Generators, motors and aircraft

Abstract

To provide technology for generators and other equipment that can minimize damage even if a short circuit occurs in the coil.SOLUTION: A generator according to the present technology has a coil element. The coil element has a magnetic core and two or more windings. The magnetic core produces a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so that they are each adjacent to the other windings in the axial direction of the magnetic core, and are independent windings that are each electrically separable from the other windings.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present technology relates to, for example, a technology for a generator mounted on an aircraft. [Background technology]

[0002] In aircraft engines, the thrust required for aircraft flight is generated by, for example, generating a jet flow through the rotation of the engine shaft. This engine shaft may be connected to a generator that generates electricity for consumption within the aircraft.

[0003] The generator consists of a rotor (permanent magnet) connected to the engine shaft, and a stator including teeth and three-phase coils wound around the teeth. When the engine shaft rotates, the rotor rotates, generating three-phase AC current in the three-phase coils.

[0004] The following Patent Document 1 can be cited as a technique related to the present application. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-79868 Summary of the Invention [Problem to be solved by the invention]

[0006] In this type of generator, malfunctions such as a short circuit in the generator coil can occur. In a generator with a normal coil, malfunctions cannot be stopped electrically and the engine must be stopped, but in aircraft applications, the rotation of the engine shaft cannot be stopped even in such a case (because that would cause the aircraft to crash). In other words, even if a malfunction such as a short circuit in the coil occurs, the engine shaft continues to rotate and the generator rotor continues to rotate.

[0007] In such a case, the counter electromotive force generated by the rotation of the engine shaft continues to generate large amounts of heat due to short-circuit current in the generator coil, which may lead to an engine fire.

[0008] In view of the above circumstances, an object of the present technology is to provide a technology for a generator or the like that can minimize damage even if a short circuit occurs in a coil. [Means for solving the problem]

[0009] In order to achieve the above object, a generator according to the present technology includes a coil element. The coil element includes a magnetic core and two or more windings. The magnetic core generates a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the magnetic core, and are independent windings that can be electrically separated from each other.

[0010] In this generator, two or more windings are wound around the magnetic core so that the same windings are not adjacent to each other, and the two or more windings are electrically separated and independent. Therefore, even if a short circuit occurs in this generator, the short circuit will occur between different windings that are electrically separated and independent, making it difficult for a loop path to form in the coil and for short-circuit current to flow. Therefore, even if a short circuit occurs in the coil, it is possible to minimize the damage caused by the short circuit.

[0011] In the generator, the two or more windings may be laminated in multiple layers in a radial direction perpendicular to the axial direction of the magnetic core, and may be adjacent to each other in the radial direction.

[0012] In the generator, the coil element may have two or more switch mechanisms provided on two or more windings and capable of switching between a connected state and a disconnected state with respect to an external circuit.

[0013] In the generator, the coil element may include a plurality of coil elements corresponding to a plurality of phases, and the switch mechanism may be capable of switching the connected state and disconnected state for each portion of the two or more windings corresponding to each phase.

[0014] In the generator, the switch mechanism may switch the connection state of at least one winding to the disconnection state when a sign of a short circuit between windings or a short circuit is detected.

[0015] In the generator, when a sign of a short circuit between windings or a short circuit is detected, a current that cancels out a change in magnetic flux occurring in the magnetic core may be supplied to at least one or more windings.

[0016] The generator may further include a detector for detecting a sign of a short circuit or a short circuit between windings.

[0017] In the generator, the two or more windings have a potential difference between adjacent windings, The detector may detect the sign of a short circuit or a short circuit by detecting the potential difference or an electrical element resulting from the potential difference.

[0018] In the generator, the two or more windings may have different winding patterns, so that there is a potential difference between adjacent windings.

[0019] In the generator, the two or more windings may have different numbers of turns.

[0020] In the generator, the magnetic core includes a first magnetic core and a second magnetic core, the first magnetic core includes a first base end portion and a first tip end portion at both ends in the axial direction, the second magnetic core includes a second base end portion and a second tip end portion at both ends in the axial direction, a first winding of the two or more windings is wound around the first magnetic core from the first base end side toward the first tip end side, and then wound around the second magnetic core from the second tip end side toward the second base end side; A second winding of the two or more windings may be wound around the second magnetic core from the second tip end toward the second base end, and then wound around the first magnetic core from the first base end toward the second tip end.

[0021] In the generator, the electrical element may be at least one of a partial discharge current between adjacent windings, a capacitance, and an insulation resistance.

[0022] In the generator, a voltage for detecting the electrical element may be applied between the windings at a predetermined cycle.

[0023] In the generator, the detector may detect a sign of a short circuit or a short circuit when the generator is generating electricity.

[0024] In the generator, the detector may detect a sign of a short circuit or a short circuit when the generator is not generating electricity.

[0025] A coil element according to the present technology includes a magnetic core and two or more windings. The magnetic core generates a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the magnetic core, and are independent windings that can be electrically separated from each other.

[0026] A motor according to the present technology includes a coil element. The coil element has a magnetic core and two or more windings. The magnetic core generates a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the magnetic core, and are independent windings that can be electrically separated from each other.

[0027] The aircraft according to the present technology is equipped with a generator. The generator includes a coil element. The coil element includes a magnetic core and two or more windings. The magnetic core generates a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the magnetic core, and are independent windings that can be electrically separated from each other.

[0028] The aircraft according to the present technology includes a motor. The motor has a coil element. The coil element includes a magnetic core and two or more windings. The magnetic core generates a magnetic flux change in the axial direction. The two or more windings are spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the magnetic core, and are independent windings that can be electrically separated from each other. [Effects of the Invention]

[0029] As described above, according to the present technology, it is possible to provide a technology for a generator or the like that can minimize damage even if a short circuit occurs in a coil. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a diagram illustrating an example of an aircraft engine mounted on an aircraft. [Figure 2] 1 is a diagram showing the configuration of a generator according to a first embodiment. [Figure 3] FIG. 10 is a diagram showing an example of a switch in the case where a portion related to a phase in which a short circuit has occurred is partially disconnected. [Figure 4] FIG. 2 is a diagram showing an example of a coil formed by a first winding and a second winding. [Figure 5] FIG. 10 is a diagram showing another example of a coil. [Figure 6] FIG. 10 is a diagram showing yet another example of a coil. [Figure 7] FIG. 10 is a diagram showing a generator according to a second embodiment. [Figure 8] 10 is a diagram comparing magnetic flux and short-circuit current in a generator according to a comparative example and a generator according to a second embodiment. FIG. [Figure 9] FIG. 10 is a diagram comparing the coil temperatures in the generator according to the comparative example and the generator according to the second embodiment. [Figure 10] FIG. 10 is a diagram showing a first example of a prediction of a short circuit or detection of a short circuit caused by two or more windings. [Figure 11] FIG. 10 is a diagram showing a potential difference ΔV between a first winding and a second winding. [Figure 12] FIG. 10 is a diagram showing an example of a partial discharge current. [Figure 13] FIG. 10 is a diagram showing the change in potential difference ΔV before and after a short circuit. [Figure 14] FIG. 10 is a diagram showing an example in which a plurality of voltmeters are provided for one phase coil. [Figure 15] FIG. 10 is a diagram showing an example in which a plurality of voltmeters are provided for three-phase coils. [Figure 16] FIG. 10 is a diagram showing an example in which a plurality of voltmeters are provided for three-phase coils. [Figure 17] FIG. 10 is a diagram showing partial discharge current when a probe voltage is applied. [Figure 18] FIG. 10 is a diagram showing a second example of detection of a sign of a short circuit or a short circuit caused by two or more windings. [Figure 19] FIG. 10 is a diagram showing a potential difference ΔV between a first winding and a second winding. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0032] First Embodiment <Overall configuration of generator 14 and configuration of each part> [Configuration of aircraft engine 10] Fig. 1 is a diagram showing an example of an aircraft engine 10 installed in an aircraft. As shown in Fig. 1, the aircraft engine 10 is, for example, a jet engine (turbojet, turbofan, turboprop, turboshaft), and includes a compressor 11, a combustion unit 12, a turbine 13, a generator 14, and an engine shaft 15. The engine shaft 15 is connected to the compressor 11, the combustion unit 12, the turbine 13, and the generator 14.

