JP2017158402A - Distributed power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersed power generation system capable of making a more contribution to environmental protection and reduction in utility cost (usage charge of fossil fuel) even when a suppression signal of inverse load flow power is output.SOLUTION: A controller 10 provided for a dispersed power generation system 1 controls generation power of fuel cell power generation apparatus 3 so that inverse load flow power is not more than allowable power expressed by a suppression signal of inverse load flow power when the suppression signal is input.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a distributed power generation system.

  A distributed power generation system including a power generation device that is grid-connected to a commercial power system can self-consume the power generated by the power generation device, and can supplement power that cannot be covered by the power generated by the power generation device with commercial power. Configured as follows.

  When a distributed power generation system is equipped with a power generation device that generates power using renewable energy (hereinafter sometimes referred to as a green power generation device), surplus power out of the power generated by the green power generation device Can be sold by reverse power flow to the commercial power system. On the other hand, if the distributed power generation system is equipped with a power generation device that generates power using fossil fuel (hereinafter sometimes referred to as non-green power generation device), excess power generated by the non-green power generation device You cannot sell electricity.

  Therefore, when the distributed power generation system is equipped with a green power generation device and a non-green power generation device, the power generated by the non-green power generation device is exclusively used for private consumption, The power generated by the green power generator is used for personal consumption and surplus power is sold.

  Patent Literature 1 discloses a distributed power generation system that can be installed in combination with a solar power generation device (solar cell). This distributed power generation system generates power and heat by generating power using supplied fuel (fossil fuel), and supplies the generated power and heat to the power load and heat load. And a controller for controlling the distributed power generator. Then, the controller controls the distributed power generation device so that the distributed power generation device generates power more preferentially than other time zones in the time zone in which the solar power generation device generates power. According to this, it is possible to maximize the surplus power generated by the solar power generation device by generating the distributed power generation device during the time period during which the solar power generation device generates power, and as a result, to maximize the amount of power sold. .

Japanese Patent No. 5254500

(Problems to be solved by the invention)
In recent years, due to the increase in green power generators, especially solar power generators, that are installed in distributed power generation systems, the amount of power that has been reversely flowed by some power companies exceeds the power control range of power companies. The possibility was shown. Therefore, in Japan, when there is a risk that the amount of reverse flowed power may exceed the power amount control range of the power company, a reverse flow power suppression signal is output to each distributed power generation system, and the distributed type It is becoming a rule to limit the reverse power flow from the green power generator provided in the power generation system.

  In a distributed power generation system including a green power generation device and a non-green power generation device, when a suppression signal is output for the reason described above and the reverse power flow from the green power generation device is limited, the green power generation is usually performed. The generated power (output) of the device is suppressed (limited). However, in this case, a situation is created in which the amount of power generation using fossil fuel is not suppressed while the amount of power generation using renewable energy is suppressed. Such a situation is not preferable from the viewpoint of environmental protection and reduction of utility costs (fossil fuel usage fee).

  The present invention is a distributed power generation system including a green power generation device and a non-green power generation device, and can contribute to environmental protection even when a reverse power flow suppression signal is output, and An object of the present invention is to provide a distributed power generation system that can contribute to a reduction in costs (fossil fuel usage fee).

(Means for solving the problem)
A distributed power generation system (1) according to the present invention includes a green power generation device (2) that generates power using renewable energy, a non-green power generation device (3) that generates power using fossil fuel, And a control device (10) for controlling the generated power of the power generator and the non-green power generator. The green power generator and the non-green power generator are connected to the commercial power system (C). In addition, it is configured such that surplus power generated by the green power generator can be reversely flowed.

  Then, the control device provided in the distributed power generation system according to the present invention, when the reverse flow power suppression signal is input, so that the reverse flow power is equal to or less than the allowable power represented by the suppression signal, Control power generated by non-green power generators.

  According to the distributed power generation system according to the present invention, the control device uses the non-green power instead of the power generated by the green power generator so that the reverse power flow is equal to or less than the allowable power when the suppression signal is input. Controls the power generated by the power generator. For example, when there is a need to suppress the reverse power flow below the allowable power due to the input of the suppression signal, for example, when the surplus power or the rated power of the green power generator is larger than the allowable power, the control device The generated power of the non-green power generator is reduced so that the tidal power is less than the allowable power. When the generated power of the non-green power generator decreases, the surplus power of the green power generator is allocated to self-consumption by the reduced amount. As a result, surplus power of the green power generator decreases, and accordingly, reverse power flow from the green power generator to the commercial power system decreases. Due to such a decrease in the reverse power flow, the reverse power flow is suppressed to power that is less than or equal to the allowable power. By executing such control by the control device, it is possible to realize a situation in which the decrease in the amount of power generation using renewable energy is suppressed (or not decreased) while the amount of power generation using fossil fuel is decreased. . By realizing such a situation, the amount of fossil fuel used can be reduced, which can contribute to environmental protection and can contribute to the reduction of utility costs (fossil fuel usage fee).

  In the present invention, “reverse power flow” is surplus power that flows backward from a distributed power generation system (specifically, a green power generation device) to a commercial power system. Further, the “allowable power” of the reverse power flow is an upper limit value of the reverse power flow when the reverse power control signal is input.

  The suppression signal may be a signal indicating the upper limit value of the reverse flow power, a signal indicating the reduction amount of the reverse flow power, or a signal indicating the reduction rate of the reverse flow power. May be. When the suppression signal is a signal representing the upper limit value of the reverse flow power, the allowable power is the upper limit value represented by the suppression signal. When the suppression signal represents the reduction amount of the reverse power flow, the allowable power is, for example, the reduction amount (for example, 5 kW) represented by the suppression signal from the rated power of the generated power of the green power generation device (for example, the solar power generation device). Is the power minus. When the suppression signal represents a reduction rate of the reverse power flow, the allowable power is, for example, a ratio (for example, 10%) represented by the suppression signal to the rated power of the generated power of the green power generation device (for example, the solar power generation device). The power obtained by multiplying the power by subtracting the surplus power (or rated power).

