Eccentricity estimation system

Abstract

To detect the eccentricity of a rotating electrical machine without increasing its size or cost. [Solution] An eccentricity estimation system for a rotating electric machine, to which a resolver 4 is attached, having a ring-shaped stator 12 having multiple magnetic poles 13 at predetermined angles, excitation coils 14 and two output coils, a first induction coil 15 and a second induction coil 16, arranged on each of the multiple magnetic poles 13, and a rotor 11 arranged opposite to the inside of the stator 12, wherein an induced voltage V is provided in one of the first induction coil 15 or the second induction coil 16 in one or more magnetic poles 13. +Y A lead wire 17 capable of measuring the voltage V, and the induced voltage V measured by the lead wire 17. +Y This allows us to estimate the eccentricity of the rotor 11 relative to the stator 12.

Description

[Technical Field]

[0001] This disclosure relates to an eccentricity estimation system for rotating electric machines. [Background technology]

[0002] Patent Document 1 below discloses a technique for detecting the position of a measuring gear provided on a rotating body using a position detection sensor, and detecting the presence or absence of eccentricity based on the time difference with the detection signal of an initial state without eccentricity. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-253375 [Overview of the project] [Problems that the invention aims to solve]

[0004] In Patent Document 1, a measuring gear and a position detection sensor are added specifically for eccentricity measurement, which results in an increase in size to secure mounting space and an increase in cost due to the addition of parts.

[0005] This disclosure aims to detect the eccentricity of a rotating electric machine without increasing its size or cost. [Means for solving the problem]

[0006] This disclosure relates to an eccentricity estimation system for a rotating electric machine to which a resolver is attached, the resolver having a ring-shaped stator having a plurality of magnetic poles at predetermined angles, excitation coils and two output coil systems arranged on each of the plurality of magnetic poles, and a rotor arranged opposite to the inside of the stator, the system comprising: a lead wire provided on any one of the output coil systems and capable of measuring the induced voltage at one or more magnetic poles; and an eccentricity estimation unit that estimates the eccentric state of the rotor relative to the stator based on the induced voltage measured by the lead wire. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to detect the eccentricity state of a rotating electrical machine without increasing the physical size or cost.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a block diagram showing the overall configuration of an eccentricity estimation system according to the present embodiment. [Figure 2] FIG. 2 is a diagram for explaining the configuration of the resolver shown in FIG. 1. [Figure 3] FIG. 3 is a diagram for explaining the relationship between the eccentricity amount and the induced voltage in the resolver shown in FIG. 2. [Figure 4] FIG. 4 is a diagram for explaining another example of the resolver shown in FIG. 2. [Figure 5] FIG. 5 is a diagram for explaining the relationship between the eccentricity amount and the induced voltage in the resolver shown in FIG. 4. [Figure 6] FIG. 6 is a diagram for explaining another example of the resolver shown in FIG. 2. [Figure 7] FIG. 7 is a diagram for explaining the relationship between the eccentricity amount and the induced voltage in the resolver shown in FIG. 6. [Figure 8] FIG. 8 is a diagram for explaining the relationship between the eccentricity amount and the induced voltage in the resolver shown in FIG. 6. [Figure 9] FIG. 9 is a diagram for explaining another example of the resolver shown in FIG. 2. [Figure 10] FIG. 10 is a diagram for explaining another example of the resolver shown in FIG. 2. [Figure 11] FIG. 11 is a diagram for explaining another example of the resolver shown in FIG. 2. [Figure 12] FIG. 12 is a diagram for explaining the output voltage waveform with respect to the rotation angle of the resolver rotor. [Figure 13] FIG. 13 is a diagram for explaining the sampling period of the output voltage.

Mode for Carrying Out the Invention

[0009] This embodiment will now be described with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0010] The eccentricity estimation system 2 according to this embodiment will be described with reference to Figure 1. The eccentricity estimation system 2 comprises a rotating electric machine 3, a resolver 4, an excitation voltage generation unit 5, and an eccentricity estimation unit 6. The rotating electric machine 3 generates rotational driving force upon receiving power, and has a stator and a rotor. The rotating electric machine 3 is mounted on, for example, an automobile and generates the driving force of the automobile.

