Motor device

Abstract

To provide a motor device capable of suppressing noise and vibrations, whose torque pulsation is small.SOLUTION: According to a motor device that is a switched reluctance motor whose rotor (11) is constituted from a ferromagnetic material, the motor device comprises the rotor (11) rotatably arranged with a revolving shaft as a center, and a stator (12) in which a plurality of teeth (13) are formed. Windings are wound on the plurality of teeth (13) in the order of A-phase, B-phase, C-phase, D-phase, E-phase, and F-phase along a circumferential direction of the stator (12). A first partial winding wound in a first direction; a second partial winding wound in a second direction opposite to the first direction, and a third partial winding in the first direction are connected in series, and the first partial winding, the second partial winding, and the third partial winding are wound around the three consecutive teeth (13), respectively.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor device, and more particularly to a switched reluctance motor device that uses a ferromagnetic material in the rotor. [Background technology]

[0002] Three-phase motors, which can control the rotation speed by changing the frequency of AC and can obtain a stable rotation speed, have been used as power sources in various technical fields. Switched reluctance motors, which use a ferromagnetic material for the rotor, have also been proposed (see, for example, Patent Document 1). Motor devices with multiple systems of polyphase windings with multiple phases have also been proposed.

[0003] In a conventional motor device with two three-phase winding systems, the first system has A-phase coils, E-phase coils, and C-phase coils as three-phase windings, and the second system has D-phase coils, B-phase coils, and F-phase coils as three-phase windings. In such a conventional motor device, by using switches corresponding to each phase to alternately switch the timing at which current flows to the windings of each phase, current flows appropriately to the coils of each phase, allowing the switched reluctance motor to rotate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-103957 Summary of the Invention [Problem to be solved by the invention]

[0005] In such conventional switched reluctance motors, the current waveform is not controlled, which causes torque ripple and increases noise and vibration.

[0006] SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems of the prior art, and has as its object to provide a motor device that has small torque pulsation and is capable of suppressing noise and vibration. [Means for solving the problem]

[0007] In order to solve the above problem, the motor device of the present invention is a switched reluctance motor having a rotor rotatable about a rotation axis and a stator having a plurality of teeth formed on its inner circumference, the rotor being made of a ferromagnetic material, wherein windings are wound around the plurality of teeth in the circumferential direction of the stator in the order of A, B, C, D, E, and F phases, and the A, B, C, D, E, and F phases are each connected in series with a first partial winding wound in a first direction, a second partial winding wound in a second direction opposite to the first direction, and a third partial winding wound in the first direction, and the first partial winding, the second partial winding, and the third partial winding are wound around three consecutive teeth.

[0008] In such a motor device of the present invention, phases A to F each have a first partial winding wound in a first direction, a second partial winding wound in a second direction, and a third partial winding wound in the first direction, and the first partial winding, second partial winding, and third partial winding are connected in series and wound around three consecutive teeth, thereby making it possible to reduce torque pulsation and suppress noise and vibration.

[0009] In one aspect of the present invention, the ratio of the number of poles P of the rotor to the number of slots S of the teeth portion is P:S=17:18.

[0010] In one aspect of the present invention, the ratio of the number of poles P of the rotor to the number of slots S of the teeth portion is P:S=19:18.

[0011] In one aspect of the present invention, the A phase, the B phase, the C phase, the D phase, the E phase, and the F phase are arranged with a phase difference of 60 electrical degrees.

[0012] In one aspect of the present invention, the first partial winding, the second partial winding, and the third partial winding are arranged with a phase difference of 20 electrical degrees.

[0013] In one aspect of the present invention, the A phase, the E phase, the C phase, the D phase, the B phase, and the F phase are star-connected with one end connected to a neutral point.

[0014] In one aspect of the present invention, the A phase, the B phase, the C phase, the D phase, the E phase, and the F phase are connected in series in a ring shape in this order, and are hexagonally connected.

