Field modulation motor, motor system and control method of motor system

Abstract

The present application relates to a magnetic field modulation motor, a motor system and a control method for the motor system; the magnetic field modulation motor comprises a stator assembly arranged on the inner side of the magnetic field modulation motor and a rotor assembly arranged on the outer side of the magnetic field modulation motor, wherein the stator assembly comprises a stator core and a stator winding, the stator core comprises a stator yoke and a stator tooth portion, the stator winding is sleeved on the stator tooth portion, the bottom end of the stator tooth portion is connected to the stator yoke portion, and the top end of the stator tooth portion is provided with a stator split tooth, the rotor assembly comprises a rotor core and a rotor winding, the rotor winding is wound in the rotor core, the rotor core is connected to the stator split teeth, and the number of pole pairs of the rotor winding is the absolute value of the difference between the number of pole pairs of the stator winding and the number of stator split teeth; the use of the above-mentioned magnetic field modulation motor can enhance the output capacity of electromagnetic torque and improve the speed regulation performance of the magnetic field modulation motor.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a magnetic field modulation motor, a motor system, and a control method for the motor system. Background Art

[0002] At present, magnetic field modulation motors have the characteristics of low speed and large torque, and have broad application prospects in direct drive fields such as wind power generation and robot joints; however, the existing magnetic field modulation motors only generate electromagnetic torque in the fundamental magnetic field, and have the problem of poor speed regulation performance. Summary of the invention

[0003] Based on this, it is necessary to provide a magnetic field modulation motor, a motor system and a control method of a motor system that can improve the speed regulation performance in order to address the above technical problems.

[0004] In a first aspect, the present application provides a magnetic field modulation motor, comprising:

[0005] A stator assembly is arranged inside the magnetic field modulation motor, the stator assembly includes a stator core and a stator winding, the stator core includes a stator yoke and a stator tooth, the stator winding is sleeved on the stator tooth, the bottom end of the stator tooth is connected to the stator yoke, and the top end of the stator tooth is provided with a stator split tooth;

[0006] A rotor assembly is arranged outside the magnetic field modulation motor, the rotor assembly comprises a rotor core and a rotor winding, the rotor winding is wound in the rotor core, and the rotor core is connected to the stator split teeth;

[0007] Among them, the number of pole pairs of the rotor winding is P f , the number of pole pairs of stator winding P a and the number of stator split teeth Z s The relationship between them is shown as follows:

[0008] .

[0009] In one embodiment, the stator core and the rotor core are both formed by laminating silicon steel sheets.

[0010] In one embodiment, the rotor winding is an electric field winding;

[0011] The bottom end of the stator tooth portion is connected to the stator yoke portion by a dovetail structure.

[0012] In a second aspect, the present application further provides a motor system, the motor system comprising a first converter, a second converter, a controller and the above-mentioned magnetic field modulation motor;

[0013] The controller is connected to the input end of the first converter and the input end of the second converter respectively to control the current frequency output by the first converter and the second converter. The output end of the first converter is connected to the input end of the stator winding, and the output end of the second converter is connected to the input end of the rotor winding.

[0014] In one embodiment, when the number of stator split teeth Z s Greater than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula:

[0015] ;

[0016] When the number of stator split teeth Z s Smaller than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula:

[0017] .

[0018] In one embodiment, when the stator winding receives the current output by the first converter, the number of magnetic field pole pairs generated by the stator split teeth is P k,j Satisfy the following formula:

[0019] ;

[0020] Among them, P a is the number of pole pairs of the stator winding; Z s is the number of stator split teeth; k is a positive integer; j is an integer.

[0021] In one embodiment, the first converter is a frequency converter; the second converter is a frequency converter.

[0022] In a third aspect, the present application further provides a control method for a motor system, which is applied to the controller of the above-mentioned motor system, and the method comprises:

[0023] In response to the control instruction, the first converter and the second converter are respectively instructed to output at corresponding current frequencies based on the control instruction.

[0024] In one embodiment, the method further comprises:

[0025] The current phase sequences output by the first converter and the second converter are adjusted respectively according to the control instructions.

[0026] In a fourth aspect, the present application also provides an electric power device, comprising the above-mentioned motor system.

