CN102680804B - Lightning electric field change signal measuring system and method - Google Patents

Abstract

The invention discloses a lightning electric field change signal measurement system, which relates to the technical field of meteorological monitoring and includes: a detection antenna, a fast electric field change receiver, and a signal processing module, and the fast electric field change receiver is respectively connected to the detection antenna and the Signal processing module; the detection antenna is used to transmit the electric field change signal generated by the induced lightning to the fast electric field change receiver; the electric field fast change receiver is used to process the electric field change signal to obtain the lightning electric field The fast-changing signal, and the fast-changing signal of the lightning electric field is transmitted to the signal processing module; the signal processing module is used to collect and process the fast-changing signal of the lightning electric field to obtain a slow-changing signal of the lightning electric field; the present invention also discloses A measurement method of lightning electric field change signal corresponding to the above measurement system is proposed. The system and method of the invention realize the integrated measurement of fast and slow changing signals of lightning electric field.

Description

Lightning electric field change signal measurement system and method

technical field

The invention relates to the technical field of meteorological monitoring, in particular to a measurement system and method for lightning electric field change signals.

Background technique

Lightning is one of the most serious natural disasters in my country. Due to its characteristics of high current and strong electromagnetic radiation, it often causes forest fires, oil depot explosions, power supply interruptions, communication failures, equipment damage and other accidents, and it is easy to cause casualties. According to conservative estimates, thousands of casualties are caused by lightning disasters in my country every year, and direct economic losses exceed hundreds of millions of yuan, while the resulting indirect economic losses and impacts are difficult to estimate. Lightning disasters have affected all walks of life and all aspects of life. .

As a long-distance discharge phenomenon, lightning can produce strong electromagnetic radiation. Each lightning discharge contains discharge electron processes of various frequencies, and shows different forms of pulses in the characteristics of electric field waveforms. Observational studies reveal the fundamental physical process of lightning discharges. At the same time, the lightning electric field variation waveform is also an important basis for clarifying the mechanism of lightning electromagnetic radiation on electronic equipment, evaluating the protection effectiveness, and studying lightning electromagnetic pulse protection measures.

Therefore, the signal detection of lightning electric field changes has always been an important tool in the research of lightning physics and lightning protection. For a long time, there are two types of equipment used to measure lightning electric field changes at home and abroad: fast-changing lightning electric field detectors (often called fast antennas) and lightning electric field slow-changing detectors (often called slow antennas). Both are used to observe discharge events of different scales in the lightning process. Usually, the lightning electric field fast change detector is used to observe the fast discharge process of the lightning process, such as the pre-breakdown process, the return strike process, the leading process, the K process, etc., and the electric field slow change signal detector is mainly used to observe the lightning process The slow discharge process, such as continuous current (duration can be as long as hundreds of milliseconds), etc. The detection principle is as follows: the metal induction plate will generate induced charges under the action of the external electric field. When lightning occurs, the space electric field will change, and the change of the space electric field will cause the induced charge on the metal plate to change accordingly. The generated current will flow through the integral circuit, and after integral conditioning, the output voltage will be linearly related to the change of the electric field. The difference between the fast-changing lightning electric field detector and the slow-changing lightning electric field detector is the difference in the integral time constant. Generally, the time constant of the fast-changing lightning electric field detector is on the order of milliseconds, and the time constant of the detector on the slow-changing lightning electric field is on the order of seconds. .

Although the above-mentioned detection methods and means have been widely used, in actual observation experiments, especially in close-range lightning observations, such as the observation of artificially triggered lightning, it is found that traditional electric field change detection devices, especially lightning electric field slow change detection devices , the range of electric field strength that can be measured is not large enough, and the problem of response saturation often occurs for strong short-distance lightning. In order to solve this problem, researchers have also taken some corresponding measures. The main method is to adjust the value of R (resistance) and C (capacitance) in the integral circuit. However, due to the limitation of the current device technology level, some corresponding measures are also It is difficult to meet the requirements of lightning return strength at close range. Moreover, the fast-changing signal and slow-changing signal of the lightning electric field are measured by different equipment, and the degree of integration is not high.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the invention is: how to realize the integrated measurement of fast and slow changes of lightning electric field.

