A high-efficiency large-torque controllable motor

Abstract

The application discloses a high-efficiency large-torque controllable motor, which comprises a first electromagnet group, a second electromagnet group, a third electromagnet group and an armature, 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, the third electromagnet group is used for being connected with a third alternating current source, the armature is oppositely arranged with the first electromagnet group, the armature can move relative to each electromagnet group, the three electromagnet groups are arranged in parallel and sequentially, and the phase difference of the three alternating current sources is 2 / 3Pi sequentially, when the controllable motor is powered and starts to work, the armature moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group. The high-efficiency large-torque controllable motor provided by the application prolongs the service life of a permanent magnet motor, has small reactive power loss and high power factor.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a high-efficiency, high-torque controllable electric motor. Background Technology

[0002] In today's world, electric motors are virtually ubiquitous. From their simple function as power sources, they have evolved into actuators in automatic control systems. DC motors in conventional applications suffer from poor controllability (their transfer function is second-order), while induction motors lack control capabilities. When the power system in an equipment cannot be manually intervened in and must be automatically adjusted, the traditional method is to insert servo circuits and add feedback to form a closed-loop control. This results in a complex system structure, a narrow stability region, and relatively inferior quality. Therefore, exploring high-torque controllable motors has become a sought-after goal. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a high-efficiency, high-torque controllable electric motor. The technical solution is as follows:

[0004] This invention provides a high-efficiency, high-torque controllable electric motor, the controllable electric motor comprising:

[0005] A first electromagnet assembly, wherein the first electromagnet assembly is used to connect to a first AC source;

[0006] The second electromagnet assembly is used to connect to the second AC source;

[0007] The third electromagnet group is used to connect to the third AC source;

[0008] An armature is disposed opposite to the first electromagnet group, and the armature is movable relative to each electromagnet group.

[0009] Three electromagnet groups are arranged side by side in sequence, and the phase difference between the three AC sources is 2 / 3π. When the controllable motor is powered on and starts working, the armature moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group.

[0010] Furthermore, the first electromagnet group, the second electromagnet group, and the third electromagnet group each include two electromagnets arranged side by side, and each electromagnet includes a pair of magnetic poles. The distribution direction of the magnetic poles is parallel or approximately parallel to the arrangement direction of the electromagnet group. When the electromagnet group is energized, the magnetic pole distribution directions of the two electromagnets in the same group are opposite.

[0011] Furthermore, a recess is provided between the two poles of any electromagnet.

[0012] Furthermore, the width of the magnetic pole is equal to or approximately equal to the width of the recess.

[0013] Furthermore, the distance between adjacent electromagnets is equal to or approximately equal to the width of the recess.

[0014] Furthermore, the length of the armature is 2.5 to 3.5 times the width of the recess.

[0015] Furthermore, there are multiple armatures, each armature is provided with a permanent magnet, such that the side of the armature facing the electromagnet is magnetic, and the magnetic properties of adjacent armatures facing the electromagnet are opposite.

[0016] Furthermore, the controllable motor is a rotary motor, each electromagnet is arranged on the circumference of the first virtual circle, and multiple armatures are arranged on the circumference of the second virtual circle. The electromagnets are fixedly arranged relative to the center of the first virtual circle, and the armatures are rotatable relative to the center of the second virtual circle. The first virtual circle and the second virtual circle are communicatively connected, and the diameter of the first virtual circle is larger than the diameter of the second virtual circle.

[0017] Furthermore, the number of electromagnets is 12*N, and the number of armatures is 8*N, where N is a positive integer.

[0018] Furthermore, N = 2.

[0019] The beneficial effects of the technical solution provided by this invention are as follows:

[0020] Permanent magnets are not easily demagnetized, which improves the service life of motors using permanent magnets; it reduces the frequency of core excitation polarity changes and greatly shortens the core magnetization circuit, reducing iron losses and achieving high efficiency; it has low reactive power loss and high power factor; and it has high motor output density, which greatly reduces size and weight. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a voltage-time image of the three-phase power supply of the controllable motor provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of a twelve-tooth scheme for a controllable electric motor provided in an embodiment of the present invention;

[0024] Figure 3This is a schematic diagram of a rotary motor with a 24-tooth controllable motor according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram illustrating the principle of an embodiment of the present invention.

