CN103296798B - A kind of double speed wound stator surface-adhered type doubly salient permanent magnet motor - Google Patents

Abstract

The invention discloses a dual-speed winding stator surface-mounted double salient pole permanent magnet motor adopting a modular rotor. The motor consists of a stator core (1), a high-speed concentrated armature winding (2), and a low-speed concentrated armature winding ( 3), permanent magnet (4), rotor core (5) and magnetic isolation mechanism (6), each coil of the high-speed centralized armature winding straddles on a stator core tooth, and the low-speed centralized armature winding Each coil straddles each stator permanent magnet tooth respectively. Through the distribution of control signals, the motor can be switched between low-speed operation and high-speed operation, so that the dual-speed winding stator surface-mounted double-salient permanent magnet motor with modular rotor can meet the requirements of the low-speed area at the same time. And the performance requirements in the high-speed area, so that the large torque output in the constant torque area and the wide speed regulation operation in the constant power area can be realized on this two-speed winding flux switching motor.

Description

A double-salient pole permanent magnet motor with two-speed winding stator surface mount type

technical field

The invention relates to the technical field of motor manufacturing, in particular to a stator surface-mounted double salient pole permanent magnet motor with a double-speed winding and a modular rotor.

Background technique

With the continuous aggravation of the energy crisis, it is of great theoretical significance and practical value to research, develop, and popularize the application of new structure high-efficiency rare earth permanent magnet motors to save energy. Especially the hybrid electric vehicle which is extensively researched at present requires the motor drive system among them to be small in size, light in weight, high in efficiency, large in torque output, and wide in speed regulation range. As a typical stator permanent magnet double salient pole permanent magnet motor, the stator surface mount double salient pole permanent magnet motor has neither permanent magnets nor windings on the rotor, and the permanent magnets and concentrated armature windings are located on the stator. Working according to the principle of "magnetic flux reversal", it has the advantages of no-load induced potential close to square wave or sine wave, simple and solid rotor structure, suitable for high-speed operation, and high power density. It is used in industrial drives, electrical speed regulation, stirring systems, electric vehicles , household appliances, textile machinery and other fields have shown strong competitiveness and broad application prospects.

The application occasions represented by the electric vehicle drive system require the motor system to be able to achieve large torque output in the constant torque area and wide speed regulation operation in the constant power area. However, for conventional motor drive systems, it is difficult to meet these two requirements simultaneously. The reason is that the large torque output in the low-speed area and the constant power field-weakening operation in the high-speed area are a pair of irreconcilable contradictions. When designing the motor and controller, usually only the performance requirements of the two areas can be considered, and the respective performance requirements cannot be fully utilized. the maximum capacity of the region. Specifically, the traditional stator surface-mounted double salient pole (double salient pole stator and rotor are both salient pole structure) permanent magnet motor stator has several teeth evenly distributed, the tooth shape is exactly the same, and the winding adopts a uniform winding method. That is, each stator tooth is covered with a centralized coil with the same number of turns and the same wire diameter, and a stator slot is divided into two halves, and the coil sides of the two coils belonging to different phases are arranged side by side in the same stator slot . The multi-phase symmetrical winding coils are evenly distributed along the circumference of the stator. Several coils are connected in series, parallel or mixed according to the performance requirements to form a phase winding, and all the coils forming the phase are energized when a certain phase of the motor is working. The stator surface-mounted doubly salient permanent magnet motor using the above-mentioned traditional winding structure can only show good performance in a certain operating area in the low-speed area or high-speed area, and it is difficult to meet the high performance in the entire operating range at the same time. Requirements limit its further promotion and development in applications such as electric vehicles that require short-term low-speed high-torque output capabilities and a wide range of high-speed constant power ranges. Therefore, a new technical solution is needed to solve the above problems.

Contents of the invention

The purpose of the present invention is to provide a stator surface-mounted double salient pole permanent magnet motor capable of simultaneously realizing large torque output in the constant torque region and wide speed regulation operation in the constant power region in view of the deficiencies in the prior art.

