CN210863870U - Lightning current measuring device of lightning fan based on tunnel magnetoresistance effect - Google Patents
Lightning current measuring device of lightning fan based on tunnel magnetoresistance effect Download PDFInfo
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- CN210863870U CN210863870U CN201920773675.8U CN201920773675U CN210863870U CN 210863870 U CN210863870 U CN 210863870U CN 201920773675 U CN201920773675 U CN 201920773675U CN 210863870 U CN210863870 U CN 210863870U
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Abstract
A lightning current measuring device of a lightning fan based on a tunnel magnetoresistance effect can solve the technical problems of large error and inconvenient installation when lightning current is measured in the prior art. The device comprises a front-end measuring module, a signal transmission module and a signal receiving and processing module, wherein the front-end measuring device adopts a three-dimensional measuring probe, and the signal transmission module comprises an AD (analog-to-digital) amplification module; the AD amplifying module is arranged in the electromagnetic shielding box; the three-dimensional measuring probe is connected with the input end of the AD amplifying module through a shielded cable; the output end of the AD amplifying module is connected with the electro-optical converter through a collecting card; the utility model discloses an install measuring device on fan tower section of thick bamboo wall, the transient state magnetic field signal that the lightning current produced is sensed to the measuring device probe to carry out data reception and read through fiber transmission to the PC end after with its signal processing, calculate the reduction through demarcation and obtain the lightning current waveform, the precision reliability is high, device simple to operate, and is with low costs, small.
Description
Technical Field
The utility model relates to a current measurement technical field, concretely relates to thunderbolt fan lightning current measuring device based on tunnel magnetoresistance effect.
Background
Wind power generation has been developed vigorously in recent decades due to its advantages of being clean, pollution-free, capable of being used for a long time, and the like, and this rapid development is accompanied with increasingly serious threat of lightning disasters. Especially, along with the improvement of the single machine capacity of the wind turbine generator system at present, the overall height of the fan is increased, so that the lightning drawing capability of the fan is greatly improved, and the lightning current carrying huge energy can generate an electromagnetic field with transient change inside the tower of the wind turbine generator system, and can possibly generate electromagnetic interference in electric power, a signal circuit and an electronic control system and further threaten the safe and stable operation of the wind turbine generator system. Therefore, the measurement of the lightning current parameters has very important significance for safe and stable operation of the wind turbine generator, discussion of lightning protection measures and improvement of the performance of lightning protection equipment.
In the aspect of lightning current parameter measurement, at present, the following methods are mainly available at home and abroad: the bar magnet method, the magnetic tape, and the rogowski coil method. The magnetic steel bar method is widely applied in China at first, and although a large amount of lightning measurement data are obtained in practical application, the measurement method has large measurement error, cannot record repeatedly and is very inconvenient to install and read. Later, a magnetic tape method was developed, which has significantly improved measurement accuracy stability and the like compared to a magnetic steel bar method, but cannot measure a lightning current waveform as in the magnetic steel bar method. The Rogowski coil method can measure the waveform and amplitude of lightning current more accurately, and measurement accuracy is high, and the interference killing feature is strong, but must pass coil center with the conductor measured when measuring, for example when the lightning current of Tokyo sky tree tower in Japan measures, just used the Rogowski coil to measure, cover two huge Rogowski coils on Tokyo sky tree tower, one is used for surveying high frequency lightning current signal, one is used for measuring low frequency lightning current signal, this just makes at the measurement installation process very inconvenient. At present, the lightning stroke current applied to the tower drum of the fan is mainly measured by the Rogowski coil, so that the installation is inconvenient, and the cost is very expensive.
SUMMERY OF THE UTILITY MODEL
The utility model provides a pair of thunderbolt fan lightning current measuring device based on tunnel magnetoresistance effect can solve prior art and measure the big and inconvenient technical problem of installation of error to lightning current.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
a lightning current measuring device of a lightning stroke fan based on a tunnel magnetic resistance effect comprises:
the method comprises the steps of adopting a front end measuring device and a signal receiving and processing end, installing the front end measuring device on the wall of a fan tower cylinder, measuring the amplitude, gradient and polarity of a transient magnetic field generated by lightning current when a fan is struck by lightning, transmitting a measured signal to a rear end signal receiving and processing end through photoelectric conversion to read and record, and obtaining the actual lightning current through calibration and calculation.
