Direct current asynchronous motor

Abstract

The application discloses a direct-current asynchronous motor and relates to the technical field of motor driving, which comprises the following steps: the number of winding phases is X, X tooth portions form a tooth group, X is greater than or equal to 2, a stator comprises at least one tooth group; a rotor is arranged in a nested mode with the stator; a control circuit is used to output X-phase independent power supplies, the X-phase independent power supplies are electrically connected with X-phase windings of the stator respectively, the control circuit synchronously supplies power to the X-phase windings of the stator, the X-phase windings are wound on the tooth portions to form coils, and the X tooth portions in each tooth group are respectively wound with coils corresponding to the X-phase windings; the coils on the tooth portions belonging to the same phase winding are connected in series in a head-to-tail mode in sequence, and the coils on any two adjacent tooth portions are out-of-phase coils; the X-phase windings comprise a reference phase winding, and a phase difference theta is formed between a driving signal of a Yth phase winding and a driving signal of the reference phase winding Y； Each phase of the X-phase windings has independent incoming and outgoing wires, and one-phase independent power supply output by the control circuit is connected with the incoming and outgoing wires of one-phase winding.

Description

Technical Field

[0001] This invention relates to the field of motor drive technology, and in particular to a DC asynchronous motor. Background Technology

[0002] Existing asynchronous motors often employ capacitor phase-shifting starting. However, these motors are directly powered by AC, and the power frequency cannot be adjusted, thus limiting speed control. To achieve multiple speeds, multiple wire ends need to be pulled from the windings, resulting in higher production costs and limited power density. Furthermore, capacitor phase-shifting motors exhibit uneven magnetic force at low speeds, generating harmonic vibrations that cannot be eliminated. Summary of the Invention

[0003] The main objective of this invention is to propose a DC asynchronous motor that aims to solve the problems of maximum speed limitation and multi-speed regulation limitation of capacitor phase-shifting asynchronous motors in the prior art, eliminate harmonic and harmonic vibration noise, and improve the power density of asynchronous motors.

[0004] To achieve the above objectives, the present invention proposes a DC asynchronous motor, comprising a stator, a rotor, and a control circuit. The stator includes multiple teeth and windings wound around each stator, wherein the number of phases of the windings is X, and X teeth form a tooth group, X≥2. The stator includes at least one tooth group. The rotor is a non-magnetic rotor and is nested with the stator. The control circuit outputs X-phase independent power supplies, which are electrically connected to the X-phase windings of the stator respectively. The control circuit synchronously supplies power to the X-phase windings of the stator. The X-phase windings are wound around the teeth to form coils, and coils corresponding to the X-phase windings are wound on the X teeth within each tooth group. Coils on the teeth belonging to the same phase winding are connected in series end-to-end, and coils on any two adjacent teeth are out-of-phase coils. The X-phase winding includes a reference phase winding, and a phase difference θ is formed between the drive signal of the Y-phase winding and the drive signal of the reference phase winding. Y； Each phase of the X-phase winding has an independent input and output line, and the independent power supply output by the control circuit is connected to the input and output lines of one phase of the winding.

[0005] In one embodiment, the minimum phase difference between the drive signal of the Y-phase winding and the drive signal of the reference phase winding is: ;

[0006] The maximum phase difference between the driving signal of the Y-phase winding and the driving signal of the reference phase winding is: .

[0007] In one embodiment, the rotor includes an iron core, a plurality of conductors, and two conductive rings; a plurality of conductor slots are uniformly formed along the circumference of the iron core, each conductor slot is formed along the axial direction of the iron core, and each conductor passes through the conductor slot; the conductive rings are disposed on both sides of the iron core, and the conductive rings are fixedly connected to both ends of each conductor.

[0008] In one embodiment, the rotor is a squirrel cage structure, and the conductor passes through the iron core and is electrically connected to the conductive rings on both sides.