[0011] The resolver 4 is a device for detecting the rotation angle of the rotating electric machine 3, and is a resolver attached to the rotor (not shown) of the rotating electric machine 3. The resolver 4 will be described in detail later. The excitation voltage generation unit 5 is the part that applies an excitation voltage to the excitation coil (not shown in Figure 1) of the resolver 4. The excitation voltage generation unit 5 may be provided, for example, in the resolver IC provided in the resolver 4.

[0012] The eccentricity estimation unit 6 uses the induced voltage V output from the resolver 4. +Y This section estimates the eccentricity of the rotor of the rotating electric machine 3 based on the above. The method for estimating the eccentricity by the eccentricity estimation unit 6 will be described in detail later.

[0013] Next, the resolver 4 will be described with reference to Figure 2. The resolver 4 comprises a rotor 11 and a stator 12. The rotor 11 is connected to the rotor of the rotating electric machine 3 and is configured to rotate together with the rotor. The stator 12 is ring-shaped, with the rotor 11 positioned opposite it on its inner circumference. The stator 12 is fixed to the housing (not shown) of the rotating electric machine 3.

[0014] The stator 12 is provided with multiple magnetic poles 13 that are spaced apart in the circumferential direction and protrude inward. These magnetic poles 13 are also called teeth. A winding is wound around each magnetic pole 13, forming an excitation coil 14 and a first induction coil 15 and a second induction coil 16, which serve as two separate output coils.

[0015] When an AC voltage is applied to the excitation coil 14, the magnetic pole 13 is excited. When the magnetic pole 13 is excited, an induced voltage V is generated in the first induction coil 15 and the second induction coil 16. +Y This occurs. In the first induction coil 15 and the second induction coil 16, due to the rotation of the rotor 11 around the rotation axis C, an induced voltage V is generated that corresponds to the changing air gap length between the magnetic pole 13 and the rotor 11. +Y The following will be output.

[0016] The rotor 11 is, for example, a plate-shaped member and is made of the same soft magnetic material as the stator 12. A rotating shaft (not shown) connected to the rotor of a rotating electric machine may be fitted into the rotor 11 so as to be coaxial with the rotation axis C of the rotor 11.

[0017] The rotor 11 is rotatably positioned inside the stator 12, with a gap between it and the tip surfaces of the magnetic poles 13 of the stator 12. The rotor 11 is formed such that the length of the air gap between it and the magnetic poles 13 changes as it rotates around its axis of rotation C. Specifically, the rotor 11 has an elliptical outer shape.

[0018] Induced voltage V at each magnetic pole 13 +Y The magnitude of the induced voltage V changes depending on the air gap length with the opposing rotor 11. If the angle of the rotor 11 is the same, the air gap length corresponds to the eccentricity of the rotor 11, so the induced voltage V +Y The eccentricity of the rotor 11 can be estimated from its size. Since the rotor 11 is fixed coaxially with the rotor of the rotating electric machine 3, if the eccentricity of the rotor 11 can be estimated, the eccentricity of the rotor of the rotating electric machine 3 can be estimated.

[0019] Induced voltage V at magnetic pole 13 +YIt can be measured by providing a lead wire to the magnetic pole 13 to be measured. In the example shown in FIG. 2, a lead wire 17 is provided to the first induction coil 15 provided to one magnetic pole 13 to be measured. Incidentally, a lead wire 17 may be provided to the second induction coil 16.

[0020] FIG. 3 shows an example of the amount of eccentricity and the induced voltage V at the angle where the lead wire 17 is provided. +Y State (a) is a state in which the salient pole of the rotor 11 approaches the side where the lead wire 17 is provided, and the rotation axis C of the rotor 11 is eccentric with an eccentricity of "da". State (b) is a state in which the salient pole of the rotor 11 approaches the side opposite to the side where the lead wire 17 is provided, and the rotation axis C of the rotor 11 is eccentric with an eccentricity of "db". The eccentricity estimation unit 6 estimates the eccentricity of the rotor 11 and the eccentricity of the rotor of the rotating electrical machine 3 based on the relationship between the eccentricity and the induced voltage V as illustrated in FIG. 3. +Y