The dual-speed winding stator surface-mounted double salient pole permanent magnet motor adopting a modular rotor of the present invention includes: the motor is composed of a stator core, a high-speed centralized armature winding (also called a high-speed winding), and a low-speed centralized armature winding ( Also known as low-speed winding), permanent magnet, U-shaped rotor magnetic core and magnetic isolation mechanism; it is characterized in that: the stator core and rotor core are salient pole structures; the stator teeth are divided into two groups, respectively in the stator The stator permanent magnet teeth with permanent magnets attached to the surface of the teeth facing the air gap and the stator core teeth without permanent magnets on the surface of the stator teeth facing the air gap; the stator permanent magnet teeth and the stator core teeth are alternately distributed in a ring shape along the circumference, The coils of the high-speed centralized armature winding straddle the stator core teeth respectively, and the coils of the low-speed centralized armature winding respectively straddle a stator permanent magnet tooth; the radial magnetization The permanent magnets are mounted on the surface of a fixed low-speed stator tooth facing the rotor, and the magnetization directions of the two adjacent permanent magnets are opposite; the rotor is composed of a U-shaped rotor core and a magnetic isolation mechanism, and each U-shaped The lower ends of the rotor cores are respectively embedded in the magnetic isolation mechanism; the U-shaped magnetic units of the rotor can be connected together by connecting bridges. The internal magnetic field of the connecting bridges is highly saturated and the magnetic resistance is large, which can effectively prevent magnetic flux leakage .

Both the stator core and the rotor core are salient pole structures; the permanent magnets, high-speed concentrated armature windings and low-speed concentrated armature windings are located on the stator side; the rotor includes a U-shaped rotor core and a magnetic isolation mechanism .

The high-speed concentrated armature winding coil or the low-speed concentrated armature winding coil can be connected into a three-phase or multi-phase structure as required.

The radially magnetized permanent magnets are respectively mounted on the surface of a fixed low-speed stator tooth facing the rotor, and the magnetization directions of the two adjacent permanent magnets are opposite, and there is a stator core tooth between the adjacent two permanent magnets. , the material of the permanent magnet is ferrite or NdFeB permanent magnet material.

The two sets of windings of the motor are independent of each other, and the mutual inductance between each phase of each set of windings is small.

The U-shaped rotor magnet cores of the rotors are connected as a whole by connecting bridges. The internal magnetic field of the bridges is highly saturated and has no magnetic conduction effect, and only plays the role of connecting the U rotor magnet cores into a whole.

The U-shaped magnetic core of the rotor and the magnetic isolation mechanism can be located outside the stator to form an outer rotor structure.

The materials of the stator core, the rotor core and the connecting bridge are all magnetically conductive materials such as silicon steel sheets.

The permanent magnet can be an electric excitation mechanism, or a hybrid excitation mechanism composed of electric excitation and permanent magnet excitation.

The material of the magnetic isolation mechanism is copper, aluminum or other non-magnetic materials.

The electrical machine can be operated as a generator or as an electric motor.

Compared with the prior art, the stator of the double-speed winding stator surface-mounted double salient pole permanent magnet motor of the present invention is provided with low-speed stator teeth and high-speed stator teeth, and the motor can be operated at a low speed through the distribution of control signals. Switching between energized windings and high-speed operation makes this double-speed winding stator surface-mounted double salient permanent magnet motor meet the performance requirements of low-speed and high-speed regions at the same time, so that the large torque output in the constant torque region and the The wide speed regulation operation in the constant power area can be realized on the double-speed winding stator surface mount type double salient permanent magnet motor.

Further, the stator and the rotor are salient pole structures, the permanent magnets, low-speed concentrated armature windings and high-speed concentrated armature windings are all located on the stator, and the rotor has neither windings nor permanent magnets. The rotor is composed of a U-shaped magnetic core and a magnetic isolation mechanism, and each U-shaped magnetic core is respectively embedded in the magnetic isolation mechanism. The magnetic core can be a magnetic material such as a silicon steel sheet. The magnetic isolation mechanism can also reduce wind resistance while fixing the U-shaped magnetic core of the rotor. The magnetic isolation mechanism can be made of non-magnetic materials such as copper and aluminum.

