CN205081660U - A Double Winding High Power Density Hybrid Excitation Permanent Magnet Linear Generator - Google Patents

Abstract

The utility model discloses a double-winding high power density hybrid excitation permanent magnet linear generator, which comprises a stator, an even number of stator teeth is evenly arranged on the stator, stator slots are arranged in two adjacent stator teeth, the stator slot yoke and the stator There is a permanent magnet between the back yoke, and a main air gap is set between the stator teeth and the mover teeth of the mover; the stator slots include armature slots and excitation slots, the armature slots and excitation slots are arranged alternately, two adjacent There is a set of armature windings in the armature slot, and a set of excitation windings in the two adjacent excitation slots. The excitation windings pass DC current in the same direction; the yoke of the stator slot where the excitation windings are located is provided with additional air. Part of the magnetic flux generated by two adjacent permanent magnets enters the mover through the main air gap to form the main magnetic flux, and the other part passes through the additional air gap to form the leakage flux. The utility model can adjust the size of the leakage magnetic flux by adjusting the direction and size of the current in the excitation winding, and plays the role of magnetization and demagnetization.

Description

A Double Winding High Power Density Hybrid Excitation Permanent Magnet Linear Generator

technical field

The utility model relates to a double winding high power density hybrid excitation permanent magnet linear generator.

Background technique

The linear motor drive device can directly convert the input electric energy into linear kinetic energy on the required occasion, realize linear motion, save the mechanical transmission conversion device in the traditional motion-linear conversion drive mode, and greatly reduce the volume of the transmission device. It improves the reliability and efficiency of the whole system, and effectively reduces the cost and maintenance cost of the equipment. Not only that, but also the high speed, high precision and robustness that the traditional motion-linear conversion drive method cannot achieve. In addition, the transmission conversion device will significantly increase the vibration and noise of the transmission system, reducing the control accuracy and performance of the system. Therefore, in the modern industrial production process, especially in all special applications, such as precision instruments, aerospace instruments, medical instruments, etc., linear motors have been more and more widely used.

The linear generator can directly convert the kinetic energy generated by the linear motion into electrical energy. Using the linear generator to generate electricity directly can significantly enhance the mechanical mutual matching between the moving parts and the power generation device, and the kinetic energy capture rate is high, especially in the low-speed linear motion system. It is more advantageous to use a linear generator.

At present, there are the following types of linear generators, 1) linear induction generators, which are characterized by: obvious end effects, especially when running at high speed, the end effects make the motor propulsion significantly reduced; the efficiency and power factor are relatively low , usually the efficiency is 50% to 60%, the power factor is only about 0.5, and the control system and control strategy are very complicated; 2) The permanent magnet linear generator has the advantages of high power density and high efficiency, and has been applied to ocean wave energy direct current. drive power generation system. However, most of the permanent magnets of the existing permanent magnet linear motors are located on the mover. With the reciprocating motion of the mover, the magnetic properties of the permanent magnet materials are easily affected by external environmental factors such as temperature, rust and vibration. Therefore, for the operating environment The permanent magnet linear generator is not suitable for relatively harsh occasions; 3) The linear switched reluctance generator has a simple structure of the motor body, low manufacturing cost, high operational reliability, and has the advantage of being able to operate under various harsh conditions. low cost. In addition, its overall system efficiency is higher than that of linear induction motors, and it has a wide economical operating range, and can achieve a series of satisfactory performances through various flexible control strategies, but the power density of linear switched reluctance generators is relatively low. Low.

