CN202334220U - Hybrid rotor brushless synchronous motor - Google Patents

Abstract

A hybrid rotor brushless synchronous motor, including a rotating shaft, a rotor outside the rotating shaft, a stator outside the rotor, and a casing outside the stator. It is characterized in that a steel sleeve is installed between the rotating shaft and the rotor, and the steel sleeve is positioned through The pin and the rotating shaft are fixed together; the rotor adopts a hybrid rotor structure with 2 p _a + 2 p _e poles, and the rotor laminations made of silicon steel sheet materials are laminated in the radial direction; two sets of windings are embedded in the stator, which are connected to each other during operation. The stator three-phase AC armature winding on the frequency converter, and the stator single-phase DC field winding connected to the adjustable DC power supply during operation. The utility model saves electric brushes and slip rings, improves operational reliability; reduces high-order harmonics, lowers temperature rise and noise, and improves operational performance; moreover, the motor has large starting torque, large output torque, and The torque ripple is small, it is not easy to lose steps, and the operation is stable.

Description

A Hybrid Rotor Brushless Synchronous Motor

technical field

The utility model relates to the field of motors, in particular to a hybrid rotor brushless synchronous motor.

Background technique

Commonly used motors include induction motors, electrically excited synchronous motors, permanent magnet synchronous motors and other special motors, each of which has its own advantages and disadvantages and plays an important role in different application fields. Induction motors often operate as electric motors, among which the squirrel-cage induction motor has the advantages of simple structure and brushless reliability, while the wound-wire induction motor has better performance than the squirrel-cage motor: such as adjustable starting performance, easy to realize cascade Or double-fed speed regulation, etc., but its inherent brush slip ring structure greatly reduces its operational reliability, and it cannot be used in flammable and explosive occasions. Electric excitation synchronous motors are widely used in both electric and power generation: compared with induction motors, their efficiency and power factor are higher and the power factor is adjustable, but their starting performance is not as good as that of induction motors, and they also have a brush structure and poor reliability. , the application in explosion-proof occasions is also limited; the electric excitation synchronous generator is the main equipment for electric energy production, but the structure of the brush slip ring affects its long-term reliable operation, especially in large-scale wind power generation systems where maintenance is very difficult, its application is very restricted limit. Permanent magnet motors have recognized excellent operating performance and are mechanically brushless and reliable, but the high price of permanent magnet materials limits the application field.

Contents of the invention

A hybrid rotor brushless synchronous motor of the present invention saves the brushes and slip rings that are prone to failure, fully improves the operation reliability of the synchronous motor, adopts a new rotor structure with high magnetic field conversion capability, and has excellent operation performance , The rotor does not need permanent magnet materials, and the cost is low.

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

The hybrid rotor brushless synchronous motor includes a rotating shaft, a rotor outside the rotating shaft, a stator outside the rotor and a casing outside the stator. The shafts are fixed together; the rotor adopts a hybrid rotor structure with 2 p _a + 2 p _e poles, and the rotor laminations are stacked radially; the stator is embedded with two sets of windings, and the three-phase AC armature of the stator connected to the frequency converter during operation winding, and the stator single-phase DC field winding connected to the adjustable DC power supply during operation.

The rotor has a total of p _a + p _e salient poles, and each half of two adjacent salient poles together form a lamination group, and the entire circumference of the rotor is composed of p _a + p _e completely identical lamination groups Composition, each lamination group passes through three fixed screws in the axial direction, the ends of the fixed screws are fixed with nuts, there is a dovetail at the bottom of the lamination group, and the dovetail is fixed in the dovetail groove punched on the steel sleeve; two adjacent Conductive cages are placed between the laminations along the axial direction close to the rotor surface, p _a + p _e conductive cages are placed on the entire circumference of the rotor, and the two ends of the conductive cages are compressed with conductive rings to realize short-circuit connection.

