Stator for a rotating field machine

Abstract

The invention relates to a stator for a rotating field machine, comprising a stator main part (3), wherein the stator (1) is associated with a geometric machine axis (4), and the stator (1) has stator slots (5) and a stator coil assembly (6) comprising multiple stator coil strands (7) which can be connected to a three-phase supply voltage at respective phase connections (8) in order to generate a rotating magnetic field. Each of the stator coil strands (7) has a bundle (9) comprising a plurality of conductors (101, 102,... 10n), the conductors (101, 102,... 10n) of each bundle (9) are arranged together in the stator slots (5) so as to form star-connected inductors (11), each of the conductors (101, 102,... 10n) has a phase connection-side section (12) and a star point-side section (13), and the conductors (101, 102,... 10n) of a bundle (9) are connected to the phase connection (8) of the respective stator coil strand (7) via the phase connection-side section (12). According to the invention, the conductors (101, 102,... 10n) of bundles (9) of different stator coil strands (7) are electrically connected together via the star point-side section (13) using respective star points (14), and the star points (14) are designed to be electrically decoupled from one another.

Description

[0001] Stator for a rotating induction machine

[0002] The present invention relates to a stator for a rotating induction machine according to the preamble of claim 1, a rotating induction machine according to claim 10 and a method for producing a stator for a rotating induction machine according to the preamble of claim 11.

[0003] The induction motor in question can be used in a wide variety of applications. Examples include electric motors and generators for land, air, and water vehicles. Other applications can be found in industrial automation and power generation.

[0004] The stator has a stator coil arrangement with several stator coil strands, which can be connected to a rotating supply voltage at respective phase terminals to generate a rotating magnetic field. The stator coil strands are electrically connected in a star connection to a star point.

[0005] Particularly for higher power levels to be realized by the induction motor, the stator coil phases are formed at least partially by bundles of conductors. This allows the required cross-section of the stator coil phases to be provided by multiple conductors. The conductors of the bundles of the stator coil phases are usually brought together at a common star point and electrically connected there. The star inductances are each formed by a plurality of conductors connected in parallel.

[0006] The use of conductor bundles can simplify the overall processing of stator coil strands, especially the production of windings for the star inductors, and reduce AC losses. However, the design of the conductor bundles can lead to additional electrical losses.

[0007] The invention is based on the problem of designing and developing a stator for a rotating induction machine in such a way that the electrical losses in the stator coil arrangement are further reduced. The above problem is solved by the features of the characterizing part of claim 1.

[0008] The invention is based on the fact that the stator coil strands each comprise a bundle with a plurality of conductors, wherein the conductors of a bundle are arranged together in the stator slots to form respective star inductances of the stator coil strand. The conductors each comprise a phase-connection-side section and a star-point-side section, wherein the conductors of a bundle are electrically connected to the phase connection of the respective stator coil strand via the phase-connection-side section.

[0009] The invention is based on the fundamental insight that voltage differences can occur between individual conductors due to variations, particularly in the position and length of the conductors. The conventional short circuit of the star-point sections of the conductors of different stator coil strands to a single, common star point can lead to circulating currents and thus to significant electrical losses due to the resulting direct parallel connection of the conductors of the respective bundles.

[0010] The fundamental idea is that the conductors of the bundles of a stator coil strand are interconnected via several independently provided star points. This separation into star connections for the individual conductors largely suppresses circulating currents in the conductors of a bundle.

[0011] In detail, it is proposed that the conductors of bundles of different stator coil strands are electrically connected to one another via the star-point side section by means of respective star points and that the star points are designed to be electrically decoupled from one another.

[0012] In the embodiments according to claims 2 and 3, respective star-point triples that are electrically insulated from one another are provided, so that a star-delta connection for the stator coil strands can also be implemented on the basis of the teachings of the present invention. Delta inductances provided between the star points of the star point triples are preferably formed by further bundles of conductors. Also particularly interesting is the embodiment according to claim 5, according to which the conductors of a bundle are arranged geometrically in a sequence in the stator slots and are thus at least partially ordered. The conductors of different stator coil strands, however, are electrically connected to one another via the star points in a random manner, so that any voltage differences that arise due to the arrangement and lengths of the conductors are statistically at least partially compensated. Accordingly, the occurrence of voltage differences can be largely minimized.

[0013] The bundles of conductors are preferably used in wound inductors, which is the subject of claim 6. A configuration as plug-in inductors using hairpins is also conceivable. Further preferred configurations of the bundles are specified in claim 7.

