CN114714917B

CN114714917B - Traction control method and device for magnetic levitation train

Info

Publication number: CN114714917B
Application number: CN202110008902.XA
Authority: CN
Inventors: 肖健; 徐娟; 李俊; 陈明锋; 赵海涛; 钟思琦
Original assignee: Zhuzhou CRRC Times Electric Co Ltd
Current assignee: Zhuzhou CRRC Times Electric Co Ltd
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2025-07-18
Anticipated expiration: 2041-01-05
Also published as: CN114714917A

Abstract

The present invention relates to a maglev train, a traction control method and device, and a computer-readable storage medium. The traction control method comprises the steps of: determining the target traction of the maglev train; and distributing the target traction to at least one stator segment located at the train position according to the train position of the maglev train, the stator segment positions of multiple stator segments arranged on the tracks on both sides of the running line, and the stator segment working conditions, wherein one of the multiple stator segments on the track on the same side is selected to run, and one of the corresponding stator segments on the tracks on both sides is selected to change steps. The present invention can overcome the defects of the total traction reduction and power loss of the train while retaining the advantages of the two-step method, thereby improving the comfort of passengers.

Description

Traction control method and device for magnetic levitation train

Technical Field

The present invention relates to a traction control technology for a magnetic levitation train, and more particularly, to a traction control method for a magnetic levitation train and a traction control device for a magnetic levitation train.

Background

The magnetic levitation railway supports and floats the whole train on the line track by means of the characteristic that like poles repel and opposite poles attract of an electromagnetic field. The magnetic levitation train can be accelerated and braked comfortably along the calculated speed curve rapidly, safely and reliably through planning and commanding of the operation control system and accurate adjustment and control of the traction and braking force (hereinafter referred to as traction force) of the magnetic levitation train by the traction control system.

Unlike conventional wheel track traction system, the traction system of the high-speed magnetic levitation train is a long stator linear traction system, and the basic principle is based on the linear synchronous motor driving technology. In order to be able to continuously pull a maglev train, a plurality of stator segments are typically connected in place with one or more feeder cable systems. These feeder cable systems are separated from each other and can supply power from multiple converters to the stator segments at the same time. In the process that the train moves from one stator section to the next stator section, a vacuum contactor in a stator switch station performs switching action according to the working condition of each stator section, and the control converter is powered by the previous stator section and supplies power to the next stator section. This process is known as stator segment pacing.

According to the current operating line configuration and research conditions of scientific research, the common step-changing modes comprise a three-step method and a two-step method. The three-step method has the advantages of no traction force drop, no power loss and high redundancy in the step change process, and has the disadvantages of high cost of the feed cable and the converter and larger equipment and arrangement space requirements. In contrast, the existing two-step method has the advantages of lower cost of the feeder cable system and the current transformer and lower equipment and arrangement space requirements, and has the disadvantages of lower traction force, power loss and passenger comfort in the step-change process.

Referring to fig. 1A to 1C, fig. 1A shows a single-phase circuit schematic diagram of a traction system, fig. 1B shows a switching process schematic diagram of a two-step method, and fig. 1C shows a current timing schematic diagram of the two-step method.

As shown in fig. 1A, in the conventional two-step method, a plurality of stator segments n to n+5 may be alternately arranged on the left and right sides of a train running track, and four converters 111, 112, 121, 122 are respectively connected by two sets of feeder cable systems 11, 12. The stator segments (e.g., n +2, n + 4) provided on the same side of the track may be arranged on the same side of the track as the corresponding feeder cable 11, so as to be powered by the same current transformers 111, 112. The two-step feeder cable system 11, 12 and current transformers 111, 112, 121, 122 architecture has the advantage of low cost and low equipment and layout space requirements compared to the three-step approach described above.

However, as shown in FIG. 1B, during a step change of the prior two-step method, since adjacent stator segments (e.g., n and n+2) of the same side rail are supplied by the same current transformer, both cannot be supplied simultaneously. That is, when the switching is performed, the upper stator segment n needs to be powered off, and then the next stator segment n+2 needs to be powered on. Therefore, as shown in fig. 1C, in the conventional two-step method, there are drawbacks of reduced total traction force and power loss of the train, and comfort of passengers is easily affected.

In order to overcome the above-mentioned drawbacks of the prior art, there is a need in the art for a traction control technology of a maglev train, which is used to overcome the defects of total traction reduction, power loss, etc. of the train while maintaining the advantages of the two-step method, so as to improve the comfort of passengers.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In order to overcome the defects in the prior art, the invention provides a traction control method of a magnetic levitation train, a traction control device of the magnetic levitation train, a computer readable storage medium and the magnetic levitation train, which can overcome the defects of total traction reduction, power loss and the like of the train while maintaining the advantages of a two-step method, thereby improving the comfort of passengers.

