CN117526658A

CN117526658A - Hybrid non-magnetic motor

Info

Publication number: CN117526658A
Application number: CN202311824064.9A
Authority: CN
Inventors: 科兹洛夫·伊利亚·尼古拉耶维奇; 叶戈罗夫·阿列克谢; 亚历山大·别罗索夫; 谢军
Original assignee: Houhua Tianjin Power Technology Co ltd
Current assignee: Houhua Tianjin Power Technology Co ltd
Priority date: 2023-12-28
Filing date: 2023-12-28
Publication date: 2024-02-06
Anticipated expiration: 2043-12-28
Also published as: CN117526658B

Abstract

The application provides a hybrid non-magnetic motor, which comprises a motor shell, a fixed shaft, an annular stator, an annular rotor and a squirrel cage rotor, wherein the motor shell is of a hollow cylindrical cavity structure, the motor shell is coaxially sleeved on the fixed shaft and is rotationally connected, and the annular stator is arranged on the fixed shaft in the motor shell; an annular rotor is fixedly arranged in the motor shell corresponding to the periphery of the annular stator, and a squirrel-cage rotor is fixedly nested in the annular rotor. Compared with a traditional synchronous reactance motor, the rotor structure has the advantages that the annular rotor is additionally provided with the squirrel-cage winding, higher starting torque can be generated, and starting current in the stator winding is reduced. The method provides possibility for shortening the output time from the rotor rotating speed to the rated working condition and reducing the thermal effect of starting current on stator winding insulation, and can improve the service life of the motor.

Description

Hybrid non-magnetic motor

Technical Field

The application belongs to the field of electric vehicle motors, and particularly relates to a hybrid non-magnetic motor.

Background

The method of converting electromagnetic energy into mechanical energy has been widely used in asynchronous motors and synchronous reactance motors. Currently, electric bicycles and electric motorcycles are mainly driven by brushless direct current motors. The core component of the rotor of the brushless direct current motor is a permanent magnet, and the sensor for detecting the rotating position of the rotor is a Hall magneto-sensitive element. The permanent magnet used in the motor is made of rare earth materials, which are very expensive and rare, and in addition, the electric vehicle has high requirements on the performances such as sensitivity and the like of the Hall sensor, so the Hall sensor suitable for the electric vehicle has high price. The two key components determine that the manufacturing cost of the motor for the electric vehicle is very high at present. The existing non-magnetic motor has the problems of high power consumption, low starting speed, large rotor inertia and the like.

No published patent document is found that is the same or similar to the present patent application.

Disclosure of Invention

The purpose of this application is to overcome prior art's shortcoming, provides a hybrid magneto, can provide good travelling performance, high controllability, reduce cost for electric vehicle.

The invention provides a hybrid non-magnetic motor which adopts the following technical scheme:

a hybrid non-magnetic motor comprises a motor shell, a fixed shaft, an annular stator, an annular rotor and a squirrel-cage rotor, wherein the motor shell is of a hollow cylindrical cavity structure, the motor shell is coaxially sleeved on the fixed shaft and is rotationally connected, and the annular stator is arranged on the fixed shaft in the motor shell; an annular rotor is fixedly arranged in the motor shell corresponding to the periphery of the annular stator, and a squirrel-cage rotor is fixedly nested in the annular rotor.

By adopting the technical scheme, compared with the synchronous reactance motor in the traditional form, the technical scheme of the application has the advantages that the squirrel-cage winding is additionally arranged on the annular rotor in the rotor structure, so that higher starting torque can be generated, and the starting current required by the stator winding is further reduced. Meanwhile, the method provides possibility for shortening the output time from the rotor rotating speed to the rated working condition and reducing the thermal effect of starting current on stator winding insulation, and can improve the service life of the motor.

Furthermore, a plurality of groups of axial penetrating cavities are uniformly arranged in the annular rotor.

Through adopting above-mentioned technical scheme, utilize the annular rotor to go up to set up and run through the die cavity and produce magnetic resistance in annular rotor to the drive annular rotor is rotatory, and the fretwork can also lighten self weight, guarantees good acceleration and deceleration control performance.

