Power generation management device

Abstract

To further improve the accuracy of an actual amount of demand response.SOLUTION: A power generation management device sets a power generation amount instruction value for a distributed power generation device for each predetermined time during a target period, and outputs the set power generation amount instruction value to the distributed power generation device to implement demand response. At the start of the target period, the power generation management device sets the power generation amount instruction value based on a maximum power generation amount per predetermined time of the distributed power generation device, and thereafter, at each lapse of the predetermined time, calculates a remaining total power demand amount based on an actual power generation amount value, and repeats the process of setting the power generation amount instruction value for the next predetermined time based on the smaller of the maximum power generation amount per predetermined time and the remaining total power demand amount until the remaining total power demand amount becomes zero.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This specification discloses a power generation management apparatus. [Background technology]

[0002] Conventionally, in a distributed power supply system having a plurality of power generating devices that supply power to each load device, a system has been proposed in which the total power consumption consumed by each load device is measured, the power generation output output from each power generating device is measured, an evaluation function is set based on each power generation output and the total power consumption under constraint conditions based on the maximum power generation and minimum power generation of each power generating device, and an evaluation function defined based on each power generation output previously measured based on the measured total power consumption is solved by the least squares method to derive the power generation amount instruction value of each power generating device and transmit it to each power generating device (see, for example, Patent Document 1). The evaluation function includes a term obtained by summing up the squared value of the difference between the power generation amount instruction value and the power generation output of each power generating device for all power generating devices, and a term obtained by summing up the squared value of the difference between the sum of each power generation amount instruction value and the total power consumption. The power generation amount instruction value is transmitted to each power generating device at a predetermined time interval, and each power generating device generates power at a power generation amount according to the power generation amount instruction value received this time until the next power generation amount instruction value is received. The predetermined time is the elapsed time from the present time when there is a high probability that the total power consumption will be the same as the current total power consumption, and is set to 60 seconds. This makes it possible to minimize fluctuations in the amount of power generated by each power generation device, and to match the total power consumption with the total amount of power generated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-166746 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned system, since the power generation command value is derived so as to follow the total power consumption at each predetermined time, the power generation command value may fluctuate multiple times. In this case, for example, in a power generation device such as a fuel cell, the response performance of the output increase is low, so that the power generation command value and the power generation output of each power generation device may diverge, and the power generation output may be insufficient relative to the power demand.

[0005] A power generation management device according to the present disclosure is a power generation management device that manages the amount of power generation output relative to the amount of electricity demand during a period covered by demand response, and the main object of the device is to further improve the accuracy of the actual amount of demand response. [Means for solving the problem]

[0006] The power generation management device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The power generation management device of the present disclosure is A power generation management device that manages power generation of a distributed power generation device in response to a demand response request, a total power demand acquisition unit that acquires a total power demand, which is a total amount of power demand within a target period of the demand response; a power generation amount actual value acquisition unit that acquires a power generation amount actual value of the distributed power generation device; a power generation instruction value setting unit that sets a power generation instruction value of the distributed power generation device for each predetermined time during the target period and outputs the set power generation instruction value to the distributed power generation device to implement the demand response, and at the start of the target period, sets the power generation instruction value based on a maximum power generation amount per predetermined time of the distributed power generation device, and thereafter, at each elapse of the predetermined time, calculates a remaining total power demand, which is the remaining amount of the total power demand, based on the power generation actual value acquired by the power generation actual value acquisition unit, and repeats the process of setting the power generation instruction value for the next predetermined time based on the smaller of the maximum power generation amount per predetermined time and the remaining total power demand until the remaining total power demand becomes zero; The gist of the project is to provide the following:

