阅读说明：本技术 一种绕组式永磁耦合调速电机 (Winding type permanent magnet coupling speed regulating motor ) 是由 田宏伟 王煜伟 任志平 张禹 于 2019-11-08 设计创作，主要内容包括：本发明涉及交流调速电机,尤其涉及绕组式永磁耦合调速电机,包括定子、电动转子和绕组转子,其中,定子包括定子铁心和励磁绕组,励磁绕组采用三相整数槽分布式排列；电动转子包括电动转子铁心、鼠笼导条和永磁体,电动转子铁心贴近绕组转子一侧表贴以聚磁阵列方式充磁的永磁体；绕组转子包括绕组转子铁心和感应绕组,绕组转子铁心贴近电动转子一侧开槽,感应绕组设置于开槽中,另外在相邻感应绕组之间开槽以形成调制齿,调制齿用来对永磁磁场和感应磁场进行调制,感应绕组采用三相双层分数槽集中式排列。本发明提供的电机,具备低电压穿越能力,此外通过调制齿引入磁场调制效应,对感应绕组所匝链磁通进行调制,提高了电机转矩密度。(The invention relates to an alternating current speed regulating motor, in particular to a winding type permanent magnet coupling speed regulating motor, which comprises a stator, an electric rotor and a winding rotor, wherein the stator comprises a stator core and an excitation winding, and the excitation winding is distributed in a three-phase integer slot; the electric rotor comprises an electric rotor iron core, a squirrel cage conducting bar and permanent magnets, and the permanent magnets magnetized in a magnetism gathering array mode are attached to the surface of one side, close to the winding rotor, of the electric rotor iron core; the winding rotor comprises a winding rotor core and induction windings, wherein a groove is formed in one side, close to the electric rotor, of the winding rotor core, the induction windings are arranged in the grooves, in addition, grooves are formed between the adjacent induction windings to form modulation teeth, the modulation teeth are used for modulating a permanent magnetic field and an induction magnetic field, and the induction windings are arranged in a three-phase double-layer fractional groove centralized mode. The motor provided by the invention has low voltage ride through capability, and in addition, the magnetic field modulation effect is introduced through the modulation teeth to modulate the flux of the turn-linkage of the induction winding, so that the torque density of the motor is improved.)

1. Winding formula permanent magnetism coupling buncher, its characterized in that:

the motor comprises a stator, an electric rotor and a winding rotor;

the stator comprises a stator iron core and an excitation winding, and the electric rotor comprises an electric rotor iron core, a squirrel cage conducting bar and a permanent magnet;

one side of the electric rotor core, which is close to the stator, is designed to be an open slot, the squirrel cage conducting bars are placed in the open slot of the electric rotor core, the end parts of the squirrel cage conducting bars are in short circuit through end rings to obtain induced eddy currents, and permanent magnets magnetized in a magnetism gathering array mode are attached to the surface of one side of the electric rotor core, which is close to the winding rotor;

the winding rotor comprises a winding rotor core and induction windings, wherein a groove is formed in one side, close to the electric rotor, of the winding rotor core, the induction windings are arranged in the groove, in addition, a groove is formed between every two adjacent induction windings to form a modulation tooth, the modulation tooth is used for modulating a permanent magnetic field and an induction magnetic field, the induction windings are arranged in a fractional groove centralized mode and are connected with an external controller through collecting rings and electric brushes, and slip power is fed back to an electric network.

2. The wound permanent magnet coupled electric variable speed machine of claim 1, wherein: the stator core is provided with an open slot, the excitation winding is arranged in the open slot of the stator core, the excitation winding is distributed in an integer slot arrangement and supplies alternating current through an inverter to generate a rotating magnetic field, and each winding coil is wound on a stator tooth.

3. The wound permanent magnet coupled electric variable speed machine of claim 1, wherein: the motor is a rotating motor, and the stator core is grooved along the circumferential direction and at one side close to the squirrel-cage rotor.

4. The wound permanent magnet coupled electric variable speed machine of claim 1, wherein: the electric rotor core is provided with permanent magnets along the circumferential direction and close to one side of the winding rotor, and the permanent magnets are p in total₂And each counter pole consists of 3 permanent magnets, and the 3 permanent magnets are magnetized in a radial inward mode, a tangential mode and a radial outward mode in sequence to form a magnetism gathering array.

5. The wound permanent magnet coupled electric variable speed machine of claim 1, wherein: the stator iron core, the electric rotor iron core and the winding rotor iron core are formed by laminating tooth-groove silicon steel sheets, and the permanent magnet is made of rare earth permanent magnet materials.