[0009] In one embodiment, the conductor is inclined relative to the axis of the iron core, and the angle between the extension direction of the conductor and the end face of the conductive ring is an acute angle.

[0010] In one embodiment, the conductive ring is a distributed conductive ring structure; The distributed conductive ring includes multiple arc segments, each arc segment having an equal radius, and every two opposite arc segments are connected to the same number of conductors. The distributed conductive rings on at least one side of the iron core are spliced ​​together to form mutually spaced circular rings.

[0011] In one embodiment, the DC asynchronous motor is an internal rotor motor; the teeth surround and form a stator cavity, and the rotor is rotatably disposed in the stator cavity; a motor shaft is provided at the center of the rotor, and the motor shaft is fixedly connected to the iron core; Alternatively, the DC asynchronous motor is an external rotor motor; the rotor has an internal cavity, and the stator passes through the internal cavity; the center of the stator is connected to a support shaft via a bearing.

[0012] In one embodiment, in the winding of the same phase, the coils on two adjacent teeth are spaced apart by X-1 teeth, and the winding directions of the coils on two adjacent teeth are opposite.

[0013] In one embodiment, the stator further includes a yoke; the yoke is an annular ring, and each of the teeth is fixedly connected to the surface of the yoke; each of the teeth extends radially along the yoke. Each tooth has a boot at its end, and the end of the boot facing the rotor has an arcuate surface, the axis of which coincides with the rotation center of the rotor.

[0014] In one embodiment, the included angle between every two adjacent teeth

[0015] Where θ c θ is the angle between any two adjacent teeth. c minθ is the minimum value of the included angle between two adjacent teeth. c max Z represents the maximum angle between two adjacent teeth, and Z represents the number of teeth in a single stator.

[0016] The technical solution of this invention optimizes the stator magnetic field distribution and reduces leakage flux and harmonic losses by adopting a winding connection method that connects the ends of the windings and the windings are adjacent to each other in opposite phases.

[0017] By using a concentrated winding structure with independent coils and an adjacent, out-of-phase layout, compared to the distributed windings of traditional capacitor motors, the winding ends are shorter, the slot utilization rate is higher, the power density is increased, and a larger magnetic flux can be generated in the same volume, thus reducing the size of the motor while maintaining the same power.

[0018] Each tooth's coil is connected end-to-end with its adjacent in-phase coil, while the input terminals of out-of-phase coils are adjacent, and their output terminals are adjacent as well. This differs from traditional sinusoidal windings or conventional distributed windings, optimizing the magnetomotive force waveform and reducing ineffective high-order harmonic components. Reduced harmonics mean lower core losses and rotor stray losses, directly improving motor efficiency. Furthermore, the arrangement of the input and output terminals of adjacent out-of-phase coils helps shorten the end winding length, reducing copper losses.

[0019] Compared to traditional technologies, this invention can improve motor efficiency by 10%-20%, while also having a more compact structure. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

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

[0022] Figure 1 This is a schematic diagram of a DC asynchronous motor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the stator structure of an embodiment of a DC asynchronous motor provided by the present invention; Figure 3This is a schematic diagram of the rotor structure of an embodiment of the DC asynchronous motor provided by the present invention; Figure 4 A schematic diagram of the rotor core of an embodiment of a DC asynchronous motor provided by the present invention; Figure 5 A schematic diagram of the structure of an integral rotor of a DC asynchronous motor according to another embodiment of the present invention; Figure 6 A schematic diagram of the stator structure of another embodiment of the DC asynchronous motor provided by the present invention; Figure 7 A schematic diagram of the external rotor structure of another embodiment of the DC asynchronous motor provided by the present invention; Figure 8 A schematic diagram of the inner stator structure of another embodiment of the DC asynchronous motor provided by the present invention; Figure 9 A schematic diagram of the control circuit for a DC asynchronous motor provided by the present invention; Figure 10 A schematic diagram of the control circuit for a DC asynchronous motor provided by the present invention; Figure 11 A schematic diagram of the control circuit for a DC asynchronous motor provided by the present invention.