[0026] The reference numerals in the attached drawings are as follows: 1-electromagnet, 2-magnetic pole, 3-armature, 4-excitation core, 5-coil, 6-recess. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0029] One embodiment of the present invention provides a high-efficiency, high-torque controllable motor, the controllable motor comprising:

[0030] A first electromagnet assembly, wherein the first electromagnet assembly is used to connect to a first AC source;

[0031] The second electromagnet assembly is used to connect to the second AC source;

[0032] The third electromagnet group is used to connect to the third AC source;

[0033] An armature 3 is disposed opposite to the first electromagnet group, and the armature 3 is movable relative to each electromagnet group.

[0034] Three electromagnet groups are arranged side by side, with the phase difference between the three AC sources being 2 / 3π. When the controllable motor is energized and starts working, the armature 3 moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group. See [link to relevant documentation]. Figure 2 The direction indicated by the center mark.

[0035] Three AC sources can also be called a three-phase power supply, see [link to relevant documentation]. Figure 1 .

[0036] See Figure 2 In one embodiment of the present invention, the first electromagnet group, the second electromagnet group, and the third electromagnet group each include two electromagnets 1 arranged in parallel. Each electromagnet includes 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 group. When the electromagnet group is energized, the magnetic pole distribution directions of the two electromagnets in the same group are opposite. The opposite distribution of magnetic poles can be achieved by the opposite winding direction of the two electromagnets or the opposite power supply direction.

[0037] In one embodiment of the present invention, a recess 6 is provided between the two magnetic poles of any electromagnet 1.

[0038] In one embodiment of the present invention, the width of the magnetic pole 2 is equal to or approximately equal to the width of the recess 6.

[0039] In one embodiment of the present invention, the distance between adjacent electromagnets 1 is equal to or approximately equal to the width of the recess 6.

[0040] In one embodiment of the present invention, the length of the armature 3 is 2.5 to 3.5 times the width of the recess.

[0041] In one embodiment of the present invention, there are multiple armatures, and a permanent magnet is provided on the armature 3 such that the side of the armature 3 facing the electromagnet 1 is magnetic, and the magnetic properties of adjacent armatures 3 facing the electromagnet 1 are opposite.

[0042] In one embodiment of the present invention, the controllable motor is a rotary motor, each electromagnet 1 is disposed on the circumference of a first virtual circle, and a plurality of armatures 3 are disposed on the circumference of a second virtual circle. The electromagnets 1 are fixedly disposed relative to the center of the first virtual circle, and the armatures 3 are rotatable relative to the center of the second virtual circle. The first virtual circle and the second virtual circle are communicatively connected, and the diameter of the first virtual circle is larger than the diameter of the second virtual circle.

[0043] In one embodiment of the present invention, the number of electromagnets is 12*N and the number of armatures is 8*N, where N is a positive integer.

[0044] In one embodiment of the invention, N = 2, see [link / reference] Figure 3 .

[0045] To explain the technical solutions in the embodiments of the present invention, it is necessary to first understand the reasons for the uncontrollability problems of DC motors and AC induction motors in current widespread applications; the working mechanism of traditional motors is based on Faraday's electromagnetic principle and Biotsava's electromagnetic law; magnetic fields exert a force on flowing electrons, that is:

[0046]

[0047] In equation (1), F M The force exerted by the magnetic field on the conductor;

[0048] dL is the effective element length of the conductor in the magnetic field B;

[0049] i is the current in conductor L;

[0050] If conductor L is perpendicular to the direction of magnetic field B, then equation (1) can be simplified to

[0051] F M =BLi (2)

[0052] If the force exerted by the magnetic field B on conductor L in equation (2) is conceived as a rotational electromagnetic torque with radius r, then...