  In this case, when the suppression signal is input, the control device provided in the distributed power generation system according to the present invention calculates the suppression power that is the power to be reduced in order to suppress the reverse power flow to the allowable power or less. Suppressed power calculation processing (S103) and when the suppressed power is greater than 0 and less than or equal to the generated power of the non-green power generator, the generated power of the non-green power generator is reduced from the current generated power. The first suppression process (S105) for controlling the generated power of the non-green power generation apparatus so as to decrease to a power equal to or less than the subtracted power may be executed.

  According to this, when the control device executes the first suppression process, the power for the power (suppressed power) to be reduced in order to suppress the reverse power flow to the allowable power or less is all non-green power generator. It will be covered by the reduced power generated. For this reason, it is possible to suppress the reverse power flow to an allowable power or lower without reducing the power generated by the green power generator. Accordingly, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

  In the above, “suppressed power” is, for example, an allowable power expressed by a suppress signal from surplus power (for example, 10 kW) that can be reversely flowed from the green power generator to the commercial power system when the suppress signal is input. The power (for example, 2 kW) obtained by subtracting the power (for example, 8 kW). Since the surplus power of the green power generator is less than the rated power, the power obtained by subtracting the allowable power from the rated power may be used as the suppressed power. That is, the suppression power may be determined based on the rated power of the green power generator.

  In addition, the control device stops the power generation of the non-green power generator when the suppression power is larger than the power generated by the non-green power generator, and the generated power of the green power generator is The second suppression process for controlling the power generated by the green power generator so that the power obtained by subtracting the power reduced by the stoppage of power generation by the non-green power generator from the suppressed power is reduced to a power equal to or lower than the subtracted power. (S111) may be executed.

  According to this, the control device executes the above-described second suppression process, and suppresses the reverse power flow below the allowable power while minimizing the suppression amount (reduction amount) of the generated power of the green power generation device. can do. Moreover, by stopping the power generation of the non-green power generation apparatus, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

  The distributed power generation system according to the present invention may further include a storage battery (4) capable of charging and discharging electric power. In this case, when the suppression power is greater than the power generated by the non-green power generator and is equal to or less than the power represented by the sum of the power generated by the non-green power generator and the charged power of the storage battery. In addition, it is preferable to execute the third suppression process (S109) for stopping the power generation of the non-green power generation apparatus and operating the storage battery so that the generated power of the green power generation apparatus is charged in the storage battery.

  According to this, the control device executes the third suppression process described above to stop the power generation of the non-green power power generation device, and charges the storage battery with the power generated by the green power power generation device. Without reducing the generated power, the reverse flow power can be suppressed to an allowable power or less. Moreover, by stopping the power generation of the non-green power generation apparatus, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee). Furthermore, the power generated by the green power generator can be used effectively by charging the storage battery with the generated power of the green power generator.

  In this case, the control device stops power generation of the non-green power generator when the suppression power is larger than the power represented by the sum of the generated power of the non-green power generator and the charging power of the storage battery, The storage battery is operated so that the generated power of the green power generator is charged to the storage battery, and the generated power of the green power generator is changed from the current generated power to the non-green power generator by stopping the generation of power. The fourth suppression process (S110) is performed to control the generated power of the green power generator so that the power obtained by subtracting the reduced power and the power obtained by subtracting the charging power of the storage battery are reduced to a power equal to or lower than the subtracted power. Good.

  According to this, the control device executes the fourth suppression process described above to stop the power generation of the non-green power generation device, and the storage battery is charged with the generated power of the green power generation device, and then the green power generation By reducing the generated power of the device, the reverse flow power can be suppressed to an allowable power or less while minimizing the amount of suppression (reduction amount) of the generated power of the green power generator. In this case, by stopping the power generation of the non-green power generation apparatus, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

It is the schematic which shows the state in which the distributed power generation system which concerns on this embodiment was installed in the house. 1 is a schematic configuration diagram of a distributed power generation system according to an embodiment. It is a flowchart which shows the flow of the suppression control processing routine which a control apparatus performs. It is a flowchart which shows the flow of the suppression control processing routine which a control apparatus performs. It is a flowchart which shows the flow of the 1st suppression process routine which a control apparatus performs. It is a flowchart which shows the flow of the 2nd suppression process routine which a control apparatus performs. It is a flowchart which shows the flow of the 3rd suppression process routine which a control apparatus performs. It is a flowchart which shows the flow of the 4th suppression process routine which a control apparatus performs. It is a graph which shows each time change of self-power consumption, the generated power of a solar power generation device, and the generated power of a fuel cell power generation device.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating a state where a distributed power generation system 1 according to the present embodiment is installed in a house, and FIG. 2 is a schematic configuration diagram of the distributed power generation system 1 according to the present embodiment. As shown in FIG. 1, a distribution board 100 is installed in a house H. The distribution board 100 is connected to the commercial power system C. Electric power is supplied from the commercial power system C to the distribution board 100. The power supplied from the commercial power system C is alternating current, and the voltage is, for example, 100V or 200V. In FIGS. 1 and 2, the solid line indicates a power line, and the broken line indicates a communication line.

  Further, the distributed power generation system 1 according to the present embodiment includes a solar power generation device 2, a fuel cell power generation device 3, a storage battery 4, and a control device 10, as shown in FIGS.

  The solar power generation device 2 is mounted on the roof R of the house H. The solar power generation device 2 converts light energy into electrical energy. The solar power generation device 2 is a power generation device that generates power using sunlight that is renewable energy. In this specification, a power generation device that generates power using renewable energy is referred to as a green power generation device.