[0033] The compressor 11 takes in and compresses air in front of it by rotating, and sends the generated airflow to the combustor 12 in the rear. The combustor 12 burns fuel in a combustion chamber, expands the compressed air, and sends the high-temperature airflow to the turbine 13 in the rear. The turbine 13 is rotated by the airflow from the combustor 12 and exhausts the airflow to the rear.

[0034] The rotation of the turbine 13 rotates the engine shaft 15. The rotational force of the engine shaft 15 is used as power to rotate the compressor 11 and also as power to generate electricity using the generator 14.

[0035] In the description of each embodiment, a generator 14 that converts dynamic energy into electrical energy will be mainly taken as an example of a device equipped with a coil element according to the present technology. On the other hand, the device equipped with a coil element may be a motor that converts electrical energy into dynamic energy, or may be a device other than the generator 14 or a motor.

[0036] Furthermore, in the description of each embodiment, the generator 14 is described as being an aircraft generator 14, but the generator 14 may be a normal generator 14 used on the ground. This also applies to motors and other devices.

[0037] [Configuration of Generator 14] 2 is a diagram showing the configuration of the generator 14. In this embodiment, a three-phase AC generator will be described as an example of the generator 14. However, the generator 14 may be a single-phase AC generator or the like.

[0038] 2, the generator 14 has a rotor 20 and a stator 30. The rotor 20 includes a permanent magnet 21. The rotor 20 is connected to the engine shaft 15 and rotates in response to the rotation of the engine shaft 15.

[0039] The stator 30 has an annular back yoke portion 31, a plurality of teeth 32 (magnetic cores) protruding radially inward from the back yoke portion 31, and coils 33 provided on each of the teeth 32. The coil element is composed of the teeth 32 (magnetic cores), the coils 33 (two or more windings), etc. (It may also include a switch, etc., which will be described later).

[0040] The teeth 32 (magnetic core) generate magnetic flux changes in the axial direction (length direction) due to the rotation of the permanent magnets 21 in the rotor 20. The coils 33 generate electric power due to the induced electromotive force caused by the magnetic flux changes generated in the teeth 32.

[0041] The teeth 32 include three teeth 32: U-phase teeth 32U, V-phase teeth 32V, and W-phase teeth 32W. Similarly, the coils 33 include three coils 33: U-phase coil 33U, V-phase coil 33V, and W-phase coil 33W. Note that, although the number of teeth 32 and the number of coils 33 are three in the example shown in Fig. 2, the number of teeth 32 and the number of coils 33 are not particularly limited.

[0042] In this specification, when three components having basically the same configuration for the three phases U, V, and W are particularly distinguished from one another, they are referred to as the U-phase coil, the V-phase coil, and the W-phase coil (for example, U-phase coil 33U, V-phase coil 33V, and W-phase coil 33W).On the other hand, when the three components are not particularly distinguished from one another, they are simply referred to by their names (for example, coil 33).

[0043] The U-phase coil 33U, the V-phase coil 33V, and the W-phase coil 33W basically have the same configuration. Each of the coils 33 is configured by a first winding 34 and a second winding 35.

[0044] FIG. 4 is a diagram showing an example of a coil 33 formed by a first winding 34 and a second winding 35. As shown in FIG.

[0045] 4, the first winding 34 and the second winding 35 are alternately spirally wound around the magnetic core so as to be adjacent to each other in the axial direction of the teeth portion 32 (magnetic core). Furthermore, the first winding 34 and the second winding 35 are electrically isolated from each other and are electrically independent windings (i.e., they are not electrically or physically connected).

[0046] In order to improve the insulation between the first winding 34 and the second winding 35, a filler made of an insulating material such as resin may be filled so as to cover the first winding 34 and the second winding 35.

[0047] 2, the U-phase first winding 34U, the V-phase first winding 34V, and the W-phase first winding 34W are electrically connected to each other. Similarly, the U-phase second winding 35U, the V-phase second winding 35V, and the W-phase second winding 35W are electrically connected to each other.

[0048] The first winding 34 is connected in a delta connection (the connection method can be changed as needed) and is connected to a first converter 41 via three first switches 39a, 39b, and 39c. The second winding 35 is also connected in a delta connection (the connection method can be changed as needed) and is connected to a second converter 42 via three second switches 40a, 40b, and 40c.

[0049] The base end side (toward the back yoke 30) of the U-phase first winding 34U and the tip end side (toward the rotor 20) of the W-phase first winding 34W are connected to a U-phase input terminal of a first converter 41 via a switch 39a. The base end side of the V-phase first winding 34V and the tip end side of the U-phase first winding 34U are connected to a V-phase input terminal of the first converter 41 via a switch 39b. The base end side of the W-phase first winding 34W and the tip end side of the V-phase first winding 34V are connected to a W-phase input terminal of the first converter 41 via a switch 39c.

[0050] The base end (toward the back yoke 30) of the U-phase second winding 35U and the tip end (toward the rotor 20) of the W-phase second winding 35W are connected to a U-phase input terminal of a second converter 42 via a switch 40a. The base end of the V-phase second winding 35V and the tip end of the U-phase second winding 35U are connected to a V-phase input terminal of the second converter 42 via a switch 40b. The base end of the W-phase second winding 35W and the tip end of the V-phase second winding 35V are connected to a W-phase input terminal of the second converter 42 via a switch 40c.

[0051] The three first switches 39 (switch mechanisms) are capable of switching between a connected state and a disconnected state between the first winding 34 (coil 33) and external devices (first device 43, second device 44). The three second switches 40 (switch mechanisms) are capable of switching between a connected state and a disconnected state between the second winding 35 (coil 33) and external devices.

[0052] Typically, when a short circuit or a pre-existing short circuit occurs in the coil 33, the first switch 39 and the second switch 40 switch the connection state between the first winding 34 and the second winding 35 and the external device to a disconnection state as necessary.

[0053] Details of the detection of a sign of a short circuit or a short circuit in the coil 33 will be described later (see the third embodiment). The switching operations of the first switch 39 and the second switch 40 will also be described later in detail.

[0054] The first converter 41 and the second converter 42 each have three input terminals including a U-phase input terminal, a V-phase input terminal, and a W-phase input terminal, and one output terminal. The first converter 41 converts the three-phase AC current generated in the first winding 34 into a DC current and provides it to the first device 43 and the second device 44. The second converter 42 converts the three-phase AC current generated in the second winding 35 into a DC current and provides it to the first device 43 and the second device 44.

[0055] The first device 43 and the second device 44 are connected to the first converter 41 and the second converter 42 via a DC bus 45. The first device 43 and the second device 44 are various devices mounted inside the aircraft, and are driven using the electric power generated by the generator 14.

[0056] When the present technology is used as a motor for an aircraft, for example, a power supply 46 is provided on the side of the first device 43 and the second device 44, and an inverter that converts direct current from the power supply 46 (see, for example, FIG. 7 described later) into alternating current is provided instead of the converters 41 and 42. In addition, for example, a thruster (object to be rotated) that generates thrust for the aircraft is connected to the rotor 20 axis.

[0057] <Short circuit of coil 33> Next, we will explain short-circuiting of the coil 33. First, as comparative examples, we will explain a case where the coil 33 is composed of one winding, and a case where the coil 33 is composed of two windings but the two windings are electrically connected (see Patent Document 1 above).

