CN105141104A - Yoke excitation winding high power density hybrid excitation permanent magnet linear generator - Google Patents

Abstract

The invention discloses a high power density hybrid excitation permanent magnet linear generator with excitation windings on the yoke. 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 the armature slot, and the armature windings are connected with alternating current, and a set of excitation windings is arranged in the excitation slot, and the excitation windings pass a direct current with a constant direction; There is a main air gap, and the yoke of the stator slot above the slot where the excitation winding is located is disconnected radially, and an additional air gap is provided; the stator teeth are made The change of the magnetic flux on the stator and the mover generates torque by using the change of reluctance between the stator and the mover. The invention effectively reduces the number of power switching devices, reduces the possibility of failure of the power switching devices in the motor control circuit, and improves reliability.

Description

A high power density hybrid excitation permanent magnet linear generator with yoke excitation winding

technical field

The invention relates to a high power density hybrid excitation permanent magnet linear generator of a yoke excitation winding.

Background technique

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. widely used.

Conventional AC permanent magnet motors are usually divided into the following categories: asynchronous start permanent magnet synchronous motors, permanent magnet brushless DC motors, and speed-adjustable permanent magnet synchronous motors.

The brushless DC motor and the variable speed permanent magnet synchronous motor are basically the same in structure, with multi-phase windings on the stator and permanent magnets on the mover. The main difference between them is that the brushless DC motor realizes self-synchronization according to the position information of the mover. Their advantages are: (1) the brush commutator is eliminated, and the reliability is improved; (2) the loss is mainly generated by the stator, and the heat dissipation condition is good; (3) the volume is small and the weight is light.

The structural difference between the asynchronous starting permanent magnet synchronous motor and the speed regulating permanent magnet synchronous motor is that the former has a starting winding or an integral core with a starting effect on the mover, which can realize self-starting and can be connected to the grid without a control system.

In addition, there are single-phase permanent magnet motors. Single-phase permanent magnet motors need to be started and operated with supporting capacitors, which are bulky, high in cost, and have low overall operating efficiency and power factor.

Due to the fixed magnetomotive force of the permanent magnet in the existing permanent magnet motor, the main magnetic flux of the motor cannot be adjusted, resulting in a narrow constant power operating range and a wide range of speed regulation. In addition, the motor winding is generally 3 phases, the number of stator slots is large, and the winding off-line process Complicated; the permanent magnets of most existing permanent magnet motors are located on the mover, and they rotate 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 magnets. The permanent magnet is located on the mover, and it is difficult to dissipate heat during operation. The temperature rise and the vibration caused by the rotation of the mover will cause damage to the mechanical structure of the permanent magnet and irreversible demagnetization; the existing permanent magnet motor is generally three-phase, requiring the power of the motor to reverse The inverter circuit needs at least 6 power switching devices, such as IGBT or MOSFET, etc., and the corresponding driving circuit and protection circuit for driving the power switching devices, so that the cost of the motor power inverter circuit is quite high, even reaching two times the cost of the motor body. To three times, 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 decreases during operation.

In view of the shortcomings of the existing permanent magnet 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 the permanent magnet magnetic potential and the 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 magnetic potential The structure connected in parallel with the magnetic potential of the excitation winding, 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. More, making 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, phase-to-phase insulation needs to be added in the slot, the winding process is complicated, the slot utilization rate is low, and , need to open the excitation slot, the mechanical structure of the motor is seriously fragmented, it is difficult to assemble and fix, 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 body A hybrid excitation permanent magnet motor with simple structure, low cost, flexible magnetic field adjustment function but a small number of power switching devices, and low cost controller and power circuit is very important. A hybrid excitation permanent magnet motor with high function but a small number of power switching devices and low cost of controller and power circuit is very important.

In addition, the existing permanent magnet motors mostly use distributed windings or concentrated windings spanning multiple pole pitches, which generally have long winding ends, a large amount of copper, high manufacturing costs, high copper consumption during motor operation, and low efficiency. Disadvantages, especially for motors with large outer diameter and small axial length, that is, a large ratio of diameter to length, this disadvantage is particularly prominent, and special winding coil connection methods are required to reduce the winding end and reduce the use of Copper to improve motor operating efficiency.

