CN113644760A

CN113644760A - High-efficiency large-torque controllable motor

Info

Publication number: CN113644760A
Application number: CN202110928349.1A
Authority: CN
Inventors: 乐秀峰
Original assignee: Lesen Taicang Electric Technology Co ltd
Current assignee: Lesen Taicang Electric Technology Co ltd
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2021-11-12

Abstract

The invention discloses a controllable motor with high efficiency and large torque, comprising: first electro-magnet group, second electro-magnet group, third electro-magnet group, armature, first electro-magnet group is used for being connected with first interchange source, second electro-magnet group is used for being connected with second interchange source, third electro-magnet group is used for being connected with the third interchange source, armature with first electro-magnet group sets up relatively, armature can move for each electro-magnet group, and three electro-magnet group sets gradually side by side, and the phase difference in three interchange sources is 2/3 pi in proper order, works as controllable motor circular telegram and start working, armature follows under the effect of each electro-magnet group first electro-magnet group department to third electro-magnet group department removes. The high-efficiency large-torque controllable motor provided by the invention has the advantages that the service life of the permanent magnet motor is prolonged, the reactive loss is small, and the power factor is high.

Description

High-efficiency large-torque controllable motor

Technical Field

The invention relates to the technical field of motors, in particular to a controllable motor with high efficiency and large torque.

Background

In the modern times, electric motors are almost ubiquitous. The device is simply used as a power source and gradually developed into an execution device in an automatic control system. In conventional application, the controllability of a direct current motor is poor (a transfer function is a second-order link), and an induction asynchronous motor has no control performance. When a power system in the equipment device cannot intervene manually and needs to be adjusted automatically, a servo link is inserted and feedback is added to form closed-loop control in the traditional method. Thus, the system structure is complicated, the stability region is narrow, and the quality is relatively poor. Therefore, it is a desired goal to search for a large torque controllable motor.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a controllable motor with high efficiency and large torque. The technical scheme is as follows:

the invention provides a controllable motor with high efficiency and large torque, which comprises:

the first electromagnet group is used for being connected with a first alternating current source;

the second electromagnet group is used for being connected with a second alternating current source;

a third electromagnet group, the third electromagnet group being configured to be connected to a third alternating current source;

the armature is arranged opposite to the first electromagnet group, and the armature can move relative to each electromagnet group;

the three electromagnet groups are arranged in parallel in sequence, the phase difference of three alternating current sources is 2/3 pi in sequence, and when the controllable motor is electrified and starts to work, the armature moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group.

Furthermore, the first electromagnet group, the second electromagnet group and the third electromagnet group respectively comprise two electromagnets which are arranged in parallel, wherein any electromagnet comprises a pair of magnetic poles, and the distribution direction of the magnetic poles is parallel or approximately parallel to the arrangement direction of the electromagnet groups; when the electromagnet group is electrified, the magnetic poles of the two electromagnets in the same group are distributed in opposite directions.

Furthermore, a concave part is arranged between the two magnetic poles of any electromagnet.

Further, the width of the magnetic pole is equal or substantially equal to the width of the recess.

Further, the distance between adjacent electromagnets is equal to or substantially equal to the width of the recess.

Further, the length of the armature is 2.5-3.5 times of the width of the recess.

Further, the number of the armatures is multiple, permanent magnets are arranged on the armatures, so that the side parts, facing the electromagnet, of the armatures have magnetism, and the magnetism of the side parts, facing the electromagnet, of the adjacent armatures is opposite.

Furthermore, the controllable motor is a rotary motor, each electromagnet is arranged on the circumference of a first virtual circle, a plurality of armatures are arranged on the circumference of a second virtual circle, the electromagnets are fixedly arranged relative to the center of the first virtual circle, the armatures can rotate relative to the center of the second virtual circle, the first virtual circle and the second virtual circle are arranged in a communication mode, and the diameter of the first virtual circle is larger than that of the second virtual circle.

