JP2003079083A - Permanent magnet dynamo-electric machine and compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet dynamo-electric machine, which uses a concentrated winding stator and a magnet-embedded rotor, wherein good performance may be achieved even when driven by a 120-degree and 180-degree electrification inverter not provided with a position sensor. SOLUTION: The permanent magnet dynamo-electric machine has a stator provided with armature winding in a plurality of slots formed on the core and a rotor having a plurality of permanent magnets stored in a plurality of permanent magnet insertion holes formed on the core. The permanent magnets protrude from the outer peripheral surface of the rotor core in roughly arc shapes while at the same time forming recesses between the poles on the outer peripheral surface of the rotor core.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type rotating electric machine, for example, a permanent magnet type rotating electric machine mounted on a compressor of an air conditioner.

[0002]

2. Description of the Related Art Conventionally, permanent magnet type rotary electric machines of this type that have been generally adopted have various shapes of permanent magnets. For example, in a permanent magnet type rotating electric machine described in Japanese Patent Laid-Open No. 6-339241, a stator having concentrated armature windings surrounding a plurality of teeth formed on a stator core and a rotor core. A rotor in which permanent magnets are housed in a plurality of permanent magnet insertion holes formed in
The reluctance torque is used to improve the output of the rotating electric machine.

[0003]

SUMMARY OF THE INVENTION In the above prior art, a stator having concentrated armature windings surrounding a plurality of teeth formed on the stator core and a rotor core are formed. The rotor has a permanent magnet housed in a plurality of permanent magnet insertion holes, and the efficiency of the rotating electric machine can be improved by effectively utilizing the reluctance torque.
Dedicated to 20-degree energizing inverter, position sensorless 18
When driven by a 0-degree energizing inverter, there is a problem that the harmonic current increases and the characteristics deteriorate.

The present invention has been made in view of the above points. An object of the present invention is to provide a permanent magnet type rotary electric machine that can obtain good characteristics even when driven by 120-degree and 180-degree energizing inverters. Another object of the present invention is 12
It is an object of the present invention to provide a compressor that can obtain good characteristics even if it is driven by a 0-degree and 180-degree energizing inverter, and an air conditioner using the same.

[0005]

The above object is to provide a stator having armature windings formed in a plurality of slots formed in a stator core and a plurality of permanent magnet insertion holes formed in a rotor core. In a permanent magnet type rotating electric machine having a rotor in which a permanent magnet is housed, the permanent magnet is formed into a substantially arcuate convex shape with respect to the outer peripheral surface of the rotor core, and the gap between the outer peripheral surface of the rotor core is This is achieved by forming a recess in the.

Another object of the present invention is to provide a compressor and an air conditioner using the same, a stator having armature windings provided in a plurality of slots formed in the stator core, and a rotor core. And a rotor in which permanent magnets are housed in a plurality of permanent magnet insertion holes formed in the permanent magnet, the permanent magnet having a substantially arcuate convex shape with respect to the outer peripheral surface of the rotor core, and This is achieved by using a permanent magnet type rotating electric machine having a concave portion between the poles of the outer peripheral surface as a drive source.

The above and other features of the present invention will be further explained by the following description.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the permanent magnet type rotating electric machine of the present invention, the permanent magnet is formed into a substantially arcuate convex shape with respect to the outer peripheral surface of the rotor core, and a concave portion is provided between the outer peripheral surface of the rotor core. When formed, the induced voltage has a substantially sinusoidal shape. As a result, when driven by a position sensorless 180-degree conduction inverter, a harmonic current does not flow, the magnet torque can be effectively used, and the characteristics can be improved. Further, when driven by a position sensorless 120-degree energizing inverter, the current waveform in the 120-degree energizing section becomes somewhat ridged, but a significant increase in harmonic current does not occur and good characteristics can be obtained.
Here, in the present invention, since the recess is formed between the poles on the outer peripheral surface of the rotor iron core, reluctance torque cannot be used, but when the iron core is provided between the poles, a large amount of armature reaction magnetic flux flows, and the reluctance torque is increased. It has been experimentally confirmed that the increase in iron loss due to armature reaction leads to deterioration in characteristics. Therefore, according to the present invention, it is possible to provide a permanent magnet type rotating electric machine that can obtain good characteristics even when driven by 120-degree and 180-degree energizing inverters. Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows a radial cross-sectional shape of a permanent magnet type rotary electric machine according to an embodiment of the present invention. In FIG. 1, a permanent magnet type rotary electric machine 1 has an armature winding 7 (U-phase winding 7A, V-phase winding 7B, W) in a plurality of slots 6 formed with teeth 4 of a stator core 3 and a core back 5. The stator 2 is configured by winding the concentrated winding of the phase winding 7C. The teeth inner peripheral surface 9 of the stator core 3 has a linear shape orthogonal to the line XO extending from the axis of the rotor 8 to the center of the teeth 4.

