An inner-outer rotor hybrid permanent magnet synchronous motor

Abstract

This invention discloses a hybrid permanent magnet synchronous motor with internal and external rotors, belonging to the field of permanent magnet synchronous motor technology. It includes a housing and a drive controller module. A motor shaft is rotatably mounted inside the housing. An external rotor motor module is located on the outer wall of one end of the motor shaft, and an internal rotor motor module is located on the other end. An end cover is located at one end of the housing, mounting ears are installed on the outer wall of the housing, a fan mounting plate is installed on the outer wall of the housing, and a fan is located on the outer wall of the motor shaft. In this invention, by using surface-mounted magnets for the external rotor motor module and built-in tangentially magnetized spoke magnets for the internal rotor motor module, the hybrid motor combines the advantages of both while overcoming their respective disadvantages, improving power density, making the back electromotive force waveform closer to an ideal sine waveform, reducing motor torque ripple, improving vibration and noise reduction, and increasing power density. This allows a small frame size motor to output the power of a larger frame size motor.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet synchronous motor technology, and particularly relates to a hybrid permanent magnet synchronous motor with internal and external rotors. Background Technology

[0002] With the rapid development of power electronics technology and the improved cost-effectiveness of permanent magnet materials, permanent magnet synchronous motors have been widely used in recent years due to their advantages such as simple structure, good control performance, and high efficiency. Structurally, permanent magnet synchronous motors are generally divided into internal rotor permanent magnet synchronous motors and external rotor permanent magnet synchronous motors. Currently, most applications use internal rotor permanent magnet synchronous motors. This type of motor has a small rotor moment of inertia and a fast dynamic response speed, making it suitable for servo motors that require frequent starts and stops. In addition, internal rotor permanent magnet synchronous motors have a wide speed range, and high-speed motors with speeds exceeding 10,000 rpm often use internal rotor structures. However, the starting torque of internal rotor motors is usually relatively small, which brings certain limitations to their applications. For example, elevator drive applications require a large starting torque, and using an internal rotor motor requires a gearbox to increase the starting torque of the motor.

[0003] Traditional external rotor permanent magnet synchronous motors are placed at the center of the impeller to drive the impeller of the wind turbine. When the wind turbine needs a larger air volume and a higher speed, the motor needs to increase its power. The way to increase the power is to increase the axial length of the motor. This will face two situations. One situation is that the added part goes deep into the impeller and obstructs the airflow in the flow channel, producing a wind blockage effect, which reduces the efficiency of the wind turbine. The other situation is that the manufacturing capacity is limited and the equipment limit is reached, so it is impossible to continue to lengthen the axial length of the motor. Summary of the Invention

[0004] The purpose of this invention is to propose a hybrid permanent magnet synchronous motor with internal and external rotors to solve the problem of difficulty in increasing the power of traditional motors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a hybrid permanent magnet synchronous motor with internal and external rotors, comprising a housing and a drive controller module. A motor shaft is rotatably mounted inside the housing. An external rotor motor module is provided on the outer wall of one end of the motor shaft, and an internal rotor motor module is provided on the other end of the motor shaft. An end cover is provided on one end of the housing. Mounting ears are installed on the outer wall of the housing. A fan mounting plate is installed on the outer wall of the housing. A fan is provided on the outer wall of the motor shaft, and the fan is positioned between the external rotor motor module and the internal rotor motor module.

[0006] As a further description of the above technical solution: The outer rotor motor module and the inner rotor motor module share the same motor shaft, which is used to drive the wind turbine. The windings of the outer rotor motor module and the inner rotor motor module are interconnected.

[0007] As a further description of the above technical solution: The outer rotor motor module and the inner rotor motor module share a common drive controller module, which simultaneously drives and controls both the inner rotor motor module and the outer rotor motor module.

[0008] As a further description of the above technical solution: The outer rotor motor module is responsible for connecting to the wind turbine and driving the wind turbine to rotate, while the inner rotor motor module is responsible for providing the output of the outer rotor motor module.

[0009] As a further description of the above technical solution: The drive controller module can be installed on one side of the end cover of the inner rotor motor module, or it can be placed separately in other locations.

[0010] As a further description of the above technical solution: The outer rotor motor module magnets are surface-mounted, while the inner rotor motor module magnets are built-in tangential magnetized spokes.

[0011] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: In this invention, by using surface-mount magnets for the outer rotor motor module and built-in tangential magnetized spokes for the inner rotor motor module, the hybrid motor combines the advantages of both while overcoming their respective disadvantages, thereby improving power density, making the back electromotive force waveform more like an ideal sine waveform, reducing motor torque ripple, improving vibration and noise, and increasing power density. This allows a small frame size motor to output the power of a larger frame size motor. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the planar structure of a hybrid internal and external rotor permanent magnet synchronous motor.

[0013] Figure 2 This is a wiring diagram of the external rotor motor module, the internal rotor motor module, and the drive controller module in a hybrid permanent magnet synchronous motor with internal and external rotors.

