Magnet temperature information output device, rotary electric machine, and magnet temperature acquisition device

Abstract

To provide a magnet temperature information output device which outputs temperature information regarding a temperature of a permanent magnet as an electric signal regarding voltage.SOLUTION: A magnet temperature information output device 1 comprises: an element unit 50 provided in a rotor; an element unit 60 provided in a stator; an electric resistance element 70; and an output unit 80. The element unit 50 has a thermosensitive element 51 and a coil 53. In the thermosensitive element 51, electric resistance varies according to a temperature of a permanent magnet. The coil 53 is electrically connected with the thermosensitive element 51. The element unit 60 has a coil 61. The coil 61 is magnetically coupled with the coil 53. The electric resistance element 70 is electrically connected with the element unit 60. The output unit 80 is electrically connected with the element unit 60 and the electric resistance element 70. The output unit 80 outputs an electric signal corresponding to magnitude of voltage drop which occurs in the electric resistance element 70 as temperature information regarding the temperature of the permanent magnet.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a magnet temperature information output device, a rotating electric machine provided with the magnet temperature information output device, and a magnet temperature acquisition device including the magnet temperature information output device. [Background technology]

[0002] A magnet temperature information output device is known that is provided in a rotating electric machine having a stator and a rotor in which a permanent magnet is arranged, and outputs temperature information related to the temperature of the permanent magnet (see, for example, Patent Document 1). This magnet temperature information output device includes a temperature sensor, a first coil, a second coil, and an output unit. The temperature sensor is provided in the rotor, and its electrical resistance changes depending on the temperature of the permanent magnet. The first coil is electrically connected to the temperature sensor. The second coil is provided in the stator and magnetically coupled to the first coil. The output unit outputs an electrical signal corresponding to the magnitude of the current flowing through the second coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-39019 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present invention aims to provide a magnet temperature information output device that outputs temperature information related to the temperature of a permanent magnet as an electrical signal related to voltage. Another aspect of the present invention aims to provide a rotating electric machine that is provided with the above-mentioned magnet temperature information output device. Yet another aspect of the present invention aims to provide a magnet temperature acquisition device that includes the above-mentioned magnet temperature information output device. [Means for solving the problem]

[0005] A magnet temperature information output device according to one aspect is provided for a rotating electric machine having a stator and a rotor in which a permanent magnet is arranged, and outputs temperature information related to the temperature of the permanent magnet. The magnet temperature information output device includes a first element unit provided on the rotor, a second element unit provided on the stator, an electric resistance element, and an output unit. The first element unit has a temperature sensing element and a first coil. The electric resistance of the temperature sensing element changes depending on the temperature of the permanent magnet. The first coil is electrically connected to the temperature sensing element. The second element unit has a second coil. The second coil is magnetically coupled to the first coil. The electric resistance element is electrically connected to the second element unit. The output unit is electrically connected to the second element unit and the electric resistance element. The output unit outputs an electric signal corresponding to the magnitude of the voltage drop occurring in the electric resistance element as temperature information.

[0006] In one aspect, the magnet temperature information output device includes an electrical resistance element electrically connected to the second element unit. The second coil of the second element unit is magnetically coupled to the first coil, and therefore power is supplied to the first coil. The electrical resistance of the temperature-sensing element electrically connected to the first coil changes in accordance with the temperature of the permanent magnet, and therefore the current flowing through the second coil changes in accordance with the change in the electrical resistance of the temperature-sensing element. As the current flowing through the second coil changes, the magnitude of the voltage drop occurring in the electrical resistance element also changes. The output unit outputs an electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element. Therefore, the electrical signal output from the output unit changes in accordance with the temperature of the permanent magnet. That is, in one aspect, temperature information regarding the temperature of the permanent magnet is output from the output unit as an electrical signal related to voltage. From the above, one aspect outputs temperature information regarding the temperature of the permanent magnet as an electrical signal related to voltage.

[0007] In one embodiment, the electrical resistance element is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 1500.71 The electrical resistance may be: 150 may be a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature of the temperature sensitive element is 150°C. o may be a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature sensitive element is separated from the first element unit. The electrical resistance element is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 The configuration having the following electrical resistance accurately outputs temperature information regarding the temperature of the permanent magnet.

[0008] In the above-described one aspect, the second element unit may include a capacitor that configures an LC resonant circuit together with the second coil. The second element unit includes a capacitor that forms an LC resonant circuit with the second coil, which accurately detects changes in the electrical resistance of the temperature sensor, and therefore accurately outputs temperature information related to the temperature of the permanent magnet.

[0009] In the above-described one aspect, the first element unit may include a capacitor that configures an LC resonant circuit together with the first coil. The first element unit includes a capacitor that forms an LC resonant circuit with the first coil, which accurately detects changes in the electrical resistance of the temperature sensing element and therefore accurately outputs temperature information related to the temperature of the permanent magnet.

[0010] In the above aspect, the first element unit may further include a capacitor that configures an LC resonant circuit together with the first coil, and the second element unit may further include a capacitor that configures an LC resonant circuit together with the second coil. The configuration in which the first element unit and the second element unit have a capacitor allows temperature information relating to the temperature of the permanent magnet to be output with high accuracy.

[0011] In the one aspect, a voltage having a frequency lower than a predetermined resonant frequency that excites the first coil may be applied to the second coil. A configuration in which a voltage having a frequency lower than the predetermined resonant frequency that excites the first coil is applied to the second coil allows temperature information relating to the temperature of the permanent magnet to be output with high accuracy.

[0012] In the one aspect described above, the difference between the frequency of the voltage applied to the second coil and the predetermined resonant frequency may be 5 kHz or more and 30 kHz or less. A configuration in which the difference between the frequency of the voltage applied to the second coil and the resonant frequency is 5 kHz or more and 30 kHz or less allows temperature information relating to the temperature of the permanent magnet to be output with high precision.

[0013] A rotating electric machine according to another aspect is provided with the magnet temperature information output device described above. In the above-mentioned another aspect, the magnet temperature information output device is provided, and therefore temperature information relating to the temperature of the permanent magnet is output as an electric signal relating to voltage.

[0014] In another aspect above, the first coil and the second coil may be arranged so as to face each other in the direction of the rotation axis of the rotor when the rotor is at a predetermined rotational angle position.

[0015] In the above-mentioned another aspect, the rotor may have a rotor core. The entire permanent magnet and at least a part of the first coil may be disposed within the rotor core. The permanent magnet may have a pair of faces perpendicular to the rotational axis direction of the rotor. The temperature-sensitive element may be disposed so as to contact one of the pair of faces that is closer to the second coil when the rotor is at a predetermined rotational angle position.

[0016] In the above-described another aspect, the rotor core may include a pair of end faces perpendicular to the rotational axis of the rotor, and one of the pair of end faces located closer to the second coil may be flush with one end of the first coil in the rotational axis direction of the rotor.

[0017] In the above-mentioned another aspect, the rotor core may include a plurality of steel plates stacked in the rotation axis direction and a plate. The plurality of steel plates may be magnetic. The plate may be conductive. The plate may be disposed on a steel plate, among the plurality of steel plates, that is located outermost in the rotation axis direction of the rotor and closer to the second coil. The first coil may be embedded in the plate.

[0018] A magnet temperature acquisition device according to yet another aspect includes the magnet temperature information output device described above, acquires an electrical signal output from the magnet temperature information output device, and obtains the temperature of the permanent magnet based on the acquired electrical signal. The above-mentioned still another aspect includes the magnet temperature information output device, and therefore obtains the temperature of the permanent magnet based on the electrical signal related to the voltage. [Effects of the Invention]

[0019] According to one aspect of the present invention, there is provided a magnet temperature information output device that appropriately and easily outputs temperature information related to the temperature of a permanent magnet arranged in a rotor. According to another aspect of the present invention, there is provided a rotating electric machine provided with the above-mentioned magnet temperature information output device. According to yet another aspect of the present invention, there is provided a magnet temperature acquisition device including the above-mentioned magnet temperature information output device. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a magnet temperature information output device and a rotating electric machine according to one embodiment. [Figure 2] FIG. 2 is a circuit diagram showing an example of a magnet temperature information output device. [Figure 3] FIG. 3 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 4] FIG. 4 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 5]FIG. 5 is a diagram showing a cross-sectional configuration of the rotor core. [Figure 6] FIG. 6 is a circuit diagram showing another example of the magnet temperature information output device. [Figure 7] FIG. 7 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 8] FIG. 8 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 9] FIG. 9 is a circuit diagram showing yet another example of a magnet temperature information output device. [Figure 10] FIG. 10 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 11] FIG. 11 is a circuit diagram showing an equivalent circuit used when setting the electrical resistance of an electrical resistance element. [Figure 12] FIG. 12 is a diagram showing a cross-sectional configuration of the rotor core. [Figure 13] FIG. 13 is a diagram showing a cross-sectional configuration of the rotor core. [Figure 14] FIG. 14 is a circuit diagram showing an equivalent circuit used when determining the relationship between the electrical resistance of an electrical resistance element and the accuracy of temperature information. [Figure 15] FIG. 15 is a chart showing the relationship between the electrical resistance of the electrical resistance element and the accuracy of the temperature information. [Figure 16] FIG. 16 is a chart showing the relationship between the electrical resistance of the electrical resistance element and the accuracy of the temperature information. [Figure 17] FIG. 17 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. [Figure 18] FIG. 18 is a diagram showing the relationship between the voltage drop occurring in the electrical resistance element and the temperature. [Figure 19] FIG. 19 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. [Figure 20] FIG. 20 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. [Figure 21] FIG. 21 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. [Figure 22] FIG. 22 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. [Figure 23] FIG. 23 is a diagram showing the relationship between the voltage drop occurring in an electric resistance element and the temperature. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be denoted by the same reference numerals, and redundant description will be omitted.

[0022] The configuration of a magnet temperature information output device 1 according to this embodiment and a rotating electric machine MT provided with the magnet temperature information output device 1 will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the configuration of the magnet temperature information output device and the rotating electric machine according to this embodiment.

[0023] As shown in FIG. 1, the magnet temperature information output device 1 is provided in a rotating electric machine MT. The rotating electric machine MT is, for example, a motor. The motor includes, for example, an IPM motor or an SPM motor. As shown in FIG. 1, the rotating electric machine MT includes a stator 10 and a rotor 20. The rotor 20 is located inside the stator 10.

[0024] The rotor 20 includes a shaft 21, a rotor core 23, and a plurality of permanent magnets 25. The shaft 21 has a cylindrical shape. The rotor core 23 has a cylindrical shape. An axial hole into which the shaft 21 is fitted is formed in the rotor core 23. The shaft 21 and the rotor core 23 rotate together around the central axis of the shaft 21. Each permanent magnet 25 is arranged in the rotor core 23 so that its extension direction is parallel to the central axis of the shaft 21. The phrase "the extension direction of the permanent magnet 25 is parallel to the central axis of the shaft 21" does not necessarily mean that the extension direction of the permanent magnet 25 is parallel to the central axis of the shaft 21. The extension direction of the permanent magnet 25 may be considered to be parallel to the central axis of the shaft 21 even if there is a slight difference, manufacturing error, or measurement error within a predetermined range. When slight differences within a predetermined range are included, for example, when the angle between the extension direction of the permanent magnet 25 and the central axis of the shaft 21 is within a range of ±2 degrees, the extension direction of the permanent magnet 25 and the central axis of the shaft 21 may be considered parallel. The central axis of the shaft 21 is the rotation axis of the rotor 20. The direction in which the rotation axis of the rotor 20 extends is the rotation axis direction D of the rotor 20. One magnet may constitute one pole, or multiple magnets may constitute one pole. When one magnet constitutes one pole, the multiple permanent magnets 25 are arranged at equal angular intervals with respect to the rotation axis of the rotor 20. "Even angular intervals" does not necessarily mean that the angular intervals are the same. Even when slight differences, manufacturing errors, or measurement errors within a predetermined range are included, the angular intervals may be considered equal. If there is a slight difference within a preset range, for example, if each angular interval of the permanent magnet 25 relative to the axis of rotation of the rotor 20 is within a range of ±10% of the average angular interval of all angular intervals, then each angular interval of the permanent magnet 25 relative to the axis of rotation of the rotor 20 may be considered to be uniform.

