An online comprehensive monitoring device for high-voltage electrical equipment of a locomotive

Abstract

The utility model discloses a locomotive high -voltage electrical equipment on -line comprehensive monitoring devices is equipped with semiconductor laser, is provided with the optical path on the light output direction of semiconductor laser and sets up the optical brancher, the optical brancher has two light splitting output ends, wherein the first light splitting output end is connected with the incident port optical path of optical circulator, and the second light splitting output end is connected with the collimating lens optical path, the first exit port of optical circulator is connected with grating temperature sensor optical path, and the second exit port of optical circulator is connected with photoelectric detector optical path, the collimating lens is set up on the lens support, and is provided with the photoacoustic cell on the optical path direction of collimating lens light output, the photoacoustic cell is equipped with the casing, is provided with microphone on the casing, and the microphone is electrically connected with audio amplifier, the semiconductor laser, photoelectric detector and audio amplifier all are electrically connected with singlechip.

Description

Technical Field

[0001] This utility model relates to the field of condition monitoring of high-voltage electrical equipment, and in particular to an online integrated monitoring device for high-voltage electrical equipment in locomotives. Background Technology

[0002] Onboard transformers for electric locomotives and EMUs are core and critical equipment in the high-voltage electrical systems of rail transit vehicles. They undertake core functions such as voltage transformation and power transmission, and their operating status directly determines the stability of the locomotive's power supply and the safety of train operation. Because onboard transformers operate under complex and harsh conditions such as locomotive vibration, alternating high and low temperatures, strong electromagnetic interference, and dust and humidity, they are prone to developing latent faults such as abnormal winding temperatures, insulation aging, partial discharge, and abnormal internal gas release. If these faults are not detected and addressed in a timely manner, they can easily lead to serious malfunctions such as transformer overheating, insulation breakdown, and short circuit burnout, resulting in locomotive shutdowns, line paralysis, and even major traffic safety accidents.

[0003] Existing fixed transformer monitoring equipment is bulky, has weak anti-interference capabilities in enclosed spaces with strong electromagnetic interference, and poor adaptability. It is susceptible to interference from high-voltage frequency converters and traction currents in locomotives, making it unsuitable for direct application in locomotive onboard scenarios. Therefore, the maintenance of locomotive-mounted transformers in China's rail transit sector currently relies primarily on traditional periodic offline inspections. Periodic offline inspections require locomotives to be stored, shut down, and disassembled for testing. This not only results in long maintenance cycles and high manpower and material costs, but also only monitors the equipment status at the current moment, failing to cover hidden problems such as instantaneous anomalies and gradual aging during locomotive operation, leading to monitoring blind spots and delayed early warnings.

[0004] For assessing the operating status of power transformers, the most important monitoring targets are the transformer winding temperature and the dissolved gas content in the insulating oil caused by internal discharge. Therefore, there is an urgent need to develop a comprehensive monitoring device adapted to locomotive on-board conditions, capable of synchronous online monitoring of multiple transformer parameters, to address the many shortcomings of existing technologies and ensure the safe and stable operation of the locomotive's high-voltage electrical system. Utility Model Content

[0005] This invention addresses the aforementioned shortcomings of existing technologies by designing a comprehensive monitoring device adapted to special on-board conditions such as confined space, strong electromagnetic interference, and high-frequency vibration in locomotives. This device assesses and provides early warnings for on-board transformers by detecting two indicators: the concentration of dissolved gases in transformer oil and the temperature of transformer windings.

[0006] The technical solution of this utility model is: an online integrated monitoring device for high-voltage electrical equipment of locomotives, characterized in that: a semiconductor laser 1 is provided, and an optical splitter 2 is provided on the optical path of the output direction of the semiconductor laser 1. The optical splitter 2 has two beam splitting output ends, wherein the first beam splitting output end is connected to the optical path of the incident port of the optical circulator 3, and the second beam splitting output end is connected to the optical path of the collimating lens 4. The first output port of the optical circulator 3 is connected to the optical path of the grating temperature sensor 5, and the second output port of the optical circulator 3 is connected to the optical path of the photodetector 6. The collimating lens 4 is mounted on the lens support 7, and a photoacoustic cell 8 is provided in the light path direction of the collimating lens 4. The photoacoustic cell 8 is provided with a housing 9. The housing 9 is provided with a resonant cavity 10, a buffer cavity 11, an air inlet pipe 12, and an air outlet pipe 13 that are interconnected. The buffer cavity 11 is located at both ends of the housing 9 and is respectively sealed and connected to an input light window 14 and an output light window 15. A sound transmission hole is provided at the center of the resonant cavity 10, and a microphone 16 is provided at the end of the sound transmission hole. The microphone 16 is electrically connected to an audio amplifier 17. The semiconductor laser 1, photodetector 6, and audio amplifier 17 are all electrically connected to the microcontroller 18.

[0007] Both the input optical window 14 and the output optical window 15 are coated with an antireflection film, and the wavelength of the antireflection film is the same as the characteristic absorption wavelength of the gas being measured.