In recent years, with the improvement of high temperature resistance and price reduction of permanent magnet materials, permanent magnet motors have been more widely used in national defense, industrial and agricultural production, and daily life, and are moving towards high power, high performance and miniaturization. direction of development. At present, the power of permanent magnet motors ranges from a few milliwatts to several thousand kilowatts, and its application ranges from toy motors, industrial applications to large permanent magnet motors for ship traction, and has been widely used in various aspects of the national economy, daily life, military industry, and aerospace. Similar to the moving permanent magnet motor, the existing permanent magnet linear motor windings are generally three-phase, the number of stator slots is large, the winding process is complicated, and the manufacturing cost is high; the permanent magnets of most existing permanent magnet linear motors are located in the moving On the mover, it moves with the mover during operation. The permanent magnet needs to be fixed in a special process, and the manufacturing cost is high. Especially when the motor runs at a high speed, it is difficult to fix the permanent magnet. Since the permanent magnet is located on the mover, it is difficult to dissipate heat during operation. Lifting and vibration caused by reciprocating motion will cause damage to the permanent magnet mechanical structure and irreversible demagnetization; existing permanent magnet linear generators are generally three-phase, requiring at least 6 power switching devices, such as IGBTs, for the power inverter circuit of the motor Or MOSFET, etc., as well as the corresponding drive circuit and protection circuit for driving the power switching device, make the cost of the motor power inverter circuit quite high, even reaching two to three times the cost of the motor body. The increase in the number of power switching devices increases the control The complexity of the circuit increases the possibility of device failure and reduces the reliability of the system during operation. Most of the existing permanent magnet linear motors have permanent magnets directly facing the air gap, and the permanent magnets face the danger of non-demagnetization. Moreover, the existing permanent magnet linear motors have a large number of winding phases and a large number of inner slots in the iron core, and the manufacturing process of windings is complicated. , the amount of iron core is large, the quality of the motor is large, and the material utilization rate is low when the motor generates electricity.

Due to the fixed magnetomotive force of the permanent magnet in the existing permanent magnet linear motor, the main magnetic flux of the motor cannot be adjusted, resulting in a narrow constant power operating range, the voltage cannot be adjusted during power generation operation, and there is no function of demagnetization due to failure. The number of slots is large, and the winding off-line process is complicated; the permanent magnets of most existing permanent magnet motors are located on the mover and move with the mover during operation. The permanent magnets need to be fixed by special procedures, and the manufacturing cost is high, especially when the motor speed is high. , it is more difficult to fix the permanent magnet. Because the permanent magnet is located on the mover, it is difficult to dissipate heat during operation. The temperature rise and the vibration caused by the movement of the mover will cause damage to the permanent magnet mechanical structure and irreversible demagnetization; For three-phase, it is required that the power inverter circuit of the motor needs at least 6 power switching devices, such as IGBT or MOSFET, and the corresponding driving circuit and protection circuit for driving the power switching device, so that the cost of the motor power inverter circuit is quite High, even up to two to three times the cost of the motor body, the increase in the number of power switching devices increases the complexity of the control circuit, the possibility of device failure increases, and the reliability of the system during operation decreases.

In view of the shortcomings of existing permanent magnet linear motors that the excitation magnetic potential cannot be adjusted, relevant scholars have proposed some hybrid excitation structure motors. This type of hybrid excitation structure motors can be divided into two types in terms of excitation methods, one is permanent magnet magnetic potential and excitation Winding magnetic potential series structure, this type of structure is not widely used because the excitation flux needs to pass through the permanent magnet, the excitation current is large, the excitation loss is high, and there is a risk of irreversible demagnetization of the permanent magnet; the other type is the permanent magnet This type of structure generally adopts the stator permanent magnet type, the permanent magnet is located on the stator, and the magnetic field is adjusted by adjusting the current of the excitation winding. This type of motor has good magnetic modulation performance, but after adding the excitation winding, the motor winding More sets make the structure of the motor complex. Sometimes there are multiple sets of windings in one slot or there are both phase windings and excitation windings. The phase-to-phase insulation needs to be added in the slot, the winding process is complicated, and the slot utilization rate is low. Moreover, the excitation slot needs to be added, the mechanical structure of the motor is seriously fragmented, the assembly and fixing are difficult, the processing technology is complicated, and the cost of the motor is high. More importantly, after adding the field winding, at least one more power switching device needs to be added to control the current of the field winding, which further increases the cost of the power circuit. Moreover, the magnetic flux generated by the field winding and the main flux share the main magnetic field. circuit and main air gap, the excitation effect is limited by other design parameters of the motor. Once the motor is manufactured, the excitation effect can only be controlled by adjusting the excitation current, and the excitation flux cannot be controlled by separately designing the excitation magnetic circuit.

Therefore, it is necessary to seek a motor with less winding phases, less iron core consumption, simple motor body manufacturing process, permanent magnets located on the stator, easy installation, low cost, few switching devices in the power circuit, and low cost of the controller and power circuit. The hybrid excitation permanent magnet linear generator with magnetic field regulation function is very important.