[0021] In the resolver 4 illustrated in FIG. 2, one lead wire 17 is provided, but by increasing the number of magnetic poles provided with the lead wire, the eccentricity state including the direction can be grasped in detail. In the resolver 4A shown in FIG. 4, in addition to the lead wire 17, a lead wire 18 is provided. The lead wire 18 is provided so as to be able to measure the induced voltage V generated in the two first induction coils 15 provided in two magnetic poles 13 different from the magnetic pole 13 where the lead wire 17 is provided. +X

[0022] FIG. 5 shows an example of the amount of eccentricity and the induced voltage V at the angle where the lead wire 18 is provided. +X State (c) is a state in which the salient pole of the rotor 11 approaches the side where the lead wire 18 is provided, and the rotation axis C of the rotor 11 is eccentric with an eccentricity of "dc". State (d) is a state in which the salient pole of the rotor 11 approaches the side opposite to the side where the lead wire 18 is provided, and the rotation axis C of the rotor 11 is eccentric with an eccentricity of "dd". The eccentricity estimation unit 6 estimates the eccentricity of the rotor 11 and the eccentricity of the rotor of the rotating electrical machine 3 based on the relationship between the eccentricity and the induced voltage V as illustrated in FIG. 5. +X

[0023] ​​​The resolver 4B shown in Figure 6 is provided with lead wires 19 and 20 in addition to lead wires 17 and 18. Lead wire 19 is provided on the magnetic pole 13 opposite to the magnetic pole 13 on which lead wire 17 is provided, and the induced voltage V generated in the first induction coil 15 -Y It is provided so that it can measure. The lead wire 20 is provided on the magnetic pole 13 at a position opposite to the magnetic pole 13 on which the lead wire 18 is provided, and the induced voltage V generated in the two first induction coils 15 -X It is designed to allow measurement.

[0024] If the Y-axis is defined as the opposite axis of the magnetic pole 13 on which the leader wires 17 and 19 are installed, then the induced voltage ratio V with respect to the eccentricity on the Y-axis is... +Y / V -Y By obtaining this in advance, the accuracy of estimating the eccentricity on the Y axis can be improved. Figure 7 shows the induced voltage ratio V. +Y / V -Y An example of eccentricity on the Y-axis is shown. Similarly, if the axis opposite to the magnetic pole 13 on which leader wires 18 and 20 are installed is the X-axis, then the induced voltage ratio V with respect to eccentricity on the X-axis is shown. +X / V -X By obtaining this in advance, the accuracy of estimating the eccentricity on the X axis can be improved. Figure 8 shows the induced voltage ratio V. +X / V -X This shows an example of eccentricity along the X-axis.

[0025] In the resolver 4C shown in Figure 9, a measuring unit 21 is provided instead of the leader wire 17 of the resolver 4. The measuring unit 21 has an eccentric measuring coil 212 and a leader wire 211. The eccentric measuring coil 212 is wound around the magnetic pole 13 to be measured. In the example shown in Figure 9, it is provided on the opposite side of the second induction coil 16, with the first induction coil 15 in between.

[0026] The lead wire 211 is the induced voltage V generated in the eccentricity measurement coil 212. +Y This is a lead wire for measuring the induced voltage V in the eccentric measurement coil 212. +YThe magnitude of the induced voltage V changes depending on the air gap length with the opposing rotor 11. If the angle of the rotor 11 is the same, the air gap length corresponds to the eccentricity of the rotor 11, so the induced voltage V +Y The eccentricity of the rotor 11 can be estimated from its size. Since the rotor 11 is fixed coaxially with the rotor of the rotating electric machine 3, if the eccentricity of the rotor 11 can be estimated, the eccentricity of the rotor of the rotating electric machine 3 can be estimated.

[0027] In the resolver 4C illustrated in Figure 9, one measuring unit 21 is provided, but by increasing the number of magnetic poles on which measuring units are provided, the eccentricity state, including direction, can be grasped in more detail. In the resolver 4D shown in Figure 10, a measuring unit 22 is provided in addition to the measuring unit 21. The measuring unit 22 has two eccentricity measuring coils 222 and a lead wire 221.

[0028] The eccentricity measuring coils 222 are provided on two magnetic poles 13 that are different from the magnetic pole 13 on which the eccentricity measuring coil 212 is provided. The lead wire 221 is connected to the induced voltage V generated by the two eccentricity measuring coils 222. +X It is designed to allow measurement.

