Fault distance measuring device and system for electrified railway traction power supply system

Abstract

The utility model discloses a fault distance measuring device for an electrified railway traction power supply system, which comprises an alternating current input module, a first analog-to-digital conversion module, a second analog-to-digital conversion module, a starting CPU (central processing unit), a protection CPU, a B code time synchronization interface, a double-CPU outlet starting module and a relay module, the first analog-to-digital conversion module is arranged in the starting CPU, the second analog-to-digital conversion module is arranged in the protection CPU, the alternating current input module is respectively connected with the first analog-to-digital conversion module and the second analog-to-digital conversion module, the B code time synchronization interface is respectively connected with the starting CPU and the protection CPU, the starting CPU and the protection CPU are respectively connected with the double-CPU outlet starting module, and the double-CPU outlet starting module is connected with the relay module. The device can prevent mistaken sending of the fault distance measurement signal and improve the accuracy of sending the fault distance measurement signal.

Description

Technical Field

[0001] This utility model relates to the field of traction network fault location technology, specifically to a fault location device and system for electrified railway traction power supply systems. Background Technology

[0002] In the traction power supply system of electrified railways, the traction network is a crucial primary equipment for supplying power to electric locomotives. When a fault occurs in the traction network under AT power supply mode, a fault location device is needed to calculate the distance to the fault point based on fault parameters in order to quickly locate the fault, providing guidance for maintenance personnel to quickly isolate the fault and restore power supply.

[0003] In traction networks powered by AT (Automatic Transmission) power supply, fault location devices need to be installed at stations (booths) along the power supply arm. When a fault occurs in the traction network, the fault location device on the power supply arm collects the voltage and current at the time of the fault and sends a fault location signal to the fault location system. However, the existing fault location devices have the problem of false transmission of fault location signals. Utility Model Content

[0004] This utility model provides a fault location device and system for an electrified railway traction power supply system, which can solve the problem of erroneous transmission of fault location signals.

[0005] This utility model is achieved through the following technical solution:

[0006] In a first aspect, this utility model provides a fault location device for an electrified railway traction power supply system, comprising: an AC input module, a first analog-to-digital converter (ADC), a second ADC, a startup CPU, a protection CPU, a B-code time synchronization interface, a dual-CPU output startup module, and a relay module. The first ADC is disposed in the startup CPU, and the second ADC is disposed in the protection CPU. The AC input module is connected to the first ADC and the second ADC respectively. The B-code time synchronization interface is connected to the startup CPU and the protection CPU respectively. The startup CPU and the protection CPU are connected to the dual-CPU output startup module respectively. The dual-CPU output startup module is connected to the relay module.

[0007] Furthermore, the AC input module includes a transformer, a resistor divider network, a signal conditioning circuit, an operational amplifier circuit, and a filter circuit. The primary side of the transformer is connected to a power supply, the secondary side of the transformer is connected to the resistor divider network, the output terminal of the resistor divider network is connected to the input terminal of the signal conditioning circuit, the output terminal of the signal conditioning circuit is connected to the input terminal of the operational amplifier circuit, the output terminal of the operational amplifier circuit is connected to the input terminal of the filter circuit, and the output terminal of the filter circuit is connected to the first analog-to-digital converter module and the second analog-to-digital converter module, respectively.

[0008] Furthermore, the resistive voltage divider network includes a first resistor, a second resistor, and a third resistor connected in series, with one end of the first resistor and one end of the third resistor connected to the two ends of the secondary side of the transformer.

[0009] Furthermore, the signal conditioning circuit includes a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor, and an amplifier. One end of the fourth resistor is connected to the other end of the first resistor and one end of the second resistor. The other end of the fourth resistor is connected to one end of the fifth resistor and one end of the first capacitor. The other end of the first capacitor is connected to the inverting input terminal and the output terminal of the amplifier. The other end of the fifth resistor is connected to one end of the second capacitor and the non-inverting input terminal of the amplifier. The other end of the second capacitor is connected to one end of the third capacitor and ground. The other end of the third capacitor is connected to the power supply terminal and the 4.8V voltage of the amplifier.

