Electric power generation device

Abstract

Provided is an electric power generation device that makes it possible to reduce torque ripples without including a plurality of electric power generators. In the electric power generation device, the number of a plurality of stator coils 62d disposed in a stator 62 and the number of a plurality of magnetic poles 61c disposed in a rotor 61 satisfy the relationship of poles : stator coils=2N ((6n±1) : 6n) (N represents a natural number and n represents an exponent of 2 including 1). The plurality of stator coils 62d constitute 4Nn three-phase coils, and the 4Nn three-phase coils constitute 2Nn pairs of three-phase coils, the pairs of three-phase coils each comprising two coils having the same phase. The phase of the three-phase alternating current outputted from each of the pairs of three-phase coils is shifted from the phase of the three-phase alternating current outputted from at least one of the other pairs of three-phase coils. The electric power generation device further comprises a plurality of three-phase rectifier circuits 82 connected to the pairs of three-phase coils 81. The electric power generation device synthesizes electric power outputted from the three-phase rectifier circuits 82 and outputs the synthesized electric power to a direct current distribution system 83.

Description

power generation equipment

[0001] The present invention relates to a power generating device, and more particularly to a relatively large power generating device that generates electricity by utilizing hydrodynamic forces such as wind power and tidal power.

[0002] In power generation devices that utilize fluid power such as wind and tidal power, vibrations that occur during power generation can cause loud noise and damage to mechanical components. One of the causes of such vibrations is torque ripple (pulsating torque) generated in the generator.

[0003] It is known that when the three-phase current output from a generator is rectified using a rectifier circuit such as a three-phase diode converter, sixth-order harmonic ripples and their multiples are generated. Specifically, the rectifier ripple has a period of 2π / 6 (60 degrees), while the harmonic ripple has periods of 2π / 12 (30 degrees), 2π / 24 (15 degrees), etc. Such current ripples cause torque ripples in the generator, which can cause noise and damage to the power generating equipment.

[0004] For example, Patent Document 1 discloses a flow power generation system including a shaft on which a wind turbine is mounted, four generators attached to the shaft along the axial direction of the shaft, and a rectifier circuit and a DC / DC converter provided for each generator. The three-phase AC voltage output from each generator is rectified by the rectifier circuit, converted to DC by the DC / DC converter, and output in parallel to a system circuit. The three-phase AC voltages output from each generator are configured to be mutually phase-shifted. Specifically, the four generators are configured to output three-phase AC voltages that are each 15 degrees phase-shifted.

[0005] In Patent Document 1, the phases of the three-phase AC of each generator are shifted by 15 degrees, and therefore the phases of the ripples contained in the current rectified by the rectifier circuit are also shifted by 15 degrees from each other. As a result, torque ripples caused by current ripples are dispersed and smoothed overall, making it possible to reduce noise and vibrations caused by torque ripples.

[0006] Japanese Patent Application Laid-Open No. 2007-174733

[0007] In recent years, blades in power generation devices utilizing wind or tidal power have become increasingly larger. Accordingly, the generators in these power generation devices are now larger than 10 meters, and their output has also increased. When multiple generators are arranged along the axial direction of a rotating shaft, as in Patent Document 1, the overall structure of the power generation section becomes larger. In particular, in large power generation devices utilizing wind or tidal power, the rotating shaft may be 7 meters or more, and the generators arranged around such large-diameter rotating shafts are also very large, with diameters of approximately 10 meters. Arranging multiple such large generators along the axial direction leads to an increase in the size of the power generation mechanism and increases manufacturing costs.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a power generating device that can reduce torque ripple without providing a plurality of generators.

[0009] That is, the present invention provides a generator including a stator having a plurality of stator coils arranged in a ring shape, and a rotor having a plurality of magnetic poles arranged in a ring shape facing the stator coils, wherein each stator coil is formed by concentrated winding, the number of the plurality of magnetic poles and the plurality of stator coils is set to poles:stator coils=2N((6n±1):6n) (where N is a natural number and n is a power of 2 including 1), the plurality of stator coils constitute 4Nn three-phase coils, and 2Nn three-phase coil pairs are formed of two three-phase coils of the same phase among the 4Nn three-phase coils, and the phase of the three-phase AC output from each three-phase coil pair is shifted from the phase of the three-phase AC output from at least one of the other three-phase coil pairs; Provided is a power generation device comprising: a plurality of three-phase rectifier circuits, each having a three-phase AC input terminal and a DC output terminal, and each having a three-phase AC input terminal to which a three-phase AC output from a corresponding one of the 2Nn three-phase coil pairs is input; and wherein powers output from the DC output terminals of each three-phase rectifier circuit are combined and output to a DC power distribution system.

[0010] According to this power generating device, a generator consisting of a single stator and rotor can output multiple three-phase AC currents that are out of phase with each other. By rectifying these three-phase AC currents using a three-phase rectifier circuit and then combining them, the rectification ripples contained in the rectified currents can be canceled out and smoothed. This makes it possible to reduce torque ripple caused by rectification ripple. With this power generating device, torque ripple can be effectively reduced using only a generator consisting of a single stator and rotor, without arranging multiple generators axially as in the past.

[0011] The power supply may further include one or more isolated step-up DC / DC converters that step up the power output from the DC output terminals of the three-phase rectifier circuits.

[0012] Furthermore, at least one of the one or more isolated step-up DC / DC converters can be configured to control the voltage at the converter input terminal of the at least one isolated step-up DC / DC converter, and when the output of the generator is equal to or lower than a predetermined threshold output, the at least one isolated step-up DC / DC converter can reduce the voltage at the converter input terminal.

[0013] Furthermore, at least one of the one or more isolated step-up DC / DC converters is a bidirectional isolated step-up DC / DC converter, and at least one of the three-phase rectifier circuits connected to the bidirectional isolated step-up DC / DC converter is a three-phase inverter, and the three-phase inverter converts DC power supplied via the bidirectional isolated step-up DC / DC converter into three-phase AC power and supplies the AC power to the generator, thereby driving and rotating the rotor.

[0014] Furthermore, N is 2 or more, the plurality of three-phase rectifier circuits form N sets of three-phase rectifier circuit groups each made up of 2n three-phase rectifier circuits, and each set of three-phase rectifier circuit groups has one composite DC output terminal formed by interconnecting the DC output terminals of the 2n three-phase rectifier circuits included in that set of three-phase rectifier circuit groups, and the power output from the composite DC output terminals of each set of three-phase rectifier circuit groups can be composited and output to the DC distribution system.

[0015] The power supply may further include a plurality of isolated step-up DC / DC converters, each having a converter input terminal and a converter output terminal connected to the combined DC output terminal of a corresponding one of the N three-phase rectifier circuit groups, and each converter output terminal connected in series to another converter output terminal.