[0025] When the rotating electric machine MT is an IPM motor, the multiple permanent magnets 25 are arranged inside the rotor core 23. When the rotating electric machine MT is an SPM motor, the multiple permanent magnets 25 are arranged on the surface of the rotor core 23. Each permanent magnet 25 includes a rare earth permanent magnet. Each permanent magnet 25 includes, for example, a neodymium sintered magnet. Each permanent magnet 25 may include a sintered magnet other than a rare earth permanent magnet, or may include a magnet other than a sintered magnet. The magnet other than a sintered magnet includes, for example, a bonded magnet or a hot-deformed magnet.

[0026] The stator 10 includes a cylindrical stator core (not shown) that surrounds the outer periphery of the rotor 20, and multiple stator coils 11. The stator 10 may further include a case that surrounds the stator core, the multiple stator coils 11, and the rotor 20. An air gap of uniform width is provided between the stator 10 and the rotor 20. "Uniform width" does not necessarily mean that the widths of the air gaps between the stator 10 and the rotor 20 are uniform. The widths of the air gaps between the stator 10 and the rotor 20 may be considered uniform even if slight differences within a predetermined range, manufacturing errors, or measurement errors are included. If slight differences within a predetermined range are included, for example, if the widths of the air gaps between the stator 10 and the rotor 20 are within a range of ±10% of the average width of all the air gaps, the widths of the air gaps between the stator 10 and the rotor 20 may be considered uniform. The stator core holds the multiple stator coils 11. Each stator coil 11 is disposed on the inner periphery of the stator core. The plurality of stator coils 11 are disposed at equal angular intervals with respect to the rotation axis of the rotor 20.

[0027] The rotating electric machine MT is connected to a control circuit 41. The control circuit 41 is connected to a power source 43. The control circuit 41 adjusts the drive current from the power source 43 and supplies three-phase AC current to each stator coil 11. The control circuit 41 controls the value of the three-phase AC current supplied to each stator coil 11. The control circuit 41 includes, for example, an inverter circuit. When the three-phase AC current is supplied to each stator coil 11, each stator coil 11 forms a rotating magnetic field that rotates the rotor 20. The power source 43 includes, for example, an electric energy storage device. The electric energy storage device includes, for example, a secondary battery or a capacitor.

[0028] Next, the configuration of the magnet temperature information output device 1 will be described in more detail with reference to Fig. 2. Fig. 2 is a circuit diagram showing an example of a magnet temperature information output device. The magnet temperature information output device 1 outputs temperature information related to the temperature of the permanent magnet 25. To achieve this function, the magnet temperature information output device 1 includes an element unit 50, an element unit 60, an electrical resistance element 70, and an output unit 80. In this embodiment, there is one element unit 50 and one element unit 60. The element unit 50 is provided on the rotor 20. The element unit 60 is provided on the stator 10. The element unit 60 is provided, for example, on the stator core. The element unit 50 and the element unit 60 are arranged to face each other in a direction parallel to the rotation axis of the rotor 20 when the rotor 20 is at a predetermined rotation angle position. The term "parallel to the rotation axis of the rotor 20" does not necessarily mean only a direction parallel to the rotation axis of the rotor 20. Even if a slight difference, manufacturing error, or measurement error within a predetermined range is included, the direction may be considered to be parallel to the rotation axis of the rotor 20. If there is a slight difference within a preset range, for example, if the angle formed with the rotation axis of rotor 20 is within a range of ±2 degrees, the direction may be considered to be parallel to the rotation axis of rotor 20.

[0029] As shown in FIG. 2 , the element unit 50 includes a temperature sensor 51 and a coil 53. The temperature sensor 51 and the coil 53 are provided on the rotor 20. The temperature sensor 51 is provided on at least one of the multiple permanent magnets 25. In this embodiment, the temperature sensor 51 is provided on only one permanent magnet 25. The temperature sensor 51 is arranged so as to be in contact with the permanent magnet 25. The temperature sensor 51 may be arranged near the permanent magnet 25. The electrical resistance of the temperature sensor 51 changes depending on the temperature of the permanent magnet 25. The electrical resistance of the temperature sensor 51 decreases as the temperature of the permanent magnet 25 increases. The temperature sensor 51 may be, for example, a thermistor or a Hall element. The thermistor may be, for example, an NTC thermistor. The coil 53 is electrically connected to the temperature sensor 51. In this embodiment, both ends of the coil 53 are electrically connected to both ends of the temperature sensor 51.

[0030] The element unit 60 includes a coil 61 and a capacitor 63. The coil 61 is disposed on the stator 10 so as to face the coil 53 in the rotational axis direction D of the rotor 20 when the rotor 20 is at a predetermined rotation angle position. The coils 53 and 61 are disposed so as to face each other in the rotational axis direction D of the rotor 20 when the rotor 20 is at a predetermined rotation angle. The coil 61 is magnetically coupled to the coil 53. The coil 61 is electrically connected to an AC power supply PS. The AC power supply PS may be, for example, an inverter. An AC signal of a predetermined frequency is applied to the coil 61 from the AC power supply PS. An AC voltage is applied to the coil 61 from the AC power supply PS. The predetermined frequency is higher than the drive frequency of the rotating electric machine MT. The predetermined frequency is, for example, 10 to 2000 times the drive frequency of the rotating electric machine MT. The capacitor 63 and the coil 61 form an LC resonant circuit. The capacitor 63 may form an LC resonant circuit together with the coil 53 and the coil 61. The capacitor 63 is inserted, for example, so as to be connected in parallel with the coil 61. For example, when the coil 53 forms a first coil, the coil 61 forms a second coil.

[0031] For example, the predetermined frequency may be equal to or lower than a predetermined resonant frequency that excites coil 53. In other words, the frequency of the voltage applied to coil 61 may be equal to or lower than the predetermined resonant frequency that excites coil 53. The predetermined resonant frequency is, for example, the resonant frequency of a circuit equivalent to the circuit in magnet temperature information output device 1 when coils 53 and 61 are magnetically coupled and the temperature of thermosensitive element 51 is at a predetermined temperature. In this embodiment, the circuit is a circuit including thermosensitive element 51, coil 53, coil 61, and capacitor 63. The predetermined temperature is, for example, room temperature. Room temperature is, for example, 15°C or higher and 30°C or lower. In this embodiment, the predetermined temperature is 25°C.

[0032] The electric resistance element 70 is electrically connected to the element unit 60. The electric resistance element 70 may be electrically connected to the coil 61. In this embodiment, the electric resistance element 70 is provided on the stator 10 and inserted between the coil 61 and the AC power supply PS. The output unit 80 is electrically connected to the element unit 60 and the electrical resistance element 70. The output unit 80 may be electrically connected to the coil 61. That is, the coil 61 may be electrically connected to the electrical resistance element 70 and the output unit 80. In this embodiment, the output unit 80 is provided on the stator 10. The output unit 80 outputs an electrical signal corresponding to the magnitude of a voltage drop occurring in the electrical resistance element 70. The output unit 80 may output an electrical signal indicating the magnitude of the voltage drop occurring in the electrical resistance element 70. The output unit 80 includes, for example, a voltmeter. The voltmeter may be configured with a computing device including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The computing device may be, for example, a microcomputer. In this case, the voltmeter loads a program stored in the ROM into the RAM and executes the program on the CPU, thereby outputting the above-mentioned electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element 70.

[0033] A magnetic flux corresponding to the AC voltage applied from the AC power supply PS is generated in the coil 61. When the rotor 20 rotates and the coil 61 and the coil 53 approach each other, the magnetic flux generated in the coil 61 passes through the coil 53. When the magnetic flux generated in the coil 61 passes through the coil 53, power corresponding to the change in the magnetic flux passing through the coil 53 is generated in the coil 53. In other words, when the rotor 20 rotates and the coil 61 and the coil 53 approach each other, the coil 61 and the coil 53 are magnetically coupled. Alternatively, it can be said that the coil 61 excites the coil 53 and supplies power to the coil 53.

[0034] Since the electrical resistance of the temperature sensitive element 51 changes in accordance with the temperature of the permanent magnet 25, the magnetic flux generated in the coil 61 changes in accordance with the change in the electrical resistance of the temperature sensitive element 51. This causes a change in the current flowing through the coil 61. The change in the current flowing through the coil 61 causes a change in the magnitude of the voltage drop occurring in the electrical resistance element 70.

[0035] As the temperature of the permanent magnet 25 rises and the electrical resistance of the temperature-sensitive element 51 decreases, the magnetic flux generated in the coil 61 increases. As a result, the current flowing through the coil 61 increases, and the magnitude of the voltage drop generated in the electrical resistance element 70 also increases. As the temperature of the permanent magnet 25 falls and the electrical resistance of the temperature-sensitive element 51 increases, the magnetic flux generated in the coil 61 decreases. As a result, the current flowing through the coil 61 decreases, and the magnitude of the voltage drop generated in the electrical resistance element 70 also decreases. In other words, as the temperature of the permanent magnet 25 rises, the magnitude of the voltage drop generated in the electrical resistance element 70 increases. Similarly, as the temperature of the permanent magnet 25 falls, the magnitude of the voltage drop generated in the electrical resistance element 70 decreases.

[0036] The output unit 80 detects the magnetic flux generated in the coil 61 as the magnitude of the voltage drop occurring in the electrical resistance element 70. The magnitude of the voltage drop detected by the output unit 80 corresponds to a change in the electrical resistance of the temperature sensing element 51, i.e., a change in the temperature of the permanent magnet 25. Therefore, the electrical signal output from the output unit 80 includes temperature information related to the temperature of the permanent magnet 25. In other words, the output unit 80 outputs an electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element 70 as the temperature information. As a result, temperature information related to the temperature of the permanent magnet 25 is transmitted wirelessly between the element unit 50 and the output unit 80 via the element unit 60.

[0037] The electrical signal output from the output unit 80 is input to the control circuit 41 as the temperature information. The control circuit 41 acquires the electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element 70 output from the magnet temperature information output device 1. The control circuit 41 acquires the temperature of the permanent magnet 25 based on the acquired electrical signal. That is, in this embodiment, the control circuit 41 functions as a magnet temperature acquisition device. The control circuit 41 obtains the temperature of the permanent magnet 25, for example, as follows. First, the control circuit 41 refers to data indicating the relationship between the temperature and an electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element 70. The data may be stored in the control circuit 41, or may be stored in an external server different from the control circuit 41. Next, the control circuit 41 obtains the temperature corresponding to the obtained electrical signal from the data as the temperature of the permanent magnet 25.

[0038] The control circuit 41 controls the driving state of the rotating electric machine MT based on the obtained temperature of the permanent magnet 25. For example, the control circuit 41 controls the driving state of the rotating electric machine MT as follows: When the control circuit 41 determines that the obtained temperature of the permanent magnet 25 has risen to a predetermined first threshold, the control circuit 41 controls the supply power to limit the rotational speed of the rotating electric machine MT. When the control circuit 41 determines that the obtained temperature of the permanent magnet 25 has fallen to a predetermined second threshold that is lower than the first threshold, the control circuit 41 controls the supply power to release the limit on the rotational speed of the rotating electric machine MT.

[0039] The control circuit 41 may control the drive state of the rotating electric machine MT as follows. That is, the control circuit 41 may control, for example, the drive frequency input to the rotating electric machine MT based on the obtained temperature of the permanent magnet 25. When the control circuit 41 determines that the obtained temperature of the permanent magnet 25 has risen to a predetermined first threshold, the control circuit 41 controls the drive frequency to decrease so as to limit the rotation speed of the rotating electric machine MT. When the control circuit 41 determines that the obtained temperature of the permanent magnet 25 has fallen to a predetermined second threshold that is smaller than the first threshold, the control circuit 41 controls the drive frequency to increase so as to remove the limit on the rotation speed of the rotating electric machine MT.

[0040] The control circuit 41 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control circuit 41 obtains the temperature of the permanent magnet 25 and controls the driving state of the rotating electric machine MT, for example, by loading a program stored in the ROM into the RAM and executing the program on the CPU.