Further, the squirrel-cage rotor comprises copper wires and copper rings, the copper wires are uniformly arranged in corresponding penetrating cavities at intervals, and two ends of each copper wire penetrate out of two ends of each penetrating cavity respectively; and copper rings are respectively arranged at two axial ends of the annular rotor, and are fixedly connected with the ends of the copper wires at the corresponding ends.

By adopting the technical scheme, the squirrel-cage rotor is used as an additional short-circuit winding, the torque is increased, and the acceleration of the transient process is assisted, specifically, when the rotor and the stator field synchronously rotate, no current exists in the lead wire of the stator winding. When the supply frequency of the stator windings changes, the rotation frequency cannot change suddenly, which will be smaller or larger than the rotation frequency of the stator field. As a result of this frequency difference, currents and additional torque are generated in the wires of the squirrel cage windings. If the rotational speed of the rotor is less than the rotational speed of the stator field, the torque is accelerated, and if the opposite is the braking torque.

Furthermore, a plurality of groups of axial through grooves are formed in the annular stator, three-phase windings are arranged in the through grooves, and the three-phase windings are connected with three-phase alternating-current voltage source wires through wires.

By adopting the technical scheme, the three-phase windings are arranged in the annular stator, current is introduced into the three-phase windings to generate a magnetic field, and the number of the three-phase windings is matched with the number of poles of a multi-pole magnetic system formed when the rotor rotates.

Further, the annular rotor is made of laminated multi-layer rotor sheets, the annular stator is made of laminated multi-layer stator sheets, and the rotor sheets of the annular rotor and the stator sheets of the annular stator are overlapped layer by layer along the axial direction of the fixed shaft.

Through adopting above-mentioned technical scheme, annular rotor and annular rotor all adopt the lamination electrical steel sheet that is provided with hollow out construction to make, and electrical steel sheet is the material that is commonly used for making motor core, and self structural strength is high, and horizontal layered rotor structure has more stable circumference performance in the rotation.

Further, the ends of the penetrating cavities are all arranged at the same circumferential position of the rotor sheet.

Through adopting above-mentioned technical scheme, the tip position that runs through the die cavity is used for spacing installation copper wire, and copper wire and fixed axle coaxial setting, and every copper wire is the same with the distance of fixed axle for constitute squirrel cage winding.

Further, the penetrating cavity comprises a plurality of penetrating cavities which are arranged at equal intervals from inside to outside, each penetrating cavity is of a symmetrical broken line groove structure, and two ends of the broken line groove structure are arranged at the same circumferential position of the annular rotor.

Through adopting above-mentioned technical scheme, the hollow out construction of multilayer through cavity can lighten rotor weight, reduces inertia to symmetrical structure processing positioning accuracy is high, is convenient for install the squirrel cage.

A controller circuit is used for any motor, the controller circuit comprises a controller, an inverter, a storage battery and a phase line, a control circuit of the controller is connected to the inverter, the inverter is respectively and electrically connected with the storage battery, an output line of the inverter is connected with the phase line of the motor, a rotor is arranged in a magnetic field range generated by the phase line, and the rotor can rotate under the driving action of the magnetic field.

By adopting the technical scheme, the phase line connected with the stator winding can generate a magnetic field, the action of the motor is derived from an algorithm built in the controller, the controller generates a control signal, and the frequency of the power supply voltage of the phase line of the stator winding is changed, so that the rotating speed of the rotor is controlled.

Furthermore, the controller is also connected with a position sensor, and the position of the rotor is acquired by adopting a mode of taking voltage differences by three resistors which are respectively connected with the MOS tube in series in the inverter, and the voltage signals are transmitted to the controller.