FIG. 2 is an enlarged view of the rotor shown in FIG. 1, showing a radial cross-sectional shape of the rotor according to an embodiment of the present invention.
In FIG. 2, the rotor 8 has an arc-shaped permanent magnet 12 (shown here by four poles) and a shaft (not shown) which are arranged in an arc-shaped permanent magnet insertion hole 11 provided in the rotor core 10. The shaft fitting hole 13 for fitting to (No.).
In addition, a rivet hole 14 for fixing the rotor core 10
In addition, a recess 15 is formed between the arc-shaped permanent magnets 12. Although the concave portion is shown here as an arc, it may have another shape such as a small step-like shape as long as it has a concave shape as a whole (for example, a step-like shape having a width sufficiently smaller than the depth of the concave portion).

FIG. 3 shows an induced voltage waveform of the permanent magnet type rotary electric machine according to one embodiment of the present invention. The horizontal axis indicates time, and the vertical axis indicates induced voltage (induced voltage scale is 50 V /
div). It has been confirmed that the permanent magnet type rotary electric machine according to the embodiment of the present invention can obtain a substantially perfect sinusoidal waveform of the induced voltage.

FIG. 4 shows a radial cross-sectional shape of a permanent magnet type rotary electric machine according to another embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. 4 differs from FIG. 1 in that the teeth inner peripheral surface 9 of the stator core 3 is different.
An arcuate inner peripheral surface 16 concentric with the axial center of the rotor 8 is provided in a part of the above. When the permanent magnet type rotating electric machine 1 is used as a compressor driving electric motor of an air conditioner, since the center of the gap is formed between the outer peripheral surface of the rotor 8 and the inner peripheral surface of the stator 2, the compression is performed. As the electric motor for driving the machine, the gap length between the stator 2 and the rotor 8 can be made uniform, and noise and performance variations of the compressor can be minimized.

FIG. 5 shows a radial cross-sectional shape of a permanent magnet type rotary electric machine according to still another embodiment of the present invention. The same parts as those in FIG. 5 is different from FIG. 1 in that the teeth inner peripheral surface 9 of the stator core 3 is different.
Is provided with an arcuate inner peripheral surface 17 concentric with the axial center of the rotor 8. When the permanent magnet type rotating electric machine 1 is used as a compressor driving electric motor of an air conditioner, since the center of the gap is formed between the outer peripheral surface of the rotor 8 and the inner peripheral surface of the stator 2, the compression is performed. As the electric motor for driving the machine, the gap length between the stator 2 and the rotor 8 can be made uniform, and noise and performance variations of the compressor can be minimized.

FIG. 6 shows an induced voltage waveform of a permanent magnet type rotary electric machine according to another embodiment of the present invention. Take time on the horizontal axis,
The vertical axis shows the induced voltage. From this, it was confirmed that in the permanent magnet type rotary electric machine according to another embodiment of the present invention, the induced voltage is slightly deviated from the sine wave, but a substantially sine wave shape can be obtained. Corresponding to a machine to which the permanent magnet type rotary electric machine 1 is applied, experimentally the extent of the arcuate inner peripheral surface 16 which is concentric with the axial center of the rotor 8 provided on a part of the inner peripheral surface of the stator 2 is experimentally determined. Just decide.

