JP4073217B2 - Power generation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power generation system using sunlight, and more particularly, to a self-supporting power generation system capable of supplying power even in a place where a transmission and distribution network is not installed.
[0002]
[Prior art]
Conventionally, photovoltaic power generation systems using sunlight as an energy source have been widely used. The solar power generation system can be said to be a very high value power generation system because its energy source can be used permanently and it does not emit chemical pollutants that harm the environment as an energy source. However, the energy obtained from sunlight is often affected by the daily sunshine hours and seasonal weather fluctuations, and the generated power is unstable depending on the sunshine conditions. Moreover, in places where no transmission and distribution network is installed, it is necessary to use the power generated by solar power generation, for example, at night, other than the daylight hours. For this reason, many systems which store generated electric power in a storage battery and supply it according to the demand amount are adopted. Accordingly, it is possible to secure stable quality electricity by charging the storage battery with generated power during sunshine hours and supplying power from the storage battery during non-sunshine hours.
[0003]
By the way, if the storage battery is repeatedly charged / discharged excessively, as a result, the battery life becomes short, and it must be disposed of. However, disposal of storage batteries has problems in terms of environmental protection, and storage batteries that have reached the end of their lives are often left without being properly disposed of as waste, which also contributes to environmental pollution. is there.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances, and wastes power with good quality without being affected by the weather in the daylight hours and without using a storage battery that has environmental problems. and to provide a power generation system that can be supplied without causing.
[0005]
[Means for Solving the Problems]
In order to solve the aforementioned problems, power generation system of the present invention, the upper water tank, and a lower water tank, before Symbol a motor pump for pumping the water in the lower water tank to the upper water tank, the water in the upper water tank In the power generation system comprising a turbine-type generator that generates electricity by flowing into the lower aquarium, the turbine-type generator is a turbine-type generator that does not have a flow rate adjusting mechanism, and the rotation of the turbine-type generator comprising a governor for controlling the number, of the generated power of the waterwheel generator by該調speed device, to supply the surplus electric power supplied to the motor pump demand home side, from the lower water tank the so as to pumping to the upper water tank, it is characterized in that the control to keep the generated power and the rotational speed of the waterwheel generator constant.
The upper water tank is provided with an inflow path for introducing water from a nearby river.
The lower tank has a pit for pumping up groundwater.
The motor pump operated by the speed governor uses a direct current motor.
Another aspect of the power generation system of the present invention includes the power generation system and a solar power generation device, supplies the generated power of the solar power generation device to a motor pump, and pumps water from the lower water tank to the upper water tank. It is characterized by doing so.
[0006]
According to the present invention described above, the water in the lower aquarium is pumped to the upper aquarium by a pump using the power of solar power generation during the sunshine hours, and the effective head that is pumped outside the sunshine hours at night is used. Electricity can be generated by running water from the upper tank to the lower tank. As a result, even in places where there is no power transmission / distribution network, energy can be stored in the sunshine hours, and power can be supplied without using a storage battery at night when generated power is required. Therefore, the problem of disposal of the storage battery is eliminated, and the photovoltaic power generation system can be a truly environmentally friendly power generation system.
[0007]
In the power generation system of the present invention , power is generated by running the generator from the upper water tank at a constant water wheel inlet valve opening, thereby obtaining a constant power output corresponding to the head and flow rate. And by driving a motor pump with the surplus of the electric power supplied to a consumer side using a governor, water is pumped from a lower tank to an upper tank. As a result, potential energy can be accumulated using surplus generated power, so that the generator can be operated at a constant speed in the full load state while effectively utilizing surplus generated power, and stable high quality power can be generated. Supply becomes possible.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0009]
FIG. 1 shows a photovoltaic power generation system according to an embodiment of the present invention. An upper water tank 11 is arranged at the upper part of the site, and the lower water tank 12 is arranged with a drop of, for example, several tens of meters connected by a pipe 10. A turbine-type generator 13 is disposed on the upper part of the lower water tank 12, and the turbine 13a is rotationally driven by flowing water from the pipeline 10, whereby the generator 13b generates AC power. The generator 13 is a simple generator that does not have a flow rate adjusting mechanism. The AC power generated by the generator 13b is supplied from the control panel 15 to the customer side via the power transmission line 16.
[0010]
In addition, this power generation system includes a solar cell array 17 and receives sunlight to generate power and output DC power. This generated electric power is supplied to the motor pumps 20, 21, etc., which are DC motors, via the control panel 18. Each of the motor pumps 20 and 21 includes a DC motor, operates with DC power generated by the solar cell array 17, pumps water stored in the lower water tank 12, and sends the water to the upper water tank 11.
[0011]
The upper water tank 11 is connected to a nearby river such as a stream, collects rainwater or the like that has rained near the site, and guides the water to the upper water tank 11 via the inflow path 23. Further, a pit (well) 24 is provided in the vicinity of the lower water tank 12, and groundwater is pumped up by a pump 22 and pumped into the upper water tank 11. The collected water is for use in a power generation system that uses a closed-loop, self-sustained turbine generator that circulates between the upper and lower tanks. You can also. The water collected in this way is used for replenishing the amount of water by evaporation or the like in a closed loop / self-supporting power generation system and securing the required amount of water at the start of operation.