The stator slot of the stator is divided into three layers, and two sets of windings are embedded. Among them, the two layers on the top of the slot are embedded with stator three-phase AC armature windings with a number of poles of 2pa, which is designed as a three-phase symmetrical double-layer short-distance distributed stacked winding. ; The bottom layer of the slot is embedded with a stator single-phase DC excitation winding with a pole number of 2pe, which is designed as a single-phase concentric sinusoidal winding.

A magnetic permeable layer is arranged on the lamination group, and at least three uniform magnetic barrier layers with the same width are left on the adjacent two salient pole magnetic permeable layers, and the width ratio between each magnetic barrier layer and the magnetic permeable layer is kept the same, The magnetically permeable layers are connected by radial connecting ribs, and the magnetically permeable layers are connected as a whole.

The conductive cage bars are placed in a segmented structure.

The fixing screw is made of non-magnetic material.

The steel sleeve is made of non-magnetic material.

The magnetic isolation layer of the rotor is made of epoxy resin or other high temperature resistant non-magnetic conductive materials.

The magnetic isolation layer of the hybrid rotor is U-shaped.

The magnetic isolation layer of the hybrid rotor is arc-shaped. the

The beneficial effect of the utility model is that: a hybrid rotor brushless synchronous motor is provided, which saves the brush and the slip ring and improves the operation reliability. The three-phase symmetrical armature winding of the stator and the DC excitation winding designed by the single-phase sinusoidal winding reduce high-order harmonics, reduce temperature rise and noise, and improve operating performance, and the motor has a large starting torque and output torque. The torque ripple is small, it is not easy to lose steps, and the operation is stable. The rotor adopts a hybrid rotor structure, which fully improves the magnetic field conversion capability of the two sets of stator windings, improves the operating performance of the motor, and improves efficiency. The rotor has the remarkable advantages of novel structure, simple process, low cost, high mechanical strength, reliable operation, modular structure, and convenient industrialization.

Description of drawings:

Fig. 1 is the schematic diagram of motor operation described in the utility model;

Figure 2 is a U-shaped magnetic isolation layer hybrid rotor brushless synchronous motor;

Figure 3 is a hybrid rotor brushless synchronous motor with an arc-shaped magnetic isolation layer;

Explanation of reference signs:

1. Stator, 2. Stator three-phase AC armature winding, 3. Stator unidirectional DC excitation winding, 4. Rotor, 5. Fixed screw, 6. Magnetic isolation layer, 7. Inverting magnetic layer, 8. Conductive cage, 9 .Rotating shaft, 10. Steel sleeve, 11. Dovetail, 12. Locating pin, 13. Chassis, 14. Adjustable DC power supply, 15. Power grid.

Detailed ways:

The utility model discloses a hybrid rotor brushless synchronous motor. The stator is embedded with a three-phase symmetrical AC armature winding and a stator DC excitation winding designed with a single-phase concentric sinusoidal winding. The rotor adopts a hybrid rotor structure. The armature winding on the stator And the DC winding, relying on the magnetic field conversion of the rotor to achieve good coupling. The rotor not only has excellent magnetic field conversion capability, but also is durable, safe and reliable, and has high efficiency. The motor can be used not only as a motor but also as a generator. When the motor is running, the armature winding embedded in the stator is connected to a three-phase symmetrical sinusoidal alternating current, and the stator DC winding is short-circuited to realize self-starting. After starting, the stator DC winding Both ends switch to direct current, and the motor enters a synchronous operation state, so the motor has good self-starting ability and synchronous operation performance. The external force drives the rotor to rotate, the DC excitation winding of the stator is supplied with DC, and the AC armature winding of the stator can output a three-phase symmetrical sinusoidal AC to realize synchronous power generation operation.

The utility model is described in detail below in conjunction with accompanying drawing.

Fig. 2 is the structural diagram of the motor described in the present invention, as shown in the figure, including rotating shaft 9, the rotor 4 outside the rotating shaft 9, the stator 1 outside the rotor 4 and the casing 13 outside the stator 1, between the rotating shaft 9 and the rotor 4 A steel sleeve 10 made of a non-magnetic material is installed, and the steel sleeve 10 is fixed together with the rotating shaft 9 through a positioning pin 12 on the rotating shaft 9 .

