JPS62104462A - Ac generator with permanent magnet - Google Patents

Abstract

PURPOSE:To prevent efficiency from being lowered on high speed operation, by multipole-structure in the magnetic poles of a rotor with the number of poles in three or more, and by constructing a stator core with the member of less eddy current loss in a high frequency sphere. CONSTITUTION:On the outer periphery of a rotary shaft 4, magnetic poles consisting of permanent magnets 5, 6 are arranged. The magnetic poles are multipole-organized with three poles or more. A stator is formed with a stator frame 1, a stator core 2, and stator coils 3. The stator core 2 is formed with the member of less eddy current loss in a high frequency sphere, for example, with ferrite. Due to the increased number of magnetic poles, a main magnetic field is less influenced by the reaction of an armature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application De?) The present invention relates to an alternating current generator, which prevents performance deterioration and iron loss increase due to armature reaction during high-speed rotation to 1+f. .

(Conventional example) Conventionally, as a rotating field type high speed low frequency permanent magnet generator,
A configuration as shown in FIG. 3 was used. In the figure, a stator frame 1, a stator core 2 made of laminated silicon steel plates,
, the stator side is constituted by the stator coil 3, and the rotor side is constituted by the N-pole permanent magnet 5 and the S-pole permanent magnet 6 connected to the rotating shaft 4, forming a two-pole rotor. A permanent magnet generator having such a configuration is directly connected to, for example, a two-pole turbine generator and is operated at high speed.

(Problem to be Solved by the Invention) Generally, when a three-phase alternating current flows through the "rrL armature coil of a rotating field type synchronous generator, a rotating magnetic field having the same synchronous speed as the rotor is generated, and the main magnetic field On the other hand, as with DC generators, the influence of armature reaction occurs.

The armature reaction is the armature magnetomotive force Fa, and the cross-induced F a
= F C+ F a
- Expressed as (1). Here, the armature amperage of a pair of magnetic poles is ATa, and the cross amperage is ATC.
If the number of demagnetizing amperes per demagnetization is ATd, the number of magnetic poles is P, the number of conductors is Z, and the current of each conductor is ia, formula (1) is as follows: AT a = AT c + AT d = (
i a Z ) / P... (2) It can be expressed as follows.

As is clear from equation (2), in the magnet generator,
As the load current increases, the armature reaction magnetomotive force acts on the field as a demagnetizing force, which causes a problem in that the generated voltage decreases.

Next, the iron loss Wi generated in the stator core is as follows, where wh is the hysteresis loss, We is the eddy current product, and f is the operating frequency. Wi = W h + We = K1. f
+K 2 (f) 2...(3) However, 2 in K1 and 2 is expressed as a constant. That is, the iron loss, especially the eddy current product, increases as the frequency increases.

By the way, when AC generators are required to be smaller and have higher output, the output frequency is increased by rotating the rotor at high speed, but the silicon steel plate used as the conventional stator core is not suitable for high frequency ranges. However, there was a problem in that magnetic permeability decreased, iron loss increased, and efficiency decreased.

Therefore, the present invention aims to solve these problems of the prior art.

(One Step to Solve the Problem) The present invention provides a rotating field type permanent magnet generator in which permanent magnet poles are arranged around the outer periphery of the rotating shaft.
By providing a permanent magnet generator having a multi-pole configuration with less than one pole and having a stator core made of a material with less eddying loss in a high frequency range, the problems of the prior art described above are solved. It is something.

(Function) In the present invention, the rotor magnetic poles have a multi-pole configuration of 3 or more, and the stator core is made of a material with a high frequency and low eddy current product, so ii) the influence of armature reaction is reduced. At the same time, a decrease in efficiency can be prevented.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a schematic cross-sectional configuration diagram of a permanent magnet generator of the present invention. In the case of unreleased II, a material having a small eddy current product in a high frequency range, such as ferrite, is used as the stator core.

Further, the rotor is composed of four magnetic poles. The rest of the structure is the same as the conventional example shown in FIG.

The present invention thus prevents an increase in iron loss in a high frequency range, and also reduces the influence of armature reaction. In other words, the magnetomotive force due to armature reaction is proportional to the magnitude of the current, as shown in equation (2), so in order to keep the magnetomotive force small, the current is lowered, but on the other hand, the number of magnetic poles on the rotor is increased. By lowering the voltage and increasing the power, the output frequency at the same rotation speed is increased.

FIG. 2 is a block diagram showing an example of use of the permanent magnet AC generator of the present invention.

In FIG. 2, reference numeral 10 denotes an exhaust turbine, and the turbine blades 11 are driven by the energy of exhaust gas discharged from the exhaust pipe (not shown) of the engine 20, and this driving force provides rotational force to the output shaft 12. It is something.

The rotating shaft 4 of the permanent magnet alternating current generator having the configuration shown in FIG. Generate electricity and control equipment! Supply power to I15. 16 is a rotation sensor that detects the rotation speed of the large gear 22 provided on the output shaft 2I of the engine 20;
The detected rotation signal R3 is sent to the control device 15. 17
is an AC motor, and the small gear 18 meshes with the large gear 22.
is provided on the rotating shaft, is operated by AC power supplied from the control device 15, and transmits its rotational force to the output shaft of the engine 20 via the small gear 18 and the large gear 21. The control device 15 controls the frequency of the input AC power using the rotation signal R3 from the rotation sensor 16, converts the frequency, and outputs the frequency.The frequency of the AC power supplied to the AC electric motor a17 is The alternating current motor 17 is always in full operation and is controlled to assist the rotational force of the output shaft 21 of the engine 20.

Therefore, in the usage example shown in diagram t52, the exhaust energy that drives the exhaust turbine is converted into electrical energy output from the stator coil 3, and the AC motor 1
Since the energy assists the output shaft 21 of the engine 20 through the exhaust gas 7, a highly efficient exhaust energy recovery device can be realized.

(Effects of the Invention) As described above, the present invention can increase the number of rotor magnetic poles of a permanent magnet generator and reduce the influence of armature reaction on the main magnetic field. Furthermore, since the stator core is made of a material with low eddy current in a high frequency range, such as ferrite, it is possible to prevent a decrease in efficiency during high-speed operation.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional configuration diagram of the present invention, FIG. 2 is a block diagram showing an example of use of the present invention, and FIG. 3 is a cross-sectional configuration diagram of a conventional example. l... Stator frame, 2... Stator core, 3... Stator coil, 4... Rotating shaft, 5.6... Permanent magnet.

Claims (1)

[Claims] In a rotating field type permanent magnet generator having a rotor with permanent magnet magnetic poles arranged around the outer circumference of the rotating shaft, the rotor has a multi-pole configuration with three or more magnetic poles, and the stator core is designed to operate in a high frequency range. A permanent magnet generator characterized by being constructed of materials with low eddy current loss.