Further, the low-speed winding and the high-speed winding work independently of each other, the low-speed winding is energized separately in the range of low-speed constant torque, and the high-speed winding is energized separately in the range of high-speed constant power. As the rotor rotates, when the magnetic flux of each coil turn chain of the high-speed winding undergoes a maximum-minimum-maximum electrical cycle change, the magnetic flux magnitude of each coil turn chain of the low-speed winding undergoes a maximum-minimum value —Maximum value—minimum value—the change of the two electrical cycles of the maximum value, so the alternating frequency of the induced potential of each coil of the low-speed winding is twice the alternating frequency of the induced potential of each coil of the high-speed winding, and the high-speed winding is selected in this way And the configuration of the low-speed winding can balance the switching frequency of the control circuit. Due to the existence of two sets of armature windings, even when one set of windings fails in each phase, the remaining set of normal windings can still be used to output a certain amount of power and torque to ensure the safety and reliability of the motor drive system.

Furthermore, the number of turns and wire diameters of the low-speed winding and high-speed winding can be optimized by optimizing the tooth width of the stator permanent magnet teeth and the stator core teeth respectively, so that the motor can work separately under the mechanical characteristic curves of the low-speed winding and high-speed winding Seamless connection for high-performance output across the entire operating range.

Beneficial effect:

1. Because in the motor of the present invention, the permanent magnet, the low-speed centralized armature winding and the high-speed concentrated armature winding are all located on the stator side, it is beneficial to improve the cooling conditions during the operation of the motor and facilitate the heat dissipation of the motor;

2. Since the motor stator and rotor of the present invention are all salient pole structures, it is easier to obtain permanent magnet flux linkage and no-load induced potential close to trapezoidal or sine waves, and more sinusoidal windings per phase can also be obtained through rotor chute No-load induction potential, more flexible control mode, suitable for different AC speed regulation and servo drive occasions;

3. The motor of the present invention adopts the novel winding structure, and can separately control the current of each phase low-speed winding and high-speed winding without increasing the cost and manufacturing difficulty, so that the motor can not only output large torque when running at low speed, but also can It has a wide range of speed regulation when running at high speed;

4. In the motor of the present invention, the stator core teeth provided with high-speed centralized armature windings and the stator permanent magnet teeth provided with low-speed centralized armature windings are alternately distributed along the circumference, and the two sets of armature windings of the motor work independently of each other, and each set The mutual inductance between each phase of the winding is very small, which has strong fault tolerance and improves the operation reliability of the motor;

5. Because there are two sets of armature windings in the motor of the present invention, even when all phases of one set of windings fail, the remaining set of normal windings can still be used to output certain power and torque, ensuring the safety and reliability of the motor drive system;

6. In the traditional double-salient pole permanent magnet motor with reverse magnetic flux, two permanent magnets with opposite directions of magnetization are pasted under each stator tooth, and the magnetic flux leakage between the permanent magnets is relatively serious. However, in the motor of the present invention, each stator permanent magnet tooth There is only one permanent magnet on the top, which significantly weakens the magnetic flux leakage of the permanent magnet and improves the utilization rate of the permanent magnet;

7. Compared with the traditional stator surface-mounted double-salient pole permanent magnet motor, the motor of this invention adopts a modular rotor, and only half of the number of stator teeth are attached with permanent magnets. The permanent magnet flux is bipolar, and the torque (power) of the unit permanent magnet is relatively large;

8. Since both the high-speed armature winding and the low-speed armature winding of the motor of the present invention adopt a centralized winding mode, the ends of the coils are relatively short, which is beneficial to improving the efficiency of the motor and reducing the manufacturing cost;

9. Through the reasonable selection of the stator and rotor cogging, the coils that make up the armature winding of one phase have winding complementarity, which can significantly reduce the harmonic content of the synthetic flux linkage, improve the reliability of the system operation and reduce the torque ripple.

Description of drawings

Fig. 1 is the transverse sectional view of motor of the present invention;

Fig. 2 is the lateral sectional view of the motor of the present invention adding a connecting bridge;

Fig. 3 is the three-phase induced potential waveform of the high-speed centralized armature winding of the motor of the present invention;

Fig. 4 is the three-phase induced potential waveform of the low-speed centralized armature winding of the motor of the present invention.