[0014] According to a further teaching according to claim 9, which has independent significance, a rotating induction machine with a proposed stator and a rotor that magnetically interacts with the stator coil arrangement is claimed. Reference is made to all statements regarding the proposed stator.

[0015] According to a further teaching according to claim 10, which also has independent significance, a method for producing a stator for a rotating induction machine is claimed. It is essential that the conductors of bundles of different stator coil strands are electrically connected to one another via the star-point section using respective star points, and that the star points are designed to be electrically decoupled from one another. Reference is also made to all statements regarding the proposed stator.

[0016] In the following, the invention is explained in more detail with reference to a drawing which merely represents exemplary embodiments. In the drawing,

[0017] Fig. 1 shows a proposed stator in a schematic representation, Fig. 2 shows a circuit diagram of the stator coil arrangement in a first embodiment,

[0018] Fig. 3 is a circuit diagram of the stator coil arrangement in a second embodiment and Fig. 4 is a circuit diagram of the stator coil arrangement in a third embodiment.

[0019] The stator 1 shown in Fig. 1 can be used for a wide range of rotating field machines, particularly electric motors and generators. These include, for example, synchronous machines, which can be self-excited or separately excited, asynchronous machines, and the like.

[0020] The stator 1 preferably has a hollow stator interior 2 for accommodating a rotor (not shown). Alternatively, the rotor can also be arranged outside the stator 1, particularly if the induction machine is an external rotor. In this case, the stator interior 2 can even be omitted. In a further preferred embodiment, the induction machine is designed as an axial flux motor. Furthermore, the stator 1 has a metallic stator base body 3, with a geometric machine axis 4 assigned to the stator 1. The stator base body 3 has stator slots 5. In the variant shown here with a hollow stator interior 2, stator slots 5 are provided distributed around the machine axis 4 and arranged in the stator base body 3. Fig. 1 shows a simplified embodiment of the stator 1 in a schematic representation with a machine axis 4 running perpendicular to the plane of the drawing.

[0021] A stator coil arrangement 6 serves to generate a rotating magnetic field that interacts with a rotor. For this purpose, the stator coil arrangement 6 forms electromagnetic poles when energized, the formation of which depends on the structure of the stator coil arrangement 6. The proposed solution can be implemented with different structures for the stator coil arrangement 6.

[0022] The stator coil arrangement 6 forms several, here preferably three, stator coil strands 7, each having at least one stator coil. Fig. 1 shows one stator coil per stator coil strand. In principle, in particular to form stator coil pairs, several stator coils can be provided per stator coil strand 7, which are arranged distributed around the machine axis 4. The term "stator coil strand" is therefore to be interpreted broadly in the present case. It encompasses any desired connection of a number of stator coils. The stator coil strands 7 can be connected to a rotating supply voltage u, v, w at respective phase connections 8 to generate the rotating magnetic field. The rotating supply voltage u, v, w can be a supply voltage with any number of phases, but preferably with three phases.

[0023] The stator coil strands 7 each have a bundle 9 with a plurality of conductors 10i, 102, ... 10n, wherein the conductors 10i, 102, ... 10n of a bundle 9 are arranged together to form respective star inductances 11 in the stator slots 5. The term "bundle" here means that individual conductors 10i, 102, ... 10n are electronically combined and interconnected in a manner to be explained in more detail. The conductors 10i, 102, ... 10n of a bundle 9 therefore do not necessarily have to be in a specific geometric arrangement. However, the bundles 9 are provided together in the stator slots 5, whereby the conductors 101, 102, ... 10n of a bundle 9 run at least partially in the same stator slots 5 and at least partially in the same direction. Preferably, however, the conductors 10i, 102, ... 10n of a bundle 9 also run geometrically adjacent to one another, at least in sections, as can be seen in Fig. 1. The conductors 10i, 102, ...10n of a bundle 9 may, for example, be twisted together and guided together through stator slots 5. Preferably, the conductors 10i, 102, ... 10n of a bundle 9 are of the same type and, for example, have an identical cross-section and / or are made of the same material, more preferably from a copper wire.

[0024] The conductors 10i, 102, ... 10n each have a phase-connection-side section 12 and a star-point-side section 13. Preferably, the phase-connection-side section 12 and the star-point-side section 13 are respective opposite end sections of the conductors 10l, 102, ... 10n.