  The solar power generation device 2 is electrically connected to the solar power generation grid interconnection device 5 (power conditioner). The grid connection device 5 for photovoltaic power generation converts the power generated by the photovoltaic power generation device 2 into AC power having the same phase and the same voltage as commercial power (power supplied from the commercial power grid C), The converted AC power is supplied to the commercial power system C. Thereby, the solar power generation device 2 is grid-connected to the commercial power grid C. Part of the power generated by the solar power generation device 2 (surplus power) flows backward through the commercial power system C via the system connection device 5 for solar power generation. That is, the solar power generation device 2 is configured such that surplus power of the generated power can be reversed. The reversely flowed power is sold to an electric power company equipped with a commercial power system C. Moreover, the grid connection apparatus 5 for photovoltaic power generation is configured so that the generated power of the photovoltaic power generation apparatus 2 can be adjusted by a control command from the control apparatus 10.

  Adjacent to the house H, the fuel cell power generator 3 is installed. In the present embodiment, the fuel cell power generation device 3 is a cogeneration type power generation device that generates electrical energy and thermal energy. The fuel cell power generation device 3 generates water, electricity, and heat by chemically reacting oxygen and hydrogen as a fuel source. Hydrogen as a fuel source may be filled in a hydrogen cylinder or the like, or may be generated by reforming hydrocarbons or the like. In any case, fossil fuel is used when hydrogen is produced. Therefore, the fuel cell power generation device 3 is a power generation device that generates power using fossil fuel. In this specification, a power generation device that generates power using fossil fuel is referred to as a non-green power generation device.

  The fuel cell power generator 3 is connected to the commercial power system C. The fuel cell power generation device 3 converts the generated power into AC power having the same phase and voltage as the commercial power, and supplies the converted AC power to the commercial power system C. As a result, the fuel cell power generator 3 is grid-connected to the commercial power grid C. Further, the fuel cell power generation device 3 is configured so that the generated power can be adjusted by a control command from the control device 10.

  The storage battery 4 is installed in the house H. The storage battery 4 is configured to be able to charge and discharge electric power. The storage battery 4 is also grid-connected to the commercial power system C. The storage battery 4 is provided with a remaining capacity detection unit 4a. The remaining capacity detection unit 4 a detects or estimates the remaining capacity (SOC) of the storage battery 4, and sequentially outputs the detected or estimated remaining capacity to the control device 10.

  Moreover, in the room of the house H, power loads D1 and D2 and a heat load H1 are installed. The power loads D1 and D2 are electrically connected to the distribution board 100. The power loads D1 and D2 are driven by power supplied to the room via the distribution board 100. Examples of the power load D1 and the power load D2 include a refrigerator, a lighting device, an air conditioner, and the like. The heat generated by the fuel cell power generation device 3 is supplied to the heat load H1. As the heat load H1, for example, a floor heater or a water heater can be exemplified.

  The control device 10 is installed in the room of the house H. The control device 10 is mainly composed of a microcomputer including a CPU, a ROM, a RAM, and the like. The control device 10 is connected to the photovoltaic power generation grid interconnection device 5, the fuel cell power generation device 3, and the storage battery 4 so that they can communicate with each other wirelessly or by wire. The control device 10 sequentially inputs the generated power of the solar power generation device 2 from the solar power generation grid interconnection device 5, and the generated power of the solar power generation device 2 through the solar power generation grid interconnection device 5. To control. In addition, the control device 10 sequentially inputs the generated power of the fuel cell power generation device 3 from the fuel cell power generation device 3 and controls the generated power of the fuel cell power generation device 3. Further, the control device 10 controls the operation of the storage battery 4, that is, charging / discharging of the storage battery 4.

  As described above, the distributed power generation system 1 according to this embodiment includes a green power generation device (solar power generation device 2) that generates power using renewable energy and a non-green power generation that generates power using fossil fuel. And a control device 10 for controlling the generated power of the green power generator and the non-green power generator, and the green power generator and the non-green power generator are commercial power. The grid is connected to the grid C and is configured such that surplus power generated by the green power generator can be reversely flowed. Moreover, although the distributed generation system 1 which concerns on this embodiment is provided with the storage battery 4, the suppression control process of the control apparatus 10 shown below is performed also with respect to the distributed generation system which is not provided with the storage battery 4. Can do.

  Moreover, any of the connection point of the grid connection device 5 for photovoltaic power generation, the connection point of the fuel cell power generation device 3, and the connection point of the storage battery 4 is in the middle of wiring from the commercial power system C to the distribution board 100. The ammeter 7 is installed at a position downstream of the connection point (position close to the distribution board 100). The ammeter 7 detects the current I supplied to the power loads D1 and D2 in the house H. The detected current I is input to the control device 10. Based on the input current I, the control device 10 calculates the power consumption of the power load D1 and the power load D2, that is, the private power consumption.

  In the distributed power generation system 1 configured as described above, the power generated by the fuel cell power generation device 3 is supplied to the power loads D1 and D2 via the distribution board 100. The heat generated by the fuel cell power generator 3 is supplied to the heat load H1. In this case, normally, the generated electric power of the fuel cell power generation device 3 is controlled by the control device 10 so as to generate electric power slightly lower than the electric power consumption. Such control is called self-consumption power tracking control. Moreover, the electric power generated by the solar power generation device 2 is supplied to the power loads D1 and D2 via the solar power generation grid interconnection device 5 and the distribution board 100. Moreover, the surplus electric power of the electric power generated by the solar power generation device 2 can cause the commercial power system C to flow backward as described above.