[0027] The above-mentioned magnetic field modulation motor, motor system and control method of the motor system, the magnetic field modulation motor includes a stator assembly arranged on the inner side of the magnetic field modulation motor and a rotor assembly arranged on the outer side of the magnetic field modulation motor, wherein the stator assembly includes a stator core and a stator winding, the stator core includes a stator yoke and a stator tooth portion, the stator winding is sleeved on the stator tooth portion, the bottom end of the stator tooth portion is connected to the stator yoke portion, and the top end of the stator tooth portion is provided with a stator split tooth, the rotor assembly includes a rotor core and a rotor winding, the rotor winding is wound in the rotor core, the rotor core is connected to the stator split teeth, and the number of pole pairs of the rotor winding is the absolute value of the difference between the number of pole pairs of the stator winding and the number of stator split teeth; in this application, the stator magnetic field generated by the stator split tooth modulation interacts with the rotor magnetic field formed by the rotor winding to generate an electromagnetic torque, thereby enhancing the output capacity of the electromagnetic torque and improving the speed regulation performance of the magnetic field modulation motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 is a structural schematic diagram of a magnetic field modulation motor in an embodiment;

[0030] Figure 2 is a schematic structural diagram of a stator tooth portion of a magnetic field modulation motor in one embodiment;

[0031] Figure 3 is a schematic structural diagram of a stator yoke of a magnetic field modulation motor in one embodiment;

[0032] Figure 4 is a schematic diagram of the structure of a motor system in one embodiment;

[0033] Figure 5 It is a torque curve comparison diagram of a magnetic field modulation motor and a common doubly fed motor in one embodiment. DETAILED DESCRIPTION

[0034] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0036] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0037] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0038] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least part of an element” means part or all of an element.

[0039] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0040] Existing magnetic field modulation motors usually use the fundamental magnetic field to generate electromagnetic torque, ignoring the remaining harmonic magnetic fields, resulting in poor speed regulation performance. In addition, existing magnetic field modulation motors often use permanent magnet excitation, and permanent magnets have the risk of irreversible demagnetization: when the magnetic field modulation motor encounters an emergency event that causes the instantaneous current in a certain part to be too large, it is easy to cause local irreversible demagnetization in the hot engine state, resulting in changes in the performance of the magnetic field modulation motor, and the cost of rare earth permanent magnet materials is relatively high.

[0041] The embodiments of the present application provide a magnetic field modulation motor, a motor system and a control method for a motor system. The top of the stator tooth portion of the magnetic field modulation motor is provided with a stator split tooth. The stator magnetic field generated by modulating the stator split teeth interacts with the rotor magnetic field formed by the rotor winding to generate an electromagnetic torque, thereby enhancing the output capacity of the electromagnetic torque and improving the speed regulation performance of the magnetic field modulation motor.

[0042] In an exemplary embodiment, Figure 1 As shown, a magnetic field modulation motor is provided, comprising:

[0043] A stator assembly is arranged inside the magnetic field modulation motor, the stator assembly includes a stator core and a stator winding 4, the stator core includes a stator yoke 5 and a stator tooth 3, the stator winding 4 is sleeved on the stator tooth 3, the bottom end of the stator tooth 3 is connected to the stator yoke 5, and the top end of the stator tooth 3 is provided with a stator split tooth;

[0044] A rotor assembly is arranged outside the magnetic field modulation motor, the rotor assembly comprises a rotor core 1 and a rotor winding 2, the rotor winding 2 is wound in the rotor core 1, and the rotor core 1 is connected to the stator split teeth;

[0045] Among them, the number of pole pairs of the rotor winding is P f , the number of pole pairs of stator winding P a and the number of stator split teeth Z s The relationship between them is shown as follows:

[0046] .

[0047] Specifically, Figure 1 As shown, the stator core can adopt a modular structure, the stator winding 4 can be a multi-phase winding, and the stator winding 4 can adopt a formed coil to be sleeved on the stator tooth part 3, which is easy to process and manufacture; the rotor core 1 is provided with a slot, the slot type is a semi-closed slot, and the rotor winding 2 is embedded in the slot; the stator split teeth can modulate the magnetic field, that is, the stator split teeth can modulate the rotor magnetic field (fundamental magnetic field) formed by the rotor winding to generate a stator magnetic field (harmonic magnetic field), and the rotor magnetic field and the stator magnetic field interact to generate electromagnetic torque, thereby enhancing the output capacity of the electromagnetic torque and improving the speed regulation performance of the magnetic field modulation motor, and the number of pole pairs of the rotor winding is the absolute value of the difference between the number of pole pairs of the stator winding and the number of stator split teeth.

