Power generation system

Abstract

To enable an assist of an increase of the rotational number of a power generator when an input energy to a turbine is small while reducing a frequency of an exchange and a repair.SOLUTION: A power generation system that generates a power by using a wind force or a water force of a renewable energy, comprises: a turbine that is rotated by the wind force or the water force; a power generator that generates a power by using a rotational energy of the turbine; a power supply line that electrically connects the power generator with a load to which a power generated by the power generator is supplied; and a non-contact relay that is provided to a power supply line, and is constructed so that a state of the power supply line can be changed to a state that a supply of the power cannot be made in the case where a voltage of the power generated by the power generator is a preset setting voltage or lower.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power generation system that generates power using wind power or hydropower, which is a type of renewable energy. [Background technology]

[0002] In wind power generation equipment and hydroelectric power generation equipment, the starting torque of the generator is relatively large, so when the input energy to the turbine is small, such as when the wind speed is low or the amount of water is small, the increase in the rotation speed of the generator is delayed, resulting in a decrease in power generation efficiency. In response to this, for example, Patent Document 1 discloses a wind power generation equipment equipped with a changeover switch that switches the circuit connected to the generator between a load and a power source. This changeover switch is designed to connect the generator to the power source side when the rotation speed of the rotor is low and the rotor is located in a low-efficiency rotation range, and to assist the rotation of the generator with the electric power supplied from the power source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-210914 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, a contact relay with physical contacts is used in the changeover switch so that the power of the power source can be supplied to the generator. Contact relays have a relatively short product life, so they require frequent replacement and repair. In addition, in order for the generator to effectively use the power supplied from the power source, an auxiliary motor or the like must be installed, which may increase costs.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a power generation system that can assist in increasing the rotation speed of the generator when the input energy to the turbine is small, while reducing the frequency of replacement or repair. [Means for solving the problem]

[0006] In order to achieve the above-mentioned objective, the power generation system of the present disclosure is a power generation system that generates electricity using wind or hydropower, a renewable energy source, and includes a turbine that rotates by the wind or hydropower, a generator that generates electricity using the rotational energy of the turbine, a power supply line that electrically connects the generator and a load to which the electricity generated by the generator is supplied, and a contactless relay that is provided on the power supply line and is configured to be able to switch the power supply line to a state in which the electricity cannot be supplied when the voltage of the electricity generated by the generator is equal to or lower than a predetermined set voltage. Effect of the Invention

[0007] According to the power generation system of the present disclosure, it is possible to assist in increasing the rotation speed of the generator when the input energy to the turbine is small, while reducing the frequency of replacement or repair. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a power generation system according to an embodiment. [Figure 2A] FIG. 4 is a diagram showing a change over time in the rotation speed of a generator according to an embodiment. [Figure 2B] FIG. 4 is a diagram showing the change over time in power supplied to a load according to an embodiment. [Figure 2C] FIG. 13 is a diagram showing a change in voltage over time at a connection position according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a power generation system according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, and does not limit the present disclosure. The embodiment can be arbitrarily modified within the scope of the technical idea of ​​the present disclosure.

[0010] <Power generation system> (composition) The power generation system according to the present disclosure generates power using wind or hydroelectric power, which are renewable energies. The power generation system is installed in an electric power demand facility, such as an office building, an apartment building, a factory, or a detached house. The electric power demand facility may be supplied with electric power from an electric utility such as an electric power company, or may be provided with a private power generation facility such as a solar power generation facility.

[0011] Fig. 1 is a diagram illustrating a schematic configuration of a power generation system 1 according to one embodiment. As illustrated in Fig. 1, the power generation system 1 includes a turbine 2, a generator 4, a power supply line 6, and a contactless relay 8. In one embodiment, the power generation system 1 further includes a commercial power line 10, a DC / DC converter 12, and a DC / AC converter 14.

[0012] The turbine 2 rotates by wind or water power. In one embodiment, the turbine 2 is arranged on the rooftop of a facility that demands electricity, and rotates by wind power. The turbine 2 has a rotating shaft 3 and turbine blades (not shown) attached to the rotating shaft 3, and is configured to rotate the turbine blades by wind blowing against the turbine 2, such as wind around buildings.

[0013] The generator 4 is mechanically connected to the rotating shaft 3 of the turbine 2 and generates electric power using the rotational energy of the turbine 2. In one embodiment, the generator 4 is a permanent magnet generator that uses a permanent magnet to generate a magnetic field. The permanent magnet generator has a rotor that is rotatably supported and a stator that is arranged outside the rotor, with a permanent magnet arranged on one of the rotor and the stator and a coil arranged on the other. In such a permanent magnet generator, when the rotor rotates, the magnetic flux that links with the coil changes and induces a voltage in the coil by electromagnetic induction. Note that the present disclosure does not limit the generator 4 to a permanent magnet generator.

