A multi-excitation source partition level variable-pole type axial magnetic field permanent magnet motor and variable working condition driving control system

Abstract

The application discloses a multi-excitation-source partition-level variable-pole type axial magnetic field permanent magnet motor and a variable working condition driving control system, mainly comprising two parts of a main magnetic pole and an auxiliary magnetic pole, wherein the main magnetic pole is responsible for providing a main magnetic flux of an air gap and is connected in series with a double-stator magnetic circuit; the auxiliary magnetic pole is responsible for adjusting an air gap magnetic field and is connected in parallel with the double-stator magnetic circuit; the main magnetic pole and the auxiliary magnetic pole magnetic flux jointly constitute the air gap magnetic field, and the magnetic flux path of the auxiliary magnetic pole can be controlled by controlling the current size added to the excitation winding, thereby adjusting the air gap magnetic flux, widening the motor speed regulation range, realizing the multi-variable working condition operation of the motor, and further reducing the torque ripple, improving the power density, realizing the high-efficiency and high-reliability operation of the motor, and improving the dynamic working performance of the motor.

Description

Technical Field

[0001] This invention relates to an axial magnetic field permanent magnet motor, and more particularly to a multi-excitation source magnetic pole partition type dual-stator axial magnetic field controllable permanent magnet motor and its drive control, belonging to the field of special motor technology. Background Technology

[0002] As a crucial sector for "carbon neutrality, carbon peaking," and a low-carbon economy, the "decarbonization" and "green efficiency" of the transportation industry have become hot topics and focal points. Significantly increasing the proportion of new energy vehicles is a key measure to effectively control carbon dioxide emissions from gasoline-powered vehicles. As the core of the powertrain system of electric vehicles, the drive motor's torque density, mechanical strength, speed ratio, noise, cost, efficiency, and control strategy complexity directly affect vehicle performance. Permanent magnet motors, due to their advantages of high torque density, high power factor, and high efficiency, have become the preferred choice for electric drive vehicle motors.

[0003] In terms of topology, permanent magnet motors are divided into radial magnetic field permanent magnet motors and axial magnetic field permanent magnet motors. In axial magnetic field permanent magnet motors, the stator and rotor are parallel to each other along the axial direction, the air gap is planar, and the air gap magnetic flux is distributed along the motor axis and perpendicular to the stator and rotor. In recent years, many scholars at home and abroad have conducted in-depth research on the topology of axial magnetic field permanent magnet motors, focusing on high power density, high efficiency, emphasis on magnetic capability, and high reliability. To improve the efficiency of axial motors, some scholars have proposed a yokeless stator-segmented axial motor to reduce core losses and winding copper losses, thereby increasing power density. For example, the P400R series yokeless axial magnetic field permanent magnet motor from YASA in the UK achieves a power density of 5.7 kW / kg; the AXF185 series yokeless axial magnetic field permanent magnet motor from MagnaX in Belgium achieves a power density of 12.5 kW / kg. To further reduce motor losses, some scholars have proposed coreless axial motors, where the stator has only concentrated windings, eliminating core losses and resulting in even higher efficiency. Furthermore, amorphous alloy axial motors show significantly reduced iron losses and even more significant efficiency improvements. To improve the reliability of axial motors, some scholars have proposed an asymmetric dual three-phase axial motor, which improves the fault tolerance of axial motors.

[0004] It is evident that, due to its unique and compact topology, high torque / power density, and superior and convenient heat dissipation capabilities, the axial magnetic field permanent magnet motor (AMP) offers significant advantages in electric vehicle drive motor applications, whether centralized or distributed, where space is of the essence. However, the short magnetic circuit, pronounced magnetization effect, and high air gap magnetic flux density of traditional AMP motors make field weakening difficult, resulting in a narrow constant power operating range and severely limited speed regulation range. This makes them unsuitable for meeting the diverse operating conditions and wide speed regulation range requirements of electric vehicles. Although hybrid excitation AMP motors ("A Hybrid Excitation AMP Synchronous Motor Structure", Patent No.: ZL 202011388266.X) and AMP memory motors ("An Axial Magnetic Flux Switching Surface-Modulated Permanent Magnet Memory Motor", Patent No.: ZL 201310432668.9) have been proposed, problems such as limited magnetic adjustment range, low efficiency, and magnetic fatigue of adjustable permanent magnets still exist. Therefore, the targeted design and development of new structures for axial magnetic field permanent magnet motors is of great theoretical and economic significance for effectively expanding the speed range and improving the efficiency of this type of motor. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in traditional axial magnetic field permanent magnet motors by proposing a multi-excitation source pole-partitioned dual-stator axial magnetic field adjustable permanent magnet motor. Utilizing the controllable effects of variable reluctance and leakage flux, a unique pole-partitioned topology is constructed, mainly comprising two parts: a main pole and an auxiliary pole. The main pole provides the main air gap flux and is connected in series with the dual-stator magnetic circuit; the auxiliary pole regulates the air gap magnetic field and is connected in parallel with the dual-stator magnetic circuit. The fluxes of the main and auxiliary poles together constitute the air gap magnetic field. The flux path of the auxiliary pole can be controlled by adjusting the current applied to the excitation winding, thereby adjusting the air gap flux, widening the motor speed range, enabling multi-condition operation, further reducing torque ripple, increasing power density, achieving high-efficiency and high-reliability operation, and improving the dynamic performance of the motor.

