Field winding type rotary machine

Abstract

Field winding rotary machine, with: a stator (24) having a stator core (32) and a stator coil (34) wound around the stator core; a rotor (26) having a rotor core (42) and a rotor field coil (44) wound around the rotor core; a rectifier element (52) connected between both ends of the rotor field coil; and a capacitor (54, 502) having one end connected to one end of the rectifier element and the other end connected to any point of the rotor field coil, wherein the rotor field coil has a first field coil part (44-1) connected in parallel with the capacitor and a second field coil part (44-2) connected between the other end of the rectifier element and the other end of the capacitor.

Description

[Technical field]

[0001] The present disclosure relates to a field winding type rotary machine. [Background]

[0002] A field-winding type rotating machine, such as that disclosed in Patent Literature 1, which generates a magnetic field by exciting a stator coil, is well known. The field-winding rotating machine includes a stator and a rotor. The stator has a stator core and a stator coil wound around the stator core. The rotor has a rotor core and a rotor field winding wound around the rotor core. The rotor field coil is short-circuited by a diode, which is a rectifying element. That is, a diode is connected between both ends of the rotor field coil.

[0003] The above field-wound rotating machine includes an inverter circuit and a control circuit. The inverter circuit is connected to the stator coil. The control circuit controls the inverter circuit so that a current flows through the stator coil depending on the rotational position of the rotor. The current flowing through the stator coil is the sum of a fundamental current (i.e., a synchronous current) and an excitation current. The fundamental current is a current component for generating torque. The excitation current is a current component for rotor excitation. The excitation current is a current with a shorter cycle (i.e., a higher frequency) than the fundamental current and is formed into a pulsed waveform. When the excitation current flows through the stator coil, an excitation magnetic flux connects to a main magnetic pole of the rotor core. Then, a voltage is generated in the rotor field coil to induce an excitation current.

[0004] As described above, the diode is connected between both ends of the rotor field coil. Accordingly, even if an alternating voltage is generated in the rotor field coil due to a fluctuation in the excitation magnetic flux, a current flows through the rotor field coil in only one direction. This excites the rotor core in a predetermined direction to form a pair of field poles (specifically, an N pole and an S pole). A field magnetic flux for forming the pair of field poles is generated by supplying the excitation current for rotor excitation to the stator coil and rectifying the current in the rotor field coil.

[0005] Thus, the field-wound rotating machine receives the excitation magnetic flux from the stator through the rotor field coil and rectifies the current in one direction through the diode to form the field pole. In the rotating machine, to generate torque, the excitation magnetic flux is caused to combine with the main magnetic pole of the rotor core to excite the rotor core. Excitation of the rotor core is achieved by superimposing the pulsed excitation current on the fundamental current to induce the excitation current in the rotor field coil. [List of prior art][Patent literature]

[0006] PTL 1: JP 2008-178211 A

[0007] US 2008 / 0 079 375 A1 discloses a rotating electrical device comprising a field-winding type synchronous machine, an inverter, a DC power supply, a current flow regulator, and a controller. The DC power supply outputs a first voltage having a first voltage value and a second voltage having a second voltage value higher than the first voltage value. The current flow regulator regulates directions of currents flowing through a field winding by rotor excitation currents in one direction, wherein the current flow regulator is electrically connected to the field winding. The controller controls the inverter such that the inverter generates armature currents consisting of synchronized currents that generate rotating fields depending on a rotational position of a rotor, and rotor excitation currents that differ in waveforms from the synchronized currents and are superimposed on the synchronized currents.At least the rotor excitation currents are supplied with a second voltage from the DC power supply.

[0008] US 2015 / 0 155 753 A1 discloses a rotor for a rotating electrical device comprising a rotor coil wound on each of the salient poles of the rotor, a retaining element supported by a rotor core, and an external magnetic element. The retaining element has a beam that bridges between the adjacent salient rotor poles and prevents the rotor coil from falling out. The external magnetic element is provided at one end of the beam. [Summary of the invention][Technical problem]

[0009] The rotor field coil of the field pole has an inductance. The rotor field coil of each pole forms a partial inductance in each pole. Magnetic fluxes flowing through the field pole include stray magnetic flux, harmonic magnetic flux, and the like. Accordingly, the directions of voltages generated in the corresponding partial inductances of the rotor field coil are not uniform and vary depending on time and rotor rotation position. When mutually canceling voltages are generated in the corresponding partial inductances of the rotor field coil, the voltage of the entire rotor field coil is reduced, and the excitation current is reduced. As a result, a loss of excitation energy may occur.

[0010] The present disclosure provides a field winding type rotating machine capable of preventing an excitation energy loss from occurring when the voltages generated in the respective partial inductances of the rotor field coil cancel each other out. [Solution to the problem]

[0011] A field-winding rotating machine, which is one aspect of a technique of the present disclosure, includes a stator having a stator core and a stator coil wound around the stator core, a rotor having a rotor core and a rotor field coil wound around the rotor core, and a rectifier element connected between both ends of the rotor field coil. The field-winding rotating machine includes a capacitor, one end (first terminal) of which is connected to one end (anode terminal) of the rectifier element, and the other end (second terminal) of which is connected to an intermediate point (predetermined position) of the rotor field coil. The rotor field coil includes a first field coil part and a second field coil part. The first field coil part is connected in parallel with a capacitor.The second field coil part is connected between the other end (cathode terminal) of the rectifier element and the other end of the capacitor.

[0012] According to this configuration, when voltages generated in the respective partial inductances of the rotor field coil due to leakage magnetic flux, harmonic magnetic flux, and the like cancel each other, the field-winding rotating machine of the present disclosure stores excitation energy in a capacitor depending on the canceling voltages. Then, when the voltage directions change and the voltages are in canceling directions, the field-winding rotating machine of the present disclosure outputs the energy stored in the capacitor to the rotor field coil and converts the energy into an excitation current that excites the rotor core.Thereby, in the field winding rotating machine of the present disclosure, occurrence of the excitation energy loss when the voltages generated in the respective partial inductances of the rotor field coil cancel each other can be prevented.

[0013] In the field winding rotating machine which is an aspect of a technique of the present disclosure, a current flowing through the stator coil is a current obtained by superimposing a fundamental current for generating a torque and a harmonic current having a shorter cycle than the fundamental current.

[0014] According to this configuration, when a harmonic current flows through the stator coil, the field-winding rotating machine of the present disclosure generates an excitation magnetic flux depending on the harmonic current. Thus, in the field-winding rotating machine of the present disclosure, the excitation current that generates an alternating voltage in the rotor field coil can be induced to excite the rotor core.

