CN106291429A - The detecting system of shelf depreciation instrument sensitivity - Google Patents

Abstract

The invention discloses a detection system for the sensitivity of a partial discharge instrument. The system includes: a coaxial speaker; a signal generator, used to generate a sine wave signal; a power amplifier, connected between the signal generator and the coaxial speaker, used to drive the coaxial speaker to operate according to the sine wave signal; an acoustic emission sensor, It is used to output the first response signal according to the audio signal output by the coaxial speaker when it is running; the partial discharge instrument is used to output the second response signal according to the audio signal output by the coaxial speaker when it is running; the detection equipment is respectively connected with the acoustic emission sensor and the local The discharge instrument is connected to determine the sensitivity of the partial discharge instrument based on the first response signal of the acoustic emission sensor and the second response signal of the partial discharge instrument. The invention solves the technical problem that the sensitivity of the partial discharge meter cannot be accurately detected in the related art.

Description

Sensitivity Detection System of Partial Discharge Instrument

technical field

The invention relates to the field of cable partial discharge detection, in particular to a detection system for the sensitivity of a partial discharge instrument.

Background technique

With the rapid development of power network, higher requirements are put forward for the safety of power network and power consumption. As far as cables are concerned, their safe operation and safe maintenance have become an important part of power safety. The main reason is the deterioration and failure of insulation performance, and partial discharge is the main reason for the deterioration of cable insulation performance. At present, partial discharge instruments are widely used in discharge detection, but since there are many types of partial discharge instruments on the market, and their sensitivities are not the same, in order to use them better, it is necessary to carry out the sensitivities of various partial discharge instruments However, due to the different effects of various interference sources on various partial discharge instruments, the accuracy of sensitivity measured by existing equipment using fixed algorithms is low, which will affect the use of partial discharge instruments.

Aiming at the technical problem of not being able to accurately detect the sensitivity of the partial discharge instrument in the related art, no effective solution has been proposed yet.

Contents of the invention

An embodiment of the present invention provides a detection system for the sensitivity of a partial discharge instrument to at least solve the technical problem in the related art that the sensitivity of the partial discharge instrument cannot be accurately detected.

According to an embodiment of the present invention, a detection system for the sensitivity of a partial discharge instrument is provided, and the system includes: a coaxial speaker; a signal generator for generating a sine wave signal; a power amplifier connected between the signal generator and the coaxial speaker The time is used to drive the coaxial speaker to operate according to the sine wave signal; the acoustic emission sensor is used to output the first response signal according to the audio signal output by the coaxial speaker during operation; the partial discharge instrument is used to output the first response signal according to the output of the coaxial speaker during operation The audio signal outputs a second response signal; the detection device is connected to the acoustic emission sensor and the partial discharge meter respectively, and is used to determine the sensitivity of the partial discharge meter based on the first response signal of the acoustic emission sensor and the second response signal of the partial discharge meter.

Further, when the frequency of the sine wave signal is fm, if the sensitivity of the acoustic emission sensor is S1(fm), the amplitude of the first response signal output by the acoustic emission sensor is U1(fm), and the second response signal output by the partial discharge instrument is The amplitude of the response signal is U2(fm), then the sensitivity of the partial discharge instrument when the frequency is fm

Further, the frequency range of the sine wave signal is 20kHz to 80kHz, wherein the amplitudes of the sine wave signals corresponding to each frequency value are the same.

Further, the detection device includes: an amplifier module, the amplifier module includes a first adaptive amplifier and a second adaptive amplifier for power amplification, the first adaptive amplifier is connected to the acoustic emission sensor, and the second adaptive amplifier is connected to the detection device ; The oscilloscope is respectively connected to the first adaptive amplifier and the second adaptive amplifier, and is used to detect the amplitude of the first response signal after power amplification and/or the amplitude of the first response signal.

Further, the system also includes: a computer, respectively connected to the first adaptive amplifier, the second adaptive amplifier and the power amplifier, for recording the signals output by the first adaptive amplifier, the second adaptive amplifier and the power amplifier, and Calculate the sensitivity of the partial discharge meter.

