JP2004282889A - Permanent magnet rotor and wind power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wind power generator having a high efficiency and reliability, a wide variable speed range and having output characteristics desired for a wind power generation and to provide a permanent magnet rotor for constituting the wind power generator. <P>SOLUTION: The permanent magnet rotor 2 constitutes a permanent magnet rotary electric machine by embedding a permanent magnet 4 in a rotor core 2a and forming a rotor pole 2b. In the permanent magnet rotor 2, changes in the generating end voltage and current of the permanent magnet rotary electric machine respectively fall within a range of 20% in a rotational speed range of 110 to 125% of the rated rotational speed from the rated rotational speed of the permanent magnet rotary electric machine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a permanent magnet rotor configured by attaching a permanent magnet to a rotor core, and a wind power generator including the permanent magnet rotor.
[0002]
[Prior art]
As described in Patent Document 1, a permanent magnet rotating electric machine for a generator uses a permanent magnet disposed on a rotor to form a magnetic pole, and further generates a moving magnetic field on the armature side to generate rotational energy. This is a synchronous rotating machine that transmits power to the armature side through the moving magnetic field to extract power, and high operating efficiency can be obtained by its operation principle. In recent years, variable speed operation has become possible by combining a permanent magnet rotating machine with an inverter, and it has been applied to applications having a wide operating speed range.
[0003]
Incidentally, permanent magnets have recently been invented as neodymium magnets which are classified as rare earth sintered magnets and have a high energy density and a low price, and have been applied to various motors. In particular, it can be said that the application to a large rotating machine is growing because there is no feeling of pressure in the cost as compared with the conventional magnet.
[0004]
Sintered magnets also contribute to increasing motor output, but because they are sintered products or because they are hard and brittle, they cannot be formed into complex shapes. Since it can be formed only to the extent that it can be adjusted, arc shapes and flat plate shapes are widely used. Therefore, it is necessary to form a magnetic pole with a minimum usage amount without deteriorating the energy density.
[0005]
At present, the mainstream wind power generators are induction generators, wound synchronous generators, and the like. Since wind power has a low energy density, it is necessary to efficiently convert that energy into electric power. For this reason, it is necessary for wind turbines to capture the maximum amount of wind energy, and technical developments such as optimal shape design of blades and pitch control for obtaining high efficiency in a wide range of wind speeds are being advanced. Also, in a generator, since it is necessary to efficiently convert rotational energy transmitted from a windmill into electric energy, it is desired to expand the variable speed range, that is, to improve the ability and efficiency of converting power as power at any wind speed. It is rare.
[0006]
As a feature of the power generation system of wind power generation, power generation is started from the cut-in wind speed, and the power generation output increases by approximately the third power of the wind speed, and shifts to a constant output operation at a wind speed after the rated wind speed. After the rated wind speed, even if the wind speed increases, the rotation speed of the wind turbine is controlled to maintain a constant rotation speed by utilizing its stall characteristic. This is due to the strength limit of the blade.
[0007]
However, the rotation speed after the actual rated wind speed is not constant due to the mechanical delay of the pitch control. That is, since the wind speed fluctuates in a short time due to the fluctuation of the wind speed in seconds and minutes or the change of the wind direction, the pitch control cannot be followed and the rotation speed greatly pulsates. According to our investigation, it was found that a fluctuation of 10% to 25% actually occurred with respect to the rated rotation speed (at the rated wind speed).
[0008]
As described above, the characteristic of the wind turbine is variable speed drive having a constant output range of about 20%, and the combination of a generator matching this characteristic contributes to an increase in output as a wind power generation system.
[0009]
An induction generator, which is a conventional wind power generator, employs a pole number conversion method and slip control to enable variable speed operation. In the case of such a system, the influence on the system such as an inrush current is large, and the installation equipment becomes large due to the installation of the protection circuit or the like. In addition, a reduction in the power factor is inevitable, and the in-flight consumption of energy is large, including the originally low efficiency.