6. The wound permanent magnet coupled electric variable speed machine of claim 1, wherein: the excitation winding adopts a single-layer or double-layer arrangement mode, and the induction winding adopts a double-layer arrangement mode.

Technical Field

The invention relates to the field of alternating-current speed regulating motors, in particular to a winding type permanent magnet coupling speed regulating motor.

Background

In recent years, the economy of China is rapidly developed, particularly the industrial development is prominent, and the demand for electric power is promoted. Thermal power generation is used as a main power generation mode in China, accounts for more than 70% of the total power generation amount in the country in 2018, and when environmental protection and energy conservation become important directions for structure adjustment of the Chinese power industry, domestic thermal power equipment is also updated in an accelerating way. In a thermal power plant, one type of auxiliary machine is the most important power-consuming auxiliary equipment, and the auxiliary equipment has large capacity and large power consumption, and in addition, the equipment is continuously operated for a long time and is often in a low-load operation state, so that the development direction of the auxiliary equipment is toward reducing the volume and improving the power density per unit volume. In addition, the investigation shows that the running efficiency of the auxiliary machine of the unit above 50MW in China is more than half of that of the unit below 70%, and about 20% of that below 50%, because the load of the unit is low, the efficiency of the auxiliary machine is lower, and as a result, a large amount of electric energy is wasted in a blank area, so that energy conservation also becomes the key point for the improvement of the auxiliary machine equipment.

At present, in heat-engine plants in China, besides a small number of hydraulic couplers and double-speed motors, a large number of auxiliary machines adopt a frequency converter speed regulation mode, and therefore tripping accidents of units are caused by transient voltage fluctuation of all levels of power grids in China. The main reason of the accident is that when the power grid fault voltage is reduced, the frequency converter of one type of auxiliary machine (especially a coal mill, a coal feeder, an induced draft fan and the like) of the power plant does not have a low voltage ride through function, the frequency converter of the auxiliary machine cannot avoid the fault time, the low voltage protection action trips, the auxiliary machine exits, so that the accidents of unit tripping, unplanned separation from the power grid and the like are caused, the safe and stable operation of the power system is seriously influenced, and the problem of low voltage ride through is faced, and the following four schemes are mainly adopted in the prior frequency converter speed regulation system for improving the reliability of one type of auxiliary machine (especially a coal mill:

(1) additionally installing a battery pack on a direct current bus of the frequency converter;

(2) an alternating current voltage stabilizing device is additionally arranged on the frequency converter;

(3) a three-phase UPS is installed on the coal feeder;

(4) and each coal feeder is provided with a single-phase UPS power supply.

However, the four schemes for solving the speed-regulating low-voltage ride-through capability of the frequency converter all need to add equipment, the transformation investment is high, the capacitor, the UPS, the storage battery and the like have aging problems along with the prolonging of the operation time, and the later maintenance cost is high.

The technical purpose is as follows:

the invention aims to solve the existing problems of the auxiliary machine of the thermal power plant, and provides a winding type permanent magnet coupling speed regulating motor which has low voltage ride through capability, high torque density, high power density and energy saving on the premise of not increasing equipment.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a winding type permanent magnet coupling speed regulating motor.

The technical scheme of the invention is as follows:

the winding type permanent magnet coupling speed regulating motor is characterized by comprising a stator, an electric rotor and a winding rotor, wherein the stator comprises a stator iron core and an excitation winding, the electric rotor comprises an electric rotor iron core, a squirrel cage conducting bar and a permanent magnet, one side, close to the stator, of the electric rotor iron core is designed into an open slot, the squirrel cage conducting bar is placed in the open slot of the electric rotor iron core, the end part of the squirrel cage conducting bar is in short circuit through an end ring to obtain induced eddy current, and one side, close to the winding rotor, of the electric rotor iron core is pasted with the permanent magnet magnetized in a magnetism; the winding rotor comprises a winding rotor core and an induction winding, wherein a slot is formed in one side, close to the electric rotor, of the winding rotor core, the induction winding is arranged in the slot, a modulation tooth is formed by slotting between adjacent induction windings and used for modulating a permanent magnetic field and an induction magnetic field, the induction winding is arranged in a fractional slot centralized mode and is connected with an external controller through a collecting ring and an electric brush, and slip power is fed back to an electric network.

Furthermore, the stator core is designed to be an open slot, the excitation windings are arranged in the open slot of the stator core, the excitation windings are distributed in an integer slot arrangement and are supplied with alternating current through the inverter to generate a rotating magnetic field, and each winding coil is wound on a stator tooth.