[0058] In this comparative example, substantially identical windings are short-circuited, forming a loop path due to the short circuit and allowing a short-circuit current to flow. In such a case, if the rotation of the engine shaft 15 were to be stopped to stop the drive of the generator 14, the aircraft would crash, so the rotation of the engine shaft 15 cannot be stopped. As a result, the rotor 20 continues to rotate, and the magnetic flux change caused by the rotation of the rotor 20 may cause the coil 33 to heat up, which may lead to a fire.

[0059] On the other hand, in this embodiment, the first winding 34 and the second winding 35 are wound spirally around the teeth 32 so that each of the first winding 34 and the second winding 35 is adjacent to the other winding.

[0060] Therefore, in this embodiment, the first windings 34 are not adjacent to each other, and the second windings 35 are not adjacent to each other. Therefore, a short circuit occurs not between the first windings 34 or between the second windings 35, but between the first windings 34 and the second windings 35.

[0061] Furthermore, in this embodiment, the first winding 34 and the second winding 35 are electrically separated and independent. Therefore, even if a short circuit occurs between the first winding 34 and the second winding 35, a loop path due to the short circuit is unlikely to be formed, and short-circuit current is unlikely to flow. Therefore, even in a situation where the engine shaft 15 must be kept driven and the rotor 20 must be kept rotating, for example, damage due to a short circuit can be minimized.

[0062] <Switching of the first switch 39 and the second switch 40> Next, switching between the connected state and the disconnected state of the first switch 39 and the second switch 40 will be described.

[0063] In this embodiment, as described above, the first winding 34 and the second winding 35 are spirally wound around the tooth portion 32 so as to be adjacent to each other, and the first winding 34 and the second winding 35 are electrically separated and independent, thereby minimizing damage caused by a short circuit in the coil 33. In addition, in this embodiment, when a short circuit is detected or a short circuit occurs in the coil 33, the first switch 39 and the second switch 40 cut off the connection between the coil 33 (the first winding 34 and the second winding 35) and the external devices (the first device 43 and the second device 44), thereby further reducing damage caused by a short circuit in the coil 33.

[0064] [1. Cutting at least one of the first winding and the second winding] [A. Cutting all three phases of one of the first winding 34 and the second winding 35] Suppose that a short circuit occurs between the U-phase first winding 34U and the U-phase second winding 35U in the U-phase coil 33U. In this case, one of the three first switches 39 and the three second switches 40 is switched from the connected state to the disconnected state. In this case, the other three switches remain in the connected state.

[0065] In this case, one of the three-phase first winding 34 and the three-phase second winding is disconnected from the external device. Also, in this case, one of the first converter 41 and the second converter 42 converts three-phase AC current to DC current. In contrast, the other converter does not function.

[0066] [B. All short-circuited phases are disconnected regardless of the phase in which the short circuit occurred] Suppose that a short circuit occurs between the U-phase first winding 34U and the U-phase second winding 35U in the U-phase coil 33U, in which case all of the three first switches 39 and three second switches 40 are switched from the connected state to the disconnected state.

[0067] In this case, all of the three-phase first windings 34 and the three-phase second windings 35 are disconnected from the external devices. Also, in this case, the first converter 41 and the second converter 42 do not function. In this case, the external devices (first device 43, second device 44) are driven by power from another generator 14 (for example, driven by the rotation of another engine shaft 15) or by power from an emergency battery.

[0068] [2. Cut off the part related to the phase where the short circuit occurred] Here, in the first winding 34 and the second winding 35, the portions related to the phase in which the short circuit occurred can be cut off, and the portions not related to the phase in which the short circuit occurred can be left connected to continue generating power.

[0069] Fig. 3 is a diagram showing an example of a switch for partially disconnecting a portion related to a phase where a short circuit has occurred. In the example shown in Fig. 3, unlike the example shown in Fig. 2, the number of first switches 1 and the number of second switches 2 are each six.

[0070] As shown in FIG. 3, the base end side (back yoke 30 side) of the U-phase first winding 34U is connected to the U-phase input terminal of the first converter 41 via switch 1a, and the tip end side (rotor 20 side) of the W-phase first winding 34W is connected to the U-phase input terminal of the first converter 41 via switch 1b.

[0071] In addition, the base end side of the V-phase first winding 34V is connected to the V-phase input terminal of the first converter 41 via switch 1c, and the tip end side of the U-phase first winding 34U is connected to the V-phase input terminal of the first converter 41 via switch 1d.

[0072] In addition, the base end side of the W-phase first winding 34W is connected to the W-phase input terminal of the first converter 41 via switch 1e, and the tip end side of the V-phase first winding 34V is connected to the W-phase input terminal of the first converter 41 via switch 1f.

[0073] The base end of the U-phase second winding 35U is connected to the U-phase input terminal of the second converter 42 via the switch 2a, and the tip end of the W-phase second winding 35W is connected to the U-phase input terminal of the second converter 42 via the switch 2b.

[0074] In addition, the base end side of the V-phase second winding 35V is connected to the V-phase input terminal of the second converter 42 via switch 2c, and the tip end side of the U-phase second winding 35U is connected to the V-phase input terminal of the second converter 42 via switch 2d.

[0075] In addition, the base end side of the W-phase second winding 35W is connected to the W-phase input terminal of the second converter 42 via switch 2e, and the tip end side of the V-phase second winding 35V is connected to the W-phase input terminal of the second converter 42 via switch 2f.

[0076] In the example shown in FIG. 3, the switches (switch mechanisms) 1 and 2 are capable of switching between a connected state and a disconnected state for each portion of the first winding 34 and the second winding 35 that corresponds to each phase.

[0077] [C. Cutting off one of the first winding 34 and the second winding 35 in the phase where the short circuit occurs] Here, it is assumed that a short circuit occurs between the U-phase first winding 34U and the U-phase second winding 35U in the U-phase coil 33U.

[0078] In this case, of the six first switches 1, switch 1a and switch 1d connected to U-phase first winding 34U are switched from the connected state to the disconnected state. Alternatively, of the six second switches 2, switch 2a and switch 2d connected to U-phase second winding 35U are switched from the connected state to the disconnected state. The other 10 switches remain in the connected state.

[0079] In this case, one of the U-phase first winding 34U and the U-phase second winding 35U is disconnected from the external device.

[0080] [D. Disconnect both the first winding 34 and the second winding 35 in the phase where the short circuit occurs] Let us assume that a short circuit occurs between the U-phase first winding 34U and the U-phase second winding 35U in the U-phase coil 33U.

[0081] In this case, of the six first switches 1, switch 1a and switch 1d connected to U-phase first winding 34U are switched from the connected state to the disconnected state. In addition, of the six second switches 2, switch 2a and switch 2d connected to U-phase second winding 35U are switched from the connected state to the disconnected state. The other eight switches remain in the connected state.

[0082] In this case, both the U-phase first winding 34U and the U-phase second winding 35U are disconnected from the external device.

[0083] [Converters 41 and 42 perform switching] Here, the first converter 41 and the second converter 42 can also serve as the first switch 39 and the second switch 40 (in this case, the converters are considered to be the switch mechanism). In this case, the switches 39 and 40 (or the switches 1 and 2) can be omitted.

[0084] In other words, by controlling the first converter 41 and the second converter 42, the connection state and disconnection state between the coil 33 (first winding 34 and second winding 35) and the external device (first device 43, second device 44) can be switched.

[0085] For example, in the example of A above, when a short circuit or a sign of a short circuit occurs in some of the coils 33, the drive of one of the first converter 41 and the second converter 42 is stopped. As a result, one of the first winding 34 and the second winding 35 is disconnected from the external device (first device 43, second device 44).

[0086] Further, in the example of B above, when a short circuit or a sign of a short circuit occurs in some of the coils 33, the operation of both the first converter 41 and the second converter 42 is stopped. As a result, both the first winding 34 and the second winding 35 are disconnected from the external devices (the first device 43 and the second device 44).