The sensor probe comprises three identical high-frequency tunnel magnetoresistive sensors, and the signal processing module comprises an AD (analog-to-digital) amplification module, a power supply module and an electromagnetic shielding box; wherein the content of the first and second substances,
the three-dimensional sensor probe adopts two vertically placed PCB boards, three sensor chips are vertically welded on the boards in pairs, the two boards are fixed through four signal interfaces, and the four interfaces transfer the output and power supply of one sensor to the boards where other two sensors are located, so that the layout of the measuring device is optimized. The sensor probe is composed of three identical high-frequency tunnel magnetoresistive sensors, the size of each sensor is 5mm x 1.5mm, a sensor circuit adopts four non-shielding high-sensitivity tunnel magnetoresistive elements to form a Wheatstone bridge, and the Wheatstone full bridge circuit provides differential voltage output. The three sensors are respectively fixed on three side surfaces of the probe, the sensitive axes of each sensor are mutually vertical, transient magnetic field strengths in different directions generated by lightning current can be sensed, and the spatial positions of the three sensors are smaller than 6 mm.
The differential voltage output of the Wheatstone full-bridge circuit is adopted, so that the output of small signals can be identified, the small signals can be accurately processed, the external electromagnetic interference can be greatly reduced, the mutual perpendicularity of the sensitive axes of each magnetic field sensor is ensured, and the sensor probe can realize the function of omnidirectional sensing. And the probe has small size, so that a single-point magnetic field is ensured to be detected, and the measurement precision is higher.
The AD amplifying module converts the three pairs of output differential signal analog quantities into single-ended output for amplification, and the single-ended output is transmitted to a PC (personal computer) end for data reading through the acquisition card and the electro-optical converter.
A power supply module: the power uses 12V lithium cell, adopts 12V to change 5V voltage stabilizing module and obtains 5V steady voltage output and give measuring device power supply, can work for a long time in practical application.
Electromagnetic shielding box: when lightning current of a tower cylinder of a fan is struck by lightning is measured, severe electromagnetic signals on a high-voltage line may be coupled into a signal processing circuit to cause electromagnetic interference. An electromagnetic shielding design for the measurement system is required. For a sensing system operating in a strong electromagnetic interference environment, a single material shielding cannot meet application requirements, and a multi-material combined shielding is required. The shielding performance of the electric field shielding and the magnetic field shielding is comprehensively considered, the rear-end signal processing circuit is electromagnetically shielded by using the combined shielding shell of 1mm pure copper and 2mm permalloy, and meanwhile, the signal processing module except the probe is fixedly installed by using the combined shielding shell. And a shielded cable is adopted for transmission in the signal transmission process, so that the measuring device is not influenced by high-frequency electromagnetic interference in practical application.
According to the above technical scheme, the utility model discloses a thunderbolt fan lightning current measuring device based on tunnel magnetoresistance effect installs measuring device on fan tower section of thick bamboo wall for lightning current produces the amplitude in magnetic field, the gradient, polarity when measuring the thunderbolt fan. And then the measured signal is transmitted to a back-end signal receiving and processing end through photoelectric conversion for reading and recording. Because the special symmetrical structure of fan tower section of thick bamboo, the utility model discloses a magnetic field signal that records is markd and is calculated the size that reachs lightning current.
The utility model discloses the device is through fixing three the same high frequency tunnel magnetoresistive sensor based on tunnel magnetoresistive effect makes respectively on three faces of sensor probe, and the three sensitive axle mutually perpendicular of sensor can realize producing the magnetic field size of same any direction to the lightning current and carry out the sensing to with measuring signal transmission to terminal processing record, thereby realize transient state lightning current's non-contact measurement.
The utility model discloses a measuring device simple to operate, it is with low costs, measuring probe is small, and the precision is high, and it is big to measure the lightning current scope, is applicable to fan tower section of thick bamboo, the measurement of thunderbolt transient state heavy current such as high-speed railway overpass.