The traction control method of the magnetic levitation train comprises the steps of determining target traction of the magnetic levitation train, and distributing the target traction to at least one stator segment positioned at the position of the train according to the train position of the magnetic levitation train, the stator segment positions of a plurality of stator segments arranged on the tracks on two sides of a running line and the working condition of the stator segments, wherein the plurality of stator segments on the same side track selectively run, and the corresponding stator segments on the tracks on two sides selectively change steps.

Optionally, in some embodiments of the present invention, the traction control method may further include the steps of planning a target speed curve of the maglev train according to a target position instruction provided by a transportation control system, calculating a target acceleration of the maglev train according to the target speed curve and an actual speed feedback of the maglev train, and calculating the target traction according to the target acceleration.

Preferably, in some embodiments of the present invention, the traction control method may further include the steps of collecting the relative displacement of the maglev train in real time, calculating an actual speed feedback of the maglev train according to the relative displacement, calculating an actual acceleration feedback of the maglev train according to the actual speed feedback, and performing PID control to calculate the target traction according to the relative displacement, the actual speed feedback, and the actual acceleration feedback.

Alternatively, in some embodiments of the present invention, the step of assigning the target tractive effort may include determining at least one stator segment located at the train location based on the train location and the stator segment locations of the plurality of stator segments, determining whether the at least one stator segment is in an operating condition, calculating a coupling length of the at least one stator segment to the train based on the train location and the stator segment locations of the at least one stator segment, and assigning the target tractive effort to the stator segment in the operating condition based on the coupling length of the at least one stator segment to the train.

Preferably, in some embodiments of the present invention, the plurality of stator segments may be respectively powered by corresponding current transformers, wherein the plurality of stator segments of the same side rail are powered by the same current transformer and the plurality of stator segments of different side rails are powered by different current transformers. The step of distributing the target traction force to the stator segment under the operation condition may further include sending a traction force distribution instruction to a converter corresponding to the stator segment under the operation condition, so as to control the converter to output a corresponding power supply current to the stator segment under the operation condition.

Preferably, in some embodiments of the present invention, the step of distributing the target tractive effort to the stator segments in the operating condition may further include determining a maximum tractive effort of the corresponding side stator segment according to a maximum allowable output current of the current transformer, controlling the stator segments to output the maximum tractive effort in response to the tractive effort distributed to any of the stator segments being greater than the maximum tractive effort of the stator segments, and redistributing the remaining target tractive effort to the remaining stator segments in the operating condition according to the maximum tractive effort corresponding to the remaining stator segments of the train position.

Optionally, in some embodiments of the invention, the step of distributing the target tractive effort to the stator segments of the operating condition may further comprise distributing the target tractive effort solely to the stator segments of the second side rail in the operating condition in response to a step change of the stator segments of the first side rail.

Optionally, in some embodiments of the present invention, the traction control method may further include the steps of controlling the stator segment in the operation condition to output traction force according to the input power supply current so as to pull the maglev train, collecting actual output traction force of the stator segment in the operation condition, and controlling the power supply current output to the stator segment in the operation condition in a closed loop manner according to the traction force distribution command and the actual output traction force.

According to another aspect of the present invention, there is also provided a traction control device of a maglev train.

The traction control device of the maglev train provided by the invention comprises a memory and a processor. The processor is connected with the memory and comprises a first control unit. The first control unit is configured to determine target traction force of the magnetic levitation train, and distribute the target traction force to at least one stator segment located at the train position according to the train position of the magnetic levitation train, the stator segment positions of a plurality of stator segments located on the tracks on two sides of a running line and the working conditions of the stator segments, wherein the plurality of stator segments located on the same side of the track are operated alternatively, and the corresponding stator segments of the tracks on two sides are changed alternatively.

Optionally, in some embodiments of the present invention, the first control unit may be further configured to plan a target speed profile of the maglev train according to a target position instruction provided by a transportation control system, calculate a target acceleration of the maglev train according to the target speed profile and an actual speed feedback of the maglev train, and calculate the target traction according to the target acceleration.

Preferably, in some embodiments of the present invention, the first control unit may be further configured to acquire a relative displacement of the maglev train in real time, calculate an actual speed feedback of the maglev train according to the relative displacement, calculate an actual acceleration feedback of the maglev train according to the actual speed feedback, and perform PID control to calculate the target traction force according to the relative displacement, the actual speed feedback, and the actual acceleration feedback.