Utility model content

In order to solve the above problems, the utility model proposes a double-winding high power density hybrid excitation permanent magnet linear generator. The stator of the permanent magnet motor has a set of stator armature windings and a set of excitation windings. In each slot of the motor, only There is a set of windings. During operation, only one set of armature windings passes through AC current, and the other set of excitation windings passes through DC current. There is no need for phase-to-phase insulation in the slot, the slot fullness rate is high, and the motor winding off-line process is simple, and the entire cost is lower than Various existing three-phase induction motors and permanent magnet motors; the permanent magnets are fixed on the stator and do not follow the reciprocating motion of the mover. The resulting mechanical stress is damaged, and the permanent magnet has disadvantages such as poor heat dissipation.

In order to achieve the above object, the utility model adopts the following technical solutions:

A double-winding high power density hybrid excitation permanent magnet linear generator, including a stator, a mover, an additional air gap and a main air gap, wherein:

An even number of stator teeth are uniformly arranged on the stator, stator slots are arranged in two adjacent stator teeth, permanent magnets are arranged between the stator slot yoke and the stator back yoke, the gap between the stator teeth and the mover teeth of the mover There is a main air gap between;

The stator slots include armature slots and excitation slots, the armature slots and excitation slots are alternately arranged at intervals, a set of armature windings surrounds two adjacent armature slots, and a set of excitation windings surrounds two adjacent excitation slots winding, and the armature winding passes an alternating current, and the field winding passes a direct current with a constant direction;

An additional air gap is set in the yoke of the stator slot where the excitation winding is located. Part of the magnetic flux generated by two adjacent permanent magnets enters the mover through the main air gap to form the main magnetic flux, and the other part passes through the additional air gap to form a leak. flux.

Furthermore, when the motor is running, it is only necessary to control the current magnitude and direction of a set of armature windings. The interaction between the armature current magnetic field and the magnetic field generated by the permanent magnet makes the magnetic flux on the stator teeth mutually strengthen or cancel each other. The stator magnetic field is at a certain The direction is continuously turned on or off, and the change of reluctance between the stator and the mover is used to generate torque and generate electricity. Only one set of armature windings is placed in the stator slot, no interphase insulation is required in the stator slot, the slot utilization rate is high, the winding off-line process is simple, and the manufacturing cost is low.

The setting that the permanent magnet does not rotate with the mover makes installation easy and is conducive to heat dissipation, which eliminates the shortcomings of ordinary single-phase permanent magnet motors such as mechanical stress damage and poor heat dissipation of the permanent magnet caused by the permanent magnet rotating with the mover.

Further, each permanent magnet is magnetized by a whole permanent magnet or spliced by multiple permanent magnets with narrower widths, and the widths of the permanent magnets can be the same or different.

The number of the stator teeth is an even number greater than or equal to 4.

The number of the mover teeth is greater than or equal to 1/2 of the number of the stator teeth.

The number of blocks of the permanent magnet is m times of the mover teeth, and m is a natural number greater than or equal to 1.

The magnetic flux generated by the field winding passes through the additional air gap, the stator teeth, the main air gap and the mover teeth to form a closed loop, the magnetic flux generated by the field winding does not pass through the permanent magnet, and forms a parallel relationship with the magnetic flux generated by the permanent magnet, reducing The magnetic resistance of the corresponding circuit of the excitation flux is reduced, and the same excitation current can generate a larger excitation flux, which not only effectively improves the efficiency of field weakening, but also avoids the reverse magnetization of the permanent magnet caused by the excitation flux passing through the permanent magnet. The risk of irreversible demagnetization, such as the decrease of magnetic performance, enhances the reliability of the motor.

The permanent magnet is in close contact with both the stator back yoke core and the stator slot yoke core.

The stator slot yoke is located at the bottom of the stator slot close to the outer direction, the magnetization directions of the permanent magnets on the same stator slot yoke are the same, and the magnetization directions of the permanent magnets on two adjacent stator slot yokes are opposite.

The additional air gap can be a uniform air gap with the same width everywhere, or a non-uniform air gap with different widths everywhere, and the width of the additional air gap can be changed or the upper and lower air gap structures with unequal widths can be used to obtain different magnetization. And magnetic field weakening characteristics, in order to meet the needs of different applications.

The size of the additional air gap determines the size of the leakage flux, and the size of the additional air gap should be determined according to the leakage flux, the number of turns and the current of the excitation winding.

The armature winding passes through the slot where one armature winding is located, and passes through the adjacent armature slot. The windings in two adjacent armature slots form an armature coil, and each armature coil spans two The stator pitch, the currents of the windings in two adjacent armature slots have the same magnitude and opposite directions.

