CN106525219A - Tower material vibration displacement real time monitoring method for power transmission iron tower - Google Patents

Abstract

The invention discloses a method for real-time monitoring of the vibration displacement of a power transmission iron tower material. Step 1 is to obtain the acceleration signal of the iron tower material; The frequency spectrum is divided by ω ² , ω is the angular frequency; step 3, select a high-pass channel to truncate and filter the frequency domain signal obtained in step 2, and then convert it into a displacement spectrum; step 4, inverse Fourier transform the displacement spectrum into a displacement Time-domain signal to obtain the real-time displacement of the tower material. The invention can monitor the vibration displacement of the tower material in real time, and it is convenient for electric power workers to monitor the displacement of the tower in real time under the state of the dancing wire, so as to judge the safety state of the tower. Once the tower has a dangerous tendency, it can Take remedial measures in a timely manner.

Description

A real-time monitoring method for vibration displacement of transmission tower materials

technical field

The invention relates to the field of power transmission iron tower monitoring, in particular to a method for real-time monitoring of vibration displacement of power transmission iron tower materials.

Background technique

The galloping phenomenon of high-voltage transmission lines in northern China is the main problem that threatens the safe operation of the power grid, especially the main network lines of 500kV and above. It will also seriously threaten the security and reliability of the power grid.

In recent years, with the development of power grid construction and the influence of disastrous meteorological conditions, the frequency and intensity of galloping accidents on overhead transmission lines in my country have increased significantly. In addition to causing electrical accidents, the galloping of ice-coated wires can also lead to serious accidents such as disconnection, damage to the iron tower, or even the collapse of the tower. Galloping generally first causes the tower material bolts to loosen, and then the cross arm breaks, and then a disconnection accident occurs. Before galloping produces bad consequences, real-time monitoring and analysis of galloping vibration characteristics of tower materials is crucial to research and early warning of line galloping hazards.

Publication No. CN 104501769 provides a method and device for detecting the state of a transmission line pole and tower, including the steps of measuring data through a distance measuring device, calculating latitude, longitude, and altitude, and calculating an offset. Publication No. CN102494650 provides a tower displacement monitoring system, including a tower displacement monitoring terminal and an underground displacement monitoring terminal electrically connected to it; The ground tower displacement sensor, power module and communication module; the underground displacement monitoring terminal is set on the underground bedrock, including the control module and the displacement sensor electrically connected to it. By using the displacement sensor to monitor the displacement of the tower and the bedrock respectively, the displacement of the tower and bedrock displacement, the displacement of the tower relative to the bedrock can be calculated.

The Chinese patent with publication number CN201233275 discloses a detection device for accurately measuring the amplitude and frequency of high-voltage line galloping, including a sealed casing and a power supply induction circuit and a data processing circuit arranged in the casing; the data processing circuit includes a low-power single-chip microcomputer, a vibration Amplitude detection circuit, vibration frequency detection circuit, signal amplification circuit, sample and hold circuit, A/D conversion circuit and long-distance signal transmission circuit. The Chinese patent with publication number CN201134152 provides an overhead transmission line galloping monitoring device and system, including: an acceleration sensor, a signal conditioning unit, a wireless transceiver unit, and a power supply; the acceleration sensor is coupled with the signal conditioning unit, and the signal conditioning unit is connected to the wireless transceiver unit. Coupling; the acceleration sensor monitors the galloping acceleration signal of the galloping monitoring point on the overhead transmission line conductor, and transmits the monitored acceleration signal to the signal conditioning unit; the signal conditioning unit performs signal conditioning on the acceleration signal, and the generated acceleration standard signal The transmission is sent to the wireless transceiver unit; the wireless transceiver unit transmits the received acceleration standard signal wirelessly; the power supply is used to provide working electric energy.

The tower material vibration caused by wire galloping is different from the general vibration type, which belongs to the low-frequency and ultra-low-frequency vibration of 0.1-3Hz, so the measurement method is different from the general tower displacement measurement. Existing transmission line galloping measurement technologies mostly focus on the measurement of conductor galloping trajectory; conductor galloping is characterized by low frequency and large amplitude, while tower material vibration displacement is characterized by low frequency and small displacement, so the measurement method is different from that of conductor galloping trajectory. At present, there is no device for monitoring the galloping displacement of transmission tower materials.

Contents of the invention

In view of this, the purpose of the present invention is to provide a real-time monitoring method for the vibration displacement of the tower material of the transmission iron tower, which is used to monitor the vibration displacement of the tower material in real time.

To achieve the above object, the present invention adopts the following technical solutions:

A method for real-time monitoring of the vibration displacement of a power transmission tower material, comprising the following steps:

Step 1, obtaining the acceleration signal of the tower material;

Step 2, using Fourier transform to convert the acceleration time-domain signal into a frequency-domain signal, and divide the acceleration spectrum by ω ² , where ω is the angular frequency;

Step 3, select a high-pass channel to convert the frequency domain signal obtained in step 2 into a displacement spectrum after truncation and filtering;

Step 4, inverse Fourier transforming the displacement spectrum into a displacement time-domain signal to obtain the real-time displacement of the tower material.