[0041] Next, the electrical resistance of the electrical resistance element 70 will be described with reference to Figures 3 and 4. Figures 3 and 4 are circuit diagrams showing equivalent circuits used when setting the electrical resistance of the electrical resistance element. As described above, the electrical resistance of the temperature sensing element 51 changes depending on the temperature of the permanent magnet 25. The range of electrical resistance of the electrical resistance element 70, which clearly detects changes in the temperature of the permanent magnet 25, also changes depending on the change in electrical resistance of the temperature sensing element 51. In this embodiment, the electrical resistance of the electrical resistance element 70 is set to a range that clearly detects changes in the temperature of the permanent magnet 25.

[0042] Hereinafter, the range of electrical resistance possessed by the electrical resistance element 70 that significantly detects changes in the temperature of the permanent magnet 25 may be referred to as the "preferable range of electrical resistance possessed by the electrical resistance element 70," and the range of electrical resistance possessed by the electrical resistance element 70 that significantly detects changes in the temperature of the permanent magnet 25 may be referred to as the "more preferable range of electrical resistance possessed by the electrical resistance element 70." Furthermore, hereafter, the electrical resistance possessed by the electrical resistance element 70 that most significantly detects changes in the temperature of the permanent magnet 25 may be referred to as the "optimal electrical resistance possessed by the electrical resistance element 70."

[0043] In addition to the preferred range of the electrical resistance of the electrical resistance element 70, the impedance of the entire magnet temperature information output device 1, including the element unit 50 and the element unit 60, also changes in response to changes in the electrical resistance of the temperature sensing element 51. That is, the composite impedance of the element unit 50 and the element unit 60 also changes in response to changes in the electrical resistance of the temperature sensing element 51. Therefore, the inventors focused on the relationship between the preferred range of the electrical resistance of the electrical resistance element 70 and the composite impedance of the element unit 50 and the element unit 60. To clarify the relationship between the preferred range of the electrical resistance of the electrical resistance element 70 and the composite impedance of the element unit 50 and the element unit 60, the inventors conducted an experiment using an equivalent circuit EC1 shown in FIG. 3 . The equivalent circuit EC1 is a circuit equivalently representing a circuit including the temperature sensing element 51, the coil 53, the coil 61, and the capacitor 63 in the magnet temperature information output device 1. Therefore, the equivalent circuit EC1 includes elements corresponding to the temperature sensing element 51, the coil 53, the coil 61, and the capacitor 63.

[0044] In this embodiment, as shown in Fig. 3, the equivalent circuit EC1 includes an element R1, elements L1 and R2, element L2, elements L3 and R3, and element C1. The element R1 corresponds to the temperature sensing element 51. In this embodiment, the element R1 includes an element corresponding to the electrical resistance of the temperature sensing element 51. The elements L1 and R2 correspond to the coil 53. In this embodiment, the element L1 includes an element corresponding to the inductance of the coil 53, and the element R2 includes an element corresponding to the electrical resistance of the coil 53. In the equivalent circuit EC1, the element R1 and the elements L1 and R2 are electrically connected.

[0045] Elements L3 and R3 correspond to the coil 61. In this embodiment, element L2 includes an element corresponding to the inductance of coil 61, and element R3 includes an element corresponding to the electrical resistance of coil 61. Element R3 is inserted so as to be connected in series to element L3. Element L2 corresponds to the magnetic coupling between coil 53 and coil 61. In this embodiment, element L3 includes an element corresponding to the mutual inductance between coil 53 and coil 61. Element C1 corresponds to capacitor 63. In this embodiment, element C1 includes an element corresponding to the capacitance component of capacitor 63. Element C1 is inserted so as to be connected in parallel to element L3. In the equivalent circuit EC1, the end closer to element C1 is open. In the equivalent circuit EC1, the portion composed of element R1 and elements R2 and L1 corresponds to element unit 50, and the portion composed of elements L3, R3 and element C1 corresponds to element unit 60.

[0046] The inventors changed the temperature of the element R1 corresponding to the thermosensitive element 51 and determined the relationship between the impedance in the equivalent circuit EC1 at that temperature and the preferred range of the electrical resistance, the more preferred range of the electrical resistance, and the optimum electrical resistance of the electrical resistance element 70 when the thermosensitive element 51 is at that temperature. As a result, the inventors set the temperature of the element R1 to T°C, and determined that the composite impedance of the element unit 50 and the element unit 60 in the equivalent circuit EC1 at that temperature was Z1 T When the electric resistance element 70 has a preferable range of electric resistance, a×Z1 T0.28 More than a×Z1 T 0.71 The more preferable range of electrical resistance is a × Z1 T 0.38 More than a×Z1 T 0.63 Furthermore, the inventors have found that the optimum electrical resistance of the electrical resistance element 70 is a×Z1 T 0.50 Here, "a" represents a proportionality coefficient set for each circuit.

[0047] Next, the inventors conducted research to calculate the proportionality coefficient a. As a result, they found that the proportionality coefficient a is equivalent to the composite impedance of the element unit 50 and the element unit 60 when the temperature sensor 51 is separated from the element unit 50. Therefore, the inventors obtained the composite impedance Z2 of the element unit 50 and the element unit 60 in the equivalent circuit EC2 shown in FIG. 4 and calculated the proportionality coefficient a based on the composite impedance Z2. The equivalent circuit EC2 is an equivalent circuit that represents a circuit in which the temperature sensor 51 is separated from a circuit including the temperature sensor 51, the coil 53, the coil 61, and the capacitor 63 in the magnet temperature information output device 1. In the equivalent circuit EC2, the element R1 corresponding to the temperature sensor 51, which is included in the equivalent circuit EC1, is released. Therefore, in the equivalent circuit EC2, the proportionality coefficient a and the composite impedance Z2 are related by the following equation: Z2 = a × Z2 0.50 That is, the proportionality coefficient a is calculated by using the synthetic impedance Z2 as follows: 0.50 It is expressed as: From the above, in the magnet temperature information output device 1, when the thermosensitive element 51 is separated from the element unit 50, the preferable range of the electrical resistance of the electrical resistance element 70 is Z0, where Z0 is the composite impedance of the element unit 50 and the element unit 60. o 0.50 ×Z T 0.28 More than Z o 0.50 ×Z T 0.71 A more preferable range of the electrical resistance is Z o0.50 ×Z T 0.38 More than Z o 0.50 ×Z T 0.63 Similarly, in the magnet temperature information output device 1, the optimum electrical resistance of the electrical resistance element 70 is Z o 0.50 ×Z T 0.50 It is understood that.

[0048] The temperature T is set based on the temperature range of the permanent magnet 25 when the rotating electric machine MT is used, for example. In this embodiment, the temperature range of the permanent magnet 25 is 120°C or more and 170°C or less, and the temperature T is set to T=150. Therefore, in this embodiment, the range of the electrical resistance of the electrical resistance element 70 is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 That is, in this embodiment, the electrical resistance element 70 may be set to Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 Alternatively, the electrical resistance element 70 may have an electrical resistance of Z o 0.50 ×Z 150 0.38 More than Z o 0.50 ×Z 150 0.63 It may have the following electrical resistance:

[0049] Synthetic impedance Z T The synthetic impedance Z1 obtained in the equivalent circuit EC1 is TAlternatively, the actual measurement value of the composite impedance of the element unit 50 and the element unit 60 when the coil 53 and the coil 61 are magnetically coupled and the temperature of the temperature sensing element 51 is T°C may be used. That is, the composite impedance Z 150 The synthetic impedance Z1 obtained in the equivalent circuit EC1 is 150 Alternatively, the actual measurement value of the composite impedance of the element unit 50 and the element unit 60 when the coil 53 and the coil 61 are magnetically coupled and the temperature of the temperature sensing element 51 is 150° C. may be used. Similarly, the composite impedance Z o For this, the synthetic impedance Z2 obtained in the equivalent circuit EC2 may be used, or the actual measured value of the synthetic impedance of the element unit 50 and the element unit 60 when the coil 53 and the coil 61 are magnetically coupled and the thermosensitive element 51 is separated from the element unit 50 may be used.

[0050] The actual measured value of the composite impedance of the element unit 50 and the element unit 60 when the coil 53 and the coil 61 are magnetically coupled and the temperature of the temperature sensing element 51 is T°C is measured, for example, as follows. First, with the coil 53 and the coil 61 magnetically coupled, the relative positions of the element unit 50 and the element unit 60 are maintained. Next, the temperature sensing element 51 is heated to T°C. When measuring the above actual measured value when the temperature of the temperature sensing element 51 is 150°C, the temperature sensing element 51 is heated to 150°C. Next, the composite impedance of the element unit 50 and the element unit 60 is measured. Note that during the measurement, the electrical resistance element 70 and the output section 80, which are electrically connected to the element unit 60, may be disconnected.

[0051] The actual measured value of the composite impedance of the element unit 50 and the element unit 60 when the coil 53 and the coil 61 are magnetically coupled and the temperature sensing element 51 is detached from the element unit 50 is measured, for example, as follows. First, the relative positions of the element unit 50 and the element unit 60 are maintained with the coil 53 and the coil 61 magnetically coupled. Next, the temperature sensing element 51 is detached from the element unit 50. Next, the composite impedance of the element unit 50 and the element unit 60 is measured. Note that during the measurement, the electrical resistance element 70 and the output section 80, which are electrically connected to the element unit 60, may be disconnected.

[0052] Next, the arrangement of the permanent magnets 25, the temperature sensitive element 51, and the coil 53 will be described in more detail with reference to Fig. 5. Fig. 5 is a diagram showing the cross-sectional configuration of the rotor core. The rotor core 23 includes a pair of end faces 23a, 23b and one side face. The end face 23a is located closer to the element unit 60. That is, the end face 23a is located closer to the coil 61. The end face 23b is located on the opposite side of the end face 23a in the rotational axis direction D. That is, the pair of end faces 23a, 23b are perpendicular to the rotational axis direction D and face in opposite directions. The phrase "the pair of end faces 23a, 23b are perpendicular to the rotational axis direction D" does not necessarily mean that the pair of end faces 23a, 23b are perpendicular to the rotational axis direction D. It is also acceptable to say that the pair of end faces 23a, 23b are perpendicular to the rotational axis direction D even when slight differences, manufacturing errors, or measurement errors within a preset range are included. If there is a slight difference within a preset range, for example, if the angle between the pair of end faces 23a, 23b and the rotation axis direction D is within a range of ±1 degree from perpendicular, the pair of end faces 23a, 23b may be considered to be perpendicular to the rotation axis direction D.

[0053] As shown in FIG. 5 , the rotor core 23 is configured by stacking a plurality of steel plates M1 in the rotational axis direction D. The rotor core 23 includes a plurality of steel plates M1 stacked in the rotational axis direction D. The steel plates M1 are magnetic. The steel plates M1 may be, for example, silicon steel plates. In this embodiment, of the plurality of steel plates M1, the steel plate M1 located closest to the coil 61 includes an end face 23a as its surface.

[0054] The permanent magnet 25 is disposed in the rotor core 23. In this embodiment, as shown in FIG. 5 , the entire permanent magnet 25 is disposed within the rotor core 23. The permanent magnet 25 has a pair of faces 25a, 25b and four side faces. The face 25a is located closer to the coil 61. The face 25b is located on the opposite side of the face 25a in the rotational axis direction D. That is, the pair of faces 25a, 25b are perpendicular to the rotational axis direction D and face in opposite directions. The phrase "the pair of faces 25a, 25b are perpendicular to the rotational axis direction D" does not necessarily mean that the pair of faces 25a, 25b are perpendicular to the rotational axis direction D. It is also possible to say that the pair of faces 25a, 25b are perpendicular to the rotational axis direction D even when slight differences, manufacturing errors, or measurement errors within a predetermined range are included. If there is a slight difference within a preset range, for example, if the angle between the pair of surfaces 25a, 25b and the rotation axis direction D is within a range of ±2 degrees from perpendicular, the pair of surfaces 25a, 25b may be considered to be perpendicular to the rotation axis direction D.

