JPH04138054A - Brake winding of permanent magnet synchronous machine - Google Patents

Abstract

PURPOSE:To obtain a brake winding of a permanent magnet synchronous machine, whose current conduction is facilitated by strengthening magnetic coupling to an armature and further weakening self inductance, by separating the brake winding from a permanent magnet to approach the armature, and fixing the brake winding to a rotor, in an air gap between a stator and the rotor. CONSTITUTION:A brake winding 6 is separated from a permanent magnet 2, serving as a field pole, by a holding mechanism 13 by the thickness of its mounting part to approach an armature, and the brake winding 6 is mounted to a rotor iron core 1a mutually between the permanent magnets in which N and S poles are alternately arranged. Since the brake winding 6 is fixed to the rotor iron core approaching the armature, magnetic coupling of the brake winding 6 to the armature is strengthened, and further since the brake winding 6 is separated from the permanent magnet 2, which is a magnetic substance, and the rotor iron core 1a, leakage flux, interlinked in the brake winding 6 itself, is reduced to decrease self inductance of the brake winding 6. As a result, the brake winding 6 sensitively reacts relating to a current change of the armature.

Description

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

The present invention relates to a brake winding for a permanent magnet synchronous machine equipped with permanent magnets for excitation.

[Conventional technology]

Permanent magnet synchronous machines are used to excite submarine drive motors because of their small size, light weight, and high efficiency. Rotating field type synchronous machines are broadly divided into structures in which permanent magnets are attached to the surface of a cylindrical rotor and structures in which permanent magnets are embedded inside the rotor. Recently, the structure of the rotor is simple,
The former structure is the mainstream because it has a high utilization rate of permanent magnets. FIG. 3(A) is a sectional view showing a part of a conventional permanent magnet synchronous machine, and FIG. 3(B) is an enlarged view of part B in FIG. 3(A). In FIG. 3(A), in the permanent magnet synchronous machine, permanent magnets 2 are attached on the surface of a rotor core 1a of a cylindrical rotor I according to the number of poles. The permanent magnet 2 is installed so as to have polarity in the radial direction, such as N on the outer circumferential side and S on the inner circumferential side if it is a N pole. The permanent magnet 2 has N poles and S poles arranged alternately. As a result, permanent magnet 2
The magnetic flux generated in the air gap 3. A circulating magnetic path 5 is formed via the armature 4. The brake winding 6 is arranged between the permanent magnets 2,
The outer circumferences of the permanent magnet 2 and the brake winding 6 are wrapped with a protective winding 7 made of glass fiber to protect them from flying out due to centrifugal force. The brake winding is made of a copper rod or a brass rod, and is electrically short-circuited by short-circuiting rings 8 at both ends of the rotor in the axial direction. FIG. 4 is a sectional view showing the action of the damper winding when the armature current of the permanent magnet synchronous machine changes, and FIG. 5 is a perspective view showing the flux linkage to the damper winding in FIG. 4. In FIG. 4, a brake winding 6 is attached to the rotor between permanent magnets 2, and an armature winding 9 is housed in a groove in the armature, which is a stator. An air gap magnetic flux 1o exists in the air gap 3 between the rotor 1 and the rotor 1. During operation, when a fault such as a line short circuit occurs, the current in the armature winding 9 suddenly changes and the air gap magnetic flux 10 changes, causing the magnetic flux 11 interlinking with the brake winding 6 to change. As a result, the damper winding 6 acts as a short circuit with low impedance for the reverse phase rotating magnetic field, and a current 12 flows in the damper winding 6 in a direction that limits changes in the flux linkage 11.
Changes in the air gap magnetic flux 10 are suppressed. This effect is observed as suppression of voltage fluctuations at the armature terminals, that is, a reduction in transient actance, as well as suppression of power fluctuations, suppression of magnetic flux due to harmonic electromotive force when the load is an inverter, and suppression of magnetic flux due to harmonic electromotive force when the load is an inverter. During starting, it is used to generate motor torque.

[Problem to be solved by the invention]

A permanent magnet synchronous machine uses two permanent magnets with different magnetic poles in the air gap between the stator, which is an armature, and the rotor. The protective winding 7 and the preliminary space are included, and the gap length is generally large compared to the size of the equipment, and the magnetic coupling between the armature 4 and the damper winding 6 tends to be weak. There was a case where 1 did not function at all due to electrical fluctuations on the machine side. Another drawback is that the brake winding itself cannot efficiently respond to changes in magnetic flux due to the large self-inductance of the brake winding. SUMMARY OF THE INVENTION An object of the present invention is to provide a damper winding for a permanent magnet synchronous machine that strengthens magnetic coupling with the armature and weakens self-inductance to facilitate current flow.

