25Hz phase-sensitive track circuit traction current imbalance monitoring system

Abstract

The utility model relates to the technical field of railway signal monitoring, in particular to a 25Hz phase-sensitive track circuit traction current imbalance monitoring system, which comprises a current acquisition module arranged at the power transmitting end and the power receiving end of a steel rail and comprising a plurality of current transformers coupled to the secondary side of a choke transformer; the signal conditioning modules are respectively configured at the rear stage of each current transformer, and each signal conditioning module comprises a pre-amplification unit, a band-pass filtering unit, a rear amplification unit and an analog-to-digital conversion unit which are electrically connected in sequence; and the data processing module is configured at the rear stage of the plurality of signal conditioning modules and comprises a data processing chip U8. According to the utility model, through a multi-stage processing flow, weak signals are firstly subjected to primary amplification, then interference signals are subjected to band-pass filtering, and finally secondary amplification and analog-to-digital conversion are carried out, so that the signal-to-noise ratio and the precision of the signals are greatly improved, and high-quality digital signals are provided for subsequent data processing.

Description

Technical Field

[0001] The utility model relates to the technical field of railway signal monitoring, in particular to a 25Hz phase-sensitive track circuit traction current imbalance monitoring system. Background Art

[0002] The 25Hz phase-sensitive track circuit is a key device in railway signaling systems used to detect train occupancy and ensure driving safety. It transmits a 25Hz signal through the rails and uses its phase-sensitive characteristics to determine whether a train is occupying a track section. In actual operation, factors such as uneven rail material, fluctuations in contact network current, poor track connections, and degradation of choke transformer performance can easily lead to an imbalance in the traction current between the two rails.

[0003] The utility model patent with announcement number CN220709242U discloses an intelligent measurement system based on track unbalanced traction current. The intelligent measurement system includes a card-type sensor module for sensing the traction current signal in the rail, and also includes a data processing module for collecting and recording the sensor output signal; the measurement system also includes a wireless communication module and a handheld maintenance terminal.

[0004] Although this utility model realizes the functions of real-time acquisition, display, processing and analysis of rail traction current test data at the railway site, greatly improving work efficiency and saving labor costs, it only uses a filtering circuit and lacks amplification processing of the traction signal, resulting in insufficient signal-to-noise ratio and accuracy of the signal, which in turn affects subsequent judgments. Utility Model Content

[0005] The purpose of the present utility model is to provide a 25Hz phase-sensitive track circuit traction current imbalance monitoring system to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] 25Hz phase-sensitive track circuit traction current imbalance monitoring system, including:

[0008] Current acquisition module: configured at the power transmission and receiving ends of the rail, used to collect the traction current signal in the rail in real time. The current acquisition module includes several current transformers, which are coupled to the secondary side of the choke transformer to sense the unbalanced current and convert it into a voltage signal;

[0009] Several signal conditioning modules: respectively configured at the rear stage of each current transformer, including a preamplifier unit, a bandpass filter unit, a postamplifier unit and an analog-to-digital conversion unit electrically connected in sequence, wherein the preamplifier unit is used to initially amplify the signal, the bandpass filter unit is used to filter out interference signals in the traction current signal, the postamplifier unit is used to further amplify the filtered signal, and the analog-to-digital conversion unit is used to convert the analog signal into a digital signal;

[0010] Data processing module: configured at the back end of several of the signal conditioning modules, including a data processing chip U8, used to calculate the amplitude difference and phase difference of the two-rail current signals and generate an imbalance index.

[0011] Preferably, the preamplifier unit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, an operational amplifier U1 and a resistor R5;

[0012] The first end of resistor R1 and the first end of resistor R2 are connected to the two output ends of the current transformer respectively, the second end of resistor R1 is connected to the non-inverting input end of operational amplifier U1, the second end of resistor R2 is connected to the inverting input end of operational amplifier U1, the first end of resistor R3 is grounded, the second end of resistor R3 is connected to the non-inverting input end of operational amplifier U1, the first end of resistor R4 is connected to the inverting input end of operational amplifier U1, the second end of resistor R4 is connected to the output end of operational amplifier U1, and the first end of resistor R5 is connected to the output end of operational amplifier U1.