[0055] The temperature sensing element 51 is arranged so as to be in contact with the permanent magnet 25. The temperature sensing element 51 is arranged on the surface 25a of the permanent magnet 25. In this embodiment, the temperature sensing element 51 is arranged so as to be in contact with the surface 25a of the permanent magnet 25. In this embodiment, the temperature sensing element 51, like the permanent magnet 25, is also arranged entirely within the rotor core 23.

[0056] The coil 53 is also arranged in the rotor core 23, similar to the permanent magnet 25. In this embodiment, at least a portion of the coil 53 is arranged in the rotor core 23. The coil 53 is arranged in the rotor core 23 closer to the end face 23a than the permanent magnet 25. One end 53a of the coil 53 in the rotation axis direction D is exposed from the rotor core 23. The one end 53a is exposed at the end face 23a of the rotor core 23. In this embodiment, only the one end 53a of the coil 53 is exposed from the rotor core 23, and the rest of the coil 53 is embedded in the rotor core 23. As shown in FIG. 5, in this embodiment, the end face 23a is flush with the one end 53a of the coil 53. "End surface 23a is flush with one end 53a" includes not only that end surface 23a is flush with one end 53a, but also that there is a step between end surface 23a and one end 53a, the step being, for example, 1% or less of the length in the rotational axis direction D of rotor 20. At least a portion of coil 53 needs to be disposed within rotor core 23, and a portion other than one end 53a may be exposed from rotor core 23. In this case, for example, a portion of the side of coil 53 that is located closer to one end 53a may be exposed from rotor core 23, and end surface 23a does not need to be flush with one end 53a.

[0057] As described above, the magnet temperature information output device 1 has the electric resistance element 70 electrically connected to the element unit 60. The coil 61 of the element unit 60 is magnetically coupled to the coil 53, and therefore, power is supplied to the coil 53. The electric resistance of the temperature sensing element 51 electrically connected to the coil 53 changes in accordance with the temperature of the permanent magnet 25, and therefore the current flowing through the coil 61 changes in accordance with the change in the electric resistance of the temperature sensing element 51. The change in the current flowing through the coil 61 also changes the magnitude of the voltage drop occurring in the electric resistance element 70. The output unit 80 outputs an electric signal corresponding to the magnitude of the voltage drop occurring in the electric resistance element 70. Therefore, the electric signal output from the output unit 80 changes in accordance with the temperature of the permanent magnet 25. That is, in the magnet temperature information output device 1, temperature information regarding the temperature of the permanent magnet 25 is output from the output unit 80 as an electric signal related to voltage. As described above, the magnet temperature information output device 1 outputs temperature information regarding the temperature of the permanent magnet 25 as an electric signal related to voltage. The rotating electric machine MT is provided with the magnet temperature information output device 1 described above, and therefore temperature information relating to the temperature of the permanent magnet 25 is output as an electric signal relating to voltage. The control circuit 41, which functions as a magnet temperature acquisition device, includes the magnet temperature information output device 1, and therefore obtains the temperature of the permanent magnet 25 based on the electrical signal related to the voltage.

[0058] In the magnet temperature information output device 1, the electrical resistance element 70 is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 It has the following electrical resistance: Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71As described above, the following electrical resistance is the range of electrical resistance possessed by the electrical resistance element 70 that significantly detects changes in the temperature of the permanent magnet 25. Therefore, the magnet temperature information output device 1 outputs temperature information related to the temperature of the permanent magnet 25 with high accuracy.

[0059] The magnet temperature information output device 1 includes a capacitor 63 that is provided on the stator 10 and that, together with the coil 61, forms an LC resonant circuit. The magnet temperature information output device 1 accurately detects the change in the electrical resistance of the temperature sensitive element 51. Therefore, the magnet temperature information output device 1 outputs temperature information related to the temperature of the permanent magnet 25 with high accuracy.

[0060] In the rotating electric machine MT, the coil 53 and the coil 61 are arranged so as to face each other in the direction D of the rotation axis of the rotor 20 when the rotor 20 is at a predetermined rotation angle position. In the rotating electric machine MT, the magnetic flux generated in the stator coil 11 is unlikely to affect the coils 53 and 61 .

[0061] When outputting temperature information related to the temperature of the permanent magnet 25, a configuration is conceivable in which the stator 10 does not include an electrical resistance element 70, and an electrical signal related to the current flowing through the coil 61 is output as the temperature information. In this configuration, when acquiring the electrical signal related to the current and obtaining the temperature of the permanent magnet 25 based on the electrical signal, the magnet temperature acquisition device must convert the acquired electrical signal related to the current into an electrical signal related to the voltage. On the other hand, since the magnet temperature information output device 1 includes the electrical resistance element 70, an electrical signal related to the voltage is output as the temperature information related to the temperature of the permanent magnet 25. Therefore, the control circuit 41, which functions as the magnet temperature acquisition device, does not need to convert the electrical signal related to the current into an electrical signal related to the voltage. As described above, the magnet temperature information output device 1 outputs the temperature information that allows the temperature of the permanent magnet 25 to be easily obtained.

[0062] Next, the configuration of a modified example of the magnet temperature information output device 1 will be described with reference to Figs. 6, 7, and 8. Fig. 6 is a circuit diagram showing another example of the magnet temperature information output device. Figs. 7 and 8 are circuit diagrams showing equivalent circuits used when setting the electrical resistance of an electrical resistance element. This modified example differs from the above-described embodiment in terms of the configuration of the element unit 50. Below, the differences between the above-described embodiment and this modified example will be mainly described.

[0063] In this modification, as shown in FIG. 6 , the element unit 50 includes a capacitor 55 in addition to the temperature sensor 51 and the coil 53. The capacitor 55 and the coil 53 form an LC resonant circuit. The capacitor 55 may also form an LC resonant circuit with the coil 53 and the coil 61. The capacitor 55 is inserted, for example, so as to be connected in parallel to the coil 53. The capacitance of the capacitor 55 may be equal to or different from the capacitance of the capacitor 63. When the capacitance of the capacitor 55 and the capacitance of the capacitor 63 are different from each other, the capacitance of the capacitor 55 may be 30% to 200% of the capacitance of the capacitor 63, or 70% to 130% of the capacitance of the capacitor 63. The capacitor 55 may have a capacitance of 100 nF or less, for example, or may have a capacitance of 1 nF to 100 nF. The capacitance component of the capacitor 55 is not limited to the above range, and may be less than 1 nF or greater than 100 nF.

[0064] As described above, a magnetic flux corresponding to the applied AC voltage is generated in the coil 61. Then, when the rotor 20 rotates and the coil 61 approaches the coil 53, the coil 61 excites the coil 53. In this modification, a voltage having a frequency lower than a predetermined resonant frequency for exciting the coil 53 is applied to the coil 61. As described above, the predetermined resonant frequency is, for example, the resonant frequency of a circuit equivalent to the circuit in the magnet temperature information output device 1 when the coils 53 and 61 are magnetically coupled and the temperature of the temperature sensor 51 is at a predetermined temperature. In this modification, the circuit includes the temperature sensor 51, the coil 53, the coil 61, the capacitor 55, and the capacitor 63. Hereinafter, the "resonant frequency of a circuit equivalent to the circuit in the magnet temperature information output device 1 when the coils 53 and 61 are magnetically coupled and the temperature of the temperature sensor 51 is at a predetermined temperature" may be referred to as the reference resonant frequency. In this modification, the difference between the frequency of the voltage applied to the coil 61 and the predetermined resonance frequency is 5 kHz or more and 30 kHz or less.

[0065] In this modification, the synthetic impedance Z T , Z0 may be obtained using the equivalent circuit EC3 shown in FIG. 7 and the equivalent circuit EC4 shown in FIG. The equivalent circuit EC3 is a circuit that equivalently represents a circuit including the temperature sensor 51, coil 53, capacitor 55, coil 61, and capacitor 63 in the magnet temperature information output device 1 in which the element unit 50 has the above-described configuration. Therefore, the equivalent circuit EC3 includes elements corresponding to the temperature sensor 51, coil 53, capacitor 55, coil 61, and capacitor 63. In this modification, as shown in FIG. 7, the equivalent circuit EC3 includes element R1, elements L1, R2, element C2, element L2, elements L3, R3, and element C1. Element C2 corresponds to capacitor 55. In this modification, element C2 includes an element corresponding to the capacitance component of capacitor 55.

[0066] In the equivalent circuit EC3, the element R3 is inserted so as to be connected in series to the element L3. The element C1 is inserted so as to be connected in parallel to the element L3. The element C2 is inserted so as to be connected in parallel to the element L1. In the equivalent circuit EC3, the end closer to the element C1 is open. In the equivalent circuit EC3, the portion consisting of the elements R1, R2, L1, and C2 corresponds to the element unit 50, and the portion consisting of the elements L3, R3, and C1 corresponds to the element unit 60.

[0067] The equivalent circuit EC4 is a circuit equivalently showing a circuit in which the temperature sensor 51 is separated from the circuit including the temperature sensor 51, coil 53, capacitor 55, coil 61, and capacitor 63 in the magnet temperature information output device 1 in which the element unit 50 has the temperature sensor 51, coil 53, and capacitor 55. In the equivalent circuit EC4, the element R1 included in the equivalent circuit EC3 and corresponding to the temperature sensor 51 is released.

[0068] In this modification, the synthetic impedance Z T The synthetic impedance Z3 obtained in the equivalent circuit EC3 is T may be used. T is the composite impedance of the element unit 50 and the element unit 60 in the equivalent circuit EC3 at the temperature T°C of the element R1. 150 The synthetic impedance Z3 obtained in the equivalent circuit EC3 is 150 Similarly, the synthetic impedance Z o The composite impedance Z4 obtained in the equivalent circuit EC4 may be used for the impedance ΔV. The composite impedance Z4 is the composite impedance of the element unit 50 and the element unit 60 in the equivalent circuit EC4.

[0069] In this modification, as described above, the synthetic impedance Z T has a synthetic impedance Z3 T may be used, and the synthetic impedance Z oTherefore, in this modification, the synthetic impedance Z3 T and the synthetic impedance Z4, a preferred range of the electrical resistance, a more preferred range of the electrical resistance, and an optimum electrical resistance of the electrical resistance element 70 may be set.

[0070] In this modification, the element unit 50 has a capacitor 55. In this case, the magnet temperature information output device 1 accurately detects changes in the electrical resistance of the temperature sensing element 51. Therefore, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25. When the capacitance component of the capacitor 55 is equal to the capacitance component of the capacitor 63, the magnet temperature information output device 1 outputs temperature information relating to the temperature of the permanent magnet 25 with high accuracy.

[0071] As described above, in this modified example, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25. The relationship between this modified example and accurately outputting temperature information related to the temperature of the permanent magnet 25 will be described in more detail below. In this modified example, the magnet temperature information output device 1 more accurately detects changes in the electrical resistance of the thermosensitive element 51. For example, a configuration in which the element unit 60 has the capacitor 63 and the element unit 50 has the capacitor 55 detects changes in the electrical resistance of the thermosensitive element 51 more accurately than a configuration in which the element unit 60 has the capacitor 63 and the element unit 50 does not have the capacitor 55.

[0072] Although there are design values ​​for the inductance of coils 53 and 61 and the capacitance of capacitors 55 and 63, these values ​​may deviate from the design values ​​due to, for example, manufacturing errors. There is also a design value for the coupling constant between coils 53 and 61, but this value may deviate from the design value due to, for example, a deviation in the opposing distance between coils 53 and 61 caused by an installation error when installing coils 53 and 61.

[0073] If deviations from the design values ​​occur, variations may occur in the electrical signal that corresponds to the magnitude of the voltage drop occurring in the electrical resistance element 70 and is output as temperature information. The variations in the electrical signal affect the accuracy of the temperature information. For example, the smaller the variations in the electrical signal, the more accurate the temperature information. However, manufacturing errors and installation errors are difficult to eliminate. Therefore, it is desirable to suppress the variations in the electrical signal even when deviations from the design values ​​occur due to manufacturing errors and installation errors.

