Switching device for multiphase motors

Abstract

To provide a multi-phase motor switching device that changes characteristics of a multi-phase motor while simplifying a structure.SOLUTION: A multi-phase motor switching device 10 is used for a motor 100 including coils 32A, 32B, 32C of a plurality of phases, each of the coils 32A, 32B, 32C having first coil units 1U, 3U, 1V, 3V, 1W, 3W and second coil units 2U, 4U, 2V, 4V, 2W, 4W. The multi-phase motor switching device 10 includes a switching unit 80 that switches the number of series connections of the first coil units 1U, 3U, 1V, 3V, 1W, 3W and the second coil units 2U, 4U, 2V, 4V, 2W, 4W in each of the coils 32A, 32B, 32C.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a switching device for a polyphase motor.

Background Art

[0002] Patent Document 1 discloses a configuration in which the winding connection state of a three-phase AC motor is switched between winding parallel and winding series by a winding switching device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a configuration for switching the connection state between winding parallel and winding series, the configuration shown in FIG. 9 can be considered. This configuration is a configuration in which two coil portions 50 and 51 are connected by three relay switches 52, 53, and 54. In the case of this configuration, by turning off the relay switches 52 and 54 and turning on the relay switch 53, the coil portions 50 and 51 can be connected in series. On the other hand, by turning on the relay switches 52 and 54 and turning off the relay switch 53, the coil portions 50 and 51 can be connected in parallel. When the relay switches 52, 53, and 54 are enlarged assuming that a relatively large current flows through the relay switches 52, 53, and 54, it is also necessary to consider suppressing the mounting space.

[0005] An object of the present disclosure is to provide a switching device for a polyphase motor that changes the characteristics of the polyphase motor while simplifying the structure.

Means for Solving the Problems

[0006] The switching device for a polyphase motor of the present disclosure is A switching device for a multiphase motor, which is used in a multiphase motor equipped with multiple phase coils, each of which has multiple coil sections, Each coil is equipped with a switching unit that switches the number of series connections of the multiple coil sections. [Effects of the Invention]

[0007] The characteristics of the multiphase motor can be changed while simplifying the structure. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of the motor of Embodiment 1. [Figure 2] Figure 2 is a circuit diagram showing a configuration in which a multi-phase motor switching device is provided to the motor of Embodiment 1. [Figure 3] Figure 3 is a graph showing the relationship between torque and rotational speed in the motor of Embodiment 1. [Figure 4] Figure 4 is a schematic diagram of the motor of Embodiment 2. [Figure 5] Figure 5 is a circuit diagram showing a configuration in which a multi-phase motor switching device is provided to the motor of Embodiment 2. [Figure 6] Figure 6 is a schematic diagram of the motor according to Embodiment 2, in which the reference numerals of each coil section are clearly indicated. [Figure 7] Figure 7 is a graph showing the relationship between torque and rotational speed in the motor of Embodiment 2. [Figure 8] Figure 8 is a circuit diagram showing an example of the connection between the coil section and the switching section in another embodiment. [Figure 9] Figure 9 is a circuit diagram showing an example of a conventional connection between the coil section and the switching section. [Modes for carrying out the invention]

[0009] Embodiments of the present disclosure are listed and illustrated below. The features [1] to [7] illustrated below may be combined in any way that is not contradictory.

[0010] [1] The multiphase motor switching device of the present disclosure is used in a multiphase motor that has multiple phase coils, and each coil has multiple coil sections. The multiphase motor switching device of the present disclosure includes a switching unit that switches the number of series connections of multiple coil sections in each coil.

[0011] This configuration allows for various changes in the characteristics of a multiphase motor by switching the number of coils connected in series. Here, the number of coils connected in series refers to the number of coils connected in series that are capable of conducting electricity.

[0012] [2] In the multiphase motor switching device described in [1] above, the switching unit has a plurality of relay switches, and the number of series connections can be switched by individually switching each relay switch between an ON state and an OFF state.

[0013] The multi-phase motor switching device described in [2] above can have a simpler configuration by using a relay switch.

[0014] [3] In the multiphase motor switching device described in [2] above, the coil has a first coil section and a second coil section, one end of the first coil section may be connected to a first conductive path, and the other end of the second coil section may be connected to a second conductive path. The switching section may have a first relay switch provided between the other end of the first coil section and the other end of the second coil section, and a second relay switch provided between the other end of the first coil section and one end of the second coil section. The connection between one end of the second coil section and the first conductive path may always be configured to be non-short-circuited.

[0015] The multiphase motor switching device in [3] allows the number of coils connected in series to be changed between the first coil section only and the first coil section and the second coil section by alternately switching the first relay switch and the second relay switch. Here, a short-circuit configuration is a configuration in which current is always passed through the coil when current is passed between one end of the second coil section and the first conductive path, and a non-short-circuit configuration is a configuration in which there is no short-circuit configuration (i.e., there is no path through which current is passed without going through the coil).

[0016] 〔4〕In the switching device for a polyphase motor according to 〔2〕 above, the plurality of coil portions are connected in series, and the switching portion is configured to switch so as to connect one of both ends of the coil portions connected in series and between all the coil portions to a first conductive path and the other to a second conductive path.

[0017] The switching device for a polyphase motor according to 〔4〕 can utilize a desired portion of the coil portion.

[0018] 〔5〕In the switching device for a polyphase motor according to 〔1〕 or 〔2〕 above, the plurality of coil portions are arranged in an annular shape, and the coil portions removed from the usage range by the switching portion can be arranged so as to be discrete in the circumferential direction.

[0019] The switching device for a polyphase motor according to 〔5〕 can disperse the influence of the coil portions removed from the usage range in the circumferential direction. Here, the usage range means the coil portions in which current flows among the coil portions, and being out of the usage range means the coil portions in which current does not flow.

