Traction systems, methods, electronic equipment and storage media for rail transit vehicles

Abstract

This invention relates to the field of rail transit and discloses a traction system, method, electronic device, and storage medium for rail transit vehicles. The traction system includes a traction inverter, a traction motor, a battery power supply path, an auxiliary converter, and a control unit. When the rail transit vehicle is in battery traction mode, the control unit controls the battery power supply branch to draw power from the battery, and the auxiliary converter boosts the obtained DC power before providing it to the traction inverter for conversion into three-phase AC power to drive the traction motor. Furthermore, when the rail transit vehicle is in external power supply traction mode, the control unit controls the traction inverter to draw power from the external AC power grid and converts the obtained electrical energy into three-phase AC power to drive the traction motor. This solution provides traction power for multiple scenarios, including battery traction mode and external power supply traction mode, allowing the vehicle to flexibly switch traction modes according to actual scenario requirements.

Description

Technical Field

[0001] This invention relates to the field of rail transit, and particularly to a traction system, method, electronic device, and storage medium for rail transit vehicles. Background Technology

[0002] Rail transit vehicles are powered by an external power grid. After power is supplied to the vehicle, it drives the traction motor through the onboard traction system to provide power. Due to the design requirements of rail transit lines, not all sections of the line can provide power to the vehicles; there are areas without power, such as phase-splitting areas, entry and exit points, and outdoor parking lots. If a rail transit vehicle stops in an area without power due to an anomaly, the external power supply cannot provide energy to the traction system to move the vehicle away from the area, leading to line rescue operations. This will have a significant impact on the operation and maintenance of rail transit vehicles and the line.

[0003] For areas without electricity on rail transit lines, there are various scenarios, such as phase separation zones on the main line, access lines between stations, car wash lines, outdoor parking lots, etc. The conditions such as the slope and length of the line are different for different areas without electricity. Therefore, the battery traction mode needs to comprehensively consider all operating conditions and have the ability to operate on steep slopes and over long distances.

[0004] Existing rail transit vehicle battery traction system technologies focus on directly powering the traction inverter through the battery, with the traction inverter performing power conversion. Due to the low battery voltage, the output of the traction inverter is only suitable for short-term emergency traction on gentle slopes, resulting in a relatively low overall performance of the technology.

[0005] Therefore, designing a traction system that can be applied to multiple scenarios is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a traction system, method, electronic device, and storage medium for rail transit vehicles, which provides traction power for rail transit vehicles in multiple scenarios, including battery traction mode and external power supply traction mode (external grid AC power supply), so that the vehicle can flexibly switch traction modes according to actual scenario requirements.

[0007] In one aspect, this application provides a traction system for a rail transit vehicle, including: a traction inverter, a traction motor, a battery power supply path, an auxiliary converter, and a control unit;

[0008] The input terminal of the traction inverter is used to connect to the external AC power supply, and is also connected to one end of the battery power supply branch through the auxiliary converter; the output terminal of the traction inverter is connected to the traction motor; the other end of the battery power supply branch is used to connect to the battery.

[0009] The control unit is configured to, when the rail transit vehicle is in battery traction mode, control the battery power supply branch to obtain power from the battery, and provide the obtained DC power to the traction inverter through the auxiliary converter to convert it into three-phase AC power to drive the traction motor to rotate; and, when the rail transit vehicle is in external power supply traction mode, control the traction inverter to obtain power from the external AC power grid, and convert the obtained electrical energy into three-phase AC power to drive the traction motor to rotate.

[0010] Optionally, the battery power supply path includes an input circuit and a boost module arranged sequentially along the power transmission direction; the input circuit is used to control the control unit to connect or disconnect the DC power from the battery; the boost module is used to boost the DC power obtained by the input circuit and provide the boosted DC power to the auxiliary converter.

[0011] Optionally, an isolation circuit is further provided on the battery power supply path, and located between the boost module and the auxiliary converter; the isolation circuit is used to control the control unit to keep it in an open state when the rail transit vehicle is in external power supply traction mode, so as to disconnect the battery power supply branch from the auxiliary converter; and to keep it in a connected state when the rail transit vehicle is in battery traction mode, so as to connect the battery power supply branch from the auxiliary converter.

[0012] Optionally, the traction system further includes: a cooling system connected in the path between the auxiliary converter and the isolation circuit; the auxiliary converter is further configured to obtain power from the external AC power grid when the rail transit vehicle is in external power supply traction mode, and convert the obtained power into DC power to provide to the cooling system; the cooling system is configured to obtain DC power from the auxiliary converter to operate and cool the traction system when the rail transit vehicle is in external power supply traction mode; or, when the rail transit vehicle is in battery traction mode, obtain DC power through the battery power supply branch to operate and cool the traction system.

[0013] Secondly, this application also provides a traction method for rail transit vehicles, applied to the traction system of the rail transit vehicles as described above, characterized in that the traction method for rail transit vehicles includes at least a battery traction mode control method and an external power supply traction mode control method.

[0014] The battery traction mode control method includes:

[0015] Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle;

[0016] When the battery traction mode flag is valid and the battery traction input voltage is greater than a preset voltage threshold, the rail transit vehicle is determined to be in battery traction mode.

[0017] When the rail transit vehicle is in battery traction mode, the battery power supply branch is controlled to obtain power from the battery, and the obtained DC power is boosted by the auxiliary converter and then supplied to the traction inverter.

