EP3721532A1

EP3721532A1 - Multi-tooth coil winding for a three-phase rotating field machine

Info

Publication number: EP3721532A1
Application number: EP18812162.8A
Authority: EP
Inventors: Gerhard Huth; Jens Krotsch
Original assignee: Ebm Papst Mulfingen GmbH and Co KG
Current assignee: Ebm Papst Mulfingen GmbH and Co KG
Priority date: 2017-12-05
Filing date: 2018-12-03
Publication date: 2020-10-14
Also published as: DE102017128832A1; US11791683B2; CN208707501U; WO2019110523A1; US20210104929A1

Abstract

The invention relates to a three-phase rotating field machine having a 2p-pole stator with winding teeth (Z), which is designed with a winding arrangement in tooth coil technology comprising three winding phases (W1, W2, W3), wherein the winding arrangement is formed from wound coil groups (G) with coils nested in one another several times, wherein the coil sections (T) of said coil groups (G) are arranged concentrically surrounding one another from the inside to the outside, and comprise two or a plurality of winding teeth (Z), wherein the respective coil winding numbers are arranged in the grooves (N) between the winding teeth (Z) such that in each case an essentially uniform coating of each groove (N) with the same effective total conductor cross section of the coils per groove cross section is given.

Description

Multi-tooth coil winding for a 3-phase induction machine

Description:

The invention relates to a winding arrangement for a 3-strand rotary field machine and a 3-strand rotary field machine with such a winding arrangement.

Inverter-fed permanent magnet synchronous machines (PM synchronous machines) are used in a large number of technical applications. For reasons of cost PM synchronous machines are increasingly running with so-called tooth coil windings. The tooth coil technology simplifies the stator structure of a PM synchronous machine and also enables a segmented stator structure, so that the stator can be manufactured in modules in a kind of modular concept. A disadvantage of tooth coil windings is that they form a broad air gap field spectrum which, depending on the design of the motor, can be more or less disturbing. In the prior art, different winding concepts are already known for tooth coil windings. The document US 20120228981 A1 sets the reduction of a subharmonic with respect to the working field wave to the task and suggests as a solution a multilayer winding consisting of at least two coil sides per groove, before, the number of conductors of the coil sides in a first groove of the number of conductors Coil sides is different in a second groove, wherein the coils are designed as tooth coils.

In the document US 20120001512 A1 we propose a stator with a double number of slots compared with the prior art. The coils enclose two teeth each. The coils are characterized by different numbers of turns with the same coil width.

The document US 20140035425 A1 is concerned with the reduction of unwanted upper fields by a cost-producible winding. It is proposed a multilayer tooth coil winding, wherein the individual coils of a strand aufwei sen different numbers of turns and wear the teeth a different number of tooth coils. Also, this winding topology is not effective for small numbers of poles.

In the case of so-called AC line-start motors, there is a need for line-start functionality, whereby the wide air gap field spectrum of the toothed coil windings has a disruptive effect, since the run-up of the line-start motors as a whole is disturbed by the resulting harmonic torques is prevented. Squirrel cage motors and PM line-start motors are therefore not meaningful executable with the tooth coil windings known in the prior art.

In contrast, z. B. small PM synchronous motors, which are field-oriented operated on the inverter and are increasingly used in the field of high-speed drives, basically in dental coil technology run.

Another fundamental problem is the use of tooth coil winding at low pole numbers. Since tooth coil windings are subject to conditional too If the number of pole pairs is higher, PM synchronous motors with a low number of poles (for example 2-pole or 4-pole) can only be implemented to a very limited extent for high-speed drives with the known tooth coil windings.

It is therefore an object of the present invention to overcome the above-mentioned drawbacks and a winding topology in the form of a tooth coil winding for a 3-strand induction machine, such. For example, to propose a 3-stranded motor design that can be used effectively even at low pole numbers (2-pole and 4-pole) and also has a favorable winding field spectrum.

This object is achieved by the feature combination according to claim 1.

