A generator with constant frequency and variable frequency function

Abstract

The application discloses a generator with constant-speed frequency modulation function, which comprises a stator and a rotor, the stator comprises a stator core, a first winding and a second winding, the first winding and the second winding are both wound on the stator core, the second winding is closer to the rotor in the radial direction of the stator than the first winding, the rotor comprises a rotating shaft, a first rotor magnetic pole group and a second rotor magnetic pole group arranged in the circumferential direction of the rotating shaft, the second rotor magnetic pole group is closer to the stator in the radial direction of the rotor than the first rotor magnetic pole group, the polarity of the magnets constituting the first rotor magnetic pole group and the second rotor magnetic pole group changes alternately in the respective circumferential directions, the pole number of the first rotor magnetic pole group and the second rotor magnetic pole group is different, the pole number of the first rotor magnetic pole group is the same as that of the first winding, and the pole number of the second rotor magnetic pole group is the same as that of the second winding. The application can realize variable frequency output under constant rotating speed without adopting power power electronic devices frequency conversion.

Description

TECHNICAL FIELD

[0001] The present application relates to a generator, in particular to a generator with constant speed frequency modulation function. BACKGROUND

[0002] With the rapid development of traffic electrification, the load power and speed level of electric drive vehicle auxiliary systems tend to be diverse. Permanent magnet motors have the advantages of high power density, high efficiency and good dynamic characteristics, and are widely used in various traffic electric drive systems. The rotor magnetic field of brushless permanent magnet motor is established by high-performance permanent magnets, and the pole number and magnetic performance are constant after magnetization is completed, so it has excellent output characteristics and torque retention capability. However, the constant magnet performance and pole number result in that the motor speed cannot be adjusted autonomously like asynchronous motor, and power electronic devices must be used to realize frequency modulation and speed regulation. Similarly, in the generator system, when the prime mover speed is constant, the output alternating electromagnetic quantity frequency is constant, and only by means of power electronic devices can frequency modulation or rectification, inversion be realized to provide for various frequency loads.

[0003] When power electronic devices are used for frequency modulation, the complexity and volume of the system are greatly improved, the power density and efficiency are reduced, the processing and manufacturing difficulty is increased, and the cost is significantly increased. On the other hand, various power electronic devices have low temperature resistance, poor overload capacity, weak anti-electromagnetic interference ability, and low control algorithm redundancy, and have low reliability in complex working conditions and special application environments. At the same time, for applications that do not require continuous frequency modulation, the advantages of power electronic speed regulation cannot be fully utilized, and there is no performance comparison advantage. In addition, power electronic devices will introduce new interference in the process of rectification, voltage stabilization and inversion, which is not conducive to the stable operation of the driven load and other equipment in the same installation environment. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the present application provides a generator with constant speed frequency modulation function, which solves the problem of frequency conversion when the prime mover speed is constant and realizes two-stage frequency conversion output.

[0005] The technical scheme of the present application is as follows: a generator with constant-speed frequency modulation function, comprising a stator and a rotor, the stator comprises a stator core, a first winding and a second winding, the first winding and the second winding are both wound on the stator core, the second winding is closer to the rotor in the radial direction of the stator than the first winding, the rotor comprises a rotating shaft, a first rotor magnetic pole group and a second rotor magnetic pole group arranged circumferentially on the rotating shaft, the second rotor magnetic pole group is closer to the stator in the radial direction of the rotor than the first rotor magnetic pole group, the polarity of the magnets constituting the first rotor magnetic pole group and the second rotor magnetic pole group alternates in the respective circumferential directions, the number of poles of the first rotor magnetic pole group and the second rotor magnetic pole group is different, the number of poles of the first rotor magnetic pole group is the same as that of the first winding, and the number of poles of the second rotor magnetic pole group is the same as that of the second winding.

[0006] Further, the stator is arranged on the periphery of the rotor, and the second rotor magnetic pole group is an integral magnetic ring. In this way, a non-magnetic protection sleeve no longer needs to be arranged outside the second rotor magnetic pole group.

[0007] Another technical scheme of the present application is as follows: a generator with constant-speed frequency modulation function, comprising a stator, a first rotor and a second rotor, the stator is arranged between the first rotor and the second rotor, the stator comprises a stator core, a first winding and a second winding, the first winding and the second winding are both wound on the stator core, the first winding is close to the first rotor in the radial direction, and the second winding is close to the second rotor in the radial direction, the first rotor and the second rotor have a common rotating shaft, the first rotor is provided with a first rotor magnetic pole group arranged circumferentially outside the stator, the second rotor is provided with a second rotor magnetic pole group arranged circumferentially inside the stator, the number of poles of the first rotor magnetic pole group and the second rotor magnetic pole group is different, the number of poles of the first rotor magnetic pole group is the same as that of the first winding, and the number of poles of the second rotor magnetic pole group is the same as that of the second winding.

