Optical microphone partial discharge monitoring device

Abstract

The utility model discloses a partial discharge monitoring device for an optical microphone, which comprises a main case, and a detection mainboard is arranged in the main case. A central processing unit is mounted in the detection mainboard, and a signal modulation light path is arranged on the detection mainboard; sound vibration during partial discharge of the electrical equipment enables the cavity length of the sensing ultrasonic sensor to change, light coupled by the 3 * 3 coupler is divided into three paths of signals, partial discharge ultrasonic identification is completed after demodulation by the three diodes, and filtering, amplification, data processing and graphic display are performed through the central processing unit, so that the measurement process of partial discharge is completed, and the measurement accuracy is improved. And the optical fiber acoustic sensor is connected with the measuring instrument through the optical fiber, and the length of the optical fiber can reach 1Km, so that the measurement safety and the stability of the measuring instrument are greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of partial discharge detection, in particular to an optical microphone partial discharge monitoring device. Background Art

[0002] The fiber optic acoustic sensing system includes sensing elements, sensors and demodulation systems. The overall sensing system design plays a very important role in the experiment. The optical microphone partial discharge ultrasonic detection uses ultrasonic technology to detect the sound signals generated during the partial discharge process. Such sounds can be bubbles in oil, air gaps in solids, or expansion and contraction.

[0003] However, partial discharge monitoring of electrical equipment usually utilizes the current and voltage changes caused by partial discharge and uses current and voltage sensors for detection. However, traditional current and voltage sensors are difficult to identify tiny changes in partial discharge of electrical equipment in environments such as strong electricity, oil, and water. In addition, the length distance between traditional sensors and measuring instruments is limited, which makes the measurement safety and the stability of the measuring instruments low. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art.

[0005] To this end, one purpose of the utility model is to propose an optical microphone partial discharge monitoring device. When electrical equipment has partial discharge, the optical microphone partial discharge monitoring device senses the change in cavity length of an ultrasonic sensor, which is divided into three signals through a coupler and identified by diode demodulation. The ultrasonic sensor is connected to a measuring instrument using optical fiber, and the length can be up to 1 km, thereby improving the safety and stability of partial discharge monitoring.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an optical microphone partial discharge monitoring device, comprising a main housing, a detection mainboard is arranged inside the main housing, a central processing unit is installed inside the detection mainboard, a signal modulation optical path is arranged on the detection mainboard, the signal modulation optical path is connected to the central processing unit signal, the signal modulation optical path comprises a 2×2 coupler, an input end of the 2×2 coupler is connected to a 3×3 coupler, one output end of the 2×2 coupler and two output ends of the 3×3 coupler are connected to diodes, two input ends of the 3×3 coupler are respectively connected to a sensing arm and a reference arm, the sensing arm and the reference arm are signal-connected with an ultrasonic detection mechanism, the ultrasonic detection mechanism comprises a sensing ultrasonic sensor and a reference ultrasonic sensor, the sensing ultrasonic sensor is arranged outside the main housing, the reference ultrasonic sensor is arranged inside the main housing, the reference ultrasonic sensor is signal-connected to the reference arm, and the sensing ultrasonic sensor is signal-connected to the sensing arm.

[0007] Preferably, the two input ends of the 2×2 coupler are respectively connected to an optical isolator and a 3×3 coupler, and the light source input end of the optical isolator is connected to a narrow linewidth laser.

[0008] Preferably, an FC-APC interface is provided on the outer wall of the detection main board, the FC-APC interface is connected to the sensor arm signal, and the sensing ultrasonic sensor is connected to the FC-APC interface via a FC-APC connector.

[0009] Preferably, a key switch is installed on the front surface of the main housing, and a power interface is provided on the rear surface of the main housing.

[0010] Preferably, a serial interface and a network port are respectively provided on the rear surface of the main housing, and both the serial interface and the network port are communicatively connected to the detection mainboard.

[0011] Preferably, an SD card socket is provided on the rear surface of the main housing, and the SD card socket is communicatively connected to the detection mainboard via a wire.

[0012] Preferably, a touch screen and a small keyboard are installed on the front surface of the main housing, and both the touch screen and the small keyboard are connected to the detection mainboard signal.

[0013] Compared with the prior art, the utility model has the following beneficial effects: the sound vibration during partial discharge of electrical equipment causes the cavity length of the sensing ultrasonic sensor to change, and the light coupled by the 3×3 coupler is divided into three signals, which are then demodulated by three diodes to complete the ultrasonic identification of partial discharge, and filtered, amplified, data processed, and graphically displayed by the central processing unit, thereby completing the measurement process of partial discharge and realizing ultrasonic detection of measurable partial discharge. The optical fiber acoustic sensor and the measuring instrument are connected by an optical fiber, and the optical fiber length can be up to 1 km, which greatly improves the safety of the measurement and the stability of the measuring instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an optical microphone partial discharge monitoring device according to an embodiment of the utility model;

