Electric 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

Power generation system and control method

[0001] This application claims priority to Japanese Patent Application No. 2022-076849, filed May 9, 2022, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 describes a rotary machine (gas turbine power generating device) in which a DC motor powered by a storage battery is used as a starter.

[0003] JP 2009-150362 A

[0004] The rotary machine described in Patent Document 1 had a problem in that when it was necessary to repeatedly start and stop the gas turbine in a short period of time, for example during test operation, the capacity of the storage battery had to be made larger than the capacity required under normal circumstances.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a power generation system and a control method that can appropriately set the capacity of a storage battery for supplying power to a starting device of a rotating machine.

[0006] In order to solve the above problem, the power generation system of the present disclosure is a power generation system including a rotary machine, a storage battery that discharges when the rotary machine is started, and a discharge control unit that controls the discharge of the storage battery, and when the gas turbine is started, the discharge control unit controls the discharge from the storage battery so that the power required to start the rotary machine can be covered by power from the grid and the discharge power from the storage battery.

[0007] The control method disclosed herein 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, and when the gas turbine is started, the discharge from the storage battery is controlled so that the power required to start the rotating machine can be covered by power from the grid and the discharged power from the storage battery.

[0008] According to the power generation system and control method of the present disclosure, it is possible to appropriately set the capacity of the storage battery for supplying power to the starting device of the rotary machine.

[0009] FIG. 1 is a configuration diagram illustrating an example configuration of a power generation system according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram illustrating an example start-up process of a gas turbine according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 5 is a flowchart illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 6 is a schematic diagram for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 7 is a flowchart illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 8 is a schematic diagram for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 9 is a schematic diagram for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 10 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment.

[0010] A power generation system and a control method according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 17 . FIG. 1 is a configuration diagram illustrating an example configuration of a power generation system according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram illustrating an example start-up process of a gas turbine according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIGS. 5 and 6 are flowcharts illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIGS. 7 to 9 are schematic diagrams for explaining an example operation of a power generation system according to an embodiment of the present disclosure. FIGS. 10 and 11 are flowcharts illustrating an example operation of a power generation system according to an embodiment of the present disclosure. FIGS. 12 to 17 are schematic diagrams for explaining an example operation of a power generation system according to an embodiment of the present disclosure. Note that the same or corresponding components in each drawing are designated by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0011] (Configuration of Power Generation System) As shown in FIG. 1 , a power generation system 1 according to this embodiment includes a power generation facility 2 and a power storage facility 3. An input / output line 11 of power to the power generation facility 2 is connected to a power transmission / distribution line 6 via a watt-hour meter 73. An input / output line 12 of power to the power storage facility 3 is connected to the power transmission / distribution line 6. An input / output line 13 of power to the production facility 4 is connected to the power transmission / distribution line 6. The power transmission / distribution line 6 is connected to a grid 5 via a transformer 72 and a watt-hour meter 71. The grid 5 is also referred to as a power system. In this embodiment, power input from the grid 5 to the power transmission / distribution line 6 is referred to as received power. Power output from the power generation facility 2 to the power transmission / distribution line 6 is referred to as generated power. Power input to the power generation facility 2 from the power transmission / distribution line 6 is referred to as power generation facility consumption. Power output from the power storage facility 3 to the power transmission / distribution line 6 is referred to as discharged power. Power input to the power storage facility 3 from the power transmission / distribution line 6 is referred to as charged power. The power input to the production facility 4 from the power transmission and distribution lines 6 is called the production facility power consumption. The production facility 4 is, for example, a facility in a factory, and consumes the power supplied from the power transmission and distribution lines 6 as a load. The system 5 is a system that generates, transforms, transmits, and distributes power. The part of the system 5 that transmits and distributes power is the grid 5a. The power transmission and distribution lines 6 are also a grid. The power storage facility 3 is charged from the grid.