[0023] Explanation of icon numbers: 10. Stator; 11. Yoke; 12. Tooth section; 13. Boot section; 14. Coil; 15. Stator inner cavity; 20. Rotor; 21. Iron core; 22. Conductor; 221. Conductor slot; 23. Conductor ring; 231. Integrated conductor ring; 24. Rotor inner cavity; 30. Motor shaft; 31. Support shaft; 32. Bearing.

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] This invention proposes a DC asynchronous motor.

[0029] Please see Figures 1 to 2 In one embodiment of the present invention, the DC asynchronous motor includes a stator 10, a rotor 20, and a control circuit. The stator 10 includes a plurality of teeth 12 and windings wound around each stator 10. The number of phases of the windings is X, and X teeth 12 form a tooth group, where X ≥ 2. The stator 10 includes at least one tooth group. The rotor 20 is a non-magnetic rotor and does not have magnetic poles. It is nested with the stator 10. The control circuit is used to output X independent power supplies, which are electrically connected to the X phase windings of the stator 10 respectively. Then, the control circuit synchronously supplies power to the X-phase winding of the stator 10; wherein, the X-phase winding is wound around the tooth 12 to form a coil 14, and the X teeth 12 in each tooth group are respectively wound with coils corresponding to the X-phase winding; the coils 14 on the teeth 12 belonging to the same phase winding are connected in series end to end, and the coils 14 on any two adjacent teeth are out-of-phase coils; the X-phase winding includes a reference phase winding, and the driving signal of the Y-phase winding and the driving signal of the reference phase winding form a phase difference θ. Y； Each phase of the X-phase winding has an independent input and output line, and the independent power supply output by the control circuit is connected to the input and output lines of one phase of the winding.

[0030] Specifically, the stator 10 and the rotor 20 are nested together and coaxially arranged. Each tooth 12 is wound with at least one turn of coil 14. The coil 14 on the tooth 12 is electrically connected to the X phase. Each tooth 12 coil 14 is connected end to end with the adjacent same-phase coil 14 in sequence. The input ends of the opposite-phase coils 14 are adjacent, and the output ends of the opposite-phase coils 14 are adjacent.

[0031] The minimum phase difference between the drive signal of the Y-phase winding and the drive signal of the reference phase winding is: ; The maximum phase difference between the drive signal of the Y-phase winding and the drive signal of the reference phase winding is: .

[0032] Where X is the total number of phases, the reference phase winding is the first phase winding, the Y-th phase winding is any one of the X phases except the reference phase, and 1 < Y ​​≤ X.

[0033] The reference phase winding is the first winding.

[0034] The torque of the asynchronous motor can be changed by controlling the phase difference of the X-phase winding, thus achieving stepless speed regulation. The use of a concentrated winding configuration with adjacent, opposite-phase windings significantly shortens the length of the winding ends. The end windings do not participate in electromagnetic energy conversion; they only generate heat. Shortening the ends directly reduces ineffective resistance, thereby lowering copper losses.

[0035] For an X-phase asynchronous motor, the strength and shape (circular or elliptical) of the rotating magnetic field directly depend on the phase difference of the X-phase current. When the phase difference is close to the ideal value, the resulting magnetic field is close to a circular rotating magnetic field, and the motor output torque is at its maximum. When the phase difference deviates from the limit value, the resulting magnetic field gradually becomes a flattened elliptical magnetic field, and the effective torque component decreases. The control circuit can directly change the characteristics of the resulting magnetic field by continuously adjusting the phase difference θ of each phase within a certain wide range, thereby linearly changing the motor's output torque. Under a constant load, the change in torque directly manifests as a change in speed, thus achieving stepless speed regulation.

