CN109038903B - A Two-Phase Fractional Slot Hollow-Core Compensated Pulse Generator - Google Patents

Abstract

The invention relates to a two-phase fractional-slot hollow-core compensated pulse generator, comprising a stator and a rotor, wherein the stator includes two-phase armature windings, and the two-phase armature windings differ from each other by an electrical angle of 90°, and the two-phase armature The windings are composed of two coils. All the coils of the two-phase winding are concentric concentrated windings. All the coils of the two-phase winding are evenly distributed in the stator space, and the coils of different phases are staggered. There is no gap between the coils, the rotor includes an excitation winding, and the excitation winding is composed of six excitation coils. The above-mentioned pulse generator is a pulse motor with two phases, four slots and six poles, and the fractional slot winding with a pitch of 1 is satisfied. The combination constraints of the number of slots and poles avoid the cross-overlap problem of the ends of different-phase coils of traditional distributed windings, greatly reducing the manufacturing difficulty of the stator windings of the air-core pulse generator, and at the same time, the discharge output capacity of the motor can be effectively improved.

Description

A Two-Phase Fractional Slot Hollow-Core Compensated Pulse Generator

technical field

The invention relates to the technical field of electric motors, in particular to a two-phase fractional slot hollow-core compensation pulse generator.

Background technique

In the existing air-core compensated pulse generator, a composite material with a high strength/density ratio is used to replace the traditional ferromagnetic material, thereby improving the energy density and power density of the motor. Because the composite material is not magnetically conductive and has poor processability, the motor is usually designed as a slotless structure, and the stator armature winding is generally processed into a concentric racetrack shape, with a large overall volume, and is bonded to the inner wall of the stator with epoxy resin. For a motor with a two-phase armature winding structure, the existing integer-slot distributed winding design structure inevitably crosses and overlaps at the ends of the two-phase windings. Therefore, additional shaping processing is required, which brings great difficulties to the manufacture of the windings. great difficulty.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a two-phase fractional-slot hollow-core compensated pulse generator that can avoid cross-overlap at the ends of the two-phase windings and reduce the manufacturing difficulty.

The technical solution adopted by the present invention is a two-phase fractional slot hollow-core compensated pulse generator, comprising a stator and a rotor, the stator comprising two-phase armature windings, and the difference between the two-phase armature windings is an electrical angle of 90°. , the two-phase armature windings are composed of two coils, all the coils of the two-phase windings are concentric concentrated windings, the number of turns, cross-sectional area and structure are exactly the same, and they are made of transposed Litz wires, and adopt Slotless structure, all the coils of the two-phase winding are evenly distributed in the stator space, the coils of different phases are staggered, and no gap is left between two adjacent coils, the rotor includes an excitation winding, and the excitation The winding consists of six excitation coils.

The beneficial effect of the present invention is: although the above-mentioned coil adopts a slotless structure in the mechanical structure, but in the electrical structure, the motor stator has 4 coils, and no gap is left between the coils, which is equivalent to the motor having 4 "virtual" coils. slot” (Z=4), then the above two-phase fractional slot hollow compensation pulse generator is a pulse generator with 2 phases (m=2), 4 slots (Z=4), and 6 poles (2p=6). Its number of slots per pole and phase is fractional (q=Z/2pm=1/3), and it satisfies the combination constraint condition of fractional slot windings with a pitch of 1, that is, the stator armature winding can adopt a pitch of 1 The double-layer centralized winding structure of the air-core pulse generator avoids the cross-overlap problem of the ends of different-phase coils of the traditional distributed winding, and greatly reduces the manufacturing difficulty of the stator winding of the air-core pulse generator. At the same time, the end length of the concentrated winding is small, the impedance of the motor end is also reduced, and the discharge output capacity of the motor can be effectively improved.

As a priority, the stator also includes a stator yoke and a stator sheath, the two-phase armature windings are bonded on the stator sheath by epoxy resin, and the stator yoke is wound on the two-phase armature windings by applying a pre-tightening force. The armature winding is firmly fixed between the stator yoke and the stator sheath to overcome the electromagnetic force generated at the moment of discharge.

As a priority, the stator sheath is a cylindrical structure formed by winding high-strength glass fibers, and the stator yoke uses high-strength glass fibers wound on two-phase armature windings to form a cylindrical structure.

As a priority, the rotor also includes a rotor yoke, a rotor sheath and a rotating shaft. The excitation winding of the rotor is bonded on the rotor yoke by epoxy resin, and the rotor sheath is wound on the excitation winding by applying a pre-tightening force. With this structure, it is possible to make The field winding is firmly fixed between the rotor yoke and the rotor sheath to overcome the centrifugal force of high-speed rotation.