[0016] Furthermore, the isolated step-up DC / DC converter connected to the position where the voltage is lowest among the plurality of isolated step-up DC / DC converters is a bidirectional isolated step-up DC / DC converter, and at least one of the plurality of three-phase rectifier circuits constituting the three-phase rectifier circuit group connected to the isolated step-up DC / DC converter connected to the position where the voltage is lowest is a three-phase inverter, and the three-phase inverter converts DC power supplied via the bidirectional isolated step-up DC / DC converter into three-phase AC power and supplies the AC power to the generator, thereby driving and rotating the rotor.

[0017] Furthermore, the voltage generated between the generator and the converter input terminal of each isolated step-up DC / DC converter can be 400 V or less, and the voltage generated at the converter output terminal of each isolated step-up DC / DC converter can be 1.2 kV or more.

[0018] The wind turbine may also include a shaft base connected to the generator and a rotary wind turbine fixed to the shaft base, and the generator may generate electricity by rotating the shaft base using wind force received by the rotary wind turbine.

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a power generating device according to the present invention will now be described with reference to the accompanying drawings.

[0020] 1 is an explanatory diagram of the overall configuration of a power generating device according to a first embodiment of the present invention; FIG. 2 is an enlarged view of part II in FIG. 1; FIG. 3 is a perspective view showing an example of a bearing module; FIG. 4 is a perspective view showing an example of a bearing module and a generator; FIG. 5 is a perspective view showing an example of a rotor; (a) is a perspective view showing an example of a rotor base, and (b) is a perspective view showing an example of a magnetic pole core. FIG. 6 is a perspective view showing an example of a stator part; (a) is a partial detailed view of the generator shown in FIG. 4, and (b) is a perspective view showing an example of an excitation core. (a) is a perspective view showing an example of a connecting unit, and (b) is a cross-sectional view showing a state in which the rotor is fitted in the air gap of the connecting unit. (a) and (b) are explanatory views showing an example of a procedure for removing the stator part; (a) is an explanatory view showing the flow of magnetic flux; (a) is a development view showing the positional relationship between the magnetic poles and the stator coils, (b) is an explanatory view showing the electrical angle phases of each coil, and (c) is an explanatory view showing the electrical connection relationship of the coils; (b) is an explanatory view showing the configuration of a power circuit; (c) is an explanatory view showing the configuration of an isolated step-up DC / DC converter; 18. A graph showing the output voltage of a three-phase rectifier circuit. An explanatory diagram of the configuration of magnetic poles and stator coils of a power generating device according to a second embodiment of the present invention. An explanatory diagram of a power circuit in the power generating device of FIG. 17. An explanatory diagram of another power circuit in the power generating device of FIG. 17. An explanatory diagram showing the configuration of a three-phase inverter. An explanatory diagram of the configuration of magnetic poles and stator coils of a power generating device according to a third embodiment of the present invention. (a) is a perspective view showing another example of a rotor base, and (b) is a detailed partial view of the rotor base of (a). An explanatory diagram showing an example of a case where generators are installed in multiple stages. An explanatory diagram showing an example when the power generating device of the present invention is applied to a horizontal axis wind turbine power generating device. An explanatory diagram showing an example when the power generating device of the present invention is applied to a vertical axis tidal power generating device.

[0021] (Embodiment) An example of an embodiment of a power generation device of the present invention will be described with reference to the drawings. Here, a floating wind power generation device in which a vertical axis wind turbine is connected to the tip of a float will be described as an example. Below, the structure, operation, and effects of the power generation device of this embodiment will be described, followed by a description of modified examples of the power generation device.

[0022] <Structure of the power generation device of the first embodiment> As an example, a floating wind turbine power generation device according to the first embodiment shown in FIG. 1 includes a float 10, a shaft base 20, a rotary wind turbine 30, a bearing support 40, a bearing module 50, a generator 60, and a mooring line 70.

[0023] The float 10 is a member that floats on water, such as the sea or a lake. The float 10 in this embodiment is a hollow cylinder, and contains ballast material inside to maintain balance. The ballast material can be water, iron, rocks, or other materials.

[0024] 2, a shaft base 20 is provided on the tip side (upper end side in the illustrated example) of the floating body 10. A rotary wind turbine 30 is connected to the tip side (upper end side in the illustrated example) of the shaft base 20.

[0025] The shaft base 20 is a portion on which the generator 60 and the bearing module 50 are mounted, and does not necessarily have to be an independent member. For example, the shaft base 20 may be a part of the floating body 10 or a part of the shaft 31 of the rotary wind turbine 30.

[0026] The rotary windmill 30 is a member that rotates when it receives wind force (a force-receiving rotor). The rotary windmill 30 in this embodiment is a vertical axis type, and includes a shaft 31, a plurality of arms 32 that protrude laterally from the shaft 31, and blades 33 that are attached to the tips of the arms 32.

[0027] A bearing support 40 that supports the bearing module 50 is provided at a position outside the shaft base 20 around the axis and closer to the floating body 10. The bearing support 40 in this embodiment is disk-shaped, and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0028] The bearing support 40 is provided on the outer side around the axis of the shaft base 20 inserted through the insertion hole. The bearing support 40 is fixed to the shaft base 20 at the periphery of the insertion hole, and is configured to rotate in the same direction as the shaft base 20 as the shaft base 20 rotates.

[0029] The bearing module 50 is a member that supports the stator 62. In a broader sense, the bearing module 50 is a member that supports the generator 60 that includes the stator 62 and the rotor 61. In other words, the bearing module 50 is a member that directly supports the stator 62 and indirectly supports the rotor 61 via the bearing support 40 and the shaft base 20.

[0030] As shown in FIG. 3 , the bearing module 50 of this embodiment includes a bearing base 51 , a first load receiver 52 , and a second load receiver 53 .

[0031] The bearing base 51 is a member that serves as the base of the bearing module 50. The bearing base 51 is disposed around the axis of the shaft base 20 on the outer side so as not to rotate together with the shaft base 20. The bearing base 51 in this embodiment has a triangular shape in a plan view, and is provided with mooring line attachment portions 51a that protrude outward at each corner.

[0032] The mooring line attachment portion 51a is provided with locking holes 51b. One end of a mooring line 70 is attached to each locking hole 51b. The other end of each mooring line 70 is provided with an anchor (not shown) and is fixed to the seabed or lakebed at the installation location.

[0033] An insertion hole through which the shaft base 20 can be inserted is provided in the center of the bearing base 51. A plurality of first load receivers 52 are provided around the periphery of the insertion hole of the bearing base 51. The first load receivers 52 are members that receive a load (radial load) in a first direction (horizontal direction in the illustrated example) applied from the shaft base 20, and are composed of a group of a plurality of horizontal rollers.

[0034] The second load receiving body 53 is a member that receives a load (axial load) in the second direction (vertical direction in the illustrated example) applied from the bearing support body 40, and is composed of a group of multiple vertical rollers. Specifically, one vertical roller is provided near the base of each of the three mooring rope attachment portions 51 a of the bearing base 51.

[0035] The bearing module 50 of this embodiment presses down (supports from above) the float 10 and the shaft base 20 and bearing support 40 connected to it to prevent them from floating up due to the buoyancy of the float 10 via the second load receiver 53, and holds the shaft base 20 horizontally via the first load receiver 52 to prevent the float 10 and shaft base 20 from moving horizontally.