FIG. 7 is a diagram showing an example of an inverter drive system according to the present invention. 70 is an inverter, 71
Is a single-phase AC power supply, 72 is a rectifying and smoothing circuit, 73 is a PAM circuit, 74 is a smoothing capacitor, 75 is a switching circuit,
76 is a driver for the switching circuit 75, 77 is a PAM
A driver for the circuit 73, 78 is a microcomputer, 7
Reference numeral 9 denotes a sensorless position detection unit (for example, configured by software on a microcomputer), 62 is a compressor, in which the permanent magnet type rotating electric machine 1 of one embodiment of the present invention or another embodiment is hermetically sealed. Has been done. The symbol S is a command signal.

In FIG. 7, a microcomputer 78
When a command signal S, which is an operation signal, is input to the permanent magnet type rotary electric machine 1, current is supplied to the permanent magnet type rotary electric machine 1 to operate at a desired rotation speed. Here, the difference between 180-degree and 120-degree energization is the difference between whether the voltage supplied from the switching circuit 75 is a rectangular wave voltage in the 120-degree energization section or a sine wave voltage is applied in the 180-degree energization section. The harmonics of the current flowing through the permanent magnet type rotary electric machine 1 depend on the induced voltage waveform. However, it is necessary to detect the position of the permanent magnet when driving the permanent magnet type rotating electrical machine 1, but it can be determined by detecting the induced voltage during the rest period of 60 degrees for 120 degree energization, and for energization for 180 degree energization. Since there is no pause period, the sensorless position detection unit 7 having a software configuration is used for the determination by using the voltage vector from the voltage equation of the permanent magnet type rotary electric machine 1.
It is 9.

As a result, when the permanent magnet type rotary electric machine 1 is driven by the 180-degree conduction inverter, since the induced voltage is a sine wave with respect to the sine wave voltage, the harmonic current is suppressed and the harmonic iron loss is suppressed. The characteristics can be improved because of the decrease in the torque, and the torque ripple at the time of commutation can be decreased, so that the noise can be reduced. On the other hand, when the permanent magnet type rotary electric machine 1 is driven by the 120-degree conduction inverter, since the induced voltage is a sine wave with respect to the rectangular wave voltage, the harmonic current slightly increases, but there is a recess between the poles. Since 15 is provided to reduce the armature reaction magnetic flux, the harmonic iron loss is reduced and the characteristics can be improved.

FIG. 8 shows a radial cross-sectional shape of a rotor according to still another embodiment of the present invention. In the figure, the same parts as those in FIG. The difference from FIG. 2 is that a rivet hole 14 provided in the rotor core 10 is provided.
The rotor 8 is provided with an inter-electrode rivet hole 18 connecting the recess 15 and the recess 15. As a result, the armature reaction magnetic flux and the leakage magnetic flux between the permanent magnets can be reduced, and it goes without saying that the same effects as those of the other embodiments of the present invention can be obtained.

FIG. 9 is a diagram for explaining the refrigeration cycle of the air conditioner according to the embodiment of the present invention. 60 is an outdoor unit,
Reference numeral 61 is an indoor unit, and 62 is a compressor. Inside the compressor 62, the permanent magnet type rotating electrical machine 1 and the compression unit 63 are enclosed.
64 is a condenser, 65 is an expansion valve, and 66 is an evaporator. The refrigeration cycle circulates the refrigerant in the direction of the arrow,
Compresses the refrigerant to perform heat exchange between the outdoor unit 60 including the condenser 64 and the expansion valve 65 and the indoor unit 61 including the evaporator 66, thereby exerting a cooling function. When the permanent magnet type rotating electric machine 1 shown in the embodiment of the present invention is used in a compressor such as an air conditioner, a refrigerator and a freezer, the output of the permanent magnet type rotating electric machine 1 is improved by about 10%, so that the input can be reduced. It has the effect of reducing CO ₂ emissions that lead to global warming.