[0048] Exemplarily, the magnetic field modulation motor can adopt the multi-field harmonic working principle. The stator split teeth can modulate the rotor magnetic field (fundamental magnetic field) formed by the rotor winding to generate a stator magnetic field (harmonic magnetic field). Electromagnetic torque can also be generated between each stator magnetic field (harmonic magnetic field), thereby enhancing the output capacity of the electromagnetic torque and improving the speed regulation performance of the magnetic field modulation motor.

[0049] Compared with the existing magnetic field modulation motor, the above-mentioned magnetic field modulation motor only generates the fundamental magnetic field to generate electromagnetic torque, and the harmonic magnetic field cannot generate useful electromagnetic torque. The stator magnetic field generated by stator split tooth modulation interacts with the rotor magnetic field formed by the rotor winding to generate electromagnetic torque, thereby enhancing the output capacity of the electromagnetic torque and improving the speed regulation performance of the magnetic field modulation motor.

[0050] In one embodiment, the stator core and the rotor core are both formed by laminating silicon steel sheets.

[0051] Specifically, Figure 2 The structure of the stator teeth is shown as an example. Figure 2 As shown, a stator split tooth 31 is arranged at the top of the stator tooth body 32, and a dovetail structure 33 is arranged at the bottom of the stator tooth body 32. The stator winding 4 can be formed into a coil sleeve on the stator tooth part, which is convenient for processing and manufacturing; wherein, the stator core and the rotor core are both made of laminated silicon steel sheets.

[0052] In one embodiment, the rotor winding is an electric field winding;

[0053] The bottom end of the stator tooth portion is connected to the stator yoke portion by a dovetail structure.

[0054] Specifically, in order to ensure the high reliability requirements of special working conditions, the rotor winding adopts an electric excitation winding. Compared with the existing magnetic field modulation motor using permanent magnets, the electric excitation winding can achieve real-time demagnetization, thereby improving high temperature resistance and reducing costs.

[0055] Figure 3 The structure of the stator yoke is shown as an example. Figure 3 As shown, the stator yoke body 53 plays a role of mechanical support. The outer side of the stator yoke body 53 is provided with stator yoke teeth 51 and stator yoke dovetail slots 52. The bottom end of the stator teeth can be connected through the stator yoke dovetail slots 52. The stator yoke dovetail slots 52 and the stator yoke teeth 51 together play a role of fixing the modular stator teeth.

[0056] In the embodiment of the present application, by adopting an electric excitation winding as the rotor winding, the problems of poor speed regulation performance, high cost and high temperature demagnetization brought about by the existing magnetic field modulation motor using permanent magnets are overcome, real-time demagnetization is achieved, high temperature resistance is improved while reducing costs; the bottom end of the stator tooth and the stator yoke are connected by a dovetail structure, so that the connection between the stator tooth and the stator yoke is tighter, thereby improving the quality of the magnetic field modulation motor.

[0057] In an exemplary embodiment, Figure 4As shown, a motor system is provided, the motor system includes a first converter, a second converter, a controller and the above-mentioned magnetic field modulation motor;

[0058] The controller is connected to the input end of the first converter and the input end of the second converter respectively to control the current frequency output by the first converter and the second converter. The output end of the first converter is connected to the input end of the stator winding, and the output end of the second converter is connected to the input end of the rotor winding.

[0059] Among them, Figure 4 As shown, the magnetic field modulation motor can be a doubly fed magnetic field modulation motor, the first converter is a stator power electronic converter, the second converter is a rotor power electronic converter, the output end of the first converter is connected to the stator winding arranged on the inner side of the doubly fed magnetic field modulation motor, and the output end of the second converter is connected to the rotor winding arranged on the outer side of the doubly fed magnetic field modulation motor.

[0060] Specifically, Figure 4 As shown, a doubly-fed magnetic field modulation motor is used in the motor system, and it works with dual electrical ports, that is, there are energy paths on both the stator side (stator winding) and the rotor side (rotor winding) of the doubly-fed magnetic field modulation motor. The power can flow in both directions not only through the stator winding, but also through the rotor power electronic converter. Most of the power of the doubly-fed magnetic field modulation motor flows directly through the stator winding, so that the capacity of the rotor power electronic converter accounts for a relatively low proportion of the total capacity of the doubly-fed magnetic field modulation motor. For example, the capacity of the second converter is only 30% of the total capacity of the magnetic field modulation motor of the same power level, which reduces the cost of the motor system; the controller can control the current frequency output by the first converter and the second converter to achieve the speed regulation of the doubly-fed magnetic field modulation motor.