[0020] 〔6〕In the switching device for a polyphase motor according to 〔1〕 or 〔2〕 above, the plurality of coil portions are arranged in an annular shape, and the coil portions removed from the usage range by the switching portion can be arranged to be biased in the circumferential direction.

[0021] The switching device for a polyphase motor according to 〔6〕 can easily have a configuration in which the positions where the switching portion is connected to the coil portions are grouped in the circumferential direction, so space saving can be expected.

[0022] 〔7〕The switching device for a polyphase motor according to 〔1〕 or 〔2〕 above may further include a control device that controls the operation of the switching portion.

[0023] The switching device for a polyphase motor according to 〔7〕 can easily perform the operation of the switching portion well by the control device. <实

[0024] <Embodiment 1> [Configuration of Motor] The multiphase motor switching device 10 of Embodiment 1 is used with a motor 100, which is a multiphase motor that utilizes a multiphase AC power supply. As shown in Figure 1, the motor 100 comprises a stator section 21 and a rotor section 23.

[0025] [Status of the stator section] The stator section 21 is housed in a housing (not shown). The stator section 21 includes a stator core 31 and a plurality of coils 32A, 32B, 32C. For example, the stator core 31 is a cylindrical metal with electrical conductivity.

[0026] Multiple coils 32A, 32B, and 32C are configured as three-phase segment coils. Coil 32A corresponds to the first phase (U phase), coil 32B corresponds to the second phase (V phase), and coil 32C corresponds to the third phase (W phase). Coil 32A, the first phase (U phase), has first coil sections 1U and 3U, and second coil sections 2U and 4U. Coil 32B, the second phase (V phase), has first coil sections 1V and 3V, and second coil sections 2V and 4V. Coil 32C, the third phase (V phase), has first coil sections 1W and 3W, and second coil sections 2W and 4W.

[0027] Each of the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W has a form in which the wires forming it are wound in a spiral (coil) shape. As shown in Figure 2, the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W are electrically connected so as to radiate from the second conductive path C, which is the neutral part. For example, the second conductive path C is formed by a busbar or the like.

[0028] In this disclosure, "electrically connected" preferably means a configuration in which the two connected objects are connected in a state of conduction (a state in which current can flow) such that the potentials of both objects are equal. However, the disclosure is not limited to this configuration. For example, "electrically connected" may mean a configuration in which the two connected objects are connected in a state in which they can conduct electricity while an electrical component is interposed between them.

[0029] As shown in Figure 1, the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W are arranged in a ring shape along the inner circumference of the stator core 31. Specifically, the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W are arranged so that their axes perpendicular to the winding direction are perpendicular to the central axis of the stator core 31.

[0030] Each of the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W has a pair of terminal sections T. The terminal sections T of each of the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W, which are arranged along the inner circumference of the stator core 31, are drawn out to one side in the axial direction of the stator core 31.

[0031] In Figure 1, the symbols with an "x" inside a circle and the symbols with a black circle inside a circle correspond to a pair of terminals T in each of the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W. The terminals corresponding to the symbols with an "x" inside a circle are located on the outside (away from the second conductive path C) in Figure 2, while the terminals corresponding to the symbols with a black circle inside a circle are located on the inside (closer to the second conductive path C) in Figure 2.

[0032] As shown in Figure 2, the terminals of the first coil sections 1U, 1V, and 1W that are furthest from the second conductive path C are electrically connected to the first conductive paths 41, 42, and 43. The first conductive paths 41, 42, and 43 are formed, for example, by busbars and function as conductive paths interposed between an inverter (not shown) and coils 32A, 32B, and 32C.

[0033] [Rotor Configuration] As shown in Figure 1, the rotor 23 is rotatably positioned inside the stator 21. Multiple permanent magnets 24 are arranged on the outer periphery of the rotor 23.

[0034] [Configuration of a switching device for multi-phase motors] As shown in Figure 2, the multiphase motor switching device 10 includes a switching unit 80 and a control device 90. The switching unit 80 includes a first switching unit 81, a second switching unit 82, and a third switching unit 83. The first switching unit 81 switches the number of series connections in the first coil units 1U, 3U and the second coil units 2U, 4U that constitute the first phase (U phase) coils. The second switching unit 82 switches the number of series connections in the first coil units 1V, 3V and the second coil units 2V, 4V that constitute the second phase (V phase) coils. The third switching unit 83 switches the number of series connections in the first coil units 1W, 3W and the second coil units 2W, 4W that constitute the third phase (W phase) coils.

[0035] The first switching unit 81 includes a first relay switch 81A and a second relay switch 81B. The first relay switch 81A and the second relay switch 81B are configured as semiconductor relays. Semiconductor relays are composed of, for example, MOSFETs, GaNFETs, IGBTs, bipolar transistors, etc. The first relay switch 81A and the second relay switch 81B are switched between an ON state and an OFF state by an ON instruction or OFF instruction from a control device 90, which will be described later. The first relay switch 81A and the second relay switch 81B enter an ON state, allowing current to flow through them, when an ON instruction is received from the control device 90, and enter an OFF state, blocking current flow through them, when an OFF instruction is received from the control device 90.

[0036] The control device 90 is configured, for example, as an information processing device having arithmetic functions and information processing functions. The control device 90 may be configured as a microcomputer, or as any other type of information processing device.

[0037] The second switching unit 82 has a first relay switch 82A and a second relay switch 82B. The first relay switch 82A and the second relay switch 82B have the same configuration as the first relay switch 81A and the second relay switch 81B. The third switching unit 83 has a first relay switch 83A and a second relay switch 83B. The first relay switch 83A and the second relay switch 83B have the same configuration as the first relay switch 81A and the second relay switch 81B.

