Power Generation System

Abstract

Improve the power generation efficiency of the power generation system. [Solution] The power generation system 1 of the embodiment has a drive motor 10 that rotates using the output of an AC or DC power source as a power source, a generator 20 that rotates based on the rotation of the drive motor and outputs AC power, and a voltage adjustment device 30 that converts the AC power output by the generator to a predetermined frequency and a predetermined voltage.

Description

[Technical field]

[0001] FIELD OF THE PRESENT EMBODIMENTS An embodiment of the present invention relates to a power generation system. [Background technology]

[0002] Various researches are being conducted to improve the power generation efficiency of generators. Since the higher the power generation efficiency of a generator, the more desirable it is, and further improvements are desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-247730 A Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, in the field of generators, generators that use hydraulic or steam turbine power to rotate a motor are mainstream. There are no generators that use the power of a drive motor to rotate a motor. Even in generators that use the power of a drive motor to rotate a motor, the higher the power generation efficiency, the more desirable it is.

[0005] The present invention has been made in light of the above-mentioned circumstances, and an object of the present invention is to improve the power generation efficiency of a power generation system. [Means for solving the problem]

[0006] In order to solve the above problems, the power generation system of the embodiment includes a drive motor that rotates using the output of an AC power source or a DC power source as a power source, a generator that rotates based on the rotation of the drive motor and outputs AC power, and a voltage adjustment device that converts the AC power output by the generator to a predetermined frequency and a predetermined voltage. [Brief description of the drawings]

[0007] [Figure 1]1 is a block diagram of a power generation system according to a first embodiment. [Diagram 2] FIG. 1 is a perspective view of a drive motor according to a first embodiment. [Diagram 3] 1 is a perspective view of a generator according to a first embodiment. [Figure 4] 3 is a diagram for explaining an example of connection between a drive motor and a rotating shaft of a generator in the power generation system according to the first embodiment. FIG. [Diagram 5] FIG. 11 is a block diagram of a power generation system according to a second embodiment. [Figure 6] FIG. 11 is a block diagram of a power generation system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a power generation system according to an embodiment will be described with reference to the drawings.

[0009] (Embodiment 1) 1 is a block diagram of a power generation system 1 according to embodiment 1. The power generation system 1 includes a drive motor 10, a generator 20, a voltage regulator 30, a charging device 40, and a battery 50.

[0010] The drive motor 10 rotates using a commercial power source 200 (for example, AC 200V) as a power source, and rotates a motor that constitutes the generator 20. The commercial power source is an example of an AC power source. 2 is a perspective view of the drive motor 10. Inside the body 11 of the drive motor 10, a rotor is disposed around a rotating shaft 12, and a stator is disposed around the rotor. The rotating shaft 12 of the drive motor 10 rotates when a three-phase AC voltage is applied to terminals 13a, 13b, and 13c.

[0011] In the drive motor 10, for example, a rotor made of a coil is arranged around the rotating shaft 12, and a permanent magnet is arranged around the rotor as a stator. In this case, it is assumed that sparks will occur at the brush part when the rotor rotates, resulting in energy loss. As a countermeasure, the motor constituting the drive motor 10 can be made a brushless motor, thereby eliminating energy loss due to sparks at the brush part. In a brushless motor, for example, a permanent magnet is used as the rotor, and a coil is arranged around the rotor as the stator. When the permanent magnet rotates, the magnetic flux passing through the coil changes, and a current is generated in the coil. Since the current route flowing through the coil does not repeatedly cut and contact, energy loss due to sparks can be suppressed. In addition, in order to suppress energy loss due to heat generation, it is desirable that the diameter of the coil of the motor constituting the drive motor 10 is large.

[0012] The generator 20 rotates based on the rotation of the drive motor 10 and outputs AC power. Fig. 3 is a perspective view of the generator 20. Inside the body 21 of the generator 20, a rotor is arranged around a rotating shaft 22, and a stator is arranged around the rotor. When the rotating shaft 22 is rotated by the drive motor 10, a three-phase AC voltage is output to terminals 23a, 23b, and 23c. In order to suppress energy loss due to the generation of sparks, it is desirable that the generator 20 is also configured as a brushless motor.

