Constant-frequency double-rotor permanent magnet generator suitable for offshore wind generating set

Abstract

The utility model discloses a constant frequency birotor permanent magnet generator suitable for an offshore wind generating set, comprising a first rotor, a second rotor, a generator housing and a servo speed regulation transmission system, the first rotor and the second rotor are arranged in the generator housing, the first rotor is arranged in the second rotor and is supported by the generator housing, and the second rotor is arranged in the second rotor and is supported by the servo speed regulation transmission system. The second rotor is directly connected with external input power of the generator and rotates along with input mechanical power to form a rotating magnetic field, the conductive coil is cut through the magnetic field of the first rotor, so that electric energy is generated in the second rotor, and the second rotor is connected with a servo speed regulation transmission system installed on a generator shell. The servo speed regulation transmission system adjusts the rotating speed of the first rotor in real time according to the rotating speed of the first rotor. Speed regulation design is carried out on the structure of the generator, constant-frequency power generation of the generator is achieved, and meanwhile the whole structure is simple and reliable in design, low in cost and small in efficiency loss.

Description

Technical Field

[0001] This utility model relates to the technical field of wind turbine generator transmission chains, and in particular to a constant frequency dual rotor permanent magnet generator suitable for offshore wind turbine generator sets. Background Technology

[0002] It is well known in the industry that wind power generates frequency-fluctuating electricity, which cannot be directly connected to the grid. It requires frequency regulation at the grid connection end or speed regulation at the transmission chain end (i.e., front-end speed regulation) to obtain constant-frequency power. Currently, offshore wind power commonly uses frequency regulation, and the full-power converters used are very expensive. Modern wind turbine generators incorporate protection in their generator constant-frequency control structures. For example, Chinese utility model patent CN115664080A discloses a doubly-fed induction generator scheme that can achieve constant-frequency power generation, and Chinese utility model patent CN110821757A discloses a hydraulic coupler that can adjust the gearbox speed ratio in real time to ensure a constant generator speed and achieve constant-frequency power generation.

[0003] Offshore wind turbines typically use medium-speed permanent magnet generators. For offshore units, there is an urgent need to explore an efficient and low-cost front-end speed control solution to enable the generator to operate at a constant speed, thereby achieving constant frequency grid connection of wind power and eliminating the need for the expensive full-power converter. Utility Model Content

[0004] The purpose of this utility model is to provide a constant frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets. The generator itself is designed with speed regulation, and while achieving constant frequency power generation, the entire structure is simple, reliable, low-cost, and has minimal efficiency loss.

[0005] To achieve the above objectives, the technical solution provided by this utility model is: a constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets, comprising:

[0006] The first rotor is a permanent magnet rotor, which serves as the input rotor for the generator;

[0007] The second rotor is an armature winding composed of conductive coils, which serves as the rotor for generating electrical energy;

[0008] The generator housing, as the external fixed housing of the generator, is used to support the first rotor and the servo speed control transmission system;

[0009] The servo speed control transmission system is used to control the rotational difference between the first rotor and the second rotor to remain constant at the rated speed of the generator, so that the generator can generate electricity at a constant frequency.

[0010] The first rotor and the second rotor are placed inside the generator housing. The first rotor is located inside the second rotor and is supported by the generator housing. It is directly connected to the external input power of the generator and rotates with the input mechanical power to form a rotating magnetic field. The magnetic field of the first rotor cuts the conductive coil, thereby generating electrical energy in the second rotor. The second rotor is connected to a servo speed control transmission system installed on the generator housing. The servo speed control transmission system adjusts its own speed in real time according to the speed of the first rotor.

[0011] Preferably, the servo speed control transmission system includes a slewing support bearing and a servo drive unit. The outer ring of the slewing support bearing is fixedly connected to the generator housing, and the inner ring is a gear ring structure, which is connected to the second rotor and meshes with the output gear shaft of the servo drive unit, so that the second rotor can rotate with the inner ring under the drive of the servo drive unit.

[0012] Preferably, there are multiple servo drive units, which are evenly distributed along the inner circumference.

[0013] Preferably, the servo drive unit is an electric drive system with speed servo control function.

[0014] Preferably, the rotational speed of the second rotor is greater than that of the first rotor.

[0015] Preferably, the slewing bearing is a deep groove ball bearing.

[0016] Preferably, the outer ring is connected to the generator housing by bolts.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0018] Traditional speed control mechanisms are located at the gearbox end, which are complex in structure, have large torque, and are costly. In contrast, the generator side has small torque, so speed control can be performed on the generator side, resulting in lower transmission costs.

[0019] By converting fluctuating wind power into high-quality electricity through constant frequency grid connection, a full-power converter can be eliminated. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the constant frequency dual-rotor permanent magnet generator provided in this embodiment.