[0006] The technical solution of the present invention is as follows: a multi-excitation source magnetic pole partitioning type dual-stator axial magnetic field controllable permanent magnet motor, comprising a first stator (1), a second stator (2), a first permanent magnet (3), a second permanent magnet (4), a third permanent magnet (5), a fourth permanent magnet (6), a first rotor yoke (7), a second rotor yoke (8), a first armature winding (9), a second armature winding (10), a first excitation winding (11), a second excitation winding (12), a first air gap (13), and a second air gap (14). The first stator (1) and the second stator (2) are symmetrically placed on the outside of the motor with their slots facing inward; the first armature winding (9) is wound in a distributed structure on the stator teeth of the first stator (1), the second armature winding (10) is wound in a distributed structure on the stator teeth of the second stator (2), the first excitation winding (11) is wound in a concentrated structure on the stator teeth of the first stator (1), and the second excitation winding (12) is wound in a concentrated structure on the stator teeth of the second stator (2); the first rotor yoke (7) The second rotor yoke (8) is symmetrically placed inside the motor with its slots facing inward. Multiple fan-shaped slots are evenly distributed inside the first rotor yoke (7), and a third permanent magnet (5) is embedded in each fan-shaped slot. Similarly, multiple fan-shaped slots are evenly distributed inside the second rotor yoke (8), and a fourth permanent magnet (6) is embedded in each fan-shaped slot. The fan-shaped slots on the first rotor yoke (7) and the second rotor yoke (8) are completely symmetrical. A first permanent magnet (3) and a second permanent magnet (4) are placed between the first rotor yoke (7) and the second rotor yoke (8). The first permanent magnet (3) and the second permanent magnet (4) are spaced apart and arranged circumferentially staggered from the third permanent magnet (5) and the fourth permanent magnet (6); a first air gap (13) is provided between the inner side of the first stator (1) and the outer side of the first rotor yoke (7), and a second air gap (14) is provided between the inner side of the second stator (2) and the outer side of the second rotor yoke (8); the axis of the first stator (1) and the second stator (2) coincides with the axis of rotation of the first rotor yoke (7) and the second rotor yoke (8).

[0007] Furthermore, the stator cores of the first stator (1) and the second stator (2) are made of silicon steel sheets wound in the circumferential direction, and the stator facing the rotor is stator teeth; the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) are made of silicon steel sheets wound in the circumferential direction; when designing a high-speed multi-excitation source magnetic pole partition type double stator axial magnetic field controllable permanent magnet motor, the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) are die-cast from soft magnetic material.

[0008] Furthermore, the first armature winding (9) and the second armature winding (10) are double-layer windings and have a distributed structure with a pitch ≥ 360° / (2*p); p is the number of rotor pole pairs;

[0009] The first excitation winding (11) and the second excitation winding (12) are single-layer windings and are distributed at intervals of 120°*Z / (2*p), where Z is the number of stator slots;

[0010] The inner side of the first rotor yoke (7) has 8 evenly distributed fan-shaped slots with a depth of 3mm and an arc of 0.285*360° / (2*p), with the interval between adjacent fan-shaped slots being (1-0.285)*360° / (2*p). The inner side of the second rotor yoke (8) also has 8 evenly distributed fan-shaped slots with a depth of 3mm and an arc of 0.285*360° / (2*p), with the interval between adjacent fan-shaped slots also being (1-0.285)*360° / (2*p).

[0011] 5. Further, the first permanent magnet (3) and the second permanent magnet (4) have a pole pair number of p, and are distributed alternately with N and S along the circumferential direction. The first permanent magnet (3) and the second permanent magnet (4) are magnetized along the motor axis and in opposite directions. The third permanent magnet (5) and the fourth permanent magnet (6) are magnetized along the motor tangential direction and in opposite directions. The magnetic energy product of the first permanent magnet (3) and the second permanent magnet (4) is greater than that of the third permanent magnet (5) and the fourth permanent magnet (6). The first permanent magnet (3) and the second permanent magnet (4) are spaced apart by 0.55*360° / (2*p) and are arranged circumferentially offset from the third permanent magnet (5) and the fourth permanent magnet (6) by 0.1325*360° / (2*p).

[0012] The magnetic flux generated by the third permanent magnet (5) and the fourth permanent magnet (6) does not participate in the excitation of the air gap magnetic field when unloaded, but can enter the air gap magnetic field for excitation when loaded, thereby changing the magnetic flux of the main magnetic circuit of the motor and widening the speed regulation range of the motor. When the third permanent magnet (5) and the fourth permanent magnet (6) are AlNiCo variable permanent magnet materials, the magnetic energy product of the third permanent magnet (5) and the fourth permanent magnet (6) can be adjusted by passing DC excitation through the excitation winding.