Drawings
FIG. 1 is a schematic block diagram of the present invention;
FIG. 2 is a schematic view of the internal equivalent structure of the middle-high frequency tunnel magnetic field sensor of the present invention;
fig. 3 is a schematic diagram of a three-dimensional structure of a sensor probe of the high-frequency tunnel magnetic field sensor of the present invention;
fig. 4 is a side view of a sensor probe of the present invention;
fig. 5 is a three-dimensional structural view of the shield case of the present invention;
FIG. 6 is a schematic diagram of a sensor probe according to the present invention;
fig. 7 is a schematic diagram of an AD amplification module of the present invention;
fig. 8 is a schematic diagram of the implementation and use of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention.
Fig. 1 is a schematic block diagram of an embodiment of a lightning current measuring device of a lightning fan according to an embodiment of the present invention, which includes a three-dimensional measuring probe, an AD amplifying module, a power module, an electromagnetic shielding box, an electro-optical converter and a signal receiving and processing module; the AD amplifying module is arranged in the electromagnetic shielding box; the signal receiving and processing module is specifically a PC end data receiving processor;
further to the above, it is preferable that,
the lightning current measuring device of the lightning fan comprises a front-end measuring module, a signal transmission module and a signal receiving and processing module, wherein the front-end measuring device adopts a three-dimensional measuring probe, and the signal transmission module comprises an AD (analog-to-digital) amplification module; the AD amplifying module is arranged in the electromagnetic shielding box;
the three-dimensional measuring probe is connected with the input end of the AD amplifying module through a shielded cable;
the output end of the AD amplifying module is connected with the electro-optical converter through a collecting card;
the output end of the electro-optical converter is connected with the signal receiving end through an optical fiber;
the three-dimensional measuring probe comprises three same high-frequency tunnel magnetoresistive sensors, a first high-frequency tunnel magnetoresistive sensor 1, a second high-frequency tunnel magnetoresistive sensor 2, a third high-frequency tunnel magnetoresistive sensor 3 and two vertically-arranged probe PCB boards, wherein the first probe PCB board 4 and the second probe PCB board 5 are fixed on the second probe PCB board 5, the first high-frequency tunnel magnetoresistive sensor 1 is fixed on one side surface of the first probe PCB board 4, the second high-frequency tunnel magnetoresistive sensor 2 is fixed on the surface of the first probe PCB board 4 opposite to the first high-frequency tunnel magnetoresistive sensor 1, and the third high-frequency tunnel magnetoresistive sensor 3 is fixed on the bottom surface of the second probe PCB board 5;
the three high-frequency tunnel magnetoresistive sensor chips are vertical to each other in pairs;
the two probe PCB boards are fixed through a signal interface, and the signal interface switches the output and power supply of one sensor to the board where the other two sensors are located. Specifically, three identical high-frequency tunnel magnetoresistive sensors (TMR) are welded on three sides of the probe in the manner shown in fig. 3, and each side is provided with a TMR sensor, namely a TMR sensor 1, a TMR sensor 2, a TMR sensor 3, two probe PCB boards, namely a PCB board 4 and a PCB board 5; each sensor has a fixed sensitive axis direction, the sensitive axis directions of the sensors are as shown in fig. 3, the sensitive axes of the sensors on the three sides are perpendicular to each other, and transient magnetic fields in three different directions can be detected simultaneously.
Fig. 4 shows a right side view of the sensor probe. 6.7.8.9 shows the interfaces of the differential outputs V +, V-of the sensor 3 and the power supply +5V, GND, respectively. It has two beneficial effects, and the effect is on all switching the output of sensor 3 and power supply to PCB board 4, supplies power and transmission signal through PCB board 4 jointly, has simplified measuring device's overall arrangement more. And secondly, the PCB 4 and the PCB 5 are fixed through 6.7.8.9 interfaces, so that the PCB and the PCB are perpendicular to each other, and the measurement accuracy of the measuring device is ensured. Since each sensor is 5mm by 1.5mm in size, the spatial position formed by the three sensors is less than 6mm by 6mm, thus approximately ensuring that a single point three-dimensional magnetic field is sensed. The internal circuit of the high-frequency tunnel magnetoresistive sensor adopts four tunnel magnetoresistances to form a Wheatstone bridge (as shown in figure 2), the resistance value of each resistor is 30K ohms, when an external magnetic field is 0, the bridge is in a balanced state, the differential voltage output is 0, and when a fan is struck by lightning, lightning current generates a transient magnetic field, so that R1 and R3 change simultaneously, R2 and R4 change simultaneously, and the resistance values of two groups of resistors have the same change amount but opposite change sizes. Therefore, a differential voltage is generated at the output end, the magnitude of the differential voltage is in direct proportion to the resistance variation, and the resistance variation is in direct proportion to the magnitude of the current, so that the magnitude of the current can be obtained through calibrating and calculating the linear proportional relation between the sensor and the current.