[0008] Further, the first rotor magnetic pole group and / or the second rotor magnetic pole group is a direct-current excitation winding.

[0009] Further, the magnetization directions of the magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are the same, and are both radial or parallel magnetization.

[0010] Further, the magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are uniformly spaced in the circumferential direction.

[0011] The technical scheme provided by the present application has the following advantages:

[0012] The application does not need to realize the secondary frequency conversion output by means of power electronic frequency conversion technology, when the rotation speed of the prime mover is constant, different frequency AC can be sent out by simply switching the winding for driving the load with different frequency requirement. Secondly, the proposed generator system has simple structure, high efficiency and high reliability. Meanwhile, without using expensive power electronic devices, the material and installation application cost of the generator system is reduced, and the control difficulty is reduced. Furthermore, after eliminating the frequency conversion system, the volume of the generator is greatly reduced, the power density is high, the requirement for installation environment is reduced, the interference from the outside world is small, and the application range is more extensive. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Structure diagram of the generator with constant speed frequency modulation function of embodiment 1.

[0014] Figure 2 Structure diagram of the stator core and the first winding of the generator with constant speed frequency modulation function of embodiment 1.

[0015] Figure 3 Structure diagram of the stator core and the second winding of the generator with constant speed frequency modulation function of embodiment 1.

[0016] Figure 4 Structure diagram of the rotor of the generator with constant speed frequency modulation function of embodiment 1.

[0017] Figure 5 Structure diagram of the generator with constant speed frequency modulation function of embodiment 2.

[0018] Figure 6 Structure diagram of the stator of the generator with constant speed frequency modulation function of embodiment 2.

[0019] Figure 7 Structure diagram of the rotor of the generator with constant speed frequency modulation function of embodiment 2.

[0020] Figure 8 Structure diagram of the generator with constant speed frequency modulation function of embodiment 3.

[0021] Figure 9 Structure diagram of the stator of the generator with constant speed frequency modulation function of embodiment 3.

[0022] Figure 10 Structure diagram of the rotor of the generator with constant speed frequency modulation function of embodiment 3. DETAILED DESCRIPTION

[0023] The application will be further described in conjunction with the embodiments, but not as a limitation to the application.

[0024] Embodiment 1, please refer to Figures 1 to 4As shown, the present embodiment relates to a generator with constant-speed frequency modulation function, which has a rated power of 3000W and a rated speed of 5400r / min. The generator with constant-speed frequency modulation function comprises a stator 100 and a rotor 101, and the stator 100 is arranged outside the rotor 101, i.e. the structure of the outer stator 100 and the inner rotor 101.

[0025] The stator 100 comprises a stator core 1001 made of 0.35mm non-oriented silicon steel sheet and two sets of three-phase windings, i.e. a first winding 1002 and a second winding 1003, wound on the stator core 1001. The stator core 1001 is circumferentially provided with 18 evenly distributed slots 1001a, and 18 stator teeth 1001b formed by the slots 1001a are respectively wound with the first winding 1002 and the second winding 1003 from inside to outside. The first winding 1002 is wound as an outer coil, which comprises 9 coils, and each coil of the first winding 1002 spans two stator teeth 1001b. The pitch of the coils of the first winding 1002 is 2, and the number of turns is 12, forming a 6-pole 9-slot winding, as shown in Figure 2 The second winding 1003 is wound as an inner coil, which is closer to the rotor 101 than the first winding 1002, and also comprises 9 coils. Each coil of the second winding 1003 spans two stator teeth 1001b, and the pitch is 2, and the number of turns is 15, forming an 8-pole 9-slot winding, as shown in Figure 3

[0026] Please refer to Figure 4 As shown, the rotor 101 of the generator is located inside the stator 100, which comprises a rotating shaft 1011 and a first rotor magnetic pole group 1012 and a second rotor magnetic pole group 1013 arranged circumferentially around the rotating shaft 1011. The rotating shaft 1011 is made of 45# magnetic steel and connected to the output shaft of the diesel engine. The first rotor magnetic pole group 1012 comprises 6 permanent magnets, which are evenly distributed along the circumference and attached to the outer side of the rotating shaft 1011. The magnets are radially magnetized, and the polarities of the magnets are staggered to form 6 magnetic poles. The number of poles of the first rotor magnetic pole group 1012 is the same as that of the first winding 1002.