[0013] Furthermore, hollow heat dissipation holes are provided between the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) to reduce rotor temperature and the risk of permanent magnet demagnetization through oil cooling and air cooling. An arc-shaped slot with a depth of H ≤ 3mm can be provided on the air gap side of the first rotor yoke (7) and the second rotor yoke (8) directly opposite the first permanent magnet (3) and the second permanent magnet (4) axially. This not only helps to adjust the magnetic flux of the first permanent magnet (3), the second permanent magnet (4), the third permanent magnet (5), and the fourth permanent magnet (6), but also reduces the cogging torque and axial magnetic pull of the motor.

[0014] Furthermore, when the first excitation winding (11) and the second excitation winding (12) fail, the first armature winding (9) and the second armature winding (10) can work independently without affecting the normal operation of the motor. In addition, when the armature winding fails, the excitation winding can also replace the armature winding and drive the motor with three-phase current, which improves the fault tolerance and operational reliability of the motor.

[0015] Furthermore, the first stator (1) and the second stator (2) can be offset by a certain angle α (≤120°*Z / (2*p)). By controlling the offset angle, the leakage flux and air gap magnetic flux density of the motor can be changed, thereby changing the output torque and power level of the motor.

[0016] The present invention discloses a variable operating condition drive control system for a dual-stator axial magnetic field controllable permanent magnet motor with multiple excitation sources and magnetic pole partitioning. The motor power converter is composed of four H-bridges. The input and output ends of the first excitation winding (11) and the second excitation winding (12) are respectively connected to the center point of an H-bridge arm. The input and output ends of the two sets of armature windings on the first stator (1) and the second stator (2) are respectively connected to the center point of an H-bridge arm to form an open winding structure or a double three-phase structure. The H-bridges of the first excitation winding (11) and the second excitation winding (12) are connected in series with the busbar of the open winding structure of the three-phase winding.

[0017] Furthermore, it has multiple operating modes; when the neutral points of the two sets of three-phase windings on the first stator (1) and the second stator (2) are open, the motor operates with an open winding structure; when the neutral points of the two sets of three-phase windings on the first stator (1) and the second stator (2) are connected, the motor operates with a double three-phase structure.

[0018] Furthermore, the first excitation winding (11) and the second excitation winding (12) are controlled separately by an H-bridge. By controlling the conduction of the four switching transistors, the positive and negative excitation currents can be controlled to achieve the magnetization and demagnetization of the motor's magnetic field. Moreover, when the excitation winding fails, it will not affect the control effect of the armature winding power converter.

[0019] This invention discloses a multi-excitation source, pole-partitioned, dual-stator axial magnetic field controllable permanent magnet motor, comprising two stators, an excitation winding, an armature winding, main magnetic poles, auxiliary magnetic poles, and a symmetrical double-yoke rotor core. The two stators are symmetrically positioned on the outer side of the motor, with both the excitation and armature windings wound on their teeth. The excitation winding is energized with direct current (DC), and the armature winding is energized with alternating current (AC). The symmetrical double-yoke rotor core is positioned between the two stators, with air gaps between each stator. The main magnetic poles are positioned between the two symmetrical double-yoke rotor cores and are alternately magnetized along the motor's axial direction. The auxiliary magnetic poles are embedded within the two symmetrical double-yoke rotor cores and are alternately magnetized along the motor's tangential direction.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. When the excitation winding is not working, the magnetic flux of the auxiliary magnetic pole basically does not participate in the excitation of the air gap magnetic field. When the excitation winding is working, the magnetic flux of the auxiliary magnetic pole enters the air gap and together with the magnetic flux of the main magnetic pole forms the air gap magnetic field, which can realize the magnetic flux adjustment of the air gap magnetic field and broaden the speed regulation range of the motor.

[0022] 2. The symmetrical double stator structure can balance the axial magnetic pull of the motor, improve the power density and operational reliability of the motor, and enhance the motor's heat dissipation capacity.

[0023] 3. Compared with traditional axial magnetic field permanent magnet motors, the symmetrical double yoke rotor structure design enables the motor to have anti-salient pole characteristics, and the motor can utilize reluctance torque, which is beneficial for heavy-load operation.

[0024] 4. The main magnetic poles are placed between the symmetrical double-yoke rotor cores. The hollow structure facilitates heat dissipation and allows the heat exchange medium to carry away the rotor heat.

[0025] 5. Both stators are wound with excitation windings and armature windings. When the excitation winding fails, the armature winding can work independently without affecting the normal operation of the motor. In addition, when the armature winding fails, the excitation winding can also act as the armature winding to drive the motor to operate normally, which improves the fault tolerance and operational reliability of the motor.