Contents of the invention

In order to solve the above problems, the present invention proposes a hybrid excitation permanent magnet linear generator with high power density of excitation windings on the yoke. The permanent magnet motor has a set of stator armature windings and a set of excitation windings on the stator, and each slot of the motor Only one set of windings is placed in the slot, no phase-to-phase insulation is required in the slot, the slot fullness rate is high, and the motor winding off-line process is simple, and the whole cost is lower than the existing various three-phase induction motors and permanent magnet motors; the motor excitation slot of the present invention The excitation winding is placed inside, the excitation winding penetrates through an excitation slot, and then passes out along the outside of the stator back yoke in the outward direction to form a coil, the excitation winding surrounds the stator slot yoke, the permanent magnet and the stator back yoke are wound, each excitation slot The excitation winding inside is a set of coils; the armature winding of the present invention passes AC current, and the other group of excitation winding passes DC current, so the control circuit of the motor only needs two power electronic power switching devices, which changes the existing various induction coils. There are three-phase or more armature windings on the stator of the motor and the permanent magnet motor, which requires at least 6 power electronic power switching devices, effectively reducing the number of power switching devices and reducing the failure of power switching devices in the motor control circuit. Possibility, increased reliability.

In order to achieve the above object, the present invention adopts the following technical solutions:

A high power density hybrid excitation permanent magnet linear generator with excitation windings on the yoke, including a stator, a mover, an additional air gap and a main air gap, the mover is arranged inside the stator, wherein:

An even number of stator teeth is evenly arranged on the stator, a stator slot is arranged in two adjacent stator teeth, and a permanent magnet is arranged between the stator slot yoke and the stator back yoke in the direction of the outer side of the stator slot, and the permanent magnet does not follow the When the mover rotates, 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 stator slots include armature slots and excitation slots, the armature slots and excitation slots are alternately arranged at intervals, a set of armature windings surround two adjacent armature slots, and the armature windings pass through alternating current, the A set of excitation windings is arranged in the excitation slot, and the excitation windings pass a direct current in a constant direction;

There is a main air gap between the stator teeth and the mover teeth. The yoke of the stator slot at the bottom of the slot where the excitation winding is located is disconnected, and an additional air gap is provided. A part of the magnetic flux generated by two adjacent permanent magnets passes through the main The air gap enters the mover to form the main magnetic flux, and the other part does not enter the mover through the main air gap and passes through the additional air gap to form a leakage flux. By adjusting the current in the excitation winding, the leakage flux is adjusted, and then the passing through The magnitude of the main magnetic flux entering the mover through the main air gap is used to adjust the excitation.

The permanent magnet does not move with the mover, which is easy to install and is conducive to heat dissipation. It eliminates the shortcomings of ordinary permanent magnet generators such as mechanical stress damage and poor heat dissipation of the permanent magnet due to the rotation of the permanent magnet with the mover. Each permanent magnet can be used by a The whole permanent magnet is magnetized, and it can also be formed by splicing multiple permanent magnets with narrower widths. The widths of the permanent magnets can be the same or different.

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 number of the stator teeth is an even number greater than or equal to 2.

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.

Only one set of armature windings or excitation windings is placed in the stator slots, no phase-to-phase insulation is required in the stator slots, 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 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 regulation, 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 field winding passes through a field slot, and then passes out along the outside of the stator back yoke to form a coil. The field winding surrounds the stator slot yoke, and the permanent magnet and the stator back yoke are wound. The field winding in each field slot is A set of coils, all the coils formed can be connected in parallel or in series.

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 tooth pitch, the currents of the windings in the slots where the two adjacent armature windings are located are the same in size and opposite in direction.

Part of the magnetic flux generated by the two adjacent permanent magnets enters the mover through the main air gap to form the main magnetic flux, and the other part enters the mover without passing through the main air gap and passes through the additional air gap to form a leakage flux. The total magnetic flux generated is constant. By adjusting the current in the excitation winding, the leakage flux can be adjusted, and then the main magnetic flux entering the mover through the main air gap can be adjusted, so as to realize the function of adjusting the excitation. .

The width of the permanent magnet is determined according to the magnetic energy product or residual magnetic density of the permanent magnet, the residual magnetic density of the permanent magnet is determined according to the design air gap magnetic density of the motor, and then the magnetic energy of the permanent magnet is determined by changing the pole arc coefficient of the permanent magnet However, the existing permanent magnet motor is limited by the number of poles due to the pole arc coefficient, and 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.