[0008] In the power generation management device disclosed herein, a power generation amount instruction value of a distributed power generation device is set for each predetermined time during a target period of the demand response, and the set power generation amount instruction value is output to the distributed power generation device to implement the demand response. At the start of the target period, the power generation amount instruction value is set based on the maximum power generation amount per predetermined time of the distributed power generation device, and thereafter, the process of calculating the remaining total power demand based on the actual power generation amount value every time a predetermined time elapses and setting the power generation amount instruction value for the next predetermined time based on the smaller of the maximum power generation amount per predetermined time and the remaining total power demand until the remaining total power demand becomes zero is repeated. As a result, even in a distributed power generation device with low response performance for increasing the output, the number of times that the power generation amount instruction value requiring an increase in output is output can be reduced, and the shortage of the power generation output amount relative to the total power demand amount can be minimized. In addition, when the remaining total power demand amount becomes small during the target period, the power generation amount instruction value can be adjusted so that the total power generation output amount matches the total power demand amount by reducing the output with high response performance. As a result, the accuracy of the demand response can be further improved. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a distributed power generation system including a power generation management device. [Diagram 2] 10 is a flowchart illustrating an example of a demand response execution process executed by a power generation management device. [Diagram 3] FIG. 2 is an explanatory diagram illustrating a total power demand and a total power generation instruction value. [Figure 4] FIG. 2 is an explanatory diagram illustrating a predicted value of a total power generation output amount currently being generated. [Diagram 5] 13 is a flowchart showing a demand response execution process according to another embodiment. [Figure 6] FIG. 11 is an explanatory diagram showing a predicted total power generation output value when the output is increased and a predicted total power generation output value when the output is decreased. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will be described with reference to the drawings.

[0011] 1 is a schematic configuration diagram of a distributed power generation system 1 including a power generation management device 10. The distributed power generation system 1 includes a supply and demand management device 2 installed by an electric power company, distributed power generation devices (fuel cell systems 30) owned by consumers who have concluded a demand response contract, the power generation management device 10 of this embodiment that manages the amount of power generated by each distributed power generation device, and a communication device 20 that controls communication between the distributed power generation devices and the power generation management device 10. The power generation management device 10 and the communication device 20 are communicatively connected via a network 5 such as the Internet. Similarly, the power generation management device 10 and the supply and demand management device 2 are communicatively connected via a network.

[0012] The supply and demand management device 2 predicts a surplus or shortage of power supply based on the power generation status and future power generation plans of the power company, current weather, future weather forecast, current power consumption, and future predicted power consumption, and requests a demand response (DR) to increase or decrease the demand for electricity according to the prediction result. That is, when a shortage of power supply is predicted, the supply and demand management device 2 requests the power management device 20 to perform a downward DR to reduce the demand for electricity. Also, when an excess of power supply is predicted, the supply and demand management device 2 requests the power management device 20 to perform an upward DR to increase the demand for electricity.

[0013] The power generation management device 10 is a server device including a CPU 11, a ROM 12, a RAM 13, a storage 14 (HDD or SDD), and a communication unit 15. The communication unit 15 is communicatively connected to the supply and demand management device 2 and to a communication device 20. The communication device 20 is connected to a distributed power generation device (fuel cell system 30), and the communication unit 15 exchanges data and signals with the distributed power generation device via the communication device 20. The power generation management device 10 receives a demand response (DR) request (such as a DR start timing, a DR period, and a total power demand during the DR period) from the supply and demand management device 2, determines a power generation instruction value to be generated by each distributed power generation device so that a power generation amount according to the total power demand can be obtained from the multiple distributed power generation devices under its jurisdiction, and transmits the power generation instruction value to each distributed power generation device.

[0014] Examples of the distributed power generation device include a fuel cell system, an engine generator, a solar power generation system, etc. In this embodiment, a fuel cell system 30 is used as the distributed power generation device.

