Rail transit rectification transformer traction power supply system and misoperation-preventive locking method thereof

Abstract

The invention discloses a rail transit rectification transformer traction power supply system and an anti-misoperation locking method thereof, and the system comprises a high-voltage grounding device, a low-voltage grounding device, a high-voltage detection device, a comprehensive control device, and a three-station disconnecting link, a circuit breaker and a three-phase transformer which are sequentially connected in series. The high-voltage grounding device and the low-voltage grounding device are arranged on the high-voltage side and the low-voltage side of the three-phase transformer respectively, the comprehensive control device is connected with the three-station disconnecting link, the high-voltage detection device, the high-voltage grounding device and the low-voltage grounding device, the high-voltage detection device is further connected with the high-voltage side of the three-phase transformer, and a low-voltage detection assembly is arranged in the low-voltage grounding device. The comprehensive control device carries out anti-misjudgment on high-low voltage grounding operation, controls the high-voltage grounding device and the low-voltage grounding device to be switched on in sequence, carries out anti-misjudgment on high-low voltage dismounting grounding operation, and controls the low-voltage grounding device and the high-voltage grounding device to be switched off in sequence. According to the technical scheme, the safety and reliability of maintenance operation are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of power equipment technology, and in particular to a rectifier transformer traction power supply system for rail transit and its anti-misoperation interlocking method. Background Technology

[0002] In urban rail transit traction power supply systems, power transmission employs a multi-stage voltage transformation process: first, 110kV AC power is input from the urban power grid, then stepped down to 35kV three-phase AC power at a regional substation, then further stepped down to 1080V three-phase low-voltage AC power via a rectifier transformer, and finally converted to DC 1500V DC power by a rectifier to supply power to the vehicles. The three-phase transformer, as the core equipment, undertakes the critical task of converting 35kV high-voltage power to 1080V low-voltage power, and its operational reliability directly affects the stability of the entire power supply system. To ensure the long-term safe operation of the equipment, regular maintenance and repair of the three-phase transformer are essential.

[0003] Currently, manual grounding is commonly used for equipment grounding protection during maintenance operations. This method presents several safety hazards: First, operators need to manually test the voltage on both the high-voltage and low-voltage sides phase by phase. Given the numerous energized busbars on a three-phase transformer, the testing process is tedious and prone to omissions. Second, the entire grounding process relies entirely on the operator's experience and sense of responsibility, lacking effective technical control measures. Third, existing grounding methods cannot monitor the grounding status in real time, and the backend system cannot obtain accurate grounding information. Most importantly, manual grounding operations lack electrical interlocking mechanisms with upstream and downstream equipment (such as three-position disconnectors), potentially leading to serious safety hazards such as live grounding or misoperation. These problems not only increase the risks of maintenance operations but also pose a significant threat to personal and equipment safety. Summary of the Invention

[0004] The main purpose of this application is to provide a rectifier transformer traction power supply system for rail transit, which aims to improve the safety of three-phase transformer maintenance operations.

[0005] To achieve the above objectives, the rail transit rectifier transformer traction power supply system proposed in this application includes a high-voltage grounding device, a low-voltage grounding device, a high-voltage detection device, a comprehensive control device, and a three-position disconnect switch, a circuit breaker, and a three-phase transformer connected in series; wherein, The high-voltage grounding device and the low-voltage grounding device are respectively installed on the high-voltage side and the low-voltage side of the three-phase transformer. The integrated control device is connected to the three-position disconnect switch, the high-voltage detection device, the high-voltage grounding device and the low-voltage grounding device respectively. The high-voltage detection device is also connected to the high-voltage side of the three-phase transformer to collect the energized state of the high-voltage side of the three-phase transformer. The low-voltage grounding device has a built-in low-voltage detection component for collecting the energized state of the low-voltage side of the three-phase transformer. During the grounding process, the integrated control device performs anti-misoperation judgment on the high-voltage and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device. Based on the result of the anti-misoperation judgment, it controls the high-voltage grounding device and the low-voltage grounding device to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially. During the removal of the grounding wire, the integrated control device performs a fault prevention judgment on the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high voltage grounding device and the opening and closing status of the low voltage grounding device, and controls the low voltage grounding device and the high voltage grounding device to open in sequence based on the fault prevention judgment result, so that the low voltage side and the high voltage side of the three-phase transformer are disconnected from the grounding in sequence.

[0006] In some embodiments of this application, the integrated control device includes a communication unit, an input unit, an output unit, and a main control unit; The communication unit is connected to the high-voltage detection device and the low-voltage detection component via a bus, respectively, and is used to collect the energized state of the high-voltage side and the low-voltage side. The main control unit is connected to the communication unit, the input unit, and the output unit, respectively. During the grounding process, the main control unit, based on the switch status of the three-position disconnector, the open / closed status of the high-voltage grounding device, the open / closed status of the low-voltage grounding device, the energized status of the high-voltage side, and the energized status of the low-voltage side received by the input unit, outputs closing commands to the high-voltage grounding device and the low-voltage grounding device respectively through the output unit. During the removal of the grounding wire, the main control unit, based on the status of the three-position disconnector, the open / closed status of the high-voltage grounding device, and the open / closed status of the low-voltage grounding device received by the input unit, outputs a tripping command to the low-voltage grounding device and the high-voltage grounding device respectively through the output unit.

[0007] In some embodiments of this application, the high-voltage grounding device includes a high-voltage grounding switch and a first driving unit. The first driving unit drives the high-voltage grounding switch to close or open based on the high-voltage closing command or high-voltage opening command output by the opening unit, so as to realize the high-voltage side grounding or disconnection grounding of the three-phase transformer. The low-voltage grounding device includes a low-voltage grounding switch and a second driving unit. The second driving unit drives the low-voltage grounding switch to close or open based on the low-voltage closing command or low-voltage opening command output by the opening unit, so as to realize the low-voltage side grounding or disconnection of the three-phase transformer.

[0008] In some embodiments of this application, there are high-voltage side disconnector closing control circuit and high-voltage side disconnector opening control circuit for controlling the first drive unit, and high-voltage side disconnector closing power circuit and high-voltage side disconnector opening power circuit for executing the operation of the first drive unit. The three-position disconnect switch is equipped with a disconnect switch auxiliary switch. When the grounding state of the three-position disconnect switch is grounded, the disconnect switch auxiliary switch is triggered and the disconnect switch is turned on. The low-voltage grounding device is equipped with a low-voltage auxiliary switch. When the low-voltage grounding device is in the open state, the low-voltage auxiliary switch is triggered and the low-voltage auxiliary switch is turned on. The output unit includes a first output for outputting the high-voltage closing command and a second output for outputting the high-voltage opening command; The auxiliary switch, the low-voltage auxiliary switch, and the first switch are connected in series in the high-voltage side disconnector closing control circuit. The auxiliary switch, the low-voltage auxiliary switch, and the second switch are connected in series in the high-voltage side disconnector opening control circuit. The high-voltage side disconnector closing control circuit and the high-voltage side disconnector opening control circuit are mutually exclusive.

[0009] In some embodiments of this application, a high-voltage first relay and a high-voltage second relay are included; The high-voltage first relay includes a high-voltage first power supply coil, a high-voltage first normally closed contact, and a high-voltage first normally open contact. The high-voltage first power supply coil is connected in series with the high-voltage side disconnector closing control circuit, the high-voltage first normally closed contact is connected in series with the high-voltage side disconnector opening control circuit, and the high-voltage first open contact is connected in series with the high-voltage side closing power circuit. The high-voltage second relay includes a high-voltage second power supply coil, a high-voltage second normally closed contact, and a high-voltage second normally open contact. The high-voltage second power supply coil is connected in series in the high-voltage side disconnector opening control circuit, the high-voltage second normally closed contact is connected in series in the high-voltage side disconnector closing control circuit, and the high-voltage second open contact is connected in series in the high-voltage side disconnector power circuit.