[0013] Preferably, the bandpass filter unit includes a resistor R6, a resistor R7, a capacitor C1, a capacitor C2, a resistor R8, an operational amplifier U2, a resistor R9, a resistor R10, a capacitor C3, a capacitor C4, a resistor R11, an operational amplifier U3, a resistor R12, a resistor R13, a capacitor C5, a capacitor C6, a resistor R14, an operational amplifier U4, a resistor R15, a resistor R16, a capacitor C7, a capacitor C8, a resistor R17 and an operational amplifier U5;

[0014] A first end of resistor R6 is connected to the second end of resistor R5, a second end of resistor R6 is connected to the first end of capacitor C1, a second end of capacitor C1 is connected to the inverting input end of operational amplifier U2, a first end of resistor R7 is connected to the second end of resistor R6, a second end of resistor R7 is grounded, a first end of capacitor C2 is connected to the second end of resistor R6, a second end of capacitor C2 is connected to the output end of operational amplifier U2, a first end of resistor R8 is connected to the inverting input end of operational amplifier U2, a second end of resistor R8 is connected to the output end of operational amplifier U2, and a non-inverting input end of operational amplifier U2 is grounded;

[0015] A first end of the resistor R9 is connected to the output terminal of the operational amplifier U2, a second end of the resistor R9 is connected to the first end of the capacitor C3, a second end of the capacitor C3 is connected to the inverting input terminal of the operational amplifier U3, a first end of the resistor R10 is connected to the second end of the resistor R9, a second end of the resistor R10 is grounded, a first end of the capacitor C4 is connected to the second end of the resistor R9, a second end of the capacitor C4 is connected to the output terminal of the operational amplifier U3, a first end of the resistor R11 is connected to the inverting input terminal of the operational amplifier U3, a second end of the resistor R11 is connected to the output terminal of the operational amplifier U3, and a non-inverting input terminal of the operational amplifier U3 is grounded;

[0016] A first end of the resistor R12 is connected to the output terminal of the operational amplifier U3, a second end of the resistor R12 is connected to the first end of the capacitor C5, a second end of the capacitor C5 is connected to the inverting input terminal of the operational amplifier U4, a first end of the resistor R13 is connected to the second end of the resistor R12, a second end of the resistor R13 is grounded, a first end of the capacitor C6 is connected to the second end of the resistor R12, a second end of the capacitor C6 is connected to the output terminal of the operational amplifier U4, a first end of the resistor R14 is connected to the inverting input terminal of the operational amplifier U4, a second end of the resistor R14 is connected to the output terminal of the operational amplifier U4, and a non-inverting input terminal of the operational amplifier U4 is grounded;

[0017] The first end of resistor R15 is connected to the output end of operational amplifier U4, the second end of resistor R15 is connected to the first end of capacitor C7, the second end of capacitor C7 is connected to the inverting input end of operational amplifier U5, the first end of resistor R16 is connected to the second end of resistor R15, the second end of resistor R16 is grounded, the first end of capacitor C8 is connected to the second end of resistor R15, the second end of capacitor C8 is connected to the output end of operational amplifier U5, the first end of resistor R17 is connected to the inverting input end of operational amplifier U5, the second end of resistor R17 is connected to the output end of operational amplifier U5, and the non-inverting input end of operational amplifier U5 is grounded.

[0018] Preferably, the post-amplification unit includes a resistor R18, a resistor R19, a resistor R20 and an operational amplifier U6;

[0019] The first end of resistor R18 is connected to the output end of operational amplifier U5, the second end of resistor R18 is connected to the non-inverting input end of operational amplifier U6, the first end of resistor R19 is connected to the inverting input end of operational amplifier U6, the second end of resistor R19 is grounded, the first end of resistor R20 is connected to the inverting input end of operational amplifier U6, and the second end of resistor R20 is connected to the output end of operational amplifier U6.

[0020] Preferably, the analog-to-digital conversion unit includes an analog-to-digital conversion chip U7, the input end of the analog-to-digital conversion chip U7 is connected to the output end of the operational amplifier U6, and the output end of the analog-to-digital conversion chip U7 is correspondingly connected to the input end of the data processing chip U8.

