Power generation system and control method

Abstract

This electric power generation system comprises: a rotating machine; a storage battery that is discharged when the rotating machine is started; and a discharge control unit controlling the discharge of the storage battery, wherein the discharge control unit controls the discharge from the storage battery when the rotating machine is started, such that the electric power required to start the rotating machine can be provided by electric power from a grid and the discharged electric power from the storage battery.

Description

Technical Field

[0001] The present disclosure relates to a power generation system and a control method. This application claims priority based on Japanese Patent Application No. 2022-076849 filed in Japan on May 9, 2022, the content of which is incorporated herein by reference.

Background Art

[0002] Patent Document 1 describes a rotating machine (gas turbine power generation device) that uses a DC motor powered by a storage battery as a starting device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rotating machine described in Patent Document 1, for example, when it is necessary to repeatedly start and stop the gas turbine in a short time during a test operation or the like, there is a problem that the capacity of the storage battery must be made larger than the capacity required during normal operation.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power generation system and a control method capable of appropriately setting the capacity of a storage battery for supplying power to a starting device of a rotating machine.

Means for Solving the Problems

[0006] In order to solve the above problems, a power generation system according to the present disclosure includes a rotating machine, a storage battery that discharges when the rotating machine is started, and a discharge control unit that controls the discharge of the storage battery, wherein the discharge control unit controls the discharge from the storage battery so that when the gas turbine is started, the power required for starting the rotating machine can be covered by the power from the power grid and the discharge power from the storage battery.

[0007] A control method according to the present disclosure is a control method for a power generation system including a rotating machine, a storage battery that discharges when the rotating machine is started, and a discharge control unit that controls the discharge of the storage battery, wherein when the gas turbine is started, the discharge from the storage battery is controlled so that the power required for starting the rotating machine can be covered by the power from the power grid and the discharge power from the storage battery.

Advantages of the Invention

[0008] According to the power generation system and control method of the present disclosure, the capacity of the storage battery for supplying power to the starting device of the rotating machine can be appropriately set.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, a power generation system and a control method according to embodiments of the present disclosure will be described with reference to FIGS. 1 to 17. FIG. 1 is a configuration diagram showing a configuration example of a power generation system according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram showing an operation example of the power generation system according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram showing an example of a startup process of a gas turbine according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram for explaining an operation example of the power generation system according to an embodiment of the present disclosure. FIGS. 5 and 6 are flowcharts showing operation examples of the power generation system according to an embodiment of the present disclosure. FIGS. 7 to 9 are schematic diagrams for explaining operation examples of the power generation system according to an embodiment of the present disclosure. FIGS. 10 and 11 are flowcharts showing operation examples of the power generation system according to an embodiment of the present disclosure. FIGS. 12 to 17 are schematic diagrams for explaining operation examples of the power generation system according to an embodiment of the present disclosure. In each figure, the same or corresponding components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0011] (Configuration of Power Generation System) As shown in FIG. 1, the power generation system 1 according to the present embodiment includes a power generation facility 2 and a power storage facility 3. The power input / output line 11 of the power generation facility 2 is connected to the power transmission and distribution line 6 via a power meter 73. The power input / output line 12 of the power storage facility 3 is connected to the power transmission and distribution line 6. The power input / output line 13 of the production facility 4 is connected to the power transmission and distribution line 6. The power transmission and distribution line 6 is connected to the grid 5 via a transformer 72 and a power meter 71. The grid 5 is also referred to as a power grid. In the present embodiment, the power input from the grid 5 to the power transmission and distribution line 6 is referred to as received power. The power output from the power generation facility 2 to the power transmission and distribution line 6 is referred to as generated power. The power input from the power transmission and distribution line 6 to the power generation facility 2 is referred to as power consumption of the power generation facility. The power output from the power storage facility 3 to the power transmission and distribution line 6 is referred to as discharge power. The power input from the power transmission and distribution line 6 to the power storage facility 3 is referred to as charge power. The power input from the power transmission and distribution line 6 to the production facility 4 is referred to as power consumption of the production facility. The production facility 4 is, for example, a facility in a factory and consumes the power supplied from the power transmission and distribution line 6 as a load. The grid 5 is a system that performs power generation, transformation, power transmission, and power distribution. The part of the grid 5 that performs power transmission and distribution is the grid 5a. The power transmission and distribution line 6 is also a grid. The charging of the power storage facility 3 is performed from the grid.

[0012] FIG. 2 shows an example of the daily change in the received power supplied to the power generation system 1 and the production facility 4 shown in FIG. 1. The horizontal axis represents time, and the vertical axis represents the received power. In the example shown in FIG. 2, the power generation facility 2 stops generating electricity at night and generates electricity only during the day. Until the power generation facility 2 starts generating electricity, power is received from the grid 5 including the starting power of the power generation facility 2. When the power generation facility 2 completes startup and starts generating electricity, power is supplied from the power generation facility 2 to the production facility 4, and the received power becomes zero.