A basic idea of the present invention is to provide a tooth coil winding with a specific winding scheme for three winding strands W1, W2, W3, consisting of coil groups with multiple interlaced nested coils and preferably continuously changing width, where in the sub-coils of said coil groups from the inside to the outside (without crossing the head of the sub-coils) are arranged concentrically surrounding, one or more teeth and include the same or different coil turns numbers at a substantially equal occupancy of each groove with the same effective overall cross-section per groove cross-section.

It is particularly preferred if the coil groups are arranged diametrically symmetrical to each other and partially overlap spatially along the circumference in their arrangement in the winding layers.

According to the invention, therefore, a 3-phase induction machine is provided with a 2p-pole stator with winding teeth, formed with a Wick lungsanordnung in dental coil technology, comprising three winding strands W1, W2, W3, wherein the winding assembly formed from wound coil groups with multiple nested coils (partial coils) with the sub-coils of the said coil groups turning from the inside to the outside. are arranged centrically enclosing and comprise two or more Wi- crochet teeth, wherein the respective coil winding numbers are provided or wound in the grooves between the winding teeth, that in each case a substantially equal occupancy of each groove with the same effective overall cross section of the coils per groove cross-section given is.

It is particularly preferred if the coil groups do not overlap in the forehead area, d. H. without intersecting conductors, intersecting partial coils or crossing coil groups.

The above object can thus be achieved by a 3-stranded "multi-tooth coil winding", which also represents a distributed tooth coil winding. The basic element and thus the common part of such a 3-strand multi-tooth coil winding is a q-fold tooth coil, which occupies 2 _* q adjacent grooves of the stator in each case half (in the upper layer or the lower layer). The factor q is preferably q = 2, 3 or 4.

In an advantageous embodiment of the invention, it is accordingly provided that in each case adjacent winding teeth or grooves of the stator are wound into a part with a winding strand, namely either in the upper layer or the lower layer.

It is further provided with advantage that the number of conductors of a further outer partial coil of a coil group is greater than the number of conductors of a further inner partial coil. The partial coil arrangement is always concentric.

In an advantageous embodiment of the invention, it is provided that the number of conductors of the partial coils decreases from the outer to the inner partial coil. In a case of particularly advantageous embodiment, it is provided that the Lei terzahl of the coil sections decreases steadily from the outer to the inner coil section, so to speak, the decrease in the number of conductors from partial coil to partial coil in the moving surfaces decreases steps.

A particularly suitable embodiment for the practice provides that with q = 3 exactly 3 partial coils are wound around the corresponding multi-tooth coil and the number of conductors of the sub-coils of a multi-tooth coil are distributed as follows: a. the outermost subcoil (T): Zo conductor + DZ conductor b. the middle part coil (T): Zo ladder

c. the inner part coil (T): Zo conductor - DZ conductor

In this case, the value Zo represents a predetermined number of conductors in the said partial coil, while DZ represents the difference between the number of conductors and the respective external or internal partial coil.

Other advantageous embodiments of the invention are characterized in the subclaims or are together with the description of the preferred embodiment of the invention with reference to the figures closer Darge presents.

Show it:

Fig. 1 shows a zone plan with identification of the coil guide for the

Cases q = 2, 3 and 4,

2 shows a strand zone plan of a 2-pole, 3-strand tooth coil winding for the cases q = 2, 3 and 4,

3 shows a zone plan of a 2-pole, 3-stranded tooth coil winding for the case q = 4, FIG.

4 shows a zone plan with different numbers of conductors for a multi-

Tooth coil with q = 3,

5 shows an alternative embodiment of a zone plan to FIG. 4 with different numbers of conductors for a multi-tooth coil with q = 3,

6 shows two zone plans with different numbers of conductors for a multi

Tooth coil with q = 4 and

7 shows a zone plan of a 2-pole, 3-stranded tooth coil Winding for a multi-tooth coil with q = 4 with a decrease in the number of conductors but identical groove filling.

The invention will be described in more detail below with reference to Figures 1 to 7, wherein like reference numerals refer to the same structural or Funktionsa le features. FIG. 1 shows a zone plan with identification of the coil guide for the cases q = 2, 3 and 4 (where x and * indicate the respective winding direction or energization direction).