The excitation winding enters from the slot where one excitation winding is located, and exits from the adjacent excitation slot. The windings in two adjacent excitation slots form an excitation coil, and each excitation coil spans two stator tooth pitches. The currents of the windings in the slots where the two excitation windings are located have the same magnitude and opposite directions.

When the motor is running, it is only necessary to control the magnitude and direction of the current of a set of armature windings. The direct current flowing through the excitation windings in the same direction, the armature current magnetic field, the excitation current magnetic field and the magnetic field generated by the permanent magnet interact to make the stator teeth The magnetic fluxes of the stators strengthen or cancel each other, the stator magnetic field is continuously turned on or off in a certain direction, and the torque and power generation are generated by using the reluctance change between the stator and the mover.

The width of the permanent magnet of the motor can be flexibly determined according to the magnetic energy product or remanence density of the permanent magnet, and the remanence density of the permanent magnet can be determined according to the design air gap flux density of the motor, and then by changing the pole arc coefficient of the permanent magnet. Determine the magnetic energy product of the permanent magnet. However, the existing permanent magnet motor is limited by the number of poles due to the pole arc coefficient. Usually, only high-performance permanent magnets can meet the design flux density requirements.

The permanent magnet can be made of high energy product permanent magnet material such as neodymium iron boron or low magnetic energy product permanent magnet material such as ferrite or alnico.

The working principle of the utility model is:

The stator core and mover core mover are made of laminated silicon steel sheets or iron core materials with high magnetic permeability. When the armature winding and the field winding are not energized, a part of the magnetic flux generated by the permanent magnet Through the stator slot yoke, the stator teeth and the main air gap flow into the mover teeth, then flow out through the adjacent mover teeth to the main air gap to reach the permanent magnet under the other pole, and then close through the stator back yoke, which forms the motor Main magnetic flux; another part of the magnetic flux generated by the permanent magnet does not pass through the main air gap, but passes through the additional air gap through the stator slot yoke, and enters the permanent magnet under the other pole. After being closed by the stator back yoke, this part of the magnetic flux The flux does not enter the main air gap and the mover, but only closes inside the stator, and this part of the flux is the leakage flux. There is an excitation slot near the center of the circle under the additional air gap, and an excitation winding is placed in the excitation slot. When the excitation winding passes current, the magnetic field generated by the excitation winding will enhance or weaken the main magnetic flux according to the direction of the current. The larger the excitation winding current , the stronger the enhancement or weakening effect on the main magnetic flux, because the magnetic potential of the field winding and the permanent magnet are connected in parallel, the total magnetic flux generated by the permanent magnet is constant. Therefore, the direction and magnitude of the current in the field winding can be adjusted. The magnitude of the leakage flux, and then adjust the magnitude of the main flux entering the mover through the main air gap, so as to realize the function of adjusting the excitation. When the armature winding is energized, the magnetic field generated by the armature winding current causes the stator teeth on both sides of the armature slot where the armature winding is located to present different polarities, which is superimposed with the magnetic field generated by the permanent magnet, making one stator tooth display polarity , the main magnetic flux passes through, and the other adjacent stator tooth has no polarity and no magnetic flux flows. Since the armature winding is arranged every other slot, half of the stator teeth in the motor have polarity, and half The stator teeth have no polarity. According to the principle of minimum reluctance, the mover will move until the mover teeth coincide with the polar stator teeth. Since the number of mover teeth is half of the number of stator teeth, there is exactly one mover at this time. The teeth are all facing the stator teeth. This position is the alignment position of the mover teeth and the stator teeth. This position corresponds to the minimum magnetic resistance. At this time, if the mover wants to continue to move, it is necessary to change the direction of the current in the armature winding, so that the stator teeth that have no polarity just now show polarity, and the stator teeth that have polarity do not show polarity. At this time, according to The principle of minimum magnetic resistance will move the mover to the position where the mover teeth coincide with the polar stator teeth. Since the number of mover teeth is half of the number of stator teeth, each mover tooth is exactly opposite to the stator teeth at this time. , this position is the alignment position of the mover teeth and the stator teeth, and this position corresponds to the largest inductance and the smallest magnetic resistance. At this time, the mover continues to move, keeping the direction of the current in the armature winding unchanged, the mover will be subjected to the force that hinders its movement, and will generate electricity and run, and continue to energize in the area where the inductance drops, and the power generation process will continue. When the stator and the mover After the stators are aligned again, change the direction of the armature current so that the non-polar stator teeth show polarity just now, while the original polarized stator teeth do not show polarity, and the mover continues to receive force and generate electricity. This process will continue Repeat, the power generation process continues. Since the main magnetic flux entering the mover teeth through the main air gap can be adjusted by the above-mentioned excitation current, the motor of the utility model can realize the operation of increasing magnetization and the operation of weakening magnetic field according to the actual working conditions, widen the output voltage range of the motor, and reduce the Manufacturing cost, improve motor efficiency.

