Motor train unit electromagnetic radiation disturbance source positioning system

Abstract

The invention relates to the technical field of electromagnetic compatibility, in particular to detection and positioning of an electromagnetic radiation disturbance source of a motor train unit, and particularly relates to a positioning system for the electromagnetic radiation disturbance source of the motor train unit, which is used for detecting and accurately positioning the electromagnetic radiation disturbance source in the motor train unit and comprises a near-field probe module, a pre-amplification module, a spectrum analysis module and an upper computer, the near-field probe module is connected with the pre-amplification module, the pre-amplification module is connected with the spectrum analysis module, the spectrum analysis module is connected with the upper computer, and the upper computer is a final receiving end. The motor train unit electromagnetic radiation disturbance source positioning system has the advantages of simple operation, high detection precision, real-time data processing and high sensitivity. Compared with a traditional system, the system adopts a professional near-field probe, can accurately position an electromagnetic disturbance source, adapts to the complex environment of the motor train unit, has automatic analysis and multi-band detection capabilities, and improves the detection efficiency and accuracy.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic compatibility technology, in particular to the detection and positioning of electromagnetic radiation disturbance sources in EMUs, and specifically to an EMU electromagnetic radiation disturbance source positioning system for detecting and accurately positioning electromagnetic radiation disturbance sources in EMUs. Background Art

[0002] With the development of high-speed railway technology, EMUs have become an important part of modern transportation. EMUs involve a variety of electronic equipment during operation, which will generate certain electromagnetic radiation when working normally. If these radiations exceed the prescribed limits, they may cause electromagnetic interference to the control system, communication system and passenger electronic equipment inside the EMU, affecting their normal operation and use.

[0003] Existing methods for detecting electromagnetic radiation interference sources mainly rely on far-field detection. Although far-field detection can evaluate the overall electromagnetic environment of the EMU, it is difficult to accurately locate specific interference sources, especially in complex near-field environments where signals are weak and easily interfered with, making it impossible to achieve efficient interference troubleshooting. The electromagnetic environment inside the EMU is complex and the space is narrow, and existing technologies cannot meet the need for accurate positioning of electromagnetic interference sources. Therefore, there is an urgent need for a system that can adapt to the complex environment of the EMU and can accurately detect and locate electromagnetic radiation interference sources, so as to ensure that electromagnetic interference can be promptly troubleshooted and improve the electromagnetic compatibility of the EMU system. Summary of the invention

[0004] The purpose of the present invention is to provide a system for locating electromagnetic radiation disturbance sources in an EMU, which can accurately detect and locate electromagnetic radiation disturbance sources in the EMU, is suitable for the complex electromagnetic environment of the EMU, and improves the efficiency and accuracy of electromagnetic interference troubleshooting.

[0005] The present invention is achieved in that:

[0006] A system for locating electromagnetic radiation disturbance sources of a train set, the system comprising a near-field probe module, a preamplifier module, a spectrum analysis module and a host computer, wherein the near-field probe module is connected to the preamplifier module, the preamplifier module is connected to the spectrum analysis module, the spectrum analysis module is connected to the host computer, and the host computer is the final receiving end;

[0007] The near-field detection module includes an electric field probe and a magnetic field probe. The electric field probe is used to detect the electric field component in the electromagnetic field inside the EMU and to capture the electric field radiation signal. The electric field probe adopts a flexible coaxial cable. The flexible coaxial cable includes a central conductor, an insulating layer outside the central conductor, an outer conductor outside the insulating layer, and an outer protective layer on the outermost layer. One end is fixed by a coaxial connector. The front end of the electric field probe removes the outer conductor to expose the insulating layer, and removes part of the insulating layer to expose the central conductor to form a bare conductor.

[0008] The magnetic field probe includes an outer rubber insulation layer, an inner conductor located in the outer rubber insulation layer, and a medium filled in the outer rubber insulation layer. The inner conductor includes a ring structure formed by bending and a vertical structure connected to the ring structure, and an opening is provided at the top of the ring structure. A coaxial connector is arranged at the end of the vertical structure.

[0009] Furthermore: the output current i of the electric field probe is proportional to the electric field strength Ez, frequency ω, capacitance C and probe sensing area A, satisfying the formula i≈ωC|Ez|. The sensitivity and resolution can be adjusted by adjusting the length of the electric field probe.

[0010] Furthermore: the length of the exposed conductor is twice the length of the insulating layer exposed to the outside.

[0011] Furthermore: the top opening on the top of the magnetic field probe allows the magnetic field energy to be coupled through the signal line.

[0012] Furthermore: The magnetic field probe is designed to meet: S is the loop area, |H| is the magnetic field strength, μ0 is the magnetic permeability, the output signal of the magnetic field probe is proportional to the magnetic field strength, and jω is the frequency dependence of the signal.