[0010] In some embodiments of this application, there are low-voltage side disconnector closing control circuits and low-voltage side disconnector opening control circuits for controlling the second drive unit, as well as low-voltage side disconnector closing power circuits and low-voltage side disconnector opening power circuits for executing the actions of the second drive unit. The three-position disconnect switch is equipped with a disconnect switch auxiliary switch. When the grounding state of the three-position disconnect switch is grounded, the disconnect switch auxiliary switch is triggered and the disconnect switch is turned on. The high-voltage grounding device is equipped with a high-voltage auxiliary switch. When the high-voltage grounding device is in the closed state, the high-voltage auxiliary switch is triggered and the high-voltage auxiliary switch is turned on. The output unit includes a third output for outputting the low-voltage closing command and a fourth output for outputting the low-voltage opening command; The auxiliary switch, the high-voltage auxiliary switch, and the third switch are connected in series in the low-voltage side disconnector closing control circuit. The auxiliary switch, the high-voltage auxiliary switch, and the fourth switch are connected in series in the low-voltage side disconnector opening control circuit. The low-voltage side disconnector closing control circuit and the low-voltage side disconnector opening control circuit are mutually exclusive.

[0011] In some embodiments of this application, a low-voltage first relay and a low-voltage second relay are included; The low-voltage first relay includes a low-voltage first power supply coil, a low-voltage first normally closed contact, and a low-voltage first normally open contact. The low-voltage first power supply coil is connected in series with the low-voltage side disconnector closing control circuit, the low-voltage first normally closed contact is connected in series with the low-voltage side disconnector opening control circuit, and the low-voltage first open contact is connected in series with the low-voltage side closing power circuit. The low-voltage second relay includes a low-voltage second power supply coil, a low-voltage second normally closed contact, and a low-voltage second normally open contact. The low-voltage second power supply coil is connected in series with the low-voltage side disconnector opening control circuit, the low-voltage second normally closed contact is connected in series with the low-voltage side disconnector closing control circuit, and the low-voltage second open contact is connected in series with the low-voltage side disconnector power circuit.

[0012] Furthermore, this application embodiment also provides a method for preventing accidental interlocking, applied to the above-mentioned rail transit rectifier transformer traction power supply system, the method for preventing accidental interlocking includes the following steps: The maintenance status of the three-phase transformer in the traction power supply system of the rail transit rectifier transformer is detected, and the type of interlocking operation for the rail transit rectifier transformer traction power supply system is determined based on the maintenance status. When the blocking operation type is grounding operation, the high-voltage detection device and the low-voltage detection component of the low-voltage grounding device collect the energized state of the high-voltage side and the low-voltage side of the three-phase transformer. The integrated control device performs anti-misoperation judgment on the high-voltage and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device. Based on the result of the anti-misoperation judgment, the high-voltage grounding device and the low-voltage grounding device are controlled to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially. When the interlocking operation type is a ground wire removal operation, the integrated control device performs a fault prevention judgment on the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high voltage grounding device and the opening and closing status of the low voltage grounding device, and controls the low voltage grounding device and the high voltage grounding device to open in sequence based on the fault prevention judgment result, so that the low voltage side and the high voltage side of the three-phase transformer are disconnected from the ground in sequence.

[0013] In some embodiments of this application, the step of performing error prevention judgment on high and low voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device, and controlling the high-voltage grounding device and the low-voltage grounding device to close sequentially based on the error prevention judgment result, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially, includes: When the high-voltage side is de-energized, the low-voltage side is de-energized, the three-position disconnector is in a grounded state, the high-voltage grounding device is in an open state, and the low-voltage grounding device is in an open state, the integrated control device controls the high-voltage grounding device to close. Determine whether the high-voltage grounding device is closed. If so, the integrated control device controls the low-voltage grounding device to close.

[0014] In some embodiments of this application, the step of performing a fault-prevention judgment on the high- and low-voltage grounding disconnection operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high-voltage grounding device, and the opening and closing status of the low-voltage grounding device, and controlling the low-voltage grounding device and the high-voltage grounding device to open sequentially based on the fault-prevention judgment result, so that the low-voltage side and the high-voltage side of the three-phase transformer are disconnected from the ground in sequence, includes: When the disconnector state of the three-position disconnector is grounded, the high-voltage grounding device is closed, and the low-voltage grounding device is closed, the integrated control device controls the low-voltage grounding device to open. Determine whether the low-voltage grounding device has tripped; if so, the integrated control device controls the high-voltage grounding device to trip.

[0015] The rail transit rectifier transformer traction power supply system provided in this application embodiment, through the above-mentioned structural setting, uses a comprehensive control device to perform anti-misjudgment of high and low voltage grounding operations, and controls the high voltage grounding device and low voltage grounding device to close sequentially based on the judgment result; simultaneously, when performing high and low voltage grounding removal operations, the comprehensive control device also performs anti-misjudgment and controls the low voltage grounding device and high voltage grounding device to open sequentially, thereby effectively avoiding situations such as live grounding and misoperation. Compared with the prior art, traditional manual operation lacks the ability to interact with equipment status in real time, while this solution achieves automatic judgment of live status through high voltage detection device and low voltage detection component, avoiding the risks caused by human misjudgment. The prior art cannot form an effective interlock with the three-position disconnect switch, while this solution uses the comprehensive control device to perform anti-misjudgment to ensure that the main circuit has achieved physical isolation before the grounding operation. Compared with the operation process that relies solely on human experience, this solution establishes a programmed operation sequence, and by forcibly following the order of "high voltage side grounding first, low voltage side removal first", it eliminates the risk of live closing caused by incorrect operation sequence. This application achieves automated closed-loop control of high and low voltage side grounding operations. An electrical interlocking mechanism ensures the irreversibility of the operation sequence, thereby eliminating the possibility of human error. Real-time live-line status monitoring combined with equipment status feedback forms a multi-layered safety verification mechanism, effectively preventing serious accidents such as "connecting grounding wires while the circuit is live" or "closing the circuit with the ground wire connected." Furthermore, system status information can be uploaded to the monitoring backend in real time, providing visualized data support for equipment operation and maintenance, significantly improving the safety and reliability of maintenance work. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the rail transit rectifier transformer traction power supply system for this application; Figure 2 This is a schematic diagram of the main structure of the rail transit rectifier transformer traction power supply system in this application; Figure 3 This application describes the modular components of the integrated control device in the rail transit rectifier transformer traction power supply system. Figure 4 This is the electrical schematic diagram of the opening and closing control of the high-voltage grounding device in the traction power supply system of the rail transit rectifier transformer in this application; Figure 5This is the electrical schematic diagram of the low-voltage grounding device opening and closing control in the traction power supply system of the rail transit rectifier transformer in this application; Figure 6 This is a schematic diagram of an embodiment of the anti-misoperation interlocking method for the traction power supply system of the rail transit rectifier transformer in this application.

