Railway signal power supply output leakage current detection unit

Abstract

The utility model discloses a railway signal power output leakage current detection unit, including the casing, the both sides of casing are provided with the mounting lug, is provided with the mounting hole on mounting lug, the front end of casing is provided with serial ports terminal, address dial code switch, collection interface, with the corresponding indicator of collection interface and power inlet, the inside of casing is provided with detection mechanism, and power inlet connects the power input end of detection mechanism, and the output of address dial code switch is connected with the input of detection mechanism, and the output of detection mechanism is connected with the input of indicator, and detection mechanism is connected with monitoring unit through serial ports terminal, and detection mechanism is connected with the isolation power output channel through collection interface. The utility model has realized the two -way data interaction ability with monitoring unit, satisfies the signal power screen system of city rail transit system application and needs to have the ground leakage detection function to detection mechanism, and will detect the result and transmit to microcomputer monitoring through power screen monitoring unit.

Description

Technical Field

[0001] This utility model relates to the field of railway signal equipment testing technology, and more specifically to a railway signal power supply output leakage current detection unit. Background Technology

[0002] As the core power supply guarantee for railway signaling equipment, the stability of the leakage current output of the intelligent power supply panel system directly affects the safe operation of the signaling system. Excessive leakage current may lead to equipment insulation failure, signal malfunction, or even safety accidents. Therefore, it is necessary to accurately detect the leakage current at the L and N terminals of the isolated power supply output.

[0003] Existing leakage current detection units support a limited number of power output channels, making it difficult to meet the multi-channel detection needs of large railway signal power supply panels. This necessitates the use of multiple devices, which undoubtedly increases system complexity. Furthermore, existing detection units only support unidirectional data transmission, cannot dynamically select detection targets based on external commands, and their communication and interaction mechanisms with the monitoring system are not yet perfect, making them prone to data transmission delays or packet loss, thus affecting the reliability of remote monitoring. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a railway signal power supply output leakage current detection unit to detect poor insulation of the signal power supply system to ground, avoid mixed power faults, and ensure the safe and reliable operation of railway signal equipment.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows.

[0006] A railway signal power supply output leakage current detection unit includes a housing with mounting ears on both sides. The mounting ears have mounting holes for mounting the detection unit on the cabinet of a railway signal intelligent power supply system. The front of the housing has a serial port terminal for communication with an external monitoring unit, an address DIP switch for setting the unit address, a data acquisition interface for connecting to the isolated power supply output channel, indicator lights corresponding to the data acquisition interface for indicating the working status of the corresponding data acquisition terminal, and a power input port for connecting to the power supply. Inside the housing is a detection mechanism for detecting leakage current in the railway signal power supply. The power input port connects to the power input terminal of the detection mechanism, the output terminal of the address DIP switch connects to the input terminal of the detection mechanism, and the output terminal of the detection mechanism connects to the input terminal of the indicator lights. The detection mechanism is connected to the monitoring unit via the serial port terminal and to the isolated power supply output channel via the data acquisition interface.

[0007] To further optimize the technical solution, the detection mechanism includes a power interface module for providing stable power, an output channel detection module for detecting the output channel of the isolated power supply, a main controller for receiving signals from the monitoring unit to control the output channel detection module to detect the output channel of the isolated power supply, and a 485 communication module for communicating with an external monitoring unit. The input end of the power interface module is connected to the power input port, and the output end of the power interface module is connected to the power input end of the main controller. One end of the output channel detection module is electrically connected to the main controller, and the other end is electrically connected to the acquisition interface. One end of the 485 communication module is electrically connected to the main controller, and the other end is electrically connected to the serial port terminal.

[0008] To further optimize the technical solution, the power interface module includes U5 and U6 conversion chips for converting the DC24V voltage connected to the power input into DC5V voltage, and M1 voltage regulator chip for converting the DC5V voltage into 3.3V.