The rotor 4 adopts a hybrid rotor structure with 2 p _a + 2 p _e poles, and the rotor laminations are made of silicon steel sheets and laminated radially. Specifically: the rotor 4 has a total of p _a + p _e salient poles, and each half of two adjacent salient poles together form a lamination group. The entire circumference of the rotor 4 is composed of p _a + p _e completely identical Composed of laminations, such a symmetrical structure can realize that only one type of laminations can be processed to assemble the entire rotor, thus greatly reducing the process cost and facilitating industrialization. The laminations are stacked radially, which can reduce eddy current loss and improve efficiency; each lamination passes through three fixed screws 5 made of non-magnetic materials in the axial direction, and the ends of the fixed screws 5 are fixed with nuts . A magnetically permeable layer 7 is arranged on the lamination group, and at least three uniform magnetically isolated layers 6 with equal widths are left on the adjacent two salient pole magnetically permeable layers 7, and the width between each magnetically isolated layer 6 and the magnetically permeable layer 7 is kept The ratio is the same, at this time, the magnetic isolation layer and the magnetic permeable layer of uniform thickness are placed at intervals, and the magnetic permeable layers 7 are connected by radial connecting ribs, and the magnetic permeable layers 7 distributed at intervals are connected as a whole. The radial connecting ribs can ensure sufficient mechanical strength, and the magnetic isolation layer 6 is filled with epoxy resin or high-temperature resistant non-magnetic conductive material. The magnetic isolation layer 6 is designed to have a uniform width and is designed as a plurality of magnetic isolation layers. After the magnetic layer, its magnetic field conversion ability is significantly improved, and the more magnetic isolation layers, the more obvious the effect. When there are many magnetic isolation layers, the cost increases rapidly, so the appropriate number of magnetic isolation layers should be selected. There is a dovetail 11 at the bottom of the lamination group, and the dovetail 11 is fixed in the dovetail groove punched on the steel sleeve 10; between two adjacent lamination groups, a conductive cage bar 8 is placed in the axial direction near the surface of the rotor 4, and the conductive cage The bars 8 are placed in a segmented structure, and p _a + p _e conductive cage bars 8 are placed on the entire circumference of the rotor 4, and the two ends of the conductive cage bars 8 are compressed with conductive rings to realize short-circuit connection, thus forming a hybrid type Rotor structure. p _a + p _e conductive cage bars 8 two groups of ends are short-circuited and connected, collectively referred to as short-circuit cage bars. The conductive cage bar 8 is placed on the center line of the salient pole, and the conductive cage bar 8 adopts a layered design, the purpose of which is to overcome the skin effect of the induced current. The conductive cage is actually similar to the cage of the squirrel-cage rotor of the induction motor. After adding the conductive cage, the starting torque of the motor increases, the output torque increases, the torque ripple decreases, the embedded characteristics are greatly improved, and the running performance Significant improvement has been obtained.

Hybrid rotors can be divided into two types according to the shape of the magnetic isolation layer: U-shaped hybrid rotors and arc-shaped hybrid rotors. The two types of rotors have the same magnetic field conversion capability. Combined with process and power requirements, U-shaped hybrid rotors are more suitable It is suitable for large-capacity motors, while the arc-shaped hybrid rotor is more suitable for small and medium-sized motors.