[0015] The fuel cell system 30 includes a fuel cell module 31 including a fuel cell stack that generates electricity by an electrochemical reaction between an anode gas and a cathode gas, a reformer that uses water vapor to reform raw fuel gas (e.g., natural gas or LP gas) to generate an anode gas, and an evaporator that evaporates reforming water and supplies it to the reformer. The fuel cell system 30 also includes various auxiliary devices 32, such as a gas pump that supplies raw fuel gas to the reformer, a water pump that supplies reforming water to the evaporator, and an air blower that supplies air as a cathode gas to the fuel cell stack, a power conditioner 33 (DC / DC converter and inverter) connected to the output terminal of the fuel cell stack, and a control device 34 that controls the entire system. The fuel cell stack has a plurality of solid oxide type single cells including an electrolyte, an anode arranged on one side of the electrolyte, and a cathode arranged on the other side of the electrolyte. The anode gas is supplied from the reformer to the anode, and the cathode gas (air) is supplied from the air blower to the cathode. The fuel cell stack generates power by generating oxide ions at the cathode, which then pass through the electrolyte and react with hydrogen and the like at the anode. The output terminal of the power conditioner 33 is connected to the power grid via a relay, and the fuel cell system 30 is interconnected with the power grid to supply the power generated by the fuel cell stack to the consumer's load (electrical appliances). In addition, the fuel cell system 30 allows reverse power flow to the power grid during a demand response (DR) period, and supplies surplus power generated by the fuel cell stack to the power grid.

[0016] The control device 34 includes a CPU, ROM, RAM, and input / output ports. Detection signals from various sensors, such as a temperature sensor that detects the temperature of the fuel cell stack and a flow rate sensor that detects the flow rate of the raw fuel gas, are input to the control device 34 via the input port. In addition, the control device 34 outputs control signals to the various auxiliary devices 32 (gas pump, water pump, air blower, etc.) and control signals to the power conditioner 33 via the output port.

[0017] Outside the demand response period (outside the DR period), the control device 34 sets the smaller of the load required output required by the load and the rated output as the power generation target value, and controls the supply amounts of raw fuel gas, reforming water, and air so that the fuel cell stack generates power at an amount of power generation that matches the set power generation target value. The control of the supply amount of raw fuel gas is performed by setting a current command based on the power generation target value, setting a target gas flow rate so that a current corresponding to the set current command is output from the fuel cell stack, and controlling the gas pump. The control of the supply amount of reforming water is performed by setting a target reforming water flow rate so that steam is supplied at a predetermined ratio to the raw fuel gas, and controlling the water pump so that reforming water at the set target reforming water flow rate is supplied. The control of the supply amount of air is performed by setting a target air flow rate by feedback control so that the temperature of the fuel cell stack matches the target temperature, and controlling the air blower so that air is supplied at the set target air flow rate.

[0018] On the other hand, during the demand response period (DR period), the control device 34 sets the smaller of the power generation instruction value received from the power generation management device 10 and the rated output as the power generation target value, and controls the supply amounts of raw fuel gas, reforming water, and air so that the fuel cell stack generates power at the set power generation target value.

[0019] Next, the operation of the power generation management device 10 in the distributed power generation system 1 configured as above, in particular the operation of setting a power generation instruction value to be instructed to each fuel cell system 30 based on the downward DR, will be described. Fig. 2 is a flowchart showing an example of a demand response execution process executed by the power generation management device 10. This process is executed when a demand response request is received from the supply and demand management device 2.

[0020] When the demand response execution process is executed, the CPU 11 of the power generation management device 10 first inputs the total power demand D (the total amount of power demand within the period covered by the demand response) and the total maximum power generation Pmax, which is the maximum power generation amount per unit time that can be generated by the entire fuel cell systems 30 under its management (step S100). The CPU 11 inputs the total power demand D received from the supply and demand management device 2. The CPU 11 also inputs, for example, the maximum power generation amount received from each of the fuel cell systems 30 under its management, calculated by summing up the received maximum power generation amounts. Next, the CPU 11 sets the total power demand D input in step S100 to the remaining total power demand Dr, which is the remaining amount of the total power demand D (step S102).

