GB2549241A

GB2549241A - Rotating electric machine system or wind power generation system

Info

Publication number: GB2549241A
Application number: GB1512807.7A
Authority: GB
Inventors: Hori Masahiro; Kusuno Nobuhiro; Kimura Mamoru
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2014-07-25
Filing date: 2014-07-25
Publication date: 2017-10-18
Also published as: WO2016013097A1; GB201512807D0; JP5933123B1; JPWO2016013097A1; DE112014001206T5

Abstract

In order to reduce a weight imbalance, a rotating electric machine system is equipped with: a first rotating electric machine including a first stator having a first stator winding, and a first rotor having a first rotor winding and disposed on an inner diameter side of said first stator with a predetermined gap therebetween; a second rotating electric machine including a second stator having a second stator winding, and a second rotor having a second rotor winding and disposed on an inner diameter side of said second stator with a predetermined gap therebetween; a power converter electrically connected to said first rotor winding and said second rotor winding and disposed on the inner diameter side of at least either said first rotor or said second rotor; and capacitors provided in said power converter, and is characterized in that the number of said capacitors is a multiple of 3.

Description

DESCRIPTION

Title of Invention: ROTATING ELECTRICAL MACHINE SYSTEM AND WIND POWER GENERATION SYSTEM

Technical Field [0001]

The present invention relates to a rotating electrical machine system and a wind power generation system., particularly to a rotating electrical machine system and a wind power generation system, either of which is preferable to a system that is provided with a f irst rotating electrical machine (main generator) and a second rotating electrical machine (auxiliary generator), B a c k g; r o u n d A r t [0002]

In recent years, there has been a focus on a generation system that uses natural energy, as used in wind power generation, solar power generation, or the like, in order to prevent global warming. Among such generation systems, there are a great number of examples of using an alternating current excitation type rotating electrical machine as a generating apparatus in a wind power generation system in which wind power is used.

In a case of using an alternating current excitation type rotating electrical machine as a generating apparatus in a wind power generation system, it is necessary to supply excited power to a rotor winding in a rotating rotor during operation of the alternating current excitation type rotating electrical machine. To supply power to the rotor winding, usually, a slip ring and a brush are disposed, and conduction is provided by bringing the brush into contact with a rotating slip ring.

[0001]

However, the amount of energy tor performing generating operation in the wind power generation system is large, and when the slip ring and the brush sire disposed to supply excited power after the generating operation is performed, wearing of the brush proceeds, thus requiring periodical maintenance, [0005]

Incidentally, in the wind power generation system, the alternating current excitation type rotating electrical machine is installed in a nacelle on a tower of a windm.ilI, and periodical maintenance is necessarily performed in a limited space of the inside of the nacelle. Thus, reducing maintenance is required by, for example, making the alternating current excitation type rotating electrical machine brushless , [0006]

There is disclosed a technology for a brushless alternating current excitation type rotating electrical machine, for example, in PTL 1, The subject matter disclosed in PTL 1 is provided with a stator that includes a stator winding, a rotor that includes a rotor winding and is arranged on the inside diameter side of the stator with a set gap disposed therebetween, furthermore, a second rotating electrical machine that includes a second stator which includes a second stator winding and a second rotor which includes a second rotor winding and is arranged on the inside diameter side of the second stator with a set gap disposed therebetween, and a power converter that is electrically connected to the rotor winding and the second rotor winding. The power converter is arranged to rotate when the rotor is rotating. Accordingly, power can be supplied to the rotor of a first rotating electrical machine through the second rotating electrical machine, and the alternating current excitation type rotating electrical machine can be brushless.

Citation List

Patent Literature [ 0007) PTL 1: JP ~A~ 2 013-110 8 01 Summary of Invention I e c h n i. c a 1 Problem [0008] PTL 1 refers to arrangement of power converting modules. Three modules of a converter that are arranged in the rotor and are used for a three-phase winding can be divided into three modules. At this point, by installing the power converting modules equiaistantiy between spiders 13 inside the rotor at an interval of 120 degrees for each separate phase in the circumferential direction of the rotor, weight unbalance during the rotation of the rotor is resolved, and vibrations and the like do not occur. However, capacitors are necessary in the power converter to smooth a direct current voltage, and these capacitors also need to be arranged in the rotor. Here, arranging the capacitors without balancing the weight thereof is a cause of vibrations or eccentricity by rotation.