The beneficial effects of the utility model are:

(1) The DC current of the field winding of the utility model motor with constant direction only needs to control the current magnitude and direction of a set of armature windings, so only two power switching devices are needed, while ordinary three-phase motors need at least 6 power switches. Switching devices, the number of power switching devices required by the motor controller is small, and the cost is low;

(2) When the motor of the utility model is running, the magnetic field generated by the armature winding and the field winding strengthens or cancels each other on the stator teeth. High, high material utilization rate, motors with the same design power, the motor of the utility model saves material consumption and reduces costs;

(3) The permanent magnet of the motor of the utility model is fixed on the stator, does not move with the mover, is easy to install, is conducive to heat dissipation, eliminates the mechanical stress damage caused by the permanent magnet moving with the mover in ordinary permanent magnet generators, and the permanent magnet dissipates heat Defects and other disadvantages; only one set of windings is placed in each stator slot of the motor of the utility model, the off-line process of the motor windings is simple, and there is no need to place phase-to-phase insulation in the slots, which is conducive to improving slot fullness and slot utilization;

(4) In addition to the main air gap, the motor of the utility model is also provided with an additional air gap, which will not increase the size of the motor; part of the magnetic flux generated by two adjacent permanent magnets enters the mover through the main air gap to form the main motor. The other part of the magnetic flux enters the mover without passing through the main air gap and passes through the additional air gap to form a leakage flux. Since the total magnetic flux generated by the permanent magnet is constant, the leakage flux can be easily adjusted by adjusting the current in the excitation winding. The size of the flux, and then adjust the size of the main magnetic flux entering the mover through the main air gap, which can not only play a role in increasing the magnetism, but also play a role in weakening the magnetic field, effectively expanding the speed output range and power output range of the motor. Significantly improve the performance of the motor;

(5) The shape and size of the additional air gap can be flexibly changed according to different magnetic field weakening needs, such as equal width air gap, upper wide and lower narrow air gap or upper narrow and lower wide air gap to achieve different magnetic field weakening effects; The magnetic flux generated by the winding forms a closed loop through the additional air gap, stator teeth, main air gap and mover teeth. The magnetic flux generated by the field winding does not pass through the permanent magnet, and forms a parallel relationship with the magnetic flux generated by the permanent magnet, which reduces the excitation The magnetic flux corresponds to the reluctance of the circuit, and the same excitation current can generate a larger excitation flux, which not only effectively improves the efficiency of field weakening, but also avoids the reverse magnetization of the permanent magnet caused by the excitation flux passing through the permanent magnet. The risk of irreversible demagnetization such as magnetic performance degradation enhances the reliability of the motor;

(6) The utility model can eliminate the torque dead zone by changing the mover structure of the utility model motor, and improve the starting performance of the motor, for example, an asymmetric mover, a turbine-like mover or a stepped mover can be used;

(7) The permanent magnet in the motor of the utility model can be a permanent magnet magnetized as a whole, and can also be spliced by multiple permanent magnets. Therefore, the motor of the utility model has a simple manufacturing process and low cost, and solves the The cost of the permanent magnet is high, it is easy to break when mechanically stressed, it is difficult to install, and the mechanical strength is not as good as the problem of splicing multiple permanent magnets with smaller widths;

(8) The width of the permanent magnet of the motor of the present invention can be flexibly determined according to the design energy product of the permanent magnet or the design residual magnetic density, so the motor of the present invention can adopt the permanent magnet of the high magnetic energy product or the permanent magnet of the low magnetic energy product. Magnets can also be mixed and matched with high-energy-product permanent magnets and low-energy-product permanent magnets, which solves the problem that the existing permanent magnet motors are limited by the number of poles due to the pole arc coefficient. Usually, only high-performance permanent magnets can meet the needs of high-performance motors. question.