[0021] These four settings form a progressive signal optimization processing chain. The preamplifier unit uses a differential amplification design to suppress common-mode interference while accurately capturing weak initial voltage signals. The bandpass filter unit adopts an eighth-order MFB bandpass filter based on the Butterworth type. Compared with simple filtering circuits, the steeper roll-off characteristics can filter out interference to the maximum extent and ensure signal purity. The post-amplifier unit performs compensatory amplification for the attenuation of the filtered signal, flexibly matching the input range of the analog-to-digital conversion chip to avoid signal overflow or accuracy loss. The analog-to-digital conversion unit realizes seamless conversion of analog signals to digital signals, and the high-resolution conversion process can fully retain the signal characteristics.

[0022] Preferably, it further comprises a display module and a communication module, and both the display module and the communication module are signal-connected to the data processing module.

[0023] In this setting, the display module presents key parameters such as current waveforms and imbalance values ​​through real-time visualization, allowing on-site operation and maintenance personnel to quickly determine the status of the track circuit without relying on professional equipment, shortening the time for initial fault investigation; the communication module supports real-time transmission of data to the control center, and uses standardized communication protocols to achieve seamless connection with the railway integrated monitoring system, making it easier for managers to centrally control multiple monitoring points and trace historical data.

[0024] Preferably, an alarm module is further included, the alarm module including a power supply VCC, a resistor R21, a resistor R22, a switch tube Q1, a resistor R23, an indicator light L, a resistor R24, a resistor R25, a switch tube Q2, a resistor R26 and a buzzer BL, wherein the switch tube Q1 and the switch tube Q2 are both PNP transistors;

[0025] A first end of resistor R21 and a first end of resistor R24 ​​are connected to different output ports of data processing chip U8 respectively. A second end of resistor R21 is connected to the base of switch tube Q1. The emitter of switch tube Q1 is connected to power supply VCC. The collector of switch tube Q1 is connected to a first end of resistor R23. A second end of resistor R23 is connected to a first end of indicator light L. The second end of indicator light L is grounded. A first end of resistor R22 is connected to power supply VCC. A second end of resistor R22 is connected to the second end of resistor R21.

[0026] The second end of resistor R24 ​​is connected to the base of switch tube Q2, the emitter of switch tube Q2 is connected to power supply VCC, the collector of switch tube Q2 is connected to the first end of resistor R26, the second end of resistor R26 is connected to the first end of buzzer BL, the second end of buzzer BL is grounded, the first end of resistor R25 is connected to power supply VCC, and the second end of resistor R25 is connected to the second end of resistor R24.

[0027] In this setting, the indicator light can intuitively convey the fault level through a constant light or flashing mode, and the buzzer emits sounds of differentiated frequencies to distinguish between general warnings and emergency alarms, avoiding the risk of omissions that may occur with a single warning method.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. This utility model uses a multi-stage processing flow of pre-amplification, band-pass filtering, post-amplification and analog-to-digital conversion to first amplify the weak signal, then band-pass filter the interference signal, and finally undergo secondary amplification and analog-to-digital conversion, thereby greatly improving the signal-to-noise ratio and accuracy of the signal, and providing high-quality digital signals for subsequent data processing.

[0030] 2. The utility model can intuitively display current data, imbalance index and other information through the display module, which is convenient for on-site personnel to grasp the status in real time. It also realizes remote data transmission through the communication module and can send the monitoring results to the control center, supporting remote monitoring and data archiving, and improving operation and maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0032] Figure 2 This is a circuit diagram of the signal conditioning module in the utility model;

[0033] Figure 3 This is a circuit diagram of the preamplifier unit in the utility model;

[0034] Figure 4 This is a circuit diagram of the bandpass filter unit in the utility model;

[0035] Figure 5 This is a circuit diagram of the post-amplification unit in the utility model;

[0036] Figure 6 It is a schematic diagram of the partial structure of the utility model;

[0037] Figure 7 This is a circuit diagram of the alarm module in the utility model;

[0038] In the picture:

[0039] 100. Current acquisition module;