By adopting the technical scheme, the position sensor does not need a Hall sensor, the cost is effectively reduced, the built-in algorithm of the controller is based on a resistor connected under a field effect tube (also called an MOS tube), when current passes through the resistor, a voltage difference signal is generated, the signal is transmitted to a CPU controller, and the CPU sends out instructions of corresponding MOS on and off, so that the position of the rotor is perceived.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the synchronous reactance motor with the extra squirrel-cage windings is manufactured on the basis of an asynchronous motor, has the same size as the asynchronous motor, is installed and connected with the same size, is convenient to replace the existing motor to be installed on an electric vehicle, does not need to carry out extra design transformation on the vehicle body, and is convenient to popularize and apply.

2. The application relates to a synchronous reluctance motor with an additional squirrel-cage winding, which can generate higher rotor torque and reduce stator winding starting current compared with a traditional synchronous reluctance motor. The method provides possibility for shortening the output time from the rotor rotating speed to the rated working condition and reducing the thermal effect of starting current on stator winding insulation, and prolongs the service life of the motor.

3. Compared with other asynchronous motors, the rotor design structure with the axial air barrier can reduce the copper weight of the squirrel cage winding and reduce the weight of rotor silicon steel.

4. For 500W motors, the energy efficiency (efficiency) value of the motor system of the present application is at least 80%, and for powers above 1000W the efficiency has exceeded 84%, which is significantly higher than for an asynchronous motor of equal power and same size and a synchronous motor with field windings on the rotor, which provides a higher specific power index (W/kg).

5. The present application, through vector control, can save power (in some cases-up to 60%) because the controller transmits energy to the motor that maintains a given speed demand most of the time.

Drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of the motor.

Fig. 2 is a schematic view of a middle section perspective structure of the motor.

Fig. 3 is an enlarged partial schematic view of the portion B in fig. 2.

Fig. 4 is a schematic structural view of the annular rotor.

Fig. 5 is an enlarged partial schematic view of the portion C in fig. 4.

Fig. 6 is a schematic diagram of coordinate conversion from the fixed axes α, β of the stator to the rotation axes d, q of the rotor.

Fig. 7 is a comparative schematic diagram of a synchronous-reactance motor rotor transition from 350 rpm to 470 rpm with squirrel cage windings and no windings.

Fig. 8 is a schematic diagram of a control circuit in an embodiment.

Fig. 9 is a schematic diagram of a phase change from three phases to two phases.

Reference numerals:

1. a motor housing; 11. a hub; 12. an end cap; 13. a bearing assembly; 2. a fixed shaft; 3. an annular rotor; 311. a rotor laminate; 312. penetrating through the cavity; 3121. a first through cavity; 3122. a second through cavity; 3123. a third through cavity; 4. an annular stator; 41. a stator laminate; 42. a three-phase winding; 5. a squirrel cage rotor; 51. a copper ring; 52. copper wires.

Detailed Description

The present application is described in further detail below with reference to the accompanying drawings.

Referring to fig. 1 and 2, an end cover 12 is fixedly arranged at two axial ends of a hub 11, the end cover 12 is in sealing connection with the hub 11, the center of the end cover 12 is provided with a shaft hole for a fixed shaft 2 to pass through, a bearing component 13 is arranged in the end cover 12 at the position of the shaft hole, the end cover 12 is connected with the fixed shaft 2 through the bearing component 13, and the hub 11, the end cover 12 and the bearing component 13 form a motor shell 1 with a hollow cylindrical cavity structure;

the fixed shaft 2 is coaxially arranged in the motor shell 1, and both ends of the fixed shaft 2 extend to the outer side of the end cover 12 through the shaft hole; the bearing assembly 13 is capable of closing the gap between the end cap 12 and the stationary shaft 2, closing the inside of the motor housing 1.

Referring to fig. 2 and 3, an annular stator 4 is mounted on a fixed shaft 2 in a motor housing 1, a stator winding is mounted in the annular stator 4, and the stator winding is externally connected with a power supply through a wire to supply power to the stator winding so as to generate an electromagnetic field, thereby driving a rotor to drive the motor housing to rotate.