[0061] It should be noted that the controller can change the speed and power flow direction of the doubly fed magnetic field modulation motor by controlling the direction and phase sequence of the current output by the first converter to the stator winding and the direction and phase sequence of the current output by the second converter to the rotor winding, thereby realizing four-quadrant operation of the doubly fed magnetic field modulation motor, that is, super synchronous speed and subsynchronous speed operation under motoring and generating conditions, with excellent speed regulation performance, a wide working range, and improved operation performance of the motor system; compared with the existing (permanent magnet) magnetic field modulation motor, by using the electric excitation winding as the rotor winding, at different speeds, the excitation magnetic field of the doubly fed magnetic field modulation motor can be adjusted by adjusting the magnitude of the current output to the rotor winding to achieve stable output of electromagnetic torque at different speeds, while the motor using permanent magnets for excitation (existing magnetic field modulation motor) needs to reduce the output electromagnetic torque at high speeds, and use weak magnetic control to ensure the speed requirement of the motor, that is, it is necessary to sacrifice the torque output of the motor, while the electric excitation motor (doubly fed magnetic field modulation motor) does not have such a problem and has excellent speed regulation performance.

[0062] Exemplarily, the stator winding in the motor system can also be used to connect to the power grid. When the stator winding is connected to the power grid for operation, the stator side frequency can be set according to actual conditions. Here, the stator side frequency is fixed at 50 Hz as an example. At this time, the controller can control the current frequency output by the second converter to achieve the speed regulation of the doubly fed magnetic field modulation motor.

[0063] The above-mentioned motor system includes a first converter, a second converter, a controller and the above-mentioned magnetic field modulation motor. The controller controls the current frequency output by the first converter and the second converter to achieve regulation of the rotational speed of the magnetic field modulation motor. Since the stator winding of the magnetic field modulation motor is connected to the first converter and the rotor winding is connected to the second converter, that is, there are energy paths on the stator side (stator winding) and the rotor side (rotor winding) of the magnetic field modulation motor, the capacity of the second converter accounts for a relatively low proportion of the total capacity of the magnetic field modulation motor, thereby reducing the cost of the motor system.

[0064] In one embodiment, the first converter is a frequency converter; the second converter is a frequency converter.

[0065] Specifically, the controller can control the current frequency output by the corresponding frequency converter to adjust the rotation speed of the magnetic field modulation motor.

[0066] In one embodiment, when the number of stator split teeth Z s Greater than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula:

[0067] ;

[0068] When the number of stator split teeth Z s Smaller than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula:

[0069] .

[0070] Specifically, the controller can obtain the number Z of stator split teeth respectively s and the number of pole pairs of the rotor winding P f, and compare them. According to the comparison result, combined with the above formula, the angular velocity Ω of the rotor assembly is determined. It should be noted that the unit of angular velocity Ω is rad / s; it should be noted that the number of stator split teeth Z s and the number of pole pairs of the rotor winding P f The numbers are not equal.

[0071] In one embodiment, when the stator winding receives the current output by the first converter, the number of magnetic field pole pairs generated by the stator split teeth is P k,j Satisfy the following formula:

[0072] ;

[0073] Among them, P f is the number of pole pairs of the rotor winding; Z s is the number of stator split teeth; k is a positive integer; j is an integer.

[0074] Specifically, when the stator winding receives the current output by the first converter, that is, the magnetic field generated by the stator winding after being energized interacts with the stator split teeth, the magnetic field pole pair number P generated is k,j Satisfies the above formula; where the number of pole pairs of the stator winding P a The number of magnetic field pole pairs after modulation P 1,-1 (rotor pole pairs) are equal, which can generate stable torque, produce a deceleration similar to the reduction gearbox and amplify the electromagnetic torque; in addition, after the stator winding is energized, the magnetic field modulates the P in the air gap space of the motor. f / P a The number of pole pairs of the subharmonic magnetic field and the number of pole pairs of the rotor winding after power is applied P f The number of magnetic field pole pairs is the same, generating a stable electromagnetic torque.

[0075] For example, in order to verify the improvement of the speed regulation performance of the doubly-fed magnetic field modulation motor, the finite element analysis method is used to compare the torque of the doubly-fed magnetic field modulation motor with that of the existing doubly-fed motor (ordinary doubly-fed motor) of the same volume. The results are as follows: Figure 5 As shown, Figure 5 The double-fed vernier magnetic field modulation motor is the magnetic field modulation motor (double-fed magnetic field modulation motor) in the embodiment of the present application; Figure 5 It can be seen that the magnetic field modulation motor provided by the embodiment of the present application can effectively increase the electromagnetic torque and enhance the speed regulation performance of the magnetic field modulation motor.