[0013] The power generated by the generator 20 is proportional to the amount of change per unit time in the magnetic flux passing through the coil. Therefore, in order to output a large amount of power, it is necessary to strengthen the magnetic force of the permanent magnet, increase the surface area of ​​the permanent magnet, increase the number of turns in the coil, and rotate the rotating shaft 22 at a predetermined speed.

[0014] Increasing the number of turns of the coil increases the diameter of the generator 20 (the length in the Y-axis and Z-axis directions in FIG. 3). As the diameter of the generator 20 increases, the torque applied to the drive motor 10 increases. Therefore, if the kinetic energy of the drive motor 10 is constant, the longer the diameter of the generator 20, the greater the load torque of the drive motor 10, and the rotation speed of the rotating shaft 22 of the generator 20 decreases. Therefore, as the diameter of the generator 20 increases, the power generated by the generator 20 decreases. Alternatively, the energy consumed by the drive motor 10 increases, and the power generation efficiency of the power generation system 1 decreases.

[0015] As a countermeasure, the height of the rotor constituting the generator 20 in a direction perpendicular to the axial direction (X-axis direction in FIG. 3) of the rotating shaft 22 of the generator 20 (Y-axis and Z-axis directions in FIG. 3) is set to a predetermined height or less, and the rotor is arranged long in the axial direction (X-axis direction in FIG. 3) of the rotating shaft of the generator 20. By arranging the rotor long in the direction of the rotating shaft 22, the height of the rotor in a direction perpendicular to the axial direction (X-axis direction in FIG. 3) of the rotating shaft 22 of the generator 20 (Y-axis and Z-axis directions in FIG. 3) is set to a predetermined height or less. This reduces the load torque applied to the drive motor 10 to a predetermined value or less. The stator is arranged to cover the rotor according to the arrangement of the rotor. The predetermined height is determined by the output power of the generator 20, the allowable size and shape of the generator 20, the torque driving capacity of the drive motor 10, the allowable range of decrease in power generation efficiency of the power generation system 1, and the like.

[0016] As a means for increasing the power generated by the generator 20, there is a method of increasing the number of magnetic lines passing through the coil. As a method of increasing the number of magnetic lines passing through the coil, there are a method of strengthening the magnetic force of the permanent magnet and a method of increasing the surface area of ​​the permanent magnet. When the permanent magnet is used as the rotor, the surface area of ​​the permanent magnet can be increased by increasing the diameter of the rotor (the length in the Y-axis and Z-axis directions in FIG. 3). However, increasing the diameter of the rotor increases the load torque applied to the drive motor 10. Therefore, the surface area of ​​the permanent magnet is increased by reducing the diameter of the rotor and arranging the permanent magnet so that the length in the direction of the rotating shaft 22 (the length in the X-axis direction in FIG. 3) is increased. The coil, which is the stator, is arranged to cover the rotor according to the arrangement of the permanent magnet, which is the rotor. The stronger the magnetic lines per unit area of ​​the permanent magnet, the more preferable it is, but there is a limit to the strength. There is also a relationship with the cost required to manufacture a permanent magnet with a strong magnetic force. Therefore, arranging the permanent magnet long in the direction of the rotating shaft 22 is an effective method.

[0017] Another method for increasing the power generated by the generator 20 is to increase the number of turns of the coil to increase the number of magnetic field lines passing through the coil. When the rotor is a coil, increasing the number of turns of the coil increases the diameter of the rotor (the length in the Y-axis and Z-axis directions in FIG. 3) and increases the load torque applied to the drive motor 10. Therefore, by arranging the coil so that the length in the direction of the rotating shaft 22 is increased, the diameter of the rotor can be reduced and the load torque applied to the drive motor 10 can be reduced.

[0018] As another measure, when the coil is the rotor, the diameter of the rotor (the length in the Y-axis and Z-axis directions in FIG. 3) can be shortened by narrowing the wire length of the coil constituting the generator 20, thereby reducing the load torque applied to the drive motor 10. In this case, when the output power of the generator 20 is set to a predetermined power, it is desirable to reduce the output current of the generator 20 and increase the output voltage to suppress energy loss due to heat generation of the coil.

[0019] There is also a method of transmitting the kinetic energy of the rotating shaft 12 of the drive motor 10 to the rotating shaft 22 of the generator 20 via gears or the like. However, when gears are used, energy loss occurs due to the contact resistance of the gears, etc. Therefore, it is desirable to connect the rotating shaft 12 of the drive motor 10 and the rotating shaft 22 of the generator 20 so that they are arranged coaxially, as shown in Figure 4.