  Further, the storage battery 4 can be charged with the power generated by the fuel cell power generation device 3, the power generated by the solar power generation device 2, and the power from the commercial power system C. The storage battery 4 is discharged by a command from the control device 10. The discharged power can be consumed by the power loads D1 and D2.

  Further, when the private power consumption is larger than the power supplied from the distributed power generation system 1, the shortage of the private power consumption is supplemented by the power supplied from the commercial power grid C.

  By the way, as described above, surplus power generated by the photovoltaic power generation apparatus 2 can be reversely flowed to the commercial power system C, but surplus power that reversely flows the commercial power system C, that is, reverse power flow power. If the amount of electricity is large, it may interfere with the power amount control of the power company. In such a case, an instruction to suppress the reverse power flow is issued in order to suppress the reverse power flow. This suppression instruction is normally input to the grid connection device 5 for photovoltaic power generation as a suppression signal (hereinafter referred to as a PV suppression signal) of the generated power of the photovoltaic power generation device 2. Then, the grid connection device 5 for photovoltaic power generation operates so as to suppress (limit) the generated power of the photovoltaic power generation device 2. However, this situation is a situation where the amount of power generation using fossil fuel is not suppressed while the amount of power generation using renewable energy is suppressed, and environmental protection and utility costs (fossil fuel usage fee) ) Not preferable in terms of reduction.

  In this embodiment, as shown in FIG. 2, the PV suppression signal is input to the control device 10. And the control apparatus 10 performs the suppression control process of an electric power which is shown below regarding suppression of reverse power flow electric power.

  3 and 4 are flowcharts showing the flow of the suppression control processing routine executed by the control device 10. This suppression control processing routine is repeatedly executed every predetermined minute time. When this routine is started, the control device 10 first determines whether or not a PV suppression signal is input in step (hereinafter abbreviated as S) 101 in FIG.

  When it is determined in S101 that the PV suppression signal is input (S101: Yes), the control device 10 acquires the current reverse power flow power (S102). The reverse power flow power is power flowing backward from the distributed power generation system 1 to the commercial power system C. The reverse power flow power is basically surplus power of the solar power generation device 2. Therefore, the reverse power flow power can be obtained from the surplus power of the solar power generation device 2. Furthermore, surplus power of the solar power generation device 2 can be obtained from the generated power of the solar power generation device 2, the generated power of the fuel cell power generation device 3, the private power consumption, and the charge / discharge state of the storage battery 4.

  Next, the control device 10 calculates the suppression power Y (S103). The suppression power Y is power that should be reduced in order to suppress the reverse power flow power to be equal to or lower than the power (allowable power) allowed when the PV suppression signal is input. The suppression power Y may be calculated based on the rated power of the solar power generation device 2. For example, when a PV suppression signal indicating that the allowable power of reverse power flow is set to 8 kW is input and the rated power of the solar power generation device 2 is 10 kW, the suppression power Y is The power (2 kW) can be obtained by subtracting the allowable power (8 kW) from the rated power (10 kW). In this case, since the reverse power flow from the solar power generation device 2 is less than or equal to the rated power of the solar power generation device 2, the reverse power flow power can always be suppressed below the allowable power by setting the suppression power Y to 2 kW. . When a PV suppression signal indicating that the reverse power flow is reduced by 10% is input, the suppression power Y is obtained by multiplying the rated power (for example, 10 kW) of the solar power generation device 2 by 0.1. Electric power (for example, 1 kW) can be used. In this case, the allowable power is power (for example, 9 kW) obtained by multiplying the rated power of the solar power generation device 2 by 0.9. In addition, when it is not necessary to suppress the reverse flow power below the allowable power, that is, when the reverse flow power is below the allowable power, the suppression power Y is set to zero.

Then, the control unit 10, suppressing power Y determines whether or less generated power Q _FC of the current of the fuel cell device 3 is inputted most recently (S104). If the restraining power Y is less generated power _{Q FC} (S104: Yes), the control unit 10 advances the process to S105. On the other hand, if the restraining power Y is greater than the generated power _{Q FC} (S104: No), the control unit 10 advances the process to S106 in FIG. 4.

  In S105, the control device 10 executes a first suppression process. This first suppression process will be described later. The control apparatus 10 complete | finishes this routine, after performing a 1st suppression process in S105.

  On the other hand, in S106, the control device 10 determines whether or not the storage battery 4 is connected. Here, “whether or not the storage battery 4 is connected” means whether or not the storage battery 4 is installed in the house H (whether or not the distributed power generation system includes a storage battery), and the storage battery 4 is installed in the house H. And whether or not the storage battery 4 is connected to the commercial power system C (whether or not the storage battery 4 is operable). When the storage battery 4 is not connected (S106: No), the control apparatus 10 advances a process to S111. In S111, the control device 10 executes a second suppression process. This second suppression process will be described later. After executing the second suppression process in S111, the control device 10 ends this routine.

Further, at S106, if it is determined that the storage battery 4 is connected (S106: Yes), the controller 10 calculates the charging power _{Q BT} of the battery 4 (S107). The charging power is considered to depend on the remaining capacity (SOC) of the storage battery. Therefore, the charging power _QBT can be obtained from the remaining capacity (SOC) of the storage battery 4.

Next, the control device 10 uses the power (Q _FC + Q _BT) represented by the sum of the power generation power Q _{FC of the} current fuel cell power generation device 3 and the charging power Q _{BT of the} storage battery to which the suppression power Y is most recently input. ) or less whether, i.e., charging power _{Q BT} is suppressed power whether the Y is generated power _{Q FC} a minus power _{(Y-Q FC)} above, it is determined (S108). When the suppression power Y is less than or equal to the power (Q _FC + Q _BT ) (S108: Yes), the control device 10 advances the process to S109 and executes the third suppression process. The third suppression process will be described later. After executing the third suppression process in S109, the control device 10 ends this routine. On the other hand, the restraining power Y is power if _(Q FC ₊ Q _BT) greater than (S108: No), the controller 10 executes the fourth suppression process proceeds to S110. The fourth suppression process will be described later. The control apparatus 10 complete | finishes this routine, after performing a 4th suppression process in S110.