[0036] In existing technologies, traditional capacitor-driven asynchronous motors are difficult to miniaturize due to the need to accommodate the secondary winding and capacitor. This invention directly generates a drive signal with a phase difference through a control circuit, eliminating the need for a bulky starting capacitor and dedicated space for the secondary winding. Because it is no longer constrained by the slot requirements for accommodating the secondary winding, the stator 10 design can be more compact, significantly improving the motor's power density and solving the problem of relatively large size in existing technologies.

[0037] See Figure 2In one embodiment of the present invention, the stator winding is a three-phase winding, and the reference phase winding is the first phase winding; the phase difference of the first phase winding is: θ1=0°, the phase difference of the second phase winding is 3°≤θ2≤117°, and the phase difference of the third phase winding is 63°≤θ3≤177°; and θ1≤θ2≤θ3.

[0038] See Figure 2 In one embodiment of the present invention, the stator 10 further includes a yoke 11; the yoke 11 is an annular ring, and each of the teeth 12 is fixedly connected to the surface of the yoke 11; each of the teeth 12 extends radially along the yoke 11.

[0039] Specifically, the yoke 11 is in the shape of a ring; each tooth 12 is fixedly connected to the surface of the yoke 11, and each tooth 12 extends radially along the yoke 11; a boot 13 is fixedly connected to one end of each tooth 12 away from the yoke 11, and the coil 14 is sleeved on the circumference of the tooth 12 and extends axially.

[0040] Please see Figure 2 In one embodiment of the present invention, each of the teeth 12 is provided with a boot 13 at its end. The end of the boot 13 facing the rotor 20 has an arcuate surface, and the axis of the arcuate surface coincides with the rotation center of the rotor 20.

[0041] Specifically, the toothed portion 12 is arranged radially along the yoke portion 11 and extends toward the rotor 20. The end of the boot portion 13 facing the rotor 20 has an arc, and the end of each boot portion 13 facing the rotor 20 forms an approximately circular curved surface. The boot portion 13 is an arc surface and coaxial with the rotor 20, ensuring uniform air gap length.

[0042] See Figures 3 to 4 In one embodiment of the present invention, the rotor 20 includes an iron core 21, a plurality of conductors 22 and two conductive rings 23; a plurality of conductor grooves 221 are uniformly opened along the circumference of the iron core 21, each conductor groove 221 is opened along the axial direction of the iron core 21, and each conductor 22 passes through the conductor groove 221; the conductive rings 23 are disposed on both sides of the iron core 21, and the conductive rings 23 are fixedly connected to both ends of each conductor 22.

[0043] Specifically, the iron core 21 is provided with a plurality of conductor grooves 221, each of which is an axial through groove facing the axis of the stator 10.

[0044] In one embodiment of the present invention, the conductive ring 23 is a distributed conductive ring 23 structure; The distributed conductive ring 23 includes multiple arc segments, each arc segment having an equal radius, and every two opposite arc segments are connected to the same number of conductors 22. The distributed conductive rings 23 on at least one side of the iron core 21 are spliced ​​together to form a closed ring that is in contact with each other.

[0045] Specifically, the conductive rings 23 are distributed conductive rings 23, each with an equal arc, and the number of conductors 22 between any two opposing distributed conductive rings 23 is equal. The distributed conductive rings 23 on one side of the iron core 21 form mutually contacting rings. The distributed conductive rings 23 alter the current paths of the rotor 20, and in conjunction with the specific magnetic field distribution of the stator 10, optimize the motor's starting performance or speed regulation performance.

[0046] Please see Figure 5 In one embodiment of the present invention, the conductive ring 23 is an integral ring structure, and the conductive ring 23 is fixedly connected to both sides of each iron core 21. Specifically, the conductive ring 23 is an integral conductive ring 231. The conductive ring 23 and the conductor 22 are integrally formed by aluminum die casting process, or connected by welding copper strips to copper rings. The integral conductive ring 231 has a simple structure, low resistance, and is suitable for high-efficiency operation conditions; the integral conductive ring 231 is suitable for large-scale automated production, reducing costs.