[0009] 'The invention is devised with consideration of the above points, and an object thereof is to provide a rotating electrical, machine system or a wind power generation system, either of which can reduce weight unbalance.

Solution to Problem [0010]

According to an aspect of the invention, in order to achieve the above object, there is provided a rotating electrical machine system including a first rotating electrical machine that includes a first stator which includes a first stator winding and a first rotor which includes a first rotor winding and is arranged on an inside diameter side of the first stator with a predetermined set gap interposed therebetween, a second rotating electrical machine that includes a second stator which includes a second stator winding and a second rotor which includes a second rotor winding and is arranged on an inside diameter side of the second stator with a predetermined set gap interposed therebetween, a power converter that is electrically connected to the first rotor winding and the second rotor winding and is arranged on the inside diameter side of at least any of the first rotor and the second rotor, and a capacitor that is included in the power converter, in which the number ot capacitors is a multiple of three .

[0011] .According to another aspect of the invention, there is provided a wind power generation system including a rotor that is rotated by receiving wind, the rotating electrical machine system that is connected to the rotor via a main shaft, a nacelle that accommodates the rotating electrical machine system, and a tower that supports the nacelle, in which each rotating electrical machine is rotated, by torque of the rotor, ana each stator winding is connected to a power system.

Advantageous Effects of Invention [0012]

According to the invention, it is possible to provide a rotating electrical- machine system that can reduce weight

Brief Description of Drawings [0013] [Fig. 1] Fig. 1 is a cross-sectional view illustrating the outline of a rotating electrical machine system in a first embodiment.

[Fig, 2] Fig. 2 is a circuit diagram illustrating a power converter circuit in the first embodiment, [Fig. 3] Fig. 3 is a perspective view illustrating a connection between a main generator, a rotor shaft, and six arms in the first embodiment, [Fig. 4] Fig. 4 is a circuit diagram illustrating one phase of the power converter circuit in the first embodiment.

[Fig. 5] Fig, 0 is a circuit diagram in which the form of one phase of the power converter circuit in the first embodiment is changed in order that one phase of the power converter circuit can be arranged in a power converter arrangement space, [Fig. 6] Fig. 6 is a circuit diagram in which the form of the power converter circuit in the first embodiment is changed in order that the power converter circuit can be arranged in the power converter arrangement space.

[Fiq, 71 Fiq. 7 is a perspective view illustrating a connection between a main generator, a rotor shaft, and 12 arms in a second embodiment.

[Fig. 8] Fig, 8 is a circuit diagram, illustrating a power converter circuit in the second embodiment.

[Fig. 9] Fig. 9 is a circuit diagram illustrating one phase: of the power converter circuit in the second embodiment, [Fig. 10] Fig. 10 is a circuit diagram in which the form of one: phase of the power converter circuit in the second embodiment is changed in order that one phase of the power converter circuit can be arranged in a power converter arrangement space .

[Fig. Ill Fig, 11 is a circuit diagram in which the form of the power converter circuit in the second, embodiment is changed in order that the power converter circuit can be arranged in the power converter arrangement space.

[Fig, 12] .Fig, 12 is a cross-sectional view illustrating a third embodiment of a rotating electrical machine of the invention.

[Fig. 13] Fig. 13 is a cross-sectional view illustrating the third embodiment of the rotating electrical machine of the invention.

[Fig. 141 Fig, 14 is a cross-sectional view illustrating a fourth embodiment of the rotating electrical machine of the invention.

[Fig, 15] Fig, 1 5 is a cross-sectional view illustrating a fifth embodiment of the rotating electrical machine of the invention, [Fig, lb] Fig. 1 € i s a cross-sectional view ii lust rat ing a sixth embodiment of the rotating electrical machine of the invention.

[Fig. 17] Fig, 17 is a schematic configuration diagram illustrating a wind power generation system to which the rotating electrical, machine system, of the invention is applied (seventh embodiment), [Fig. 18] Fiqu 18 is a diagram describing an eighth embodiment of the rotating electrical machine system of the invention,

Description of Embodiments [0014]

Hereinafter, a rotating electrical machine system, and a wind power generation system of the invention will be described on the basis of the illustrated embodiments. Each embodiment will be described with the same sign for the same constituent.