[0012] Figure 2 shows an example of daily changes in the received power supplied to the power generation system 1 and production facility 4 shown in Figure 1. The horizontal axis represents time, and the vertical axis represents received power. In the example shown in Figure 2, power generation facility 2 stops generating power at night and generates power only during the day. Until power generation facility 2 starts generating power, it receives power from the grid 5, including the startup power of power generation facility 2. Once power generation facility 2 completes startup and starts generating power, power is supplied from power generation facility 2 to 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 power generated by the power generation facility 2 is consumed, for example, as power consumed by the production facility or as charging power, or is reversely flowed to the grid 5. The GTCC power generation system 20 includes a gas turbine 21, a generator 22, a steam turbine 23, a heat recovery steam generator 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., a cooling fan, equipment in a monitoring room, etc.

[0014] The gas turbine 21 is one type of rotary machine and includes an air compressor 211, a combustor 212, and a turbine 213. The gas turbine 21 is a prime mover that mixes and combusts air compressed by the air compressor 211 and natural gas fuel in the combustor 212, and applies the combustion gas, which is a fluid, to rotors in the turbine 213 to convert the kinetic energy of the fluid into rotational motion to obtain rotational power. The gas turbine 21 drives the generator 22. Note that, in this embodiment, an example will be described in which the rotary machine is the gas turbine 21, but this is not limiting in other embodiments. In other embodiments, the rotary machine may be, for example, a gas turbine starter, a compressor, a turbo chiller, a pump, or the like.

[0015] The heat recovery boiler 24 generates steam by recovering exhaust heat from gas turbine exhaust gas 241 discharged from the gas turbine 21. The heat recovery boiler 24 also recovers exhaust heat from the gas turbine exhaust gas 241 and performs denitration treatment and the like, and then discharges the gas as heat recovery boiler exhaust gas 242, which is then discharged into the atmosphere from a chimney or the like (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. When the gas turbine 21 is started, the generator 22 receives 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 steam generated in the heat recovery boiler 24 to a rotor 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 heat recovery boiler 24 via a pump or the like.

[0019] The GTCC control device 27 receives detection signals from various sensors (not shown) and control signals from a higher-level control device (not shown), and controls various actuators in the power generation facility 2. For example, when the gas turbine 21 is started up, the GTCC control device 27 controls each part of the gas turbine 21 and also controls the rotation speed and output torque of the starting device 28. The GTCC control device 27 also generates multiple types of signal signals in response to predetermined events that occur when the gas turbine is started up, and outputs these to a power storage facility control device 34 (described later) in the power storage facility 3 via a communication line 81. Examples of predetermined events include the start of gas turbine startup, reaching a spin rotation speed, ignition, and a self-sustaining rotation speed. The signal signals include a gas turbine startup start signal, a spin rotation speed reaching signal, an ignition signal, and a self-sustaining rotation speed signal, which correspond to the respective events, as well as a signal indicating the rotation speed (= rotational speed) of the gas turbine 21.

[0020] The start of gas turbine startup is an event in which the starting device 28 is started and starts to apply rotational torque to the gas turbine 21 in a turning state. The reaching of spin rotational speed is an event in which the gas turbine 21 in spin operation reaches a predetermined rotational speed suitable for purging the exhaust duct of the gas turbine 21. Here, spin operation, also known as cranking, is an operation in which the gas turbine 21 is driven only by the starting device 28 without fuel being supplied to the gas turbine 21. The purging operation is a spin operation for removing unburned fuel remaining in the combustor 212, ducts, etc. prior to ignition at startup. The ignition is an event in which fuel begins to burn due to the ignition operation. The self-sustaining rotational speed is an event in which the gas turbine 21 reaches or exceeds the rotational speed at which it can operate self-sustainably, i.e., maintain acceleration without receiving rotational torque from the starting device 28. The self-sustaining rotational speed indicates the completion of startup.

