Device and method for simulating partial discharge measurement of PCB (Printed Circuit Board) based on fluorescent optical fiber

Abstract

The invention relates to the technical field of electronic measurement, in particular to a measuring device and method for simulating partial discharge of a PCB (printed circuit board) based on a fluorescent optical fiber, which comprises a power supply, a voltage regulating device and a fixed support, the fixed support comprises an upper fixed insulating plate, a lower fixed insulating plate and the PCB, the PCB is provided with an X-shaped copper bar, and four corners of the X-shaped copper bar are connected with conducting rings; the power supply applies different voltage grades to the X-shaped copper bar through the voltage regulating device, simulates the discharge of the PCB and is used for researching the discharge characteristic of the PCB, the upper layer fixed insulating plate is provided with an optical fiber, the optical fiber is arranged on the upper layer fixed insulating plate in a circular ring form, the optical fiber is an opening, the other end of the optical fiber is connected to the avalanche photodiode APD, and the avalanche photodiode APD is connected with the power supply. And a signal of the avalanche photodiode APD is accessed to the measuring device for measurement. The discharge condition is recognized by detecting ultraviolet radiation generated during partial discharge, electromagnetic and acoustic interference in the partial discharge detection process is reduced, and the device has high sensitivity and is suitable for various electrical devices.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic measurement, and in particular to a device and method for measuring partial discharge of a simulated PCB board based on fluorescent optical fiber. Background Art

[0002] The increasing adoption of electric aircraft (MEAs / AEAs) has brought with it higher demands for aircraft safety, environmental friendliness, and efficiency. These aircraft's efficient electric drive systems require high power density and rely on a large number of printed circuit boards (PCBs) for operation. Because aircraft components operate under high-frequency electrical stresses and often in low-voltage environments, coupled with the compactness of electronic circuits to reduce aircraft weight and space, insulation performance in electric aircraft is particularly critical, even more so than in traditional electrical equipment on land.

[0003] The efficient electric drive systems in all-electric aircraft (MEAs / AEAs) rely on high power density, which means that a large number of printed circuit boards (PCBs) are required to support their complex electronic control and power management systems. Compared with traditional aircraft, electric aircraft designs often require more electronic components within a limited space. Due to strict weight control, the size and weight of the circuit boards are compressed even more compactly.

[0004] In the operating environment of electric aircraft, some critical components are subject to high-frequency electrical stresses and are often located in a low-voltage environment. This environment not only increases the requirements for electrical insulation performance but also increases the risk of partial discharge (PD) on the circuit boards. PD can cause insulation material degradation, which can lead to severe electrical failures that are unacceptable during flight. Therefore, real-time monitoring and evaluation of the insulation condition of PCBs in electric aircraft is crucial to ensure reliability and safety throughout the flight cycle.

[0005] Currently, methods based on pulse current and ultrahigh-frequency (UHF) signal detection are widely used to detect partial discharge (PD) on aircraft. These methods are suitable for 50 / 60 Hz voltages, but are susceptible to electromagnetic interference in high-frequency square voltage environments, complicating signal recognition and processing. Sagnac and Fabry-Perot optical fibers are also used to detect the acoustic vibration signals generated by partial discharge. However, during aircraft operation, significant mechanical vibration interference from the equipment degrades detection performance.

[0006] Currently, methods based on pulse current and ultra-high frequency (UHF) signal detection are widely used to detect partial discharge (PD) in aircraft. While these methods perform well in 50 / 60 Hz voltage environments, they are susceptible to electromagnetic interference (EMI) in high-frequency square voltage environments, complicating the identification and processing of detection signals. This EMI can mask the true PD signal, making fault diagnosis more difficult.

[0007] Fluorescent fiber is a specialized type of optical fiber. Its operating principle is that fluorescent substances incorporated into the fiber core absorb light radiation within a specific wavelength range, becoming excited and emitting fluorescence. When the fluorescent substance is activated by light absorption, the electrons in the fluorescent molecules transition from the ground state to an excited state. When the unstable excited electrons return to the ground state, they release photons (fluorescence), which propagate through the optical fiber, thereby detecting the light signal. Fluorescent fiber is typically made of polymethyl methacrylate (PMMA), with an average dielectric constant of approximately 3.36 and an average dielectric strength of 25.3 kV / mm. It exhibits excellent insulation properties, high light transmission efficiency, strong toughness, and chemical stability, making it ideal for use in harsh operating environments such as aircraft.