[0015] In the field winding rotary machine which is an aspect of a technique of the present disclosure, the first field coil part is arranged on a side closer to (at a position closer to) a main magnetic pole of the rotor core than the second field coil part.

[0016] According to this configuration, in the field-winding rotating machine of the present disclosure, when a leakage magnetic flux, a harmonic magnetic flux, or the like is generated, a difference in flux content between the first field coil part and the second field coil part becomes large. As a result, in the field-winding rotating machine of the present disclosure, energy stored in the capacitor can be increased by the difference in flux content. Thus, in the field-winding rotating machine of the present disclosure, a field current can be effectively obtained.

[0017] In the field winding rotating machine which is an aspect of a technique of the present disclosure, the first field coil part is arranged on a side farther from (at a position farther from) the stator core than the second field coil part.

[0018] According to this configuration, in the field-winding rotating machine of the present disclosure, when a leakage magnetic flux, a harmonic magnetic flux, or the like is generated, a difference in flux content between the first field coil part and the second field coil part becomes large. As a result, in the field-winding rotating machine of the present disclosure, energy stored in the capacitor can be increased by the difference in flux content. Thus, in the field-winding rotating machine of the present disclosure, a field current can be effectively obtained.

[0019] In the field-wound rotating machine, which is one aspect of a technique of the present disclosure, the rotor core includes a plurality of main magnetic poles and an auxiliary pole disposed between the main magnetic poles. The rotor core includes a magnet. The magnet is provided in the auxiliary pole and is magnetized in a direction of canceling the stray magnetic flux generated between the main magnetic poles.

[0020] In the field winding rotary machine which is an aspect of a technique of the present disclosure, the first field coil part is arranged on a side farther from a main magnetic pole (48) of the rotor core than the second field coil part.

[0021] In the field winding rotating machine which is an aspect of a technique of the present disclosure, the first field coil part is arranged on a side closer to the stator core than the second field coil part.

[0022] According to this configuration, in the field-winding rotating machine of the present disclosure, leakage of magnetic flux across the stator side and the rotor side between the main magnetic poles can be suppressed by the magnet provided in the auxiliary pole. Therefore, in the field-winding rotating machine of the present disclosure, the magnetic flux flowing through the field pole can be efficiently transmitted to the main magnetic pole.

[0023] Thus, in the field winding rotary machine of the present disclosure, a field current can be effectively obtained. [Brief description of the drawings] Fig. 1 is an overall configuration diagram of a field winding rotary machine according to a first embodiment. Fig. 2 is a circuit diagram of the field winding rotary machine of the first embodiment. Fig. 3 is a cross-sectional view when the field winding rotary machine of the first embodiment is cut by a plane extending in a direction perpendicular to the rotation axis. Fig. 4 is a diagram showing an example of a temporal change of a phase current flowing through a stator coil in the field winding rotary machine of the first embodiment. Fig. Figure 5 is a graph showing a time change of a torque generated when a phase current is caused to change in a waveform shown in Fig. 4, to flow through the stator coil in the field winding rotary machine of the first embodiment. Fig. 6 is a circuit diagram including a rotor field coil provided in the field winding rotary machine of the first embodiment. Fig. 7 is a diagram for explaining that a capacitor is charged in a direction in which voltages generated in respective partial inductances of the rotor field coil cancel each other out in the field winding rotary machine of the first embodiment. Fig. 8 is a diagram for explaining that a capacitor is charged in a direction in which voltages generated in respective partial inductances of the rotor field coil cancel each other out in the field winding rotary machine of the first embodiment. Fig. 9 is a diagram showing a relationship between a voltage direction of the rotor field coil, a total voltage, a generated current, and a power conversion efficiency in the field winding rotary machine of the first embodiment. Fig. 10 is a cross-sectional view when a field winding rotary machine of a second embodiment is cut by a plane extending in a direction perpendicular to a rotation axis. Fig. 11 is a cross-sectional view when a field winding rotary machine of a third embodiment is cut by a plane extending in a direction perpendicular to a rotation axis. Fig. 12 is a cross-sectional view when a field winding rotary machine of a fourth embodiment is cut by a plane extending in a direction perpendicular to a rotation axis. Fig. 13 is a circuit diagram including a rotor field coil provided in a field winding rotary machine of a fifth embodiment. Fig. 14 is a circuit diagram including a rotor field coil provided in a field winding rotary machine of a sixth embodiment. Fig. 15 is a diagram for explaining that a capacitor is charged in a direction in which voltages generated in respective partial inductances of the rotor field coil cancel each other out in the field winding rotary machine of the sixth embodiment. Fig. 16 is a diagram for explaining that a capacitor is charged in a direction in which voltages generated in respective partial inductances of the rotor field coil cancel each other out in the field winding rotary machine of the sixth embodiment. [Description of implementation examples]

[0024] Referring to Fig. 1 to Fig. 16, specific embodiments of a field winding rotary machine, which is a technical mode of the present disclosure, will be described in detail below. [First embodiment]

[0025] In the present embodiment, a field winding type rotating machine or a field winding rotating machine 20 is, for example, a synchronous generator motor mounted on a vehicle or the like. Hereinafter, the field winding rotating machine 20 is simply referred to as a rotating machine 20. The rotating machine 20 is a device that generates a driving force for driving a vehicle by being supplied with electric power from a power supply 22, such as a battery. The rotating machine 20 is a device that generates electric power for charging a battery by being supplied with driving power from an engine of the vehicle. The rotating machine 20 includes, as shown in Fig. 1, a stator 24, a rotor 26, a housing 28 and a bearing 30.

[0026] The stator 24 is housed in a space surrounded by the housing 28 and is fixed to the housing 28. The stator 24 includes a stator core 32 and a stator coil 34. The stator core 32 forms part of a flux path through which a magnetic flux flows. The stator core 32 is formed in a hollow cylindrical shape with a hole 36 in the axial center. As shown in Fig. 3, the stator core 32 includes slots 38 and teeth 40. The slots 38 open radially inward and extend along the axial direction. A plurality of slots 38 are provided in a circumferential direction, and they are arranged to be aligned at each predetermined angle. The slots 38 accommodate a linear portion of the stator coil 34. The stator coil 34 is wound around the teeth 40 of the stator core 32. The stator coil 34 includes one phase winding for each of three phases U, V, and W.

[0027] The rotor 26 is rotatably received in the hole 36 of the stator core 32. The rotors 26 are arranged opposite each other on the radially inner side of the stators 24, with a predetermined air gap therebetween. The rotor 26 is rotatably supported by the housing 28 via the bearings 30. The rotor 26 includes a rotor core 42 and a rotor field coil 44. The rotor core 42 forms part of a flux path through which a magnetic flux flows.