[0008] The reflection center wavelength of the grating temperature sensor 5 is the same as the characteristic absorption wavelength of the gas being measured.

[0009] The lens holder 7 is an adjustable lens holder.

[0010] Compared with the prior art, this utility model has the following advantages: Since the monitoring accuracy of the photoacoustic spectral unit is positively correlated with the optical power, while the monitoring accuracy of the grating temperature sensor is almost unaffected by the optical power, most (over 95%) of the optical power can be allocated to the photoacoustic spectral unit and the remaining small portion to the grating temperature sensor by adjusting the power distribution ratio of the optical splitter. Therefore, this invention uses an optical splitter to divide the emitted light from the semiconductor laser into two independent optical paths, respectively realizing the sensing and monitoring of transformer temperature and the photoacoustic spectral monitoring of fault gas. Multiple parameters of temperature and fault gas can be simultaneously monitored online using only a single light source, significantly simplifying the overall optical path structure, reducing equipment size and hardware costs, and adapting to the limited installation space of locomotive scenarios. It also avoids the problems of poor light source consistency, high power consumption, and high failure rate inherent in multi-light source structures, resulting in high integration and significantly improved operational stability.

[0011] Meanwhile, this utility model integrates semiconductor lasers, photodetectors, and audio amplifiers into a single-chip microcomputer for centralized data acquisition and processing. It features high hardware integration, simple control logic, and eliminates the drawbacks of traditional split-type monitoring equipment, such as complicated wiring and poor anti-interference capabilities.

[0012] In addition, by utilizing the fact that the gas absorption spectrum does not change with the environment and system aging, the operating wavelength of the laser can be self-calibrated through the wavelength scanning results of the photoacoustic spectrum system, which further ensures the detection stability of the grating temperature sensor.

[0013] Meanwhile, the grating temperature detection system can achieve self-monitoring of the laser output power through a photodetector, which can correct the drift caused by changes in the laser output power in the photoacoustic spectroscopy detection system.

[0014] Therefore, this integrated temperature and gas detection system is a complementary system that works together.

[0015] This invention eliminates the need for high-voltage live sensing components, enabling passive detection via a full fiber optic path. It effectively resists strong electromagnetic interference generated by high-voltage frequency conversion and high traction current in locomotives, making it suitable for the harsh onboard operating conditions of locomotives, characterized by high-frequency vibration, wide temperature range, and high electromagnetic interference. This effectively reduces the probability of false alarms and missed alarms in monitoring data and enables all-weather online monitoring of locomotive transformers. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0017] Figure 2 This is a schematic diagram of the photoacoustic cell in an embodiment of this utility model.

[0018] 1. Semiconductor laser; 2. Optical splitter; 3. Optical circulator; 4. Collimating lens; 5. Grating temperature sensor; 6. Photodetector; 7. Lens support; 8. Photoacoustic cell; 9. Housing; 10. Resonant cavity; 11. Buffer cavity; 12. Inlet pipe; 13. Outlet pipe; 14. Input optical window; 15. Output optical window; 16. Microphone; 17. Audio amplifier; 18. Microcontroller. Detailed Implementation

[0019] The specific embodiments of this utility model will be described below with reference to the accompanying drawings. Figure 1 , Figure 2 As shown: An online integrated monitoring device for high-voltage electrical equipment of locomotives, comprising a semiconductor laser 1, wherein an optical splitter 2 is provided on the optical path of the output direction of the semiconductor laser 1, the optical splitter 2 having two beam splitting output ends, wherein the first beam splitting output end is connected to the optical path of the incident port of the optical circulator 3, and the second beam splitting output end is connected to the optical path of the collimating lens 4. The first output port of the optical circulator 3 is connected to the optical path of the grating temperature sensor 5, and the second output port of the optical circulator 3 is connected to the optical path of the photodetector 6. The collimating lens 4 is mounted on the lens support 7, and a photoacoustic cell 8 is provided in the light path direction of the collimating lens 4. The photoacoustic cell 8 is provided with a housing 9. The housing 9 is provided with a resonant cavity 10, a buffer cavity 11, an air inlet pipe 12, and an air outlet pipe 13 that are interconnected. The buffer cavity 11 is located at both ends of the housing 9 and is respectively sealed and connected to an input light window 14 and an output light window 15. A sound transmission hole is provided at the center of the resonant cavity 10, and a microphone 16 is provided at the end of the sound transmission hole. The microphone 16 is electrically connected to an audio amplifier 17. The semiconductor laser 1, photodetector 6, and audio amplifier 17 are all electrically connected to the microcontroller 18.

[0020] Both the input optical window 14 and the output optical window 15 are coated with an antireflection film, and the wavelength of the antireflection film is the same as the characteristic absorption wavelength of the gas being measured.

[0021] The reflection center wavelength of the grating temperature sensor 5 is the same as the characteristic absorption wavelength of the gas being measured.

[0022] The lens holder 7 is an adjustable lens holder.