The annular stator 4 in this embodiment is an annular structure made of laminated electrical steel plates, multiple groups of through slots are uniformly arranged in the annular stator 4 at intervals along the radial direction, the through slots axially penetrate through the annular stator 4, and three-phase windings 42 are installed in the through slots, in this embodiment, the three-phase windings 42 are used as stator windings, and the three-phase windings 42 are connected with three-phase alternating voltage source phase lines and can generate a rotating electromagnetic field after being electrified.

An annular rotor 3 is fixedly arranged in a motor shell 1 corresponding to the periphery of the annular stator 4, the annular rotor 3 is formed by laminating a plurality of axially overlapped rotor sheets, the rotor sheets are made of electrical steel plates, and a plurality of groups of penetrating cavities 312 axially penetrating the annular rotor 3 are uniformly arranged in the annular rotor 3. The laterally layered rotor structure has a more stable circumferential performance in rotation, while the through cavity 312 enables to reduce the weight of the annular rotor 3, thereby reducing the rotor inertia.

The ring rotor 3 is embedded and fixed with a squirrel-cage rotor 5, and the specific structure is that copper wires 52 are axially arranged in a penetrating cavity 312 of the ring rotor 3, the distance between the copper wires 52 and the axle center of the fixed shaft 2 is the same, and two ends of the copper wires 52 respectively extend out of the axial end face of the ring rotor 3;

the two axial ends of the annular rotor 3 are respectively and coaxially provided with a copper ring 51, the copper rings 51 are fixedly connected with the ends of all copper wires 52 on the corresponding sides, the copper wires 52 and the copper rings 51 on the two ends form a cylindrical squirrel-cage winding, and when acceleration or deceleration is carried out, current and additional torque are generated in the squirrel-cage winding.

Referring to fig. 4 and 5, a plurality of groups of through cavities are uniformly distributed on the rotor sheet of the annular rotor 3 along the radial direction, each group of through cavities comprises a first through cavity 3121, a second through cavity 3122 and a third through cavity 3123 which are arranged at equal intervals from inside to outside, and the first through cavity 3121, the second through cavity 3122 and the third through cavity 3123 are symmetrical fold line groove structures; the ends of the first through-hole 3121, the second through-hole 3122, and the third through-hole 3123 are all provided on the same circumference of the rotor sheet, and the copper wire 52 is inserted in the same axial direction at the end positions of the first through-hole 3121, the second through-hole 3122, and the third through-hole 3123.

Referring to fig. 6, a rotating magnetic field is generated in the motor housing 1 by alternating current of the stator windings. Torque is generated when the rotor tries to establish its most magnetic conductive shaft (d-axis) with a magnetic field applied thereto to minimize the resistance in the magnetic circuit. In other words, the rotating magnetic field of the ring stator 4 pulls the rotor. The flux linkage amplitude of the ring stator 4 is controlled by the d-axis, while the current responsible for the torque is controlled by the q-axis, the axis leading to the motor stator.

In the rotor design discussed in this embodiment, the difference between the shaft magnetic resistances is achieved by increasing the air gap along the q-axis. The torque amplitude is proportional to the difference in longitudinal Ld and transverse Lq inductances. Thus, the greater the difference, the greater the torque generated.

The synchronous salient pole electromagnetic torque formula without excitation on the rotor is expressed as follows:

Мр = [mU2 /(2ω1 )] (1/Хq - 1/Хd ) sin 2θ,

in the formula, for the three-phase structure of the stator, m=3, ω1-rotor angular velocity, xq-inductance resistance on the q-axis of the rotor, xd-inductance resistance on the d-axis of the rotor, θ -the angle between the rotor field and the stator field of the degree of stretching of the "magnetic spring".

The extra squirrel cage windings help to accelerate rotor speed as the rotor, speed accelerates or brakes, transient when changing from one value to another. The function of the extra squirrel cage windings is represented by: torque is generated when a difference between the rotational speed of the rotor and the rotational speed of the magnetic field generated by the stator windings occurs. When the rotor rotates in synchronization with the stator field, there is no current in the copper wire of the winding, thereby increasing the run time of the battery.