[0008] Fluorescent fiber optic temperature sensors utilize the properties of rare earth fluorescent materials. When excited by ultraviolet light, these materials emit a linear spectrum in the visible spectrum, known as fluorescence and its afterglow. The decay time constant of the fluorescence afterglow is a single-valued function of temperature; generally, the higher the temperature, the smaller the time constant. By measuring the fluorescence lifetime, the current ambient temperature can be determined. The greatest advantage of this sensor is that the measured target temperature depends solely on the time constant of the fluorescent material and is independent of other system variables. Changes in light source intensity, transmission efficiency, or coupling level, for example, do not affect the measurement result. This provides a significant advantage over other temperature measurement methods.

[0009] The fluorescent fiber optic temperature measurement system has many advantages, including intrinsic safety, high-voltage insulation, and resistance to electromagnetic interference; the system operates stably and reliably without drift, and does not require calibration and verification throughout its life; it adopts a modular design, which allows for flexible networking and unlimited expansion at any time without wasting resources; digital output facilitates automated real-time control and data management; the probe and demodulator are small and flexible, easy to install and maintain. Summary of the Invention

[0010] To address the problems existing in the existing technology, a device and method for measuring partial discharge of simulated PCB boards based on fluorescent optical fiber are proposed. The principle is applicable to the detection of partial discharge of PCB boards in the harsh environment of all-electric aircraft, and is also applicable to the detection of partial discharge of PCB boards in other power system occasions.

[0011] This invention proposes a method for detecting partial discharge (PD) radiation photons. This method identifies discharge conditions by detecting the ultraviolet radiation generated during PD, reducing electromagnetic and acoustic interference during PD detection. It exhibits high sensitivity and is applicable to a variety of electrical equipment. The application of UV imaging technology to PD detection in electrical equipment clearly demonstrates the correlation between the light intensity generated by PD and the voltage value. Specifically, when the voltage exceeds the PD threshold, the light intensity generated by PD is proportional to the fifth power of the voltage value. This technological advancement provides a new detection method for the safe operation of MEA / AEA, helping to improve the reliability and safety of aircraft power systems.

[0012] The technical solutions of the present invention are as follows: A fluorescent optical fiber-based device for simulating partial discharge measurement of a printed circuit board (PCB), comprising a power supply and a voltage regulating device. The device further comprises a fixed bracket, wherein the fixed bracket comprises an upper fixed insulating plate and a lower fixed insulating plate, a PCB is mounted between the upper and lower fixed insulating plates, the upper and lower fixed insulating plates being connected to the PCB via insulating support columns, an X-shaped copper bar is provided on the PCB, and conductive rings are connected to the four corners of the X-shaped copper bar; the power supply applies different voltage levels to the conductive rings at the four corners of the X-shaped copper bar via the voltage regulating device, simulating PCB discharge for studying the discharge characteristics of the PCB; an optical fiber is provided on the upper fixed insulating plate, the optical fiber is placed on the upper fixed insulating plate in the form of a ring, the optical fiber is open, and the other end of the optical fiber is connected to an avalanche photodiode (APD); the signal of the avalanche photodiode (APD) is connected to the measuring device for measurement.

[0013] The fluorescent optical fiber-based simulated PCB board partial discharge measurement device is characterized in that the measurement device is an oscilloscope.

[0014] The fluorescent optical fiber-based simulated PCB board partial discharge measurement device is characterized in that the upper fixed insulating plate, the lower fixed insulating plate, and the four corners of the PCB board are respectively provided with openings, and the conductive rings at the four corners of the X-shaped copper bar correspond to the positions of the openings and are fixedly connected by insulating support columns.

[0015] The fluorescent optical fiber-based simulated PCB board partial discharge measurement device is characterized in that the upper fixed insulating plate, the lower fixed insulating plate, the PCB board, and the four corners of the X-shaped copper bar are threadedly connected by insulating support columns.

[0016] The fluorescent optical fiber-based simulated PCB board partial discharge measurement device is characterized in that the conductive rings at the four corners of the X-shaped copper bar are screwed with power nuts for power supply wiring, and the power nuts are sleeved outside the insulating support column.

[0017] The fluorescent optical fiber-based simulated PCB partial discharge measurement device is characterized in that the X-shaped copper bar structure is one of the following: formed by two curved copper bars connected in the middle; formed by two copper bars with bent ends connected in the middle; formed by one curved copper bar and one copper bar with bent ends connected in the middle.

[0018] The device for measuring partial discharge of a simulated PCB board based on fluorescent optical fiber is characterized in that the optical fiber is a fluorescent optical fiber.