As a priority, the rotor yoke is a cylindrical structure made of high-strength glass fibers wound, and the rotor sheath is made of high-strength carbon fibers wound on the excitation winding to form a cylindrical structure.

As a priority, the rotor yoke is bonded to the rotating shaft through epoxy resin, and the rotating shaft adopts a material with high strength and non-magnetic conductivity.

Description of drawings

1 is a schematic structural diagram of a two-phase fractional slot hollow-core compensated pulse generator of the present invention;

As shown in Figure 1: 1. A-phase armature winding; 2. B-phase armature winding; 3. Stator yoke; 4. Stator sheath; 5. Excitation winding; 6. Rotor yoke; 7. Rotor sheath; 8 , shaft.

Detailed ways

The invention is further described below with reference to the accompanying drawings and in conjunction with specific embodiments, so that those skilled in the art can implement it with reference to the description, and the protection scope of the present invention is not limited to the specific embodiments.

The present invention relates to a two-phase fractional-slot hollow-core compensated pulse generator, which includes a stator and a rotor, and the stator includes two-phase armature windings. As shown in FIG. 1 , the two-phase armature windings are A-phase armature windings 1 and 1. B-phase armature winding 2, A-phase armature winding 1 and B-phase armature winding 2 differ by 90° in electrical angle from each other, wherein A-phase armature winding 1 consists of two coils (A1 coil and A2 coil), The B-phase armature winding 2 consists of two coils (B1 coil and B2 coil), that is, the two-phase winding has a total of four coils. These four coils are concentric concentrated windings with the same number of turns, cross-sectional area and structure. It is made of transposed Litz wire and adopts a slotless structure, and A1, A2, B1 and B2 are evenly distributed in the stator space, and A1 and A2 are separated by B1 and B2, that is, different phases. The coils are staggered, and no gap is left between two adjacent coils. The rotor includes an excitation winding 5, and the excitation winding 5 is composed of six excitation coils. Among them, the two coils of the armature windings of each phase can be connected in series or in parallel according to requirements. The six excitation coils can be connected in series or in parallel as required.

In Figure 1, although the four armature coils adopt a slotless structure in terms of mechanical structure, in terms of electrical structure, the motor stator has four coils, and there is no gap between the coils, which is equivalent to the motor having four "virtual" coils. slot” (Z=4), then the two-phase fractional slot hollow compensation pulse generator in Figure 1 is a pulse generator with two-phase (m=2), four-slot (Z=4), six-pole (2p=6) Motor, its number of slots per pole and phase is fractional (q=Z/2pm=1/3), and it satisfies the combination constraint condition of fractional slot winding slot pole number with pitch 1, that is, the stator armature winding can adopt pitch It is a double-layer centralized winding structure of 1, thus avoiding the cross-overlap problem of the ends of different-phase coils of the traditional distributed winding, and greatly reducing the manufacturing difficulty of the stator winding of the air-core pulse generator. At the same time, the end length of the concentrated winding is small, the impedance of the motor end is also reduced, and the discharge output capacity of the motor can be effectively improved.

Among them, the constraint conditions for the combination of the number of poles of fractional-slot windings with a pitch of 1 are:

1) Z/m is an integer (Z/m=2), so that each phase is equally divided into the same number of slots, and the windings of each phase are symmetrical;

2) p/m≠integer (p/m=3/2), that is, p is not allowed to be a multiple of m;

3) Z=2p ₀ ±N, N=1, 2, 3..., when Z is an odd number, N should take an odd number; when Z is an even number, N should take an even number.

In the present invention, the reasons for choosing two phases (m=2) are:

Using the two-phase structure of the pulse generator, by controlling the closing angle of each phase winding, multiple short pulses can be synthesized into a wide pulse that meets the load requirements. With sufficient pulse width, the rotational speed can be increased to obtain higher energy storage density, and the output waveform is more flexible, which is especially suitable for driving high-energy electromagnetic emission. In order to enable each phase to be independently controlled, the two-phase windings are 90° electrical angle apart from each other to avoid electromagnetic coupling between the respective phase windings.

The reasons for choosing six poles (2p=6) are:

The motor is a two-phase motor, that is, m=2 is a fixed value. In order to satisfy p/m≠integer, the number of pole pairs p of the motor can only be selected as odd numbers such as 1, 3, and 5. For the air-core pulse generator, since there is no constraint of ferromagnetic materials, the amplitude of the air gap magnetic density decays exponentially with the increase of the pole pair number p, so the smaller the motor pole pair design, the better. When p=1, the electromagnetic field analysis shows that the excitation magnetic field of the motor will pass through the rotating shaft at a constant value at this time. It is necessary to use non-magnetic rotating shafts and bearings, and design corresponding electromagnetic shielding measures to overcome the self-excited magnetic field. Additional eddy current losses generated on the At the same time, the 1-pole motor still has uneven rotor force during discharge operation, which is easy to cause polarization and stress concentration problems. To sum up, the number of poles of the motor of the present invention is 6 poles (2p=6).