[0074] In this modification, the variation in the electric signal is suppressed even if deviations from the design values ​​occur in the inductance of the coils 53 and 61, the capacitance components of the capacitors 55 and 63, and the coupling constant between the coils 53 and 61. In this modification, the variation in the electric signal is suppressed, for example, within the temperature range of the permanent magnet 25 when the rotating electric machine MT is used. From the above, when the element unit 60 has the capacitor 63 and the element unit 50 has the capacitor 55, the magnet temperature information output device 1 outputs temperature information related to the temperature of the permanent magnet 25 with high accuracy.

[0075] In this modification, a voltage having a frequency lower than a predetermined resonant frequency that excites coil 53 is applied to coil 61. In this modification, an AC voltage having a frequency lower than the predetermined frequency is applied to coil 61 as a voltage having a frequency lower than the predetermined resonant frequency that excites coil 53. When a voltage having a frequency lower than the predetermined resonance frequency that excites the coil 53 is applied to the coil 61, the magnet temperature information output device 1 outputs temperature information relating to the temperature of the permanent magnet 25 with high accuracy.

[0076] In this modification, a voltage having a frequency lower than a predetermined resonant frequency that excites coil 53 is applied to coil 61. In this modification, an AC voltage having a frequency lower than the predetermined frequency is applied to coil 61 as a voltage having a frequency lower than the predetermined resonant frequency that excites coil 53. The difference between this frequency and the predetermined resonant frequency is 5 kHz or more and 30 kHz or less. In this modification, even if the coupling constant between coil 53 and coil 61 deviates from the design value, the variation in the electric signal is further suppressed. In this modification, the variation in the electric signal is further suppressed, for example, within the temperature range of the permanent magnet 25 when the rotating electric machine MT is used. Therefore, when a voltage having a frequency lower than a predetermined resonant frequency that excites coil 53 is applied to coil 61, and the difference between this frequency and the predetermined resonant frequency is 5 kHz or more and 30 kHz or less, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25.

[0077] Next, the configuration of another modified example of the magnet temperature information output device 1 will be described with reference to Figs. 9, 10, and 11. Fig. 9 is a circuit diagram showing yet another example of the magnet temperature information output device. Figs. 10 and 11 are circuit diagrams showing equivalent circuits used when setting the electrical resistance of an electrical resistance element. This modified example differs from the above-described embodiment in the configurations of the element unit 50 and the element unit 60. Below, the differences between the above-described embodiment and this modified example will be mainly described. In this modification, as shown in FIG. 9, the element unit 50 has a capacitor 55 in addition to the temperature sensing element 51 and the coil 53, and the element unit 60 does not have a capacitor 63.

[0078] In this modification, the synthetic impedance Z T ,Z o In determining this, an equivalent circuit EC5 shown in FIG. 10 and an equivalent circuit EC6 shown in FIG. 11 may be used. The equivalent circuit EC5 is a circuit that equivalently shows a circuit including the temperature sensor 51, the coil 53, the capacitor 55, and the coil 61 in the magnet temperature information output device 1 in which the element unit 50 and the element unit 60 have the configuration described above. Therefore, the equivalent circuit EC5 includes elements corresponding to the temperature sensor 51, the coil 53, the capacitor 55, and the coil 61. In this modification, as shown in Fig. 10, the equivalent circuit EC5 includes the element R1, elements L1 and R2, element C2, element L2, and elements L3 and R3.

[0079] In the equivalent circuit EC5, the element R3 is also inserted so as to be connected in series to the element L2. The element C2 is inserted so as to be connected in parallel to the element L1. In the equivalent circuit EC5, the ends closer to the elements L3 and R3 are open. In the equivalent circuit EC5, the portion composed of the elements R1, R2, L1, and C2 corresponds to the element unit 50, and the portion composed of the elements L3 and R3 corresponds to the element unit 60.

[0080] The equivalent circuit EC6 is a circuit equivalently showing a circuit in which the temperature sensor 51 is separated from a circuit including the temperature sensor 51, coil 53, capacitor 55, and coil 61 in the magnet temperature information output device 1 in which the element unit 50 and the element unit 60 have the configuration described above. In the equivalent circuit EC6, the element R1 included in the equivalent circuit EC5 and corresponding to the temperature sensor 51 is released.

[0081] In this modification, the synthetic impedance Z T The synthetic impedance Z5 obtained in the equivalent circuit EC5 is T may be used. T is the composite impedance of the element unit 50 and the element unit 60 in the equivalent circuit EC5 at the temperature T°C of the element R1. 150 The synthetic impedance Z5 obtained in the equivalent circuit EC5 is 150 Similarly, the synthetic impedance Z oFor the impedance Z6, a composite impedance Z6 determined in the equivalent circuit EC6 may be used. The composite impedance Z6 is the composite impedance of the element unit 50 and the element unit 60 in the equivalent circuit EC6.

[0082] In this modification, as described above, the synthetic impedance Z T The synthetic impedance Z5 T may be used, and the synthetic impedance Z o Therefore, in this modification, the synthetic impedance Z5 T and the synthetic impedance Z6, a preferred range of the electrical resistance, a more preferred range of the electrical resistance, and an optimum electrical resistance of the electrical resistance element 70 may be set.

[0083] In this modification, the element unit 50 also has a capacitor 55. In this case, the magnet temperature information output device 1 accurately detects the change in the electrical resistance of the temperature sensing element 51. Therefore, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25.

[0084] Next, the configuration of a modified example of the rotating electric machine MT will be described with reference to Fig. 12. Fig. 12 is a diagram showing the cross-sectional configuration of the rotor core. This modified example differs from the above-described embodiment in the configuration of the rotor core 23 and the arrangement of the coils 53. Below, the differences between the above-described embodiment and this modified example will be mainly described.

[0085] In this modification, as shown in FIG. 12 , the rotor core 23 further includes a plate M2 in addition to the multiple steel plates M1. The plate M2 is electrically conductive. The plate M2 may be made of, for example, stainless steel or aluminum. The plate M2 is disposed on the steel plate M1 that is located outermost in the rotation axis direction D and closer to the coil 61 when the rotor 20 is at a predetermined rotation angle. In this modification, the plate M2 includes an end surface 23a as its surface. In this modification, the temperature sensor 51 and the coil 53 are embedded in the plate M2. One end 53a of the coil 53 is exposed at the end surface 23a included in the plate M2. Even in this modification in which the end surface 23a is included in the plate M2, the end surface 23a is flush with the one end 53a of the coil 53. In this modified example, for example, a portion of the side of the coil 53 that is located closer to one end 53a may be exposed from the rotor core 23, and the end surface 23a of the plate M2 may not be flush with the one end 53a.

[0086] Next, the configuration of another modified example of the rotating electric machine MT will be described with reference to Fig. 13. Fig. 13 is a diagram showing the cross-sectional configuration of the rotor core. This modified example also differs from the above-described embodiment in terms of the configuration of the rotor core 23 and the arrangement of the coils 53. Below, the differences between the above-described embodiment and this modified example will be mainly described.

[0087] In this modification, as shown in FIG. 13 , the rotor core 23 further includes, in addition to the plurality of steel plates M1, a plate M2a and a plate M3 separate from the plate M2a. The plate M2a is not electrically conductive, while the plate M3 is electrically conductive. The plate M2a is disposed on the steel plate M1 that is located outermost in the rotation axis direction D and closer to the coil 61 among the plurality of steel plates M1. The plate M3 is disposed on the plate M2a. Therefore, in this modification, the plate M3 is also disposed on the steel plate M1 that is located outermost in the rotation axis direction D and closer to the coil 61 among the plurality of steel plates M1. In this modification, the plate M3 includes an end face 23a as its surface. In this modification, the temperature sensor 51 is embedded in the plate M2a, and the coil 53 is embedded in the plate M3.

[0088] One end 53a of coil 53 is exposed at end surface 23a included in plate M3. Even in this modified example in which end surface 23a is included in plate M3, end surface 23a is flush with one end 53a of coil 53. Also in this modified example, for example, a portion of the side of coil 53 that is located closer to one end 53a may be exposed from rotor core 23, and end surface 23a included in plate M3 may not be flush with one end 53a.

[0089] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0090] In the magnet temperature information output device 1, the output unit 80 may include an electric resistance element 70. When the output unit 80 includes the electric resistance element 70, the electric resistance element 70 may be an internal resistance of the output unit 80. When the electric resistance element 70 is an internal resistance of the output unit 80, the frequency of the voltage applied to the coil 61 may be a secondary resonance frequency among predetermined resonance frequencies that excite the coil 53. When the electric resistance element 70 is an internal resistance of the output unit 80 and the frequency of the voltage applied to the coil 61 is a secondary resonance frequency among the predetermined resonance frequencies, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25. When the electric resistance element 70 is not an internal resistance of the output unit 80, the frequency of the voltage applied to the coil 61 may be a primary resonance frequency among the predetermined resonance frequencies.

[0091] In the magnet temperature information output device 1, the electrical resistance element 70 is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 It is not necessary for the electrical resistance to be as follows: The electrical resistance element 70 is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 1500.71 As described above, the magnet temperature information output device 1 having the following electrical resistance outputs temperature information relating to the temperature of the permanent magnet with high accuracy.

[0092] The magnet temperature information output device 1 does not necessarily have to include the capacitor 63. As described above, the magnet temperature information output device 1 equipped with the capacitor 63 can accurately detect the change in the electrical resistance of the temperature sensitive element 51.

[0093] In the rotating electric machine MT, the coils 53 and 61 do not have to be arranged so as to face each other in the direction D of the rotation axis when the rotor 20 is at a predetermined rotational angle position. In a rotating electric machine MT in which coils 53 and 61 are arranged so as to face each other in the direction of the rotation axis D when the rotor 20 is at a predetermined rotation angle position, as described above, the magnetic flux generated in the stator coil 11 is unlikely to affect coils 53 and 61.

[0094] In the rotating electric machine MT, the temperature sensing element 51 does not have to be arranged so as to be in contact with the surface 25a of the permanent magnet 25. The entire permanent magnet 25 and a part of the coil 53 do not have to be arranged inside the rotor core 23.

[0095] The control circuit 41 does not have to function as a magnet temperature acquisition device. The control circuit 41 may control the drive state of the rotating electric machine MT based on an electrical signal corresponding to the magnitude of the voltage drop occurring in the electrical resistance element 70, which is input from the output unit 80. In this case, the control circuit 41 may control the drive state of the rotating electric machine MT as follows. When the control circuit 41 determines from the electrical signal input from the output unit 80 that the temperature of the permanent magnet 25 has risen to a predetermined first threshold, the control circuit 41 controls the drive frequency to decrease so as to limit the rotation speed of the rotating electric machine MT. When the control circuit 41 determines from the electrical signal input from the output unit 80 that the temperature of the permanent magnet 25 has fallen to a predetermined second threshold that is smaller than the first threshold, the control circuit 41 controls the drive frequency to increase so as to remove the limit on the rotation speed of the rotating electric machine MT.

[0096] Next, with reference to FIGS. 14, 15, and 16, an experiment conducted by the present inventors will be described to explain why the preferred range of electrical resistance of the electrical resistance element 70 significantly captures temperature changes of the permanent magnet 25, and why a more preferred range of electrical resistance significantly captures temperature changes of the permanent magnet 25. FIG. 14 is a circuit diagram showing an equivalent circuit used to determine the relationship between the electrical resistance of an electrical resistance element and the accuracy of temperature information. FIGS. 15 and 16 are tables showing the relationship between the electrical resistance of an electrical resistance element and the accuracy of temperature information. The present inventors conducted experiments under the following conditions 1 to 16 using the equivalent circuit EC7 shown in FIG. 14 and the equivalent circuit EC2 shown in FIG. 4.

[0097] The equivalent circuit EC7 is a circuit that equivalently shows a circuit including the temperature sensing element 51, the coil 53, the coil 61, the capacitor 63, the AC power supply PS, and the electrical resistance element 70 in the magnet temperature information output device 1. Therefore, the equivalent circuit EC7 includes elements corresponding to the temperature sensing element 51, the coil 53, the coil 61, the capacitor 63, the AC power supply PS, and the electrical resistance element 70.

[0098] The equivalent circuit EC7 includes an element R1, elements L1 and R2, element L2, elements L3 and R3, element C1, a power supply V, and element R4. The power supply V corresponds to the AC power supply PS. The element R4 corresponds to the electrical resistance element 70. In the equivalent circuit EC7, the element R4 includes an element corresponding to the electrical resistance of the electrical resistance element 70.