[0036] Furthermore, the bearing module 50 holds the stator 62 so that the stator 62 does not rotate due to torque generated in the stator 62 as the shaft base 20 and the rotor 61 rotate. When the rotary wind turbine 30 receives wind, a horizontal force is applied to the bearing module 50 via the shaft base 20 connected to the rotary wind turbine 30.

[0037] Furthermore, when the rotary wind turbine 30 rotates, torque is applied to the bearing module 50 via the stator 62. The mooring lines 70 fix the bearing module 50 to the seabed to limit movement of the bearing module 50 that is subjected to these forces.

[0038] Furthermore, the first load receiver 52 and the second load receiver 53 rotatably support the shaft base 20 and the rotary wind turbine 30 and floating body 10 fixed thereto relative to the fixed bearing module 50 .

[0039] The generator 60 is a device that generates electricity using the rotational force generated by the rotary wind turbine 30. The generator 60 includes a rotor 61 and a stator 62 that are spaced apart in the axial direction of the shaft base 20.

[0040] The rotor 61 is arranged on the outer periphery of the shaft base 20 (Figure 2) so as to rotate together with the shaft base 20, and the stator 62 and the exciter 65 are arranged on the outer periphery of the shaft base 20 so as not to rotate together with the shaft base 20.

[0041] The rotor 61 is a field magnet that generates a magnetic field. As shown in Fig. 5, the rotor 61 of this embodiment includes a rotor base 61a and a plurality of (26 in this embodiment) magnetic pole cores 61c attached to the rotor base 61a.

[0042] The rotor base 61a is a member that holds the magnetic pole core 61c and can be made of a non-magnetic, insulating material such as FRP (fiber reinforced plastic). As shown in Figure 6(a), the rotor base 61a in this embodiment is disk-shaped and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0043] The strip-shaped portion of the rotor base 61a excluding the insertion holes is provided with magnetic pole core holding portions 61d into which the magnetic pole cores 61c fit. The magnetic pole core holding portions 61d are provided radially from the center point of the shaft base 20. A plurality of magnetic pole core holding portions 61d (26 in this embodiment, the same number as the magnetic pole cores 61c) are provided at intervals along the strip-shaped portion.

[0044] Each magnetic pole core holder 61d holds one magnetic pole core 61c. As shown in Fig. 6(b), the magnetic pole core 61c in this embodiment is a rectangular parallelepiped member made of laminated steel plates, which are made by stacking electromagnetic steel plates. Making the magnetic pole core 61c from laminated steel plates has the advantage of being easy to manufacture.

[0045] A jaw 61e that fits into the magnetic pole core holding portion 61d protrudes from the surface of the magnetic pole core 61c at one end in the longitudinal direction, facing the field coil 65b. The magnetic pole core 61c is fixed to the rotor base 61a with an adhesive or the like, with the jaw 61e fitted into the magnetic pole core holding portion 61d. Every other magnetic pole core 61c is attached in a different direction.

[0046] The rotor base 61a is provided on the outer side around the axis of the shaft base 20 inserted through the insertion hole. The rotor base 61a is fixed to the shaft base 20 at the periphery of the insertion hole, and is configured to rotate in the same direction as the shaft base 20 as the shaft base 20 rotates.

[0047] 2, the stator 62 is provided on the outer side of the shaft base 20 around the axis thereof and in a position facing the rotor 61. The stator 62 is provided at an interval from the rotor 61 in the axial direction of the shaft base 20.

[0048] The stator 62 of this embodiment includes a plurality of (24 in this embodiment) stator parts 62 a arranged in a ring shape. The stator parts 62 a here refer to the components (individual pieces) that make up the stator 62.

[0049] 7, the stator part 62a includes a stator core 62c and a concentrated winding stator coil 62d wound around the stator core 62c. In this embodiment, an E-shaped core is used as the stator core 62c, and copper windings are used as the stator coil 62d.

[0050] The stator core 62c is made of laminated steel plates, which are made by stacking electromagnetic steel plates. The laminated steel plates allow for easy manufacturing. The use of an E-shaped core makes the stator coil 62d less susceptible to damage during assembly and transportation, making assembly easier.

[0051] By using an E-shaped core as an outer core, the stator coil 62d can be surrounded and held against the electromagnetic force generated by slot leakage magnetic flux acting on the stator coil 62d, making it difficult for the stator coil 62d to move. This makes it possible to avoid the effects of coil vibration, such as a reduction in insulation life. Another advantage is that the heat dissipation surface can be increased, improving cooling performance. Note that a T-shaped core can also be used for the stator core 62c.

[0052] The exciter 65 is a member that excites the magnetic pole core 61c. As shown in Fig. 8(a), the exciter 65 of this embodiment includes a plurality of excitation cores 65a arranged in a ring shape and an annular field coil 65b provided along the plurality of excitation cores 65a.

[0053] As shown in Figure 8(b), the excitation core 65a can be a block core, but in this embodiment, it is a rectangular parallelepiped member that can be made from laminated steel sheets formed by pressing and laminating electromagnetic steel sheets. Using pressed laminated steel sheets to form the magnetic pole core 61c has the advantage of being easy to manufacture. The top surface of the excitation core 65a is provided with a recessed coil placement portion 65c in which the field coil 65b is housed.

[0054] The field coil 65b is a coil that excites the magnetic pole core 61c. In this embodiment, the field coil 65b is an annular coil that is wound to have a substantially rectangular cross-sectional shape whose thickness (axial) dimension is smaller than its width (radial) dimension.

[0055] The field coil 65b is disposed at a position spanning the coil arrangement portions 65c of the multiple excitation cores 65a arranged in a ring shape. The field coil 65b does not rotate but remains stationary within the coil arrangement portions 65c of the multiple excitation cores 65a.

[0056] The field coil 65b is arranged so that its bottom surface contacts the excitation core 65a, specifically, so that the bottom surface of the field coil 65b contacts the upper surface of the coil arrangement portion 65c of the excitation core 65a. The contact here includes not only direct contact between the two, but also indirect contact via adhesive, varnish, a thin insulating member made of thin-walled resin, etc.

[0057] By bringing a part of the field coil 65b (in the illustrated example, the bottom surface) into contact with the excitation core 65a, the heat generated in the field coil 65b is transferred with low thermal resistance over a large surface area (contact area).

[0058] This action improves the heat dissipation of the field coil 65b, lengthening the time constant for temperature rise, and making it easier to respond to the short-term maximum torque required to stop the motor quickly in the event of a malfunction or strong wind by passing a short-term maximum current through the field coil 65b. This effect is particularly necessary for wind power generation, and is an advantageous effect not available in conventional technology.

[0059] 9A, the stator part 62a and the excitation core 65a in this embodiment are unitized by being connected at one longitudinal end thereof by a connecting member (hereinafter referred to as "non-magnetic connecting member") 66 made of a non-magnetic material. The non-magnetic connecting member 66 can be fixed to the stator part 62a and the excitation core 65a with fasteners such as bolts so that it can be attached and detached.

