Measuring device and method for ultrasonic detection of partial discharge

Abstract

The invention discloses a measuring device and method for ultrasonic detection of partial discharge, and belongs to the field of ultrasonic detection. The measuring device comprises a test transformer, a filter, an amplifier, an acoustic signal demodulation system, a data acquisition card, an upper computer and the like; wherein the sound wave signal demodulation system comprises an ultrasonic sensor and a photoelectric detector. The filter is used for filtering a sound signal generated by the partial discharge signal of the test transformer; the amplifier is used for amplifying the filtered sound signal; the sound wave signal demodulation system is used for converting the amplified sound signal into an electric signal; and the data acquisition card and the upper computer are respectively used for acquiring and processing electric signals. The test device is simple, the measurement method is convenient, the operability is high, and the influence on the measurement mode of partial discharge is significant.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic detection, and more specifically, relates to a measuring device and method for ultrasonic detection of partial discharge. Background Art

[0002] Partial discharge detection is based on the electrical, optical, and acoustic phenomena generated during partial discharge, and characterizes the state of partial discharge, including the location and degree of discharge, through physical quantities that can describe these phenomena. During partial discharge, electrical pulses, gas products, ultrasound, electromagnetic radiation, light, local overheating, and energy loss will be generated. The corresponding detection methods include pulse current method, gas chromatography, ultrasound method, ultra-high frequency method, optical measurement method, and other detection methods.

[0003] Commonly used electrical detection methods include pulse current method and ultra-high frequency signal detection method. The pulse current method is the longest-used and most widely used partial discharge detection method, and is also the only quantitative detection method for partial discharge recommended by IEC60270. The transferred charge generated during the partial discharge process will form a pulse current in the peripheral measurement circuit. Therefore, it is possible to determine whether partial discharge has occurred and its severity by obtaining basic information of the partial discharge pulse signal such as the discharge amount and the number of discharges. The advantage of the pulse detection method is its high detection sensitivity, and its disadvantage is that it is extremely susceptible to electromagnetic signal interference. However, in actual application scenarios, the on-site environment is complex and the electromagnetic interference is severe, so the pulse current method cannot be used in on-site monitoring or online real-time monitoring of power equipment.

[0004] The high-frequency current generated by partial discharge causes the volume of the internal defects of the insulation structure to compress and expand periodically, generating ultrasonic signals. The relevant information of partial discharge is reflected in the ultrasound in the form of sound pressure. Therefore, the occurrence and severity of partial discharge can be judged by detecting the ultrasonic signal. The ultrasonic wave generated by partial discharge propagates in the form of mechanical waves, which propagate to the outer wall of the transformer after passing through the insulating medium, insulating oil paper, iron core, and winding inside the transformer. Traditional piezoelectric ceramics (PZT) and capacitive ultrasonic sensors are installed on the outer wall of the transformer to detect ultrasonic signals. This type of sensor technology is mature and easy to operate. However, it works based on electrical principles and has low sensitivity in field applications. The internal structure of large power transformers is complex. After the partial discharge ultrasonic signal is attenuated by multiple layers of dielectrics, it propagates to the outer wall of the transformer. At this time, the sound pressure of the ultrasonic signal is small, and the detection effect of the electrical sensor is often not ideal.

[0005] Fiber optic ultrasonic sensors are gradually being used in partial discharge detection. Compared with traditional piezoelectric ceramic and capacitive sensors, they have advantages such as good insulation performance, strong anti-interference ability, and small size. They can also be placed inside the transformer to detect the weak ultrasonic signals generated by partial discharge. However, due to the limitations of existing technology, partial discharge cannot be directly measured. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to propose a measuring device and method for ultrasonic detection of partial discharge, which aims to detect the ultrasonic signal generated during partial discharge and use the optical fiber ultrasonic sensor to detect the intensity and distance of the partial discharge signal. Based on the superior sensing performance of the optical fiber ultrasonic sensor, the intensity of the output electrical signal can be detected to obtain the intensity of the partial discharge; the amplitude of the electrical signal output by the sensor at different distances can be obtained based on the empirical model of different distance detection of the sensor, and when partial discharge actually occurs, the location of the partial discharge can be inferred based on the amplitude of the partial discharge. Thereby, the intensity detection and distance detection of the partial discharge signal are realized.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a measuring device for ultrasonic detection of partial discharge, comprising a test transformer, a filter, an amplifier, an acoustic signal demodulation system, a data acquisition card and a host computer; the filter is used to filter the acoustic signal generated by the partial discharge signal of the test transformer; the amplifier is used to amplify the filtered acoustic signal; the acoustic signal demodulation system is used to convert the amplified acoustic signal into an electrical signal; the data acquisition card and the host computer are used to collect and process the electrical signal, respectively.