Further, the computer is also used to calculate the error between the sensitivity of the partial discharge instrument and the sensitivity of similar partial discharge instruments, wherein, when the error is greater than a preset value, an alarm signal is generated.

Further, the system also includes: a bearing plate for carrying the coaxial speaker; a fixing plate for fixing the partial discharge instrument and detection equipment.

Further, the fixing board is 8 cm to 12 cm higher than the bearing board in the vertical direction.

Further, the first tuning amplifier and the second tuning amplifier are dual-channel tuning amplifiers.

Further, the power amplifier is a class D amplifier.

In the embodiment of the present invention, the sine wave signal is generated by the signal generator; the power amplifier drives the coaxial speaker to run according to the sine wave signal; the acoustic emission sensor outputs the first response signal according to the audio signal output by the coaxial speaker when it is running; the partial discharge meter The second response signal is output according to the audio signal output by the coaxial speaker during operation; the detection device determines the sensitivity of the partial discharge device based on the first response signal of the acoustic emission sensor and the second response signal of the partial discharge device. Therefore, the technical problem that the sensitivity of the partial discharge instrument cannot be accurately detected in the related art is solved, and the accurate detection of the sensitivity of the partial discharge instrument is realized.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is a schematic diagram of a detection system for the sensitivity of a partial discharge instrument according to an embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

First of all, some nouns or terms appearing in the process of describing the embodiments of the present invention are applicable to the following explanations:

Coaxial loudspeaker: refers to a loudspeaker with both treble and bass generators installed on the same axis, and may also refer to a speaker with replay treble and mid-bass generators installed on the same axis at the same time.

Amplifier: refers to a device that can amplify the voltage or power of an input signal (such as a voltage amplifier and a power amplifier), and is mainly composed of electron tubes, transistors, power transformers and other electronic devices. Among them, power amplifiers can be divided into Class A, Class AB, Class B, Class C and Class D according to their different uses (such as adaptive amplifiers for audio processing).

Acoustic emission sensor: Also known as a piezoelectric sensor, it refers to a sensor made of the piezoelectric effect generated by certain dielectrics under force, that is, its sensitive elements are made of piezoelectric materials.

According to an embodiment of the present invention, an embodiment of a detection system for the sensitivity of a partial discharge meter is provided. FIG. 1 is a schematic diagram of a detection system for a sensitivity of a partial discharge meter according to an embodiment of the present invention. As shown in FIG. 1 , the system includes: Coaxial loudspeaker 10; Signal generator 20, is used to generate sine wave signal; Power amplifier 30, is connected between signal generator and coaxial loudspeaker, is used to drive coaxial loudspeaker operation according to sine wave signal; Acoustic emission sensor 40, It is used to output the first response signal according to the audio signal output when the coaxial speaker is running; the partial discharge instrument 50 is used to output the second response signal according to the audio signal output when the coaxial speaker is running; the detection device 60 is connected with the acoustic emission sensor respectively It is connected with the partial discharge meter, and is used for determining the sensitivity of the partial discharge meter based on the first response signal of the acoustic emission sensor and the second response signal of the partial discharge meter.

Through the foregoing embodiment, through the coaxial speaker; the signal generator is used to generate the sine wave signal; the power amplifier is connected between the signal generator and the coaxial speaker, and is used to drive the coaxial speaker to operate according to the sine wave signal; the acoustic emission The sensor is used to output the first response signal according to the audio signal output by the coaxial speaker when it is running; the partial discharge meter is used to output the second response signal according to the audio signal output by the coaxial speaker when it is running; the detection device is respectively connected with the acoustic emission sensor Connected with the partial discharge meter, used to determine the sensitivity of the partial discharge meter based on the first response signal of the acoustic emission sensor and the second response signal of the partial discharge meter, thereby solving the technical problem that the sensitivity of the partial discharge meter cannot be accurately detected in the related art , according to the sensitivity of the acoustic emission sensor with known sensitivity at each frequency point, the sensitivity of the partial discharge instrument can be obtained, and the accurate detection of the sensitivity of the partial discharge instrument is realized.