Further, the motor is a rotating motor, and the stator core is grooved along the circumferential direction and at one side close to the squirrel-cage rotor.

Furthermore, permanent magnets are arranged on the electric rotor iron core along the circumferential direction and close to one side of the winding rotor, the permanent magnets have p2 pairs of poles, each pair of poles consists of 3 permanent magnets, and the 3 permanent magnets are magnetized in a radial inward, tangential and radial outward mode in sequence to form a magnetism gathering array.

Further, the stator iron core, the electric rotor iron core and the winding rotor iron core are formed by laminating tooth-groove silicon steel sheets, and the permanent magnet is made of rare earth permanent magnet materials.

Further, the excitation windings are arranged in a single layer or double layer mode, and the induction windings are arranged in a double layer mode.

By the scheme, the invention at least has the following advantages:

(1) the motor has low voltage ride through capability, when the voltage of a power grid is reduced, the magnetic field intensity generated by the excitation winding is reduced, in order to keep the torque borne by the squirrel cage conducting bars unchanged, the current of the excitation winding is increased, the magnetic field intensity generated by the excitation winding is enhanced, the induction current of the squirrel cage conducting bars is increased due to the increase of the magnetic field intensity of the excitation winding, however, the voltage drop time of the power grid is short, and the squirrel cage rotor does not need to be provided with a power conversion device, so the squirrel cage rotor cannot. The squirrel-cage conducting bars are subjected to unchanged torque, the rotating speed of the electric rotor is unchanged, the rotating speed of the permanent magnets is unchanged, the rotating speed of a magnetic field generated by the permanent magnets is unchanged, and the induced current of the induction winding is only related to the slip between the permanent magnet rotor and the winding rotor, so that the induced current of the induction winding is unchanged, and the output torque of the winding rotor is unchanged. In summary, the output torque is not affected by the grid voltage drop, i.e. has a low voltage ride through capability.

(2) The permanent magnet is magnetized by adopting the magnetism gathering array, so that magnetic lines of force are forced to walk from a main magnetic path of a turn chain of the induction winding, mutual interference between an excitation magnetic field and a permanent magnetic field is reduced, magnetic leakage of the permanent magnetic field is reduced, more magnetic lines of force pass through an air gap, and the torque density and the power density of the motor are improved.

(3) The winding rotor is provided with modulation teeth to perform magnetic flux modulation on the permanent magnetic field and the induction magnetic field generated by the induction winding, and the torque output capacity of the winding rotor can be improved through the magnetic field modulation, so that the torque density of the motor is improved.

(4) The induction winding is connected with an external controller through the collecting ring and the electric brush, and the induced current is fed back to a power grid through the controller, so that energy is saved.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate a certain embodiment of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic front view of the present invention;

FIG. 2 is a schematic view of the stator structure of the present invention;

FIG. 3 is a schematic view of the electric rotor of the present invention;

fig. 4 is a schematic view of the winding rotor structure of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Referring to fig. 1 and 2, an intelligent motor control device for an electric vehicle according to a preferred embodiment of the present invention includes

Fig. 1 is a schematic structural diagram of a winding type permanent magnet coupling speed-regulating motor according to an embodiment of the present invention. As shown in fig. 1, the motor includes a stator 100, an electric rotor 200, and a winding rotor 300. As shown in fig. 2, the stator 100 includesThe stator core 101 is formed by laminating tooth-groove-type silicon steel sheets, a groove is formed in one side close to the electric rotor 200, the excitation winding 102 is arranged in the groove of the stator core, coils of each phase of winding are connected in series or in parallel or in series and parallel in a mixed mode, the excitation winding 102 is distributed in a single-layer integer groove mode and is connected with an external inverter, and three-phase alternating current is conducted; as shown in fig. 3, the electric rotor 200 includes an electric rotor core 201, a cage bar 202, a radial magnetizing permanent magnet 203 and a tangential magnetizing permanent magnet 204, the electric rotor core 201 is formed by laminating tooth-grooved silicon steel sheets, a groove is formed at a side close to the stator 100, the cage bar 202 is arranged in the groove, ends are connected by an end ring to form an induced eddy current, and a p-sheet is attached to a side of the electric rotor core 201 close to the winding rotor₂For the permanent magnets magnetized in a magnetism gathering array mode, each pair of magnetic poles consists of 3 permanent magnets, and comprises 1 permanent magnet magnetized radially inwards, 1 permanent magnet magnetized tangentially and 1 permanent magnet magnetized radially outwards, wherein the 3 permanent magnets are alternately arranged; as shown in fig. 4, the winding rotor 300 includes a winding rotor core 301, modulation teeth 302 and induction windings 303, the winding rotor core 301 is formed by laminating silicon steel sheets, a slot is formed at one side close to the electric rotor, the induction windings 303 are arranged in the slot, the induction windings are arranged in a double-layer fractional slot centralized manner and are connected to an external controller through a collecting ring and a brush, induced current flows back to a feed network, and a slot is formed between two adjacent induction winding slots to form z modulation teeth 302.