A 2-pole, 3-strand rotary stator stand with multi-tooth coil winding summarizes exactly N = 3 x 2q = 6q grooves N, which means in the case of the embodiments shown in Figure 1, at q = 2 (12 slots), at q = 3 (18 slots) and q = 4 (24 slots). Each winding strand W1, W2, W3 of the 3-strand multi-tooth coil winding consists, according to FIG. 2, of two multi-tooth coils which are located once in the lower layer US and once in the upper layer OS. The two multi-tooth coils of a winding strand are exactly offset by a pole pitch, ie by N / 2p slot pitches (where 2p is the pole number) against each other, conditions in the mentioned embodiment by 3q Nutteilun, and are thus arranged diametrically symmetrical. The winding direction and therefore the current direction of both multi-tooth coils of the winding strands W1, W2 is reversed. Although the transition to a higher stand payload increases the winding effort, but thereby improve the upper field behavior and the Wicklungsentwärmung on the laminated core of the stator. Furthermore, a smaller copper volume of the partial coils allows a simplification in the winding process.

Fig. 2 shows a strand zone plan of a 2-pole, 3-strand Zahnspu lenwicklung for the cases q = 2, 3 and 4, wherein the winding strand W1 is shown by way of example. The winding strands W1, W2, W3 of the 2-pole Drehfeldwick ment according to the figure 3 are set against each other by N / 3p slot pitches ver, which means in the embodiment 2q slot pitches. FIG. 3 shows the zone plan of a 2-pole, 3-pole tooth coil winding for the case q = 4. If a higher-pole rotary field winding is required, this can be achieved simply by multiplying the zone plan shown in FIG. 3 in accordance with the desired number of pole pairs, ie by doubling in the case of a 4-pole winding.

Considering the air-gap field spectrum for the embodiment of a 3-stranded multi-tooth coil winding, an air-gap field spectrum is excited with the following atomic numbers: v / p: 1 + 6 _* g where g = 0, ± 1, ± 2, ± 3, ± 4, ...

If the slot slot is considered to be negligible, exactly q results in different winding factors, which repeat cyclically, as shown in the following table for q-2, 3 and 4.

It is also possible to carry out the q-concentric partial coils T of a multi-tooth coil, which according to FIG. 1 represent a repeating common part, with different numbers of conductors in order to further improve the air-gap field spectrum. In this case, it makes sense if the different numbers of conductors of the partial coils T are each selected such that nevertheless an equally high groove filling is established for all the grooves.

In order to increase the fundamental field winding factor, it is necessary to len of the q concentric partial coils T of a multi-tooth coil to stagger so that the numbers of conductors from the outer part coil T toward the inner part coil T steadily, ie evenly drops. This winding state is shown in FIG. For this purpose, FIG. 4 shows a zone plan with different numbers of conductors for a multi-tooth coil with q = 3.

Accordingly, FIG. 4 shows an embodiment which is particularly relevant in practice, namely the case with q = 3. For all the grooves N of the complete 3-phase rotating field winding, an equally high slot filling results if the following graduation of the number of conductors is used ,

The number of conductors of the partial coils T of a coil group G is then distributed as follows:

a. the outermost subcoil T: Zo conductor + D Z conductor

b. the middle part coil T: Zo conductor

c. the inner part coil T: Zo conductor - D Z conductor.

In an alternative embodiment, a non-continuous graduation of the conductor numbers can be selected. Figure 5 shows an alternative Ausfüh tion of a zone plan with different numbers of conductors for a multi-tooth coil with q = 3. It remains the resulting rotating field winding continues to be symmetrical, but the stator grooves have no uniform Nutfüllung.

In this case, non-uniform groove fillings due to unequal number of conductors, the partial coils T of a multi-tooth coil winding with different Wicklungsdragt diameters can be performed. As a result, the copper volume and groove filling can be increased and the effective overall conductor cross-section over all grooves still largely uniform.

In a particularly advantageous embodiment (not shown), the partial coils T of a multi-tooth coil winding with the same winding wire diameter, but from x parallel coils with x-fold Win number can be formed to raise the Nutfüllgrad and unify chen. In the lower power range, the case q = 4 is of high practical relevance in 2-pole induction machines. FIG. 6 shows two possibilities for a conductor separation, which lead to an identical slot filling in the case of the complete 3-phase field winding in all stator slots.