Description of drawings

Fig. 1 is the power converter circuit diagram of the utility model motor;

Fig. 2 is the circuit diagram of existing brushless DC permanent magnet and permanent magnet synchronous motor power converter;

Fig. 3 is a structural schematic diagram of Embodiment 1 of the motor of the present invention;

Fig. 4 is a structural schematic diagram of Embodiment 2 of the motor of the present invention;

Among them, 1. Stator teeth, 2. Stator back yoke, 3. Stator slot yoke, 4. Armature slot, 5. Excitation slot, 6. Armature winding, 7. Excitation winding, 8. Permanent magnet, 9. Movers Teeth, 10. Mover slot, 11. Main air gap, 12. Additional air gap.

detailed description:

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

A double-winding high power density hybrid excitation permanent magnet linear generator, which includes a stator, a mover, a main air gap and an additional air gap, the stator includes a permanent magnet, a stator yoke, stator teeth, a stator slot and a stator winding; the mover includes Mover teeth and mover slots; the stator yoke includes a stator slot yoke and a stator back yoke, the stator slot yoke is located at the bottom of the stator slot close to the outer direction, a permanent magnet is arranged between the stator slot yoke and the stator back yoke, and the permanent magnet does not move The sub-movement is easy to install and is conducive to heat dissipation, which eliminates the shortcomings of ordinary permanent magnet motors such as mechanical stress damage and poor heat dissipation of the permanent magnet caused by the permanent magnet moving with the sub-movement. Each permanent magnet can be charged by a whole permanent magnet. It can also be made of multiple permanent magnets with narrow widths. The widths of the permanent magnets can be the same or different. The magnetization direction of the permanent magnets on the same stator slot yoke is the same. Two adjacent stators The magnetization direction of the permanent magnet on the slot yoke is opposite; the stator slot includes the slot where the armature winding is located (armature slot) and the slot where the excitation winding is located (excitation slot), the armature slot and the excitation slot are arranged alternately at intervals, and the armature A set of armature windings is placed in the slot, and a set of excitation windings is placed in the excitation slot. When the motor is running, it is only necessary to control the current magnitude and direction of a set of armature windings. The interaction between the armature current magnetic field, the excitation current magnetic field and the magnetic field generated by the permanent magnet makes the magnetic flux on the stator teeth strengthen or cancel each other, the stator magnetic field is continuously turned on or off in a certain direction, and the change of reluctance between the stator and the mover is used Generate torque and generate electricity; there is a main air gap between the stator teeth and the mover teeth; the yoke of the stator slot above the slot where the excitation winding is located is disconnected, and an additional air gap is provided, and the additional air gap does not increase the size of the motor; Part of the magnetic flux generated by two adjacent permanent magnets enters the mover through the main air gap to form the main flux, and the other part enters the mover without passing through the main air gap and passes through the additional air gap to form leakage flux. The total magnetic flux is constant, and the magnitude of the leakage flux can be adjusted by adjusting the current in the excitation winding, and then adjust the magnitude of the main flux entering the mover through the main air gap, so as to realize the function of adjusting the excitation.

The number n _s of stator teeth of the motor satisfies: n _s =2*n, where n is a natural number greater than or equal to 2.

The number n _r of motor rotor teeth and the number n _s of motor stator teeth satisfy: n _r ≥ n _s /2.

The number n _pm of permanent magnets and the number n _s of motor stator teeth satisfy: n _pm /m=0.5*n _s , m is a natural number greater than or equal to 1.

Only one set of armature winding or excitation winding is placed in the stator slot, no phase-to-phase insulation is required in the stator slot, the slot utilization rate is high, the winding off-line process is simple, and the manufacturing cost is low.

The magnetic flux generated by the field winding passes through the additional air gap, the stator teeth, the main air gap and the mover teeth form a closed loop, the magnetic flux generated by the field winding does not pass through the permanent magnet, and forms a parallel relationship with the magnetic flux generated by the permanent magnet, which reduces the The excitation flux corresponds to the reluctance of the circuit, and the same excitation current can generate a larger excitation flux, which not only effectively improves the efficiency of field weakening, but also avoids the reverse magnetization of the permanent magnet caused by the excitation flux passing through the permanent magnet. The risk of irreversible demagnetization such as the decline of the magnetic performance of the motor enhances the reliability of the motor.