[0060] Between the connected stator part 62a and the exciter core 65a, a space G is provided that is large enough to accommodate the thickness of the rotor 61. When the rotor 61 is fitted into this space G, as shown in Figure 9(b), a first air gap G1 is formed between the rotor 61 and the stator 62, and a second air gap G2 is secured between the rotor 61 and the exciter 65.

[0061] A support base 67 is provided around the axis of the shaft base 20 on the outer side thereof so as not to rotate together with the shaft base 20. The support base 67 (FIG. 2) in this embodiment is disk-shaped and has an insertion hole in its center through which the shaft base 20 can be inserted.

[0062] In the band-shaped portion of the support base 67 excluding the insertion holes, space is provided in which a U-shaped connected unit (hereinafter referred to as a "connecting unit") U including a stator part 62a, an excitation core 65a and a non-magnetic connecting member 66 can be arranged, and multiple connecting units U are arranged in a ring shape in the space.

[0063] The stator parts 62a in this embodiment can be individually removed and replaced by removing the non-magnetic connecting members 66. Specifically, as shown in Figures 10(a) and 10(b), the non-magnetic connecting members 66 are removed from the stator part 62a and the excitation core 65a, and then the stator part 62a is moved outward in the radial direction of the support base 67 (in other words, in a direction intersecting the axial direction of the shaft base 20), thereby allowing the stator part 62a to be removed.

[0064] In addition, the stator part 62a can be attached by first connecting it to a non-magnetic connecting member 66, then placing the stator part 62a above the magnetic pole core 61c, and then fixing the non-magnetic connecting member 66 to the excitation core 65a.

[0065] The procedure for attaching and removing the stator part 62a described here is an example, and the stator part 62a can also be attached and removed using procedures other than those described above.

[0066] <Operation of the power generating device of this embodiment> In the power generating device configured as described above, when a direct current is supplied to the field coil 65b, the magnetic pole core 61c is excited via the first air gap G1, and a magnetic circuit is formed between the excitation core 65a, the magnetic pole core 61c, and the stator part 62a, through which the magnetic flux generated by the excited field coil 65b passes.

[0067] 11, the magnetic flux generated by the excited field coil 65b passes from the excitation core 65a through the magnetic pole core 61c (referred to as the "first magnetic pole core 61x" for convenience of explanation), passes through the stator core 62c via the second air gap G2, and interlinks with the stator coil 62d. Here, because the magnetic pole cores 61c are arranged with a phase shift in the circumferential direction, the magnetic flux then changes position in the circumferential direction in the stator core 62c, passes through the magnetic pole core 61c (referred to as the "second magnetic pole core 61y" for convenience of explanation), and forms a magnetic circuit that takes a path that circumferentially returns to the excitation core 65a. The magnetic flux direction is reversed in the axial direction with a phase difference in the circumferential direction when entering the stator core 62c and when returning from the stator core 62c, and is excited to the north and south poles as viewed from the stator 62.

[0068] When the magnetic pole core 61c is excited and the rotary wind turbine 30 rotates in response to wind, the resulting rotational force rotates the shaft base 20, which in turn rotates the rotor 61 fixed to the shaft base 20. When the rotor 61 rotates, the torque of the magnetic pole core 61c is transmitted as a reaction to the stator core 62c due to the electromagnetic coupling between the magnetic pole core 61c and the stator 62 during power generation, and electricity is generated using this as power generating torque.

[0069] <Relationship between Magnetic Poles and Stator Coils> The number of magnetic poles (magnetic pole cores) 61c and stator coils 62d is set to satisfy the following formula: Formula (1) Magnetic poles: Stator coils = 2N ((6n±1): 6n) where N is a natural number and n is a power of 2 including 1 (1, 2, 4, 8, 16, ...).

[0070] In this power generating device, the number of magnetic poles 61c is 2N (6n+1), where N = 1 and n = 2. Therefore, the number of magnetic poles 61c is 26, and the number of stator coils 62d is 24.

[0071] At this time, the positional relationship between the magnetic poles 61c and the stator coils 62d is as shown in the development view of Fig. 12(a) As described above, there are 24 stator coils 62d, numbered from the 1st coil to the 24th coil.

[0072] Twenty-six magnetic poles 61c are arranged facing the stator coil 62d so that N and S poles alternate. In the illustrated state, the first magnetic pole, which is an N pole, is located at a position facing the first coil. The magnetic pole 61c moves leftward relative to the stator coil 62d as viewed in the figure. The centers of the first coil and the first magnetic pole are aligned. At this time, the electrical angle phase of the electromotive force induced by the first coil is set to 0 degrees. The second magnetic pole, which is an S pole, is located at a position facing the second coil, but the centers of the second coil and the second magnetic pole are offset. In this embodiment, the ratio of the number of poles to the number of stator coils is 26:24, so the magnetic pole pitch τ ｍ and coil pitch τ ｃ is τ ｍ :τ ｃ Therefore, the center position of the second magnetic pole is τ ｍ × (26-24) / 24, or τm × 1 / 12. This is expressed in electrical angle phase as π × 1 / 12, or 15 degrees. Note that the first coil faces the north pole while the second coil faces the south pole, but the first coil is clockwise while the second coil is counterclockwise. Therefore, the electromotive force induced in the second coil is 15 degrees out of phase with the electromotive force induced in the first coil. Similarly, the electromotive force induced in the third coil is 30 degrees out of phase with the electromotive force induced in the first coil. Furthermore, the electromotive force induced in the fourth coil is 45 degrees out of phase with the electromotive force induced in the first coil. The amounts of electrical angle phase shift of the other coils with respect to the first coil are as shown in FIG. 12(b).

[0073] As shown in FIGS. 12(b) and 12(c), the first, fifth, and ninth coils form a first three-phase coil (U1, V1, W1). Similarly, the second, sixth, and tenth coils form a second three-phase coil (U2, V2, W2). The third, seventh, and eleventh coils form a third three-phase coil (U3, V3, W3). The fourth, eighth, and twelfth coils form a fourth three-phase coil (U4, V4, W4). The thirteenth, seventeenth, and twenty-first coils form a fifth three-phase coil (U5, V5, W5). The fourteenth, eighteenth, and twenty-second coils form a sixth three-phase coil (U6, V6, W6). The fifteenth, nineteenth, and twenty-third coils form a seventh three-phase coil (U7, V7, W7). The 16th coil, the 20th coil, and the 24th coil form an eighth three-phase coil (U8, V8, W8).

[0074] The first three-phase coil (U1, V1, W1) and the fifth three-phase coil (U5, V5, W5) have the same electrical angle phase and output in-phase three-phase AC. These first three-phase coil and the fifth three-phase coil are connected in parallel as shown in FIG. 12(c) to form one three-phase coil pair. Similarly, the second three-phase coil (U2, V2, W2) and the sixth three-phase coil (U6, V6, W6), which are in-phase, are connected in parallel to form one three-phase coil pair. The third three-phase coil (U3, V3, W3) and the seventh three-phase coil (U7, V7, W7), which are in-phase, are connected in parallel to form one three-phase coil pair. The fourth three-phase coil (U4, V4, W4) and the eighth three-phase coil (U8, V8, W8), which are in-phase, are connected in parallel to form one three-phase coil pair. The neutral wire of each three-phase coil pair is independent of the others. The three-phase coils constituting each three-phase coil pair may be connected in series.

