JP7153457B2 - Power fluctuation mitigation method for renewable energy power generation system, and renewable energy power generation system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power fluctuation mitigation method for a renewable energy power generation system represented by solar power, wind power, etc. whose power generation fluctuates depending on weather conditions , and a renewable energy power generation system .

Renewable energies such as sunlight, hydraulic power, wind power, biomass, and geothermal energy are energies that emit almost no carbon dioxide. Introduction of these renewable energies is promoted as a countermeasure against depletion of fossil fuels such as petroleum, coal and natural gas, and as a countermeasure against global warming.

Power generated by renewable energy is introduced into the power system and used effectively. Until now, the introduction ratio of renewable energy was small, so it was not a problem. .

If the renewable energy power generation device is a solar power generation device or a wind power generation device, the generated power fluctuates depending on weather conditions. If a large amount of fluctuating power is introduced into the power system, it is feared that the frequency of the power system will become unstable and problems will occur during power transmission.

Therefore, electric power companies are implementing wide-area power operation that requires restrictions on the fluctuation range of power output to the power system, restrictions on whether it can be increased or decreased, and restrictions on the time periods for each site of renewable energy power generation equipment. Are considering. In response to this, on the side of each site of the renewable energy power generation equipment, the operation of mitigating fluctuations in the generated power according to the required limit and outputting it to the power system is being studied.
Hereinafter, the inventors will refer to power output to the power system as system output power.
Photovoltaic power plants generate electricity during the daytime, peaking at times when the sunlight is the strongest. Since no power is generated after the sun goes down, the power generated fluctuates from 0 to the maximum during the day. In addition, generated power fluctuates over a period of several minutes to several tens of minutes due to weather changes from sunny to cloudy.

Wind power generators can generate electricity day and night as long as there is wind. However, the wind force has fluctuations in intensity over several seconds and minutes, and fluctuations over several hours, and the generated power varies accordingly.
In this way, renewable energy power generators have fluctuations in generated power at different time intervals, and there is a need for a system that mitigates all these fluctuations.

As a method for this, there is a system in which a storage battery is provided and fluctuations are mitigated by charging and discharging the storage battery. However, when the fluctuation range and fluctuation period are large, the problem arises that the size of the storage battery increases and the cost of introducing the system soars.
To address this problem, Patent Document 1 describes that in a solar power generation device and a wind power generation device, a water electrolyzer device and a fuel cell are provided in addition to the storage battery to prevent the size of the storage battery from increasing.

Fluctuating generated power is mitigated by charging and discharging control of the storage battery, and when the storage ratio of the storage battery (hereinafter referred to as SOC) is large, power is supplied to the water electrolyzer device rather than charging the storage battery. , to produce and store hydrogen. On the other hand, if the battery has a low SOC, the stored hydrogen is used to drive the fuel cell to generate electricity and replenish power rather than discharging the battery.

In Patent Document 2, power generated by a renewable energy power generator is directly supplied to a water electrolyzer device, water oxygen gas is produced and stored, and the stored water oxygen gas is used to generate a fuel cell or an engine generator. Driving and fluctuation mitigation are described.

Japanese Patent No. 4775790 JP 2013-147735 A

According to the invention described in Patent Literature 1, energy to be stored in a storage battery is converted into hydrogen and stored as hydrogen, thereby suppressing an increase in the size of the storage battery. However, fuel cells have problems such as durability and cost reduction for practical use, and continuous development is underway.

Moreover, according to the invention described in Patent Document 2, since a storage battery is not used, it is possible to prevent the introduction cost of the system from rising. However, the water electrolyzer device has poor responsiveness compared to the storage battery, and it is difficult to mitigate the fluctuations for several seconds. In addition, a highly practical engine generator is required as a power generator that generates power using the stored fuel gas.
Therefore, a renewable energy power generation system composed of a storage battery, a water electrolysis device, and a power generation device that stores fuel gas such as hydrogen produced by the water electrolysis device and generates power using the stored fuel gas is appropriately controlled. to mitigate all generated power fluctuations over different time intervals ranging from seconds to hours.

Accordingly, the present invention provides a renewable energy power generation system in which a storage battery, a hydroelectric electrolysis device, a hydrogen storage medium, and an engine generator are added to a renewable energy power generation device whose power generation fluctuates depending on environmental conditions, without increasing the size of the storage battery. An object of the present invention is to appropriately mitigate fluctuations in system output power.

In order to solve the above-described problems, a power fluctuation mitigation method for a renewable energy power generation system of the present invention includes one or more renewable energy power generation devices, a storage battery, a water electrolyzer device, and a water electrolyser device. a hydrogen storage body that stores hydrogen stored in the storage battery; a generator that generates power using the stored hydrogen; a first threshold value for determining a storage amount of the storage battery; Two thresholds are provided, and at least one threshold is provided for determining the storage amount of the hydrogen storage body, in the power fluctuation mitigation method for a renewable energy power generation system, wherein the storage amount of the storage battery and the hydrogen measuring the storage amount of a storage medium; and using the charge/discharge power of the storage battery, the operating power of the water electrolyzer device, and the hydrogen according to the measured storage amount of the storage battery and the measured hydrogen storage amount. and at least one threshold for determining the storage capacity of the hydrogen reservoir, respectively controlling the power from the generators generated by the , if the storage amount of the hydrogen storage body is equal to or less than the threshold value, the step of reducing the power output to the power system by any allowable fluctuation range regardless of the increase or decrease in the power generated by the renewable energy power generation device; When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is between the first threshold value and the second threshold value, the power output to the power system is controlled by the renewable energy power generation device. when the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is higher than the first threshold value. is the step of increasing the power output to the power system by any allowable fluctuation range regardless of the increase or decrease in the power generated by the renewable energy power generation device; and and, when the storage amount of the storage battery is lower than the second threshold, the power output to the power system is decreased within an arbitrary allowable fluctuation range regardless of the increase or decrease in the power generated by the renewable energy power generation device. and a step of causing .
A renewable energy power generation system of the present invention comprises one or more renewable energy power generation devices, a storage battery, a water electrolyzer device, a hydrogen storage body for storing hydrogen generated in the water electrolyzer device, and the stored hydrogen. a generator for generating electricity using hydrogen, a first threshold for determining the storage capacity of the storage battery, and a second threshold lower than the first threshold, at least for determining the storage capacity of the hydrogen reservoir. One threshold is set, and the charge/discharge power of the storage battery, the operating power of the water electrolyzer device, and the power generated using the hydrogen are determined according to the storage amount of the storage battery and the hydrogen storage amount. The power from the generator is controlled so as to mitigate fluctuations in the power generated by the renewable energy, the storage amount of the hydrogen storage body is higher than the threshold, and the storage amount of the storage battery is the first threshold and the second threshold. 2 threshold, the power output to the power system is increased or decreased within an arbitrary allowable fluctuation range in accordance with the increase or decrease in the power generated by the renewable energy power generation device, and the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is higher than the first threshold value, the power output to the power system can be allowed regardless of the increase or decrease in the power generated by the renewable energy power generation device When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is lower than the second threshold value, the power generated by the renewable energy power generation device is increased or decreased. first, a control device that reduces the power output to the electric power system by an arbitrary fluctuation range that can be allowed.
Other means are described in the detailed description.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to moderate the fluctuation|variation of system output power appropriately, without enlarging a storage battery.

It is a figure which shows the wind power generation system of 1st Embodiment. FIG. 10 is a flowchart (Part 1) for controlling the wind power generation system using the level condition of the storage amount of the hydrogen tank and the level condition of the storage amount of the storage battery; FIG. It is a figure which shows an example of the behavior of a water electrolytic cell apparatus. FIG. 10 is a flowchart (part 2) for controlling the wind power generation system using the level condition of the storage amount of the hydrogen tank and the level condition of the storage amount of the storage battery; FIG. 3 is a flowchart (part 3) for controlling the wind power generation system using the level condition of the amount of storage in the hydrogen tank and the level condition of the amount of storage in the storage battery. 4 is a flowchart (part 4) for controlling the wind power generation system using the hydrogen tank storage amount level condition and the storage battery storage amount level condition; 7 is a graph showing control results of the wind power generation system; It is a figure which shows the photovoltaic power generation system of 2nd Embodiment. It is a flow chart for controlling a photovoltaic power generation system. It is a graph which shows an example of the control result of a photovoltaic power generation system. 9 is a graph showing another example of control results of the photovoltaic power generation system; It is a figure which shows the system in which the wind power generator and solar power generator of 3rd Embodiment coexist. 4 is a flow chart for controlling a system in which wind power generators and solar power generators are mixed. It is a graph which shows the control result of the system with which the wind power generator and solar power generator were mixed in 3rd Embodiment.