[0012]
Pumps 20, 21, 28 for pumping water are provided in the vicinity of the lower water tank 12, and water is sucked from a suction pipe 25 communicating with the lower water tank 12, and pumped to the upper water tank 11 through the pumping pipe 27. Here, the pumps 20 and 21 operate by receiving the power generated by the solar cell array 17, but the pump 28 converts the power generated by the generator 13 into DC power via the AC / DC converter 30. Operates in response to supply. Therefore, the pumps 20 and 21 are rotationally driven mainly by the power generated by the solar cell array 17 during the daytime, and pump the water accumulated in the lower water tank 12 into the upper water tank 11.
[0013]
On the other hand, the pump 28 is supplied with power by flowing the water in the upper water tank 11 through the pipe 10 at night or the like, converting the surplus power generated by the generator 13 into DC power. Thereby, a part of the water stored in the lower water tank 12 during the operation of the generator 13 is returned to the upper water tank 11 via the pipe line 27. That is, when the generator 13 is operated by running the water stored in the upper water tank 11, the pump 28 is driven using the surplus of the generated electric power, thereby pumping a part of the water used for power generation. A circulation channel that returns to the upper water tank 11 again through the pipe 27 is formed.
[0014]
A control device (governor) 29 is provided inside the control panel 15, and PID control is performed so that the rotational speed of the generator is constant. That is, the power consumed on the consumer side varies from moment to moment. Accordingly, when all of the generated power is supplied to the consumer side, when the power consumption on the consumer side is small, that is, when the load viewed from the generator 13b is light, the number of revolutions of the generator increases, thereby generating the power generation frequency. As the voltage increases, the generated voltage increases. When the power consumption is large on the consumer side, the load on the generator 13b becomes heavy, and the rotational speed of the generator decreases and the generated voltage decreases. For this reason, by controlling so that the load seen from the generator 13b may become constant, a fixed rotation speed is obtained and a fixed power generation frequency and power generation voltage are obtained.
[0015]
In this system, the speed governor 29 performs PID control that keeps the rotational speed of the full load state constant. That is, when the load is lightened from the full load state and the rotational speed is going to increase, the DC voltage supplied to the motor pump 28 is increased to increase the supply power, whereby the load of the generator 13b becomes the full load state, and the rotational speed is increased. Operates so as to be kept constant. Therefore, out of the constant power generated by the generator 13b, the power requested by the customer is sent through the transmission line 16, and the surplus power is converted into direct current power through the AC / DC converter 30 to the motor 28. Will be supplied.
[0016]
Therefore, by opening the valves 31 and 32 provided in the pipe line 10, a constant flow of water flows from the upper water tank 11 toward the lower water tank 12, and the amount of supplied water is constant and the rotation speed is constant. The turbine generator 13 generates a certain amount of generated power. And the surplus electric power supplied to the consumer side by the speed governor 29 is supplied to the motor pump 28, whereby the amount of water corresponding to the surplus electric power is sent from the lower water tank 12 to the upper water tank 11. That is, if the loss of the pump 28 is ignored, only the amount of water stored in the upper water tank 11 corresponding to the electric power sent to the customer side is transferred from the upper water tank 11 to the lower water tank 12, and surplus. Electric power can be recovered as position energy.
[0017]
Next, the operation of this solar power generation system will be described. First, a required amount of water is stored in the upper water tank 11. This water may be collected by collecting water from a river or the like connected thereto through the inflow pipe 23, or pumping ground water from a pit (well) 24 for use. Then, for example, at night during non-sunshine hours, the valves 31 and 32 are opened, and the water in the upper water tank 11 is caused to flow from the pipe 10 to rotate the water turbine 13a of the simplified water turbine generator 13, thereby generating the generator 13b. Outputs more generated power.
[0018]
When the valves 31 and 32 are opened and water flows through the pipe line 10, the water surface of the upper tank 11 gradually decreases. However, since the resistance of the pipe line 10 and the like is constant, a substantially constant amount of water is generated by the water turbine generator. 13 is supplied. The upper water tank 11 is preferably provided with a water storage capacity capable of supplying water at a constant water amount for about 6 hours per day, for example. Thereby, for example, power generation of about 15 kW can be continuously performed for about 6 hours.
[0019]
During this power generation, the speed governor 29 operates to perform PID control so that the rotational speed of the generator is constant. That is, when the electric power supplied to the customer side decreases with respect to the full load electric power, the rotational speed of the generator tends to increase, so the voltage supplied to the motor pump 28 is increased and the electric power supplied to the motor pump 28 is By increasing the power, the generated power as a whole generator is kept constant. Therefore, since the rotation speed of the generator is controlled to be constant, it is possible to supply the customer with high quality electric power whose frequency and voltage are kept constant. Moreover, since the electric power supplied to the motor pump 28 is used for pumping water from the lower water tank 12 to the upper water tank 11, energy can be effectively used.