[0021] FIG. 3 schematically illustrates the changes in the power generation equipment power consumption and gas turbine rotation speed when the gas turbine 21 is started. The horizontal axis represents time, and the vertical axis represents the power generation equipment power consumption and gas turbine rotation speed. The power generation equipment power consumption is indicated by a solid line. The gas turbine rotation speed is indicated by a dotted line. The power generation equipment power consumption includes the gas turbine startup power (power covered by discharge power) and the auxiliary equipment power consumption. In FIG. 3, the gas turbine startup power amount (the area covered by discharge power) is indicated by a hatched area sloping upward to the right. The auxiliary equipment power consumption amount is indicated by a hatched area sloping downward to the right. The gas turbine startup power is the power consumed by the start-up device 28. In the example illustrated in FIG. 3, startup of the gas turbine begins at time t1. The rotation speed of the gas turbine 21 reaches a predetermined spin rotation speed at time t2. Thereafter, the rotation speed of the gas turbine 21 is controlled to be approximately constant, and purge operation is performed. Then, ignition occurs at time t3. After ignition, the rotation speed of the gas turbine 21 increases and reaches the self-sustaining rotation speed at time t4. The gas turbine startup electric power increases at a substantially constant rate from time t1 to time t2. The gas turbine startup electric power is substantially constant from time t2 to time t3. The gas turbine startup electric power increases from time t3, becomes constant at a certain value, and then decreases from a certain time approaching time t4. The gas turbine startup electric power then becomes zero at time t4. Note that the change at startup shown in FIG. 3 is an example, and application of this embodiment is not limited to this example.

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

[0023] The DC / DC converter 32 is a bidirectional DC-DC converter that boosts or lowers the voltage of the DC power input from the AC / DC converter 31 and outputs it to the battery pack 33, and also boosts or lowers the voltage of the DC power input from the battery pack 33 and outputs it to the AC / DC converter 31. Furthermore, when discharging power from the battery pack 33, for example, the DC / DC converter 32 controls the discharge power from the battery pack 33 in accordance with instructions from the power storage equipment control device 34, for example, by keeping the voltage of the DC power output to the AC / DC converter 31 at 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 instructions from the power storage equipment control device 34.

[0024] The battery pack 33 includes a circuit breaker 331, a storage battery 332, a sensor unit 333, and a monitoring device 334. The storage battery 332 is configured by a combination of multiple storage battery cells (single cells) or a storage battery module (battery assembly) including multiple storage battery cells. The storage battery cells are, for example, but not limited to, lithium-ion batteries. The storage battery 332 is discharged, for example, when the gas turbine 21 is started up. The circuit breaker 331 connects and disconnects the connection between the storage battery 332 and the DC / DC converter 32. The operation of the circuit breaker 331 is controlled by, for example, a monitoring device 334. The sensor unit 333 includes multiple types of sensors, detects the voltage, current, temperature, etc. of the storage 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, and calculates the SOC (State of Charge) of the storage battery 332. Furthermore, the monitoring device 334 outputs the acquired detection results of the sensor unit 333 and information indicating the calculated SOC to the power storage equipment control device 34. Furthermore, 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 shuts off the circuit breaker 331 to protect the storage battery 332. At that time, the monitoring device 334 outputs a signal indicating that the circuit breaker 331 has been shut off to the power storage equipment control device 34. Furthermore, when the monitoring device 334 receives a predetermined instruction from the power storage equipment control device 34, it shuts off or connects the circuit breaker 331.

[0025] The power storage facility control device 34 can be configured using, for example, a computer and its peripheral circuits and devices. The power storage facility control device 34 has a functional configuration formed by a combination of hardware such as a computer and software such as a program, and includes a discharge control unit 341, a storage battery remaining energy 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 this 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 amount of discharge power of the storage battery 332. When starting up the gas turbine 21, for example, if the remaining power amount 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. Furthermore, when starting up the gas turbine 21, for example, if the remaining power amount of the storage battery 332 is insufficient, the discharge control unit 341 changes the pattern to discharge the storage battery 332 so that the amount of discharge power does not exceed the remaining power amount.

[0027] In this embodiment, the discharge control unit 341 controls discharge from the storage battery 332 in response to a predetermined event, for example, during startup of the gas turbine 21. The event includes at least one of the following events, which have been described above with reference to FIG. 3 : startup of the gas turbine 21, reaching the spin rotation speed, ignition, or the self-sustaining rotation speed. The discharge control unit 341 receives a signal representing the event as a signal from the GTCC control unit 27. The GTCC control unit 27 is an example of a configuration of a control unit of the gas turbine 21.