Further, the number of the electromagnets is 12 × N, and the number of the armatures is 8 × N, where N is a positive integer.

Further, N ═ 2.

The technical scheme provided by the invention has the following beneficial effects:

the permanent magnet is not easy to demagnetize, and the service life of the motor using the permanent magnet is prolonged; the frequency of changing the excitation polarity of the iron core is reduced, the iron core magnetizing loop is shortened to a great extent, the iron loss is reduced, and high efficiency is realized; the reactive loss is small, and the power factor is high; the motor has high output density, and the volume and weight are reduced to a great extent.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a voltage-time plot of a three-phase power supply for a controllable electric motor provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a twelve tooth solution for a controllable electric motor provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a rotary electric motor of a twenty-four tooth version of a controllable electric motor provided by an embodiment of the present invention;

fig. 4 is a schematic diagram for reference of the principle provided by the embodiment of the present invention.

Wherein the reference numerals are respectively: 1-electromagnet, 2-magnetic pole, 3-armature, 4-excitation iron core, 5-coil, 6-recess.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or device.

One embodiment of the present invention provides a controllable motor with high efficiency and large torque, the controllable motor comprising:

an armature 3, wherein the armature 3 is arranged opposite to the first electromagnet group, and the armature 3 can move relative to each electromagnet group;

the three electromagnet groups are arranged in parallel in sequence, the phase difference of the three alternating current sources is 2/3 pi in sequence, and when the controllable motor is electrified and starts to work, the armature 3 moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group, and the directions marked in the figure 2 are shown.

The three ac sources may also be referred to as three-phase supply sources, see fig. 1.

Referring to fig. 2, in an embodiment of the present invention, each of the first electromagnet group, the second electromagnet group, and the third electromagnet group includes two electromagnets 1 arranged in parallel, each of the electromagnets includes a pair of magnetic poles, and the distribution direction of the magnetic poles is parallel or substantially parallel to the arrangement direction of the electromagnet groups; when the electromagnet group is electrified, the magnetic poles of the two electromagnets in the same group are distributed in opposite directions, and the opposite distribution of the magnetic poles can be realized by the opposite winding directions or the opposite power supply directions of the two electromagnets.

In one embodiment of the invention, a recess 6 is provided between the two poles of any electromagnet 1.

In one embodiment of the invention, the width of the pole 2 is equal or approximately equal to the width of the recess 6.

In one embodiment of the invention, the distance between adjacent electromagnets 1 is equal or substantially equal to the width of the recess 6.

In one embodiment of the invention, the length of the armature 3 is 2.5-3.5 times the width of the recess.

In one embodiment of the present invention, the number of the armatures is plural, and the permanent magnets are arranged on the armatures 3, so that the side parts of the armatures 3 facing the electromagnet 1 have magnetism, and the magnetism of the side parts of the adjacent armatures 3 facing the electromagnet 1 is opposite.

In one embodiment of the present invention, the controllable electric motor is a rotary electric motor, the electromagnets 1 are disposed on the circumference of a first virtual circle, the plurality of armatures 3 are disposed on the circumference of a second virtual circle, the electromagnets 1 are fixedly disposed with respect to the center of the first virtual circle, the armatures 3 are capable of rotating with respect to the center of the second virtual circle, the first virtual circle and the second virtual circle are disposed in communication, and the diameter of the first virtual circle is larger than the diameter of the second virtual circle.

In one embodiment of the invention, the number of electromagnets is 12 × N and the number of armatures is 8 × N, where N is a positive integer.

In one embodiment of the present invention, N ═ 2, see fig. 3.