[0018] Explanation of icon numbers: 100. Traction power supply system for rail transit rectifier transformers; 10. High-voltage grounding device; 11. High-voltage side disconnector closing control circuit; 12. High-voltage side disconnector opening control circuit; 13. High-voltage side disconnector closing power circuit; 14. High-voltage side disconnector opening power circuit; HC11. High-voltage first power supply coil; HC12. High-voltage first normally closed contact; HC13. High-voltage first normally open contact; FC11. High-voltage second power supply coil; FC12. High-voltage second normally closed contact; FC13. High-voltage second normally open contact; M1. First drive unit; GH1. High-voltage auxiliary switch; SQ1. First auxiliary switch; SQ2. Second auxiliary switch; 20. Low-voltage grounding device; 21. Low-voltage side disconnector closing control circuit; 22. Low-voltage side disconnector opening control circuit; 23. Low-voltage side disconnector closing power circuit. Circuit; 24. Low-voltage side disconnector tripping power circuit; HC21. Low-voltage first power supply coil; HC22. Low-voltage first normally closed contact; HC23. Low-voltage first normally open contact; FC21. Low-voltage second power supply coil; FC22. Low-voltage second normally closed contact; FC23. Low-voltage second normally open contact; M2. Second drive unit; DF1. Low-voltage auxiliary switch; SQ3. Third auxiliary switch; SQ4. Fourth auxiliary switch; 30. High-voltage detection device; 40. Integrated control device; 41. Communication unit; 42. Input unit; 43. Output unit; D01. First output; D02. Second output; D03. Third output; D04. Fourth output; 44. Main control unit; 50. Three-position disconnector; SD1. Disconnector auxiliary switch; 60. Circuit breaker; 70. Three-phase transformer.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0023] In existing technologies, urban rail transit traction power supply systems convert high-voltage AC power into DC power to supply vehicle operation through multi-stage transformers. The three-phase transformer 70, as a critical piece of equipment, requires regular maintenance. During maintenance, reliable grounding of both high and low voltage sides is necessary to ensure personnel safety. Existing technologies use manual grounding wire connection, which suffers from drawbacks such as reliance on operator experience, inability to monitor grounding status in real time, and lack of electrical interlocking with upstream and downstream equipment, easily leading to the risk of live operation.

[0024] In one embodiment, such as Figure 1 and Figure 2As shown in the figure, this application embodiment provides a rail transit rectifier transformer traction power supply system 100. The rail transit rectifier transformer traction power supply system 100 includes a high-voltage grounding device 10, a low-voltage grounding device 20, a high-voltage detection device 30, a comprehensive control device 40, and a three-position disconnect switch 50, a circuit breaker 60, and a three-phase transformer 70 connected in series. The high-voltage grounding device 10 and the low-voltage grounding device 20 are respectively located on the high-voltage side and low-voltage side of the three-phase transformer 70. The comprehensive control device 40 is connected to the three-position disconnect switch 50, the high-voltage detection device 30, the high-voltage grounding device 10, and the low-voltage grounding device 20. The high-voltage detection device 30 is also connected to the high-voltage side of the three-phase transformer 70 to collect the energized state of the high-voltage side of the three-phase transformer 70. The low-voltage grounding device 20 has a built-in low-voltage detection component for collecting the energized state of the low-voltage side of the three-phase transformer 70. During the grounding process, the integrated control device 40 performs error prevention judgment on the high-voltage and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector 50, the opening and closing state of the high-voltage grounding device 10, and the opening and closing state of the low-voltage grounding device 20. Based on the error prevention judgment results, it controls the high-voltage grounding device 10 and the low-voltage grounding device 20 to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer 70 are grounded sequentially. During the removal of the grounding wire, the integrated control device 40 performs error prevention judgment on the high-voltage and low-voltage removal grounding operations based on the disconnection state of the three-position disconnector 50, the opening and closing state of the high-voltage grounding device 10, and the opening and closing state of the low-voltage grounding device 20. Based on the error prevention judgment results, it controls the high-voltage grounding device 10 and the low-voltage grounding device 20 to open sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer 70 are disconnected from the grounding sequentially.

[0025] The high-voltage detection device 30 is a detection unit used to monitor the voltage status of the high-voltage side of the three-phase transformer 70 in real time. It can be implemented using a voltage sensor, which determines whether the high-voltage side busbar is energized by collecting the voltage signal. The low-voltage detection component refers to the detection module integrated into the low-voltage grounding device 20, which can be implemented using a current transformer. It is used to detect whether there is residual current on the low-voltage side. The integrated control device 40 is a control device with logic operation capabilities, which can be implemented using a programmable logic controller (PLC). It controls the operation sequence of the high-voltage grounding device 10 and the low-voltage grounding device 20 by receiving signals from various sensors and executing preset interlocking logic. The three-position disconnect switch 50 is a switchgear with three positions: isolation, grounding, and operation. Its disconnect switch status can be fed back to the integrated control device 40 through auxiliary contacts to ensure that the main circuit has been reliably disconnected before operation. Of course, in other examples, the disconnect switch status of the three-position disconnect switch 50 can be fed back to the integrated control device 40 in other ways.

[0026] It is understood that, for ease of description, the high and low voltage grounding devices 20 mentioned below refer to the high voltage grounding device 10 and the low voltage grounding device 20.

[0027] Specifically, when the system enters maintenance mode, the operator first switches the three-position disconnector 50 to the grounding position. The high-voltage detection device 30 monitors the high-voltage side voltage in real time, and the low-voltage detection component detects the low-voltage side current status. The integrated control device 40 performs anti-misoperation judgment for high and low voltage grounding operations based on preset conditions, namely, the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnector status of the three-position disconnector 50, the opening and closing status of the high-voltage grounding device 10, and the opening and closing status of the low-voltage grounding device 20. Based on the result of the anti-misoperation judgment, the integrated control device 40 controls the high-voltage grounding device 10 and the low-voltage grounding device 20 to close sequentially. The moving contacts and stationary contacts in the high-voltage grounding device 10 and the low-voltage grounding device 20 come into contact with each other, the line is connected, and the high-voltage side and the low-voltage side of the three-phase transformer 70 can be grounded sequentially. If there is any residual voltage, it can be released through grounding. After maintenance is completed, when the grounding wire is removed, the integrated control device 40 performs a mis-judgment of the high and low voltage grounding removal operation according to the preset conditions. That is, it performs a mis-judgment of the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector 50, the opening and closing status of the high voltage grounding device 10 and the opening and closing status of the low voltage grounding device 20. Based on the result of the mis-judgment, the integrated control device 40 controls the low voltage grounding device 20 and the high voltage grounding device 10 to open in sequence. The moving contact and stationary contact in the high voltage grounding device 10 and the low voltage grounding device 20 separate from each other, the line is disconnected, and the low voltage side and the high voltage side of the three-phase transformer 70 are disconnected from the ground in sequence.

[0028] The rail transit rectifier transformer traction power supply system 100 provided in this application embodiment, through the above-mentioned structural setting, uses a comprehensive control device 40 to perform anti-misoperation judgment for high and low voltage grounding operations, and controls the high voltage grounding device 10 and the low voltage grounding device 20 to close sequentially based on the judgment result; simultaneously, when performing high and low voltage grounding removal operations, the comprehensive control device 40 also performs anti-misoperation judgment, and controls the low voltage grounding device 20 and the high voltage grounding device 10 to open sequentially, thereby effectively avoiding situations such as live grounding and misoperation. Compared with the prior art, traditional manual operation lacks the ability to interact with the equipment status in real time, while this solution achieves automatic judgment of the live state through the high voltage detection device 30 and the low voltage detection component, avoiding the risks caused by human misjudgment. The prior art cannot form an effective interlock with the three-position disconnect switch 50, while this solution uses the comprehensive control device 40 to perform anti-misoperation judgment, ensuring that the main circuit has achieved physical isolation before the grounding operation. Compared to operational procedures that rely solely on manual experience, this solution establishes a programmed operational sequence. By enforcing the order of "grounding the high-voltage side first, then removing the low-voltage side first," it eliminates the risk of live-line closing caused by incorrect operational sequence. This application achieves automated closed-loop control of high and low voltage side grounding operations, ensuring the irreversibility of the operational sequence through an electrical interlocking mechanism, thereby eliminating the possibility of human error. Real-time live-line status monitoring combined with equipment status feedback forms a multi-layered safety verification mechanism, effectively preventing serious accidents such as "grounding with the wire connected while energized" or "closing the circuit with the ground wire connected." Furthermore, system status information can be uploaded to the monitoring backend in real time, providing visualized data support for equipment operation and maintenance, significantly improving the safety and reliability of maintenance operations.

