Fuel cell management system

Abstract

The present invention provides a fuel cell management system capable of issuing output control commands to appropriate fuel cell devices. [Solution] A fuel cell management system is provided, wherein the fuel cell device 10 is configured to perform a flicker countermeasure operation that suppresses output power when voltage flicker occurs in the connected power distribution system 1, and to stop the flicker countermeasure operation when the conditions for stopping the flicker countermeasure operation are met, and when the management device 30 transmits an output control command to any of the multiple fuel cell devices 10 in the command transmission process, it transmits the output control command to the fuel cell device 10 that is not performing the flicker countermeasure operation, and does not transmit the output control command to the fuel cell device 10 that is performing the flicker countermeasure operation.

Description

Technical Field

[0001] The present invention relates to a fuel cell management system including a fuel cell device installed in each of a plurality of facilities and capable of outputting power, and a management device capable of communicating from a remote location outside the facilities between the plurality of fuel cell devices.

Background Art

[0002] As disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2018-125907), a system having a plurality of power resources (101) and a management device (virtual power central device 103) has been proposed based on the concept of a virtual power plant (VPP: Virtual Power Plant). Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2019-17154) also describes a similar system.

[0003] For example, in a fuel cell management system, when the management device receives a supply command for regulation power, the management device supplies the regulation power of the power supply devices of each facility to the power grid on the supply date. Thus, by aggregating a plurality of dispersed power supply devices by the management device, the plurality of power supply devices can function as a single power plant or consumption market.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When using multiple fuel cell systems to meet electricity demand, uniform power output control is not optimal due to differences in the condition and installation environment of each individual fuel cell system. Patent documents 1 and 2 describe power management that takes into account rated power generation and various external factors to maximize profits. However, fuel cell systems may perform flicker countermeasures, suppressing output power in response to voltage flicker, which is caused by short-cycle fluctuations in the power distribution system voltage. For example, flicker countermeasures may include operating the fuel cell system to zero output power. Therefore, it is necessary to consider whether or not each fuel cell system is performing flicker countermeasures when issuing output control commands to each fuel cell system in order to ensure stable VPP output.

[0006] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a fuel cell management system that can provide output control commands to an appropriate fuel cell device. [Means for solving the problem]

[0007] A characteristic configuration of the fuel cell management system according to the present invention for achieving the above objective is a fuel cell management system comprising a fuel cell device installed in each of a plurality of facilities and connected to the power distribution system of each region in which it is installed, and a management device that can communicate with the plurality of fuel cell devices from a remote location outside the facility, The management device performs a command transmission process to send output control commands to a plurality of fuel cell devices to determine the output power of the fuel cell devices. When the fuel cell device receives the output control command from the control device, it operates with the goal of supplying the output power determined based on the output control command during the control period covered by the output control command. The fuel cell device is configured to perform a flicker suppression operation to reduce output power when voltage flicker occurs in the connected power distribution system, and to stop the flicker suppression operation when the conditions for stopping the flicker suppression operation are met. The management device, when transmitting the output control command to any of the multiple fuel cell devices during the command transmission process, transmits the output control command to the fuel cell device that is not performing the flicker-prevention operation, and does not transmit the output control command to the fuel cell device that is performing the flicker-prevention operation.

[0008] According to the above characteristic configuration, the control device does not send an output increase command to fuel cells that are performing flicker-suppression operation to suppress output power, i.e., fuel cell devices for which it is not appropriate to increase output in response to an output increase command. Therefore, a fuel cell management system can be provided that can issue output control commands to appropriate fuel cell devices.

[0009] Another characteristic configuration of the fuel cell management system according to the present invention is that the management device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is preferentially transmitted to the fuel cell device that is connected to the power distribution system and has a high number of voltage flicker occurrences in a predetermined period in the past, among the fuel cell devices that are not performing the flicker countermeasure operation. In the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the output increase command is preferentially transmitted to fuel cell devices that are not performing the flicker countermeasure operation and are connected to a power distribution system with a low number of voltage flicker occurrences in a predetermined period in the past.

[0010] In power distribution systems with a high frequency of voltage flicker occurrences over a specified period in the past, the frequency of voltage flicker is likely to remain high in the future, and fuel cell devices connected to such systems are likely to frequently perform flicker reduction operations by suppressing output power. Furthermore, reducing the output power of a fuel cell device also reduces the reactive power supplied to the power distribution system, thus lowering the likelihood of voltage flicker occurring in the distribution system. In other words, it is preferable to send an output reduction command to fuel cell devices connected to power distribution systems with a high frequency of voltage flicker occurrences over a specified period in the past. Therefore, in this feature configuration, when the management device transmits an output reduction command, it preferentially transmits the output reduction command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system that has had a high number of voltage flicker occurrences in a predetermined period in the past. When transmitting an output increase command, it preferentially transmits the output increase command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system that has had a low number of voltage flicker occurrences in a predetermined period in the past. In this way, it can transmit output control commands that can suppress the occurrence of voltage flicker in each distribution system.