[0025] The conductors 10i, 102, ... 10n of a bundle 9 are electrically connected to the phase connection 8 of the respective stator coil strand 7 via the phase connection-side section 12. Thus, the stator coil strand 7—starting from the phase connection 8—is divided, as it were, by the bundle 9 into several adjacent conductors 10i, 102, ... 10n. Preferably, an electrical contact point for all conductors 10i, 102, ... 10n of a bundle 9 of the stator coil strand 7 exists at the phase connection 8 or at a supply line provided for the phase connection 8. It is now essential that the conductors 10i, 102, ... 10n of bundles 9 of different stator coil strands 7 are electrically connected to one another via the star-point-side section 13 by means of respective star points 14i, 142, ... 14n and that the star points 14i, 142, ... 14n are designed to be electrically decoupled from one another.

[0026] Instead of the conventional electrical connection of the conductors 10i, 102, ... 10n of the bundles 9 to a common star point 14i, 142, ... 14n, several star points 14i, 142, ... 14n are proposed, which electrically connect conductors 10i, 102, ... 10n of bundles 9 of different stator coil strands 7. An "electrically decoupled" design of the star points 14i, 142, ... 14n means that electrical contact between the star-point-side sections 13 of the conductors 10i, 102, ... 10n via the star points 14 is nonexistent or sufficiently low, so that electrical currents between the star points 14i, 142, ... 14n are suppressed under the conditions occurring during operation of the rotating induction machine. In this respect, the star points 14i, 142, ... 14n can also be connected to each other via comparatively high resistances or indirectly, for example via a neutral conductor connection.However, it is preferred that the star points 14i, 142, ... 14n remain at a floating potential relative to each other. In particular, the star points 14i, 142, ... 14n are only indirectly electrically connected via the stator coil strands 7, here via the phase terminals 8.

[0027] Fig. 2 shows a circuit diagram of a first embodiment of the stator 1, wherein the conductors 10i, 102, ... 10n of the bundles 9 are assigned respective individual, electrically decoupled star points 14i, 142, ... 14n. This essentially implements a plurality of star connections connected in parallel to the phase connections 8, wherein each of the parallel star connections is preferably formed via one or more conductors 10i, 102, ... 10n of the bundles 9 of the respective stator coil strands 7 and the respective star point 14i, 142, ... 14n.

[0028] Any voltage differences due to the arrangement and individual properties of the conductors 101, 102, ... 10n are largely irrelevant. Compared to a conventional star connection with bundles 9, a significantly higher electrical resistance is generated for circulating currents in the conductors 10i, 102, ... 10n, since, for example, a circulating current between two stator coil phases 7 passes through the star inductances 11 of both stator coil phases 7.

[0029] To connect the conductors 10i, 102, ... 10n of different stator coil strands 7, groups of several star points 14i, 142, ... 14n, in particular designed to be electrically decoupled from one another, can also be provided. In the further embodiment shown in Fig. 2, it is provided that the conductors 10i, 102, ... 10n of bundles 9 of different stator coil strands 7 are connected to one another via the star point-side section 13 by means of star point triples 15i, 152, ... 15n, preferably that the star point triples 15i, 152, ... 15 n are designed to be electrically decoupled from each other.

[0030] The star point triples 15i, 152, ... 15n are here and preferably electrically connected to one another via a delta connection, so that overall a star-delta connection is achieved between the phase terminals 8 for the stator coil arrangement 6.

[0031] Furthermore, according to Fig. 3 and preferably, it is provided that the stator coil arrangement 6 has further bundles 16 with a plurality of conductors 10i, 102, ... 10n, that the conductors 10i, 102, ... 10n of the further bundles 16 are each arranged together to form triangular inductances 17 in the stator slots 5, and that the conductors 10 of the further bundles 16 connect the star points of the star point triples 15i, 152, ... 15n to one another in a respective delta connection.

[0032] Fig. 3 shows the circuit diagram of the stator coil strand 6 of a further embodiment of the stator 1. Here, essentially a plurality of star-delta circuits connected in parallel to the phase connections 8 are implemented, wherein each of the parallel star-delta circuits is preferably formed via one or more conductors 101, 102, ... 10n of the bundles 9 of the respective stator coil strands 7, three or more conductors 10i, 102, ... 10n of the further bundles 16 and the respective star point triple 15i, 152, ... 15n. Here and preferably, three further bundles 16 are provided, wherein further preferably the number of conductors 101, 102, ... 10n of the further bundles 16 corresponds to the number of conductors 101, 102, ... 10n of the bundles 9 of the stator coil strands 7.