[0013] (Configuration of Power Generation Facility) The power generation facility 2 includes a gas turbine combined cycle (GTCC) power generation system 20 (hereinafter referred to as the GTCC power generation system 20). The electric power generated by the power generation facility 2 is consumed, for example, as power consumed by production facilities or charging power, or fed back to the grid 5. The GTCC power generation system 20 includes a gas turbine 21, a generator 22, a steam turbine 23, an exhaust heat recovery boiler 24, a condenser 25, an excitation thyristor rectifier 26, a GTCC control device 27, and auxiliary equipment (not shown). The generator 22 and the excitation thyristor rectifier 26 constitute a starting device 28. When starting the gas turbine 21, the starting device 28 drives the gas turbine 21 by using the generator 22 as a motor. The auxiliary equipment (not shown) includes, for example, pumps for delivering circulating water, feed water, lubricating oil, etc., cooling fans, and equipment in the monitoring room.

[0014] The gas turbine 21 is an aspect of a rotary machine and includes an air compressor 211, a combustor 212, and a turbine 213. The gas turbine 21 mixes and burns the air compressed by the air compressor 211 and the natural gas fuel in the combustor 212, and applies the combustion gas, which is a fluid, to the rotating blades in the turbine 213 to convert the kinetic energy of the fluid into rotational motion and obtain rotational power. The gas turbine 21 drives the generator 22. In this embodiment, an example in which the rotary machine is the gas turbine 21 is described, but other embodiments are not limited thereto. In other embodiments, the rotary machine may be, for example, a gas turbine starting device, a compressor, a turbo refrigerator, a pump, etc.

[0015] The exhaust heat recovery boiler 24 recovers the exhaust heat of the gas turbine exhaust gas 241 discharged from the gas turbine 21 to generate steam. In addition, the exhaust heat recovery boiler 24 recovers the exhaust heat from the gas turbine exhaust gas 241, performs denitration treatment, etc., and then discharges it as the exhaust heat recovery boiler exhaust gas 242 and discharges it into the atmosphere from a chimney (not shown).

[0016] The generator 22 is a synchronous electric machine and is configured coaxially with the gas turbine 21 and the steam turbine 23. The generator 22 operates as a synchronous generator that converts the power of the gas turbine 21 and the steam turbine 23 into electric power and outputs it to the power transmission and distribution line 6. Also, when starting the gas turbine 21, the generator 22 inputs the electric power supplied from the power transmission and distribution line 6 and operates as a synchronous motor.

[0017] The steam turbine 23 is a prime mover that applies the steam generated by the exhaust heat recovery boiler 24 to the rotating blades to obtain rotational power.

[0018] The condenser 25 condenses the steam that has passed through the steam turbine 23. The water condensed by the condenser 25 is supplied to the exhaust heat recovery boiler 24 via a pump or the like.

[0019] The GTCC control device 27 inputs detection signals from various sensors (not shown) and control signals from a higher-level control device (not shown), etc., and controls various actuators in the power generation facility 2. For example, when starting the gas turbine 21, the GTCC control device 27 controls each part of the gas turbine 21 and controls the rotational speed and output torque of the starting device 28. Also, the GTCC control device 27 generates a plurality of types of signal signals according to predetermined events during the start-up of the gas turbine, and outputs them to a power storage facility control device 34 described later in the power storage facility 3 via the communication line 81. The predetermined events are, for example, the start of gas turbine start-up, the attainment of the spin rotational speed, ignition, self-sustaining rotational speed, etc. Also, the signal signals are a gas turbine start-up signal, a spin rotational speed attainment signal, an ignition signal, a self-sustaining rotational speed signal corresponding to each event, and a signal representing the rotational speed (= rotational velocity) of the gas turbine 21, etc.

[0020] Note that the start of gas turbine startup is an event where the startup device 28 is started and rotational torque is applied from the startup device 28 to the gas turbine 21 in a turning state. The spin rotation speed reach is an event where the spin rotation speed of the gas turbine 21 being spin-operated reaches a predetermined rotation speed suitable for the purge operation of the exhaust duct. Here, the spin operation, also called cranking, is an operation in a state where the gas turbine 21 is driven only by the startup device 28 without fuel injection. Further, the purge operation is a spin operation for removing unburned fuel remaining in the combustor 212, ducts, etc. prior to ignition during startup. Ignition is an event where fuel starts to burn due to the ignition operation. The self-rotation speed is an event where the gas turbine 21 reaches a rotation speed equal to or higher than the rotation speed at which self-sustained operation can be performed, where self-sustained operation means that the gas turbine 21 can maintain acceleration without receiving rotational torque from the startup device 28. Note that the self-rotation speed means the completion of startup.