[0009] The technical solution is further optimized. The output channel detection module includes U3, U8, and U9 chips for receiving signals from the main controller and outputting high or low levels, a relay connected to the acquisition interface for controlling the on / off state of the corresponding acquisition interface, and a current detection circuit for acquiring the leakage current at the L and N terminals of the isolated power supply output channel.

[0010] To further optimize the technical solution, the 485 communication module adopts a U7 isolated transceiver chip for communication with the monitoring unit.

[0011] To further optimize the technical solution, the indicator lights include a power indicator light and a communication status indicator light.

[0012] Due to the adoption of the above technical solutions, the technological progress achieved by this utility model is as follows.

[0013] The railway signal power supply output leakage current detection unit provided by this utility model can test the ground insulation performance of each cable in each isolated power supply output path according to the instructions sent by the monitoring unit, and send the cable ground leakage current data to the monitoring unit. It realizes the two-way data interaction capability with the monitoring unit, meets the ground leakage detection function required by the signal power supply panel system for urban rail transit system applications, and transmits the detection results to the microcomputer monitoring through the power supply panel monitoring unit. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a structural block diagram of the testing mechanism of this utility model; Figure 3 This is a circuit diagram of the power interface module of this utility model; Figure 4 This is a circuit diagram of the output channel detection module of this utility model; Figure 5 This is the circuit diagram of the 485 communication module of this utility model; Figure 6 This is the circuit diagram of the main controller of this utility model; Figure 7 This is a schematic diagram of the detection principle of this utility model.

[0015] The components include: 1. Housing, 2. Mounting ear plate, 3. Mounting hole, 4. Serial port terminal, 5. Address DIP switch, 6. Data acquisition interface, 7. Indicator light, and 8. Power input. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] Railway signal power supply output leakage current detection unit, combined with Figure 1 As shown, it includes a housing 1, and mounting ears 2 are provided on both sides of the housing 1. Mounting ears 2 are provided with mounting holes 3 for mounting the detection unit on the cabinet of the railway signal intelligent power supply screen system.

[0018] The front end of housing 1 is equipped with a serial port terminal 4, an address DIP switch 5, a data acquisition interface 6, an indicator light 7, and a power input 8. Inside housing 1 is a detection mechanism used to detect leakage current of railway signal power supply. The power input 8 is connected to the power input terminal of the detection mechanism. The output terminal of the address DIP switch is connected to the input terminal of the detection mechanism. The output terminal of the detection mechanism is connected to the input terminal of the indicator light. The detection mechanism is connected to the monitoring unit through the serial port terminal 4 and to the isolated power output channel through the data acquisition interface 6.

[0019] Serial port terminal 4 is used to communicate with an external monitoring unit, enabling bidirectional communication between the monitoring unit and the current detection unit. Address DIP switch 5 is used to set the unit address information. The purpose of the address DIP switch is to assign a unique device address to the leakage current detection unit, enabling identification when multiple detection units coexist in the same monitoring system. The address DIP switch ensures that the monitoring unit can accurately identify and access the target detection unit during polling communication, avoiding communication conflicts and ensuring the orderly collaborative operation of multiple devices.

[0020] The acquisition interface 6 is used to connect to the isolated power supply output channel, realizing the electrical connection between the detection unit and the isolated power supply output channel, and serving as a bridge for the transmission of leakage current signals. In this application, 20 acquisition interfaces are set, with each group of acquisition interfaces corresponding to one isolated power supply output channel. Each group of interfaces includes terminals for connecting the L and N terminals of the channel, ensuring that the leakage current signals of the L and N terminals of each channel can be independently acquired, meeting the functional requirements of multi-channel parallel detection.

[0021] Indicator 7 corresponds to the acquisition interface and is used to indicate the working status of the corresponding acquisition end. The indicator includes a power indicator and a communication status indicator. The input terminals of the power indicator and the communication status indicator are respectively connected to the output terminal of the detection mechanism.

[0022] Power input 8 is used to connect to the power supply to power the detection unit.