[0014] The power supply line 6 electrically connects the generator 4 and the load 50 to which the power generated by the generator 4 is supplied. In other words, the power supply line 6 is electrically connected at one end to the generator 4 and at the other end to the load 50. In one embodiment, the load 50 includes a general load 50A (50) and a storage battery 50B (50). The general load 50A is provided in a power demand facility so that power can be supplied from a commercial power source 52, and is, for example, an air conditioning system, a lighting system, and an office automation device. The storage battery 50B is not particularly limited, but is, for example, a lead storage battery with a rated voltage of 12V. Note that, in some embodiments, the load 50 includes the general load 50A but does not include the storage battery 50B.

[0015] 1, the commercial power line 10 electrically connects a connection position P1 of the power supply line 6 located between the contactless relay 8 and the load 50 to a commercial power source 52. The commercial power line 10 is provided with a fuse 54, a transformer 56, a rectifier of the commercial power line 10 (hereinafter referred to as "rectifier 58"), and a backflow prevention diode of the commercial power line 10 (hereinafter referred to as "backflow prevention diode 60") in this order from the commercial power source 52 towards the connection position P1.

[0016] The fuse 54 is configured to melt when an overcurrent exceeding the rated current flows through the commercial power line 10, thereby protecting the power generation system 1 from the overcurrent. The transformer 56 converts the AC voltage from the commercial power source 52 to a predetermined voltage, for example, from 100 V to 80 V. The rectifier 58 rectifies the AC voltage from the commercial power source 52 to a DC voltage. The reverse current prevention diode 60 cuts off the supply of power from the connection position P1 to the commercial power source 52.

[0017] 1, the power supply line 6 includes a first line 16 and a second line 18. The first line 16 connects a branch position P2, which is located on the opposite side of the connection position P1 from the generator 4 side, to a general load 50A. The second line 18 is provided separately from the first line 16, and connects the branch position P2 to the storage battery 50B.

[0018] In one embodiment, a DC / DC converter 12 is provided between a connection position P1 and a branch position P2 of the power supply line 6. The DC / DC converter 12 converts a DC voltage to a predetermined voltage, for example, a voltage of 12 V. Furthermore, a DC / AC converter 14 is provided on the first line 16. The DC / AC converter 14 converts a DC voltage to an AC voltage, for example, a DC voltage of 12 V to an AC voltage of 100 V.

[0019] The contactless relay 8 is provided in the power supply line 6. As described above, the contactless relay 8 is located in a portion of the power supply line 6 between the generator 4 and the connection position P1 (hereinafter, referred to as the upstream portion 11). In one embodiment, the upstream portion 11 is provided with a rectifier (hereinafter, referred to as the "rectifier 62") and a backflow prevention diode (hereinafter, referred to as the "backflow prevention diode 64") in the upstream portion 11. The rectifier 62 is located closer to the generator 4 than the contactless relay 8, and rectifies the AC voltage from the generator 4 to a DC voltage. The backflow prevention diode 64 is located closer to the connection position P1 than the contactless relay 8, and cuts off the supply of power from the connection position P1 to the generator 4.

[0020] The contactless relay 8 is configured to be capable of switching the power supply line 6 to a state in which power cannot be supplied when the voltage of the power generated by the generator 4 is equal to or lower than a preset voltage. In one embodiment, the contactless relay 8 includes a resistive voltage divider circuit 20 and a solid-state relay 22.

[0021] The resistive voltage divider circuit 20 includes a first resistor 24 and a second resistor 26 connected in series to each other. The first resistor 24 is a resistor with a fixed resistance value. The second resistor 26 is a variable resistor with a variable resistance value. The resistive voltage divider circuit 20 is connected to the power supply line 6, and divides the voltage of the power generated by the generator 4 based on the resistance value of the first resistor 24 and the resistance value of the second resistor 26, and outputs an output voltage Vout. The resistive voltage divider circuit 20 is configured to apply this output voltage Vout to the solid-state relay 22. The second resistor 26 may be a resistor with a fixed resistance value, or may be a semi-fixed resistor with a finely adjustable resistance value.

[0022] The solid-state relay 22 is a non-contact switching element that has no moving contact portion, and is switched to the ON state when the output voltage Vout of the resistive voltage divider circuit 20 becomes equal to or higher than a set voltage. When the solid-state relay 22 is in the ON state, the generator 4 is electrically connected to each of the general load 50A and the storage battery 50B. In other words, the power supply line 6 is in a state in which power can be supplied from the generator 4 to each of the general load 50A and the storage battery 50B. When the output voltage Vout is less than a predetermined voltage and the solid-state relay 22 is in the OFF state, the generator 4 is electrically disconnected from each of the general load 50A and the storage battery 50B.