Preferably, said step 1, obtaining the acceleration signal of the iron tower material includes:

The acceleration sensor collects the acceleration signal of the tower material;

The collected acceleration signal is sent to the NIcRIO signal acquisition platform after signal conditioning and isolation;

The NIcRIO signal acquisition platform transmits the signal to the measurement and control unit through the communication unit, and reads the acceleration signal off-line.

Preferably, the acceleration sensor is a capacitive acceleration sensor.

Preferably, the acceleration sensor includes a triaxial acceleration sensor and a uniaxial acceleration sensor.

Preferably, after signal conditioning and isolation, the collected acceleration signal is transmitted to the NIcRIO signal collection platform under a standard voltage signal of 1-5V.

The beneficial effects of the present invention are:

In the present invention, a plurality of acceleration sensors are arranged on the iron tower material, which can monitor the vibration displacement of the tower material in real time; the acceleration time-domain signal of the tower vibration caused by wire galloping is converted into a displacement time-domain signal, and the method has high accuracy and precision Well, it is effective for eliminating trend items and low-frequency interference. In the state of transmission wire dancing, it is convenient for electric power workers to monitor the displacement of the tower in real time, and judge the safety status of the tower based on this. Once the tower has a dangerous tendency, remedial measures can be taken in time.

The acceleration sensor of the present invention uses a capacitive acceleration sensor as a tower material vibration displacement measurement sensor, which avoids the problem that the output of the piezoelectric sensor decreases with frequency and the error is getting larger, which is difficult to apply in the tower material vibration measurement system.

Due to the large volume of the transmission tower material, when a single sensor is used to measure data, only the displacement of a certain part of the tower material can be measured, and it is difficult to monitor the entire tower material. The invention adopts a plurality of acceleration sensors, and the acceleration sensors are installed on the parts of the tower that are prone to failure, so that the displacement of multiple monitoring points can be measured at the same time, and the galloping vibration characteristics of the entire tower can be monitored and analyzed in real time.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

Fig. 1 is a method flow chart of a method for real-time monitoring of vibration displacement of a power transmission tower material in the present invention.

Fig. 2 is a flow chart of step S101 of a real-time monitoring method for vibration displacement of a power transmission tower material in the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the present invention provides a method for real-time monitoring of the vibration displacement of the tower material of the power transmission tower, including the following steps S101-S104:

Step 101, obtaining the acceleration signal of the tower material;

Step 102, using Fourier transform to convert the acceleration time-domain signal into a frequency-domain signal, and divide the acceleration spectrum by ω ² , where ω is the angular frequency;

Step 103, select a high-pass channel to convert the frequency domain signal obtained in step 2 into a displacement spectrum after truncation and filtering;

Step 104, inverse Fourier transforming the displacement spectrum into a displacement time-domain signal to obtain the real-time displacement of the tower material.

There are generally two methods of displacement measurement, indirect and direct. Direct measurement generally requires a reference position as a fixed point. It is difficult to use this method for the vibration displacement of tower materials, and only indirect methods can be used. The indirect method needs to convert the measured physical quantity, and the selection of the displacement conversion algorithm has a great influence on the final accuracy. The invention aims at a calculation method for converting acceleration data collected by a tower material real-time vibration monitoring system into a tower material vibration displacement.

In this embodiment, for the method of measuring vibration displacement using relative quantities, displacement calculation is required. After the acceleration is measured, AVD transformation is required, that is, acceleration-velocity-displacement transformation. This process is simply an integration process: the acceleration integral becomes velocity, and the velocity integral becomes displacement. This method uses Fourier transform to convert the acceleration time-domain signal into a frequency-domain signal, and divides the acceleration spectrum by ω ² , where ω is the angular frequency; and then selects a suitable high-pass frequency for truncation filtering, converts it into a displacement spectrum, and then performs Fu The Liye inverse transform is transformed into a displacement time-domain signal. In view of the strong periodicity of the measured tower object, an appropriate filter frequency is selected according to its frequency spectrum, and the collected tower vibration acceleration signal is converted into a tower vibration displacement signal, and the vibration displacement of the tower material is monitored in real time.

Different objects have different vibration frequencies, so the selected cut-off frequency is also different, and the cut-off frequency bandwidth is adjustable. Taking a certain base tower as an example, the galloping frequency of the conductors at both ends of the tower is 0.4 Hz, and the resulting vibration frequency of the tower is also 0.4 Hz. Through repeated tests, the low-frequency cut-off frequency of the band-pass filter for the vibration of the tower can be obtained is 0.3 Hz, and the high frequency cutoff frequency is 5Hz.

In one embodiment, the acceleration sensor is a capacitive acceleration sensor.