[0023] The structural block diagram of the testing organization is as follows: Figure 2 As shown, it includes a power interface module, an output channel detection module, a main controller, and a 485 communication module. The input end of the power interface module is connected to the power input port 8, and the output end of the power interface module is connected to the power input end of the main controller. One end of the output channel detection module is electrically connected to the main controller, and the other end is electrically connected to the acquisition interface 6. One end of the 485 communication module is electrically connected to the main controller, and the other end is electrically connected to the serial port terminal.

[0024] The circuit diagram of the power interface module is as follows: Figure 3 As shown, the system includes U5 and U6 conversion chips and M1 voltage regulator chip. A DC 24V power supply is drawn from the external power input P9, and after passing through inductors, capacitors, and power modules U5 and U6, ±5V is output to power the output channel detection module. The 5V is then passed through capacitors and the M1 voltage regulator chip to output 3.3V, powering the main controller and the 485 communication module. LED D25 and current-limiting resistor R52 are connected to the power supply terminal; the LED illuminates when power is available.

[0025] The circuit diagram of the 485 communication module is as follows: Figure 5 As shown, the 485 communication module uses a U7 isolated transceiver chip for communication with the monitoring unit. The circuit diagram of the main controller is shown below. Figure 6 As shown, the core chip of the main controller is the U4C main control chip, which communicates with the monitoring unit through the 485 communication module.

[0026] The 3.3V power supply powers the U7 isolated transceiver chip. The U7 isolated transceiver chip outputs signals RS-485-A and RS-485-B to the RX1 and TX1 of the U4C main control chip through the common mode inductor L3 and the gas discharge tube GDT1. Isolated transmission and reception are achieved through communication with the main control chip.

[0027] The 3.3V power supply powers the U4C main control chip. The U4C main control chip communicates with the U7 isolation transceiver chip for isolated transmission and reception. It controls the U3, U8, and U9 chips of the channel detection module at the control end to control the output high and low levels, thereby controlling the on and off of the relays and realizing the detection of data from each channel.

[0028] The 5V voltage is divided by a resistor and output to a 3V voltage via the U11 chip and the U2D chip, providing a reference voltage for the main control chip. The main control chip acquires signals from the detection circuit to achieve leakage current detection.

[0029] The circuit diagram of the output channel detection module is as follows: Figure 4 As shown, the system includes chips U3, U8, and U9, relays, and a current detection circuit. Chips U3, U8, and U9 receive signals from the main controller and output high or low levels. The relays are connected to the circuit of the acquisition interface to control the on / off state of the corresponding acquisition interface. The current detection circuit acquires the leakage current at the L and N terminals of the isolated power supply output channel. The main control chip provides a high or low level to the input terminals of U3, U8, and U9, and then outputs a low or high level, thereby controlling the on / off state of the relays and thus detecting data from each channel.

[0030] The input terminals SW1-SW22 of chips U3, U8, and U9 are connected to the output terminals of the U4C main control chip of the main controller. The output terminals are connected to relays K1-K22. A high or low level is supplied to the input terminals of chips U3, U8, and U9 via the U4C main control chip, and the output terminals output a low or high level, thereby controlling the on / off state of the relays and thus detecting data from each channel. Current-limiting resistors R3-R22, R30 / R41, and LED green lights D31-D45, D47-D53 are connected to the two ends of the relay coil; the green light illuminates when the relay is activated.

[0031] The 5V voltage passes through the U11 chip, then through a resistor divider and the U1D chip to output 1.5V, providing a reference voltage for the current detection circuit. The relay is connected to the circuit connected to the acquisition interface to control the on / off state of the corresponding acquisition interface. The current detection circuit is used to acquire the leakage current at the L and N terminals of the isolated power supply output channel.

[0032] The measurement branch selection circuit consists of two parallel resistors and two U2 operational amplifier circuits. The front end is connected to a relay to introduce the measurement channel, and the back end output signals ALN0 and ALN1 are connected to the U4C main control chip. The U4C main control chip collects data signals, processes them, and controls the measurement of leakage current.