[0021] Next, the CPU 11 sets a total power generation command value Ptag, which is the power generation output to be generated per unit time by the fuel cell systems 30 under its control (step S104), and distributes the set total power generation command value Ptag to the fuel cell systems 30 to set and transmit the power generation command value for each fuel cell system 30 (step S106). In this embodiment, the total power generation command value Ptag is calculated by dividing the smaller of the total maximum power generation per unit time Pmax multiplied by a predetermined time ΔT (Pmax·ΔT) and the total remaining power demand Dr by the predetermined time ΔT. The predetermined time ΔT is the time interval for repeating steps S104 to S118, which will be described later. The CPU 11 repeatedly sets the total power generation command value Ptag every time the predetermined time ΔT elapses during the target period of the demand response, and distributes and transmits the set total power generation command value Ptag to each fuel cell system 30. In this embodiment, the total power generation amount indication value Ptag is distributed to each fuel cell system 30 within a range that does not exceed the maximum power generation amount of each fuel cell system 30.

[0022] Next, the CPU 11 inputs the total power generation output P (actual value) generated by each fuel cell system 30 during the previous predetermined time ΔT (step S108). The CPU 11 receives the power generation output from each of the fuel cell systems 30 under its control, and inputs the sum of the received power generation outputs as the total power generation output P. Next, the CPU 11 calculates the total power generation output α that has already been generated (step S110). The total power generation output α is calculated by adding the input total power generation output P to the previously calculated total power generation output (previous α). The CPU 11 then sets a power generation output prediction value β for the power generation currently in progress (step S112). In this embodiment, the total power generation output prediction value β for the power generation currently in progress is set to the total power generation output indication value Ptag set in step S104. The reason for this will be described later.

[0023] After calculating or setting the total power output α already generated and the predicted power output β currently being generated, the CPU 11 updates the total remaining power demand Dr by subtracting the total power output α already generated and the predicted power output β currently being generated from the total power demand D (step S114). Then, the CPU 11 determines whether the total remaining power demand Dr is equal to or less than 0 (step S116). If the CPU 11 determines that the total remaining power demand Dr is greater than 0, the CPU 11 waits for a predetermined time ΔT to elapse since the total power generation instruction value Ptag was set and the power generation instruction value was transmitted the previous time (step S118), returns to step S104, and repeats the processes of steps S104 to S118.

[0024] If the CPU 11 determines in step S116 during the process of repeating the process that the total remaining power demand Dr is equal to or less than 0, the CPU 11 ends the demand response execution process.

[0025] FIG. 3 is an explanatory diagram for explaining the total power demand and the total power generation command value. As shown in the figure, the total power generation command value is set every time a predetermined time ΔT has elapsed. The CPU 11 sets the total maximum power generation Pmax to the total power generation command value Ptag until the remaining total power demand Dr becomes less than the total maximum power generation Pmax multiplied by the predetermined time ΔT, and sets the remaining total power demand Dr divided by the predetermined time ΔT to the total power generation command value Ptag after the remaining total power demand Dr becomes less than the total maximum power generation Pmax multiplied by the predetermined time ΔT. That is, the CPU 11 generates an output increase at the total maximum power generation Pmax at the start of the target period of the demand response, continues the output increase until the remaining total power demand Dr becomes low, and then adjusts the total power generation output by decreasing the output so that the remaining total power demand Dr becomes zero. This makes it possible to prevent frequent switching between increasing and decreasing the output, and even in a distributed power generation device (fuel cell system 30) with low response performance in increasing the output, the total power generation output can be made to match the total power demand Dr during the period covered by the demand response. Also, even if a sudden power generation stop or output suppression occurs during the period covered by the demand response, the shortage of the total power generation output can be minimized. As a result, the accuracy of the demand response can be further improved.