As can be seen from the above processing flow, when the PV suppression signal is input, the control device 10 executes one of the first suppression process, the second suppression process, the third suppression process, and the fourth suppression process. . The first suppression process is executed when the suppression power Y is equal to or less than the generated power Q _FC of the fuel cell power generation device 3. Second suppression processing, the restraining power Y is greater than the generated power Q _FC of the fuel cell device 3, and is executed when the storage battery 4 is not connected. In the third suppression process, the storage battery 4 is connected, the suppression power Y is greater than the generated power Q _{FC of} the fuel cell power generation device 3, and the generated power Q _FC of the fuel cell power generation device 3 and the charging power Q of the storage battery _This is executed when the power is equal to or lower than the power (Q _FC + Q _BT ) expressed by the sum of _BT . In the fourth suppression process, the storage battery 4 is connected, the suppression power Y is larger than the power generation power Q _{FC of} the fuel cell power generation device 3, and the power generation power Q _FC of the fuel cell power generation device 3 and the charge power Q of the storage battery _This is executed when the power is larger than the power (Q _FC + Q _BT ) represented by the sum of _BT .

Next, each suppression process will be described. First, the first suppression process will be described. FIG. 5 is a flowchart showing the flow of the first suppression processing routine executed by the control device 10. When the first suppression process is executed, the control device 10 first, in S201 of FIG. 5, the current fuel cell power generation device 3 that has recently input the limit power Q _FC * of the fuel cell power generation device 3. set to the generated power _{Q FC} power obtained by subtracting the restraining power Y from _(Q FC -Y). Next, the control device 10 outputs an FC suppression instruction as an instruction signal to the fuel cell power generation device 3 so that the generated power of the fuel cell power generation device 3 is equal to or less than the limit power Q _FC * set in S201. (S202). When FC suppression instruction is output to the fuel cell power generator 3, a fuel cell power generation device 3, electric power generated limit power Q _{FC *} to be less than, to adjust the generated power of its own. Here, when the suppression power Y is 0, the power generated by the fuel cell power generation device 3 does not change. On the other hand, when the suppression power Y is larger than 0, the generated power of the fuel cell power generation device 3 is reduced by the suppression power Y.

  Next, the control device 10 proceeds to S203, and determines whether or not a PV suppression instruction to be described later is output to the solar power generation device 2. When outputting the PV suppression instruction (S203: Yes), the control device 10 cancels the PV suppression instruction (S204). Thereafter, the control device 10 advances the process to S205. On the other hand, when the PV suppression instruction is not output (S203: No), the control device 10 skips the process of S204 and advances the process to S205.

  In S205, the control device 10 determines whether or not the storage battery 4 is connected. When the storage battery 4 is connected (S205: Yes), the control apparatus 10 advances the process to S206, and determines whether or not a charge instruction to be described later is output to the storage battery 4. When the charging instruction is output (S206: Yes), the control device 10 cancels the charging instruction to the storage battery 4 (S207). Thereafter, the control device 10 ends the first suppression process. Note that the timing for releasing the charging instruction for the storage battery 4 in S207 may be set based on the amount of charge of the storage battery 4, the charging time, and the like.

  Further, when it is determined in S205 that the storage battery 4 is not connected (S205: No), and when it is determined in S206 that a charging instruction is not output to the storage battery 4 (S206: No), the control device 10 complete | finishes a 1st suppression process as it is.

When the control device 10 executes the first suppression process as described above, the generated power of the fuel cell power generation device 3 is controlled so that the generated power of the fuel cell power generation device 3 is equal to or lower than the limit power Q _FC *. Is done. In particular, when the restraining power Y is and less generated power of the fuel cell power generator 3 larger than 0, the generated power of the fuel cell power generation device 3, electric power or less obtained by subtracting the restraining power Y from the current generated power Q _FC The generated power of the fuel cell power generator 3 is reduced so as to be reduced to electric power. Thus, when the generated power of the fuel cell power generation device 3 is reduced by the execution of the first suppression process, the surplus power of the solar power generation device 2 is allocated to private consumption by the reduced power. As a result, the surplus power of the solar power generation device 2 decreases, and accordingly, the reverse power flow from the solar power generation device 2 to the commercial power system C decreases. For this reason, it is possible to realize a situation in which the amount of power generation using renewable energy is not reduced while the amount of power generation using fossil fuel is reduced (suppressed). By realizing such a situation, the amount of fossil fuel used can be reduced, which can contribute to environmental protection and can contribute to the reduction of utility costs (fossil fuel usage fee).

Also, if the first suppression processing is performed is when the restraining power Y is less generated power Q _FC of the fuel cell power generation system 3. The generated power of the fuel cell power generation system 3 in this case by executing the first suppression processing, by lowering below the power obtained by subtracting the restraining power Y from the current generated power Q _FC, suppressing power Y are all fuel cells Covered by reduced power generated by the power generation device 3. That is, it is possible to suppress the reverse power flow to an allowable power or less without reducing the generated power of the solar power generation device 2 only by reducing the generated power of the fuel cell power generation device 3. Accordingly, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

Next, the second suppression process will be described. FIG. 6 is a flowchart showing the flow of the second suppression process executed by the control device 10. When the second suppression process is executed, the control device 10 first stops the power generation of the fuel cell power generation device 3 in S301 of FIG. 6, that is, the generated power of the fuel cell power generation device 3 becomes zero. Thus, an FC suppression instruction is output to the fuel cell power generator 3 (S301). When the FC suppression instruction is output to the fuel cell power generation device 3, the fuel cell power generation device 3 sets the generated power to zero. That is, the power generation of the fuel cell power generator 3 is stopped. Next, the control device 10 determines the limit power Q _PV * of the solar power generation device 2 from the currently generated power generation power Q _PV of the solar power generation device 2 and the fuel cell power generation device 3 from the suppression power Y. The power obtained by subtracting the power δQ _FC reduced by stopping in response to the instruction in S301 (that is, the power (Y−δQ _FC )) is subtracted from the power (ie, power (Q _PV − (Y−δQ _FC ))). (S302). The power δQ _FC is equal to the power generated by the fuel cell power generation device 3 immediately before the fuel cell power generation device 3 is stopped by the instruction in S301.