The present invention has been described with reference to renewable energy power generation equipment including solar power generation equipment and wind power generation equipment whose generated power fluctuates depending on weather conditions. However, the present invention can also be applied to systems in which the generated power fluctuates, even with solar thermal power plants, hydraulic power plants, geothermal power plants, wave power plants, temperature difference power plants, and biomass power plants.

<<1st Embodiment>>
FIG. 1 is a diagram showing a wind power generation system S of the first embodiment.
A wind power generation system (renewable energy power generation system) S includes wind power generation devices (renewable energy power generation devices) 1a to 1c. 4, a hydrogen tank 5, an engine generator 6, and a control device 7 for integrally controlling them.

The wind turbine generator system S of the first embodiment includes three wind turbine generators 1a to 1c. However, the wind turbine generator system S is not limited to this, and may include a single wind turbine generator or an arbitrary number of wind turbine generators.

The wind turbine generators 1a to 1c are connected to the input side of a transformer 11, and are connected to the power system via the transformer 11. FIG. A power meter 12 for measuring the generated power P_in(t) of the wind turbine generators 1a to 1c and a power meter 13 for measuring the system output power P_out(t) are provided on the bus 14 on the output side of the transformer 11. there is The power meters 12 and 13 output the measured power information to the control device 7 . The wind turbine generators 1a to 1c are simply referred to as the wind turbine generator 1 when they are not particularly distinguished.

The wind turbine generator 1 rotates blades with wind power, and the rotational force of the blades rotates a generator to generate power. The generated power P_in(t) obtained by the wind turbine generator 1 is alternating current. The transformer 11 adjusts the power P_in(t) generated by the wind turbine generator 1 to a predetermined voltage and introduces it into the power system.
In the wind turbine generator 1, the generated power P_in(t) fluctuates due to fluctuations in the wind force. Fluctuations in the generated power P_in(t) include short-term fluctuations over several seconds to tens of seconds, medium-term fluctuations over several minutes to tens of minutes, and long-term fluctuations over several hours.

Renewable energy power generation such as wind power generation is being promoted as a clean energy power generation technology that is friendly to the environment and prevents depletion of fossil fuels and global warming. Due to the increase in the amount of renewable energy power generation introduced, output fluctuations may affect the frequency maintenance of the power grid and affect the grid users. Therefore, the operator of the wind power generation system S must mitigate the fluctuation of the generated power P_in(t) to a level that does not affect frequency adjustment.

The storage battery 3 is one of means for alleviating fluctuations in the generated power P_in(t). The storage battery 3 is connected to a bus 14 on the output side of the transformer 11 via a storage battery PCS (power control system) 31 . The storage battery storage amount meter 32 is a sensor that measures the storage amount C_bat(t) of the storage battery 3 . The storage battery storage amount meter 32 outputs the measured storage amount C_bat(t) of the storage battery 3 to the control device 7 .

The storage battery PCS 31 is a device that performs AC/DC conversion and voltage conversion. The control device 7 controls the charging and discharging of the storage battery 3 at intervals of several seconds, thereby alleviating fluctuations in the electric power P_in(t) generated by the wind turbine generator 1 on a second-by-second basis. In order to mitigate minute-by-minute and hour-by-hour fluctuations in the power P_in(t) generated by the wind turbine generator 1, the capacity of the storage battery 3 should be increased. However, the introduction of the large-capacity storage battery 3 raises a problem that the cost of constructing the system rises.

The water electrolyzer device 4 is one of means for mitigating fluctuations in the generated power P_in(t). The water electrolyzer device 4 is connected to the bus 14 via a transformer 41 and an AC/DC converter 42 . The transformer 41 converts the AC voltage applied to the bus 14 . The AC/DC converter 42 converts the alternating current output by the transformer 41 into direct current. The water electrolyzer device 4 electrolyzes water using the DC power output from the AC/DC converter 42 to produce hydrogen and oxygen. The wattmeter 43 measures the operating power P_ele(t) of the water electrolyzer device 4 .

When the storage amount C_bat(t) of the storage battery 3 is large, the control device 7 introduces electric power to the water electrolyzer device 4 to produce hydrogen and oxygen. Hydrogen produced by the water electrolyzer device 4 is stored in the hydrogen tank 5 . Moreover, although not shown, the oxygen produced by the water electrolyzer device 4 may be released into the atmosphere, or may be stored in an oxygen tank (not shown) and utilized.

The hydrogen tank 5 is a hydrogen storage body that stores the produced hydrogen and releases the hydrogen when it is used. The hydrogen storage amount meter 51 is a sensor that measures the storage amount C_H2(t) of the hydrogen tank 5 . Although the hydrogen stored in the hydrogen tank 5 may be traded, it is used as fuel for the engine generator 6 in the present invention.
The hydrogen storage is not limited to a tank that stores hydrogen gas at high pressure, and may be a system that stores and releases hydrogen using a hydrogen storage alloy or a methylcyclohexane (MCH) storage.

The engine generator 6 generates AC power and introduces it to the bus 14 . The wattmeter 62 measures the electric power P_eng(t) generated by the engine generator 6 . The electric power generated by the engine generator 6 is merged with the electric power P_in(t) generated by the wind turbine generator 1 . As a result, the storage battery 3 can be charged and the system output power P_out(t) can be compensated.

The engine generator 6 is a hydrogen co-combustion engine generator that mixes hydrogen with gasoline or light oil, and generates AC power while emitting exhaust gas 61 . Ignition reciprocating engines using gasoline as fuel and self-ignition diesel engines using light oil or LPG (Liquefied Petroleum Gas) as fuel have been put to practical use and are widely used. Hydrogen co-combustion engines that operate by adding hydrogen to these fuels are scheduled to be put into practical use soon.

Note that the engine generator 6 is not limited to this, and the engine generator 6 may be a hydrogen-fired engine generator, a hydrogen-fired gas turbine generator, or a hydrogen co-fired gas turbine generator in which hydrogen is mixed with LNG (Liquefied Natural Gas). Alternatively, it may be a fuel cell that generates electricity using hydrogen.

Hydrogen-fired engines have been developed for a long time, and there are also demonstration examples. However, the hydrogen-only combustion engine has a problem of embrittlement of the metal constituting the engine. In order to avoid the inner fire caused by the high combustion speed, the hydrogen-only combustion engine requires lean combustion and has the problem of low output. ing.

A gas turbine that uses hydrogen has a problem that nitrogen oxides (NOx) are likely to be generated, although the efficiency is improved by increasing the combustion temperature. Therefore, technology development for low NOx combustion is underway, and further development is still underway toward practical use.

Since fuel cells require high-purity hydrogen, there is a problem that a system for refining hydrogen is required. In addition, fuel cells have problems in terms of durability and cost reduction, and are currently being further developed for practical use.

In the present invention, 365-day test performance data of the wind turbine generator 1 was used to construct a system control method that can be applied throughout the year.

The control device 7 takes in the measured values of the power meters 12 and 13 , the battery storage amount meter 32 , the power meter 43 , the hydrogen storage amount meter 51 and the power meter 62 . The control device 7 further sends commands to control units attached to the storage battery 3 , the water electrolyzer device 4 and the engine generator 6 . The control device 7 causes the storage battery 3 to charge and discharge, and controls the water electrolyzer device 4 and the engine generator 6 to start and stop, thereby setting the system output power P_out(t) to a desired value. .
The monitor 71 displays each measurement value and control parameter that the control device 7 takes in.