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

[0029] In addition, when the power used to start the gas turbine 21 is supplied from multiple storage batteries 332 by discharging from the multiple storage batteries 332, if the abnormality detection unit 344 detects an abnormality in the storage battery 332, the discharge control unit 341 supplies the amount of discharge from the storage battery 332 in which the abnormality was detected from the grid 5a, and then increases the discharge power of the other storage batteries 332 in which no abnormality was detected to cover the amount of discharge from the storage battery 332 in which the abnormality was detected.

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

[0031] The power difference calculation unit 343 calculates the power difference between the predicted value of received power from the grid 5 when the gas turbine 21 is started and the total power value available from the grid 5. For example, the power difference calculation unit 343 receives information indicating the predicted value of received power from a 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 received power. In FIG. 4, the actual value of received power is indicated by a solid rectangle, and the predicted value is indicated by a dashed rectangle. The gas turbine startup power among the predicted values ​​is also indicated by a shaded area. In the example shown in FIG. 4, startup of the gas turbine 21 begins shortly after 8:30, and the received power peaks around 9:00, when the gas turbine startup power is at its maximum. The received power decreases from around 9:30, when the generator 22 starts outputting, and becomes zero after around 10:00. 4, the value of the maximum contracted power is set as the total available power value, and the power difference ΔMW is the value obtained by subtracting the predicted value MW of power received from the grid 5 at the time of startup of the gas turbine 21 from the value of the maximum contracted power. Note that the total available power value is not limited to the value of the maximum contracted power, and may 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 information acquired from each monitoring device 334. An abnormality in the storage battery 332 may be, for example, when the monitoring device 334 shuts off the circuit breaker 331, or when the temperature of the storage battery 332 exceeds a predetermined temperature.

[0033] (Operation Example of Power Generation System 1) With reference to FIGS. 5 to 17 , an operation example at the start-up of the gas turbine 21 of the power generation system 1 shown in FIG. 1 will be described. FIG. 5 shows a basic operational flow at the start-up of the gas turbine 21. As shown in FIG. 5 , in the power generation system 1, the power storage equipment control device 34 determines a discharge mode of the storage battery 332 at the start-up of the gas turbine 21 (step S1) and controls the discharge of the storage battery 332 in the determined discharge mode (step S2). In this embodiment, the discharge mode represents a manner of discharge from the power storage equipment 3. In this embodiment, as an example, the discharge modes include a mode in which no discharge is performed (discharge stop), a mode in which a relatively large amount of power from the storage battery 332 is used (large discharge mode), a mode in which the power of the storage battery 332 is used moderately (medium discharge mode), and a mode in which the power of the storage battery 332 is used only during peak times (small discharge mode), and discharge is performed or not performed using any of these modes. 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 predetermined time arrives.

[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 the same example of power generation equipment power consumption as shown in FIG. 3. However, in FIGS. 7 to 9, the gas turbine startup power amount, shown by the hatched area slanting upward to the right in FIG. 3, is divided into the hatched area slanting upward to the right (the area covered by discharge power) and the white area (the area covered by received power). In the large discharge mode shown in FIG. 7, the areas covered by the gas turbine startup power and the discharge power coincide throughout the entire period from the start of startup to the self-sustaining rotation speed. In the medium discharge mode shown in FIG. 8, a portion of the period from ignition to the self-sustaining rotation speed is covered by received power. In the small discharge mode shown in FIG. 9, a portion of the period from the start of gas turbine startup to ignition and a portion of the period from ignition to the self-sustaining rotation speed are covered by received power. In this operation example, it is assumed that before starting the gas turbine 21, an amount of electricity sufficient to cover at least the amount of discharge electricity in the small discharge mode (e.g., enough to perform multiple startups) is stored in the storage equipment 3.

[0035] 6, the power difference calculation unit 343 obtains the predicted received power value MW [W] (step S10) and calculates the power difference ΔMW (step S11). Next, the storage battery remaining energy calculation unit 342 calculates the remaining energy BR [Wh] of the storage 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 to "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 shaded portion sloping upward to the right in Fig. 7.

[0037] If the remaining power amount BR is greater than the discharge power amount [Wh] in the heavy discharge mode (step S15: YES), the discharge control unit 341 determines the discharge mode as the "heavy discharge mode" (step S16) and ends the process shown in Fig. 6. If the remaining power amount BR is not greater than the discharge power amount [Wh] in the heavy 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 shaded portion sloping upward to the right in Fig. 8.