A schematic diagram of the sensor probe is shown in fig. 6. Three pairs of differential signals output by the sensor probe need to be subjected to differential amplification and are converted into single-ended output for processing and recording. Because the measured transient signal belongs to a high-frequency signal, a shielded cable is adopted for data signal transmission. In order to reduce the influence of the noise of the amplifier on the signal, an amplification module of the measurement system is formed by a low-noise and low-distortion high-speed differential amplifier AD8129, has the characteristics of high input impedance, high common-mode rejection ratio and the like, and has the bandwidth of 200 MHz. In order to process three pairs of differential output signals of the three-dimensional sensor probe, a three-channel AD8129 amplification module is designed to process the output signals, as shown in FIG. 8.
The power supply system of the measuring device adopts the lithium battery to supply 5V direct current reference voltage generated by the voltage stabilizing power supply module to the operational amplifier and the sensor probe respectively.
In order to reduce the electromagnetic interference of the high-frequency electromagnetic field to the signal processing circuit, a combined shielding box of 3mm pure copper and 0.3mm permalloy is adopted to carry out electromagnetic shielding on the signal processing module. Specifically, the electromagnetic shielding box is of a closed box body structure, an interface 10 is arranged on the side wall of the electromagnetic shielding box, and the interface 10 is used for connecting the three-dimensional measuring probe and the signal processing module; the side wall of the electromagnetic shielding box is also provided with a through hole 11 which is used as a channel of a transmission line; as shown in fig. 5, the interface 10 is an interface for connecting the sensor probe and the signal processing module, through which the probe can be mounted and dismounted, the through hole 11 is a channel of an output signal transmission line, three signals are transmitted through a shielded cable, the mark 12 is a partition board which divides the shielding box into two layers, the lower layer is provided with a power module circuit, and the upper layer is provided with the signal processing circuit module, so that the signal shielding effect of the whole measuring device is the best.
Fig. 8 is a schematic view of the present invention. When the fan lightning current is measured, the sensor probe is connected with a signal processing circuit in the electromagnetic shielding box to form a front-end measuring device. The front end measuring device is fixedly installed on the cylinder wall of the fan tower cylinder, the measuring probe is parallel to the cylinder wall and is used for detecting the amplitude, gradient and polarity of a transient magnetic field generated by lightning current when the fan is struck by lightning, measured signals are transmitted to the AD amplification module through the shielding cable to be amplified, then are sent to the PC end data receiving processor through the acquisition card and the electro-optical converter to be read and recorded, and the waveform of the actual lightning current is obtained through calibration calculation and reduction.
The embodiment of the utility model provides a through installing measuring device on fan tower section of thick bamboo wall, the transient magnetic field signal that the lightning current produced is sensed to the measuring device probe to transmit PC end data reception processing module through shielded cable after with its signal processing and read, obtain the lightning current waveform through demarcating the calculation reduction. The measuring method and the device have the advantages of convenient installation, high precision reliability, low device cost, small volume and large-scale installation.