[0021] FIG. 3 schematically shows the changes in the power consumption of the power generation facility and the gas turbine rotational speed when starting the gas turbine 21. The horizontal axis represents time, and the vertical axis represents the power consumption of the power generation facility and the gas turbine rotational speed. The power consumption of the power generation facility is indicated by a solid line. The gas turbine rotational speed is indicated by a dashed line. The power consumption of the power generation facility includes the gas turbine starting power (the power supplied by the discharge power) and the auxiliary equipment power consumption. In FIG. 3, the gas turbine starting power amount (the area supplied by the discharge power) is shown by the upper-right shaded area. Also, the auxiliary equipment power consumption amount is shown by the lower-right shaded area. The gas turbine starting power is the power consumed by the starting device 28. In the example shown in FIG. 3, the start of the gas turbine is initiated at time t1. The rotational speed of the gas turbine 21 reaches a predetermined spin rotational speed at time t2. Thereafter, the rotational speed of the gas turbine 21 is generally controlled to be constant, and a purge operation is executed. Then, ignition occurs at time t3. After ignition, the rotational speed of the gas turbine 21 increases and reaches the self-rotating speed at time t4. Also, the gas turbine starting power increases at a generally constant rate from time t1 to time t2. Also, the gas turbine starting power is generally constant from time t2 to time t3. Also, the gas turbine starting power increases from time t3, becomes constant at a certain value, and decreases from a certain time approaching time t4. And it becomes zero at time t4. Note that the changes during startup shown in FIG. 3 are an example, and the application of this embodiment is not limited to this example.

[0022] (Configuration of the energy storage facility) The energy storage facility 3 includes an AC / DC converter 31, three DC / DC converters 32, three battery packs 33, and an energy storage facility control device 34. The AC / DC converter 31 is a bidirectional AC-DC converter that converts the AC power input from the power transmission and distribution line 6 into DC power and outputs it to the DC / DC converter 32, or converts the DC power input from the DC / DC converter 32 into AC power and outputs it to the power transmission and distribution line 6. Note that the number of the DC / DC converter 32 and the battery pack 33 may each be one, or may be a plurality other than three.

[0023] The DC / DC converter 32 is a bidirectional DC-DC converter that steps up or steps down the voltage of the DC power input from the AC / DC converter 31 and outputs it to the battery pack 33, or steps up or steps down the voltage of the DC power input from the battery pack 33 and outputs it to the AC / DC converter 31. Also, for example, during discharge from the battery pack 33, the DC / DC converter 32 controls the discharge power from the battery pack 33 by, in accordance with an instruction from the power storage facility control device 34, setting the voltage of the DC power output to, for example, the AC / DC converter 31 to a constant value and changing the current. Each DC / DC converter 32 independently controls the discharge power from each battery pack 33 in accordance with an instruction from the power storage facility control device 34.

[0024] The battery pack 33 includes a circuit breaker 331, a battery 332, a sensor unit 333, and a monitoring device 334. The battery 332 is composed of a combination of a plurality of battery cells (single cells) or battery modules (assembled batteries) composed of a plurality of battery cells. The battery cell is, for example, a lithium-ion battery (however, it is not limited to this). The battery 332 discharges, for example, when the gas turbine 21 starts up. The circuit breaker 331 connects or disconnects the connection between the battery 332 and the DC / DC converter 32. The operation of the circuit breaker 331 is controlled, for example, by the monitoring device 334. The sensor unit 333 includes a plurality of types of sensors, detects the voltage, current, temperature, etc. of the battery 332, and outputs the detected results to the monitoring device 334. The monitoring device 334 acquires the detection results of the sensor unit 333, controls the circuit breaker 331, or calculates the SOC (State Of Charge; charge rate or charge state) of the battery 332. Also, the monitoring device 334 outputs information representing the acquired detection results of the sensor unit 333 and the calculated SOC to the power storage facility control device 34. Further, when the monitoring device 334 detects a predetermined event such as overvoltage, overcurrent, or overheating based on the detection results of the sensor unit 333, it disconnects the circuit breaker 331 to protect the battery 332. At that time, the monitoring device 334 outputs a signal indicating that the circuit breaker 331 has been disconnected to the power storage facility control device 34. Also, the monitoring device 334 disconnects or connects the circuit breaker 331 when it receives a predetermined instruction from the power storage facility control device 34.

[0025] The power storage device control device 34 can be configured using, for example, a computer and its peripheral circuits and devices. The power storage device control device 34 includes, as a functional configuration composed of a combination of hardware such as a computer and software such as a program, a discharge control unit 341, a remaining battery power calculation unit 342, a power difference calculation unit 343, and an abnormality detection unit 344.

[0026] The discharge control unit 341 controls the discharge of one or more storage batteries 332. In the present embodiment, "controlling the discharge of the storage battery 332" means at least one of controlling the discharge power of the storage battery 332 and controlling the discharge power and the discharge energy amount of the storage battery 332. When starting the gas turbine 21, for example, if the remaining battery power of the storage battery 332 is sufficient, the discharge control unit 341 controls the discharge power to a predetermined pattern to discharge the storage battery 332. Also, when starting the gas turbine 21, for example, if the remaining battery power of the storage battery 332 is not sufficient, the discharge control unit 341 changes the pattern so that the discharge energy amount does not exceed the remaining battery power and discharges the storage battery 332.

[0027] In the present embodiment, the discharge control unit 341 controls the discharge from the storage battery 332 according to, for example, a predetermined event at the time of starting the gas turbine 21. The event includes at least one of the start of the gas turbine 21, the arrival of the spin speed, ignition, or the self-sustaining speed described above with reference to FIG. 3. The discharge control unit 341 receives a signal representing the event as a signal from the GTCC control device 27. Note that the GTCC control device 27 is an example of a configuration of the control unit of the gas turbine 21.

