153 results about "Memory motor" patented technology

This invention provides a multiple integral hybrid rotor magnetic circuit structure controlled flux magnet synchronous motor including motor spindle, a stator winding, a stator iron core, AlNiCo magnet, A Nd FeB magent, a rotor iron core, a position sensor, a sensor cable, a motor cable and a converter. The permanent rotor is in an integral hybrid rotor magnetic circuit structure, the magnet in the rotor iron cover is set in U shape, the NdFeB is placed tangentially and the AlNiCo magnet is in radial position characterizing in being called a memory motor since it can apply an amplitude controlled d-axis current vector to change the magnetization intensity of the rotor magnet and remember the changed flux intensity.

The invention discloses a mixed permanent magnetic pole-alternating and magnetic flux-switching memory motor and a winding switching magnetism-weakening control method thereof. The mixed permanent magnetic pole-alternating and magnetic flux-switching memory motor comprises a salient rotor and a stator, wherein the stator contains stator cores, aluminium-nickel-cobalt permanent magnets, neodymium-iron-boron permanent magnets, centralized armature windings and pulsed magnetism-adjusting windings; iron core edges of two adjacent outer U-shaped units and tangentially-magnetized long-stripped neodymium-iron-boron permanent magnets form a first permanent magnetic pole, while the circumferentially-inward (outward) and parallel-magnetized V-shaped embedded aluminium-nickel-cobalt permanent magnets and inner U-shaped units form a second permanent magnetic pole; mixed magnetic poles are in alternating polarity distribution; when the motor runs at a low speed, the pulsed magnetism-adjusting windings are in direct-current pulsed working state, while in a high-speed weak-magnetism area, the pulsed magnetism-adjusting windings are converted into alternating-current armature windings. Requirements on performance in a low-speed area and in the high-speed area can be met at the same time; influence of an armature reaction field on the aluminium-nickel-cobalt permanent magnets with low coercivity is small; the utilization rate of permanent magnetism, the torque density, and the reliability of system operation are high.

The invention discloses a magnetic flow switched and surface-mounted type permanent magnet memory motor which comprises an enclosure, a stator, a rotor and a rotary shaft. The stator, the rotor and the rotary shaft are contained in the enclosure. The rotor is a cylinder provided with a through hole, and comprises a sleeve provided with a center through hole, and block rotor iron cores. The rotary shaft is fixedly connected in the center through hole of the sleeve. The block rotor iron cores are sector-shaped, evenly distributed along the circumferential direction of the rotor, and fixedly connected on the outer surface of the sleeve. The stator comprises a stator core, permanent magnets, three-phase armature windings and pulse windings. The stator core comprises a stator yoke and stator teeth. The stator teeth are composed of permanent magnet teeth and armature teeth. The permanent magnets are tile-shaped, and fixedly connected on the outer surface of the permanent magnet teeth. The permanent magnets are magnetized along the radial direction, and the mangnetizing directions of every two adjacent permanent magnets are opposite to each other. The three-phase armature windings are wound on the armature teeth, and the pulse windings are wound on the permanent magnets. The permanent magnet memory motor can enable the weak magnet capability and a rotation speed operation range of the motor to be improved, and a no-load air gap magnetic field is adjustable.

The invention discloses an axial magnetic field magnetic flux switching type surface-mounted permanent magnet memory motor. The permanent magnet memory motor comprises a first rotor (41), a second rotor (42), a stator (1) and an installing shaft, wherein the stator (1) is arranged between the first rotor (41) and the second rotor (42) and of an axial two-side symmetrical structure, the installing shaft is used for coaxially installing the stator (1), the first rotor (41) and the second rotor (42), and the stator is located between the two rotors to form an axial two-air-gap motor. The stator (1) is of the two-side symmetrical salient pole structure and comprises a stator iron core (2), a plurality of permanent magnets (3), a three-phase armature winding (5) and a single-phase pulse winding (6). The stator iron core (2) comprises a stator yoke (2.1) and stator teeth (2.2), wherein the stator teeth (2.2) protrude in the center direction of the first rotor (41) and in the center direction of the second rotor (42) respectively from the stator yoke (2.1). By the adoption of the permanent magnet memory motor, power density of the motor is improved, and the wide rotating speed operation range is possessed.