[0008] Furthermore, the acoustic wave signal demodulation system includes an ultrasonic sensor and a photoelectric detector. The ultrasonic sensor is used to reflect acoustic signals of different degrees to obtain light signals of different intensities; the photoelectric detector is used to convert light signals of different intensities into electrical signals.

[0009] The present invention also provides a method for measuring partial discharge by ultrasonic detection, which is implemented using the above-mentioned device, and the method comprises the following steps:

[0010] (1) Cause partial discharge inside the test transformer to generate an acoustic signal;

[0011] (2) Filtering the acoustic signal;

[0012] (3) amplifying the filtered acoustic signal;

[0013] (4) converting the amplified acoustic signal into an electrical signal;

[0014] (5) Collect and process electrical signals.

[0015] The present invention also provides an electronic device, comprising: a computer-readable storage medium and a processor;

[0016] The computer-readable storage medium is used to store executable instructions;

[0017] The processor is used to read the executable instructions stored in the computer-readable storage medium to execute the above method.

[0018] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the above method.

[0019] The present invention also provides a computer program product, comprising a computer program or instructions, wherein the computer program or instructions implement the above method when executed by a processor.

[0020] Through the above technical scheme conceived by the present invention, compared with the prior art, the present invention performs ultrasonic monitoring on the sample when partial discharge occurs, as a measurement method of partial discharge, the location where partial discharge occurs and the intensity of partial discharge can be detected, thereby realizing fault location. The test device of the present invention is safe and simple, the measurement method is convenient, the operability is strong, and the test result is highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the measuring device for ultrasonic detection of partial discharge of the present invention.

[0022] Figure 2 It is a flow chart of the measurement method of ultrasonic detection of partial discharge of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] The present invention provides a measuring device for ultrasonic detection of partial discharge, comprising: a test transformer, a filter, an amplifier, a sound wave signal demodulation system, a data acquisition card and a host computer; the filter is used for filtering the sound signal generated by the partial discharge signal of the test transformer; the amplifier is used for amplifying the filtered sound signal; the sound wave signal demodulation system is used for converting the amplified sound signal into an electrical signal; the data acquisition card and the host computer are used for collecting and processing the electrical signal respectively.

[0025] Specifically, the acoustic wave signal demodulation system includes an ultrasonic sensor and a photoelectric detector. The ultrasonic sensor is used to reflect acoustic signals of different degrees to obtain light signals of different intensities; the photoelectric detector is used to convert light signals of different intensities into electrical signals.

[0026] The present invention also provides a method for measuring partial discharge by ultrasonic detection, which is implemented using the above-mentioned device, and the method comprises the following steps:

[0027] (1) Cause partial discharge inside the test transformer to generate an acoustic signal;

[0028] (2) Filtering the acoustic signal;

[0029] (3) amplifying the filtered acoustic signal;

[0030] (4) converting the amplified acoustic signal into an electrical signal;

[0031] (5) Collect and process electrical signals.

[0032] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A measuring device for ultrasonic detection of partial discharge, characterized in that: It includes a test transformer, a filter, an amplifier, an acoustic signal demodulation system, a data acquisition card and a host computer; the filter is used to filter the acoustic signal generated by the partial discharge signal of the test transformer; the amplifier is used to amplify the filtered acoustic signal; the acoustic signal demodulation system is used to convert the amplified acoustic signal into an electrical signal; the data acquisition card and the host computer are used to collect and process the electrical signal respectively.

2. The ultrasonic partial discharge detection measuring device according to claim 1, characterized in that: The acoustic wave signal demodulation system comprises an ultrasonic sensor and a photoelectric detector. The ultrasonic sensor is used to reflect acoustic signals of different degrees, thereby obtaining light signals of different intensities; and the photoelectric detector is used to convert light signals of different intensities into electrical signals.

3. A method for ultrasonic detection of partial discharge, implemented using the device of claim 1, characterized in that: The method comprises the following steps: (1) Cause partial discharge inside the test transformer to generate an acoustic signal; (2) Filtering the acoustic signal; (3) amplifying the filtered acoustic signal; (4) converting the amplified acoustic signal into an electrical signal; (5) Collect and process electrical signals.

4. The method according to claim 3, characterized in that The step (4) includes reflecting the acoustic signals of different degrees to obtain light signals of different intensities, and converting the light signals of different intensities into electrical signals.

5. An electronic device, characterized in that: include: A computer readable storage medium and a processor; The computer-readable storage medium is used to store executable instructions; The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the method according to claim 3 or 4.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to execute the method according to claim 3 or 4.

7. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the method according to claim 3 or 4 is implemented.

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