[0047] Please see Figure 6 In one embodiment of the present invention, the rotor 20 is a squirrel cage structure, and the conductor 22 passes through the iron core 21 and is electrically connected to the conductive rings 23 on both sides. The conductor 22 is inclined relative to the axis of the iron core 21, and the angle between the extension direction of the conductor 22 and the end face of the conductive ring 23 is an acute angle.

[0048] Specifically, the angle between each conductor 22 and the conductive ring 23 is an acute angle; the extension of the axis of the rotor core 21 intersects the projection of the extension of the central axis of the conductor 22 onto the vertical plane; the rotor core 21 has a plurality of inclined slots for accommodating the conductor 22 in the inner circumference, the inclination angle of the inclined slots is the same as the inclination angle of the conductor 22, and the inclined slots are coaxially arranged with the conductor 22 inside them.

[0049] Conductor 22 is inclined relative to tooth 12. When the magnetic field of tooth 12 sweeps across rotor 20, conductor 22 does not enter or leave the strong magnetic field region instantaneously, but gradually enters. This effectively weakens the high-order harmonic magnetic field caused by the concentrated winding. High-order harmonics will generate high-frequency eddy current losses on the surface of iron core 21 and in conductor 22 of rotor 20. Suppressing harmonics reduces the heat generated in this part and improves the effective output power. At the same time, the inclined conductor 22 has a larger cross-sectional area than the vertically arranged conductor 22. Each conductor 22 is helical, and the projection of each conductor 22 toward the winding coincides with at least three of the windings, thereby increasing the traction force exerted by the windings on each conductor 22 and thus increasing the torque of the overall rotor 20.

[0050] In one embodiment of the present invention, the DC asynchronous motor is an internal rotor motor; The toothed portion 12 is provided on the inner wall of the yoke portion 11 and extends inward; The teeth 12 surround and form the stator cavity 15, and the rotor 20 is rotatably disposed in the stator cavity 15. An air gap is left between the outer peripheral surface of the rotor 20 and the shoe 13. The rotor 20 has a motor shaft 30 at its center, and the motor shaft 30 is fixedly connected to the iron core 21.

[0051] Specifically, the stator 10 has a stator cavity 15, the rotor 20 is disposed in the stator cavity 15, and there is a gap between the inner wall of the stator cavity 15 and the side surface of the iron core 21.

[0052] A motor shaft 30 is inserted between the rotor 20 and the iron core 21. The motor shaft 30 is fixedly connected to the center of the iron core 21. The axis of the motor shaft 30 coincides with that of the iron core 21. The motor shaft 30 can be integrally formed with the iron core 21. Alternatively, a hole can be made in the center of the iron core 21 to allow the motor shaft 30 to be interference-fitted with the iron core 21.

[0053] Please see Figures 7 to 8 In one embodiment of the present invention, the DC asynchronous motor is an external rotor motor; The rotor 20 has a rotor cavity 24, and the stator 10 passes through the rotor cavity 24; The toothed portion 12 is provided on the outer wall of the yoke portion 11 and extends outward, and an air gap is left between the outer surface of the boot portion 13 and the inner wall of the rotor cavity 24; The center of the stator 10 is connected to a support shaft 31 via a bearing 32.

[0054] Specifically, the rotor 20 has a rotor cavity 24, the stator 10 passes through the rotor cavity 24, there is a gap between the rotor cavity 24 and each shoe part 13, and the center of the stator 10 is fixedly connected to a support shaft 31 through a bearing 32. The support shaft 31 and the rotor 20 can be connected by a support rod or other structure.

[0055] In one embodiment of the invention, the included angle between every two adjacent teeth 12

[0056] Where θ c θ is the included angle between every two adjacent teeth 12. c min θ is the minimum value of the included angle between two adjacent teeth 12. c max Z is the maximum value of the included angle between two adjacent teeth 12, and Z is the number of teeth 12 in a single stator 10.