The invention discloses a flux-switching hybrid permanent magnet memory motor with high power density. The motor comprises a stator (1), a rotor (2) and a non-magnetic revolving shaft (9), wherein the stator (1) is arranged outside the rotor (2); the rotor (2) is fixed to the non-magnetic revolving shaft (9), and is of a salient pole form; the stator comprises a stator yoke (1.1), a stator core (1.2) arranged between the stator yoke (1.1) and the rotor, a three-phase armature winding (5) and a pulse winding (6); a gap is formed between the stator yoke (1.1) and the stator core (1.2), and two types of permanent magnets, namely, an aluminum-nickel-cobalt permanent magnet (3) and a neodymium-iron-boron permanent magnet (4), are arranged in the gaps respectively for exciting together. Through the arrangement of the stator hybrid permanent magnets, high power density is realized; moreover, the residual magnetizing strength and magnetizing directions of the permanent magnets are adjusted by applying pulse current, so that efficient adjustment of the no-load gap magnetic field of the motor is realized, and the rotating speed running range is expanded.

The invention discloses a hybrid excitation-type stator partition-type hybrid permanent magnet flux switching memory motor, which comprises an outer stator, an inner partition stator and a middle rotor, wherein the inner partition stator has a structure of an inner layer and an outer layer closely attached together, the outer layer is formed by an inner stator iron core and NdFeB permanent magnets, the NdFeB permanent magnets are uniformly embedded in the inner stator iron core along the circumferential direction, the NdFeB permanent magnets are magnetized tangentially, and the magnetizing directions of two adjacent NdFeB permanent magnets are opposite; and the inner layer is formed by pulse magnetizing windings and AlNiCo permanent magnets capable of being magnetized and demagnetized in an online mode, the AlNiCo permanent magnets are uniformly arranged along the circumferential direction, an inner stator groove is arranged between adjacent two AlNiCo permanent magnets, and the pulse magnetizing windings serially connected from beginning to end in sequence are placed in the inner stator grooves and are wound on the AlNiCo permanent magnets. Thus, under the same motor size, the amount of permanent magnets and the amount of armature windings can be increased to enhance torque density, the magnetic strength of the AlNiCo permanent magnets can be adjusted in an online mode, and a wide speed regulation range is provided.

The invention discloses a magnetic flux controllable axial magnetic field mixed hybrid permanent magnet memory motor comprising two rotor discs, a stator and an installation shaft. NdFeB permanent magnets and iron core poles, which are arrayed in inner and outer circles at intervals alternately, are bonded to the inner surfaces of the rotor discs; the NdFeB permanent magnets are magnetized axially, the polarities of the NdFeB permanent magnets of the outer circle are the same, the polarities of the NdFeB permanent magnets of the inner circle are opposite to those of the NdFeB permanent magnets of the outer circle, and the magnetizing directions of the NdFeB permanent magnets arranged in corresponded positions of two rotor discs are the same; the stator comprises a stator iron core, a three-phase armature winding and a single-phase pulse winding. The motor has high power density and wide rotating speed operation range and is adaptive to relevant drive occasions of low axial size requirements, compacted structure and flux weakening requirements.

The invention discloses a segmented control method of permanent magnetic linkages of a stator permanent magnetic type memory motor. The method comprises following steps of S1, according to magnetization states of a permanent magnet, selecting k+1 permanent magnetic linkages including phipm (if0), phipm (if1), ..., phipm (if(k-1)), and phipm (ifk), wherein the phipm (if(k-1)) is larger than the phipm (ifj), and 1<=j<=k, calculating rotation speed omegaej according to direct current bus voltage Udc, the rated phase current In, and the quadrature axis inductance Lq(j) and the permanent magnetic linkage phipm (ifj) of the jth kind of magnetization state, and storing the permanent magnetic linkages of phipm (if0), phipm (if1) ..., phipm (if(k-1)), and phipm (ifk) and corresponding rotation speeds of omegae0, omegae1, ..., omegae(k-1), and omegaek into a speed-permanent magnetic linkage table, wherein the if is the magnetic field adjusting pulse; and S2, when the given rotation speed shown in the description meets the condition shown in the description, judging a magnetic field adjusting process of the permanent magnet by comparing the permanent magnetic linkage phipmo(if) and the permanent magnetic linkage phipm(ifj) corresponding to the rotation speed omegaej observed by the permanent magnetic linkage observer. According to the invention, speed adjusting range of the motor is enlarged, and effects on permanent magnetic linkage calculation accuracy imposed by motor parameters are reduced.