[0015] In one aspect of the present invention, the winding is configured as a concentrated winding wound around each of the teeth. [Effects of the Invention]

[0016] The present invention can provide a motor device that has small torque pulsation and is capable of suppressing noise and vibration. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing an example of the structure of a motor section 10 in a motor device according to a first embodiment. [Figure 2] 2A and 2B are circuit diagrams showing a method of connecting A-phase windings to F-phase windings, with FIG. 2A showing a star connection and FIG. 2B showing a hexagonal connection. [Figure 3] 1 is an equivalent circuit diagram showing the connection between a motor section 10 and a switch inverter section 20 of a motor device according to a first embodiment. [Figure 4] 4 is a timing chart showing control of the switch inverter unit 20 in the motor device according to the first embodiment, showing signals applied to each phase switch of the switch inverter unit 20. [Figure 5]These are simulation results showing the driving state of a conventional 15-salient-pole, 18-slot motor device, where FIG. 5(a) shows the output torque and FIG. 5(b) shows the coil current flowing through the windings 14 of each phase. [Figure 6] 6A and 6B show simulation results showing the driving state of the 17-salient-pole, 18-slot motor device according to the first embodiment, where FIG. 6A shows the output torque and FIG. 6B shows the coil current flowing through the windings of each phase. [Figure 7] 10 is a schematic diagram showing an example of the structure of a motor section 10 in a motor device according to a second embodiment. FIG. [Figure 8] 8A and 8B show the results of a simulation showing the driving state of a 19-salient-pole, 18-slot motor device according to the second embodiment, where FIG. 8A shows the output torque and FIG. 8B shows the coil current flowing through the windings 14 of each phase. DETAILED DESCRIPTION OF THE INVENTION

[0018] (First embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be given the same reference numerals, and redundant explanations will be omitted where appropriate. Figure 1 is a schematic diagram showing an example of the structure of a motor unit 10 in a motor device according to this embodiment.

[0019] As shown in FIG. 1, a motor unit 10 of this embodiment includes a rotor 11 and a stator 12 arranged around the rotor 11. The rotor 11 has rotor teeth (salient poles) made of a ferromagnetic material arranged along its outer periphery. The stator 12 also has a core back portion and a plurality of teeth 13 formed protruding from its inner periphery. Each tooth 13 is wound with a winding (coil) 14 as a first partial winding, a second partial winding, and a third partial winding of an A-phase winding to an F-phase winding. The first partial winding and the third partial winding are wound in the same direction (first direction) and are indicated by a plus sign (+). The second partial winding is wound in the opposite direction to the first partial winding and the third partial winding and is indicated by a minus sign (-). As shown in FIG. 1, the first partial winding, the second partial winding, and the third partial winding are wound in order around three consecutive teeth 13.

[0020] 1, the motor device is a switched reluctance motor with 17 salient poles and 18 slots. The number of salient poles (pole count) P and the number of slots S of the motor section 10 are not limited to 17 salient poles and 18 slots, but may be 34 salient poles and 36 slots or 51 salient poles and 48 slots, where the number of salient poles is 17n and the number of slots is 18n (n is a natural number), resulting in a ratio of P:S = 17:18.

[0021] The core back portion is a portion disposed outside the rotor 11 so as to surround the outer periphery of the rotor 11 in a circular shape, and a plurality of teeth 13 are formed on the inner periphery, protruding at equal intervals. Any known material can be used for the core back portion, and there are no restrictions on the material or structure that constitutes it. In addition, a separate member such as a motor housing is provided on the outer periphery of the core back portion.

[0022] The teeth 13 are protruding portions formed from the inner peripheral surface of the core back portion toward the rotor 11, and each tooth 13 is formed to be the same length and shape and is arranged at equal intervals, with spaces provided between each tooth 13 to form slots. A winding 14 is wound around each tooth 13 and slot, and a magnetic field is generated in the teeth 13 when a current flows through the winding 14.