[0010]
In contrast, wound synchronous generators can operate at relatively high efficiency and in a wide variable speed range. However, a brush must be used to supply an exciting current to the rotor winding, and there is a problem in terms of maintenance. In order to generate a DC current, it is essential to provide an exciter, but since the power for generating the excitation current is regarded as energy loss, there is naturally a limit in terms of efficiency.
[0011]
Compared with these conventional generators, the permanent magnet generator uses the magnetic force of the magnet as a field in the first place, and therefore does not require excitation by an exciter and can achieve high efficiency. Further, since a brush is not required, maintenance can be greatly improved. Furthermore, if the characteristics that match the above-described unique output characteristics of the wind power generation can be imparted to the permanent magnet generator while maintaining these characteristics, high cost performance can be achieved.
[0012]
[Patent Document 1]
JP-A-11-299197
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has a high efficiency and reliability, a wide variable speed range, and a wind power generator having output characteristics desirable for wind power generation, and a permanent magnet rotor constituting the wind power generator. The purpose is to provide.
[0014]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a permanent magnet rotor comprising a permanent magnet embedded in a rotor core to form a rotor magnetic pole to constitute a permanent magnet rotating electric machine. In the rotation speed range of 110% to 125% of the rated rotation speed from the rated rotation speed of the electric machine, each of the fluctuations in the power generation terminal voltage and the current of the permanent magnet rotating electric machine is within a range of 20%.
[0015]
According to a second aspect of the invention, two flat permanent magnets are provided to face each rotor magnetic pole, and the pole arc of the magnet pole is 92% or more. The angle formed is in the range of 75 ° to 105 °.
[0016]
According to a third aspect of the present invention, two flat permanent magnets are provided facing each other for one rotor magnetic pole, and the pole arc of the magnet pole is in a range of 70% to 92%. The angle between the permanent magnets is in the range of 60 ° to 90 °.
[0017]
According to a fourth aspect of the present invention, two flat permanent magnets are provided facing each other for each rotor magnetic pole, and the pole arc of the magnet pole ranges from 85% to 92%. The angle between the permanent magnets is in the range of 60 ° to 90 °, and a fan-shaped window having sides parallel to the permanent magnets is formed in the rotor core in front of the permanent magnets.
[0018]
The invention according to claim 5 is configured such that a fan-shaped hollow or solid magnetic piece is mounted on the fan-shaped window.
According to a sixth aspect of the present invention, two flat permanent magnets are provided facing each other for one rotor magnetic pole, and the pole arc of the magnet pole ranges from 85% to 92%. The angle between the permanent magnets is in the range of 60 ° to 90 °, a groove is formed in the rotor core in front of the permanent magnet, and the gap length is increased.
[0019]
According to a seventh aspect of the present invention, the permanent magnet is formed in an arc shape and is embedded in the outer peripheral portion of the rotating iron core, and the arc of the magnet pole ranges from 65% to 80%.
According to an eighth aspect of the present invention, the permanent magnet is formed in a camber shape and is embedded in the outer periphery of the rotary iron core, and the arc of the magnet pole ranges from 65% to 80%.
[0020]
According to a ninth aspect of the present invention, an annular magnetic body is provided on a front surface of the permanent magnet.
According to a tenth aspect of the present invention, the annular magnetic body has a joint that engages with a rotor core between adjacent rotor magnetic poles, and the joint has a cooling fin that extends in the axial direction. Configuration.
[0021]
The invention according to claim 11 is a wind power generator, comprising a permanent magnet rotor in which a permanent magnet is embedded in a rotor core to form a rotor magnetic pole, and from a rated speed, 110% or less of the rated speed. The configuration is such that the fluctuations in the power generation terminal voltage and the current are each within the range of 20% in the 125% rotation speed range.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of a permanent magnet rotor and a wind power generator according to the present invention will be described with reference to FIGS.
FIG. 1A schematically shows a cross-sectional structure of a permanent magnet rotating electric machine. An armature 1 has a configuration in which an armature coil 1b is housed in a slot formed in an armature core 1a. The rotor 2 having the rotor magnetic pole 2b formed on the rotor core 2a is arranged in the field space.