[0020]
Conventionally, a power consumption mechanism called a dummy load has been used when controlling the rotational speed of the generator using a speed governor. This is to supply a certain amount of water to the generator and operate at a certain number of revolutions, to supply surplus power to the consumer side to a resistance load (dummy load), and to convert the power energy into thermal energy. It is intended to be consumed. According to this, the generator is operated at a constant output, whereby a stable generated voltage and generated frequency can be obtained, but the surplus power supplied to the consumer is discarded as heat.
[0021]
In the photovoltaic power generation system of the present invention, the generator 13b is operated at a constant rotational speed by the speed governor 29, and surplus power supplied to the consumer side is supplied to the motor pump 28, whereby the surplus power is supplied. The corresponding water flow is fed back to the upper water tank 11 through the pumping pipe 27. Therefore, except for the loss of the pump 28, only the water flow corresponding to the power required on the customer side is used for power generation, so the water level in the upper tank is supplied while supplying a substantially constant water flow to the generator. The decrease can be made to correspond to the amount of power generation supplied to the customer side. As a result, the power generation time can be extended by an amount corresponding to the recovered amount of water while keeping the frequency and voltage of the generated power constant.
[0022]
In this way, for example, when power generation is performed for about 6 hours at night, the upper water tank 11 becomes empty and the lower water tank 12 is fully filled with water. Therefore, at this time, the operation of the simplified water turbine generator 13 is stopped. Then, when the sun rises the next day, the solar cell array 17 starts a power generation operation. When the DC output generated by the solar cell array 17 reaches a sufficient level, electric power is supplied to the motor pumps 20 and 21 via the control panel 18. At this time, the valve 33 is closed. Thereby, the water stored in the lower water tank 12 is transferred to the upper water tank 11 through the pumping pipe 27.
[0023]
The capacity of the motor pumps 20 and 21 is selected so that the total amount of water stored in the lower water tank 12 can be transferred to the upper water tank 11 by the amount of generated power within the solar hours of the solar cell array 17. Thus, the entire amount of water stored in the lower water tank 12 during the sunshine hours is transferred to the upper water tank 11, and the operation of the motor pumps 20, 21 is stopped. And it prepares for the electric power generation by the flowing water from the upper tank 11 to the lower tank 12 at night.
[0024]
Thus, in this solar power generation system, the simplified water turbine generator is configured by pumping the water in the lower tank to the upper tank using the electric power generated by the solar cell array 17 and flowing the water from the upper tank to the lower tank. 13 can be driven, so that electric power can be supplied to the customer side during non-sunshine hours such as at night. The supplied power is operated by the generator 13b at a constant rotation speed, and the water flow corresponding to the surplus power is fed back to the upper water tank 11 by the motor pump 28. There is no waste of generated power.
[0025]
In addition, the solar power generation system of this invention is not limited only to the above-mentioned embodiment, Of course, various changes can be added within the range which does not deviate from the summary of this invention.
[0026]
【The invention's effect】
As described above, according to the present invention, power is generated by a turbine-type generator by pumping water into the upper aquarium with electric power generated by receiving sunlight and then flowing into the lower aquarium. There is no release of substances, and extremely clean power generation is possible. In addition, by using the speed control device described above, it is possible to supply high-quality generated power with a stable frequency and voltage outside the sunshine hours without using a storage battery and without wasting energy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a photovoltaic power generation system according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Pipe line 11 Upper tank 12 Lower tank 13 Generator 15, 18 Control panel 16 Power transmission line 17 Solar cell array 20, 21, 22, 28 Motor pump 23 Inflow pipe 24 Pit 29 Speed governor 30 AC / DC converter

Claims (5)

Comprising an upper water tank, and a lower water tank, before Symbol a motor pump for pumping the water in the lower water tank to the upper water tank, and a waterwheel type generator which generates power by flowing water of water of the upper water tank to the lower water tank In the power generation system ,
The turbine generator is a turbine generator that does not have a flow rate adjusting mechanism, and includes a speed governor that controls the number of rotations of the turbine generator, and the power generator of the turbine generator is generated by the speed governor. certain of the power supplies the surplus electric power supplied to the motor pump demand home side, from the lower water tank such that pumping to the upper water tank, the generated power and the rotational speed of the water turbine dynamo power generation systems that control means controls to keep the. Wherein the upper water tank, power generation system according to claim 1, characterized by comprising an inflow passage for introducing water river around. Wherein the lower water tank, power generation system of claim 1, wherein further comprising a pit for pumping groundwater. The motor pump, power generation system according to any one of claims 1 to 3, characterized in that using a DC motor operated by the governor. A power generation system according to any one of claims 1 to 4 and a solar power generation device, wherein the generated power of the solar power generation device is supplied to a motor pump, and water is pumped from the lower water tank to the upper water tank. A power generation system characterized by that.

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