[0014] Figure 3 This is a schematic diagram of the rotor magnet radiation structure of the inner rotor motor module in a hybrid permanent magnet synchronous motor with both inner and outer rotors.

[0015] Figure 4 This is a schematic diagram of the rotor magnet surface-mount structure of the outer rotor motor module in a hybrid permanent magnet synchronous motor with both inner and outer rotors.

[0016] Legend: 1. External rotor motor module; 2. Mounting ear; 3. Internal rotor motor module; 4. End cover; 5. Fan; 6. Motor shaft; 7. Fan wheel mounting plate; 8. Housing; 9. Drive controller module. Detailed Implementation

[0017] 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 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 are within the scope of protection of the present invention.

[0018] Please see Figure 1 - Figure 4 The present invention provides a technical solution: a hybrid permanent magnet synchronous motor with internal and external rotors, including a housing 8 and a drive controller module 9. A motor shaft 6 is rotatably mounted inside the housing 8. An external rotor motor module 1 is provided on the outer wall of one end of the motor shaft 6, and an internal rotor motor module 3 is provided on the other end of the motor shaft 6. An end cover 4 is provided on one end of the housing 8. A mounting ear 2 is installed on the outer wall of the housing 8. A fan wheel mounting plate 7 is installed on the outer wall of the housing 8. A fan 5 is provided on the outer wall of the motor shaft 6, and the fan 5 is located between the external rotor motor module 1 and the internal rotor motor module 3. The outer rotor motor module 1 and the inner rotor motor module 3 share the same motor shaft 6, which is used to drive the wind turbine. The windings of the outer rotor motor module 1 and the inner rotor motor module 3 are interconnected. The outer rotor motor module 1 and the inner rotor motor module 3 share a drive controller module 9, which drives and controls both the inner rotor motor module 3 and the outer rotor motor module 1. The outer rotor motor module 1 is responsible for connecting to the wind turbine and driving it to rotate. The inner rotor motor module 3 is responsible for providing the output to the outer rotor motor module 1. The drive controller module 9 can be installed on one side of the end cover of the inner rotor motor module 3 or placed in other locations. The magnets of the outer rotor motor module 1 are surface-mounted, while the magnets of the inner rotor motor module 3 are built-in tangential magnetized spokes.

[0019] The specific implementation is as follows: During assembly, the head of the stator U1 winding is used as the U-phase winding lead-out terminal, and the tail of the stator U1 winding is connected to the head of the stator U2 winding; the head of the stator V1 winding is used as the V-phase winding lead-out terminal, and the tail of the stator V1 winding is connected to the head of the stator V2 winding; the head of the stator W1 winding is used as the W-phase winding lead-out terminal, and the tail of the stator W1 winding is connected to the head of the stator W2 winding; the tails of the stator U2 winding, the stator V2 winding, and the stator W2 winding are connected to complete the stator winding connection. After the winding connection is completed and the device is put into use, the stator current detection module acquires the three-phase stator current of the joint motor in real time, and the encoder acquires the current rotor angle of the joint motor. The three-phase current is processed by the Clark transformation module to obtain the current components in the stationary coordinate system. Based on the current rotor angle of the motor, the current components in the stationary coordinate system are subjected to Park transformation to obtain the d-axis current and q-axis current in the two-phase synchronous rotating coordinate system. The stator current is calculated by the speed loop and the PI regulator. The setpoint of the d-axis current loop P regulator is calculated using the maximum torque-to-current ratio algorithm. and the setpoint of the q-axis current loop PI regulator ;

[0020] In the formula It is a permanent magnet flux linkage. , The inductances are d-axis and q-axis, respectively. The d-axis current value in the two-phase synchronous rotating coordinate system is compared with the given d-axis current value, and the difference is used as the input of the d-axis current loop FI regulator. The q-axis current value in the two-phase synchronous rotating coordinate system is compared with the given q-axis current value, and the difference is used as the input of the q-axis current loop PI regulator. After calculation by the current loop PI regulator, the output voltages of the d-axis and q-axis current loop PI regulators are obtained respectively. According to the rotor angle of the motor, the output voltage of the current loop PI regulator is subjected to Park inverse transformation to obtain the voltage component in the stationary coordinate system. Then, it is passed through the space pulse modulation module to form a three-phase PWM wave signal. The three-phase PWM wave signal controls the inverter power amplifier circuit to work normally, and the inverter outputs three-phase voltage to drive the joint motor to run. The d-axis current value in the two-phase synchronous rotating coordinate system is compared with the given d-axis current value, and the difference is used as the input of the d-axis current loop PI regulator. The q-axis current value in the two-phase synchronous rotating coordinate system is compared with the given q-axis current value, and the difference is used as the input of the q-axis current loop PI regulator. After calculation by the current loop PI regulator, the output voltages of the d-axis and q-axis current loop PI regulators are obtained respectively. Based on the rotor angle of the motor, the output voltage of the current loop PI regulator is subjected to inverse Park transform to obtain the voltage component in the stationary coordinate system. This component is then processed by a space pulse modulation module to form a three-phase PWM wave signal. The three-phase PWM wave signal controls the normal operation of the inverter power amplifier circuit, and the inverter outputs a three-phase voltage to drive the joint motor to rotate. The steady-state voltage equation of the permanent magnet synchronous motor in the rotor magnetic field-oriented synchronous rotating coordinate system is: (one)