[0038] A first conductive path 41 is electrically connected to one end of the first coil section 1U. The other end of the first coil section 1U is electrically connected to one end of the first coil section 3U. A second conductive path C is electrically connected to the other end of the second coil section 4U. One end of the second coil section 4U is electrically connected to the other end of the second coil section 2U. A first relay switch 81A is provided between the other end of the first coil section 3U and the other end of the second coil section 4U. A second relay switch 81B is provided between the other end of the first coil section 3U and one end of the second coil section 2U. The second coil sections 2U and 4U are not connected to one end of the first coil section 1U or to the first conductive path 41. In other words, the connection between the second coil sections 2U and 4U and the first conductive path 41 is always non-short-circuited.

[0039] The control device 90 switches the number of coils 32A connected in series, which form the energized path between the first conductive path 41 and the second conductive path C, by giving an off command to either the first relay switch 81A or the second relay switch 81B and an on command to the other. Specifically, when the control device 90 gives an on command to the first relay switch 81A and an off command to the second relay switch 81B, the first conductive path 41, the first coil sections 1U and 3U, and the second conductive path C are electrically connected in series in this order. As a result, the first coil sections 1U and 3U are included in the operating range and current flows. In contrast, the second coil sections 2U and 4U are outside the operating range and no current flows. At this time, the number of coils 32A connected in series is 2.

[0040] When the control device 90 gives an off command to the first relay switch 81A and an on command to the second relay switch 81B, the first conductive path 41, the first coil sections 1U and 3U, the second coil sections 2U and 4U, and the second conductive path C are electrically connected in series in this order. As a result, the first coil sections 1U and 3U and the second coil sections 2U and 4U are included in the operating range, and current flows. At this time, the number of series connections in coil 32A is 4.

[0041] A first conductive path 42 is electrically connected to one end of the first coil section 1V. The other end of the first coil section 1V is electrically connected to one end of the first coil section 3V. A second conductive path C is electrically connected to the other end of the second coil section 4V. One end of the second coil section 4V is electrically connected to the other end of the second coil section 2V. A first relay switch 82A is provided between the other end of the first coil section 3V and the other end of the second coil section 4V. A second relay switch 82B is provided between the other end of the first coil section 3V and one end of the second coil section 2V. The second coil sections 2V and 4V are not connected to one end of the first coil section 1V or to the first conductive path 42. In other words, the connection between the second coil sections 2V and 4V and the first conductive path 42 is always non-short-circuited.

[0042] The control device 90 switches the number of coils 32B connected in series, which form the energizing path between the first conductive path 42 and the second conductive path C, by giving an off command to either the first relay switch 82A or the second relay switch 82B and an on command to the other. Specifically, when the control device 90 gives an on command to the first relay switch 82A and an off command to the second relay switch 82B, the first conductive path 42, the first coil section 1V, 3V, and the second conductive path C are electrically connected in series in this order. As a result, the first coil section 1V, 3V is included in the operating range and current flows. In contrast, the second coil section 2V, 4V is excluded from the operating range and no current flows. At this time, the number of coils 32B connected in series is 2.

[0043] When the control device 90 gives an off command to the first relay switch 82A and an on command to the second relay switch 82B, the first conductive path 42, the first coil section 1V, 3V, the second coil section 2V, 4V, and the second conductive path C are electrically connected in series in this order. As a result, the first coil section 1V, 3V and the second coil section 2V, 4V are included in the usable range, and current flows. At this time, the number of series connections in coil 32B is 4.

[0044] A first conductive path 43 is electrically connected to one end of the first coil section 1W. The other end of the first coil section 1W is electrically connected to one end of the first coil section 3W. A second conductive path C is electrically connected to the other end of the second coil section 4W. One end of the second coil section 4W is electrically connected to the other end of the second coil section 2W. A first relay switch 83A is provided between the other end of the first coil section 3W and the other end of the second coil section 4W. A second relay switch 83B is provided between the other end of the first coil section 3W and one end of the second coil section 2W. The second coil sections 2W and 4W are not connected to one end of the first coil section 1W or to the first conductive path 43. In other words, the connection between the second coil sections 2W and 4W and the first conductive path 43 is always non-short-circuited.

[0045] The control device 90 switches the number of coils 32C connected in series that form a current-carrying path between the first conductive path 43 and the second conductive path C by giving an off command to either the first relay switch 83A or the second relay switch 83B and an on command to the other. Specifically, when the control device 90 gives an on command to the first relay switch 83A and an off command to the second relay switch 83B, the first conductive path 43, the first coil sections 1W and 3W, and the second conductive path C are electrically connected in series in this order. As a result, the first coil sections 1W and 3W are included in the operating range and current flows. In contrast, the second coil sections 2W and 4W are excluded from the operating range and no current flows. At this time, the number of coils 32C connected in series is 2.

[0046] When the control device 90 gives an off command to the first relay switch 83A and an on command to the second relay switch 83B, the first conductive path 43, the first coil sections 1W and 3W, the second coil sections 2W and 4W, and the second conductive path C are electrically connected in series in this order. As a result, the first coil sections 1W and 3W and the second coil sections 2W and 4W are included in the operating range, and current flows. At this time, the number of coils connected in series in coil 32C is 4.

[0047] In this way, the multiphase motor switching device 10 switches the number of series connections of the multiple coil sections (first coil sections 1U, 3U, 1V, 3V, 1W, 3W, and second coil sections 2U, 4U, 2V, 4V, 2W, 4W) that constitute each of the coils 32A, 32B, and 32C.

[0048] [Regarding coil sections outside the intended use range] When the control device 90 gives an ON command to the first relay switches 81A, 82A, and 83A, and an OFF command to the second relay switches 81B, 82B, and 83B, the second coil sections 2U, 4U, 2V, 4V, 2W, and 4W are moved out of the operating range. In this case, the second coil sections 2U, 4U, 2V, 4V, 2W, and 4W that have been moved out of the operating range by the switching unit 80 are arranged to be dispersed in the circumferential direction (see Figure 1). Also, the first coil sections 1U, 3U, 1V, 3V, 1W, and 3W that are included in the operating range are also arranged to be dispersed in the circumferential direction. Specifically, the second coil sections 2U, 4U, 2V, 4V, 2W, and 4W are arranged to be evenly spaced in the circumferential direction. And the first coil sections 1U, 3U, 1V, 3V, 1W, and 3W are also arranged to be evenly spaced in the circumferential direction. Furthermore, the first coil sections 1U, 3U, 1V, 3V, 1W, 3W, which are included in the usable range, and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W, which are excluded from the usable range, are arranged alternately in the circumferential direction.