[0028] In the present embodiment, when starting the gas turbine 21, the discharge control unit 341 controls the discharge from the storage battery 332 so that the power required for starting the gas turbine 21 can be covered by the power from the power grid 5 and the discharge power from the storage battery 332.

[0029] Further, when the discharge control unit 341 supplies power for starting the gas turbine 21 from a plurality of storage batteries 332 by discharging the plurality of storage batteries 332, when the abnormality detection unit 344 detects an abnormality in the storage battery 332, after supplying the discharge amount from the storage battery 332 in which the abnormality has been detected from the grid 5a, the discharge power of the other storage batteries 332 in which no abnormality has been detected is increased so as to cover the discharge amount from the storage battery 332 in which the abnormality has been detected.

[0030] The remaining battery power calculation unit 342 calculates the remaining battery power of the storage battery 332. For example, the remaining battery power calculation unit 342 acquires the SOC calculated by the monitoring device 334 and calculates the total remaining battery power of the three storage batteries 332. Alternatively, for example, the remaining battery power calculation unit 342 calculates the charging power and the discharging power based on the current and voltage detected by the monitoring device 334, and calculates the remaining battery power by integrating them.

[0031] The power difference calculation unit 343 calculates the power difference between the predicted value of the power received from the power grid 5 when starting the gas turbine 21 and the total available power value from the power grid 5. For example, the power difference calculation unit 343 receives information representing the predicted value of the received power from the device that manages the production facility 4 via the communication line 81. FIG. 4 shows an example of calculating the power difference ΔMW. The horizontal axis represents time, and the vertical axis represents the received power. In FIG. 4, the actual value of the received power is shown by a solid-line rectangle, and the predicted value is shown by a dashed-line rectangle. Also, the gas turbine starting power in the predicted values is shown shaded. In the example shown in FIG. 4, starting the gas turbine 21 starts after 8:30, and the received power peaks at around 9:00 when the gas turbine starting power is maximum. The received power decreases from around 9:30 when the generator 22 starts outputting, and the received power becomes zero after around 10:00. In the example shown in FIG. 4, the value of the maximum contract power is used as the total available power value, and the value obtained by subtracting the predicted value MW of the power received from the power grid 5 when starting the gas turbine 21 from the value of the maximum contract power is the power difference ΔMW. Note that the total available power value is not limited to the value of the maximum contract power, and can be, for example, an upper limit value set to achieve a predetermined purpose.

[0032] The abnormality detection unit 344 detects an abnormality in the storage battery 332 based on the information acquired from each monitoring device 334. The abnormality in the storage battery 332 is, for example, that the monitoring device 334 has interrupted the circuit breaker 331, that the temperature of the storage battery 332 has exceeded a predetermined temperature, or the like.

[0033] (Operation example of the power generation system 1) With reference to FIGS. 5 to 17, an operation example at the time of starting the gas turbine 21 of the power generation system 1 shown in FIG. 1 will be described. FIG. 5 shows the basic operation flow at the time of starting the gas turbine 21. As shown in FIG. 5, in the power generation system 1, the power storage facility control device 34 determines the discharge mode of the storage battery 332 at the time of starting the gas turbine 21 (step S1), and controls the discharge of the storage battery 332 in the determined discharge mode (step S2). In the present embodiment, the discharge mode represents the mode of discharging from the power storage facility 3. In the present embodiment, as an example, as the discharge mode, a mode in which no discharge is performed (discharge stop), a mode in which a relatively large amount of power of the storage battery 332 is used (large discharge mode), a mode in which an appropriate amount of power of the storage battery 332 is used (medium discharge mode), and a mode in which the power of the storage battery 332 is used only at the peak (small discharge mode) are set, and discharge is executed or not executed using any of these. Note that the process shown in FIG. 5 may be started, for example, in response to a predetermined input operation by an operator, or may be started when a predetermined signal is received from the power generation facility 2 or the production facility 4, or when a preset time is reached.

[0034] Next, the process of determining the discharge mode (step S1) shown in FIG. 5 will be described. FIG. 6 shows the flow of step S1 for determining the discharge mode shown in FIG. 5. FIG. 7 shows an example of the large discharge mode. FIG. 8 shows an example of the medium discharge mode. FIG. 9 shows an example of the small discharge mode. FIGS. 7 to 9 show examples of the power consumption of the power generation facility identical to those shown in FIG. 3. However, in FIGS. 7 to 9, the gas turbine starting power amount shown by the upward-sloping shaded area in FIG. 3 is divided into an upward-sloping shaded area (area covered by discharge power) and a white area (area covered by received power) and shown separately. In the large discharge mode shown in FIG. 7, the areas covered by the gas turbine starting power and the discharge power match during all periods from the start of startup to the self-rotating speed. In the medium discharge mode shown in FIG. 8, an area covered by received power is set for a part of the period from ignition to the self-rotating speed. In the small discharge mode shown in FIG. 9, areas covered by received power are set for all periods from the start of gas turbine startup to ignition and for a part of the period from ignition to the self-rotating speed. In this operation example, it is assumed that, before starting the gas turbine 21, the power storage device 3 stores an amount of power sufficient to cover at least the discharge power amount in the small discharge mode (for example, an amount sufficient to execute multiple startups).

