RU2446548C1 - Low-speed end synchronous generator - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: low-speed end synchronous generator comprising a rotor arranged in the form of a disc from a non-magnetic material with an excitation system based on permanent magnets and a stator with coils, comprises sections, at the same time in each section a stator is made of one circular magnetic conductor arranged in parallel to the rotor and fixed on stiffening ribs of a casing-free generator frame, coils of stator are placed fully in slots, not protruding beyond limits of a magnetic conductor, in an excitation system the permanent magnets are installed on a rotor disc at its one lateral side in parallel to a magnetic conductor of a stator, besides, rotors of each section are arranged on a single shaft, at the same time to coordinate operation of generator sections, a rotor of each following section is displaced relative to the rotor of the previous section by the following angle: Jmag. = 360° : quantity of permanent magnets of the rotor: quantity of generator sections.

EFFECT: reduction of dimensions due to its execution of several sections, considerable reduction of generator diameter, which is especially important for submersible mini hydraulic power plants, reduction of generator weight due to the fact that its units are fixed on the frame of stiffening ribs, and a rotary rotor is equipped with a protective rim, which eliminates the necessity to use a solid casing, increased efficiency factor due to complete usage of stator coil turns placed fully in slots of a magnetic conductor and not having head parts protruding beyond its borders, making it possible to modify generator low speed when used on rivers with various speed of water flow, which is provided by variation of sections number and displacement of a rotor in each section relative to a rotor of a previous section by an angle between magnets, increased reliability of generator's operation, since availability of a frame from stiffening ribs improves cooling of stator coils protecting them against heating.

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Description

The invention relates to electrical engineering, in particular to the improvement of the design of synchronous generators that can be used in wind power plants, as well as in submersible mini-hydro power plants.

Known synchronous generator (1), containing a rotor with an excitation system of permanent magnets and a stator with coils placed on the rods around the circumference of the magnetic circuit.

The placement of the coils at half the length of the rod leads to the underutilization of the volume of steel core, which ultimately does not allow to coordinately improve the overall dimensions of the generator.

Closest to the claimed generator is a synchronous electric generator (2), containing a double stator, that is, a stator consisting of two parts with annular magnetic circuits arranged coaxially and parallel to each other, between which is placed a rotor disk with an excitation system consisting of permanent magnets, mounted on a disk of non-magnetic material from two sides symmetrically, with the same poles towards each other. In the radial grooves of the stator magnetic circuits, coils are connected around each other to form a stator winding, and the frontal parts of the coils protrude beyond the side planes of the magnetic circuits.

This generator has large overall dimensions and low efficiency.

The technical result of the claimed technical solution is as follows:

- in reducing the size due to its implementation from several sections, significantly reducing the diameter of the generator, which is especially important for submersible mini-hydroelectric power stations.

- in reducing the mass, since the generator units are mounted on the frame of stiffeners, and the rotating rotor is equipped with a protective rim, that is, there is no solid body.

- in increasing the efficiency, due to the full use of the turns of the stator coils, located completely in the grooves of the magnetic circuit and not having protruding frontal parts outside,

- the possibility of changing the low-speed generator when used on rivers with different water flow rates due to changes in the number of sections and the displacement of the rotor of each section relative to the rotor of the previous section by the angle between the magnets - Jmag.,

- to increase the reliability of the generator, since the presence of a frame of stiffeners improves the cooling of the stator coils, protecting them from overheating.

The technical result is achieved in that the low-speed end-face synchronous generator containing a rotor made in the form of a disk of non-magnetic material with a permanent magnet excitation system, and a stator with coils, consists of sections, while in each section the stator is made of one ring magnetic core located parallel to the rotor and the frame of the frameless generator fixed to the stiffeners, the stator coils are placed completely in the grooves, without protruding beyond the magnetic circuit, in the excitation system e magnets arranged on the rotor disk with one of its lateral sides parallel to the stator magnetic circuit, wherein the rotors of each section are arranged on the same shaft, in this case for consistency of operation the generator rotor sections each subsequent section is displaced relative to the previous section of the rotor at an angle

Jmag. = 360 °: number of permanent rotor magnets: number of generator sections. The main design features of the generator are that the generator is made in the form of a set of sections, each of which has a stator and a rotor. Sections are installed on one shaft. The stator is mounted on a frame formed of stiffeners, which provides more efficient cooling of the generator parts, increasing reliability and significantly reducing the weight of the generator.