[0033] In operation, this invention first sets the unit address via an address DIP switch, connects the acquisition interface to up to 20 isolated power output channels, connects the serial port terminal to the monitoring unit, and connects the power input to the power supply. During testing, the monitoring unit issues commands specifying the characteristics of each output channel. The leakage current detection unit detects the leakage current based on the received output channel characteristics. When a single cable of the tested output channel is grounded, the leakage current detection unit has a self-protection function to prevent damage to the resistance of the detection circuit due to high current. At the same time, it directly provides information that the leakage current of the single cable of this channel is the maximum value.

[0034] The specific detection principle is as follows: Figure 7 As shown, the monitoring unit accesses the leakage current detection unit in a polling manner, including communication status detection commands or leakage current detection commands. Each time the leakage current detection unit receives a polling command from the monitoring unit, it should reply with response data to the monitoring unit, including communication status detection response data or leakage current detection response data. The monitoring unit outputs alarm information for poor cable-to-ground insulation based on the cable-to-ground leakage current data and transmits the alarm information to the centralized signal monitoring system.

Claims

1. A railway signal power supply output leakage current detection unit, characterized in that: The system includes a housing (1), with mounting ears (2) on both sides of the housing (1). The mounting ears (2) have mounting holes (3) for mounting the detection unit on the cabinet of the railway signal intelligent power supply screen system. The front end of the housing (1) is provided with a serial port terminal (4) for communicating with an external monitoring unit, an address DIP switch (5) for setting the unit address, a data acquisition interface (6) for connecting to the isolated power supply output channel, an indicator light (7) corresponding to the data acquisition interface for indicating the working status of the corresponding data acquisition terminal, and a power input port (8) for connecting to the power supply. The inside of the housing (1) is provided with a detection mechanism for detecting leakage current of the railway signal power supply. The power input port (8) is connected to the power input terminal of the detection mechanism. The output terminal of the address DIP switch is connected to the input terminal of the detection mechanism. The output terminal of the detection mechanism is connected to the input terminal of the indicator light. The detection mechanism is connected to the monitoring unit through the serial port terminal (4) and the detection mechanism is connected to the isolated power supply output channel through the data acquisition interface (6).

2. The railway signal power supply output leakage current detection unit according to claim 1, characterized in that: The detection mechanism includes a power interface module for providing stable power, an output channel detection module for detecting the output channel of the isolated power supply, a main controller for receiving signals from the monitoring unit to control the output channel detection module to detect the output channel of the isolated power supply, and a 485 communication module for communicating with an external monitoring unit. The input end of the power interface module is connected to the power input port (8), and the output end of the power interface module is connected to the power input end of the main controller. One end of the output channel detection module is electrically connected to the main controller, and the other end is electrically connected to the acquisition interface (6). One end of the 485 communication module is electrically connected to the main controller, and the other end is electrically connected to the serial port terminal.

3. The railway signal power supply output leakage current detection unit according to claim 2, characterized in that: The power interface module includes U5 and U6 conversion chips for converting the DC24V voltage connected to the power input (8) into DC5V voltage, and M1 voltage regulator chip for converting DC5V voltage into 3.3V.

4. The railway signal power supply output leakage current detection unit according to claim 2, characterized in that: The output channel detection module includes U3, U8, and U9 chips for receiving signals from the main controller and outputting high or low levels, a relay connected to the acquisition interface for controlling the on / off state of the corresponding acquisition interface, and a current detection circuit for acquiring the leakage current at the L and N terminals of the isolated power supply output channel.

5. The railway signal power supply output leakage current detection unit according to claim 2, characterized in that: The 485 communication module uses a U7 isolated transceiver chip for communication with the monitoring unit.

6. The railway signal power supply output leakage current detection unit according to claim 1, characterized in that: The indicator light (7) includes a power indicator light and a communication status indicator light.

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