Optionally, in some embodiments of the present invention, the first control unit may be further configured to determine at least one stator segment located at the train location based on the train location and the stator segment locations of the plurality of stator segments, determine whether the at least one stator segment is in an operating condition, calculate a coupling length of the at least one stator segment to the train based on the train location and the stator segment locations of the at least one stator segment, and allocate the target tractive effort to the stator segments of the operating condition based on the coupling length of the at least one stator segment to the train.

Preferably, in some embodiments of the present invention, the plurality of stator segments may be respectively powered by corresponding current transformers, wherein the plurality of stator segments of the same side rail are powered by the same current transformer and the plurality of stator segments of different side rails are powered by different current transformers. The first control unit is further configured to send a traction force distribution instruction to a converter corresponding to the stator segment under the operation condition, so as to control the converter to output corresponding power supply current to the stator segment under the operation condition.

Preferably, in some embodiments of the present invention, the first control unit may be further configured to determine a maximum tractive effort of a corresponding side stator segment according to a maximum allowable output current of the current transformer, allocate the maximum tractive effort to any stator segment in response to the tractive effort allocated to the stator segment being greater than the maximum tractive effort of the stator segment, and reallocate the remaining target tractive effort to remaining stator segments in an operating condition according to the maximum tractive effort corresponding to the remaining stator segments of the train location.

Alternatively, in some embodiments of the invention, the first control unit may be further configured to individually distribute the target tractive effort to stator segments on the second side rail in an operating condition in response to a stator segment of the first side rail changing steps.

Optionally, in some embodiments of the invention, the processor may further comprise a second control unit. The second control unit can be configured to control the stator segment under the operation condition to output traction force according to the input power supply current so as to pull the maglev train, collect actual output traction force of the stator segment under the operation condition, and control the power supply current output to the stator segment under the operation condition in a closed loop mode according to the traction force distribution instruction and the actual output traction force.

According to another aspect of the present invention, there is also provided herein a computer-readable storage medium.

The present invention provides the above computer readable storage medium having computer instructions stored thereon. When the computer instructions are executed by the processor, the traction control method provided by any one of the embodiments can be implemented, so that the defects of total traction reduction, power loss and the like of the train are overcome while the advantages of the two-step method are maintained, and the comfort of passengers is improved.

According to another aspect of the invention, there is also provided a maglev train.

The magnetic levitation train provided by the invention can comprise the traction control device provided by any one embodiment, and can overcome the defects of total traction force reduction, power loss and the like of the train while maintaining the advantages of a two-step method, so that the comfort of passengers is improved.

Drawings

The above features and advantages of the present invention will be better understood after reading the detailed description of embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily to scale and components having similar related features or characteristics may have the same or similar reference numerals.

Fig. 1A shows a single-phase circuit schematic of a traction system.

Fig. 1B shows a schematic diagram of a two-step switching process.

FIG. 1C shows a schematic diagram of the current timing of a two-step process.

Fig. 2 illustrates a schematic architecture diagram of a traction control device of a maglev train provided in accordance with some embodiments of the present invention.

Fig. 3 is a schematic flow chart of a traction control method of a maglev train according to an aspect of the present invention.

Fig. 4 illustrates a schematic coupling of a maglev train to a stator segment provided in accordance with some embodiments of the invention.

Fig. 5 illustrates a current timing diagram of a two-step method provided in accordance with some embodiments of the present invention.

Detailed Description

Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present invention with specific examples. While the description of the invention will be presented in connection with a preferred embodiment, it is not intended to limit the inventive features to that embodiment. Rather, the purpose of the invention described in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the invention. The following description contains many specific details for the purpose of providing a thorough understanding of the present invention. The invention may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the invention.

In the description of the present invention, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or in communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" as used in the following description should be understood as referring to the orientation depicted in this paragraph and the associated drawings. This relative terminology is for convenience only and is not intended to be limiting of the invention as it is described in terms of the apparatus being manufactured or operated in a particular orientation.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, regions, layers and/or sections, these elements, regions, layers and/or sections should not be limited by these terms and these terms are merely used to distinguish between different elements, regions, layers and/or sections. Accordingly, a first component, region, layer, and/or section discussed below could be termed a second component, region, layer, and/or section without departing from some embodiments of the present invention.

As described above, in the conventional two-step method, there are defects such as a decrease in traction force and a loss of power, which adversely affect the comfort of passengers. In order to overcome the defects in the prior art, the invention provides a traction control method of a magnetic levitation train, a traction control device of the magnetic levitation train, a computer readable storage medium and the magnetic levitation train, which can overcome the defects of total traction reduction, power loss and the like of the train while maintaining the advantages of a two-step method, thereby improving the comfort of passengers.