Referring to fig. 7, a comparative schematic diagram of a transition from 350 rpm to 470 rpm of a synchronous-reactance motor rotor with a squirrel cage winding and a squirrel cage-less winding is shown, and the transition from 350 rpm to 470 rpm of the rotor speed is simulated by testing the effect of an additional shorting winding on the synchronous reluctance motor rotor. And, calculation experiments are performed on the idle load working conditions. The mechanical transient time of the squirrel-cage winding rotor is 85ms, and the mechanical transient time of the rotor without winding is 264ms. It is also clear from the results that the swing curve b of the rotor without the squirrel cage windings is much larger than the swing curve a of the rotor with the squirrel cage windings.

In this test, the motor was rated at 500W, the rotor outer diameter was 212mm, and the stator was a star-connected traction motor. Through experiments, the motor has the following advantages: the efficiency is not lower than 80 percent (the absolute value is increased by 10 percent compared with an asynchronous motor with the same outer diameter of the rotor); the inertia of the rotor is reduced, the asynchronous motor is 0.078 kg m2, the synchronous reactance motor is 0.07 kg m2, and the weight is lighter compared with the motor with the same power.

Referring to fig. 8, for the motor system control structure of the present embodiment, the motor system control structure includes a controller, an inverter, a storage battery and a phase line,

the control circuit of the controller is connected to the inverter, the inverter is electrically connected with the storage battery respectively, the output line of the inverter is connected with the phase line of the motor, the phase line can generate a magnetic field, a rotor is arranged in the magnetic field range generated by the phase line, and the rotor can rotate under the drive action of the magnetic field;

the controller comprises a CPU module and an electric bicycle speed control circuit, wherein a control line of the CPU module is connected to the electric bicycle speed control circuit, and the controller can change the frequency of the power supply voltage of the phase line of the stator winding so as to control the rotation speed of the rotor. The action of the motor is derived from an algorithm built in a CPU of the controller, the stator magnetizing current id and the stator current responsible for the moment iq are controlled through a speed control circuit Accel of the electric vehicle,

the controller is connected with the position sensor, the position sensor comprises three resistors, the resistors are respectively and correspondingly connected with a group of field effect transistors (also called MOS tubes) in the inverter in series, when current passes through the resistors, a voltage difference signal is generated, the signal is transmitted to the CPU of the controller, the CPU sends out corresponding MOS on and off instructions, so that the position of the rotor is sensed, and the controller obtains a control instruction based on the information number of the position sensor.

The controller can also be connected with a flow protection circuit to further protect the stable operation of the control circuit; in addition, the controller can also be connected with a wireless communication circuit to carry out wireless transmission information or receive control instructions and the like.

The working principle of the inverter is shown in fig. 9, two-phase and three-phase change is realized through a coordinate conversion assembly, the coordinate assembly rotates an input vector by a given angle by using park conversion, and BCP_1 is turned to +theta, and BCP_2 is turned to-theta; bcp—2 maps current from fixed axes α and β to fixed axes d and q to the rotor (using rotor angle); and bcp_1 performs an inverse transformation, transitioning from setting stress along d-axis and q-axis to alpha-axis and beta-axis. The three-phase current Is used for one purpose, like the two-phase current, creating a stator current vector Is pointing in the correct direction and having the correct amplitude, simply recalculated the three-phase current into the two-phase current, and using the same control system as the two-phase device.

The technical principle of the application is as follows:

a synchronous reluctance motor with a squirrel-cage winding is added, and the squirrel-cage winding is embedded into a cavity of a rotor core in the axial direction. The squirrel cage windings help to accelerate transients when rotor speed changes from one value to another during rotor acceleration or braking. When the rotor and stator fields rotate synchronously, there is no current in the wires of the squirrel cage windings.