In this embodiment, the acceleration sensor adopts the capacitive acceleration sensor as the vibration displacement measurement sensor of the tower material, which avoids the problem that the output of the piezoelectric sensor decreases with the frequency and the error becomes larger, which is difficult to apply in the tower material vibration measurement system.

In one embodiment, the acceleration sensor includes a three-axis acceleration sensor and a single-axis acceleration sensor.

In this embodiment, due to the large volume of the transmission tower material, when a single sensor is used to measure data, only the displacement of a certain part of the tower material can be measured, and it is difficult to monitor the entire tower material. The invention adopts a plurality of acceleration sensors, and the acceleration sensors are installed on the parts of the tower that are prone to failure, so that the displacement of multiple monitoring points can be measured at the same time, and the galloping vibration characteristics of the entire tower can be monitored and analyzed in real time.

In one embodiment, as shown in FIG. 2, the step S101 may be implemented as the following steps:

Step S201, the acceleration sensor collects the acceleration signal of the tower material;

Step S202, transmit the collected acceleration signal to the NIcRIO signal collection platform after signal conditioning and isolation;

Step S203, the NIcRIO signal acquisition platform transmits the signal to the measurement and control unit through the communication unit, and reads the acceleration signal off-line.

In this embodiment, the NIcRIO signal acquisition platform (referred to as the cRIO platform) of NI Corporation of the United States is used. The cRIO platform does not need to know whether the front-end sensor is a tension signal or an acceleration signal, and only needs to target the 1~5V voltage it finally sends. The signal can be collected. Since it works outdoors, it must have certain anti-jamming capabilities. The NIcRIO signal collection platform generally also comes with a GPS card for timing.

The NIcRIO signal acquisition platform is used to control the storage and transmission of signals, GPS time stamp injection, etc., and to control the acquisition card to acquire signals.

The NIcRIO signal acquisition platform includes two parts: user setting and real-time sampling. The user setting part is used to initialize the sampling frequency, set the proportional coefficient of the final output signal, and set the IP of the FTP server for uploading data. The real-time sampling part ends in the user setting After that, you can start data collection. The sampling rate can be adjusted from 0.1Hz to 1000Hz. After resetting, you need to reboot cRIO to take effect. Inject the real-time standard time obtained by the GPS card into all the collected data, and save and transmit it together with the sampled data. The data display interface includes the collected real-time voltage data of all channels and the corresponding real-time measurement curves, as well as the final data and curves with the signal proportional coefficient set. The collected data can be saved to the NIcRIO signal collection platform, and can also be uploaded in real time and synchronously to the FTP server with the IP set by the user. The storage of data in the NIcRIO signal acquisition platform is based on the principle of circular storage covering the oldest data; the data is uploaded to the FTP server in a real-time manner. The upper computer has the function of data format conversion, which can transfer the TMDS format data from the NIcRIO signal acquisition platform to the FTP server and convert it into an excel file for easy analysis and processing.

It should be noted that the above examples are only used to illustrate the technical solution of the present invention without limitation, other modifications or equivalent replacements made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and spirit of the technical solution of the present invention All should be included in the scope of the claims of the present invention.

Claims (5)

1. a kind of electric power pylon tower material vibration displacement method of real-time, it is characterised in that：Comprise the steps：

Step 1, obtains the acceleration signal of tower material of iron tower；

Acceleration time domain signal using Fourier transformation, is converted to frequency-region signal, to acceleration frequency spectrum divided by ω by step 2², ω For angular frequency；

Step 3, the frequency-region signal that selection high pass channel is obtained to step 2 are converted to shift spectrum after carrying out blocking filtering；

Step 4, it is displacement time-domain signal that the shift spectrum is carried out Fourier inversion, obtains the real-time position of tower material of iron tower Move.

2. a kind of electric power pylon tower material vibration displacement method of real-time according to claim 1, it is characterised in that：It is described Step 1, obtains the acceleration signal of tower material of iron tower, including：

Acceleration transducer gathers the acceleration signal of tower material of iron tower；

The acceleration signal for collecting is sent to into NIcRIO signals collecting platforms Jing after signal condition isolation；

Measurement and control unit is transmitted signals to by the NIcRIO signals collectings platform Jing communication units, it is offline to read acceleration letter Number.

3. a kind of electric power pylon tower material vibration displacement method of real-time according to claim 2, it is characterised in that：It is described Acceleration transducer adopts capacitance acceleration transducer.

4. a kind of electric power pylon tower material vibration displacement method of real-time according to claim 2, it is characterised in that：It is described Acceleration transducer includes 3-axis acceleration sensor and single-axis acceleration sensors.

5. a kind of electric power pylon tower material vibration displacement method of real-time according to claim 2, it is characterised in that：To adopt The acceleration signal for collecting Jing after signal condition isolation is sent to NIcRIO signals collectings under 1-5V standard voltage signals and puts down Platform.