The reasons for choosing four slots (Z=4) are:

The motor is a two-phase motor, that is, m=2 is a fixed value. In order to satisfy Z/m as an integer, the number of slots Z of the motor should be an even number; considering that the number of motor poles has been determined to be 6 poles (2p=6), in order to meet the constraints Condition 3, taking into account that the smaller N is, the larger the winding coefficient is, take N=2, and Z can be 4 and 8 at this time. After further electromagnetic field analysis, when Z=4, the winding coefficient of the armature winding is 0.783; when Z=8, the winding coefficient of the armature winding is only 0.522. To sum up, the number of slots of the motor of the present invention is selected to be 4 slots (Z=4).

As shown in FIG. 1 , the stator further includes a stator yoke 3 and a stator sheath 4. The two-phase armature windings are bonded on the stator sheath 4 by epoxy resin, and the stator yoke 3 is wound on the two-phase armature by applying a pre-tightening force. On the windings, this structure is used to firmly fix the armature windings between the stator yoke 3 and the stator sheath 4, so as to overcome the electromagnetic force generated at the moment of discharge.

As shown in FIG. 1 , the stator sheath 4 is a cylindrical structure formed by winding high-strength glass fibers, and the stator yoke 3 uses high-strength glass fibers wound on two-phase armature windings to form a cylindrical structure.

As shown in FIG. 1 , the rotor further includes a rotor yoke 6, a rotor sheath 7 and a rotating shaft 8. The excitation winding 5 of the rotor is bonded to the rotor yoke 6 by epoxy resin, and the rotor sheath 7 is wrapped around the excitation by applying a pre-tightening force. On the winding 5, with this structure, the excitation winding 5 can be firmly fixed between the rotor yoke 6 and the rotor sheath 7, thereby overcoming the centrifugal force of high-speed rotation.

As shown in FIG. 1 , the rotor yoke 6 is a cylindrical structure formed by winding high-strength glass fibers, and the rotor sheath 7 is wound on the excitation winding 5 by high-strength carbon fibers to form a cylindrical structure.

As shown in FIG. 1 , the rotor yoke 6 is bonded to the rotating shaft 8 through epoxy resin, and the rotating shaft 8 is made of a material with high strength and non-magnetic conductivity.

Claims (5)

1. A two-phase fractional slot air-core compensation pulse generator comprises a stator and a rotor, and is characterized in that: the stator comprises two-phase armature windings, the two-phase armature windings are different from each other by 90-degree electrical angles, each two-phase armature winding consists of two coils, all the coils of each two-phase armature winding are concentric concentrated windings, the number of turns, the cross-sectional area and the structure of each coil are completely the same, the coils are made of transposed litz wires and adopt a slotless structure, all the coils of each two-phase armature winding are uniformly distributed in a stator space, the coils of different phases are distributed in a staggered mode, no gap is reserved between every two adjacent coils, the rotor comprises an excitation winding (5), and the excitation winding (5) consists of six excitation coils;

the stator also comprises a stator yoke (3) and a stator sheath (4), the two-phase armature winding is bonded on the stator sheath (4) through epoxy resin, and the stator yoke (3) is wound on the two-phase armature winding by applying pretightening force.

2. The two-phase fractional-slot air-core compensated pulse generator of claim 1, wherein: the stator sheath (4) is a cylindrical structure formed by winding high-strength glass fibers, and the stator yoke (3) is wound on the two-phase armature winding by the high-strength glass fibers to form the cylindrical structure.

3. The two-phase fractional-slot air-core compensated pulse generator of claim 1, wherein: the rotor also comprises a rotor yoke (6), a rotor sheath (7) and a rotating shaft (8), the excitation winding (5) of the rotor is bonded on the rotor yoke (6) through epoxy resin, and the rotor sheath (7) is wound on the excitation winding (5) by applying pretightening force.

4. A two-phase fractional slot air-core compensated pulse generator as claimed in claim 3, wherein: the rotor yoke (6) is a cylindrical structure formed by winding high-strength glass fibers, and the rotor sheath (7) is wound on the excitation winding (5) by adopting high-strength carbon fibers to form the cylindrical structure.

5. A two-phase fractional slot air-core compensated pulse generator as claimed in claim 3 or claim 4, wherein: the rotor yoke (6) is bonded to the rotating shaft (8) through epoxy resin.

Images