Maglev railway system and control thereof

Abstract

A magnetic levitation railway system is disclosed herein. The system comprises a vehicle, a guidance track arranged for supporting the vehicle above the guidance track by magnetic levitation, and at least one linear motor comprising a mover and an elongate stator. The vehicle is provided with the mover and the guidance track is provided along its length with the stator. The linear motor is arranged to generate a propulsion force acting on the vehicle along the longitudinal direction of the guidance track for propelling the vehicle along the guidance track. The at least one linear motor is arranged to further generate a respective normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component. Further disclosed is a method of controlling such a system.

Description

[0001] MAGLEV RAILWAY SYSTEM AND CONTROL THEREOF

[0002] The present invention relates to a magnetic levitation railway system and to a vehicle and guidance track for use therein. The present invention further relates to a method of controlling such a magnetic levitation railway system.

[0003] Maglev (magnetic levitation) train technology is known as a high-speed and efficient alternative to conventional rail transport. Unlike traditional trains that rely on physical contact between wheels and tracks, maglev trains achieve levitation and propulsion through electromagnetic forces, thereby eliminating friction and enabling higher speeds with reduced maintenance requirements.

[0004] One of the implementations of maglev technology is the Transrapid system, which employs a Linear Synchronous Motor (LSM) for propulsion. In the Transrapid design, coils are integrated into the track to establish electromagnetic interaction with the train. However, over long distances coil costs have been found to be prohibitive. The adoption of the Transrapid system has thus faced substantial economic barriers, at least partially due to the high costs associated with constructing specialised rail infrastructure. The necessity to embed coils within the track not only increases the per-kilometre cost of rail construction but also mandates the development of entirely new infrastructure. Consequently, existing railway networks are incompatible with Transrapid trains, which necessitates separate infrastructure investments and therefore limits the system's scalability and implementation.

[0005] A more recently proposed Maglev -based system, referred to as the Nevomo system, similarly utilises an LSM for propulsion and incorporates aluminium plates on the exterior of the rails to achieve levitation through eddy current repulsion. Like the Transrapid approach, the Nevomo system's design requires the installation of coils within the track, which further increases the costs.

[0006] Alternative maglev approaches have explored the use of permanent magnets positioned on either side of the rails to provide suspension. However, these systems typically employ wheels for propulsion. The levitation force generated by permanent magnets often proves insufficient for heavier loads such as freight trains, compromising stability and safety. Additionally, the reliance on wheels for propulsion reintroduces mechanical friction, which undermines the primary advantage of maglev systems by increasing energy consumption and reducing efficiency. Adverse weather conditions, such as moisture, rain or snow, exacerbate these issues by extending braking distances and necessitating larger safety margins due to the unpredictable slipperiness of the rails. It is an object of the present invention, among other objects, to provide an improved magnetic levitation railway system wherein the aforesaid drawbacks are at least partially alleviated.

[0007] To that end, a magnetic levitation railway system is provided, comprising a vehicle, a guidance track arranged for supporting the vehicle above the guidance track by magnetic levitation, and at least one linear motor comprising a mover and an elongate stator, wherein the vehicle is provided with the mover and the guidance track is provided along its length with the stator, wherein the linear motor is arranged to generate a propulsion force acting on the vehicle along the longitudinal direction of the guidance track for propelling the vehicle along the guidance track, wherein the at least one linear motor is arranged to further generate a respective normal force (also called cogging force) acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component.

[0008] The at least one linear motor is preferably arranged such that the direction of the normal force is substantially horizontal. Arranging one or more linear motors such that the normal forces have a horizontal component has the following advantage. Although it is known to use a linear motor in a maglev system wherein the vehicle floats above the track, in such systems the normal force is typically directed vertically downwards to stabilise and control the levitation by countering the upward levitation force. This configuration, however, constrains the selection of the linear motor, as some motors would generate a normal force that is not suitable for such use. For instance, the normal forces may become too large and / or cannot be suitably controlled. On the other hand, arranging the linear motor such that the normal force is directed vertically upwards may be beneficial when the stator is suspended below the track and the stator extends above the vehicle, but is inconvenient in case the vehicle is to be levitated above the guidance track provided with the elongate stator. By, instead, arranging the linear motor such that the normal force has a horizontal component, a linear motor with a high power density and an elongate stator made of only steel, such as a linear flux-switching permanent magnet (LFSPM) motor, can be advantageously used. Thus, such an arrangement of the at least one linear motor allows the elongate stator to be a steel stator, which is more cost-efficient than, e.g., an elongate stator with copper windings like in a linear synchronous motor. Such a linear motor is also more efficient than a linear induction motor (LIM), which has an aluminium stator. For example, maglev designs that include the use of LIMs are typically for low-speed urban maglev systems.