Working principle of the present invention is:

The stator core and the mover core are made of laminated silicon steel sheets or core materials with high magnetic permeability. When the armature winding and the field winding are not energized, part of the magnetic flux generated by the permanent magnet passes through the stator. The slot yoke, stator teeth and 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 main magnet of the motor The other 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, enters the permanent magnet under the other pole, and is closed by the stator back yoke, this part of the magnetic flux does not enter The main air gap and mover are only closed inside the stator, and this part of the magnetic flux is the leakage flux. There is an excitation slot 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 current of the excitation winding, the greater the impact on the main The stronger the enhancement or weakening effect of the magnetic flux, the total magnetic flux generated by the permanent magnet is constant due to the parallel connection of the field winding magnetic potential and the permanent magnet magnetic potential. Therefore, the leakage flux can be adjusted by adjusting the direction and magnitude of the current in the field winding , and then adjust the size of the main magnetic 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 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 The child 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 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 that enters the mover teeth through the main air gap can be adjusted by the above-mentioned excitation current, the motor of the present invention can realize magnetization operation and field weakening operation according to actual working conditions, widen the output voltage range of the motor, and reduce the manufacturing cost. cost and improve motor efficiency.

The beneficial effects of the present invention are:

(1) In the present invention, the DC current of the field winding of the motor in the same 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 Devices, the number of power switching devices required by the motor controller is small, and the cost is low;

(2) The magnetic fields generated by the armature winding and the field winding of the motor of the present invention strengthen or cancel each other on the stator teeth when the motor is running, and the armature winding and the field winding are energized at the same time during the full cycle of the motor. Therefore, the power density of the motor of the present invention is high. The material utilization rate is high, and the motor with the same design power, the motor of the present invention saves material consumption and reduces costs;

(3) The permanent magnet of the motor of the present invention is fixed on the stator, does not rotate with the mover, is easy to install, is conducive to heat dissipation, eliminates the mechanical stress damage caused by the permanent magnet rotating with the mover in ordinary single-phase permanent magnet motors, 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 present invention, 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) The excitation winding of the motor of the present invention is a simple concentrated winding, which is wound around the stator slot yoke, the permanent magnet and the stator yoke. When the length of the stator core of the motor is large, the amount of copper used at the end of the winding can be significantly reduced, and the manufacturing cost can be reduced. Reduce copper consumption and improve motor operating efficiency;

(5) In addition to the main air gap, the motor of the present invention is also provided with an additional air gap, which is cleverly designed in the length direction of the motor, and the additional air gap will not increase the size of the motor; The magnetic flux enters the mover through the main air gap to form the main magnetic flux, and the other part does not enter the mover through the main air gap and passes through the additional air gap to form leakage flux. Since the total magnetic flux generated by the permanent magnet is constant, by adjusting the excitation The size of the current in the winding can easily adjust the size of the leakage magnetic flux, and then adjust the size of the main magnetic flux entering the mover through the main air gap, which can not only increase the magnetic field, but also play a role in weakening the magnetic field, effectively Broaden the voltage output range and power output range of the motor, and significantly improve the performance of the motor;

(6) 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;

(7) The magnetic flux generated by the field winding passes through the additional air gap, stator teeth, main air gap and 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. The reluctance 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 reversal 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 properties caused by magnetization enhances the reliability of the motor;

(8) The permanent magnet in the motor of the present invention can be a permanent magnet magnetized as a whole, and can also be spliced by a plurality of permanent magnets, so the manufacturing process is simple, the cost is low, and the permanent magnet due to the wider width of the motor is improved. The cost 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 splicing of multiple permanent magnets with smaller widths;

(9) 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 and also the permanent magnet of the low magnetic energy product, High energy product permanent magnets and low energy product permanent magnets can also be mixed and matched. In actual design, the remanence density of the permanent magnet can be determined according to the design air gap flux density of the motor, and then the required permanent magnet can be determined by the pole arc coefficient of the permanent magnet. The magnetic energy product of the magnet solves the problem that the existing permanent magnet motor is limited by the number of poles due to the pole arc coefficient, and usually only high-performance permanent magnets can meet the needs of high-performance motors;

(10) Both high energy product permanent magnets and low energy product permanent magnets can be used, and high energy product permanent magnets and low energy product permanent magnets can also be mixed and matched. In actual design, the air gap magnet can be designed according to the motor Determine the residual magnetic density of the permanent magnet closely, and then determine the magnetic energy product of the required permanent magnet through the pole arc coefficient of the permanent magnet. However, because the pole arc coefficient of the existing permanent magnet motor is limited by the number of poles, usually only high-performance permanent magnets are used. In order to meet the needs of high-performance motors.