First Embodiment [0015]

Fig. 1 illustrates a first embodiment of the rotating electrical machine system of the invention. Both a below-described main generator and an auxiliary generator are radial gap type rotating electrical machines in which a set gap between a stator and a rotor is formed in a diametrical direction. In addition, a power converter is a voltage type power converter.

[0016]

As illustrated in Fig. 1, a rotating electrical machine system 1 of the present embodiment is provided with a main generator 2 that is a first rotating electrical machine which operates as a generator to transport generated power to a power system, an auxiliary generator 3 that is a second rotating electrical machine which operates in two ways as either an exciter or a generator depending on operating conditions, and a power converter 4 that is electrically connected to the main generator 2 and the auxiliary generator 3, [0017]

The main generator 2 is configured by a main generator stator 5, a main generator rotor 6 that is arranged on the inside diameter side of the main generator stator 5 with a predetermined set gap disposed therebetween, a three-phase main generator stator winding 7 that is wound as a short-pitched double layer winding inside a slot which is disposed in the main generator stator 5. and a three-phase main generator rotor winding B that is wound as a full-pitched double layer winding inside a slot which is disposed in the main generator rotor 6. The three-phase main generator stator winding 7 and the three-phase main generator rotor winding 8 are electrically arranged at an interval of 120°, [0018]

Similarly,- the auxiliary generator 3 is configured by an auxiliary generator stator 9, an auxiliary generator rotor 10 that is arranged on the inside diameter side of the auxiliary generator stator 9 with a predetermined set gag disposed therebetween, a three-phase auxiliary generator stator winding 11 that is wound as a short-pitched double layer winding inside a slot which is disposed in the auxiliary generator stator 3, and a three-phase auxiliary generator rotor winding 12 that is wound as a foil-pitched double layer winding inside a sics which is disposed in the auxiliary generator rotor 10. The three-phase auxiliary generator stator winding 11 and the three-phase auxiliary generator rotor winding 12 are electrically arranged at an interval of 120&„ [0019]

The main generator 2 and the auxiliary generator 3 described above have different operating modes as will be described later. Specifically, the main generator 2 performs generating operation at all times, but the auxiliary generator 3 may operate as an ezciter or may operate as a generator, depending on the speed of rotation.

[0020]

The power converter 3, although represented integrally in Fig. 1, is configured by a power converter that is electrically connected to the main generator 2 and a power converter that is electrically connected to the auxiliary generator 3. The power converter that is electrically connected to the main generator 2 and the power converter that is electrically connected, to the auxiliary generator 3 are electrically connected through direct current. Accordingly, each power converter only needs to convert AC and DC, [0021]

The main generator 2, the auxiliary generator 3, and the power converter 4 described above are mechanically connected to a rotor shaft 13, [0022]

The power converter 4 is arranged in a power converter arrangement space 15 within the inside diameter of the main generator and is not arranged on the inside diameter side of the auxiliary generator. This is because the main generator has higher torque and thins is larger , Therefore, it is possible to secure a wide space for incorporating the power converter 4. Although a description is provided in the present embodiment for the case where the power converter 3 is arranged in the power converter arrangement space 15 within tie inside diameter of the main generator and is not arranged on the inside diameter side of the auxiliary generator with consideration of relevant advantages; apparently; this does not exclude a case where the power converter is also arranged on the inside diameter side of the auxiliary generator in the same manner or a case where, in contrast to the present embodiment, the power converter is arranged in a power converter arrangement space within the inside diameter of the auxiliary generator and is not arranged on the inside diameter side of the main generator. The former will be particularly described in a later-described eighth embodiment.

[00231

The power converter i needs to receive instruction information from the outside ana transmit operating status information in order to be controlled according to operating conditions. Therefore, since the power converter 4 rotartes in the present embodiment, wireless communication is effective in transmission of information; and the power converter 4 is preferably connected to a device that can transmit and receive information wirelessly. However, even if a brush is used, the extent of wearing thereof is small because the amount of energy required for transmitting information is not large. Therefore; a brush and a slip ring may be disposed in order for the power converter 4 to transmit information. Similarly; a brush and a slip rinq may be disposed for grounding.