[0026] 6. The motor can operate with the two stators offset by a certain angle α (≤120°*Z / (2*p)). At this time, the leakage flux and air gap magnetic flux density of the motor can be changed, thereby changing the output torque and power level of the motor. Attached Figure Description

[0027] Figure 1 This is an exploded three-dimensional structural diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention.

[0028] Figure 2 This is a three-dimensional structural front view of the dual-stator axial magnetic field permanent magnet motor of the present invention.

[0029] Figure 3 This is a top view of the three-dimensional structure of the dual-stator axial magnetic field permanent magnet motor of the present invention.

[0030] Figure 4 This is an exploded view of the rotor structure of the dual-stator axial magnetic field permanent magnet motor of the present invention.

[0031] Figure 5 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when stators 1 and 2 are working simultaneously and the excitation winding is not energized.

[0032] Figure 6 This is a magnetic field distribution diagram of the stator 1 and 2 of the dual-stator axial magnetic field permanent magnet motor of the present invention when the excitation winding is energized and the stator 1 and 2 are working simultaneously.

[0033] Figure 7 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when only stator 1 is working and the excitation winding is not energized.

[0034] Figure 8 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when only stator 1 is working and the excitation winding is energized.

[0035] Figure 9 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when only stator 2 is working and the excitation winding is not energized.

[0036] Figure 10 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when only stator 2 is working and the excitation winding is energized.

[0037] Figure 11 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention, where the stator 2 is offset by an angle α, stators 1 and 2 work simultaneously and the excitation winding is not energized.

[0038] Figure 12 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention, where the stator 2 is offset by an angle α, and stators 1 and 2 work simultaneously and the excitation winding is energized.

[0039] Figure 13 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when the stator 2 is offset by an angle α, only the stator 1 is working and the excitation winding is not energized.

[0040] Figure 14 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when the stator 2 is offset by an angle α, only the stator 1 is working and the excitation winding is energized.

[0041] Figure 15 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when the stator 2 is offset by an angle α, only the stator 2 is working and the excitation winding is not energized.

[0042] Figure 16 This is a magnetic field distribution diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention when the stator 2 is offset by an angle α, only the stator 2 is working and the excitation winding is energized.

[0043] Figure 17 This is a magnetic field distribution diagram of the permanent magnets 5 and 6 of the dual-stator axial magnetic field permanent magnet motor of the present invention when they are AlNiCo and in an excited state.

[0044] Figure 18 This is a magnetic field distribution diagram of permanent magnets 5 and 6 of the dual-stator axial magnetic field permanent magnet motor of the present invention when they are AlNiCo and in a weak magnetic state.

[0045] Figure 19 This is a partial control circuit diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention operating in open winding mode.

[0046] Figure 20 This is a partial control circuit diagram of the dual-stator axial magnetic field permanent magnet motor of the present invention operating in dual three-phase mode. Detailed Implementation

[0047] like Figure 1-4 As shown, this invention discloses a multi-excitation source, pole-partitioned, dual-stator axial magnetic field controllable permanent magnet motor, comprising two stators, an excitation winding, an armature winding, main magnetic poles, auxiliary magnetic poles, and a symmetrical double-yoke rotor core. The two stators are symmetrically positioned on the outside of the motor, with both the excitation winding and armature winding wound on their stator teeth. The excitation winding is energized with direct current (DC), and the armature winding is energized with alternating current (AC). The symmetrical double-yoke rotor core is positioned between the two stators, with air gaps between each stator. The main magnetic poles are positioned between the two symmetrical double-yoke rotor cores and are alternately magnetized along the motor axial direction. The auxiliary magnetic poles are embedded inside the two symmetrical double-yoke rotor cores and are alternately magnetized along the motor tangential direction.

[0048] Scenario 1 combination Figure 5 Explanation: At this time, neither the first excitation winding (11) nor the second excitation winding (12) is energized. The first permanent magnet (3) and the second permanent magnet (4) are magnetized along the motor axis and in opposite directions. At this time, most of their magnetic lines of force are closed through the double air gap and the double stator, and a small part is not closed through the air gap, but only through the double rotor yoke. The third permanent magnet (5) and the fourth permanent magnet (6) are magnetized tangentially along the motor axis and in opposite directions. The magnetic lines of force of the third permanent magnet (5) are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic lines of force of the fourth permanent magnet (6) are basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, the motor is in a state of more leakage flux, which is beneficial for light load operation.

[0049] Combining Scenario 2 Figure 6 The difference between this scenario and scenario one is that both the first excitation winding (11) and the second excitation winding (12) are supplied with positive current. At this time, the magnetic field lines of the electric excitation pass through the leakage magnetic circuit, causing the leakage magnetic circuit to gradually saturate. The magnetic field lines of the first permanent magnet (3) and the second permanent magnet (4) are basically closed through the double air gap and the double stator. However, most of the magnetic field lines of the third permanent magnet (5) and the fourth permanent magnet (6) are transferred from the rotor yoke into the air gap and the stator. Among them, the magnetic field lines of the third permanent magnet 5 are basically closed through the first air gap 13 and the first stator 1, and the magnetic field lines of the fourth permanent magnet 6 are basically closed through the second air gap 14 and the second stator 2. At this time, the leakage magnetic field of the motor is greatly reduced, the torque output capability is enhanced, and it is beneficial for heavy-load operation.