[0040] 200, signal conditioning module; 201, preamplifier unit; 202, bandpass filter unit; 203, postamplifier unit; 204, analog-to-digital conversion unit;

[0041] 300. Data processing module;

[0042] 400, display module;

[0043] 500, communication module;

[0044] 600. Alarm module. DETAILED DESCRIPTION

[0045] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] See also Figure 1-Figure 7 , this utility model provides a technical solution:

[0047] 25Hz phase-sensitive track circuit traction current imbalance monitoring system, including:

[0048] Current acquisition module 100: This module is located at the power transmission and receiving ends of the rail and is used to collect the traction current signal in the rail in real time. The current acquisition module 100 includes several current transformers, which are coupled to the secondary side of the choke transformer to sense the unbalanced current and convert it into a voltage signal.

[0049] Several signal conditioning modules 200 are respectively configured at the rear stage of each current transformer, and include a preamplifier unit 201, a bandpass filter unit 202, a postamplifier unit 203, and an analog-to-digital converter unit 204, which are electrically connected in sequence. The preamplifier unit 201 is used to initially amplify the signal, the bandpass filter unit 202 is used to filter out interference signals in the traction current signal, the postamplifier unit 203 is used to further amplify the filtered signal, and the analog-to-digital converter unit 204 is used to convert the analog signal into a digital signal.

[0050] Data processing module 300: configured in the post-stage of several signal conditioning modules 200, including data processing chip U8, used to calculate the amplitude difference and phase difference of the two-rail current signals. The amplitude difference is obtained by calculating the peak value of the two-rail current, and the phase difference is calculated by Fourier transform. The amplitude difference and phase difference are compared with the internal preset amplitude difference threshold and phase difference threshold, and an imbalance index is generated. The imbalance index is generated using weighting, and different weights are assigned to the amplitude difference and phase difference, for example, both are 50%;

[0051] The current acquisition module 100 senses the unbalanced current of the rail in real time and converts it into a voltage signal. Combined with the multi-level processing of the signal conditioning module 200, the data processing module 300 finally calculates the amplitude difference and phase difference of the current on the two rails and generates an imbalance index. The overall process greatly improves the signal-to-noise ratio and accuracy of the signal, providing high-quality data support for the precise monitoring of the unbalanced state of the traction current in the track circuit, solving the problem of misjudgment caused by poor signal quality in traditional monitoring, ensuring the accuracy of train occupancy detection, and improving railway driving safety.

[0052] In this embodiment, please refer to Figures 1-6 The preamplifier unit 201 includes resistors R1, R2, R3, R4, an operational amplifier U1, and R5. The operational amplifier U1 and its surrounding components constitute a differential amplifier circuit, which can initially amplify the weak initial voltage signal, thereby enhancing the effective signal strength in the early stages of signal processing and preventing the signal from being covered by noise during subsequent filtering and conversion. This lays a good foundation for the entire signal conditioning process and ensures that the weak unbalanced current signal can be effectively retained and transmitted.

[0053] The first end of resistor R1 and the first end of resistor R2 are connected to the two output ends of the current transformer respectively, the second end of resistor R1 is connected to the non-inverting input end of operational amplifier U1, the second end of resistor R2 is connected to the inverting input end of operational amplifier U1, the first end of resistor R3 is grounded, the second end of resistor R3 is connected to the non-inverting input end of operational amplifier U1, the first end of resistor R4 is connected to the inverting input end of operational amplifier U1, the second end of resistor R4 is connected to the output end of operational amplifier U1, and the first end of resistor R5 is connected to the output end of operational amplifier U1.

[0054] Specifically, the bandpass filter unit 202 includes a resistor R6, a resistor R7, a capacitor C1, a capacitor C2, a resistor R8, an operational amplifier U2, a resistor R9, a resistor R10, a capacitor C3, a capacitor C4, a resistor R11, an operational amplifier U3, a resistor R12, a resistor R13, a capacitor C5, a capacitor C6, a resistor R14, an operational amplifier U4, a resistor R15, a resistor R16, a capacitor C7, a capacitor C8, a resistor R17 and an operational amplifier U5. The bandpass filter unit 202 is an eighth-order MFB bandpass filter based on a Butterworth type. Compared with a simpler bandpass filter circuit, increasing the order can narrow the transition band of the filter and improve the filtering performance. The center frequency of the bandpass filter unit 202 is 25 Hz, and the bandwidth is typically 2 Hz-5 Hz, which can filter out interference signals at most.