[0029] In some examples, such as Figure 2 and Figure 3 As shown, the integrated control device 40 includes a communication unit 41, an input unit 42, an output unit 43, and a main control unit 44. The communication unit 41 is connected to the high-voltage detection device 30 and the low-voltage detection component via a bus to collect the energized status of the high-voltage side and the low-voltage side. The main control unit 44 is connected to the communication unit 41, the input unit 42, and the output unit 43. During the grounding process, the main control unit 44, based on the switch status of the three-position disconnector 50, the opening and closing status of the high-voltage grounding device 10, the opening and closing status of the low-voltage grounding device 20, the energized status of the high-voltage side, and the energized status of the low-voltage side received by the input unit 42, outputs closing commands to the high-voltage grounding device 10 and the low-voltage grounding device 20 through the output unit 43. During the removal of the grounding wire, the main control unit 44, based on the switch status of the three-position disconnector 50, the opening and closing status of the high-voltage grounding device 10, and the opening and closing status of the low-voltage grounding device 20 received by the input unit 42, outputs opening commands to the low-voltage grounding device 20 and the high-voltage grounding device 10 through the output unit 43.

[0030] The communication unit 41 is a hardware module used to transmit energized status signals between the high-voltage and low-voltage sides. Specifically, it can be implemented using an RS485 communication interface, establishing a communication link with the high-voltage detection device 30 and the low-voltage detection component via a bus protocol to acquire voltage signals or switching signals in real time. The input unit 42 is an input interface used to collect the status of the three-position disconnector 50 and the opening / closing status of the high and low voltage grounding devices 20. The output unit 43 is a control interface used to output closing or opening commands. The main control unit 44 is the core processor used to perform logical judgments and generate commands. Specifically, it can be implemented using an embedded microcontroller with a built-in anti-misoperation interlocking logic algorithm, generating sequential control commands based on the input status signals.

[0031] Specifically, during grounding operations, the main control unit 44 obtains signals uploaded by the high-voltage detection device 30 and the low-voltage detection component through the communication unit 41 to determine whether the high and low voltage sides are in a de-energized state. Simultaneously, the input unit 42 receives the grounding status signal from the three-position disconnector 50 and the opening status signal from the high and low voltage grounding devices 20. When all conditions are met, the main control unit 44 first sends a closing command to the high-voltage grounding device 10 through the output unit 43. After the high-voltage side is grounded, it then sends a closing command to the low-voltage grounding device 20. During grounding removal operations, the main control unit 44 confirms through the input unit 42 that the three-position disconnector 50 remains grounded and that the high and low voltage grounding devices 20 are closed. It then sends an opening command to the low-voltage grounding device 20 through the output unit 43. After the low-voltage side is disconnected from the ground, it then sends an opening command to the high-voltage grounding device 10. The entire process ensures the mandatory and safe operation steps through signal interaction and sequential control logic between hardware units.

[0032] This solution automatically collects the energized status of the high and low voltage sides through the communication unit 41, replacing the manual voltage testing process and eliminating human judgment errors. The main control unit 44, based on the comprehensive judgment of multiple input signals, enforces the operation sequence of closing the high voltage side first and then the low voltage side, avoiding the risk of short circuits caused by live operation or reversal of the sequence, and avoiding equipment damage or personal injury caused by incorrect operation procedures.

[0033] In some examples, such as Figure 4 As shown, the high-voltage grounding device 10 includes a high-voltage grounding switch and a first driving unit M1. The first driving unit M1 drives the high-voltage grounding switch to close or open based on the high-voltage closing command or high-voltage opening command output by the switching unit 43, so as to realize the high-voltage side grounding or disconnection of the three-phase transformer 70. The low-voltage grounding device 20 includes a low-voltage grounding switch and a second driving unit M2. The second driving unit M2 drives the low-voltage grounding switch to close or open based on the low-voltage closing command or low-voltage opening command output by the switching unit 43, so as to realize the low-voltage side grounding or disconnection of the three-phase transformer 70.

[0034] The high-voltage grounding switch is a mechanical switch used to connect or disconnect the high-voltage side of the three-phase transformer 70 from the grounding point. The first drive unit M1 is an actuator that receives electrical signals and converts them into mechanical actions. For example, it uses an electromagnetic coil or servo motor with a gear transmission structure, which can drive the high-voltage grounding switch to close when a high-voltage closing command is received, or to move in the reverse direction when a opening command is received. The low-voltage grounding switch adopts a similar structure to the high-voltage side but is adapted to low-voltage current levels. The second drive unit M2 can use the same type of actuator as the first drive unit M1, but independently controls the operation of the low-voltage grounding switch. The high-voltage closing command and the low-voltage closing command output by the output unit 43 are on different signal channels, and the controlled objects are distinguished by hard wiring or communication protocols.

[0035] Specifically, during the grounding operation, the switching unit 43 sends a high-voltage closing command to the first driving unit M1, driving the high-voltage grounding switch to close and ground the high-voltage side. After the high-voltage side grounding status is confirmed, the switching unit 43 then sends a low-voltage closing command to the second driving unit M2, driving the low-voltage grounding switch to close and complete the low-voltage side grounding. During the tripping operation, the switching unit 43 first sends a low-voltage tripping command to the second driving unit M2 to disconnect the low-voltage side grounding, and then sends a high-voltage tripping command to disconnect the high-voltage side grounding.

[0036] This solution transforms grounding operations into controlled electrical actions through a mechanical linkage structure between the high-voltage grounding switch and the drive unit. This allows the grounding status to be monitored in real time and forms a hard-wired interlock with upstream and downstream equipment. For example, the closing status of the high-voltage grounding switch can be fed back to the integrated control device 40 via auxiliary contacts.

[0037] Through the above technical solution, this application solves the problem that manual grounding wire connection cannot form an electrical interlock with upstream and downstream equipment, avoiding the risk of electric shock to maintenance personnel due to incorrect high- and low-voltage grounding sequence. Independent drive control of the high-voltage and low-voltage grounding switches achieves forced interlocking of the operation sequence. Simultaneously, the mechanical status of the high-voltage and low-voltage grounding switches can be uploaded to the integrated control device 40 in real time via auxiliary contacts, forming a complete grounding status monitoring chain. The automated operation of the drive unit based on electrical commands replaces manual connection, eliminating the possibility of human error.

[0038] In some examples, such as Figure 2 and Figure 3As shown, the rail transit rectifier transformer traction power supply system 100 includes a high-voltage side disconnect switch closing control circuit 11 and a high-voltage side disconnect switch opening control circuit 12 for controlling the first drive unit M1, and a high-voltage side disconnect switch closing power circuit 13 and a high-voltage side disconnect switch opening power circuit 14 for executing the action of the first drive unit M1. The three-position disconnect switch 50 is equipped with a disconnect switch auxiliary switch SD1. When the three-position disconnect switch 50 is in a grounded state, the disconnect switch auxiliary switch SD1 is triggered, and the disconnect switch auxiliary switch SD1 is turned on. The low-voltage grounding device 20 is equipped with a low-voltage auxiliary switch DF1. The low-voltage grounding device 20 is a... When the circuit is in the closed state, the low-voltage auxiliary switch DF1 is triggered and the low-voltage auxiliary switch DF1 is turned on. The output unit 43 includes a first output D01 for outputting a high-voltage closing command and a second output D02 for outputting a high-voltage opening command. The disconnector auxiliary switch SD1, the low-voltage auxiliary switch DF1 and the first output D01 are connected in series in the high-voltage side disconnector closing control circuit 11. The disconnector auxiliary switch SD1, the low-voltage auxiliary switch DF1 and the second output D02 are connected in series in the high-voltage side disconnector opening control circuit 12. The high-voltage side disconnector closing control circuit 11 and the high-voltage side disconnector opening control circuit 12 are mutually exclusive conducting.