[0049] [Regarding the characteristics of motor torque and rotational speed] The control device 90 gives ON instructions to the first relay switches 81A, 82A, and 83A, and OFF instructions to the second relay switches 81B, 82B, and 83B. As a result, current flows to the first coil sections 1U, 3U, 1V, 3V, 1W, and 3W that are within the operating range, and no current flows to the second coil sections 2U, 4U, 2V, 4V, 2W, and 4W that are outside the operating range. In this case, the relationship between torque and rotational speed in the motor 100 changes according to the characteristics of the solid line shown in Figure 3.

[0050] The control device 90 gives an off command to the first relay switches 81A, 82A, and 83A, and an on command to the second relay switches 81B, 82B, and 83B. As a result, current flows to the first coil sections 1U, 3U, 1V, 3V, 1W, and 3W, and the second coil sections 2U, 4U, 2V, 4V, 2W, and 4W, which are included in the operating range. In this case, the relationship between torque and rotational speed in the motor 100 changes according to the characteristics shown by the dotted line in Figure 3. In Figure 3, in both the characteristics of the solid line and the characteristics of the dotted line, the torque shows a constant value in the region where the rotational speed is relatively small. Then, when the rotational speed exceeds a predetermined speed, the torque decreases.

[0051] Comparing the characteristics of the solid line and the dotted line, the magnitude of torque in the region where torque is constant is greater in the dotted line characteristic. Furthermore, the rotational speed range in the solid line characteristic is wider than in the dotted line characteristic, extending to higher rotational speeds. Therefore, in a predetermined low rotational speed state, the first relay switches 81A, 82A, and 83A are given an off command, and the second relay switches 81B, 82B, and 83B are given an on command, so that the characteristics of the dotted line are obtained. This includes the first coil section 1U, 3U, 1V, 3V, 1W, 3W and the second coil section 2U, 4U, 2V, 4V, 2W, 4W within the operating range.

[0052] When the rotation speed is higher than the predetermined low rotation speed, the first relay switches 81A, 82A, and 83A are given an ON command and the second relay switches 81B, 82B, and 83B are given an OFF command so that the characteristics are as shown by the solid line. This includes the first coil section 1U, 3U, 1V, 3V, 1W, and 3W in the operating range. Here, the predetermined low rotation speed is, for example, a state in which the rotation speed of the motor 100 is below a predetermined threshold, for example, a state in which the rotation speed is below point Sp in Figure 3. Also, a state in which the rotation speed is higher than the predetermined low rotation speed is a state in which the rotation speed is greater than point Sp in Figure 3.

[0053] Next, we will illustrate the effects of this configuration. The multiphase motor switching device 10 is used in a motor 100 that has multiple phase coils 32A, 32B, and 32C, each of which has a first coil section 1U, 3U, 1V, 3V, 1W, 3W and a second coil section 2U, 4U, 2V, 4V, 2W, 4W. The multiphase motor switching device 10 of this disclosure includes a switching unit 80 that switches the number of series connections of the first coil section 1U, 3U, 1V, 3V, 1W, 3W and the second coil section 2U, 4U, 2V, 4V, 2W, 4W in each of the coils 32A, 32B, and 32C. With this configuration, the characteristics of the motor 100 can be changed in various ways by switching the number of series connections of the first coil section 1U, 3U, 1V, 3V, 1W, 3W and the second coil section 2U, 4U, 2V, 4V, 2W, 4W. Here, the number of series connections refers to the number of first coil sections 1U, 3U, 1V, 3V, 1W, 3W and second coil sections 2U, 4U, 2V, 4V, 2W, 4W that are connected in series and are energized.

[0054] In the multiphase motor switching device 10, the switching unit 80 has first relay switches 81A, 82A, 83A and second relay switches 81B, 82B, 83B. The switching unit 80 switches the number of series connections by individually switching each of the first relay switches 81A, 82A, 83A and the second relay switches 81B, 82B, 83B between the ON state and the OFF state. With this configuration, the switching unit 80 can be made into a simple configuration by using relay switches.

[0055] In the multiphase motor switching device 10, coils 32A, 32B, and 32C have first coil sections 1U, 3U, 1V, 3V, 1W, and 3W, and second coil sections 2U, 4U, 2V, 4V, 2W, and 4W. One end of the first coil sections 1U, 1V, and 1W is connected to the first conductive paths 41, 42, and 43, and the other end of the second coil sections 4U, 4V, and 4W is connected to the second conductive path C. The switching unit 80 has first relay switches 81A, 82A, and 83A, and second relay switches 81B, 82B, and 83B. The first relay switches 81A, 82A, and 83A are provided between the other end of the first coil sections 3U, 3V, and 3W and the other end of the second coil sections 4U, 4V, and 4W. The second relay switches 81B, 82B, and 83B are provided between the other end of the first coil section 3U, 3V, 3W and one end of the second coil section 2U, 2V, 2W. The connection between one end of the second coil section 2U, 2V, 2W and the first conductive paths 41, 42, 43 is always kept non-short-circuited. With this configuration, by alternately switching the first relay switches 81A, 82A, 83A and the second relay switches 81B, 82B, 83B, the number of coils 32A, 32B, 32C connected in series can be changed to only the first coil section 1U, 3U, 1V, 3V, 1W, 3W, or to the first coil section 1U, 3U, 1V, 3V, 1W, 3W and the second coil section 2U, 4U, 2V, 4V, 2W, 4W.