The invention discloses a magnetic flux switching type permanent magnet memory motor comprising an enclosure, a stator contained in the enclosure, a rotor (2) and a non-magnetic rotary shaft (8). The magnetic flux switching type permanent magnet memory motor is characterized in that the stator (1) is arranged at the outer part of the rotor (2); the rotor (2) is fixedly arranged on the non-magnetic rotary shaft (8) and is in a convex pole type; the rotor (2) comprises a rotor main body part and rotor teeth which protrude from the main body part to a direction which is far away from the center of the rotor; the stator comprises a stator iron core (1), a permanent magnet (3), a three-phase armature winding (4) and a pulse winding (5); the stator iron core (1) comprises a plurality of stator yokes and stator teeth (1.1) which protrude from the stator yokes to the direction of the center of the stator iron core; and the three-phase armature winding (4) is wound on the stator teeth (1.1). According to the magnetic flux switching type permanent magnet memory motor disclosed by the invention, a motor no-load gap magnetic field is adjustable, and the weak magnetism capability and the rotary speed operation speed of the motor are improved; and meanwhile, the torque and the power density of the motor are improved and the copper consumption of the motor is reduced.

The invention discloses a flux-switching type parallel hybrid permanent magnet memory motor which comprises a stator, a rotor, a non-magnetism-conductive rotating shaft, a plurality of U-shaped stator iron cores, a direct-current magnetizing coil and an alternating-current concentrated winding coil. The U-shaped stator iron cores are evenly distributed to form an annular shape. Stator teeth are arranged at the side ends of the U-shaped stator iron cores. A gap is formed between every two adjacent U-shaped stator iron cores. Each gap and the stator teeth adjacent to the gap form a salient pole. A low-coercivity permanent magnet and a high-coercivity permanent magnet are arranged in each gap in the radial direction, wherein the parallel connection is formed on magnetic circuits of the two permanent magnets, and a direct-current magnetizing coil cavity exists between the two permanent magnets. The direct-current magnetizing coil penetrates through every two adjacent direct-current magnetizing coil cavities to be wound around the U-shaped stator iron cores. The alternating-current concentrated winding coil is wound around the salient poles to form a three-phase armature winding. The magnetization state of the low-coercivity permanent magnets is adjusted by exerting the pulse current in the direct-current magnetizing coil, pulse current is removed, the low-coercivity permanent magnets can be kept in the previous magnetization state, and the variable-flux and memory purposes are achieved.

The invention discloses a double-layer permanent magnet composite magnetic circuit memory motor, comprising a hybrid permanent magnet rotor, a stator, an armature winding and a rotating shaft, whereinthe hybrid permanent magnet rotor comprises a rotor iron core, a plurality of double-layer permanent magnet regions are uniformly distributed in the circumferential direction of the rotor iron core,the double-layer permanent magnet regions comprise a U-shaped hybrid permanent magnet structure and a V-shaped permanent magnet structure, and the U-shaped hybrid permanent magnet structure comprisesa second high coercivity and a low coercivity permanent magnet. The V-shaped permanent magnet structure comprises a first high coercivity permanent magnet arranged in the opening of the U-shaped hybrid permanent magnet structure, the opening of the U-shaped hybrid permanent magnet structure and the V-shaped permanent magnet structure facing the stator, and the low coercivity permanent magnet and the second high coercivity permanent magnet are in parallel magnetic circuit and in series magnetic circuit with the first high coercivity permanent magnet. The invention combines the advantages of theparallel magnetic circuit type and the series magnetic circuit type memory motor, realizes the improvement of the torque density of the motor, avoids the demagnetization problem of the low coercive force permanent magnet load, and further widens the speed regulating range and the high efficiency operation interval of the motor.