[0087] [Safety] Here, the above-mentioned ACD pattern is based on the viewpoint that even if a short circuit occurs in the coil 33, the generator 14 is kept partially operating and power is obtained from the generator 14. On the other hand, the above-mentioned B. pattern is based on the viewpoint that if a short circuit occurs in the coil 33, the generator 14 is isolated from external devices to further improve safety.

[0088] In the above-described ACD pattern, the generator 14 is operated in a state where a partial malfunction has occurred in the coil 33. Therefore, from the viewpoint of safety, the ACD pattern is less safe than pattern B. However, in this embodiment, the configuration of two or more windings as described above makes it difficult for a short-circuit current to flow, so that even in the ACD pattern, power can be obtained from the generator 14 in a state where the necessary safety standards are fully satisfied.

[0089] [For motors] Here, a case where the present technology is used as a motor for an aircraft will be described. In this motor, for example, a thruster that generates thrust for the aircraft is connected to the rotor 20 shaft, a power supply 46 (for example, see FIG. 7 described later) is provided on the side of the first device 43 and the second device 44, and an inverter is used instead of the converters 42, 42.

[0090] In the case of this aircraft motor, similar to the ACD pattern described above, when a short circuit occurs, switches 39 and 40 (or switches 1 and 2) disconnect parts of the first winding 34 and the second winding 35 from the power supply 46, leaving other parts of the first winding 34 and the second winding 35 connected to the power supply 46. This allows the motor and thruster to continue operating even if a short circuit occurs, preventing the aircraft from crashing.

[0091] <Another example of coil 33> Next, a description will be given of another example of the coil 33. FIG.

[0092] 5, in this example, the coil 33 has a two-layer structure. Specifically, the first winding 34 and the second winding 35 are stacked in two layers in the radial direction of the teeth 32 (a direction perpendicular to the axial direction of the teeth 32) and wound around the teeth 32. The first winding 34 and the second winding 35 are wound around the teeth 32 so as to be adjacent to each other in the radial direction of the teeth 32.

[0093] 5, similarly to the example shown in Fig. 4, the first winding 34 and the second winding 35 are alternately wound spirally around the teeth 32 (magnetic core) so as to be adjacent to each other in the axial direction of the teeth 32. The first winding 34 and the second winding 35 are electrically isolated from each other and are electrically independent windings (i.e., they are not electrically or physically connected).

[0094] In the example shown in Fig. 5, the number of turns of the coil 33 per unit length can be made larger than in the example shown in Fig. 4, thereby improving the power generation capacity of the generator 14. Furthermore, in the example shown in Fig. 5, the same windings are not adjacent to each other not only in the axial direction of the teeth 32 but also in the radial direction (direction perpendicular to the axial direction) of the teeth 32. This makes it possible to appropriately prevent the same windings from short-circuiting and causing a short-circuit current to flow.

[0095] In the example shown in FIG. 5, the coil 33 has two layers, but may have three or more layers.

[0096] Fig. 6 is a diagram showing yet another example of the coil 33. In the example shown in Fig. 6, the coil 33 is configured with three windings including a first winding 34, a second winding 35, and a third winding 36.

[0097] 6, the first winding 34, the second winding 35, and the third winding 36 are alternately wound spirally around the teeth 32 (magnetic core) so as to be adjacent to each other in the axial direction of the teeth 32. Furthermore, the first winding 34, the second winding 35, and the third winding 36 are electrically isolated from each other and are electrically independent windings (i.e., they are not electrically or physically connected).

[0098] In addition, the first winding 34, the second winding 35, and the third winding 36 are stacked in two layers so that they are adjacent to each other in the radial direction of the tooth portion 32 (a direction perpendicular to the axial direction of the tooth portion 32), and are wound around the tooth portion 32.

[0099] 6, when the number of windings is increased, the distance between the same windings increases. For example, in the axial direction of the teeth 32, two windings, the second winding 35 and the third winding 36, are interposed between the first windings 34, further increasing the distance between the first windings 34. This more appropriately prevents the same windings from shorting out and causing a short-circuit current to flow.

[0100] In the example shown in Fig. 6, the number of windings is three, but it may be four or more. Also, in the example shown in Fig. 6, the number of layers of the coil 33 is two, but it may be one layer or three or more layers.

[0101] When a third winding is added, a third converter that converts the three-phase AC current generated by the third winding into DC current, and a third switch interposed between the third winding and the third converter are further added.

[0102] <Effect, etc.> Next, the operation of the generator 14 in this embodiment will be described.

[0103] First, for comparison, we will explain the case of a normal generator 14 used on the ground. In this normal generator 14, when a malfunction occurs in a component such as the coil 33, it is common to use a method in which the power supply to the generator 14 is stopped to stop its operation and prevent the malfunction from spreading.

[0104] On the other hand, in the case of an aircraft generator 14 that generates electricity using the rotational energy of the aircraft engine shaft 15, as in this embodiment, unlike a normal generator 14 used on the ground, it is not possible to simply stop the power supply to the generator 14 to stop its operation. This is because stopping the engine shaft 15 would cause the aircraft to crash.

[0105] For example, consider a typical coil 33 consisting of a single winding, or a coil 33 consisting of two electrically connected windings (see Patent Document 1). In this case, the same windings are short-circuited, forming a loop path due to the short circuit, causing a short-circuit current to flow. The counter electromotive force generated by the rotation of the engine shaft 15 continues to generate a large amount of heat in the coil 33 of the generator 14 due to the short-circuit current, which may lead to an engine fire.

[0106] On the other hand, in order to avoid such a situation, it is possible to provide a decoupling mechanism that decouples the engine shaft 15 from the rotor 20 of the generator 14. For example, an example of the decoupling mechanism is a clutch mechanism that mechanically decouples the engine shaft 15 from the rotor 20 of the generator 14. Another example of the decoupling mechanism is a shear pin that breaks when torque exceeding a threshold is applied between the engine shaft 15 and the rotor 20, thereby decoupling the engine shaft 15 from the rotor 20 of the generator 14.

[0107] However, the clutch mechanism significantly increases the weight and costs. Furthermore, in the case of a shear pin, there are cases where the torque between the engine shaft 15 and the rotor 20 shaft caused by a short circuit in the coil 33 falls within a threshold, and in such cases the shear pin does not operate effectively. In other words, the shear pin is unreliable.

[0108] Furthermore, motors that drive thrusters that generate thrust for aircraft also have the same problems as the aircraft generator 14. That is, unlike ordinary motors used on the ground, when a short circuit occurs in an aircraft motor, it is not possible to simply cut off the power to the motor to stop its operation. This is because stopping the motor would cause the aircraft to crash. Alternatively, fans and propellers connected to the motor may continue to rotate due to wind from the front during flight, even if the power supply to the motor is cut off, and it may still be impossible to stop them during flight.

[0109] When a short circuit occurs in a normal coil 33 with a single winding, if power is supplied to the coil 33 to continue flying the aircraft or if the motor continues to be rotated by an external force, a large amount of heat will continue to be generated in the coil 33 due to the short circuit current, which may lead to a motor fire.

[0110] Therefore, in this embodiment, two or more windings are spirally wound around the tooth portion 32 so that each winding is adjacent to the other windings in the axial direction of the tooth portion 32 (magnetic core), and the two or more windings are independent windings that are electrically isolated from each other.

[0111] As a result, in this embodiment, short circuits between the same windings are prevented, and even if a short circuit occurs between different windings, a loop path due to the short circuit is unlikely to be formed, making it difficult for short-circuit current to flow. Therefore, even in a situation where the engine shaft 15 must be kept driven and the rotor 20 must be kept rotating (or a situation where an aircraft motor must be kept rotating), damage caused by a short circuit can be minimized. In other words, in this embodiment, fires and other hazards caused by short circuits in the coil 33 can be appropriately prevented while continuing to fly the aircraft safely.