[0023] As shown in FIG. 1, the windings 14 are arranged in order from phase A to phase F along the circumference of the stator 12, and each phase is wound in the order of a first partial winding (+), a second partial winding (-), and a third partial winding (+), forming a total of 18 slots.

[0024] As described above, the first partial winding (+), second partial winding (-), and third partial winding (+) of phases A to F constitute 18 slots per period. Furthermore, phases A, B, C, D, E, and F are arranged with a phase difference of 60 electrical degrees, and the first partial winding, second partial winding, and third partial winding of each layer are arranged with a phase difference of 20 electrical degrees. Therefore, the three-phase combination of phases A, E, and C, and the three-phase combination of phases D, B, and F constitute three-phase AC with a phase difference of 120 electrical degrees.

[0025] 2A and 2B are circuit diagrams showing how the A-phase to F-phase windings are connected, with FIG. 2A showing a star connection and FIG. 2B showing a hexagonal connection. The connection shown in FIG. 2A is a star connection, with one end of the A-phase, E-phase, C-phase, D-phase, B-phase, and F-phase windings 14 connected to a common neutral point and the other end connected to a switch inverter unit 20 (described later). The connection shown in FIG. 2B is a hexagonal connection, with the A-phase, B-phase, C-phase, D-phase, E-phase, and F-phase windings 14 connected in series in a circular fashion, with the spaces between each phase connected to the switch inverter unit 20. As shown in FIGS. 2A and 2B, the A-phase to F-phase windings each have a first partial winding (+), a second partial winding (-), and a third partial winding (+) connected in series.

[0026] FIG. 3 is an equivalent circuit diagram showing the connection between the motor unit 10 and the switch inverter unit 20 of the motor device according to this embodiment. As shown in FIG. 3, the switch inverter unit 20 of this embodiment has six switches A to F connected in parallel between a power supply voltage (+V) and a ground voltage (0V). The switches A, C, and E have freewheeling diodes connected in series downstream, and the switches B, D, and F have freewheeling diodes connected in series upstream. This configuration configures a three-phase asymmetric switch inverter unit 20 with a total of six switches (switches A to F) and six freewheeling diodes. Each switch has its drain connected to the power supply voltage side (upstream) and its source connected to the ground voltage side (downstream). When MOSFETs are used as the switches, an equivalent circuit is formed in which a parasitic diode is connected in reverse parallel between the source and drain. The operation of each switch is controlled by a switch control unit (not shown).

[0027] 3 shows a three-phase asymmetrical six-switch inverter as switch inverter unit 20, but there are no limitations on the specific configuration of switch inverter unit 20. As an example, an improved nine-switch inverter may be used in which three switch groups (AD group, EB group, CF group) are connected in parallel between the power supply voltage (+V) and the ground voltage (0V), and two switches are connected in series with reverse-connected freewheeling diodes between them, resulting in a total of six switches (switch A phase to switch F phase) and three freewheeling diodes.

[0028] The A-phase, E-phase, C-phase, D-phase, B-phase, and F-phase windings of the winding 14 are each formed by connecting a first partial winding, a second partial winding, and a third partial winding in series, with one end of each partial winding connected to a common neutral point to form a star connection. The other ends of the A-phase, E-phase, C-phase, D-phase, B-phase, and F-phase windings are each connected to the switch inverter unit 20.

[0029] In the star connection shown in Figure 2(a), the other end of phase A is connected between switch A and the freewheel diode. The other end of phase B is connected between switch B's freewheel and the diode. The other end of phase C is connected between switch C and the freewheel diode. The other end of phase D is connected between switch D and the freewheel diode. The other end of phase E is connected between switch E and the freewheel diode. The other end of phase F is connected between switch F and the freewheel diode.

