JP2008263721A - Motor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the anti-noise performance of a resolver mounted to a rotating electric machine, and to enhance the accuracy of the position detection of a rotor. <P>SOLUTION: The winding distribution of a coil winding 170 of a resolver stator 160 is not uniform in a motor circumferential direction. Owing to this arrangement, the contour of a coil end 135 is formed so that a distance d2 between the coil end 135 and the resolver stator 160 in a region where the number of winding times of the coil winding is large becomes longer than a distance d1 between the coil end and the resolver stator in a region where the number of winding times of the coil winding is small (d1<d2). More concretely, a contour dimension (height) of the coil end 135 in the radial direction is made relatively small in an area which opposes the region where the number of winding times of the coil winding is large. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor system, and more particularly to a motor system including a resolver for detecting a rotor position of a rotating electrical machine.

  In order to control the driving of a rotating electrical machine such as an electric motor or a generator, a sensor for detecting the position of the rotor in the rotational direction is generally installed. In order to appropriately control the rotating electrical machine, it is necessary to accurately detect the rotational position by the position detection sensor, and thus reducing the noise influence on the sensor is an important issue.

  As the rotor position detection sensor, a Hall sensor using a Hall element, a resolver, or the like is used. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-78393), in a rotating machine equipped with a resolver, the resolver is disposed outside the housing case of the rotating machine, thereby being affected by electromagnetic noise generated by the rotating machine. A configuration that makes it difficult and facilitates the assembly work is disclosed.

In Patent Document 2 (Japanese Patent Laid-Open No. 2006-25537), in a brushless motor provided with a Hall element as a position detection sensor, electromagnetic noise is obtained by disposing the Hall element away from the magnetized portion of the speed detection means. There is disclosed a drive / control circuit-integrated brushless motor in which the influence of noise is reduced and detection accuracy is improved.
JP 2001-78393 A JP 2006-25537 A

  A resolver is generally applied from the viewpoint of noise resistance as a rotor position detection sensor in a rotating machine with a relatively large capacity and high output, such as a driving force generation motor of a hybrid vehicle. On the other hand, in such a large-capacity, high-output motor, the power supplied to the rotating electrical machine is large, so that electromagnetic noise due to this is large.

  The resolver includes a rotor configured to rotate in the same phase as the rotor of the rotating electrical machine (hereinafter referred to as a resolver rotor) and a stator around which coil windings are wound (hereinafter referred to as a resolver stator). However, in order to improve the detection accuracy, the number of turns of the coil winding of the resolver stator may not be uniform, and there may be a non-uniform number of turns when viewed in the circumferential direction. When such a resolver is used, there are places where it is easy to pick up electromagnetic noise from the rotating electrical machine and places where it is difficult to pick up when viewed in the circumferential direction, and it is necessary to take measures against the noise of the resolver in consideration of this point. .

  The present invention has been made to solve such problems, and an object of the present invention is to increase the noise detection resistance of a resolver provided in a rotating electrical machine and improve the position detection accuracy of a rotor. is there.

  A motor system according to the present invention includes a rotating electrical machine and a resolver that detects a position in a rotational direction of a rotor of the rotating electrical machine. The rotating electrical machine includes a stator around which an exciting coil winding is wound, and a rotor that is arranged to face the stator in the radial direction. The resolver is provided in a region facing the coil end of the exciting coil winding in the radial direction, and has a resolver rotor and a resolver stator. The resolver rotor is attached to the rotating shaft of the rotating electrical machine so as to rotate in the same phase as the rotor. The resolver stator is provided so as to face the resolver rotor in the radial direction, and is disposed adjacent to the coil end in the radial direction. The resolver stator is wound with a non-uniform winding distribution when viewed in the circumferential direction, and the coil end is a portion where the number of windings of the resolver stator coil winding is relatively large when viewed in the circumferential direction. Is formed in an outer shape such that the distance from the coil winding is relatively large.

  According to the motor system of the present invention, it is possible to ensure a relatively large separation distance from the coil end serving as a noise generation source at a portion where the number of coil turns is relatively large in the resolver stator and noise is easily picked up. Therefore, it is possible to suppress the electromagnetic noise from the exciting coil winding of the rotating electrical machine from adversely affecting the position detection by the resolver and improve the position detection accuracy of the rotor.

  Preferably, the outer shape of the coil end on the surface facing the coil winding of the resolver has a relatively small radial dimension in a region facing a portion where the number of turns of the coil winding is relatively large. The dimension in the radial direction is relatively large in a region facing a portion having a relatively small number of turns.