[0076] It should be noted that finite element analysis is a simulation software. By building a motor model in the software, the torque output characteristics of the motor can be obtained.

[0077] In an exemplary embodiment, a control method of a motor system is provided, which is applied to the controller of the motor system, and the method includes:

[0078] In response to the control instruction, the first converter and the second converter are respectively instructed to output at corresponding current frequencies based on the control instruction.

[0079] Specifically, the control instructions can be set according to actual conditions and are not limited in the embodiments of the present application; the controller can instruct the first converter and the second converter to output at corresponding current frequencies based on the control instructions to achieve the adjustment of the speed of the doubly fed magnetic field modulation motor.

[0080] In one embodiment, the method further comprises:

[0081] The current phase sequences output by the first converter and the second converter are adjusted respectively according to the control instructions.

[0082] Specifically, the controller can change the speed and power flow of the doubly fed magnetic field modulation motor by controlling the direction and phase sequence of the current output by the first converter to the stator winding and the direction and phase sequence of the current output by the second converter to the rotor winding, thereby realizing four-quadrant operation of the doubly fed magnetic field modulation motor, that is, supersynchronous speed and subsynchronous speed operation under motoring and generating conditions, with excellent speed regulation performance, a wide working range, and improved operating performance of the motor system.

[0083] In an exemplary embodiment, an electric power device is provided, comprising the above-mentioned motor system.

[0084] It should be noted that the data involved in this application (including but not limited to data used for analysis, stored data, displayed data, etc.) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0085] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0086] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0087] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A magnetic field modulation motor, characterized in that: Applied to a motor system, the motor system includes a first converter and a second converter, the output end of the first converter and the output end of the second converter are both connected to the magnetic field modulation motor, and the magnetic field modulation motor includes: A stator assembly is arranged inside the magnetic field modulation motor, the stator assembly includes a stator core and a stator winding, the stator core includes a stator yoke and a stator tooth, the stator winding is sleeved on the stator tooth, the bottom end of the stator tooth is connected to the stator yoke, and the top end of the stator tooth is provided with a stator split tooth; A rotor assembly is arranged outside the magnetic field modulation motor, the rotor assembly comprises a rotor core and a rotor winding, the rotor winding is wound in the rotor core, and the rotor core is connected to the stator split teeth; Among them, the number of pole pairs of the stator winding is P a , the number of pole pairs P of the rotor winding f and the number of stator split teeth Z s The relationship between them is shown as follows: ； The output end of the first converter is connected to the input end of the stator winding, and the output end of the second converter is connected to the input end of the rotor winding; When the number of stator split teeth Z s Greater than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula: ； When the number of stator split teeth Z s Less than the number of pole pairs P of the rotor winding f When the angular velocity Ω of the rotor assembly and the current frequency f output by the first converter are a and the current frequency f output by the second converter e The relationship between them satisfies the following formula: 。 2. The magnetic field modulation motor according to claim 1, characterized in that: The stator core and the rotor core are both formed by laminating silicon steel sheets.

3. The magnetic field modulation motor according to claim 1, characterized in that: The rotor winding is an electric excitation winding; The bottom end of the stator tooth portion is connected to the stator yoke portion by a dovetail structure.

4. A motor system, characterized in that: The motor system comprises a first converter, a second converter, a controller and a magnetic field modulation motor according to any one of claims 1 to 3; Wherein, the controller is respectively connected to the input end of the first converter and the input end of the second converter to control the current frequency output by the first converter and the second converter, the output end of the first converter is connected to the input end of the stator winding, and the output end of the second converter is connected to the input end of the rotor winding.

5. The motor system according to claim 4, characterized in that: When the stator winding receives the current output by the first converter, the number of magnetic field pole pairs generated by the stator split teeth is P k,j Satisfy the following formula: ； Among them, the P f is the number of pole pairs of the rotor winding; s is the number of stator split teeth; k is a positive integer; j is an integer.

6. The motor system according to claim 4, characterized in that: The first converter is a frequency converter; the second converter is a frequency converter.

7. A control method for a motor system, characterized in that: A controller for a motor system according to any one of claims 4 to 6, wherein the method comprises: In response to a control instruction, the first converter and the second converter are respectively instructed to output at corresponding current frequencies based on the control instruction.

8. The method according to claim 7, characterized in that The method further comprises: The current phase sequences output by the first converter and the second converter are adjusted respectively according to the control instruction.

9. An electric power device, characterized in that: A motor system comprising any one of claims 4 to 6.

Images