[0023]
As shown in detail in FIG. 1B, the rotor 2 is configured such that two plate-shaped magnets 4 per magnetic pole 2b are opposed to a magnetic pole mounting punching portion provided on the rotor core 2a. And the poles β / α of the magnet poles are set to 92% or more, and the angle γ between the magnets 4 arranged at the same magnetic pole is in the range of 75 ° to 105 °.
[0024]
When a permanent magnet rotating electric machine is applied as a wind power generator, it is necessary to add power generation characteristics suitable for the output characteristics of a windmill on the prime mover side. As a feature of the power generation system of the wind power generation system, the power generation is started from the cut-in wind speed, and the power generation output increases by approximately the third power of the wind speed, and shifts to the constant output operation at the wind speed after the rated wind speed. After the rated wind speed, even if the wind speed increases, the rotation speed of the wind turbine is controlled to maintain a constant rotation speed by utilizing its stall characteristic. This is due to the strength limit of the blade.
[0025]
Therefore, the generator ideally needs to conform to the relationship between the rotational speed and the output (hereinafter referred to as load characteristics) as shown by the load curve in FIG. In this case, as the permanent magnet rotor, a surface magnet arrangement type rotor configuration as shown in FIG. 1 is preferable because a high power factor can be obtained.
[0026]
FIG. 2A shows output characteristics of a generator employing the rotor, using load current as a parameter. Since the load characteristics can be covered only by the rated current, there is no change in the generator output, and high-quality power generation is possible.
[0027]
However, the actual rotation speed after the rated wind speed is not constant as in the load characteristics of FIG. 2A due to the mechanical delay of the pitch control. That is, since the wind speed fluctuates in a short time due to the fluctuation of the wind speed in units of seconds and minutes or the change of the wind direction, pitch control cannot be followed, and the rotation speed greatly pulsates.
[0028]
According to our investigation, it was found that a fluctuation of 10% to 25% actually occurred with respect to the rated rotation speed (at the rated wind speed). This is likewise the output v. s. In terms of the number of rotations, a relationship as shown in FIG. 2B is obtained. This sets the fluctuation range to 20% of the rated rotation speed.
[0029]
It is impossible to cover such load characteristics with a constant current with the generator characteristics. Further, even when a 120% current flows, the load cannot be covered. For example, when the current can be covered by 130% current, it leads to a power factor reduction of 20% or more, the output fluctuation becomes large, and high-quality power cannot be supplied.
[0030]
Even if it is considered that the output fluctuation is stabilized by the power electronics device installed at the subsequent stage, the fluctuation range of the current and voltage at the power generation end is within 120%, respectively, and the fluctuation that exceeds that limit is generated. Therefore, it is necessary to install a power storage device such as a battery and a flywheel device, and the power generation system itself becomes large, and in particular, it often cannot be realized in terms of cost as a wind power generation system. As described above, the characteristic of the wind turbine is variable speed drive having a constant output range of about 20%, and the combination of a generator matching this characteristic contributes to an increase in output as a wind power generation system.
[0031]
In the permanent magnet rotor according to the present embodiment, since the interval between the magnets 4 of the adjacent magnetic poles 2b is almost nonexistent (pole arc 93% or more), when the angle γ exceeds the above range, the output characteristics thereof are almost not shown. It becomes the same as that of 2 (a). However, when γ falls within the above range, a space in which the reluctance magnetic flux having an effect of stabilizing the output flows in the iron core portion in front of the magnet 4 in addition to the magnetic flux of the magnet 4.
[0032]
Thus, the permanent magnet rotor of the present embodiment achieves high output by the magnet magnetic flux, and has a function of maintaining high output by the reluctance magnetic flux. Therefore, from the cut-in wind speed to the rated wind speed (rotational speed), the output of the wind turbine can be converted into electric energy without any excess. Further, even when the rotational speed fluctuates between the rated wind speed and the cut-out wind speed, the power can be reduced. The fluctuation of the load current can be suppressed within an allowable range of the electronic device, and as a result, a constant output can be obtained.