[0112] Furthermore, in this embodiment, weight and costs can be reduced compared to when a clutch mechanism is provided, and reliability can be improved compared to when a shear pin is provided.

[0113] Furthermore, in this embodiment, in the example shown in Figures 5 and 6, two or more windings are stacked in multiple layers in the radial direction of the tooth portion 32 (magnetic core), and the two or more windings are wound around the tooth portion 32 so that they are adjacent to each other in this radial direction.

[0114] In this way, by stacking two or more windings in multiple layers in the radial direction of the tooth portion 32 (magnetic core), the number of turns of the coil 33 per unit length can be increased, thereby improving the power generation capacity of the generator 14 (driving force of the motor).

[0115] Furthermore, by arranging two or more windings so that each winding is adjacent to the other windings in the radial direction of the teeth 32, it is possible to prevent the same windings from being adjacent to each other not only in the axial direction of the teeth 32 but also in the radial direction (direction perpendicular to the axial direction) of the teeth 32. This makes it possible to more appropriately prevent the same windings from short-circuiting and causing a short-circuit current to flow.

[0116] In addition, in this embodiment, a switch (switch mechanism) is provided corresponding to each winding, which can switch between a connected state and a disconnected state between the coil 33 and an external circuit (first device 43, second device 44: power supply in the case of a motor).

[0117] As a result, when a short circuit or a premonition of a short circuit occurs between the windings, each switch can be used to cut off the connection between the windings and external equipment as necessary, further reducing damage caused by a short circuit between the windings.

[0118] Furthermore, when the switches are switched in a manner that connects some of the windings and external equipment and disconnects others, as in the above-mentioned ACD pattern, it is possible to obtain power from the generator 14 while fully satisfying the necessary safety standards (in the case of a motor, the aircraft can continue to fly). On the other hand, when all of the windings and external equipment are disconnected, as in the above-mentioned B pattern, safety can be further improved.

[0119] Second Embodiment Next, a second embodiment of the present technology will be described. In the descriptions of the second and subsequent embodiments, components having the same configurations and functions as those of the first embodiment described above will be denoted by the same reference numerals, and descriptions thereof will be omitted or simplified, and only differences from the first embodiment will be described.

[0120] 2, let us consider a case in which the first winding 34 and the second winding 35 of the U-phase coil 33U are short-circuited at two or more locations. In this case, as in a normal short circuit between the same windings, a loop path is formed, resulting in the generation of a short-circuit current. This cannot be addressed by disconnecting the coil 33 from the external device by switching the switches 39 and 40 (or the switches 1 and 2) or by stopping the drive of the converters 41 and 42, and the short-circuit current cannot be prevented.

[0121] That is, in the first embodiment described above, it is possible to cope with a short circuit in one place in the coil 33, but it may not be possible to cope with a short circuit in two or more places in the coil 33.

[0122] Therefore, in the second embodiment, a technique is provided that minimizes damage caused by short-circuit current even if two or more short circuits occur in the coil 33.

[0123] 7 is a diagram showing a generator 14 according to a second embodiment. Unlike the first embodiment, the second embodiment does not include the switches 39 and 40 (or the switches 1 and 2) (note that the switches 39, 40, 1 and 2 can also be omitted in the first embodiment when the converter functions as a switch mechanism).

[0124] Furthermore, in the second embodiment, unlike the first embodiment, a power supply 46 that supplies power to the first device 43 and the second device 44 is further connected to the DC bus 45. This power supply 46 may be another generator 14 that generates power using power from another engine shaft 15, or may be an emergency battery, etc.

[0125] The first converter 41 converts the three-phase AC current generated in the first winding 34 into a DC current and provides it to external devices (first device 43, second device 44). The second converter 42 converts the three-phase AC current generated in the second winding 35 into a DC current and provides it to external devices.

[0126] Furthermore, when short circuits occur at two locations in the first winding 34 and the second winding 35 and a short-circuit current flows, the first converter 41 converts the DC current from the power source 46 into three-phase AC current and provides this three-phase AC current to the three-phase first winding 34.

[0127] Similarly, when short circuits occur at two locations in the first winding 34 and the second winding 35 and a short-circuit current flows, the second converter 42 converts the DC current from the power source 46 into three-phase AC current and provides this three-phase AC current to the three-phase second winding 35.

[0128] In other words, the first converter 41 and the second converter 42 function as converters that convert AC current to DC current under normal circumstances, but function as inverters that convert DC current to AC current under abnormal circumstances in which a short-circuit current occurs.

[0129] Typically, in the event of an abnormality in which a short-circuit current occurs, the first converter 41 and the second converter 42 supply current to the first winding 34 and the second winding 35, at least in the phase in which the short circuit occurs, to cancel out the magnetic flux change in the tooth portion 32.

[0130] In addition, one of the first converter 41 and the second converter 42 can supply a current to one of the first winding 34 and the second winding 35 to cancel out the magnetic flux change, and the other converter can be stopped.

[0131] A specific example will be given below: Suppose that two or more short circuits occur between the U-phase first winding 34U and the U-phase second winding 35U in the U-phase coil 33U, causing a short-circuit current to flow in the U-phase coil 33U.

[0132] In this case, the first converter 41 and the second converter 42 convert the DC current from the power supply 46 via the DC bus 45 into three-phase AC current. The first converter 41 and the second converter 42 then provide the U-phase first winding 34U and the U-phase second winding 35U with a current that cancels out the magnetic flux change in the U-phase teeth portion 32U as the U-phase AC current.

[0133] Meanwhile, the first converter 41 and the second converter 42 provide, as a V-phase AC current, a current that cancels out magnetic flux changes in the V-phase teeth 32V to the V-phase first winding 34V and the V-phase second winding 35V. Similarly, the first converter 41 and the second converter 42 provide, as a W-phase AC current, a current that cancels out magnetic flux changes in the W-phase teeth 32W to the W-phase first winding 34W and the W-phase second winding 35W.

[0134] Alternatively, one of the first converter 41 and the second converter 42 provides a current that cancels out the magnetic flux change in the U-phase tooth portion 32U as a U-phase AC current to one of the U-phase first winding 34U and the U-phase second winding 35U, and the other converter is stopped.

[0135] In this case, one of the first converter 41 and the second converter 42 provides a V-phase AC current to one of the V-phase first winding 34V and the V-phase second winding 35V, which cancels out the magnetic flux change in the V-phase tooth portion 32V. Similarly, one of the first converter 41 and the second converter 42 provides a W-phase AC current to one of the W-phase first winding 34W and the W-phase second winding 35W, which cancels out the magnetic flux change in the W-phase tooth portion 32W.

[0136] In the above description, when a short-circuit current occurs in one phase, the change in magnetic flux in the teeth 32 is canceled out by the other phases that are not short-circuited. On the other hand, when a short-circuit current occurs in one phase, power may be drawn from the other phases that are not short-circuited to continue power generation. For example, when a short-circuit current flows in the U phase, power may be drawn from the V phase and the W phase.

[0137] At this time, the electric power generated in the V-phase and W-phase may be used by the first device 43, the second device 44, etc., or may be used in the U-phase as electric power for canceling out the magnetic flux change in the U-phase tooth portion 32U. In this case, the power supply 46 may be omitted.

[0138] Fig. 8 is a diagram comparing magnetic flux and short-circuit current in the generator 14 according to the comparative example and the generator 14 according to the second embodiment of the present technology. Fig. 9 is a diagram comparing temperatures of the coil 33 in the generator 14 according to the comparative example and the generator 14 according to the second embodiment of the present technology.