[0018] Based on the collected train speed signal and driver control handle position signal of the current rail transit vehicle, the traction inverter is controlled to operate according to the preset battery traction characteristics, and the received boosted DC power is converted into three-phase AC power to drive the traction motor to rotate.

[0019] The external power supply traction mode control method includes:

[0020] Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle;

[0021] When the battery traction mode flag is invalid and the battery traction input voltage is less than a preset voltage threshold, the rail transit vehicle is determined to be in external power supply traction mode.

[0022] When the rail transit vehicle is in external power supply traction mode, the traction inverter is controlled to obtain power from the external AC power grid.

[0023] Based on the collected train speed signal and driver control handle position signal of the current rail transit vehicle, the traction inverter is controlled to operate according to the preset battery traction characteristics, converting the received external grid AC power into three-phase AC power to drive the traction motor to rotate.

[0024] Optionally, the traction method for the rail transit vehicle may further include a battery traction energy management method;

[0025] The battery traction energy management method includes:

[0026] A tiered threshold value is set for the control object parameters and control target parameters that require tiered management. The control object parameters include the real-time output power of the traction motor, the real-time temperature of the cooling system, and the train speed signal of the rail transit vehicle. The tiered threshold value of the control object parameters includes an upper limit value for output power, an upper limit value for temperature, and an upper limit value for train speed. The control target parameters include the intermediate traction voltage of the battery output by the auxiliary converter. The tiered threshold value of the control target parameters includes a lower limit value and an upper limit value for the intermediate traction voltage of the battery.

[0027] When the rail transit vehicle is in battery traction mode, the real-time collected control object parameters are compared with the graded threshold values ​​of the control object parameters, and the battery traction condition is identified based on the comparison results. The working state of the cooling system is adjusted, and / or the control target parameters are adjusted to meet the preset relationship with the graded threshold values ​​of the control target parameters.

[0028] Optionally, the step of comparing the real-time collected parameters of the controlled object with the graded threshold values ​​of the controlled object parameters, identifying the battery traction condition based on the comparison result, controlling the working state of the cooling system, and / or controlling the control target parameters to meet the preset relationship with the graded threshold values ​​of the control target parameters includes:

[0029] When the train speed signal is less than the upper limit of the train speed, it is identified that the rail transit vehicle is in the starting stage, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery.

[0030] When the train speed signal is greater than the upper limit of the train speed and the real-time temperature is greater than the upper limit of the temperature, it is identified that the rail transit vehicle is under long-term traction, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery.

[0031] When the train speed signal is greater than the upper limit of the train speed and the real-time output power is greater than the upper limit of the output power, it is identified that the rail transit vehicle is traction on a steep slope, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery.

[0032] When the train speed signal is greater than the upper limit of the train speed, the real-time output power is greater than the lower limit of the output power and less than the upper limit of the output power, and the real-time temperature is less than the upper limit of the temperature, it is identified that the rail transit vehicle is traction on a small slope, and the cooling system is controlled to be in a non-working state. At the same time, the intermediate voltage of the battery traction is controlled to be greater than the upper limit of the battery traction intermediate voltage.

[0033] When the train speed signal is greater than the upper limit of the train speed, the real-time output power is less than the lower limit of the output power, and the real-time temperature is less than the upper limit of the temperature, it is identified that the rail transit vehicle is traction on a straight track, and the cooling system is controlled to be in a non-operating state. At the same time, the intermediate traction voltage of the battery is controlled to be less than the lower limit of the intermediate traction voltage of the battery.

[0034] Optionally, the traction method of the rail transit vehicle also includes a switching control method for external power supply traction mode and battery traction mode;

[0035] The method for switching between external power supply traction mode and battery traction mode includes:

[0036] Real-time acquisition of train speed signals and driver controller handle position signals of the current rail transit vehicles;

[0037] When the train speed signal is greater than the preset upper limit of train speed, and / or the driver's controller handle position signal is valid, the rail transit vehicle is controlled to continue operating in the current traction mode, and traction mode switching is prohibited.

[0038] Thirdly, this application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the traction method for rail transit vehicles as described in the first aspect.

[0039] Fourthly, this application also provides a storage medium storing a computer program that, when executed by one or more processors, implements the traction method for rail transit vehicles as described in the first aspect.

[0040] The traction system, method, electronic equipment, and storage medium for rail transit vehicles provided in this application are configured to simultaneously include two traction modes: external power supply traction (powered from external AC power grid) and battery traction (powered from a battery). When the rail transit vehicle is in battery traction mode, the battery power supply branch is controlled to draw power from the battery, and the obtained DC power is boosted by an auxiliary converter before being supplied to the traction inverter to convert it into three-phase AC power to drive the traction motor. Conversely, when the rail transit vehicle is in external power supply traction mode, the traction inverter is controlled to draw power from the external AC power grid and convert the obtained electrical energy into three-phase AC power to drive the traction motor. This solution can activate the traction circuit in different traction modes according to actual multi-scenario needs, thereby better providing traction power to the rail transit vehicle. Attached Figure Description

[0041] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0042] Figure 1 A schematic diagram of the structure of a traction system for a rail transit vehicle provided in an embodiment of this application;

[0043] Figure 2a A schematic flowchart illustrating a battery traction mode control method provided in an embodiment of this application;

[0044] Figure 2b A schematic diagram of energy flow in a battery traction mode provided in an embodiment of this application;

[0045] Figure 3a A flowchart illustrating an external power supply traction mode control method provided in an embodiment of this application;

[0046] Figure 3b A schematic diagram of energy flow in an external grid power supply traction mode provided for an embodiment of this application;

[0047] Figure 4a A schematic flowchart illustrating a battery traction energy management method provided in an embodiment of this application;

[0048] Figure 4b A schematic flowchart illustrating another battery traction energy management method provided in this application embodiment;

[0049] Figure 5 A flowchart illustrating a method for switching between external power supply traction mode and battery traction mode, provided in an embodiment of this application;

[0050] Figure 6A schematic flowchart illustrating a traction method for a rail transit vehicle provided in an embodiment of this application;

[0051] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0053] Example 1:

[0054] This embodiment provides a traction system for a rail transit vehicle, such as... Figure 1 As shown, the traction system includes: traction inverter 1, traction motor 2, battery power supply path 3, auxiliary converter 4, and control unit 5.