[0033]
In addition, the wind power generator according to the present embodiment can keep the fluctuations of the power generation terminal voltage and the load current within the range of 20%, respectively, so that the fluctuations can be absorbed by the stabilizing action of the subsequent power electronics device. A low-cost wind system can be provided without installing any additional equipment.
[0034]
Next, a second embodiment of the present invention will be described. As shown in FIG. 3, the permanent magnet rotor of the present embodiment is configured such that two flat magnets 4 per pole 2 b face the magnet mounting punching portion provided on the rotor core 2 a. And the arc β / α of the magnet pole is set in the range of 70% to 92%, and the angle γ formed by the magnets 4 arranged on the same magnetic pole is set in the range of 60 ° to 90 °. ing.
[0035]
When the pole arc β / α is in the above range, the reluctance magnetic flux passes through the iron core existing between the magnets of the adjacent magnetic poles, and a space where the magnetic flux flows after the magnet 4 is secured. However, when the angle γ exceeds this angle range, the amount of the reluctance magnetic flux is greatly reduced, and the amount of the magnetic flux of the magnet is also reduced, thereby preventing the output from being increased by the magnet. As a result, although the function of maintaining the output is attached, the shortage of the magnet magnetic flux is covered by increasing the current in order to exhibit the rated output, and the overall power factor is reduced. When the angle γ is set in the above range, the amount of reluctance magnetic flux increases, and a magnet magnetic flux sufficient to prevent a decrease in power factor can be obtained.
[0036]
Therefore, from the cut-in wind speed to the rated wind speed (rotational speed), the output of the wind turbine can be converted into electric energy without any excess. Further, even when the rotational speed fluctuates between the rated wind speed and the cut-out wind speed, the power can be reduced. The fluctuation of the load current can be suppressed within an allowable range of the electronic device, and as a result, a constant output can be obtained.
[0037]
Next, a third embodiment of the present invention will be described. As shown in FIG. 4, the permanent magnet rotor according to the present embodiment has a structure in which the magnet 4 is arranged when the pole arc β / α of the magnet pole is in a relatively high pole arc range of 85% to 92%. In this configuration, a fan-shaped window 3 having sides parallel to the magnet is formed on the front surface.
[0038]
Depending on the dimensional specifications of the generator, the magnet flux may be insufficient. In this case, when the amount of magnetic flux is increased, the length of the magnet is increased, the magnet interval between the adjacent magnetic poles is reduced, and the space for the reluctance magnetic flux is insufficient, and the output maintaining function is reduced.
[0039]
In this case, if the fan-shaped window 3 is formed on the front surface of the magnet 4 with a cross-sectional area that does not hinder the flow of the magnetic flux of the magnet 4, that is, the iron core 2a does not cause magnetic saturation, the reluctance magnetic flux can be increased. . That is, by shutting off the magnetic circuit in the direction of the center of the magnetic pole of the magnet 4, the reluctance magnetic flux leaking there can be guided to a desired flow path passing after the magnet 4, and as a result, the reluctance magnetic flux Can be supplemented.
[0040]
Therefore, from the cut-in wind speed to the rated wind speed (rotational speed), the output of the wind turbine can be converted into electric energy without any excess. Further, even when the rotational speed fluctuates between the rated wind speed and the cut-out wind speed, the power can be reduced. The fluctuation of the load current can be suppressed within an allowable range of the electronic device, and as a result, a constant output can be obtained.
[0041]
Next, as shown in FIG. 5, the permanent magnet rotor according to the fourth embodiment of the present invention has a configuration in which a fan-shaped hollow or solid magnetic piece 5 is mounted on a fan-shaped window which is wide open in advance. is there.