[0057] Specifically, the included angle of the teeth 12 does not need to be set uniformly. The minimum included angle between any two adjacent teeth 12 is 6°, and the maximum included angle between any two adjacent teeth 12 is 54°. The teeth 12 are allowed to be between these two extreme values, which reduces the difficulty of production and assembly.

[0058] like Figure 9 As shown, the control circuit includes a main circuit, X pre-drive circuits, and X inverter circuits. The main circuit generates X sets of pulse width modulation (PWM) signals. The X pre-drive circuits, connected to the main circuit, receive the X sets of PWM signals and output corresponding X sets of power drive signals. The X inverter circuits have their power supply terminals connected to a DC power source, their output terminals connected to X stator windings, and their controlled terminals connected to the signal output terminals of the X pre-drive circuits. The X inverter circuits convert the received DC power source into X independent alternating voltages based on the X sets of power drive signals. Each alternating voltage drives one stator winding. There is a certain phase difference between any two adjacent alternating voltages.

[0059] Among them, X pre-drive circuits and X inverter circuits correspond to X phase windings; the function of the inverter circuit is to convert the input DC power supply into alternating voltage. The inverter circuit can be composed of a bridge structure composed of switching transistors, such as an H-bridge full-bridge topology composed of four power switching devices, such as MOSFET, IGBT and transistor.

[0060] Among them, the pulse width modulation signal refers to the logic level signal generated by the main circuit whose duty cycle changes regularly with time. This pulse width modulation signal is usually a low voltage (such as 3.3V or 5V) and low current weak signal. It carries modulation information such as frequency, phase and amplitude used to control the inverter output waveform, but its driving capability is insufficient to directly drive high-power switching transistors.

[0061] The power drive signal refers to the high-voltage control signal output by the pre-drive circuit after amplifying the voltage, enhancing the current, and shifting the level of the aforementioned pulse width modulation signal. This power drive signal has a high voltage amplitude (e.g., 10V-15V) and a strong instantaneous current output capability, which can overcome the gate capacitance effect of the power switch and ensure that the power switch can quickly enter the fully on or off state.

[0062] In this embodiment, the alternating voltage is the form of electrical energy output after conversion by the inverter circuit, used to drive the load.

[0063] In one feasible implementation, the main circuit is configured to output X groups of pulse width modulation (PWM) signals. These X groups of PWM signals can be generated by a microcontroller with multiple PWM output channels, with the output timing and waveform of each channel programmed. Alternatively, multiple independent oscillators and phase-shifting circuits can be used to generate logic control signals with specific phase relationships.

[0064] The power supply terminals of the X inverter circuits are used to connect to a DC power source. This DC power source can be directly generated by connecting an external AC power source through the rectifier circuit built into the control circuit, or it can be a DC power source input after being rectified and filtered by an external rectifier circuit (such as an external power adapter or switching power supply module) connected to an AC power source. Furthermore, the DC power source can also be a pure DC power source directly provided by a battery pack, lithium battery pack, supercapacitor, or photovoltaic power generation unit. In this way, this control circuit can flexibly adapt to various application scenarios such as mains power supply, industrial DC bus power supply, and mobile battery power supply.

[0065] In this architecture, X pre-drive circuits are connected between the main circuit and X inverter circuits. The controlled terminals of the X inverter circuits are connected one-to-one with the signal output terminals of the X pre-drive circuits, while the input terminals of the X pre-drive circuits are connected one-to-one with the multiple signal output terminals of the main circuit. Each inverter circuit converts the DC power supply into an alternating voltage based on the power drive signal it receives from the corresponding pre-drive circuit. For example, each inverter circuit can consist of an H-bridge composed of four switching transistors. In this architecture, the main circuit first outputs X sets of pulse width modulation signals containing complementary logic. After level shifting and power amplification by the corresponding pre-drive circuits, the X sets of pulse width modulation signals form X sets of power drive signals that can drive the gates of the switching transistors, thereby periodically turning the switching transistors on and off, and generating an alternating voltage at the output.