[0011] Another characteristic configuration of the fuel cell management system according to the present invention is that the management device is When transmitting an output reduction command to reduce the output of the fuel cell device in the command transmission process, the output reduction command is preferentially transmitted to the fuel cell devices that are connected to a distribution system with a large number of interconnected distributed power sources, among the fuel cell devices that are not performing the flicker countermeasure operation. In the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the output increase command is preferentially transmitted to fuel cell devices that are not performing the flicker-prevention operation and are connected to a power distribution system with a small number of connected distributed power sources.

[0012] Considering that reactive power is supplied from distributed power sources to the distribution system for the purpose of detecting islanding, it can be said that in distribution systems with a large number of interconnected distributed power sources, the frequency of voltage flicker is higher, and fuel cell devices connected to such distribution systems are more likely to perform flicker reduction operations by suppressing output power. Furthermore, reducing the output power of the fuel cell device also reduces the reactive power supplied to the distribution system, thus reducing the likelihood of voltage flicker occurring in the distribution system. In other words, it is preferable to send output reduction commands to fuel cell devices connected to distribution systems with a large number of interconnected distributed power sources. Therefore, in this feature configuration, when the management device transmits an output reduction command, it preferentially transmits the output reduction command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system with a large number of connected distributed power sources. When transmitting an output increase command, it preferentially transmits the output increase command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system with a small number of connected distributed power sources. In this way, it can transmit output control commands that can suppress the occurrence of voltage flicker in each distribution system.

[0013] Another characteristic configuration of the fuel cell management system according to the present invention is that the management device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is preferentially transmitted to the fuel cell device that is connected to the distribution system with a large total rated output power of the connected distributed power sources, among the fuel cell devices that are not performing the flicker countermeasure operation. In the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the output increase command is preferentially transmitted to fuel cell devices that are not performing flicker-prevention operation and are connected to a power distribution system with a low total rated output power of the connected distributed power sources.

[0014] Considering that reactive power is supplied from distributed power sources to the distribution system for the purpose of detecting islanding, it can be said that in distribution systems where the total rated output power of the connected distributed power sources is large, i.e., where there are many connected distributed power sources, the frequency of voltage flicker will be higher, and fuel cell devices connected to such distribution systems will be more likely to perform flicker reduction operations by suppressing their output power. Furthermore, reducing the output power of the fuel cell device also reduces the reactive power supplied to the distribution system, thus reducing the likelihood of voltage flicker occurring in the distribution system. In other words, it is preferable to send an output reduction command to fuel cell devices connected to distribution systems where the total rated output power of the connected distributed power sources is large. Therefore, in this feature configuration, when the management device transmits an output reduction command, it preferentially transmits the command to fuel cell devices that are not performing flicker-countermeasure operation and are connected to a distribution system with a large total rated output power of the connected distributed power sources. When transmitting an output increase command, it preferentially transmits the command to fuel cell devices that are not performing flicker-countermeasure operation and are connected to a distribution system with a small total rated output power of the connected distributed power sources. In this way, it can transmit output control commands that can suppress the occurrence of voltage flicker in each distribution system.

[0015] Another characteristic configuration of the fuel cell management system according to the present invention is that the management device is When transmitting an output reduction command to reduce the output of the fuel cell device in the command transmission process, the output reduction command is preferentially transmitted to the fuel cell device that is not performing the flicker reduction operation and is located at a longer distance from the distribution substation to the power receiving point. In the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the output increase command is preferentially transmitted to the fuel cell device that is not performing the flicker countermeasure operation and is located at a shorter distance from the power distribution substation to the power receiving point.

[0016] In power distribution systems where fuel cell devices are connected over long distances from the distribution substation to the point of reception, thinner wires are typically used, leading to a higher frequency of voltage flicker. Consequently, fuel cell devices connected to such systems are more likely to perform flicker reduction operations by suppressing their output power. Furthermore, reducing the output power of a fuel cell device also reduces the reactive power supplied to the distribution system, thus lowering the likelihood of voltage flicker occurring in the distribution system. Therefore, it is preferable to send output reduction commands to fuel cell devices that are located over long distances from the distribution substation to the point of reception. Therefore, in this feature configuration, when the management device transmits an output reduction command, it preferentially transmits the output reduction command to fuel cell devices that are not performing flicker countermeasure operation and are located at a long distance from the distribution substation to the point of power reception. When transmitting an output increase command, it preferentially transmits the output increase command to fuel cell devices that are not performing flicker countermeasure operation and are located at a short distance from the distribution substation to the point of power reception. This enables the transmission of output control commands that can suppress the occurrence of voltage flicker in each distribution system.

[0017] Another characteristic configuration of the fuel cell management system according to the present invention is that the management device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is transmitted preferentially to fuel cell devices that are not performing flicker countermeasure operation, specifically those connected to a distribution system with a high number of voltage flicker occurrences in a predetermined period in the past, those connected to a distribution system with a large number of connected distributed power sources, those connected to a distribution system with a large total rated output power of the connected distributed power sources, and those that are located far from the distribution substation to the point of power reception, according to a predetermined priority order for output reduction. When transmitting an output increase command for increasing the output of the fuel cell device in the instruction transmission process, among the fuel cell devices not performing the flicker countermeasure operation, the fuel cell devices connected to the distribution system with a small number of occurrences of the voltage flicker in a past predetermined period, the fuel cell devices connected to the distribution system with a small number of connected distributed power sources, the fuel cell devices connected to the distribution system with a small total rated output power of the connected distributed power sources, and the fuel cell devices with a short distance from the distribution substation to the power receiving point, the output increase command is preferentially transmitted according to a predetermined output increase priority order. Here, the management device may separately set the output decrease priority order and the output increase priority order in a predetermined power generation increase time zone including noon, which is predicted to have an increasing power generation of the solar cell device as the distributed power source, and a time zone other than the power generation increase time zone.

