JP2016084708A - Energy storage device and wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy storage device capable of stably and continually supplying a constant power generation amount by restricting voltage fluctuation and frequency variation.SOLUTION: A wind power generator 1 comprises: a blade 2 rotating by receiving wind power; a rotor 3 rotating integrally with the blade 2; a speed-increasing gear 5 connected to a revolution shaft 4a of the rotor 3 for increasing the revolution of the revolution shaft 4a; a fly wheel 6 connected to a revolution shaft 4b which is increased in speed by the speed-increasing gear 5; a toroidal type non-stage transmission 7 connected to the revolution shaft 4b for regulating the revolution of the fly wheel 6; and a dynamo 8 connected to a revolution shaft 4c which is regulated to a stable revolution by the toroidal type non-stage transmission 7 for generating power.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an energy storage device that stores natural energy as rotational kinetic energy of a flywheel, and more particularly to a technique for suppressing voltage fluctuation, frequency fluctuation, and the like in a power generation device that uses natural energy such as wind power generation.

  In recent years, wind power generation, solar power generation and the like using natural energy have been used as power generation methods considering environmental problems. However, the output of a power generation device using natural energy such as wind power or sunlight is unstable and fluctuates at intervals of several seconds to several tens of seconds. Such electric power is not only difficult to use, but when linked with an existing electric power system, there is a risk of causing voltage fluctuations and frequency fluctuations in the electric power system and various adverse effects. Therefore, in order to actively introduce natural energy such as wind power generation, it is necessary to suppress fluctuations in frequency and stabilize the output.

  In the case of wind power generation, since natural wind power is used, the rotation of the windmill that drives the generator is not constant. For this reason, a technique is known in which a fixed amount of electric power can be stably supplied by shifting the speed of the windmill using a transmission (Patent Document 1).

  On the other hand, Patent Document 2 is a wind power generator configured to drive a generator by increasing the rotation of a windmill to a predetermined rotational speed by a speed increasing device. The structure which mounts the flywheel which relieves rotation fluctuation | variation is disclosed. With this configuration, rotational kinetic energy can be stored and released, and fluctuations in rotation are reduced to a required level, thereby realizing stable power supply.

Japanese Patent Laid-Open No. 6-200864 JP 2002-155850 A

  Since the flywheel has features such as high stored energy density, environmental friendliness, and long life, it can be used as a power storage technology that leveles the power generation capacity and improves the stability of the power system. However, although the output is stabilized by mounting the flywheel on the rotating shaft of the generator, the rotational speed of the flywheel changes in proportion to the amount of energy of the rotational motion stored therein. Therefore, in order to stabilize the frequency of power generation, it is necessary to separately install a variable speed power generation (power conversion) device, an inverter device, and the like. Furthermore, power converters such as inverter devices generate a large amount of heat (conversion efficiency is low).

  Moreover, in order to suppress the fluctuation | variation of output electric power, the method of installing an energy storage device in parallel with a generator is also considered. With the increase or decrease in natural energy, stable power can be supplied to the power system by storing power in the energy storage device when the generated power is large and taking out the power from the energy storage device when the generated power is small. Generally, a battery (storage battery) is used as an energy storage device, but the life of the battery is short, and environmental problems occur when it is discarded.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an energy storage device that can suppress voltage fluctuations and frequency fluctuations and can constantly supply a certain amount of power generation stably.

In order to solve the above problems, an energy storage device of the present invention includes a flywheel that is rotationally driven by natural energy, and stores the natural energy as rotational kinetic energy of the flywheel.
In particular, in the energy storage device of the present invention, an input shaft of a toroidal continuously variable transmission is coupled to the flywheel.

  The wind power generator of the present invention includes a rotor that rotates by receiving wind power that is natural energy, a speed increasing device that increases the rotational speed of the rotor, and a power generator. An energy storage device is provided between the machines.

According to the present invention, since the energy storage device including the flywheel and the toroidal continuously variable transmission is provided between the speed increaser and the generator, voltage fluctuation and frequency fluctuation are suppressed, and constant power generation is achieved. It is possible to provide a power generation device that can always supply the amount stably.
That is, wind power, which is natural energy, is stored in the flywheel as rotational kinetic energy, but the amount of kinetic energy stored in the flywheel (that is, the rotational speed of the flywheel) varies due to changes in wind speed and the like. And after absorbing the fluctuation | variation of a wind energy with a flywheel, the rotational energy of the stable rotational speed can be transmitted to a generator through the toroidal type continuously variable transmission which can adjust a gear ratio continuously. In this way, electric power can always be stably generated by a general generator. Moreover, the flywheel and the toroidal type continuously variable transmission are mechanical products, are cheaper and more environmentally friendly than electrochemical products such as batteries, are small and have a long life.