[0010] Furthermore, the filter circuit includes a sixth resistor and a fourth capacitor. One end of the sixth resistor is connected to the output terminal of the amplifier, and the other end of the sixth resistor is connected to one end of the fourth capacitor and the first analog-to-digital converter module and the second analog-to-digital converter module, respectively. The other end of the fourth capacitor is grounded.

[0011] Furthermore, the dual-CPU output startup module includes two output startup circuits connected in series, each of which includes an optocoupler isolation circuit, a transistor driving circuit, and a relay control circuit connected in sequence.

[0012] Furthermore, the optocoupler isolation circuit includes a seventh resistor and an optocoupler. The seventh resistor drives the internal light-emitting diode of the optocoupler. The output terminal of the optocoupler is connected to the input terminal of the transistor driving circuit. The transistor driving circuit includes an eighth resistor, a ninth resistor, and a first transistor. One end of the eighth resistor is connected to the output terminal of the optocoupler. The other end of the eighth resistor is connected to one end of the ninth resistor and the base of the first transistor. The other end of the ninth resistor is connected to the emitter of the first transistor and then grounded. The collector of the first transistor is connected to a relay control circuit. The relay control circuit includes a relay and a first diode. The first diode is connected in parallel across the two ends of the relay coil. The negative terminal of the first diode is connected to a 24V power supply, and the positive terminal of the first diode is connected to the collector of the first transistor.

[0013] Furthermore, it also includes a signal output circuit, which is connected to the startup CPU and the relay module respectively. The signal output circuit includes a main controller, a communication module and a buffer module. The main controller is connected to the backplane connector through the communication module and to the relay module through the buffer module.

[0014] Furthermore, the main controller is a GD32F450ZI.

[0015] Secondly, another embodiment of this utility model provides a fault location system for an electrified railway traction power supply system, including a voltage transformer, a current transformer, a power exchange, a location channel, and the fault location device for an electrified railway traction power supply system described in the above embodiment.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0017] This utility model provides a fault location device and system for an electrified railway traction power supply system. Through a single-board dual-CPU design, the start CPU controls the start relay, and the protection CPU controls the output relay. When a fault occurs, the start CPU and the protection CPU make judgments respectively. When both the protection CPU and the start CPU are enabled, they drive the dual-CPU output start module, which drives the output circuit to perform a protection output action, preventing false fault location signals and improving the accuracy of fault location signal transmission. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 A structural block diagram of a fault location device for an electrified railway traction power supply system provided by this utility model;

[0020] Figure 2 for Figure 1 The circuit diagram of the AC input module in the middle;

[0021] Figure 3 for Figure 1 Circuit diagram of the dual-CPU output startup circuit;

[0022] Figure 4 for Figure 1 Block diagram of the signal output circuit. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0024] Please see Figure 1-4The first embodiment of this utility model provides a fault location device for an electrified railway traction power supply system, comprising: an AC input module, a first analog-to-digital converter (ADC) module, a second ADC module, a startup CPU, a protection CPU, a B-code time synchronization interface, a dual-CPU output startup module, and a relay module. The first ADC module is disposed in the startup CPU, and the second ADC module is disposed in the protection CPU. The AC input module is connected to the first ADC module and the second ADC module respectively. The B-code time synchronization interface is connected to the startup CPU and the protection CPU respectively. The startup CPU and the protection CPU are connected to the dual-CPU output startup module respectively. The dual-CPU output startup module is connected to the relay module.