[0018] Here, when the control target period is included in the power generation increase time zone, the management device sets the output decrease priority order in the order of description of the fuel cell devices connected to the distribution system with a large number of occurrences of the voltage flicker in a past predetermined period, the fuel cell devices connected to the distribution system with a large total rated output power of the connected distributed power sources, the fuel cell devices connected to the distribution system with a large number of connected distributed power sources, and the fuel cell devices with a long distance from the distribution substation to the power receiving point, and sets the output increase priority order in the order of description of the fuel cell devices connected to the distribution system with a small number of occurrences of the voltage flicker in a past predetermined period, the fuel cell devices connected to the distribution system with a small total rated output power of the connected distributed power sources, the fuel cell devices connected to the distribution system with a small number of connected distributed power sources, and the fuel cell devices with a short distance from the distribution substation to the power receiving point.

[0019] Further, when the control target period is not included in the power generation increase time zone, the management device sets the priority for output reduction in the order of description of the fuel cell device connected to the distribution system with a large number of occurrences of the voltage flicker in a past predetermined period, the fuel cell device with a long distance from the distribution substation to the power reception point, the fuel cell device connected to the distribution system with a large number of connected distributed power sources, and the fuel cell device connected to the distribution system with a large total rated output power of the connected distributed power sources, and sets the priority for output increase in the order of description of the fuel cell device connected to the distribution system with a small number of occurrences of the voltage flicker in a past predetermined period, the fuel cell device with a short distance from the distribution substation to the power reception point, the fuel cell device connected to the distribution system with a small number of connected distributed power sources, and the fuel cell device connected to the distribution system with a small total rated output power of the connected distributed power sources.

[0020] In power distribution systems with a high frequency of voltage flicker occurrences over a specified period in the past, it can be said that the frequency of voltage flicker occurrences will also be high in the future, and that fuel cell devices connected to such power distribution systems will be more likely to perform flicker-f Furthermore, in power distribution systems where fuel cell devices are connected over long distances from the distribution substation to the point of power reception, thinner wires are typically used, which increases the frequency of voltage flicker. Consequently, fuel cell devices connected to such power distribution systems are more likely to perform flicker reduction operations by suppressing their output power. In addition, reducing the output power of a fuel cell device also reduces the reactive power supplied to the power distribution system, thus lowering the likelihood of voltage flicker occurring in the distribution system. In other words, it is preferable to send output reduction commands to power distribution systems with a high number of voltage flicker occurrences in a given period, to power distribution systems with a large number of connected distributed power sources, to power distribution systems with a large total rated output power of connected distributed power sources, to power distribution systems where fuel cell devices are connected over long distances from the distribution substation to the point of power reception, and to power distribution systems where fuel cell devices are connected over long distances from the distribution substation to the point of power reception. Therefore, in this feature configuration, when the management device transmits an output reduction command, it preferentially transmits the output reduction command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system with a high number of voltage flicker occurrences in a predetermined period in the past, to a distribution system with a large number of connected distributed power sources, to a distribution system with a large total rated output power of connected distributed power sources, and to fuel cell devices that are far from the distribution substation to the point of power reception, according to a predetermined priority order for output reduction. When transmitting an output increase command, it preferentially transmits the output increase command to fuel cell devices that are not performing flicker countermeasure operation and are connected to a distribution system with a low number of voltage flicker occurrences in a predetermined period in the past, to a distribution system with a small number of connected distributed power sources, to a distribution system with a small total rated output power of connected distributed power sources, and to fuel cell devices that are far from the distribution substation to the point of power reception, according to a predetermined priority order for output increase. In this way, the management device can transmit an output control command that can suppress the occurrence of voltage flicker in each distribution system. [Brief explanation of the drawing]

[0021] [Figure 1] This diagram illustrates the relationship between the facility, the management system, and the aggregation coordinator. [Figure 2] This is a diagram showing an example of the facility's configuration. [Figure 3] This diagram schematically illustrates the controlled period and the uncontrolled period. [Figure 4] This flowchart explains the method for determining which fuel cell device will receive output control commands. [Modes for carrying out the invention]

[0022] Figure 1 shows the relationship between a facility 20 where a fuel cell device 10 and a power load device 4 are installed, a management device 30, and an aggregation coordinator 40. Figure 2 shows an example of the configuration of facility 20. The fuel cell management system comprises a fuel cell device 10 installed in each of the multiple facilities 20, capable of supplying power to power lines 2 connected to the power distribution system 1 at each of the multiple facilities 20, and a management device 30 capable of communicating with the multiple fuel cell devices 10 from a remote location outside the facility 20. Note that the number of management devices 30 and the number of facilities 20 shown in Figure 1 can be changed as appropriate.