[0019] A fluorescent optical fiber-based method for simulating partial discharge measurement of a printed circuit board (PCB), characterized in that the PCB is fixed between an upper fixed insulating plate and a lower fixed insulating plate, an X-shaped copper bar is provided on the PCB, an optical fiber is placed on the upper fixed insulating plate, the optical fiber is placed on the upper fixed insulating plate in the form of a ring, the optical fiber is open, and the other end of the optical fiber is connected to an avalanche photodiode (APD), and the signal of the avalanche photodiode (APD) is connected to a measuring device for measurement; a power supply applies different voltage levels to the four corners of the X-shaped copper bar through a voltage regulating device to simulate PCB discharge for studying the discharge characteristics of the PCB; the optical fiber receives the discharge signal and transmits it to the avalanche photodiode (APD), and the output signal of the avalanche photodiode (APD) is connected to the measuring device to measure the discharge information.

[0020] The fluorescent optical fiber-based method for measuring partial discharge of simulated PCB boards is characterized in that the measuring device is an oscilloscope and the optical fiber is a fluorescent optical fiber.

[0021] The fluorescent optical fiber-based simulated PCB board partial discharge measurement method is characterized in that the material of the fluorescent optical fiber is polymethyl methacrylate, with an average dielectric constant of 3.36 and an average dielectric strength of 25.3 kV / mm.

[0022] The present invention uses fluorescent optical fibers to detect partial discharges on PCB boards, thereby improving the detection efficiency of the device in low-pressure, high-frequency voltage conditions, and in the presence of acoustic and electromagnetic interference, thereby protecting the safety of all-electric aircraft. The use of an optical fiber fluorescence detection system in place of a traditional fluorescent spatial light detection system reduces the use of discrete optical components, lowers device costs, and simplifies assembly, debugging, and maintenance. Because the optical fiber light path has advantages such as a simple structure, a closed optical path, simple debugging, and ease of maintenance, the device can operate stably even in harsh environments such as all-electric aircraft. The design of the device facilitates the integration and portability of the detection system, making it easier to conduct on-site detection and maintenance in all-electric aircraft and other environments.

[0023] The present invention has the following advantages: The key points and protection points of the fluorescent fiber-based simulated PCB partial discharge measurement device and measurement method are mainly concentrated in the following aspects: 1. Fluorescent fiber technology: The device uses fluorescent fiber as the core component for detecting partial discharge. It uses the property of fluorescent material in the core of the optical fiber to emit fluorescence after absorbing incident light to detect ultraviolet radiation generated by partial discharge.

[0024] 2. Anti-interference ability: Since fluorescent optical fiber has good anti-electromagnetic interference ability, the device can work stably in harsh environments with acoustic and electromagnetic interference, especially under low air pressure and high frequency voltage conditions.

[0025] 3. Structural Design: The device's structural design is simple, easy to install and maintain, while ensuring efficient detection. The multi-layer fiber optic coil design makes the sensor small and compact, making it easy to install inside the power transformer.

[0026] 4. Fiber optic material: The material of fluorescent fiber is polymethyl methacrylate (PMMA), which has an average dielectric constant of about 3.36 and an average dielectric strength of 25.3 kV / mm. It has good insulation performance, high light transmission efficiency, strong toughness, and stable chemical properties.

[0027] 5. Environmental adaptability: Due to the characteristics of PMMA materials, fluorescent optical fiber is suitable for use in harsh working environments such as aircraft, including low air pressure and high frequency voltage conditions.

[0028] 6. Real-time monitoring capability: The device can realize real-time monitoring of partial discharge activities, which is crucial for the safe operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structural principle of the present invention.

[0030] Figure 2 This is a diagram of a partial fixing bracket for a PCB board according to the present invention.

[0031] Figure 3 It is an X-shaped copper bar formed by connecting two curved copper bars in the middle.

[0032] Figure 4 An X-shaped copper bar is formed by connecting a curved copper bar with a copper bar bent at both ends in the middle.

[0033] Figure 5 An X-shaped copper bar is formed by connecting two copper bars with bent ends in the middle.

[0034] See also Figure 1-5 .

[0035] Example 1 like Figure 1As shown, a fluorescent optical fiber-based simulated PCB board partial discharge measurement device includes a power supply, a voltage regulating device, the voltage regulating device includes a voltage regulating platform, and a transformer. The power supply is connected to the transformer, the transformer is installed on the voltage regulating platform, and a protective resistor is connected in series in the power supply circuit.