[0015] Figure 2 It is a schematic diagram of the connection structure of the sensing ultrasonic sensor and the FC-APC connector in the optical microphone partial discharge monitoring device according to an embodiment of the utility model;

[0016] Figure 3 It is an internal layout diagram of a signal modulation optical path in an optical microphone partial discharge monitoring device according to an embodiment of the utility model;

[0017] Figure 4It is a schematic diagram of the rear view structure of the main housing in the optical microphone partial discharge monitoring device according to an embodiment of the utility model;

[0018] Figure 5 It is a schematic diagram of the front structure of the main housing in the optical microphone partial discharge monitoring device according to an embodiment of the utility model;

[0019] Figure 6 The figure is a schematic diagram of the conversion process of the photocurrent signal in the optical microphone partial discharge monitoring device according to an embodiment of the utility model.

[0020] In the figure: 1. Detection main board; 2. Ultrasonic detection mechanism; 21. Sensing ultrasonic sensor; 22. FC-APC connector; 23. Reference ultrasonic sensor; 24. FC-APC interface; 3. Signal modulation optical path; 31. Narrow linewidth laser; 32. Optical isolator; 34. Diode; 35. Sensing arm; 36. 2×2 coupler; 37. 3×3 coupler; 38. Reference arm; 4. Central processing unit; 5. SD card slot; 6. Network port; 7. Serial interface; 8. Power interface; 9. Key switch; 10. Touch screen; 11. Keypad; 12. Main casing. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1 and Figure 4 An embodiment of the utility model provides an optical microphone partial discharge monitoring device, including: a main housing 12 and a detection mainboard 1.

[0023] Among them, Figure 1 As shown, the detection mainboard 1 is arranged inside the main housing 12, and a central processing unit 4 is installed inside the detection mainboard 1. A signal modulation optical path 3 is provided on the detection mainboard 1, and the signal modulation optical path 3 is connected to the central processing unit 4 by signal.

[0024] Among them, Figure 1 and Figure 3As shown, the signal modulation optical path 3 includes a 2×2 coupler 36, the input end of the 2×2 coupler 36 is connected to a 3×3 coupler 37, one output end of the 2×2 coupler 36 and two output ends of the 3×3 coupler 37 are connected to a diode 34, the two input ends of the 3×3 coupler 37 are respectively connected to a sensor arm 35 and a reference arm 38, the other input end of the 2×2 coupler 36 is connected to an optical isolator 32, and the light source input end of the optical isolator 32 is connected to a narrow linewidth laser 31.

[0025] Among them, Figure 1-Figure 3 As shown, the sensing arm 35 and the reference arm 38 are signal-connected with an ultrasonic detection mechanism 2, and the ultrasonic detection mechanism 2 includes a sensing ultrasonic sensor 21 and a reference ultrasonic sensor 23. The sensing ultrasonic sensor 21 is arranged on the outside of the main housing 12, and the reference ultrasonic sensor 23 is arranged on the inside of the main housing 12. The reference ultrasonic sensor 23 is signal-connected with the reference arm 38, and the sensing ultrasonic sensor 21 is signal-connected with the sensing arm 35. The reference ultrasonic sensor 23 is placed on the inside of the main housing 12, and the sensing ultrasonic sensor 21 is placed on the outside of the main housing 12. When the sensing element of the sensing ultrasonic sensor 21 is vibrated by sound, it is deformed and the FP cavity length of the sensing arm 35 is changed.

[0026] For further reference, Figure 2 and Figure 4 An FC-APC interface 24 is provided on the outer wall of the detection main board 1, and the FC-APC interface 24 is connected to the sensor arm 35 signal, and the sensing ultrasonic sensor 21 is connected to the FC-APC interface 24 through the FC-APC connector 22, and the sensing ultrasonic sensor 21 is connected to the FC-APC connector 22 through an optical cable conductor, thereby extending the measuring length of the sensor.

[0027] like Figure 4 As shown, a push button switch 9 is installed on the front surface of the main casing 12, a power interface 8 is provided on the rear surface of the main casing 12, and a serial interface 7, a network port 6 and an SD card slot 5 are respectively provided on the rear surface of the main casing 12. The serial interface 7, the network port 6 and the SD card slot 5 are all communicatively connected with the detection mainboard 1. The SD card slot 5 is used to install an SD storage card to save data. The serial interface 7 adopts an expansion interface of a serial communication method, and the network port 6 can be directly plugged into a network cable.

[0028] like Figure 5 As shown, in order to facilitate measurement personnel to observe partial discharge monitoring data through graphics, a touch screen 10 and a keypad 11 are installed on the front surface of the main housing 12. The touch screen 10 and the keypad 11 are both connected to the detection mainboard 1 signal to obtain graphic information after data processing in the central processor 4.

[0029] It should be noted that, refer to Figure 3-Figure 6The three diodes 34 can convert the optical signal into a weak photocurrent signal. After the photocurrent is amplified by the transimpedance amplifier, it is converted into a voltage signal. After the voltage signal is initially analog filtered by the analog filter, the high frequency component of the signal is removed. The signal is then converted into a digital signal by the ADC module and enters the central processor 4.