[0038] If 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 to be the "medium discharge mode" (step S18) and ends the process shown in Fig. 6. If 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 to be the "small discharge mode" (step S19) and ends the process shown in Fig. 6.

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

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

[0041] In the process shown in FIG. 10 , the discharge power from the power storage facility 3 is controlled in accordance with the patterns shown in FIGS. 7 to 9 , triggered by the reception of a predetermined signal. For example, in the large discharge mode shown in FIG. 7 , discharge from the power storage facility 3 is initiated after a gas turbine startup signal is received at time t1. Thereafter, the discharge power is increased at a predetermined rate of increase according to the elapsed time from time t1. Thereafter, when a spin rotation speed reach signal is received at time t2, the discharge power is controlled to a predetermined constant value. Thereafter, when an ignition signal is received at time t3, the discharge power is gradually increased at a predetermined rate of increase 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 rate of decrease. Thereafter, when a self-sustaining rotation speed signal is received at time t4, the discharge from the power storage facility 3 is stopped. Note that the control of the discharge power is not limited to this. 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 mode (step S20). If the discharge mode is the discharge stop mode (step S20: YES), the discharge control unit 341 terminates the process shown in FIG. 10 without discharging from the power storage equipment 3. If the discharge mode is not the discharge stop mode (step S20: NO), the discharge control unit 341 waits for reception of a gas turbine startup start signal (step S21: NO is repeated). When the gas turbine startup 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). If 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 depending on the elapsed time since the gas turbine startup start signal was received (step S24). Next, the discharge control unit 341 determines whether or not a spin rotation speed reach signal has been received (step S25). If the spin rotation speed reach signal has not been received (step S25: NO), the discharge control unit 341 again increases the discharge power at a predetermined increase rate according to the elapsed time since the gas turbine startup start signal was received (step S24). The processes of steps S24 and S25 are executed at a fixed cycle (i.e., a fixed waiting time is set between repeated processes).

[0043] If the spin rotation speed reach signal has been received (step S25: YES), the discharge control unit 341 controls the discharge power at a constant predetermined value (step S26). Next, the discharge control unit 341 determines whether or not an ignition signal has been received (step S27). If an ignition signal has not been received (step S27: NO), the discharge control unit 341 continues to control the discharge power at a constant predetermined value (step S26). The processes of steps S26 and S27 are executed at regular intervals.

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

[0045] If an 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 corresponding to the discharge mode (step S28). Next, the discharge control unit 341 determines whether or not a self-sustaining rotation speed signal is received (step S29). If a self-sustaining rotation speed signal is not received (step S29: NO), the discharge control unit 341 continues to control the discharge power in a predetermined pattern corresponding to the discharge mode (step S28). Note that the processing of step S28 and the processing of step S29 are executed at regular intervals.

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

[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 steps S23, S24, S26, and S28 shown in Fig. 10. When the process shown in Fig. 11 starts, 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, at a power appropriate 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 so that the power increases at a predetermined rate each time the process is executed. 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 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 the process is executed.

[0049] Next, the discharge control unit 341 equally allocates the total discharge power of all the storage batteries 332 to each storage battery 332 (step S41). For example, if the total discharge power of all the storage batteries 332 is P, in this embodiment, P / 3 of power is equally 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, if no abnormality has been detected (step S42: NO), the discharge control unit 341 controls the discharge of each storage battery 332 so that the discharge power becomes the allocated discharge power (step S44), and ends the process shown in FIG.

[0051] On the other hand, if an abnormality is detected (step S42: YES), the discharge control unit 341 increases the discharge power of the other storage batteries 332 for which no abnormality has been detected so as to cover the amount of discharge from the storage battery 332 for which the abnormality has been detected (step S43). For example, if an abnormality is detected in one storage battery 332, the discharge control unit 341 sets the discharge power allocated to that storage battery 332 to "0" and increases the amount of 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 that the allocated discharge power is reached (step S44), and ends the process shown in FIG. 11 .

