WO2009082875A1

WO2009082875A1 - A hybrid excitation synchronous generator

Info

Publication number: WO2009082875A1
Application number: PCT/CN2008/001219
Authority: WO
Inventors: Guangshun Wang
Original assignee: Guangshun Wang
Priority date: 2008-01-02
Filing date: 2008-06-24
Publication date: 2009-07-09
Also published as: CN101478208A

Abstract

A hybrid excitation synchronous generator includes a main shaft (1), a rotor fixed mounted on the main shaft (1), and a stator (3) provided around the rotor. The stator (3) is mounted on the main shaft (1) by means of bearings. The rotor includes two claw-pole plates (2) which are oppositely positioned. Permanent magnets (4) and cores (51) are fixed mounted between the two claw-pole plates (2). Excitation coils (5) are wound on the cores (51). The permanent magnets (4) and the cores (51) are uniformly distributed around the main shaft (1). A connection sheath (6) is fixed mounted on the main shaft (1) by means of flat keys. The two claw-pole plates (2) are respectively fixed mounted on two ends of the connection sheath (6).

Description

Composite excitation synchronous generator

The present invention relates to a generator, and more particularly to a composite excitation synchronous generator suitable for use in a low speed multi-pole generator. Background technique

In order to meet the requirements of grid-connected power generation, permanent magnet generators need to be able to adjust the output voltage with fluctuations in grid voltage or reactive load requirements. Nowadays, the rectifier-inverter method is commonly used to electronically adjust the output voltage. Due to the complicated structure and failure rate. High and high cost have become a major obstacle for grid-connected power generation of permanent magnet generators. Ordinary permanent magnet generators can not achieve the adjustment of the output voltage, and the existing composite excitation generators mostly adopt the structure of two rotors, namely a permanent magnet rotor and an excitation rotor. When the composite excitation generator is short-circuited between turns Although the switch can cut off the external circuit, it can not cut off the internal short-circuit fault. Even if the excitation rotor current is cut off, the generator still generates a strong potential under the action of the inertia and the permanent magnet rotor, and it is easy to burn the generator. Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hybrid excitation synchronous generator which is simple in structure, can be directly connected to the grid, and can change output voltage and reactive power without rectifying an inverter device.

In order to achieve the above object, the present invention employs the following technical solution: A composite excitation synchronous generator according to the present invention includes a main shaft, a rotor fixedly mounted on the main shaft, and a stator disposed around the rotor, the stator being mounted through the bearing The main shaft is characterized in that: the rotor comprises two claw plates arranged opposite to each other, a plurality of permanent magnets and an iron core are fixedly mounted between the two claw plates, the excitation coil is wound on the iron core, and the permanent magnet and the iron core are evenly distributed. Distributed around the main axis.

A connecting sleeve is fixedly mounted on the main shaft by a flat key, and the two claw plates are fixedly mounted at both ends of the connecting sleeve.

After adopting the above technical solution, the present invention has the following advantages:

1. The excitation coil is used to change the magnetic flux to adjust the output voltage and reactive power. The action is fast and the output voltage adjustment range is large, which can meet the needs of various working conditions.

2. It is convenient to realize multi-pole generators to meet the design requirements of large-diameter and low-speed generators;

3. Simple structure, low manufacturing cost, easy to popularize; 4, using a distributed small-diameter excitation coil structure, its small resistance, low energy consumption, is conducive to reducing manufacturing costs;

5. The stator and rotor are directly mounted on the same main shaft. The concentricity is high and the air gap is small, which can save permanent magnetic materials, reduce production cost and improve generator stability. DRAWINGS

Figure 1 is a schematic structural view of an embodiment of the present invention;