The invention discloses a fault- tolerant type stator segmentation flux switching memory motor which comprises a stator (1), a rotor (2) and a non-magnetic rotary shaft (8). The stator (1) is arranged outside the rotor (2), the rotor (2) is fixed to the non-magnetic rotary shaft (8) and is of a salient pole type, and the stator (1) comprises a stator iron core (1.2) with an opening at one end, a permanent magnet (3), a three-phase armature winding (4), a pulse winding (5) and a stator yoke (1.1). The stator iron core (1.2) comprises a bottom edge, a first magnetic iron core edge (1.21) and a second magnetic iron core edge (1.22), wherein the first magnetic iron core edge (1.21) and the second magnetic iron core edge (1.22) extend vertically from the bottom edge, the permanent magnet (3) is arranged between the bottom edge of the stator yoke (1.1) and the bottom edge of the stator iron core (1.2), and the stator iron core (1.2) further comprises a fault-tolerant gear (1.2.3) vertically extending from the bottom edge and arranged between the two magnetic iron core edges. The fault-tolerant type stator segmentation flux switching memory motor has a strong ability of operating with faults and a weak magnetic speed extension ability.

The invention discloses a magnetism-gathering-type magnetic flux switching permanent magnet memory motor, which comprises a stator, a rotor (2) and an un-conducted magnetic shaft (8), wherein the stator (1) is arranged outside the rotor (2); the rotor (2) is fixed on the un-conducted magnetic shaft (8) and is in a salient pole type; the stator comprises a stator core (1), a first permanent magnet (3a), a second permanent magnet (3b), a three-phase armature winding (6), a first pulsed winding (4a) and a second pulse winding (4b); the stator core (1) comprises a plurality of stator yokes and stator teeth protruding to the center direction of the stator core from the stator yokes; and a stator slot is formed between the adjacent stator teeth. With the adoption of the magnetism-gathering-type magnetic flux switching permanent magnet memory motor, the residual magnetization of the permanent magnet is adjusted through applying pulse current to a pulse winding; a motor no-load air-gap field can be adjusted; the weak magnetic ability of the motor and the rotating speed operation range are improved; and meanwhile, the torque and power density of the motor can be effectively improved through magnetism-gathering-type armature teeth, and the copper loss of the motor is reduced.

The invention discloses a method for restraining the flux-adjusting torque ripple of a memory motor based on current decoupling, including setting given values of d, q-axis current, Both and d, The deviation from the q-axis current setpoint is input to the PI regulator, the output of the d-axis current PI regulator is subtracted from omega eLqiq to obtain the d-axis voltage given value, To the output of q-axis current PI regulator, [omega]e(Ldid + [psi]r) is added to get the given value of q-axis voltage. D, q-axis voltage is controlled by coordinate transformation and SVPWM modulation to drive the inverter motor. When the rotational speed of the motor is higher than the base speed, the magnetization state of the permanent magnet is adjusted discretely by using the memory magnetization method, and the d-axis current weakening method is used to continuously adjust the magnetization state in each magnetization state, and the q-axis decoupling current is applied at the same time as the d-axis current is applied, so as to keep the torque constant during the magnetization adjustment period and suppress the torque ripple during the magnetization adjustment period.

The invention discloses a stator magnetism gathering type mixed permanent magnet memory motor and belongs to the field of adjustable magnetic flux permanent magnet motors. The stator magnetism gathering type mixed permanent magnet memory motor comprises a rotor and stator cores which are both of a salient pole structure. A stator of the motor comprises the six T-shaped stator cores, embedded alnico permanent magnets, neodymium iron boron permanent magnets embedded between the two adjacent T-shaped stator cores and a whole layer of stator yoke. In the magnetism increasing operation, the alnico permanent magnets and the neodymium iron boron permanent magnets of a V-shaped magnetism gathering type structure of adjacent stator units form the magnetism gathering effect to provide air gap main flux, and in the weak magnetism operation, the neodymium iron boron magnetic potential is short circuited by a large amount in the stator cores by alnico. The alnico permanent magnets conduct magnetizing towards the interior or the exterior of a circle center in parallel and are opposite in polarity, the design of magnetizing in the tangential direction and alternative distributing of polarities is adopted for the neodymium iron boron permanent magnets. According to the stator magnetism gathering type mixed permanent magnet memory motor, due to the arrangement of the stator magnetism gathering type mixed permanent magnets, the power density of the motor is improved, pulse current is exerted for adjusting the residual magnetization intensity and the magnetization direction of the permanent magnets, and the efficient adjustment of a no-load air-gap magnetic field of the motor is achieved.