The stator slot of the stator 1 is divided into three layers, and two sets of windings are embedded. The stator three-phase AC armature winding 2 with a number of poles of 2 p _a is embedded in the two layers on the top of the slot, which is designed as a three-phase symmetrical double-layer short-distance distributed Stacked windings, connected to the frequency converter during operation, can effectively suppress high-order harmonics. The stator single-phase DC excitation winding 3 with a pole number of 2 p _e is embedded in the bottom layer of the slot. It is designed as a single-phase concentric sinusoidal winding, which can weaken high-order harmonics, reduce temperature rise, reduce electromagnetic noise, improve efficiency, and save copper. line to reduce the slot full rate; it is connected to the adjustable DC power supply during operation, and the stator DC excitation winding is fed with DC current during stable operation, and placed at the bottom of the slot, which can reduce the leakage reactance of the motor. The running diagram is shown in Figure 1. The design should meet the requirements so as to reduce the unilateral magnetic pull, thereby reducing the impact of vibration and noise on the performance of the motor. In each group of slots, the number of conductors in the slots gradually increases when viewed from the center line to both sides, so that the total effective turns of the coils placed in each slot are distributed along the circumference according to the sinusoidal law from the perspective of the entire circumference. Because the AC armature windings that generate the rotating magnetic field and the DC excitation windings that generate the excitation magnetic field are embedded in the stator, there is no brush slip ring on the rotor of the motor. This brushless structure greatly improves the operating reliability of the motor. .

The rotor adopts a hybrid rotor structure, the equivalent number of poles is 2 ( p _a + p _e ) (the number of salient poles is ( p _a + p _e )), and the two sets of stator windings generate magnetic fields corresponding to the number of poles in the air gap. That is, there are two magnetic fields with different numbers of poles in the air gap, one is the circular rotating magnetic field generated by the three-phase AC armature winding of the stator, and the other is the exciting magnetic field generated by the stator single-phase DC excitation winding designed for sinusoidal windings, two different poles Several magnetic fields rely on the magnetic field conversion effect of the hybrid rotor to complete the electromechanical energy exchange between the stator and the rotor.

The motor can be operated as a motor or as a generator.

When running as a motor, the motor has excellent self-starting ability. Unlike other synchronous motors, it does not need any additional starting windings. The three-phase AC armature winding of the stator is connected to the three-phase symmetrical sinusoidal AC through the frequency converter, and the DC winding of the stator is short-circuited. At this time, two magnetic fields are generated in the air gap, one is the circular rotating magnetic field generated by the stator armature winding, and the other is the excitation magnetic field generated by the induced current of the stator excitation winding. The special magnetic field conversion effect realizes the joint action of the two magnetic fields to generate a large starting torque, so that the rotor can be rotated. When the speed reaches about 90% of the synchronous speed, the speed sensor detects the speed signal and quickly feeds the speed signal back to the controller on the stator side, so that the DC winding is switched to the adjustable DC power supply, the magnetic field generated by the stator armature winding and the stator DC winding. The generated magnetic fields work together, and the air gap will generate a magnetic field with 2 p _a pole and 2 p _e pole harmonics as the main harmonics, relying on the magnetic field conversion of the hybrid rotor with the equivalent pole number of 2 ( p _a + p _e ) The role is to complete the energy exchange between the stator and the rotor, and the motor finally runs at a synchronous speed to reach a steady state.

When operating as a generator, the rotor is driven by the prime mover, and the stator DC winding is connected to the adjustable DC power supply. Since the equivalent number of poles of the rotor is 2 ( p _a + p _e ), the stator DC winding relies on the hybrid rotor The magnetic field conversion effect of the magnetic field is established to establish a magnetic field, which will generate a magnetic field with 2 p _a pole and 2 p _e pole as the main harmonics in the air gap. The 2 p _e pole harmonic realizes the excitation of the stator DC winding, and the 2 p _a pole harmonic The wave induces a three-phase symmetrical sinusoidal alternating current in the stator armature windings. When working, the initial position of the DC excitation winding can be changed by the controller, thereby changing the angle between the no-load electromotive force and the terminal voltage, so that the generator can work in an over-excited state, so that the generator can generate inductive reactive power, thereby improving the power grid. The power factor can also be realized by adjusting the excitation current to achieve weak field speed regulation. Because this hybrid rotor has a novel structure and the existence of the magnetic isolation layer, the magnetic field conversion efficiency is greatly increased. Waves are greatly reduced. The existence of the short-circuit cage in the rotor not only enables the motor to have a larger starting torque, the starting time is further shortened, but also the starting overshoot is small, and the stable running speed can be quickly reached.