[0055] The input terminal of the traction inverter 1 is used to connect to the external AC power supply (external input), and is also connected to one end of the battery power supply branch 3 through the auxiliary converter 4; the output terminal of the traction inverter 1 is connected to the traction motor 2; the other end of the battery power supply branch 3 is used to connect to the battery (battery input).

[0056] The control unit 5 is used to control the battery power supply branch 3 to obtain power from the battery when the rail transit vehicle is in battery traction mode, and to provide the obtained DC power to the traction inverter 1 for conversion into three-phase AC power to drive the traction motor 2 to rotate after the auxiliary converter 4 boosts the obtained DC power; and to control the traction inverter 1 to obtain power from the external grid AC power supply when the rail transit vehicle is in external power supply traction mode, and to convert the obtained electrical energy into three-phase AC power to drive the traction motor 1 to rotate.

[0057] The functions of each unit are described below:

[0058] Traction Inverter 1

[0059] In battery traction mode, traction inverter 1 is used to invert the electrical energy output from auxiliary converter 4 to provide three-phase AC power to traction motor 2 to drive the train. Traction inverter 1 can also be used in external power supply traction mode (traction inverter 1 draws power from the external input side), also operating in inverter mode, converting external grid AC power into three-phase AC power to power traction motor 2.

[0060] Traction motor 2

[0061] Traction motor 2 operates by receiving three-phase AC power from traction inverter 1, providing traction power to the rail transit vehicle it is connected to.

[0062] Battery power supply path 3

[0063] The battery power supply path 3 includes an input terminal and an output terminal in sequence according to the power transmission direction. The input terminal is used to connect to the battery (battery input) to obtain electrical energy from the battery. The output terminal is used to connect to the auxiliary converter 4 to transmit the obtained battery power to the auxiliary converter 4. After being stepped up by the auxiliary converter 4, it is then supplied to the traction inverter 1. The traction inverter 1 inverts the received electrical energy to provide three-phase AC power to the traction motor 2 to drive the train.

[0064] In some embodiments, such as Figure 1 As shown, the battery power supply path 3 may include an input circuit 31 and a boost module 32 arranged sequentially along the power transmission direction.

[0065] Input circuit 31 is used by the controlled control unit 5 to connect or disconnect DC power from the battery.

[0066] In battery traction mode, the train's battery energy is output to the entire traction system through input circuit 31. The main function of input circuit 31 is to control the DC input of the battery into the entire traction system when entering battery traction mode. At the same time, in the event of an abnormality in the traction system, input circuit 31 is cut off to provide protection and control for the battery and traction system, and to isolate the DC input after exiting battery traction mode.

[0067] The boost module 32 is used to boost the DC power obtained from the input circuit 31 and provide the boosted DC power to the auxiliary converter 4.

[0068] The boost module 32 is connected after the input circuit 31. Its function is to boost the input power of the battery to a higher voltage level. It has two uses: first, to provide power for the auxiliary converter 4 to work in reverse; second, the boosted high voltage level can directly drive other electrical equipment in the traction system to work, providing power for the battery traction system.

[0069] Furthermore, such as Figure 1 As shown, an isolation circuit 33 is also provided on the battery power supply path 3, and between the boost module 32 and the auxiliary converter 4.

[0070] The isolation circuit 33 is used by the controlled control unit 5 to remain disconnected when the rail transit vehicle is in external power supply traction mode, so as to disconnect the battery power supply branch 3 from the auxiliary converter 4; and to remain connected when the rail transit vehicle is in battery traction mode, so as to connect the battery power supply branch 3 to the auxiliary converter 4.

[0071] Specifically, the isolation circuit 33 is mainly used to control the switching of the battery traction mode. When the control unit 5 detects that the traction system is in battery traction mode, it controls the boost module 32 to start and controls the isolation circuit 33 to be in the working state. The control module 5 introduces the boosted power output from the boost module 32 into the downstream circuit. When the control unit 5 detects that the traction system is in external power supply traction mode, it controls the isolation circuit 33 to be in the blocking isolation state, isolating the battery traction-related components from the main circuit of the conventional traction system, thereby realizing the switching in and out of the battery traction mode.

[0072] Auxiliary converter 4

[0073] Under battery traction conditions, the auxiliary converter 4 receives the output after being boosted by the boost module 32 and converts the electrical energy into a DC voltage that can drive the traction motor 2 normally by the traction inverter 1.

[0074] In addition, the auxiliary inverter 4 can also be used in the external power supply traction mode of the train (the auxiliary inverter 4 takes power from the external input side). At this time, the working direction of the auxiliary inverter 4 is opposite to that in the battery traction mode, and it converts the external power input into DC to provide auxiliary load power for the train.