[0039] The high-voltage side disconnector closing control circuit 11 is an electrical circuit that controls the closing action of the high-voltage grounding disconnector. Specifically, it can be implemented by connecting relay contacts and an output signal in series, used to trigger the closing operation when the interlocking conditions are met. The high-voltage side disconnector opening control circuit 12 is an electrical circuit that controls the opening action of the high-voltage grounding disconnector. Specifically, it can be implemented by connecting relay contacts and an output signal in series, used to trigger the opening operation when the interlocking conditions are met. The disconnector auxiliary switch SD1 is a status detection device installed on the three-position disconnector 50, specifically implemented as a microswitch. When the disconnector is in the grounded position, mechanical linkage triggers conduction, used to confirm that the system has been de-energized and isolated. The low-voltage auxiliary switch DF1 is a status detection device installed on the low-voltage grounding device 20, specifically implemented as a limit switch. When the low-voltage grounding disconnector is in the open state, the contacts close, used to forcibly verify that the low-voltage side is not grounded. The mutual exclusion conduction relationship can be implemented using a double relay interlocking circuit to ensure that the two circuits cannot conduct simultaneously, or it can be set through the program of the integrated control device 40.

[0040] Specifically, when a high-voltage side grounding operation is required, the three-position disconnector 50 must be in a grounded state to trigger the disconnector auxiliary switch SD1 to conduct, and simultaneously, the low-voltage grounding device 20 must be in an open state to trigger the low-voltage auxiliary switch DF1 to conduct. At this time, if the integrated control device 40 outputs a high-voltage closing command through the first output D01, the current flows sequentially through the disconnector auxiliary switch SD1, the low-voltage auxiliary switch DF1, and the first output D01 contact, forming a closed loop that drives the high-voltage side disconnector closing control circuit 11 to operate, thereby completing the closing operation through the power circuit. Similarly, the opening operation requires satisfying both the disconnector grounding and low-voltage opening conditions, and the opening control circuit is triggered by the second output D02 command.

[0041] This solution, through the series design of the auxiliary disconnect switch SD1 and the low-voltage auxiliary switch DF1, mandates that high-voltage side operations must meet the status conditions of both upstream and downstream equipment. For example, high-voltage closing operations must simultaneously confirm that the three-position disconnect switch 50 is grounded and the low-voltage side is not grounded, forming a double interlocking mechanism. The series connection of the three-position disconnect switch 50 and the low-voltage auxiliary switch DF1 forcibly verifies the equipment status conditions, ensuring that high-voltage side operations are only performed under the safe condition of system power-off isolation and low-voltage side not grounded. The mutually exclusive conduction control loop design eliminates the possibility of concurrent closing and opening operations, avoiding malfunctions caused by abnormal electrical signals. This solution implements mandatory interlocking of the operation logic through hardware circuitry, replacing the traditional manual judgment method and improving the safety and reliability of grounding operations.

[0042] In some examples, such as Figure 2 and Figure 3 As shown, the rail transit rectifier transformer traction power supply system 100 includes a high-voltage first relay and a high-voltage second relay. The high-voltage first relay includes a high-voltage first power supply coil HC11, a high-voltage first normally closed contact HC12, and a high-voltage first normally open contact HC13. The high-voltage first power supply coil HC11 is connected in series with the high-voltage side disconnector closing control circuit 11, the high-voltage first normally closed contact HC12 is connected in series with the high-voltage side disconnector opening control circuit 12, and the high-voltage first open contact is connected in series with the high-voltage side closing power circuit. The high-voltage second relay includes a high-voltage second power supply coil FC11, a high-voltage second normally closed contact FC12, and a high-voltage second normally open contact FC13. The high-voltage second power supply coil FC11 is connected in series with the high-voltage side disconnector opening control circuit 12, the high-voltage second normally closed contact FC12 is connected in series with the high-voltage side disconnector closing control circuit 11, and the high-voltage second open contact is connected in series with the high-voltage side opening power circuit.

[0043] When the high-voltage side disconnector closing control circuit 11 is activated, the high-voltage first power supply coil HC11 is energized, triggering the high-voltage first relay to operate. The high-voltage first normally closed contact HC12 remains closed when the relay is not activated, forming an electrical interlock in the high-voltage side disconnector opening control circuit 12. The high-voltage first normally open contact HC13 closes after the relay operates, used to connect the high-voltage side closing power circuit. The function of the high-voltage second power supply coil FC11 corresponds to that of the high-voltage first power supply coil HC11, but it is connected in series in the opening control circuit and is triggered by an opening command. The high-voltage second normally closed contact FC12 and the high-voltage first normally closed contact HC12 form an interlock relationship, ensuring that the closing and opening control circuits cannot be activated simultaneously.

[0044] Specifically, when the high-voltage grounding disconnect switch needs to perform a closing operation, the high-voltage side disconnect switch closing control circuit 11 is triggered and energized. The high-voltage first power supply coil HC11 is then energized and closes. At this time, the high-voltage first normally closed contact HC12 disconnects the high-voltage side disconnect switch opening control circuit 12, while the high-voltage first normally open contact HC13 closes to activate the high-voltage side closing power circuit. During this process, the high-voltage second normally closed contact FC12 remains closed to maintain the conduction of the closing control circuit. When the high-voltage grounding disconnect switch needs to perform a opening operation, the high-voltage side disconnect switch opening control circuit 12 is activated, energizing the high-voltage second power supply coil FC11. The high-voltage second normally closed contact FC12 immediately disconnects the closing control circuit, while the high-voltage second normally open contact FC13 closes to activate the high-voltage side opening power circuit. Through the cross-connection of the normally closed contacts of the two sets of relays with the power supply coils, a mutually exclusive logic for closing and opening operations is formed at the control circuit level. In the power circuit, the operation command and the actuator are linked through the action of the normally open contacts.

[0045] This solution employs an electrical interlocking design with two sets of relays to forcibly establish mutually exclusive conditions for closing and opening operations in the control circuit. Simultaneously, it ensures the uniqueness of operation commands through contact linkage in the power circuit, fundamentally eliminating the possibility of operational conflicts. During the closing operation, the opening control circuit is automatically disconnected to prevent the opening command from interfering with the grounding process; during the opening operation, the closing control circuit is simultaneously disconnected to ensure that the equipment cannot re-establish a connection before the grounding is removed. This relay-based electrical interlocking mechanism effectively improves the safety and reliability of high-voltage side grounding operations.

[0046] In some examples, such as Figure 4As shown, the high-voltage grounding device 10 is also equipped with a first auxiliary switch SQ1 and a second auxiliary switch SQ2. When the high-voltage grounding device 10 is in the closed state, triggering the first auxiliary switch SQ1 will disconnect and conduct. When the high-voltage grounding device 10 is in the open state, triggering the second auxiliary switch SQ2 will disconnect and conduct. The first auxiliary switch SQ1 is connected in series in the high-voltage side disconnector closing control circuit 11, and the second auxiliary switch SQ2 is connected in the high-voltage side disconnector opening control circuit 12. With this configuration, when the high-voltage grounding device 10 is closed, triggering the first auxiliary switch SQ1 will disconnect the high-voltage side disconnector closing control circuit 11, thereby stopping the first drive unit M1 from working. When the high-voltage grounding device 10 is open, triggering the second auxiliary switch SQ2 will disconnect the high-voltage side disconnector opening control circuit 12, thereby stopping the first drive unit M1 from working.