[0075] <Configuration of Power Circuit> The power generation device includes a power circuit 80 shown in Fig. 13. As described above, four three-phase coil pairs 81-1 to 81-4 formed from 24 stator coils output power to a DC power distribution system 83 via three-phase rectifier circuits 82-1 to 82-4. Specifically, the first three-phase coil pair 81-1 is connected to a three-phase AC input terminal 84 of a first three-phase rectifier circuit 82-1, and the three-phase AC output from the first three-phase coil pair 81-1 is input to the first three-phase rectifier circuit 82-1 and rectified. The rectified current is output from a DC output terminal 85-1 of the first three-phase rectifier circuit 82-1. Similarly, the second to fourth three-phase coil pairs 81-2 to 81-4 are connected to the three-phase AC input terminals 84 of the second to fourth three-phase rectifier circuits 82-2 to 82-4, respectively, and rectified currents are output from the DC output terminals 85-2 to 85-4 of the three-phase rectifier circuits 82-2 to 82-4. The DC output terminals 85-1 to 85-4 of the first to fourth three-phase rectifier circuits 82-1 to 82-4 are connected in parallel to form a single composite DC output terminal 86. Therefore, the powers output from the DC output terminals 85-1 to 85-4 of the first to fourth three-phase rectifier circuits 82-1 to 82-4 are combined at the composite DC output terminal 86. 13, for example, the first three-phase coil pair 81-1 outputs a three-phase AC signal obtained by combining three-phase AC signals from a three-phase coil (U1, V1, W1) and a three-phase coil (U5, V5, W5), but because the phases of both three-phase coils (U1, V1, W1) and (U5, V5, W5) are the same, the phases are shown as (U1, V1, W1) for convenience. The same applies to the three-phase AC signals of the other three-phase coil pairs 81-2 to 81-4.

[0076] Each of the three-phase rectifier circuits 82-1 to 82-4 is a diode bridge circuit in which six diodes are bridge-connected as shown in FIG. 14, and is an element formed as a single package.

[0077] As shown in Figure 13, an isolated step-up DC / DC converter 87 is connected to the composite DC output terminal 86. The isolated step-up DC / DC converter 87 can be configured, for example, as a dual active bridge (DAB) circuit as shown in Figure 15. A DAB circuit is a bidirectional isolated step-up DC / DC converter that has a bridge on each of the primary and secondary sides of a transformer and can convert power not only from the primary side to the secondary side but also from the secondary side to the primary side by controlling the phase of the primary side and the phase of the secondary side. Note that the isolated step-up DC / DC converter 87 does not necessarily have to be a bidirectional isolated step-up DC / DC converter like a DAB circuit, and can be any of various DC / DC converters known in the art.

[0078] This isolated step-up DC / DC converter 87 boosts the output from the three-phase rectifier circuit 82 and outputs it to the DC distribution system 83. The isolated step-up DC / DC converter 87 of this embodiment boosts 400 V to 1.2 kV and outputs it. Naturally, the input voltage and output voltage of the isolated step-up DC / DC converter 87 can also be other magnitudes. Furthermore, the isolated step-up DC / DC converter 87 is not necessarily required, and the output from the combined DC output terminal 86 of the three-phase rectifier circuit 82 may be output directly to the DC distribution system 83.

[0079] 16, the current 88-1 output from the DC output terminal 85-1 of the first three-phase rectifier circuit 82-1 is accompanied by a rectification ripple that fluctuates in a 60-degree cycle. The current 88-2 output from the DC output terminal 85-2 of the second three-phase rectifier circuit 82-2 is also accompanied by a rectification ripple that fluctuates in a 60-degree cycle. However, because the three-phase AC (U2, V2, W2) output from the second three-phase coil pair 81-2 is shifted in phase by 15 degrees from the three-phase AC (U1, V1, W1) output from the first three-phase coil pair 81-1, the current 88-2 output from the second three-phase rectifier circuit 82-2 has a rectification ripple that fluctuates in a 15-degree cycle with respect to the current 88-1 output from the first three-phase rectifier circuit 82-1. Similarly, the current 88-3 output from the third three-phase rectifier circuit 82-3 has a rectification ripple that fluctuates periodically with a 30-degree phase shift, and the current 88-4 output from the fourth three-phase rectifier circuit 82-4 has a rectification ripple that fluctuates with a 45-degree phase shift. When currents 88-1 to 88-4, each with a rectification ripple that is 15 degrees out of phase with each other, are connected in parallel and combined, a combined DC current 89 is obtained, as shown in FIG. 15 . The ripple in the combined DC current 89 is significantly reduced, resulting in an output that is closer to DC. The average voltage is also increased. As a result, the output at the combined DC output terminal 86 has less ripple and a higher average output. The effect of reducing ripple can also be achieved by connecting the DC output terminals 85-1 to 85-4 of the three-phase rectifier circuits 82-1 to 82-4 in series.

[0080] As shown in FIG. 12 , a smoothing capacitor 90 is disposed between the combined DC output terminal 86 and the isolated step-up DC / DC converter 87. This smoothing capacitor 90 charges when the voltage of the combined DC 89, which fluctuates due to rectification ripple, is high, and discharges when that voltage is low. This further reduces the ripple remaining in the combined DC 89, allowing a smoothed current with less ripple to be input to the isolated step-up DC / DC converter 87. Generally, the larger the voltage fluctuation, the larger the capacity of this smoothing capacitor 90. As described above, in this power generation device, the rectification ripple is significantly reduced by connecting and combining multiple voltages with out-of-phase rectification ripples, allowing the use of a capacitor with a relatively small capacity. This contributes to the miniaturization of the entire device.

[0081] Furthermore, by providing the isolated step-up DC / DC converter 87, the three-phase coil pair 81, the three-phase rectifier circuit 82, the smoothing capacitor 90, and their terminals can be electrically isolated from the DC power distribution system 83. Therefore, the ground voltage of the three-phase coil pair 81 (stator core 62c, stator coil 62d), the three-phase rectifier circuit 82, the smoothing capacitor 90, etc. can be set to a relatively low voltage of 400 V or less. This simplifies the insulation of the output terminal and coil end of the stator coil 62d, making them smaller and less expensive. Furthermore, since the three-phase rectifier circuit 82 can use general-purpose elements available for general industrial use, the overall power generation system can be manufactured at low cost.