Hereinafter, the inventors will explain the control method of the power fluctuation mitigation system in the renewable energy power generator of the present invention.
2 and 4 to 6 are flowcharts for controlling the wind power generation system S using the storage amount C_H2(t) of the hydrogen tank 5 and the storage amount C_bat(t) of the storage battery 3. FIG.
The wind power generation system S must store hydrogen in the hydrogen tank 5 . This is to enable the engine generator 6 to be activated to compensate for the output power when the system output power P_out(t) is insufficient.

Therefore, the control device 7 acquires the measured value C_H2(t-Δt) of the storage amount of the hydrogen tank 5 at the previous time (t-Δt) (step S10), and sets the threshold value as the level condition of the storage amount of the hydrogen tank 5. C_H2_H1 (high) is set (step S11).

In step S12, if the measured value C_H2(t-Δt) of the storage amount of the hydrogen tank 5 is equal to or lower than the threshold value C_H2_H1 (high) (Yes), the control device 7 proceeds to step S14 via step S13 and stores hydrogen. made to store. The threshold C_H2_H1 (high) for the storage amount of the hydrogen tank 5 is preferably set to a high value so that the engine generator 6 can operate for a long time.
If the measured value C_H2(t-Δt) of the storage amount of the hydrogen tank 5 exceeds the threshold value C_H2_H1 (high), the controller 7 proceeds to step S30 in FIG.

In step S13, the wind power generation system S needs to operate the water electrolyzer device 4 to store hydrogen. Therefore, the control device 7 sets the fluctuation width ΔP_c of the system output power.
Further, in step S14, if the setting 01, 04 where the electric power company has recognized a decrease in the system output power P_out(t) (Yes), the control device 7 outputs the system output power P_out( This fluctuation range ΔP_c is subtracted from t−Δt) and set as the system output power P_out(t) at the current time t (step S15).

In other words, in settings 01 and 04, if the amount of storage in the hydrogen tank 5 is equal to or less than the threshold value C_H2_H1, the control device 7 outputs the system output to the power system regardless of the increase or decrease in the power generated by the wind power generator 1 Decrease the power P_out(t) by any permissible fluctuation width ΔP_c. By this operation, the wind power generation system S can supply electric power to the storage battery 3 and the water electrolyzer device 4 .
In step S14, if the setting 01 or 04 is not recognized by the electric power company to reduce the system output power P_out(t) (No), the process proceeds to step S16.

In step S16, the control device 7 acquires the storage amount C_bat(t-Δt) of the storage battery 3 at the previous time (t-Δt), and then sets the threshold value C_bat_H2 (high and high) of the storage battery 3 (step S17). .

Then, in step S18, if the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or greater than the threshold value C_bat_H2 (high-high) (Yes), the control device 7 proceeds to step S19 to A certain minimum operating power P_ele_start is acquired, and the water electrolyzer device 4 is started to produce hydrogen (step S20). At step S20 in FIG. 2, the start-up of the water electrolyzer device 4 is described as "P_ele(t)=P_ele_start". P_ele(t) is the operating power of this water electrolyzer device 4 . After that, the control device 7 proceeds to the process of step S50 in FIG.
On the other hand, in step S18, if the storage amount C_bat(t-Δt) of the storage battery 3 is lower than the threshold value C_bat_H2 (high and high) (No), the control device 7 proceeds to the process of step S38 in FIG.

FIG. 3 is a diagram schematically showing the behavior of the water electrolytic cell device 4. As shown in FIG.
When the storage amount C_bat(t-Δt) of the storage battery 3 exceeds the threshold value C_bat_H1 at time t1, the water electrolyzer device 4 is activated. A minimum operating power P_ele_start is required to start the water electrolyzer device 4 . That is, the water electrolyzer device 4 cannot operate with power lower than the minimum operating power P_ele_start.
At time t2, the water electrolyzer device 4 reaches the rated power. That is, it takes time (t2-t1) for the water electrolyzer device 4 to reach the rated power. The time (t2-t1) to reach the rated power is several minutes.

When the storage amount C_bat(t-Δt) of the storage battery 3 falls below the threshold C_bat_L2 at time t3, the water electrolyzer device 4 stops.

The rate at which the water electrolyzer device 4 produces hydrogen is proportional to the current flowing. If the water electrolyzer device 4 is controlled in a short time of several seconds, the time (t2-t1) cannot be secured, the charging current is small, and the hydrogen production rate is low. Therefore, the water electrolyzer device 4 is not suitable for alleviating short-term fluctuations in the generated power P_in(t). Therefore, we decided to construct a control method that operates continuously for several tens of minutes, in order to use it to mitigate medium-term fluctuations.

FIG. 4 is a flowchart (part 2) for controlling the wind power generation system S using the level condition of the storage amount C_H2(t) of the hydrogen tank 5 and the level condition of the storage amount C_bat(t-Δt) of the storage battery 3. be.
If the measured value C_H2(t-Δt) of the storage amount of the hydrogen tank 5 at time (t-Δt) is greater than the storage amount threshold C_H2_H1 (see node A in FIG. 2), proceed to step S30 in FIG. The system output power P_out(t) is controlled according to the storage amount C_bat(t-Δt) of the storage battery 3 . In step S30, the control device 7 acquires the storage amount C_bat(t-Δt) of the storage battery 3 at the previous time (t-Δt).
In step S<b>31 , the control device 7 sets a threshold C_bat_L2 (low) as a level condition of the storage battery 3 .

Here, a threshold C_bat_H1 (high) and a threshold C_bat_L2 (low) are newly provided as conditions for determining the storage amount C_bat(t-Δt) of the storage battery 3 .

In step S32, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is equal to or greater than the threshold C_bat_L2 and equal to or less than the threshold C_bat_H1, the process proceeds to step S40 in FIG. -Δt) is less than the threshold C_bat_L2 or exceeds the threshold C_bat_H1, the process proceeds to step S33, and multiple branching is performed according to the setting.

In step S33, the controller 7 proceeds to the process of step S34 if the setting is 01, to the process of step S35 if the setting is 02, to the process of step S36 if the setting is 03, and to the process of step S37 if the setting is 04. proceed to

Setting 01 is a mode in which the electric power company permits an increase or decrease in the system output power P_out(t). In step S34, if the storage amount C_bat(t-Δt) of the storage battery 3 at time (t-Δt) is smaller than the threshold value C_bat_L2, regardless of the generated power P_in(t) at time t this time, The system output power P_out(t) at time t is set by subtracting the fluctuation width ΔP_c from the system output power P_out(t−Δt) at the previous time (t−Δt). That is, the control device 7 performs control to charge the storage battery 3 by decreasing the system output power P_out(t).

On the other hand, in step S34, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is greater than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous is set by adding the variation width ΔP_c to the system output power P_out(t−Δt) at time (t−Δt). That is, the control device 7 controls to discharge the storage battery 3 by increasing the system output power P_out(t). After the process of step S34, the control device 7 proceeds to the process of step S38.

Setting 02 is a mode in which the electric power company permits an increasing change in the system output power P_out(t), but prohibits a decreasing change. In step S35, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is smaller than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous It is set to be the same as the system output power P_out(t-Δt) at time (t-Δt). That is, the control device 7 prevents the power system from being affected by not decreasing the system output power P_out(t). Such control is useful, for example, in the morning when the power system demand is high.

On the other hand, in step S35, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is greater than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous is set by adding the variation width ΔP_c to the system output power P_out(t−Δt) at time (t−Δt). That is, the control device 7 controls to discharge the storage battery 3 by increasing the system output power P_out(t). After the process of step S35, the control device 7 proceeds to the process of step S38.

Setting 03 is a mode in which an increase or decrease in system output power P_out(t) is prohibited. In step S36, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is smaller than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous It is set to be the same as the system output power P_out(t-Δt) at time (t-Δt). That is, the control device 7 prevents the influence on the power system by not changing the system output power P_out(t). Such control is necessary, for example, during the daytime when the power system continues to have a high demand.