[0027] The second rotor magnetic pole group 1013 comprises 8 permanent magnets, which are evenly distributed along the circumference and attached to the outer side of the first rotor magnetic pole group 1012. The magnets are radially magnetized, and the polarities of the magnets are staggered to form 8 magnetic poles. The number of poles of the second rotor magnetic pole group 1013 is the same as that of the second winding 1003. In this embodiment, the outer side of the second rotor magnetic pole group 1013 is sleeved with a non-magnetic sheath 1014 made of Inconel 718 alloy steel.

[0028] ​As a preferred embodiment, the second rotor 101 magnetic pole group can be set as a complete magnetic ring, so that the radial position of the first rotor 101 magnetic pole group is limited by the second rotor 101 magnetic pole group, and thus an additional non-magnetic sheath is not needed.

[0029] As another preferred embodiment, the permanent magnets of the first rotor magnetic pole group 1012 and the second rotor magnetic pole group 1013 can be replaced by DC field windings. When the DC field windings of the first rotor magnetic pole group 1012 are energized, the DC field windings of the second rotor magnetic pole group 1013 are set to an open circuit state. When the DC field windings of the second rotor magnetic pole group 1013 are energized, the DC field windings of the first rotor magnetic pole group 1012 are set to an open circuit state. By setting the on-off state of the two sets of DC field windings, the current of the rotor DC field windings is synchronized with the generator load torque, enhancing the stability of the generator speed and frequency. Alternatively, the permanent magnets of either the first rotor magnetic pole group 1012 or the second rotor magnetic pole group 1013 can be replaced by DC field windings.

[0030] During the operation of the generator with constant-speed frequency modulation function in this embodiment, the diesel engine output shaft is connected to the rotating shaft of the rotor 101, the rotor 101 rotates, the first rotor magnetic pole group 1012 induces a three-phase alternating voltage with a frequency of 270 Hz in the first winding 1002, and the second rotor magnetic pole group 1013 induces a three-phase alternating voltage with a frequency of 360 Hz in the second winding 1003. The use of a switch to switch between the first winding 1002 and the second winding 1003 achieves a constant-speed two-stage frequency modulation function, driving loads with different frequency requirements.

[0031] Embodiment 2, please refer to Figures 5 to 7 As shown in the figure, another structure of the generator with constant-speed frequency modulation function includes a stator 200 and a rotor 201, and the stator 200 is arranged inside the rotor 201, which is an outer rotor and inner stator structure.

[0032] The stator 200 includes a stator core 2001, and two sets of three-phase windings, i.e., a first winding 2002 and a second winding 2003, wound on the stator core 2001. The outer circumferential surface of the stator core 2001 is circumferentially provided with uniformly distributed grooves 2001a, and the stator teeth 2001b formed between the grooves 2001a are wound with the first winding 2002 and the second winding 2003. The first winding 2002 is an inner coil winding close to the center of the stator core 2001, and the second winding 2003 is an outer coil winding.

[0033] The rotor 201 of the generator is in a cylindrical shape, surrounds the stator 200, includes a sheath 2011, and has a first rotor magnetic pole group 2012 and a second rotor magnetic pole group 2013 arranged in the sheath 2011. The rotating shaft (not shown in the figure) of the rotor 201 is coaxially arranged with the sheath 2011 and fixed with the sheath 2011, and is driven by a diesel engine. The first rotor magnetic pole group 2012 includes 8 radially magnetized permanent magnets, which are evenly distributed along the circumference of the inner wall of the sheath 2011, and the pole number of the first rotor magnetic pole group 2012 is the same as that of the first winding 2002. The second rotor magnetic pole group 2013 includes 6 radially magnetized permanent magnets, which are evenly distributed along the circumference of the inner wall of the first rotor magnetic pole group 2012, and the pole number of the second rotor magnetic pole group 2013 is the same as that of the second winding 2003. Thus, when the rotor 201 is driven to rotate by the diesel engine, different frequency alternating voltages can be induced in the first winding 2002 and the second winding 2003 at the same rotating speed, realizing the constant rotating speed two-stage frequency modulation function and driving loads with different frequency requirements.

[0034] In Example 3, please refer to Figures 8 to 10 The structure of the generator with the constant rotating speed frequency modulation function includes a stator 300 and two rotors, i.e., a first rotor 301 and a second rotor 302, and the stator 300 is arranged between the first rotor 301 and the second rotor 302.