[0075] Control Unit 5

[0076] The control unit 5 receives the train's battery traction mode command and enters battery traction mode after meeting the relevant conditions. It controls the battery power supply branch 3 to connect to the battery and supplies power to the traction inverter 1 through the auxiliary converter 4. This involves closing the input circuit 31 and the isolation circuit 33, and controlling the operation of components such as the boost module 32, the auxiliary converter 4, and the traction inverter 1. In external power supply traction mode, the control unit 5 controls the traction system to operate according to the external power supply traction condition, with the overall energy flow direction opposite to that in the battery traction condition. Simultaneously, it controls the isolation circuit 33 to block and isolate the system. Furthermore, the control unit 5 monitors the operating status of each component of the entire traction system and diagnoses related faults to provide system protection when the traction system malfunctions.

[0077] Furthermore, such as Figure 1 As shown, the traction system may further include a cooling system 6 connected in the path between the auxiliary converter 4 and the isolation circuit 33;

[0078] Correspondingly, the auxiliary converter 4 is also used to obtain power from the external AC power grid when the rail transit vehicle is in the external power supply traction mode, and convert the obtained power into DC power to provide to the cooling system 6;

[0079] The cooling system 6 is used to obtain DC power from the auxiliary converter 4 to cool the traction system when the rail transit vehicle is in external power supply traction mode; or, when the rail transit vehicle is in battery traction mode, it obtains DC power from the battery power supply branch 3 to cool the traction system.

[0080] Specifically, under battery traction conditions, the cooling system 6 can be activated after the boost module 32 operates, providing cooling for various components of the traction system, such as the boost module 32, auxiliary converter 4, and traction inverter 1. The cooling system 6 is also powered by the boost module 32. The output mode of the boost module 32 must be consistent with the operating mode of the cooling system 6.

[0081] The cooling system 6 can also be used in the external power supply traction mode of the train (the cooling system 6 draws power from the output of the auxiliary inverter 4). The cooling system 6 draws power from the back end of the auxiliary inverter 4 to provide cooling for various components of the traction system, such as the auxiliary converter 4 and the traction inverter 1.

[0082] The traction system for rail transit vehicles provided in this embodiment can perform train traction functions under different operating conditions. Furthermore, the working paths of each component within the traction system need to be changed under different traction conditions. By analyzing the traction mode requirements in different scenarios, selecting the appropriate traction mode for traction control and flexible switching of traction modes can better ensure the operation and maintenance of rail transit vehicles.

[0083] Example 2

[0084] This embodiment provides a traction method for rail transit vehicles based on the aforementioned traction system. This method may include control methods for multiple control links and can be applied to… Figure 1 In the traction system of the rail transit vehicle shown, the actuator can be... Figure 1 Control unit 5. The traction method for rail transit vehicles will be described below through several embodiments. First, the traction method for rail transit vehicles includes at least a battery traction mode control method and an external power supply traction mode control method.

[0085] like Figure 2aAs shown, the above-mentioned battery traction mode control method may include the following steps:

[0086] Step 201: Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle.

[0087] Specifically, when a rail transit vehicle is in an area without power, the train needs to enter battery traction mode to drive the train forward. The train will provide the battery traction mode indicator BAT-SIGN signal to the control unit. At the same time, the control unit also needs to obtain the battery traction input voltage to determine whether the current battery operating voltage can support the train to carry out traction work in battery traction mode.

[0088] Step 202: When the battery traction mode flag is valid and the battery traction input voltage is greater than the preset voltage threshold, the rail transit vehicle is determined to be in battery traction mode.

[0089] Specifically, the control unit determines whether the train enters battery traction mode based on the following conditions (all of the following conditions must be met):

[0090] 1. The battery traction mode indicator BAT-SIGN is valid;

[0091] 2. The battery traction input voltage Ubat is greater than the threshold.

[0092] Based on the above conditions, the control unit determines that the train is in battery traction mode and has the necessary power input for battery traction, which is a necessary prerequisite.

[0093] Step 203: When the rail transit vehicle is in battery traction mode, control the battery power supply branch to obtain power from the battery, and provide the obtained DC power to the traction inverter after boosting the voltage through the auxiliary converter.

[0094] Specifically, the traction system can be switched to battery traction mode via the control unit. Once in battery traction mode, the control unit controls the operation of each component of the traction system. Combined with... Figure 2b The diagram illustrates the energy flow in battery traction mode. In this mode, the control unit directs the battery power supply branch to draw power from the battery. The battery input voltage sequentially passes through the input circuit, the boost module, and the auxiliary converter. The auxiliary converter then boosts the DC power received before supplying it to the traction inverter. This boosted voltage can be denoted as the battery traction intermediate voltage U. d (U d (The voltage must be greater than a certain threshold) to drive the intermediate voltage U through the battery. d Power is supplied to the traction inverter.

[0095] Step 204: Based on the collected current train speed signal of the rail transit vehicle and the position signal of the driver's controller handle, control the traction inverter to work according to the preset battery traction characteristics, and convert the received boosted DC power into three-phase AC power to drive the traction motor to rotate.

[0096] Specifically, the control unit needs to control the traction inverter to operate according to the designed battery traction characteristics based on the current train speed signal (V) and the driver's handle position signal (Garde), and provide three-phase AC power to drive the traction motor to rotate through the operation of the traction inverter.

[0097] like Figure 3a As shown, the above-mentioned external power supply traction mode control method may include the following steps:

[0098] Step 301: Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle.