(2) Technical solution

In order to solve the above technical problems, the present invention provides a lightning electric field change signal measurement system, including: a detection antenna, a fast electric field change receiver, and a signal processing module, and the fast electric field change receiver is respectively connected to the detection antenna and the Signal processing module;

The detection antenna is used to transmit the electric field change signal generated by the sensed lightning to the fast electric field change receiver;

The fast electric field change receiver is used to process the electric field change signal to obtain a lightning fast electric field change signal, and transmit the lightning fast electric field fast change signal to the signal processing module;

The signal processing module is used for triggering acquisition and processing the fast-changing lightning electric field signal to obtain a slow-changing lightning electric field signal.

Wherein, the signal processing module includes: a digitizer and a digital processor, and the digitizer is respectively connected to the digital processor and the fast-changing electric field receiver for digitizing the received lightning fast-changing electric field signal After that, it is transmitted to the digital processor, and the digital processor performs deconvolution digital signal processing on the digitized fast-changing lightning electric field signal to obtain the slow-changing lightning electric field signal.

Wherein, also include: GPS antenna and GPS receiver, described GPS antenna is connected with described GPS receiver, and described GPS receiver is connected with described signal processing module, and described GPS antenna receives GPS satellite signal and transmits to described GPS to receive machine, the signal processing module triggers the GPS receiver to output time information when lightning occurs while processing the fast-changing lightning electric field signal.

Wherein, it also includes: a storage module, which is connected to the digital processor and the GPS receiver, and is used for storing the fast-changing signal of the lightning electric field, the slow-changing signal of the lightning electric field and the time information when the lightning occurs.

Wherein, it also includes a special processing platform oriented to the instrument system, and the digitizer, digital processor, GPS receiver and storage module are integrated on the special processing platform oriented to the instrument system.

Wherein, the detection antenna is a hollow circular panel antenna in shape, the GPS antenna is a mushroom head antenna, the head of the induction signal is located on the panel surface of the circular panel antenna, and the tail is located on the circular panel antenna of the circular panel antenna. in the hole.

Among them, it also includes an insulator, a shielding chamber and a support frame, the insulator is connected to the detection antenna and the shielding chamber, the electric field fast change receiver is located in the shielding chamber, and the support frame is connected to the shielding chamber , used to support the detection antenna, the insulator and the shielding chamber.

The present invention also provides a method for measuring lightning electric field change signals, comprising the following steps:

S1: Sense the electric field change signal generated by lightning, and obtain the fast change signal of lightning electric field after conditioning and integrating the electric field change signal;

S2: Process the fast-changing lightning electric field signal to obtain the slow-changing lightning electric field signal.

Wherein, the step S2 specifically includes:

S2.1: Determine whether the fast-changing lightning electric field signal meets the preset trigger conditions;

S2.2: Perform deconvolution digital signal processing on the fast-changing lightning electric field signal meeting the preset triggering conditions to obtain a slow-changing lightning electric field signal.

Among them, it also includes obtaining GPS time information when lightning occurs.

(3) Beneficial effects

The lightning electric field change measurement system and method of the present invention obtains the lightning electric field fast change signal through the electric field fast change receiver, and processes the lightning fast electric field fast change signal to obtain the lightning electric field slow change signal, and realizes the lightning electric field fast and slow change signal. Integrated measurement effectively solves the problem of saturation of the output of the slow-changing lightning electric field detection caused by the strong lightning signal at close range.

Description of drawings

Fig. 1 is a schematic structural diagram of a lightning electric field change measurement system according to an embodiment of the present invention;

Fig. 2 is the schematic structural diagram of the electric field fast-changing receiver in Fig. 1;

Fig. 3 is the comparison chart of the output signal waveform of the fast and slow change signal of the electric field obtained by the traditional fast/slow change detector of the electric field and the deconvoluted signal of the fast change of the electric field;

Fig. 4 is a flow chart of a method for measuring lightning electric field changes according to an embodiment of the present invention;

FIG. 5 is a flow chart of the system shown in FIG. 1 .

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

As shown in Figure 1, the lightning electric field change measurement system of the present embodiment includes: a flat plate antenna 1, a fast electric field change receiver 5 and a signal processing module for detecting the electric field change signal produced by lightning, and the fast electric field change receiver 5 is respectively connected A flat panel antenna 1 and a signal processing module. The panel antenna transmits the electric field change signal generated by the induced lightning to the fast electric field change receiver 5, and the electric field fast change receiver 5 processes the electric field change signal generated by the lightning, that is, obtains the lightning electric field fast change signal after signal conditioning and integration, And transmit the fast-changing lightning electric field signal to the signal processing module; the signal processing module triggers the collection and processes the fast-changing lightning electric field signal to obtain the slow-changing lightning electric field signal.