[0055] A first end of resistor R6 is connected to the second end of resistor R5, a second end of resistor R6 is connected to the first end of capacitor C1, a second end of capacitor C1 is connected to the inverting input end of operational amplifier U2, a first end of resistor R7 is connected to the second end of resistor R6, a second end of resistor R7 is grounded, a first end of capacitor C2 is connected to the second end of resistor R6, a second end of capacitor C2 is connected to the output end of operational amplifier U2, a first end of resistor R8 is connected to the inverting input end of operational amplifier U2, a second end of resistor R8 is connected to the output end of operational amplifier U2, and a non-inverting input end of operational amplifier U2 is grounded;

[0056] A first end of the resistor R9 is connected to the output terminal of the operational amplifier U2, a second end of the resistor R9 is connected to the first end of the capacitor C3, a second end of the capacitor C3 is connected to the inverting input terminal of the operational amplifier U3, a first end of the resistor R10 is connected to the second end of the resistor R9, a second end of the resistor R10 is grounded, a first end of the capacitor C4 is connected to the second end of the resistor R9, a second end of the capacitor C4 is connected to the output terminal of the operational amplifier U3, a first end of the resistor R11 is connected to the inverting input terminal of the operational amplifier U3, a second end of the resistor R11 is connected to the output terminal of the operational amplifier U3, and a non-inverting input terminal of the operational amplifier U3 is grounded;

[0057] A first end of the resistor R12 is connected to the output terminal of the operational amplifier U3, a second end of the resistor R12 is connected to the first end of the capacitor C5, a second end of the capacitor C5 is connected to the inverting input terminal of the operational amplifier U4, a first end of the resistor R13 is connected to the second end of the resistor R12, a second end of the resistor R13 is grounded, a first end of the capacitor C6 is connected to the second end of the resistor R12, a second end of the capacitor C6 is connected to the output terminal of the operational amplifier U4, a first end of the resistor R14 is connected to the inverting input terminal of the operational amplifier U4, a second end of the resistor R14 is connected to the output terminal of the operational amplifier U4, and a non-inverting input terminal of the operational amplifier U4 is grounded;

[0058] The first end of resistor R15 is connected to the output end of operational amplifier U4, the second end of resistor R15 is connected to the first end of capacitor C7, the second end of capacitor C7 is connected to the inverting input end of operational amplifier U5, the first end of resistor R16 is connected to the second end of resistor R15, the second end of resistor R16 is grounded, the first end of capacitor C8 is connected to the second end of resistor R15, the second end of capacitor C8 is connected to the output end of operational amplifier U5, the first end of resistor R17 is connected to the inverting input end of operational amplifier U5, the second end of resistor R17 is connected to the output end of operational amplifier U5, and the non-inverting input end of operational amplifier U5 is grounded.

[0059] Furthermore, the post-amplification unit 203 includes resistors R18, R19, R20, and an operational amplifier U6, which amplify the signal again. The operational amplifier U6 and its surrounding components constitute a common-mode amplifier circuit. Since the filtering process may cause signal amplitude attenuation, the post-amplification can specifically enhance the amplitude of the effective signal to reach the optimal input range of the analog-to-digital conversion unit 204, thereby avoiding the problem of reduced conversion accuracy due to too low signal amplitude, further improving the overall accuracy of signal processing, and providing a more reliable digital signal source for accurate calculation of the data processing module 300.

[0060] The first end of resistor R18 is connected to the output end of operational amplifier U5, the second end of resistor R18 is connected to the non-inverting input end of operational amplifier U6, the first end of resistor R19 is connected to the inverting input end of operational amplifier U6, the second end of resistor R19 is grounded, the first end of resistor R20 is connected to the inverting input end of operational amplifier U6, and the second end of resistor R20 is connected to the output end of operational amplifier U6.