[0023] The management device 30, also known as a resource aggregator, is a business that controls the customer-side energy resources of a facility 20 that has entered into a VPP (Virtual Power Plant) service contract by transmitting control information to the fuel cell device 10 and power load device 4, which are customer-side energy resources. The aggregation coordinator 40 is a business that bundles the amount of electricity controlled by each management device 30 and conducts electricity trading with general transmission and distribution companies and retail electricity companies in the electricity trading market, etc.

[0024] The management device 30 sequentially collects and stores device information from multiple facilities 20, such as the output power of the fuel cell device 10, the load power of the power load devices 4, and the power at the point of reception at the facility 20 (i.e., the actual reverse power flow supplied from the facility 20 to the distribution system 1, and the power received supplied from the distribution system 1 to the facility 20). As will be described later, the fuel cell device 10 can determine the reverse power flow supplied from the facility 20 to the distribution system 1 (an example of the power at the point of reception) by referring to the measurement results of the power measurement unit 8, and can transmit that reverse power flow (an example of the power at the point of reception) to the management device 30 as one of the above device information. In this embodiment, when "load power of power load devices 4" is mentioned, it means the total load power of all power load devices 4 installed in the facility 20. The management device 30 then predicts the amount of power that can be supplied from each facility 20 during a predetermined time period in the future and transmits this to the aggregation coordinator 40. This available power is the adjustment capacity, such as the ability to increase or decrease the power at the point of power reception of facility 20. In this embodiment, "increasing the power at the point of power reception" means increasing the power received from distribution system 1 to power line 2, or decreasing the reverse power flow from power line 2 to distribution system 1. "Decreasing the power at the point of power reception" means decreasing the power received from distribution system 1 to power line 2, or increasing the reverse power flow from power line 2 to distribution system 1.

[0025] For example, to increase the power at the point of power reception of facility 20, at least one of the following must be done: decrease the output power of the fuel cell device 10 and increase the load power of the power load device 4. Therefore, the adjustment margin on the upward side when increasing the power at the point of power reception of facility 20 indicates how much margin there is to decrease the output power of the fuel cell device 10 and how much margin there is to increase the load power of the power load device 4. Also, to decrease the power at the point of power reception of facility 20, at least one of the following must be done: increase the output power of the fuel cell device 10 and decrease the load power of the power load device 4. Therefore, the adjustment margin on the downward side when decreasing the power at the point of power reception of facility 20 indicates how much margin there is to increase the output power of the fuel cell device 10 and how much margin there is to decrease the load power of the power load device 4.

[0026] Furthermore, the management device 30 determines the baseline power at the multiple facilities 20 under its management. This baseline power at the base point corresponds to the total power at the base point of each facility 20, which is predicted to be achieved if no adjustment power (i.e., adjustment power provided to transmission and distribution operators and supply power provided to retail operators, etc.) is provided from each facility 20.

[0027] The aggregation coordinator 40 aggregates the available power received from each control device 30 and conducts power transactions with general transmission and distribution companies and retail electricity companies by bidding in power trading markets such as the supply and demand adjustment market, the wholesale power market, and the capacity market. When the aggregation coordinator 40 receives a supply order for adjustment capacity, etc., for a predetermined control period in the future from the general transmission and distribution company or retail electricity company with which it has conducted transactions, it distributes and transmits the adjustment capacity, etc., specified in the supply order to each control device 30.

[0028] When the management device 30 receives a supply order from the aggregation coordinator 40, it distributes and transmits the adjustment power, etc., specified in the supply order to each facility 20. In other words, the management device 30 receives a power supply order from the aggregation coordinator 40, which conducts power trading in the power trading market, for a controlled period determined by that power trading, and transmits output control orders to the multiple fuel cell devices 10 that are installed in each of the multiple facilities 20 determined based on the supply order. As a result, each facility 20 receives adjustment power, etc., which increases or decreases the power at the point of power reception of the facility 20 compared to a future controlled period, by controlling the fuel cell devices 10 and power load devices 4 as consumer-side energy resources.

[0029] Facility 20 is equipped with a fuel cell device 10 and a power load device 4. The fuel cell device 10 and the power load device 4 are connected to power lines 2 which are connected to the power distribution system 1.

[0030] The power load device 4 is a variety of devices, such as lighting equipment and air conditioning equipment, and can receive power from at least one of the fuel cell device 10 and the power distribution system 1 installed in the facility 20.

[0031] The fuel cell device 10 includes a fuel cell unit 12 connected to a power line 2 connected to a power distribution system 1, a power conversion unit 11 that converts the power generated by the fuel cell unit 12 to a predetermined voltage, frequency, and phase and supplies it to the power line 2, a fuel cell control unit 13 that controls the operation of the fuel cell unit 12 and the power conversion unit 11, and a storage unit 14 that stores information handled by the fuel cell device 10. The fuel cell device 10 may also include a fuel reformer that generates hydrogen, which is the fuel gas for the fuel cell unit 12.