[0023] The working process of the online integrated monitoring device for high-voltage electrical equipment of locomotives in this embodiment of the utility model is as follows: First, the grating temperature sensor 5 is set in the oil inlet opened on the top of the transformer under test, so as to directly contact the transformer insulating oil and collect the oil temperature parameters in real time. The laser emitted by semiconductor laser 1 enters optical splitter 2, where it splits into two laser beams, which enter the input port of optical circulator 3 and collimating lens 4 respectively. The wavelengths of these two laser beams are the same as those of the laser emitted by semiconductor laser 1. A light beam enters from the incident port of the optical circulator 3, exits from its bidirectional port, and enters the grating temperature sensor 5. The grating temperature sensor 5 reflects a specific wavelength of light beam back to the bidirectional port of the optical circulator 3. The reflected laser beam enters the bidirectional port of the optical circulator 3 and reaches the photodetector 6 through the output port of the optical circulator 3. The photodetector 6 converts the received optical signal into a photocurrent signal and transmits it to the microcontroller 18. The microcontroller 18 collects the photocurrent change data in real time. The wavelength at which the reflected photocurrent reaches its maximum value is recorded as λ0. This wavelength λ0 is linearly correlated with the temperature value detected by the grating temperature sensor 5. That is, the temperature of the grating temperature sensor 5 (i.e., the real-time temperature value of the insulating oil in the transformer) can be accurately obtained by calculating the offset of the wavelength λ0. The other beam is collimated into a parallel beam by the collimating lens 4 and then passes through the input optical window 14, the resonant cavity 10 and the output optical window 15 of the photoacoustic cell 8 in sequence. Since the resonant cavity 10 is filled with dissolved gas in transformer oil, the dissolved gas generates photoacoustic effect under the action of photoacoustic effect. The dissolved gas generates periodic sound wave signal when excited by laser of a specific wavelength, and its sound wave intensity is directly proportional to the concentration of the gas to be measured.

[0024] Microphone 16 collects sound wave signals in real time and converts the sound wave signals into weak voltage signals proportionally. The voltage signals are amplified and filtered by audio amplifier 17 and then transmitted to microcontroller 18. Microcontroller 18 can accurately calculate the real-time concentration of dissolved gas by analyzing the amplitude of the voltage signal. In the above process, the antireflection film provided on the input optical window 14 and the output optical window 15 can effectively eliminate the reflected noise and interference sound waves generated at the optical window during laser transmission, eliminate the detection noise introduced by the optical structure itself, and greatly improve the purity and accuracy of photoacoustic signal detection. After accurately measuring the temperature of the oil and the concentration of gas in the transformer, the measured data is compared with the standard parameter threshold range built into the microcontroller 18. If the monitored data is within the standard range, the transformer is determined to be operating normally, and the device continues to monitor without taking any action. If the monitored data exceeds the standard range, the microcontroller 18 sends a signal to the on-board warning device, which then issues a warning message to remind staff to check, intervene, and handle the fault in a timely manner, thus achieving early prediction and proactive warning of high-voltage transformer faults in locomotives.

Claims

1. An online integrated monitoring device for high-voltage electrical equipment in locomotives, characterized in that: A semiconductor laser (1) is provided, and an optical splitter (2) is provided on the optical path of the output direction of the semiconductor laser (1). The optical splitter (2) has two beam splitting output ends, wherein the first beam splitting output end is connected to the optical path of the incident port of the optical circulator (3), and the second beam splitting output end is connected to the optical path of the collimating lens (4). The first output port of the optical circulator (3) is connected to the optical path of the grating temperature sensor (5), and the second output port of the optical circulator (3) is connected to the optical path of the photodetector (6). The collimating lens (4) is mounted on the lens support (7), and a photoacoustic cell (8) is provided in the light path direction of the collimating lens (4). The photoacoustic cell (8) is provided with a housing (9). The housing (9) is provided with a resonant cavity (10), a buffer cavity (11), an air inlet pipe (12), and an air outlet pipe (13) that are interconnected. The buffer cavity (11) is located at both ends of the housing (9) and is respectively sealed and connected to an input light window (14) and an output light window (15). A sound transmission hole is provided at the center of the resonant cavity (10), and a microphone (16) is provided at the end of the sound transmission hole. The microphone (16) is electrically connected to an audio amplifier (17). The semiconductor laser (1), photodetector (6) and audio amplifier (17) are all electrically connected to the microcontroller (18).

2. The online integrated monitoring device for high-voltage electrical equipment in locomotives according to claim 1, characterized in that: Both the input optical window (14) and the output optical window (15) are coated with antireflection films, and the wavelength of the antireflection films is the same as the characteristic absorption wavelength of the gas being measured.

3. The online integrated monitoring device for high-voltage electrical equipment of locomotives according to claim 1 or 2, characterized in that: The reflection center wavelength of the grating temperature sensor (5) is the same as the characteristic absorption wavelength of the gas being measured.

4. The online integrated monitoring device for high-voltage electrical equipment in locomotives according to claim 3, characterized in that: The lens holder (7) is an adjustable lens holder.

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