[Means to solve the problem]

The above object is to provide a permanent magnet synchronous machine including a stator consisting of an armature, a rotor consisting of permanent magnets having different magnetic poles, a brake winding, and a rotor core, in which This is achieved by fixing the damper winding to the rotor by moving the damper winding away from the permanent magnets and closer to the armature in the air gap. The above object further includes, in a brake winding of a permanent magnet synchronous machine, separating the brake winding from the permanent magnets using a non-magnetic holding mechanism, moving the brake windings closer to the armature, and fixing the brake windings to the rotor core between the permanent magnets. achieved by. The above object is further achieved by separating the brake winding from the permanent magnet by sandwiching the brake winding between a protective winding that covers the outer circumference of the permanent magnet and a protective winding that covers the outer circumference of the brake winding. This is achieved by placing them close to the armature and fixing them between permanent magnets.

[For use]

In this invention, the brake winding is fixed to the rotor by approaching the armature from the different magnetic pole side in the gap between the stator and the rotor of a permanent magnet synchronous machine, so that the armature and the brake winding are fixed to the rotor. The gap between the armature and the brake winding becomes narrower as the brake winding approaches the armature, and the magnetic coupling between the armature and the brake winding becomes stronger. Furthermore, since the brake winding is separated from the magnetic poles of the rotor and the rotor core, leakage magnetic flux interlinking with the brake winding itself is reduced, and as a result, the self-inductance of the brake winding is reduced. When the armature current fluctuates, a braking winding current flows to suppress the armature current, thereby suppressing the fluctuation. According to claim 2 of the present invention, the brake winding is separated from the permanent magnet by a non-magnetic holding mechanism and brought close to the armature, and is fixed to the rotor core between the permanent magnets. The magnetic coupling with the winding becomes stronger. moreover,
Since the brake winding is separated from the magnetic poles of the rotor and the rotor core, the leakage magnetic flux interlinking with the brake winding itself is reduced, and as a result, the self-inductance of the brake winding is reduced. When the armature current fluctuates, a braking winding current flows to suppress the armature current, thereby suppressing the fluctuation. According to claim 3 of the present invention, the brake winding is sandwiched between a protective winding that covers the outer periphery of the permanent magnet and a protective winding that covers the outer periphery of the brake winding, and is moved away from the permanent magnet and closer to the armature. Since the permanent magnets are fixed between each other, the magnetic coupling between the armature and the damper winding is strong. Furthermore, since the brake winding is separated from the magnetic poles of the rotor and the rotor core, leakage magnetic flux interlinking with the brake winding itself is reduced, and as a result, the self-inductance of the brake winding is reduced. When the armature current fluctuates, a braking winding current flows to suppress the armature current, thereby suppressing the fluctuation.

【Example】

The present invention will be described in detail below based on the drawings. FIG. 1 is a perspective view showing a part of a rotor of a permanent magnet synchronous machine equipped with a brake winding according to an embodiment of the present invention. In FIG. 1, on the outer periphery of the rotor core 1a, a brake winding 6 is held by a holding mechanism 13 between permanent magnets 2 having N poles and S poles arranged alternately. The armature is attached to the rotor core 1a at a distance of the thickness of the mounting portion of the holding mechanism 13 from the armature 2, and the armature winding is housed in a groove in the armature (not shown). Brake winding 6
approaches the armature by the thickness of the mounting portion of the holding mechanism 13. The holding mechanism 13 uses a non-magnetic wire such as SO3. Since the brake winding 6 is fixed to the rotor core close to the armature, the magnetic coupling between the brake winding 6 and the armature 4 is strengthened, and the brake winding 6 is connected to the permanent magnet 2, which is a magnetic material, and the rotor core. Since it is separated from the child core 1a, the leakage magnetic flux interlinking with the brake winding 6 itself is reduced, and the self-inductance of the brake winding is reduced. As a result, the brake winding 6 responds sharply to changes in the armature current. FIG. 2 is a sectional view showing a part of a permanent magnet synchronous machine equipped with a damper winding according to another embodiment of the present invention. In FIG. 2, permanent magnets 2 are arranged around the outer periphery of the rotor core 1a in alternating north and south poles, and between the permanent magnets 2, a protective winding 7 and a brake winding 6 covering the outer periphery of the permanent magnets 2 are arranged. Protective winding 7 that covers the outer circumference of
The brake winding 6 was fixed to the rotor by sandwiching the brake winding 6 away from the permanent magnet 2 having different magnetic poles and approaching the armature. The protective winding 7 is made of glass fiber. Since the brake winding 6 is fixed to the rotor core close to the armature, the magnetic coupling between the brake winding 6 and the armature 4 is strengthened, and the brake winding 6 is connected to the permanent magnet 2, which is a magnetic material, and the rotor core. Since it is separated from the child core 1a, the leakage magnetic flux interlinking with the brake winding 6 itself is reduced, and the self-inductance of the brake winding is reduced. As a result, the brake winding 6 responds sharply to changes in the armature current.