[0009] Hence, by arranging the linear motor in accordance with the present disclosure, the installation costs for a magnetic levitation railway system can be reduced, especially over longer distances. This way, an economically viable and widely deployable maglev train system can be realised. In particular, the vehicle may be used for the transport of passengers or freight.

[0010] For levitation, the system may be provided with an electromagnetic suspension system. Preferably, the vehicle is provided with electromagnets arranged to generate a magnetic levitation force for supporting the vehicle above the guidance track. The electromagnets may be arranged to extend below a ferromagnetic portion of the guidance track, wherein the magnetic levitation force is an upward attraction force for levitating the vehicle by attraction to said ferromagnetic portion of the guidance track. The ferromagnetic portion of the guidance track is preferably made of steel, more preferably laminated steel.

[0011] The stator preferably comprises a plurality of stator teeth distributed along the length of the guidance track. The stator teeth preferably extend and / or protrude substantially laterally from the guidance track and / or face horizontally away from the guidance track. The stator is preferably made of a ferromagnetic material such as steel, more preferably laminated steel.

[0012] The manufacture and / or installation of such laminated material is cost-efficient as steel plate material is widely available and providing the material in the required shapes is easy and highly automatable. The material is, for example, M235-35A steel with a thickness of 0.35 millimetre. The use of a laminated material reduces induced eddy currents in the stator, and thus reduces eddy current losses.

[0013] Preferably, the mover comprises one or more coils arranged to generate one or more electromagnetic fields to generate the propulsion force and the normal force. In particular in case of propulsion means for magnetic levitation railway systems, the component of the propulsion means that remains stationary is typically the component that does not comprise electromagnets. The component of the propulsion means that comprises the electromagnets typically moves with the vehicle, and is thus referred to as the ‘mover’ .

[0014] Specifically, it is preferred that the stator and mover of the at least one linear motor extend substantially adjacent to each other in the horizontal plane. In other words, the stator and mover are preferably positioned at the same height and laterally spaced. This way, it can be ensured that the normal force is substantially horizontal.

[0015] According to a preferred embodiment of the magnetic levitation railway system, the linear motor is arranged for using the normal force for horizontal guidance of the vehicle to keep the vehicle centred above the guidance track. Thereto, it is preferred if the system further comprises a guidance control system arranged to control the at least one linear motor for horizontal guidance of the vehicle using said normal force.

[0016] The magnetic levitation railway system preferably comprises at least one pair of linear motors, wherein the linear motors of the pair are arranged for generating respective propulsion forces acting on the vehicle for propelling the vehicle along the guidance track. Preferably, the respective propulsion forces act in substantially the same direction. The linear motors are preferably spaced laterally from each other. The pair thus comprises a left-side motor and a right-side motor.

[0017] Providing a pair of linear motors to propel the vehicle with similar forces enhances the stability of the moving vehicle. It is then further preferred if the linear motors of the pair are arranged for further generating respective normal forces acting on the vehicle in respective directions with mutually opposite horizontal components. This way, the normal forces can counter each other to keep the vehicle balanced above the guidance track.

[0018] According to a further preferred embodiment of the magnetic levitation railway system, the linear motor comprises a switched reluctance linear motor (SRLM), or a linear flux-switching permanent magnet (LFSPM) motor, preferably a modular LFSPM (MLFSPM) motor, more preferably a complementary and modular LFSPM (CMLFSPM) motor, or any other type of switched reluctance machine. Switched reluctance machines beneficially use stators which are made of a ferromagnetic material such as steel, rather than stators comprising permanent magnets. At the same time, a high power density can be achieved. Alternatively, the linear motor may be a linear induction motor (LIM). Linear induction motors use a stator that is made of a conductive material, such as aluminium, which is also preferred over stators comprising permanent magnets.