[0023] In one embodiment, the set voltage is the voltage (80 V) of the power supplied from the commercial power supply 52 at the connection position P1. In some embodiments, the set voltage is the voltage (100 V) of the power supplied from the commercial power supply 52.

[0024] (Action and effect) The operation and effect of the power generation system 1 according to one embodiment will be described. FIG. 2A is a diagram showing the change over time in the rotation speed of the generator 4 according to one embodiment. FIG. 2B is a diagram showing the change over time in the power supplied to the load 50 according to one embodiment. FIG. 2C is a diagram showing the change over time in the voltage at the connection position P1 according to one embodiment. Each of FIG. 2A, FIG. 2B, and FIG. 2C has a common horizontal axis representing time. In FIG. 2B, the solid line indicates the generator power W1 supplied from the generator 4 to the load 50 (general load 50A and storage battery 50B), the dotted line indicates the commercial power W2 supplied from the commercial power source 52 to the load 50, and the dashed dotted line indicates the magnitude L of the power consumed by the load 50.

[0025] 2A, between timing t1 and timing t2, the speed of the wind blowing against the turbine 2 is low, so the rotation speed of the generator 4 is 0. Since the wind speed increases from timing t2, the rotation speed of the generator 4 gradually increases from timing t2 to timing t4. Then, after timing t4, the rotation speed of the generator 4 is maintained at a constant value (approximately 500 rpm).

[0026] As shown in Fig. 2B, a case will be described where the magnitude L of the power consumed by the load 50 is constant. Between timing t1 and timing t2 when the generator 4 is not generating power, the load 50 consumes power supplied from the commercial power source 52. The generator 4 generates power between timing t2 and timing t3, but the voltage is lower than the set voltage, so the generator 4 is electrically disconnected from the load 50 by the non-contact relay 8 (solid-state relay 22). In other words, during this period, the generator 4 is not affected by the load 50 (the generator 4 operates without a load), and therefore it is easy to accelerate rotation.

[0027] After timing t3, the generator 4 generates power whose voltage is equal to or higher than the set voltage, and is electrically connected to the load 50. After timing t3, the load 50 consumes the power generated by the generator 4. Between timing t3 and timing t4, the load 50 consumes the power generated by the generator 4 and the power supplied from the commercial power source 52. Then, after timing t4, the rotation speed of the generator 4 reaches a certain value, and the load 50 begins to consume only the power generated by the generator 4.

[0028] 2C, the voltage at connection position P1 is the voltage (80V) of the power supplied from commercial power source 52 between timing t1 and timing t3. After timing t3, as described above, the voltage of the power generated by generator 4 is also applied to connection position P1, so the voltage at connection position P1 rises. Then, the voltage at connection position P1 becomes the voltage of the power generated by generator 4 at timing t4, and is maintained at this voltage after timing t4 because the rotation speed of generator 4 is constant.

[0029] According to one embodiment, the power generation system 1 includes a contactless relay 8 having a resistive voltage divider circuit 20 and a solid-state relay 22. Therefore, when the voltage of the generated power is equal to or lower than a set voltage, the generator 4 is electrically disconnected from each of the general load 50A and the storage battery 50B, and the generated power is not consumed. In other words, when the rotation speed of the generator 4 is low because the wind speed blowing on the turbine 2 is low, the generator 4 can be placed in an unloaded state to assist an increase in the rotation speed of the generator 4. In this way, the power generation system 1 according to the present disclosure is electrically connected to the load 50 only after the turbine blades of the generator 4 have been increased to a certain rotation speed or higher, so that it is easier to increase the rotation speed of the turbine blades to a rotation speed at which power can be generated efficiently compared to the conventional technology. In addition, since the contactless relay 8 is adopted, the frequency of replacement and repair can be reduced compared to the case of adopting a contact relay.

[0030] According to one embodiment, since the power generation system 1 includes the commercial power line 10, the general load 50A and the storage battery 50B can consume the power supplied from the commercial power source 52 until the voltage of the power generated by the generator 4 exceeds the set voltage (until the generator 4 reaches a rotation speed at which power generation efficiency is high). According to one embodiment, the set voltage is the voltage of the power supplied from the commercial power source 52 at the connection position P1. Therefore, until the voltage of the power generated by the generator 4 becomes higher than the voltage of the power supplied from the commercial power source 52 (until timing t3), the general load 50A and the storage battery 50B can consume the power supplied from the commercial power source 52 and assist in increasing the rotation speed of the generator 4.

[0031] According to one embodiment, since the load 50 includes a general load 50A and a storage battery 50B, the power generated by the generator 4 can be consumed by the general load 50A and can be stored in the storage battery 50B. Furthermore, the power stored in the storage battery 50B can also be consumed by the general load 50A.