On the other hand, in step S36, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is greater than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous is set to be the same as the system output power P_out(t-Δt) at time (t-Δt). That is, the control device 7 prevents the influence on the power system by not changing the system output power P_out(t). Such control is necessary, for example, during a time period when the power system demand is low, such as at night. After the process of step S36, the control device 7 proceeds to the process of step S38.

Setting 04 is a mode in which an increasing fluctuation of the system output power P_out(t) is prohibited, but a decreasing fluctuation is permitted. In step S37, if the storage amount C_bat(t-Δt) of the storage battery 3 at time (t-Δt) is smaller than the threshold value C_bat_L2, regardless of the generated power P_in(t) at time t this time, The system output power P_out(t) at time t is set by subtracting the fluctuation width ΔP_c from the system output power P_out(t−Δt) at the previous time (t−Δt). That is, the control device 7 performs control to charge the storage battery 3 by decreasing the system output power P_out(t).

On the other hand, in step S37, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is greater than the threshold value C_bat_L2, the control device 7 changes the system output power P_out(t) at the current time t to the previous is set to be the same as the system output power P_out(t-Δt) at time (t-Δt). That is, the control device 7 prevents the power system from being affected by not increasing the system output power P_out(t). Such control is necessary, for example, during times of low demand in the power system, such as at night. After the process of step S37, the control device 7 proceeds to the process of step S38.

2, when the storage amount C_bat(t-Δt) of the storage battery 3 at time (t-Δt) is less than the threshold value C_bat_H1 (see node B in FIG. 2), the control device 7 It was made to progress to step S38.

In step S38, the control device 7 calculates the system output power P_out(t) from the generated power P_in(t), and the operating power P_ele(t) of the water electrolyzer device 4 if the water electrolyzer device 4 is in operation. By subtracting, the charge/discharge power P_bat(t) of the storage battery 3 is controlled. Here, positive charge/discharge power P_bat(t) represents charging, and negative charge/discharge power P_bat(t) represents discharging. After the process of step S38, the control device 7 proceeds to the process of step S51 in FIG.
At this point, one type of threshold value C_H2_H1 for the storage amount of the hydrogen tank 5 and two types of the first threshold value C_bat_H1 and second threshold value C_bat_L2 for the storage amount of the storage battery 3 become control parameters.

FIG. 5 is a flowchart (part 3) for controlling the wind power generation system S using the level condition of the storage amount of the hydrogen tank 5 and the level condition of the storage amount of the storage battery 3 .
The control device 7 measures the generated power P_in(t) (step S40), acquires the fluctuation width ΔP_c of the output power (step S41), and measures the system output power P_out(t−Δt) (step S42). Proceeding to step S43, multiple branching occurs according to the set mode.

In step S43, the control device 7 proceeds to the process of step S44 if the setting is 01, to the process of step S45 if the setting is 02, to the process of step S46 if the setting is 03, and to the process of step S47 if the setting is 04. proceed to

Setting 01 is a mode in which the power company permits an increase or decrease in the system output power P_out(t). In step S44, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is zero or negative, the current The system output power P_out(t) at time t is set by subtracting the fluctuation width ΔP_c from the system output power P_out(t−Δt) at the previous time (t−Δt).

Further, in step S44, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is positive, the current The system output power P_out(t) at time t is set by adding the variation width ΔP_c to the system output power P_out(t−Δt) at the previous time (t−Δt). After the process of step S44, the control device 7 proceeds to the process of step S48.

That is, if the system output power P_out(t-Δt) is smaller than the generated power P_in(t), the control device 7 reduces the system output power P_out(t), If P_out(t-Δt) is large, control is performed to increase the system output power P_out(t). Here, the fluctuation width ΔP_c is set to a constant equal to or less than the allowable fluctuation width for the system output power P_out(t) requested by the electric power company.

Setting 02 is a mode in which the electric power company permits an increasing change in the system output power P_out(t), but prohibits a decreasing change. In step S45, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is zero or negative, the current The system output power P_out(t) at time t is set to be the same as the system output power P_out(t-Δt) at the previous time (t−Δt).

On the other hand, in step S45, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is positive, the current The system output power P_out(t) at time t is set by adding the variation width ΔP_c to the system output power P_out(t−Δt) at the previous time (t−Δt). After the process of step S45, the control device 7 proceeds to the process of step S48.

That is, if the system output power P_out(t-Δt) is smaller than the generated power P_in(t), the control device 7 does not change the system output power P_out(t), and the system output If the power P_out(t-Δt) is large, control is performed to increase the system output power P_out(t).

Setting 03 is a mode in which an increase or decrease in system output power P_out(t) is prohibited. In step S46, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is zero or negative, the current The system output power P_out(t) at time t is set to be the same as the system output power P_out(t-Δt) at the previous time (t−Δt).

On the other hand, in step S46, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is positive, the current The system output power P_out(t) at time t is set to be the same as the system output power P_out(t-Δt) at the previous time (t−Δt). After the process of step S46, the control device 7 proceeds to the process of step S48.
That is, the control device 7 does not change the system output power P_out(t) regardless of the magnitude relationship between the generated power P_in(t) and the system output power P_out(t-Δt).

Setting 04 is a mode in which an increasing fluctuation of the system output power P_out(t) is prohibited, but a decreasing fluctuation is permitted. In step S47, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is zero or negative, the current The system output power P_out(t) at time t is set by subtracting the fluctuation width ΔP_c from the system output power P_out(t−Δt) at the previous time (t−Δt).

On the other hand, in step S47, if the difference between the generated power P_in(t) at the current time t and the system output power P_out(t-Δt) at the previous time (t-Δt) is positive, The system output power P_out(t) at time t is set to be the same as the system output power P_out(t-Δt) at the previous time (t−Δt). After the process of step S47, the control device 7 proceeds to the process of step S48.

That is, if the system output power P_out(t-Δt) is smaller than the generated power P_in(t), the control device 7 reduces the system output power P_out(t), If P_out(t-Δt) is large, control is performed to increase the system output power P_out(t). Here, the fluctuation width ΔP_c is set to a constant equal to or less than the allowable fluctuation width for the system output power P_out(t) requested by the electric power company.

In step S48, the control device 7 calculates the system output power P_out(t) from the generated power P_in(t), and the operating power P_ele(t) of the water electrolyzer device 4 if the water electrolyzer device 4 is in operation. By subtracting, the charge/discharge power P_bat(t) of the storage battery 3 is controlled. Here, positive charge/discharge power P_bat(t) represents charging, and negative charge/discharge power P_bat(t) represents discharging. After the process of step S48, the control device 7 proceeds to the process of step S51 in FIG.

FIG. 6 is a flowchart (part 4) for controlling the wind power generation system S using the level condition of the storage amount of the hydrogen tank 5 and the level condition of the storage amount of the storage battery 3 .
In step S19 of FIG. 2, when the control device 7 starts the water electrolytic cell device 4, the process proceeds to step S50 via the node C of FIG. In step S<b>50 , the control device 7 acquires a threshold C_bat_L2 as a level condition for the storage amount C_bat(t−Δt) of the storage battery 3 .

After finishing the process of step S38 in FIG. 4 and the process of step S48 in FIG. 5, the control device 7 proceeds to the process of step S51 via node E in FIG. In step S51, the control device 7 determines whether or not the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or less than the threshold value C_bat_L2. If the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or less than the threshold value C_bat_L2 (Yes), the control device 7 stops the water electrolytic cell device 4 (step S52), and proceeds to the process of step S53. If the storage amount C_bat(t-Δt) of the storage battery 3 exceeds the threshold value C_bat_L2 (No), the controller 7 proceeds to the process of step S57.

In step S<b>53 , the control device 7 acquires a threshold C_bat_L<b>1 as a level condition for the storage amount C_bat(t−Δt) of the storage battery 3 . Furthermore, in step S54, the control device 7 determines whether or not the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or less than the threshold value C_bat_L1. In step S54, if the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or less than the threshold value C_bat_L1 (Yes), the control device 7 acquires the start condition P_eng_start of the engine generator 6 (step S55). is activated (step S56), and the process proceeds to step S58.
On the other hand, in step S54, if the storage amount C_bat(t-Δt) of the storage battery 3 exceeds the threshold value C_bat_L1 (No), the controller 7 proceeds to step S57.