[0019] The use of permanent magnets as part of the mover in an LFSPM provides a field source, which increases the overall efficiency of the motor as the volume of the electromagnet windings and associated losses is reduced.

[0020] For a switched reluctance type motor, the stator preferably comprises a plurality of projecting ‘teeth’ which act as salient magnetic poles. The mover on the other hand comprises a series of projecting electromagnetic poles and electromagnets. The operational principle of the motor is that the mover moves along the stator, and propulsion force is generated by selectively activating specific electromagnets to attract a magnetic pole that is ahead of the electromagnet, and thus unaligned with the electromagnet, and to subsequently deactivate the specific electromagnet as the pole comes into alignment with the electromagnet. In the aligned position, the force generated is entirely in a direction perpendicular to the direction of movement. This perpendicular force is the normal or cogging force. The further the respective pole is removed from the electromagnet, the more aligned the force between the electromagnet and the pole is with the direction of movement. A switched reluctance motor, in particular an SRLM or (CM)LFSPM, comprises a series of electromagnets. If the pitch between the poles on the stator and the electromagnets on the mover is different, the individual electromagnets will be located at different distances to respective poles. In use, the respective attractive forces between the individual electromagnets and poles are thus less or more in either the normal (cogging) direction or propulsion direction. By momentarily increasing or decreasing the power of individual electromagnets, the ratio of the combined propulsion force and cogging force of the entire mover can thus be changed. In other words, by momentarily changing the commutation angle of the electromagnets in a mover, the normal force acting towards the stator can be momentarily increased or decreased. In particular if two movers and corresponding stators are oriented such that the normal forces act towards each other or away from each other, increasing or decreasing the normal force generated by one or both of the movers allows for guidance of the vehicle along the guidance track. By real-time monitoring of the distance between a mover and corresponding stator and adjusting the commutation of the mover based on that, the position of the vehicle on the guidance rail in the lateral direction can be controlled.

[0021] For horizontal guidance of the vehicle, the guidance control system is preferably arranged to adjust at least one of the respective normal forces relative to the other and / or relative to at least one of the respective propulsion forces. More specifically, the guidance control system may be arranged to adjust the one normal force relative to the other normal force using an angle offset between the one normal force and the respective propulsion force.

[0022] Preferably, the guidance control system is arranged to adjust the one normal force relative to the other normal force by providing one of the linear motors with a positive commutation angle offset and the other linear motor with a negative commutation angle offset of the same magnitude as the positive angle offset. This enables an increase of the normal force generated by one of the motors, for instance the left-side motor, and / or a decrease of the normal force generated by the other (rightside) motor, or vice versa, while maintaining equal propulsion forces from the respective motors, since a positive angular offset and a negative angular offset of the same magnitude result in the same propulsion force, but one decreases the normal force and the other increases it. This way, the motors can be controlled for horizontal guidance. For example, if the left-side motor of the pair is controlled with an angle offset of 50 degrees and the right-side motor is controlled with an angle offset of -50 degrees, the motors generate the same propulsion force, which enhances stability, while the guidance force of the left-side motor is increased and the guidance force of the right-side motor is decreased.

[0023] Said guidance system is especially advantageous in combination with linear flux switching motors (LFSM). However, the same principle may be applied in combination with linear induction motors. However, as these motors produce a repulsive force between the stator and mover, rather than an attractive (cogging) force between stator and mover as in case of an LFSM, the guidance principle is inverted compared to what is described above. Moreover, instead of an angle offset, a slip / frequency offset is provided.

[0024] According to a further preferred embodiment of the magnetic levitation railway system, the guidance track includes a pair of mutually parallel rail head portions arranged for wheels of a train to roll thereon for the train to travel along the guidance track. This way, a conventional train can also travel along the track. As conventional trains can also use the track, the integration of the magnetic levitation railway system in existing, conventional railway systems can be facilitated. The magnetic levitation railway system thus has improved scalability.

[0025] Further provided is a magnetic levitation vehicle as such, preferably a vehicle as described above for use in a magnetic levitation railway system according to any of the above embodiments, wherein the vehicle is provided with a mover for a linear motor for generating a propulsion force acting on the vehicle and for generating a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component. In particular, the vehicle preferably comprises at least two mover units, each comprising a plurality of coils, wherein each mover unit is configured to act as part of a linear motor, wherein each mover unit is arranged to interact with a substantially horizontally adjacent stator to generate a propulsion force and a normal force that is perpendicular to the direction of the propulsion force and has a horizontal component.