[0036] The device also includes a fixed bracket, comprising an upper fixed insulating plate 1 and a lower fixed insulating plate 5. A PCB 4 is mounted between the upper and lower fixed insulating plates. An X-shaped copper strip 3 is provided on the PCB 4. Openings are provided at the four corners of the upper fixed insulating plate 1, the lower fixed insulating plate 5, and the PCB 4. Conductive rings are provided at the four corners of the X-shaped copper strip 3, corresponding to the positions of the openings, and are fixedly connected to the insulating support column 2 via threads. Electrical nuts are threaded onto the conductive rings at the four corners of the X-shaped copper strip 3 for power supply wiring, and the electrical nuts are sleeved onto the outside of the insulating support column 2.

[0037] The power supply applies different voltage levels to the conductive rings at the four corners of the X-shaped copper bar 3 through a voltage regulating device to simulate the discharge of the PCB board, which is used to study the discharge characteristics of the PCB board. A fluorescent optical fiber 6 is provided on the upper fixed insulating plate 1. The fluorescent optical fiber 6 is placed on the upper fixed insulating plate 1 in the form of a ring. The end of the fluorescent optical fiber 6 is open, and the other end of the fluorescent optical fiber 6 is connected to the avalanche photodiode APD. The signal of the avalanche photodiode APD is connected to the oscilloscope for measurement.

[0038] Protective resistor: Used to limit current in a circuit and protect subsequent components from damage due to excessive current.

[0039] Power supply: Provides the required electrical energy for the entire system's X-shaped copper bars.

[0040] Transformer voltage regulator: used to adjust the voltage level, which may be used for different operating voltage conditions or to provide a stable voltage source for the system.

[0041] Fluorescent fiber: An optical fiber capable of transmitting light signals, which may be used here to detect ultraviolet radiation generated during partial discharge, thereby identifying the discharge event.

[0042] Avalanche Photodiode (APD): A highly sensitive photodetector capable of detecting weak optical signals and potentially used to detect and measure optical radiation generated by partial discharges.

[0043] Oscilloscope: An electronic measuring instrument used to observe and analyze electrical signals, which in this case may be used to display the waveform of a partial discharge signal for analysis and diagnosis.

[0044] like Figure 2 As shown, the fixing bracket consists of the following parts: The upper layer is fixed with insulating board 1: 100 mm long, 100 mm wide, and 1 mm thick. The hole diameter is 4.2 mm, and the hole spacing is 40 mm and 16 mm. It is made of insulating material. Optical fibers are fixed on it to detect partial discharges on PCBs.

[0045] Insulating support column 2: The support column is a cylinder with a length of 150mm and a diameter of 4mm. The support column needs to be made of insulating material and needs to be threaded to facilitate fixing with nuts.

[0046] Power nut: The nut is round, 5mm long, 5mm in diameter, and 4mm in diameter. It contacts the rings at the four corners of the X-shaped copper bar to provide grounding and power to the bar.

[0047] PCB board 4: 50mm long, 25mm wide, 1mm thick. The four holes are 16mm and 40mm apart, with a diameter of 4.2mm.

[0048] Lower fixed insulation board 5: Length and width are 200mm, thickness is 20mm. The four holes in the middle are 16mm and 40mm apart, with a diameter of 4mm and a depth of 15mm. The holes are threaded.

[0049] The structure of the X-shaped copper bar 3 is one of the following: like Figure 3 , which is made of two curved copper bars connected in the middle; like Figure 5 , which is made of two copper bars with bent ends connected in the middle; like Figure 4 , which consists of a curved copper bar connected in the middle with a copper bar bent at both ends.

[0050] This bracket secures the PCB 4, which is powered and grounded via the electrical nuts and the rings at the ends of the X-shaped copper bar 3. The height of the upper fixed insulating plate 1 and the PCB is adjustable, allowing experiments to test the detection effect of the fluorescent fiber 6 at different distances and angles from the PCB 4.

[0051] The working principle of the whole device: When partial discharge occurs on simulated PCB 4, it generates signals such as electrical pulses, electromagnetic radiation, ultrasonic waves, and optical radiation. The APD detects these signals and displays them on an oscilloscope. Fluorescent optical fibers may be used to transmit these signals, while protective resistors and power supplies ensure stable and safe operation of the entire system. Such devices are crucial for monitoring and evaluating the insulation condition of power equipment, helping to prevent failures and extend equipment life.

[0052] Example 2 See 1-5.