[0030] The central processing unit 4 integrates a high-speed signal acquisition module, a high-speed signal demodulation module, a signal processing module and a QT / GUI module. The digital signal is collected by the high-speed signal acquisition module inside the central processing unit 4, and then high-speed signal demodulation is performed by a 3×3 demodulation algorithm. The demodulated signal is processed by the DSP signal and finally displayed on the touch display screen 10 by QT or GUI.

[0031] According to the above technical scheme, the working steps of this scheme are summarized and sorted out: the two arms of the signal modulation optical path 3, 3×3 coupler 37 in the utility model are respectively the sensing arm 35 and the reference arm 38, the end of the sensing arm 35 is connected to the sensing ultrasonic sensor 21, the end of the reference arm 38 is connected to the reference ultrasonic sensor 23, the reference ultrasonic sensor 23 is placed inside the main housing 12, the sensing ultrasonic sensor 21 is placed outside the main housing 12 and is plugged into the FC-APC interface 24 through the FC-APC connector 22 to connect to the detection main board 1.

[0032] The sensing element of the ultrasonic sensor 21 is deformed by the sound vibration, which will change the FP cavity length of the sensing arm 35. At the same time, the cavity length of the reference arm 38 remains unchanged. The light reflected back by the optical probe of the sensing arm 35 and the reference arm 38 is coupled into one signal by the 3×3 coupler 37 and then divided into three signals. The optical power phase difference of the three signal outputs is 120°, and the three optical signals are respectively converted into weak photocurrent signals by the diode 34 for demodulation. The demodulated signals can reflect the change in cavity length.

[0033] The three diodes 34 convert the optical signal into a weak photocurrent signal. After the photocurrent is amplified by the transimpedance amplifier, it is converted into a voltage signal. After the voltage signal is initially analog filtered by the analog filter, the high frequency components of the signal are removed. The signal is then converted into a digital signal by the ADC module and enters the central processor 4. After DSP signal processing, it is finally displayed on the touch screen 10 through QT or GUI, thereby completing the measurement process of partial discharge and realizing ultrasonic detection of measurable partial discharge. The fiber optic acoustic sensor and the measuring instrument are connected by an optical fiber, and the optical fiber length can be up to 1 km, which greatly improves the measurement safety and the stability of the measuring instrument.

[0034] Parts not involved in the present invention are the same as the prior art or can be implemented by the prior art. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. An optical microphone partial discharge monitoring device, comprising a main housing (12), wherein a detection mainboard (1) is arranged inside the main housing (12), characterized in that: A central processing unit (4) is installed inside the detection mainboard (1), and a signal modulation optical path (3) is provided on the detection mainboard (1), and the signal modulation optical path (3) is connected to the central processing unit (4) by signal; The signal modulation optical path (3) comprises a 2×2 coupler (36), an input end of the 2×2 coupler (36) is connected to a 3×3 coupler (37), one output end of the 2×2 coupler (36) and two output ends of the 3×3 coupler (37) are connected to a diode (34), two input ends of the 3×3 coupler (37) are respectively connected to a sensor arm (35) and a reference arm (38), and the sensor arm (35) and the reference arm (38) are signal-connected to an ultrasonic detection mechanism (2); The ultrasonic detection mechanism (2) comprises a sensing ultrasonic sensor (21) and a reference ultrasonic sensor (23); the sensing ultrasonic sensor (21) is arranged outside the main housing (12); the reference ultrasonic sensor (23) is arranged inside the main housing (12); the reference ultrasonic sensor (23) is connected to the reference arm (38) by signal; and the sensing ultrasonic sensor (21) is connected to the sensing arm (35) by signal.

2. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: The two input ends of the 2×2 coupler (36) are respectively connected to an optical isolator (32) and a 3×3 coupler (37), and the light source input end of the optical isolator (32) is connected to a narrow linewidth laser (31).

3. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: An FC-APC interface (24) is provided on the outer wall of the detection main board (1), the FC-APC interface (24) is signal-connected to the sensing arm (35), and the sensing ultrasonic sensor (21) is connected to the FC-APC interface (24) via a FC-APC connector (22).

4. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: A key switch (9) is installed on the front surface of the main housing (12), and a power interface (8) is provided on the rear surface of the main housing (12).

5. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: The rear surface of the main housing (12) is provided with a serial interface (7) and a network port (6), respectively; the serial interface (7) and the network port (6) are both communicatively connected to the detection mainboard (1).

6. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: The rear surface of the main housing (12) is provided with an SD card socket (5), and the SD card socket (5) is communicatively connected with the detection mainboard (1) via a wire.

7. The optical microphone partial discharge monitoring device according to claim 1, characterized in that: A touch display screen (10) and a small keyboard (11) are installed on the front surface of the main housing (12); the touch display screen (10) and the small keyboard (11) are both connected to the detection mainboard (1) by signal.

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