[0047] In some examples, such as Figure 5 As shown, the rail transit rectifier transformer traction power supply system 100 includes a low-voltage side disconnector closing control circuit 21 and a low-voltage side disconnector opening control circuit 22 for controlling the second drive unit M2, and a low-voltage side disconnector closing power circuit 23 and a low-voltage side disconnector opening power circuit 24 for executing the action of the second drive unit M2. The three-position disconnector 50 is equipped with a disconnector auxiliary switch SD1. When the three-position disconnector 50 is in a grounded state, the disconnector auxiliary switch SD1 is triggered, and the disconnector auxiliary switch SD1 is turned on. The high-voltage grounding device 10 is equipped with a high-voltage auxiliary switch GH1, and the high-voltage grounding device 10 is closed. When the state is active, the high-voltage auxiliary switch GH1 is triggered and the high-voltage auxiliary switch GH1 is turned on. The output unit 43 includes a third output D03 for outputting a low-voltage closing command and a fourth output D04 for outputting a low-voltage opening command. The disconnector auxiliary switch SD1, the high-voltage auxiliary switch GH1 and the third output D03 are connected in series in the low-voltage side disconnector closing control circuit 21. The disconnector auxiliary switch SD1, the high-voltage auxiliary switch GH1 and the fourth output D04 are connected in series in the low-voltage side disconnector opening control circuit 22. The low-voltage side disconnector closing control circuit 21 and the low-voltage side disconnector opening control circuit 22 are mutually exclusive conducting.

[0048] The low-voltage side disconnector closing control circuit 21 is an electrical circuit used to control the closing action of the low-voltage grounding disconnector. Its function is to ensure that the low-voltage side grounding operation is triggered only when the high-voltage side is grounded and the three-position disconnector 50 is in the correct position. The low-voltage side disconnector opening control circuit 22 is an electrical circuit used to control the opening action of the low-voltage grounding disconnector. Its structure can be interlocked with the low-voltage side disconnector closing circuit to prevent the closing and opening operations from being performed simultaneously. The disconnector auxiliary switch SD1 is a mechanical position sensor installed on the three-position disconnector 50. Specifically, it can be implemented using a limit switch or a micro switch. When the three-position disconnector 50 is in the grounded position, its contacts are open to verify that the main circuit has been physically isolated. The high-voltage auxiliary switch GH1 is a status detection switch installed on the high-voltage grounding device 10. Specifically, it can be a normally open contact linked with the high-voltage grounding disconnector. When the high-voltage grounding disconnector is fully closed, the contacts are closed to confirm that the high-voltage side has been reliably grounded.

[0049] Specifically, when the three-position disconnector 50 is not grounded, the auxiliary switch SD1 remains open, and the low-voltage side closing control circuit cannot be connected. When the high-voltage grounding device 10 is not closed, the high-voltage auxiliary switch GH1 remains open, similarly blocking the circuit. Only when both the auxiliary switch SD1 and the high-voltage auxiliary switch GH1 are closed and the third output D03 signal is valid, the low-voltage side disconnector closing control circuit 21 is connected, driving the second drive unit M2 to perform the closing operation. During the opening operation, it must be ensured that the three-position disconnector 50 is still grounded and the high-voltage grounding device 10 remains closed. At this time, the fourth output D04 signal triggers the opening control circuit, driving the low-voltage grounding disconnector to open.

[0050] This solution adds auxiliary switches to the three-position disconnector 50 and the high-voltage grounding device 10, and connects these status signals in series to the low-voltage side control circuit, thus enforcing the operating sequence at the hardware level. For example, even if the operator accidentally triggers the low-voltage closing command without confirming the high-voltage side grounding, the control circuit will still not conduct because the high-voltage auxiliary switch GH1 is not closed, fundamentally eliminating the dangerous operation of grounding the low-voltage side before the high-voltage side. This solution embeds the operating logic into the electrical circuit, avoiding potential logical loopholes in software control, such as malfunctions caused by program errors or communication interruptions. Simultaneously, the mutually exclusive conduction design prevents simultaneous execution of closing and opening operations, protecting the power circuit equipment from short-circuit current surges.

[0051] In some examples, such as Figure 5As shown, the rail transit rectifier transformer traction power supply system 100 includes a low-voltage first relay and a low-voltage second relay. The low-voltage first relay includes a low-voltage first power supply coil HC21, a low-voltage first normally closed contact HC22, and a low-voltage first normally open contact HC23. The low-voltage first power supply coil HC21 is connected in series with the low-voltage side disconnector closing control circuit 21, the low-voltage first normally closed contact HC22 is connected in series with the low-voltage side disconnector opening control circuit 22, and the low-voltage first open contact is connected in series with the low-voltage side closing power circuit. The low-voltage second relay includes a low-voltage second power supply coil FC21, a low-voltage second normally closed contact FC22, and a low-voltage second normally open contact FC23. The low-voltage second power supply coil FC21 is connected in series with the low-voltage side disconnector opening control circuit 22, the low-voltage second normally closed contact FC22 is connected in series with the low-voltage side disconnector closing control circuit 21, and the low-voltage second open contact is connected in series with the low-voltage side opening power circuit.

[0052] Specifically, when the low-voltage grounding disconnect switch needs to perform a closing operation, the low-voltage side disconnect switch closing control circuit 21 is triggered and energized. After the low-voltage first power supply coil HC21 is energized, it drives the low-voltage first normally closed contact HC22 to open. At this time, the low-voltage side disconnect switch opening control circuit 22 cannot form a closed loop because the low-voltage first normally closed contact HC22 is open, and the opening operation is forcibly blocked. Simultaneously, the low-voltage first normally open contact HC23 closes, causing the low-voltage side closing power circuit to conduct, driving the low-voltage grounding disconnect switch to complete the closing action. When the low-voltage grounding disconnect switch needs to perform an opening operation, the low-voltage side disconnect switch opening control circuit 22 is triggered and energized. After the low-voltage second power supply coil FC21 is energized, it drives the low-voltage second normally closed contact FC22 to open. At this time, the low-voltage side disconnect switch closing control circuit 21 cannot form a closed loop because the low-voltage second normally closed contact FC22 is open, and the closing operation is forcibly blocked. At the same time, the closure of the low-voltage second normally open contact FC23 enables the low-voltage side tripping power circuit to be connected, driving the low-voltage grounding switch to complete the tripping action.

[0053] This solution employs a dual-relay structure with cross-interlocked contacts to create a mechanically mutually exclusive conduction relationship at the control circuit level, ensuring complete time isolation between closing and opening operations. This effectively prevents accidents caused by incorrect operating sequences during maintenance of the low-voltage side grounding device, such as live connection or load-bearing opening. The mechanical interlocking characteristics of the relay contacts eliminate safety hazards caused by human error, while also preventing equipment malfunctions due to control circuit logic conflicts.

[0054] In some examples, such as Figure 5As shown, the low-voltage grounding device 20 is also equipped with a third auxiliary switch SQ3 and a fourth auxiliary switch SQ4. When the low-voltage grounding device 20 is in the closed state, triggering the third auxiliary switch SQ3 will disconnect and conduct. When the low-voltage grounding device 20 is in the open state, triggering the fourth auxiliary switch SQ4 will disconnect and conduct. The third auxiliary switch SQ3 is connected in series in the low-voltage side disconnector closing control circuit 21, and the fourth auxiliary switch SQ4 is connected in the low-voltage side disconnector opening control circuit 22. With this configuration, when the low-voltage grounding device 20 is closed, triggering the third auxiliary switch SQ3 will disconnect the low-voltage side disconnector closing control circuit 21, thereby stopping the second drive unit M2. When the low-voltage grounding device 20 is open, triggering the fourth auxiliary switch SQ4 will disconnect the low-voltage side disconnector opening control circuit 22, thereby stopping the second drive unit M2.

[0055] In one embodiment, such as Figure 6 As shown in the embodiments of this application, a method for preventing misoperation in a rail transit rectifier transformer traction power supply system is also provided. This method, applied to the rail transit rectifier transformer traction power supply system described in the above embodiments, specifically includes the following steps: 101. Inspect the maintenance status of the three-phase transformers in the traction power supply system of the rail transit rectifier transformer, and determine the type of interlocking operation for the rail transit rectifier transformer traction power supply system based on the maintenance status.