[0053] T M =F M r = BLir (3)

[0054] The excitation polarity always presents a pair of equal-sized but opposite-direction dipoles, i.e., B2 = -B1. When energized by an N-turn coil, the electromagnetic torque of the rotor with diameter D formed by conductor L is:

[0055]

[0056] (4) In the formula, N is the total number of turns of the coil, and P is the number of coils 5. From the parameters of the basic expression for electromagnetic torque, there are no state variables that reflect the motor's displacement. This indicates that direct control of traditional motors is difficult.

[0057] 5. This technology directly utilizes the principle of the excitation core generating an attractive force on the magnetized armature in its magnetic circuit to construct an electric motor; the breakdown is as follows, see below. Figure 4 :

[0058] A current I flows through the coil W to excite the magnetic core, generating a magnetic flux Φ that forms a magnetic circuit through the armature, causing the armature to be magnetized and generating an attractive force on the iron core. According to Maxwell's theory of electromagnetic attraction, it is proportional to the area of ​​the air gap through which the magnetic field lines pass and the square of the air gap magnetic induction intensity, expressed as:

[0059]

[0060] (5) In the formula F M B is the electromagnetic attraction force (N) of the armature. δ Let S be the air gap magnetic flux density (T). δ air gap cross-sectional area (cm²) 2 ), because B δ =Φ δ / S δ Substituting into equation (5), we get:

[0061] F M =49×10 -7 Φ δ 2 / S δ (6)

[0062] (6) where Φ δ This is the air gap magnetic flux (Maxwell Wb). When the working air gap is very small, leakage flux is negligible and can be tolerated as Φ. δ =Φ, and assuming the magnetic circuit is not saturated, then the magnetic reluctance, i.e., R, can be ignored. m =0,R m L = 0, because IW = 2ΦR δ And set Φ = IW / 2R δ With R δ =δ / μ0S δ Substituting into equation (6), we get the attraction force of the excitation magnet core on the armature as follows:

[0063] F M =12.25 (IW) 2 S δ δ -2 10 -7 (7)

[0064] (7) In the formula, IW is the ampere-turns (A) of the coil on the excitation core; S δ The effective area of ​​the working air gap (CM) 2 ); δ is the working air gap length (cm);

[0065] If the armature is conceived as a motor rotor with radius r, then the torque of the armature about the center of rotation is:

[0066] M M =12.25 (IW) 2 S δ (αr) -2 10 -7 (8)

[0067] (8) M MThe excitation of the electromagnet leads to the magnetization of the armature, generating a torque (NM) about the center distance; r is the radius (M) of the trajectory of the armature stroke point in radians (Rd) about the rotation center O; α is the angle between the center of the iron core magnetic pole and the working center of the armature at the rotation center.

[0068] As can be seen from equation (8):

[0069] a. When the excitation circuit is determined, the working surface of the stroke between the magnetic pole and the armature is determined, and the only torque strain is the included angle α.

[0070] b. The angle α determines the range of motion. The maximum motion is set according to the structure. As the angle α decreases, the suction force increases. When α→0, M... M →∞ indicates the inflection point extreme value;

[0071] c, (IW) 2 With (αr) -2 Mathematically, the direction is not fixed, meaning that the armature can be randomly positioned on the left or right side, i.e., it has no orientation.

[0072] The above demonstrates that as long as the directionality of the attraction force is resolved, the principle of attraction between the excitation core and the armature can be used as a new type of electric motor development mechanism.

[0073] Therefore, a technical solution for a controllable electric motor was obtained by using the excitation of the iron core 4 to magnetize the armature 3 and generate attraction force.

[0074] The excitation core generates attraction and torque for the four magnetized armatures, which is the strain of the armature's displacement. The inflection point extreme value is a special point in mathematics, which can be used as a connection point to identify the force motion of the armature under the action of the excitation source, that is, the state identification point.

[0075] The following explains how to achieve directional characteristics, feasible magnetic circuit structures, feeding waveforms, and the mechanism, specific adaptation measures, and effects of the variable frequency source;

[0076] A. If a three-phase sinusoidal voltage waveform is used as the excitation power supply, the phase difference between the U, V, and W phases is: Every The alternating positive and negative voltage peaks in each phase correspond to the point of maximum suction torque, i.e., α = 0. Figure 2 For a rotary electric motor, the geometric angles must be integer multiples of the electrical angles. The frequency of the excitation source determines the synchronous speed of the motor. Within the range without losing synchronization, the torque also increases with the frequency. This indicates that an electric motor constructed using the mechanism of generating attraction through magnetized armatures can obtain a large torque as long as the magnetic circuit is not saturated.