[0020] Returning to FIG. 1, the voltage regulator 30 converts the AC power output by the generator 20 into a predetermined frequency (including DC) and a predetermined voltage. Since fluctuations in the load of the generator 20 cause fluctuations in the load torque of the drive motor 10, it is not easy to keep the output voltage of the generator 20 constant. It is also difficult to increase the output power of the generator 20 and adjust the frequency of the AC power output by the generator 20 to 50 Hz or 60 Hz. Therefore, by providing the voltage regulator 30, the output frequency and output voltage of the power generation system 1 are stabilized at predetermined values.

[0021] The voltage regulator 30 can be configured, for example, with an AC / AC converter. For example, the voltage regulator 30 adjusts the output so that the output frequency of the power generation system 1 is 50 Hz and the output voltage is 200 V. The AC power output by the voltage regulator 30 may be single-phase or three-phase, and may be 100 V or 200 V. An AC / AC converter according to the output conditions may be adopted.

[0022] The output of the voltage regulator 30 is used as power for the electric device 100. When the load on the power generation system 1 is light (when the power consumption of the electric device 100 is small), surplus power is stored in the battery 50 via the charging device 40. The battery is an example of a DC power source. The battery 50 is formed, for example, of a lithium ion battery. The charging device 40 converts the output of the voltage regulator 30 into a voltage and current suitable for charging the battery 50. The charging device 40 also has a function of preventing the battery 50 from being overcharged.

[0023] (Description of prototype device) A prototype of the power generation system 1 will be described. In the prototype, the drive motor 10 is configured as a three-phase AC motor of 1120 W (200 V, 5.6 A). The generator 20 is configured as a three-phase AC motor of 6000 W (200 V, 30 A). By using a motor with a large rating (one with a strong permanent magnet magnetic force and a large number of coil turns) for the generator 20, it is possible to output a large amount of power.

[0024] In the prototype device, the motor described above was used, but by increasing the rating of the generator 20, for example, by 10 times or 100 times, it is possible to construct a power generation system 1 capable of outputting large power. Specifically, the magnetic force of the permanent magnet of the generator 20 is strengthened, the surface area of ​​the permanent magnet is increased, the number of turns of the coil is increased, and the thickness of the coil is made thicker according to the magnitude of the generated current. Also, since increasing the rating of the generator 20 makes the rotor of the generator 20 heavier, the driving force of the drive motor 10 is increased according to the required torque.

[0025] As described above, the power generation system 1 according to the embodiment generates electric power by rotating the rotating shaft of the generator 20 with the drive motor 10. By increasing the rotation speed of the rotating shaft 22 of the generator 20, by increasing the magnetic force of the permanent magnets constituting the generator 20, by increasing the surface area of ​​the permanent magnets constituting the generator 20, and by increasing the number of windings of the coils constituting the generator 20, the generator 20 can generate large electric power. The power generation system 1 according to the embodiment is configured by combining the drive motor 10 and the generator 20, and can generate large electric power by utilizing this characteristic, thereby improving power generation efficiency.

[0026] In addition, by coaxially fixing the rotating shaft 12 of the drive motor 10 and the rotating shaft 22 of the generator 20, it is possible to reduce energy loss when transmitting kinetic energy from the drive motor 10 to the generator 20. This makes it possible to improve the power generation efficiency of the power generation system 1.

[0027] Furthermore, in the power generation system 1 according to the embodiment, the height of the rotor constituting the generator 20 in the direction perpendicular to the axial direction of the rotating shaft 22 of the generator 20 is set to a predetermined height or less, and the rotor is disposed in the axial direction of the rotating shaft 22 of the generator 20, thereby reducing the load torque applied to the drive motor 10 to a predetermined value or less. This makes it possible to improve the power generation efficiency of the power generation system 1.

[0028] Furthermore, in the power generation system 1 according to the embodiment, when the rotor of the generator 20 is configured with a coil, the wire diameter of the coil is adjusted to make the height of the rotating shaft 22 of the generator 20 in the direction perpendicular to the axial direction equal to or less than a predetermined height, thereby reducing the load torque applied to the drive motor 10 to a predetermined value or less. This makes it possible to improve the power generation efficiency of the power generation system 1.