[0082] The isolated step-up DC / DC converter 87 is designed to boost 400 V to 1.2 kV during normal operation, but is capable of controlling the voltage at its converter input terminal 93. For example, if the output of the generator 60 is below a predetermined threshold output due to insufficient wind power or other reasons, the three-phase AC voltage output from each three-phase coil pair 81 may become lower than the voltage of the smoothing capacitor 90. This prevents the diodes of the three-phase rectifier circuit 82 from turning on, preventing power from being supplied to the isolated step-up DC / DC converter 87. In such a case, the isolated step-up DC / DC converter 87 reduces the voltage at its converter input terminal 93, turning on the diodes of the three-phase rectifier circuit 82 and allowing power to be supplied to the isolated step-up DC / DC converter 87. At this time, the isolated step-up DC / DC converter 87 increases the boost voltage so as to maintain 1.2 kV at the converter output terminal 94.

[0083] Alternatively, the field current supplied to the field coil 65b may be stopped when the output of the generator 60 is below a predetermined threshold. Stopping the field current prevents the magnetic pole core 61c from being excited, reducing cogging torque and iron loss due to the magnetic poles. This facilitates rotation of the rotor 61, allowing the rotary wind turbine 30 to rotate even in relatively weak winds. When the wind speed increases and reaches the cut-in wind speed, the supply of field current to the field coil 65b is resumed to start power generation. Because the field current has been stopped up to this point, the temperature of the field coil remains low. Therefore, a large current can be passed through the field coil 65b for a short period of time. Therefore, when starting low-speed power generation, the field current is increased compared to normal operation to maximize the generated voltage. At the same time, the boost ratio of the isolated step-up DC / DC converter 87 is increased to reduce the voltage at the converter input terminal. This makes it easier for the diodes in the three-phase rectifier circuit 82 to turn on, enabling the rotary wind turbine 30 to generate power even at slower rotation speeds.

[0084] Second Embodiment A power generating apparatus according to a second embodiment of the present invention is a larger power generating apparatus having 156 magnetic poles 61c and 144 stator cores 62c and stator coils 62d, as shown in Fig. 16. The number of magnetic poles 61c and stator coils 62d corresponds to the case where N = 6 and n = 2 in the above-mentioned formula (1). In this embodiment, the stator cores 62c have a T-shaped cross section, and the magnetic poles 61c are permanent magnets. The other structures are the same as those of the first embodiment, and are therefore omitted from Fig. 17.

[0085] In this power generation device, six sets of magnetic poles 61c and stator coils 62d are arranged in a ring shape, as shown in FIG. 12(b). A power circuit 80′ in this embodiment includes six isolated step-up DC / DC converters 87 connected in series, as shown in FIG. 18. In this embodiment, 144 stator coils 62d are provided, and 24 stator coils 62d arranged adjacently as shown in FIG. 12(b) constitute one three-phase coil group 91, each consisting of four three-phase coil pairs 81. The four three-phase coil pairs 81 included in this set of three-phase coil group 91 are configured to output three-phase AC currents that are shifted in phase by 15 degrees from each other. Similarly, another set of four three-phase coil pairs 81 (not shown in FIG. 18) is configured with another 24 stator coils 62d. The four three-phase coil pairs included in this set of three-phase coil group are also configured to output three-phase AC currents that are shifted in phase by 15 degrees from each other. Similarly, four more three-phase coil groups (omitted from FIG. 17 ) are configured. In this way, a total of six three-phase coil groups 91 (24 three-phase coil pairs 81) are formed. The number of three-phase coil groups 91 is the same as N in equation (1), and the number of three-phase coil pairs 81 included in each group is the same as 2n.

[0086] The four three-phase coil pairs 81 included in one three-phase coil group 91 are each connected to a three-phase rectifier circuit 82. Therefore, the power circuit 80′ is provided with 24 three-phase rectifier circuits 82, the same number as the three-phase coil pairs 81. Furthermore, of the 24 three-phase rectifier circuits 82, four three-phase rectifier circuits 82 constitute one set of three-phase rectifier circuit groups 92, for a total of six sets of three-phase rectifier circuit groups 92.

[0087] Each set of three-phase rectifier circuit groups 92 has one composite DC output terminal 86 formed by connecting the DC output terminals 85 of the four (2n) three-phase rectifier circuits 82 included in that set of three-phase rectifier circuit groups 92 in parallel with each other. The powers output from the DC output terminals 85 of the four three-phase rectifier circuits 82 in each set of three-phase rectifier circuit groups 92 are combined at the composite DC output terminal 86. A converter input terminal 93 of one isolated step-up DC / DC converter 87 is connected to each composite DC output terminal 86. A smoothing capacitor 90 is disposed between the composite DC output terminal 86 and the isolated step-up DC / DC converter 87.

[0088] As described above, the converter output terminals 94 of the six isolated step-up DC / DC converters 87 are connected in series with each other. In this embodiment, during normal operation, each isolated step-up DC / DC converter 87 is set to step-up 400 V to 1.2 kV. Therefore, 7.2 kV, which is six times 1.2 kV, is output to the DC distribution system 83. The number of isolated step-up DC / DC converters 87 is the same as N in equation (1).

[0089] By providing the isolated step-up DC / DC converter 87, the three-phase coil pair 81, the three-phase rectifier circuit 82, the smoothing capacitor 90, and their terminals can be electrically isolated from the DC power distribution system 83. Therefore, the ground voltage of the three-phase coil pair 81 (stator core 62c, stator coil 62d), the three-phase rectifier circuit 82, the smoothing capacitor 90, and the like can be kept relatively low, at 400 V or less. In particular, even though the voltage of the DC power distribution system 83 becomes high (e.g., 7.2 kV) when multiple isolated step-up DC / DC converters 87 are connected in series, the ground voltage of the three-phase coil pair 81, etc. can remain at 400 V or less. This simplifies the insulation of the output terminal and coil end of the stator coil 62d, thereby enabling their miniaturization and cost reduction. Furthermore, since the three-phase rectifier circuit 82 can be made of general-purpose components available for general industrial use, the overall power generation system can be manufactured at low cost.

[0090] As in a power circuit 80″ shown in FIG. 19 , a three-phase rectifier circuit included in a three-phase rectifier circuit group 92″ connected to one of a plurality of isolated step-up DC / DC converters 87 may be used as a three-phase inverter 95. This three-phase inverter 95 may be a commonly used voltage-source inverter (VSI) as shown in FIG. 20 . This three-phase inverter 95 has six transistors, and by controlling the switching timing of each transistor, any three-phase AC can be output from an output terminal 96. The three-phase AC currents output from each three-phase inverter 95 to each three-phase coil pair 81 of the three-phase coil group 91" can be shifted in phase by 15 degrees from each other. Specifically, with respect to the three-phase AC output from the first three-phase inverter 95-1 as a reference, the three-phase AC current output from the second three-phase inverter 95-2 can be shifted in phase by 15 degrees, the three-phase AC current output from the third three-phase inverter 95-3 can be shifted in phase by 30 degrees, and the three-phase AC current output from the fourth three-phase inverter 95-4 can be shifted in phase by 45 degrees. This phase shift is the same as the phase shift of the three-phase ACs output from each three-phase coil pair 81 during power generation. By shifting the phases in this way, torque ripples caused by the three-phase AC currents can be mutually canceled out or smoothed, thereby reducing vibrations generated in the rotary wind turbine 30, the shaft base 20, etc.