Description of drawings

Fig. 1 is the power converter circuit diagram of motor of the present invention;

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 schematic structural diagram of motor embodiment 2 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 ways:

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

A high power density hybrid excitation permanent magnet linear generator with yoke excitation winding, which includes a stator, a mover, a main air gap and an additional air gap, and the stator includes a permanent magnet, a stator yoke, stator teeth, a stator slot and a stator winding; The stator includes the mover teeth and the mover slot; the stator yoke includes the stator slot yoke and the stator back yoke, the stator slot yoke is located near the outer side of the stator slot, and there is a permanent magnet between the stator slot yoke and the stator back yoke, and the permanent magnet does not follow the mover Movement, easy installation, good heat dissipation, eliminates the shortcomings of ordinary permanent magnet generators such as mechanical stress damage and poor heat dissipation of permanent magnets due to the rotation of permanent magnets with the mover, and 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 directions of the permanent magnets on the slot yoke are opposite; the stator slots include the slots where the armature windings are located (armature slots) and the slots where the excitation windings are located (excitation slots), the armature slots and the excitation slots are alternately arranged at intervals, and the A set of armature winding is placed in the armature slot, and a set of excitation winding 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 winding. The interaction between current, armature current magnetic field, 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, and the stator magnetic field is continuously turned on or off in a certain direction, using the magnetic field between the stator and the mover The resistance changes to 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 at the bottom of the slot where the excitation winding is located is disconnected, and an additional air gap is set. 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 ns of stator teeth of the motor satisfies: ns=2*n, where n is a natural number greater than or equal to 1.

The number nr of motor rotor teeth and the number ns of motor stator teeth satisfy: nr≥ns/2.

The number npm of permanent magnets and the number ns of motor stator teeth satisfy: npm/m=0.5*ns, 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, stator teeth, main air gap and 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, 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 the field adjustment, 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 field winding penetrates through a field slot, and then passes out along the outside of the stator back yoke to form a coil, the field winding surrounds the stator slot yoke, the permanent magnet and the stator back yoke are wound, and the field winding in each field slot is a set Coils, a total of 4 sets of excitation coils are formed, and the 4 sets of coils can be connected in parallel or in series;

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 the slots where the two adjacent armature 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 NdFeB or low energy product permanent magnet material such as ferrite or AlNiCo.

The excitation magnetic field can be adjusted when the motor of the present invention is running, and the magnetic flux density in the air gap of the motor can be adjusted by adjusting the current of the excitation winding F. The excitation winding of the motor of the present invention is placed under the additional air gap, and the two are placed side by side. The magnetic flux directly passes through the additional air gap, and the stator teeth, the main air gap and the mover teeth form a closed loop. The excitation magnetic flux does not pass through the permanent magnet, and forms a parallel relationship with the magnetic flux generated by the permanent magnet, which not only effectively improves the field weakening efficiency, Moreover, the risk of irreversible demagnetization such as the decline in magnetic properties of permanent magnets due to reverse magnetization is avoided. The permanent magnets of the motor of the present invention are flexible in selection, and permanent magnets with high magnetic energy products can also be selected. Ferrite and other low magnetic energy products can also be selected. permanent magnet, because the remanence density of the permanent magnet can be determined by the design air gap flux density of the motor, and then the magnetic energy product of the permanent magnet can be determined by changing the pole arc coefficient of the permanent magnet, while the existing permanent magnet motor is affected by the pole arc coefficient Due to the limitation of the number of poles, usually only high-performance permanent magnets can meet the needs of the design magnetic density.

Since the difference in the width of the additional air gap will significantly change the reluctance of the motor magnetic circuit, affect the leakage flux between the permanent magnets, and then affect the magnetization and field weakening effects of the motor, therefore, the width of the additional air gap can be changed or the upper and lower Different width air gap structure, different motor characteristics can be obtained by changing the additional air gap width of the motor, so as to meet the needs of different applications.