[0028] The rotor core 42 includes a main body 46 and salient pole pieces 48. The main body 46 is formed in a cylindrical shape, and a rotor shaft 50 is inserted into its hollow hole. The salient pole pieces 48 protrude radially outward from the main body 46. A plurality of salient pole pieces 48 are provided in a circumferential direction and are arranged to align with each other at every predetermined interval. The salient pole pieces 48 are a main magnetic pole that forms a pair of field poles (specifically, N pole and S pole). The rotor field coil 44 is wound around the salient pole pieces 48 of the rotor core 42. The rotor field coil 44 is wound to surround the rotor core 42. The rotor field coil 44 is wound intensively for each salient pole piece 48.

[0029] As in Fig. 2 and Fig. As shown in Figure 6, the rotary machine 20 includes a rectifier element 52. The rectifier element 52 is a diode connected between both ends of the rotor field coil 44. An anode terminal of the rectifier element 52 is connected to one end (first terminal) of the rotor field coil 44. A cathode terminal of the rectifier element 52 is connected to the other end (second terminal) of the rotor field coil 44. The rectifier element 52 has a function of half-wave rectifying an alternating voltage induced in the rotor field coil 44 and restricting the direction of the current flowing through the rotor field coil 44 to one direction. By this function of the rectifier element 52, the salient pole part 48 is energized to generate either an N pole or an S pole.The protruding pole parts 48 are excited so that protruding pole parts 48 as N-poles and protruding pole parts 48 as S-poles are arranged alternately in the circumferential direction.

[0030] The rotary machine 20 includes a capacitor 54. One end (first terminal) of the capacitor 54 is connected to the anode terminal of the rectifying element 52. The other end of the capacitor 54 (second terminal) is connected to any point (predetermined position) of the rotor field coil 44. The capacitor 54 is a passive element capable of storing an electric charge. A connection position between the other end of the capacitor 54 and the rotor field coil 44 is desirably a boundary position for dividing the rotor field coil 44 into the following sections. Specifically, it is desirably a boundary position for dividing the rotor field coil 44 into a section easily affected by a stray magnetic flux, a harmonic magnetic flux, and the like of the magnetic fluxes flowing through the field pole, and a section hardly affected by them.The circuit of the rotor field coil 44, the rectifier element 52 and the capacitor 54 may be arranged for each pole or for each pair of poles or may be arranged together as a set.

[0031] The rotor field coil 44 includes a first field coil portion 44-1 and a second field coil portion 44-2. The first field coil portion 44-1 is connected in parallel with the capacitor 54. The second field coil portion 44-2 is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54. When the direction of a voltage e1 generated between both ends of the first field coil portion 44-1 and the direction of a voltage e2 generated between both ends of the second field coil portion 44-2 are opposite to each other, and the voltages E1 and E2 cancel each other, the capacitor 54 has a function of storing excitation energy depending on the mutually canceling voltages.

[0032] The first field coil part 44-1 and the second field coil part 44-2 are obtained by dividing the rotor field coil 44 into sections described below. Specifically, the rotor field coil 44 is divided into a section easily affected by the leakage magnetic flux, the harmonic magnetic flux, and the like of the magnetic fluxes flowing through the field pole, and a section hardly affected by them. The first field coil part 44-1 is arranged on a side close to (at a position close to) the salient pole part 48 of the rotor core 42 in the circumferential direction. The second field coil part 44-2 is arranged on a side far from (at a position far from) the salient pole part 48 of the rotor core 42 in the circumferential direction. That is, the first field coil part 44-1 is arranged on one side closer to the protruding pole parts 48 of the rotor core 42 than the second field coil part 44-2.

[0033] The first field coil part 44-1 and the second field coil part 44-2 may be arranged, for example, such that the first field coil part 44-1 is wound around the salient pole part 48 of the rotor core 42, and then the second field coil part 44-2 is wound outside the first field coil part 44-1 in the circumferential direction. The first field coil part 44-1 and the second field coil part 44-2 may be obtained by dividing one winding, with the connection position to the other end of the capacitor 54 as a boundary. The first field coil part 44-1 and the second field coil part 44-2 may be obtained by connecting different windings (for example, two windings) at the connection position to the other end of the capacitor 54.

[0034] An inverter circuit 60 is connected to the rotary machine 20. The inverter circuit 60 is connected in parallel to the power supply 22. The inverter circuit 60 is connected to the stator coil 34 and is a circuit that applies voltages to corresponding phase windings of phases U, V, and W of the stator coil 34. The inverter circuit 60 includes an upper arm element 62 and a lower arm element 64 connected in series between both ends of the power supply 22. The three upper arm elements 62 and the three lower arm elements 64 are provided corresponding to the corresponding phase windings of phases U, V, and W.

[0035] Each of the upper-arm elements 62 and each of the lower-arm elements 64 includes a switching element 66, such as an insulated-gate bipolar transistor (IGTB) or a metal-oxide-semiconductor (MOS) field-effect transistor, and a freewheeling diode 68. In each of phases U, V, and W, the switching element 66 of the upper-arm element 62 and the switching element 66 of the lower-arm element 64 are turned on / off in opposite phases to each other. In each of phases U, V, and W, the switching element 66 of the upper-arm element 62 is turned on for a predetermined period with a predetermined phase difference.

[0036] A smoothing capacitor 70 is connected between both ends of the inverter circuit 60. The smoothing capacitor 60 is connected between both ends of the power supply 22 and is connected in parallel with the power supply 22. The smoothing capacitor 70 smoothes a voltage generated between both ends of the inverter circuit 60.

[0037] A control circuit 72 is connected to the inverter circuit 60. The control circuit 62 is connected to corresponding switching elements of the upper arm elements 62 and the lower arm elements 64 of the inverter circuit 60 and controls the inverter circuit 60. The control circuit 72 is connected to a position sensor 74 for detecting a rotational position of the rotor 26. The control circuit 72 controls the inverter circuit 60 so that a desired current flows through the stator coil 34 based on the rotational position of the rotor 26 obtained from the position sensor 74. The inverter circuit 60 applies voltages to corresponding phase windings of phases U, V, and W so that a desired rotating magnetic field is generated by the stator coil 34 by driving the switching element 66 according to a driving instruction from the control circuit 72.

[0038] Now, a description will be given of an operation of the rotary machine 20 of the present embodiment.

[0039] The control circuit 72 supplies an excitation current, which is a current component for rotor excitation, through the stator coil 34 to induce an alternating voltage at the rotor field coil 44. This excitation current is different from a fundamental current (i.e., a synchronous current), which is a current component for generating torque. As shown in Fig. As shown in Figure 4, the current flowing through the stator coil 34 is the sum of a fundamental current and the excitation current. The excitation current for rotor excitation is a current with a shorter cycle (i.e., a higher frequency) than the fundamental current and also a current with a smaller amplitude than the fundamental current. This excitation current is a current that pulsates with respect to the fundamental current and is a harmonic current with respect to the fundamental current.