[0025] In this embodiment, the fault location device for the electrified railway traction power supply system adopts a dual MCU architecture and a single-board dual-CPU design. The startup CPU and protection CPU each have independent on-chip memory, Flash memory, and analog-to-digital conversion modules. The two systems operate in parallel, performing data acquisition and logic judgment respectively. The startup CPU controls the startup relay, and the protection CPU controls the output relay. The output trip only occurs when the protection logic of both the startup CPU and the protection CPU is satisfied, greatly improving the reliability of the device. The first and second analog-to-digital conversion modules use successive approximation analog-to-digital converters with 19 multiplexed channels, capable of converting analog signals from 16 external channels, 2 internal channels, and one battery voltage (VBAT) channel.

[0026] In this embodiment, the AC input module includes a transformer, a resistor divider network, a signal conditioning circuit, an operational amplifier circuit, and a filter circuit. The primary side of the transformer is connected to a power supply, and the secondary side of the transformer is connected to the resistor divider network. The output of the resistor divider network is connected to the input of the signal conditioning circuit, the output of the signal conditioning circuit is connected to the input of the operational amplifier circuit, the output of the operational amplifier circuit is connected to the input of the filter circuit, and the output of the filter circuit is connected to the first analog-to-digital converter (ADC) module and the second ADC module. The input voltage signal is converted into a low-voltage signal by the transformer and enters the CPU. The on-chip ADC module performs analog-to-digital conversion on the voltage signal. The resistor divider network includes resistors R1, R2, and R3 connected in series. One end of resistor R1 and one end of resistor R3 are connected to the two ends of the secondary side of the transformer, respectively. The signal conditioning circuit includes resistor R4, fifth resistor R5, capacitors C1, C2, and C3, and an amplifier. One end of resistor R4 is connected to the other ends of resistors R1 and R2, respectively. The other end of resistor R4 is connected to one end of resistor R5 and one end of capacitor C1, respectively. The other end of capacitor C1 is connected to the inverting input and output of the amplifier. The other end of resistor R5 is connected to one end of capacitor C2 and the non-inverting input of the amplifier, respectively. The other end of capacitor C2 is connected to one end of capacitor C3 and ground, respectively. The other end of capacitor C3 is connected to the power supply and 4.8V voltage of the amplifier, respectively. The filtering circuit includes resistor R6 and capacitor C4. One end of resistor R6 is connected to the output of the amplifier, and the other end of resistor R6 is connected to one end of capacitor C4 and the first and second analog-to-digital converter modules, respectively. The other end of capacitor C4 is grounded.

[0027] The primary side of the transformer provides electrical isolation for the input AC voltage u1, preventing strong electrical interference from directly entering subsequent circuits. It also allows for voltage amplitude adjustment as needed. The secondary side of the transformer is connected to a resistor divider network. The voltage output from the secondary side is divided by a voltage divider circuit composed of resistors R1, R2, and R3, with REF_QD as the reference voltage. This resistor divider network can adjust the signal voltage to a suitable range for subsequent circuit processing. Resistor R4 and capacitor C1 form a first-order RC low-pass filter to filter out high-frequency noise, allowing low-frequency signals to pass smoothly. Resistor R5, capacitors C2 and C3, and an operational amplifier form an active filter to further filter the signal and improve its purity. The operational amplifier can amplify or buffer the signal appropriately and adjust the signal amplitude to ensure the voltage input to the CPU is within the ADC's range. 4.8V_QD provides the bias voltage for this part of the circuit. Resistor R6 and capacitor C4 form a low-pass filter circuit to further suppress high-frequency interference, making the AD_IN1 signal input to the CPU more stable and ensuring ADC sampling accuracy. The final processed signal is input to the CPU's ADC pin (AD_IN1), where the CPU performs analog-to-digital conversion and subsequent processing.

[0028] This circuit converts the input voltage u1 into a standard voltage signal that the MCU can acquire through isolation, voltage division, filtering, and signal conditioning, ensuring strong anti-interference capability during signal transmission and meeting the input requirements of the analog-to-digital converter module.