[0050] Combining three scenarios Figure 7 The difference between this scenario and scenario one is that only the first stator 1 is working, while the second stator 2 is idle. Neither the first excitation winding (11) nor the second excitation winding (12) is energized. Most of the magnetic lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, while a small portion does not pass through the air gap but only through the double rotor yoke. The magnetic lines of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small portion is closed through the first air gap 13 and the first stator 1. The magnetic lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small portion is closed through the second air gap 14 and the second stator 2. At this time, the motor is in a state of more leakage flux, and only the torque generated by the working first stator 1 is reduced compared to scenario one, and the power level is reduced, which is beneficial for light load operation.

[0051] Combining four scenarios Figure 8 The difference between this scenario and scenario three is that when a positive current is applied to the first excitation winding 11, its electromagnetic field lines gradually saturate the leakage magnetic circuit of the first rotor yoke 7. Most of the magnetic field lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part passes through the first air gap 13, the first stator 1 and the second rotor yoke 8, and basically do not pass through the first rotor yoke 7. The magnetic field lines of the third permanent magnet 5 are basically closed through the first air gap 13 and the first stator 1, and the magnetic field lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part passes through the second air gap 14 and the second stator 2. At this time, the leakage magnetic field of the motor is reduced compared with scenario three, and the torque is increased, but the increase is limited, and it is still beneficial for light load operation.

[0052] Combining five scenarios Figure 9 The difference between this scenario and scenario three is that only the second stator 2 is working, the first stator 1 is idle, the first excitation winding 11 and the second excitation winding 12 are not energized, most of the magnetic lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part does not pass through the air gap, but only passes through the double rotor yoke; while the magnetic lines of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1, and the magnetic lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2; at this time, the motor is in a state of more leakage flux, and only the torque generated by the second stator 2 is working. Compared with scenario one, the torque is reduced, the power level is reduced, which is beneficial for light load operation.

[0053] Combining six scenarios Figure 10The difference between this scenario and scenario five is that when a positive current is applied to the second excitation winding 12, its electromagnetic field lines gradually saturate the leakage magnetic circuit of the second rotor yoke 8. Most of the magnetic field lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part passes through the second air gap 14, the second stator 2 and the first rotor yoke 7, and basically do not pass through the second rotor yoke 8. The magnetic field lines of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic field lines of the fourth permanent magnet 6 are basically closed through the second air gap 14 and the second stator 2. At this time, the leakage magnetic field of the motor is reduced compared with scenario five, and the torque is increased, but the increase is limited, and it is still beneficial for light load operation.

[0054] Combination of Situation 7 Figure 11 The difference between this scenario and scenario one is that the second stator 2 is offset by an angle α. At this time, most of the magnetic lines of force of the first permanent magnet (3) and the second permanent magnet (4) are closed through the double air gap and the double stator, and a small part is not closed through the air gap, but only through the double rotor yoke. The magnetic lines of force of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic lines of force of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, the motor is in a state with more leakage flux, which is basically the same as scenario one, and is also conducive to light load operation.

[0055] Combination of Situation 8 Figure 12 The difference between this scenario and scenario two is that the second stator 2 is offset by an angle α. At this time, the electric excitation magnetic lines of the first excitation winding 11 gradually saturate the leakage magnetic circuit of the first rotor yoke 7, while the electric excitation magnetic lines of the second excitation winding 12 do not pass through the leakage magnetic circuit of the second rotor yoke 8, thus weakening the leakage magnetic control effect on the fourth permanent magnet 6. The magnetic lines of the first permanent magnet (3) and the second permanent magnet (4) are basically closed through the double air gap and the double stator. Most of the magnetic lines of the third permanent magnet 5 are transferred from the rotor yoke into the air gap and the stator, and are basically closed through the first air gap 13 and the first stator 1. The magnetic lines of the fourth permanent magnet 6 are still basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, the leakage magnetic amount of the motor is increased compared with scenario two, and the torque output capability is slightly reduced, but it is still beneficial for heavy-load operation.

[0056] Combination of Situation Nine Figure 13The difference between this scenario and scenario three is that the second stator 2 is offset by an angle α, and neither the first excitation winding (11) nor the second excitation winding (12) is energized. At this time, most of the magnetic lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part does not pass through the air gap, but only passes through the double rotor yoke. The magnetic lines of the permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, the motor is in a state of more leakage flux, and only the torque generated by the operation of the first stator 1 is basically the same as that in scenario three, which is conducive to light load operation.