Reference signs: 1 - stator core, 2 - high-speed centralized armature winding, 3 - low-speed concentrated armature winding, 4 - permanent magnet, 5 - rotor core, 6 - magnetic isolation mechanism, 7 - connecting bridge.

detailed description

The present invention will be further explained below with reference to the accompanying drawings.

As shown in Fig. 1, according to the double-speed winding stator surface mount type double salient pole permanent magnet motor adopting the modular rotor of the present invention, it comprises the stator core 1 of salient pole structure, the rotor core 5 of salient pole structure, the high-speed centralized Armature winding 2, low-speed centralized armature winding 3, permanent magnet 4 and magnetic isolation mechanism 6. Both the stator core 1 and the rotor core 5 of the dual-speed winding stator surface-mounted double salient pole permanent magnet motor adopting a modular rotor of the present invention can be made by laminating silicon steel punching sheets, and the stator core 1 and the rotor core 5 Both are salient pole structures; the stator is provided with a high-speed centralized armature winding 2, a low-speed centralized armature winding 3 and a permanent magnet 4. The stator teeth are divided into two groups, which are stator permanent magnet teeth (that is, in the stator Permanent magnets 4) and stator core teeth are pasted on the surface of the teeth facing the air gap (that is, there is no permanent magnet 4 on the surface of the stator teeth facing the air gap); the stator permanent magnet teeth and stator core teeth are alternately distributed in a ring along the circumference; Each coil of the high-speed centralized armature winding 2 straddles each stator core tooth, and each coil of the low-speed centralized armature winding 3 straddles each stator permanent magnet tooth. The three-phase high-speed centralized armature winding 2 has six coils in total, and the three-phase low-speed centralized armature winding 3 also has six low-speed centralized armature winding coils. And the coils of the high-speed concentrated armature winding 2 and the coils of the low-speed concentrated armature winding 3 are alternately distributed along the circumference.

The first high-speed concentrated armature winding coil 201 and the fourth high-speed concentrated armature winding coil 204 of the three-phase high-speed centralized armature winding 2 are connected in series to form the A-phase high-speed centralized armature winding, and the two winding coils must be energized The flow direction of the subsequent magnetic linkage is the same.

The second high-speed concentrated armature winding coil 202 of the three-phase high-speed centralized armature winding 2 and the fifth high-speed concentrated armature winding coil 205 are connected in series to form a B-phase high-speed centralized armature winding, and the two winding coils must be energized The flow direction of the subsequent magnetic linkage is the same.

The third high-speed concentrated armature winding coil 203 of the three-phase high-speed centralized armature winding 2 and the sixth high-speed concentrated armature winding coil 206 are connected in series to form a C-phase high-speed centralized armature winding, and the two winding coils must be energized The flow direction of the subsequent magnetic linkage is the same.

The first low-speed concentrated armature winding coil 301 and the fourth low-speed concentrated armature winding coil 304 of the three-phase low-speed concentrated armature winding 3 are sequentially connected in series to form the a-phase low-speed concentrated armature winding, and it is necessary to ensure that the two winding coils After electrification, the flux linkage flows in the same direction.

The second low-speed concentrated armature winding coil 302 of the three-phase low-speed concentrated armature winding 3 and the fifth low-speed concentrated armature winding coil 305 are sequentially connected in series to form a b-phase low-speed concentrated armature winding, and the two winding coils must be guaranteed After electrification, the flux linkage flows in the same direction.

The third low-speed concentrated armature winding coil 303 and the sixth low-speed concentrated armature winding coil 306 of the three-phase low-speed concentrated armature winding 3 are sequentially connected in series to form a c-phase low-speed concentrated armature winding, and the two winding coils must be guaranteed After electrification, the flux linkage flows in the same direction.