[0077] B. A permanent magnet is inserted into the end of each armature, so that the N and S polarities of each armature are distributed in a continuous and intermittent manner. In this way, the preset armature polarity can identify the initial static position of the excitation core relative to the armature, so as to put it into the start-up state in the shortest time and move it in tandem with the phase sequence of the excitation source. The phase sequence of the three-phase excitation source determines the direction of armature movement.

[0078] CU, V, W, three-phase excitation cores are grouped into sets of six. They are excited alternately with opposite polarities. (The remaining text appears to be incomplete and possibly contains errors.) Figure 3 The schematic diagram is converted into an unfolded diagram of the actual structure of the electric motor. Figure 4 It consists of 12 excitation teeth as the stator and 4 pairs of polar armatures as the rotor, forming a 3-phase magnetic circuit with an electrical angle of 2π.

[0079] The armature and core have equal pole faces and consist of four pairs of poles spaced at N and S intervals. The phase difference of the three-phase waves of the excitation source is 2 / 3π. Within the same time sequence of U, V, and W three-phase waves, the corresponding time coordinates are t1, t2, ..., t6. Figure 2 Its feed voltage V has 6 alternating positive and negative peak values ​​V. max If we start from t1=0 as shown in the diagram, under the strong excitation at each peak point in the time sequence, the armature will engage once at the corresponding time, i.e., align once. If the armature moves to the right by π / 12, then the 3-phase wave moves by Π / 2 in one cycle, and the 3-phase wave armature displacement is 2Π in four time periods.

[0080] D. Magnetic induction intensity of iron core excitation B s With the magnetic induction intensity B of the permanent magnet source of the armature p It should exhibit a superimposed working state to conform to the principle of superposition of magnetic induction intensity; This not only strengthens the air gap magnetic induction intensity B δ This increases the motor's output. More importantly, it ensures that the permanent magnet in the armature operates in a paramagnetic state, and that the armature's permanent magnet is independent of its load. This results in a strong overload capacity for the motor. In early permanent magnet motors, the permanent magnet, acting as the magnetic field source, was always in a demagnetized state. Overload or improper operating conditions would lead to demagnetization of the permanent magnet. Strict selection of the permanent magnet's operating point often failed to mitigate demagnetization and thus affected its lifespan. Therefore, the mechanism described above significantly improves the service life of motors using permanent magnets.

[0081] E. In practical applications of rotary electric motors, three-phase excitation cores should be used in even-number combinations. Since the excitation cores generate axial forces on the armature (i.e., the motor rotor), even-number combinations allow these axial forces to cancel each other out. Even with multiple odd-number combinations, it is difficult to avoid generating significant lateral forces on the shaft. This is detrimental to normal motor operation and also generates mechanical vibration and noise.

[0082] F. The iron loss of an electric motor is extremely sensitive to the AC excitation frequency. Besides making adaptive selections from existing materials, a suitable structural magnetic circuit and tooth pole distribution are crucial. The mechanism described herein helps reduce the frequency of core excitation polarity changes and significantly shortens the core magnetization circuit, thereby reducing iron loss and achieving high efficiency.

[0083] G. When the motor operates continuously, it sequentially passes through torque extreme points, which is a characteristic of synchronicity. Therefore, its load current and voltage phase difference is small, reactive power loss is small, and power factor is high. The existence of these extreme points makes it easy to determine point t0, thus facilitating time-based control. This overcomes the uncontrollability inherent in conventional synchronous motors.

[0084] Therefore, the conclusion is:

[0085] A. By using the excitation core to generate an attractive force on the magnetized armature, the above-mentioned structural combination can form an electromagnetic attraction-type controllable motor.