In some non-limiting embodiments, the traction control method of the magnetic levitation train provided by the invention can be implemented in the circuit architecture shown in fig. 1A, and follows the switch switching process requirement shown in fig. 1B, and only the defects of total traction reduction, power loss and the like of the train are overcome by optimizing the traction system control strategy, so that the comfort of passengers is improved. By following the circuit architecture of the existing two-step method and following the switching process requirements of the existing two-step method, the invention can retain the advantages of low cost and low equipment and arrangement space requirements of the existing two-step method.

In some embodiments, the traction control method of the maglev train may be implemented by a traction control device of the maglev train. In particular, the traction control device may include a memory and a processor. The memory may include a computer-readable storage medium having stored thereon computer instructions. The processor may be coupled to the memory and adapted to execute computer instructions stored on the memory to implement the traction control method of the maglev train described above.

Referring to fig. 2, fig. 2 is a schematic diagram illustrating a traction control device of a maglev train according to some embodiments of the invention.

As shown in fig. 2, in the above embodiment, the processor of the traction control device may include one traction power supply control unit (Motor Power Supply Control Unit, MCU) and two converter control units (Converter Control Unit, CCU). The traction power supply control unit MCU is mainly used for calculating a target traction force required to be distributed to each stator segment (for example, stator segments n, n+2, n+4), and sending a traction force distribution instruction to the corresponding converters 111, 112. The converter control unit CCU1 is adapted to control the converters 111, 112 to output supply currents to the corresponding stator segments n, n+2, n+4 according to the traction force distribution instruction provided by the MCU, so as to be responsible for the tracking implementation of the traction forces of the stator segments n, n+2, n+4. Correspondingly, the converter control unit CCU2 is adapted to control the converters 121, 122 to output supply currents to the corresponding stator segments n+1, n+3, n+5 according to the traction force distribution instruction provided by the MCU, so as to be responsible for tracking the traction force of the stator segments n+1, n+3, n+5. That is, the plurality of stator segments n, n+2, n+4 located on the same side rail may be supplied with power by the same current transformers 111, 112, and the plurality of stator segments n+1, n+3, n+5 located on the same side rail may be supplied with power by the same current transformers 121, 122. Conversely, each stator segment on a different side rail is powered by a different current transformer.

It is understood that the traction power supply control unit MCU and the converter control units CCU1 and CCU2 may be physical controllers provided in the traction control device, or may be virtual software units configured in the traction control device. In some embodiments, the converter control units CCU1, CCU2 may be replaced by one integrated converter control unit CCU.

The traction control method of the maglev train will be described below in conjunction with the traction control device shown in fig. 2. It will be appreciated by those skilled in the art that the implementation of the traction control method with the traction control device shown in fig. 2 is merely a non-limiting example provided by the present invention, and is intended to clearly illustrate the main concept of the present invention and to provide a specific solution for public implementation without limiting the scope of the present invention.

Referring to fig. 2 and fig. 3 in combination, fig. 3 is a schematic flow chart illustrating a traction control method of a maglev train according to an aspect of the present invention.

As shown in fig. 3, the traction control method of the magnetic levitation train provided by the invention may include a step 301 of determining a target traction of the magnetic levitation train.

In some embodiments of the present invention, the traction power supply control unit MCU may be communicatively connected to a running control system of the maglev train, and adapted to obtain the target position command S ₀ (t) of the maglev train in real time. The target position command S ₀ (t) indicates the target position that the train should reach at each moment, and is used for commanding the magnetically levitated train to run according to the predetermined schedule quasi-points in order. The traction power supply control unit MCU can plan a target speed curve v ₀ (t) of the magnetic levitation train according to the mileage difference DeltaS ₀ and the time difference Deltat between the target positions S ₀ (t), and calculate the target acceleration a of the magnetic levitation train according to the target speed curve v ₀ (t) and the actual speed feedback v (t) of the magnetic levitation train. Then, the traction power supply control unit MCU may calculate the target traction force F _ref of the maglev train according to the calculated target acceleration a and the mass M of the maglev train, i.e. F _ref =m×a.

Those skilled in the art will appreciate that the above-mentioned scheme of planning the target speed curve v ₀ (t), calculating the target acceleration a, and calculating the target traction force F _ref by the traction power supply control unit MCU is only a non-limiting embodiment provided by the present invention, and is not intended to limit the protection scope of the present invention.

Alternatively, in other embodiments, the traction power supply control unit MCU may also acquire the relative displacement S (t) of the maglev train in real time. Then, the traction power supply control unit MCU can perform differential operation on the acquired relative displacement S (t) so as to calculate the actual speed feedback v (t) of the maglev train. The traction power supply control unit MCU can also perform differential operation on the actual speed feedback v (t) of the maglev train so as to calculate the actual acceleration feedback a (t) of the maglev train. Then, the traction power supply control unit MCU can perform PID control according to the relative displacement S (t), the actual speed feedback v (t) and the actual acceleration feedback a (t) of the maglev train so as to calculate the target traction force F _ref of the maglev train.