[0013] Further: The diameter of the ring structure ranges from 2 cm to 20 cm.

[0014] A system for locating electromagnetic radiation disturbance sources of a train set, the system comprising:

[0015] A near-field probe module, a preamplifier module, a spectrum analysis module and a host computer, wherein the near-field probe module is connected to the preamplifier module, the preamplifier module is connected to the spectrum analysis module, the spectrum analysis module is connected to the host computer, and the host computer is the final receiving end.

[0016] Furthermore, the near-field detection module includes an electric field probe and a magnetic field probe.

[0017] Furthermore, the electric field probe is used to detect the electric field component in the electromagnetic field inside the EMU, and is specifically used to capture the electric field radiation signal. The electric field probe is sensitive to high-frequency electromagnetic interference signals and can effectively detect the radiation source of electronic equipment.

[0018] Furthermore, the magnetic field probe is used to detect magnetic field components, mainly used to capture magnetic field radiation signals, and is particularly suitable for detecting low-frequency interference sources. The magnetic field probe can identify magnetic field disturbances caused by high-power equipment or current flow.

[0019] Furthermore, the preamplifier module is responsible for amplifying the weak electromagnetic signal collected by the near-field probe to improve the signal-to-noise ratio of the signal and ensure the accuracy of subsequent analysis. The amplified signal is filtered and transmitted to the spectrum analysis module to facilitate accurate detection of weak interference source signals.

[0020] Furthermore, the spectrum analysis module receives the amplified signal transmitted by the preamplifier module, performs spectrum analysis on the electromagnetic radiation signal, and extracts information such as the frequency characteristics and signal strength of the interference source. The module can identify interference signals in various frequency bands, covering a wide spectrum range from low frequency to high frequency, and provide accurate data support for further positioning of the interference source.

[0021] Furthermore, the preamplifier module adopts a high dynamic range preamplifier.

[0022] Furthermore, the spectrum analysis module uses a BB60C spectrum analyzer.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the electromagnetic radiation interference source positioning system of the EMU of the present invention has high precision, real-time performance and automated analysis capabilities, and can accurately locate the electromagnetic interference source in the complex electromagnetic environment of the EMU. By adopting near-field probes and preamplifier modules, the system can effectively capture and amplify weak electromagnetic signals to ensure that the data is accurate. The spectrum analysis module covers a wide frequency band and provides high-precision data support for further precise positioning. The overall system is easy to operate and has strong adaptability. It can quickly detect and locate abnormal radiation sources, significantly improving the detection efficiency, thereby ensuring the electromagnetic compatibility performance of the EMU and protecting the safety of passengers and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an overall block diagram provided by an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the structure of an electric field probe provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the structure of a magnetic field probe provided by an embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of the structure of a preamplifier provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] See also Figure 1 As shown, the present invention provides a system for locating electromagnetic radiation disturbance sources in an EMU, which is used to detect and accurately locate electromagnetic radiation disturbance sources in the EMU, and includes a near-field probe module, a preamplifier module, a spectrum analysis module and a host computer, wherein the near-field probe module is connected to the preamplifier module, the preamplifier module is connected to the spectrum analysis module, the spectrum analysis module is connected to the host computer, and the host computer is the final receiving end.

[0030] The near-field probe module includes an electric field probe and a magnetic field probe. The electric field probe is used to detect the electric field component in the electromagnetic field inside the EMU and to capture the electric field radiation signal; the electric field probe uses a flexible coaxial cable.

[0031] See also Figure 2 As shown, the electric field probe uses a flexible coaxial cable as the main material. The flexible coaxial cable is composed of a central conductor 1, an insulating layer 2, an outer conductor 3, an outer protective layer 4, and a first coaxial connector 5, and has the characteristics of good flexibility, high durability and stable electromagnetic performance. The flexible coaxial cable has low loss and good shielding performance, and is suitable for precise electromagnetic signal detection. The flexible coaxial cable includes a central conductor, an insulating layer outside the central conductor, an outer conductor outside the insulating layer, and an outer protective layer on the outermost layer, one end of which is fixed by a first coaxial connector, the front end of the electric field probe removes the outer conductor to expose the insulating layer, and removes part of the insulating layer to expose the central conductor to form a bare conductor.

[0032] By designing the exposed length of the central conductor, it can be made more sensitive to the surrounding electric field radiation signals. The exposed central conductor can effectively capture the electric field signals inside the EMU, especially the high-frequency signals.

[0033] The rear end of the flexible coaxial cable remains intact and is connected to the preamplifier module through a standard coaxial connector. This connection ensures that the signal collected by the electric field probe can be transmitted to the amplifier module without loss for subsequent processing.