[0042]
According to the present embodiment, the balance between the magnetic flux and the reluctance magnetic flux is increased when the fluctuation range of the rotation speed at the wind speed equal to or higher than the rated wind speed becomes large, or when it becomes necessary to match the load characteristic specifications of different wind turbines. When broken, as a result, it becomes impossible to maintain a constant output, by resizing the window to the required size, it restores its balance and changes in the load current within the acceptable range of the power electronics device. Can be suppressed. Further, since the characteristics of the generator can be easily adjusted to the output of the windmill, the generator can be used as a common component, and the production cost can be reduced.
[0043]
Next, as shown in FIG. 6, the permanent magnet rotor according to the fifth embodiment of the present invention has a sector-shaped window in which the pole arc β / α of the magnet pole is limited to a range of 85% to 92%. Instead of this, a groove having a depth t is formed on the surface of the rotor core 2a facing the front surface of the magnet 4, and the gap length is increased only in that portion.
[0044]
As the depth t of the groove increases, the effect of increasing the reluctance magnetic flux increases, but the gap length increases, which leads to a decrease in the magnetic flux of the magnet and cannot be increased unnecessarily. According to our investigation, it has been found that the value of t is preferably in the range of 10% to 30% with respect to the normal gap length.
[0045]
Next, in a permanent magnet rotor according to a sixth embodiment of the present invention, as shown in FIG. 7, an arc-shaped magnet 4a is inserted into a magnet mounting punching portion provided on a rotor core 2a, and The configuration is such that the pole arc β / α of the magnet pole is in the range of 65% to 80%.
[0046]
In this embodiment, there is no space for the reluctance magnetic flux to flow on the front surface of the magnet 4a, and only the magnetic circuit flowing between the magnets of the adjacent magnetic poles and passing behind the magnet is the flow path. Therefore, the interval between the magnets needs to be relatively wide, and the above range is set. The arc-shaped magnet 4a has a shape along the outer periphery of the rotor. For example, the magnet 4a may be arranged in an inverted arc state.
[0047]
According to the permanent magnet rotor of this embodiment, the output of the windmill can be converted into electric energy from the cut-in wind speed to the rated wind speed (rotation speed) without any excess, and the cut-out wind speed can be further reduced from the rated wind speed. Even in the intermittent rotation speed fluctuation, the fluctuation of the load current can be suppressed within an allowable range of the power electronic device, and as a result, a constant output can be obtained.
[0048]
The arc-shaped magnet 4a may be a single magnet, but its fan-shaped angle is set smaller than the punched hole of the iron core 2a, and the fourth hole is formed in the gap formed in the punched hole. By arranging the magnetic pieces as in the embodiment, it is possible to arbitrarily and easily adjust the reluctance magnetic flux flow path, that is, the ratio of the reluctance magnetic flux amount to the magnet magnetic flux amount.
[0049]
As a result, the balance between the magnetic flux and the reluctance magnetic flux is broken, for example, when the fluctuation range of the rotation speed at the wind speed equal to or higher than the rated wind speed becomes large, or when it becomes necessary to match the load characteristic specifications of different wind turbines, as a result, When it becomes impossible to maintain a constant output, the balance can be restored by arbitrarily changing the amount of magnetic flux and the reluctance magnetic flux flow path, and the fluctuation of the load current can be suppressed within the allowable range of the power electronics device. . Further, since the characteristics of the generator can be easily adjusted to the output of the windmill, the generator can be used as a common component, and the production cost can be reduced.
[0050]
Next, a permanent magnet rotor according to a seventh embodiment of the present invention uses a Kamaboko-shaped magnet 4b as a permanent magnet as shown in FIG. The designation of the pole arc β / α is the same as in the sixth embodiment. The effect of the cam-shaped magnet 4b is basically the same as that of the arc magnet, but further increases the reluctance magnetic flux and obtains an excellent output maintaining ability.
[0051]
The reluctance magnetic flux can be increased by securing the flow path, but can also be increased by eliminating leakage in the direction of the magnet as described above. The magnet 4b in the shape of a camber has a large magnet thickness at the center of the pole, but since the magnet has a function of inhibiting the flow of the reluctance magnetic flux, the magnet center has a large effect. Furthermore, since the leakage of the reluctance magnetic flux tends to be large at the pole center, the leakage of the reluctance magnetic flux can be strongly and effectively shut off by the effect of the magnet 4b having a camber shape. As a result, the output maintaining ability of the permanent magnet rotating electric machine can be improved with a small amount of magnetic flux, and the power factor and efficiency can be improved.