[0056] Here, a short-circuit configuration is one in which, when current is passed between one end of the second coil section 2U, 2V, 2W and the first conductive path 41, 42, 43, the current is always passed through coils 32A, 32B, 32C, and a non-short-circuit configuration is one in which there is no short-circuit configuration (i.e., there is no path through which current is passed without going through coils 32A, 32B, 32C).

[0057] In the multiphase motor switching device 10, the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W are arranged in a ring shape. The second coil sections 2U, 4U, 2V, 4V, 2W, 4W that are excluded from the operating range by the switching unit 80 are arranged to be discrete in the circumferential direction. With this configuration, the influence of the second coil sections 2U, 4U, 2V, 4V, 2W, 4W that are excluded from the operating range can be dispersed in the circumferential direction. Here, the operating range refers to the coil sections of the first coil sections 1U, 3U, 1V, 3V, 1W, 3W and the second coil sections 2U, 4U, 2V, 4V, 2W, 4W that are in a state where current is flowing, and being excluded from the operating range refers to the coil sections that are in a state where no current is flowing.

[0058] The multiphase motor switching device 10 further includes a control device 90 that controls the operation of the switching unit 80. With this configuration, the control device 90 makes it easier to ensure smooth operation of the switching unit 80.

[0059] <Embodiment 2> The multiphase motor switching device 110 of Embodiment 2 differs from Embodiment 1 in the configuration of the connection between the switching unit 180 and the coils 132A, 132B, and 132C, and in the switching method of the relay switch in the switching unit 180. Also, the motor 200 of Embodiment 2 differs from Embodiment 1 in the configuration of the coils 132A, 132B, and 132C. Detailed explanations of configurations similar to those of Embodiment 1 are omitted.

[0060] As shown in Figure 4, the motor 200 of Embodiment 2 has coils 132A, 132B, and 132C. As shown in Figure 5, coil 132A is configured such that coil sections 11U, 13U, 12U, and 14U are connected in series in that order. One end of coil section 11U is electrically connected to the first conductive path 41.

[0061] Coil 132B is configured with coil sections 13V, 11V, 14V, and 12V connected in series in that order. One end of coil section 13V is electrically connected to the first conductive path 42. Coil 132C is configured with coil sections 11W, 13W, 12W, and 14W connected in series in that order. One end of coil section 11W is electrically connected to the first conductive path 43.

[0062] [Configuration of a switching device for multi-phase motors] The multiphase motor switching device 110 includes a switching unit 180 and a control device 190. The switching unit 180 comprises a first switching unit 181, a second switching unit 182, and a third switching unit 183. The first switching unit 181 switches the number of series connections that form a path for energizing between the first conductive path 41 and the second conductive path C among the coil units 11U, 13U, 12U, and 14U that constitute the first phase (U phase) coil. The second switching unit 182 switches the number of series connections that form a path for energizing between the first conductive path 41 and the second conductive path C among the coil units 13V, 11V, 14V, and 12V that constitute the second phase (V phase) coil. The third switching unit 183 switches the number of series connections among the coil sections 11W, 13W, 12W, and 14W that constitute the third phase (W phase) coil, which form a path that conducts current between the first conductive path 41 and the second conductive path C.

[0063] The first switching unit 181 includes a first relay switch 181A, a second relay switch 181B, a third relay switch 181C, and a fourth relay switch 181D. The first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D are configured as semiconductor relays. Semiconductor relays are composed of, for example, MOSFETs, GaNFETs, IGBTs, bipolar transistors, etc.

[0064] The first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D are switched between ON and OFF operations by control signals from the control device 190, which will be described later. The first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D become ON, allowing power to flow through them, upon an ON instruction from the control device 190. The first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D become OFF, cutting off power flow through them, upon an OFF instruction from the control device 90.

[0065] The control device 190 is configured, for example, as an information processing device having arithmetic functions and information processing functions. The control device 190 may be configured as a microcomputer, or as any other type of information processing device.

[0066] The second switching unit 182 includes a first relay switch 182A, a second relay switch 182B, a third relay switch 182C, and a fourth relay switch 182D. The first relay switch 182A, the second relay switch 182B, the third relay switch 182C, and the fourth relay switch 182D have the same configuration as the first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D.

[0067] The third switching unit 183 includes a first relay switch 183A, a second relay switch 183B, a third relay switch 183C, and a fourth relay switch 183D. The first relay switch 183A, the second relay switch 183B, the third relay switch 183C, and the fourth relay switch 183D have the same configuration as the first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D.

[0068] One end of the first relay switch 181A is electrically connected to the connection point between the other end of coil section 11U and one end of coil section 13U. The other end of the first relay switch 181A is electrically connected to the second conductive path C. One end of the second relay switch 181B is electrically connected to the connection point between the other end of coil section 13U and one end of coil section 12U. The other end of the second relay switch 181B is electrically connected to the second conductive path C. One end of the third relay switch 181C is electrically connected to the connection point between the other end of coil section 12U and one end of coil section 14U. The other end of the third relay switch 181C is electrically connected to the second conductive path C. One end of the fourth relay switch 181D is electrically connected to the other end of coil section 14U. The other end of the fourth relay switch 181D is electrically connected to the second conductive path C.

[0069] One end of the first relay switch 182A is electrically connected to the connection point between the other end of coil section 13V and one end of coil section 11V. The other end of the first relay switch 182A is electrically connected to the second conductive path C. One end of the second relay switch 182B is electrically connected to the connection point between the other end of coil section 11V and one end of coil section 14V. The other end of the second relay switch 182B is electrically connected to the second conductive path C. One end of the third relay switch 182C is electrically connected to the connection point between the other end of coil section 14V and one end of coil section 12V. The other end of the third relay switch 182C is electrically connected to the second conductive path C. One end of the fourth relay switch 182D is electrically connected to the other end of coil section 12V. The other end of the fourth relay switch 182D is electrically connected to the second conductive path C.

