Urban rail transit vehicle and air compressor control system therefor, and air compressor start-stop control method

Abstract

An urban rail transit vehicle and an air compressor control system therefor, and an air compressor start-stop control method. The method comprises: if at least one auxiliary inverter of an urban rail transit train is successfully started and the total air pressure value is less than a first set value, sending a starting instruction to one air compressor; and determining whether the total air pressure value is less than a second set value, and if yes, when all the auxiliary inverters are started, sending the starting instruction to the other air compressor. According to the present invention, the pressure of an air supply module of a train braking system and air compressor devices can be dynamically controlled on the basis of the train operation condition and the device maintenance state, so that overcurrent protection or damage failures of the auxiliary converters can be effectively avoided, thereby improving the operation reliability of trains.

Description

Urban rail vehicle, air compressor control system, and air compressor start-stop control method Technical Field

[0001] The present invention relates to the technical field of rail transportation, and in particular to an urban rail vehicle and an air compressor control system and an air compressor start-stop control method thereof. Background Art

[0002] In existing technology, the braking system of urban rail trains relies on an auxiliary inverter to drive an air compressor to provide air for the braking system. All pressure sensors on the main air duct are set to 7.0-9.0 bar (bar is a unit of pressure), and the air compressor is controlled by hard wiring to start and stop. When the pressure falls below 7.0 bar, relays K1 and K2 close, and the air compressor starts operating. When the pressure reaches 9.0 bar, relays K1 and K2 open, and the air compressor stops pressurizing. A schematic diagram of the control system is shown in Figure 1.

[0003] Typically, each train is equipped with four auxiliary inverters and two air compressors, and the air supply module is equipped with two pressure switches. The signals from the two pressure switches in the air supply module are ORed together to control K1 and K2, causing air compressors 1 and 2 to operate simultaneously.

[0004] The train's auxiliary inverters use a grid-connected power supply to provide AC power to train equipment. Because grid connection of all auxiliary inverters takes time, the power capacity and maximum inrush current available to all equipment are limited until this stage is complete. Consequently, during train startup, the two air compressors cannot be started simultaneously to increase pressure due to the incomplete grid connection of the auxiliary inverters. However, existing startup and control systems do not account for this scenario, and during train startup, overcurrent protection or damage to the auxiliary inverters could occur, impacting train operations.

[0005] At the same time, in the existing technical solution, the air compressor is completely controlled by the pressure sensor hard line, and there is no program or personnel manual control interface. The pressure of the train braking system air supply module and the air compressor equipment cannot be dynamically controlled according to the train operation status and equipment maintenance status, and no operating interface can be provided for manual adjustment by staff.

[0006] The existing startup and control system uses only the pressure sensor signal as the control input, lacks redundant backup control, and does not provide a control interface for train operators or the train control system (TCMS). In addition, the two air compressors are controlled simultaneously based on the status of any unit pressure switch, which has certain usability defects.

[0007] The existing control solution's logic is relatively simple and cannot determine or distinguish the startup and operating status of the train and other onboard equipment. It cannot handle even slightly more complex startup and control logic, and its reliability, scalability, and maintainability cannot be fully guaranteed. It also cannot support future features such as intelligent train maintenance. The existing system has the following issues: During train startup, insufficient air pressure in the main air duct may cause both air compressors to start simultaneously. In this case, because the auxiliary inverter is not fully connected to the grid, the startup inrush current of the two air compressors is too high, exceeding the maximum inrush current provided by the train's auxiliary inverter, causing the auxiliary inverter to overcurrent protection or damage. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an urban rail vehicle and its air compressor control system, and an air compressor start-stop control method to dynamically control the pressure of the air supply module of the train braking system and the air compressor equipment.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a control system for an urban rail vehicle air compressor, comprising a first pressure sensor and a second pressure sensor arranged in a main air duct; a first air compressor and a second air compressor are provided on the main air duct, and the first air compressor and the second air compressor are connected to the AC bus through the normally open contact of the first relay and the normally open contact of the second relay respectively; the first pressure sensor and the second pressure sensor are both connected to the TCMS control network; the I / O port of the first pressure sensor and the I / O port of the second pressure sensor are respectively connected to the two normally open contacts of the fourth relay; the two normally open contacts of the fourth relay are respectively connected in parallel with the first normally closed contact and the second normally closed contact of the fourth relay, and the two parallel branches are respectively connected to the coil of the first relay and the coil of the second relay; the coil of the first relay and the coil of the second relay are respectively connected to the first normally closed contact and the second normally closed contact of the fourth relay; the two normally closed contacts of the fourth relay are both connected to the TCMS control network bus; the coil of the fourth relay is connected to the emergency traction button.

