Auxiliary winding of generator and generator

Abstract

The embodiment of the invention discloses a generator auxiliary winding and a generator, and the generator auxiliary winding comprises a winding main body which is arranged in a stator groove of a stator; the winding main body comprises a plurality of coils, and the space phase difference of the adjacent coils is 60-degree electrical angle. And the voltage stability in a wide rotating speed range of the motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, in particular to a generator auxiliary winding and a generator. BACKGROUND

[0002] As a common device in aviation, ship and industrial power supply systems, the brushless synchronous generator usually adopts a permanent magnet generator coaxial with the main generator to provide the excitation power supply for the automatic voltage regulator (AVR). However, the existing hidden pole brushless synchronous generator has poor excitation power supply stability when running in a wide speed range, and has the following problems:

[0003] Firstly, under the low speed running condition, the AVR power supply voltage is often insufficient, which easily leads to AVR power loss, so that the normal excitation control of the main generator cannot be realized. Secondly, under the high speed running condition, the AVR power supply voltage may be too high, which causes the electronic devices in the AVR power loop to bear a large voltage stress, and there is a risk of damage.

[0004] In addition, the linear working interval of the existing hidden pole brushless synchronous generator is narrow, usually covering only about 40% to 100% of the rated speed range. In the case of exceeding the speed range, the voltage fluctuation of the excitation power supply increases significantly, and is easily disturbed by harmonic components, causing the AVR power supply quality to decrease.

[0005] At present, there is no effective solution to the above problems in the prior art. SUMMARY

[0006] To solve the above problems, the present application provides a generator auxiliary winding and a generator, which effectively offsets high harmonic interference by additionally installing the winding main body in the stator slot of the stator, so as to realize the stability of voltage output in a wide speed range, thereby solving the problems of large voltage fluctuation and serious harmonic interference of the generator in a wide speed range.

[0007] To achieve the above purpose, the present application provides a generator auxiliary winding, comprising: a winding main body, which is arranged in the stator slot of a stator; the winding main body comprises a plurality of coils, and the spatial phase difference between adjacent coils is 60° electrical angle.

[0008] Further optionally, the winding main body is a short-pitch winding.

[0009] Further optionally, the pitch of the winding main body is 1 / 3.

[0010] Further optionally, the number of turns of the winding main body satisfies the following formula:

[0011]

[0012] wherein, is the third harmonic voltage output value of the winding main body, f is the third harmonic frequency of the generator, is the winding factor of the winding main body, is the third harmonic magnetic flux of the generator.

[0013] In another aspect, the application also provides a generator comprising a stator and a rotor, and the stator slot of the stator is provided with the auxiliary winding of the generator.

[0014] Further, the stator slot of the stator is a pear-shaped slot.

[0015] Further, the depth-width ratio of the stator slot is 1:1.2.

[0016] Further, the rotor pole arc coefficient of the rotor is 0.78-0.82.

[0017] Further, the air gap permeance modulation coefficient is 1.1-1.2.

[0018] Further, the end of the auxiliary winding of the generator is fixedly bound with the main winding of the stator.

[0019] The above technical solution has the following beneficial effects: the application sets the distributed short auxiliary winding in the stator slot to effectively extract the third harmonic energy; through the reasonable arrangement of the coil, the interference of the partial harmonic is suppressed; in combination with the optimized stator slot structure, the rotor pole arc coefficient and the air gap permeance modulation parameter, the auxiliary winding can efficiently extract the third harmonic potential and suppress the high-order harmonic interference, thereby significantly improving the reliability of the AVR excitation power supply. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0021] Figure 1 is the auxiliary winding installation structure schematic diagram of the generator provided by the embodiment of the application;

[0022] Figure 2 is the main winding distribution structure schematic diagram provided by the embodiment of the application;

[0023] Figure 3 is the auxiliary winding distribution structure schematic diagram provided by the embodiment of the application.

[0024] The drawings show that: 1-winding main body; 2-main winding; 3-stator. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0026] To solve the problems of large voltage fluctuation and serious harmonic interference of a generator in a wide speed range in the prior art, the embodiment of the present application provides a generator auxiliary winding, Figure 1 is a schematic diagram of a generator auxiliary winding installation structure provided by the embodiment of the present application, as Figure 1 shown, the auxiliary winding comprises: a winding main body 1, the winding main body 1 is arranged in a stator slot of a stator 3; the winding main body comprises a plurality of coils, and the spatial phase difference between adjacent coils is 60° electrical angle.