Optionally, in other embodiments, the traction power supply control unit MCU may also directly obtain the target speed curve v ₀ (t), the target acceleration a, or the target traction force F _ref of the maglev train from the operation control system of the maglev train or other modules, devices, interfaces, so as to determine the target traction force F _ref of the maglev train.

As shown in fig. 3, the traction control method of the magnetic levitation train provided by the invention may further include a step 302 of distributing the target traction to at least one stator segment located at the train position according to the train position of the magnetic levitation train, the stator segment position of each stator segment and the stator segment working condition.

As described above, the traction system of the high-speed maglev train is a long stator linear traction system. Based on the principle of the linear synchronous motor driving technology, the linear motor can be understood as a rotary motor which is cut from the axial direction and is unfolded along the longitudinal direction. The body of the maglev train corresponds to the rotor of the synchronous motor. The running track of the magnetic levitation railway is equivalent to the stator of the synchronous motor. The stator of the motor is powered by three-phase currents of variable frequency and amplitude provided by stationary inverters arranged along the track. The converters 111, 112, 121, 122 are arranged along the track in a traction substation.

Referring further to fig. 4, fig. 4 illustrates a schematic coupling diagram of a maglev train with a stator segment provided in accordance with some embodiments of the present invention.

As shown in fig. 1A and 4, in some embodiments, the long stator winding may be composed of a plurality of stator segments n, n+1, n+2, n+3, n+4, n+5 respectively laid on the left and right side tracks. The stator segments may have a length greater than the length of the maglev train. In order to be able to continuously pull a maglev train, with the train moving from one stator segment n to the next stator segment n+2, vacuum contactors mounted in stator switchyard along the track may be closed or opened in accordance with the direction of movement of the maglev train to effect the current transformer to be powered by the front stator segment n and in turn to the next stator segment n+2. By only allowing power to be supplied to the stator segments (e.g., stator segments n and n+1) where the train is located, but not to the remaining stator segments without the train load, the multiple stator segments (e.g., stator segments n, n+2, n+4) of the same side track in the invention alternatively operate, thereby effectively reducing losses and improving the energy efficiency of the magnetic levitation railway.

In some embodiments, the stator segments n, n+1, n+2, n+3, n+4, n+5 may be interleaved with each other along the direction of travel of the maglev train on the left and right side rails of the travel route. By adopting the staggered paving mode, the corresponding stator sections of the tracks at two sides can alternately select steps, thereby improving the redundancy of the traction system and the comfort of the maglev train.

When the target traction force F _ref of the magnetic levitation train is distributed, the traction power supply control unit MCU can firstly acquire the real-time position of the magnetic levitation train and judge the stator section positioned at the current position of the train. Taking fig. 4 as an example, the left side of the train is located on stator segment n+1, while the right side is located on stator segment n and stator segment n+2. Thus, the traction power control unit MCU can determine that the stator segments n, n+1, n+2 are all located at the train location.

In some embodiments, the traction power supply control unit MCU may query the working state of the corresponding converter in real time according to the numbers of the stator segments n, n+1, n+2 and the line configuration file, so as to determine the working condition of each stator segment. In particular, each uniquely numbered stator segment may correspond to two current transformers to which power is supplied. For example, stator segments n, n+2, n+4 correspond to converters 111, 112, while stator segments n+1, n+3, n+5 correspond to converters 121, 122. When judging the working condition of the stator segment n, the traction power supply control unit MCU may first query the working state of the corresponding converters 111, 112. If the inverter current outputs of the converters 111, 112 are in a stopped state, the traction power supply control unit MCU may determine that the stator segment n is in a standby condition. Conversely, if the inverter current outputs of the converters 111, 112 are in an operating state, the traction power supply control unit MCU may determine that the stator segment n is in an operating condition. Based on the same principle, the stator segments n+1, n+2 located at the train position can also judge the working conditions in the same way.

And then, the traction power supply control unit MCU can calculate the coupling length of the magnetic levitation train and each stator segment according to the train position and the stator segment positions of the stator segments n, n+1 and n+2. The traction power control unit MCU may then distribute the target traction force F _ref to the stator segments in the operating mode thereof, depending on the coupling length of each stator segment to the train. Specifically, the traction power control unit MCU may calculate the target traction force F _nref to be distributed to each stator segment according to the following formula:

Wherein S _n is the coupling length of the stator section n and the train, S _n+1 is the coupling length of the stator section n+1 and the train, S _n+2 is the coupling length of the stator section n+2 and the train, and k _n、k_n+1、k_n+2 is the stator section working condition of each stator section.