[0010] This invention shifts the air compressor control system from hardwired control to a train control system (TCMS). All pressure sensor signals on the train should be accessible to the TCMS, and the startup status of all auxiliary inverters should be available to the TCMS from the train control network (MVB). These two signals can be used in the control logic, allowing the two air compressors on the train to be started and stopped independently under TCMS control. This allows for dynamic control of the pressure in the train's brake system's air supply module and the air compressors. Furthermore, this invention incorporates both hardwired and network control redundancy to mitigate TCMS failures, thereby increasing vehicle availability.

[0011] In the present invention, the two normally open contacts of the fourth relay are connected to the normally open contacts of the third relay and the normally open contacts of the fifth relay, respectively; the normally open contact of the third relay is connected to the coil of the fifth relay; the coil of the fifth relay shares a common ground with the coil of the first relay; and the coil of the third relay is connected to the AC bus via a voltage sensor. The fifth relay can be a time-delay relay to facilitate delayed start and stop control of the air compressor.

[0012] The AC bus is connected to a plurality of auxiliary inverters; the network interfaces of the plurality of auxiliary inverters are all connected to the TCMS control network bus.

[0013] As an inventive concept, the present invention also provides a method for controlling the start and stop of an air compressor using the above-mentioned urban rail vehicle air compressor control system, the method comprising:

[0014] S1. If at least one auxiliary inverter of the urban rail train is successfully started and the total air pressure value is less than a first set value, a start command is sent to the first air compressor;

[0015] S2. Determine whether the total wind pressure value is lower than a second set value. If so, send a start command to the second air compressor when all auxiliary inverters have completed startup.

[0016] The first set value is greater than the second set value; the total wind pressure value is obtained through the first pressure sensor or the second pressure sensor.

[0017] The present invention can dynamically control the pressure of the air supply module of the train braking system and the air compressor equipment according to the train operation situation and equipment maintenance status, thereby realizing precise start and stop control of the air compressor.

[0018] In the present invention, after determining that the total wind pressure value is lower than the second set value and before determining whether all auxiliary inverters have completed startup, the following operation is further performed: determining whether the first air compressor has been started, and if not, starting the first air compressor.

[0019] In the present invention, if at least one auxiliary inverter of the urban rail train is successfully started and the total wind pressure value is not less than the first set value, the process returns to step S2 after a delay of a set time.

[0020] In the present invention, when a start command is sent to the first air compressor and the total air pressure value is not lower than the second set value, or after starting the two air compressors, the following operations are also performed:

[0021] Determine whether the total air pressure value is greater than the first set value. If so, return to step S2 after a delay of the set time; otherwise, determine whether the air compressor startup time exceeds the set time. If it exceeds the set time, the TCMS system issues a fault command. If it does not exceed the set time, re-determine whether the total air pressure is greater than the first set value.

[0022] In the present invention, in order to facilitate the provision of an operating interface for manual adjustment by staff, after the TCMS system issues a fault command, it determines whether the second air compressor has been started. If not, the first air compressor is turned off, the start time of the first air compressor is reset, and the second air compressor is started; otherwise, the second air compressor is shut down.

[0023] The present invention also provides a rail transit vehicle, which adopts the above-mentioned urban rail vehicle air compressor control system.