[0027] The generator auxiliary winding provided by the embodiment of the present application is characterized in that a set of special auxiliary winding is additionally arranged in the stator slot. The winding main body is composed of a plurality of coils, and the coils are arranged according to a predetermined spatial phase difference, and the phase difference between adjacent coils is 60° electrical angle.

[0028] This arrangement enables the auxiliary winding to effectively extract the third harmonic potential from the operating magnetic field of the generator, while suppressing the interference of other high-order harmonics (such as 5th and 7th harmonics), so as to ensure that relatively stable potential data can be obtained at low speed and high speed, and the effective working interval of the generator in a wide speed range can be expanded.

[0029] Figure 1 The stator 3 shown in FIG. 1 is a stator with 120 stator slots. First, the coils of the main winding 2 are respectively embedded in the 120 stator slots to form a structure as Figure 2 shown in FIG. 2, and then the first coil of the winding main body 1 is embedded in the No. 1 and No. 5 stator slots, and the other coils are embedded according to a spatial phase difference of 60°, and the wiring between the coils is connected in a way that the coil head is connected to the coil tail. Finally, a structure as Figure 3 shown in FIG. 3 is formed.

[0030] As an optional embodiment, the winding main body is a short-pitch winding.

[0031] The short-pitch winding refers to a winding crossing slot pitch smaller than the full-pitch slot pitch. In the embodiment, the short-pitch winding is selected to effectively reduce the end leakage reactance, reduce the copper loss and additional loss of the winding end. At the same time, the short-pitch design helps to weaken the influence of high-order harmonic electromotive force and enhance the extraction capacity of the third harmonic component, thereby further improving the potential waveform quality of the auxiliary winding and providing a more stable excitation power source for the automatic voltage regulator.

[0032] As an optional embodiment, the pitch of the winding body is 1 / 3.

[0033] In the embodiment, the short-pitch winding with 1 / 3 or close to 1 / 3 pitch is adopted to reduce the end leakage reactance and improve the harmonic energy extraction efficiency. The maximum extraction efficiency can reach 89%.

[0034] As an optional embodiment, the number of turns of the winding body satisfies the following formula:

[0035]

[0036] wherein, is the third harmonic voltage output value of the winding body, f is the third harmonic frequency of the generator, is the winding factor of the winding body, is the third harmonic magnetic flux of the generator.

[0037] According to the above formula, the number of turns required by the auxiliary winding can be accurately calculated according to the third harmonic magnetic field characteristics of the generator and the target voltage output value. In this way, the auxiliary winding can obtain stable third harmonic potential during operation, avoiding the situation of excessively high or low voltage caused by unreasonable winding design. Therefore, not only the matching degree between the voltage output and the third harmonic magnetic flux of the generator is improved, but also the automatic voltage regulator can obtain stable excitation power source in a wide speed range.

[0038] The embodiment of the present application also provides a generator comprising a stator and a rotor, characterized in that the stator slot of the stator is provided with the auxiliary winding of the generator.

[0039] By directly embedding the auxiliary winding in the stator slot, the main winding structure of the generator does not need to be changed, and the extraction channel of the third harmonic energy can be added in the existing stator structure. In this way, the electromagnetic compatibility with the original main winding is ensured, and an additional and stable voltage source can be provided for the automatic voltage regulator during the operation of the generator, thereby improving the operation stability and reliability of the generator in a wide speed range.

[0040] As an optional embodiment, the stator slot of the stator is a pear-shaped slot.

[0041] The pear-shaped slot is a special slot type with asymmetric width from top to bottom, which has a narrow slot opening and a wide slot bottom, and the overall shape is similar to a pear. The design of this slot type is beneficial to improve the magnetic flux distribution of the stator tooth, making the magnetic density more uniform at the tooth root and reducing the risk of local magnetic saturation. At the same time, the pear-shaped slot can optimize the air gap magnetic field distribution under the armature reaction, reduce the interference of harmonic magnetic flux to the auxiliary winding, and thus improve the extraction efficiency of the third harmonic potential and the stability of the voltage output

[0042] As an optional embodiment, the depth-width ratio of the stator slot is 1:1.2.

[0043] By designing the depth and width of the stator slot in a ratio of 1:1.2, the tooth magnetic flux distribution can be made more reasonable while ensuring that the slot body can accommodate the winding space. On the one hand, this ratio avoids the problem of excessive depth of the stator slot leading to excessive tooth magnetic density and causing local saturation, and on the other hand, it also avoids the problem of excessive width of the stator slot causing increased leakage and reduced motor power factor, thereby optimizing the magnetic flux distribution.

