Track current balance monitoring device

Abstract

The utility model relates to the technical field of track circuit fault monitoring, and discloses a track current balance monitoring device, which comprises a housing, and a power supply module, a signal acquisition unit and a signal processing unit are respectively arranged in the housing. A current sensor CT1 and a current sensor CT2 which are used for acquiring current signals are connected to the position, close to the signal acquisition unit, of the housing through wires, and a power-taking current transformer CT3 which is used for charging the battery is connected to the position, close to the power module, of the housing through a wire. Through the design of the current sensor CT1 and the current sensor CT2, current signals can be obtained in real time, online monitoring is achieved, insulation abnormity of track circuit equipment and track insulation is found in time, and off-line detection can be carried out without interrupting operation of a track circuit; by calculating the magnitude of two paths of current signals and carrying out quantitative comparison, insulation abnormity is visually presented through flickering of an alarm lamp, and the insulation damage condition is accurately estimated.

Description

Technical Field

[0001] This utility model relates to the field of track circuit fault monitoring technology, specifically a track current balance monitoring device. Background Technology

[0002] Most train operation failures in the electrical system are caused by turnout and track circuit failures, and most track circuit failures are caused by insulation damage, track bed leakage (reduced track circuit impedance), and poor contact of the plug connection wire.

[0003] Most track insulation damage is caused by electrochemical corrosion, chemical power source effect, mechanical displacement, etc. Track insulation includes various types of track insulation such as rail end insulation, turnout installation device insulation, and gauge rod insulation. In the daily maintenance of railway signaling equipment, it is necessary to judge the track insulation performance.

[0004] A search revealed that patent application number CN202120225556.6 discloses a DC leakage current monitoring system for rail transit, including a leakage current measurement circuit, an MCU processing unit, and an alarm module. The input of the leakage current measurement circuit is connected to the positive and negative terminals of the secondary DC power supply system of the EMU, and the output is connected to the AD sampling channel of the MCU processing unit. The MCU processing unit communicates with the alarm module, processes the sampled values ​​from the AD sampling channel according to a proportional algorithm, makes a comprehensive judgment based on the calculation results, and then transmits the judgment result to the alarm module. The alarm module reports faults and issues alarms based on real-time faults. Through this method, the utility model of the DC leakage current monitoring system for rail transit can effectively solve the balance problem of non-resistive loads and dynamic systems. Based on the proportional method detection, it achieves accurate real-time monitoring and alarm functions for abnormal leakage current, and its application in actual rail transit products has been successful.

[0005] Currently, the main method to determine the insulation quality of the track circuit equipment at both ends of the track insulation and the track insulation itself is by measuring the track voltage (comparison method). However, multimeters or megohmmeters cannot directly measure and estimate the insulation damage online. Therefore, we need to propose a track current balance monitoring device. Utility Model Content

[0006] The purpose of this invention is to provide a track current balance monitoring device. Through the design of current sensors CT1 and CT2, current signals can be acquired in real time to achieve online monitoring and timely detection of insulation abnormalities in track circuit equipment and track insulation without interrupting track circuit operation for offline testing. By calculating the magnitude of the two current signals and performing quantitative comparison, the insulation abnormality is visually presented through the flashing of an alarm light, and the insulation damage is accurately estimated, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a track current balance monitoring device, including a housing, inside which a power module, a signal acquisition unit, and a signal processing unit are respectively installed. A current sensor CT1 and a current sensor CT2 for acquiring current signals are connected to the housing near the signal acquisition unit via wires. A current transformer CT3 for charging a battery is connected to the housing near the power module via wires. An alarm unit for alerting the threshold value of the current difference between the two circuits is also provided on the housing.

[0008] Preferably, the housing is provided with two signal input ports, which are respectively connected to current sensor CT1 and current sensor CT2.

[0009] Preferably, a power interface is provided on the housing near the power module, and the current transformer CT3 is connected to the power interface via a wire.

[0010] Preferably, the alarm unit includes a first alarm light and a second alarm light. When the current value obtained by the current sensor CT2 is greater than twice the current value obtained by the current sensor CT1, the first alarm light flashes.

[0011] When the current value obtained by the current sensor CT1 is greater than twice the current value obtained by the current sensor CT2, the second alarm light flashes.

[0012] Preferably, the housing is also provided with a reserved communication interface for transmitting signals to the main control and monitoring computer.