As shown in Figure 1, the direction indicated by the arrow in the figure is the magnetization direction of the permanent magnet 4 where it is located, and each permanent magnet 4 is radially magnetized, and each permanent magnet 4 is mounted on each The permanent magnet teeth of the stator face the surface of the rotor, and the magnetization directions of two adjacent permanent magnets 4 are opposite (there is a stator core tooth between two adjacent permanent magnets 4); the stator surface mount double salient pole permanent magnet motor The work follows the principle of minimum reluctance. As the rotor rotates, the permanent magnetic flux linkage of the turn chains in the coils of the high-speed centralized armature winding 2 changes in bipolarity, and is induced in each coil of the high-speed centralized armature winding 2. The no-load induced potential is close to the trapezoidal wave change, and as the rotor rotates, the permanent magnet flux linkage of each coil turn chain of the low-speed centralized armature winding 3 presents a unipolar change, and induces an alternating no-load induced potential, When the flux linkage of each coil of the high-speed centralized armature winding 2 experiences a maximum value-minimum value-maximum change in an electric cycle, the flux linkage of each coil of the low-speed centralized armature winding 3 experiences the maximum value-minimum value-maximum value- The change of minimum value-maximum two electrical cycles, so the alternating frequency of the induced potential of each coil of the low-speed centralized armature winding 3 is twice the alternating frequency of the induced potential of each coil of the high-speed concentrated armature winding 2. Therefore, when the three-phase centralized low-speed armature winding 3 is fed with three-phase symmetrical alternating current, the motor has a stable speed and electromagnetic torque output, and the motor works at a low-speed and high-torque output state; When the three-phase centralized high-speed armature winding 2 is fed with three-phase symmetrical alternating current, the motor also has stable rotational speed and electromagnetic torque output, and the motor works at a high-speed and low-torque output state.

Under the condition of not changing the iron core and magnet of the stator and rotor of the motor, the invention can enable the motor to output high torque at low speed operation and have a wide speed regulation range at high speed operation only by changing the winding structure, which meets the following requirements A generation of drive motor function requirements.

In addition to the three-phase 12/10-pole motor in this embodiment, the motor of the present invention can also be designed as a three-phase 6/4-pole motor, single-phase or multi-phase motor, etc. as required.

With this new winding structure, the current of the low-speed winding and high-speed winding of each phase can be controlled separately without increasing the cost and manufacturing difficulty, so that the motor can not only output high torque at low speed, but also have high performance at high speed. Wide speed range.

The permanent magnet teeth of the motor are equipped with low-speed winding coils suitable for low-speed operation, and the core teeth are equipped with high-speed winding coils suitable for high-speed operation. Therefore, the permanent magnet teeth and core teeth can be treated separately, and their respective shapes and sizes can be optimized to further improve motor performance.

The material of the permanent magnet 4 can be other permanent magnetic materials such as ferrite or NdFeB. The rotor is composed of U-shaped magnetically permeable cores 5 and magnetic isolation mechanisms 6, and the lower ends of each U-shaped magnetic permeable cores 5 are respectively embedded in the magnetic isolation mechanisms 6, and the rotor part has neither permanent magnets nor windings. The U-shaped rotor cores 5 can be connected together by a connecting bridge 7, so that the motor rotor cores 5 are integrated, as shown in FIG. 2 . The internal magnetic field of the connecting bridge 7 is highly saturated, and the magnetic permeability of the connecting bridge 7 is close to air, which can significantly weaken the magnetic flux leakage, so that the connecting bridge 7 has no magnetic conduction effect, and only plays the role of connecting the rotor U-shaped magnetically permeable core 5 as a whole. effect.

Fig. 3 is the no-load three-phase induced potential waveform of the high-speed centralized armature winding 2 of the motor of the present invention under a rotor mechanical cycle, as can be seen from the figure, as the rotor rotates, a connection similar to that will be generated in the high-speed centralized armature winding 2 Three-phase symmetrical no-load induced potential of trapezoidal waves. Fig. 4 is the no-load three-phase induced potential waveform of the low-speed centralized armature winding 3 of the motor of the present invention under one rotor mechanical cycle. It can be seen by comparing the potential waveforms of Fig. 3 and Fig. 4 that as the rotor rotates, the low-speed centralized armature The alternating frequency of induced potential of winding 3 is twice the alternating frequency of induced potential of high-speed centralized armature winding 2, while the induced potential of low-speed centralized armature winding 3 and the induced potential of high-speed centralized armature winding 2 have the same Therefore, by reasonably configuring the high-speed winding 2 and the low-speed winding 3, the switching frequency of the control circuit can be balanced.