[0066] It should be noted that each pre-drive circuit is used to receive a set of pulse width modulation signals and output a corresponding set of power drive signals. Accordingly, the pre-drive circuit can have multiple independent units to receive multiple pulse width modulation signals from a set of pulse width modulation signals respectively.

[0067] There is a certain phase difference between each pair of alternating voltages, which can be achieved through the clock management unit or timer module inside the main circuit. By precisely delaying the start time of each pulse width modulation signal, the relative phase of each power drive signal after amplification by the pre-drive circuit is indirectly controlled. For example, a specific delay value can be set for each pulse width modulation signal through software programming to ensure that the final output alternating voltage meets the preset phase relationship.

[0068] Optionally, the specific number of pulse width modulation (PWM) signals in each group depends on the number of switching transistors that need to be controlled in each inverter circuit. For example, if the inverter circuit is a half-bridge structure and needs to control two switching transistors, then each group of PWM signals includes two PWM signals, which are processed by the pre-drive circuit to output two power drive signals to control the on / off state of the two bridge arm switching transistors respectively. If the inverter circuit is a full-bridge (H-bridge) structure and needs to control four switching transistors, then each group of PWM signals includes four PWM signals, which are converted into four power drive signals by the pre-drive circuit to control the on / off state of the four bridge arm switching transistors respectively.

[0069] Understandably, this control circuit can be matched according to the number of phases of the DC asynchronous motor. For example, if the DC asynchronous motor has two phases, the main circuit outputs two sets of pulse width modulation signals, which are amplified by two pre-drive circuits and then output as two sets of power drive signals to drive two inverter circuits. These two inverter circuits generate two alternating voltages with a certain phase difference to control the energization of two independent windings of the motor stator. Similarly, if the motor has X phases, then X inverter circuits (and their corresponding pre-drive circuits) are configured for independent driving.

[0070] In its working principle, this control circuit modulates the DC power supply into X independent alternating voltages with specific phase differences (e.g., 180 / X degrees), which are then applied to X stator windings. Because the windings are physically completely decoupled, the main circuit can adjust the voltage amplitude and waveform of each winding individually without causing forced electrical interference to other windings. The magnetic fields generated by each phase combine to form a rotating magnetic field in the air gap, traction or propulsion of the poleless rotor, simplifying the control algorithm.

[0071] like Figure 10 and Figure 11 As shown, the output voltage waveform timing diagrams of this control circuit under different drive configurations are displayed intuitively. Figure 2 Corresponding to the application scenario of X=2 (i.e., two-phase drive), it can be seen that "A-path alternating voltage" and "B-path alternating voltage" are two independent paths with a specific phase difference (e.g., 90 degrees, reflected in...). The sequentially lagging sinusoidal waves, together drive the synthesis of a rotating magnetic field; Figure 3 The embodiment corresponding to X=3 (i.e., three-phase drive) shows that the three alternating voltages A, B, and C exhibit a uniform phase change relationship on the time axis (reflected in the sequential lag), and a preset phase difference (e.g., 60 degrees) is maintained between adjacent voltages, thereby driving three independent stator windings to generate a continuous and smooth rotating magnetic field. Figure 2 and Figure 3 This clearly verifies the logic of this application to independently and accurately modulate multiple alternating voltages through the timing of control signals.

[0072] Working principle and effects: The DC asynchronous motor provided by this invention is powered by a sinusoidal power supply with a 90-degree phase difference in the X phase. The stator 10, with its end-to-end, opposite-phase adjacent connections, generates a rotating magnetic field in the air gap. This magnetic field cuts through the rotor 20 conductor 22, inducing a current in the conductor 22. The induced current interacts with the rotating magnetic field to generate electromagnetic torque, driving the rotor 20 to rotate.