[0013] Preferably, the current sensor CT1 includes a chip U29, a capacitor C110 is connected between pins 5 and 6 of the chip U29, a capacitor C109 is connected between pins 5 and 8 of the chip U29, and a resistor R65 and a capacitor C111 are connected in series on pin 7 of the chip U29.

[0014] Preferably, the current transformer CT3 includes a chip U4, with a resistor R21 connected between pins 1 and 2 of the chip U4, a resistor R22 connected to pin 2 of the chip U4, a resistor R24 ​​connected to pin 3 of the chip U4, pin 4 of the chip U4 connected to a negative 12V power supply, and pin 8 of the chip U4 connected to a positive 12V power supply.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. Through the design of current sensor CT1 and current sensor CT2, this utility model can acquire current signals in real time, realize online monitoring, and promptly detect insulation abnormalities of track circuit equipment and track insulation without interrupting track circuit operation for offline testing;

[0017] 2. This utility model calculates the magnitude of two current signals and performs quantitative comparison, visually presenting insulation abnormalities through the flashing of an alarm light, and accurately estimating the extent of insulation damage.

[0018] 3. This utility model has a built-in energy storage battery and an external current transformer. It can be charged when a train passes by and there is a current of about 250A on the power line. No additional complex power supply system is required, so it can achieve self-powering and improve the independence and adaptability of the device. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the wireless communication of this utility model;

[0021] Figure 3 This is a top view of the present invention;

[0022] Figure 4 This is a side view of the present invention;

[0023] Figure 5 This is the circuit diagram of the current sensor of this utility model;

[0024] Figure 6 This is the circuit diagram of the current transformer for power extraction according to this utility model. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figure 1-6 This utility model provides a technical solution: a track current balance monitoring device, which can detect the current of two transmission lines in real time, calculate the magnitude of the two current signals, and issue an alarm based on the set threshold of the difference between the two currents.

[0027] The device includes a housing, inside which a power module, a signal acquisition unit, and a signal processing unit are installed. Near the signal acquisition unit on the housing, current sensors CT1 and CT2 for acquiring current signals are connected by wires. Near the power module on the housing, a current transformer CT3 for charging the battery is connected by wires. The housing also has an alarm unit for alerting the threshold of the current difference between the two circuits.

[0028] The normal current of the power line between current sensor CT1, current sensor CT2 and the signal input port is about 0.1A~3A (25Hz), and the current is about 250A when a train passes by.

[0029] The housing has two signal input ports, which are connected to current sensor CT1 and current sensor CT2 respectively.

[0030] A power interface is located on the casing near the power module, and the current transformer CT3 is connected to the power interface via a wire.

[0031] The alarm unit includes alarm light one and alarm light two. When the current value obtained by current sensor CT2 is greater than twice the current value obtained by current sensor CT1, alarm light one flashes.

[0032] When the current value obtained by current sensor CT1 is greater than twice the current value obtained by current sensor CT2, the second alarm light will flash.

[0033] The enclosure also has a reserved communication interface for transmitting signals to the main control and monitoring computer. The communication method is similar to signal transmission from beacon towers, relaying signals one by one until they reach the main control and monitoring computer.

[0034] Two current signals are obtained by current sensors CT1 and CT2 installed on the conductor. The device detects and calculates the magnitude of the current signals. The overload capacity of the current sensors (CT1 and CT2) must reach 300A.

[0035] Calculate the magnitudes i1 and i2 of the two current signals. When i2 > 2 * i1, alarm light 2 flashes; when i1 > 2 * i2, alarm light 1 flashes; simultaneously, the device operation light is activated; (i1 is the current value on current sensor CT1, and i2 is the current value on current sensor CT2)

[0036] When a train passes by, if there is a current of about 250A on the power line connected to the power interface, the battery will be charged through the current transformer CT3.

[0037] The current sensor CT1 includes a chip U29. A capacitor C110 is connected between pins 5 and 6 of the chip U29, a capacitor C109 is connected between pins 5 and 8 of the chip U29, and a resistor R65 and a capacitor C111 are connected in series on pin 7 of the chip U29.

[0038] Chip U29 is used to measure current and convert the passing AC or DC current into a proportional voltage output; resistor R65 serves to limit current and divide voltage, and specifically in this circuit, it is used to adjust the amplitude of the sensor output signal so that it meets the input requirements of the subsequent circuit.