[0061] In addition, the analog-to-digital conversion unit 204 includes an analog-to-digital conversion chip U7, the input end of the analog-to-digital conversion chip U7 is connected to the output end of the operational amplifier U6, and the output end of the analog-to-digital conversion chip U7 is correspondingly connected to the input end of the data processing chip U8, thereby realizing high-precision conversion of analog signals to digital signals, ensuring the integrity of information during the digitization process of the signal, facilitating the data processing module 300 to perform quantitative calculations on the digital signal, providing an accurate digital basis for the generation of the imbalance index, and avoiding the defect that the analog signal is susceptible to interference during transmission and calculation.

[0062] In this embodiment, please refer to Figure 1 and Figure 6 , also includes a display module 400 and a communication module 500. The display module 400 usually uses a display screen U9, and the communication module 500 usually uses a communication chip U10, which can be a wireless communication chip such as a 4G chip or a 5G chip. The display module 400 and the communication module 500 are both connected to the data processing module 300 by signal. The display module 400 enables the imbalance index, current signal parameters and other information generated by the data processing module 300 to be intuitively presented through the display module 400, making it convenient for on-site operation and maintenance personnel to grasp the track circuit status in real time, and remotely transmit it to the control center through the communication module 500 to realize remote storage, analysis and centralized management of monitoring data.

[0063] In this embodiment, please refer to Figure 1 and Figure 7, also includes an alarm module 600, which includes a power supply VCC, a resistor R21, a resistor R22, a switch tube Q1, a resistor R23, an indicator light L, a resistor R24, a resistor R25, a switch tube Q2, a resistor R26 and a buzzer BL. The switch tubes Q1 and Q2 are both PNP-type transistors, which can synchronously trigger light warnings and sound alarms to promptly alert on-site personnel or a remote monitoring center that there are abnormalities in the track circuit, shorten the response time for fault discovery and troubleshooting, and avoid the track circuit from misjudging the train occupancy status due to long-term current imbalance, thereby effectively reducing driving safety risks and ensuring the stable operation of the railway signal system;

[0064] A first end of resistor R21 and a first end of resistor R24 ​​are connected to different output ports of data processing chip U8 respectively. A second end of resistor R21 is connected to the base of switch tube Q1. The emitter of switch tube Q1 is connected to power supply VCC. The collector of switch tube Q1 is connected to a first end of resistor R23. A second end of resistor R23 is connected to a first end of indicator light L. The second end of indicator light L is grounded. A first end of resistor R22 is connected to power supply VCC. A second end of resistor R22 is connected to the second end of resistor R21.

[0065] The second end of resistor R24 ​​is connected to the base of switch tube Q2, the emitter of switch tube Q2 is connected to power supply VCC, the collector of switch tube Q2 is connected to the first end of resistor R26, the second end of resistor R26 is connected to the first end of buzzer BL, the second end of buzzer BL is grounded, the first end of resistor R25 is connected to power supply VCC, and the second end of resistor R25 is connected to the second end of resistor R24.

[0066] When the 25Hz phase-sensitive track circuit traction current imbalance monitoring system of the present invention is in use, the current acquisition module 100 senses the traction current imbalance signal in the two rails in real time through the current transformers configured at the power supply end and the power receiving end of the rail, and converts it into a weak voltage signal;

[0067] The voltage signal enters the preamplifier unit 201 of the signal conditioning module 200, where the differential amplifier circuit formed by the operational amplifier U1 performs initial amplification on the weak signal to enhance the effective signal strength. The amplified signal enters the bandpass filter unit 202, where interference signals are filtered out by a four-stage filter circuit. The filtered signal is amplified again by the postamplifier unit 203, where the in-phase amplifier circuit formed by the operational amplifier U6 further increases the signal amplitude to meet the subsequent analog-to-digital conversion requirements. The analog-to-digital conversion chip U7 of the analog-to-digital conversion unit 204 converts the processed analog signal into a digital signal and transmits it to the data processing module 300.