Next, the control device 10 causes the photovoltaic power generation system 2 so that the generated power of the solar power generation device 2 is equal to or lower than the limit power Q _PV * set in S302 (preferably to the limit power Q _PV *). A PV suppression instruction as an instruction signal is output to the interconnection device 5 (S303). When the PV suppression instruction is output to the grid connection device 5 for photovoltaic power generation, the grid interconnection device 5 for photovoltaic power generation has a power generated by the photovoltaic power generation device 2 that is less than or equal to the limit power Q _PV * (preferably Adjusts the generated power of the solar power generation device 2 so as to decrease to the limit power Q _PV *). Thereafter, the control device 10 ends the second suppression process.

When the control device 10 executes the second suppression process as described above, the power generation of the fuel cell power generation device 3 is stopped, and the generated power of the solar power generation device 2 is limited from the current generated power Q _PV. The power less than Q _PV *, that is, the power (Y−δQ _FC ) obtained by subtracting the power (δQ _FC ) reduced by stopping the power generation of the fuel cell power generation device 3 from the suppression power Y (Q _PV − (Y−δQ _FC )) The generated power of the solar power generation device 2 is controlled so as to decrease to the following power.

When the second suppression processing is performed, the storage battery 4 has not been connected, and, restraining power Y is greater than the generated power Q _FC of the fuel cell power generation system 3. In this case, since the reverse flow power cannot be suppressed below the allowable power only by reducing the generated power of the fuel cell power generator 3, the generated power of the solar power generator 2 must be reduced. However, according to the second suppression process, in order to stop the power generation of the fuel cell power generation device 3, only the power obtained by subtracting the power reduced by the stop of the power generation of the fuel cell power generation device 3 from the suppression power, What is necessary is just to make it the electric power for the fall of the electric power generated by the electric power generating apparatus 2. For this reason, it is possible to suppress the reverse power flow to an allowable power or less while minimizing the suppression amount (reduction amount) of the generated power of the solar power generation device 2. In addition, by stopping the power generation of the fuel cell power generation device 3, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

  Next, the third suppression process will be described. FIG. 7 is a flowchart showing the flow of the third suppression process executed by the control device 10. When the third suppression process is executed, the control device 10 first stops the power generation of the fuel cell power generation device 3 in S401 of FIG. 7, that is, the generated power of the fuel cell power generation device 3 becomes zero. Thus, an FC suppression instruction is output to the fuel cell power generator 3 (S301). Thereby, the power generation of the fuel cell power generator 3 is stopped. Next, the control device 10 outputs a charging instruction to the storage battery 4. Thereby, the surplus electric power of the solar power generation device 2 is charged in the storage battery 4.

  Next, the control device 10 determines whether or not a PV suppression instruction is output (S403). When the PV suppression instruction is output (S403: Yes), the control device 10 cancels the PV suppression instruction (S404). Thereafter, the control device 10 ends the third suppression process. On the other hand, when the PV suppression instruction is not output (S403: No), the control device 10 ends the third suppression process without executing the process of S404.

  When the control device 10 executes the third suppression process as described above, the power generation of the fuel cell power generation device 3 is stopped and the power generated by the solar power generation device 2 is charged in the storage battery 4.

When the third suppression process is executed, the storage battery 4 is connected, the suppression power Y is greater than the generated power Q _FC of the fuel cell power generation device 3, and the generated power Q _FC and the charging power Q _{BT of the} storage battery 4 _Is less than or equal to the power represented by the sum of (Q _FC + Q _BT ). In this case, by executing the third suppression process, the suppression power Y is all covered by the power reduced by stopping the fuel cell power generation device 3 and the power charged in the storage battery 4 from the solar power generation device 2. For this reason, it is possible to suppress the reverse power flow to an allowable power or less without reducing the generated power of the solar power generation device 2. Accordingly, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee). In addition, by stopping the power generation of the fuel cell power generation device 3, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee). Furthermore, the electric power generated by the solar power generation device 2 can be effectively used by charging the storage battery 4 with the generated power of the solar power generation device 2.

  Next, the fourth suppression process will be described. FIG. 8 is a flowchart showing the flow of the fourth control process executed by the control device 10. When the fourth suppression process is executed, the control device 10 first stops the power generation of the fuel cell power generation device 3 in S501 of FIG. 8, that is, the generated power of the fuel cell power generation device 3 becomes zero. Thus, an FC suppression instruction is output to the fuel cell power generation device 3. Thereby, the power generation of the fuel cell power generator 3 is stopped.

Next, the control device 10 determines the limit power Q _PV * of the solar power generation device 2 from the currently generated power generation power Q _PV of the solar power generation device 2 and the fuel cell power generation device 3 from the suppression power Y. power obtained by subtracting the power .delta.Q _FC which is reduced by stopping an instruction S501 (i.e., the power (Y-δQ _FC)) charging power _{Q BT} and of the battery 4, minus power (i.e., power _{(Q PV} - (Y−δQ _FC ) −Q _BT )) (S502).