[0040] The control circuit 72 controls the inverter circuit 60 so that a current obtained by superimposing the fundamental current for generating torque with the harmonic current having a shorter cycle than the fundamental current flows through the stator coil 34. The control circuit 72 controls the amplitude and cycle of each of the fundamental current and the harmonic current independently of each other.

[0041] When the fundamental current from the inverter circuit 60 flows through each phase winding of the stator coil 34 according to the drive instruction from the control circuit 72, the rotating magnetic field that rotates the rotor 26 is generated. When the harmonic current flows through each phase winding of the stator coil 34, an alternating current magnetic field is generated depending on the harmonic current to generate the excitation magnetic flux. In this case, the excitation magnetic flux connects to the salient pole portion 48 of the rotor core 42, and an alternating voltage is generated across the rotor field coil 44 to induce the field current.

[0042] The rectifying element 62 is connected between both ends of the rotor field coil 44, and the rotor field coil 44 is short-circuited via the rectifying element 52. Therefore, as described above, even when an alternating voltage is generated at the rotor field coil 44, a current flows only in one direction through the rotor field coil 44. This excites the rotor core 42 in a predetermined direction to form a pair of field poles in the rotor core 42. The field magnetic flux for forming this pair of field poles is generated by applying the excitation current for rotor excitation to the stator coil 34 and rectifying the current through the rotor field coil 44.

[0043] The rotor field coil 44 includes an inductance. That is, the rotor field coil 44 of each pole forms a partial inductance in each pole. Magnetic fluxes flowing through the field pole include stray magnetic flux, harmonic magnetic flux, and the like. Therefore, the magnitudes and directions of the penetrating magnetic fluxes differ from each other depending on the position of the rotor field coil 44. The directions of the voltages generated in the corresponding partial inductances of the rotor field coil 44 are not uniform and vary depending on time and the rotor rotation position.

[0044] As in Fig. As shown in Figure 9, directions of voltages generated at the rotor field coil 44 have four patterns. Specifically, the directions include a case (Pattern 1 and Pattern 4) where the direction of the voltage e1 generated at the first field coil part 44-1 and the direction of the voltage e2 generated at the second field coil part 44-2 are the same, and a case (Pattern 2 and Pattern 3) where the directions are opposite to each other. Then, as shown in Pattern 2 and Pattern 3, when voltages that cancel each other are generated in the respective partial inductances of the rotor field coil 44, the total voltage of the rotor field coil 44 decreases to reduce the excitation current. As a result, a loss of excitation energy may occur.

[0045] In contrast, in the rotary machine 20 of the present embodiment, the rectifier element 52 is connected between both ends of the rotor field coil 44, and the capacitor 54 is connected between the anode terminal of the rectifier element 52 and any point of the rotor field coil 44. That is, the rotary machine 20 is provided with the capacitor 54, one end of which is connected to the anode terminal of the rectifier element 52 and the other end of which is connected to any point of the rotor field coil 44.

[0046] In such a structure of the rotary machine 20, when the voltage direction is the pattern 2, the current flowing through the first field coil part 44-1 and the current flowing through the second field coil part 44-2 flow to the capacitor 54. Specifically, as shown in Fig. As shown in Fig. 7, the voltage directions between the first field coil part 44-1 and the second field coil part 44-2, which are divided at the connection position between the other end of the capacitor 54 and the rotor field coil 44, are opposite to each other. Thus, the voltages e1 and e2 cancel each other. Then, these voltages e1 and e2 are applied to the first field coil part 44-1 and the second field coil part 44-2, respectively, so that the currents flow from the connection portion side with the rectifier element 52 to the connection portion side with the other end of the capacitor 54. In such a case, in the rotary machine 20 of the present embodiment, the currents flow through the first field coil part 44-1 and the second field coil part 44-2, respectively, to the capacitor 54.As a result, in the rotary machine 20 of the present embodiment, the excitation energy depending on the voltages canceling each other between the first field coil part 44-1 and the second field coil part 44-2 is stored in the capacitor 54 to charge the capacitor 54.

[0047] After charging the capacitor 54, when the voltage direction is pattern 3, the currents from the capacitor 54 flow through the first field coil part 44-1 and the second field coil part 44-2 in the rotary machine 20, respectively. Specifically, as shown in Fig. As shown in Fig. 8, the voltage directions of the first field coil part 44-1 and the second field coil part 44-2 are switched. Then, these voltages e1 and e2 are applied to the first field coil part 44-1 and the second field coil part 44-2, respectively, in mutually canceling directions, so that the currents flow from the connecting portion side with the other end of the capacitor 54 to the connecting portion side with the rectifying element 52. In such a case, in the rotary machine 20 of the present embodiment, the currents flow respectively from the capacitor 54 side through the first field coil part 44-1 and the second field coil part 44-2. As a result, in the rotary machine 20 of the present embodiment, the energy stored in the capacitor 54 is released to the first field coil part 44-1 and the second field coil part 44-2, respectively, to discharge the capacitor 54.

[0048] As described above, in the rotary machine 20 of the present embodiment, when the voltage e1 generated at the first field coil part 44-1 and the voltage e2 generated at the second field coil part 44-2 cancel each other due to the leakage magnetic flux, the harmonic magnetic flux, and the like, a voltage acting on the entire rotor field coil 44 decreases. However, the rotary machine 20 may store the excitation energy in the capacitor 54 depending on the mutually canceling voltages. Then, after charging the capacitor 54 and when the above voltage directions are switched, the rotary machine 20 releases the energy stored in the capacitor 54 to the rotor field coil 44.Thus, in the rotary machine 20 of the present embodiment, the energy stored in the capacitor 54 is converted into an exciting current that excites the rotor core 42.

[0049] Therefore, according to the rotary machine 20 of the present embodiment, when voltages in mutually canceling directions are generated at corresponding partial inductances of the rotor field coil 44, excitation energy generated in the rotor field coil 44 is efficiently converted into an excitation current. This allows the rotary machine 20 to ensure a field current. Consequently, the rotary machine 20 of the present embodiment can prevent the occurrence of excitation energy loss associated with a reduction in an excitation current when the voltages in mutually canceling directions are generated at the corresponding partial inductances of the rotor field coil 44. Furthermore, the rotary machine 20 can efficiently excite the rotor core 42 even when the voltages cancel each other.