[0070] One end of the first relay switch 183A is electrically connected to the connection point between the other end of coil section 11W and one end of coil section 13W. The other end of the first relay switch 183A is electrically connected to the second conductive circuit C. One end of the second relay switch 183B is electrically connected to the connection point between the other end of coil section 13W and one end of coil section 12W. The other end of the second relay switch 183B is electrically connected to the second conductive circuit C. One end of the third relay switch 183C is electrically connected to the connection point between the other end of coil section 12W and one end of coil section 14W. The other end of the third relay switch 183C is electrically connected to the second conductive circuit C. One end of the fourth relay switch 183D is electrically connected to the other end of coil section 14W. The other end of the fourth relay switch 183D is electrically connected to the second conductive circuit C.

[0071] The control device 190 switches the number of series connections in coil 132A by giving an ON command to one of the first relay switch 181A, second relay switch 181B, third relay switch 181C, and fourth relay switch 181D, and an OFF command to the others. Specifically, the control device 190 gives an ON command to the first relay switch 181A and an OFF command to the others. As a result, the first conductive path 41, coil section 11U, and second conductive path C are electrically connected in series in this order. This includes coil section 11U in the operating range, and current flows through it. In contrast, coil sections 13U, 12U, and 14U are excluded from the operating range, and no current flows through them. At this time, the number of series connections in coil 132A is 1.

[0072] The control device 190 gives an ON command to the second relay switch 181B and an OFF command to the others. As a result, the first conductive path 41, coil sections 11U and 13U, and the second conductive path C are electrically connected in series in this order. This brings coil sections 11U and 13U into the operating range, and current flows through them. In contrast, coil sections 12U and 14U are excluded from the operating range, and no current flows through them. At this time, the number of coils connected in series in coil 132A is 2.

[0073] The control device 190 gives an ON command to the third relay switch 181C and an OFF command to the others. As a result, the first conductive path 41, coil sections 11U, 13U, 12U, and the second conductive path C are electrically connected in series in this order. This brings coil sections 11U, 13U, and 12U into the operating range, and current flows through them. In contrast, coil section 14U is excluded from the operating range, and no current flows through it. At this time, the number of coils connected in series in coil 132A is 3.

[0074] The control device 190 gives an ON command to the fourth relay switch 181D and an OFF command to the others. As a result, the first conductive path 41, the coil sections 11U, 13U, 12U, 14U, and the second conductive path C are electrically connected in series in this order. This brings the coil sections 11U, 13U, 12U, and 14U into the usable range, and current flows. At this time, the number of coils connected in series in coil 132A is 4. In this way, the control device 190 switches the number of coil sections 11U, 13U, 12U, and 14U connected in series by individually switching the first relay switch 181A, the second relay switch 181B, the third relay switch 181C, and the fourth relay switch 181D.

[0075] The control device 190 switches the operating range of coil 132B by giving an ON command to one of the first relay switch 182A, second relay switch 182B, third relay switch 182C, and fourth relay switch 182D, and an OFF command to the others. Specifically, the control device 190 gives an ON command to the first relay switch 182A and an OFF command to the others. As a result, the first conductive path 42, coil section 13V, and second conductive path C are electrically connected in series in this order. This includes coil section 13V in the operating range, and current flows through it. In contrast, coil sections 11V, 14V, and 12V are excluded from the operating range, and no current flows through them. At this time, the number of series connections in coil 132B is 1.

[0076] The control device 190 gives an ON command to the second relay switch 182B and an OFF command to the others. As a result, the first conductive path 42, the coil sections 13V and 11V, and the second conductive path C are electrically connected in series in this order. This brings the coil sections 13V and 11V into the usable range, and current flows through them. In contrast, the coil sections 14V and 12V are excluded from the usable range, and no current flows through them. At this time, the number of series connections in coil 132B is 2.

[0077] The control device 190 gives an ON command to the third relay switch 182C and an OFF command to the others. As a result, the first conductive path 42, the coil sections 13V, 11V, 14V, and the second conductive path C are electrically connected in series in this order. This brings the coil sections 13V, 11V, and 14V into the usable range, and current flows through them. In contrast, the coil section 12V is excluded from the usable range, and no current flows through it. At this time, the number of series connections in coil 132B is 3.

[0078] The control device 190 gives an ON command to the fourth relay switch 182D and an OFF command to the others. As a result, the first conductive path 42, the coil sections 13V, 11V, 14V, 12V, and the second conductive path C are electrically connected in series in this order. This brings the coil sections 13V, 11V, 14V, and 12V into the usable range, and current flows. At this time, the number of series connections in coil 132B is 4.

[0079] The control device 190 switches the operating range of coil 132C by giving an ON command to one of the first relay switch 183A, second relay switch 183B, third relay switch 183C, and fourth relay switch 183D, and an OFF command to the others. Specifically, the control device 190 gives an ON command to the first relay switch 183A and an OFF command to the others. As a result, the first conductive path 43, coil section 11W, and second conductive path C are electrically connected in series in this order. This includes coil section 11W in the operating range, and current flows through it. In contrast, coil sections 13W, 12W, and 14W are excluded from the operating range, and no current flows through them. At this time, the number of series connections in coil 132C is 1.

[0080] The control device 190 gives an ON command to the second relay switch 183B and an OFF command to the others. As a result, the first conductive path 43, coil sections 11W and 13W, and the second conductive path C are electrically connected in series in this order. This brings coil sections 11W and 13W into the operating range, and current flows through them. In contrast, coil sections 12W and 14W are excluded from the operating range, and no current flows through them. At this time, the number of coils connected in series in coil 132C is 2.