[0099] In the equivalent circuit EC7, the element L3 is electrically connected to a power supply V. A voltage is applied to the element L3 from the power supply V. In the equivalent circuit EC7, a voltage corresponding to the AC voltage applied to the coil 61 from the AC power supply PS is applied to the element L3 from the power supply V. The element R4 is inserted between the element R3 and the power supply V. In the equivalent circuit EC7, the portion formed by the element R1 and the elements R2 and L1 corresponds to the element unit 50, and the portion formed by the elements L3, R3 and element C1 corresponds to the element unit 60.

[0100] (Condition 1) In condition 1, the power supply V was set as a power supply that applied an AC voltage of 4.5 V at a frequency of 85 kHz to element L3. Elements R2 and R3 were set as elements having an electrical resistance of 2.4 Ω. Elements L1 and L3 were set as elements having an inductance of 160 μH. Element L2 was set as an element having a coupling constant of 0.7. Element C1 was set as an element having a capacitance component of 22 nF. Element R4 was set as an element having an electrical resistance of 300 Ω. The composite impedance Z 150 was set to 294 Ω. o was set to 2980 Ω.

[0101] Under condition 1, the composite impedance Z 150 and the synthetic impedance Z o The preferred range of the electrical resistance of the electrical resistance element 70, set using the above formula, was 268.07 Ω or more and 3087.70 Ω or less. Furthermore, under condition 1, the more preferred range of the electrical resistance of the electrical resistance element 70 was 473.24 Ω or more and 1959.60 Ω or less. That is, under condition 1, the electrical resistance of element R4 was within the preferred range of electrical resistance but outside the more preferred range of electrical resistance.

[0102] Under condition 1, we calculated the magnitude of the voltage drop across element R4 when the temperature of element R1 was T°C, and the magnitude of the voltage drop across element R4 when the temperature of element R1 was -40°C. The temperature T of element R1 was set in the range of 120°C to 170°C. Hereinafter, the magnitude of the voltage drop across element R4 when the temperature of element R1 is between 120°C and 170°C will be referred to as V(T), and the magnitude of the voltage drop across element R4 when the temperature of element R4 is -40°C will be referred to as V(-40). For example, the magnitude of the voltage drop across element R4 when the temperature of element R1 is 120°C will be referred to as V(120).

[0103] Furthermore, indicators A1, A2, and A3 were calculated as indicators indicating the accuracy of the temperature information, and indicators A4, A5, and A6 were calculated as indicators indicating the relative accuracy of the temperature information. Index A1 is expressed by the relationship A1 = V(120) - V(-40), index A2 is expressed by the relationship A2 = V(150) - V(-40), and index A3 is expressed by the relationship A3 = V(170) - V(-40). Index A4 is expressed by the relationship A4 = {V(120) - V(-40)} / Vmax, index A5 is expressed by the relationship A5 = {V(150) - V(-40)} / Vmax, and index A6 is expressed by the relationship A6 = {V(170) - V(-40)} / Vmax. Here, Vmax indicates the maximum value of V(T) within the temperature range of 120°C to 170°C.

[0104] (Condition 2) Under condition 2, except that element R4 was set as an element having an electrical resistance of 500 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 2, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0105] (Condition 3) Under condition 3, except that element R4 was set as an element having an electrical resistance of 1000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 3, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0106] (Condition 4) Under condition 4, except that element R4 was set as an element having an electrical resistance of 2000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 4, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0107] (Condition 5) Under condition 5, except that element R4 was set as an element having an electrical resistance of 3000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 5, the electrical resistance of element R4 was within the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0108] (Condition 6) Under condition 6, except that element R4 was set as an element having an electrical resistance of 100 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 6, the electrical resistance of element R4 was outside the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0109] (Condition 7) Under condition 7, except that element R4 was set as an element having an electrical resistance of 5000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 1. Under condition 7, the electrical resistance of element R4 was outside the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0110] (Condition 8) In condition 8, the power supply V was set as a power supply that applied an AC voltage of 420 kHz and 5.0 V to element L3. Elements R2 and R3 were set as elements having an electrical resistance of 2.4 Ω. Elements L1 and L3 were set as elements having an inductance of 30 μH. Element L2 was set as an element having a coupling constant of 0.5. Element C1 was set as an element having a capacitance component of 4.7 nF. Element R4 was set as an element having an electrical resistance of 400 Ω. The composite impedance Z 150 was set to 148.8Ω. The combined impedance Z o was set to 2330 Ω.

[0111] In condition 8, the synthetic impedance Z 150 and the synthetic impedance Z oThe preferred range of the electrical resistance of the electrical resistance element 70, set using the above formula, was 317.50 Ω or more and 5728.95 Ω or less. Furthermore, under condition 6, the more preferred range of the electrical resistance of the electrical resistance element 70 was 622.18 Ω or more and 3344.57 Ω or less. That is, under condition 8, the electrical resistance of element R4 was within the preferred range of electrical resistance but outside the more preferred range of electrical resistance. Under condition 8, similarly to conditions 1 to 7, the indices A1, A2, and A3 were calculated as indices indicating the accuracy of the temperature information, and the indices A4, A5, and A6 were calculated as indices indicating the relative accuracy of the temperature information.

[0112] (Condition 9) Under condition 9, except that element R4 was set as an element having an electrical resistance of 700 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 9, the electrical resistance of element R4 was within the preferred range of electrical resistances and within the more preferred range of electrical resistances.

[0113] (Condition 10) Under condition 10, except that element R4 was set as an element having an electrical resistance of 1000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 10, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0114] (Condition 11) Under condition 11, except that element R4 was set as an element having an electrical resistance of 2000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 11, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0115] (Condition 12) Under condition 12, except that element R4 was set as an element having an electrical resistance of 3000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 12, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0116] (Condition 13) Under condition 13, except that element R4 was set as an element having an electrical resistance of 4000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 13, the electrical resistance of element R4 was within the preferred range of electrical resistance and within the more preferred range of electrical resistance.

[0117] (Condition 14) Under condition 14, except that element R4 was set as an element having an electrical resistance of 5000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 14, the electrical resistance of element R4 was within the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0118] (Condition 15) Under condition 15, except that element R4 was set as an element having an electrical resistance of 100 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 15, the electrical resistance of element R4 was outside the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0119] (Condition 16) Under condition 16, except that element R4 was set as an element having an electrical resistance of 6000 Ω, the indices A1, A2, A3 and A4, A5, A6 were calculated in the same manner as under condition 8. Under condition 16, the electrical resistance of element R4 was outside the preferred range of electrical resistance and outside the more preferred range of electrical resistance.

[0120] The calculation results for conditions 1 to 7 are shown in Fig. 15. Fig. 15 shows the indicators A1, A2, A3 and A4, A5, and A6 together with the electrical resistance of element R4 under conditions 1 to 7. The calculation results for conditions 8 to 16 are shown in Fig. 16. Fig. 16 shows the indicators A1, A2, A3 and A4, A5, and A6 together with the electrical resistance of element R4 under conditions 8 to 16.

[0121] 15 and 16, it can be seen that under conditions 1 to 5 and conditions 8 to 14, where the electrical resistance of element R4 is within the preferred range of electrical resistance, the indicators A4, A5, and A6 are 60% or more. Therefore, it can be understood that the preferred range of electrical resistance allows for a significant detection of temperature changes in permanent magnet 25. Furthermore, under conditions 2 to 4 and conditions 9 to 12, where the electrical resistance of element R4 is within the more preferred range of electrical resistance, it can be seen that the indicators A4, A5, and A6 are 80% or more. Therefore, it can be understood that the more preferred range of electrical resistance allows for a more significant detection of temperature changes in permanent magnet 25.

[0122] 17 and 18, an experiment conducted by the present inventors will be described to explain that the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25 when the element unit 60 has a capacitor 63 and the element unit 50 has a capacitor 55. Figs. 17 and 18 are diagrams showing the relationship between the voltage drop occurring in an electrical resistance element and the temperature.

[0123] The present inventors conducted experiments under the following conditions 17 to 23 using an equivalent circuit obtained by adding element R4 and power supply V to equivalent circuit EC1 shown in FIG. 3. In the equivalent circuit obtained by adding element R4 and power supply V to equivalent circuit EC1, power supply V is electrically connected to element L3, and element R4 is inserted between element R3 and power supply V. A voltage corresponding to the AC voltage applied to coil 61 from AC power supply PS is applied to element L3 from power supply V. For example, a voltage corresponding to the difference between the corresponding voltage and the voltage drop occurring across element R4 is applied to element L3. This allowed the present inventors to confirm the relationship between voltage drop and temperature when element unit 60 includes capacitor 63 and element unit 50 does not include capacitor 55.

[0124] The present inventors conducted experiments under the following conditions 24 to 30 using an equivalent circuit obtained by adding element R4 and power supply V to equivalent circuit EC3 shown in FIG. 7. In the equivalent circuit obtained by adding element R4 and power supply V to equivalent circuit EC3, power supply V is electrically connected to element L3, and element R4 is inserted between element R3 and power supply V. A voltage corresponding to the AC voltage applied to coil 61 from AC power supply PS is applied to element L3 from power supply V. For example, a voltage corresponding to the difference between the corresponding voltage and the voltage drop occurring across element R4 is applied to element L3. This allowed the present inventors to confirm the relationship between voltage drop and temperature in a configuration in which element unit 60 includes capacitor 63 and element unit 50 includes capacitor 55.

[0125] (Condition 17) In condition 17, the power supply V was set as a power supply that applied an AC voltage, the frequency of which was the reference resonant frequency and the voltage of which was the reference voltage, to element L3. Elements R2 and R3 were set as elements having a first reference electrical resistance. Elements L1 and L3 were set as elements having a reference inductance. Element L2 was set as an element having a reference coupling constant. Element C1 was set as an element having a first reference capacitance component. Element R4 was set as an element having a second reference electrical resistance. An AC voltage, the frequency of which was the reference resonant frequency and the voltage of which was the reference voltage, was applied to element L3 from the power supply V via element R4. That is, a voltage corresponding to the difference between the reference voltage and the voltage drop occurring across element R4 was applied to element L3.

[0126] The reference voltage, first reference electrical resistance, reference inductance, first reference capacitance component, and second reference electrical resistance were set based on the specifications of coil 53, coil 61, capacitor 63, and electrical resistance element 70, for example, that will be adopted when magnet temperature information output device 1 is actually used. The reference coupling constant was the coupling constant between coil 53 and coil 61 when the opposing distance between coil 53 and coil 61 was 3.0 mm. Under condition 17, the relationship between the electrical signal and temperature was determined by acquiring an electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 while changing the temperature of element R1. Under condition 17, an electrical signal indicating the voltage across element C1 was acquired as the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4.

[0127] (Condition 18) Under condition 18, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and the temperature was determined in the same manner as under condition 17, except that elements L1 and L3 were set as elements having an inductance that was 5% greater than the reference inductance.

[0128] (Condition 19) Under condition 19, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and the temperature was determined in the same manner as under condition 17, except that elements L1 and L3 were set as elements having an inductance that was 5% less than the reference inductance.

[0129] (Condition 20) Under condition 20, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was obtained in the same manner as under condition 17, except that element C1 was set as an element having a capacitance component that was 5% greater than the first reference capacitance component.

[0130] (Condition 21) Under condition 21, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 17, except that element C1 was set as an element having a capacitance component that was 5% less than the first reference capacitance component.

[0131] (Condition 22) Under condition 22, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 17, except that element L2 was set as an element having a coupling constant that was 5% greater than the reference coupling constant.

[0132] (Condition 23) Under condition 23, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 17, except that element L2 was set as an element having a coupling constant that was 5% lower than the reference coupling constant.