[0034] The flexible design of the coaxial cable allows the probe to be moved and adjusted at different locations inside the EMU while maintaining the stability of signal transmission. This design enables the electric field probe to detect electric field signals at more locations, helping to locate the source of electromagnetic interference.

[0035] When electromagnetic radiation exists in the EMU, the exposed central conductor will sense the change of the surrounding electric field. This induced charge forms a weak voltage signal on the central conductor, which is then transmitted to the subsequent signal processing module through the coaxial cable.

[0036] In this embodiment, for the electric field probe, i≈ωC|Ez|

[0037] This formula shows that the probe output current i is proportional to the electric field strength Ez, frequency ω, capacitance C and probe sensing area A. The capacitance C of the probe is proportional to the length of its outer conductor, so the longer the probe is, the greater the capacitance, the higher the sensitivity, but the lower the resolution. Conversely, the shorter the probe is, the lower the sensitivity but the higher the resolution.

[0038] The length of the outer conductor of the probe must be long enough to ensure that it can sense the weak high-frequency electromagnetic radiation signal inside the EMU. In the design, the length of the exposed conductor is twice the length of the insulation layer exposed to the outside, which can increase the capacitance C and improve the sensitivity, so that the probe can capture more subtle electric field signals.

[0039] In order to improve the spatial resolution of the probe, the size of the probe should not be too large. A small probe can be more sensitive to local changes in the electric field, so it can more accurately locate the source of electromagnetic radiation interference. The exposed conductor area A of the probe should also be moderately controlled to ensure that the spatial resolution of the probe is not reduced while capturing sufficient electric field signals.

[0040] See also Figure 3 As shown, the magnetic field probe includes an outer rubber insulation layer 6, an inner conductor 8 located in the outer rubber insulation, and a medium 7 filled in the outer rubber insulation layer. The inner conductor includes a ring structure formed by bending and a vertical structure connected to the ring structure, and an opening 10 is provided at the top of the ring structure. A coaxial connector is arranged at the end of the vertical structure.

[0041] The magnetic field signal is captured by bending the cable into a loop structure. The bent part of the cable forms a closed loop that can sense changes in the magnetic field.

[0042] To reduce the influence of the electric field on the magnetic field probe, a top opening 10 is provided on the top of the probe so that the magnetic field energy can be coupled by the signal line. The opening can prevent the external electric field from interfering with the operation of the magnetic field probe, ensuring that the probe is only sensitive to the magnetic field signal.

[0043] The working principle of the magnetic field probe can be described by the following formula: S is the ring area. The larger the area, the higher the sensitivity of the probe. |H| is the magnetic field strength. The output signal of the probe is proportional to the magnetic field strength. jω is the frequency dependence of the signal. The higher the frequency, the stronger the induced signal.

[0044] In order to facilitate the detection of electromagnetic interference sources in the magnetic field, magnetic field probes are designed with probes of different sizes. According to specific needs, the diameter of the probe ranges from 2cm to 20cm, which can meet the sensitivity and resolution requirements in different application scenarios.

[0045] The magnetic field probe has high sensitivity and can detect weak magnetic field signals, but a larger probe size will reduce the resolution. Therefore, the probe size should be adjusted according to the detection requirements. Usually, the ring area of ​​a large-sized probe is more than twice that of a small-sized probe.

[0046] See also Figure 4 As shown in the figure, the preamplifier module is the core component used to amplify the weak signals collected by the electric field probe and the magnetic field probe. Since the signals collected by the probe are often very weak, the preamplifier module needs to provide high gain, low noise and wide bandwidth response to ensure that the signal remains stable and pure during transmission. The preamplifier module includes a first amplifier, a resistor R7 and a resistor R5 connected to the in-phase input end of the first amplifier, one end of a capacitor C7 is connected between the resistor R7 and the resistor R5, the other end of the capacitor C7 is connected to the output end of the first amplifier, the in-phase input end of the first amplifier is also connected to the capacitor C5, the other end of the capacitor C5 is grounded, the inverting input end of the first amplifier is connected to one end of the resistor R6, the other end of the resistor R6 is grounded, the inverting input end of the first amplifier is also connected to the output end of the first amplifier through a resistor R8, the positive voltage end of the first amplifier is connected to the positive power supply +Vcc, one end of the capacitor C9 and the capacitor C10 are connected in parallel and grounded, and the other end is connected to the positive voltage end of the first amplifier, one end of the capacitor C11 and the capacitor C12 are connected in parallel and grounded, and the other end is connected to the negative voltage end of the first amplifier, and the output end of the first amplifier is sequentially connected to capacitors C13, C14, and C15. Resistors R10, R11 and R12 are connected to the non-inverting input terminal of the second amplifier, one end of capacitor C14 is connected between capacitor C13 and resistor R10, and the other end of capacitor C14 is grounded, one end of capacitor C15 is connected between resistor R10 and resistor R11, and the other end of capacitor C15 is grounded; the non-inverting input terminal of the second amplifier is connected to capacitor C16, and the other end of capacitor C16 is grounded, the inverting input terminal of the second amplifier is connected to resistor R13, and the other end of resistor R13 is grounded, the inverting input terminal and the output terminal of the second amplifier are connected to resistor R14, the negative voltage terminal of the second amplifier is connected to capacitor C19 and capacitor C20 in parallel, and the other ends of capacitor C19 and capacitor C20 are grounded, and the positive voltage terminal of the second amplifier is connected to capacitor C17 and capacitor C18 in parallel, and the other ends of capacitor C17 and capacitor C18 are grounded.