[0035] In the process shown in FIG. 6, the power difference calculation unit 343 acquires the predicted received power value MW[W] (step S10) and calculates the power difference ΔMW (step S11). Next, the battery remaining power amount calculation unit 342 calculates the remaining power amount BR[Wh] of the battery 332 (step S12).

[0036] Next, the discharge control unit 341 determines whether the power difference ΔMW[W] is greater than "0" (step S13). If the power difference ΔMW[W] is greater than "0" (step S13: YES), the discharge control unit 341 determines the discharge mode as "discharge stop" (step S14) and ends the process shown in FIG. 6. If the power difference ΔMW[W] is not greater than "0" (step S13: NO), the discharge control unit 341 determines whether the remaining power amount BR is greater than the discharge power amount [Wh] in the large discharge mode (step S15). Here, the discharge power amount [Wh] in the large discharge mode corresponds to the area of the upward-sloping shaded area shown in FIG. 7.

[0037] When the remaining power amount BR is greater than the discharge power amount [Wh] in the large discharge mode (step S15: YES), the discharge control unit 341 determines the discharge mode as the "large discharge mode" (step S16) and ends the process shown in FIG. 6. When the remaining power amount BR is not greater than the discharge power amount [Wh] in the large discharge mode (step S15: NO), the discharge control unit 341 determines whether the remaining power amount BR is greater than the discharge power amount [Wh] in the medium discharge mode (step S17). Here, the discharge power amount [Wh] in the medium discharge mode corresponds to the area of the upward-sloping shaded portion shown in FIG. 8.

[0038] When the remaining power amount BR is greater than the discharge power amount [Wh] in the medium discharge mode (step S17: YES), the discharge control unit 341 determines the discharge mode as the "medium discharge mode" (step S18) and ends the process shown in FIG. 6. When the remaining power amount BR is not greater than the discharge power amount [Wh] in the medium discharge mode (step S17: NO), the discharge control unit 341 determines the discharge mode as the "small discharge mode" (step S19) and ends the process shown in FIG. 6.

[0039] Note that in the determination processes in step S13, step S15, and step S17, the magnitude relationship may be determined with a certain margin. For example, in step S13, instead of determining whether it is greater than "0", it may be determined whether it is greater than a certain margin "α" (α > 0).

[0040] Next, the process of discharge control (step S2) shown in FIG. 5 will be described. FIG. 10 shows the flow of step S2 for controlling the discharge shown in FIG. 5. FIG. 11 shows the flow of the process executed in the processes (step S23, step S24, step S26, and step S28) for controlling the discharge from the storage battery 332 in FIG. 10.

[0041] In the process shown in FIG. 10, the discharge power from the power storage facility 3 is controlled upon receiving a predetermined signal in accordance with the patterns shown in FIGS. 7 to 9. For example, in the large discharge mode shown in FIG. 7, after the gas turbine start signal is received at time t1, the discharge from the power storage facility 3 starts. Thereafter, the discharge power is increased at a predetermined rising rate according to the elapsed time from time t1. Thereafter, when the spin rotation speed reach signal is received at time t2, the discharge power is controlled to a predetermined constant value. Thereafter, when the ignition signal is received at time t3, the discharge power is gradually increased at a predetermined rising rate according to the elapsed time from time t3. Then, when the discharge power reaches a predetermined value, the discharge power is controlled to a predetermined constant value. Thereafter, for example, when the elapsed time from time t3 reaches a predetermined value, the discharge power is decreased at a predetermined falling rate. Thereafter, when the self-rotation speed signal is received at time t4, the discharge from the power storage facility 3 stops. Note that the control of the discharge power is not limited thereto, and for example, the discharge power may be increased or decreased according to the rotation speed of the gas turbine 21.

[0042] In the process shown in FIG. 10, first, the discharge control unit 341 determines whether the discharge mode is the discharge stop (step S20). When the discharge mode is the discharge stop (step S20: YES), the discharge control unit 341 ends the process shown in FIG. 10 without discharging from the power storage facility 3. When the discharge mode is not the discharge stop (step S20: NO), the discharge control unit 341 waits for the reception of the gas turbine start start signal (repetition of step S21: NO). When the gas turbine start start signal is received (step S21: YES), the discharge control unit 341 determines whether the discharge mode is the large discharge mode or the medium discharge mode (step S22). When the discharge mode is the large discharge mode or the medium discharge mode (step S22: YES), the discharge control unit 341 starts discharging from the storage battery 332 (step S23). Next, the discharge control unit 341 increases the discharge power at a predetermined increase rate according to the elapsed time since the reception of the gas turbine start start signal (step S24). Next, the discharge control unit 341 determines whether the spin rotation speed arrival signal has been received (step S25). When the spin rotation speed arrival signal has not been received (step S25: NO), the discharge control unit 341 increases the discharge power at a predetermined increase rate according to the elapsed time since the reception of the gas turbine start start signal again (step S24). Note that the processes of step S24 and step S25 are executed at a constant cycle (that is, a constant waiting time is set during the repeated process).