[0024]

Fig. 2 illustrates an example of circuits of the power converter. The circuits of the power converter are configured by, on a main generator side, a U-phase upper phase power converting module 14, a U~pha.se lower phase power converting module 15, a V-phase upper phase power converting module 16, a V-phase lower phase power converting module 17, a W-phase upper phase power converting module 18, a W-phase lower phase power converting module 13, on. the main, generator side of an auxiliary generator side, a U-phase upper phase power converting module 20, a ϋ-phase lower phase power converting module 21, a V-phase upper phase power converting module 22, a V-phase lower phase power converting module 23, a W-phase upper phase power converting module 24, a W-phase lower phase power converting module 25, and a capacitor 26, One phase of the power converter is provided with one phase of the power converting module and a capacitor.

Here, as illustrated in Fig. 3, the inside diameter of the main generator rotor (power converter arrangement space) is divided by an arm because the main generator and the rotor shaft are connected via an arm 27. Thus, it is necessary to arrange the power converter in a divided power converter arrangement space 28 in a manner of preventing weight unbalance. In the present embodiment, the power converter 4 is arranged in the power converter arrangement space 15 within the inside diameter of the main generator while not being disposed on the inside diameter side of the auxiliary generator. In addition, the power converter 4 is arranged in the main generator rotor but is not arranged in the auxiliary generator rotor. Here, the main generator side conversion power converter module has three phases, and thus the number thereof is necessarily a multiple of three. Similarly, the auxiliary generator side conversion power converter module also has three phases, and thus the number thereof is necessarily a multiple of three. Accordingly, in order to arrange the power converter i in a manner of preventing weight unbalance, it is necessary to provide six of the power converter arrangement space 28 and alternately arrange one phase of the main generator side conversion power converter module and one phase of the auxiliary generator side conversion power converter module. Therefore, it is preferable to provide six arms after the power converting modules are arranged in the form of not wasting the space (in a case of placing all of the power converter modules in one rotating electrical machine). Apparently, it is possible to form six or more arms, of which the number is a multiple of three, in a rotationaily symmetrical manner.

In addition, the capacitor 26 that is provided in the power converter 4 also needs to be arranged in the divided power converter arrangement space. Thus, when N capacitors are arranged in the space where one phase of the main generator side conversion power converter module is arranged, and M capacitors are arranged in the space where one phase of the auxiliary generator side conversion power converter module is arranged, the number of capacitors is hi x 3 a M x 3 :::: 3 (N f M) , Here, N and M are integers greater than or equal to zero, and Π3 t M) is an integer greater than or equal to one., That is to say, the number of capacitors needs to be a multiple of three in order to arrange the power converter in & manner of preventing weight unbalance, The capacitors are arranged between the plurality of arms in a rotationaily symmetrical manner .

[0025]

Fig, 4 illustrates one phase of the main generator side and the auxiliary generator side circuits in Fig. 2 in a case of N :::: 1 and M = 2, Changing the form of the circuits in Fig. 4 in order to arrange the circuits in the power converter arrangement space 28 results in the circuits in Fug, 5, As illustrated in Fig. 5, an upper phase power converting module 29, a lower phase power converting module 30, and a capacitor 31 are lined up in this order in the direction of the shaft. Next, connecting all phases of the circuits in Fig. 5 results in the circuits in Fig. 6, The dot-dashed line in Fig, 6 illustrates sections divided by the arms. As is apparent from F’ig. 6, wiring (crossover busbar 32) that crosses the sections divided by the arms is necessary. The crossover busbar 32 is provided with as upper phase crossover busbar that connects the upper phase power converting modules on both of the main generator side and the auxiliary generator side of one phase of the power converter, the upper phase power converting modules being alternately arranged between the neighboring arms 27, and a. lower phase crossover busbar that connects the lower phase power converting modules on both of the main generator side and the auxiliary generator side of one phase of the power converter, the lower phase power converting modules being alternately arranged between the neighboring arms 27 . The arms are desirably arranged on the capacitor side in the direction of the shaft because the crossover busbars are arranged on the power converting module side in the direction of the shaft. Accordingly, the arms do not impede the crossover busbars, and it is not necessary to bend the crossover busbars in order to avoid the arms or provide a hole in the arms to allow the crossover busbars to pass therethrough, [0026]