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

Fig. 3 is a schematic exploded view of the claw plate. detailed description

As shown in FIG. 1, a hybrid excitation synchronous generator according to the present invention comprises a main shaft 1, a rotor fixedly mounted on the main shaft 1, and a stator 3 disposed around the rotor, and the stator 3 is mounted on the main shaft 1 through a bearing. on. The rotor includes two claw plates 2 disposed opposite to each other, and a permanent magnet 4 and a core 51 mounted on the claw plate 2. The core 51 is wound with an exciting coil 5, and the claw plate 2 is disc-shaped, and has magnetic permeability. The good material is made of a plurality of toothed claw poles 21 which are circumferentially branched at the edge portion thereof. The claw pole 21 has an approximately trapezoidal shape, and the claw pole 21 is disposed parallel to the axis of the main shaft 1. The two claw plates 2 are arranged in parallel with the claw poles 21 staggered. The permanent magnets 4 and the iron cores 51 are fixedly mounted on the inner sides of the claw poles 21 between the two claw plates 2, and the excitation coil is wound on the iron core 51. 5. The permanent magnet 4 and the iron core 51 are evenly distributed around the main shaft 1.

Of course, the connection between the claw plate 2 and the main shaft 1 can be various. In order to facilitate the installation and reduce the production cost, the embodiment has a connecting sleeve 6 fixed on the main shaft 1 by a flat key, and the two claw plates 2 are respectively fixed. Installed at both ends of the connecting sleeve 6. The connecting sleeve 6 should be made of a non-magnetic material. If a magnetically permeable steel material is used for cost reduction, at least a gasket made of a non-magnetic material should be disposed between the connecting sleeve 6 and the claw plate 2. .

The rotor may be in the form of a rotor or two small rotors. In this embodiment, two rotors of the same shape and size are symmetrically mounted on the main shaft 1. The stator 3 is a cylindrical structure with end caps at both ends, and the end cap is mounted on the main shaft 1 through a bearing, and the inner side wall of the stator 3 is fixedly mounted with the stator coil 7 at a position corresponding to the claw pole 21. The two stator coils 7 are phase-shifted by 60 degrees to form a 60-degree phase band, which satisfies the requirements of the low-speed generator output voltage waveform with a small number of slots per pole.

Both ends of the exciting coil 5 are connected to an external circuit through the slip ring 11. During operation, the magnetic flux generated by the permanent magnet 4 and the exciting coil 5 reaches the claw pole 21 through the guiding of the claw plate 2, and a strong magnetic field is generated between the two sets of opposing claw poles 21, and the power mechanism drives the spindle 1 to rotate, so that the claw pole The strong magnetic field generated between 21 rotates around the main shaft 1 to generate a relative motion of the cutting magnetic lines with the stationary stator coil 7, and an electric potential is generated in the stator coil 7. The potential is converted to an electrical energy output by a corresponding circuit connection.

When it is necessary to change the voltage of the output electric energy, the intensity of the combined magnetic field generated between the claw poles 21 can be changed by adjusting the magnitude of the exciting current in the exciting coil 5 by an external circuit, thereby finally changing the voltage for changing the output electric energy. This portion of the external adjustment circuit is a prior art and will not be discussed in detail herein.

In the case of a short circuit between turns, when the automatic device reduces the exciting current to zero, the iron core 51 not only no longer generates a magnetic potential, but also short-circuits the magnetic flux generated by the permanent magnet 4, so that the combined magnetic field between the claw poles 21 Decreasing to near zero value greatly reduces the short-circuit current between turns, thus effectively protecting the generator from being burnt.

Claims

Claim

A composite excitation synchronous generator comprising a main shaft (1), a rotor fixedly mounted on the main shaft (1), and a stator (3) disposed around the rotor, the stator (3) being mounted on the main shaft through the bearing (1) The upper part is characterized in that: the rotor comprises two claw plates (2) disposed opposite each other, and a plurality of permanent magnets (4) and iron cores (51) are fixedly mounted between the two claw plates (2), the iron core (51) The upper excitation coil (5) is wound, and the permanent magnet (4) and the iron core (51) are hooked around the main shaft (1).

2. A compound excitation synchronous generator according to claim 1, characterized in that: a connecting sleeve (6) is fixedly mounted on the main shaft (1) by a flat key, and the two claw plates (2) are fixedly mounted respectively. At both ends of the connection sleeve (6).