[0073] Compared with traditional capacitor motors, the motor of this invention has reduced leakage reactance and improved power factor. Tests have verified that it can improve operating efficiency by 10%-20%, and it also has the advantages of small size and light weight.

[0074] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A DC asynchronous motor, characterized in that, include: A stator includes a plurality of teeth and a winding wound around each of the stators, the winding having two phases, two of the teeth forming a tooth group, and the stator including at least one tooth group; The rotor is a squirrel-cage structure, a non-magnetic rotor, and nested with the stator. The rotor includes an iron core, multiple conductors, and two conductive rings. Multiple conductor slots are evenly distributed circumferentially on the iron core, each slot being axially aligned with the iron core, and the conductors pass through these slots. The conductive rings are located on both sides of the iron core and are fixedly connected to both ends of each conductor. The conductors penetrate the iron core and are electrically connected to the conductive rings on both sides. The control circuit is used to output two independent power supplies, which are electrically connected to the two phase windings of the stator respectively. The control circuit synchronously supplies power to the two phase windings of the stator. Wherein, the two-phase windings are wound around the teeth to form coils, and the two teeth in each tooth group are respectively wound with coils corresponding to the two-phase windings; The coils on the teeth of the winding belonging to the same phase are connected in series end to end, and any two adjacent coils on the teeth are out-of-phase coils; The winding of phase 2 includes a reference phase winding, and the drive signal of the Y-phase winding forms a phase difference θ with the drive signal of the reference phase winding. Y The control circuit continuously adjusts the phase difference θ between each phase. Y The characteristics of the synthesized magnetic field are changed, thereby linearly changing the output torque of the motor; each phase of the two-phase winding has an independent input and output line, and the independent power supply output by the control circuit is connected to the input and output line of one phase of the winding. The minimum phase difference between the drive signal of the Y-phase winding and the drive signal of the reference phase winding is: ; The maximum phase difference between the drive signal of the Y-phase winding and the drive signal of the reference phase winding is: ; The included angle between each two adjacent teeth , ; Where θ c θ is the angle between any two adjacent teeth. c min θ is the minimum value of the included angle between two adjacent teeth. c max Z is the maximum value of the included angle between two adjacent teeth, Z is the number of teeth in a single stator, and X=2.

2. The DC asynchronous motor as described in claim 1, characterized in that, The conductor is inclined relative to the axis of the iron core, and the angle between the extension direction of the conductor and the end face of the conductive ring is an acute angle.

3. The DC asynchronous motor as described in claim 2, characterized in that, The conductive ring is a distributed conductive ring structure; The distributed conductive ring includes multiple arc segments, each arc segment having an equal radius, and every two opposite arc segments are connected to the same number of conductors. The distributed conductive rings on at least one side of the iron core are spliced ​​together to form mutually spaced circular rings.

4. The DC asynchronous motor as described in claim 3, characterized in that, The DC asynchronous motor is an internal rotor motor; the teeth surround and form a stator cavity, and the rotor is rotatably disposed in the stator cavity; a motor shaft is provided at the center of the rotor, and the motor shaft is fixedly connected to the iron core; Alternatively, the DC asynchronous motor is an external rotor motor; the rotor has an internal cavity, and the stator passes through the internal cavity; the center of the stator is connected to a support shaft via a bearing.

5. The DC asynchronous motor as described in claim 1, characterized in that, In the winding of the same phase, the coils on two adjacent teeth are spaced apart by one tooth, and the winding directions of the coils on two adjacent teeth are opposite.

6. The DC asynchronous motor as described in claim 5, characterized in that, The stator further includes a yoke; each tooth is fixedly connected to the surface of the yoke; each tooth extends radially along the yoke; Each tooth has a boot at its end, and the end of the boot facing the rotor has an arcuate surface, the axis of which coincides with the rotation center of the rotor.

Images