[0026] FIG. 4 is an explanatory diagram for explaining the predicted value of the total power generation output amount currently being generated. In this embodiment, the CPU 11 cannot receive the power generation output amount (actual value) currently being generated from the multiple fuel cell systems 30 under its control until the current predetermined time ΔT has elapsed. On the other hand, since the output increase continues from the start of the target period of the demand response until the remaining total power demand Dr becomes small, the total power generation output amount currently being generated is within a range of not less than the total power generation output amount (actual value) generated in the previous predetermined time ΔT and not more than the total power generation output instruction value instructed in the current predetermined time ΔT. In this embodiment, the CPU 11 sets the total power generation instruction value Ptag instructed in the current predetermined time ΔT as the predicted value β of the power generation output amount currently being generated. In this case, since the response performance of the output increase is low, the predicted value β of the total power generation output amount becomes larger than the actual total power generation output amount (actual value) currently being generated, and the remaining total power demand Dr is estimated to be smaller than the actual amount, so that the total power generation output amount may be insufficient for the total power demand D. On the other hand, the response performance of output reduction is relatively high, so the total power output forecast value β generally coincides with the total power output currently being generated (actual value). Therefore, when output is reduced, the remaining total power demand Dr is estimated to be equal to the actual value based on the total power output already generated α based on the actual value and the total power output forecast value β, and the power output that is insufficient when output is increased is adjusted when output is reduced. This makes it possible to match the total power output with the total power demand Dr during the period covered by the demand response.

[0027] 2 can be preferably used mainly for an evaluation method in which the total power generation output amount relative to the total power demand amount of a downward DR is evaluated only by the amount of power sold. On the other hand, the demand response execution process described below is preferably used for an evaluation method in which the total power generation output amount relative to the total power demand amount of a downward DR is evaluated by the amount of power sold offset by the amount of power purchased. Note that the evaluation method to be used is actually determined based on an agreement with the resource aggregator.

[0028] Fig. 5 is a flowchart showing a demand response execution process according to another embodiment. Among the processes in the demand response execution process in Fig. 5, the same processes as those in the demand response execution process in Fig. 2 are assigned the same step numbers, and their descriptions will be omitted to avoid duplication.

[0029] In the demand response execution process according to another embodiment, after step S110, the CPU 11 judges whether the total power generation command value Ptag for the current predetermined time ΔT set in step S104 is equal to or greater than the total power generation command value for the previous predetermined time ΔT (previous Ptag) (step S120). This judgment is made to judge whether the power generation output of the entire fuel cell systems 30 under its control is in an output increase state or an output decrease state. When the CPU 11 judges that the total power generation command value Ptag for the current predetermined time ΔT is equal to or greater than the previous Ptag, it judges that the output is in an output increase state, sets the power generation output prediction value β to the total power generation output P (actual value) for the previous predetermined time ΔT input in step S108 (step S122), and updates the total remaining power demand Dr (step S114). On the other hand, if the CPU 11 determines that the total power generation instruction value Ptag for the current specified time ΔT is less than the previous Ptag, it determines that the output is being reduced, sets the power generation output prediction value β to the total power generation instruction value Ptag for the current specified time ΔT (step S112), and updates the total remaining power demand Dr (step S114).

[0030] 6 is an explanatory diagram showing the predicted total power output when increasing the output and the predicted total power output when decreasing the output. As described above, in the fuel cell system 30, when increasing the output, the predicted total power output β is set to the total power output (actual value) generated in the previous predetermined time ΔT (see FIG. 6(a)), and when decreasing the output, the predicted total power output β is set to the total power output command value Ptag for the current predetermined time ΔT (see FIG. 6(b)). In this case, the predicted total power output β becomes smaller than the total power output (actual value) currently being generated, and the remaining total power demand Dr is estimated to be higher than the actual amount, which may result in the total power output being excessive relative to the total power demand D.