In phases 1 and 2 shown in fig. 1B, the left side of the maglev train is fully coupled to stator segment n+1, with coupling length S _n+1 always equal to the train length. In contrast, the right side of the maglev train is stepping from stator segment n to stator segment n+2, with coupling length S _n decreasing over time and coupling length S _n+2 increasing over time. Because the midpoint of the magnetic levitation train does not pass through the junction of the stator section n and the stator section n+2, the stator sections n and n+1 are in an operation working condition, and the stator section n+2 is in a standby working condition. The traction power supply control unit MCU can practically distribute the target traction force F _ref to the stator sections n and n+1 in the running working condition, namely F _ref＝F_nref+F_(n+1)ref according to the coupling length of the magnetic levitation train and each stator section. The target traction force F _ref is distributed according to the coupling length, and the target traction force distributed by each stator section n and n+1 can be continuously changed along with the coupling area of the rotor arranged at the bottom of the train and each stator section, so that the constant motor parameters are adapted to maintain the stability of the total traction force of the train.

The traction power supply control unit MCU may then send a traction force allocation command indicating the target traction force F _nref to the corresponding converter 111, 112, the converter 111, 112 being controlled by the converter control unit CCU1 to output the corresponding power supply current i _n to the stator segment n to generate the corresponding traction force F _n. Specifically, according to the formula f=cm×i, the converter control unit CCU1 may define that the stator current i is in direct proportion to the traction force F, where Cm is a motor parameter of the maglev train. As shown in fig. 2, the converter control unit CCU1 may control the converters 111, 112 to output corresponding stator currents i _n according to the traction distribution command F _nref provided by the traction power supply control unit MCU, and control the stator segment n to output corresponding traction force F _n according to the input power supply current i _n, so as to complete tracking implementation of the target traction force F _nref.

Based on the same principle, the traction power supply control unit MCU may also send a traction force allocation command indicating the target traction force F _(n+1)ref to the corresponding converter 121, 122, and the converter control unit CCU2 controls the converter 121, 122 to output the corresponding power supply current i _n+1 to the stator segment n+1 to generate the corresponding traction force F _n+1. The converter control unit CCU2 may control the converters 121 and 122 to output the corresponding stator currents i _n+1 according to the traction force distribution command F _(n+1)ref provided by the traction power supply control unit MCU, and control the stator segment n+1 to output the corresponding traction force F _n+1 according to the input power supply current i _n+1, so as to complete the tracking implementation of the target traction force F _(n+1)ref.

In some preferred embodiments, the traction power control unit MCU may determine the maximum traction force F _max1 of the corresponding side stator segment n, n+2, n+4 from the maximum allowable output current i _max1 of the converters 111, 112. If the target traction force F _nref allocated to the stator segment n is greater than the maximum traction force F _max1 of the stator segment n, the traction power supply control unit MCU may send a traction force allocation command indicating the maximum traction force F _max1 to the corresponding current transformer 111, 112, and the current transformer control unit CCU1 controls the current transformer 111, 112 to output the corresponding power supply current i _max1 to the stator segment n to generate the corresponding traction force F _n. Thereafter, the traction power control unit MCU may also redistribute the remaining target traction force F _rem＝F_ref-F_max1 to the stator segment n+1 according to the maximum traction force F _max2 of the stator segment n+1.

Specifically, if F _rem≤F_max2, the traction power supply control unit MCU may send a traction power distribution instruction indicating the remaining traction force F _rem to the converters 121, 122, and the converter control unit CCU2 controls the converters 121, 122 to output the corresponding power supply current i _rem to the stator segment n+1 to generate the corresponding traction force F _n+1. Conversely, if F _rem>F_max2, the traction power supply control unit MCU may send a traction power distribution command indicating the maximum traction force F _max2 to the converters 121, 122, and the converter control unit CCU2 controls the converters 121, 122 to output the corresponding power supply current i _max2 to the stator segment n+1 to generate the corresponding traction force F _n+1. At this time, the traction system may output the traction force of f=f _n+F_n+1 to pull the maglev train to run.

As described above, the power supply converters 111, 112 of two adjacent stator segments n and n+2 in the same side rail are identical, according to the requirements of the two-step switching process. As shown in fig. 1B, since the vacuum contactor of the switching station can be opened and closed only under no current condition, the step-changing process of the two-step method needs to open the switch of the previous stator segment n, and close the switch of the next stator segment n+2 after the supply current of the previous stator segment n drops from the rated value to 0.