The fast-changing electric field receiver 5 is an integral conditioning circuit, and its main function is to convert the input signal to obtain a fast-changing lightning electric field signal. Matching parts such as 54, the time constant is on the order of ms or hundreds of microseconds, and the bandwidth is 1K ~ 5MHz; the integration circuit can use active integration or passive integration. The received signal is the induction signal of the panel antenna 1, and the signal is sent to the signal processing module after integral conditioning.

In this embodiment, the signal processing module includes: a digitizer 8 and a digital processor 9 (which may be an FPGA or a CPLD programming digital processor), and the digitizer 8 and the digital processor 9 are connected. The digitizer 8 is also called a data acquisition card, which can convert the lightning electric field fast-changing signal (analog signal) output by the integral conditioning circuit into a digital signal, and transmit the digital signal to the digital processor 9 at the same time, and the digital processor 9 converts the digitized The fast-changing lightning electric field signal is deconvoluted to obtain the original signal detected by the panel antenna 1 . The original signal obtained by deconvolution is a broadband signal including the slow changing signal of the lightning electric field, and also includes the fast changing signal of the lightning electric field. However, the slow changing signal of the lightning electric field is more obvious. The measured broadband signal, the slow-varying signal of the lightning electric field in the present invention refers to the broadband signal.

Of course, in order to directly obtain the slow-changing lightning electric field signal, a slow-changing electric field receiver (an integral conditioning circuit) can be used. Due to the long-time integration of the slow-changing lightning electric field signal (the integral constant is generally on the order of seconds), the output The voltage exceeds the requirements of the electronic components. For this reason, the present invention obtains the slow-changing electric field signal through digital signal processing through the fast-changing electric field signal of lightning, and the method is as follows: the low-frequency component of the electric field changing output signal after being adjusted and integrated by the fast-changing electric field receiver is suppressed, and has a smaller output signal magnitude, which can be reliably measured. If you know how the integral conditioning circuit changes the input signal (generally represented by a transfer function), you can restore the original signal. details as follows:

The signal E input by the panel antenna before integral conditioning, the output signal after the signal conditioning integral circuit is U, if the transfer function of the signal conditioning integral circuit is H, then the input-output relationship in the time domain is, U(t)=E (t)*H(t), where U(t) is the analog signal collected directly by the digitizer, and "*" represents the convolution operation. Perform deconvolution operation on U(t)=E(t)*H(t), H(t) and U(t) are parameters that can be measured, and obtain the original input signal E(t) through deconvolution operation . The signal U(t) output by the fast-changing electric field receiver has a small amplitude. Usually, when the integral constant is 0.1 ms, the output voltage for close-range lightning is within 10 volts, and there will be no saturation problem. Figure 3 shows the electric field fast and slow change signal obtained by the traditional electric field fast and slow change detector and the output signal after deconvoluting the fast electric field change signal. It can be seen that the slow change signal of lightning electric field measured by the traditional method has been saturated. Deconvolute the fast-changing lightning electric field signal to obtain a signal containing the slow-changing lightning electric field information. The slow-changing part of the signal is consistent with the slow-changing lightning electric field signal measured by the traditional method, and there will be no saturation of the slow-changing lightning electric field signal. question.

In this embodiment, a fast-changing lightning electric field signal is acquired by a fast-changing electric field receiver, and the fast-changing lightning electric field signal is processed to obtain a slow-changing lightning electric field signal, thereby realizing integrated measurement of fast and slow-changing lightning electric field. The method of deconvoluting the fast-changing lightning electric field signal avoids the problem of saturation of the response to strong short-distance lightning caused by the insufficient range of the electric field intensity measured by the traditional lightning electric field slow-changing detector, thus realizing Reliable detection of high-intensity close-range lightning electric field variation signals.

Further, it also includes: GPS antenna 2, GPS receiver 11, storage module 10, GPS receiver 11, storage module 10, digitizer 8 and digital processor 9, integrated together by a dedicated processing platform facing the instrument system, the Special-purpose expansion platform comprises: platforms such as PCI, PXI or PCIE, adopt PXI platform 12 to integrate GPS receiver 11, memory module 10, digitizer 8 and digital processor 9 in the present embodiment, PXI platform 12 is for industrial data Acquisition and automation applications Tailor-made modular instrument platform with time bus. The GPS antenna 2 is connected to a GPS receiver 11 , and both the GPS receiver 11 and the digital processor 9 are connected to a storage module 10 . The GPS antenna 2 is used to acquire GPS satellite signals and transmit the GPS satellite signals to the GPS receiver 11 . The digitizer 8 digitizes the fast-changing lightning electric field signal and transmits it to the digital processor 9 .