Specifically, in operation, an external power source energizes the field winding 102 with alternating current to produce a fundamental pole pair number p in the field winding₁At a rotational speed of n₁The squirrel cage conducting bars 202 are arranged in the rotating magnetic field to cut magnetic lines of force to induce eddy currents, and the number of pole pairs generated by the induced eddy currents is p₁At a rotational speed of n₁The rotating magnetic field interacts with the magnetic field generated by the exciting winding to generate torque, so that the electric rotor rotates, and when the torque reaches a stable value, the rotating speed of the electric rotor is n₂The rotating speed of the exciting magnetic field and the rotating speed of the electric rotor satisfy n_2<n₁So as to ensure that the squirrel cage conducting bars cut the magnetic force lines of the excitation magnetic field.

The electric rotor 200 drives the permanent magnet to rotate at the same rotation speed n₂The permanent magnet thus generates a number p of pole pairs₂At a rotational speed of n₂The induction winding 303 is arranged in the rotating magnetic field to cut magnetic lines of force to induce current, and the number of pole pairs generated by the induced current is p₂At a rotational speed of n₂The induction magnetic field and the permanent magnetic field interact to generate torque, so that the winding rotor rotates, and the rotating speed of the winding is n₃The rotating speed of the permanent magnetic field and the rotating speed of the winding rotor meet n₃<n₂So as to ensure that the induction winding cuts the magnetic line of the permanent magnetic field. The induced current generated in the induction winding is fed back to the power grid through the controller, and energy conservation can be realized. According to the expression, the excitation magnetic field and the permanent magnetic field respectively play their own roles and theoretically do not interfere with each other, however, because the permanent magnet is arranged on the electric rotor and is very close to the excitation magnetic field, the excitation magnetic field and the permanent magnetic field are coupled with each other inevitably, in order to reduce the interference between the excitation magnetic field and the permanent magnetic field, the permanent magnet is arranged into a magnetism gathering array, a tangential magnetizing permanent magnet is added in the original radial magnetizing magnetic pole, the magnetic field of the permanent magnet close to one side of an air gap is enhanced, the weakened magnetic field of the permanent magnet close to one side of a squirrel cage conducting bar is reduced, so that the leakage flux coupled with the excitation magnetic field in the permanent magnetic field is reduced, more magnetic lines of force pass through the air gap, the output torque of the motor is increased, and the torque density. When the winding rotor rotates, the modulation teeth 302 can modulate and generate other useful harmonic components of orders besides the flux density fundamental component of the permanent magnet air gap, although the frequency of the harmonic components of other useful orders is different from the frequency of the fundamental wave, the harmonic components of other useful orders can also contribute to generating counter electromotive force of the fundamental wave, thereby improving the torque output capacity of the winding rotor, and the torque density of the motor is improved again. During speed regulation, the controller is used for regulating the magnitude of induced current in the winding rotor to change the magnetic field intensity generated by the induced current, so that the magnitude of torque transmitted between the induced magnetic field and the permanent magnetic field is regulated, the speed is increased when the electromagnetic torque is greater than the load torque, and the speed is reduced when the electromagnetic torque is less than the load torque, thereby achieving the purpose of speed regulation.

When the voltage of a power grid is reduced, the input voltage of an excitation winding is reduced, and the excitation magnetic field is enhanced by increasing the current of a stator excitation winding so as to ensure that the torque transmitted between the excitation magnetic field and a squirrel-cage conducting bar induced magnetic field is unchanged; the rotating speed of the electric rotor is unchanged when the torque borne by the squirrel-cage conducting bars is unchanged, so that the rotating speed of the permanent magnet is unchanged, the torque borne by the winding rotor is only related to the rotating speed difference between the permanent magnet and the winding rotor and the magnitude of induced current in the induction winding, and the output torque of the winding rotor cannot be influenced when the voltage of a power grid is reduced, namely the low-voltage ride through capability is realized.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.