In the above description, the case where concentrated winding is used for the armature winding has been described, but it goes without saying that it may be applied to conventional distributed winding. Although the PAM inverter is used as the inverter in the above description, it goes without saying that there is no problem even if a PWM inverter of another method is used because the voltage applied to the permanent magnet type rotating electrical machine 1 is a rectangular wave or a sine wave.

As described in detail above, according to the embodiment of the present invention, the permanent magnet is formed in a substantially arcuate convex shape with respect to the outer peripheral surface of the rotor core, and the permanent magnet is provided between the outer peripheral surface of the rotor core. By forming the concave portion, the induced voltage can have a substantially sinusoidal shape. As a result, when driven by the position sensorless 180-degree conduction inverter, the harmonic current is reduced, the magnet torque can be effectively used, and the characteristics can be improved. Further, when driven by a position sensorless 120-degree energizing inverter, the current waveform in the 120-degree energizing section becomes somewhat ridged, but a significant increase in harmonic current does not occur and good characteristics can be obtained. Therefore, according to the present invention, it is possible to provide a permanent magnet type rotating electric machine that can obtain good characteristics even when driven by 120-degree and 180-degree energizing inverters.

[0022]

According to the present invention, the position sensorless 12
It is possible to provide a permanent magnet type rotating electric machine that can obtain good characteristics even when driven by a 0-degree and 180-degree conduction inverter. Also,
ADVANTAGE OF THE INVENTION According to this invention, the compressor and the air conditioner using the same which can obtain a favorable characteristic can be provided, even if it drives with a 120-degree and 180-degree electricity supply inverter.

[Brief description of drawings]

FIG. 1 is a diagram showing a radial cross-sectional shape of a permanent magnet type rotary electric machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a radial cross-sectional shape of a rotor according to an embodiment of the present invention.

FIG. 3 is a diagram showing an induced voltage waveform according to an embodiment of the present invention.

FIG. 4 is a view showing a radial cross-sectional shape of a permanent magnet type rotary electric machine according to another embodiment of the present invention.

FIG. 5 is a radial cross-sectional view of a permanent magnet type rotary electric machine according to still another embodiment of the present invention.

6 is a diagram showing an induced voltage waveform of the rotor according to the embodiment of FIG.

FIG. 7 is a diagram showing an example of an inverter drive system according to the present invention.

FIG. 8 is a radial cross-sectional view of a rotor according to yet another embodiment of the present invention.

FIG. 9 is a diagram showing an example of a refrigeration cycle of an air conditioner according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Permanent magnet type rotating electric machine, 2 ... Stator, 3 ... Stator core, 4 ... Teeth, 5 ... Core back, 6 ... Slot, 7
... Armature winding, 8 ... Rotor, 9 ... Teeth inner peripheral surface, 10
... rotor core, 11 ... permanent magnet insertion hole, 12 ... permanent magnet, 13 ... shaft fitting hole, 14 ... rivet hole, 15 ...
Recesses, 16, 17 ... Arc-shaped inner circumferential surface, 18 ... Inter-electrode rivet hole, 60 ... Outdoor unit, 61 ... Indoor unit, 62 ... Compressor, 63
... compression part, 64 ... condenser, 65 ... expansion valve, 66 ... evaporator, 70 ... inverter, 71 ... single-phase AC power supply, 72 ... rectifying / smoothing circuit, 73 ... PAM circuit, 74 ... smoothing capacitor, 75 ... switching circuit , 76 ... Driver for switching circuit 75, 77 ... Driver for PAM circuit 73, 7
8 ... Microcomputer, 79 ... Sensorless position detector, S ... Command signal.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryoichi Takahata             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Shoji Senoo             Chiba Prefecture Narashino City Higashi Narashino 7-1-1             Hitachi, Ltd. Hitachi Drive System             Within (72) Inventor Keiji Noma             Chiba Prefecture Narashino City Higashi Narashino 7-1-1             Hitachi, Ltd. Hitachi Drive System             Within (72) Inventor Satoshi Kikuchi             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Mamoru Kimura             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Mika Yoshitaka             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Hiroshi Hirayama             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi Co., Ltd., Cooling & Heat Division (72) Inventor Koji Seshita             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi Co., Ltd., Cooling & Heat Division F-term (reference) 5H002 AA09 AE07 AE08                 5H622 AA03 CA02 CA07 CB03 CB04