For the explanation of the technical solution in the embodiment of the present invention, the reason for the uncontrollable problem of the dc motor and the ac induction motor in the current wide application needs to be known first; the working mechanism of the traditional motor is derived from a Faraday electromagnetic principle and a BioSaval electromagnetic law; the magnetic field has an action on the streaming electrons, namely:

in the formula (1), F_MActing force of magnetic field applied on the conductor;

dL is the effective element length of the conductor in the magnetic field B;

i is the current in conductor L;

if the conductor L is perpendicular to the direction of the magnetic field B, the formula (1) can be simplified into

F_M＝BLi (2)

Assuming that the acting force of the magnetic field B on the conductor L in formula (2) is a rotating electromagnetic torque with radius r, then

T_M＝F_Mr＝BLir (3)

The field polarities always being equal in magnitude and opposite in direction dipoles presented in pairs, i.e. B₂＝-B₁When the N-turn coil is excited, the electromagnetic torque with the diameter D of the rotor formed by the conductor L is;

(4) in the formula, N is the total number of turns of the coil, and P is the number of the coils 5. From the parameters of the basic expression of the electromagnetic torque, no state quantity capable of reflecting the operation displacement of the motor exists. This illustrates the difficulty in directly controlling a conventional motor.

5, the technology directly utilizes the principle that an exciting iron core generates attraction force on a magnetized armature in a magnetic circuit to form the motor; the division is as follows, see fig. 4:

the current is taken as I to flow through the exciting iron core of the coil W, and the generated magnetic flux phi forms a magnetic conduction loop through the armature, so that the armature is magnetized to generate attraction force on the iron core. According to Maxwell electromagnetic attraction; it is in direct proportion to the magnetic pole air gap area penetrated by the magnetic force line and the square of the air gap magnetic induction intensity, and the expression is as follows;

(5) in the formula F_MIs the electromagnetic attraction (N), B of the armature_δIs the air gap magnetic induction (T), S_δIs the cross-sectional area (cm) of air gap²) Due to B_δ＝Φ_δ/S_δSubstituting the formula (5) with the formula (I);

F_M＝49×10^-7Φ_δ ²/S_δ (6)

(6) in the formula phi_δIs the air gap flux (maxwell Wb). When the working air gap is small, neglecting the magnetic leakage and being tolerable to phi_δAssuming again that the magnetic circuit is not saturated, the reluctance, i.e. R, can be ignored_m＝0,R_mL is 0 because IW is 2 Φ R_δAnd changes phi to IW/2R_δAnd R_δ＝δ/μ₀S_δSubstituting the formula (6) to obtain the attraction force of the exciting iron core to the armature iron;

F_M＝12.25(IW)²S_δδ^-210^-7 (7)

(7) in the formula, IW is the ampere turn number (A) of a coil on the excitation iron core; s_δIs the effective area (CM) of the working air gap²) (ii) a Delta is the working air gap length (cm);

if the armature is conceived as a motor rotor with radius r, the torque of the armature to the rotation center is;

M_M＝12.25(IW)²S_δ(αr)^-210^-7 (8)

(8) in the formula M_MGenerating a torque (N-M) to the center distance for the magnetization from the electromagnet excitation conductor to the armature, wherein r is the radius (M) of the rotating center O point of the track of the radian (Rd) of the armature stroke point; alpha is the included angle between the center of the iron core magnetic pole and the working center of the armature at the rotating center.

As can be seen from the formula (8):

a, when an excitation loop is determined, a stroke working surface between a magnetic pole and an armature is determined, and the only torque dependent variable is an included angle alpha;

b, determining the range of the stroke by the size of the included angle alpha, setting the maximum stroke according to the structure, wherein the included angle alpha is changed from large to small, the suction force is changed from small to large, and when alpha → 0, M_MAn inflection point extremum occurs → ∞;

c，(IW)²and (alpha r)^-2A mathematical non-directional quantity means that the armature can be randomly stopped on the left and right, i.e. non-directional.

The principle of attraction of the exciting iron core to the armature can be used as a novel motor development mechanism as long as the attraction directionality is solved.