[0026] It is further preferred if, as described above, the vehicle is provided with electromagnets arranged to generate a magnetic levitation force for supporting the vehicle above the guidance track.

[0027] Further provided is a magnetic levitation guidance track as such, preferably a guidance track for use in a magnetic levitation railway system according to any of the above embodiments, wherein the guidance track is provided along its length with an elongate stator for a linear motor for generating a propulsion force acting on the vehicle of the system and for generating a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component.

[0028] In particular, the guidance track preferably comprises at least one elongate stator section extending along the length of the guidance track, wherein the at least one stator section extends vertically to a nonzero height, wherein the at least one stator section is configured to act as the stator portion of a linear motor.

[0029] The guidance track preferably further comprises at least one ferromagnetic levitation section extending along the length of the guidance track, wherein the levitation section extends horizontally to a nonzero width. Preferably, the levitation section is arranged above the stator section such that a corresponding mover section of a linear motor may pass underneath the levitation section.

[0030] According to a further preferred embodiment of the magnetic levitation guidance track, the guidance track further comprises a rail head section for a wheel of a conventional train to run thereon.

[0031] The guidance track may comprise a section of railway track extending along the length of the guidance track, wherein the stator section extends on one side of the railway track, and wherein the levitation section extends on one side of the railway track. Said section of railway track may comprise the rail head section.

[0032] Preferably, the at least one stator section comprises a plurality of stator teeth extending along the length of the guidance track, wherein the plurality of teeth each extend or protrude substantially horizontally.

[0033] The guidance track may comprise at least one elongate L-shaped section extending along the length of the guidance track adjacent to the railway track, wherein one leg of the L-shaped section comprises the stator section and extends substantially vertically. The other leg of the L-shaped section connects to the top of the stator section, extends horizontally away from the railway track, and may be provided with the levitation section.

[0034] Preferably, the guidance track comprises two L-shaped sections extending on either side of the railway track, wherein the levitation sections of the two L-shaped sections extend outwards and away from the railway track and each other. Preferably, the at least one levitation section and the at least one stator section each comprise a plurality of sheets of laminated steel extending along at least part of the length of the guidance track. The laminated steel thereby forms the elongate stator and enable the magnetic levitation.

[0035] Further provided is a method of controlling a magnetic levitation railway system according to any of the above embodiments, wherein the method comprises the following steps:

[0036] supporting the vehicle of the system above the guidance track of the system by magnetic levitation;

[0037] propelling the vehicle along the guidance track by generating, using the at least one linear motor of the system, a propulsion force acting on the vehicle along the longitudinal direction of the guidance track;

[0038] keeping the vehicle centred above the guidance track by further generating, using said linear motor, a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component for horizontal guidance of the vehicle.

[0039] In the following, a preferred embodiment of the present invention is illustrated with reference to the accompanying drawings, wherein:

[0040] figure 1 shows a frontal overview of a guidance track;

[0041] figure 2 shows a standard rail;

[0042] figure 3 shows a perspective view of the guidance track;

[0043] figure 4 shows a front view of a magnetic levitation railway system;

[0044] figure 5 shows the guidance tracks in combination with propulsion / levitation units; figures 6A, B show schematic views of a linear flux switching permanent magnet motor; figure 7 shows a railway track ramp; and

[0045] figure 8 shows a graph of the normalized normal and thrust forces generated by an electric motor.

[0046] Figure 1 shows a frontal cross-sectional overview of a guidance track 1 for use as part of a magnetic levitation railway system. The guidance track 1 comprises an elongate stator section 21a, b which functions as the stator of a linear motor. The stator section 21a, b extends at least partially in the vertical direction h, such that clearance is created for a mover portion of the linear motor to be placed horizontally adjacent to the stator section 21a, b. The guidance track 1 further comprises an elongate levitation section 23a, 23b which allows a magnetically levitating vehicle (not shown) to levitate using electromagnets that interact with the levitation section 23a, b. The levitation section 23a, b extends at least partially in the horizontal direction to a width w, such that components of the vehicle 10 may pass underneath the levitation section 23a, b. The stator section 21a, b and the levitation section 23a, b form part of a guidance track body 2, also called an inverted L-shaped body 2, with one leg comprising the stator portion 21a, b, and another leg comprising the levitation section 23a, b. The stator section 21a, b extends vertically, for example from a surface S, and the levitation section 23a, b connects at the top of the stator section 21a, b. Both the stator section 21a, b and the levitation section 23 a, b comprise a plurality of sheets of laminated steel, respectively 22a, b and 24a, b.