[0139] 8 and 9, coil 33 is configured with a single winding. In the comparative example shown in Fig. 8, when a short circuit occurs in the winding of a specific phase, the change in magnetic flux in teeth portion 32 due to the rotation of rotor 20 remains the same as before the short circuit, and a large short-circuit current flows through coil 33 due to this change in magnetic flux.

[0140] Furthermore, in the comparative example, as shown in FIG. 9, the temperature of the coil 33 increases due to the short-circuit current, which may cause damage such as a fire.

[0141] On the other hand, in the case of the second embodiment of the present technology, as shown in FIG. 8, when a short circuit occurs in the winding of a specific phase, the change in magnetic flux in the teeth portion 32 due to the rotation of the rotor 20 is canceled out, thereby preventing the flow of short-circuit current.

[0142] Moreover, in the second embodiment of the present technology, as shown in FIG. 9, a temperature rise due to a short-circuit current is suppressed, thereby making it possible to prevent damage such as a fire from occurring.

[0143] The generator 14 according to the second embodiment is particularly advantageous in that it can cope with the occurrence of short circuits at two or more locations between the first winding 34 and the second winding 35.

[0144] Third Embodiment Next, a third embodiment of the present technology will be described. In the third embodiment, detection of a sign of a short circuit or a short circuit caused by two or more windings will be described. Note that the detection of a sign of a short circuit or a short circuit according to the third embodiment can be applied to the first and second embodiments described above.

[0145] <Short circuit detection: First example> FIG. 10 is a diagram showing a first example of a prediction of a short circuit or detection of a short circuit caused by two or more windings.

[0146] 10, the stator 30 of the generator 14 has two teeth 32 corresponding to the same phase (for example, the U phase). In the description of the third embodiment, one of the two teeth 32 corresponding to the same phase is referred to as a first teeth 32A, and the other teeth 32 is referred to as a second teeth 32B.

[0147] The first winding 34 is composed of one winding corresponding to the same phase (for example, the U phase), and the second winding 35 is composed of one winding corresponding to the same phase (for example, the U phase).

[0148] As in the above-described embodiments, the first winding 34 and the second winding 35 are spirally wound around the teeth 32 so as to be adjacent to each other in the axial direction of the teeth 32. The first winding 34 and the second winding 35 are independent windings that are electrically isolated from each other. The number of layers of the coil 33 may be two or more (see FIG. 5), and the number of windings may be three or more (see FIG. 6).

[0149] Here, since the configurations of the three phases, U phase, V phase, and W phase, are basically the same, one of the three phases will be representatively described in the explanation of Fig. 10. Note that the generator 14 may be a single-phase generator 14 or the like.

[0150] The first converter 51 converts the AC current generated in the first winding 34 into a DC current and provides it to external devices (first device 43, second device 44). The second converter 52 converts the AC current generated in the second winding 35 into a DC current and provides it to external devices (first device 43, second device 44). The first converter 51 and the second converter 52 each have a Bus+ and a Bus-.

[0151] One end of the first winding 34 is connected to Bus+ of the first converter 51, and the other end of the first winding 34 is connected to Bus- of the first converter 51. Furthermore, one end of the second winding 35 is connected to Bus+ of the second converter 52, and the other end of the second winding 35 is connected to Bus- of the second converter 52.

[0152] Here, in the first winding 34 and the second winding 35, the part connected to Bus+ and which is the start of winding with respect to the tooth portion 32 is called the winding start. On the other hand, in the first winding 34 and the second winding 35, the part connected to Bus- and which is the end of winding with respect to the tooth portion 32 is called the winding end.

[0153] In FIG. 10, the first winding 34 and the second winding 35 are numbered in order from the start to the end of the winding.

[0154] As can be seen from Fig. 10, the first winding 34 and the second winding 35 have different numbers of turns wound around the teeth 32. In the example shown in Fig. 10, the first winding 34 has a larger number of turns than the second winding 35 on the first teeth 32A and the second teeth 32B.

[0155] Therefore, the electromotive forces in the first winding 34 and the second winding 35 are different, which causes a potential difference ΔV between the first winding 34 and the second winding 35 .

[0156] 11 is a diagram showing the potential difference ΔV between the first winding 34 and the second winding 35. The first winding 34 has a larger number of turns than the second winding 35, and therefore has a higher potential than the second winding 35, as shown in FIG. 11. Therefore, a constant potential difference ΔV occurs between the first winding 34 and the second winding 35 from the start of winding to the end of winding.

[0157] An ammeter 53 (detector) that detects a partial discharge current based on the potential difference ΔV is provided between the first winding 34 and the second winding 35. Note that instead of or in addition to the ammeter 53, a voltmeter 60 (detector: see, for example, FIG. 14 described later) that detects the potential difference ΔV may be provided.

[0158] The control unit 50 (detector) acquires the partial discharge current detected by the ammeter 53 from the ammeter 53, and detects a sign of a short circuit or a short circuit between the first winding 34 and the second winding 35 based on this partial discharge current.

[0159] 12 is a diagram showing an example of a partial discharge current. As shown in FIG. 12, the partial discharge current fluctuates over time as the rotor 20 rotates.

[0160] The control unit 50 determines whether the partial discharge current is less than a predetermined threshold Ith. If the partial discharge current is less than the threshold Ith, the control unit 50 determines that the state is normal, and if the partial discharge current is equal to or greater than the threshold Ith, the control unit 50 determines that the state is a sign of a short circuit.

[0161] On the other hand, if the first winding 34 and the second winding 35 are short-circuited, the potential difference ΔV between the first winding 34 and the second winding 35 becomes 0, and the partial discharge current becomes 0. Therefore, the control unit 50 determines that a short circuit has occurred when a predetermined time has passed since the partial discharge current became 0 (to distinguish it from the partial discharge current of a sine wave, which is 0).

[0162] That is, in the first example, a potential difference ΔV is provided between the first winding 34 and the second winding 35, so that a sign of a short circuit or a short circuit can be easily detected.

[0163] Here, when a voltmeter 60 (see, for example, FIG. 14 described later) is used, it may be possible to determine whether a short circuit has occurred by detecting a change in the potential difference ΔV before and after the short circuit using the voltmeter 60. FIG. 13 is a diagram showing the change in the potential difference ΔV before and after the short circuit.

[0164] As shown in FIG. 13, the rate of change in the potential difference ΔV before and after the short circuit varies depending on the short circuit position, so the short circuit position can also be identified from the rate of change in the potential difference ΔV before and after the short circuit.

[0165] On the other hand, if the short-circuit location is relatively far from the voltmeter 60, or near the reference potential of the first winding 34 and the second winding 35 (for example, near the reference potential when the phase in question is connected to Bus- inside the first converter 51 or the second converter 52), the rate of change in the potential difference ΔV before and after the short-circuit is small, making it difficult to detect.

[0166] To address this, a plurality of voltmeters 60 may be installed at different positions on the coil 33 (for example, between the phase input terminals of the first converter 51 and the second converter 52 or between the neutral points), and the occurrence and location of the short circuit may be identified from the potential differences ΔV measured by these voltmeters 60. Alternatively, the occurrence and location of the short circuit may be identified by measuring the potential difference ΔV when the device is not connected to Bus-.

[0167] Fig. 14 is a diagram showing an example in which a plurality of voltmeters 60 are provided in one phase coil 33 (for example, the U phase). In the example shown in Fig. 14, two voltmeters 60 including a first voltmeter 60a and a second voltmeter 60b are provided.

[0168] The first voltmeter 60a is interposed between the first winding 34 and the second winding 35 near Bus+ (between Bus+ and the start of the winding) of the first converter 51 and the second converter 52. On the other hand, the second voltmeter 60b is interposed between the first winding 34 and the second winding near Bus− (between Bus− and the end of the winding) of the first converter 51 and the second converter 52.