Therefore, the technical scheme of the conception controllable motor that the iron core excitation 4 magnetizes the armature 3 to generate the attraction force is obtained;

the excitation iron core 4 can generate attraction force and form torque to the magnetized armature, and is the movement displacement strain of the armature. The extreme value of the inflection point is a special point in mathematical theory, and can be used as a correlation point for identifying the forced motion of the armature under the action of the excitation source, namely a state identification point.

How to realize the directional characteristic, the feasible magnetic circuit structure, the mechanism explanation and the specific adaptive measure and effect of the feed waveform and the variable frequency source are as follows;

A. if a three-phase sine voltage waveform is adopted as an excitation power supply, the U, V, W three-phase difference is

Every other

The positive and negative voltage peaks appear alternately at each phase, which is the corresponding maximum attractive torque point, i.e. α is 0 (fig. 2). The geometric angle of the rotating motor is integral multiple of the electrical angle, the excitation source frequency determines the synchronous rotating speed of the motor, and the torque rises along with the frequency in the range without step-out. This illustrates that the motor is constructed with a mechanism in which the magnetized armature creates an attractive force, as long as the magnetic circuit is not saturated to achieve a large torque.

B. The permanent magnets are embedded at the end of each armature 3, so that the polarity of each armature N, S is distributed continuously at intervals. Therefore, the initial stop position of the excitation iron core relative to the armature can be identified by presetting the polarity of the armature, the starting state is started in the shortest time, the excitation source phase sequence makes a traction movement, and the three-phase excitation source phase sequence determines the movement direction of the armature.

C.U, V, W, the three-phase field core is named as "one group" of 6. And exciting in positive and negative polarity intervals. Converting the schematic diagram (figure 3) into an expanded diagram (figure 4) of the actual structure of the motor; it is composed of 12 exciting teeth as stator and 4 pairs of polar armatures as rotor, and is a 3-phase magnetic loop with 2 pi electric angle.

The armature and the pole face of the iron core group are equal in length and are composed of N, S pairs of poles at intervals of 4. The excitation source three-phase wave phase difference 2/3 pi is shown in corresponding time coordinates t1, t2, … t6 (fig. 2) in the same time sequence U, V, W three-phase wave, and the feed voltage V has 6 times of positive and negative alternative peak values V_max. If starting from the graph t1 being 0, under the action of strong excitation at each peak point according to the time sequence, the armature will be attracted once correspondingly, i.e. aligned once. When the armature moves to the right by pi/12, the 3-phase wave moves pi/2 in 1 period and the 3-phase wave armature moves in 4 periodsThe displacement is 2 pi.

D. Magnetic induction B of iron core excitation_sMagnetic induction intensity B with armature permanent magnet source_pThe overlapped working state is to be presented, and the principle of magnetic induction intensity overlapping is attached;

this not only enhances the air gap magnetic induction B_δAnd the motor output is improved. More importantly, the armature permanent magnet of the magnetic circuit is in a paramagnetic working state. And leaves the armature permanent magnet in no direct relationship to its load. The overload capability of the motor is thus strong. In the magnetic circuit of the early permanent magnet motor, the permanent magnet is used as a magnetic field source, the working point is always in a demagnetizing state, the overload or improper working state can lead to the demagnetization of the permanent magnet, and the strict working point of the permanent magnet is selected, so that the service life is not influenced by the demagnetization phenomenon. Thus, the mechanism greatly improves the service life of the motor using permanent magnets.

E. In practical application of the rotary motor, even number of groups of the three-phase excitation iron cores are combined. Since the field core generates an axial force on the armature, i.e. the motor rotor, the even number of combinations cancel the axial force components. Even if the combination of odd groups is combined, great lateral force components are difficult to avoid to generate on the shaft. The normal operation of the motor is not facilitated, and mechanical vibration noise is generated.

F. The iron loss of the motor is extremely sensitive to alternating current excitation frequency, and besides the adaptability selection in the existing materials, the distribution of a proper structural magnetic circuit and a tooth pole is extremely important. The mechanism is beneficial to reducing the frequency of changing the excitation polarity of the iron core, shortening the iron core magnetizing loop to a great extent, reducing the iron loss and realizing high efficiency.