Claims (13)

[Claims] 1. A stator having armature windings formed in a plurality of slots formed in a stator core, and permanent magnets housed in a plurality of permanent magnet insertion holes formed in a rotor core. In a permanent magnet type rotating electric machine having a rotor, the permanent magnet is formed into a convex shape of a substantially arc with respect to an outer peripheral surface of the rotor core, and a concave portion is formed between poles on the outer peripheral surface of the rotor core. A permanent magnet type rotating electrical machine characterized by the above. 2. A stator having concentrated armature windings surrounding a plurality of teeth formed on a stator core and a plurality of permanent magnet insertion holes formed on the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a magnet is housed, the permanent magnet is formed into a substantially arcuate convex shape with respect to an outer peripheral surface of the rotor core, and a gap between outer peripheral surfaces of the rotor core is formed. A permanent magnet type rotating electric machine characterized in that a concave portion is formed in the. 3. A stator having concentrated armature windings surrounding a plurality of teeth formed on a stator core and a plurality of permanent magnet insertion holes formed on the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a magnet is housed, an inner peripheral surface of the teeth of the stator core is formed in a straight line shape orthogonal to a line extending from the shaft of the rotor to the center of the teeth. A permanent magnet type rotating electric machine characterized in that the permanent magnet is formed into a convex shape of a substantially arc with respect to an outer peripheral surface of the rotor core, and a concave portion is formed between poles of the outer peripheral surface of the rotor core. 4. A stator having concentrated armature windings surrounding a plurality of teeth formed on a stator core and a plurality of permanent magnet insertion holes formed on the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a magnet is housed, a straight line shape and a straight line which are orthogonal to a line extending from the shaft of the rotor to the center of the teeth on the inner peripheral surface of the teeth of the stator core. And an arc shape from the axis of the child, the permanent magnet is formed into a convex shape of a substantially arc with respect to the outer peripheral surface of the rotor core, and a recess is formed between the poles of the outer peripheral surface of the rotor core. A permanent magnet type rotating electrical machine characterized by the above. 5. A stator having concentrated armature windings surrounding a plurality of teeth formed on the stator core and a plurality of permanent magnet insertion holes formed on the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a magnet is housed, an inner peripheral surface of the teeth of the stator core is formed in an arc shape from an axis of the rotor core, and the permanent magnet is the rotor. A permanent magnet type rotating electric machine characterized by having a convex shape with respect to the outer peripheral surface of an iron core, and forming a recess between the poles of the outer peripheral surface of the rotor iron core. 6. A permanent magnet type rotary electric machine according to claim 1, wherein rivet holes are formed between the poles of the rotor core. 7. The permanent magnet according to claim 6, wherein rivet holes are formed between the poles of the rotor core, and the rivet holes are arranged between the poles on the outer peripheral surface of the rotor core. Rotary electric machine. 8. A compressor using the permanent magnet type rotating electric machine according to claim 1 as a drive source. 9. A compressor according to claim 8, further comprising a 180-degree conduction inverter for driving a permanent magnet type rotary electric machine. 10. The compressor according to claim 8, further comprising a 120-degree conduction inverter for driving the permanent magnet type rotating electric machine. 11. A permanent magnet type rotary electric machine comprising a stator core having an armature winding and a rotor core having a plurality of permanent magnets, wherein the permanent magnet is provided on an outer peripheral surface of the rotor core. On the other hand, a permanent magnet type rotating electric machine having a substantially arcuate convex shape and having concave portions between the outer peripheral surfaces of the rotor core. 12. A compressor using the permanent magnet type rotary electric machine according to claim 11 as a drive source. 13. An air conditioner having the compressor according to claim 12.