[0053] A fluorescent optical fiber-based method for measuring partial discharge of a simulated PCB board comprises the following steps: a PCB board 4 is fixed between an upper fixed insulating plate 1 and a lower fixed insulating plate 5; an X-shaped copper bar 3 is provided on the PCB board 4; a fluorescent optical fiber 6 is fixedly placed on the upper fixed insulating plate 1; the fluorescent optical fiber 6 is fixedly placed on the upper fixed insulating plate 1 in the form of a ring; the fluorescent optical fiber 6 is open; the other end of the fluorescent optical fiber 6 is connected to an avalanche photodiode (APD); the signal of the avalanche photodiode (APD) is connected to an oscilloscope for measurement; a power supply applies different voltage levels to the four corners of the X-shaped copper bar 3 through a voltage regulating device to simulate PCB board discharge for studying the discharge characteristics of the PCB board; the fluorescent optical fiber 6 receives the discharge signal and transmits it to the avalanche photodiode (APD); the oscilloscope measures the discharge information.

[0054] The material of the fluorescent optical fiber 6 is polymethyl methacrylate, with an average dielectric constant of 3.36 and an average dielectric strength of 25.3 kV / mm.

Claims

1. A fluorescent optical fiber-based simulated PCB partial discharge measurement device, comprising a power supply and a voltage regulator, characterized in that: The present invention also includes a fixed bracket, which includes an upper fixed insulating plate and a lower fixed insulating plate. A PCB board is installed between the upper and lower fixed insulating plates. The upper fixed insulating plate, the lower fixed insulating plate and the PCB board are connected by insulating support columns. An X-shaped copper bar is provided on the PCB board, and conductive rings are connected to the four corners of the X-shaped copper bar. The power supply applies different voltage levels to the conductive rings at the four corners of the X-shaped copper bar through a voltage regulating device to simulate the discharge of the PCB board for studying the discharge characteristics of the PCB board. An optical fiber is provided on the upper fixed insulating plate. The optical fiber is placed on the upper fixed insulating plate in the form of a circular ring. The optical fiber is open, and the other end of the optical fiber is connected to an avalanche photodiode APD. The signal of the avalanche photodiode APD is connected to a measuring device for measurement.

2. A fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 1, characterized in that: The measuring device is an oscilloscope.

3. The fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 1, characterized in that: The upper fixed insulating plate, the lower fixed insulating plate and the four corners of the PCB board are respectively provided with openings, and the conductive rings at the four corners of the X-shaped copper bar correspond to the positions of the openings and are fixedly connected by insulating support columns.

4. The fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 3, characterized in that: The upper fixed insulating plate, the lower fixed insulating plate, the PCB board and the four corners of the X-shaped copper bar are connected by threads through insulating support columns.

5. A fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 3 or 4, characterized in that: The conductive rings at the four corners of the X-shaped copper bar are screwed with power nuts for power connection, and the power nuts are sleeved outside the insulating support column.

6. The fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 1, characterized in that: The X-shaped copper bar structure is one of the following: formed by two curved copper bars connected in the middle; formed by two copper bars with bent ends connected in the middle; formed by one curved copper bar and one copper bar with bent ends connected in the middle.

7. The fluorescent optical fiber-based simulated PCB partial discharge measurement device according to claim 1, characterized in that: The optical fiber is a fluorescent optical fiber.

8. A method for measuring partial discharge of a simulated PCB board based on fluorescent optical fiber, characterized in that: The PCB board is fixed between the upper fixed insulating plate and the lower fixed insulating plate, an X-shaped copper bar is set on the PCB board, and an optical fiber is placed on the upper fixed insulating plate. The optical fiber is placed on the upper fixed insulating plate in the form of a ring, the optical fiber is open, and the other end of the optical fiber is connected to an avalanche photodiode APD. The signal of the avalanche photodiode APD is connected to a measuring device for measurement; the power supply applies different voltage levels to the four corners of the X-shaped copper bar through a voltage regulating device to simulate the discharge of the PCB board, which is used to study the discharge characteristics of the PCB board. The optical fiber receives the discharge signal and transmits it to the avalanche photodiode APD. The output signal of the avalanche photodiode APD is connected to the measuring device to measure the discharge information.

9. The method for measuring partial discharge of a simulated PCB board based on fluorescent optical fiber according to claim 8, wherein: The measuring device is an oscilloscope, and the optical fiber is a fluorescent optical fiber.

10. The method for measuring partial discharge of a simulated PCB board based on fluorescent optical fiber according to claim 9, characterized in that: The material of the fluorescent optical fiber is polymethyl methacrylate, with an average dielectric constant of 3.36 and an average dielectric strength of 25.3 kV / mm.

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