[0050] When the field current can be ensured as described above, the rotary machine 20 of the present embodiment can suppress the harmonic current, which is to be superimposed on the fundamental current flowing through the stator coil 34 and is necessary for forming a field pole on the rotor core 42, to a small amplitude. Consequently, the rotary machine 20 can reduce a torque ripple smaller than when the amplitude of the harmonic current is large (see Fig. 5).

[0051] In the rotary machine 20 of the present embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the salient pole part 48 of the rotor core 42. Specifically, the first field coil part 44-1, which is connected in parallel with the capacitor 54, is arranged on a side closer to the salient pole part 48 of the rotor core 42 in the circumferential direction. The second field coil part 44-2, which is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54, is arranged on a side far from the salient pole part 48 of the rotor core 42 in the circumferential direction. The magnetic fluxes that penetrate the salient pole part 48 of the rotor core 42 include a leakage magnetic flux and the like.Therefore, the magnitudes and directions of the penetrating magnetic fluxes differ from each other depending on the position of the rotor field coil 44. This phenomenon is particularly conspicuous in the harmonic magnetic flux. Specifically, the difference in the flux content between the side near the salient pole portion 48 of the rotor field coil 44 (i.e., the main magnetic pole side) and the side away from the salient pole portion 48 (i.e., between the main magnetic poles) is large. Consequently, according to the structure of the rotary machine 20, the energy to be stored in the capacitor 54 can be increased accordingly. Thus, in the rotary machine 20 of the present embodiment, a field current can be effectively obtained.

[0052] As is clear from the above description, the rotary machine 20 of the present embodiment is a field-winding type rotary machine, including the stator 24 having the stator core 32 and the stator coil 34 wound around the stator core 32, the rotor 26 having the rotor core 42 and the rotor field coil 44 wound around the rotor core 42, and the rectifier element 52 connected between both ends of the rotor field coil 44. In addition, the rotary machine 20 includes the capacitor 54, one end of which is connected to the anode terminal of the rectifier element 52 and the other end of which is connected to any point of the rotor field coil 44.

[0053] According to this configuration, the rotary machine 20 of the present embodiment stores excitation energy in the capacitor 54 depending on the canceling voltages when voltages generated in the respective partial inductances of the rotor field coil 44 cancel each other due to leakage magnetic flux, harmonic magnetic flux, and the like. Then, the rotary machine 20 outputs the energy stored in the capacitor 54 to the rotor field coil 44 and converts the energy into an excitation current that excites the rotor core 42 when the voltage directions are switched to be canceling directions. Thus, the rotary machine 20 can prevent energy loss from occurring when the voltages generated at the respective partial inductances of the rotor field coil 44 cancel each other.

[0054] In the rotary machine 20 of the present embodiment, the current flowing through the stator coil 34 is obtained by superimposing a fundamental current for generating torque with a harmonic current having a shorter cycle than the fundamental current.

[0055] According to the configuration, the rotary machine 20 of the present embodiment generates an excitation magnetic flux depending on the harmonic current when the harmonic current flows through the stator coil 34. Therefore, in the rotary machine 20, an alternating voltage can be generated in the rotor field coil 44 to induce an excitation current that excites the rotor core 42.

[0056] Additionally, in the rotary machine 20 of the present embodiment, the rotor field coil 44 includes the first field coil portion 44-1 and the second field coil portion 44-2. The first field coil portion 44-1 is connected in parallel with the capacitor 54. The second field coil portion 44-2 is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54. The first field coil portion 44-1 is disposed on the side closer to the salient pole portion 48 of the rotor core 42 than the second field coil portion 44-2.

[0057] According to the configuration, in the rotary machine 20 of the present embodiment, the difference in flux content between the first field coil part 44-1 and the second field coil part 44-2 becomes large when a leakage magnetic flux, a harmonic magnetic flux, or the like is generated. As a result, the rotary machine 20 can increase the energy to be stored in the capacitor 54 by the difference in flux content. Thus, a field current can be effectively maintained in the rotary machine 20.

[0058] In the rotary machine 20 of the present embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the salient pole part 48 of the rotor core 42. Specifically, the first field coil part 44-1, which is connected in parallel with the capacitor 54, is arranged on the side near the salient pole part 48 of the rotor core 42 in the circumferential direction. The second field coil part 44-2, which is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54, is arranged on a side remote from the salient pole part 48 of the rotor core 42 in the circumferential direction. However, the technique of the present disclosure is not limited to this.For example, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 in the circumferential direction, and the second field coil portion 44-2 may be disposed on the side near the salient pole portion 48 of the rotor core 42 in the circumferential direction. That is, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 than the second field coil portion 44-2. [Second embodiment]

[0059] In the first embodiment, the first field coil part 44-1 is arranged on the side close to (at a position close to) the salient pole part 48 of the rotor core 42 in the circumferential direction, and the second field coil part 44-2 is arranged on the side remote from (at a position remote from) the salient pole part 48 of the rotor core 42 in the circumferential direction. Fig. 10, the same components as those described in the above embodiment are given the same reference numerals and the description thereof is omitted or simplified.

[0060] In contrast, as in Fig. As shown in Fig. 10, in a rotary machine 100 of the present embodiment, a first field coil part 44-1 and a second field coil part 44-2 of a rotor field coil 44 are arranged at positions as described below with respect to a stator core 32. Specifically, the first field coil part 44-1, which is connected in parallel to a capacitor 54, is arranged on a side far from the stator core 32 in a radial direction. The second field coil part 44-2, which is connected between the cathode terminal of the rectifier element 52 and the other end (a second terminal) of the capacitor 54, is arranged on a side close to the stator core 32 in the radial direction. That is, the first field coil part 44-1 is arranged on a side farther from (i.e., an inner side in the radial direction of) the stator core 32 than the second field coil part 44-2.

[0061] It should be noted that the first field coil part 44-1 and the second field coil part 44-2 could, for example, be arranged such that the first field coil part 44-1 is wound around the protruding pole part 48 of the rotor core 42, and then the second field coil part 44-2 is wound outside the first field coil part 44-1 in the radial direction.

[0062] The magnetic fluxes that penetrate the salient pole portion 48 of the rotor core 42 include stray magnetic flux and the like. Therefore, the magnitudes and directions of the penetrated magnetic fluxes differ from each other depending on the position of the rotor field coil 44. This phenomenon is particularly conspicuous in the harmonic magnetic flux. Specifically, the difference in the flux content is large between the side of the rotor field coil 44 near the stator core 32 and the side away from the stator core 32 (i.e., the side of the main body 46 of the rotor core 42). Consequently, also in the structure of the rotary machine 100 of the present embodiment, the energy to be stored in the capacitor 54 can be increased accordingly. Thus, in the rotary machine 100 of the present embodiment, a field current can be effectively obtained.