In step S57, the control device 7 stops the engine generator 6, and proceeds to the process of step S58. In step S58, the control device 7 updates the time t by the time interval Δt, and returns to step S10 of FIG.

In a series of controls, the control device 7 stops the water electrolytic cell device 4 when the storage amount C_bat(t-Δt) of the storage battery 3 becomes smaller than the threshold value C_bat_L2. That is, the control device 7 controls the operating power P_ele(t) of the water electrolyzer device 4 to be zero.
The water electrolyzer device 4 starts when the storage amount C_bat(t-Δt) of the storage battery 3 becomes larger than the threshold value C_bat_H1, and stops when it becomes smaller than the threshold value C_bat_L2. do.

Furthermore, in this embodiment, a threshold value C_bat_L1 is provided as a level condition for the storage amount C_bat(t-Δt) of the storage battery 3 . The threshold C_bat_L1 may be the threshold C_bat_L2, but it is desirable that the threshold C_bat_L1 is lower than the threshold C_bat_L2. When the storage amount C_bat(t−Δt) of the storage battery 3 becomes equal to or less than the threshold value C_bat_L1, the engine generator 6 is started to charge the storage battery 3 .

The engine generator 6 has a minimum power output and a load-up operation time. Therefore, the engine generator 6 also needs to be able to operate continuously for an arbitrary time. Control to start and stop within the range of the storage level of the storage battery 3 is desirable, and control is performed to start when the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or less than the threshold C_bat_L1 and to stop when it exceeds the threshold C_bat_L2.

At this point, as control parameters, one type of threshold value C_H2_H1 is required as a level condition of the storage amount of the hydrogen tank 5, and two types of threshold values C_bat_H1 and C_bat_L2 are required as level conditions of the storage amount of the storage battery 3. Furthermore, it is desirable to add a threshold value C_bat_L1 as a level condition of the storage amount of the storage battery 3 and set three types.

The inventors have verified the control method of the first embodiment using 365-day test performance data of the wind power generation system S, and the result will be described below with reference to FIG. 7 .

FIG. 7 is a graph showing control results of the wind power generation system S. FIG. This graph is a control state diagram for one day out of 365 days.
The first graph from the top is a graph showing power generated P_in(t) by the wind turbine generator 1 and system output power P_out(t). The generated power P_in(t) indicated by the lightly hatched solid line has a predetermined fluctuation. However, the system output power P_out(t) indicated by the thick black dashed line is less fluctuating.

A setting 01 in the graph is a time period during which the system output power P_out(t) may be increased or decreased within a predetermined fluctuation value range. Setting 02 is a time period during which the system output power P_out(t) may be kept constant or increased, but not decreased. Setting 03 is a time period in which the system output power P_out(t) is kept constant and cannot be increased or decreased. Setting 04 is a time period during which the system output power P_out(t) may be kept constant or decreased, but not increased.

The second graph from the top is a graph showing the storage amount C_bat(t) of the storage battery 3 . The maximum capacity MAX of the storage battery 3 is indicated in the graph, and the threshold H2 (C_bat_H2), the threshold H1 (C_bat_H1), the threshold L2 (C_bat_L2), and the threshold L1 (C_bat_L1) are indicated as the storage amount level conditions. These thresholds are calculated using the graph of the operating power P_ele(t) of the water electrolyzer device 4 on the third row from the top and the graph of the power generated by the engine generator 6 P_eng(t) on the fifth row from the top. explain.

When the storage amount C_bat(t) of the storage battery 3 reaches the threshold value C_bat_H2 at times t10, t12, and t14, the water electrolyzer device 4 is activated as shown in the third graph. At times t11, t13, and t15, when the storage amount C_bat(t) of the storage battery 3 falls below the threshold value C_bat_L2, the water electrolyzer device 4 stops, as shown in the third graph. The two thresholds C_bat_H2 and C_bat_L2 of the storage amount C_bat(t) of the storage battery 3 can ensure the continuous operation time of the water electrolyzer device 4 .

Based on the test performance data for 365 days, it was found that setting the threshold value C_bat_H2 of the storage battery 3 facilitates control. Therefore, it is desirable to set four types of thresholds C_bat_H2, C_bat_H1, C_bat_L2, and C_bat_L1 as level conditions of the storage battery 3 .

When the storage amount C_bat(t) of the storage battery 3 falls below the threshold C_bat_L1 at time t16, the engine generator 6 starts as shown in the graph on the fifth tier. When the storage amount C_bat(t) of the storage battery 3 reaches the threshold C_bat_L2 at time t17, the engine generator 6 stops as shown in the graph on the fifth tier. The two thresholds C_bat_L1 and C_bat_L2 of the storage amount of the storage battery 3 can ensure the continuous operating time of the engine generator 6 .

In the graph of the generated power P_in(t) and the grid output power P_out(t) shown in the first row, the time period related to the second setting 02 is the time when the grid output power P_out(t) cannot be reduced. Obi. In the second half of this time period, the storage battery 3 is discharged to compensate for the system output power P_out(t), and when the storage amount C_bat(t) of the storage battery 3 becomes smaller than the threshold value C_bat_L1, the engine generator 6 is started, The generated power P_eng(t) compensates for the system output power P_out(t).

The fourth graph from the top is a graph of the storage amount C_H2(t) of the hydrogen tank 5 . The maximum capacity MAX of the hydrogen tank 5 is indicated in the graph, and the threshold value H1 (C_H2_H1) is indicated as the level condition of the storage amount C_H2(t).

From the graph of the storage amount C_H2(t) of the hydrogen tank 5 and the graph of the generated power P_in(t) and the grid output power P_out(t), the grid output power is It can be seen that P_out(t) is suppressed. At this time, the control device 7 charges the storage battery 3 and operates the water electrolyzer device 4 according to the storage amount of the storage battery 3 to increase the storage amount of the hydrogen tank 5 .

Also, although the storage amount C_H2(t) of the hydrogen tank 5 decreases due to the operation of the engine generator 6, a sufficient hydrogen storage amount is ensured even at this time.
Thus, in both the graph of the storage amount C_bat(t) of the storage battery 3 shown in the second row and the graph of the storage amount C_H2(t) of the hydrogen tank 5 shown in the fourth row, each storage amount is maximum. Appropriate control is achieved without exceeding the capacity and never becoming 0.

In the wind power generation system S using the wind power generator 1, as shown in the graph of FIG. t), the operating power P_ele(t) of the water electrolyzer device 4, the storage amount of the hydrogen tank 5, and the power generated by the engine generator 6 P_eng(t) are displayed on the monitor 71 of the control device 7. In addition, it is desirable that the threshold values C_bat_H2, C_bat_H1, C_bat_L2, and C_bat_L1 of the storage amount C_bat(t) of the storage battery 3 and the threshold value C_H2_H1 of the storage amount of the hydrogen tank 5 are written together. Thereby, the operator can easily grasp the control state of the wind power generation system S.

<<Second embodiment>>
The power generated by a photovoltaic power generation system has short-term fluctuations of several seconds to tens of seconds, medium-term fluctuations of several minutes to tens of minutes, and long-term fluctuations of several hours. only during the daytime. Furthermore, the power generated by the photovoltaic power generation device exhibits behavior of being high during the daytime and low during the morning and evening. Therefore, the control of the power fluctuation mitigation method for the photovoltaic power generator is simpler than the control of the power fluctuation mitigation method for the wind power generator. Therefore, the inventors constructed a simpler control method by using only a storage battery as a fluctuation mitigation device.

FIG. 8 is a diagram showing a photovoltaic power generation system Sa of the second embodiment.
The photovoltaic power generation system Sa includes a photovoltaic power generation device 2, a storage battery 3, and a control device 7 for integrally controlling the storage battery 3 in order to mitigate fluctuations in the generated power P_in2(t).

The photovoltaic power generation device 2 is connected to a photovoltaic power generation PCS (power control system) 21 , and is connected to the power system via the photovoltaic power generation PCS 21 and a bus line 24 . The bus line 24 is provided with a power meter 22 that measures the power generated by the photovoltaic power generation device 2 P_in2(t) and a power meter 23 that measures the system output power P_out2(t). The power meters 22 and 23 output the measured power information to the control device 7 .