[0024] Compared with the existing technology, the beneficial effects of the present invention are: the present invention can dynamically control the pressure of the air supply module and the air compressor equipment of the train braking system according to the train operation conditions and equipment maintenance status, which can effectively avoid overcurrent protection or damage failure of the auxiliary converter, and improve the train operation reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the current air compressor control logic diagram;

[0026] FIG2 is a circuit diagram of an embodiment of the present invention;

[0027] FIG3 is a flow chart of the start and stop control of an air compressor according to an embodiment of the present invention;

[0028] FIG4 is a flow chart of emergency traction control according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0030] In this document, the terms "first", "second" and other similar words are not intended to imply any order, quantity and importance, but are merely used to distinguish different elements. In this document, the terms "one", "an" and other similar words are not intended to indicate that there is only one of the things described, but rather that the relevant description is only for one of the things described, and the things described may have one or more. In this document, the terms "comprise", "include" and other similar words are intended to indicate logical relationships, and cannot be regarded as indicating relationships in spatial structure. For example, "A includes B" is intended to indicate that B logically belongs to A, and does not mean that B is spatially located inside A. In addition, the meanings of the terms "comprise", "include" and other similar words should be regarded as open, not closed. For example, "A includes B" is intended to indicate that B belongs to A, but B does not necessarily constitute the whole of A, and A may also include other elements such as C, D, and E. Example

[0031] In this embodiment of the present invention, the air compressor is controlled by the TCMS control unit. The TCMS control unit obtains data such as total air pressure and the operating status of the auxiliary inverter through the TCMS control network as input to the operational control logic. Furthermore, an emergency traction control circuit is added to the train to ensure that the air compressor can operate correctly during emergency traction.

[0032] The circuit control logic of this embodiment is shown in Figure 2. When the train is operating normally, the emergency traction knob is not operated, relay K4 is de-energized, K4's normally open contact disconnects the pressure sensor IO output signal, and K4's normally closed contact closes. The TCMS control unit's IO signal controls the start and stop of the air compressor through the TCMS control network. Based on the start signal received from the auxiliary inverter network interface, the grid connection completion signal, and the actual value of the pressure sensor, the TCMS control unit outputs an IO signal to control contactor K1 to be energized. After K1 is energized, its normally open contact closes, and air compressor 1 starts. After a delay of a set period of time after air compressor 1 starts, the TCMS control unit outputs an IO signal to energize contactor K2. After K2 is energized, the normally open contact closes, and air compressor 2 starts. When the pressure sensor pressure reaches 9.0 BAR, the TCMS control unit shuts down all air compressors and outputs a low-level IO signal.

[0033] In the event of a vehicle failure or emergency traction, the TCMS control network or TCMS control unit may be unavailable. By operating the emergency traction knob, the operator energizes relay K4, closing its normally open contact and connecting the pressure sensor IO output signal. Simultaneously, the normally closed contact of K4 opens, disconnecting the TCMS control unit IO output. When an auxiliary inverter on the train is activated, it outputs three-phase AC voltage. Upon detecting the presence of three-phase AC voltage, the three-phase voltage contactor K3 energizes, closing its normally open contact. When pressure sensor 1 or 2 detects a pressure below 7.0 bar, it outputs a high-level signal. At this time, contactor K1 is energized. After K1 is energized, the normally open contact closes, and air compressor 1 starts. At the same time, delay relay K5 is also energized. After the preset delay time, it can ensure that other auxiliary inverters complete startup and grid connection. At this time, K5 normally open contact closes, contactor K2 is energized. After K2 is energized, the normally open contact closes, and air compressor 2 starts, thereby realizing staggered start of the air compressor under emergency traction status. Example

[0034] This embodiment provides an air compressor start-stop control method, as shown in FIG3 , and the specific implementation process is as follows.

[0035] After the train vehicle is activated, the driver controls the pantograph to rise, the TCMS control unit completes the startup, detects the startup status of the auxiliary inverter in real time, and monitors the startup status of all auxiliary inverters. At the same time, the TCMS control unit collects the total wind pressure value of the braking system in real time.