[0033] In principle, it is conceivable that several star points 14i, 142, ... 14n are provided, but several conductors 10i, 102, ... 10n of a bundle 9 are electrically connected to one or more of these star points 14i, 142, ... 14n. However, it is particularly preferred that each conductor 10i, 102, ... 10n of a bundle 9 is assigned exactly one star point 14i, 142, ... 14n or exactly one star point triple 15i, 152, ... 15n, to which the star point-side section 13 is electrically connected. This optimally suppresses the occurrence of ring currents in the stator coil arrangement 6.

[0034] In one embodiment, it is provided that the conductors 10i, 102, ... 10n of a bundle 9 are arranged geometrically in a sequence with a respective conductor index in the stator slots 5 to form the respective star windings.

[0035] Such a sequence can result from the conductors 10i, IO2 being arranged, in particular wound, next to one another in the stator slots 5 as shown in Fig. 1. Accordingly, a certain regularity results in the geometric arrangement of the conductors 101, IO2, ... 10n relative to one another. For example, the conductors 101, IO2 in Fig. 1, viewed in the radial direction from the machine axis 4, are arranged in the order (10i - IO2 - 10i - IO2 - 10i - IO2) in the stator coils. This can result in systematic deviations in the properties of the conductors 101, IO2, which in turn could lead to voltage differences.

[0036] Therefore, the conductors 101, 102, ... 10n of bundles 9 of different stator coil strands 7 with different conductor indices are preferably electrically connected to one another via the star-point section 13. In Fig. 1, for example, the conductor 10i intended for the rotating supply voltage U and the conductors 102 intended for the rotating supply voltage V, W are connected to the star point 142. Systematic deviations in the properties of the conductors 10i, 102, ... 10n can be at least partially compensated by "mixing" the conductor indices, which in turn results in lower overall voltage differences.

[0037] The proposed teaching is particularly preferred for stators 1 with wound stator coil arrangements 6. Here, and preferably, it is provided that the star inductors 11 are designed as star windings. In the aforementioned embodiments with delta inductors 17, it is provided that the delta inductors 17 are designed as delta windings. Alternatively or additionally, it is also conceivable for the stator coil arrangement 6 to be at least partially plugged in, with the star inductors 11 and / or delta inductors 17 being formed by bundles 9 with a plurality of hairpins as conductors 10i, 102, ... 10n. In this case, fewer requirements are placed on the geometry of the hairpins.

[0038] Fig. 1 schematically shows the stator 1 in a simple configuration with concentrated inductances and only three star inductances 11 configured as star windings. All of the above statements apply accordingly to other possible structural configurations of the stator coil arrangement 6. In a particularly preferred configuration of the stator 1, the stator coil arrangement 6 is configured with distributed inductances, in particular distributed star windings. As already mentioned, a larger number of stator coils and in particular stator coil pairs is possible.

[0039] The star inductors 11 can each be configured by a plurality of inductors, in particular star windings, electrically connected in series on a conductor 10i, 102, ... 10n. Fig. 4 shows a further circuit diagram which, in addition to the circuit diagram in Fig. 1, has a respective series connection of inductors, here windings, for each of the conductors 10i, 102, ... 10n, which form the star inductors 11. For example, the series-connected inductors of a conductor 10i, 102, ... 10n are arranged in different stator slots 5. In the present case, the conductors of the conductors 10i, 102, ... 10n are also electrically decoupled from one another between the series-connected inductors in order to prevent possible circulating currents.

[0040] At least two conductors 10i, 102, ... 10n are provided per bundle 9. It is further preferred that the number of conductors 10i, 102, ... 10n per bundle 9 is a maximum of 20 and preferably a maximum of ten.

[0041] In particular, with a maximum number of seven conductors 101, IO2, ... 10n per bundle 9, an improved processing of the conductors 10 results with an optimal overall cross-section of the bundles 9 for many applications.

[0042] For connecting the conductors 10i, 102, ... 10n of bundles 9 of different stator coil strands 7, electrical connecting elements are provided here and preferably via the star point-side section 13, in particular arranged axially on a stator front side and / or a stator rear side with respect to the machine axis 4.