[0133] (Condition 24) Under condition 24, power supply V was configured to apply an AC voltage having a frequency equal to the reference resonant frequency and a voltage equal to the reference voltage to element L3. Elements R2 and R3 were configured as elements having a first reference electrical resistance. Elements L1 and L3 were configured as elements having a reference inductance. Element L2 was configured as an element having a reference coupling constant. Element C1 was configured as an element having a first reference capacitance component. Element C2 was configured as an element having a second reference capacitance component. Element R4 was configured as an element having a second reference electrical resistance. The second reference capacitance component was set, for example, based on the specifications of capacitor 55 employed when the magnet temperature information output device 1 is actually used. An AC voltage having a frequency equal to the reference resonant frequency and a voltage equal to the reference voltage was applied to element L3 from power supply V via element R4. That is, a voltage corresponding to the difference between the reference voltage and the voltage drop occurring across element R4 was applied to element L3. Under condition 24, an electrical signal corresponding to the magnitude of the voltage drop occurring across element R4 was acquired, and the relationship between the electrical signal and temperature was determined. Under condition 24, a signal indicating the voltage across element C1 was acquired as the electrical signal corresponding to the magnitude of the voltage drop occurring across element R4.

[0134] (Condition 25) Under condition 25, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and the temperature was determined in the same manner as under condition 24, except that elements L1 and L3 were set as elements having an inductance that was 5% greater than the reference inductance.

[0135] (Condition 26) Under condition 26, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that elements L1 and L3 were set as elements having an inductance that was 5% less than the reference inductance.

[0136] (Condition 27) Under condition 27, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that element C1 was set as an element having a capacitance component in which the first reference capacitance component was increased by 5%.

[0137] (Condition 28) Under condition 28, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that element C1 was set as an element having a capacitance component that was 5% less than the first reference capacitance component.

[0138] (Condition 29) Under condition 29, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that element C2 was set as an element having a capacitance component in which the second reference capacitance component was increased by 5%.

[0139] (Condition 30) Under condition 30, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was obtained in the same manner as under condition 24, except that element C2 was set as an element having a capacitance component that was 5% smaller than the second reference capacitance component.

[0140] (Condition 31) Under condition 31, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that element L2 was set as an element having a coupling constant that was 5% greater than the reference coupling constant.

[0141] (Condition 32) Under condition 32, the relationship between the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 and temperature was determined in the same manner as under condition 24, except that element L2 was set as an element having a coupling constant that was 5% lower than the reference coupling constant.

[0142] The results for conditions 17 to 23 are shown in Figure 17. The results for conditions 24 to 32 are shown in Figure 18. In the graphs shown in Figures 17 and 18, the horizontal axis represents temperature [°C], and the vertical axis represents voltage value [V] based on an electrical signal corresponding to the magnitude of the voltage drop. In FIG. 17, relationship G1 shows the relationship between voltage drop and temperature obtained under condition 17. Relationship G2 shows the relationship between voltage drop and temperature obtained under condition 18. Relationship G3 shows the relationship between voltage drop and temperature obtained under condition 19. Relationship G4 shows the relationship between voltage drop and temperature obtained under condition 20. Relationship G5 shows the relationship between voltage drop and temperature obtained under condition 21. Relationship G6 shows the relationship between voltage drop and temperature obtained under condition 22. Relationship G7 shows the relationship between voltage drop and temperature obtained under condition 23.

[0143] In FIG. 18, relationship G8 shows the relationship between voltage drop and temperature obtained under condition 24. Relationship G9 shows the relationship between voltage drop and temperature obtained under condition 25. Relationship G10 shows the relationship between voltage drop and temperature obtained under condition 26. Relationship G11 shows the relationship between voltage drop and temperature obtained under condition 27. Relationship G12 shows the relationship between voltage drop and temperature obtained under condition 28. Relationship G13 shows the relationship between voltage drop and temperature obtained under condition 29. Relationship G14 shows the relationship between voltage drop and temperature obtained under condition 30. Relationship G15 shows the relationship between voltage drop and temperature obtained under condition 31. Relationship G16 shows the relationship between voltage drop and temperature obtained under condition 32.

[0144] In each of the relationships G1 to G16, the large change in voltage value with increasing temperature indicates improved accuracy in detecting changes in the electrical resistance of the temperature sensitive element 51. For example, in relationship G1, the voltage value at 25°C is approximately 3.6V, and the voltage value at 150°C is approximately 2.6V. That is, in relationship G1, the difference between the voltage value at 25°C and the voltage value at 150°C is approximately 1.0V. In contrast, in the relationship G8, the voltage value at 25°C is approximately 3.1 V, and the voltage value at 150°C is approximately 1.1 V. That is, in the relationship G8, the difference between the voltage value at 25°C and the voltage value at 150°C is approximately 2.0 V. Therefore, it can be seen that the change in voltage value with increasing temperature is greater in the relationship G8 than in the relationship G1.

[0145] 17 and 18, it can be seen that the changes in voltage value with increasing temperature are larger in the relationships G9 to G16 as well, compared to the relationships G2 to G7. From these, it can be seen that when the element unit 60 has the capacitor 63 and the element unit 50 has the capacitor 55, the changes in voltage value with increasing temperature are larger than when the element unit 60 has the capacitor 63 and the element unit 50 does not have the capacitor 55.

[0146] 17 and 18, it can be seen that in the range of 100°C or higher, the variation of each of the relationships G9 to G16 with respect to the relationship G8 is smaller than the variation of each of the relationships G2 to G7 with respect to the relationship G1. From this, it can be seen that even if the inductance of the coils 53 and 61, the capacitance components of the capacitors 55 and 63, and the coupling constant between the coils 53 and 61 deviate from the design values, when the element unit 60 includes the capacitor 63 and the element unit 50 includes the capacitor 55, the variation in the amplitude of the output electrical signal is suppressed. Therefore, when the element unit 60 includes the capacitor 63 and the element unit 50 includes the capacitor 55, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25.

[0147] Next, with reference to FIGS. 19, 20, 21, 22, and 23, the inventors of the present invention conducted an experiment to demonstrate that the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of the permanent magnet 25 when a voltage having a frequency lower than a predetermined resonant frequency that excites the coil 53 is applied to the coil 61 and the difference between the frequency and the predetermined resonant frequency is 5 kHz or more and 30 kHz or less. FIGS. 19, 20, 21, 22, and 23 are diagrams showing the relationship between the temperature and the voltage drop occurring in an electrical resistance element. The inventors conducted an experiment under the following conditions 33 to 44 using the equivalent circuit EC2 shown in FIG. 7, in which the element R4 and the power supply V are added. The inventors confirmed the relationship between the voltage drop and the temperature when the frequency of the voltage applied to the coil 61 is lower than the predetermined resonant frequency and the difference between the frequency and the predetermined resonant frequency is 5 kHz or more and 30 kHz or less.

[0148] (Condition 34) Under condition 34, the power supply V was configured as a power supply that applied an AC voltage, the frequency of which was the reference resonant frequency and the voltage of which was the reference voltage, to element L3. As described above, the reference resonant frequency is an example of a predetermined resonant frequency that excites coil 53. Therefore, under condition 34, the frequency of the voltage applied to element L3 was set to the predetermined resonant frequency that excites coil 53. Elements R2 and R3 were configured as elements having a first reference electrical resistance. Elements L1 and L3 were configured as elements having a reference inductance. Element L2 was configured as an element having a reference coupling constant. Element C1 was configured as an element having a first reference capacitive component. Element C2 was configured as an element having a second reference capacitive component. Element R4 was configured as an element having a second reference electrical resistance. An AC voltage, the frequency of which was the reference frequency and the voltage of which was the reference voltage, was applied to element L3 from the power supply V via element R4. That is, a voltage corresponding to the difference between the reference voltage and the voltage drop across element R4 was applied to element L3. Under condition 34, the relationship between the electrical signal and temperature was determined by acquiring an electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 while changing the temperature of element R1. Under condition 34, a signal indicating the voltage across element C1 was acquired as the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4.

[0149] (Condition 35) Under condition 35, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that element L2 was set as the element having the first coupling constant. The first coupling constant was the coupling constant between coil 53 and coil 61 when the opposing distance between coil 53 and coil 61 was 2.5 mm.

[0150] (Condition 36) Under condition 36, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that element L2 was set as the element having the second coupling constant. The second coupling constant was the coupling constant between coil 53 and coil 61 when the opposing distance between coil 53 and coil 61 was 3.5 mm.

[0151] (Condition 37) Under condition 37, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that power supply V was set as a power supply that applied an AC voltage having a frequency 5 kHz lower than the reference resonance frequency to element L3. That is, under condition 37, the frequency of the voltage applied to element L3 was set to be 5 kHz lower than the predetermined resonance frequency that excites coil 53.

[0152] (Condition 38) Under condition 38, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 37, except that element L2 was set as the element having the first coupling constant.

[0153] (Condition 39) Under condition 39, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 37, except that element L2 was set as the element having the second coupling constant.

[0154] (Condition 40) Under condition 40, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that power supply V was set as a power supply that applied an AC voltage having a frequency 10 kHz lower than the reference resonance frequency to element L3. That is, under condition 40, the frequency of the voltage applied to element L3 was set to a frequency 10 kHz lower than the predetermined resonance frequency that excites coil 53.

[0155] (Condition 41) Under condition 41, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 40, except that element L2 was set as the element having the first coupling constant.

[0156] (Condition 42) Under condition 42, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 40, except that element L2 was set as the element having the second coupling constant.

[0157] (Condition 43) Under condition 43, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that power supply V was set as a power supply that applied an AC voltage having a frequency 20 kHz lower than the reference resonance frequency to element L3. That is, under condition 43, the frequency of the voltage applied to element L3 was set to a frequency 20 kHz lower than the predetermined resonance frequency that excites coil 53.

[0158] (Condition 44) Under condition 44, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 43, except that element L2 was set as the element having the first coupling constant.

[0159] (Condition 45) Under condition 45, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 43, except that element L2 was set as the element having the second coupling constant.

[0160] (Condition 46) Under condition 46, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 34, except that power supply V was set as a power supply that applied an AC voltage having a frequency 30 kHz lower than the reference resonance frequency to element L3. That is, under condition 46, the frequency of the voltage applied to element L3 was set to a frequency 30 kHz lower than the predetermined resonance frequency that excites coil 53.

[0161] (Condition 47) Under condition 47, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 46, except that element L2 was set as the element having the first coupling constant.

[0162] (Condition 48) Under condition 48, the relationship between the temperature and the electrical signal corresponding to the magnitude of the voltage drop occurring in element R4 was determined in the same manner as under condition 46, except that element L2 was set as the element having the second coupling constant.

[0163] The results for conditions 34 to 36 are shown in Figure 19. The results for conditions 37 to 39 are shown in Figure 20. The results for conditions 40 to 42 are shown in Figure 21. The results for conditions 43 to 45 are shown in Figure 22. The results for conditions 46 to 48 are shown in Figure 23. In the graphs shown in Figures 19 to 23, the horizontal axis represents temperature [°C], and the vertical axis represents voltage value [V] based on an electrical signal corresponding to the magnitude of the voltage drop.

[0164] 19, relationship G17 shows the relationship between voltage drop and temperature obtained under condition 34. Relationship G18 shows the relationship between voltage drop and temperature obtained under condition 35. Relationship G19 shows the relationship between voltage drop and temperature obtained under condition 36. 20, relationship G20 shows the relationship between voltage drop and temperature obtained under condition 37. Relationship G21 shows the relationship between voltage drop and temperature obtained under condition 38. Relationship G22 shows the relationship between voltage drop and temperature obtained under condition 39. 21, relationship G23 shows the relationship between voltage drop and temperature obtained under condition 40. Relationship G24 shows the relationship between voltage drop and temperature obtained under condition 41. Relationship G25 shows the relationship between voltage drop and temperature obtained under condition 42.

[0165] 22, relationship G26 shows the relationship between voltage drop and temperature obtained under condition 43. Relationship G27 shows the relationship between voltage drop and temperature obtained under condition 44. Relationship G28 shows the relationship between voltage drop and temperature obtained under condition 45. 23, relationship G29 shows the relationship between voltage drop and temperature obtained under condition 46. Relationship G30 shows the relationship between voltage drop and temperature obtained under condition 47. Relationship G31 shows the relationship between voltage drop and temperature obtained under condition 48.