[0029] Furthermore, in the power generation system 1 according to the embodiment, at least one of the drive motor 10 and the generator 20 is configured as a brushless motor, thereby reducing energy loss. This can improve the power generation efficiency of the power generation system 1.

[0030] In the above description, the input of the power generation system 1 is described as three-phase AC power of 200V, but the input power does not need to be limited to this. For example, the input power may be single-phase AC power of 100V. A drive motor 10 according to the input power may be adopted.

[0031] Although the above description has been given of a case in which the output of the power generation system 1 is an AC voltage, the power generation system 1 may output DC power. In this case, the voltage adjustment device 30 may be configured with, for example, an AC / DC converter.

[0032] (Embodiment 2) 5 shows a case where a plurality of drive motors (second drive motors) 110, generators (second generators) 120, and a voltage regulator (second voltage regulator) 130 are connected in parallel to the output of the power generation system 1. Although not shown in FIG. 5, a charging device and a battery may be disposed at the output of the voltage regulator 130.

[0033] The ratings of the drive motor 110 and the generator 120 may be smaller than the ratings of the drive motor 10 and the generator 20. The ratings of the drive motor 110 and the generator 120 may be set according to their respective loads.

[0034] (Embodiment 3) In the first embodiment, the case where the input power of the power generation system 1 is an AC power supply has been described. In the third embodiment, the case where the input power of the power generation system 1 is a DC power supply will be described.

[0035] 6 shows the configuration of a power generation system 1 according to embodiment 3. Electric power generated by a solar panel 140 is stored in a battery 141. The battery 141 supplies DC power to the drive motor 10.

[0036] The drive motor 10 according to the third embodiment is configured as a DC motor, not a three-phase AC motor.

[0037] It is extremely costly to build a power plant and lay cables to carry electricity from the power plant to a consumer area several hundred kilometers away. In developing countries, including Africa, it is often difficult to raise such huge funds. However, if solar panels are used, there is no need to build a power plant or lay cables to carry electricity. In addition, Africa and deserts are suitable areas for solar power generation because of the strong sunlight. Therefore, by using the power generation system according to the third embodiment, it is possible to efficiently supply electricity with low investment even in remote areas.

[0038] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are included in the invention and its equivalents described in the scope of the utility model registration claims. [Explanation of symbols]

[0039] 1. Power generation system 10...Drive motor 11...Main body 12...Rotation axis 13a, 13b, 13c...Terminals 20…Generator 21...Main body 22...Rotation axis 23a, 23b, 23c...terminals 30…Voltage regulator 40…Charging device 50…Battery 100...Electrical equipment 110... Drive motor (second drive motor) 120…Generator (second generator) 130...Voltage regulator (second voltage regulator) 140…Solar panel 141…Battery (DC power source) 200…Commercial power supply (AC power supply)

Claims

1. A drive motor that rotates using the output of an AC power supply or a DC power supply as a power source; a generator that rotates based on the rotation of the drive motor and outputs AC power; a voltage regulator that converts the AC power output by the generator into a predetermined frequency and a predetermined voltage; A power generation system having the above configuration.

2. The rotating shaft of the drive motor and the rotating shaft of the generator are formed coaxially. The power generation system according to claim 1 .

3. The generator is characterized in that a height of a rotor constituting the generator in a direction perpendicular to an axial direction of a rotation shaft of the generator is set to a predetermined height or less, thereby reducing a torque applied to the drive motor to a predetermined value or less. The power generation system according to claim 1 .

4. The generator is characterized in that the height of the generator in a direction perpendicular to the axial direction of the rotation shaft is set to a predetermined height or less by arranging the rotor in the axial direction of the rotation shaft of the generator or by adjusting the wire diameter of the coil, and the torque applied to the drive motor is reduced to a predetermined value or less. The power generation system according to claim 3 .

5. At least one of the drive motor and the generator is configured as a brushless motor. The power generation system according to claim 1 .

6. The voltage regulator is an AC / AC converter or an AC / DC converter. The power generation system according to claim 1 .

7. a second drive motor that is rotated using the output of the voltage regulator as a power source; a second generator that rotates based on the rotation of the second drive motor and outputs AC power; having The power generation system according to claim 1 .

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