  By adopting such a configuration, the radial dimension of the coil end is formed in the circumferential direction in the coil end forming step, so that the resolver stator can be compared with the resolver stator in a region where the number of coil windings of the resolver stator is relatively large. The coil end distance can be secured.

  According to the motor system of the present invention, it is possible to improve the noise resistance of the resolver provided in the rotating electrical machine and increase the rotational position detection accuracy of the rotor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and detailed description will not be repeated in principle.

FIG. 1 is a cross-sectional view illustrating the configuration of a motor system according to an embodiment of the present invention.
Referring to FIG. 1, the motor system according to the embodiment of the present invention includes rotating electric machine 100, output shaft 140, and resolver 150. The rotating electrical machine 100 can be configured by an arbitrary type of electric motor, generator, or generator motor (motor generator), but in the present embodiment, it is configured by a permanent magnet type synchronous motor as an example. The rotating electrical machine 100 includes a rotor 120 and a stator 130.

  The rotor 120 is configured by providing a through hole in a rotor core made of laminated steel plates, and attaching a permanent magnet 125 to the through hole. Stator 130 includes a stator core made of laminated steel plates and exciting coil windings wound around the stator core. The exciting coil winding is pressure-molded to form a coil end 135 at both ends of the stator core along the motor rotation axis direction.

  The exciting coil winding is applied with an AC voltage (typically a three-phase AC voltage) from an inverter (not shown) to generate a rotating magnetic field. The rotor 120 is rotated by the rotating magnetic field, whereby the output shaft 140 connected to the rotor 120 is rotated. Further, when the rotating electrical machine 100 generates power, a magnetic field is generated by the rotation of the rotor 120, and a current is generated in the exciting coil winding.

The resolver 150 includes a resolver stator 160 and a resolver rotor 180.
FIG. 2 is a conceptual diagram for explaining the principle of detecting the position of the resolver.

  Referring to FIG. 2, resolver rotor 180 has an elliptical shape and is attached to output shaft 140 shown in FIG. Therefore, the resolver rotor 180 is configured to rotate in the same phase as the rotor 120 rotates.

  The resolver stator 160 includes coil windings 170a to 170c. An exciting alternating current 175a is applied to the coil winding 170a. Coil windings 170b and 170c are arranged with an electrical shift of 90 degrees. When the elliptical resolver rotor 180 rotates while the exciting AC current 175a is applied to the coil winding 170a, the coil winding 170b changes as the gap length between the resolver rotor 180 and the resolver stator 160 changes. And 170c generate output signals 175b and 175c corresponding to the position of the resolver rotor 180, respectively. Therefore, based on the phase difference between the output signals 175b and 175c, the absolute position in the rotational direction of the resolver rotor 180, that is, the absolute position in the rotational direction of the rotor 120 of the rotating electrical machine 100 can be detected.

  Referring to FIG. 1 again, in the motor system according to the embodiment of the present invention, in order to obtain a compact resolver arrangement, resolver 150 is arranged in an area on the inner peripheral side of rotor 120, that is, in a radial direction with coil end 135. Arranged in adjacent areas. As a result, electromagnetic noise generated when the exciting coil winding of the rotating electrical machine 100 is energized reaches the coil winding of the resolver stator 160 through the gap 200 between the coil end 135 and the resolver 150 (particularly the resolver stator 160). May be superimposed on the output signal of the resolver.

  On the other hand, the number of turns of the coil winding in the resolver stator 160 does not have a uniform distribution as viewed in the circumferential direction, but a non-uniform distribution. This is a measure for improving the rotational position detection accuracy by the resolver 150. Therefore, there is a problem of how to take measures against noise in response to the non-uniform distribution of the number of turns of the coil winding 170 in the resolver stator 160 in the circumferential direction.

  Next, the gap distribution in the circumferential direction between the coil end and the resolver stator in the motor system according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a development of the gap 200 shown in FIG. 1 in the circumferential direction.

  Referring to FIG. 3, the winding number distribution of coil winding 170 of resolver stator 160 is non-uniform in the motor circumferential direction. In the example of FIG. 3, it is assumed that the number of turns is large at both ends of the circumferential development and the number of turns is small at the center. As a result, electromagnetic noise from the coil end can be easily picked up at a part having a large number of turns.