[0029] The resolver 4E shown in Figure 11 is provided with measuring units 23 and 24 in addition to measuring units 21 and 22. Measuring unit 23 is provided on the magnetic pole 13 opposite to the magnetic pole 13 on which measuring unit 21 is provided. Measuring unit 23 has an eccentric measuring coil 232 and a lead wire 231. The lead wire 231 measures the induced voltage V generated in the eccentric measuring coil 232. -Y It is provided so that it can measure the voltage. The measuring unit 24 is provided on the magnetic pole 13 at a position opposite to the magnetic pole 13 on which the measuring unit 22 is provided. The measuring unit 24 has two eccentric measuring coils 242 and a lead wire 241. The lead wire 241 measures the induced voltage V generated in the two eccentric measuring coils 242. -X It is designed to allow measurement.

[0030] Figure 12 shows the induced voltage V. +YAn example of the output waveform is shown. State (c) is when the salient pole of the rotor 11 approaches the side where the lead wire 17 or the measurement unit 21 is located, and the rotation axis C of the rotor 11 is eccentric. State (d) is when the rotor 11 has rotated 90° from state (c). In state (c), when the salient pole of the rotor 11 approaches the side where the lead wire 17 or the measurement unit 21 is located, the induced voltage V is the output voltage. +Y The amplitude increases.

[0031] Figure 13 shows the induced voltage V, which is the output voltage. +Y An example of the sampling period is shown. The induced voltage V is the output voltage. +Y The amplitude period is equal to the reference period obtained by dividing the rotation period of the rotor 11 by the number of salient poles of the rotor 11 (2 in this embodiment), so the sampling period is obtained by multiplying this by an integer.

[0032] The embodiments have been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Modifications made to these specific examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the aforementioned specific examples are not limited to those illustrated and can be modified as appropriate. The elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise.

[0033] [Note] Notes 1 to 3 below can be combined in any way as long as they do not contradict each other technically.

[0034] [Note 1] An eccentricity estimation system 2 for a rotating electric machine 3 to which a resolver 4 is attached, the resolver 4 having a ring-shaped stator 12 having multiple magnetic poles 13 at predetermined angles, excitation coils 14 and two output coils, a first induction coil 15 and a second induction coil 16, arranged on each of the multiple magnetic poles 13, and a rotor 11 arranged opposite to the inside of the stator 12, Provided in any one output coil (either the first induction coil 15 or the second induction coil 16), the induced voltage V in one or more magnetic poles 13+Y A leader wire 17 capable of measuring, Induced voltage V measured by lead wire 17 +Y The system includes an eccentricity estimation unit 6 that estimates the eccentricity state of the rotor 11 relative to the stator 12.

[0035] The inventors of the present invention have found that, in a resolver commonly used as an angle sensor for the rotor of a rotating electric machine mounted in an automobile, an imbalance occurs in the magnetic flux component generated by the resolver's excitation coil at a position opposite the rotor's rotation center due to rotor eccentricity. They noticed that by adopting a configuration that adds a function to detect this magnetic flux imbalance at the opposing position to the resolver, it becomes possible to detect the eccentricity of the rotor, which is coaxially fixed to the rotor, even when the rotating electric machine is driven under load, in addition to the original angle detection function, and thus conceived the configuration described in Appendix 1.

[0036] According to Appendix 1, an alternating magnetic field is generated in the stator 12 by the excitation coil 14, and the magnetic flux of the magnetic poles 13 at a predetermined rotation angle changes depending on the air gap length with respect to the rotor 11. When the rotor 11 becomes eccentric, an induced voltage V is generated in the output coils (either the first induction coil 15 or the second induction coil 16) installed on each magnetic pole 13. +Y Because it increases or decreases, the induced voltage V with respect to the eccentricity is predetermined. +Y If you understand its characteristics, the induced voltage V +Y The eccentricity of the rotor 11 can be estimated from its size, and the eccentricity of the rotor, which is coaxially fixed to the rotor 11, can also be estimated. The output coils provided on the resolver 4 are provided on each magnetic pole 13 and are connected in series all around, so by providing lead wires 17, the voltage distributed by the output coils to which the lead wires 17 are provided can be measured, and the voltage of the magnetic pole 13 located in the direction in which the eccentricity is to be determined can be extracted.