As the train proceeds, in stage 3 shown in fig. 1B, when the right side rail of the maglev train is stepped from stator segment n to stator segment n+2, the midpoint of the maglev train is located exactly at the junction of stator segment n and stator segment n+2. The vacuum contactor switches of the stator section n and the stator section n+2 are all opened, and the stator sections n and n+2 are in standby working conditions. At this time, the stator segment n no longer generates traction force, and the traction system can only output the traction force of f=f _n+1 to drive the maglev train to run. In order to alleviate the power loss of the traction system at the time of two-step change to improve the comfort of passengers, the traction power supply control unit MCU may maximally distribute the target traction force F _ref to the stator segment n+1 on the left track alone within the range of the maximum allowable output current i _max1. The traction force produced by stator segment n+1 rises from original F _nref＝Cm*i_n to F _nref＝Cm*i_max1.

Referring to fig. 5, fig. 5 is a schematic diagram illustrating a current timing diagram of a two-step method according to some embodiments of the invention.

As shown in fig. 5, when the right side rail of the maglev train is stepped from the stator segment n to the stator segment n+2, the traction power supply control unit MCU can maximally distribute the target traction force F _ref alone to the stator segment n+1 on the left side rail within the range of the maximum allowable output current i _max1. Conversely, when the left side rail of the maglev train is stepped from stator segment n+1 to stator segment n+3, the traction power supply control unit MCU can maximally distribute the target traction force F _ref alone to stator segment n+2 on the right side rail within the range of the maximum allowable output current i _max2. In some embodiments, by configuring the traction system with a converter with a sufficiently large maximum allowable output current, the traction force of the stator segment on the other side can be increased to fully compensate the power loss of the traction system when the stator segment on any side changes steps, so that the comfort of passengers is further improved.

Then, as the train proceeds, in stage 4 shown in fig. 1B, the midpoint of the maglev train has passed the junction of stator segment n and stator segment n+2, stator segment n enters the standby condition, and stator segment n+2 enters the operating condition. At this time, the traction power supply control unit MCU may transmit a traction force allocation command indicating the target traction force F _(n+2)ref to the corresponding current transformers 111, 112, and the current transformers 111, 112 are controlled by the current transformer control unit CCU1 to output the corresponding power supply current i _n+2 to the stator segment n+2 to generate the corresponding traction force F _n+2. The converter control unit CCU1 may control the converters 111, 112 to output the corresponding stator current i _n+2 according to the traction force distribution command F _(n+2)ref provided by the traction power supply control unit MCU, and control the stator segment n+2 to output the corresponding traction force F _n+2 according to the input power supply current i _n+2, so as to complete the tracking implementation of the target traction force F _(n+2)ref. At this time, the traction system may output the traction force of f=f _n+2+F_n+1 to pull the maglev train to run.

In some embodiments of the invention, as shown in fig. 2, the converter control unit CCU1 may also collect the actual output tractive effort F ₁ provided by the stator section n in operation to the high speed maglev train. After that, the converter control unit CCU1 may feed back the collected actual output traction force F ₁ to the input end of the traction force distribution command F _nref, and perform closed-loop control on the supply current i _n output by the converters 111 and 112 to the stator segment n. Compared with the rough control scheme that the existing two-step method takes the target current i _ref as a distribution instruction and does not quantitatively control the traction actually output by the stator section n, the invention takes the target traction F _nref as the distribution instruction so as to enable the traction to be comparable with the traction actually output by the stator section n, thereby realizing the closed-loop control of the traction and improving the stability of a traction system.

It will be appreciated by those skilled in the art that although the above embodiments all employ the circuit architecture of the double-ended power supply shown in fig. 1A, that is, the architecture in which two converters 111, 112 supply the power to the power supply cable 11 and two converters 121, 122 supply the power to the power supply cable 12, this is not intended to limit the scope of the present invention. Alternatively, in other embodiments, those skilled in the art may implement the above-described concept of the present invention based on a single-ended power circuit architecture, i.e., an architecture in which only one current transformer is used to power the feeder cable 11 and one current transformer is used to power the feeder cable 12.

While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as would be understood and appreciated by those skilled in the art.

The present invention provides the above computer readable storage medium having computer instructions stored thereon. When the computer instructions are executed by the processor, the traction control method provided by any one of the embodiments can be implemented, so that the defects of total traction reduction, power loss and the like of the train are overcome while the advantages of the two-step method are maintained, and the comfort of passengers is improved. The working principle of the computer readable storage medium is the same as that of the traction control method, and is not described herein.