The schematic block diagram of the wind power generator provided with the energy storage device concerning this invention. Schematic which shows the principle structure of a toroidal continuously variable transmission.

  FIG. 1 is a schematic configuration diagram of a wind turbine generator 1 including an energy storage device according to an embodiment of the present invention. As shown in the figure, the wind power generator 1 is coupled to a blade 2 that rotates by receiving wind force, a rotor 3 that rotates integrally with the blade 2, and a rotation shaft 4a of the rotor 3, and increases the rotation speed of the rotation shaft 4a. Speed increasing gear 5, flywheel 6 coupled to rotating shaft 4 b accelerated by speed increasing device 5, and toroidal continuously variable transmission coupled to rotating shaft 4 b and adjusting the rotational speed of flywheel 6 And a generator 8 coupled to the rotating shaft 4c adjusted to a stable and constant rotational speed by the toroidal-type continuously variable transmission 7. The flywheel 6 and the toroidal continuously variable transmission 7 constitute an energy storage device 10.

The speed increaser 5 is a variable speed ratio type speed increasing device with a variable speed ratio. The speed increaser 5 increases the rotational speed of the rotary shaft 4a that is rotationally driven by wind power to a rotational speed suitable for power generation, and the blade 2 Is accumulated in the flywheel 6 by changing the rotational speed of the rotary shaft 4b.
The flywheel 6 is made of a metal such as steel, and the moment at the time of rotation is increased by increasing the thickness of the outer peripheral portion, so that large kinetic energy can be stored. In order to reduce the frictional resistance between the flywheel 6 and air, the flywheel 6 can be housed in a housing and evacuated.
Further, the rotating shaft 4b is rotatably supported by a deep groove ball bearing or a magnetic bearing having a small frictional resistance.

  As shown in FIG. 2, the toroidal continuously variable transmission 7 fixes the input side disk 22 concentrically with the input shaft 21 coupled to the rotating shaft 4b, and is disposed concentrically with the input shaft 21 so as to be connected to the rotating shaft 4c. An output side disk 24 is fixed to the output shaft 23 to be coupled. Inside the casing (not shown) in which the toroidal-type continuously variable transmission 7 is housed, a pair of swinging about a pivot (tilting shaft) 25 that is twisted with respect to the input shaft 21 and the output shaft 23. A trunnion 26 is provided. Each trunnion 26 rotatably supports a power roller 31, and each power roller 31 is sandwiched (rolled) between the input side disk 22 and the output side disk 24.

  The cross sections of the circumferential surfaces of the input side disk 22 and the output side disk 24 facing each other form concave surfaces obtained by rotating an arc centered on the pivot 25 or a curve close to such an arc. The peripheral surfaces of the power rollers 31 formed in a spherical convex shape are in contact with the peripheral surfaces of the input side disk 22 and the output side disk 24.

  In the toroidal type continuously variable transmission 7 having such a configuration, when the input shaft 21 is rotated, the input side disk 22 fixed to the input shaft 21 is rotated. The rotation of the input side disk 22 is transmitted to the output side disk 24 via each power roller 31, and the output shaft 23 fixed to the output side disk 24 rotates.

When the rotational speed of the input shaft 21 and the output shaft 23 is changed and the speed is increased between the input shaft 21 and the output shaft 23, each trunnion 26 is swung around the pivot 25, As shown in FIG. 2, each trunnion 26 is arranged so that the peripheral surface of the power roller 31 abuts on a portion near the outer periphery of the peripheral surface of the input side disk 22 and a portion near the center of the peripheral surface of the output side disk 24. Tilt.
On the other hand, when decelerating, each trunnion 26 is swung so that the peripheral surface of each power roller 31 is closer to the center of the peripheral surface of the input side disk 22 and the outer periphery of the peripheral surface of the output side disk 24. Each trunnion 26 is inclined so as to come into contact with each portion. If the inclination angle of each trunnion 26 is set to the middle between deceleration and acceleration, an intermediate gear ratio can be obtained between the input shaft 21 and the output shaft 23.

  In the wind turbine generator 1 of the present embodiment, a flywheel 6 that is an energy storage device and a toroidal continuously variable transmission 7 are connected between the speed increaser 5 and the generator 8, and wind energy is supplied to the flywheel 6. It is stored as rotational kinetic energy. According to such a configuration, when the wind is weak, power supply can be stabilized by supplying the generator 8 with the kinetic energy stored in the flywheel 6.