It should be noted that the detection system of this application is mainly used for non-contact partial discharge instruments (such as ultrasonic partial discharge instruments).

In order to ensure the stability of the detection, the system of the present application may further include: a bearing plate for carrying the coaxial speaker; a fixing plate for fixing the partial discharge instrument and the detection equipment. The fixing plate is 8 cm to 12 cm higher than the bearing plate in the vertical direction, so as to ensure that the partial discharge instrument and the detection equipment are facing the audio output part of the coaxial speaker.

Specifically, the coaxial speaker is used as the emission source of the calibration system, and the reference sensor (that is, the acoustic emission sensor) is placed on the same level as the coaxial speaker, and the coaxial speaker is connected to the power amplifier and connected to the signal generator , in order to improve the efficiency of the power amplifier, the power amplifier can use a class D amplifier.

The above-mentioned detection equipment may include: an amplifier module, the amplifier module includes a first adaptive amplifier and a second adaptive amplifier for power amplification, the first adaptive amplifier is connected with the acoustic emission sensor, and the second adaptive amplifier is connected with the detection device ; The oscilloscope is respectively connected to the first adaptive amplifier and the second adaptive amplifier, and is used to detect the amplitude of the first response signal after power amplification and/or the amplitude of the first response signal.

Optionally, the first adaptive amplifier and the second adaptive amplifier are dual-channel adaptive amplifiers. In order to amplify the power of the signal without introducing new noise to the signal, an ABC and D filter can be used. Dual-channel microphone adjustment amplifier, using this filter, the signal can be filtered first and then power amplified, so that the obtained signal can be more accurate for subsequent measurement.

Specifically, when the frequency of the sine wave signal is fm, if the sensitivity of the acoustic emission sensor is S1(fm), the amplitude of the first response signal output by the acoustic emission sensor is U1(fm), and the second response signal output by the partial discharge instrument is The amplitude of the response signal is U2(fm), then the sensitivity of the partial discharge instrument when the frequency is fm

It should be noted that the frequency range of the above-mentioned sine wave signal is 20kHz (that is, kilohertz, which is a frequency unit) to 80kHz, wherein the amplitudes of the sine wave signals corresponding to each frequency value are the same.

In order to improve computing efficiency, the system of the present application may also include: a computer, connected to the first tuning amplifier, the second tuning amplifier and the power amplifier respectively, for recording the first tuning amplifier, the second tuning amplifier and the power amplifier output signal and calculate the sensitivity of the partial discharge meter.

Optionally, the computer is also used to calculate the error between the sensitivity of the partial discharge instrument and the sensitivity of similar partial discharge instruments, wherein when the error is greater than a preset value, an alarm signal is generated. The preset value can be 10%, that is, when the error between the sensitivity of the partial discharge meter and the sensitivity of the same kind of partial discharge meter reaches 10%, it means that its quality is poor, there will be certain problems in stability, and it is prone to failure during use , this type of partial discharge meter should be used with caution.

When using the detection system of the present application, it can be detected through the following steps:

Step S1, instrument connection: fix the reference sensor (that is, the acoustic emission sensor), the coaxial speaker, and the ultrasonic partial discharge meter, connect the coaxial speaker to the power amplifier and connect it to the signal generator, and connect the reference sensor to the oscilloscope through the signal amplifier .

Step S2, reference value measurement: the signal generator emits a group of sine wave signals from 20 kHz to 80 kHz, and records the signal amplitude U1 (fm) measured by the reference sensor.

Step S3, measuring by the instrument under test: the signal generator emits a group of sine wave signals from 20 kHz to 80 kHz, and records the signal amplitude U2 (fm) of the ultrasonic partial discharge instrument.

Step S4, data calculation: use the formula Calculate the sensitivity S2(fm) of the ultrasonic partial discharge instrument to be tested.

Step S5, extracting results: draw a sensitivity curve according to S1(fm), take the point with the maximum amplitude value between 20kHz and 80kHz as the sensitivity value of the ultrasonic partial discharge instrument, and the corresponding frequency is the main resonance frequency of the instrument.