[0043] Further preferably, the connecting elements are provided as connecting conductors, connecting rails, and / or connecting terminals, thus achieving a simplified provision of the multiple star points 14i, 142, ... 14n. A conductor such as a wire can also be used as the connecting conductor. In a simple case, the conductors 10i, 102, ... 10n of the bundles 9 are integrally connected to one another to form the respective star point 14i, 142, ... 14n.

[0044] Fig. 1 shows an embodiment of the connecting elements with a connecting rail, which is arranged on a stator front or rear side and runs, for example, in a ring shape along the stator base body 3. The respective conductors 10i, 102, ... 10n can be electrically connected to the connecting rail. A connecting terminal, in particular, provides an electrical connection of the conductors 10i, 102, ... 10n to a respective star point 14i, 142, ... 14n, which is not based on a material connection.

[0045] According to a further teaching, which has independent significance, a rotating induction machine (not shown) is proposed with a proposed stator 1 and a rotor which interacts magnetically with the stator coil arrangement 6.

[0046] As mentioned above, the rotating field machine can be an electric motor or generator. Any type of machine can be used. Examples include synchronous machines, which can be self-excited or separately excited, asynchronous machines, or the like. Reference is made to all statements regarding the proposed stator 1.

[0047] According to a further teaching, which also has independent significance, a method for producing a stator 1 for a rotating induction machine is proposed, wherein a stator base body 3 is provided, wherein the stator 1 is assigned a geometric machine axis 4 and stator slots 5 arranged around it in the stator base body 3, wherein a stator coil arrangement 6 is provided with a plurality of stator coil strands 7 which can be connected to a rotating supply voltage at respective phase connections 8 to generate a rotating magnetic field, wherein the stator coil strands 7 each have a bundle 9 with a plurality of conductors 10i, 102, ... 10n, wherein the conductors 101, 102, ... 10n of a bundle 9 are arranged together to form respective star inductances 11 in the stator slots 5, and wherein the conductors 10i, 102, ...10n each have a phase connection side section 12 and a star point side section 13, wherein the conductors 10i, IO2, ... 10n of a bundle 9 are electrically connected via the phase connection side section 12 to the phase connection 8 of the respective stator coil strand 7.

[0048] In the proposed method, it is essential that the conductors 101, 102, ... 10n of bundles 9 of different stator coil strands 7 are electrically connected to one another via the star point side section 13 by means of respective star points 14i, 142, ... 14n and that the star points 14i, 142, ... 14 n are designed to be electrically decoupled from one another. Reference is made to all statements regarding the proposed stator 1 and the proposed rotating induction machine.

[0049] Furthermore, it is preferably provided here that the star inductors 11 are produced as star windings by means of a flyer winder, preferably that the stator coil arrangement 6 has further bundles 16 with a plurality of conductors 10i, 102, ... 10n, that the conductors 10i, 102, ... 10n of the further bundles 16 are each arranged together to form delta windings in the stator slots 5, and that the conductors 10i, 102, ... 10n of the further bundles 16 connect the star points 14i, 142, ... 14n of star point triples 15i, 152, ... 15n to one another in a respective delta connection and that the delta inductors 17 are produced as delta windings by means of a flyer winder.

[0050] The proposed method allows, as already mentioned for the proposed stator 1, a simplified processing of the stator coil strands 7, wherein in particular a flyer winder can be used to produce wound inductors due to the comparatively small cross sections of the conductors 10i, 102, ... 10n of the bundles 9.

[0051] Alternatively or additionally, plug-in inductors can be used, particularly using hairpin technology.

Claims

Patent claims 1. Stator for a rotating induction machine with a stator base body (3), wherein the stator (1) is assigned a geometric machine axis (4), wherein the stator (1) has stator slots (5) and a stator coil arrangement (6) with a plurality of stator coil strands (7), which can be connected to a rotating supply voltage at respective phase connections (8) to generate a rotating magnetic field, wherein the stator coil strands (7) each have a bundle (9) with a plurality of conductors (10i, 102, ... 10n), wherein the conductors (10i, 102, ... 10n) of a bundle (9) are arranged together in the stator slots (5) to form respective star inductances (11) of the stator coil strand (7), and wherein the conductors (101, 102, ... 10n) each have a phase connection-side section (12) and a star point side section (13), wherein the conductors (10i, IO2, ...10n) of a bundle (9) are electrically connected to the phase connection (8) of the respective stator coil strand (7) via the phase connection-side section (12), characterized in that the conductors (10i, I O2, ... 10n) of bundles (9) of different stator coil strands (7) are electrically connected to one another via the star point-side section (13) by means of respective star points (14i, 142, ... 14n) and that the star points (14i, 142, ... 14n) are designed to be electrically decoupled from one another.