It should be noted that, since there are two sets of armature windings in the motor of the present invention, even when all phases of one set of windings fail, the remaining set of normal windings can still be used to output a certain amount of power and torque, ensuring Safe and reliable motor drive system.

The above descriptions are only preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments, but all equivalent modifications or changes made by those of ordinary skill in the art according to the disclosure of the present invention should be included within the scope of protection described in the claims.

Claims (8)

1. a double speed wound stator surface-adhered type doubly salient permanent magnet motor for Modular rotor, this motor comprises: this motor is by stator core (1), the centralized armature winding of high speed (2), the centralized armature winding of low speed (3), permanent magnet (4), U-shaped rotor magnetic conductive iron (5) and form every magnetic mechanism (6); It is characterized in that: described stator core (1) and U-shaped rotor magnetic conductive iron (5) are salient-pole structure; Stator tooth is divided into two groups, be respectively stator tooth to post towards the surface of air gap permanent magnet stator permanent magnet tooth and at stator tooth towards the surface of air gap without the stator core tooth of permanent magnet; Described stator permanent magnet tooth and stator core tooth are circumferentially alternately distributed circlewise, each coil of the centralized armature winding of high speed (2) is respectively across in each stator core tooth, and each coil of the centralized armature winding of low speed (3) is respectively across on each stator permanent magnet tooth; The permanent magnet (4) of radial magnetizing is mounted on the surface of a stator tooth towards rotor respectively, and the magnetizing direction of adjacent two pieces of permanent magnets is contrary; Rotor is by U-shaped rotor magnetic conductive iron (5) and form every magnetic mechanism (6), and the lower end of each U-shaped rotor magnetic conductive iron (5) is embedded in respectively in magnetic mechanism (6); Linked together by connecting bridge (7) between U-shaped rotor magnetic conduction unit, connecting bridge (7) internal magnetic field height is saturated, and magnetic resistance is comparatively large, effectively can prevent leakage field; Described stator core (1) and U-shaped rotor magnetic conductive iron (5) are salient-pole structure; Described permanent magnet (4), the centralized armature winding of high speed (2) and the centralized armature winding of low speed (3) are all positioned at stator side; Described rotor comprises U-shaped rotor magnetic conductive iron (5) and every magnetic mechanism (6); High speed centralized armature winding coil or the centralized armature winding coil of low speed connect into three-phase or heterogeneous structure.

2. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of Modular rotor according to claim 1, it is characterized in that, the magnetizing direction of adjacent two pieces of permanent magnets is contrary, be separated with a stator core tooth between adjacent two pieces of permanent magnets, the material of described permanent magnet (4) is the permanent magnetic material of ferrite or neodymium iron boron.

3. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of Modular rotor according to claim 1, it is characterized in that, motor double winding is separate, and the mutual inductance of often overlapping between each phase of winding is all less.

4. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of Modular rotor according to claim 1, it is characterized in that, described U-shaped rotor magnetic conductive iron (5) connects into as a whole by connecting bridge (7), described connecting bridge (7) internal magnetic field height is saturated, without magnetic conduction effect, only play and each U-shaped rotor magnetic conductive iron (5) connected into an overall effect.

5. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of Modular rotor according to claim 1, it is characterized in that, U-shaped rotor magnetic conductive iron (5) and be positioned at the outside of stator every magnetic mechanism (6), becomes outer-rotor structure.

6. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of the Modular rotor according to any one of claim 1-5, it is characterized in that, the material of described stator core (1), U-shaped rotor magnetic conductive iron (5) and connecting bridge (7) is silicon steel sheet permeability magnetic material.

7. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of the Modular rotor according to any one of claim 1-5, it is characterized in that, described permanent magnet (4) is electric excitation mechanism, or the composite excitation mechanism be made up of electric excitation and permanent magnet excitation.

8. the double speed wound stator surface-adhered type doubly salient permanent magnet motor of the Modular rotor according to any one of claim 1-5, is characterized in that, the described material every magnetic mechanism (6) is non-magnet_conductible material.