[0063] As is clear from the above description, in the rotary machine 100 of the present embodiment, the rotor field coil 44 includes the first field coil part 44-1 and the second field coil part 44-2. The first field coil part 44-1 is connected in parallel with the capacitor 54. The second field coil part 44-2 is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54. The first field coil part 44-1 is arranged on the side farther from the stator core 32 than the second field coil part 44-2.

[0064] According to the configuration, in the rotary machine 100 of the present embodiment, the difference in flux content between the first field coil part 44-1 and the second field coil part 44-2 becomes large when leakage magnetic flux, harmonic magnetic flux, or the like is generated. As a result, the rotary machine 100 can increase the energy to be stored in the capacitor 54 by the difference in flux content. Thus, a field current can be effectively maintained in the rotary machine 100.

[0065] Note that in the rotary machine 100 of the present embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the stator core 32. Specifically, the first field coil part 44-1, which is connected in parallel with a capacitor 54, is arranged on a side remote from the stator core 32 in a radial direction. The second field coil part 44-2 is arranged between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54 on the side close to the stator core 32 in the radial direction. However, the technique of the present disclosure is not limited to this. For example, the first field coil part 44-1 may be arranged on the side close to the stator core 32 in the radial direction, and the second field coil part 44-2 may be arranged on the side away from the stator core 32 in the radial direction.That is, the first field coil part 44-1 may be arranged on the side closer to (i.e., on the outer side in the radial direction of) the stator core 32 than the second field coil part 44-2. [Third embodiment]

[0066] The magnetic fluxes flowing through the field pole include stray magnetic fluxes. The stray magnetic fluxes include magnetic fluxes that escape or stray across one side of the stator 24 and one side of the rotor 26 between protruding pole pieces 48, which are the main magnetic poles. Thus, efficient formation of magnetic fluxes could be blocked. Fig. 11, the same reference numerals are attached to the same components as those described in the above embodiments, and the description thereof is omitted or simplified.

[0067] In contrast, as in Fig. 11, in a rotary machine 200 of the present embodiment, a rotor core 42 includes a main portion 46 and a plurality of salient pole portions 48, and further includes an auxiliary pole portion 202. The salient pole portions 48 are main magnetic poles constituting a pair of field poles. The auxiliary pole portion 202 is disposed between the salient pole portions 48 and is provided for each interval between the auxiliary pole portions 48. The auxiliary pole portions 202 are provided in plural in the circumferential direction and are arranged to be alternately aligned with the salient pole portions 48 at a predetermined angle. The auxiliary pole portion 202 is an auxiliary pole provided to provide a boundary between the salient pole portions 48 that are adjacent to each other in the circumferential direction. The auxiliary pole portion 202 protrudes outward from the main portion 46 in the radial direction.

[0068] It should be noted that the auxiliary pole part 202 may have a smaller circumferential width than the salient pole part 48. In addition, a gap between the front end of the auxiliary pole part 202 and the front end of the tooth 40 of the stator core 42 may be larger than an air gap between the front end of the salient pole part 48 and the tooth 40.

[0069] The rotary machine 200 includes a magnet 204. The magnet 204 is provided at the auxiliary pole part 202. The magnet 204 is magnetized in a direction of canceling a leakage magnetic flux that leaks across the stator 24 side and the stator 26 side between the protruding pole parts 48. The magnet 204 is arranged to be magnetized in the direction of canceling the leakage magnetic flux. The magnet 204 is embedded in the auxiliary pole part 202 such that the N pole is disposed inside the auxiliary pole part 202 in the radial direction, and the S pole is disposed outside it in the radial direction. The magnet 204 has a function of suppressing the leakage of the magnetic flux across the stator 24 side and the rotor 26 side between the protruding pole parts 48.

[0070] With such a structure of the rotary machine 200, the magnet 204 provided in the auxiliary pole part 202 can prevent magnetic flux from leaking or leaking between the protruding pole parts 48 on the stator 24 side or the rotor 26 side. Therefore, according to the rotary machine 200 of the present embodiment, the magnetic flux flowing through the field pole can be efficiently conducted. Thus, a field current can be effectively maintained in the rotary machine 200.

[0071] In the rotary machine 200 of the present embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the salient pole part 48 of the rotor core 42. Specifically, the first field coil part 44-1, which is connected in parallel with the capacitor 54, is arranged on the side close to (at a position close to) the salient pole part 48 of the rotor core 42 in the circumferential direction. The second field coil part 44-2, which is connected between the cathode terminal of the rectifier element 52 and the other end (second terminal) of the capacitor 54, is arranged on the side far from (at a position far from) the salient pole part 48 of the rotor core 42 in the circumferential direction. However, the technique of the present disclosure is not limited to this.For example, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 in the circumferential direction, and the second field coil portion 44-2 may be disposed on the side near the salient pole portion 48 of the rotor core 42 in the circumferential direction. That is, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 than the second field coil portion 44-2. [Fourth embodiment]

[0072] In the third embodiment, the first field coil part 44-1 is arranged on the side close to (at a position close to) the salient pole part 48 of the rotor core 42 in the circumferential direction, and the second field coil part 44-2 is arranged on the side remote from (at a position remote from) the salient pole part 48 of the rotor core 42 in the circumferential direction. Fig. 12, the same reference numerals are attached to the same components as those described in each of the above embodiments, and the description thereof is omitted or simplified.

[0073] In contrast, as in Fig. As shown in Fig. 12, in a rotary machine 300 of the present embodiment, a first field coil part 44-1 and a second field coil part 44-2 of a rotor field coil 44 are arranged at positions as described below with respect to a stator core 32. Specifically, the first field coil part 44-1, which is connected in parallel to a capacitor 54, is arranged on a side distant from the stator core 32 in a radial direction. The second field coil part 44-2, which is connected to the cathode terminal of a rectifying element 52 and the other end (a second terminal) of the capacitor 54, is arranged on a side close to the stator core 32 in the radial direction. That is, the first field coil part 44-1 is arranged on a side farther from (i.e., a different side in the radial direction from) the stator core 32 than the second field coil part 44-2.

[0074] In the rotary machine 300 of the present embodiment, the rotor core 42 includes a main portion 46 and a plurality of salient pole portions 48, and further includes an auxiliary pole portion 302. The salient pole portions 48 are main magnetic poles that form a pair of field poles. As in the auxiliary pole portion 202 of the third embodiment, the auxiliary pole portion 302 is disposed between the salient pole portions 48 and is provided for each interval between the salient pole portions 48. The auxiliary pole portions 302 are provided in plural numbers in the peripheral direction and are arranged to be alternately aligned with the salient pole portions 48 at a predetermined angle. The auxiliary pole portion 302 is an auxiliary pole arranged to provide a boundary between the salient pole portions 48 that are adjacent to each other in the peripheral direction. The auxiliary pole portion 302 protrudes outward from the main portion 46 in the radial direction.