[0057] Combination of ten situations Figure 14 The difference between this scenario and scenario four is that the second stator 2 is offset by an angle α, and the first excitation winding 11 is supplied with a positive current. Its electric excitation magnetic field lines gradually saturate the leakage magnetic circuit of the first rotor yoke 7. At this time, most of the magnetic field lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part passes through the first air gap 13, the first stator 1 and the second rotor yoke 8, and basically do not pass through the first rotor yoke 7. The magnetic field lines of the third permanent magnet 5 are basically closed through the first air gap 13 and the first stator 1, and the magnetic field lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part passes through the second air gap 14 and the second stator 2. At this time, the motor operating state is basically the same as that of scenario four, which is still conducive to light load operation.

[0058] Combining Scenario 11 Figure 15 The difference between this scenario and scenario five is that the second stator 2 is offset by an angle α, and neither the first excitation winding (11) nor the second excitation winding (12) is energized. At this time, most of the magnetic lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part does not pass through the air gap, but only passes through the double rotor yoke. The magnetic lines of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic lines of the fourth permanent magnet 6 are basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, the motor is in a state of more leakage flux, and only the torque generated by the operation of the second stator 2 is basically the same as that in scenario five, which is conducive to light load operation.

[0059] Combination of Situation Twelve Figure 16The difference between this scenario and scenario six is ​​that the second stator 2 is offset by an angle α, and the second excitation winding 12 is supplied with a positive current. However, its electric excitation magnetic field lines do not pass through the leakage magnetic circuit of the second rotor yoke 8, thus weakening the leakage magnetic control effect on the fourth permanent magnet (6). At this time, most of the magnetic field lines of the first permanent magnet (3) and the second permanent magnet (4) pass through the double air gap and the double stator, and a small part passes through the second air gap 14, the second stator 2 and the first rotor yoke 7, and basically do not pass through the second rotor yoke 8. The magnetic field lines of the third permanent magnet 5 are basically closed through the first rotor yoke 7, and a very small part is closed through the first air gap 13 and the first stator 1. The magnetic field lines of the fourth permanent magnet 6 are still basically closed through the second rotor yoke 8, and a very small part is closed through the second air gap 14 and the second stator 2. At this time, compared with scenario eleven, the leakage magnetic amount of the main poles of the motor is reduced, the leakage magnetic amount of the auxiliary poles remains basically unchanged, and the torque is increased, but the increase is limited, which is still beneficial for light load operation.

[0060] Situation Thirteen Combination Figure 17 In this case, the first permanent magnet (3) and the second permanent magnet (4) are neodymium iron boron, the third permanent magnet (5) and the fourth permanent magnet (6) are aluminum nickel cobalt, and the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) are die-cast from soft magnetic material. The first excitation winding (11) and the second excitation winding (12) are supplied with positive DC current, and the motor is in an excitation state. By changing the magnitude of the DC current, the magnetization level of the third permanent magnet (5) and the fourth permanent magnet (6) can be changed, thereby adjusting the magnetic energy product and air gap magnetic flux density of the third permanent magnet (5) and the fourth permanent magnet (6). At this time, the first permanent magnet (3) and the second permanent magnet (4) are magnetized along the motor axis and in opposite directions. Their magnetic lines of force basically pass through the double air gap and the double stator closure. The third permanent magnet (5) and the fourth permanent magnet (6) are magnetized along the motor tangentially and in opposite directions. The magnetization direction of the third permanent magnet (5) and the fourth permanent magnet (6) is the same as the direction of the magnetic field of the first excitation winding (11) and the second excitation winding (12). The greater the amplitude of the positive DC current applied to the first excitation winding (11) and the second excitation winding (12), the greater the magnetic energy product of the third permanent magnet (5) and the fourth permanent magnet (6), and the greater the magnetic flux density of the motor air gap, until the third permanent magnet (5) and the fourth permanent magnet (6) reach the saturation magnetization state.

[0061] Situation Fourteen Combination Figure 18In this case, the first permanent magnet (3) and the second permanent magnet (4) are neodymium iron boron, the third permanent magnet (5) and the fourth permanent magnet (6) are aluminum nickel cobalt, and the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) are die-cast from soft magnetic material. The difference between this case and case thirteen is that the first excitation winding (11) and the second excitation winding (12) are supplied with negative DC current, and the motor is in a weak magnetic state. At this time, the magnetic lines of force of the first permanent magnet (3) and the second permanent magnet (4) are basically closed by the double air gap and the double stator; while the magnetization direction of the third permanent magnet (5) and the fourth permanent magnet (6) is opposite to the direction of the magnetic field of the first excitation winding (11) and the second excitation winding (12). The larger the amplitude of the negative DC current passed through the first excitation winding (11) and the second excitation winding (12), the smaller the magnetic energy product of the third permanent magnet (5) and the fourth permanent magnet (6), and the smaller the magnetic flux density of the motor air gap, until the third permanent magnet (5) and the fourth permanent magnet (6) reach the lowest demagnetization level.