[0043] When the spin rotation speed arrival signal has been received (step S25: YES), the discharge control unit 341 controls the discharge power to be constant at a predetermined value (step S26). Next, the discharge control unit 341 determines whether the ignition signal has been received (step S27). When the ignition signal has not been received (step S27: NO), the discharge control unit 341 continues to control the discharge power to be constant at a predetermined value (step S26). Note that the processes of step S26 and step S27 are executed at a constant cycle.

[0044] On the other hand, when the discharge mode is not the large discharge mode or the medium discharge mode (step S22: NO), the discharge control unit 341 waits for the reception of the ignition signal (repetition of step S31: NO).

[0045] When the ignition signal is received in step S27 or step S31 (step S27: YES or step S31: YES), the discharge control unit 341 controls the discharge power in a predetermined pattern according to the discharge mode (step S28). Next, the discharge control unit 341 determines whether or not an independent rotation speed signal has been received (step S29). When the independent rotation speed signal has not been received (step S29: NO), the discharge control unit 341 continues to control the discharge power in a predetermined pattern according to the discharge mode (step S28). Note that the processes of step S28 and step S29 are executed at a constant cycle.

[0046] When the independent rotation speed signal has been received (step S29: YES), the discharge control unit 341 stops the discharge from the storage battery 332 (step S30) and ends the process shown in FIG. 10.

[0047] Next, the process shown in FIG. 11 will be described. As described above, the process shown in FIG. 11 is the process executed in step S23, step S24, step S26, and step S28 shown in FIG. 10. When the process shown in FIG. 11 is started, the discharge control unit 341 first determines the total discharge power of all the storage batteries (step S40).

[0048] When the process shown in FIG. 11 is executed in step S23, the total discharge power of all the storage batteries is determined only once with a power suitable for the start of discharge. When the process shown in FIG. 11 is executed in step S24, the total discharge power of all the storage batteries is determined such that the power increases at a predetermined increase rate each time it is executed, for example. When the process shown in FIG. 11 is executed in step S26, the total discharge power of all the storage batteries is always determined to be a constant predetermined value. When the process shown in FIG. 11 is executed in step S28, the total discharge power of all the storage batteries is determined according to the patterns shown in FIGS. 7 to 9 each time it is executed.

[0049] Next, the discharge control unit 341 evenly allocates the total discharge power of all the storage batteries to each storage battery 332 (step S41). For example, when the total discharge power of all the storage batteries is P, in this embodiment, the power of P / 3 is evenly allocated to the three storage batteries 332.

[0050] Next, the discharge control unit 341 determines whether the abnormality detection unit 344 has detected an abnormality in the storage battery 332 (step S42). On the other hand, when no abnormality is detected (step S42: NO), the discharge control unit 341 controls the discharge of each storage battery 332 so as to obtain the allocated discharge power (step S44), and ends the process shown in FIG. 11.

[0051] On the other hand, when an abnormality is detected (step S42: YES), the discharge control unit 341 increases the discharge power of the other storage batteries 332 in which no abnormality is detected so as to cover the discharge amount from the storage battery 332 in which the abnormality is detected (step S43). For example, when an abnormality is detected in one storage battery 332, the discharge control unit 341 sets the discharge power allocated to the storage battery 332 to "0", and increases the discharge power allocated to the other storage batteries 332 to P / 2. Next, the discharge control unit 341 controls the discharge of each storage battery 332 so as to obtain the allocated discharge power (step S44), and ends the process shown in FIG. 11.

[0052] Note that, as described above, the processes in steps S24, S26, and S28 are executed at a fixed cycle. Therefore, for example, in the case of an abnormality such as the circuit breaker 331 being interrupted by the monitoring device 334, a delay of about that cycle will occur from when the circuit breaker 331 is interrupted until the discharge power of the other battery 332 increases. In this case, when the discharge control unit 341 supplies power used for starting the gas turbine 21 from a plurality of batteries 332, and when the abnormality detection unit 344 detects an abnormality in the battery 332, after supplying the discharge amount from the battery 332 in which the abnormality is detected from the grid 5a (or the power transmission and distribution line 6), the discharge power of the other batteries 332 in which no abnormality is detected is increased so as to cover the discharge amount from the battery 332 in which the abnormality is detected.

[0053] Figures 12 to 14 show operation examples when the circuit breaker 331 is interrupted by one of the three batteries 332 during the start-up of the gas turbine 21. In Figures 12 to 14, the three batteries 332 are designated as battery 332(A), battery 332(B), and battery 332(C). Figure 12 shows a state where the battery 332(C) has stopped discharging when the starting power P is evenly supplied from the battery 332(A), the battery 332(B), and the battery 332(C) at P / 3 each during the start-up of the gas turbine 21. In this case, as shown in Figure 13, power of P / 3 is supplied from the grid 5a before the discharge power of the other batteries 332(A) and 332(B) increases. Then, when the discharge power of the batteries 332(A) and 332(B) increases, as shown in Figure 14, the supply of power from the grid 5a stops, and power supply to the starting device 28 continues only with the batteries 332(A) and 332(B).