[0036] When the TCMS control unit detects that at least one auxiliary inverter has successfully started and the total air pressure is less than 9.0 BAR, the TCMS control unit immediately starts air compressor 1. If the total air pressure is less than 7.0 BAR at this time, the control unit checks whether all auxiliary inverters have started. Once all auxiliary inverters have started, it starts air compressor 2. Low air pressure can affect the vehicle's air brake and emergency brake. To avoid the risk of air brake failure and vehicle braking, when the total air pressure is detected to be less than 7.0 BAR, both air compressors are started simultaneously to increase the air pressure to 9.0 BAR in the shortest possible time, ensuring normal use of the air brake and ensuring operational safety. To ensure that the output capacity and surge current resistance of the auxiliary inverter meet the air compressor startup and operating conditions, the number of auxiliary inverters in operation must be determined when the air compressor is started.

[0037] After starting the air compressor, the TCMS control unit records and monitors the air compressor operating time in real time. If the total air pressure still fails to reach the preset value (9.0 BAR) after the air compressor has been running for more than 25 minutes (the time can be set), the TCMS control unit will report a fault and check whether both air compressors are fully turned on. If only air compressor 1 is started on the train at this time, air compressor 1 will be turned off, the operating time of air compressor 1 will be reset, and air compressor 2 will be started. According to the air volume calculation of a single air compressor, the total air pressure can reach the preset value (9.0 BAR) after 25 minutes (the time can be set) of continuous air blowing. If the total air pressure value does not reach the preset value after this time, it can be judged that the air compressor is faulty or there is an air leakage in the air circuit. Therefore, air compressor 1 will be turned off and air compressor 2 will be turned on to repeat the total air pressure value. This solution is generally performed before the train is put into operation, which can effectively avoid the occurrence of situations such as passenger clearance or rescue due to vehicle failure operation.

[0038] When the total air pressure reaches the high pressure setting value (9.0BAR), the TCMS control unit shuts down all air compressors and waits for the total air pressure to drop to the low pressure setting value (7.0BAR). When the total air pressure reaches the high pressure setting value (9.0BAR), it indicates that the maximum operating air pressure has been reached. The total air pressure will decrease during the vehicle's braking process. When the total air pressure is less than 6.0BAR, the air brake may become unavailable during operation, and the vehicle will not be able to brake. Therefore, the TCMS will perform a traction blockade when it detects that the total air pressure has dropped to less than 6.0BAR. To avoid triggering a traction blockade due to low total air pressure during vehicle operation, the TCMS will simultaneously start both air compressors to blow air when it detects that the total air pressure has dropped to the low pressure setting value (7.0BAR), so that the total air pressure reaches the high pressure setting value (9.0BAR).

[0039] At the same time, the TCMS controller is also equipped with an air compressor start button on the train display. When the staff is performing maintenance, the air compressor can be automatically started according to demand. At this time, the start and stop of the air compressor are operated by the staff within the preset safe total air pressure value range.

[0040] In this embodiment, as shown in FIG4 , the emergency traction control logic is as follows:

[0041] Operate the emergency traction knob to enter emergency traction mode. At this point, relay K4 is energized, closing its normally open contact and connecting the pressure sensor output signal. K4's normally closed contact opens, disconnecting the TCMS I / O output. When at least one auxiliary inverter in the train is successfully started, it outputs three-phase AC voltage.

[0042] At this time, the three-phase voltage contactor K3 on the power supply detects a valid power signal and is energized, and the normally open contact of K3 is closed. At this time, if the pressure sensor 1 or 2 detects that the pressure is lower than 7.0 BAR, it will output a high-level IO signal, so that the contactor K1 is energized.

[0043] After K1 is energized, the normally open contact closes, and air compressor 1 starts. At the same time, the delay relay K5 is also energized. After a delay period (which can be set), other auxiliary inverters can be guaranteed to complete startup and grid connection. The normally open contact of K5 closes, and contactor K2 is energized. After K2 is energized, the normally open contact closes, and air compressor 2 starts, thereby achieving staggered starting.

[0044] When the air compressor is started, when pressure sensor 1 or 2 detects that the pressure is higher than 9.0 BAR, it outputs a low-level IO signal, causing K1 and K2 to lose power, the normally open contacts of K1 and K2 to disconnect, and air compressor 1 and air compressor 2 to stop working. Example

[0045] Embodiment 3 of the present invention provides an urban rail vehicle corresponding to the above-mentioned embodiment 1, and the vehicle adopts the control circuit of embodiment 1.