[0021] Figure 2 This is a perspective view of the constant frequency dual-rotor permanent magnet generator provided in this embodiment. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0023] like Figure 1 and Figure 2 As shown, this embodiment discloses a constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets, comprising:

[0024] The first rotor 1 is a permanent magnet rotor, which serves as the input rotor of the generator;

[0025] The second rotor 2 is an armature winding composed of conductive coils, which serves as the rotor for generating electrical energy;

[0026] The generator housing 3 serves as the external, fixed housing of the generator, supporting the first rotor 1 and the servo speed control transmission system.

[0027] The servo speed control transmission system is used to control the rotational difference between the first rotor 1 and the second rotor 2 to be constant at the rated speed of the generator, so that the generator generates electricity at a constant frequency.

[0028] The first rotor 1 and the second rotor 2 are placed inside the generator housing 3. The first rotor 1 is located inside the second rotor 2 and is supported by the generator housing 3. It is directly connected to the external input power of the generator and rotates with the input mechanical power to form a rotating magnetic field. The magnetic field of the first rotor 1 cuts the conductive coil, thereby generating electrical energy in the second rotor 2. The second rotor 2 is connected to a servo speed control transmission system installed on the generator housing 3. The servo speed control transmission system adjusts its own speed in real time according to the speed of the first rotor 1.

[0029] Specifically, the servo speed control transmission system includes a slewing support bearing 4 and a servo drive unit 5. The outer ring 41 of the slewing support bearing 4 is fixedly connected to the generator housing 3 by bolts, and the inner ring 42 is a gear ring structure and is connected to the second rotor 2. There are multiple servo drive units 5, and their output gear shafts mesh with the inner ring 42 respectively and are evenly distributed along the circumference of the inner ring 42. The servo drive unit 5 can adjust the speed of the second rotor 2 in real time according to the speed of the first rotor 1, and can drive the inner ring 42 of the slewing support bearing 4 to rotate. Since the inner ring 42 of the slewing support bearing 4 is connected to the second rotor 2, the second rotor 2 can be rotated under the control of the servo drive unit 5.

[0030] Specifically, the slewing support bearing 4 is a deep groove ball bearing; the servo drive unit 5 is an electric drive system with speed servo control function.

[0031] When the input speed n1 of the first rotor 1 is lower than the rated speed N of the generator, the servo drive unit 5 drives the second rotor 2 to rotate at a speed of n2. The control strategy of the servo drive unit 5 is to always ensure that |n2-n1|=N, the control accuracy is no greater than 1%, and the servo drive unit 5 has a sufficiently large braking torque to ensure that the second rotor 2 does not slip or run away under extreme electromagnetic torque.

[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets, characterized in that, include: The first rotor (1) is a permanent magnet rotor, which serves as the input rotor of the generator; The second rotor (2) is an armature winding composed of conductive coils, which serves as the rotor for generating electrical energy; The generator housing (3) serves as the external fixed housing of the generator and is used to support the first rotor (1) and the servo speed control transmission system. The servo speed control transmission system is used to control the rotational difference between the first rotor (1) and the second rotor (2) to be constant at the rated speed of the generator, so that the generator generates electricity at a constant frequency. The first rotor (1) and the second rotor (2) are placed inside the generator housing (3). The first rotor (1) is located inside the second rotor (2) and is supported by the generator housing (3). It is directly connected to the external input power of the generator and rotates with the input mechanical power to form a rotating magnetic field. The magnetic field of the first rotor (1) cuts the conductive coil, so that electrical energy is generated in the second rotor (2). The second rotor (2) is connected to a servo speed control transmission system installed on the generator housing (3). The servo speed control transmission system adjusts its own speed in real time according to the speed of the first rotor (1).

2. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 1, characterized in that, The servo speed control transmission system includes a slewing support bearing (4) and a servo drive unit (5). The outer ring (41) of the slewing support bearing (4) is fixedly connected to the generator housing (3), and the inner ring (42) is a gear ring structure, which is connected to the second rotor (2) and meshes with the output gear shaft of the servo drive unit (5), so that the second rotor (2) can rotate with the inner ring (42) under the drive of the servo drive unit (5).

3. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 2, characterized in that, There are multiple servo drive units (5), which are evenly distributed circumferentially along the inner circle (42).

4. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 3, characterized in that, The servo drive unit (5) is an electric drive system with speed servo control function.

5. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 1, characterized in that, The rotational speed of the second rotor (2) is greater than that of the first rotor (1).

6. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 2, characterized in that, The slewing support bearing (4) is a deep groove ball bearing.

7. A constant-frequency dual-rotor permanent magnet generator suitable for offshore wind turbine generator sets according to claim 2, characterized in that, The outer ring (41) is connected to the generator housing (3) by bolts.

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