[0037] [Note 2] An eccentricity estimation system 2 for a rotating electric machine 3 to which a resolver 4 is attached, the resolver 4 having a ring-shaped stator 12 having multiple magnetic poles 13 at predetermined angles, excitation coils 14 and two output coils, a first induction coil 15 and a second induction coil 16, arranged on each of the multiple magnetic poles 13, and a rotor 11 arranged opposite to the inside of the stator 12, In one or more magnetic poles 13, an eccentricity measurement coil 212 is provided together with the excitation coil 14 and two output coils (first induction coil 15 and second induction coil 16), and the induced voltage V measured by the eccentricity measurement coil 212 is measured. +Y A measuring unit 21 including a leader wire 211 capable of measuring, The induced voltage V measured by the measurement unit 21 +Y The system includes an eccentricity estimation unit 6 that estimates the eccentricity state of the rotor 11 relative to the stator 12.

[0038] According to Appendix 2, by adding an eccentricity measurement coil 212 to the magnetic pole 13 in the direction in which the eccentricity is to be determined, it is possible to detect the change in magnetic flux of the magnetic pole 13 due to the change in air gap length associated with the eccentricity of the rotor 11. If the characteristics of the output voltage of the eccentricity measurement coil 212 with respect to the eccentricity are known in advance, the eccentricity of the rotor 11 can be estimated, and the eccentricity of the rotor coaxially fixed to the rotor 11 can also be estimated. According to Appendix 2, even if it is difficult to provide the lead wire 17 as in Appendix 1, eccentricity estimation can be performed in the same way as when the lead wire 17 is provided as in Appendix 1 by additionally providing the eccentricity measurement coil 212 and the lead wire 211.

[0039] [Note 3] The eccentricity estimation unit 6 uses the period obtained by dividing the rotation period of the rotor 11 by the number of salient poles of the rotor 11 (in this embodiment, "2") as the reference period, and uses a sampling period that is an integer multiple of the reference period to induce the voltage V +Y An eccentricity estimation system 2 as described in Appendix 1 or 2, which samples the following.

[0040] According to Appendix 3, the opposing surfaces of the rotor 11 to the magnetic pole 13 can sample the output voltage at the same time, and the voltage change that depends on the shape of the rotor 11 can be subtracted in eccentricity measurement. [Explanation of Symbols]

[0041] 2: Eccentricity Estimation System 3: Rotating electric machines 4,4A,4B,4C,4D,4E: Resolvers 5: Excitation voltage generation unit 6: Eccentricity estimation part 11: Rotor 12: Status 13:Magnetic pole 14: Excitation coil 15: First induction coil (output coil) 16: Second induction coil (output coil) 17, 18, 19, 20: Leader lines 21, 22, 23, 24: Measurement section 211, 221, 231, 241: Leader lines 212,222,232,242: Eccentricity measurement coil

Claims

1. An eccentricity estimation system for a rotating electric machine, to which a resolver is attached, having a ring-shaped stator having multiple magnetic poles at predetermined angles, excitation coils and two output coils arranged on each of the multiple magnetic poles, and a rotor arranged opposite to the inside of the stator, A lead wire provided in any one of the output coils, capable of measuring the induced voltage at one or more of the magnetic poles, An eccentricity estimation system comprising: an eccentricity estimation unit that estimates the eccentricity state of the rotor relative to the stator based on the induced voltage measured by the aforementioned lead wire.

2. An eccentricity estimation system for a rotating electric machine, to which a resolver is attached, having a ring-shaped stator having multiple magnetic poles at predetermined angles, excitation coils and two output coils arranged on each of the multiple magnetic poles, and a rotor arranged opposite to the inside of the stator, A measuring unit including an eccentricity measuring coil provided together with the excitation coil and the two output coils in one or more magnetic poles, and a lead wire capable of measuring the induced voltage measured by the eccentricity measuring coil, An eccentricity estimation system comprising: an eccentricity estimation unit that estimates the eccentricity state of the rotor relative to the stator based on the induced voltage measured by the measurement unit.

3. The eccentricity estimation system according to claim 1 or 2, wherein the eccentricity estimation unit uses a period obtained by dividing the rotation period of the rotor by the number of salient poles of the rotor as a reference period, and samples the induced voltage at a sampling period that is an integer multiple of the reference period.

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