[0091] In particular, in large wind power generators, wind power cannot be effectively converted into rotational force until the rotary wind turbine 30 rotates at a certain speed or higher, resulting in inefficient power generation. In such cases, DC power is supplied to the three-phase inverters 95 via the bidirectional isolated step-up DC / DC converter 87, and each three-phase inverter 95 converts the DC power into three-phase AC and supplies it to each three-phase coil pair 81, thereby applying rotational torque to the rotor 61 to rotate it. This rotational force assists the rotation of the shaft base 20 and the rotary wind turbine 30 connected to the rotor 61. When the rotation of the rotary wind turbine 30 reaches a certain speed or higher, the power supply from the three-phase inverters 95 to the three-phase coil pairs 81 is stopped. After this, each three-phase inverter 95 stops switching its transistors and functions as a rectifier circuit similar to the three-phase rectifier circuit 82 consisting of a diode bridge. Therefore, the three-phase AC generated by the three-phase coil pair 81 connected to the three-phase inverter 95 is rectified by the three-phase inverter 95 and output to the isolated step-up DC / DC converter 87''.

[0092] The three-phase inverter 95 is connected to an isolated step-up DC / DC converter 87" that is connected to the position where the lowest voltage is obtained among the plurality of isolated step-up DC / DC converters 87 connected in series. In the above embodiment, all four three-phase rectifier circuits that make up the three-phase rectifier circuit group 92" connected to this isolated step-up DC / DC converter 87" are three-phase inverters 95. However, if there is a margin in the driving capacity of each three-phase inverter 95, only three, two or one three-phase rectifier circuit 82 may be three-phase inverters 95. Alternatively, if the driving capacity of only four three-phase inverters 95 is insufficient, In this case, three-phase rectifier circuits 82 included in other three-phase rectifier circuit groups 92 may also be three-phase inverters 95. The number of three-phase rectifier circuits 82 to be configured as three-phase inverters 95 can be appropriately determined taking into consideration various conditions such as the size of the rotary wind turbine 30 and the amount of power supplied to the three-phase inverters 95. Furthermore, it is not necessary to configure the three-phase rectifier circuit 82 connected to the isolated step-up DC / DC converter 87″ connected to the position where the voltage is lowest as the three-phase inverter 95, and three-phase rectifier circuits 82 connected to isolated step-up DC / DC converters 87 connected to other positions may be configured as three-phase inverters 95. In the first embodiment, some or all of the three-phase rectifier circuits 82 may be configured as three-phase inverters 95.

[0093] Third Embodiment As shown in FIG. 21 , a power generating device according to a third embodiment of the present invention is a large-scale power generating device equipped with 156 magnetic poles (permanent magnets) 61c and 144 stator cores 62c and stator coils 62d. The number of magnetic poles 61c and stator coils 62d corresponds to the case where N = 6 and n = 2 in the above-described formula (1). The stator cores 62c and stator coils 62d are divided into eight groups, each group consisting of 24 cores. The stator cores 62c and stator coils 62d of each group are arranged in a hexagonal shape facing the magnetic poles 61c. While the magnetic poles 61c are arranged in a circular ring shape, the stator coils 62d are arranged in a hexagonal ring shape. In this embodiment, the stator cores 62c also have a T-shaped cross section. The magnetic poles 61c are permanent magnets. Other structural features are similar to those of the first embodiment and are therefore omitted from FIG. 21 . Even when this arrangement is adopted, the power generating device can operate in the same manner as the second embodiment.

[0094] The configurations of the above-described embodiments are merely examples, and the configuration of the power generation device of the present application is not limited to the configurations of the above-described embodiments. The power generation device of the present application can be modified, such as by omitting, replacing, or adding components, to the extent that the intended purpose can be achieved. For example, the following modifications are envisioned.

[0095] The number of magnetic poles (magnetic pole cores, permanent magnets) 61c and stator coils 62d can be changed as appropriate in accordance with equation (1). The number of three-phase coil pairs 81 included in one three-phase coil group 91 is 2n, and the phase difference between these three-phase coil pairs 81 is given by 30 / n. Therefore, as n increases, the number of three-phase coil pairs 81 included in one three-phase coil group 91 increases, the phase difference decreases, and the amplitude of the rectification ripple included in the output power rectified and combined by the three-phase rectifier circuit 82 decreases. The number of three-phase coil groups 91, and therefore the number of isolated step-up DC / DC converters 87, is N. Therefore, as N increases, the number of isolated step-up DC / DC converters 87 connected in series increases, and the final output voltage to the DC power distribution system 83 increases. Taking these characteristics into consideration, the values ​​of N and n in equation (1) can be changed as desired. In addition, in all of the above embodiments, the number of magnetic poles 61c in equation (1) is set to 2N(6n+1), so that the number of magnetic poles 61c is greater than the number of stator coils 62d, but the number of magnetic poles 61c can also be set to 2N(6n-1), so that the number of magnetic poles 61c is less than the number of stator coils 62d.

[0096] In the above embodiment, an example is given in which the magnetic pole cores 61c are arranged in a ring shape on the rotor base 61a. However, as shown in Figures 22(a) and 22(b), the rotor base 61a may be configured such that the inner diameter and outer diameter are connected at a position surrounding the magnetic pole cores 61c in units of a multiple of two magnetic pole cores 61c (for example, one pole pair pitch, etc.), and cutout portions 61f that interrupt the current path may be provided at locations where a current path is formed that surrounds the magnetic pole cores 61c (61x, 61y) for one pole alone with respect to the axial magnetic flux.

[0097] By providing such cutouts 61f, the integral value of the magnetic flux passing through the loop of the pole component of the main magnetic flux between the cutouts 61f and its harmonic components can be set to zero, and as a result, eddy currents of the pole component that link with the rotor base 61a can be suppressed. When such cutouts 61f are provided, the rotor base 61a can be made of a metal material or the like.

[0098] Preferably, a non-magnetic insulating material such as FRP is embedded in the cutout 61f to form a composite with the metal, thereby preventing a decrease in strength and rigidity even when the cutout 61f is provided. Note that the same effect can be expected by providing a metal rib instead of the cutout 61f.

[0099] In the above embodiment, the force-receiving rotating body is an example of a rotary wind turbine 30, but the force-receiving rotating body may be anything other than a rotary wind turbine 30 as long as it rotates by receiving the force of a fluid (gas or fluid), specifically, natural energy such as wind power or water power (including tidal power).

[0100] In the above embodiment, an example is shown in which one generator 60 is provided, but two or more generators 60 may be provided in the axial direction of the shaft base 20 as shown in Fig. 23. In this case, it is preferable that the two or more generators 60 are arranged so that the magnetic forces of the rotors 61 of adjacent generators 60 cancel each other out.