[0035] The stator 300 comprises a stator core 3001, and two groups of three-phase windings, i.e. a first winding 3002 and a second winding 3003, wound on the stator core 3001. The outer circumferential surface and the inner circumferential surface of the stator core 3001 are both provided with uniformly distributed outer slots 3001a and inner slots 3001b in the circumferential direction, the first winding 3002 is wound on the outer stator teeth 3001c formed between the outer slots 3001a, and the second winding 3003 is wound on the inner stator teeth 3001d formed between the inner slots 3001b. The first rotor 301 and the second rotor 302 have the same rotation axis (not shown in the figure), and the magnetic pole groups on the first rotor 301 and the second rotor 302 are arranged in the circumferential direction around the rotation axis. Specifically, the first rotor 301 is arranged at the periphery of the stator 300, comprises an outer sheath 3011, and 8 radially magnetized permanent magnets are attached to the inner wall of the outer sheath 3011 in the circumferential direction to form a first rotor magnetic pole group 3012, the number of poles of which is the same as that of the first winding 3002. The second rotor 302 is arranged inside the stator 300, comprises a rotor core 3021, and 6 radially magnetized permanent magnets are attached to the outer wall of the rotor core 3021 in the circumferential direction to form a second rotor magnetic pole group 3022, the number of poles of which is the same as that of the second winding 3003. After the drive shaft of the diesel engine is connected with the rotation axis to drive the first rotor 301 and the second rotor 302 to rotate at the same time, different frequency alternating voltages can be induced in the first winding 3002 and the second winding 3003, the constant speed two-stage frequency modulation function is realized, and loads with different frequency requirements are driven.

Claims

1. A generator with constant speed and frequency regulation function, comprising a stator and a rotor, characterized in that, The stator includes a stator core, a first winding, and a second winding. Both the first winding and the second winding are wound around the stator core. The first winding and the second winding are three-phase windings with a common magnetic circuit. The second winding is closer to the rotor in the radial direction of the stator than the first winding. The rotor includes a shaft and a first rotor magnetic pole group and a second rotor magnetic pole group disposed circumferentially around the shaft. The second rotor magnetic pole group is closer to the stator in the radial direction of the rotor than the first rotor magnetic pole group. The polarities of the magnets constituting the first rotor magnetic pole group and the second rotor magnetic pole group alternate in their respective circumferential directions. The first rotor magnetic pole group and the second rotor magnetic pole group have different pole numbers. The first rotor magnetic pole group has the same number of poles as the first winding, and the second rotor magnetic pole group has the same number of poles as the second winding.

2. The generator with constant speed and frequency regulation function according to claim 1, characterized in that, The stator is disposed on the periphery of the rotor, and the second rotor magnetic pole group is an integral magnetic ring.

3. The generator with constant speed and frequency regulation function according to claim 1, characterized in that, The first rotor pole group and / or the second rotor pole group are DC excitation windings.

4. The generator with constant speed and frequency regulation function according to claim 1, characterized in that, The magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are magnetized in the same direction, either radially or in parallel.

5. The generator with constant speed and frequency regulation function according to claim 1, characterized in that, The magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are arranged at uniform intervals in the circumferential direction.

6. A generator with constant speed and frequency regulation function, characterized in that, The system includes a stator, a first rotor, and a second rotor. The stator is disposed between the first rotor and the second rotor. The stator includes a stator core, a first winding, and a second winding. Both the first winding and the second winding are wound around the stator core. The first winding and the second winding are three-phase windings with a common magnetic circuit. The first winding is radially closer to the first rotor, and the second winding is radially closer to the second rotor. The first rotor and the second rotor have a common axis of rotation. The first rotor has a first rotor magnetic pole group arranged circumferentially around the outer side of the stator, and the second rotor has a second rotor magnetic pole group arranged circumferentially around the inner side of the stator. The first rotor magnetic pole group and the second rotor magnetic pole group have different numbers of poles. The first rotor magnetic pole group has the same number of poles as the first winding, and the second rotor magnetic pole group has the same number of poles as the second winding.

7. The generator with constant speed and frequency regulation function according to claim 6, characterized in that, The first rotor pole group and / or the second rotor pole group are DC excitation windings.

8. The generator with constant speed and frequency regulation function according to claim 6, characterized in that, The magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are magnetized in the same direction, either radially or in parallel.

9. The generator with constant speed and frequency regulation function according to claim 6, characterized in that, The magnets of the first rotor magnetic pole group and the second rotor magnetic pole group are arranged at uniform intervals in the circumferential direction.

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