[0081] The control device 190 gives an ON command to the third relay switch 183C and an OFF command to the others. As a result, the first conductive path 43, coil sections 11W, 13W, and 12W, and the second conductive path C are electrically connected in series in this order. This brings coil sections 11W, 13W, and 12W into the usable range, and current flows through them. In contrast, coil section 14W is excluded from the usable range, and no current flows through it. At this time, the number of coils connected in series in coil 132C is 3.

[0082] The control device 190 gives an ON command to the fourth relay switch 183D and an OFF command to the others. As a result, the first conductive path 43, the coil sections 11W, 13W, 12W, 14W, and the second conductive path C are electrically connected in series in this order. This brings the coil sections 11W, 13W, 12W, and 14W into the usable range, and current flows. At this time, the number of coils connected in series in coil 132C is 4.

[0083] In this way, the multiphase motor switching device 110 switches the number of series connections in each of the coils 132A, 132B, and 132C.

[0084] [Regarding coil sections outside the intended use range] When the control device 190 gives an ON command to the first relay switches 181A, 182A, and 183A, and an OFF command to the other relay switches, the coil sections 13U, 12U, 14U, 11V, 14V, 12V, 13W, 12W, and 14W are removed from the operating range. In this case, the coil sections 11U, 13V, and 11W that have been designated as operating range by the switching unit 180 are arranged to be discrete in the circumferential direction. Specifically, the coil sections 11U, 13V, and 11W are arranged to be evenly spaced in the circumferential direction (see Figure 6).

[0085] When the control device 190 gives an ON command to the second relay switches 181B, 182B, and 183B, and an OFF command to the other relay switches, the coil sections 12U, 14U, 14V, 12V, 12W, and 14W are moved out of the operating range. In this case, the coil sections 12U, 14U, 14V, 12V, 12W, and 14W that have been moved out of the operating range by the switching unit 180 are arranged to be dispersed circumferentially (see Figure 6). Also, the coil sections 11U, 13U, 13V, 11V, 11W, and 13W that are included in the operating range are also arranged to be dispersed circumferentially (see Figure 6). Specifically, the coil sections 12U, 14U, 14V, 12V, 12W, and 14W are arranged to be evenly spaced in the circumferential direction. And the coil sections 11U, 13U, 13V, 11V, 11W, and 13W are also arranged to be evenly spaced in the circumferential direction.

[0086] When the control device 190 gives an ON command to the third relay switches 181C, 182C, and 183C, and an OFF command to the other relay switches, the coil sections 14U, 12V, and 14W are moved out of the operating range. In this case, the coil sections 14U, 12V, and 14W that have been moved out of the operating range by the switching unit 180 are arranged to be discrete in the circumferential direction (see Figure 6). Specifically, the coil sections 14U, 12V, and 14W are arranged to be evenly spaced apart in the circumferential direction.

[0087] When the control device 190 gives an ON command to the fourth relay switches 181D, 182D, and 183D, and an OFF command to the other relay switches, the coil units 11U, 13U, 12U, 14U, 13V, 11V, 14V, 12V, 11W, 13W, 12W, and 14W remain within their operating range.

[0088] [Regarding the characteristics of motor torque and rotational speed] When the switching unit 180 sets coil sections 11U, 13V, and 11W to the usable range, current flows through coil sections 11U, 13V, and 11W. In contrast, coil sections 13U, 12U, 14U, 11V, 14V, 12V, 13W, 12W, and 14W are outside the usable range, and no current flows through them. In this case, the relationship between the torque and rotational speed of the motor 200 changes according to the characteristics shown by the solid line in Figure 7.

[0089] When the switching unit 180 sets coil sections 11U, 13U, 13V, 11V, 11W, and 13W to the usable range, current flows through these coil sections. In contrast, coil sections 12U, 14U, 14V, 12V, 12W, and 14W are outside the usable range, and no current flows through them. In this case, the relationship between the torque and rotational speed of the motor 200 changes according to the characteristics shown by the dashed line in Figure 7.

[0090] When the switching unit 180 sets the usable range to coils 11U, 13U, 12U, 13V, 11V, 14V, 11W, 13W, and 12W, current flows through these coils. In contrast, coils 14U, 12V, and 14W are outside the usable range, and no current flows through them. In this case, the relationship between the torque and rotational speed of the motor 200 changes according to the characteristics shown by the dashed line in Figure 7.

[0091] Current flows through the coil sections 11U, 13U, 12U, 14U, 13V, 11V, 14V, 12V, 11W, 13W, 12W, and 14W that are included in the operating range by the switching unit 180. In this case, the relationship between the torque and rotational speed of the motor 200 changes according to the characteristics shown by the dotted line in Figure 7.

[0092] In each characteristic shown in Figure 7, the torque remains constant in the region of relatively low rotational speeds. Then, beyond a predetermined rotational speed, the torque decreases.

[0093] Comparing each characteristic, in the region where torque is constant, the magnitude of torque is largest for the dotted line characteristic, followed by the dashed-dotted line characteristic, then the double-dotted line characteristic, and finally the solid line characteristic, which has the smallest torque. Focusing on the rotational speed range, the solid line characteristic has the widest rotational speed range and extends to the high-speed side, followed by the double-dotted line characteristic, then the dashed-dotted line characteristic, and finally the dotted line characteristic has the narrowest range.

[0094] In the multiphase motor switching device 110, coil sections 11U, 13U, 12U, and 14U are connected in series, coil sections 13V, 11V, 14V, and 12V are connected in series, and coil sections 11W, 13W, 12W, and 14W are connected in series. The switching unit 180 connects both ends of the series-connected coil sections 11U, 13U, 12U, and 14U, coil sections 13V, 11V, 14V, and 12V, and one of the connections between all of the coil sections 11U, 13U, 12U, 14U, 13V, 11V, 14V, 12V, 11W, 13W, 12W, and 14W to the first conductive paths 41, 42, and 43. At the same time, it connects the others to the second conductive path C. With this configuration, any portion of the coil sections 11U, 13U, 12U, 14U, 13V, 11V, 14V, 12V, and 11W, 13W, 12W, 14W can be used.