[0052] As described above, the processes of steps S24, S26, and S28 are executed at regular intervals. Therefore, for example, in the case of an abnormality in which the circuit breaker 331 is tripped by the monitoring device 334, a delay of, for example, about the same period occurs between the tripping of the circuit breaker 331 and the increase in the discharge power of the other storage batteries 332. In this case, when the power used to start the gas turbine 21 is supplied from the multiple storage batteries 332 by discharging from the multiple storage batteries 332, if the abnormality detection unit 344 detects an abnormality in the storage battery 332, the discharge control unit 341 supplies the amount of power discharged from the storage battery 332 in which the abnormality was detected from the grid 5a (or the transmission / distribution line 6), and then increases the discharge power of the other storage batteries 332 in which no abnormality is detected to cover the amount of power discharged from the storage battery 332 in which the abnormality was detected.

[0053] 12 to 14 show an example of operation when the circuit breaker 331 of one of the three storage batteries 332 is tripped during startup of the gas turbine 21. In FIGS. 12 to 14, the three storage batteries 332 are designated as storage battery 332(A), storage battery 332(B), and storage battery 332(C). FIG. 12 shows a state in which storage battery 332(C) stops discharging when startup power P is supplied equally from storage battery 332(A), storage battery 332(B), and storage battery 332(C) at the startup of the gas turbine 21. In this case, as shown in FIG. 13, power of P / 3 is supplied from grid 5a before the discharge power of the other storage batteries 332(A) and 332(B) is increased. Thereafter, when the discharge power of the storage batteries 332(A) and 332(B) increases, the supply of power from the grid 5a is stopped, as shown in FIG. 14, and power supply to the starting device 28 continues only from the storage batteries 332(A) and 332(B).

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

[0055] (Actions and Effects) As described above, in the power generation system 1 of this embodiment, the discharge control unit 341 controls the discharge from the storage battery 332 when starting up the gas turbine 21 so that the power required for starting up the gas turbine 21 can be covered by the power from the grid 5 and the discharged power from the storage battery 332. Therefore, according to the power generation system 1 of this 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] Furthermore, the discharge control unit 341 controls the discharge from the storage battery 332 according to the remaining power amount of the storage battery. With this configuration, when the power from the grid 5 and the discharged power from the storage battery 332 are used to cover the electricity, the ratio between the power from the grid 5 and the discharged power from the storage battery 332 can be appropriately set.

[0057] Furthermore, 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 startup of the gas turbine 21. According to this configuration, the capacity of the storage battery 332 can be set more appropriately.

[0058] Furthermore, the discharge control unit 341 controls the discharge from the storage battery 332 so that the discharge power from the storage battery 332 is maximized during the period from ignition of the gas turbine 21 to completion of startup of the gas turbine 21. With this configuration, the capacity of the storage battery 332 can be set more appropriately.

[0059] Furthermore, the discharge control unit 341 controls discharge from the storage battery in accordance with the power difference between the predicted value of power received from the grid 5 at the time of startup of the gas turbine 21 and the total power value available from the grid 5, and the remaining power amount in the storage battery. With this configuration, it is possible to control discharge from the storage battery 332 so as not to exceed the total power value available.

[0060] The discharge control unit 341 also controls discharge from the storage battery 332 in response to a predetermined event that occurs during startup of the gas turbine 21. This configuration simplifies the discharge control. The event includes at least one of the start of startup of the gas turbine 21, reaching the spin rotation speed, ignition, and the self-sustaining rotation speed. The discharge control unit 341 also receives a signal representing the event from the GTCC control device 27.

[0061] While the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design changes and the like within the scope of the present disclosure. Note that in the above embodiment, the discharge control unit 341, the storage battery remaining energy calculation unit 342, the power difference calculation unit 343, and the abnormality detection unit 344 are configured to be provided within the power storage facility 3, but this is not limiting and they may be provided within the GTCC control device 27, for example.

[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 equipment control device 34 and the GTCC control device 27 are implemented in the computer 90. The operations of the above-described processing units are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-described processing in accordance with the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to the above-described storage units in accordance with the program.