[0029] The dual-CPU output startup module includes two series-connected output startup circuits. Each output startup circuit comprises an optocoupler isolation circuit, a transistor driver circuit, and a relay control circuit connected in sequence. The optocoupler isolation circuit includes a resistor R7 and an optocoupler. Resistor R7 drives the internal LED of the optocoupler. The output of the optocoupler is connected to the input of the transistor driver circuit. The transistor driver circuit includes resistors R8 and R9 and a transistor Q1. One end of resistor R8 is connected to the output of the optocoupler. The other end of resistor R8 is connected to one end of resistor R9 and the base of transistor Q1. The other end of resistor R9 is connected to the emitter of transistor Q1 and then grounded. The collector of transistor Q1 is connected to the relay control circuit. The relay control circuit includes a relay and a first diode D1. Diode D1 is connected in parallel across the relay coil. The cathode of diode D1 is connected to a 24V power supply, and the anode of diode D1 is connected to the collector of transistor Q1.

[0030] In this embodiment, the optocoupler is model ORPC-815S, used to achieve electrical isolation between the input signal and the back-end circuit. The left optocoupler input signals are "QD_START_P" and "QD_START_N", and the right optocoupler input signals are "RH_START_P" and "RH_START_N". After current limiting by resistors (R7, R10), they drive the internal LEDs of the optocoupler. Output side: The output terminals of the optocoupler (pins 3 and 4) are connected to the transistor driver circuit to isolate the high and low voltage circuits and prevent interference. Transistors: Q1 and Q2 are NPN transistors, used as relay drive switches. After the optocoupler is turned on, the current drives the base of the transistor through resistors (R8, R11), turning on the transistor. Resistor configuration: R9 and R12 are transistor emitter resistors used to stabilize the operating current; R8 and R11 are base current limiting resistors to ensure that the transistor operates in a suitable state. Relay control module: Relays: RL1 and RL2 are 24V relays, with freewheeling diodes (D1 and D2) connected in parallel across the coil. When the transistor is turned on, the relay coil is energized, the contacts actuate, and the 24V circuit (24V_QD) is switched on and off. Freewheeling protection: Diodes D1 and D2 provide a circuit for the induced current when the relay coil is de-energized, preventing back electromotive force from damaging the transistor. The circuit uses a 24VCC power supply, and the relay contacts are connected to the 24V high-voltage circuit (24V_QD). The relay contacts are used to switch the 24V circuit to control external loads.

[0031] The dual-CPU output startup circuit works as follows: When the input signal (such as "QD_START_P" or "RH_START_P") is high, the internal LED of the optocoupler conducts, and the output side of the optocoupler is turned on. The output current of the optocoupler drives transistors Q1 and Q2 to conduct, energizing the relay coil. The relay contacts close, connecting the 24V high-voltage circuit (24V_QD), enabling control of external devices. When the relay coil is de-energized, the freewheeling diodes D1 and D2 release the energy stored in the coil, protecting the transistors from reverse voltage surges.

[0032] The output start-up circuit is controlled by a start-up CPU and a protection CPU connected in series. The output drive power supply is 24VCC. Under normal operating conditions, both the start-up CPU and the protection CPU send START enable signals to drive the switch. This means there is no voltage difference across the relay coil, the contacts remain open, and there is no start-up power supply driving the output circuit. When a fault occurs, the protection CPU and the start-up CPU each perform protection logic checks. When both the protection CPU and the start-up CPU enable START to drive the switch, the 24V_QD start-up power supply obtains a 24V level, driving the output circuit to perform the protection output action. This dual-CPU series control of the output start-up function prevents false fault location signals and improves the accuracy of fault location signal transmission.