[0030] Therefore, the source potential Va of the switch A phase is applied to the other end of the A phase winding. Similarly, the drain potential Vb of the switch B phase is applied to the other end of the B phase winding. Similarly, the source potential Vc of the switch C phase is applied to the other end of the C phase winding. Similarly, the drain potential Vd of the switch D phase is applied to the other end of the D phase winding. Similarly, the source potential Ve of the switch E phase is applied to the other end of the E phase winding. Similarly, the drain potential Vf of the switch F phase is applied to the other end of the F phase winding.

[0031] In the case of the hexagonal connection shown in FIG. 2(b), the connection between phases A and B is made to the B-phase switch of the switch inverter unit 20. Furthermore, the connection between phases B and C is made to the C-phase switch of the switch inverter unit 20. Furthermore, the connection between phases C and D is made to the D-phase switch of the switch inverter unit 20. Furthermore, the connection between phases D and E is made to the E-phase switch of the switch inverter unit 20. Furthermore, the connection between phases E and F is made to the F-phase switch of the switch inverter unit 20. Furthermore, the connection between phases F and A is made to the A-phase switch of the switch inverter unit 20.

[0032] Therefore, the potential Vf of the switch F phase and the potential Va of the switch A phase are applied to both ends of the A phase. Similarly, the potential Vb of the switch B phase and the potential Vc of the switch C phase are applied to both ends of the B phase. Similarly, the potential Vc of the switch C phase and the potential Vd of the switch D phase are applied to both ends of the C phase. Similarly, the potential Vd of the switch D phase and the potential Ve of the switch E phase are applied to both ends of the D phase. Similarly, the potential Ve of the switch E phase and the potential Vf of the switch F phase are applied to both ends of the F phase. Similarly, the potential Vf of the switch F phase and the potential Va of the switch A phase are applied to both ends of the F phase.

[0033] FIG. 4 is a timing chart showing the control of the switch inverter unit 20 in the motor device according to this embodiment, illustrating signals applied to each phase switch of the switch inverter unit 20. The horizontal axis of FIG. 4 represents the electrical angle (degrees), and the vertical axis represents the on signal and off signal applied to each switch. As shown in FIG. 4, on signals and off signals are applied alternately to each switch of phases A to F, in increments of 180 degrees (π). The on signals and off signals of phases A to F are shifted in phase by 60 degrees (π / 3). Signals that are inverted from each other and out of phase with a 180 degree (π) difference are applied to phases A and D, phases B and E, and phases C and F.

[0034] In other words, two three-phase voltage signals, one for phases A, C, and E, and the other for phases B, D, and F, are applied to each switch for phases A through F. Therefore, phases A through F are controlled by switches A through F, and function as a motor with a total of six phases, each equipped with two three-phase motors. By applying the signal shown in FIG. 4 to switch inverter unit 20 shown in FIG. 3, a ninth-order field magnetic field is generated in stator 12 of motor unit 10 shown in FIG. 1. This ninth-order field magnetic field is modulated into an eighth-order rotating magnetic field by 17 salient poles in rotor 11. As a result, rotor 11 is driven to rotate counterclockwise in the figure in synchronization with the eighth-order rotating magnetic field.

[0035] In the motor device of this embodiment, whether the motor section 10 is star-connected as shown in FIG. 2(a) or hexagonally connected as shown in FIG. 2(b), by using the switch inverter section 20 shown in FIG. 3 and applying the signal shown in FIG. 4, the rotor 11 can be rotated clockwise, suppressing iron loss and continuously outputting torque.

[0036] Next, a coupled analysis with the electrical circuit was performed using a simulation using the finite element method. The simulation conditions were a combination of the switch inverter unit 20 and motor unit 10 configuration shown in Figure 3, with a switch inverter and star connection. The rotor 11 had a diameter of 230 mm, a length of 180 mm, and eight turns for the first partial winding (+), second partial winding (-), and third partial winding (+) for each of the A to F phases. The power supply voltage was 300 V, hysteresis control was performed with a maximum current of 600 A, and the rotation speed was 2000 rpm.