The storage battery 3 is one of means for alleviating variations in the generated power P_in2(t). The storage battery 3 is connected to the bus 24 via the storage battery PCS 31 . The storage battery storage amount meter 32 is a sensor that measures the storage amount of the storage battery 3 . The storage battery storage amount meter 32 outputs the measured storage amount of the storage battery 3 to the control device 7 .

Electric power P_in2(t) generated by the photovoltaic power generation device 2 is direct current, is converted into alternating current by the PCS 21 for photovoltaic power generation, and is further adjusted to a predetermined voltage. Fluctuations in the generated power P_in2(t) of the photovoltaic power generation device 2 are mitigated by controlling the charging and discharging of the storage battery 3 via the storage battery PCS 31 .

FIG. 9 is a flowchart for controlling the photovoltaic power generation system Sa.
In this photovoltaic power generation system Sa, two types of threshold C_bat_H1 (high) and threshold C_bat_L2 (low) are provided as level conditions for the storage amount C_bat(t) of the storage battery 3 .

The control device 7 measures the storage amount C_bat(t-Δt) of the storage battery 3 at time (t-Δt) (step S60), and sets the threshold C_bat_L2 as the level condition for the storage amount C_bat(t-Δt) of the storage battery 3. After obtaining (step S61), the threshold value C_bat_H1 is obtained (step S62).
Next, the control device 7 determines whether or not the storage amount C_bat(t-Δt) of the storage battery 3 is equal to or greater than the threshold C_bat_L2 and equal to or less than the threshold C_bat_H1 (step S63). If the storage amount C_bat(t-Δt) of the storage battery 3 is greater than or equal to the threshold C_bat_L2 and less than or equal to the threshold C_bat_H1 (Yes), the control device 7 measures the generated power P_in2(t) at the current time t (step S64), A fluctuation range ΔP_c of the output power P_out(t) is obtained (step S65), and the system output power P_out2(t−Δt) at the previous time (t−Δt) is measured (step S66).
On the other hand, in step S63, if the storage amount C_bat(t-Δt) of the storage battery 3 is less than the threshold C_bat_L2 or exceeds the threshold C_bat_H1 (No), the controller 7 proceeds to the process of step S68.

In step S67, if the difference between the generated power P_in2(t) and the system output power P_out2(t-Δt) is 0 or less, the control device 7 changes the system output power P_out2(t) at the current time t to the previous time It is set by subtracting the fluctuation width ΔP_c from the system output power P_out2(t−Δt) at (t−Δt). That is, the control device 7 performs control to decrease the system output power P_out2(t). Here, the fluctuation width ΔP_c is a constant equal to or less than the allowable fluctuation width for the system output power P_out2(t) requested by the electric power company.

On the other hand, in step S67, if the difference between the generated power P_in2(t) and the system output power P_out2(t-Δt) is greater than 0, the control device 7 changes the system output power P_out2(t) at the current time t to the previous is set by adding the variation width ΔP_c to the system output power P_out2(t−Δt) at time (t−Δt). That is, the control device 7 performs control to increase the system output power P_out2(t). After completing the processing of step S67, the control device 7 proceeds to step S69.

In step S68, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is smaller than the threshold value C_bat_L2, the control device 7 generates power P_in2(t) at the current time t. , the system output power P_out2(t) at the current time t is set by subtracting the variation width ΔP_c from the system output power P_out2(t−Δt) at the previous time (t−Δt). That is, the control device 7 performs control to charge the storage battery 3 by decreasing the system output power P_out2(t).

On the other hand, in step S68, if the storage amount C_bat(t-Δt) of the storage battery 3 at the time (t-Δt) is greater than the threshold value C_bat_H1, the control device 7 is irrelevant to the generated power P_in2(t) at the current time t. Then, the system output power P_out2(t) at the current time t is set by adding the fluctuation range ΔP_c to the system output power P_out2(t−Δt) at the previous time (t−Δt). That is, the control device 7 controls to discharge the storage battery 3 by increasing the system output power P_out2(t). After completing the process of step S68, the control device 7 proceeds to step S69.

In step S69, the control device 7 controls the charge/discharge power P_bat(t) of the storage battery 3 by subtracting the system output power P_out2(t) from the generated power P_in2(t). When the charge/discharge power P_bat(t) is positive, it indicates charging, and when it is negative, it indicates discharging.
In step S70, the control device 7 updates the time t by the time interval Δt, and returns to step S60 to execute continuous control.

FIG. 9 illustrates a case where positive and negative fluctuations of the system output power P_out2(t) are allowed. The photovoltaic power generation device 2 can generate power only during the daytime, and the generated power P_in2(t) is generally high at noon and low in the morning and evening.
In addition, the electric power company may impose a request to prohibit positive or negative fluctuations of the system output power P_out2(t) during the daytime hours. In that case, the processing in step S67 or step S68 should be changed.

The inventors verified the control method of the second embodiment using 365-day test performance data of the photovoltaic power generation system Sa. FIG. 10 is a graph showing an example of control results of the photovoltaic power generation system Sa.

The rated output of the photovoltaic power generation device 2 is 1/2 of the rated output of the wind power generation device 1 described in the first embodiment, and there is no increase/decrease limit or time period limit for the system output power P_out2(t). The allowable fluctuation width ΔP_c is a constant.

The upper graph is a graph of generated power P_in2(t) and system output power P_out2(t). The generated power P_in2(t) indicated by the lightly hatched solid line has short-term fluctuations of several seconds to tens of seconds and medium-term fluctuations of several minutes to tens of minutes. This day is a day in which the short-term fluctuation and medium-term fluctuation of the generated power P_in2(t) are small. The system output power P_out2(t) indicated by the thick black dashed line changes along with the generated power P_in2(t).

The lower part is a graph of the storage amount C_bat(t) of the storage battery 3 . The solid line is the storage amount C_bat(t) of the storage battery 3, and two types of threshold H1 (C_bat_H1) and threshold L2 (C_bat_L2), which are level conditions for the storage amount of the storage battery 3, are described in the graph. The storage amount of the storage battery 3 is constant between the threshold C_bat_H1 and the threshold C_bat_L2 of the storage amount of the storage battery 3, and while the obtained generated power P_in(t) is moderated, almost the entire amount is reduced to the system output power P_out2(t) is output as

FIG. 11 is a graph showing another example of control results of the photovoltaic power generation system Sa.
As can be seen from the generated power P_in2(t) indicated by the lightly hatched solid line in the upper row, this is a day with a wide range of short-term fluctuations of several seconds to tens of seconds and medium-term fluctuations of several minutes to tens of minutes. The system output power P_out2(t) indicated by the thick black dashed line showed a monotonically increasing and decreasing behavior.

From the lower graph of the storage amount C_bat(t) of the storage battery 3, the time when the storage amount C_bat(t) of the storage battery 3 is equal to or greater than the threshold C_bat_H1 and the time when the storage amount C_bat(t) of the storage battery 3 is equal to or less than the threshold C_bat_L2 be. The system output power P_out2(t) monotonically increases in the process in which the storage amount C_bat(t) of the storage battery 3 becomes equal to or greater than the threshold C_bat_H1, and the system output power P_out2(t) increases in the process in which the storage amount of the storage battery 3 becomes equal to or less than the threshold C_bat_L2. Decrease monotonically.

Even when the range of short-term fluctuation and medium-term fluctuation was large in this way, the control device 7 was able to perform control within the range of the capacity of the storage battery 3 . Also, the control device 7 was able to control all power generation data for 365 days. Here, when the capacity of the storage battery 3 is made small, there are times when the storage amount of the storage battery 3 exceeds the maximum capacity or when the storage amount becomes 0 during 365 days. These time periods are uncontrollable time periods.

<<Third Embodiment>>
FIG. 12 is a diagram showing a power generation system Sb in which the wind turbine generator 1 and the solar power generator 2 of the third embodiment are mixed.
The inventors added the wind power generator 1 of the first embodiment and the solar power generator 2 of the second embodiment, and used the same storage battery 3, water electrolyzer device 4, and hydrogen tank 5 as in the first embodiment. and the engine generator 6 constitute a power generation system Sb.

