical transmitting module 310 is configured to convert the electrical signal output by the collecting module 200 into an optical signal. The optical-electrical receiving module 320 is configured to convert the optical signal sent by the optical-electrical sending module 310 into an electrical signal, so that the signal processing module 400 can process the electrical signal.

In this embodiment of the application, the signal processing module 400 is configured to perform an integral operation on the short-circuit current of the extra-high voltage dc circuit transmitted by the transmission module 300 to obtain the surge up current I, or obtain the surge up current I obtained by performing an integral operation by the acquisition module 200. The signal processing module 400 then analyzes the impact rising current I to set restart parameters of the ultra-high voltage direct current transmission line according to the amplitude and duration of the impact rising current I. The signal processing module 400 is arranged at a position far away from the rogowski coil 100, so that the risk of electric shock of an operator is avoided.

It is understood that the signal processing module 400 may be a mobile terminal such as a mobile phone and a tablet, or may be a fixed terminal such as a personal computer and a server. The signal processing module 400 can perform visualization processing on the current data transmitted by the transmission module 300 to convert the current data into a specific numerical value for display. The signal processing module 400 may further store and transmit the current data for an external device (e.g., a server or the like) to use in data analysis and parameter setting of the uhv dc circuit.

Referring again to fig. 2, in another embodiment, the current measuring apparatus 10 further includes an electromagnetic shielding cavity 600 and an insulating member 700. In the embodiment of the present application, the electromagnetic shielding cavity 600 is disposed at the periphery of the optoelectronic transmitting module 310, the collecting module 200 and the power supply 500.

It can be understood that the ultra-high voltage direct current line may generate an electromagnetic field when short-circuited, which may affect the accuracy of the measurement of the optoelectronic transmitting module 310, the collecting module 200 and the power supply 500. Therefore, the electromagnetic shielding cavity 600 can shield the electromagnetic field generated by the extra-high voltage direct current line during short circuit, so as to reduce the influence on the photoelectric transmission module 310, the acquisition module 200 and the power supply 500, thereby improving the measurement accuracy of the current measuring device 10.

It can be understood that the insulator 700 has good insulating performance, and can prevent the acquisition module 200 from being broken down due to the short-circuit current transmitted to the acquisition module 200 through the rogowski coil 100.

Fig. 3 is a schematic diagram of the electromagnetic shielding cavity 600 of fig. 2. As shown in fig. 3, the electromagnetic shielding cavity 600 includes a first shielding layer 610, a second shielding layer 620 and a third shielding layer 630. The second shielding layer 620 is disposed inside the first shielding layer 610, and the third shielding layer 630 is disposed inside the second shielding layer 620.

It can be understood that when the extra-high voltage direct current line is short-circuited, the generated electromagnetic interference includes a low-frequency electric field, a low-frequency magnetic field and a high-frequency magnetic field. The low-frequency magnetic field may cause large interference to the acquisition module 200 and the transmission module 300, and affect the accuracy of the data acquired by the acquisition module 200. Therefore, the electromagnetic shielding cavity 600 is used in the embodiment of the present application to shield the optoelectronic transmitting module 310, the collecting module 200 and the power supply 500 from electromagnetic interference. The first shielding layer 610 is used to shield a low-frequency electric field and a part of a high-frequency magnetic field. The second shielding layer 620 is used for shielding a high-frequency magnetic field and can shield a part of a low-frequency magnetic field. The third shielding layer 630 is used for shielding a low frequency magnetic field. In the embodiment of the present application, the electromagnetic shielding cavity 600 is used to reduce the electromagnetic interference suffered by the current measuring apparatus 10, and improve the stability of the current measuring apparatus 10 during operation.

In the embodiment, the material of the first shielding layer 610 is a good conductor, such as copper, zinc, aluminum, silver, gold, or their alloys and plating layers. The first shielding layer 610 is electrically connected to a first ground point 611. The first shielding layer 610 is further electrically connected to a first capacitor C1 and a second ground point 612 in turn. Since the first shielding layer 610 uses a good conductor and the first shielding layer 610 is electrically connected to the first grounding point 611, the low-frequency electric field can be guided to the ground through the first grounding point 611, thereby preventing the low-frequency electric field from interfering with the acquisition module 200 and the transmission module 300.