As shown in Figure 1, the motor is a hybrid excitation permanent magnet motor. There is only one set of stator armature windings A and one set of field windings F on the stator, and only one set of windings is placed in each slot of the motor. There is no need for phase-to-phase insulation in the slots. The off-line process of the motor winding is simple, and the whole cost is lower than that of the existing three-phase induction motors and permanent magnet motors. Since the phase-to-phase insulation is not required in the slot, the slot filling rate is high; the armature winding of the motor is placed in the slot of the motor of the present invention. , the armature winding passes through an armature slot, and then passes through the stator back yoke in the outer diameter direction to form a coil. The armature winding is wound around the stator slot yoke, permanent magnet and stator back yoke, and each armature slot The armature winding is a set of coils, and all the coils can be connected in series or in parallel; the permanent magnet of the motor of the present invention is fixed on the stator, does not rotate with the mover, is easy to install, is conducive to heat dissipation, and eliminates the common single-phase permanent magnet motor. Mechanical stress damage caused by the rotation of the mover, poor heat dissipation of the permanent magnet and other shortcomings; the motor of the present invention has high power density, high material utilization rate, and a motor with the same design power, the motor of the present invention saves material consumption and reduces costs; the motor of the present invention During operation, only one set of armature winding A passes AC current, while the field winding F passes DC current with a constant direction, so the control circuit of the motor only needs two power electronic power switching devices, 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 motor control system of the present invention requires less 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.

The excitation magnetic field can be adjusted when the motor of the present invention is running, and the magnetic flux density in the air gap of the motor can be adjusted by adjusting the current of the excitation winding F. The excitation winding of the motor of the present invention is placed under the additional air gap, and the two are placed side by side. The magnetic flux directly passes through the additional air gap, and the stator teeth, the main air gap and the mover teeth form a closed loop. The excitation magnetic flux does not pass through the permanent magnet, and forms a parallel relationship with the magnetic flux generated by the permanent magnet, which not only effectively improves the field weakening efficiency, Moreover, the risk of irreversible demagnetization such as the decline in magnetic properties of permanent magnets due to reverse magnetization is avoided. The permanent magnets of the motor of the present invention are flexible in selection, and permanent magnets with high magnetic energy products can also be selected. Ferrite and other low magnetic energy products can also be selected. permanent magnet, because the remanence density of the permanent magnet can be determined by the design air gap flux density of the motor, and then the magnetic energy product of the permanent magnet can be determined by changing the pole arc coefficient of the permanent magnet, while the existing permanent magnet motor is affected by the pole arc coefficient Due to the limitation of the number of poles, usually only high-performance permanent magnets can meet the needs of the design magnetic density.

Since the difference in the width of the additional air gap will significantly change the reluctance of the motor magnetic circuit, affect the leakage flux between the permanent magnets, and then affect the magnetization and field weakening effects of the motor, therefore, the width of the additional air gap can be changed or the upper and lower Different width air gap structure, different motor characteristics can be obtained by changing the additional air gap width of the motor, so as to meet the needs of different applications.

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 excitation winding 7 is placed in the excitation slot 5, and the excitation winding 7 penetrates from one excitation slot 5, and then passes out along the stator back yoke 2 in the outer direction , forming a coil, the excitation winding 7 is wound around the stator slot yoke 3, the permanent magnet 8 and the stator back yoke 2, the excitation winding in each excitation slot is a set of coils, and a total of 4 sets of coils are formed, and the 4 sets of coils can be connected in series or In parallel, the armature winding 6 is placed in the armature slot 4, and the armature winding 6 penetrates from one armature slot 4 and passes out from the other adjacent armature slot to form a coil, so that every two adjacent armature The currents in the pivot 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 the permanent magnet is made of ferrite permanent magnet material with low magnetic energy product. The magnetic direction is opposite; the mover includes mover teeth 9 and mover slots 10, and a main air gap 11 is provided between the mover teeth 9 and stator teeth 1; Additional air gap 12, the width of each additional air gap 12 is equal.