[0099] Specifically, after the train leaves the area without power and enters an area with external power supply, it needs to switch to normal external power input mode. The train cancels the battery traction mode indicator signal to the control unit. At the same time, the control unit also needs to obtain the battery traction input voltage to determine whether the current battery operating voltage can support the train to continue traction operation in battery traction mode.

[0100] Step 302: When the battery traction mode flag is invalid and the battery traction input voltage is less than the preset voltage threshold, determine that the rail transit vehicle is in external power supply traction mode.

[0101] Specifically, the control unit determines whether to enter the external power supply traction mode based on the following conditions (all of the following conditions must be met):

[0102] 1. The battery traction mode indicator BAT-SIGN is invalid;

[0103] 2. The traction input voltage of the battery, Ubat, is less than the threshold.

[0104] Based on the above conditions, the control unit determines that the train has the necessary power input for external power supply traction, which is a necessary prerequisite.

[0105] Step 303: When the rail transit vehicle is in external power supply traction mode, control the traction inverter to obtain power from the external AC power grid.

[0106] Specifically, the traction system can be controlled by the control unit to enter an external power supply traction mode. In this mode, the control unit controls the operation of each component of the traction system, meaning that both the traction inverter and the auxiliary converter operate simultaneously via external input. Combined with... Figure 3bThe energy flow shown is in the external power supply traction mode. In this mode, the traction inverter can continue to drive the traction inverter after being powered, while the auxiliary converter can continue to supply power to other load devices in the traction system after being powered.

[0107] Step 304: Based on the collected current train speed signal of the rail transit vehicle and the position signal of the driver's controller handle, control the traction inverter to work according to the preset battery traction characteristics, and convert the received external grid AC power into three-phase AC power to drive the traction motor to rotate.

[0108] Specifically, the control unit needs to control the traction inverter to operate according to the designed external power supply traction characteristics based on the current train speed signal (V) and the driver's handle position signal (Garde). The traction inverter provides three-phase AC power to drive the traction motor. Simultaneously, it supplies power to other load devices in the traction system after obtaining power through the auxiliary converter. At the same time, the control unit also controls the isolation circuit to disconnect and lock related components, preventing the battery traction system from receiving power in external power supply traction mode, and cancels the battery traction mode feedback to the entire vehicle.

[0109] Example 3

[0110] In addition to the aforementioned battery traction mode control method and external power supply traction mode control method, the traction method for the above-mentioned rail transit vehicles may also include a battery traction energy management method. As can be seen from the battery traction mode control method in the above embodiments, the battery traction mode involves components such as a boost module, auxiliary converter, traction inverter, cooling system, and traction motor. Energy consumption and efficiency losses occur in these components, causing the energy actually used to drive the train forward to be consumed in other components, resulting in a certain degree of reduction in battery traction capacity. However, these components are indispensable for achieving high-power, long-term battery traction. Therefore, this embodiment provides a battery traction energy management method to balance and optimize the battery traction capacity and internal efficiency of battery traction.

[0111] like Figure 4a As shown, the battery traction energy management method may include the following steps.

[0112] Step 401: Set hierarchical threshold values ​​for the control object parameters and control target parameters that require hierarchical management; wherein, the control object parameters include the real-time output power (P) of the traction motor, the real-time temperature (T) of the cooling system, and the train speed signal (V) of the rail transit vehicle, and the hierarchical threshold values ​​of the control object parameters include the lower limit of output power (P1), the upper limit of output power (P2), and the upper limit of temperature (T). high ), train speed limit (V) highThe target control parameters include the battery traction intermediate voltage (U) output from the auxiliary converter. d The graded threshold values ​​for the control target parameters include the lower limit of the battery traction intermediate voltage (U). d-low ) and the upper limit of the intermediate voltage of the battery traction (U d-high ).

[0113] In this context, the control object in hierarchical management can be considered as the data used to determine whether hierarchical management is necessary, while the hierarchical threshold value of the control object parameter can be considered as the criterion data for determining whether hierarchical management is necessary. The control target parameter can be considered as the data of the object to be managed and controlled when hierarchical management is required, while the hierarchical threshold value of the control target parameter can be considered as the management and control objective to be achieved when management and control of the control target parameter is required, i.e., to achieve a preset relationship with the hierarchical threshold value of the control target parameter, such as a preset magnitude relationship.

[0114] Step 402: When the rail transit vehicle is in battery traction mode, the real-time collected control object parameters are compared with the graded threshold values ​​of the control object parameters. Based on the comparison results, the battery traction condition is identified, and the working state of the cooling system is adjusted, and / or the control target parameters are adjusted to meet the preset relationship with the graded threshold values ​​of the control target parameters.

[0115] Specifically, the current battery traction condition is determined by comparing the real-time collected control parameters with the corresponding graded threshold values. Battery traction conditions include: start-up, long-duration traction, steep incline traction, gentle incline traction, and straight-line traction. After determining the current battery traction condition, the operating state of the cooling system can be adjusted purposefully according to the actual conditions, such as adjusting whether the cooling system is in an active or inactive state; or adjusting the control target parameters to satisfy a preset relationship with the corresponding graded threshold values; or adjusting both simultaneously. The purpose of these adjustments is to ensure a balance and optimization between battery traction capacity and internal battery traction efficiency.

[0116] In some embodiments, it can be combined Figure 4b The above step 402 will be explained in detail.