The invention discloses a magnetic field modulation type stator-rotor mixed permanent magnet memory motor of high torque density. The motor comprises a rotor and an inner stator, the rotor is located outside the stator and is of a cylindrical-cup-shaped structure as a whole. Rotor salient poles are extended in the radius direction. Neodymium-iron- boron permanent magnets are arranged among the rotor salient poles, wherein Hal Bach type poles are distributed in an alternative mode. The inner stator comprises a stator yoke, six stator cores of multi-tooth structures, three-phase armature windings and pulse magnet regulating windings, wherein the stator cores are arranged between the stator yoke and the rotor and evenly distributed in the peripheral direction. Each stator core is composed of a plurality of stator teeth, and aluminum- nickel-cobalt permanent magnets capable of conducting bidirectional magnetization are arranged between adjacent stator teeth. The three-phase armature windings are wound around every two adjacent stator cores and placed in grooves formed by every two adjacent stator cores. The single-phase pulse magnet regulating windings are placed into grooves formed in the two sides of each aluminum- nickel-cobalt permanent magnet. According to the magnetic field modulation type stator-rotor mixed permanent magnet memory motor, bidirectional modulation of a stator-rotor bilateral mixed permanent magnetic field is achieved through multi-tooth stator poles and the rotor salient poles, so that low-speed large torque can be achieved; meanwhile, a pulse current can be applied for adjusting the residual magnetization intensity and magnetization direction of the permanent magnets, efficient regulation of a motor no-load air gap magnetic field is achieved, the rotation speed potation range is broadened, and thus the magnetic field modulation type stator-rotor mixed permanent magnet memory motor is quite applicable to the field of wind direct-drive power generation.

The invention discloses a double-stator double-power-winding magnetic concentrating hybrid permanent magnet memory motor. The motor comprises an external stator, a rotor and an internal stator. The internal and external stators are coaxially arranged in a sleeving way from inside to outside. The external stator comprises armature iron core teeth, stator yokes and first armature windings which are arranged on the armature iron core teeth. The internal stator comprises an internal stator iron core provided with two internal slots, Nd-Fe-B permanent magnets, Al-Ni-Co permanent magnets, second armature windings which are arranged in the first internal slot of the internal stator, and pulse magnetic adjusting windings which are arranged in the second internal slot. The two types of co-excitation permanent magnets are parallel in space and are arranged in a magnetic concentrating tangential magnetizing way. The weakness of relatively low torque density of a conventional signal stator structure can be solved, high power density is realized via arrangement of two sets of double-stator power windings and internal stator hybrid permanent magnets, and pulse current is applied to adjust magnetizing level and direction of the permanent magnets so that motor magnetic field high-efficiency adjustment is realized and rotating speed operation range is enhanced.

The invention discloses an axial magnetic flux hybrid excitation memory motor which comprises a stator disc and a rotor disc of a Halbach structure, the stator disc is composed of a stator core and three-phase armature windings, the stator core comprises a stator yoke and stator teeth, a stator groove is formed between every two adjacent stator teeth, and the three-phase armature windings are wound on the stator teeth; the rotor disc meets a Halbach composite array, the outer side of the rotor disc is composed of a plurality of aluminum-nickel-cobalt permanent magnets and a plurality of pulseexcitation windings connected in series, the magnetizing directions of every two adjacent aluminum-nickel-cobalt permanent magnets are opposite, a soft magnetic material is arranged between every twoadjacent aluminum-nickel-cobalt permanent magnets, and the pulse excitation windings are wound on the aluminum-nickel-cobalt permanent magnets; neodymium-iron-boron permanent magnets are attached to the inner side of the rotor disc in a surface-mounted mode at a certain angle, and the magnetizing directions of every two adjacent neodymium-iron-boron permanent magnets are opposite. The motor is compact in structure, can achieve the flexible adjustment of an air-gap magnetic field of the motor, is wider in speed adjusting range, and is low in speed and large in torque.

The invention discloses a magnetization state selection and weak magnetic control coordinated control method of a stator permanent-magnet memory motor. The constant-power working range of the stator permanent-magnet memory motor is expanded by combining a weak magnetic control method under different permanent magnetization states. According to the method, different current allocation strategies are employed at different rotational speed zones, and the control performance of the motor is optimized; compared with a segmented permanent-magnetic flux control method, the method has the advantage that the torque output capability of the motor at the different rotational speed zones is improved; and meanwhile, under the constant load torque, the efficiency of the stator permanent-magnet memory motor at different rotational speed zones is improved by the method.