[0033] The signal output circuit includes a main controller, a communication module, and a buffer module. The main controller connects to the backplane connector via the communication module and to the relay module via the buffer module. The main controller uses a GD32F450ZI and is responsible for power supply control, output control, and action event storage. The main controller has an "M4 Start" pin for microcontroller startup control, ensuring the system starts according to a preset process. An external 5V power supply is input, one path directly powering the relay module; the other path is converted to 3.3V via an LDO (5V-3.3V) to power the GD32F450ZI main controller and voltage-sensitive chips. The 5V power supply controls the on / off state of the 5V_QD via two switches, "Start 1" and "Start 2," thereby controlling the startup of circuit modules dependent on the 5V_QD power supply. The relay module's operation is controlled by the CPU. The relay startup power supply uses a two-stage startup: "Start 2" is controlled by the startup CPU, and "Start 1" is controlled by "M4 Start." Resistors R13 and R14 (0Ω) serve as connections. The relay module consists of 16 relays, providing 16 instantaneous contacts for output. Each contact can be directly connected to a DC 220V / 110V high-voltage circuit. The panel terminals provide physical interfaces for connecting external devices, achieving electrical isolation and control through the relays. The panel terminals provide 32 interfaces (e.g., RELAY1 to RELAY16), with each relay connected to the GPIO pins of the GD32F450ZI via a buffer module (Buf). The main controller outputs level signals through GPIO to drive the relays to engage or disengage, achieving electrical control of external devices (e.g., circuit on / off, device start / stop). The communication module includes: CAN bus communication: The CAN1 and CAN2 pins of the GD32F450ZI are connected to CAN transceiver 1 and CAN transceiver 2 respectively, and interface with CANBUS1 and CANBUS2 through backplane connectors, enabling high-speed and reliable communication between multiple devices in industrial environments. RS485 Communication: Utilizing UART0 to connect to an RS485 transceiver, and via the RS485 interface on the backplane connector, it supports long-distance, multi-node serial data transmission, suitable for industrial sensor or instrument communication. Serial Port (UART1) and RS232 Chip: UART1 connects to a RS232 chip, enabling serial communication with external devices via the RX, TX, and GND pins of the connector, commonly used for debugging and data pass-through scenarios. I2C and EEPROM: The microcontroller's SCL / SDA pins connect to the EEPROM via the I2C bus, used to store system configuration parameters, calibration data, and other information that needs to be retained even after power loss. Backplane Connector: Serving as the system's external interface, it integrates pins for 5V power supply, GND, CPU startup signal, CANBUS, and RS485, enabling data interaction with the GD32F450ZI main controller and power control of the relay module.

[0034] This utility model provides a fault location device for an electrified railway traction power supply system. Through a single-board dual-CPU design, the start CPU controls the start relay, and the protection CPU controls the output relay. When a fault occurs, the start CPU and the protection CPU make judgments respectively. When both the protection CPU and the start CPU are enabled, they drive the dual-CPU output start module, which drives the output circuit to perform a protection output action, preventing false fault location signals and improving the accuracy of fault location signal transmission.

[0035] Another embodiment of this utility model provides a fault location system for an electrified railway traction power supply system, including a voltage transformer, a current transformer, a power exchange, a location channel, and the fault location device for an electrified railway traction power supply system described in the first embodiment.

[0036] Another embodiment of this utility model provides a fault location system for an electrified railway traction power supply system and a fault location device for an electrified railway traction power supply system. They have the same inventive concept and the same beneficial effects, and will not be described again here.

[0037] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fault location device for an electrified railway traction power supply system, characterized in that, include: The system comprises an AC input module, a first analog-to-digital converter (ADC) module, a second ADC module, a startup CPU, a protection CPU, a B-code time synchronization interface, a dual-CPU output startup module, and a relay module. The first ADC module is located in the startup CPU, and the second ADC module is located in the protection CPU. The AC input module is connected to both the first and second ADC modules. The B-code time synchronization interface is connected to both the startup CPU and the protection CPU. The startup CPU and the protection CPU are connected to the dual-CPU output startup module, and the dual-CPU output startup module is connected to the relay module.