FIG. 7 shows in each case a zone plan of a 2-pole, 3-strand tooth coil winding for a multi-tooth coil with q = 4 with a decreasing number of conductors but identical slot filling, whereby in the upper view a continuous reduction of the number of conductors takes place in the lower view, a zone plan is shown with a quasi-steady decrease in the number of conductors.

A quasi-steadily decreasing number of conductors, where only two different numbers of conductors are used, can always be realized if q is divisible by 2 integers, that is, for q = 2, 4, 6, ...

If Za denotes the higher number of conductors of the outer partial coils T and Zi the lower number of conductors of the inner partial coils T, then a division of the numbers of conductors in a ratio of Zi / Za with a value of approximately 0.73 can be selected the winding factors of the 5th and 7th order are brought to zero and the basic field winding factor can be increased simultaneously, as shown in the following table for the case q = 4.

By further reducing the ratio of Zi / Za, the basic field winding factor can be further increased. For a ratio of about 0.53 If one considers winding factors for the upper fields of the 5th and 7th order corresponding to the case Zi / Za = 1, the basic field winding factor can be further increased to the value of 0.5480. This corresponds to an increase of around 15% compared to the division Zi / Za = 1. The following table clarifies this again using the example q = 4.

Claims

claims

1. induction machine with a 2p ~ pole stator with winding teeth (Z), formed with a winding arrangement in tooth coil technology comprising three winding strands (W1, W2, W3), wherein the winding arrangement of wound coil groups (G) with multiple nested coils is formed, wherein the sub-coils (T) of said coil groups (G) are arranged from the inside to the outside concentrically enclosing ßend and two or more winding teeth (Z), wherein the respective coil winding numbers in the grooves (N) between the winding teeth ( Z) are provided so that in each case a substantially equal occupancy of each groove (N) with the same effective total conductor cross-section of the coils per groove cross-section is given ben.

2. 3-phase rotating field machine according to claim 1, characterized in that the winding arrangement is formed so that the coil lenellen len in the front region of the winding heads of the coils and overlap without intersecting partial coils (T) or coil groups (G) are.

3. 3-phase induction machine according to claim 1 or 2, characterized ge

indicates that the coils have a changing, preferably continuously changing width.

4. 3-strand induction machine according to one of the preceding Ansprü surfaces, characterized in that the coils of the coil groups (G) are arranged diametrically symmetrical to each other and at least partially cover spatially along the circumference in the winding layers.

5. 3-phase induction machine according to one of the preceding claims, characterized in that for a coil group (G) a q-fold dental coil is provided, the 2 _* q adjacent grooves of Stän DERS each half with the winding of a winding strand (W1, W2; W3), where q = 2, 3 or 4.

6. 3-strand induction machine according to one of the preceding Ansprü surfaces, characterized in that each adjacent winding teeth (Z) or grooves (N) of the stator, which are wound to a part with a winding strand (W1, W2, W3), either in the upper layer (OS) or the lower layer (US) are wound.

7. 3-strand induction machine according to one of the preceding Ansprü chen, characterized in that the number of conductors of a further outer partial coils (T) of a coil group (G) is higher than the number of conductors of this further outer part of the coil concentrically to the inner circumference Partial coil (T).

8. 3-phase induction machine according to claim 7, marked thereby, that the number of conductors of the partial coils (T) from the outer to the inner part coil (T) decreases towards.

9. 3-phase induction machine according to claim 7 or 8, characterized ge

indicates that the number of conductors of the partial coils (T) decreases steadily from the outer to the inner partial coil.

10.3-strand induction machine according to claim 5 and one of claims 7 to 9, characterized in that at q = 3, the number of Lei ter of the partial coils (T) of a coil group (G) is distributed as follows: a. the outermost subcoil (T): Zo conductor + DZ conductor b. the middle part coil (T): Zo ladder

c the inner part coil (T): Zo conductor - D Z conductor.