[0037] Figure 5 shows the simulation results of the driving state of a conventional 15-salient-pole, 18-slot motor. Figure 5(a) shows the output torque, and Figure 5(b) shows the coil current flowing through the windings 14 of each phase. In Figure 5, the horizontal axis represents elapsed time (seconds), the vertical axis of Figure 5(a) represents torque (Nm), and the vertical axis of Figure 5(b) represents phase current (A) flowing through the windings 14. By applying the signal shown in Figure 4 to the switch inverter unit 20, the rotor 11 rotates as shown in Figures 5(a) and 5(b), allowing the motor to continuously output torque. From the graph in Figure 5(a), the maximum torque, minimum torque, and average torque were calculated. (Maximum torque - minimum torque) × 100 / average torque was calculated, resulting in a torque ripple of 14%.

[0038] FIG. 6 shows the results of a simulation of the driving state of the 17-salient-pole, 18-slot motor device according to this embodiment, with FIG. 6(a) showing the output torque and FIG. 6(b) showing the coil current flowing through the windings of each phase. The simulation conditions are the same as those in FIG. 5. In FIG. 6, the horizontal axis also shows elapsed time (seconds), the vertical axis in FIG. 6(a) shows torque (Nm), and the vertical axis in FIG. 6(b) shows phase current (A) flowing through winding 14. Furthermore, the maximum torque, minimum torque, and average torque were determined from the graph in FIG. 6(a), and the calculation (maximum torque - minimum torque) × 100 / average torque was performed, resulting in a torque ripple of 5.7%.

[0039] As shown in Figures 5(a) and 6(a), the average torque is slightly smaller with 17 salient poles and 18 slots than with 15 salient poles and 18 slots, but the torque pulsation is significantly smaller. Therefore, the switched reluctance motor with 17 salient poles and 18 slots of this embodiment can continuously output rotation with small torque pulsation in the low rotation range. Furthermore, when such a motor is used for power generation, it is suitable for applications that generate power at a low rotation frequency, and one example is a wind turbine generator.

[0040] As described above, in the motor device of this embodiment, phases A to F each have a first partial winding wound in a first direction, a second partial winding wound in a second direction, and a third partial winding wound in the first direction, and the first partial winding, second partial winding, and third partial winding are connected in series and wound around three consecutive tooth portions 13, thereby making it possible to reduce torque pulsation and suppress noise and vibration.

[0041] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Figures 7 and 8. Description of content that overlaps with the first embodiment will be omitted. Figure 7 is a schematic diagram showing an example of the structure of a motor section 10 in a motor device according to this embodiment.

[0042] 7, the motor device is a switched reluctance motor with 19 salient poles and 18 slots. The number of salient poles (pole count) P and the number of slots S of the motor section 10 are not limited to 19 salient poles and 18 slots, but may be 38 salient poles and 36 slots or 57 salient poles and 54 slots, where the number of salient poles is 19n and the number of slots is 18n (n is a natural number), resulting in a ratio of P:S = 19:18.

[0043] 7, in the motor section 10 of this embodiment, the windings (coils) 14 are wound around each tooth section 13 as a first partial winding (+), a second partial winding (-), and a third partial winding (+) of the A-phase to F-phase windings. Also, as shown in FIG. 7, the first partial winding, the second partial winding, and the third partial winding are wound in order around three consecutive teeth sections 13.

[0044] In the motor device of this embodiment, a 9th-order field magnetic field is generated in the stator 12 of the motor unit 10 shown in Fig. 7 by applying the signal shown in Fig. 4 to the switch inverter unit 20 shown in Fig. 3. This 9th-order field magnetic field is modulated into a 10th-order rotating magnetic field by the 19 salient poles of the rotor 11. As a result, the rotor 11 is driven to rotate clockwise in the figure in synchronization with the 10th-order rotating magnetic field.