[0052]
Next, an eighth embodiment of the present invention will be described. In the permanent magnet rotor of this embodiment, as shown in FIG. 9, an iron core portion (annular portion) provided on the outer surface of an arc-shaped magnet 4a is formed by an annular magnetic body 6 separate from the iron core 2a. In this configuration, the annular magnetic body 6 is fixed using the iron core portion sandwiched between the adjacent magnets 4a as a joint.
[0053]
By making this annular portion a member different from the iron core 2a, the shape or material of this portion can be arbitrarily selected. For example, when it is difficult to prevent the scattering due to the centrifugal force of the magnet 4a when the maximum number of rotations is large, the configuration of FIG. 7 must be dealt with by increasing the thickness of the annular portion. Since the position of the magnet 4a inevitably moves to the inner peripheral side, the amount of magnetic flux decreases, and the leakage component of the magnet magnetic flux flowing through the annular portion increases. Will drop.
[0054]
In this embodiment, in this case, by using a high-strength material such as maraging steel for the annular portion material, the wall thickness can be reduced, and as a result, a decrease in output can be prevented. Also, the configuration of FIG. 7 can be easily adopted only by removing the annular portion.
[0055]
Furthermore, by making the shape of the annular portion a convex arc shape, the distribution of magnetic flux flowing through the gap can be shaped into a sine wave shape, thereby reducing harmonic magnetic flux components. As a result, it is possible to reduce the harmonic loss caused by the harmonic magnetic flux component, and it is also possible to improve the efficiency. As described above, according to the present embodiment, the generator performance can be easily adapted to various wind turbine characteristics or load specifications.
[0056]
Next, a ninth embodiment of the present invention will be described. As shown in FIG. 10, the permanent magnet rotor according to this embodiment is provided with cooling fins 7 in the axial direction at the joint portion of the annular magnetic body 6 in the permanent magnet rotor according to the eighth embodiment. It was done. Since the annular portion of the iron core 2a can be formed into an arbitrary shape by using another material, the annular portion is extended in the axial direction to form the fin 7. In the figure, axial fins are formed, but only the fins 7 may be made non-magnetic.
[0057]
There are several effects of the fins 7, and one of them is an effect of quickly releasing heat from the fins 7 due to surface loss or the like generated in the permanent magnet 4a and the annular magnetic body 6. Further, as another effect, there is an effect of circulating cooling the end portion of the armature coil 1b, which tends to have a relatively high temperature, by the cooling air generated by the rotation of the fins 7.
[0058]
Generally, a wind power generator is housed in a nacelle, but the nacelle often employs a closed structure to protect other electric components. In addition, the cooling of the generator is generally natural cooling, and the cooling condition is poor, so that the generator tends to be manufactured relatively large. In the present embodiment, the armature coil end portion, which is the hot spot, can be cooled by the fins 7, so that the cooling performance is dramatically improved and the generator itself can be downsized. As a result, the weight, size and loss of the generator are reduced, and it is possible to improve the output and reduce the size of the nacelle.
[0059]
【The invention's effect】
According to the present invention, it is possible to provide a wind generator having high efficiency and reliability, a wide variable speed range, and output characteristics desirable for wind power generation, and a permanent magnet rotor constituting the wind generator.
[Brief description of the drawings]
FIGS. 1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a radial cross-sectional view schematically showing a permanent magnet rotating electric machine including a permanent magnet rotor according to the embodiment, and FIG. FIG. 3 is a partial sectional view showing the permanent magnet rotor.
FIG. 2 is a curve diagram for explaining an operation (b) of the permanent magnet rotor according to the first embodiment of the present invention in comparison with an operation (a) of a conventional permanent magnet rotor.
FIG. 3 is a partial sectional view of a permanent magnet rotor according to a second embodiment of the present invention.