[0117] like Figure 4b As shown, after the train enters the battery traction energy management scheme, the control unit first calculates the real-time output power of traction (P), the real-time temperature of the cooling system (T), and the train speed signal (V). Then, it continues to perform subsequent judgment, traction condition identification, and control operations. The following is a detailed explanation of this subsequent operation (a refinement of step 402).

[0118] (1) When the train speed signal (V) is less than the upper limit of train speed (V) high When the system detects that the rail transit vehicle is in the starting phase, it controls the cooling system to operate and simultaneously controls the intermediate traction voltage (U) of the battery. d ) greater than the upper limit of the battery traction intermediate voltage (U) d-high ).

[0119] That is, when the train speed signal (V) is less than the upper limit of train speed (V0). high When the train is in the starting phase of a non-high-speed operation, the control unit identifies that the train is in this phase. At this time, the control unit controls the cooling system to operate and simultaneously controls the intermediate traction voltage U of the battery. d >U d-high The output provides the train with maximum output performance, supporting full torque output at the moment of train start-up.

[0120] (2) When the train speed signal (V) is greater than the upper limit of train speed (V) high The real-time temperature (T) is greater than the upper temperature limit (T). high When the system detects that the rail transit vehicle is under prolonged traction, it controls the cooling system to operate and simultaneously controls the intermediate traction voltage (U) of the battery. d ) greater than the upper limit of the battery traction intermediate voltage (U) d-high ).

[0121] (3) When the train speed signal (V) is greater than the upper limit of the train speed and the real-time output power (P) is greater than the upper limit of the output power (P2), it is identified that the rail transit vehicle is traction on a steep slope, and the cooling system is controlled to be in working state. At the same time, the intermediate voltage of the battery traction (U) is controlled. d ) greater than the upper limit of the battery traction intermediate voltage (U) d-high ).

[0122] It should be noted that, with Figure 4b Unlike other methods, here, determining the traction condition on a steep gradient does not require considering the real-time temperature (T) of the cooling system. It only requires assessing the relationship between the train speed signal (V) and real-time output power (P) and the corresponding threshold values. When the train is in a steep gradient traction condition, the above control operations can provide the train with maximum output performance, supporting its operation on the steep gradient.

[0123] (4) When the train speed signal (V) is greater than the upper limit of the train speed, the real-time output power (P) is greater than the lower limit of the output power (P1) and less than the upper limit of the output power (P2), and the real-time temperature (T) is less than the upper limit of the temperature (T2), the train speed signal (V) is greater than the upper limit of the train speed, the real-time output power (P) is greater than the lower limit of the output power (P1) and less than the upper high When the system detects that the rail transit vehicle is being traction-equipped on a slight incline, it controls the cooling system to be inactive and simultaneously controls the intermediate traction voltage (U) of the battery.d ) greater than the upper limit of the battery traction intermediate voltage (U) d-high ).

[0124] That is, through the above control operation, a certain output power can be provided to the train when the train is in the traction condition of a small gradient, but the cooling system is not working at this time, in order to reduce the energy loss of the traction system in the battery traction condition.

[0125] (5) When the train speed signal (V) is greater than the upper limit of the train speed, the real-time output power (P) is less than the lower limit of the output power (P1), and the real-time temperature (T) is less than the upper limit of the temperature (T1), the train speed signal (V) is greater than the upper limit of the train speed (P1). high When the system detects that the rail transit vehicle is traction on a straight track, it controls the cooling system to be inactive and simultaneously controls the intermediate traction voltage (U) of the battery. d () less than the lower limit of the battery traction intermediate voltage (U) d-low ).

[0126] That is, through the above control operation, when the train is in the traction condition on a straight track, the traction system can be provided with only the minimum output voltage / power to maintain the train's operation on a straight track, while the cooling system is stopped.

[0127] Table 1. Graded Management of Battery Traction Energy

[0128]

[0129] Example 4

[0130] In addition to the aforementioned battery traction mode control method, external power supply traction mode control method, and battery traction energy management method, the traction methods for the above-mentioned rail transit vehicles may also include a switching control method between external power supply traction mode and battery traction mode.

[0131] like Figure 5 As shown, the method for switching between external power supply traction mode and battery traction mode may include the following steps.

[0132] Step 501: Real-time acquisition of train speed signals and driver control handle position signals of the current rail transit vehicles.

[0133] Specifically, to prevent the train from frequently switching between external power supply traction mode and battery traction mode, this embodiment uses the monitoring of train speed signal (V) and driver's controller handle grade signal (Grade) to determine whether the traction mode can be switched.

[0134] Step 502: When the train speed signal is greater than the preset upper limit of train speed and / or the driver's controller handle position signal (Garde) is valid, control the rail transit vehicle to continue operating in the current traction mode and prohibit switching traction modes.

[0135] Specifically, exiting the current traction mode is not allowed under the following conditions (any one of the conditions must be met):

[0136] (1) Train speed signal V > threshold;

[0137] (2) The Grade signal of the controller handle is not 0.

[0138] In this embodiment, the switching of traction modes is clearly defined, with the aim of preventing the traction system from frequently switching traction modes. The switching between the two modes can only be done in the parking mode, which reduces the risk of equipment failure and damage that may occur when the traction system switches traction modes, and helps to improve train availability.

[0139] Example 5

[0140] Based on the various existing control methods, this embodiment also adds fault diagnosis and control methods under fault modes to the traction method of rail transit vehicles.