[0169] 15 and 16 are diagrams showing an example in which a plurality of voltmeters 60 are provided for three-phase coils 33. Fig. 15 shows an example of a plurality of voltmeters 60 when the coils 33 are connected in a delta connection, and Fig. 16 shows an example of a plurality of voltmeters 60 when the coils are connected in a Y connection. Note that in Figs. 15 and 16, a potential difference ΔV occurs between the first winding 34 and the second winding 35, for example, due to the different numbers of turns.

[0170] Referring to FIG. 15, in this example using delta connection, three voltmeters 60 are provided, including a first voltmeter 60c, a second voltmeter 60d, and a third voltmeter 60e.

[0171] The first voltmeter 60c is interposed between a conductor connected to the U-phase input terminal of the first converter 41 (a conductor drawn from and connected to the U-phase first winding 34U and the W-phase first winding 34W) and a conductor connected to the U-phase input terminal of the second converter 42 (a conductor drawn from and connected to the U-phase second winding 35U and the W-phase second winding 35W).

[0172] In addition, the second voltmeter 60d is interposed between a conductor connected to the V-phase input terminal of the first converter 41 (a conductor drawn from and connected to the V-phase first winding 34V and the U-phase first winding 34U) and a conductor connected to the V-phase input terminal of the second converter 42 (a conductor drawn from and connected to the V-phase second winding 35V and the U-phase second winding 35U).

[0173] In addition, the third voltmeter 60e is interposed between a conductor connected to the W-phase input terminal of the first converter 41 (a conductor drawn from and connected to the W-phase first winding 34W and the V-phase first winding 34V) and a conductor connected to the W-phase input terminal of the second converter 42 (a conductor drawn from and connected to the W-phase second winding 35W and the V-phase second winding 35V).

[0174] Referring to FIG. 16, in this example of a Y-connection, three voltmeters 60 are provided, including a first voltmeter 60f, a second voltmeter 60g, a third voltmeter 60h, and a fourth voltmeter 60i.

[0175] The first voltmeter 60f is interposed between a conductor connected to the U-phase input terminal of the first converter 41 (a conductor drawn from the U-phase first winding 34U) and a conductor connected to the U-phase input terminal of the second converter 42 (a conductor drawn from the U-phase second winding 35U).

[0176] In addition, the second voltmeter 60g is interposed between the conductor connected to the V-phase input terminal of the first converter 41 (the conductor drawn from the V-phase first winding 34V) and the conductor connected to the V-phase input terminal of the second converter 42 (the conductor drawn from the V-phase second winding 35V).

[0177] In addition, the third voltmeter 60g is interposed between the conductor connected to the W-phase input terminal of the first converter 41 (the conductor drawn from the W-phase first winding 34W) and the conductor connected to the W-phase input terminal of the second converter 42 (the conductor drawn from the W-phase second winding 35W).

[0178] The fourth voltmeter 60i is interposed between the neutral point of the Y-connection of the first winding 34 and the neutral point of the Y-connection of the second winding 35.

[0179] 14, 15, and 16, the occurrence and location of a short circuit are identified from the potential differences ΔV measured by the voltmeters 60. This makes it possible to accurately identify the occurrence and location of a short circuit regardless of the location of the short circuit.

[0180] When a short circuit or a sign of a short circuit is detected, for example, the control unit 50 stops driving one of the first converter 51 and the second converter and disconnects one of the first winding 34 and the second winding 35 from the external device. Alternatively, the control unit 50 stops driving both the first converter 51 and the second converter and disconnects both the first winding 34 and the second winding 35 from the external device.

[0181] Alternatively, in a configuration in which switches 39, 40 (or switches 1, 2) are provided, as in the first embodiment, when a sign of a short circuit or a short circuit is detected, the control unit 50 may switch the switches 39, 40, 1, 2 to disconnect (partially or completely) the first winding 34 and the second winding 35 (coil 33) from the external device.

[0182] Alternatively, when a sign of a short circuit or a short circuit is detected, as in the second embodiment, the control unit 50 may drive the first converter 51 and the second converter as inverters to cancel out the change in magnetic flux generated in the teeth portion 32 due to the rotation of the rotor 20. Furthermore, when a sign of a short circuit or a short circuit is detected, the control unit 50 may notify a higher-level system or a pilot of the sign of a short circuit or the short circuit.

[0183] Here, the first winding 34 and the second winding 35 may be covered with a filler made of an insulating material such as resin. In this case, in a high-voltage, low-pressure environment, it may be difficult to monitor the partial discharge current based on the potential difference ΔV between the first winding 34 and the second winding 35.

[0184] Therefore, the control unit 50 may control the first converter 51 and the second converter 52 to apply a probe voltage (e.g., a rectangular wave) from the converters 51, 52 between the first winding 34 and the second winding 35. This probe voltage is applied for a short period (about several ms) at a predetermined cycle (about several seconds).

[0185] 17 is a diagram showing the partial discharge current when the probe voltage is applied. The control unit 50 repeats the process of applying the probe voltage between the first winding 34 and the second winding 35 for a short period of time at a predetermined cycle.

[0186] The control unit 50 also determines whether the partial discharge current is less than a predetermined threshold Ith. If the partial discharge current is less than the threshold Ith, the control unit 50 determines that the state is normal. On the other hand, if the partial discharge current is equal to or greater than the threshold Ith, the control unit 50 determines that a short circuit has occurred. If the partial discharge current remains at 0 even after applying the exploration voltage, the control unit 50 determines that a short circuit has occurred.

[0187] In the first example, the partial discharge current is monitored, but the capacitance between the first winding 34 and the second winding 35 may also be monitored. Also, the insulation resistance between the first winding 34 and the second winding 35 may also be monitored. Alternatively, a combination of two or more of the partial discharge current, capacitance, and insulation resistance (electrical elements based on the potential difference ΔV) may also be monitored.

[0188] In the above description, a case has been described in which a sign of a short circuit or a short circuit is detected by monitoring the partial discharge current, capacitance, insulation resistance, etc. between the first winding 34 and the second winding 35 when the generator 14 is generating electricity (when the motor is driving, in the case of a motor). On the other hand, a sign of a short circuit or a short circuit may also be detected by monitoring the partial discharge current, capacitance, insulation resistance, etc. between the first winding 34 and the second winding 35 when the generator 14 is not generating electricity (when the motor is not driving, in the case of a motor).

[0189] For example, when an aircraft is parked at an airport, the aircraft generator 14 is not generating electricity (the aircraft motor is not driving). On the other hand, the probe voltage shown in Fig. 17 can be applied even when the generator 14 is not generating electricity (when the motor is not driving). The control unit 50 can then detect a sign of a short circuit or a short circuit by monitoring the partial discharge current, capacitance, insulation resistance, etc. based on the potential difference generated by this probe voltage.

[0190] Furthermore, the detected values ​​of partial discharge current, capacitance, insulation resistance, etc. may be recorded in chronological order (regardless of whether power generation is being performed or not). In this case, for example, the control unit 50 may determine whether maintenance of the generator 14 (or motor) is required based on the transition of these values ​​over time, and notify a higher-level system, pilot, mechanic, etc. This allows the maintenance intervals of the generator 14 (or motor) to be maintained appropriately, thereby reducing maintenance costs.

[0191] <Short circuit detection: second example> Next, a second example of detecting a sign of a short circuit or a short circuit caused by two or more windings will be described. Fig. 18 is a diagram showing a second example of detecting a sign of a short circuit or a short circuit caused by two or more windings.

[0192] The second example will be described mainly with respect to the differences from the first example described above. The second example differs from the first example in the way the first winding 34 and the second winding 35 are wound.

[0193] In FIG. 18, the first winding 34 and the second winding 35 are numbered in order from the start to the end of the winding.