【Effect of the invention】

In this invention, the brake winding is moved away from the permanent magnet in the gap between the stator and rotor of a permanent magnet synchronous machine, brought closer to the armature, and fixed to the rotor, so that the armature and the brake winding are separated. This strengthens the magnetic coupling between the brake windings and reduces leakage magnetic flux interlinking with the brake windings themselves, making it easier to conduct current to the brake windings, and when applied to a synchronous generator, it reduces load changes. It is possible to suppress accompanying voltage fluctuations and suppress power fluctuations with other adjacent generators. Furthermore, when applied as a synchronous motor, it is possible to increase asynchronous starting torque and suppress rotor oscillation due to pulsation of load torque. In this invention, the brake winding is fixed to the rotor core between the permanent magnets using a non-magnetic holding mechanism, and the brake winding is brought closer to the armature from the permanent magnets, so that the brake winding between the armature and the brake winding is Magnetic coupling is strengthened, and leakage magnetic flux interlinking with the damper winding itself is reduced. As a result, when applied to a synchronous generator, voltage fluctuations due to load changes can be suppressed, and power fluctuations with other adjacent generators can be suppressed. Furthermore, when applied as a synchronous motor, it is possible to increase asynchronous starting torque and suppress rotor oscillation due to pulsation of load torque. In this invention, the brake winding is fixed between the permanent magnets by being sandwiched between a protective winding that covers the outer circumference of the permanent magnet and a protective winding that covers the outer circumference of the brake winding, and the brake winding is separated from the permanent magnet. Since the armature is placed close to the brake winding, the magnetic coupling between the armature and the brake winding is strengthened, and leakage magnetic flux interlinking with the brake winding itself is reduced. As a result, when applied to a synchronous generator, voltage fluctuations due to load changes can be suppressed, and power fluctuations with other adjacent generators can be suppressed. Furthermore, when applied as a synchronous motor, it is possible to increase asynchronous starting torque and suppress rotor oscillation due to pulsation of load torque.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a part of a permanent magnet synchronous machine equipped with a brake winding according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a part of a permanent magnet synchronous machine equipped with a brake winding according to another embodiment of the present invention. 3(A) is a sectional view showing a part of a conventional permanent magnet synchronous machine, and FIG. 3(B) is a sectional view showing a part of a conventional permanent magnet synchronous machine.
), Figure 4 is a sectional view showing the action of the damper winding when the armature current of the permanent magnet synchronous machine fluctuates, and Figure 5 shows the flux linkage to the brake winding in Figure 4. FIG. l: Rotor 1a: Rotor iron core, 2: Permanent magnet with different magnetic poles, 3: Air gap, 4: Armature as stator, 6: Brake winding, 7: Protective winding, 9: Armature winding, 13: Retention mechanism. Hoi+t! The map of the map

Claims (1)

[Scope of Claims] 1) A permanent magnet synchronous machine including a stator consisting of an armature, a rotor consisting of permanent magnets having different magnetic poles, a brake winding, and a rotor iron core, in which the stator and the rotating A brake winding of a permanent magnet synchronous machine, characterized in that the brake winding is fixed to the rotor by moving the brake winding away from the permanent magnet and approaching the armature in a gap between the brake and the rotor. line. 2) In the brake winding of the permanent magnet synchronous machine according to claim 1, the brake winding is separated from the permanent magnets and brought close to the armature by a non-magnetic holding mechanism, and fixed to the rotor core between the permanent magnets. A brake winding for a permanent magnet synchronous machine characterized by: 3) In the brake winding of the permanent magnet synchronous machine according to claim 1, the brake winding is sandwiched between a protective winding that covers the outer circumference of the permanent magnet and a protective winding that covers the outer circumference of the brake winding, and is separated from the permanent magnet. A brake winding for a permanent magnet synchronous machine, characterized in that the brake winding is brought close to the armature and fixed between the permanent magnets.