The above step S2 and step S3 can be performed simultaneously.

Through the above-mentioned embodiment, the verification of the sensitivity characteristic parameters of the non-contact partial discharge instrument can be completed only by using a set of sine wave sweep signal transmission and reception. The calculation method is simple and traceable, and fundamentally solves the problem of non-contact partial discharge There is no effective and stable calibration method for the discharge ultrasonic detector. The operation is simple, the implementation is convenient, and the results are accurate. One-key operation can complete the calibration of the linearity error between the ultrasonic sensor of the ultrasonic partial discharge instrument and the instrument, and provides an effective method for regular instrument performance evaluation and periodic testing.

The serial numbers of the above embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

In the above-mentioned embodiments of the present invention, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed technical content can be realized in other ways. Wherein, the device embodiments described above are only illustrative. For example, the division of the units may be a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or may be Integrate into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of units or modules may be in electrical or other forms.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, server or network device, etc.) execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage media include: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes. .

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. the detecting system of a shelf depreciation instrument sensitivity, it is characterised in that including:

Coaxial loudspeaker；

Signal generator, is used for generating sine wave signal；

Power amplifier, is connected between described signal generator and described coaxial loudspeaker, for according to described sinusoidal wave letter Number drive described coaxial loudspeaker run；

Acoustic emission sensor, audio signal output the first response signal of output in time running according to described coaxial loudspeaker；

Shelf depreciation instrument, audio signal output the second response signal of output in time running according to described coaxial loudspeaker；

Detection equipment, is connected with described acoustic emission sensor and described shelf depreciation instrument respectively, for passing based on described acoustic emission First response signal of sensor and the second response signal of described shelf depreciation instrument determine the sensitivity of described shelf depreciation instrument.

System the most according to claim 1, it is characterised in that when the frequency of described sine wave signal is fm, if described The sensitivity of acoustic emission sensor is S1 (fm), and the amplitude of the first response signal of described acoustic emission sensor output is U1 (fm), the amplitude of the second response signal of described shelf depreciation instrument output is U2 (fm), and the most described shelf depreciation instrument in frequency is Sensitivity during fm

System the most according to claim 2, it is characterised in that the frequency range of described sine wave signal be 20kHz extremely 80kHz, wherein, the amplitude of the sine wave signal that each frequency values is corresponding is the most identical.

System the most according to claim 3, it is characterised in that described detection equipment includes:

Amplifier module, described amplifier module includes amplifying for the first modification amplifier and second suitable tune of power amplification Device, described first modification amplifier is connected with described acoustic emission sensor, described second modification amplifier and described detection equipment Connect；

Oscillograph, is connected with described first modification amplifier and described second modification amplifier respectively, for detection through overpower The amplitude of the described first response signal after amplification and/or the amplitude of described first response signal.

System the most according to claim 4, it is characterised in that described system also includes:

Computer, is connected with described first modification amplifier, described second modification amplifier and described power amplifier respectively, For recording described first modification amplifier, described second modification amplifier and the signal of described power amplifier output, and Calculate the sensitivity of described shelf depreciation instrument.

System the most according to claim 5, it is characterised in that described computer is additionally operable to calculate described shelf depreciation instrument Error between sensitivity with the sensitivity of similar shelf depreciation instrument, wherein, when described error is more than preset value, generates alarm signal Number.

System the most according to claim 1, it is characterised in that described system also includes:

Loading plate, is used for carrying described coaxial loudspeaker；

Fixed plate, is used for fixing described shelf depreciation instrument and described detection equipment.

System the most according to claim 7, it is characterised in that described fixed plate in the vertical direction is than described carrying plate hight 8 centimetres to 12 centimetres.

System the most according to claim 4, it is characterised in that described first modification amplifier and the described second suitable tune are amplified Device is dual pathways modification amplifier.

System the most as claimed in any of claims 1 to 9, it is characterised in that described power amplifier is that D class is put Big device.