[0054] Figs. 15 to 17 show examples of the time variations of the discharge power and the discharge energy from the storage batteries 332(A), 332(B), and 332(C) when the gas turbine 21 is started. The solid line represents the discharge power from the power storage facility 3. The dashed line represents the discharge energy from the power storage facility 3. The chain line represents the discharge energy from each of the storage batteries 332(A), 332(B), and 332(C). Fig. 15 shows the case where all of the storage batteries 332(A), 332(B), and 332(C) are normal. Fig. 16 shows the case where the discharge of the storage battery 332(C) stops at time t11. In this case, the storage batteries 332(A) and 332(B) increase the discharge power at time t12. In this case, the drop in the discharge power from time t11 to time t12 is supplied from the grid 5a. Fig. 17 shows the case where the discharge of the storage battery 332(C) stops immediately before the start of startup. In this case, the storage batteries 332(A) and 332(B) increase the discharge power from the start of startup.

[0055] (Function and Effect) As described above, in the power generation system 1 of the present embodiment, the discharge control unit 341 controls the discharge from the storage battery 332 so that the power required for starting the gas turbine 21 can be covered by the power from the system 5 and the discharge power from the storage battery 332 when the gas turbine 21 is started. Therefore, according to the power generation system 1 of the present embodiment, the capacity of the storage battery 332 for supplying power to the starting device 28 of the gas turbine 21 can be appropriately set.

[0056] Further, the discharge control unit 341 controls the discharge from the storage battery 332 according to the remaining energy of the storage battery. According to this configuration, when covering with the power from the system 5 and the discharge power from the storage battery 332, the ratio of the power from the system 5 and the discharge power from the storage battery 332 can be appropriately set.

[0057] Further, the discharge control unit 341 discharges the storage battery 332 during any period from the ignition of the gas turbine 21 to the completion of the startup of the gas turbine 21. According to this configuration, the capacity of the storage battery 332 can be set more appropriately.

[0058] Further, the discharge control unit 341 controls the discharge from the storage battery 332 so that the discharge power from the storage battery 332 becomes maximum during the period from the ignition of the gas turbine 21 to the completion of the start-up of the gas turbine 21. According to this configuration, the capacity of the storage battery 332 can be set more appropriately.

[0059] Further, the discharge control unit 341 controls the discharge from the storage battery according to the power difference between the predicted value of the power received from the power system 5 during the start-up of the gas turbine 21 and the total available power value from the power system 5, and the remaining battery power of the storage battery. According to this configuration, the discharge of the storage battery 332 can be controlled so as not to exceed the total available power value.

[0060] Further, the discharge control unit 341 controls the discharge from the storage battery 332 according to a predetermined event during the start-up of the gas turbine 21. According to this configuration, the control of the discharge can be simplified. The event includes at least one of the start of the start-up of the gas turbine 21, the attainment of the spin speed, ignition, or the self-rotation speed. Further, the discharge control unit 341 receives a signal representing the event from the GTCC control device 27.

[0061] (Other Embodiments) As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included. In the above embodiment, the discharge control unit 341, the remaining battery power calculation unit 342, the power difference calculation unit 343, and the abnormality detection unit 344 are provided in the power storage facility 3. However, the present invention is not limited to this, and for example, they may be provided in the GTCC control device 27.

[0062] <Computer Configuration> FIG. 18 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The above-described power storage device control device 34 and the GTCC control device 27 are implemented in the computer 90. Then, the operations of the above-described respective processing units are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, expands it in the main memory 92, and executes the above processing according to the program. Further, the processor 91 secures a storage area corresponding to each of the above-described storage units in the main memory 92 according to the program.

[0063] The program may be for realizing a part of the functions to be exhibited by the computer 90. For example, the program may exhibit functions by a combination with other programs already stored in the storage or a combination with other programs implemented in other devices. In other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of the PLD include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), and the like. In this case, part or all of the functions realized by the processor may be realized by the integrated circuit.

[0064] Examples of the storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), a semiconductor memory, and the like. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or may be an external medium connected to the computer 90 via the interface 94 or a communication line. Further, when this program is distributed to the computer 90 via a communication line, the computer 90 that has received the distribution may expand the program in the main memory 92 and execute the above processing. In at least one embodiment, the storage 93 is a non-transitory tangible storage medium.

[0065] <Appendix> The power generation system 1 described in each embodiment is understood as follows, for example.

[0066] (1) The power generation system 1 according to the first aspect includes a generator 22, a rotating machine (gas turbine 21) that drives the generator, a storage battery 332 that discharges when the rotating machine is started, and a discharge control unit 341 that controls the discharge of the storage battery. The discharge control unit controls the discharge from the storage battery so that, when the rotating machine is started, the power required for starting the rotating machine can be covered by the power from the grid 5 and the discharge power from the storage battery. According to this aspect and the following aspects, the capacity of the storage battery 332 for supplying power to the starting device 28 of the rotating machine can be appropriately set.