Although, in this description, the number of power, converting modules of the main generator side power converter is 3 x 2 (upper and lower) x 3 (phases) ------ IS, the number of power converting modules of the auxiliary generator side power converter is 2 x 2 (upper and lower) x 3 (phases) 12, and the number of capacitors is nine, it is needless to say that. the same effect as in this description is achieved with different numbers of components provided that the above conditions are satisfied. Furthermore, although L, given that L is the number of serial capacitors, is one in this description, it is needless to say that the same effect as in this description is achieved when L is greater than or equal to two. To describe more generally, one phase of the main generator side power converter that includes one phase of the main generator side power converting module and N x L capacitors and one phase of the auxiliary generator side power converter that includes one phase of the auxiliary generator side power converting module and M x L capacitors are alternately arranged between the neighboring arms 27, Accordingly, the power converters can be arranged in a rotatfonally symmetrical manner, and weight unbalance can be reduced.

Second Embodiment [ 0 Q 2 7 ]

In the first embodiment, the number of arms 27 is six, and the converter arrangement space 23 is divided into six sections to arrange the power converters in a manner of preventing weight unbalance. Even when the number of arms 33 is 12 as illustrated in Fig, 7, weight unbalance can be avoided while the space is effectively used. In the first embodiment, one converter arrangement space between arms is used for one phase of the power converting module on one rotating electrical machine of the main generator and the auxiliary generator side. Meanwhile, in the present embodiment, one phase of the power converting module on one rotating electrical machine side as further divided into two of an upper phase and a lower phase ones, and one position space is used for each separate [0028]

Fig, 8 illustrates the circuits or the power converter , Fig, 9 illustrates one phase of the main generator side and the auxiliary generator side circuits in Fig. 8 with N ::: 2 and M - 2, Changing the form of the circuits in Fig. 9 in order to arrange the circuits in the power converter arrangement space that is divided into sections by arms results in the circuits in Fig. 10. In Fig, 10, upper phase power converting modules and lower phase power converting modules are arranged in a circumferential direction. Accordingly, upper phase power converting modules and lower phase power converting modules can be arranged in each of converter arrangement spaces 34 that are divided by the arms 33, Connecting all phases of the circuits in Fig, 10 results in the circuits in Fig, 11, The dot-dashed, line in Fig. 11 i.ilustrates sections divided by the arms 33, As is apparent from Fig, 11, trie crossover busbar 32 is required even when the number of arms 33 is 12. In this case, the arms are desirably arranged on the power converting module side.

[0029]

Although, in the present embodiment, the number of main converter side power concerting modules is 3 x 2 (upper and lower] x 3 (phases) === 18, the number of main converter side power converting modules is 2x2 (upper and lower) x 3 (phases; === 12, and the number of capacitors is 1.2, the same effect as in the present embodiment is achieved with different numbers of components provided that the above conditions are satisfied.. The present embodiment may be further generalized and described as follows , When Nl, M2, Ml, and M2 are integers greater than or equal to zero where (Nl e M2 -l· Ml a M2) is greater than or equal to one. and L is an integer greater than or equal to one, 3 (hi 4 M2 f Ml 4 M2) of the capacitors constituting the power converter are connected in parallel, and L arrays of the capacitors are connected in series. Mi indicates the number of capacitors that are arranged in the space where the upper phase of one phase of the main generator side conversion power converter module is arranged. N2 indicates the number of capacitors that are arranged in the space where the lower phase of one phase of the main generator side conversion power converter module is arranged. Mi indicates the number of capacitors that are arranged in the space where the upper please of one phase of the auxiliary generator side conversion power converter module is arranged. M2 indicates the number of capacitors that are arranged in the space where the lower phase of one phase of the auxiliary generator side conversion pouer converter module is arranged. L represents the number of serial capacitors as in the first embodiment.

[00301

The upper phase of one phase of the main generator side power converter that includes the upper phase of one phase of the main generator side power converting module and Ml x L capacitors, the lower phase of one phase of the main generator side power converter that includes the lower phase of one phase of the main generator side power converting module and N2 x L capacitors, the upper phase of one phase of the auxiliary generator side power converter that includes the upper phase of one phase of the auxiliary generator side power converting module and HI x L capacitors, and the lower phase of one phase of the auxiliary generator side power converter that includes the lower phase of one phase of the auxiliary generator side power converting module and M2 x L capacitors are alternately arranged between the neighboring arms. Accordingly, the power converters can be arranged in a rotationally symmetrical manner, and weight unbalance can be reduced.