[0095] <Other Embodiments> The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

[0096] Unlike Embodiment 1, a mechanical relay may be used for the relay switch.

[0097] The number of turns in each coil section may be the same or different. Also, the number of coil sections in each phase may be more than four or less than four.

[0098] Unlike Embodiment 1, the configuration of each coil may be as shown in Figure 9, and a relay switch 52 may be used to connect one end of coil section 50 to one end of coil section 51. The relay switch 52 can be kept in the OFF state at all times, and the operating range can be switched by complementaryly switching relay switches 53 and 54. Alternatively, coil section 50 and coil section 51 can be connected in parallel by turning relay switches 52 and 54 ON and relay switch 53 OFF. Alternatively, coil section 50 and coil section 51 can be connected in series by turning relay switches 52 and 54 OFF and relay switch 53 ON. In other words, with this configuration, two (even number) coil sections 50 and 51 can be used in series, half the number in series (1) can be used in parallel, or only half the number in series (1) can be included in the operating range.

[0099] Unlike Embodiment 2, the other end of the series-connected coil section may be connected to the second conductive path, and the other end of each relay switch may be connected to the first conductive path.

[0100] As shown in Figure 8, multiple coil sections 21U, 23U, 22U, 24U connected in series may be connected to the relay switches 281A, 281B, 281C, 281D, 281E, 281F, 281G, 281H of the switching unit 281. In this case, by turning on only one of 281A, 281B, 281C, 281D and only one of 281E, 281F, 281G, 281H, it is possible to switch the ends of the series-connected coil sections 21U, 23U, 22U, 24U and one of the spaces between all the coil sections 21U, 23U, 22U, 24U to the first conductive path 41, and the others to the second conductive path C. This makes it possible to use desired portions of the coil sections 21U, 23U, 22U, 24U. Furthermore, when the relay switches directly connected to each other are turned ON in 281A, 281B, 281C, 281D and 281E, 281F, 281G, 281H, the first conductive path 41 and the second conductive path C are electrically connected without going through the coil sections 21U, 23U, 22U, 24U. Figure 8 is an example of the U phase, and it is preferable that the V phase and W phase have similar configurations.

[0101] Unlike Embodiment 2, the coils 11U, 12U, 11V, 12V, 11W, and 12W may be included in the usable range, while the coils 13U, 14U, 13V, 14V, 13W, and 14W may be excluded from the usable range (see Figure 6). In other words, the coils 13U, 14U, 13V, 14V, 13W, and 14W that are excluded from the usable range by the switching unit may be arranged circumferentially. In this case, it is easier to consolidate the configuration of connecting the switching unit to the coils in a circumferential area, thus saving space. [Explanation of Symbols]

[0102] 1U, 1V, 1W, 3U, 3V, 3W… First coil section (coil section) 2U, 2V, 2W, 4U, 4V, 4W… Second coil section (coil section) 10,110…Multiphase motor switching device 11U, 11V, 11W, 12U, 12V, 12W, 13U, 13V, 13W, 14U, 14V, 14W, 21U, 22U, 23U, 24U, 50, 51… Coil section 21... Stator section 23…Rotor section 24…Permanent magnets 31… Stator core 32A, 32B, 32C, 132A, 132B, 132C… coils 41, 42, 43… First conductive path 80, 180, 281… Switching section 81,181…First switching section 81A, 82A, 83A, 181A, 182A, 183A… 1st relay switch 81B, 82B, 83B, 181B, 182B, 183B… Second relay switch 82,182…Second switching section 83,183…Third switching section 90,190…Control device 100, 200... motors (multiphase motors) 181C, 182C, 183C…Third relay switch 181D, 182D, 183D… 4th relay switch 52, 53, 54, 281A, 281B, 281C, 281D, 281E, 281F, 281G, 281H… Relay switches C...Second conductive path T... Terminal part

Claims

1. A switching device for a multiphase motor, which is used in a multiphase motor equipped with multiple phase coils, each of which has multiple coil sections, Each coil is equipped with a switching unit that switches the number of series connections of multiple coil sections in each of the coils, Multiple coil sections are arranged in a ring shape. A pair of coil sections that are outside the usable range in one phase of the coil are positioned in opposite positions across the central axis of a plurality of coil sections arranged in a ring shape. A switching device for a multiphase motor, wherein in one phase of the coil, a pair of coil portions that are outside the operating range are adjacent in the circumferential direction to a pair of coil portions that are not outside the operating range.

2. The switching device for a multiphase motor according to claim 1, wherein the switching unit has a plurality of relay switches, and the number of series connections is switched by individually switching each of the relay switches between an ON state and an OFF state.

3. The coil has a first coil section and a second coil section, One end of the first coil section is connected to the first conductive path, The other end of the second coil section is connected to the second conductive path. The switching unit includes a first relay switch provided between the other end of the first coil and the other end of the second coil, and a second relay switch provided between the other end of the first coil and one end of the second coil. The switching device for a multiphase motor according to claim 2, wherein the connection between one end of the second coil and the first conductive path is always configured to be non-short-circuited.

4. Multiple of the aforementioned coil sections are connected in series. One end of the series-connected coil section is connected to a first conductive path, and the other end of the series-connected coil section and each of the spaces between the coil sections are connected to a second conductive path by the relay switches. A switching device for a multiphase motor according to claim 2, wherein the number of series connections is switched by turning on one of the multiple relay switches and turning off the others.

5. The multiphase motor switching device according to claim 1 or claim 2, wherein the coil portion that is excluded from the operating range by the switching unit is arranged to be discrete in the circumferential direction.

6. A switching device for a multiphase motor according to claim 1 or claim 2, further comprising a control device for controlling the operation of the switching unit.

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