The GPS receiver 11 is connected to the digital processor 9, and the digital processor 9 judges the trigger condition. If the lightning electric field fast-changing signal (that is, the signal U(t) output by the electric field fast-changing receiver) exceeds the set trigger threshold or other trigger conditions (such as: set the signal amplitude to exceed 0.5V, and the rising edge triggers), the GPS receiver 11 is triggered to output time information; or the GPS receiver 11 is connected to the digitizer 8, and the digitizer 8 judges the trigger condition, and when the trigger condition is met , while transmitting the fast-changing lightning electric field signal to the digital processor 9, the GPS receiver 11 is triggered to output time information.

The GPS receiver in this embodiment is a PXI bus receiver. The storage module 10 is used for storing fast-changing lightning electric field signals, slow-changing lightning electric field signals, spatial position information of stations, and accurate time information when lightning occurs.

Furthermore, the plate antenna 1 uses a metal plate as the induction medium, and the induced charge on it can change with the change of the space electric field, and is used to detect the change signal of the space electric field when lightning occurs. The design shape is a hollow ring plate, and the hollow part is used To install the GPS antenna 2; the GPS antenna is a mushroom-head antenna encapsulated by insulating material, which can detect the transmission signal of the GPS satellite. For signal shielding, the sensing part of the GPS antenna 2 is above the horizontal plane of the metal plate of the panel antenna 1, forming an integrated antenna of the panel antenna 1 and the GPS antenna 2. The integrated antenna uses a coaxial cable to output signals, wherein the panel antenna 1 directly transmits the signal to the fast-changing electric field receiver 5 , and the GPS antenna 2 transmits the signal to the GPS receiver 11 .

Further, it also includes an insulator 3 , a shielding chamber 4 , a support rod 6 and a support base 7 . The insulator 3 is a high-voltage insulator of composite material (rated insulation voltage 50kV), and its geometric structure is a hollow structure, which is used to insulate the integrated antenna from the ground, and at the same time play a role in supporting the integrated antenna. The hollow part is used to pass the integrated antenna The coaxial signal transmission line; the upper and lower ends of the insulator are respectively connected to the integrated antenna and the shielding chamber 4.

Among them, the shielding chamber 4 is made of metal material and is used to place the receiver 5 with fast changing electric field, which can effectively shield the interference of the electromagnetic field in space, and simultaneously play the role of shielding and supporting, and its lower part is connected with the support rod 6 .

Among them, the support rod 6 and the support base 7 are made of stainless steel, wherein the support rod 6 is a hollow structure, the upper part is connected with the shielding chamber 4, and the lower part is connected with the support base 7, and the supporting shielding chamber 4 and the same for transmitting signals Axis; the support base 7 is processed with a fixing hole, and the upper part is connected with the support rod 6, which is used to fix the system when erecting (or laying).

The present invention also provides a method for measuring lightning electric field changes by using the above-mentioned lightning electric field change measurement system, as shown in Figure 4, including:

In step S401, the electric field change signal generated by lightning is sensed by the panel antenna 1, and the fast electric field change receiver 5 performs conditioning and integration on the electric field change signal to obtain the lightning fast electric field change signal. The panel antenna 1 has a large bandwidth and can detect fast and slow changing signals of the lightning electric field.

In step S402, the signal processing module performs deconvolution digital signal processing on the fast-changing lightning electric field signal to obtain a slow-changing lightning electric field signal. Specifically include: In order to eliminate the interference of non-lightning electromagnetic signals, judge whether the fast-changing lightning electric field signal meets the preset trigger conditions (such as: set a rising edge trigger and the signal amplitude exceeds 0.5V), and determine whether the lightning electric field that meets the preset trigger conditions The fast-changing signal is deconvoluted and digitally processed to obtain the slow-changing lightning electric field signal.

During the measurement, it also includes detecting the GPS satellite signal of the measurement location through the GPS antenna 2, and outputting the time information through the GPS receiver 11 after obtaining the fast changing signal of the lightning electric field.