Third Embodiment [0031]

Fug. 12 illustrates a third embodiment of the present generator system. In the embodiment illustrated in Fig. 12, a plate 34 is arranged between arms. As illustrated in Fig. 13, fixing a power converting nodule 35 and a capacitor 36, both of which constitute the power converter, on the inside diameter side of the plate can prevent the power converting nodule and the capacitor iron dispersing against a centrifugal force caused by rotation.

[0032]

Although the number of arms is six in Figs. 12 and 13, the same number of arms as in the embodiment described above is applicable to the present embodiment, For example, the same effect as in the present embodiment is achieved even when the number of anas is 12,

Fourth Embodiment [0033]

Fig. 14 illustrates a third embodiment of the present generator system. In the embodiment illustrated in Fig. 11, a cooling fin 37 is attached further on a side in the direction of the centrifugal force (outside in the direction of the centrifugal force, specifically) than the power converting module 35. Accordingly, performance of cooling the power converting module can be increased, the position of terminals of the capacitor and the power converting module can be close to each other, ana the busbar can be simplified. In a case of cooling with cooling wind, the capacitor is desirably arranged above the cooling wind, compared with the power converting module. This is because the capacitor generally has a low heat resistance temperature.

Fifth Embodiment [0034]

Fiq. 15 illustrates a fifth embodiment of the present generator system. In the embodiment illustrated In Fig. 15, the main generator 2, the auxiliary generator 3, and the power converter 4 are arranged in the same frame 38. Accordingly, a space between the main generator and the auxiliary generator is decreased. Furthermore,, the main generator and the auxiliary generator can be cooled by one cooling heat exchanger. Thus, the generator system can be downsized.

Sixth Embodiment [0035]

Fiq. 16 illustrates a sixth embodiment of the present generator system. In the embodiment illustrated in Fig. 16, the main generator 2 and the power converter 4 are arranged in the same frame 39, the auxiliary generator 3 is arranged in another frame 40, each rotor shaft of the main generator 2 and the auxiliary generator 3 is connected by a hollow coupling 41, and the rotor winding of the auxiliary generator of the power converter is connected through the hollow coupling 41. This facilitates manufacturing and transporting of the mam generator and the auxiliary generator because the main generator and the auxiliary generator can be separated. The main generator 2 and the auxiliary generator 3 may be desirably connected at the time of installing the generation system. Seventh Embodiment [0036]

Fig. 17 illustrates a seventh embodiment in which the rotating electrical machine system, of the invention is applied to a wind power generation system.. As illustrated in Fig. 1.7 f a wind power system in the present embodiment is configured by a rotor it that is rot sited by receiving wind, a rotating electrical machine system 4 2 of the invention that is connected to the rotor 44 via a speed increases 43, a nacelle 50 that accommodates the rotating electrical machine system 42, and a tower 51 that supports the nacelle 50. In the present embodiment, the speed in.crea.ser 43 and a below-described circuit breaker 49 are also arranged in the nacelle 50 in addition to the rotating electrical machine system 42. Amain generator 45 and an auxiliary generator 46 are rotated by torque of the rotor 44, and a main generator stator winding and an auxiliary generator stator winding are connected to a power system 47.

[0037]

Accordingly, the rotating electrical machine system 42 can convert the energy of wind that the rotor 4 4 receives into electrical energy and transmit the electrical energy to the power system 47, [0038]

Since the present embodiment, adopts the rotating electrical machine system described above, the wind power generation system can stably perform generating operation without concern about vibrations or eccentricity by rotation.

[0039]

The circuit breaker 49 may be disposed in parallel with a power converter 48. Accordingly, the power converter 48 can be protected from excessive power that is applied at the time of a system failure. In addition, the invention may be applied to a geariess system that does not have the speed increaser 43.

Eighth Embodiment [0010]

In each embodiment described above, descriptions are provided for a case where the power converter is arranged in the rotor of the main generator but is not arranged in the rotor of the auxiliary generator.