The permanent magnets are in close contact with both the stator back yoke core and the stator slot yoke core.

The additional air gap can be a uniform air gap with the same width everywhere, or a non-uniform air gap with different widths everywhere. The width of the additional air gap can be changed or the upper and lower air gap structures with different widths can be used to obtain different magnetization and weakening. Magnetic properties to meet the needs of different applications.

The armature winding passes through the slot where one armature winding is located, and passes through the adjacent armature slot. The windings in two adjacent armature slots form an armature coil, and each armature coil spans two stator teeth. The currents of the windings in two adjacent armature slots have the same magnitude and opposite directions.

The field winding enters from the slot where the field winding is located, and passes out from the adjacent field slot. The windings in two adjacent field slots form a field coil. Each field coil spans two stator pitches, and two adjacent The currents of the windings in the slots where the excitation windings are located are the same in magnitude and opposite in direction.

The width of the permanent magnet of the motor can be flexibly determined according to the magnetic energy product or residual magnetic density of the permanent magnet. The magnetic energy product of the magnet, while the current permanent magnet motor is limited by the number of poles due to the pole arc coefficient, usually only high-performance permanent magnets can meet the design flux density requirements.

The permanent magnet can be made of high energy product permanent magnet material such as neodymium iron boron or low magnetic energy product permanent magnet material such as ferrite or alnico.

As shown in Figure 1, there is only one set of stator armature windings A and one set of excitation windings F on the stator, and only one set of windings is placed in each slot of the motor, and phase-to-phase insulation is not required in the slots. The off-line process of the motor winding is simple, and the entire The cost is lower than that of the existing three-phase induction motors and permanent magnet motors. Since the slot does not need interphase insulation, the slot fullness rate is high; the permanent magnet of the utility model motor is fixed on the stator and does not move with the mover, so it is easy to install and has It is beneficial to heat dissipation, and eliminates the mechanical stress damage of ordinary permanent magnet generators due to the movement of permanent magnets with the mover, and the shortcomings of permanent magnets such as poor heat dissipation; the utility model motor has high power density and high material utilization. , the motor of the utility model saves the amount of materials and reduces the cost; when the motor of the utility model is running, only one set of armature winding A passes AC current, while the field winding F passes DC current with the same direction, so the control circuit of the motor only needs two A power electronic power switching device, such as IGBT or MOSFET.

As shown in Fig. 2, all kinds of induction motors and permanent magnet motors have three-phase or more armature windings on their stators, which require at least six power electronic power switching devices. Therefore, the control system of the electric motor of the utility model requires few switching devices, low cost and simple structure. In addition, due to the small number of power switching devices, the possibility of failure of the power switching devices in the motor control circuit is reduced, and the reliability is improved.

Embodiment one:

As shown in Figure 3, the number of stator teeth of the motor is 8, the number of teeth of the mover is 4, and the number of permanent magnet blocks is 4. This embodiment includes a stator, a mover, a main air gap and an additional air gap, and the stator includes a stator core, a permanent magnet and stator slots, the stator core includes stator teeth 1, stator back yoke 2 and stator slot yoke 3, the stator core is made of ferromagnetic material with high magnetic permeability, the stator core is provided with stator slots, and the stator slots include armature slots 4 and excitation slot 5, the armature slot 4 and the excitation slot 5 are alternately arranged at intervals, and the armature winding 6 is placed in the armature slot 4, and the armature winding 6 penetrates from one armature slot 4, and from the adjacent another The armature slots pass through to form a coil, so that the currents in each adjacent two armature slots are the same in size and opposite in direction, and the excitation winding 7 is placed in the excitation slot 5, and the excitation winding 7 penetrates from one excitation slot 5, from the phase Another adjacent excitation slot passes through to form a coil, so that the current in each adjacent two excitation slots has the same magnitude and opposite direction; a permanent magnet 8 is placed between the stator slot yoke 3 and the stator back yoke 2, and the permanent magnet 8 Ferrite permanent magnet material with low magnetic energy product is used, and the magnetization directions of two adjacent permanent magnets are opposite; the mover includes mover teeth 9 and mover slots 10, mover teeth 9 are evenly distributed, mover teeth 9 and stator The main air gap 11 is set between the teeth 1; the stator slot yoke 3 above the slot where the excitation winding 7 is located is disconnected, and an additional air gap 12 is provided, and the width of the additional air gap 12 is equal everywhere.