[0032] The fuel cell control unit 13 can adjust the output power from the fuel cell device 10 to the power line 2 between a predetermined upper limit output power and a predetermined lower limit output power. Therefore, if the output power of the fuel cell device 10 is equal to the upper limit output power, there is no room to increase the output power, and if the output power of the fuel cell device 10 is less than the upper limit output power, there is room to increase the output power. Also, if the output power of the fuel cell device 10 is equal to the lower limit output power, there is no room to decrease the output power, and if the output power of the fuel cell device 10 is greater than the lower limit output power, there is room to decrease the output power. Furthermore, if the operation of the fuel cell device 10 is controlled in each facility 20 so as not to receive power from the power distribution system 1, that is, if the operation of the fuel cell device 10 is controlled so that the output power of the fuel cell device 10 is equal to or greater than the load power of the power load device 4, then if the output power of the fuel cell device 10 is equal to the load power of the power load device 4, there is no room to decrease the output power, and if the output power of the fuel cell device 10 is greater than the load power of the power load device 4, there is room to decrease the output power.

[0033] The fuel cell control unit 13 can maintain the output power of the fuel cell device 10 at its upper limit output power for continuous operation. The fuel cell control unit 13 can also operate the fuel cell device 10 so that its output power follows the load power of the power load device 4. For example, the fuel cell control unit 13 can adjust the output power of the fuel cell device 10 so that the power measured by the power measurement unit 8 (i.e., the power supplied from the power distribution system 1 to the facility 20) is zero or close to zero, thereby causing the fuel cell control unit 13 to operate in accordance with the load power of the power load device 4. Alternatively, the fuel cell control unit 13 can adjust the output power of the fuel cell device 10 so that the power measured by the power measurement unit 8 is a predetermined negative power (i.e., a predetermined reverse power flow).

[0034] The fuel cell control unit 13 has information about the output power supplied from the power conversion unit 11 to the power line 2 and information about the power measured by the power measurement unit 8, so it can derive the load power of the power load device 4 (= output power + measured power). If the sign of the power measured by the power measurement unit 8 is positive, it means that the load power is greater than the output power of the fuel cell device 10, and if the sign of the power measured by the power measurement unit 8 is negative, it means that the output power of the fuel cell device 10 is greater than the load power (i.e., reverse power flow is being supplied from the facility 20 to the power distribution system 1).

[0035] The fuel cell device 10 is connected to a remote control 7, which is operated by users of the facility 20 when they issue commands to the fuel cell device 10. Information about the output power and load power of the fuel cell device 10 is transmitted to the management device 30 via the remote control 7 and router 6. For example, information about the output power and load power of the fuel cell device 10 is transmitted to the management device 30 at predetermined intervals, such as every minute.

[0036] With the increase in reverse power flow from distributed power sources such as fuel cell devices 10 and other power generation devices (e.g., solar cell devices) connected to the distribution system 1, it is becoming difficult for the administrator of the distribution system 1 (transmission and distribution company) to manage power quality. Therefore, strengthening of flicker countermeasures on the distributed power source side is required. Accordingly, the fuel cell control unit 13 is configured to refer to the voltage measured by the voltage measurement unit 9 and perform flicker countermeasure operation to suppress output power if voltage flicker occurs in the connected distribution system 1, and to stop the flicker countermeasure operation when the conditions for stopping the flicker countermeasure operation (e.g., no voltage flicker occurs) are met. The method for determining whether or not voltage flicker occurs in the distribution system 1 by referring to the voltage measured by the voltage measurement unit 9 can be a known method that refers to the voltage frequency, for example. Furthermore, in flicker countermeasure operation, the fuel cell control unit 13 sets the output power from the fuel cell device 10 to the power line 2 to zero. For example, in flicker countermeasure operation, the fuel cell control unit 13 puts the power conversion unit 11 into an idling state where it does not output power to the power line 2.

[0037] Furthermore, voltage flicker is expected to occur frequently in the future in locations far from power distribution substations, in locations with a large number of distributed power sources, in locations with high output from distributed power sources, and in locations where voltage flicker occurs frequently.

[0038] As described above, the control device 30 can send output control commands to multiple fuel cell devices 10 that specify a target reverse power flow, which is the target value of the reverse power flow to be supplied from the facility 20 to the power distribution system 1. When a fuel cell device 10 receives an output control command from the control device 30, it operates in a first operating mode during the controlled period covered by the output control command, aiming to supply the output power determined based on the output control command, and operates in a second operating mode, which is different from the first operating mode, during the non-controlled period outside of the controlled period.

[0039] The second operating mode is an operating mode that is pre-set in multiple fuel cell devices 10. Alternatively, the control device 30 can send an operating mode control command to multiple fuel cell devices 10 to determine the second operating mode, and the fuel cell devices 10 determine the second operating mode according to the operating mode control command received from the control device 30.

[0040] Figure 3 is a schematic diagram illustrating the controlled period and the uncontrolled period. In the example shown in Figure 3, the control information (output control command) specifies that the period from 12:00 to 15:00 is the controlled period. Therefore, this fuel cell device 10 operates in the first operating mode during the controlled period from 12:00 to 15:00, and in the second operating mode during the other uncontrolled periods. The following describes a specific example of the first operating mode.