[0047] The guidance track 1 shown comprises two guidance track bodies 2a, b with the levitation sections extending laterally in opposite directions. In the clearance between the track bodies 2a, b a rail 3 is arranged which allows conventional trains with train wheels to make use of the guidance track 1.

[0048] Figure 2 shows a standard rail 3’, with a standard height web 32’ extending between the head 31 and the bottom 33’. As the height of the guidance track bodies 2a, b is higher than a standard rail 3’, the height of the rail 3 may be increased by increasing the height of the centre web 32 which connects the bottom 33 to the head 31. Alternatively, a conventional rail 3’ may be used that is placed on a support to raise the rail 3’.

[0049] Figure 3 shows a perspective view of the guidance track 1. The stator section 21a, b comprises a plurality of stator teeth 25a, b extending sideways in the horizontal direction to a width d.

[0050] Figure 4 shows a front view of a magnetic levitation vehicle 10 and two guidance tracks 1 forming a magnetic levitation railway system. The magnetic levitation vehicle 10 comprises four propulsion / levitation units 1 la, b, 12a, b which comprise the mover portion of a linear motor and / or electromagnets to provide the levitation. In the shown embodiment, the magnetic levitation vehicle comprises sets of four laterally spaced propulsion / levitation units 1 la, b, 12a, b, such sets being distributed along the length of the vehicle 10 in a mutually spaced manner. Embodiments with such sets of only two propulsion / levitation units 1 la, b, 12a, b, for instance only the outermost units 12a, b, can also be envisioned.

[0051] Figure 5 shows the guidance tracks 1 in combination with the propulsion / levitation units 1 la, b, 12a, b in more detail. For the sake of simplicity, the technical features will be explained in relation to the leftmost propulsion / levitation units Ila, 12a in combination with the leftmost guidance track 1. The rightmost propulsion / levitation units 11b, 12b are identical, but mirrored. The units Ila, b comprise slot-shaped openings 16a, b to provide space for the levitation sections 23a, b of the guidance tracks 1. In other words, the units Ila, 12a extend around and underneath the levitation sections 23a, b. This allows the units Ila, 12a to be horizontally adjacent to the stator sections 21a, b. The mover sections 13a, b of the linear motors are thus located horizontally adjacent to the stator sections 21a, b. The vehicle 10 further comprises electromagnets 15a-d which are arranged to interact with the levitation sections 23a, b to provide downwards downforce. Similarly, the propulsion / levitation units Ila, 12a comprise electromagnets 14a, b which are located underneath the levitation sections 23a, b and generate an attraction force to lift the vehicle 10 upwards to provide levitation. Depending on requirements, the configuration of the inboard (Ila) and outboard (12a) propulsion / levitation units may be adapted. For example, it can be envisaged that only one of the two holds a mover section 13 a, b.

[0052] Figure 6A shows a schematic cross section view of a linear flux switching permanent magnet (LFSPM) motor 13 comprising an elongate stator 21, provided on the track 1, and a set of mover units 130 provided on the vehicle 10. The shown motor 13 comprises six mover units 130, but this number may be larger or smaller depending on requirements. Each mover unit 130 comprises an electromagnet (armature) winding indicated as 131 in figure 6A extending around a permanent magnet 133. The armature windings 131, and permanent magnet 133 are mounted on a mover body 134, which is preferably ferromagnetic and may be geometrically adjusted to adjust and optimize the magnetic field lines generated by the combined permanent magnet 133 and armature windings 131. The stator 21 (earlier referred to as the stator section 21a, b) comprises a plurality of stator teeth 25 which function as magnetic stator poles 25. These poles magnetically interact with the magnetic fields generated by the mover units 130 to propel the mover units 130 along the stator 21 in the direction of movement and propulsion M. The pitch Ps between stator poles 25 is different, preferably smaller, than the pitch Pc between armature windings 131 of a mover unit 130. This reduces torque ripple and facilitates the guidance through adjusting the commutation angle of one or more of the electromagnets 131, as described below.