Figure 1 shows a generator in section (shown two of its sections in section);

Figure 2 - stator, consisting of a magnetic circuit 7 and coils 8;

Figure 3 - rotor with permanent magnets 2.

The generator consists of sections. Each section of the generator (figure 1) contains a rotor and a stator. The rotor is made in the form of a disk 1 of non-magnetic material, for example aluminum, with magnets 2 built into it, made of soft magnetic steel. There is a steel ring 3 on the rotor to secure the rotor disk. The rotor disk 1 with the ring 3 is pressed onto the sleeve 4. The ring 3 is attached to the disk 1 and to the sleeve 4 by welding 5. Each section of the generator has a protective steel rim 6. The stator consists of a magnetic circuit 7 with coils 8, while the magnetic circuit 7 is mounted on stiffeners 9 frame and made of electrical tape steel. The rotors of all sections of the generator are mounted on a common shaft 10 mounted on bearings 11 with an offset around the circumference of one rotor relative to another in each section, while the rotor of one section relative to the rotor of the other section is rotated by turning the sleeve 4 on the shaft 10 while fixing it in the desired position with a locking screw 12. The rotation angle of the rotors relative to each other (Jmag.) for the coordinated operation of the generator sections is determined as follows. For example, in a rotor there are eight symmetrically arranged magnets. The angle between the magnets is

360 °: 8 = 45 °

For example, in our generator there are four sections, therefore the angle of displacement of the rotors in the sections will be

Jmag. = 45 °: 4 = 11.2 °

If we need to increase the low-speed of the generator, then we will add, for example, two sections to the generator, then the angle of displacement of the rotors in the sections will be

Jmag. = 45 °: 6 = 7.5 °

Therefore, for a generator of six sections, on the rotor of which there are eight symmetrically arranged magnets, the rotor of the second section is shifted relative to the rotor of the first section by an angle of Jmag. = 7.5 °, the rotor of the third section is shifted relative to the rotor of the second section by the same angle of Jmag. = 7 , 5 °, etc. The stator coils in the generator sections are located identically relative to each other. All metal parts in the generator are galvanized, and the coils in the magnetic circuit are filled with epoxy.

The generator operates as follows.

A primary engine, such as a mini-hydroelectric turbine, rotates the rotors of the generator sections, where the magnetic field of the permanent magnets crosses the coils of the stator coils and induces an emf in them.

A generator with reduced weight and size indicators, increased efficiency and more reliable operation, which allows you to change the low-speed when using it on rivers with different speeds of water flow, will find industrial application.

Information sources

1. Synchronous electric generator, ed. testimonial. USSR N 1169094, B.I. N 27, 1985

2. The multi-pole low-speed end-face synchronous generator, patent RU 2152118, MPK-7, Н02К 19/16, Н02К 23/54.

Claims (1)

A low-speed end-face synchronous generator containing a rotor made in the form of a disk of non-magnetic material with a permanent magnet excitation system and a stator with coils, characterized in that the generator consists of sections, while in each section the stator is made of one annular magnetic circuit located in parallel the rotor and the frameless generator frame fixed to the stiffeners, the stator coils are placed completely in the grooves, not protruding beyond the magnetic circuit, the permanent magnets p are placed on the rotor disk on one side of it parallel to the stator magnetic circuit, and the rotors of each section are located on the same shaft, and for the consistency of the generator sections, the rotor of each next section is offset relative to the rotor of the previous section by an angle of Jmag. = 360 °: the number of permanent rotor magnets : number of generator sections.

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