2. The fault location device for electrified railway traction power supply system according to claim 1, characterized in that, The AC input module includes a transformer, a resistor divider network, a signal conditioning circuit, an operational amplifier circuit, and a filter circuit. The primary side of the transformer is connected to a power supply, and the secondary side of the transformer is connected to the resistor divider network. The output terminal of the resistor divider network is connected to the input terminal of the signal conditioning circuit, the output terminal of the signal conditioning circuit is connected to the input terminal of the operational amplifier circuit, the output terminal of the operational amplifier circuit is connected to the input terminal of the filter circuit, and the output terminal of the filter circuit is connected to the first analog-to-digital converter module and the second analog-to-digital converter module, respectively.

3. The fault location device for electrified railway traction power supply system according to claim 2, characterized in that, The resistor voltage divider network includes a first resistor, a second resistor, and a third resistor connected in series. One end of the first resistor and one end of the third resistor are connected to the two ends of the secondary side of the transformer, respectively.

4. The fault location device for electrified railway traction power supply system according to claim 3, characterized in that, The signal conditioning circuit includes a fourth resistor, a fifth resistor, a first capacitor, a second capacitor, a third capacitor, and an amplifier. One end of the fourth resistor is connected to the other end of the first resistor and one end of the second resistor. The other end of the fourth resistor is connected to one end of the fifth resistor and one end of the first capacitor. The other end of the first capacitor is connected to the inverting input and output terminals of the amplifier. The other end of the fifth resistor is connected to one end of the second capacitor and the non-inverting input terminal of the amplifier. The other end of the second capacitor is connected to one end of the third capacitor and ground. The other end of the third capacitor is connected to the power supply terminal and a 4.8V voltage of the amplifier.

5. The fault location device for electrified railway traction power supply system according to claim 4, characterized in that, The filter circuit includes a sixth resistor and a fourth capacitor. One end of the sixth resistor is connected to the output terminal of the amplifier, and the other end of the sixth resistor is connected to one end of the fourth capacitor and the first analog-to-digital converter module and the second analog-to-digital converter module, respectively. The other end of the fourth capacitor is grounded.

6. The fault location device for electrified railway traction power supply system according to claim 1, characterized in that, The dual-CPU output startup module includes two output startup circuits connected in series. Each output startup circuit includes an optocoupler isolation circuit, a transistor driving circuit, and a relay control circuit connected in sequence.

7. The fault location device for electrified railway traction power supply system according to claim 6, characterized in that, The optocoupler isolation circuit includes a seventh resistor and an optocoupler. The seventh resistor drives the internal light-emitting diode of the optocoupler. The output terminal of the optocoupler is connected to the input terminal of the transistor driving circuit. The transistor driving circuit includes an eighth resistor, a ninth resistor, and a first transistor. One end of the eighth resistor is connected to the output terminal of the optocoupler. The other end of the eighth resistor is connected to one end of the ninth resistor and the base of the first transistor. The other end of the ninth resistor is connected to the emitter of the first transistor and then grounded. The collector of the first transistor is connected to a relay control circuit. The relay control circuit includes a relay and a first diode. The first diode is connected in parallel across the two ends of the relay coil. The negative terminal of the first diode is connected to a 24V power supply, and the positive terminal of the first diode is connected to the collector of the first transistor.

8. The fault location device for electrified railway traction power supply system according to claim 1, characterized in that, It also includes a signal output circuit, which is connected to the startup CPU and the relay module respectively. The signal output circuit includes a main controller, a communication module and a buffer module. The main controller is connected to the backplane connector through the communication module and to the relay module through the buffer module.

9. The fault location device for electrified railway traction power supply system according to claim 8, characterized in that, The main controller is a GD32F450ZI.

10. A fault location system for an electrified railway traction power supply system, characterized in that, It includes voltage transformers, current transformers, power switches, distance measuring channels, and fault location devices for electrified railway traction power supply systems as described in any one of claims 1-9.

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