The invention discloses a less-rare-earth multi-excitation-source double-stator flux-switching memory motor, which belongs to the technical field of motor body design and operating principles. Coaxial outer stators, rotors and inner stators are sleeved together in turns from outside to inside to compose the memory motor, wherein a radial air gap exists between the outer stators and the rotors, the rotors and the inner stators, the outer stators are composed of armature core teeth, fault-tolerant teeth and stator yokes, and the rotors are composed of a rotor support, a magnetic silicon steel block and a magnetic insulation block, and meanwhile, the inner stators are composed of the inner stator core and a combined permanent-magnet cell block. The double-stator structure of the motor realizes the separation of armature winding and permanent magnet and solves the problem that multiple excitation sources inside the traditional flux-switching permanent magnet motors restrain each other, thereby easily increasing motor power density and torque density. The memory motor maintains high air-gap flux density and ensures of the motor power density and the torque density, meanwhile, the consumption of rare-earth permanent-magnetic materials is effectively lowered. On the other side, the memory motor can realize flexible adjustment of a motor air-gap field and expand the range of speed operation.

The invention discloses a dual-stator axial magnetic field flux switching type hybrid permanent magnet memory motor. The dual-stator axial magnetic field flux switching type hybrid permanent magnet memory motor comprises two salient pole stators and a salient pole rotor. The two stators are of the same structure and named as a first stator and a second stator which are arranged at opposite positions. The rotor is coaxially disposed between the two stators. One of the two stators is made of a neodymium iron boron permanent magnet and the other stator is made of an aluminum nickel cobalt permanent magnet. The permanent magnet of each of the two stators is alternately magnetized in the circumferential direction. The magnetization directions of the permanent magnets of the two stators at relative opposite positions are opposite. The two permanent magnets are in series connection in a magnetic circuit. The stator made of the neodymium iron boron permanent magnet is used for generating constant flux. The stator made of the aluminum nickel cobalt permanent magnet is used for generating variable flux for adjusting an air-gap magnetic field. The dual-stator axial magnetic field flux switching type hybrid permanent magnet memory motor provides an excitation mode of hybrid permanent magnet of a series structure and has the advantages of maintaining high power density of a traditional permanent magnet motor and being wide in rotation speed running range and high in efficiency of a memory motor.

The invention discloses a high efficiency and wide-range speed control method for a stator permanent magnet type memory motor. The method comprises the steps that the area where the motor rotating speed is located is judged through an area judging module, and different current distribution modes are adopted in different areas according to a division control strategy. In the low-speed area, a minimum value of which input power is in an AlNiCo permanent magnet flux linkage changing interval is looked up through a step-size adaptive search algorithm to achieve efficiency optimizing control of the motor, not only is the problem that a large error is generated when calculation is conducted by adopting a motor loss formula method avoided, but also inverter losses, stray losses and the like which are difficult to calculate through mathematical modeling are included in efficiency optimizing control, a difference from actual losses of a control system is decreased, and the efficiency optimizing control precision is improved. In the high-speed area, by means of the flux weakening method that a flux weakening flux linage needed in flux weakening control is obtained through a voltage difference method and a formula method, the stator permanent magnet type memory motor can achieve the high stability margin and dynamic property in a wide speed range.

The invention discloses a permanent magnet crossed type axial magnetic field magnetic flow switching type memory motor. The permanent magnet crossed type axial magnetic field magnetic flow switching type memory motor comprises two stators with convex pole structures and a rotor with a convex pole structure, wherein the structures of the two stators are the same and the two stators are marked into a first stator and a second stator respectively; the positions of the stators are opposite; the rotor is coaxially arranged between the two stators; each stator comprises a U-shaped magnetism-conductive iron core, a permanent magnet, a three-phase armature winding and a direct-current magnetizing winding; the permanent magnets comprises a high coercivity permanent magnet A and a low coercivity permanent magnet B; the iron cores and the permanent magnets are peripherally and alternatively arranged to form a circular ring shape; the two permanent magnets are alternatively arranged, and the magnetizing directions of the adjacent permanent magnets are opposite; the magnetizing directions of the permanent magnets on the corresponding positions of the two stators are opposite; columnar rotor teeth are uniformly arranged on a non-magnetism-conductive annular rotary shaft along the peripheral direction. The memory motor adopts a mixed permanent magnet excitation manner and has higher torque density; the flux weakening is carried out through adjusting the magnetizing level of the low coercivity permanent magnet, and the flux weakening capability and constant-power operation efficiency of the memory motor are improved.