[0039] Capacitors C109 and C111 act as filters, removing high-frequency noise from the power supply, making the power supply to chip U29 more stable and improving measurement accuracy. Capacitor C110 is a filter capacitor for a specific pin (FILT pin) of chip U29, used to further stabilize the operating state of the internal signal processing circuitry of chip U29.

[0040] Chip U29 receives the measured current signal (I_A, I+B, IA, IB) through pins 1, 2 and 3, 4 respectively. The internal circuit processes the current and then outputs a voltage signal proportional to the input current from the VO pin (pin 7). The power supply is filtered by capacitors C109, C110 and C111 before supplying power to chip U29, ensuring stable operation of chip U29.

[0041] After passing through resistor R65, the output signal is output as a HEAT_CUR signal, which is then processed and analyzed by subsequent circuits (such as the ADC acquisition port of the microcontroller) to calculate the actual current value.

[0042] The current transformer CT3 includes a chip U4. A resistor R21 is connected between pins 1 and 2 of chip U4. A resistor R22 is connected to pin 2 of chip U4. A resistor R24 ​​is connected to pin 3 of chip U4. Pin 4 of chip U4 is connected to a negative 12V power supply. Pin 8 of chip U4 is connected to a positive 12V power supply.

[0043] Resistors R21 and R22 form a feedback network, with R21 being the feedback resistor and R22 the input resistor. Together, they determine the operational amplifier's gain. Resistor R24 ​​is the bias resistor at the inverting input terminal, its function being to ensure that the input bias current of the operational amplifier is equal at both input terminals, thereby reducing errors caused by the input bias current. Its value is typically chosen to be equal to or close to the input resistance (R22) to achieve better balance.

[0044] The input signal is input from the left end of resistor R22 to the inverting input terminal (pin 2) of chip U4. The non-inverting input terminal (pin 3) is grounded through resistor R24.

[0045] Based on the "virtual short" and "virtual open" characteristics of chip U4, the voltages at the inverting and non-inverting input terminals are approximately equal (virtual short), and the current flowing into the input terminal of chip U4 is approximately 0 (virtual open).

[0046] The input signal is amplified by the feedback network composed of resistors R21 and R22. The amplified signal is output from pin 1 (OUT1). The output signal AOUT is out of phase with the input signal and amplified according to the set gain.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rail current balance monitoring device comprising a housing, characterised in that: The housing contains a power module, a signal acquisition unit, and a signal processing unit. A current sensor CT1 and a current sensor CT2 for acquiring current signals are connected to the housing near the signal acquisition unit via wires. A current transformer CT3 for charging the battery is connected to the housing near the power module via wires. An alarm unit for alerting the threshold of the current difference between the two circuits is also provided on the housing.

2. The rail current balance monitoring device according to claim 1, characterized in that: The housing is provided with two signal input ports, which are respectively connected to current sensor CT1 and current sensor CT2.

3. The rail current balance monitoring device according to claim 1, characterized in that: A power interface is provided on the housing near the power module, and the current transformer CT3 is connected to the power interface via a wire.

4. The rail current balance monitoring apparatus according to claim 1, characterized by: The alarm unit includes a signal alarm light one and a signal alarm light two. When the current value obtained by the current sensor CT2 is greater than twice the current value obtained by the current sensor CT1, the alarm light one flashes. When the current value obtained by the current sensor CT1 is greater than twice the current value obtained by the current sensor CT2, the second alarm light flashes.

5. The track current balance monitoring device according to claim 1, characterized in that: The housing is also provided with a reserved communication interface for transmitting signals to the main control and monitoring computer.

6. The rail current balance monitoring apparatus according to claim 1, characterized by: The current sensor CT1 includes a chip U29. A capacitor C110 is connected between pins 5 and 6 of the chip U29, a capacitor C109 is connected between pins 5 and 8 of the chip U29, and a resistor R65 and a capacitor C111 are connected in series on pin 7 of the chip U29.

7. The rail current balance monitoring device according to claim 1, characterized in that: The current transformer CT3 includes a chip U4. A resistor R21 is connected between pins 1 and 2 of the chip U4. A resistor R22 is connected to pin 2 of the chip U4. A resistor R24 ​​is connected to pin 3 of the chip U4. Pin 4 of the chip U4 is connected to a negative 12V power supply. Pin 8 of the chip U4 is connected to a positive 12V power supply.

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