[0141] In battery traction mode, the traction system relies on the vehicle's battery for power input. Short circuits, open circuits, grounding, or faults in the power electronic components of the traction system can cause damage to related components and loss of train power. To ensure train safety, when the control unit detects abnormalities such as undervoltage or overcurrent in the input voltage and current signals during battery traction mode, it will promptly diagnose the corresponding fault and take appropriate protective measures for the traction system. Simultaneously, the control unit will upload the abnormal operating conditions diagnosed and the traction system shutdown status to the train network control system and notify the driver and relevant personnel via the onboard display screen.

[0142] When the traction system is in external power grid power supply mode, its fault diagnosis method is the same as that in battery mode. The difference is that the control unit performs relevant fault diagnosis based on the voltage, current and other parameters of the external power grid input side. At the same time, the fault diagnosis logic is slightly different according to the differences in power level and energy flow direction between the two modes.

[0143] When a single traction mode of the traction system fails while another traction mode is normal, the train can resume operation by stopping and switching traction modes. This can improve train availability and reduce the occurrence of train delays, rescue operations, and other phenomena that affect the normal operation of trains and lines.

[0144] Example 6

[0145] Based on the various control methods included in the traction methods of rail transit vehicles described above, this embodiment provides a schematic diagram of the overall control process of the traction method for rail transit vehicles in multiple application scenarios. For example... Figure 6 As shown, the overall control process includes the following steps.

[0146] Step 1: The control unit first determines whether the current train speed signal (V) is 0 and whether the driver's controller handle level signal (Grade) is 0. If the determination result is "yes", it is considered that the current vehicle is in a stopped state, and the traction mode can be determined, i.e., proceed to steps 2 and 5; if the determination result is "no", this step is repeated.

[0147] Step 2: The control unit determines whether the train meets the relevant conditions for battery traction mode; if the result is "yes", proceed to step 3; if the result is "no", repeat this step.

[0148] Step 3: Determine if the traction system is working properly. If the result is "yes", then enter the battery traction mode and enter the battery traction energy management control mode. If the result is "no", proceed to step 4.

[0149] Step 4: Determine whether the current train meets the relevant conditions for traction mode switching. If the result is "yes", proceed to Step 2 and Step 5 to re-perform the traction mode determination steps. If the result is "no", determine that the traction mode is faulty and execute the corresponding fault diagnosis and control method flow under the fault mode.

[0150] Step 5: The control unit determines whether the train meets the relevant conditions for external power supply traction mode; if the result is "yes", proceed to step 6; if the result is "no", repeat this step.

[0151] Step 6: Determine if the traction system is working properly. If the result is "yes", then enter the external power supply traction mode; if the result is "no", proceed to step 4.

[0152] The main features of the traction method for rail transit vehicles provided in this embodiment are as follows:

[0153] (1) By collecting signals from each link of the traction system and the relevant mode signals of the whole vehicle through the control unit itself, the mode of the traction system can be identified and the train traction control can be performed according to the corresponding power supply mode. At the same time, this traction method reasonably restricts the mode switching of battery traction, which can prevent the traction system from frequently switching traction modes. The switching between the two modes of battery traction / external power supply traction can only be performed in the parking mode, which reduces the risk of equipment failure and damage that may occur when the battery traction system switches modes, and helps to improve the availability of the train.

[0154] Under battery traction conditions, without relying on external command input, the current operating conditions of the train can be adaptively identified by real-time monitoring of the inverter output power of the traction inverter, and a graded control strategy can be adopted for different operating conditions. This allows for graded management of energy consumption under battery traction conditions, maximizing battery traction efficiency and the duration and distance of battery traction.

[0155] The traction method of this rail transit vehicle can protect the traction system when the traction system detection mode is abnormal or malfunctions, preventing control misalignment or further expansion of the fault.

[0156] Example 7

[0157] Another embodiment of this application relates to an electronic device, such as... Figure 7 As shown, it includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to implement the above method steps.

[0158] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0159] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0160] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for executing the methods in the above embodiments.

[0161] Example 8

[0162] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the above-described method steps.

[0163] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0164] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A traction system for a rail transit vehicle, characterized in that, include: Traction inverter, traction motor, battery power supply branch, auxiliary converter and control unit; The input terminal of the traction inverter is used to connect to the external AC power supply, and is also connected to one end of the battery power supply branch through the auxiliary converter; the output terminal of the traction inverter is connected to the traction motor; the other end of the battery power supply branch is used to connect to the battery. The control unit is configured to, when the rail transit vehicle is in battery traction mode, control the battery power supply branch to obtain power from the battery, and provide the obtained DC power to the traction inverter through the auxiliary converter to convert it into three-phase AC power to drive the traction motor to rotate; and, when the rail transit vehicle is in external power supply traction mode, control the traction inverter to obtain power from the external AC power grid, and convert the obtained electrical energy into three-phase AC power to drive the traction motor to rotate. The battery power supply branch includes an input circuit and a boost module arranged sequentially along the power transmission direction; The input circuit is used to control the control unit to connect or disconnect the DC power from the battery; The boost module is used to boost the DC power obtained from the input circuit and provide the boosted DC power to the auxiliary converter; An isolation circuit is also provided on the battery power supply branch, between the boost module and the auxiliary converter; The isolation circuit is configured to be controlled by the control unit to remain disconnected when the rail transit vehicle is in external power supply traction mode, so as to disconnect the battery power supply branch from the auxiliary converter; and to remain connected when the rail transit vehicle is in battery traction mode, so as to connect the battery power supply branch from the auxiliary converter.