[0032] The contents described in each of the above embodiments can be understood, for example, as follows.

[0033] [1] The power generation system (1) according to the present disclosure is a power generation system that generates power using wind power or hydropower among renewable energy sources, A turbine (2) that rotates by the wind or water power; a generator (4) that generates electricity using the rotational energy of the turbine; a power supply line (6) electrically connecting the generator and a load (50) to which the power generated by the generator is supplied; and a contactless relay (8) that is provided in the power supply line and is configured to be able to switch the power supply line to a state in which the power cannot be supplied when the voltage of the power generated by the generator is equal to or lower than a preset voltage.

[0034] According to the configuration described in [1] above, when the voltage of the generated power is equal to or lower than the set voltage, the generator is electrically disconnected from the load, and the generated power is not consumed by the load. In other words, when the input energy to the turbine is small and the rotation speed of the generator is low, the generator is placed in an unloaded state, and the increase in the rotation speed of the generator can be assisted. In addition, since a non-contact relay is used, the frequency of replacement and repair can be reduced compared to when a contact relay is used.

[0035] [2] In some embodiments, in the configuration described in [1] above, The power supply system further includes a commercial power line (10) that electrically connects a connection position (P1) of the power supply line that is located between the contactless relay and the load to a commercial power source (52).

[0036] According to the configuration described in [2] above, the load can consume power supplied from the commercial power source until the voltage of the power generated by the generator exceeds the set voltage (until the generator reaches a rotation speed at which power generation is efficient).

[0037] [3] In some embodiments, in the configuration described in [2] above, The load includes a general load (50A) and a storage battery (50B), the power supply line includes a first line (16) that connects the storage battery to a branch position (P2) located on the opposite side of the connection position from the generator side, and a second line (18) that connects the branch position to the general load; a DC / DC converter (12) provided between the connection position and the branch position of the power supply line; The power supply system further includes a DC / AC converter (14) provided in the first line.

[0038] According to the configuration described in [3] above, the power generated by the generator can be stored in the storage battery and can be consumed by general loads. Furthermore, the power stored in the storage battery can also be consumed by general loads.

[0039] [4] In some embodiments, in the configuration according to any one of [1] to [3] above, The non-contact relay has a resistive voltage divider circuit (20) and a solid-state relay (22) that is switched to an on state when an output voltage (Vout) of the resistive voltage divider circuit becomes equal to or higher than the set voltage.

[0040] According to the configuration described in [4] above, it is possible to assist in increasing the rotation speed of the generator when the input energy to the turbine is small at low cost.

[0041] [5] In some embodiments, in the configuration according to any one of [1] to [4] above, The generator is a permanent magnet generator.

[0042] According to the configuration described in [5] above, it is possible to provide a power generation system equipped with a permanent magnet generator. [Explanation of symbols]

[0043] 1. Power generation system 2. Turbine 3 Rotation Axis 4. Generator 6. Power Supply Lines 8. Non-contact relay 10 Commercial power lines 11 Upstream of power supply line 12 DC / DC converter 14 DC / AC converter 16 First Line 18 2nd Line 20 Resistor divider circuit 22 Solid State Relay 24 The First Resistance 26 The Second Resistance 50 Load 50A general load 50B storage battery 52 Commercial power supply 54 Fuse 56 Transformer 58 Rectifier 60 Reverse current prevention diode 62 Rectifier 64 Reverse current diode P1 Connection position P2 Branch position Vout Output voltage W1 Generator Power W2 Commercial power

Claims

1. A power generation system that generates power using wind or hydroelectric power among renewable energies, A turbine rotated by the wind or the water; a generator that generates electricity using the rotational energy of the turbine; a power supply line electrically connecting the generator and a load to which the power generated by the generator is supplied; a contactless relay that is provided in the power supply line and is configured to be able to switch the power supply line to a state in which the power cannot be supplied when the voltage of the power generated by the generator is equal to or lower than a preset voltage; Power generation system.

2. a commercial power line electrically connecting a connection position of the power supply line located between the contactless relay and the load to a commercial power source, The power generation system according to claim 1 .

3. The load includes a general load and a storage battery, the power supply line includes a first line connecting the storage battery to a branch position located on an opposite side of the connection position from the generator side, and a second line connecting the branch position to the general load; a DC / DC converter provided between the connection position and the branch position of the power supply line; A DC / AC converter is provided in the first line. The power generation system according to claim 2 .

4. The non-contact relay includes a resistive voltage divider circuit and a solid-state relay that is switched to an ON state when an output voltage of the resistive voltage divider circuit becomes equal to or higher than the set voltage. The power generation system according to claim 1 .

5. The generator is a permanent magnet generator. The power generation system according to claim 1 .

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