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 4 and the excitation slot 5 are alternately arranged at intervals, and the excitation winding 7 is placed in the excitation slot 5, and the excitation winding 7 penetrates from one excitation slot 5, and then passes out along the stator back yoke 2 in the outer direction , forming a coil, the excitation winding 7 is wound around the stator slot yoke 3, the permanent magnet 8 and the stator back yoke 2, the excitation winding in each excitation slot is a set of coils, and a total of 4 sets of coils are formed, and the 4 sets of coils can be connected in series or In parallel, the armature winding 6 is placed in the armature slot 4, and the armature winding 6 penetrates from one armature slot 4 and passes out from the other adjacent armature slot 4 to form a coil, so that every two adjacent The currents in the armature 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 there are 2 permanent magnets on each stator slot yoke, and the permanent magnets are made of neodymium iron with high magnetic energy product Boron permanent magnet material, the two permanent magnets on the same stator slot yoke have the same magnetization direction, and the magnetization directions of the permanent magnets on different adjacent stator slot yokes are opposite; the mover includes mover teeth 9 and mover slots 10. There is a main air gap 11 between the mover tooth 9 and the stator tooth 1; the yoke of the stator slot above the field winding 7 is disconnected, and an additional air gap 12 is set, and the width of the additional air gap 12 is equal everywhere .

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

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

Claims (10)

1. A yoke excitation winding high power density hybrid excitation permanent magnet linear generator, comprising a stator, a mover, an additional air gap and a main air gap, the mover is arranged inside the stator, wherein: An even number of stator teeth is evenly arranged on the stator, a stator slot is arranged in two adjacent stator teeth, and a permanent magnet is arranged between the stator slot yoke and the stator back yoke in the direction of the outer side of the stator slot, and the permanent magnet does not follow the When the mover rotates, 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; It is characterized in that: the stator slots include armature slots and excitation slots, the armature slots and excitation slots are alternately arranged at intervals, two adjacent armature slots are surrounded by a set of armature windings, and the armature windings are connected Alternating current, a set of excitation windings is arranged in the excitation slot, and the excitation windings pass a direct current with a constant direction; There is a main air gap between the stator teeth and the mover teeth. The yoke of the stator slot at the bottom of the slot where the excitation winding is located is disconnected, and an additional air gap is provided. A part of the magnetic flux generated by two adjacent permanent magnets passes through the main The air gap enters the mover to form the main magnetic flux, and the other part does not enter the mover through the main air gap and passes through the additional air gap to form a leakage flux. By adjusting the current in the excitation winding, the leakage flux is adjusted, and then the passing through The magnitude of the main magnetic flux entering the mover through the main air gap is used to adjust the excitation. 2 . The high power density hybrid excitation permanent magnet linear generator with yoke excitation windings according to claim 1 , wherein the number of the stator teeth is an even number greater than or equal to 2. 3 . 3. A high power density hybrid excitation permanent magnet linear generator with yoke excitation windings as claimed in claim 1, characterized in that: the number of teeth of the mover is greater than or equal to 1/2 of the number of teeth of the stator. 4. A kind of yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the number of blocks of the permanent magnets is m times of the mover teeth, and m is greater than A natural number equal to 1. 5. A kind of yoke field winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the magnetic flux generated by the field winding passes through the additional air gap, stator teeth, main air gap and The mover teeth form a closed loop, and 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. 6. A yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the excitation winding penetrates through an excitation slot, and then passes outward along the outer side of the stator back yoke A coil is formed, the excitation winding is wound around the stator slot yoke, the permanent magnet and the stator back yoke, the excitation winding in each excitation slot is a set of coils, and all the coils formed are connected in parallel or in series. 7. A yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the armature winding penetrates from the slot where one armature winding is located, and enters from the adjacent motor The windings in two adjacent armature slots form an armature coil, each armature coil spans two stator tooth pitches, and the currents of the windings in the slots where the two adjacent armature windings are located are the same, in the opposite direction. 8. A kind of yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the width of the permanent magnet is determined according to the magnetic energy product or remanence density of the permanent magnet, according to The design air gap magnetic density of the motor determines the residual magnetic density of the permanent magnet, and then the magnetic energy product of the permanent magnet is determined by changing the pole arc coefficient of the permanent magnet. 9. A kind of yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the additional air gap is a uniform air gap with the same width everywhere, by changing the additional air gap The width, get different magnetization and weakening characteristics. 10. A yoke excitation winding high power density hybrid excitation permanent magnet linear generator as claimed in claim 1, characterized in that: the additional air gap is a non-uniform air gap with different widths at different places, and adopts different heights. The wide air gap structure obtains different magnetization and weakening characteristics.