[0041]

However, as illustrated in Fig, 18, it is also possible to dispose arms in each of the inside of the rotor of the main generator and the inside of the rotor of the auxiliary generator and dispose the main generator side power converter arrangement space within the inside diameter of the main generator and the power converter arrangement space of the auxiliary generator within the inside diameter of the auxiliary generator separately. Accordingly, the number of arms 33 of each of the main generator and the auxiliary generator can be three, and the arrangement space can be enlarged since the number of each power converter arrangement space is three. In this case, it is also possible to set the number of arms to a multiple of three less than six (that is, three), (0042]

Although, in this description, the number of main converter side power converting modules is 3 x 2 (upper and lower) x 3 (phases) == IS, the number of main converter side power converting modules is 2 x 2 (upper and lower) x 3 (phases) == 12, and the number of capacitors is nine, the same effect as in the present embodiment is achieved with different, numbers of components provided that the above conditions are satisfied.

[0043]

The invention is not limited to the above embodiments and includes various modification examples. For example, the above embodiments are described in detail in order to facilitate understanding of the invention, and not all of the described configurations are necessarily included in an embodiment of the invention. In addition, it is possible to replace a part of configurations in an embodiment with configurations in another embodiment, and it is also possible to add configurations in another embodiment to configurations in an embodiment , In addition, a part of configurations of each embodiment can be removed, or replaced with another configuration, or another configuration can be added thereto.

Reference Signs List [ 0 Q d 4 j 1 rotating electrical machine system, 2 main generator, 3 auxiliary generator, 4 power converter, 5 main generator stator, 6 main generator rotor, 7 main generator stator winding, 8 main generator rotor winding, 9 auxiliary generator stator, 10 auxiliary generator rotor, 11 auxiliary generator stator winding, 12 auxiliary generator rotor winding, 13 rotor shaft, 14 main generator side U-phase upper phase power converting module, 15 main generator side U-phase lower phase power converting module, 16 main generator side V-phase upper phase power converting module, 17 main generator side V-phase lower phase power converting module, 18 main generator side W-phase upper phase power converting module, 13 main generator side W-phase lower phase power converting module, 20 auxiliary generator side ϋ-phase upper phase power converting module, 21 auxiliary generator side D-phase lower phase power converting module, 22 auxiliary generator side V-phase upper phase power converting module, 23 auxiliary generator side V-phase lower phase power converting module, 24 auxiliary generator side W-phase upper phase power converting module, 25 auxiliary generator side W-phase lower phase power converting module, 26, 31, 36 capacitor, 27, 33 arm, 28, 34 power converter arrangement space, 2 9 upper phase power converting module, 30 lower phase power converting module, 32 crossover busbar, 34 plate, 35 power converting raoduie, 37 cooling fin, 38, 39, 40 frame, il coupling, 42 generation system, 43 speed inereaser, 44 rotor, 45 main generator, 46 auxiliary generator, 47 power system, 48 power converter, 49 circuit breaker, 50 nacelle, 51 tower