  Specifically, when the wind is strong, the gearbox 5 is shifted in a direction in which the rotational speed of the flywheel 6 increases, and kinetic energy is accumulated in the flywheel 6. On the other hand, the toroidal type continuously variable transmission 8 shifts in a direction in which the rotational speed of the flywheel 6 decreases so that the rotational speed of the generator 8 becomes constant. Thereby, while accumulating energy in the flywheel 6, the rotational speed of the generator 8 is kept constant and stable power generation is possible. At this time, the speed increaser 5 increases the load torque for increasing the speed of the flywheel 6, so that the rotational speed of the rotor 3 is lowered so that the rotational speed of the rotor 3 does not increase too much.

  On the other hand, when the rotational speed of the rotor 3 is low (when the wind is weak), the output of the rotating shaft 4b of the speed increaser 5 may be insufficient for driving the generator 8 to rotate. In this case, it is possible to supplement the power supply from the kinetic energy stored in the flywheel 6. At this time, although the rotational speed of the flywheel decreases, the rotational speed of the generator 8 can be kept constant by adjusting the transmission ratio of the toroidal-type continuously variable transmission 7.

In the wind turbine generator 1 of the present embodiment having the above configuration, the flywheel 6 and the toroidal continuously variable transmission 7 constituting the energy storage device 10 are provided between the speed increaser 5 and the generator 8. Therefore, voltage fluctuations and frequency fluctuations can be suppressed, and a constant power generation amount can always be supplied stably.
That is, natural wind energy is accumulated in the flywheel 6 as rotational kinetic energy, but the energy accumulated in the flywheel 6 (the rotational speed of the flywheel) fluctuates due to changes in wind speed and the like. Then, after absorbing the fluctuation of the wind energy with the flywheel 6, the rotational energy at a stable rotational speed is transmitted to the generator 8 through the toroidal continuously variable transmission 7 whose gear ratio can be continuously adjusted. Can do. In this way, the general generator 8 can always stably generate power. Moreover, the flywheel 6 and the toroidal type continuously variable transmission 7 are mechanical products, are cheaper and more environmentally friendly than electrochemical products such as batteries, are small and have a long life.

Although the rotational speed of the flywheel 6 fluctuates due to the accumulation and release of kinetic energy, the energy storage device 10 of the present invention has a fluctuating rotation of the flywheel 6 due to the combination of the flywheel 6 and the toroidal everyday transmission 7. The speed can be changed to the rated speed, and a constant rotation speed can always be output.
The rotational speed of the flywheel 6 can be adjusted by the toroidal type continuously variable transmission 7 (the gear ratio is continuously variable), and the generator 8 can be stably driven at the rated rotational speed. Stable power at a constant frequency can be supplied. In addition, the toroidal type continuously variable transmission can transmit large torque compared to other continuously variable transmissions such as belt (chain) type continuously variable transmissions, so that it accumulates a large amount of energy and generates power. Suitable for equipment to do.

The configuration of the energy storage device of the present invention is not limited to a wind power generator, and can be applied to a power generator using any natural energy (solar heat, geothermal, ocean current, wave power, tidal power, etc.).
Further, as the toroidal continuously variable transmission, a so-called single cavity type in which one input disk and one output disk are provided is illustrated, but a plurality of input disks and output disks are respectively provided. By adopting a configuration (such as a double cavity type) that is arranged in parallel with each other in the power transmission direction, higher torque can be transmitted. Thereby, a large amount of energy can be stored, and the power generation capacity is improved.

The energy storage device of the present invention can be suitably used for a power generation device using natural energy such as a wind power generation device.

DESCRIPTION OF SYMBOLS 1 Wind power generator 2 Blade 3 Rotor 4a, 4b, 4c Rotating shaft 5 Gearbox 6 Flywheel 7 Toroidal type continuously variable transmission 8 Generator 10 Energy storage device 21 Input shaft 22 Input side disk 23 Output shaft 24 Output side disk 25 Axis 31 Power Roller

Claims (2)

An energy storage device comprising a flywheel that is rotationally driven by natural energy, and storing natural energy as rotational kinetic energy of the flywheel,
An energy storage device, wherein an input shaft of a toroidal type continuously variable transmission is coupled to the flywheel.   A rotor that rotates by receiving wind power that is natural energy, a speed increasing device that increases the rotational speed of the rotor, and a generator, and between the speed increasing device and the power generator, A wind power generator comprising the energy storage device described above.

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