2. Stator according to claim 1, characterized in that the conductors (101, 102, ... 10n) of bundles (9) of different stator coil strands (7) are connected to one another via the star-point-side section (13) by means of star-point triples (15i, 152, ... 15n), preferably in that the star-point triples (15i, 152, ... 15 n ) are designed to be electrically decoupled from each other.

3. Stator according to claim 2, characterized in that the stator coil arrangement (6) has further bundles (16) with a plurality of conductors (101, IO2, ... 10n), that the conductors (101, IO2, ... 10n) of the further bundles (16) are each arranged together to form delta inductances (17) in the stator slots (5), and that the conductors (101, IO2, ... 10n) of the further bundles (16) connect the star points of the star point triples (15i, 152, ... 15n) to one another in a respective delta connection.

4. Stator according to one of the preceding claims, characterized in that each conductor (10i, 102, ... 10n) of a bundle (9) is assigned exactly one star point (14i, 142, ... 14n) or exactly one star point triple (15i, 152, ... 15n), to which the star point side section (13) is electrically connected.

5. Stator according to one of the preceding claims, characterized in that the conductors (10i, 2, ... 10n) of a bundle (9) for forming the respective star windings in the stator slots (5) are geometrically arranged in a sequence with a respective conductor index and that the conductors (10i, 2, ... 10n) of bundles (9) of different stator coil strands (7) with different conductor indices are electrically connected to one another via the star-point-side section (13).

6. Stator according to one of the preceding claims, characterized in that the star inductances (11) are designed as star windings, preferably that the delta inductances (17) are designed as delta windings.

7. Stator according to one of the preceding claims, characterized in that the star inductances (11) are each designed by a plurality of inductances, in particular star windings, electrically connected in series on a conductor (10i, 102, ... 10n).

8. Stator according to one of the preceding claims, characterized in that the number of conductors (10i, 2, ... 10n) per bundle (9) is a maximum of 20, preferably a maximum of 10, more preferably a maximum of 7.

9. Stator according to one of the preceding claims, characterized in that for connecting the conductors (10i, 2, ... 10n) of bundles (9) of different stator coil strands (7) via the star point side section (13) electrical connecting elements are provided, in particular arranged axially on a stator front side and / or a stator rear side with respect to the machine axis (4), preferably that the connecting elements are provided as connecting conductors, connecting rails and / or connecting terminals.

10. Rotating rotary field machine with a stator (1) according to one of the preceding claims and a rotor which interacts magnetically with the stator coil arrangement (6).

11. A method for producing a stator (1) for a rotating induction machine, wherein a stator base body (3) is provided, wherein the stator (1) is assigned a geometric machine axis (4), wherein a stator coil arrangement (6) with a plurality of stator coil strands (7) is provided, which can be connected to a rotary supply voltage at respective phase connections (8) to generate a rotating magnetic field, wherein the stator coil strands (7) each have a bundle (9) with a plurality of conductors (10i, 102, ... 10n), wherein the conductors (101, 2, ... 10n) of a bundle (9) are arranged together to form respective star inductances (11) in stator slots (5) in the stator base body (3), and wherein the conductors (10i, 2, ... 10n) each have a phase connection-side section (12) and a star point-side section (13), wherein the ladder (101, 2, ...10n) of a bundle (9) are electrically connected to the phase connection (8) of the respective stator coil strand (7) via the phase connection-side section (12), characterized in that the conductors (10i, 2, ... 10n) of bundles (9) of different stator coil strands (7) are electrically connected to one another via the star point-side section (13) by means of respective star points (14i, 142, ... 14n) and that the star points (14i, 142, ... 14n) are designed to be electrically decoupled from one another.

12. The method according to claim 11, characterized in that the star inductors (11) are produced as star windings by means of a flyer winder, preferably in that the stator coil arrangement (6) has further bundles (16) with a plurality of conductors (10i, 2, ... 10n), in that the conductors (10i, 2, ... 10n) of the further bundles (16) are each arranged together to form delta windings in the stator slots (5), and in that the conductors (10i, 102, ... 10n) of the further bundles (16) connect the star points of star point triples (15i, 152, ... 15n) to one another in a respective delta connection, and in that the delta inductors (17) are produced as delta windings by means of a flyer winder.

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