Similarly, in order to avoid the sudden increase of the potential at the moment of short circuit, which may result in the first shielding layer 610 not being effectively grounded, the first shielding layer 610 further includes another grounding line, i.e. the first capacitor C1 and the second grounding point 612 are electrically connected in sequence to achieve grounding. Since the capacitor has a charging process, the potential across the first capacitor C1 does not change instantaneously, and the first shielding layer 610 can be reliably grounded. Meanwhile, due to the characteristics of the good conductor itself, the high-frequency magnetic field can be partially shielded. Accordingly, the first shielding layer 610 may shield a low frequency electric field and a part of a high frequency electric field to protect the collection module 200 and the transmission module 300 within the electromagnetic shielding cavity 600.

In the embodiment of the present application, the second shielding layer 620 is made of iron. Because iron has high-frequency magnetic field magnetic permeability, the high-frequency magnetic field generated when the ultrahigh-voltage direct-current line is short-circuited can be shielded, and part of the low-frequency magnetic field can be shielded, so that the acquisition module 200 and the transmission module 300 in the electromagnetic shielding cavity 600 are protected.

In the embodiment of the present application, the third shielding layer 630 is made of permalloy (iron-nickel alloy), because permalloy has a high low-frequency magnetic permeability. Therefore, most of the low-frequency magnetic field can be shielded, and the acquisition module 200 and the transmission module 300 in the electromagnetic shielding cavity 600 can be protected.

In the embodiment of the present application, the collection module 200 and the transmission module 300 need to be powered to achieve current collection and photoelectric conversion. The current output by the power supply 500 may be affected by the short-circuit current of the extra-high voltage dc line, so that the power supply 500 is disposed inside the electromagnetic shielding cavity 600 to prevent the output current of the power supply 500 from being interfered by the external current.

Referring to fig. 4, as shown in fig. 4, the insulating member 700 includes an insulating branch 710 and a receiving cavity 720. The insulating branch 710 is arranged on the periphery of the accommodating cavity 720.

In this embodiment of the application, the accommodating cavity 720 is used for accommodating a ground terminal of the extra-high voltage direct current transmission line during a short circuit. The rogowski coil 100 is disposed at the periphery of the insulator 700, and can be disposed in an irregular space since the rogowski coil 100 is a flexible coil.

It can be understood that there is an air gap between the insulating branches 710 to improve the insulating performance of the insulating member 700, and prevent the acquisition module 200 from being broken down due to the short-circuit current transmitted to the acquisition module 200 through the rogowski coil 100. Since the extra-high voltage dc circuit uses a non-metallic grounding element when grounding, a higher measurement front end air gap is required to improve the withstand voltage level of the current measuring apparatus 10. The air gaps between the insulating branches 710 can improve the withstand voltage level of the current measuring device 10, and prevent the collection module 200 from being broken down.

Fig. 5 is a schematic diagram of test results provided by an embodiment of the present application.

In the embodiment of the present application, when the current measuring device 10 is used to detect the short circuit of the extra-high voltage dc circuit with a current of 20kA for a duration of 200ms, the detection result is as shown in fig. 5, and the detected peak current is about 22kA for a duration of 200 ms. Meanwhile, as shown in fig. 5, the detection result may show the impulse component and ripple of the current, and the impulse, ripple, dc and other components in the complex current can be accurately measured.

It can be understood that the current measuring device 10 provided in the embodiment of the present application can indirectly measure the short-circuit current of the extra-high voltage direct current circuit through the rogowski coil 100, and output a voltage. The acquisition module 200 is connected to the rogowski coil 100 to acquire the output voltage and restore the output voltage to a current variation value in a corresponding time period. The transmission module 300 transmits the current variation value to the signal processing module 400, so as to realize remote measurement of the short-circuit current of the extra-high voltage direct current circuit.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present application and are not used as limitations of the present application, and that suitable modifications and changes of the above embodiments are within the scope of the claims of the present application as long as they are within the spirit and scope of the present application.