In order to control the rotational speed of the rotor, the frequency of the supply voltage to the stator windings is changed. When the stator winding power supply frequency changes, the rotational speed cannot change rapidly. At the initial moment this frequency will be smaller or larger than the rotational frequency of the stator magnetic field. Due to this difference in rotor speed and stator winding magnetic field, current and additional torque are generated in the wires of the additional squirrel cage windings. If the rotor rotation speed is smaller than the stator magnetic field rotation speed, the acceleration moment is the acceleration moment, and otherwise, the braking moment is the braking moment. This accelerates the transition from one rotor rotation mode to another and avoids rotor oscillations common to synchronous reactance motors.

The various technical features of the above embodiments may be combined arbitrarily. The foregoing examples illustrate only a few embodiments of the invention and are described in greater detail and are not to be construed as limiting the scope of the invention. It should be noted that modifications and improvements can be made by those skilled in the art without departing from the concept of the present invention, and are within the scope of the present invention. Accordingly, the scope of the invention should be determined by the appended claims.

Claims

1. A hybrid non-magnetic motor, characterized by: the motor comprises a motor shell (1), a fixed shaft (2), an annular stator (4), an annular rotor (3) and a squirrel cage rotor (5), wherein the motor shell (1) is of a hollow cylindrical cavity structure, the motor shell (1) is coaxially sleeved on the fixed shaft (2) and is rotationally connected, and the annular stator (4) is arranged on the fixed shaft (2) in the motor shell (1); an annular rotor (3) is fixedly arranged in a motor shell (1) corresponding to the periphery of the annular stator (4), and a squirrel-cage rotor (5) is nested and fixedly arranged in the annular rotor (3).

2. The hybrid magneto of claim 1, wherein: a plurality of groups of axial penetrating cavities (312) are uniformly arranged in the annular rotor (3).

3. The hybrid magneto of claim 2, wherein: the squirrel-cage rotor (5) comprises copper wires (52) and copper rings (51), wherein the copper wires (52) are uniformly arranged in corresponding penetrating cavities (312) at intervals, and two ends of each copper wire (52) respectively penetrate out of two ends of each penetrating cavity (312); two copper rings (51) are respectively arranged at the two axial ends of the annular rotor (3), and the copper rings (51) are fixedly connected with the ends of copper wires (52) at the corresponding ends.

4. The hybrid magneto of claim 1, wherein: a plurality of groups of axial through grooves are formed in the annular stator (4), three-phase windings (42) are arranged in the through grooves, and the three-phase windings (42) are connected with three-phase alternating-current voltage source wires through wires.

5. The hybrid magneto of claim 1, wherein: the annular rotor (3) is made of a plurality of layers of rotor sheets in a laminated mode, the annular stator (4) is made of a plurality of layers of stator sheets in a laminated mode, and the rotor sheets of the annular rotor (3) and the stator sheets of the annular stator (4) are overlapped layer by layer along the axial direction of the fixed shaft (2).

6. The hybrid magneto of claim 2, wherein: the ends of the through cavities (312) are all arranged at the same circumferential position of the rotor sheet.

7. The hybrid magneto of claim 6, wherein: the penetrating cavity (312) comprises a plurality of penetrating cavities which are arranged at equal intervals from inside to outside, each penetrating cavity is of a symmetrical broken line groove structure, and two ends of the broken line groove structure are arranged at the same circumferential position of the annular rotor (3).

8. A non-magnetic motor control circuit, characterized in that: the hybrid magneto-less motor according to any one of claims 1 to 7, wherein the control circuit comprises a controller, an inverter, a storage battery and a phase line, a control line of the controller is connected to the inverter, the inverters are respectively and electrically connected with the storage battery, an output line of the inverter is connected with the phase line of the motor, a rotor is arranged in a magnetic field range generated by the phase line, and the rotor can rotate under the driving action of the magnetic field.

9. The magneto-less control circuit of claim 8, wherein: the controller is also connected with a position sensor, and the position of the rotor is acquired by adopting a mode of taking voltage differences by three resistors which are respectively connected with MOS tubes in series in the inverter, and the voltage signals are transmitted to the controller.