[0086] B. When this type of motor is subjected to three-phase excitation, the armature rotor will have 6 torque extreme points in each power supply waveform period. The higher the excitation source frequency, the denser the extreme points per unit time, the greater the torque, and the smoother the speed.

[0087] C. A three-phase excitation system consisting of 2 iron cores per phase, with 6 iron cores forming a group, is the optimal combination structure. This structure results in a consistent magnetic circuit cross-section, fewer additional harmonics, and more reasonable stator and rotor tooth pole forces.

[0088] D. The magnetic circuit design should avoid saturation. The existence of mathematical extrema points ensures that the motor operates synchronously, resulting in low losses and high efficiency.

[0089] E, the peak voltage of the excitation source corresponds to the extreme point of the motor's output torque, and the extreme point reflects the state of the motor's rotor. Therefore, by using the peak point of the excitation source as the time base, accurate control of the motor's operating state variables can be achieved.

[0090] F, the mechanism described herein results in a high power density for the electric motor, which significantly reduces its size and weight.

[0091] Here is an application example:

[0092] See Figure 3 The example shown is a 35kW high-efficiency, high-torque controllable motor for practical application. It consists of two sets of 12 excitation magnet cores, which is similar to the stator core of a conventional motor with 24 slots. The rotor corresponds to 8 pole pairs forming the armature circuit.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency, high-torque controllable electric motor, characterized in that, The controllable motor includes: A first electromagnet assembly, wherein the first electromagnet assembly is used to connect to a first AC source; The second electromagnet assembly is used to connect to the second AC source; The third electromagnet group is used to connect to the third AC source; An armature is provided, which is disposed opposite to the first electromagnet group and is movable relative to each electromagnet group; a permanent magnet is provided on the armature, such that the side of the armature facing the electromagnet is magnetic, and the magnetic properties of the sides of adjacent armatures facing the electromagnet are opposite. The first electromagnet group, the second electromagnet group, and the third electromagnet group each include two electromagnets arranged side by side. Each electromagnet includes a pair of magnetic poles. The distribution direction of the magnetic poles is parallel or approximately parallel to the arrangement direction of the electromagnet group. When the electromagnet group is energized, the magnetic pole distribution directions of the two electromagnets in the same group are opposite. The free end of the magnetic pole is not provided with a coil. A recess (6) is provided between the two magnetic poles of any electromagnet (1). The length of the armature (3) is 2.5 to 3.5 times the width of the recess (6). Three electromagnet groups are arranged side by side in sequence, and the phase difference of the three AC sources is 2 / 3π respectively. When the controllable motor is powered on and starts to work, the armature moves from the first electromagnet group to the third electromagnet group under the action of each electromagnet group. The controllable motor is a rotary motor. Each electromagnet is arranged on the circumference of the first virtual circle, and multiple armatures are arranged on the circumference of the second virtual circle. The electromagnets are fixedly arranged relative to the center of the first virtual circle, and the armatures can rotate relative to the center of the second virtual circle. The first virtual circle and the second virtual circle are concentric, and the diameter of the first virtual circle is larger than the diameter of the second virtual circle. The number of electromagnets is 12*N, and the number of armatures is 8*N, where N is a positive integer; The electromagnets of the first electromagnet group, the second electromagnet group, and the third electromagnet are arranged on the circumference of the first virtual circle, and adjacent electromagnets are kept in contact. The armature is of equal length to the core pole face of each electromagnet group, and the magnetic induction intensity of the electromagnet core excitation is superimposed with the magnetic induction intensity of the permanent magnet source of the armature; the permanent magnet of the armature (3) is in a paramagnetic working state, and the permanent magnet is not directly related to the load. A three-phase excitation system is formed by two iron cores per phase and six iron cores per phase. The motor is subjected to three-phase excitation, and the armature rotor has six torque extreme points in each power supply waveform period.

2. The controllable electric motor as described in claim 1, characterized in that, The width of the magnetic pole is equal to or approximately equal to the width of the recess.

3. The controllable electric motor as described in claim 2, characterized in that, The distance between adjacent electromagnets is equal to or approximately equal to the width of the recess.

4. The controllable electric motor as described in claim 1, characterized in that, N＝2。

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