Embodiment two:

As shown in Figure 4, the number of stator teeth of the motor is 8, the number of teeth of the mover is 4, and the number of permanent magnet blocks is 8. This embodiment includes a stator, a mover, a main air gap and an additional air gap, and the stator includes a stator core, a permanent magnet and stator slots, the stator core includes stator teeth 1, stator back yoke 2 and stator slot yoke 3, the stator core is made of ferromagnetic material with high magnetic permeability, the stator core is provided with stator slots, and the stator slots include armature slots 4 and excitation slot 5, the armature slot and the excitation slot are alternately arranged at intervals, armature winding 6 is placed in armature slot 4, armature winding 6 penetrates from one armature slot, and passes through another adjacent armature slot A coil is formed, so that the currents in every two adjacent armature slots are the same in size and opposite in direction, and the excitation winding 7 is placed in the excitation slot 5, and the excitation winding 7 penetrates from one excitation slot, and from the adjacent other The excitation slots pass through to form a coil, so that the currents in each adjacent two excitation slots have the same magnitude and opposite directions; a permanent magnet 8 is placed between the stator slot yoke 3 and the stator back yoke 2, and each stator slot yoke 3 There are 2 permanent magnets, the permanent magnet 8 is made of NdFeB permanent magnet material with high magnetic energy product, the magnetization direction of the 2 permanent magnets on the same stator slot yoke is the same, and the magnetization direction of the permanent magnets on different adjacent stator slot yokes The magnetization direction is opposite; the mover includes mover teeth 9 and mover slots 10; the main air gap 11 is provided between the mover teeth 9 and the stator teeth 1; the yoke of the stator slot above the slot where the excitation winding 7 is located is disconnected, An additional air gap 12 is provided, and the width of each additional air gap 12 is equal.

At the same time, according to the different application fields of the motor provided by the utility model, it is easy for those skilled in the art to make non-creative changes to the motor structure of the utility model for different specific application environments and objects, and it should also belong to In the protection scope of the present utility model.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (8)

1. a double winding high power density composite excitation permanent magnet linear electric generator, is characterized in that: comprise stator, mover, additional air gap and main air gap, wherein:

Described stator is evenly provided with even number stator tooth, is provided with stator slot in adjacent two stator tooths, between stator slot yoke and stator back yoke, is provided with permanent magnet, between the mover tooth of described stator tooth and mover, be provided with main air gap;

Described stator slot comprises armature slot and excitation groove, armature slot and the arrangement of excitation groove alternate intervals, a set of armature winding is surrounded with in two adjacent armature slots, set of excitation winding is surrounded with in two adjacent excitation grooves, and described armature winding indirect current stream, described excitation winding leads to the constant direct current in direction;

Be provided with additional air gap in the yoke portion of the stator slot at described excitation winding place, the magnetic flux part that adjacent two pieces of permanent magnets produce enters mover through main air gap and forms main flux, and another part is through additional air gap closed formation leakage flux.

2. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, is characterized in that: described permanent magnet does not rotate with mover, and every block permanent magnet is magnetized by a monoblock permanent magnet and forms or be spliced by polylith permanent magnet.

3. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, is characterized in that: the number of described stator tooth be more than or equal to 4 even number.

4. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, is characterized in that: the number of described mover tooth is more than or equal to 1/2 of stator tooth number.

5. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, is characterized in that: the several number of block of described permanent magnet be the m of mover tooth doubly, m be more than or equal to 1 natural number.

6. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, it is characterized in that: the magnetic flux that described excitation winding produces forms closed-loop path through additional air gap, stator tooth, main air gap and mover tooth, the magnetic flux that excitation winding produces is without permanent magnet, and the magnetic flux produced with permanent magnet forms parallel relationship.

7. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, it is characterized in that: described armature winding penetrates from an armature winding place groove, pass from adjacent armature slot, winding in adjacent two armature slots forms an armature coil, each armature coil is across two stator tooth distances, in adjacent two armature slots, the size of current of winding is identical, and direction is contrary.

8. a kind of double winding high power density composite excitation permanent magnet linear electric generator as claimed in claim 1, it is characterized in that: described excitation winding penetrates from an excitation winding place groove, pass from adjacent excitation groove, winding in adjacent two excitation grooves forms a magnet exciting coil, each magnet exciting coil is across two stator tooth distances, in adjacent two excitation winding place grooves, the size of current of winding is identical, and direction is contrary.