[0046] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0047] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. An air compressor control system for urban rail vehicles, comprising a first pressure sensor and a second pressure sensor arranged in the main air duct; a first air compressor and a second air compressor are provided on the main air duct, and the first air compressor and the second air compressor are respectively connected to the AC bus through the normally open contacts of a first relay and the normally open contacts of a second relay; characterized in that, The first pressure sensor and the second pressure sensor are both connected to the TCMS control network; the I / O ports of the first pressure sensor and the I / O ports of the second pressure sensor are respectively connected to two normally open contacts of the fourth relay; the two normally open contacts of the fourth relay are respectively connected in parallel with the first normally closed contact and the second normally closed contact of the fourth relay, and the two parallel branches are respectively connected to the coils of the first relay and the second relay; the coils of the first relay and the second relay are respectively connected to the first normally closed contact and the second normally closed contact of the fourth relay; the two normally closed contacts of the fourth relay are both connected to the TCMS control network bus; the coil of the fourth relay is connected to the emergency traction button.

2. The air compressor control system for urban rail vehicles according to claim 1, characterized in that, The two normally open contacts of the fourth relay are respectively connected to the normally open contact of the third relay and the normally open contact of the fifth relay; the normally open contact of the third relay is connected to the coil of the fifth relay; the coil of the fifth relay is grounded together with the coil of the first relay; the coil of the third relay is connected to the AC bus through a voltage sensor.

3. The air compressor control system for urban rail vehicles according to claim 1, characterized in that, The two normally open contacts of the fourth relay are respectively connected to the normally open contact of the third relay and the normally open contact of the fifth relay; the normally open contact of the third relay is connected to the coil of the fifth relay; the coil of the fifth relay is grounded together with the coil of the first relay; the coil of the third relay is connected to the AC bus through a voltage sensor.

4. A method for controlling the start and stop of an air compressor of an urban rail vehicle by using the air compressor control system of the urban rail vehicle according to any one of claims 1 to 3, characterized in that, The method includes: S1. If at least one auxiliary inverter of the urban rail train is successfully started and the total air pressure value is less than the first set value, a start command is sent to the first air compressor. S2. Determine whether the total air pressure value is lower than the second set value. If so, when all the auxiliary inverters are successfully started, a start command is sent to the second air compressor. The first set value is greater than the second set value; the total air pressure value is obtained through the first pressure sensor or the second pressure sensor.

5. The method according to claim 4, wherein After determining that the total air pressure value is lower than the second set value and before determining whether all the auxiliary inverters are successfully started, the following operations are also performed: Determine whether the first air compressor has been started. If not, start the first air compressor.

6. The method according to claim 4, wherein If at least one auxiliary inverter of the urban rail train is successfully started and the total air pressure value is not less than the first set value, after a set time delay, return to step S2.

7. The method according to claim 4, wherein When a start command is sent to the first air compressor and the total air pressure value is not lower than the second set value, or after starting two air compressors, the following operations are also performed: Determine whether the total air pressure value is greater than the first set value. If so, after a set time delay, return to step S2; otherwise, determine whether the start time of the air compressor exceeds the set time. If it exceeds the set time, the TCMS system issues a fault command. If it does not exceed the set time, re-determine whether the total air pressure is greater than the first set value.

8. The method according to claim 7, wherein After the TCMS system issues a fault command, determine whether the second air compressor has been started. If not, turn off the first air compressor, reset the start time of the first air compressor, and start the second air compressor; otherwise, turn off the second air compressor.

9. The method according to claim 7, wherein After the TCMS system issues a fault command, it determines whether the second air compressor has been started. If not, it shuts down the first air compressor, resets the start time of the first air compressor, and starts the second air compressor; otherwise, it shuts down the second air compressor.

10. The method according to claim 7, wherein After the TCMS system issues a fault command, it determines whether the second air compressor has been started. If not, it shuts down the first air compressor, resets the start time of the first air compressor, and starts the second air compressor; otherwise, it shuts down the second air compressor.

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