Another important function of the short-circuit cage is to make the motor have a strong dive-in characteristic. Under the action of the induced current of the short-circuit cage, the time required for the motor to dive into synchronous operation after starting is greatly reduced, and the belt load when the load starts The loading capacity has also been greatly improved. Therefore, the rotor integrated with magnetic isolation reluctance and short-circuit cage bars not only has high magnetic field conversion capability and operating efficiency, but also has excellent starting performance, large output torque, small torque ripple, and is not easy to lose steps. operating performance.

Claims (10)

1. A hybrid rotor brushless synchronous motor, including a rotating shaft (9), a rotor (4) outside the rotating shaft (9), a stator (1) outside the rotor (4), and a casing (13) outside the stator (1) ), characterized in that: a steel sleeve (10) is installed between the rotating shaft (9) and the rotor (4), and the steel sleeve (10) is fixed together with the rotating shaft (9) through the positioning pin (12) on the rotating shaft (9) ; The rotor (4) adopts a hybrid rotor structure with 2 p _a + 2 p _e poles of magnetic isolation reluctance and short-circuit cage bars, and the rotor laminations are stacked in the radial direction; two sets of windings are embedded in the stator (1). The stator three-phase AC armature winding (2) connected to the frequency converter, and the stator single-phase DC excitation winding (3) connected to the adjustable DC power supply during operation. 2. The hybrid rotor brushless synchronous motor according to claim 1, characterized in that: the rotor (4) has a total of p _a + p _e salient poles, and two adjacent salient poles are composed of one-half of each One lamination group, the entire circumference of the rotor (4) is composed of p _a + p _e identical lamination groups, and each lamination group passes through three fixed screws (5) in the axial direction, and the fixed screws (5 ) ends are fixed with nuts, and a dovetail (11) is left at the bottom of the laminations, and the dovetails (11) are fixed in the dovetail groove punched on the steel sleeve (10); 4) Place conductive cage bars (8) along the axial direction on the surface, place p _a + p _e conductive cage bars (8) on the entire circumference of the rotor (4), and use conductive rings at both ends of the conductive cage bars (8) Compress to achieve a short circuit connection. 3. The hybrid rotor brushless synchronous motor according to claim 1, characterized in that: the stator slot of the stator (1) is divided into three layers, and two sets of windings are embedded, and the two layers at the top of the slot are embedded with the number of poles The stator three-phase AC armature winding (2 ) with 2 p _a is designed as a three-phase symmetrical double-layer short-pitch distributed stacked winding; the bottom layer of the slot is embedded with a _stator single-phase DC excitation winding (3 ), designed as a single-phase concentric sinusoidal winding. 4. The hybrid rotor brushless synchronous motor according to claim 2, characterized in that: a magnetic conductive layer (7) is provided on the lamination stack, and at least two adjacent salient pole magnetic conductive layers (7) are left Three uniform magnetic isolation layers (6) with the same width, and keep the same width ratio between each magnetic isolation layer (6) and the magnetic conduction layer (7), and the magnetic conduction layers (7) are connected by radial connecting ribs, Connect each magnetic permeable layer (7) as a whole. 5. The hybrid rotor brushless synchronous motor according to claim 2, characterized in that: the conductive cage (8) is placed in a segmented structure. 6. The hybrid rotor brushless synchronous motor according to claim 2, characterized in that: the fixing screw (5) is made of a non-magnetic material. 7. The hybrid rotor brushless synchronous motor according to claim 1, characterized in that: the steel sleeve (10) is made of a non-magnetic material. 8 . The hybrid rotor brushless synchronous motor according to claim 4 , characterized in that: the magnetic isolation layer ( 6 ) of the rotor ( 4 ) is made of epoxy resin or other high temperature resistant non-magnetic conductive materials. 9. The hybrid rotor brushless synchronous motor according to claim 1, characterized in that: the hybrid rotor magnetic isolation layer (6) is U-shaped. 10. The hybrid rotor brushless synchronous motor according to claim 1, characterized in that: the hybrid rotor magnetic isolation layer (6) is arc-shaped.

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