The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (10)
1. The utility model provides a thunderbolt fan lightning current measuring device based on tunnel magnetoresistance effect, includes front end measurement module, signal transmission module and signal reception processing module, its characterized in that: the front-end measuring module adopts a three-dimensional measuring probe, and the signal transmission module comprises an AD (analog-to-digital) amplifying module; the AD amplifying module is arranged in the electromagnetic shielding box;
the three-dimensional measuring probe is connected with the input end of the AD amplifying module through a shielded cable;
the output end of the AD amplifying module is connected with the electro-optical converter through a collecting card;
the output end of the electro-optical converter is connected with the signal receiving end through an optical fiber;
the three-dimensional measuring probe comprises three same high-frequency tunnel magnetoresistive sensors, a first high-frequency tunnel magnetoresistive sensor (1), a second high-frequency tunnel magnetoresistive sensor (2), a third high-frequency tunnel magnetoresistive sensor (3) and two vertically-placed probe PCB boards, wherein the first probe PCB board (4) and the second probe PCB board (5) are vertically fixed on the second probe PCB board (5), the first high-frequency tunnel magnetoresistive sensor (1) is fixed on one side surface of the first probe PCB board (4), the second high-frequency tunnel magnetoresistive sensor (2) is fixed on the surface, opposite to the first high-frequency tunnel magnetoresistive sensor (1), of the first probe PCB board (4), and the third high-frequency tunnel magnetoresistive sensor (3) is fixed on the bottom surface of the second probe PCB board (5);
the three high-frequency tunnel magnetoresistive sensor chips are vertical to each other in pairs;
the two probe PCB boards are fixed through a signal interface, and the signal interface switches the output and power supply of one sensor to the board where the other two sensors are located.
2. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 1, characterized in that: the internal circuit of the high-frequency tunnel magnetoresistive sensor adopts four tunnel magnetoresistances to form a Wheatstone bridge, and the resistance value of each resistor is 30K ohms.
3. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 1, characterized in that: the dimensions of each of the high frequency tunnel magnetoresistive sensors are 5mm 1.5 mm.
4. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 3, characterized in that: the spatial position formed by the three high-frequency tunnel magneto-resistive sensors is less than 6 mm.
5. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 1, characterized in that: the AD amplifying module comprises a high-speed differential amplifier AD8129 with low noise and low distortion.
6. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 1, characterized in that: still include power module, power module sets up in the electromagnetic shield box, power module is connected with three-dimensional measurement probe, AD amplifier module respectively and is supplied power for it.
7. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 6, characterized in that: the power module adopts a lithium battery to supply power to the AD amplification module and the three-dimensional measuring probe respectively for 5V direct current reference voltage generated by the voltage stabilizing power supply module.
8. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 1, characterized in that: the electromagnetic shielding box is a shielding box combined by 3mm pure copper and 0.3mm permalloy.
9. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 8, characterized in that: the electromagnetic shielding box is of a closed box body structure, an interface (10) is arranged on the side wall of the electromagnetic shielding box, and the interface (10) is used for connecting the three-dimensional measuring probe and the signal processing module;
the side wall of the electromagnetic shielding box is also provided with a through hole (11) which is used as a channel of a transmission line.
10. The lightning stroke fan lightning current measuring device based on the tunnel magnetoresistance effect according to claim 9, characterized in that: a partition plate (12) is arranged inside the electromagnetic shielding box, and the electromagnetic shielding box is divided into an upper layer and a lower layer by the partition plate (12).
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112505480A (en) * | 2020-11-19 | 2021-03-16 | 云南电网有限责任公司普洱供电局 | Non-invasive transient overvoltage detection sensor and detection method |
| CN113325343A (en) * | 2021-05-24 | 2021-08-31 | 合肥工业大学 | Method for measuring single-shaft tunnel reluctance current |
| CN113466531A (en) * | 2021-06-03 | 2021-10-01 | 合肥工业大学 | Lightning current measuring method based on tunnel magnetoresistive sensor |
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2019
- 2019-05-27 CN CN201920773675.8U patent/CN210863870U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112505480A (en) * | 2020-11-19 | 2021-03-16 | 云南电网有限责任公司普洱供电局 | Non-invasive transient overvoltage detection sensor and detection method |
| CN113325343A (en) * | 2021-05-24 | 2021-08-31 | 合肥工业大学 | Method for measuring single-shaft tunnel reluctance current |
| CN113466531A (en) * | 2021-06-03 | 2021-10-01 | 合肥工业大学 | Lightning current measuring method based on tunnel magnetoresistive sensor |
| CN113466531B (en) * | 2021-06-03 | 2022-05-03 | 合肥工业大学 | Lightning current measuring method based on tunnel magnetoresistive sensor |
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