  Corresponding to the coil turn distribution of the resolver stator, the outer shape of the coil end 135 is such that the separation distance d2 between the coil end 135 and the resolver stator 160 in the region where the coil turns are large is the separation distance d1 in the region where the coil turns are small. (D1 <d2). Specifically, the outer dimension (height) in the radial direction of the coil end 135 is relatively small in a portion facing a region having a large number of coil turns. The outer shape of the coil end 135 can be created according to the working conditions (the magnitude of the load and the load application site) in the process of forming the exciting coil winding by applying the load.

  As a result, as shown in FIG. 4, the separation distance between the coil end 135 and the resolver coil winding 170 can be increased in a portion where the number of turns of the coil winding 170 of the resolver stator is large and electromagnetic noise is easily superimposed. .

  FIG. 5 shows a gap distribution in the circumferential direction between the coil end and the resolver stator in the motor system shown as the comparative example. FIG. 5 shows the same part as FIG. 3 developed in the circumferential direction.

  As can be seen by comparing FIG. 5 with FIG. 3, in the motor system of the comparative example, the winding number distribution of the coil winding 170 of the resolver is the same as that of FIG. The outer dimension (height) of FIG. 3 has a distribution opposite to that in FIG.

  That is, the separation distance d2 between the coil end 135 and the resolver stator 160 in the region with the large number of coil turns is smaller than the separation distance d1 in the region with the small number of coil turns (d1> d2). Specifically, the outer dimension (height) in the radial direction of the coil end 135 is relatively large at a portion facing a region where the number of turns of the coil winding is large.

  As shown in FIG. 6, in such a gap distribution, the separation distance from the coil end 135 is small at a portion where the number of turns of the coil winding 170 of the resolver stator where electromagnetic noise is likely to be superimposed. As a result, the electromagnetic noise generated in the coil winding at the part tends to affect the resolver 150.

  On the other hand, in the motor system according to the embodiment of the present invention shown in FIG. 3 and FIG. 4, the outer dimensions (radial direction) of the coil end corresponding to the winding number distribution (circumferential direction) of the coil winding of the resolver. By adjusting the above, it is possible to ensure a relatively large separation distance (gap) between the coil end 135 and the resolver stator 160 in a region where the number of coil turns of the resolver is large and electromagnetic noise is easily superimposed. Thereby, it can prevent that the electromagnetic noise which generate | occur | produced in the exciting coil winding of a rotary electric machine has a bad influence on the detection precision of the rotor rotational position by a resolver. As a result, it is possible to realize a motor system in which the noise resistance of the resolver provided in the rotating electrical machine is increased and the rotational position detection accuracy of the rotor is increased.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing explaining the structure of the motor system by embodiment of this invention. It is a conceptual diagram explaining the position detection principle of the resolver shown in FIG. It is a conceptual diagram explaining the gap between the coil end and resolver stator in the motor system by embodiment of this invention. It is a conceptual diagram explaining the circumferential direction distribution of the noise influence in the motor system shown in FIG. It is a conceptual diagram explaining the gap between the coil end and resolver stator in the motor system shown as a comparative example. It is a conceptual diagram explaining the circumferential direction distribution of the noise influence in the motor system shown in FIG.

Explanation of symbols

  100 rotating electric machine, 120 rotor, 125 permanent magnet, 130 stator, 135 coil end, 140 output shaft, 150 resolver, 160 resolver stator, 170, 170a to 170c coil winding (resolver), 175a AC current for excitation, 175b, 175c Output signal, 180 resolver rotor, 200 gap, d1, d2 separation distance.

Claims (2)

A rotating electrical machine having a stator around which an exciting coil winding is wound, and a rotor arranged to face the stator in a radial direction;
A resolver for detecting a position in a rotational direction of the rotor, provided in a region facing the radial direction with respect to a coil end of the exciting coil winding;
The resolver is
A resolver rotor attached to a rotating shaft of the rotating electrical machine so as to rotate in phase with the rotor;
A resolver stator provided opposite to the resolver rotor in the radial direction and disposed adjacent to the coil end in the radial direction;
In the resolver stator, the coil winding is wound with a non-uniform winding number distribution in the circumferential direction,
The coil end has an outer shape such that a separation distance from the coil winding is relatively large in a region facing a portion where the number of turns of the coil winding of the resolver stator is relatively large when viewed in the circumferential direction. A motor system composed of shapes.   The outer shape of the coil end on the surface facing the coil winding has a relatively small radial dimension in a region facing a portion where the number of turns of the coil winding is relatively large. The motor system according to claim 1, wherein the radial dimension is relatively large in a region facing a portion having a relatively small number of turns.

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