G. When the motor runs continuously, the torque extreme points are sequentially passed, and the representation of synchronism is carried out. Therefore, the load current and the voltage phase difference is small, the reactive loss is small, and the power factor is high. It is the existence of the extreme point that easily determines t₀And the time-based control mode is easy to realize. The uncontrollable nature of the conventional synchronous motor is changed.

It was thus concluded that:

a, the exciting iron core generates suction force to the magnetized armature, and the electromagnetic suction type controllable motor can be formed by combining the structure.

B, the motor with the structure is excited in three phases, 6 moment extreme points can appear on the armature rotor in each feeding waveform period, the higher the excitation source frequency is, the denser the extreme points in space unit time is, the larger the moment is, and the rotating speed is smoother.

And C, forming a group of three-phase excitation by 2 iron cores and 6 iron cores in each phase, wherein the three-phase excitation is an optimal combined structure. The magnetic path section is consistent due to the structure. The working additional harmonic wave is less, and the tooth pole acting force of the stator and the rotor is reasonable.

And D, the magnetic circuit design should avoid saturation, and the existence of mathematical extreme points enables the motor to be in synchronous operation, so that the loss is low and the efficiency is high.

And E, the voltage peak value of the excitation source corresponds to an extreme point of the output torque of the motor, and the extreme point reflects the state position of the rotor of the motor. Therefore, the operation state quantity of the motor can be accurately controlled based on the peak point of the excitation source.

F, the motor formed by the mechanism has high output density, and the volume and weight are reduced to a great extent.

The following is an example of an application:

see fig. 3 for a practical 35Kw high efficiency high torque controllable motor. There are 2 groups of 12 field cores, i.e. a conventional motor stator core similar to 24 slots. The rotor thus forms an armature circuit for 8 pole pairs.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. An efficient large torque controllable electric motor, said controllable electric motor comprising:

2. The controllable electric motor of claim 1 wherein said first electromagnet group, said second electromagnet group, and said third electromagnet group each comprise two electromagnets arranged in parallel, each of which comprises a pair of magnetic poles, the arrangement of the magnetic poles being parallel or substantially parallel to the arrangement of the electromagnet groups; when the electromagnet group is electrified, the magnetic poles of the two electromagnets in the same group are distributed in opposite directions.

3. A controllable electric motor as claimed in claim 2, wherein a recess is provided between the poles of any electromagnet.

4. A controllable electric motor as claimed in claim 3, characterized in that the width of the pole is equal or approximately equal to the width of the recess.

5. The controllable electric motor of claim 4, wherein the distance between adjacent electromagnets is equal or substantially equal to the width of said recess.

6. The controllable electric motor according to claim 4 or 5, wherein the length of the armature is 2.5 to 3.5 times the width of the recess.

7. The controllable electric motor of claim 6, wherein said number of said armatures is plural, said armatures having permanent magnets disposed thereon such that the sides of said armatures facing said electromagnet are magnetic and the sides of adjacent armatures facing said electromagnet are opposite in polarity.

8. The controllable electric motor of claim 2, wherein said controllable electric motor is a rotary electric motor, said electromagnets are disposed on a circumference of a first imaginary circle, a plurality of armatures are disposed on a circumference of a second imaginary circle, said electromagnets are fixedly disposed with respect to a center of said first imaginary circle, said armatures are rotatable with respect to a center of said second imaginary circle, said first imaginary circle and said second imaginary circle are communicatively disposed, and a diameter of said first imaginary circle is larger than a diameter of said second imaginary circle.

9. The controllable electric motor of claim 8, wherein said number of electromagnets is 12N and said number of armatures is 8N, wherein N is a positive integer.

10. A controllable electric motor as claimed in claim 9, wherein N-2.