[0053] Figure 6B shows a perspective view of an LFSPM motor 13. The armature windings of a mover unit 130 appear to be made up of distinctive parts, all indicated by 131. However, the parts indicated by 131 preferably form a single winding 131 extending around the permanent magnet 133.

[0054] Figure 7 shows a railway track ramp 3” which allows a conventional train to roll from a rail of regular height 3’ onto a rail of increased height 3 as used in combination with the guidance track 1.

[0055] Figure 8 shows a graph of the normalized guidance (normal or cogging) force and normalized thrust (propulsion) force of an electric motor, in the present case a linear motor such as a flux switching linear motor, as a function of the commutation angle offset. By changing the commutation angle offset of a motor, the instantaneous ratio between the normal and propulsion forces can be changed to facilitate guidance of the vehicle 10 along the track 1. For example, in the case of the system shown in figure 5, if the left-side motor 13a, 13c of each motor pair is controlled with an angle offset of 50 degrees and the right-side motor 13b, 13d of each motor pair is controlled with an angle offset of -50 degrees, the motors 13 generate the same propulsion force (about 0.82 of the maximum), which enhances stability, while the guidance force of the left-side motors 13a, 13c is increased and the guidance force of the right-side motors 13b, 13d is decreased. That is, at respective angle offsets of 50 degrees and of -50 (or 310) degrees, the leftward and rightward guidance forces are respectively about 0.88 and 0.12 of the maximum, such that the net horizontal force can be used to keep the vehicle 10 centred above the tracks 1.

[0056] The drawings and the above description serve to illustrate specific embodiments of the invention and do not limit the scope of protection defined by the appended claims.

Claims

CLAIMS1. Magnetic levitation railway system, comprising a vehicle, a guidance track arranged for supporting the vehicle above the guidance track by magnetic levitation, and at least one linear motor comprising a mover and an elongate stator, wherein the vehicle is provided with the mover and the guidance track is provided along its length with the stator, wherein the linear motor is arranged to generate a propulsion force acting on the vehicle along the longitudinal direction of the guidance track for propelling the vehicle along the guidance track, wherein the at least one linear motor is arranged to further generate a respective normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component.

2. System according to claim 1, wherein the direction of the normal force is substantially horizontal.

3. System according to claim 1 or 2, wherein the linear motor is arranged for using the normal force for horizontal guidance of the vehicle to keep the vehicle centred above the guidance track.

4. System according to claim 3, further comprising a guidance control system arranged to control the at least one linear motor for horizontal guidance of the vehicle using said normal force.

5. System according to any of the preceding claims, comprising at least one pair of linear motors, wherein the linear motors of the pair are arranged for generating respective propulsion forces acting on the vehicle for propelling the vehicle along the guidance track, and wherein the linear motors of the pair are arranged for further generating respective normal forces acting on the vehicle in respective directions with mutually opposite horizontal components.

6. System according to at least claims 4 and 5, wherein the guidance control system is arranged to adjust at least one of the respective normal forces relative to the other and / or relative to at least one of the respective propulsion forces.

7. System according to claim 6, wherein the guidance control system is arranged to adjust the one normal force relative to the other normal force using an angle offset between the one normal force and the respective propulsion force.

8. System according to claim 7, wherein the guidance control system is arranged to adjust the one normal force relative to the other normal force by providing one of the linear motors with a positive angle offset and the other linear motor with a negative angle offset of the same magnitude as the positive angle offset.

9. System according to any of the preceding claims, wherein the guidance track includes a pair of mutually parallel rail head portions arranged for wheels of a conventional train to roll thereon for the conventional train to travel along the guidance track.

10. System according to any of the preceding claims, wherein the mover comprises one or more coils arranged to generate one or more electromagnetic fields to generate the propulsion force and the normal force.

11. System according to any of the preceding claims, wherein the stator comprises a plurality of stator teeth distributed along the length of the guidance track.