A specific control flow of the above lightning electric field change measurement system is shown in Figure 5. After the system starts to work, when no lightning occurs, it is in a waiting state for triggering, and the signal processing module continuously converts analog signals into digital signals; when lightning occurs, If the lightning electric field fast-changing signal exceeds the set trigger threshold (or other trigger conditions), then deconvolution processing is performed, and the output trigger signal is given to the GPS receiver 11, and the GPS receiver 11 outputs time information after receiving the trigger signal For the PXI platform 12; the signal processing module performs deconvolution digital signal processing on the digitized fast electric field data, obtains the original signal containing the slow change information of the lightning electric field, and then outputs the slow change data and fast change data of the electric field to the storage module for preservation , and use the precise time output by GPS as the data file name to facilitate recording and query.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all Equivalent technical solutions also belong to the category of the present invention, and the scope of patent protection of the present invention should be defined by the claims.

Claims (5)

1. a lightning electric field change Signal Measurement System, is characterized in that, comprising: exploring antenna, electric field change receiver, signal processing module soon, and described electric field changes receiver soon and connects described exploring antenna and described signal processing module respectively;

The ring plate antenna of described exploring antenna to be shape be hollow, changes receiver soon for electric field change Signal transmissions to the described electric field produced by the lightning sensed;

It is integration modulate circuit that described electric field changes receiver soon, comprise integrating amplifier, traffic filter, driver output and impedance matching, the time constant of described integrating amplifier is millisecond or hundred musec order, bandwidth is 1K ~ 5MHz, the integrating circuit of wherein said integrating amplifier adopts active integration or passive integration, described electric field changes receiver soon for the treatment of described electric field change signal, to obtain the fast variable signal of lightning electric field, and the fast variable signal of described lightning electric field is transferred to described signal processing module;

Described signal processing module is used for triggering collection and adopts the fast variable signal of lightning electric field described in the process of FPGA or CPLD program numbers processor to obtain lightning electric field slow-changing signals, comprise: digitizer and digital processing unit, described digitizer connects described digital processing unit respectively and described electric field changes receiver soon, for transferring to described digital processing unit by after the digitizing of the described lightning electric field received fast variable signal, described digital processing unit carries out deconvolution digital signal processing to the fast variable signal of lightning electric field after digitizing and obtains described lightning electric field slow-changing signals,

Described system also comprises the dedicated processes PXI platform towards instrument system, and this platform has Time BUS;

Described system also comprises: gps antenna and GPS, and described gps antenna connects described GPS; Described GPS connects described digital processing unit or described digitizer, when described GPS connects described digital processing unit, described digital processing unit judges trigger condition, GPS output time information is triggered when trigger condition meets, when described GPS connects described digitizer, described digitizer judges trigger condition, when meeting trigger condition, described digitizer, by while transferring to described digital processing unit after the lightning electric field fast variable signal digitizing received, triggers GPS output time information;

Described gps antenna receives gps satellite signal and transfers to described GPS, and be cone type antenna, the head of induced signal is positioned in the platen surface of described ring plate antenna, and afterbody is arranged in the looping pit of described ring plate antenna.

2. lightning electric field change Signal Measurement System as claimed in claim 1, it is characterized in that, also comprise: memory module, connect described digital processing unit and GPS, for storing the temporal information comprised when the fast variable signal of lightning electric field, lightning electric field slow-changing signals and lightning occur.

3. lightning electric field change Signal Measurement System as claimed in claim 2, is characterized in that, described digitizer, digital processing unit, GPS and memory module are integrated in described towards on the dedicated processes PXI platform of instrument system.

4. lightning electric field change Signal Measurement System as claimed in claim 1, it is characterized in that, also comprise insulator, shielding bin and bracing frame, described insulator connects described exploring antenna and described shielding bin, described electric field changes receiver soon and is positioned at described shielding bin, support frame as described above connects shielding bin, for supporting described exploring antenna, insulator and shielding bin.

5. a lightning electric field change signal measurement method, is characterized in that, comprise the following steps:

S1: the electric field change signal that induction lightning produces, to electric field change signal through integration amplification, signal filtering, driver output and impedance matching process, obtains the fast variable signal of lightning electric field after carrying out conditioning integration, and obtains gps time information when lightning occurs;

S2: by FPGA or CPLD program numbers processor, process is carried out to the fast variable signal of lightning electric field and obtains lightning electric field slow-changing signals, specifically comprise:

S2.1: judge whether the fast variable signal of lightning electric field meets the trigger condition preset;

S2.2: deconvolution digital signal processing is carried out to the fast variable signal of lightning electric field meeting the trigger condition preset and obtains lightning electric field slow-changing signals.