Subsequently, the control device 10 uses the power for solar power generation so that the power generated by the solar power generation device 2 is equal to or lower than the limit power Q _PV * set in S502 (preferably to the limit power Q _PV *). A PV suppression instruction as an instruction signal is output to the grid interconnection device 5 (S503). When the PV suppression instruction is output to the grid connection device 5 for photovoltaic power generation, the grid interconnection device 5 for photovoltaic power generation has a power generated by the photovoltaic power generation device 2 that is less than or equal to the limit power Q _PV * (preferably Adjusts the generated power of the solar power generation device 2 so as to decrease to the limit power Q _PV *).

  Next, the control device 10 instructs the storage battery 4 to charge (S504). Thereafter, the control device 10 ends the fourth suppression process.

When the control device 10 executes the fourth suppression process as described above, the power generation of the fuel cell power generation device 3 is stopped, the generated power of the solar power generation device 2 is charged in the storage battery 4, and the solar power generation the power generated by the device 2, the current generated power Q _PV, limit power Q _{PV *} less power, i.e., is reduced from the current generated power Q _PV, by stopping the power generation of the fuel cell power generation system 3 from the restraining power Y power (.delta.Q _FC) and power obtained by subtracting charge electric power _{Q BT (Q PV - (Y} -δQ FC) -Q BT) to decrease below the power, the power generated by the photovoltaic power generator 2 is controlled .

When the fourth suppression process is executed, the storage battery 4 is connected, and the suppression power Y is represented by the sum of the generated power Q _FC of the fuel cell power generation device 3 and the charging power Q _BT of the storage battery 4. This is a case where the power is larger than the power (Q _FC + Q _BT ). In this case, the reverse power flow cannot be suppressed below the allowable power only by stopping the power generation of the fuel cell power generation device 3 and charging the power generation power of the solar power generation device 2 to the storage battery 4. The generated power of the device 2 must also be reduced. However, according to the fourth suppression process, the power generation of the fuel cell power generation device 3 is stopped and the generated power of the solar power generation device 2 is charged into the storage battery 4. Only the power obtained by subtracting the power and the charging power of the storage battery 4 from the suppression power may be used as the power corresponding to the decrease in the power generated by the solar power generation device 2. For this reason, it is possible to suppress the reverse power flow to the allowable power or less while minimizing the amount of reduction in the generated power of the solar power generation device 2. In addition, by stopping the power generation of the fuel cell power generation device 3, it is possible to further contribute to environmental protection and to reduce utility costs (fossil fuel usage fee).

  If it is determined in S101 of FIG. 3 that the PV suppression signal is not input (S101: No), the first to fourth suppression controls described above are not performed, and each power generator 2, 3 is simply performed. And the instruction | indication to the storage battery 4 is cancelled | released. Briefly describing this, when the determination result in S101 is No, the control device 10 determines whether or not a PV suppression instruction is output in S112 of FIG. 3, and outputs a PV suppression instruction. In the case (S112: Yes), after canceling the PV suppression instruction in S113, the process proceeds to S114. When the PV suppression instruction is not output (S112: No), the process of S113 is performed without executing the process of S113. To proceed.

  In S114, the control device 10 determines whether or not an FC suppression instruction is output. If the FC suppression instruction is output (S114: Yes), the control apparatus 10 cancels the FC suppression instruction in S115 and then proceeds to S116. When the process is advanced and the FC suppression instruction is not output (S114: No), the control device 10 advances the process to S116 without executing the process of S115.

  In S116, the control device 10 determines whether or not the storage battery 4 is connected. If the storage battery 4 is connected (S116: Yes), the control apparatus 10 determines whether a charging instruction is output to the storage battery 4 in S117. When the charging instruction is output to the storage battery 4 (S117: Yes), the control device 10 cancels the charging instruction in S118, and thereafter ends this routine. On the other hand, when the storage battery 4 is not connected (S116: No) and when a charge instruction is not output to the storage battery 4 (S117: No), the control device 10 ends this routine as it is. Note that the timing for releasing the charging instruction for the storage battery 4 in S118 may be set based on the charge amount, the charging time, and the like of the storage battery 4.

  Incidentally, when the PV suppression signal is not input, the fuel cell power generation device 3 executes the above-described self-power consumption tracking control. For this reason, when the PV suppression signal is not input, most of the self-power consumption is covered by the power generated by the fuel cell power generation device 3.

  As described above, in the distributed power generation system 1 according to the present embodiment, when the PV suppression signal is input to the control device 10, the recyclable energy is reduced so that the reverse flow power is equal to or less than the allowable power. The generated power of the fuel cell power generator 3 using fossil fuel is controlled in preference to the solar power generator 2 used. In FIG. 9 (FIG. 9C), when the first suppression process of the present embodiment is executed, the self-consumption power, the generated power of the solar power generation device 2, and the generated power of the fuel cell power generation device 3 are The graph showing a time change is shown. For reference, FIG. 9 (a) shows a graph showing the change over time of each power when no suppression signal is input, and FIG. 9 (b) shows the input of the suppression signal, thereby generating solar power. The graph showing the time change of each electric power at the time of reducing the generated electric power of the apparatus 2, ie, when performing the conventional suppression control, is shown. In FIG. 9, the solid line graph A shows the time change of the private power consumption, the broken line graph B shows the time change of the generated power of the fuel cell power generation device 3, and the dashed line C shows the solar power generation device 2. The changes over time of the generated power are shown.

  As shown in graph C of FIG. 9A, the generated power of the solar power generation device 2 varies greatly depending on the time zone. Specifically, the generated power of the solar power generator 2 is large during the sunshine hours, and the generated power of the solar power generator 2 is very small at night. Moreover, as shown in the graph B of FIG. 9A, the power generated by the fuel cell power generation device 3 normally changes following the self-consumption power so as to be slightly smaller than the self-consumption power.