FIG. 13 is a flowchart for controlling the power generation system Sb in which the wind power generator 1 and the solar power generator 2 are mixed. FIG. 13 is obtained by deleting the items related to the storage battery 3 in FIG. 9 , and the storage amount of the storage battery 3 is irrelevant to the fluctuation mitigation of the photovoltaic power generation device 2 .
The control device 7 measures the generated power P_in2(t) at the current time t (step S64), acquires the fluctuation width ΔP_c of the system output power P_out2(t) (step S65), and calculates the previous time (t-Δt ) is measured (step S66).

In step S67, if the difference between the generated power P_in2(t) and the system output power P_out2(t-Δt) is 0 or less, the control device 7 changes the system output power P_out2(t) at the current time t to the previous time It is set by subtracting the fluctuation width ΔP_c from the system output power P_out2(t−Δt) at (t−Δt). That is, the control device 7 performs control to decrease the system output power P_out2(t). Here, the fluctuation width ΔP_c is a constant equal to or less than the allowable fluctuation width for the system output power P_out2(t) requested by the electric power company.

On the other hand, in step S67, if the difference between the generated power P_in2(t) and the system output power P_out2(t-Δt) is greater than 0, the control device 7 changes the system output power P_out2(t) at the current time t to the previous is set by adding the variation width ΔP_c to the system output power P_out2(t−Δt) at time (t−Δt). That is, the control device 7 performs control to increase the system output power P_out2(t). After completing the processing of step S67, the control device 7 proceeds to step S69.

In step S69, the control device 7 controls the charge/discharge power P_bat(t) of the storage battery 3 by subtracting the system output power P_out2(t) from the generated power P_in2(t). When the charge/discharge power P_bat(t) is positive, it indicates charging, and when it is negative, it indicates discharging.
In step S70, the control device 7 updates the time t by the time interval Δt, and returns to step S64 to execute continuous control.

Here, FIG. 13 illustrates a case where fluctuations in the system output power P_out2(t) are allowed. If the electric power company requests that the system output power P_out2(t) be prohibited from fluctuating during the daytime hours, the process of step S67 may be changed to steps S43 to S47 in FIG.

The control method for reducing the power generated P_in(t) by the wind turbine generator 1 is the same as in the first embodiment. Here, from the system diagram of FIG. 12, after the power generated P_in(t) by the wind turbine generator 1 and the power generated by the solar power generator 2 P_in2(t) are combined, fluctuations are mitigated in the power generation system Sb. It will be output to the power system later.

However, the system output power P_out(t) of the wind power generation system S of the first embodiment is subject to an increase/decrease limit and a time zone limit, and the system output power P_out2(t) of the photovoltaic power generation system Sa of the second embodiment is There was no increase or decrease limit or time period limit. The reason why these different limits are set is that the limits required by electric power companies may differ depending on the type of renewable energy power generator.

In the present invention, when combining different types of renewable energy power generation equipment, the restrictions imposed on each renewable energy power generation equipment are complied with. In other words, the system output power is output as one system output power, and the system output power is controlled by the wind turbine generator 1 and the solar power generator 2 respectively.

The inventors verified the control method using 365-day test performance data of the wind power generator 1 and the solar power generator 2 .
FIG. 14 is a graph showing control results of a system in which the wind power generator 1 and the solar power generator 2 are mixed in the third embodiment. The day when this control result was measured is a day when the short-term, medium-term, and long-term fluctuation ranges are large for both the wind power generator 1 and the solar power generator 2 .

The first row from the top shows the power generated P_in2(t) by the solar power generator 2 and the system output power P_out2(t), and the second row from the top shows the power generated P_in(t) by the wind power generator 1 and the system output power. P_out(t). The lightly hatched solid lines in the first and second graphs are the generated power P_in(t) and P_in2(t).

The black dashed lines in the first and second graphs are the system output powers P_out(t) and P_out2(t), respectively. 10, the system output power P_out2(t) of the solar power generation device 2 monotonously increases or decreases monotonically, but since it is controlled independently of the storage amount C_bat(t) of the storage battery 3, the generated power P_in2( t).
Here, the reason why the control of the system output power P_out2(t) of the photovoltaic power generation device 2 is made irrelevant to the storage amount C_bat(t) of the storage battery 3 will be explained.

When the storage amount C_bat(t) of the storage battery 3 is added to the fluctuation mitigation control of the photovoltaic power generation device 2, the generated power P_in2(t) of the photovoltaic power generation device 2 is small, and the power generation P_in(t) of the wind power generation device 1 is When it was large, a behavior occurred in which the system output power P_out2(t) in the photovoltaic power generation device 2 increased more than the generated power P_in2(t). In other words, the power P_in(t) generated by the wind turbine generator 1 was output as the power P_in2(t) generated by the solar power generator 2 .
In the present invention, the system output power P_out2(t) of the photovoltaic power generation device 2 and the system output power P_out(t) of the wind power generation device 1 are controlled separately. As a result, it turned out that control of the solar power generation device 2 can be performed easily.

The third graph from the top is a graph showing the storage amount C_bat(t) of the storage battery 3 . The maximum capacity MAX of the storage battery 3 is shown in the graph, and the threshold H2 (C_bat_H2), threshold H1 (C_bat_H1), threshold L2 (C_bat_L2), and threshold L1 (C_bat_L1) are shown as level conditions for the storage amount C_bat(t). there is
The fourth graph from the top is a graph of the operating power P_ele(t) of the water electrolyzer device 4 . At times t30, t32, and t38, the storage amount C_bat(t) of the storage battery 3 exceeds the threshold C_bat_H2, so the water electrolyzer device 4 is activated and the operating power P_ele(t) rises. At times t31, t33, and t39, the storage amount C_bat(t) of the storage battery 3 becomes equal to or less than the threshold value C_bat_L2, so the water electrolyzer device 4 stops and the operating power P_ele(t) becomes zero.

The fifth graph from the top is a graph of the storage amount C_H2(t) of the hydrogen tank 5 . The maximum capacity MAX of the hydrogen tank 5 is indicated in the graph, and the threshold value H1 (C_H2_H1) is indicated as the level condition of the storage amount C_H2(t).
The sixth graph from the top is a graph of power P_eng(t) generated by the engine generator 6 . At times t34 and t36, the storage amount C_bat(t) of the storage battery 3 becomes equal to or less than the threshold value C_bat_L1, so the engine generator 6 is activated and the generated power P_eng(t) rises. At times t35 and t37, the storage amount C_bat(t) of the storage battery 3 exceeds the threshold C_bat_L2, so the engine generator 6 stops and the generated power P_eng(t) becomes zero.

The threshold value C_bat_H2 of the storage amount of the storage battery 3 and the activation of the water electrolyzer device 4 correspond to each other. The threshold value C_bat_L2 of the storage amount of the storage battery 3 and the stoppage of the water electrolyzer device 4 correspond to each other. The continuous operation time of the water electrolytic cell device 4 can be ensured by the two threshold values of the storage amount of the storage battery 3 .

The threshold C_bat_L1 of the storage amount of the storage battery 3 and the activation of the engine generator 6 correspond, and the threshold C_bat_L2 of the storage amount of the storage battery 3 and the stop of the engine generator 6 correspond. The continuous operation time of the engine generator 6 can be ensured by the two threshold values of the storage amount of the storage battery 3 .

Setting 02 is a time zone in which the system output power P_out(t) cannot be increased or decreased, and there is a time zone in which the generated power P_in(t) is lower than the system output power P_out(t). At this time, the storage battery 3 is discharged to compensate for the system output power P_out(t). (t) is supplemented to the system output power P_out(t).

The fifth graph from the top is a graph of the storage amount C_H2(t) of the hydrogen tank 5 . The maximum capacity MAX of the hydrogen tank 5 is indicated in the graph, and the storage amount threshold value H1 (C_H2_H1) is indicated. Although the storage amount C_H2(t) of the hydrogen tank 5 decreases due to the operation of the engine generator 6, a sufficient hydrogen storage amount C_H2(t) is secured at this time.