[0062] The present invention combines a portion of the control circuitry of the motor operating in an open-winding structure mode. Figure 19 The diagram shows the inverter control circuit on the left and the excitation winding control circuit on the right. Most current OWEM systems, which are the subject of much research, are formed by opening the neutral point of the stator winding of a conventional asynchronous motor or permanent magnet synchronous motor. Therefore, similar to conventional motors, high-performance control strategies must be studied to achieve excellent control performance. In addition to the direct torque control used when the OWEM system was first proposed, vector control, maximum torque / current ratio control, field weakening control, and sensorless technology can also be applied to the OWEM system to obtain better control effects and broaden its application range.

[0063] The present invention combines a portion of the control circuitry of the motor operating in a dual three-phase structure mode. Figure 20 Note that, unlike the open-winding structure operation mode, the neutral points of the two sets of three-phase windings are connected in this mode. The control strategy of the dual three-phase motor is basically the same as that of the traditional three-phase motor. The main idea is to extend the control scheme of the three-phase motor to a six-dimensional space, which can be roughly divided into vector control, direct torque control, and model predictive control. Vector control generally maps the voltage space vector in the six-phase stationary coordinate system to three mutually orthogonal two-dimensional sub-planes for analysis, allowing control of each sub-plane separately. Direct torque control generally performs vector synthesis of the flux linkages of the two windings, and then uses the traditional lookup table method applied in three-phase motors to control the synthesized flux linkage. The main idea of ​​model predictive control is to predict the impact of the currently applied voltage vector on the future performance of the system based on the predictive model. By traversing all possible voltage vectors, the optimization problem of the system is solved online in a given time domain. Finally, the optimal voltage space vector is selected and applied to the motor to obtain the ideal control effect.

[0064] This invention discloses a multi-excitation source magnetic pole partition type dual-stator axial magnetic field controllable permanent magnet motor, which can adapt to the needs of various operating conditions. It can operate in both open winding structure mode and dual three-phase structure mode. Moreover, the air gap magnetic field can be jointly composed of the permanent magnet magnetic field generated by the main magnetic pole and auxiliary magnetic pole, the electric excitation magnetic field generated by the excitation winding, and the armature reaction magnetic field generated by the armature winding. The air gap magnetic field can be adjusted bidirectionally, so that the motor not only has the advantages of high power density and strong heat dissipation capacity of traditional axial magnetic field permanent magnet motors, but also has the advantages of wide speed range and low torque ripple.

Claims

1. A multi-excitation source, pole-partitioned, dual-stator axial magnetic field controllable permanent magnet motor, characterized in that, The motor includes a first stator (1), a second stator (2), a first permanent magnet (3), a second permanent magnet (4), a third permanent magnet (5), a fourth permanent magnet (6), a first rotor yoke (7), a second rotor yoke (8), a first armature winding (9), a second armature winding (10), a first excitation winding (11), a second excitation winding (12), a first air gap (13), and a second air gap (14). The first stator (1) and the second stator (2) are symmetrically placed on the outside of the motor with their slots facing inward. The first armature winding (9) is wound in a distributed structure on the stator teeth of the first stator (1), the second armature winding (10) is wound in a distributed structure on the stator teeth of the second stator (2), the first excitation winding (11) is wound in a concentrated structure on the stator teeth of the first stator (1), and the second excitation winding (12) is wound in a concentrated structure on the stator teeth of the second stator (2). The first rotor yoke (7) and the second rotor yoke (8) are symmetrically placed on the inside of the motor. Furthermore, with the slots facing inward, multiple fan-shaped slots are evenly distributed on the inner side of the first rotor yoke (7), and a third permanent magnet (5) is embedded in the fan-shaped slots; multiple fan-shaped slots are also evenly distributed on the inner side of the second rotor yoke (8), and a fourth permanent magnet (6) is embedded in the fan-shaped slots. The positions of the fan-shaped slots on the first rotor yoke (7) and the second rotor yoke (8) are completely symmetrical; a first permanent magnet (3) and a second permanent magnet (4) are placed between the first rotor yoke (7) and the second rotor yoke (8), and the first permanent magnet (3)... The first stator (1) and the second permanent magnet (4) are spaced apart and arranged circumferentially staggered from the third permanent magnet (5) and the fourth permanent magnet (6); a first air gap (13) is provided between the inner side of the first stator (1) and the outer side of the first rotor yoke (7), and a second air gap (14) is provided between the inner side of the second stator (2) and the outer side of the second rotor yoke (8); the axis of the first stator (1) and the second stator (2) coincides with the axis of rotation of the first rotor yoke (7) and the second rotor yoke (8).

2. The multi-excitation source magnetic pole partitioning type dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, The stator cores of the first stator (1) and the second stator (2) are made of silicon steel sheets wound in a circumferential direction, and the stator facing the rotor is stator teeth; the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) are made of silicon steel sheets wound in a circumferential direction, or are die-cast from soft magnetic materials.