12. System according to claim 11, wherein the stator teeth extend substantially laterally from the guidance track.

13. System according to any of the preceding claims, wherein the stator and mover of the at least one linear motor extend substantially adjacent to each other in the horizontal plane.

14. System according to any of the preceding claims, wherein the stator is made of steel, preferably laminated steel.

15. System according to any of the preceding claims, wherein the vehicle is provided with electromagnets arranged to generate a magnetic levitation force for supporting the vehicle above the guidance track.

16. System according to claim 15, wherein the electromagnets are arranged to extend below a ferromagnetic portion of the guidance track, wherein the magnetic levitation force is an14upward attraction force for levitating the vehicle by attraction to said ferromagnetic portion of the guidance track.

17. System according to claim 16, wherein the ferromagnetic portion of the guidance track is made of steel, preferably laminated steel.

18. System according to any of the preceding claims, wherein the linear motor is a linear induction motor (LIM), a switched reluctance linear motor (SRLM) or a linear fluxswitching permanent magnet (LFSPM) motor, preferably a modular LFSPM (MLFSPM) motor, more preferably a complementary and modular LFSPM (CMLFSPM) motor.

19. Magnetic levitation vehicle for use as the vehicle in a magnetic levitation railway system according to any of the preceding claims, wherein the vehicle is provided with a mover for a linear motor for generating a propulsion force acting on the vehicle and for generating a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component.

20. Vehicle according to claim 19, comprising at least two mover units each comprising a plurality of coils, wherein each mover unit is configured to act as part of a linear motor, wherein each mover unit is arranged to interact with a substantially horizontally adjacent stator to generate a propulsion force and a normal force that is perpendicular to the direction of the propulsion force and has a horizontal component.

21. Magnetic levitation guidance track for use as the guidance track in a magnetic levitation railway system according to any of the preceding claims 1 - 18, wherein the guidance track is provided along its length with an elongate stator for a linear motor for generating a propulsion force acting on the vehicle of the system and for generating a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component.

22. Guidance track according to claim 21, wherein the guidance track comprises at least one elongate stator section extending along the length of the guidance track, wherein the at least one stator section extends vertically to a nonzero height, wherein the at least one stator section is configured to act as the stator portion of a linear motor, wherein the guidance track further comprises at least one ferromagnetic levitation section extending along the length of the guidance track, wherein the levitation section extends horizontally to a nonzero width,15and wherein the levitation section is arranged above the stator section such that a corresponding mover section of a linear motor may pass underneath the levitation section, wherein the guidance track further comprises a rail head section for a wheel of a conventional train to run thereon.

23. Guidance track according to claim 22, wherein the guidance track comprises a section of railway track extending along the length of the guidance track and comprising the rail head section, wherein a stator section extends on one side of the railway track, and wherein a levitation section extends on one side of the railway track.

24. Guidance track according to claim 22 or 23, wherein the at least one stator section comprises a plurality of stator teeth extending along the length of the guidance track, wherein the plurality of teeth each extend substantially horizontally.

25. Guidance track according to at least claim 22, wherein the guidance track comprises at least one elongate L-shaped section extending along the length of the guidance track adjacent to the railway track, wherein one leg of the L-shaped section comprises the stator section and extends substantially vertically, and wherein the other leg of the L-shaped section connects to the top of the stator section and extends horizontally away from the railway track.

26. Guidance track according to claim 25, wherein the guidance track comprises two L-shaped sections extending on either side of the railway track, wherein the levitation sections of the two L-shaped sections extend outwards and away from the railway track and each other.

27. Guidance track according to at least claim 22, wherein the at least one levitation section and the at least one stator section each comprise a plurality of sheets of laminated steel extending along at least part of the length of the guidance track.

28. A method of controlling a magnetic levitation railway system according to any of the preceding claims 1 - 18, the method comprising the following steps:- supporting the vehicle of the system above the guidance track of the system by magnetic levitation;- propelling the vehicle along the guidance track by generating, using the at least one linear motor of the system, a propulsion force acting on the vehicle along the longitudinal direction of the guidance track;16- keeping the vehicle centred above the guidance track by further generating, using said linear motor, a normal force acting on the vehicle in a direction that is perpendicular to the direction of the propulsion force and has a horizontal component for horizontal guidance of the vehicle.

Images