2. The traction system for rail transit vehicles according to claim 1, characterized in that, The traction system further includes a cooling system on the path connecting the auxiliary converter and the isolation circuit; The auxiliary converter is also used to obtain power from the external AC power grid when the rail transit vehicle is in external power supply traction mode, and convert the obtained power into DC power to provide to the cooling system; The cooling system is used to obtain DC power from the auxiliary converter to cool the traction system when the rail transit vehicle is in external power supply traction mode; or, when the rail transit vehicle is in battery traction mode, it obtains DC power from the battery power supply branch to cool the traction system.

3. A traction method for a rail transit vehicle, applied to the traction system of the rail transit vehicle as described in claim 2, characterized in that, The traction method of the rail transit vehicle includes at least a battery traction mode control method and an external power supply traction mode control method. The battery traction mode control method includes: Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle; When the battery traction mode flag is valid and the battery traction input voltage is greater than a preset voltage threshold, the rail transit vehicle is determined to be in battery traction mode. When the rail transit vehicle is in battery traction mode, the battery power supply branch is controlled to obtain power from the battery, and the obtained DC power is boosted by the auxiliary converter and then supplied to the traction inverter. Based on the collected train speed signal and driver control handle position signal of the current rail transit vehicle, the traction inverter is controlled to operate according to the preset battery traction characteristics, and the received boosted DC power is converted into three-phase AC power to drive the traction motor to rotate. The external power supply traction mode control method includes: Obtain the battery traction mode indicator and battery traction input voltage of the rail transit vehicle; When the battery traction mode flag is invalid and the battery traction input voltage is less than a preset voltage threshold, the rail transit vehicle is determined to be in external power supply traction mode. When the rail transit vehicle is in external power supply traction mode, the traction inverter is controlled to obtain power from the external AC power grid. Based on the collected train speed signal and driver control handle position signal of the current rail transit vehicle, the traction inverter is controlled to operate according to the preset battery traction characteristics, converting the received external grid AC power into three-phase AC power to drive the traction motor to rotate.

4. The traction method for rail transit vehicles according to claim 3, characterized in that, The traction method for the rail transit vehicle also includes a battery traction energy management method; The battery traction energy management method includes: A tiered threshold value is set for the control object parameters and control target parameters that require tiered management. The control object parameters include the real-time output power of the traction motor, the real-time temperature of the cooling system, and the train speed signal of the rail transit vehicle. The tiered threshold value of the control object parameters includes an upper limit value for output power, an upper limit value for temperature, and an upper limit value for train speed. The control target parameters include the intermediate traction voltage of the battery output by the auxiliary converter. The tiered threshold value of the control target parameters includes a lower limit value and an upper limit value for the intermediate traction voltage of the battery. When the rail transit vehicle is in battery traction mode, the real-time collected control object parameters are compared with the graded threshold values ​​of the control object parameters, and the battery traction condition is identified based on the comparison results. The working state of the cooling system is adjusted, and / or the control target parameters are adjusted to meet the preset relationship with the graded threshold values ​​of the control target parameters.

5. The traction method for rail transit vehicles according to claim 4, characterized in that, The step of comparing the real-time collected parameters of the controlled object with the graded threshold values ​​of the controlled object parameters, identifying the battery traction condition based on the comparison result, controlling the working state of the cooling system, and / or controlling the control target parameters to meet the preset relationship with the graded threshold values ​​of the control target parameters includes: When the train speed signal is less than the upper limit of the train speed, it is identified that the rail transit vehicle is in the starting stage, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery. When the train speed signal is greater than the upper limit of the train speed and the real-time temperature is greater than the upper limit of the temperature, it is identified that the rail transit vehicle is under long-term traction, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery. When the train speed signal is greater than the upper limit of the train speed and the real-time output power is greater than the upper limit of the output power, it is identified that the rail transit vehicle is traction on a steep slope, and the cooling system is controlled to be in working state. At the same time, the intermediate traction voltage of the battery is controlled to be greater than the upper limit of the intermediate traction voltage of the battery. When the train speed signal is greater than the upper limit of the train speed, the real-time output power is greater than the lower limit of the output power and less than the upper limit of the output power, and the real-time temperature is less than the upper limit of the temperature, it is identified that the rail transit vehicle is traction on a small slope, and the cooling system is controlled to be in a non-working state. At the same time, the intermediate voltage of the battery traction is controlled to be greater than the upper limit of the battery traction intermediate voltage. When the train speed signal is greater than the upper limit of the train speed, the real-time output power is less than the lower limit of the output power, and the real-time temperature is less than the upper limit of the temperature, it is identified that the rail transit vehicle is traction on a straight track, and the cooling system is controlled to be in a non-operating state. At the same time, the intermediate traction voltage of the battery is controlled to be less than the lower limit of the intermediate traction voltage of the battery.

6. The traction method for rail transit vehicles according to claim 3, characterized in that, The traction method for the rail transit vehicle also includes a control method for switching between external power supply traction mode and battery traction mode. The method for switching between external power supply traction mode and battery traction mode includes: Real-time acquisition of train speed signals and driver controller handle position signals of the current rail transit vehicles; When the train speed signal is greater than the preset upper limit of train speed, and / or the driver's controller handle position signal is valid, the rail transit vehicle is controlled to continue operating in the current traction mode, and traction mode switching is prohibited.

7. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, which, when executed by the processor, implements the traction method for rail transit vehicles as described in any one of claims 3-6.

8. A storage medium, characterized in that, The storage medium stores a computer program that, when executed by one or more processors, implements the traction method for rail transit vehicles as described in any one of claims 3-6.

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