JPH02311156A - Brake winding for permanent magnet synchronous machine - Google Patents

Abstract

PURPOSE:To secure a volume of brake winding sufficient by employing copper in the side wall for containing a permanent magnet and supporting the permanent magnet on the rotor core and constituting a supporting mechanism integrally in the axial direction then short-circuiting the axial opposite ends of the side wall through a short-circuit ring. CONSTITUTION:Stainless steel is generally employed, in view point of strength, for a non-magnetic supporting mechanism 4 which contains and supports a permanent magnet 2 made by laminating magnet chips made of ferromagnetic material such as ferrite around a rotor core 1. But strength is actually required only by the outer circumferential wall 5 and inner circumferential wall 6 which protect the permanent magnet 2 from centrifugal force, and the side walls 7, 8 for protecting the radial wall is only required to support a micro force corresponding to the rotary torque. Consequently, when the side walls 7, 8 are provided integrally over the length of the rotor and the axial opposite ends of the wall on the rotor are short-circuited through an annular conductive short circuit ring, function of brake winding can be provided. By such arrangement volume of the brake winding can be secured sufficiently.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a brake winding on a rotor of a synchronous machine which is operated as a generator or an electric motor by being excited by a permanent magnet provided in the rotor.

[Conventional technology]

Synchronous machines that use permanent magnets are used, for example, in the electric propulsion of ships, and many have a structure in which permanent 6n stones are attached to the rotor surface in order to increase the efficiency of using permanent magnets.On the other hand, in synchronous machines, To deal with negative phase or harmonic components caused by noise generated by the rectifier or unbalanced power supply or load, damper windings are placed on the rotor at a position closest to the armature where they have the strongest effect, and these surplus components are removed. Figure 3 is a cross-sectional view of the rotor of a conventional permanent magnet synchronous machine, in which permanent magnets 2 are arranged around the outer periphery of the rotor core 1 as N poles and S poles alternately. A brake winding 3 was placed between each of the coils 2 and 2.

[Problems to be Solved by the Invention] As shown in Fig. 3, in the conventional permanent magnet M machine, the permanent magnet 2 is arranged at the outermost periphery of the rotor, and it is not possible to further provide a brake winding on the outer periphery. This increases the air gap length between the armature and the rotor, resulting in a significant decrease in excitation efficiency. Therefore, as shown in Fig. 3, the brake winding 3 is arranged on the circumference of the same diameter as the permanent magnet 2, filling the space between the permanent magnets 2. However, since the permanent magnet 2 is already present, the brake winding 3 However, there was not enough storage space, and the damper winding had a small volume and weak absorption capacity. The brake winding shown in Figure 3 generates heat due to small harmonics, so in a synchronous machine that uses permanent magnets with poor temperature characteristics, the magnetic characteristics of the permanent magnet will be impaired due to the temperature rise of the permanent magnet, so the brake winding was a fatal flaw. An object of the present invention is to provide a damper winding with a sufficient volume without increasing the diameter of the outer circumference of the rotor. [Means for Solving the Problems] The above object is to construct an integral member in the axial direction using copper for a part of the support mechanism that houses the permanent magnet 2 and supports it on the rotor core, and to form an integral member in the axial direction. Conductive annular shorting rings 9. This is achieved by a damper winding of a permanent magnet synchronous machine short-circuited with lO.

[For use]

This invention uses copper as a part of the support mechanism that supports the permanent magnets of the permanent magnet synchronous machine on the rotor core to form an integral member in the axial direction. Since the damper winding was configured by short-circuiting with the short-circuit ring,
The side wall and the shorting ring act as a damper winding of the permanent magnet synchronous machine and can absorb negative phase components and harmonic components.

【Example】

The present invention will be described in detail below based on the drawings. FIG. 1 is a sectional view showing a permanent magnet support mechanism of a permanent magnet synchronous machine equipped with a brake winding according to an embodiment of the present invention. The non-magnetic support mechanism 4 that accommodates and supports the permanent magnet 2, which is constructed by stacking magnet pieces made of ferrite or other ferromagnetic material around the outer periphery of the rotor core 1, is generally made of stainless steel due to strength issues. has been done. However, in reality, only the outer circumferential wall 5 and the inner circumferential wall 6, which protect the permanent magnet 2 from centrifugal force, need to be strong; It is sufficient to support the corresponding minute force. Therefore, if the side wall 7.8 is made in one piece over the rotational length, and furthermore, both axial ends on the rotor are short-circuited with an electrically conductive annular short-circuit ring, it acts as a damper winding. FIG. 2 is a view taken along the line A--A in FIG. 1, and the same parts as in FIG. 1 are designated by the same numbers. In Figure 2, permanent magnet 2
The braking windings are formed by short-circuiting both axial ends of the rotor of the side walls 7 and 8 running in the axial direction with conductive annular shorting rings 9 and 10, respectively. Line 11 was constructed. FIG. 2 shows a part of the damper winding 11, and the side wall 7 for each permanent magnet is shown as a whole.
8, and the shorting rings 9, 10 are connected in an annular manner. Brake winding 1 consisting of side walls 7, 8 and shorting rings 9, 10
1 generates heat when it absorbs harmonics, but in order to prevent the permanent magnet 2 from rising in temperature, it is also possible to provide a heat insulating layer between the side ← 7 and the permanent magnet 2. Also, the side wall 7
．． It is also possible to actively cool the permanent magnet 8 to prevent the temperature of the permanent magnet 2 from rising.

[Inventive effect]

The side wall, which is part of the support mechanism that houses the permanent magnets on the rotor of a permanent magnet synchronous machine and supports them on the rotor core, is made of copper and is integrated in the axial direction, and both ends of this side wall in the axial direction are short-circuited. When the damper winding is configured by short-circuiting with a ring, a sufficient volume of the damper winding can be ensured, and the absorption capacity can be more than twice that of a conventional structure. Therefore, antiphase components or harmonic components can be sufficiently absorbed. Furthermore, since the temperature rise of the permanent magnet is reduced, there is no need to worry about damaging the magnetic properties of the permanent magnet.

[Brief explanation of the drawing]

FIG. 1 shows a damper winding according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the permanent magnet support mechanism of the permanent magnet synchronous machine according to the conventional example; FIG. 2 is a view taken along arrow A-A in FIG. 1; FIG. be. l: Rotor core, 2: Permanent magnet, 4: Support mechanism, 7.8
: Side wall, 9, 10: Short circuit ring, ll: Brake winding. ”j, c2.・

Claims (1)

[Claims] 1) In a permanent magnet synchronous machine with a permanent magnet in the rotor, a part of the support mechanism that accommodates the permanent magnet and supports it on the rotor core is made of copper and constitutes an integral member in the axial direction. A brake winding for a permanent magnet synchronous machine, characterized in that both ends of the member in the axial direction are short-circuited with conductive annular short-circuit rings.