[0056] 102. When the interlocking operation type is grounding operation, the high-voltage detection device and the low-voltage detection component of the low-voltage grounding device collect the energized status of the high-voltage side and low-voltage side of the three-phase transformer. The integrated control device performs anti-misoperation judgment on the high-voltage and low-voltage grounding operations based on the energized status of the high-voltage side, the energized status of the low-voltage side, the disconnection status of the three-position disconnector, the opening and closing status of the high-voltage grounding device, and the opening and closing status of the low-voltage grounding device. Based on the result of the anti-misoperation judgment, the high-voltage grounding device and the low-voltage grounding device are controlled to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially.

[0057] 103. When the interlocking operation type is the ground wire removal operation, the integrated control device makes a misjudgment of the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high voltage grounding device and the opening and closing status of the low voltage grounding device, and controls the high voltage grounding device and the low voltage grounding device to open in sequence based on the result of the misjudgment, so that the high voltage side and the low voltage side of the three-phase transformer are disconnected from the ground in sequence.

[0058] The interlocking operation is divided into two modes: grounding wire operation and grounding wire removal operation. Specifically, it can be implemented through the operation command input module or the automatic status recognition module to distinguish between the installation and removal processes of high and low voltage grounding.

[0059] Specifically, when a three-phase transformer is detected to be in maintenance mode, the system selects either grounding operation or grounding wire removal operation mode based on maintenance requirements. In grounding mode, the high-voltage detection device and low-voltage detection component collect electrical parameters, and the integrated control device receives the mechanical position signals of the three-position disconnector, the open / closed position signals of the high-voltage grounding device, and the open / closed position signals of the low-voltage grounding device. When all input signals meet the conditions (e.g., high-voltage side voltage is below the safety threshold, low-voltage side current approaches zero, three-position disconnector is in the grounding position, and both high- and low-voltage grounding disconnectors are in the open state), the integrated control device generates a closing command. In grounding wire removal mode, the integrated control device continuously monitors the closing status of the high- and low-voltage grounding disconnectors. When the three-position disconnector remains in the grounding position and both high- and low-voltage grounding disconnectors are in the closed state, the integrated control device generates a opening command.

[0060] Through the above technical solution, this application solves the problem that manual operation cannot achieve equipment status interlocking and forced control of operation sequence, eliminating the safety hazard of live grounding caused by misoperation during maintenance. By automatically detecting the live status of the high and low voltage sides and forming an electrical interlock with the three-position disconnect switch, the risk of oversight by manual voltage testing is avoided. The step-by-step sequence control strategy of high and low voltage grounding devices ensures that the operating procedure of prioritizing grounding of the high voltage side and prioritizing removal of the low voltage side is strictly implemented, fundamentally protecting the personal safety of maintenance personnel and the safety of equipment.

[0061] In some examples, the method of preventing misoperation of high- and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device, and controlling the high-voltage grounding device and the low-voltage grounding device to close sequentially based on the result of the misoperation prevention judgment, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially, includes: When the high-voltage side is de-energized, the low-voltage side is de-energized, the three-position disconnector is in the grounded state, the high-voltage grounding device is in the open state, and the low-voltage grounding device is in the open state, the integrated control device controls the high-voltage grounding device to close; it then determines whether the high-voltage grounding device is closed, and if so, the integrated control device controls the low-voltage grounding device to close.

[0062] Compared to existing technologies, current grounding operations rely on manual voltage testing and manual connection of grounding wires, which cannot monitor equipment status in real time and lack interlocking with upstream equipment. This solution, however, uses automated status detection and sequential control to mandate that the high-voltage and low-voltage sides be grounded sequentially. Through a step-by-step verification mechanism, this solution ensures that the low-voltage side is grounded only after the high-voltage side is completed, avoiding the risk of electrical surges caused by simultaneous operations.

[0063] In some examples, the method of preventing misoperation of high and low voltage grounding disconnection operations based on the disconnector status of the three-position disconnector, the open / closed status of the high-voltage grounding device, and the open / closed status of the low-voltage grounding device, and controlling the high-voltage grounding device and low-voltage grounding device to open sequentially based on the result of the misoperation prevention judgment, so that the high-voltage side and low-voltage side of the three-phase transformer are disconnected from the grounding sequentially, includes: When the three-position disconnector is in the grounding state, the high-voltage grounding device is in the closed state, and the low-voltage grounding device is in the closed state, the integrated control device controls the low-voltage grounding device to open; it then determines whether the low-voltage grounding device has opened, and if so, the integrated control device controls the high-voltage grounding device to open.

[0064] When both the high-voltage and low-voltage grounding devices are detected to be in the closed state, the integrated control device generates a low-voltage trip command and sends it to the control circuit of the low-voltage grounding device. Only after confirming that the low-voltage side has been fully tripped will the integrated control device send a trip command to the high-voltage grounding device.

[0065] Through the above technical solution, this application effectively prevents the risk of equipment energization caused by incorrect grounding device tripping sequence, ensuring operational safety when the system restores power after maintenance. By mandating tripping sequence interlocking, it avoids residual charge on the high-voltage side from forming a loop through the undisconnected grounded low-voltage side, and eliminates potential judgment errors or operational oversights during manual operation.

[0066] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A rectifier transformer traction power supply system for rail transit, characterized in that, It includes a high-voltage grounding device, a low-voltage grounding device, a high-voltage detection device, a comprehensive control device, and a three-position disconnect switch, a circuit breaker, and a three-phase transformer connected in series; among which, The high-voltage grounding device and the low-voltage grounding device are respectively installed on the high-voltage side and the low-voltage side of the three-phase transformer. The integrated control device is connected to the three-position disconnect switch, the high-voltage detection device, the high-voltage grounding device and the low-voltage grounding device respectively. The high-voltage detection device is also connected to the high-voltage side of the three-phase transformer to collect the energized state of the high-voltage side of the three-phase transformer. The low-voltage grounding device has a built-in low-voltage detection component for collecting the energized state of the low-voltage side of the three-phase transformer. During the grounding process, the integrated control device performs anti-misoperation judgment on the high-voltage and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device. Based on the result of the anti-misoperation judgment, it controls the high-voltage grounding device and the low-voltage grounding device to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially. During the removal of the grounding wire, the integrated control device performs a fault prevention judgment on the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high voltage grounding device and the opening and closing status of the low voltage grounding device, and controls the low voltage grounding device and the high voltage grounding device to open in sequence based on the fault prevention judgment result, so that the low voltage side and the high voltage side of the three-phase transformer are disconnected from the grounding in sequence.

2. The rail transit rectifier transformer traction power supply system as described in claim 1, characterized in that, The integrated control device includes a communication unit, an input unit, an output unit, and a main control unit; The communication unit is connected to the high-voltage detection device and the low-voltage detection component via a bus, respectively, and is used to collect the energized state of the high-voltage side and the low-voltage side. The main control unit is connected to the communication unit, the input unit, and the output unit, respectively. During the grounding process, the main control unit, based on the switch status of the three-position disconnector, the open / closed status of the high-voltage grounding device, the open / closed status of the low-voltage grounding device, the energized status of the high-voltage side, and the energized status of the low-voltage side received by the input unit, outputs closing commands to the high-voltage grounding device and the low-voltage grounding device respectively through the output unit. During the removal of the grounding wire, the main control unit, based on the status of the three-position disconnector, the open / closed status of the high-voltage grounding device, and the open / closed status of the low-voltage grounding device received by the input unit, outputs a tripping command to the low-voltage grounding device and the high-voltage grounding device respectively through the output unit.