[0075] The auxiliary pole portion 302 may have a smaller circumferential width than the salient pole portion 48. In addition, a gap between the upper end of the auxiliary pole portion 302 and the upper end of the tooth 40 of the stator core 32 may be larger than an air gap between the upper end of the salient pole portion 48 and the tooth 40.

[0076] The rotary machine 300 includes a magnet 304. The magnet 304 is provided at the auxiliary pole part 302. The magnet 304 is magnetized in a direction of canceling a leakage magnetic flux that escapes or leaks between the protruding pole parts 48 on the stator 24 side and the rotor 26 side. The magnet 304 is arranged to be magnetized in the direction of canceling the leakage magnetic flux. The magnet 304 is embedded in the auxiliary pole part 302 such that the N pole is arranged inside the auxiliary pole part 302 in the radial direction and the S pole is arranged outside it in the radial direction. The magnet 304 has a function of suppressing a leakage of the magnetic flux between the protruding pole parts 48 and the stator 24 side.

[0077] In such a structure of the rotary machine 300, the magnet 304 provided in the auxiliary pole part 302 can prevent the magnetic flux from leaking or leaking between the protruding pole parts 48 on the stator 24 side and the rotor 26 side. Therefore, according to the rotary machine 300 of the present embodiment, the magnetic flux flowing through the field pole can be efficiently conducted. Therefore, a field current can be effectively maintained in the rotary machine 300.

[0078] As is clear from the above description, in the rotary machine 200 and the rotary machine 300 of the third and fourth embodiments, the rotor core 42 includes a plurality of salient pole pieces 48, and the auxiliary pole piece 202 and the auxiliary pole piece 302 disposed between the salient pole pieces 48. The rotor core 42 includes the magnet 204 and the magnet 304. The magnet 204, 304 is provided at the auxiliary pole piece 202 and the auxiliary pole piece 302 and is magnetized in the direction of canceling the leakage magnetic flux generated between the salient pole pieces 48.

[0079] According to this configuration, in the rotary machine 200 and the rotary machine 300 of the third and fourth embodiments, the magnet 204 and the magnet 304 provided in the auxiliary pole part 202 and the auxiliary pole part 302 can prevent the magnetic flux from leaking between the salient pole parts 48 via the stator 24 side and the rotor 26 side. Therefore, the rotary machine 200 and the rotary machine 300 can efficiently transmit the magnetic flux flowing through the field pole to the salient pole part 48. Thus, a field current can be effectively obtained in the rotary machine 200 and the rotary machine 300.

[0080] In the rotary machine 300 of the fourth embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the stator core 32. Specifically, the first field coil part 44-1, which is connected in parallel to a capacitor 54, is arranged on a side remote from the stator core 32 in a radial direction. The second field coil part 44-2, which is connected between the cathode terminal of the rectifier element 52 and the other end of the capacitor 54, is arranged on the side near the stator coil 32 in the radial direction. However, the technique of the present disclosure is not limited to this. For example, the first field coil part 44-1 may be arranged on the side near the field coil 32 in the radial direction, and the second field coil part 44-2 may be arranged on the side remote from the stator core 32 in the radial direction.That is, the first field coil part 44-1 may be arranged on the side closer to (i.e., an outer side in the radial direction of) the stator core 32 than the second field coil part 44-2. [Fifth embodiment]

[0081] In each of the above embodiments, a capacitor is not connected in parallel with a rectifying element 52 provided in the rotary machine 52. Fig. 13, the same reference numerals are attached to the same components as those described in each of the above embodiments, and the description thereof is omitted or simplified.

[0082] In contrast, as in Fig. As shown in FIG. 13, in a rotary machine 400 of the present embodiment, a capacitor 402 is connected in parallel to a rectifying element 52. The capacitor 402 has a function of smoothing an alternating voltage induced in a rotor field coil 44 and rectified to a half-wave by the rectifying element 52 to reduce pulsation. According to the rotary machine 400 provided with such a capacitor 402, it is possible to smooth an alternating voltage rectified to a half-wave by the rectifying element 52 and reduce its pulsation. [Sixth embodiment]

[0083] In the above embodiments, the capacitor 54 is provided, one end (first terminal) of which is connected to the anode terminal of the rectifier element 52, and the other end (second terminal) of which is connected to any point (predetermined position) of the rotor field coil 44. Fig. 14 to 16, the same reference numerals are attached to the same components as those described in the above embodiment, and the description thereof is omitted or simplified.

[0084] In contrast, a rotary machine 500 of the present embodiment includes a capacitor 502 instead of the capacitor 54 in the first embodiment. As shown in Fig. As shown in Figure 14, one end (first terminal) of capacitor 502 is connected to the anode terminal of a rectifier element 52. The other end (second terminal) of capacitor 502 is connected to any point of a rotor field coil 44. Rotor field coil 44 includes a first field coil portion 44-1 and a second field coil portion 44-2. First field coil portion 44-1 is connected in parallel with capacitor 502. Second field coil portion 44-2 is connected between the anode terminal of rectifier element 52 and the other end of capacitor 502.When the direction of a voltage e1 generated between both ends of the first field coil part 44-1 and the direction of a voltage e2 generated between both ends of the second field coil part 44-2 are opposite to each other, and the voltages e1 and e2 cancel each other, the capacitor 502 includes a function of storing excitation energy depending on the voltages that cancel each other.

[0085] In such a rotary machine 500, when the voltage direction is pattern 2, the current flowing through the first field coil part 44-1 and the current flowing through the second field coil part 44-2 flow to the capacitor 502. Specifically, as shown in Fig. As shown in FIG. 15, the voltage directions between the first field coil part 44-1 and the second field coil part 44-2, which are divided at the connection position between the other end of the capacitor 502 and the rotor field coil 44, are opposite to each other. Thus, the voltages e1 and e2 cancel each other. Then, these voltages e1 and e2 are respectively applied to the first field coil part 44-1 and the second field coil part 44-2, so that the currents flow from the connection portion sides with the rectifier element 52 to the connection portion side with the other end of the capacitor 502. In such a case, in the rotary machine 500 of the present embodiment, the currents that respectively flow through the first field coil part 44-1 and the second field coil part 44-2 flow to the capacitor 502.As a result, in the rotary machine 500 of the present embodiment, the excitation energy depending on the voltages between the first field coil part 44-1 and the second field coil part 44-2, which cancel each other, is stored in the capacitor 502 to charge the capacitor 502.