FIG. 4 is a partial sectional view of a permanent magnet rotor according to a third embodiment of the present invention.
FIG. 5 is a partial sectional view of a permanent magnet rotor according to a fourth embodiment of the present invention.
FIG. 6 is a partial sectional view of a permanent magnet rotor according to a fifth embodiment of the present invention.
FIG. 7 is a partial sectional view of a permanent magnet rotor according to a sixth embodiment of the present invention.
FIG. 8 is a partial sectional view of a permanent magnet rotor according to a seventh embodiment of the present invention.
FIG. 9 is a partial sectional view of a permanent magnet rotor according to an eighth embodiment of the present invention.
FIG. 10 is an axial sectional view of a wind power generator provided with a permanent magnet rotor according to a ninth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Armature, 1a ... Armature core, 1b ... Armature coil, 2 ... Rotor, 2a ... Rotor core, 2b ... Rotor magnetic pole, 3 ... Window, 4, 4a, 4b ... Magnet, 5 ... Magnetic piece , 6 ... Annular magnetic body, 7 ... Fin, 8 ... Shaft.

Claims (11)

In a permanent magnet rotor constituting a permanent magnet rotating electric machine by embedding a permanent magnet in a rotor core to form a rotor magnetic pole, 110% to 125% of the rated rotation speed based on the rated rotation speed of the permanent magnet rotating electric machine. Wherein the fluctuations in the voltage at the power generating end and the current of the permanent magnet rotating electric machine are within 20% in the range of the number of rotations of the permanent magnet rotating electric machine. Two flat permanent magnets are provided facing each other for each rotor magnetic pole, the arc of the magnet poles is 92% or more, and the angle between the two permanent magnets is 75 ° to 105 °. 2. The permanent magnet rotor according to claim 1, wherein the permanent magnet rotor is in a range. Two flat permanent magnets are provided facing each other for each rotor magnetic pole, the arc of the magnet poles ranges from 70% to 92%, and the angle between the two permanent magnets is 60 °. 2. The permanent magnet rotor according to claim 1, wherein the angle is in a range of from 90 to 90 degrees. Two flat permanent magnets are provided facing each other for each rotor magnetic pole, the arc of the magnet poles is in the range of 85% to 92%, and the angle formed by the two permanent magnets is 60 °. The permanent magnet rotor according to claim 1, wherein a fan-shaped window having a side parallel to the permanent magnet is formed in a rotor core in a range of from 90 to 90 ° and in front of the permanent magnet. . The permanent magnet rotor according to claim 4, wherein a fan-shaped hollow or solid magnetic piece is mounted on the fan-shaped window. Two flat permanent magnets are provided facing each other for each rotor magnetic pole, the arc of the magnet poles is in the range of 85% to 92%, and the angle formed by the two permanent magnets is 60 °. 2. The permanent magnet rotor according to claim 1, wherein a groove is formed in the rotor core on the front surface of the permanent magnet to increase a gap length. 2. The permanent magnet rotor according to claim 1, wherein the permanent magnet is formed in an arc shape and is buried in an outer peripheral portion of the rotary iron core, and a pole arc of a magnet pole is in a range of 65% to 80%. 2. The permanent magnet rotor according to claim 1, wherein the permanent magnet is embedded in the outer periphery of a rotary iron core in the shape of a crevice, and an arc of a magnet pole is in a range of 65% to 80%. 9. The permanent magnet rotor according to claim 7, wherein an annular magnetic body is provided on a front surface of the permanent magnet. The said annular magnetic body has a joint part which engages with a rotor core between the adjacent rotor magnetic poles, and this joint part is provided with the cooling fin which extends in the axial direction. 9. The permanent magnet rotor according to item 9. A permanent magnet rotor in which a permanent magnet is formed by burying a permanent magnet in a rotor core, and a fluctuation of a power generation terminal voltage and a current in a rotation speed range of 110% to 125% of the rated rotation speed from a rated rotation speed. Are each in the range of 20%.

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