[0194] The first winding 34 is wound around the first tooth portion 32A from the base end side (back yoke portion 31 side) of the first tooth portion 32A toward the tip end side (rotor 20 side), and then wound around the second tooth portion 32B from the tip end side (rotor 20 side) of the second tooth portion 32B toward the base end side (back yoke portion 31 side).

[0195] On the other hand, the second winding 35 is wound around the second tooth portion 32B from the tip end (rotor 20 side) of the second tooth portion 32B toward the base end side (back yoke portion 31 side), and then wound around the first tooth portion 32A from the base end side (back yoke portion 31 side) of the first tooth portion 32A toward the tip end side (rotor 20 side).

[0196] 19 is a diagram showing the potential difference ΔV between the first winding 34 and the second winding 35. In the first winding 34, the voltage is highest at the beginning of the winding and lowest at the end of the winding, reaching 0, and gradually decreases from the beginning to the end of the winding.

[0197] On the other hand, the voltage of the second winding 35 is approximately half that of the first winding 34 at the beginning of the winding, gradually decreases, and becomes zero halfway between the beginning and end of the winding. Then, this voltage rises sharply to double the value of the first winding 34, then gradually decreases toward the end of the winding, and at the end of the winding, it becomes the same value as at the beginning of the winding.

[0198] Therefore, the potential difference ΔV between the first winding 34 and the second winding 35 takes a constant positive value from the beginning to the middle position of the winding, and takes a constant negative value from the middle position to the end of the winding.

[0199] In the second example, as in the first example, a potential difference ΔV is provided between the first winding 34 and the second winding 35, so that a sign of a short circuit or a short circuit can be easily detected. In particular, in the second example, the potential difference ΔV can be easily increased, making it even easier to detect a sign of a short circuit or a short circuit.

[0200] The first and second examples can be combined. For example, in the winding method of the first winding 34 and the second winding 35 shown in Fig. 18, the number of turns of the first winding 34 and the second winding 35 can be made different. [Explanation of symbols]

[0201] 14...Generator 20...Rotor 30...Stator 32...Teeth part 33...Coil 34...First winding 35...Second winding 39, 40...Switch 41, 42, 51, 52... Converter 50...Control unit 53…Ammeter

Claims

1. a coil element including a magnetic core that generates a magnetic flux change in an axial direction, and a first winding and a second winding that are spirally wound around the magnetic core so as to be adjacent to other windings in the axial direction of the magnetic core, and to be interposed between the other windings in the axial direction and alternate in the axial direction, the first winding and the second winding being electrically and physically independent of the other windings and having a potential difference between them; a detector that detects a sign of a short circuit or a short circuit between the first winding and the second winding by detecting the potential difference or an electrical element caused by the potential difference; a first switch mechanism capable of switching between a connected state and a disconnected state between the first winding and an external device to which power is supplied from the generator, and a second switch mechanism capable of switching between a connected state and a disconnected state between the second winding and the external device, wherein when the detector detects a sign of a short circuit or a short circuit between the first winding and the second winding, the switch mechanism switches the connected state of at least one of the first winding and the second winding to the disconnected state; A generator comprising:

2. 2. The generator of claim 1, The first winding and the second winding are laminated in a plurality of layers in a radial direction perpendicular to the axial direction of the magnetic core, and are adjacent to each other in the radial direction. Generator.

3. 3. The generator according to claim 1 or 2, the coil elements include a plurality of coil elements corresponding to a plurality of phases, the first switch mechanism is capable of switching between the connected state and the disconnected state for each portion of the first winding corresponding to each phase, The second switch mechanism is capable of switching between the connected state and the disconnected state for each portion of the second winding corresponding to each phase. Generator.

4. A generator according to any one of claims 1 to 3, When a sign of a short circuit or a short circuit between the first winding and the second winding is detected, a current that cancels out a change in magnetic flux occurring in the magnetic core is supplied to at least one of the first winding and the second winding. Generator.

5. 2. The generator of claim 1, The first winding and the second winding have different winding patterns, so that a potential difference exists between the first winding and the second winding. Generator.

6. 6. The generator according to claim 5, The first winding and the second winding have different numbers of turns. Generator.

7. 7. The generator according to claim 5 or 6, the magnetic core includes a first magnetic core and a second magnetic core, the first magnetic core includes a first base end portion and a first tip end portion at both ends in the axial direction, the second magnetic core includes a second base end portion and a second tip end portion at both ends in the axial direction, the first winding is wound around the first magnetic core from the first base end side toward the first tip end side, and then wound around the second magnetic core from the second tip end side toward the second base end side; The second winding is wound around the second magnetic core from the second tip end toward the second base end, and then wound around the first magnetic core from the first base end toward the second tip end. Generator.

8. A generator according to any one of claims 1 to 7, The electrical element is at least one of a partial discharge current between the first winding and the second winding, a capacitance, and an insulation resistance. Generator.

9. 9. The generator of claim 8, A voltage for detecting the electrical element is applied between the first winding and the second winding at a predetermined cycle. Generator.

10. A generator according to any one of claims 1 to 9, The detector detects a sign of a short circuit or a short circuit when the generator is generating power. Generator.

11. A generator according to any one of claims 1 to 9, The detector detects a sign of a short circuit or a short circuit when the generator is not generating power. Generator.

12. a coil element including a magnetic core that generates a magnetic flux change in an axial direction, and a first winding and a second winding that are spirally wound around the magnetic core so as to be adjacent to other windings in the axial direction of the magnetic core, and to be interposed between the other windings in the axial direction and alternate in the axial direction, the first winding and the second winding being electrically and physically independent of the other windings and having a potential difference between them; a detector that detects a sign of a short circuit or a short circuit between the first winding and the second winding by detecting the potential difference or an electrical element caused by the potential difference; a first switch mechanism capable of switching between a connection state and a disconnection state between the first winding and a power source that supplies power to the motor, and a second switch mechanism capable of switching between a connection state and a disconnection state between the second winding and the power source, wherein when the detector detects a sign of a short circuit or a short circuit between the first winding and the second winding, the switch mechanism switches the connection state of at least one of the first winding and the second winding to the disconnection state; A motor comprising:

13. a magnetic core that generates a magnetic flux change in the axial direction; and a coil element having first and second windings that are spirally wound around the magnetic core so as to be adjacent to other windings in the axial direction of the magnetic core, and to be interposed between other windings in the axial direction and alternate in the axial direction, and which are electrically and physically independent of the other windings and have a potential difference between them; a detector that detects a sign of a short circuit or a short circuit between the first winding and the second winding by detecting the potential difference or an electrical element caused by the potential difference; a first switch mechanism capable of switching between a connected state and a disconnected state between the first winding and an external device to which power is supplied from the generator, and a second switch mechanism capable of switching between a connected state and a disconnected state between the second winding and the external device, wherein when the detector detects a sign of a short circuit or a short circuit between the first winding and the second winding, the switch mechanism switches the connected state of at least one of the first winding and the second winding to the disconnected state; A generator having An aircraft equipped with:

14. a coil element including a magnetic core that generates a magnetic flux change in an axial direction, and a first winding and a second winding that are spirally wound around the magnetic core so as to be adjacent to other windings in the axial direction of the magnetic core, and to be interposed between the other windings in the axial direction and alternate in the axial direction, the first winding and the second winding being electrically and physically independent of the other windings and having a potential difference between them; a detector that detects a sign of a short circuit or a short circuit between the first winding and the second winding by detecting the potential difference or an electrical element caused by the potential difference; a first switch mechanism capable of switching between a connection state and a disconnection state between the first winding and a power source that supplies power to the motor, and a second switch mechanism capable of switching between a connection state and a disconnection state between the second winding and the power source, wherein when the detector detects a sign of a short circuit or a short circuit between the first winding and the second winding, the switch mechanism switches the connection state of at least one of the first winding and the second winding to the disconnection state; A motor having An aircraft equipped with:

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