[0041] Figure 4 is a flowchart illustrating the method for determining the fuel cell device 10 that will issue the output control command. In step #10, the control device 30 notifies each facility 20 that it will issue an output control command before the controlled period begins. In response, the fuel cell control unit 13 of the fuel cell device 10 in each facility 20 transmits the status of the flicker prevention operation to the control device 30. Then, in step #11, the control device 30 receives the status of the flicker prevention operation from each facility 20 and stores it in the storage unit 14.

[0042] In step #12, the control device 30 excludes the fuel cell unit 10 performing flicker-prevention operation from the target of the output control command. In other words, when the control device 30 sends an output control command to any of the multiple fuel cell units 10 during the command transmission process, it sends the output control command to the fuel cell unit 10 that is not performing flicker-prevention operation, and does not send an output control command to the fuel cell unit 10 that is performing flicker-prevention operation.

[0043] In step #13, when the control device 30 transmits an output control command to any of the multiple fuel cell devices 10 during the command transmission process, it refers to at least one of the following: the distance from the distribution substation to the power receiving point of the fuel cell device 10, the number of distributed power sources (fuel cell devices 10 and other power generation devices (such as solar cells)) connected to each distribution system 1, the sum of the rated output powers of the distributed power sources connected to each distribution system 1, and the number of voltage flicker occurrences in each distribution system 1 over a predetermined period in the past, to determine the content of the output control command for the fuel cell device 10 that is not performing flicker countermeasure operation. For example, if the four fuel cell devices 10 (10A~10D) shown in Table 1 below are connected to any of the distribution systems 1 (1X~1Z), the control device 30 stores the information shown in Tables 1 and 2 below.

[0044] [Table 1]

[0045] [Table 2]

[0046] Then, when the control device 30 transmits an output reduction command to reduce the output of the fuel cell device 10 during the command transmission process, it preferentially transmits the output reduction command to the following fuel cell devices 10 that are not performing flicker countermeasure operation: fuel cell devices 10 connected to a distribution system 1 that has had a high number of voltage flicker occurrences in a predetermined period in the past; fuel cell devices 10 connected to a distribution system 1 that has a large number of connected distributed power sources; fuel cell devices 10 connected to a distribution system 1 that has a large total rated output power of connected distributed power sources; and fuel cell devices 10 that are located far from the distribution substation to the point of power reception, according to a predetermined priority order for output reduction.

[0047] Furthermore, when the control device 30 transmits an output increase command to increase the output of a fuel cell device 10 during the command transmission process, it prioritizes transmitting the output increase command to fuel cell devices 10 that are not performing flicker countermeasure operation, specifically those connected to a distribution system 1 with a low number of voltage flicker occurrences in a predetermined period in the past, those connected to a distribution system 1 with a small number of connected distributed power sources, those connected to a distribution system 1 with a small total rated output power of connected distributed power sources, and those that are located a short distance from the distribution substation to the point of power reception, according to a predetermined priority order for output increase.

[0048] Here, the management device 30 can separately set priority levels for output reduction and output increase for a predetermined period of increased power generation, including noon, when the power generated by the solar cell equipment as a distributed power source is expected to increase, and for periods other than the period of increased power generation.

[0049] For example, if the control target period includes a period of increased power generation, the management device 30 sets the priority order for output reduction in the following order: fuel cell devices 10 connected to distribution system 1 with a high number of voltage flicker occurrences in a predetermined period in the past, fuel cell devices 10 connected to distribution system 1 with a high total rated output power of connected distributed power sources, fuel cell devices 10 connected to distribution system 1 with a large number of connected distributed power sources, and fuel cell devices 10 with a long distance from the distribution substation to the point of power reception. The priority order for output increase is set in the following order: fuel cell devices 10 connected to distribution system 1 with a low number of voltage flicker occurrences in a predetermined period in the past, fuel cell devices 10 connected to distribution system 1 with a low total rated output power of connected distributed power sources, fuel cell devices 10 connected to distribution system 1 with a small number of connected distributed power sources, and fuel cell devices 10 with a short distance from the distribution substation to the point of power reception.

[0050] In contrast, if the control target period does not include the power generation increase period, the management device 30 can set the priority order for output reduction in the following order: fuel cell devices 10 connected to distribution system 1 with a high number of voltage flicker occurrences in a predetermined period in the past, fuel cell devices 10 with a long distance from the distribution substation to the power receiving point, fuel cell devices 10 connected to distribution system 1 with a large number of connected distributed power sources, and fuel cell devices 10 connected to distribution system 1 with a large total rated output power of connected distributed power sources. The priority order for output increase can be set in the following order: fuel cell devices 10 connected to distribution system 1 with a low number of voltage flicker occurrences in a predetermined period in the past, fuel cell devices 10 with a short distance from the distribution substation to the power receiving point, fuel cell devices 10 connected to distribution system 1 with a small number of connected distributed power sources, and fuel cell devices 10 connected to distribution system 1 with a small total rated output power of connected distributed power sources.