[0021] The electromagnetic torque equation of a permanent magnet synchronous motor is: (two)

[0022] In equations (i) and (ii), Here, is the output voltage of the d-axis current regulator, is the output voltage of the q-axis current regulator, and is the actual feedback value of the d-axis current. This represents the actual feedback value of the q-axis current, where R is the stator resistance. , Let be the d-axis and q-axis inductances, respectively, and ω be the electric angular velocity of the motor. denoted as , where is the permanent magnet flux linkage; e is the back electromotive force generated by the permanent magnet flux linkage in the winding. This represents the number of pole pairs of the motor. Based on the stator three-phase winding configuration, the steady-state voltage equation of the motor of this invention in the synchronous rotating coordinate system is as follows: (three)

[0023] The electromagnetic torque equation of the motor of this invention is as follows: (Four)

[0024] When assembling the motors, the back EMFs of the two motors are adjusted to be in phase, then in formulas (iii) and (iv)... Since the angle is close to zero, the steady-state voltage equation of the motor of this invention in the synchronous rotating coordinate system is obtained as follows: (five)

[0025] The electromagnetic torque equation of the motor of this invention is as follows: (six)

[0026] In equations (iii) to (vi), The output voltage of the d-axis current regulator. This is the output voltage of the q-axis current regulator. This is the actual feedback value of the d-axis current. This represents the actual feedback value of the q-axis current, where R is the stator resistance. , These are the d-axis and q-axis inductances of the internal rotor motor, respectively. , Let be the d-axis and q-axis inductances of the external rotor motor, respectively, and ω be the electric angular velocity of the motor. For the permanent magnet flux linkage of an internal rotor motor, For external rotor motor permanent magnet flux linkage, This refers to the back electromotive force generated in the windings by the permanent magnet flux linkage of an internal rotor motor. This refers to the back electromotive force generated in the windings by the permanent magnet flux linkage of an external rotor motor. This represents the number of pole pairs of the motor. Back EMF of internal rotor motor Back EMF of internal rotor motor The phase difference; If the back EMFs of the two motors are adjusted to be in phase, then in formulas (iii) and (iv) Since the angle is close to zero, it can be seen from the formula that the electromagnetic torque generated by the hybrid motor is the sum of the electromagnetic torques generated by the two motors, which ensures that the working efficiency of the motor of the present invention is basically the same as that of the two motors.

[0027] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hybrid permanent magnet synchronous motor with internal and external rotors, comprising: The housing (8) and drive controller module (9) are provided. A motor shaft (6) is rotatably installed inside the housing (8). An outer rotor motor module (1) is provided on the outer wall of one end of the motor shaft (6), and an inner rotor motor module (3) is provided on the other end of the motor shaft (6). The housing (8) is characterized by having an end cap (4) on one end, an mounting ear (2) on the outer wall of the housing (8), a fan wheel mounting plate (7) on the outer wall of the housing (8), and a fan (5) on the outer wall of the motor shaft (6), which is located between the outer rotor motor module (1) and the inner rotor motor module (3).

2. The hybrid permanent magnet synchronous motor with internal and external rotors according to claim 1, characterized in that, The outer rotor motor module (1) and the inner rotor motor module (3) share the same motor shaft (6), and the motor shaft (6) is used to drive the wind turbine. The winding parts of the outer rotor motor module (1) and the inner rotor motor module (3) are interconnected.

3. The hybrid permanent magnet synchronous motor with internal and external rotors according to claim 2, characterized in that, The outer rotor motor module (1) and the inner rotor motor module (3) share a drive controller module (9), which simultaneously drives and controls the inner rotor motor module (3) and the outer rotor motor module (1).

4. A hybrid permanent magnet synchronous motor with internal and external rotors according to claim 3, characterized in that, The outer rotor motor module (1) is responsible for connecting to the wind turbine and driving the wind turbine to rotate, while the inner rotor motor module (3) is responsible for providing the output of the outer rotor motor module (1).

5. A hybrid permanent magnet synchronous motor with internal and external rotors according to claim 4, characterized in that, The drive controller module (9) can be installed on one side of the end cover of the inner rotor motor module (3), or it can be placed separately in other locations.

6. A hybrid permanent magnet synchronous motor with internal and external rotors according to claim 5, characterized in that, The magnets of the outer rotor motor module (1) are surface-mounted, and the magnets of the inner rotor motor module (3) are built-in tangential magnetized spokes.

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