[0047] In this embodiment, the preamplifier module provides a gain of 20dB to 40dB, which can effectively amplify weak electric and magnetic field signals to ensure that they are strong enough for subsequent spectrum analysis modules. The amplifier circuit adopts a low-noise design to reduce the additional electrical noise introduced during the amplification process and ensure that the signal maintains a high signal-to-noise ratio after amplification. The noise coefficient is controlled within 1 to 2dB to ensure high-quality signal transmission.

[0048] The preamplifier covers a wide frequency range from tens of Hz to hundreds of MHz, and can effectively amplify electromagnetic interference source signals from low frequency to high frequency in the EMU. The preamplifier module also has basic filtering functions, which can remove noise signals in irrelevant frequency bands and improve the accuracy of spectrum analysis.

[0049] The spectrum analysis module is used to perform spectrum analysis on the signal processed by the preamplifier module to extract key information such as the frequency characteristics and signal strength of the electromagnetic disturbance source. This module can cover wide-band signals from low frequency to high frequency and is suitable for electromagnetic signal detection at multiple frequencies.

[0050] The host computer is the final data processing and display terminal of the system. Its main functions include receiving data transmitted by the spectrum analysis module and performing further data processing and interference source location through software.

[0051] 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 system for locating electromagnetic radiation disturbance sources of a train, characterized in that: The system includes a near-field probe module, a preamplifier module, a spectrum analysis module and a host computer, wherein the near-field probe module is connected to the preamplifier module, the preamplifier module is connected to the spectrum analysis module, the spectrum analysis module is connected to the host computer, and the host computer is the final receiving end; The near-field detection module includes an electric field probe and a magnetic field probe. The electric field probe is used to detect the electric field component in the electromagnetic field inside the EMU and to capture the electric field radiation signal. The electric field probe adopts a flexible coaxial cable. The flexible coaxial cable includes a central conductor, an insulating layer outside the central conductor, an outer conductor outside the insulating layer, and an outer protective layer on the outermost layer. One end is fixed by a coaxial connector. The front end of the electric field probe removes the outer conductor to expose the insulating layer, and removes part of the insulating layer to expose the central conductor to form a bare conductor. The magnetic field probe includes an outer rubber insulation layer, an inner conductor located in the outer rubber insulation layer, and a medium filled in the outer rubber insulation layer. The inner conductor includes a ring structure formed by bending and a vertical structure connected to the ring structure, and an opening is provided at the top of the ring structure. A coaxial connector is arranged at the end of the vertical structure.

2. The electromagnetic radiation disturbance source positioning system for a train set according to claim 1 is characterized in that: The output current i of the electric field probe is proportional to the electric field strength Ez, frequency ω, capacitance C and probe sensing area A, satisfying the formula i≈ωC|Ez|. The sensitivity and resolution can be adjusted by adjusting the length of the electric field probe.

3. The electromagnetic radiation disturbance source positioning system for a train set according to claim 2 is characterized in that: The exposed conductor length is twice the length of the exposed insulation layer.

4. The electromagnetic radiation disturbance source positioning system for a train set according to claim 1 is characterized in that: The top opening of the magnetic field probe allows the magnetic field energy to be coupled through the signal line.

5. The system for locating electromagnetic radiation disturbance sources of a train set according to claim 4 is characterized in that: The magnetic field probe is designed to meet: S is the loop area, |H| is the magnetic field strength, μ0 is the magnetic permeability, the output signal of the magnetic field probe is proportional to the magnetic field strength, and jω is the frequency dependence of the signal.

6. The system for locating electromagnetic radiation disturbance sources of a train set according to claim 5 is characterized in that: The diameter of the ring structures ranges from 2 cm to 20 cm.

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