[0101] When two or more generators 60 are provided, the orientation of each generator 60 can be the same or opposite. Furthermore, when two or more generators 60 are provided, a bearing support 40 and a bearing module 50 can be provided for each generator 60, but it is also possible to provide a bearing support 40 and a bearing module 50 only for the lowest generator 60, and omit these for the second and subsequent generators. Note that in the present invention, the reason for providing two or more generators 60 is to increase the amount of power generation, not to reduce torque ripple.

[0102] In the above embodiment, the rotary wind turbine 30 is a vertical axis type, but the rotary wind turbine 30 may be a horizontal axis type as shown in Fig. 24. The rotary wind turbine 30 may be a lift type or a drag type. Note that Fig. 24 shows a case where two generators 60 are provided in the axial direction of the shaft base 20, but the number of generators 60 may be more or less than two.

[0103] In the above embodiment, a floating wind power generation system in which the power generation system floats on water is used as an example, but the power generation system of the present invention can also be configured as an offshore (water-based) power generation system installed on water such as the ocean or a lake, or as a land-based power generation system installed on land.

[0104] In the above embodiment, the power generation device is a floating vertical axis type wind turbine power generation device as an example, but the power generation device can also be configured as a floating vertical axis type tidal power generator as shown in Figure 25.

[0105] The embodiments disclosed in this application are merely examples and are not intended to limit the technical scope of the power generation device of the present invention. The technical scope of the power generation device of the present invention is defined by the claims. The technical scope of the present invention also includes equivalents to the claims.

[0106] The power generation device disclosed in the present application can be applied to various power generation devices, and in particular can be suitably used as a floating vertical axis type wind power generation device that floats on the ocean, such as on the sea or on a lake.

[0107] REFERENCE SIGNS LIST 10 Floating body 20 Shaft base 30 Rotary wind turbine (force-receiving rotor) 31 Shaft 32 Arm 33 Blade 40 Bearing support 50 Bearing module 51 Bearing base 51a Mooring line attachment portion 51b Locking hole 52 First load receiver 53 Second load receiver 60 Generator 61 Rotor 61a Rotor base 61b Permanent magnet 61c Magnetic pole core, magnetic pole 61d Magnetic pole core holding portion 61e Jaw portion 61f Rib 61x First magnetic pole core 61y Second magnetic pole core 62 Stator 62a Stator part 62b Module constituent body 62c Stator core 62d Stator coil 65 Exciter 65a Exciter core 65b Field coil 65c Coil arrangement portion 66 Non-magnetic connecting member 67 Support base 68 Unit holding portion 70 Mooring rope 80, 80', 80" Power circuit 81 (81-1 to 81-4) Three-phase coil pair 82 (82-1 to 82-4) Three-phase rectifier circuit 83 DC distribution system 84 Three-phase AC input terminal 85 (85-1 to 85-4) DC output terminal 86 Combined DC output terminal 87 Insulated step-up DC / DC converter 88-1 to 88-4 Current 89 Combined DC 90 Smoothing capacitor 91, 91" Three-phase coil group 92, 92" Three-phase rectifier circuit group 93 Converter input terminal 94 Converter output terminal 95 (95-1 to 95-4) Three-phase inverter 96 Output terminal G Space G1 First air gap G2 Second air gap U Connecting unit τ ｃ Coil pitch τ ｍ Pole pitch

Claims

1. A generator having a stator having a plurality of stator coils arranged in a ring shape, and a rotor having a plurality of magnetic poles arranged in a ring shape facing the stator coils, wherein each stator coil is formed by concentrated winding, the number of the plurality of magnetic poles and the plurality of stator coils is set to poles:stator coils = 2N ((6n±1):6n) (where N is a natural number and n is a power of 2 including 1), the plurality of stator coils constitute 4Nn three-phase coils, and 2Nn three-phase coil pairs are formed from two three-phase coils of the same phase among the 4Nn three-phase coils, and the phase of the three-phase AC output from each three-phase coil pair is shifted from the phase of the three-phase AC output from at least one of the other three-phase coil pairs; a plurality of three-phase rectifier circuits, each having a three-phase AC input terminal and a DC output terminal, and each three-phase rectifier circuit receiving a three-phase AC output from a corresponding one of the 2Nn three-phase coil pairs at its three-phase AC input terminal; and a power generation device configured to combine powers output from the DC output terminals of each three-phase rectifier circuit and output the combined power to a DC power distribution system.

2. The power generating device according to claim 1, further comprising one or more isolated step-up DC / DC converters that step up the power output from the DC output terminals of the plurality of three-phase rectifier circuits.

3. The power generation device according to claim 2, wherein at least one of the one or more isolated step-up DC / DC converters is capable of controlling the voltage at the converter input terminal of the at least one isolated step-up DC / DC converter, and when the output of the generator is equal to or lower than a predetermined threshold output, the at least one isolated step-up DC / DC converter reduces the voltage at the converter input terminal.

4. The power generating device according to claim 3, wherein at least one of said one or more isolated step-up DC / DC converters is a bidirectional isolated step-up DC / DC converter, at least one of said three-phase rectifier circuits connected to said bidirectional isolated step-up DC / DC converter is a three-phase inverter, and said three-phase inverter converts DC power supplied via said bidirectional isolated step-up DC / DC converter into three-phase AC power and supplies the AC power to said generator, thereby driving and rotating said rotor.

5. A power generating device according to claim 1, wherein N is 2 or more, the plurality of three-phase rectifier circuits constitute N sets of three-phase rectifier circuit groups each made up of 2n three-phase rectifier circuits, each set of three-phase rectifier circuit groups having one composite DC output terminal formed by interconnecting the DC output terminals of the 2n three-phase rectifier circuits included in that set of three-phase rectifier circuit groups, and the power output from the composite DC output terminals of each set of three-phase rectifier circuit groups is composited and output to the DC power distribution system.

6. The power generation device according to claim 5, further comprising a plurality of isolated step-up DC / DC converters, each having a converter input terminal connected to the combined DC output terminal of a corresponding one of the N three-phase rectifier circuit groups, and a converter output terminal, and each converter output terminal is connected in series with the other converter output terminals.

7. The power generating device according to claim 6, wherein the isolated step-up DC / DC converter connected to the position where the voltage is lowest among the plurality of isolated step-up DC / DC converters is a bidirectional isolated step-up DC / DC converter, at least one of the plurality of three-phase rectifier circuits constituting the three-phase rectifier circuit group connected to the isolated step-up DC / DC converter connected to the position where the voltage is lowest is a three-phase inverter, and the three-phase inverter converts DC power supplied via the bidirectional isolated step-up DC / DC converter into three-phase AC power and supplies the three-phase AC power to the generator, thereby driving and rotating the rotor.

8. The power generation device according to claim 6, wherein the voltage generated between the generator and the converter input terminals of each isolated step-up DC / DC converter is 400 V or less, and the voltage generated at the converter output terminals of each isolated step-up DC / DC converter is 1.2 kV or more.

9. The power generating device according to claim 1, comprising: a shaft base connected to the generator; and a rotary wind turbine fixed to the shaft base, wherein the generator generates electricity by rotating the shaft base using wind force received by the rotary wind turbine.

Images