  The PV suppression signal is usually input in a time zone when the generated power of the solar power generation device 2 is large. When the conventional suppression control for reducing the generated power of the solar power generation device 2 in response to the input of the PV suppression signal is performed, the generated power of the solar power generation device 2 as shown in the graph C of FIG. All of the power near the peak (the hatched portion in FIG. 9B) is cut. For this reason, environmentally friendly and economical power generation using renewable energy is suppressed. On the other hand, when the control of this embodiment that preferentially controls the generated power of the fuel cell power generation device 3 in response to the input of the PV suppression signal is executed, as shown in the graph B of FIG. While the signal is being input, the power generated by the fuel cell power generator 3 is reduced. Since the generated power of the fuel cell power generation device 3 is reduced in this way, the surplus power of the generated power of the solar power generation device 2 is allocated to private power consumption, and the surplus power of the solar power generation device 2 is reduced accordingly. The tidal power is suppressed below the allowable power. That is, as a result of surplus power of the generated power of the solar power generation device 2 that is conventionally cut when the PV suppression signal is input, in the present embodiment, the power generated by the fuel cell power generation device 3 is reduced to private consumption. As shown in graph C of FIG. 9C, even when the PV suppression signal is input, the solar power generation device 2 can generate power without reducing the generated power of the solar power generation device 2. . Therefore, according to the distributed power generation system 1 according to the present embodiment, it is possible to further utilize power generation using renewable energy, contribute to environmental protection, and implement an economical power generation operation. it can.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the above embodiment, a solar power generation device is shown as a power generation device that uses renewable energy, but a power generation device that uses any renewable energy, such as a wind power generation device, a hydroelectric power generation device, or a geothermal power generation device, It can be applied as a green power generator of the present invention. In the above embodiment, a fuel cell power generation device is shown as a power generation device using fossil fuel. However, a power generation device using an internal combustion engine such as a gas engine, a power generation device using thermal power, or the like is used as a fuel source. Any non-green power generator can be applied as the non-green power generator of the present invention. Moreover, in the said embodiment, although the cogeneration type fuel cell power generation device was shown as a non-green electric power generation apparatus, it is not necessary to produce | generate heat in a non-green electric power generation apparatus. Moreover, although the example which installed the control apparatus 10 in the house H individually was shown in the said embodiment, the control apparatus 10 may be provided in the fuel cell power generation apparatus 3, for example, or it is sunlight. The power generation grid interconnection device 5 may be provided. The present invention can also be applied to a distributed power generation system including a plurality of green power generation devices and a distributed power generation system including a plurality of non-green power generation devices. Moreover, the control apparatus 10 is good also as a structure also provided with the function which controls the storage battery 4 based on the charging / discharging characteristic of the storage battery 4, charging / discharging time, etc. FIG. Thus, the present invention can be modified without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Distributed power generation system, 2 ... Solar power generation device (green power power generation device), 3 ... Fuel cell power generation device (non-green power power generation device), 4 ... Storage battery, 5 ... System interconnection device for solar power generation, 7 ... ammeter, 10 ... control device, C ... commercial power system, Y ... suppressed power

Claims (5)

A green power generator that uses renewable energy to generate electricity,
A non-green power generator that generates power using fossil fuels;
A control device for controlling the power generated by the green power generator and the power generated by the non-green power generator;
With
The green power generation device and the non-green power generation device are connected to a commercial power system, and the dispersion is configured such that surplus power generated by the green power generation device can be reversely flowed Type power generation system,
The controller is
A distributed type that controls the generated power of the non-green power generation device so that the reverse flow power is equal to or less than the allowable power represented by the suppression signal when a reverse flow power suppression signal is input. Power generation system. The distributed power generation system according to claim 1,
The controller is
When the suppression signal is input, a suppression power calculation process for calculating a suppression power that is a power to be reduced in order to suppress the reverse power flow to the allowable power or less,
When the suppressed power is greater than 0 and less than or equal to the generated power of the non-green power generator, the generated power of the non-green power generator is less than or equal to the current power generated by subtracting the suppressed power Performing a first suppression process for controlling the generated power of the non-green power generation device so as to decrease to electric power,
Distributed generation system. The distributed power generation system according to claim 2,
The controller is
When the suppressed power is larger than the generated power of the non-green power generator, the power generation of the non-green power generator is stopped, and the generated power of the green power generator is Second suppression for controlling the generated power of the green power generator so that the power obtained by subtracting the power reduced by stopping the power generation of the non-green power generator from the suppressed power is reduced to a power equal to or lower than the subtracted power. Execute the process,
Distributed generation system. The distributed power generation system according to claim 2 or 3,
The battery further includes a storage battery capable of charging and discharging power,
The controller is
When the suppression power is greater than the generated power of the non-green power generator and is equal to or less than the power represented by the sum of the generated power of the non-green power generator and the charged power of the storage battery, While stopping the power generation of the non-green power generator, and performing a third suppression process to operate the storage battery so that the generated power of the green power generator is charged to the storage battery,
Distributed generation system. The distributed power generation system according to claim 4,
The controller is
When the suppression power is greater than the power represented by the sum of the power generated by the non-green power generator and the charged power of the storage battery, the power generation of the non-green power generator is stopped and the green power The storage battery is operated such that the generated power of the power generation device is charged in the storage battery, and the generated power of the green power power generation device is generated from the suppressed power from the current power generation power of the non-green power power generation device. Executing a fourth suppression process for controlling the generated power of the green power generator so that the power reduced by stopping the power and the charging power of the storage battery are reduced to a power equal to or lower than the subtracted power,
Distributed generation system.

Images