[0068] The data processing chip U8 of the data processing module 300 receives the digital signal, calculates the amplitude difference and phase difference of the two rail currents, obtains them by peak value calculation and Fourier transform respectively, compares them with the internal preset amplitude difference threshold and phase difference threshold respectively, and generates the imbalance index according to the preset weight;

[0069] The display module 400 receives signals from the data processing module 300 and displays information such as current parameters and imbalance indicators in real time for easy on-site viewing. The communication module 500 transmits data to the control center to support remote monitoring and data archiving.

[0070] If the imbalance exceeds the standard, the data processing module 300 triggers the alarm module 600, the indicator light L lights up, and a light warning is issued, or a PWM signal is sent through the data processing chip U8 to make the indicator light L flash, and the buzzer BL is started to issue an audible alarm, prompting the operation and maintenance personnel to deal with it in time.

[0071] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. 25Hz phase-sensitive track circuit traction current imbalance monitoring system, characterized by: include: A current acquisition module (100) is configured at the power transmission end and the power receiving end of the rail and is used to collect the traction current signal in the rail in real time. The current acquisition module (100) includes a plurality of current transformers, which are coupled to the secondary side of the choke transformer and are used to sense the unbalanced current and convert it into a voltage signal. A plurality of signal conditioning modules (200): respectively configured at the rear stage of each current transformer, comprising a preamplifier unit (201), a bandpass filter unit (202), a postamplifier unit (203) and an analog-to-digital conversion unit (204) electrically connected in sequence, wherein the preamplifier unit (201) is used for initially amplifying the signal, the bandpass filter unit (202) is used for filtering out interference signals in the traction current signal, the postamplifier unit (203) is used for re-amplifying the filtered signal, and the analog-to-digital conversion unit (204) is used for converting the analog signal into a digital signal; A data processing module (300) is configured at the rear stage of the plurality of signal conditioning modules (200), and includes a data processing chip U8, and is used to calculate the amplitude difference and phase difference of the two-rail current signals and generate an imbalance index.

2. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 1 is characterized in that: The preamplifier unit (201) comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, an operational amplifier U1, and a resistor R5; The first end of resistor R1 and the first end of resistor R2 are connected to the two output ends of the current transformer respectively, the second end of resistor R1 is connected to the non-inverting input end of operational amplifier U1, the second end of resistor R2 is connected to the inverting input end of operational amplifier U1, the first end of resistor R3 is grounded, the second end of resistor R3 is connected to the non-inverting input end of operational amplifier U1, the first end of resistor R4 is connected to the inverting input end of operational amplifier U1, the second end of resistor R4 is connected to the output end of operational amplifier U1, and the first end of resistor R5 is connected to the output end of operational amplifier U1.

3. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 2 is characterized in that: The bandpass filter unit (202) comprises a resistor R6, a resistor R7, a capacitor C1, a capacitor C2, a resistor R8, an operational amplifier U2, a resistor R9, a resistor R10, a capacitor C3, a capacitor C4, a resistor R11, an operational amplifier U3, a resistor R12, a resistor R13, a capacitor C5, a capacitor C6, a resistor R14, an operational amplifier U4, a resistor R15, a resistor R16, a capacitor C7, a capacitor C8, a resistor R17 and an operational amplifier U5; A first end of resistor R6 is connected to the second end of resistor R5, a second end of resistor R6 is connected to the first end of capacitor C1, a second end of capacitor C1 is connected to the inverting input end of operational amplifier U2, a first end of resistor R7 is connected to the second end of resistor R6, a second end of resistor R7 is grounded, a first end of capacitor C2 is connected to the second end of resistor R6, a second end of capacitor C2 is connected to the output end of operational amplifier U2, a first end of resistor R8 is connected to the inverting input end of operational amplifier U2, a second end of resistor R8 is connected to the output end of operational amplifier U2, and a non-inverting input end of operational amplifier U2 is grounded; A first end of the resistor R9 is connected to the output terminal of the operational amplifier U2, a second end of the resistor R9 is connected to the first end of the capacitor C3, a second end of the capacitor C3 is connected to the inverting input terminal of the operational amplifier U3, a first end of the resistor R10 is connected to the second end of the resistor R9, a second end of the resistor R10 is grounded, a first end of the capacitor C4 is connected to the second end of the resistor R9, a second end of the capacitor C4 is connected to the output terminal of the operational amplifier U3, a first end of the resistor R11 is connected to the inverting input terminal of the operational amplifier U3, a second end of the resistor R11 is connected to the output terminal of the operational amplifier U3, and a non-inverting input terminal of the operational amplifier U3 is grounded; A first end of the resistor R12 is connected to the output terminal of the operational amplifier U3, a second end of the resistor R12 is connected to the first end of the capacitor C5, a second end of the capacitor C5 is connected to the inverting input terminal of the operational amplifier U4, a first end of the resistor R13 is connected to the second end of the resistor R12, a second end of the resistor R13 is grounded, a first end of the capacitor C6 is connected to the second end of the resistor R12, a second end of the capacitor C6 is connected to the output terminal of the operational amplifier U4, a first end of the resistor R14 is connected to the inverting input terminal of the operational amplifier U4, a second end of the resistor R14 is connected to the output terminal of the operational amplifier U4, and a non-inverting input terminal of the operational amplifier U4 is grounded; The first end of resistor R15 is connected to the output end of operational amplifier U4, the second end of resistor R15 is connected to the first end of capacitor C7, the second end of capacitor C7 is connected to the inverting input end of operational amplifier U5, the first end of resistor R16 is connected to the second end of resistor R15, the second end of resistor R16 is grounded, the first end of capacitor C8 is connected to the second end of resistor R15, the second end of capacitor C8 is connected to the output end of operational amplifier U5, the first end of resistor R17 is connected to the inverting input end of operational amplifier U5, the second end of resistor R17 is connected to the output end of operational amplifier U5, and the non-inverting input end of operational amplifier U5 is grounded.

4. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 3 is characterized by: The post-amplification unit (203) comprises a resistor R18, a resistor R19, a resistor R20 and an operational amplifier U6; The first end of resistor R18 is connected to the output end of operational amplifier U5, the second end of resistor R18 is connected to the non-inverting input end of operational amplifier U6, the first end of resistor R19 is connected to the inverting input end of operational amplifier U6, the second end of resistor R19 is grounded, the first end of resistor R20 is connected to the inverting input end of operational amplifier U6, and the second end of resistor R20 is connected to the output end of operational amplifier U6.

5. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 4 is characterized in that: The analog-to-digital conversion unit (204) comprises an analog-to-digital conversion chip U7, the input end of the analog-to-digital conversion chip U7 is connected to the output end of the operational amplifier U6, and the output end of the analog-to-digital conversion chip U7 is correspondingly connected to the input end of the data processing chip U8.

6. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 1 is characterized in that: It also includes a display module (400) and a communication module (500), and both the display module (400) and the communication module (500) are connected to the data processing module (300) via signals.

7. The 25Hz phase-sensitive track circuit traction current imbalance monitoring system according to claim 1 is characterized by: It also includes an alarm module (600), the alarm module (600) including a power supply VCC, a resistor R21, a resistor R22, a switch tube Q1, a resistor R23, an indicator light L, a resistor R24, a resistor R25, a switch tube Q2, a resistor R26 and a buzzer BL, wherein the switch tube Q1 and the switch tube Q2 are both PNP-type triodes; A first end of resistor R21 and a first end of resistor R24 ​​are connected to different output ports of data processing chip U8 respectively. A second end of resistor R21 is connected to the base of switch tube Q1. The emitter of switch tube Q1 is connected to power supply VCC. The collector of switch tube Q1 is connected to a first end of resistor R23. A second end of resistor R23 is connected to a first end of indicator light L. The second end of indicator light L is grounded. A first end of resistor R22 is connected to power supply VCC. A second end of resistor R22 is connected to the second end of resistor R21. The second end of resistor R24 ​​is connected to the base of switch tube Q2, the emitter of switch tube Q2 is connected to power supply VCC, the collector of switch tube Q2 is connected to the first end of resistor R26, the second end of resistor R26 is connected to the first end of buzzer BL, the second end of buzzer BL is grounded, the first end of resistor R25 is connected to power supply VCC, and the second end of resistor R25 is connected to the second end of resistor R24.

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