[0051] Furthermore, the control device 30 may determine which fuel cell device 10 to send an output control command to by considering only the number of voltage flicker occurrences in a predetermined period in the past. In other words, when the control device 30 sends an output reduction command to reduce the output of a fuel cell device 10 in the command transmission process, it may preferentially send the output reduction command to a fuel cell device 10 connected to a power distribution system 1 that has a high number of voltage flicker occurrences in a predetermined period in the past among the fuel cell devices 10 that are not performing flicker countermeasure operation. When the control device 30 sends an output increase command to increase the output of a fuel cell device 10 in the command transmission process, it may preferentially send the output increase command to a fuel cell device 10 connected to a power distribution system 1 that has a low number of voltage flicker occurrences in a predetermined period in the past among the fuel cell devices 10 that are not performing flicker countermeasure operation.

[0052] Furthermore, the management device 30 may determine which fuel cell devices 10 to transmit output control commands to by considering only the number of distributed power sources connected to the power distribution system 1. In other words, when the management device 30 transmits an output reduction command to reduce the output of a fuel cell device 10 during the command transmission process, it may preferentially transmit the output reduction command to fuel cell devices 10 that are not performing flicker countermeasure operation and are connected to a power distribution system 1 with a large number of connected distributed power sources. When the management device 30 transmits an output increase command to increase the output of a fuel cell device 10 during the command transmission process, it may preferentially transmit the output increase command to fuel cell devices 10 that are not performing flicker countermeasure operation and are connected to a power distribution system 1 with a small number of connected distributed power sources.

[0053] Alternatively, the control device 30 may determine which fuel cell devices 10 to send output control commands to by considering only the sum of the rated output powers of the distributed power sources connected to the distribution system 1. In other words, when the control device 30 sends an output reduction command to reduce the output of a fuel cell device 10 during the command transmission process, it may preferentially send the output reduction command to fuel cell devices 10 connected to the distribution system 1 that have a large sum of the rated output powers of the connected distributed power sources among the fuel cell devices 10 that are not performing flicker countermeasure operation. When the control device 30 sends an output increase command to increase the output of a fuel cell device 10 during the command transmission process, it may preferentially send the output increase command to fuel cell devices 10 connected to the distribution system 1 that have a small sum of the rated output powers of the connected distributed power sources among the fuel cell devices 10 that are not performing flicker countermeasure operation.

[0054] Alternatively, the control device 30 may determine which fuel cell devices 10 to transmit output control commands to by considering only the distance from the distribution substation to the point of power reception. In other words, when the control device 30 transmits an output reduction command to reduce the output of a fuel cell device 10 during the command transmission process, it may preferentially transmit the output reduction command to fuel cell devices 10 that are not performing flicker countermeasure operation and are located at a long distance from the distribution substation to the point of power reception. When the control device 30 transmits an output increase command to increase the output of a fuel cell device 10 during the command transmission process, it may preferentially transmit the output increase command to fuel cell devices 10 that are not performing flicker countermeasure operation and are located at a short distance from the distribution substation to the point of power reception.

[0055] <Another Embodiment> In the above embodiments, the configuration of the fuel cell management system of the present invention has been described with specific examples, but the configuration can be modified as appropriate.

[0056] In the above embodiment, specific numerical values ​​were used as examples to explain the fuel cell management system. However, these values ​​are provided for illustrative purposes only and can be changed as appropriate.

[0057] In the above embodiment, an example was described in which the fuel cell device 10 communicates with the management device 30 via a remote control 7 and a router 6 acting as communication relay devices. However, communication with the management device 30 may be performed via other devices. For example, information communication between the fuel cell device 10 and the management device 30 may be performed using a communication relay device that utilizes a mobile phone communication standard such as LTE.

[0058] The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0059] The present invention can be used in a fuel cell management system that can provide output control commands to an appropriate fuel cell device. [Explanation of Symbols]

[0060] 1 Power distribution system 2 Power lines 4 Power load device 6 Routers 7 Remote control 8 Power Measurement Unit 9. Voltage measurement section 10 Fuel cell device 11 Power Conversion Unit 12 Fuel cell section 13 Fuel cell control unit 14 Storage section 20 facilities 30 Management device 40 Aggregation Coordinator

Claims

1. A fuel cell management system comprising fuel cell devices installed in each of multiple facilities and connected to the power distribution system of each region where they are installed, and a management device capable of communicating with the multiple fuel cell devices from a remote location outside the facilities, The management device performs a command transmission process to send output control commands to a plurality of fuel cell devices to determine the output power of the fuel cell devices. When the fuel cell device receives the output control command from the control device, it operates with the goal of supplying the output power determined based on the output control command during the control period covered by the output control command. The fuel cell device is configured to perform a flicker suppression operation to reduce output power when voltage flicker occurs in the connected power distribution system, and to stop the flicker suppression operation when the conditions for stopping the flicker suppression operation are met. The control device, in the command transmission process, transmits the output control command to any of the multiple fuel cell devices, and transmits the output control command to the fuel cell device among the multiple fuel cell devices that is not performing the flicker-prevention operation, and does not transmit the output control command to the fuel cell device that is performing the flicker-prevention operation.

2. The aforementioned control device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is preferentially transmitted to the fuel cell device that is connected to the power distribution system and has a high number of voltage flicker occurrences in a predetermined period in the past, among the fuel cell devices that are not performing the flicker countermeasure operation. The fuel cell management system according to claim 1, wherein when transmitting an output increase command to increase the output of the fuel cell device in the command transmission process, the output increase command is preferentially transmitted to the fuel cell device that is connected to the power distribution system and has a low number of voltage flicker occurrences in a predetermined period in the past, among the fuel cell devices that are not performing the flicker countermeasure operation.