[0031] When the CPU 11 updates the total remaining power demand Dr, it determines whether the total remaining power demand Dr is equal to or less than 0 (step S116), and if it determines that the total remaining power demand Dr is greater than 0, it waits for a predetermined time ΔT to elapse (step S118), returns to step S104, and repeats the process. On the other hand, if the CPU 11 determines that the total remaining power demand Dr is equal to or less than 0, it waits for a predetermined time ΔT to elapse (step S124), and sets the smaller of the total remaining power demand Dr and the value 0 divided by the predetermined time ΔT as the total power generation command value Ptag (step S126). Then, the CPU 11 distributes and transmits the set total power generation command value Ptag to the multiple fuel cell systems 30 under its control (step S128), and ends the demand response execution process. In the process of step S126, if the remaining total power demand Dr is 0, the total power generation command value Ptag is 0, and if the remaining total power demand Dr is less than 0, the total power generation command value Ptag is a negative value. That is, if the remaining total power demand Dr is less than 0, the CPU 11 commands the purchase of power so that the power consumption is greater than the power generation output in the entire fuel cell systems 30 under its control. As described above, when the output is reduced, the response performance of the output reduction is relatively high, so that the total power generation output forecast value β generally coincides with the total power generation output (actual value) currently being generated. Therefore, the remaining total power demand Dr is estimated to be equal to the actual value by the total power generation output α based on the actual value and the total power generation output forecast value β, and the power generation output that becomes excessive when the output is increased is adjusted by the power purchase amount when the output is reduced. This makes it possible to match the total power generation output offset by the power purchase amount during the target period of the demand response with the total power demand Dr.

[0032] In the above-described embodiment, the CPU 11 executes the demand response execution process exemplified in Fig. 2 and Fig. 5, but may appropriately select and execute from a plurality of processes including other demand response execution processes. As an example of the other demand response execution process, there may be mentioned a process of dividing the total power demand D by a number obtained by dividing the target period of the demand response by a predetermined time ΔT, thereby setting a total power generation amount indication value Ptag averaged for every predetermined time ΔT.

[0033] The above describes the form for implementing the present disclosure using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0034] The present disclosure is applicable to the manufacturing industry of power generation management devices and distributed power generation systems. [Explanation of symbols]

[0035] 10 power generation management device, 11 CPU (power generation amount instruction value setting unit), 15 communication unit (total power demand amount acquisition unit, power generation amount actual value acquisition unit), 30 fuel cell system (distributed power generation device).

Claims

1. A power generation management device that manages power generation of a distributed power generation device in response to a demand response request, a total power demand acquisition unit that acquires a total power demand, which is a total amount of power demand within a target period of the demand response; a power generation amount actual value acquisition unit that acquires a power generation amount actual value of the distributed power generation device; a power generation instruction value setting unit that sets a power generation instruction value of the distributed power generation device for each predetermined time during the target period and outputs the set power generation instruction value to the distributed power generation device to implement the demand response, and at the start of the target period, sets the power generation instruction value based on a maximum power generation amount per predetermined time of the distributed power generation device, and thereafter, at each elapse of the predetermined time, calculates a remaining total power demand, which is the remaining amount of the total power demand, based on the power generation actual value acquired by the power generation actual value acquisition unit, and repeats the process of setting the power generation instruction value for the next predetermined time based on the smaller of the maximum power generation amount per predetermined time and the remaining total power demand until the remaining total power demand becomes zero; A power generation management device comprising:

2. The power generation management device according to claim 1, the power generation amount instruction value setting unit calculates the remaining total power demand by subtracting from the total power demand a power generation prediction value, which is a prediction value of the amount of power generated by the distributed power generation device in the current specified time, and a cumulative value of the power generation actual value acquired up to the previous specified time during the target period; Power generation management device.

3. The power generation management device according to claim 2, the power generation amount instruction value setting unit calculates the remaining total power demand for the next predetermined time period using a value based on the power generation amount instruction value set for the current predetermined time period as the power generation amount prediction value; Power generation management device.

4. The power generation management device according to claim 2, the power generation amount instruction value setting unit calculates the remaining total power demand for the next specified time using a value based on the power generation actual value acquired at the previous specified time as the power generation amount prediction value when the remaining total power demand calculated at the current specified time is equal to or greater than the maximum power generation amount per specified time, and calculates the remaining total power demand for the next specified time using a value based on the power generation amount instruction value set at the current specified time as the power generation amount prediction value when the remaining total power demand calculated at the current specified time is less than the maximum power generation amount per specified time. Power generation management device.

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