[0086] After charging the capacitor 502, when the voltage direction is pattern 3, the currents flow from the capacitor 502 through the first field coil part 44-1 and the second field coil part 44-2 into the rotary machine 500, respectively. Specifically, as shown in Fig.As shown in Fig. 16, the voltage directions of the first field coil part 44-1 and the second field coil part 44-2 are switched. Then, in mutually canceling directions, these voltages e1 and e2 are applied to the first field coil part 44-1 and the second field coil part 44-2, respectively, so that the currents flow from the connecting portion side with the other end of the capacitor 502 to the connecting portion sides with the rectifying element 52. In such a case, in the rotary machine 500 of the present embodiment, the currents flow from the capacitor 502 side through the first field coil part 44-1 and the second field coil part 44-2, respectively. As a result, in the rotary machine 500 of the present embodiment, the energy stored in the capacitor 502 is released to the first field coil part 44-1 and the second field coil part 44-2, respectively, to discharge the capacitor 502.

[0087] Therefore, even in the rotary machine of the present embodiment, when voltages in mutually canceling directions are generated at corresponding partial inductances of the rotor field coil 44, excitation energy generated in the rotor field coil 44 is efficiently converted into excitation current. This allows the rotary machine 500 to ensure a field current. Consequently, the rotary machine 500 of the present embodiment can prevent the occurrence of excitation energy loss accompanied by a reduction in excitation current when the voltages in mutually canceling directions are generated at the corresponding partial inductances of the rotor field coil 44. Furthermore, the rotary machine 500 can efficiently excite the rotor core 42 even when the voltages cancel each other.Thus, in the rotary machine 500, the same effects as in the first embodiment can be obtained.

[0088] In the sixth embodiment, the first field coil part 44-1 and the second field coil part 44-2 of the rotor field coil 44 are arranged at positions as described below with respect to the salient pole part 48 of the rotor core 42. Specifically, the first field coil part 44-1, which is connected in parallel with the capacitor 502, is arranged on the side close to (at a position close to) the salient pole part 48 of the rotor core 42 in the circumferential direction. The second field coil part 44-2, which is connected between the anode terminal of the rectifier element 52 and the other end of the capacitor 502, is arranged on the side far from (at a position far from) the salient pole part 48 of the rotor core 42 in the circumferential direction. However, the technique of the present disclosure is not limited to this.For example, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 in the circumferential direction, and the second field coil portion 44-2 may be disposed on the side near the salient pole portion 48 of the rotor core 42 in the circumferential direction. That is, the first field coil portion 44-1 may be disposed on the side remote from the salient pole portion 48 of the rotor core 42 than the second field coil portion 44-2.

[0089] In addition, for example, the first field coil part 44-1 may be arranged on the side farther from the stator core 32 in the radial direction, and the second field coil part 44-2 may be arranged on the side near the stator core 32 in the radial direction. That is, the first field coil part 44-1 may be arranged on the side farther from (i.e., the inner side of the radial direction of) the stator core 32 than the second field coil part 44-2.

[0090] Conversely, the first field coil part 44-1 may be arranged on the side near the stator core 32 in the radial direction, and the field coil part 44-2 may be arranged on the side far from the stator core 32 in the radial direction. That is, the first field coil part 44-1 may be arranged on the side closer to (i.e., an outer side in the radial direction of) the stator core 32 than the second field coil part 44-2.

[0091] The rotary machine 500 of the sixth embodiment may employ the configuration of the third embodiment or the fifth embodiment.

[0092] Furthermore, in each of the above first to sixth embodiments, the rotor field coil 44 is intensively wound for each salient pole piece 48. However, the technique of the present disclosure is not limited thereto. For example, the technique of the present disclosure can be applied to a rotary machine having a configuration in which the rotor field coil 44 is dispersedly wound around some of the salient pole pieces 48.

[0093] Furthermore, in the third to sixth embodiments, the magnet of the auxiliary pole part may be configured with an electromagnet using a coil.

[0094] The technique of the present disclosure is not limited to the embodiments and variations described above. The technique of the present disclosure can be variously modified within a range that does not deviate from the gist of the disclosure. [List of reference symbols] 20, 100, 200, 300, 400, 500 field winding rotary machine or rotary machine of the field winding type 22 Power supply 24 Stator 26 Rotor 32 Stator core 34 Stator coil 42 rotor core 44 Rotor field coil 44-1 first field coil part 44-2 second field coil part 48 protruding pole part (main magnetic pole) 52 Rectifier element 54, 502 capacitor 60 inverter circuit 72 Control circuit 202, 302 auxiliary pole part (auxiliary pole) 204, 304 Magnet

Claims

[1] Field winding rotary machine, with: a stator (24) having a stator core (32) and a stator coil (34) wound around the stator core; a rotor (26) having a rotor core (42) and a rotor field coil (44) wound around the rotor core; a rectifier element (52) connected between both ends of the rotor field coil; and a capacitor (54, 502) having one end connected to one end of the rectifier element and the other end connected to any point of the rotor field coil, wherein the rotor field coil has a first field coil part (44-1) connected in parallel with the capacitor and a second field coil part (44-2) connected between the other end of the rectifier element and the other end of the capacitor. [2] Field winding rotary machine according to claim 1, characterized by , that: a current flowing through the stator coil is a current obtained by superimposing a fundamental current for generating a torque and a harmonic current having a shorter cycle than the fundamental current. [3] Field winding rotary machine according to claim 1 or 2, characterized by , that: the first field coil part is arranged on one side closer to a main magnetic pole (48) of the rotor core than the second field coil part. [4] Field winding rotary machine according to claim 1 or 2, characterized by , that: the first field coil part is arranged on a side further away from the stator core than the second field coil part. [5] Field winding rotary machine according to one of claims 1 to 4, characterized by that the rotor core a plurality of main magnetic poles (48) and an auxiliary pole (202, 302) arranged between the main magnetic poles, and a magnet (204, 304) provided in the auxiliary pole and magnetized in a direction of canceling a stray magnetic flux generated between the main magnetic poles. [6] Field winding rotary machine according to one of claims 1 to 5, characterized by that a connection position between the other end of the capacitor and the rotor field coil is a boundary position that divides the rotor field coil into a portion more affected by a stray magnetic flux and a harmonic magnetic flux of a magnetic flux flowing through the field pole and a portion less affected by them. [7] Field winding rotary machine according to claim 1 or 2, characterized by , that: the first field coil part is arranged on a side further away from a main magnetic pole (48) of the rotor core than the second field coil part. [8] Field winding rotary machine according to claim 1 or 2, characterized by , that: the first field coil part is arranged on one side closer to the stator core than the second field coil part.

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