3. The multi-excitation source magnetic pole partitioning type dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, The first armature winding (9) and the second armature winding (10) are double-layer windings with a distributed structure and a pitch ≥ 360° / (2*p); p is the number of rotor pole pairs; The first excitation winding (11) and the second excitation winding (12) are single-layer windings and are distributed at intervals of 120°*Z / (2*p), where Z is the number of stator slots; The first rotor yoke (7) has 8 fan-shaped slots evenly distributed on its inner side. Each fan-shaped slot has a depth of 3mm and an arc of 0.285*360° / (2*p). The interval between adjacent fan-shaped slots is (1-0.285)*360° / (2*p). The second rotor yoke (8) also has 8 fan-shaped slots evenly distributed on its inner side. Each fan-shaped slot has a depth of 3mm and an arc of 0.285*360° / (2*p). The interval between adjacent fan-shaped slots is (1-0.285)*360° / (2*p).

4. The multi-excitation source magnetic pole partitioning type dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, The first permanent magnet (3) and the second permanent magnet (4) have p pole pairs, and are distributed alternately with N and S along the circumferential direction. The first permanent magnet (3) and the second permanent magnet (4) are magnetized along the motor axis and in opposite directions. The third permanent magnet (5) and the fourth permanent magnet (6) are magnetized along the motor tangential direction and in opposite directions. The magnetic energy product of the first permanent magnet (3) and the second permanent magnet (4) is greater than that of the third permanent magnet (5) and the fourth permanent magnet (6). The first permanent magnet (3) and the second permanent magnet (4) are spaced 0.55*360° / (2*p) apart and are circumferentially offset from the third permanent magnet (5) and the fourth permanent magnet (6) by 0.1325*360° / (2*p). The magnetic flux generated by the third permanent magnet (5) and the fourth permanent magnet (6) does not participate in the excitation of the air gap magnetic field when unloaded, but can enter the air gap magnetic field for excitation when loaded, thereby changing the magnetic flux of the main magnetic circuit of the motor and widening the speed regulation range of the motor. When the third permanent magnet (5) and the fourth permanent magnet (6) are AlNiCo variable permanent magnet materials, the magnetic energy product of the third permanent magnet (5) and the fourth permanent magnet (6) can be adjusted by passing DC excitation through the excitation winding.

5. A multi-excitation source, pole-partitioned, dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, Hollow heat dissipation holes are provided between the rotor cores of the first rotor yoke (7) and the second rotor yoke (8) to reduce rotor temperature and the risk of permanent magnet demagnetization through oil cooling and air cooling. An arc-shaped slot with a depth of H ≤ 3mm can be provided on the air gap side of the first rotor yoke (7) and the second rotor yoke (8) directly opposite the first permanent magnet (3) and the second permanent magnet (4) axially. This slot can adjust the magnetic flux of the first permanent magnet (3), the second permanent magnet (4), the third permanent magnet (5), and the fourth permanent magnet (6), while reducing the cogging torque and axial magnetic pull of the motor.

6. The multi-excitation source magnetic pole partitioning type dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, When the first excitation winding (11) and the second excitation winding (12) fail, the first armature winding (9) and the second armature winding (10) can work independently; in addition, when the armature winding fails, the excitation winding can also replace the armature winding and drive the motor to run by passing three-phase current.

7. A multi-excitation source, pole-partitioned, dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, The first stator (1) and the second stator (2) can be offset by a certain angle α, where α≤120°*Z / (2*p). By controlling the offset angle, the leakage flux and air gap magnetic flux density of the motor can be changed, thereby changing the output torque and power level of the motor.

8. The variable operating condition drive control system for a multi-excitation source magnetic pole partition type dual-stator axial magnetic field controllable permanent magnet motor according to claim 1, characterized in that, The motor power converter is constructed using four H-bridges. The input and output ends of the first excitation winding (11) and the second excitation winding (12) are respectively connected to the center point of an H-bridge arm. The input and output ends of the two sets of armature windings on the first stator (1) and the second stator (2) are respectively connected to the center point of an H-bridge arm to form an open winding structure or a double three-phase structure. The H-bridges of the first excitation winding (11) and the second excitation winding (12) are connected in series with the busbar of the open winding structure formed by the two sets of armature windings on the first stator (1) and the second stator (2).

9. The variable operating condition drive control system for a multi-excitation source magnetic pole partition type dual-stator axial magnetic field controllable permanent magnet motor according to claim 8, characterized in that, It has multiple operating modes; when the neutral point of the two sets of three-phase windings on the first stator (1) and the second stator (2) is open, the motor operates with an open winding structure; when the neutral point of the two sets of three-phase windings on the first stator (1) and the second stator (2) is connected, the motor operates with a double three-phase structure.

10. The variable operating condition drive control system for a multi-excitation source magnetic pole partition type dual-stator axial magnetic field controllable permanent magnet motor according to claim 8, characterized in that, The first excitation winding (11) and the second excitation winding (12) are controlled by an H-bridge. The positive and negative excitation currents are controlled by controlling the conduction of four switching transistors, thereby achieving the magnetization and demagnetization of the motor's magnetic field. Furthermore, when the excitation winding fails, it will not affect the control of the armature winding power converter.

Images