Claims

A rotating electrical machine system comprising: a first rotating electrical machine that includes a first stator which includes a first stator winding and a first rotor which includes a first rotor winding and is arranged on an inside diameter side of the first stator with a predetermined set gap interposed therebetween; a second rotating electrical machine that includes a second stator which includes a second stator winding and a second rotor which includes a second rotor winding and is arranged on an inside diameter side of the second stator with a predetermined set gap interposed therebetween; a power converter that is electrically connected to the first rotor winding and the second rotor winding and is arranged on the inside diameter side of at least any of the first rotor and the second rotor; and a capacitor that is included in the power converter; wherein the number of capacitors is a multiple of three. [Claim 2] The rotating electrical machine system according to Claim 1, further comprising; a plurality of arms that is connected to a rotor shaft in at least any of the rotors. wherein the capacitor is arranged between the plurality of arms in a rotationslly symmetrical manner. [Claim 3] The rotating electrical machine system according to Claim 2, wherein the power converter is arranged in the first rotor and is not arranged in the second rotor. [Claim fj The rotating electrical machine system according to Claim 3, wherein the number of arms is a multiple of three greater than or equal to six. [Claim 5] The rotating electrical machine system according to Claim 4, wherein the number of arms is six, given that N and M are integers greater than or equal to zero where (N t M) is greater than or equal to one, and L is an integer greater than or equal to one, 3 (N t M) of the capacitors that constitute the power converter are connected in parallel, and L arrays of the capacitors are connected in series, and one phase of a first rotating electrical machine side power converter that includes one phase of a first rotating electrical machine side power converting module ana N x L capacitors and one phase of a second rotating electrical machine side power converter that includes one phase of a second rotating electrical machine side power converting module and M x L capacitors, doth of which constitute the power converter, are alternately arranged between the neighboring arms. [Claim 6] The rotating electrical machine system according to Claim 5, further coraprising:: an upper phase crossover busbar that connects upper phase power converting modules of one phase of the first rotating electrical machine side power converter and one phase of the second rotating electrical machine side power converter, both of which are alternately arranged between the neighboring arms; and a lower phase crossover busbar that connects lower phase power converting modules of one phase of the first rotating electrical machine side power converter and one phase of the second rotating electrical machine side power converter, both of which are alternately arranged between the neighboring arms, [Claim 7] The rotating electrical machine system according to C i a im i, wherein the number of arias is 12, given that Ml, M2, Mi, and M2 are integers greater than or equal to zero where (hi a M2 a Ml f M2) is greater than or equal to one, and. L is an integer greater than or equal to one, 3 (til a N2 + Ml 1- M2) of the capacitors that constitute the power converter are connected, in parallel., and L arrays of the capacitors are connected in senes, an upper phase of one phase of the first rotating electrical machine side power converter that includes an upper phase of one phase of the first electrical machine side power converting module and hi x L capacitors, a lower phase of one phase of the first rotating electraced machine side power converter that includes a lower phase of one phase of the first electrical machine side power converting module and Id2 x L capacitors, an upper phase of one phase of the second rotating electrical machine side power converter that includes an upper phase of one phase of the second electrical machine side power converting module and Ml x L capacitors, and a lower phase of one chaise of the second rotating electrical machine side power converter that includes a lower phase of one phase of the second electrical machine side power converting module and M2 x L capacitors, all of which constitute the power converter, are alternately arranged between the n e i q h b o r i n. g arms. [Claim 8] The rotating electrical machine system according to Claim 7, further comprising: a crossover busbar that connects the upper phase power converting modules of one phase of the first rotating electrical machine side power converter and one phase of the second rotating electrical machine side power converter; ana a crossover busbar that connects the lower phase power converting modules of one phase of the first rotating electrical machine side power converter and one phase of the second rotating electrical machine side power converter, [Claim 9] The rotating electrical machine system according to i.-r arm s, wherein the number of arms is a multiple of three, the arm is disposed in each of the first rotor and the second rotor, and the number of arms disposed in each rotating electrical machine is a multiple of three, and the power converter is arranged in each of the first rotor and the second rotor, [Claim 10] The rotating electrical machine system according to any one of Claims 1 to 9, further comprising: a plate that is arranged between the arms, wherein the power converter is arranged on an inside diameter side of the plate, [Claim 11] The rotating electrical machine system according to any one of Claims 1 to 10, wherein a cooling fin is installed further on a side in the direction of a centrifugal force than the power converting module that constitutes the power converter, [ C1 a ini 12 ] The rotating electrical machine system according to any one of Claims 1 to 11, further comprising: a frame that accommodates the first rotating electrical machine, the second rotating electrical machine, and the power converter , [Claim 13] The rotating electrical machine system according to any one of Claims 1 to .11, further comprising; a first frame that accommodates the first rotating electrical machine and the power converter; a second frame that accommodates the second rotating electrical machine; and a hollow coupling that connects a rotor shaft of each rotating electrical machine, [Claim 14] A wind power generation system comprising; a rotor that is rotated by receiving wind; the rotating electrical machine system according to any one of Claims 1 to 13 that is connected to the rotor via a main shaft; a nacelle that accommodates the rotating electrical machine system; and a tower that supports the nacelle, wherein each rotating electrical machine is rotated by torque of the rotor, and each stator winding is connected to a power system, [Claim 15] The wind power generation system according to Claim 14, further comprising; a circuit breaker that is arranged in parallel with the power converter ,