[0044] As an optional embodiment, the rotor pole arc coefficient of the rotor is 0.78-0.82.

[0045] The pole arc coefficient refers to the ratio of the rotor magnetic pole arc length to the magnetic pole pitch, and its value has an important influence on the waveform of the air gap magnetic field. When the pole arc coefficient is too large, it can easily lead to severe air gap magnetic field distortion and increased high-order harmonic content; when the pole arc coefficient is too small, it can reduce the main magnetic flux density and weaken the output performance of the motor.

[0046] Controlling the pole arc coefficient within the range of 0.78-0.82 can effectively suppress the generation of high-order harmonic components in the air gap while ensuring the main magnetic field strength, i.e., balancing the air gap harmonics and the main magnetic field strength to make the extraction of the third harmonic potential more stable. Preferably, in the present embodiment, the rotor pole arc coefficient is selected as 0.8.

[0047] As an optional embodiment, the air gap permeance modulation coefficient is 1.1-1.2.

[0048] The air gap permeance modulation coefficient is used to characterize the modulation degree of the air gap magnetic field distribution on the harmonic components, and its value directly affects the amplitude of different harmonic magnetic fluxes. When this coefficient is too low, the third harmonic component is insufficient, and the auxiliary winding cannot obtain effective potential; when this coefficient is too high, it can easily introduce too many high-order harmonics, leading to voltage waveform distortion. Controlling the air gap permeance modulation coefficient within the range of 1.1-1.2 can enhance the third harmonic potential while effectively suppressing the interference of other high-order harmonics, thereby enabling the auxiliary winding to maintain stable voltage output within a wide speed range and ensuring reliable power supply of the automatic voltage regulator by the generator. Preferably, in the present embodiment, the air gap permeance modulation coefficient is selected as 1.15.

[0049] As an optional implementation, the end of the generator auxiliary winding is bound and fixed with the main winding of the stator.

[0050] By binding the auxiliary winding and the main winding at the end, the two can be mechanically integrated to enhance the structural strength and vibration resistance of the winding, and avoid loosening and displacement due to electromagnetic force or centrifugal force during high-speed operation of the generator.

[0051] Through the above matching design of the auxiliary winding topological structure and the magnetic circuit parameters, the effect of output voltage fluctuation rate ≤ ± 5% in the range of 50%-150% rated speed can be realized. It is suitable for AVR stable power supply of the fixed pitch propeller shaft with a hidden pole brushless synchronous generator in a wide speed range.

[0052] The above technical scheme has the following beneficial effects: the present application sets a distributed short auxiliary winding in the stator slot to effectively extract the third harmonic energy; through the reasonable arrangement of the coil, the interference of part of the harmonic is suppressed; cooperating with the optimized stator slot structure, rotor pole arc coefficient and air gap permeance modulation parameters, the auxiliary winding can efficiently extract the third harmonic potential and suppress the high-order harmonic interference, thereby significantly improving the reliability of the AVR excitation power supply.

[0053] The specific embodiments of the above application further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above content is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A generator auxiliary winding, characterized by, Comprise: a winding body, which is arranged in a stator slot of a stator; the winding body comprises a plurality of coils, and a spatial phase difference between adjacent coils is 60° electric angle.

2. The auxiliary winding of the generator according to claim 1, characterized in that: the winding body is a short-pitch winding.

3. The auxiliary winding of the generator according to claim 2, characterized in that: a pitch of the winding body is 1 / 3.

4. The generator auxiliary winding of claim 1, wherein, a number of turns of the winding body satisfies the following formula: ； wherein, is the third harmonic voltage output value of the winding body, f is the third harmonic frequency of the generator, is the winding factor of the winding body, is the third harmonic magnetic flux of the generator.

5. An electric generator comprising a stator and a rotor, characterised in that, the stator slot of the stator is provided with the auxiliary winding of the generator according to any one of claims 1-4.

6. The generator according to claim 5, characterized in that: the stator slot of the stator is a pear-shaped slot.

7. The generator according to claim 6, characterized in that: a depth-width ratio of the stator slot is 1:1.

2.

8. The generator according to claim 5, characterized in that: a rotor pole arc coefficient of the rotor is 0.78-0.

82.

9. The generator according to claim 5, characterized in that: an air gap permeance modulation coefficient is 1.1-1.

2.

10. The generator according to claim 5, characterized in that: end portions of the auxiliary winding of the generator are fixedly bound with a main winding of the stator.

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