Those of skill in the art would understand that information, signals, and data may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

Although the traction power supply control unit MCU and the converter control units CCU1, CCU2 described in the above embodiments may be implemented by a combination of software and hardware. It is understood that the traction power control unit MCU and the converter control units CCU1, CCU2 may also be implemented in software or hardware alone. For hardware implementation, the traction power control unit MCU and the converter control units CCU1, CCU2 may be implemented in one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic devices for performing the above functions, or a selected combination of the above. For software implementation, the traction power control unit MCU and the converter control units CCU1, CCU2 may be implemented by separate software modules, such as program modules (procedures) and function modules (functions), running on a common chip, each of which may perform one or more of the functions and operations described herein.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A traction control method for a maglev train, comprising:

determining a target traction force of the maglev train;

Determine at least one stator segment located at the train position according to the train position of the maglev train, the stator segment positions of a plurality of stator segments arranged on tracks at both sides of the running line, and the stator segment working conditions;

determining whether the at least one stator segment is in an operating condition;

calculating a coupling length between the at least one stator segment and the train according to the train position and the stator segment position of the at least one stator segment; and

The target traction force is distributed to the stator segment in the running condition according to the coupling length between the at least one stator segment and the train, wherein one of the multiple stator segments on the same side track is selectively operated, and one of the corresponding stator segments on the two side tracks is selectively changed.

2. The traction control method according to claim 1, further comprising:

Planning a target speed curve of the maglev train according to a target position instruction provided by the operation control system;

Calculating a target acceleration of the maglev train according to the target speed curve and actual speed feedback of the maglev train; and

The target traction force is calculated according to the target acceleration.

3. The traction control method according to claim 2, further comprising:

collecting the relative displacement of the maglev train in real time;

Calculating actual speed feedback of the maglev train according to the relative displacement;

Calculating actual acceleration feedback of the maglev train according to the actual speed feedback; and

PID control is performed according to the relative displacement, the actual speed feedback, and the actual acceleration feedback to calculate the target traction force.

4. The traction control method according to claim 1, characterized in that the plurality of stator segments are respectively powered by corresponding converters, wherein the plurality of stator segments on the same side track are powered by the same converter, and the plurality of stator segments on different side tracks are powered by different converters, and the step of allocating the target traction to the stator segments in the operating condition further comprises:

A traction force distribution instruction is sent to the converter corresponding to the stator segment in the operating condition to control the converter to output the corresponding power supply current to the stator segment in the operating condition.

5. The traction control method according to claim 4, characterized in that the step of allocating the target traction to the stator segments in the operating condition further comprises:

Determining the maximum traction force of the stator segment on the corresponding side according to the maximum allowable output current of the converter;

In response to the traction force distributed to any stator segment being greater than the maximum traction force of the stator segment, controlling the stator segment to output the maximum traction force; and

According to the maximum traction forces corresponding to the remaining stator segments at the train position, the remaining target traction forces are redistributed to the remaining stator segments in the operating condition.

6. The traction control method according to claim 4, characterized in that the step of allocating the target traction to the stator segments in the operating condition further comprises:

In response to the stator segments on the first side track changing steps, the target traction force is distributed solely to the stator segments on the second side track that are in the operating condition.

7. The traction control method according to claim 4, further comprising:

Controlling the stator segment in the running state to output traction force according to the input power supply current to pull the maglev train;

collecting the actual output traction force of the stator segment in the operating condition; and

According to the traction force distribution instruction and the actual output traction force, a power supply current output to the stator segment in the operating condition is controlled in a closed loop.

8. A traction control device for a maglev train, comprising:

Memory; and

A processor, the processor is connected to the memory and includes a first control unit, wherein the first control unit is configured to:

determining a target traction force of the maglev train;

9. The traction control device according to claim 8, wherein the first control unit is further configured to:

The target traction force is calculated according to the target acceleration.

10. The traction control device according to claim 9, wherein the first control unit is further configured to:

collecting the relative displacement of the maglev train in real time;

11. The traction control device according to claim 10, characterized in that the plurality of stator segments are respectively powered by corresponding converters, wherein the plurality of stator segments on the same side track are powered by the same converter, and the plurality of stator segments on different side tracks are powered by different converters, and the first control unit is further configured as follows:

12. The traction control device according to claim 11, wherein the first control unit is further configured to:

In response to the traction force allocated to any stator segment being greater than the maximum traction force of the stator segment, allocating the maximum traction force to the stator segment; and

13. The traction control device according to claim 11, wherein the first control unit is further configured to:

14. The traction control device according to claim 11, wherein the processor further comprises a second control unit, and the second control unit is configured to:

15 . A computer-readable storage medium having computer instructions stored thereon, wherein when the computer instructions are executed by a processor, the traction control method according to any one of claims 1 to 7 is implemented.

16. A maglev train, characterized by comprising the traction control device according to any one of claims 8 to 14.