3. The rail transit rectifier transformer traction power supply system as described in claim 2, characterized in that, The high-voltage grounding device includes a high-voltage grounding switch and a first driving unit. The first driving unit drives the high-voltage grounding switch to close or open based on the high-voltage closing command or high-voltage opening command output by the opening unit, so as to realize the high-voltage side grounding or disconnection of the three-phase transformer. The low-voltage grounding device includes a low-voltage grounding switch and a second driving unit. The second driving unit drives the low-voltage grounding switch to close or open based on the low-voltage closing command or low-voltage opening command output by the opening unit, so as to realize the low-voltage side grounding or disconnection of the three-phase transformer.

4. The rail transit rectifier transformer traction power supply system as described in claim 3, characterized in that, It includes a high-voltage side disconnector closing control circuit and a high-voltage side disconnector opening control circuit for controlling the first drive unit, and a high-voltage side disconnector closing power circuit and a high-voltage side disconnector opening power circuit for executing the operation of the first drive unit. The three-position disconnect switch is equipped with a disconnect switch auxiliary switch. When the grounding state of the three-position disconnect switch is grounded, the disconnect switch auxiliary switch is triggered and the disconnect switch is turned on. The low-voltage grounding device is equipped with a low-voltage auxiliary switch. When the low-voltage grounding device is in the open state, the low-voltage auxiliary switch is triggered and the low-voltage auxiliary switch is turned on. The output unit includes a first output for outputting the high-voltage closing command and a second output for outputting the high-voltage opening command; The auxiliary switch, the low-voltage auxiliary switch, and the first switch are connected in series in the high-voltage side disconnector closing control circuit. The auxiliary switch, the low-voltage auxiliary switch, and the second switch are connected in series in the high-voltage side disconnector opening control circuit. The high-voltage side disconnector closing control circuit and the high-voltage side disconnector opening control circuit are mutually exclusive.

5. The rail transit rectifier transformer traction power supply system as described in claim 4, characterized in that, Including a high-voltage first relay and a high-voltage second relay; The high-voltage first relay includes a high-voltage first power supply coil, a high-voltage first normally closed contact, and a high-voltage first normally open contact. The high-voltage first power supply coil is connected in series with the high-voltage side disconnector closing control circuit, the high-voltage first normally closed contact is connected in series with the high-voltage side disconnector opening control circuit, and the high-voltage first open contact is connected in series with the high-voltage side closing power circuit. The high-voltage second relay includes a high-voltage second power supply coil, a high-voltage second normally closed contact, and a high-voltage second normally open contact. The high-voltage second power supply coil is connected in series in the high-voltage side disconnector opening control circuit, the high-voltage second normally closed contact is connected in series in the high-voltage side disconnector closing control circuit, and the high-voltage second open contact is connected in series in the high-voltage side disconnector power circuit.

6. The rail transit rectifier transformer traction power supply system as described in claim 3, characterized in that, It includes a low-voltage side disconnector closing control circuit and a low-voltage side disconnector opening control circuit for controlling the second drive unit, and a low-voltage side disconnector closing power circuit and a low-voltage side disconnector opening power circuit for executing the operation of the second drive unit; The three-position disconnect switch is equipped with a disconnect switch auxiliary switch. When the grounding state of the three-position disconnect switch is grounded, the disconnect switch auxiliary switch is triggered and the disconnect switch is turned on. The high-voltage grounding device is equipped with a high-voltage auxiliary switch. When the high-voltage grounding device is in the closed state, the high-voltage auxiliary switch is triggered and the high-voltage auxiliary switch is turned on. The output unit includes a third output for outputting the low-voltage closing command and a fourth output for outputting the low-voltage opening command; The auxiliary switch, the high-voltage auxiliary switch, and the third switch are connected in series in the low-voltage side disconnector closing control circuit. The auxiliary switch, the high-voltage auxiliary switch, and the fourth switch are connected in series in the low-voltage side disconnector opening control circuit. The low-voltage side disconnector closing control circuit and the low-voltage side disconnector opening control circuit are mutually exclusive.

7. The rail transit rectifier transformer traction power supply system as described in claim 6, characterized in that, Including a low-voltage first relay and a low-voltage second relay; The low-voltage first relay includes a low-voltage first power supply coil, a low-voltage first normally closed contact, and a low-voltage first normally open contact. The low-voltage first power supply coil is connected in series with the low-voltage side disconnector closing control circuit, the low-voltage first normally closed contact is connected in series with the low-voltage side disconnector opening control circuit, and the low-voltage first open contact is connected in series with the low-voltage side closing power circuit. The low-voltage second relay includes a low-voltage second power supply coil, a low-voltage second normally closed contact, and a low-voltage second normally open contact. The low-voltage second power supply coil is connected in series with the low-voltage side disconnector opening control circuit, the low-voltage second normally closed contact is connected in series with the low-voltage side disconnector closing control circuit, and the low-voltage second open contact is connected in series with the low-voltage side disconnector power circuit.

8. A method for preventing misoperation in a rail transit rectifier transformer traction power supply system, applied to the rail transit rectifier transformer traction power supply system as described in any one of claims 1-7, characterized in that, The method includes: The maintenance status of the three-phase transformer in the traction power supply system of the rail transit rectifier transformer is detected, and the type of interlocking operation for the rail transit rectifier transformer traction power supply system is determined based on the maintenance status. When the blocking operation type is grounding operation, the high-voltage detection device and the low-voltage detection component of the low-voltage grounding device collect the energized state of the high-voltage side and the low-voltage side of the three-phase transformer. The integrated control device performs anti-misoperation judgment on the high-voltage and low-voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device. Based on the result of the anti-misoperation judgment, the high-voltage grounding device and the low-voltage grounding device are controlled to close sequentially, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially. When the interlocking operation type is a ground wire removal operation, the integrated control device performs a fault prevention judgment on the high and low voltage grounding removal operation based on the disconnection status of the three-position disconnector, the opening and closing status of the high voltage grounding device and the opening and closing status of the low voltage grounding device, and controls the low voltage grounding device and the high voltage grounding device to open in sequence based on the fault prevention judgment result, so that the low voltage side and the high voltage side of the three-phase transformer are disconnected from the ground in sequence.

9. The anti-misoperation interlocking method for the traction power supply system of a rail transit rectifier transformer as described in claim 8, characterized in that, The method of performing error prevention judgment on high and low voltage grounding operations based on the energized state of the high-voltage side, the energized state of the low-voltage side, the disconnection state of the three-position disconnector, the opening and closing state of the high-voltage grounding device, and the opening and closing state of the low-voltage grounding device, and controlling the high-voltage grounding device and the low-voltage grounding device to close sequentially based on the error prevention judgment result, so that the high-voltage side and the low-voltage side of the three-phase transformer are grounded sequentially, includes: When the high-voltage side is de-energized, the low-voltage side is de-energized, the three-position disconnector is in a grounded state, the high-voltage grounding device is in an open state, and the low-voltage grounding device is in an open state, the integrated control device controls the high-voltage grounding device to close. Determine whether the high-voltage grounding device is closed. If so, the integrated control device controls the low-voltage grounding device to close.

10. The anti-misoperation interlocking method for the traction power supply system of a rail transit rectifier transformer as described in claim 8, characterized in that, The method for preventing errors in high- and low-voltage grounding disconnection operations based on the disconnector status of the three-position disconnector, the open / closed status of the high-voltage grounding device, and the open / closed status of the low-voltage grounding device, and controlling the low-voltage grounding device and the high-voltage grounding device to open sequentially based on the result of the error prevention judgment, so that the low-voltage side and the high-voltage side of the three-phase transformer are disconnected from the ground in sequence, includes: When the disconnector state of the three-position disconnector is grounded, the high-voltage grounding device is closed, and the low-voltage grounding device is closed, the integrated control device controls the low-voltage grounding device to open. Determine whether the low-voltage grounding device has tripped; if so, the integrated control device controls the high-voltage grounding device to trip.

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