[0067] (2) The power generation system 1 according to the second aspect is the power generation system 1 of (1), further including a storage battery remaining power amount calculation unit 342 that calculates the remaining power amount of the storage battery. The discharge control unit controls the discharge from the storage battery according to the remaining power amount of the storage battery. According to this aspect, the capacity of the storage battery 332 for supplying power to the starting device 28 of the rotating machine can be set more appropriately.

[0068] (3) The power generation system 1 according to the third aspect is the power generation system 1 of (1) or (2), and the discharge control unit discharges the storage battery during any period from the start of startup of the rotating machine to the completion of startup of the rotating machine. According to this aspect, the capacity of the storage battery 332 for supplying power to the startup device 28 of the rotating machine can be set more appropriately.

[0069] (4) The power generation system 1 according to the fourth aspect is the power generation system 1 of (1) to (3), and the discharge control unit controls the discharge from the storage battery so that the discharge power from the storage battery becomes maximum during the period from the start of startup of the rotating machine to the completion of startup of the rotating machine. According to this aspect, the capacity of the storage battery 332 for supplying power to the startup device 28 of the gas turbine 21 can be set more appropriately.

[0070] (5) The power generation system 1 according to the fifth aspect is the power generation system 1 of (1) to (4), and the rotating machine is a gas turbine.

[0071] (6) The power generation system 1 according to the sixth aspect is the power generation system 1 of (2), (3) citing (2), (4) citing (3) citing (2), (4) citing (2), (5) citing (2) to (4), and further includes a power difference calculation unit 343 that calculates the power difference between the predicted value of the power received from the power grid during startup of the rotating machine and the total available power value from the power grid. The discharge control unit controls the discharge from the storage battery according to the power difference and the remaining power amount of the storage battery. According to this aspect, the discharge power can be controlled so as not to exceed the total available power value from the power grid.

[0072] (7) The power generation system 1 according to the seventh aspect is the power generation system 1 of (1) to (6), and the discharge control unit controls the discharge from the storage battery according to a predetermined event at the time of startup of the rotating machine. According to this aspect, the configuration can be simplified.

[0073] (8) The power generation system 1 according to the eighth aspect is the power generation system 1 of (7), wherein the event includes at least one of start-up initiation of the rotating machine, reaching the spin rotation speed, ignition, or self-rotating speed.

[0074] (9) The power generation system 1 according to the ninth aspect is the power generation system 1 of (8), wherein the discharge control unit receives a signal representing the event from the control unit (GTCC control device 27) of the rotating machine.

Industrial Applicability

[0075] According to the power generation system and control method of the present disclosure, the capacity of the storage battery for supplying power to the starting device of the rotating machine can be appropriately set.

Explanation of Signs

[0076] 1…Power generation system 2…Power generation facility 3…Power storage facility 4…Production facility 5…System 5a…Grid 6…Power transmission and distribution line (grid) 20…GTCC power generation system 21…Gas turbine (rotating machine) 22…Generator 27…GTCC control device (control unit) 28…Starting device 332…Storage battery 341…Discharge control unit 342…Storage battery remaining power amount calculation unit 343…Power difference calculation unit 344…Abnormality detection unit

Claims

1. A rotating machine, a storage battery that discharges when the rotating machine is started, a discharge control unit that controls the discharge of the storage battery, A power generation system comprising: When starting the rotating machine, the discharge control unit controls the discharge from the storage battery so that the power required for starting the rotating machine can be covered by the power from the grid and the discharge power from the storage battery. A storage battery remaining power amount calculation unit that calculates the remaining power amount of the storage battery, The power generation system further includes a power difference calculation unit that calculates a power difference between a predicted value of the power received from the grid when the rotating machine is started and the total available power value from the grid. The discharge control unit controls the discharge from the storage battery according to the power difference and the remaining power amount of the storage battery. Power generation system.

2. The discharge control unit discharges the storage battery during any period from the start of starting the rotating machine to the completion of starting the rotating machine. The power generation system according to Claim 1.

3. The discharge control unit controls the discharge from the storage battery so that the discharge power from the storage battery is maximized during the period from the start of starting the rotating machine to the completion of starting the rotating machine. The power generation system according to Claim 2.

4. The rotating machine is a gas turbine. The power generation system according to Claim 3.

5. The discharge control unit controls the discharge from the storage battery according to a predetermined event when the rotating machine is started. The power generation system according to Claim 4.

6. The event includes at least one of the start of starting the rotating machine, reaching the spin speed, ignition, or self-rotating speed. The power generation system according to Claim 5.

7. The discharge control unit receives a signal representing the event from the control unit of the rotating machine. The power generation system according to Claim 6.

8. A rotating machine, a storage battery that discharges when the rotating machine is started, a discharge control unit that controls the discharge of the storage battery, A control method for a power generation system comprising: When starting the rotating machine, the discharge control unit controls the discharge from the storage battery so that the power required for starting the rotating machine can be covered by the power from the grid and the discharge power from the storage battery. The power generation system is A storage battery remaining power amount calculation unit that calculates the remaining power amount of the storage battery, The power generation system further includes a power difference calculation unit that calculates a power difference between a predicted value of the power received from the grid when the rotating machine is started and the total available power value from the grid. The discharge control unit controls the discharge from the storage battery according to the power difference and the remaining power amount of the storage battery. Control method.

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