[0063] The program may be for realizing some of the functions to be performed by the computer 90. For example, the program may be combined with other programs already stored in storage or implemented in other devices to perform the functions. 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 PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0064] Examples of storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of computer 90, or an external medium connected to computer 90 via interface 94 or a communication line. Furthermore, if this program is distributed to computer 90 via a communication line, computer 90 that receives the program may load the program into main memory 92 and execute the above-described processing. In at least one embodiment, storage 93 is a non-transitory tangible storage medium.

[0065] <Additional Notes> The power generation system 1 described in each embodiment can be understood, for example, as follows.

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

[0067] (2) A power generation system 1 according to a second aspect is the power generation system 1 of (1), further including a battery remaining energy calculation unit 342 that calculates the remaining energy of the storage battery, and the discharge control unit controls discharge from the storage battery in accordance with the remaining energy 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 more appropriately set.

[0068] (3) A power generation system 1 according to a third aspect is the power generation system 1 according to (1) or (2), in which the discharge control unit discharges the storage battery during a 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 starting device 28 of the rotating machine can be more appropriately set.

[0069] (4) A fourth aspect of the power generation system 1 is the power generation system 1 of any one of (1) to (3), wherein the discharge control unit controls discharge from the storage battery so that discharge power from the storage battery is maximized during a period from start of startup of the rotating machine to completion of startup of the rotating machine. According to this aspect, the capacity of the storage battery 332 for supplying power to the start-up device 28 of the gas turbine 21 can be more appropriately set.

[0070] (5) A fifth aspect of the power generation system 1 is the power generation system 1 according to any one of (1) to (4), in which the rotary machine is a gas turbine.

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

[0072] (7) A seventh aspect of the power generation system 1 is the power generation system 1 of any one of (1) to (6), wherein the discharge control unit controls discharge from the storage battery in response to a predetermined event at the start of the rotating machine. According to this aspect, the configuration can be simplified.

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

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

[0075] According to the power generation system and control method of the present disclosure, it is possible to appropriately set the capacity of the storage battery for supplying power to the starting device of the rotary machine.

[0076] DESCRIPTION OF SYMBOLS 1... Power generation system 2... Power generation equipment 3... Power storage equipment 4... Production equipment 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 energy calculation unit 343... Power difference calculation unit 344... Abnormality detection unit

Claims

1. A rotating machine; A storage battery that is discharged when the rotating machine is started; A discharge control unit that controls discharge of the storage battery; A power generation system comprising: the discharge control unit controls discharging from the storage battery so that, at the time of starting up the rotating machine, power required for starting the rotating machine can be covered by power from a grid and discharged power from the storage battery; a battery remaining energy calculation unit that calculates a remaining energy amount of the battery; a power difference calculation unit that calculates a power difference between a predicted value of power received from the grid at the time of start-up of the rotating machine and a total power value available from the grid, The discharge control unit controls discharge from the storage battery in accordance with the power difference and a remaining amount of power in the storage battery. Power generation system.

2. The discharge control unit discharges the storage battery during a period from a start of startup of the rotating machine to a completion of startup of 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 a period from a start of the startup of the rotating machine to a completion of the startup of the rotating machine. The power generation system according to claim 2 .

4. The rotary machine is a gas turbine. The power generation system according to claim 3 .

5. The discharge control unit controls discharge from the storage battery in response to a predetermined event at the start-up of the rotating machine. The power generation system according to claim 4 .

6. The event includes at least one of a start-up of the rotating machine, a spin speed reaching, an ignition, or a self-sustaining speed. The power generation system according to claim 5 .

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

8. A rotating machine; A storage battery that is discharged when the rotating machine is started; A discharge control unit that controls discharge of the storage battery; A control method for a power generation system comprising: the discharge control unit controls discharging from the storage battery so that, at the time of starting up the rotating machine, power required for starting the rotating machine can be covered by power from a grid and discharged power from the storage battery; The power generation system includes: a battery remaining energy calculation unit that calculates a remaining energy amount of the battery; a power difference calculation unit that calculates a power difference between a predicted value of power received from the grid at the time of start-up of the rotating machine and a total power value available from the grid, The discharge control unit controls discharge from the storage battery in accordance with the power difference and a remaining amount of power in the storage battery. Control methods.