In both the graph of the storage amount C_bat(t) of the storage battery 3 and the graph of the storage amount C_H2(t) of the hydrogen tank 5, appropriate control is performed so that each storage amount does not exceed the maximum capacity MAX and does not become 0. It has been verified that it works.

As in the first embodiment, the power generated by the wind power generator 1 P_in(t), the system output power P_out(t), the storage amount C_bat(t) of the storage battery 3, and the operating power of the water electrolyzer device 4 The measured values of P_ele(t), the storage amount C_H2(t) of the hydrogen tank 5, and the power generated by the engine generator 6 P_eng(t) are displayed on the monitor 71 of the control device 7. FIG. Furthermore, it is desirable that the monitor 71 displays both the threshold value of the storage amount of the storage battery 3 and the threshold value of the storage amount of the hydrogen tank 5 . This facilitates understanding of the control state of the power generation system Sb in the wind turbine generator 1 of the present invention and prediction of the next control state.

In the system of the first embodiment shown in FIG. 1 and the system of the third embodiment shown in FIG. 12, the capacities of the storage battery 3, the water electrolyzer device 4, the engine generator 6 and the hydrogen tank 5 are the same. be. Even if a photovoltaic power generation device 2 with half the rated output is added to the wind power generation device 1, the same power generation system Sb may be used, and the fluctuation mitigation control of the wind power generation device 1 can be applied as it is. Furthermore, fluctuation mitigation control for the photovoltaic power generation device 2 is simpler than fluctuation mitigation by itself.

That is, the power generation system Sb composed of the storage battery 3, the water electrolyzer device 4, the engine generator 6, and the hydrogen tank 5 generates electric power from the wind power generator 1 or a plurality of renewable energy power generators including the wind power generator 1. effective in relieving
Further, when the power generated by the wind power generator 1 and the solar power generator 2 was mixed and the fluctuation was alleviated only by the storage battery 3, the storage battery capacity was about 10 times the storage battery capacity of the present invention. Therefore, by combining the storage battery 3 with the water electrolyzer device 4, the engine generator 6, and the hydrogen tank 5, the storage battery capacity can be reduced to 1/10, and the introduction cost of the fluctuation mitigation system can be greatly reduced.

(Modification)
The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. A part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is also possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Some or all of the above configurations, functions, processing units, processing means, etc. may be realized by hardware such as integrated circuits. Each of the above configurations, functions, etc. may be realized by software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, and files that implement each function can be stored in recording devices such as memory, hard disks, SSDs (Solid State Drives), or recording media such as flash memory cards and DVDs (Digital Versatile Disks). can.
In each embodiment, control lines and information lines indicate those considered necessary for explanation, and not all control lines and information lines are necessarily indicated on the product. In fact, it may be considered that almost all configurations are interconnected.

Modifications of the present invention include, for example, the following (a) to (c).

(a) Wind power generators are renewable energy power generators with fluctuations in generated power, such as solar thermal power generators, hydraulic power generators, geothermal power generators, wave power generators, temperature difference power generators, and biomass power generators. good.
(b) The engine generator 6 may be an engine generator that fires only hydrogen, a gas turbine generator that fires only hydrogen, or a gas turbine generator that mixes hydrogen with LNG, and further uses hydrogen to generate electricity. It may be a fuel cell.
(c) The number of wind turbine generators 1 is not limited to three, and may be one or more.

S Wind power generation system (an example of a renewable energy power generation system)
Sa Photovoltaic power generation system (an example of a renewable energy power generation system)
Sb power generation system (an example of a renewable energy power generation system)
1 Wind power generator (an example of a renewable energy power generator)
11 transformers 12, 13, 22 power meter 2 photovoltaic power generation device (an example of a renewable energy power generation device)
21 PCS for photovoltaic power generation
3 storage battery 31 PCS for storage battery
32 Storage battery storage meter 4 Water electrolyzer device 41 Transformer 42 AC/DC converter 43 Power meter 5 Hydrogen tank (hydrogen storage)
51 Hydrogen storage meter 6 Engine generator (generator)
61 Exhaust 62 Power meter 7 Control device 71 Monitor

Claims (8)

One or a plurality of renewable energy power generators, a storage battery, a water electrolyzer device, a hydrogen storage body that stores hydrogen generated by the water electrolyzer device, and a generator that generates power using the stored hydrogen A first threshold for determining the storage amount of the storage battery and a second threshold lower than the first threshold are provided, and at least one threshold for determining the storage amount of the hydrogen storage body In a power fluctuation mitigation method for a renewable energy power generation system in which two thresholds are provided ,
measuring the storage amount of the storage battery and the storage amount of the hydrogen storage body;
According to the measured storage amount of the storage battery and the hydrogen storage amount, the charging and discharging power of the storage battery, the operating power of the water electrolyzer device, and the power from the generator generated using the hydrogen, respectively controlling to mitigate fluctuations in renewable energy generated power;
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is between the first threshold value and the second threshold value, the power output to the power system is controlled by the renewable energy power generation device. A step of increasing or decreasing within any allowable fluctuation range according to the increase or decrease in the generated power of
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is higher than the first threshold value, output to the power system regardless of increase or decrease in power generated by the renewable energy power generation device. increasing the power to be applied by any amount of variation that can be tolerated;
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is lower than the second threshold value, output to the power system regardless of increase or decrease in power generated by the renewable energy power generation device. reducing the power to be applied by any amount of variation that can be tolerated;
A power fluctuation mitigation method for a renewable energy power generation system, characterized by: activating the water electrolyzer device when the storage amount of the storage battery is equal to or greater than the first threshold;
2. The power fluctuation mitigation method for a renewable energy power generation system according to claim 1 , wherein: stopping the water electrolyzer device when the storage amount of the storage battery is equal to or less than the second threshold;
3. The power fluctuation mitigation method for a renewable energy power generation system according to claim 2 , wherein: activating the generator when the storage amount of the storage battery is equal to or less than the second threshold;
2. The power fluctuation mitigation method for a renewable energy power generation system according to claim 1 , wherein: stopping the generator when the storage amount of the storage battery is equal to or greater than the second threshold;
5. The power fluctuation mitigation method for a renewable energy power generation system according to claim 4 , wherein: The power generated by the renewable energy power generation device, the power output to the power system, the storage amount of the hydrogen storage body, the storage amount of the storage battery, the threshold set by the storage amount of the hydrogen storage body, and the a step of displaying the first and second thresholds set by the storage amount of the storage battery on the display device;
The power fluctuation mitigation method for a renewable energy power generation system according to any one of claims 1 to 5 , characterized in that: The renewable energy power generation system includes one or more wind turbines.
The power fluctuation mitigation method for a renewable energy power generation system according to any one of claims 1 to 6 , characterized in that: one or more renewable energy generators;
a storage battery;
a water electrolyzer device;
a hydrogen storage body for storing hydrogen generated in the water electrolytic cell device;
a generator that generates electricity using the stored hydrogen;
A first threshold for determining the storage amount of the storage battery, a second threshold lower than the first threshold, and at least one threshold for determining the storage amount of the hydrogen storage body are set, According to the storage amount of the storage battery and the storage amount of the hydrogen, the charging and discharging power of the storage battery, the operating power of the water electrolyzer device, and the power from the generator generated using the hydrogen are converted into renewable energy. Control each to mitigate fluctuations in generated power,
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is between the first threshold value and the second threshold value, the power output to the power system is controlled by the renewable energy power generation device. Increase or decrease within any permissible fluctuation range according to the increase or decrease of the generated power,
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is higher than the first threshold value, output to the power system regardless of increase or decrease in power generated by the renewable energy power generation device. increase the power to be applied by any amount of variation that can be tolerated,
When the storage amount of the hydrogen storage body is higher than the threshold value and the storage amount of the storage battery is lower than the second threshold value, output to the power system regardless of increase or decrease in power generated by the renewable energy power generation device. a control device that reduces the power to be applied by any permissible fluctuation range;
A renewable energy power generation system comprising:

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