3. The aforementioned control device is When transmitting an output reduction command to reduce the output of the fuel cell device in the command transmission process, the output reduction command is preferentially transmitted to the fuel cell devices that are connected to a distribution system with a large number of interconnected distributed power sources, among the fuel cell devices that are not performing the flicker countermeasure operation. The fuel cell management system according to claim 1, wherein when transmitting an output increase command to increase the output of the fuel cell device in the command transmission process, the output increase command is preferentially transmitted to fuel cell devices that are not performing the flicker countermeasure operation and are connected to a power distribution system with a small number of connected distributed power sources.

4. The aforementioned control device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is preferentially transmitted to the fuel cell device that is connected to the distribution system with a large total rated output power of the connected distributed power sources, among the fuel cell devices that are not performing the flicker countermeasure operation. The fuel cell management system according to claim 1, wherein when transmitting an output increase command to increase the output of the fuel cell device in the command transmission process, the output increase command is preferentially transmitted to the fuel cell device that is connected to the distribution system where the total rated output power of the connected distributed power sources is small, among the fuel cell devices that are not performing the flicker countermeasure operation.

5. The aforementioned control device is When transmitting an output reduction command to reduce the output of the fuel cell device in the command transmission process, the output reduction command is preferentially transmitted to the fuel cell device that is not performing the flicker reduction operation and is located at a longer distance from the distribution substation to the power receiving point. The fuel cell management system according to claim 1, wherein, in the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the output increase command is preferentially transmitted to the fuel cell device that is not performing the flicker countermeasure operation and is located at a shorter distance from the power distribution substation to the power receiving point.

6. The aforementioned control device is In the command transmission process, when transmitting an output reduction command to reduce the output of the fuel cell device, the output reduction command is transmitted preferentially to fuel cell devices that are not performing flicker countermeasure operation, specifically those connected to a distribution system with a high number of voltage flicker occurrences in a predetermined period in the past, those connected to a distribution system with a large number of connected distributed power sources, those connected to a distribution system with a large total rated output power of the connected distributed power sources, and those that are located far from the distribution substation to the point of power reception, according to a predetermined priority order for output reduction. The fuel cell management system according to claim 1, in the command transmission process, when transmitting an output increase command to increase the output of the fuel cell device, the system preferentially transmits the output increase command to fuel cell devices that are not performing the flicker countermeasure operation, which are connected to a power distribution system that has had few occurrences of voltage flicker in a predetermined period in the past, which are connected to a power distribution system that has had few connected distributed power sources, which are connected to a power distribution system that has had a small total rated output power of connected distributed power sources, and which are connected to a fuel cell device that is located a short distance from the power distribution substation to the power receiving point.

7. The fuel cell management system according to claim 6, wherein the management device separately sets the priority order for output reduction and the priority order for output increase for a predetermined period of increased power generation, including noon, when it is predicted that the power generated by the solar cell equipment as a distributed power source will increase, and for periods of time other than the period of increased power generation.

8. The aforementioned control device is If the control period includes the power generation increase period, The priority order for output reduction is set in the following order: fuel cell devices connected to the distribution system with a high number of voltage flicker occurrences in a predetermined past period; fuel cell devices connected to the distribution system with a high total rated output power of the connected distributed power sources; fuel cell devices connected to the distribution system with a large number of connected distributed power sources; and fuel cell devices with a long distance from the distribution substation to the power receiving point. The fuel cell management system according to claim 7, wherein the priority order for increasing output is set in the following order: fuel cell devices connected to a distribution system with a low number of voltage flicker occurrences in a predetermined past period; fuel cell devices connected to a distribution system with a low total rated output power of the connected distributed power sources; fuel cell devices connected to a distribution system with a small number of connected distributed power sources; and fuel cell devices with a short distance from the distribution substation to the power receiving point.

9. The aforementioned control device is If the control period is not included in the power generation increase period, The priority order for output reduction is set in the following order: fuel cell devices connected to the distribution system with a high number of voltage flicker occurrences in a predetermined past period; fuel cell devices with a long distance from the distribution substation to the power receiving point; fuel cell devices connected to the distribution system with a large number of connected distributed power sources; and fuel cell devices connected to the distribution system with a large total rated output power of the connected distributed power sources. The fuel cell management system according to claim 7, wherein the priority order for increasing output is set in the following order: fuel cell devices connected to a distribution system with a low number of voltage flicker occurrences in a predetermined period in the past; fuel cell devices located at a short distance from the distribution substation to the power receiving point; fuel cell devices connected to a distribution system with a small number of connected distributed power sources; and fuel cell devices connected to a distribution system with a small total rated output power of the connected distributed power sources.

10. The fuel cell management system according to any one of claims 1 to 9, wherein the management device receives a power supply command for the controlled period determined by the power trading from an aggregation coordinator that conducts power trading in the power trading market, and transmits an output control command to the plurality of fuel cell devices that determine the output power of the fuel cell devices installed in each of the plurality of facilities determined based on the supply command.

Images