[0166] 19 and 20, it can be seen that in the range of 100°C or higher and 180°C or lower, the variation of each of the relationships G21 and G22 relative to the relationship G20 is smaller than the variation of each of the relationships G18 and G19 relative to the relationship G17. In the relationships G20 to G22, the variation of each of the relationships G21 and G22 relative to the relationship G20 is suppressed, particularly around 120°C. This shows that even if the coupling constant between coil 53 and coil 61 deviates from the design value, when the frequency of the voltage applied to coil 61 is 5 kHz lower than the predetermined resonant frequency that excites coil 53, the variation in the amplitude of the output electrical signal is suppressed in the range of 100°C or higher and 180°C or lower.

[0167] 19 and 21, it can be seen that in the range of 100°C or higher and 180°C or lower, the variation of each of the relationships G24 and G25 with respect to the relationship G23 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. In particular, in the range of 120°C or higher and 180°C or lower, it can be seen that the variation of each of the relationships G24 and G25 with respect to the relationship G23 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. Among the relationships G23 to G25, the variation of each of the relationships G24 and G25 with respect to the relationship G23 is suppressed, particularly around 130°C. This shows that even if the coupling constant between coil 53 and coil 61 deviates from the design value, when the frequency of the voltage applied to coil 61 is 10 kHz lower than the predetermined resonant frequency that excites coil 53, the variation of the amplitude of the output electrical signal is suppressed in the range of 100°C or higher and 180°C or lower.

[0168] 19 and 22, it can be seen that in the range of 100°C to 180°C, the variation of each of the relationships G27 and G28 with respect to the relationship G26 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. In particular, in the range of 130°C to 180°C, it can be seen that the variation of each of the relationships G27 and G28 with respect to the relationship G26 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. Among the relationships G26 to G28, the variation of each of the relationships G27 and G28 with respect to the relationship G26 is suppressed, particularly around 150°C. This shows that even if the coupling constant between coil 53 and coil 61 deviates from the design value, when the frequency of the voltage applied to coil 61 is 20 kHz lower than the predetermined resonant frequency that excites coil 53, the variation of the amplitude of the output electrical signal is suppressed in the range of 100°C to 180°C.

[0169] 19 and 23, in the temperature range of 100°C to 180°C, the variation of each of the relationships G30 and G31 with respect to the relationship G29 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. In particular, in the temperature range of 140°C to 180°C, the variation of each of the relationships G30 and G31 with respect to the relationship G29 is smaller than the variation of each of the relationships G18 and G19 with respect to the relationship G17. In the relationships G29 to G31, the variation of each of the relationships G30 and G31 with respect to the relationship G29 is suppressed, especially around 170°C. This indicates that even if the coupling constant between coil 53 and coil 61 deviates from the design value, the variation in the amplitude of the output electrical signal is suppressed in the temperature range of 100°C to 180°C when the frequency of the voltage applied to coil 61 is 30 kHz lower than the predetermined resonant frequency that excites coil 53.

[0170] From the above, it can be seen that even if the coupling constant between coil 53 and coil 61 deviates from the design value, variation in the amplitude of the output electrical signal is suppressed when the frequency of the voltage applied to coil 61 is lower than the predetermined resonant frequency that excites coil 53 and the difference between this frequency and the predetermined resonant frequency is 5 kHz to 30 kHz. Therefore, when the frequency of the voltage applied to coil 61 is lower than the predetermined resonant frequency that excites coil 53 and the difference between this frequency and the predetermined resonant frequency is 5 kHz to 30 kHz, the magnet temperature information output device 1 accurately outputs temperature information related to the temperature of permanent magnet 25.

[0171] As can be understood from the above description of the embodiments and modifications, this specification includes disclosure of the following aspects. (Appendix 1) 1. A magnet temperature information output device that is provided to a rotating electric machine having a stator and a rotor in which a permanent magnet is arranged, and that outputs temperature information related to a temperature of the permanent magnet, a first element unit provided on the rotor, the first element unit having a temperature sensing element whose electrical resistance changes depending on the temperature of the permanent magnet and a first coil electrically connected to the temperature sensing element; a second element unit provided on the stator, the second element unit having a second coil magnetically coupled to the first coil; an electric resistance element electrically connected to the second element unit; an output section electrically connected to the second element unit and the electrical resistance element, The output unit outputs an electrical signal corresponding to the magnitude of a voltage drop occurring in the electrical resistance element as the temperature information. (Appendix 2) The electrical resistance element is Z o 0.50 ×Z 150 0.28 More than Z o 0.50 ×Z 150 0.71 It has the following electrical resistance: where Z150 is a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature of the temperature sensing element is 150°C, Z o is a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature-sensing element is detached from the first element unit. (Appendix 3) 3. The magnet temperature information output device according to claim 1, wherein the second element unit further includes a capacitor that configures an LC resonant circuit together with the second coil. (Appendix 4) 4. The magnet temperature information output device according to any one of appendices 1 to 3, wherein the first element unit further includes a capacitor that configures an LC resonant circuit together with the first coil. (Appendix 5) the first element unit further includes a capacitor that configures an LC resonant circuit together with the first coil, 3. The magnet temperature information output device according to claim 1, wherein the second element unit further includes a capacitor that configures an LC resonant circuit together with the second coil. (Appendix 6) 6. The magnet temperature information output device according to claim 5, wherein a voltage having a frequency lower than a predetermined resonant frequency that excites the first coil is applied to the second coil. (Appendix 7) 7. The magnet temperature information output device according to claim 6, wherein the difference between the frequency and the predetermined resonant frequency is 5 kHz or more and 30 kHz or less. (Appendix 8) A rotating electric machine provided with the magnet temperature information output device according to any one of Supplementary notes 1 to 7. (Appendix 9) A rotating electric machine as described in Appendix 8, wherein the first coil and the second coil are arranged so as to face each other in the direction of the rotational axis of the rotor when the rotor is at a predetermined rotational angle position. (Appendix 10) the rotor has a rotor core; the entire permanent magnet and at least a portion of the first coil are disposed within the rotor core; the permanent magnet has a pair of surfaces perpendicular to the rotation axis direction of the rotor, A rotating electric machine as described in Appendix 8 or 9, wherein the temperature-sensing element is arranged so as to contact the surface of the pair of surfaces that is located closer to the second coil when the rotor is at a predetermined rotational angle position. (Appendix 11) the rotor core includes a pair of end faces perpendicular to the rotation axis direction of the rotor, A rotating electric machine as described in Appendix 10, wherein of the pair of end faces, the end face located closer to the second coil is flush with one end of the first coil in the direction of the rotation axis of the rotor. (Appendix 12) The rotor core includes a plurality of steel plates stacked in the rotation axis direction and a plate, the plurality of steel plates are magnetic, the plate is electrically conductive and is disposed on a steel plate, among the plurality of steel plates, that is located outermost in the rotation axis direction of the rotor and that is located closer to the second coil, 12. The rotating electric machine according to claim 10, wherein the first coil is embedded in the plate. (Appendix 13) The magnet temperature information output device according to any one of appendices 1 to 7 includes: a magnet temperature acquisition device that acquires the electrical signal output from the magnet temperature information output device and obtains the temperature of the permanent magnet based on the acquired electrical signal; (Appendix 14) 1. A temperature information output device that is provided to a rotating electric machine including a stator and a rotor in which a permanent magnet is arranged, and that outputs temperature information related to temperatures of portions of the rotor, a first element unit provided on the rotor, the first element unit having a temperature sensing element whose electrical resistance changes depending on the temperature of the portion and a first coil electrically connected to the temperature sensing element; a second element unit provided on the stator, the second element unit having a second coil magnetically coupled to the first coil; an electric resistance element electrically connected to the second element unit; an output section electrically connected to the second element unit and the electrical resistance element, The output section outputs an electrical signal corresponding to the magnitude of a voltage drop occurring in the electrical resistance element as the temperature information. [Explanation of symbols]

[0172] 1...magnet temperature information output device, 10...stator, 20...rotor, 23...rotor core, 25...permanent magnet, 25a, 25b...surface, 50...element unit, 51...thermosensitive element, 53...coil, 53a...one end, 60...element unit, 61...coil, 63...capacitor, 70...electrical resistance element, 80...output section, D...rotation axis direction, M1...steel plate, M2, M2a...plate, 23a, 23b...end surface, MT...rotating electric motor.

Claims

1. 1. A magnet temperature information output device that is provided for a rotating electric machine having a stator and a rotor in which a permanent magnet is arranged, and outputs temperature information related to a temperature of the permanent magnet, a first element unit provided on the rotor, the first element unit having a temperature sensor whose electrical resistance changes in response to a temperature of the permanent magnet and a first coil electrically connected to the temperature sensor; a second element unit provided on the stator, the second element unit having a second coil magnetically coupled to the first coil; an electric resistance element electrically connected to the second element unit; an output section electrically connected to the second element unit and the electrical resistance element, The output section outputs an electrical signal corresponding to a magnitude of a voltage drop occurring in the electrical resistance element as the temperature information.

2. The electrical resistance element is Z ｏ ０．５０ xZ １５０ ０．２８ More than Z ｏ ０．５０ xZ １５０ ０．７１ It has the following electrical resistance: Here, Z １５０ is a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature of the temperature sensing element is 150° C., Z ｏ is a composite impedance of the first element unit and the second element unit when the first coil and the second coil are magnetically coupled and the temperature sensing element is separated from the first element unit.

3. The magnet temperature information output device according to claim 1 , wherein the second element unit further includes a capacitor that configures an LC resonant circuit together with the second coil.

4. The magnet temperature information output device according to claim 1 , wherein the first element unit further includes a capacitor that configures an LC resonant circuit together with the first coil.

5. The first element unit further includes a capacitor that configures an LC resonant circuit together with the first coil, The magnet temperature information output device according to claim 1 , wherein the second element unit further includes a capacitor that configures an LC resonant circuit together with the second coil.

6. 6. The magnet temperature information output device according to claim 5, wherein a voltage having a frequency lower than a predetermined resonant frequency for exciting the first coil is applied to the second coil.

7. 7. The magnet temperature information output device according to claim 6, wherein a difference between the frequency and the predetermined resonant frequency is 5 kHz to 30 kHz.

8. A rotating electric machine provided with the magnet temperature information output device according to any one of claims 1 to 7.

9. 9. The rotating electric machine according to claim 8, wherein the first coil and the second coil are arranged to face each other in a rotational axis direction of the rotor when the rotor is at a predetermined rotational angular position.

10. The rotor has a rotor core, the entirety of the permanent magnet and at least a portion of the first coil are disposed within the rotor core, The permanent magnet has a pair of faces perpendicular to the rotation axis direction of the rotor, The rotating electric machine according to claim 8 , wherein the temperature-sensing element is arranged so as to be in contact with one of the pair of surfaces that is closer to the second coil when the rotor is at a predetermined rotational angle position.

11. the rotor core includes a pair of end faces perpendicular to the rotation axis direction of the rotor, The rotating electric machine according to claim 10 , wherein of the pair of end faces, the end face located closer to the second coil is flush with one end of the first coil in the direction of the rotation axis of the rotor.

12. The rotor core includes a plurality of steel plates laminated in the rotation axis direction and a plate, The plurality of steel plates are magnetic, the plate is electrically conductive and is disposed on a steel plate that is located outermost in the rotation axis direction of the rotor and is located closer to the second coil among the plurality of steel plates, The rotating electric machine according to claim 10 , wherein the first coil is embedded in the plate.

13. The magnet temperature information output device according to claim 1, a magnet temperature acquisition device that acquires the electrical signal output from the magnet temperature information output device, and obtains the temperature of the permanent magnet based on the acquired electrical signal.

14. 1. A temperature information output device that is provided for a rotating electric machine including a stator and a rotor in which a permanent magnet is arranged, and outputs temperature information related to temperatures of portions of the rotor, a first element unit provided on the rotor, the first element unit having a temperature sensor whose electrical resistance changes in response to the temperature of the portion and a first coil electrically connected to the temperature sensor; a second element unit provided on the stator, the second element unit having a second coil magnetically coupled to the first coil; an electric resistance element electrically connected to the second element unit; an output section electrically connected to the second element unit and the electrical resistance element, The output section outputs an electrical signal corresponding to a magnitude of a voltage drop occurring in the electrical resistance element as the temperature information.

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