[0045] In the motor device of this embodiment, whether the motor section 10 is star-connected as shown in FIG. 2(a) or hexagonally connected as shown in FIG. 2(b), by using the switch inverter section 20 shown in FIG. 3 and applying the signal shown in FIG. 4, the rotor 11 can be rotated clockwise, suppressing iron loss and continuously outputting torque.

[0046] FIG. 8 shows the results of a simulation showing the driving state of the 19-salient-pole, 18-slot motor device according to this embodiment, with FIG. 8(a) showing the output torque and FIG. 8(b) showing the coil current flowing through the windings 14 of each phase. The simulation conditions are the same as those of the first embodiment. In FIG. 8 as well, the horizontal axis represents elapsed time (seconds), the vertical axis of FIG. 8(a) represents torque (Nm), and the vertical axis of FIG. 8(b) represents phase current (A) flowing through the windings 14. Furthermore, the maximum torque, minimum torque, and average torque were determined from the graph of FIG. 8(a), and the calculation (maximum torque - minimum torque) × 100 / average torque was performed, resulting in a torque ripple of 5.6%.

[0047] As shown in Figures 5(a) and 8(a), the average torque is slightly smaller with the 19 salient poles, 18 slots than with the 15 salient poles, 18 slots, but the torque pulsation is significantly smaller. Therefore, the switched reluctance motor with 19 salient poles, 18 slots of this embodiment can continuously output rotation with small torque pulsation in the low rotation range. Furthermore, when such a motor is used for power generation, it is suitable for applications that generate power at a low rotation frequency, and one example is a wind turbine generator.

[0048] As described above, the motor device of this embodiment also has a first partial winding wound in a first direction for phases A to F, a second partial winding wound in a second direction, and a third partial winding wound in the first direction, and the first partial winding, second partial winding, and third partial winding are connected in series and wound around three consecutive tooth portions 13, making it possible to reduce torque pulsation and suppress noise and vibration.

[0049] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0050] 10...Motor section 11...Rotor 12...Stator 13...Teeth part 14...winding 20...Switch inverter section

Claims

1. A motor device that is a switched reluctance motor, comprising: a rotor that is rotatably arranged around a rotation axis; and a stator that has a plurality of teeth formed on an inner periphery thereof, the rotor being made of a ferromagnetic material, Windings are wound around the plurality of teeth in the circumferential direction of the stator in the order of A-phase, B-phase, C-phase, D-phase, E-phase, and F-phase, the A-phase, the B-phase, the C-phase, the D-phase, the E-phase, and the F-phase each include a first partial winding wound in a first direction, a second partial winding wound in a second direction opposite to the first direction, and a third partial winding wound in the first direction, all connected in series; The motor device is characterized in that the first partial winding, the second partial winding, and the third partial winding are wound around three consecutive teeth portions.

2. 2. The motor device according to claim 1, A motor device characterized in that the ratio of the number of poles P of the rotor to the number of slots S of the teeth portion is P:S=17:

18.

3. 2. The motor device according to claim 1, A motor device characterized in that the ratio of the number of poles P of the rotor to the number of slots S of the teeth portion is P:S=19:

18.

4. 2. The motor device according to claim 1, The motor device is characterized in that the A phase, the B phase, the C phase, the D phase, the E phase, and the F phase are arranged with a phase difference of 60 electrical degrees.

5. 2. The motor device according to claim 1, The motor device is characterized in that the first partial winding, the second partial winding, and the third partial winding are arranged with a phase difference of 20 degrees in electrical angle.

6. 2. The motor device according to claim 1, The motor device is characterized in that the A phase, the B phase, the C phase, the D phase, the E phase, and the F phase are star-connected with one end connected to a neutral point.

7. 2. The motor device according to claim 1, The motor device is characterized in that the A phase, the B phase, the C phase, the D phase, the E phase, and the F phase are connected in series in a ring shape in this order and are hexagonally connected.

8. 8. The motor device according to claim 1, The motor device is characterized in that the winding is configured as a concentrated winding wound around each of the teeth.

Images