JP2006191748A - Collective power network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide improvement in economics for introduction of a dispersed power source, and reduction in power purchase cost for total users in a local area. <P>SOLUTION: The plurality groups of users exist in a prescribed local area L including first user groups A, B, C, E, F, G having the dispersed power source, such as a fuel battery system, a gas engine, and a solar light power generation system, and second user groups D, H not having the dispersed power source, a common power system 81 is provided which enables power supply between the users. The common power system 81 and a commercial power system 80 are connected by a linkage point J, power supply to the respective users A-H is enabled from the dispersed power source provided in the first user group by a power controller 90 through the common power system 81, thus enabling power supply from the commercial power system 80. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a group of electric power consumers existing in a predetermined local area, for example, a detached house or an apartment group in a specific area, a store or a small business group, and the like, such as a fuel cell system and a solar power generation system. When a customer with a distributed power source and a customer without such a distributed power source coexist, power generation generated by the distributed power source within a group of power consumers existing in the local area The present invention relates to a collective power network system in which power can be interchanged.

  Conventionally, as a power supply method for an apartment house such as a condominium, for example, as shown in FIG. 11, each consumer A via a commercial power system 80 from a commercial power supply source (power plant) 80G of a power company. A method in which ~ H is supplied individually is common. That is, each consumer A-H is a system which concludes what is called a "small power purchase contract" with an electric power company, and purchases electric power individually via individual electric power meters 800A-800H.

  By the way, in recent years, there are an increasing number of cases where private power generation facilities such as a fuel cell system and a solar power generation system (in the present specification, these are referred to as “distributed power sources”) are held in ordinary homes and small businesses. In FIG. 11, consumers A and B are a polymer electrolyte fuel cell (PEFC) system 20, consumers C are a solid oxide fuel cell (SOFC) system 30, customers E are a gas engine 50, and consumers F and G show examples in which a photovoltaic power generation (PV) system 60 is provided as a distributed power source. The consumers D and H are not provided with a distributed power source, the consumer D is provided with a general gas appliance 40 (and a general power load), and the consumer H is provided with an all-electric power load 70. An example is shown.

Then, for example, the consumers F and G equipped with the solar power generation system 60 use the generated power exclusively for private use, and sell the surplus power and purchase the insufficient power directly to the commercial power system 80. A method is adopted (for example, Patent Document 1). On the other hand, in the customers A to C in which the PEFC system 20 and the SOFC system 30 are introduced, purchase of insufficient power is performed directly from the commercial power system 80, but so-called “reverse power flow” is generally not allowed, so surplus power is not allowed. A method is employed in which operation control is performed so that no generation occurs or the generated surplus power is stored in a battery or converted into heat (hot water) by an electric heater or the like. That is, even if the consumers A to H are present in a predetermined local area such as the same apartment house or an area (such as a residential district, a shopping street, or an industrial park) that is closely connected to the region, the consumers A to H The fact is that there is no coordination between Hs, and each consumer is individually processing surplus power and insufficient power.
JP 2004-12376 A

  The electric load and the heat load such as heating and hot water change every moment, and the temporal fluctuation becomes large especially for small consumers such as ordinary households. In particular, with regard to the electric power load, since electric appliances in the home are frequently started and stopped, the electric load greatly fluctuates in a short time in seconds. FIG. 12 shows a power load fluctuation state in which the electric load in a single-family home is measured in seconds. As shown in the figure, a large electric power load fluctuation is constantly generated in a detached house, and in this measurement example, the minimum load is about 300 W, the maximum load is about 3000 W, and there is a fluctuation of up to 10 times.

  However, it is difficult for the distributed power source provided in each consumer to follow such load fluctuations. For example, in solar power generation and wind power generation, the generated power cannot be controlled inherently. As for the fuel cell, the load follow-up performance of the home fuel cell having the reformer is limited to about 10% / min, and cannot be operated following the instantaneous load fluctuation as described above. For this reason, there may occur a case where surplus power or insufficient power is constantly generated and the economic efficiency of the distributed power supply is impaired. In addition, as a measure against shortage of electricity, each customer must be connected to the commercial power system, and an individual power receiving contract must be concluded with the power company so that sudden load changes can be supplied from the commercial power system. Since such a contract is usually a small power receiving contract, it cannot be denied that it is relatively expensive.

  Therefore, in order to eliminate the inconvenience when surplus power and shortage power are processed for each consumer having a distributed power source, the present invention refers to a consumer existing in a predetermined local area instead of a “point”. A collective power network system that can be grasped in terms of “sides” including consumers who are not equipped, improve the economics of introducing distributed power sources, and reduce the cost of purchasing power for all consumers in the local area. The purpose is to provide.

  A collective power network system according to claim 1 of the present invention includes a plurality of local power systems that exist in a predetermined local area including a first consumer group having a distributed power source and a second consumer group having no distributed power source. A common power system that enables power supply between the consumers, and a link point between the shared power system and the commercial power system, and each consumer in the local area is provided with the common power system. It is possible to supply power from the distributed power source provided to each consumer of the first consumer group via the power system, and from the commercial power source via the commercial power system and the linkage point. It is possible to supply power.

  In the present invention, although the power load fluctuation is large as shown in FIG. 12 when viewed by individual consumers, the power load fluctuation is considerably suppressed when viewed in units of a plurality of consumers (existing in a predetermined local area). It was made with the fact that FIG. 13 shows the power load fluctuation state measured in the entire apartment house. In this case, the load change curve is smoothed as compared with the case of the detached house in FIG. 12, and in this measurement example, the minimum load is about 8000 W and the maximum load is about 30000 W, which is about 3.8 times. It is within the fluctuation range. This is because various households gather in the housing complex, so that the power and heat load are leveled as a whole.

  Therefore, a load unit with relatively little fluctuation in power load can be constructed by networking a plurality of customer groups existing in the local area with a shared power system, including the second customer group not provided with a distributed power source. become able to. And since surplus power generated in each consumer of the first consumer group equipped with a distributed power supply can be accommodated to other consumers via the shared power system, surplus power can be effectively utilized, The amount of commercial power purchased can be reduced. In addition, the second consumer group not provided with the distributed power supply has an advantage that it can contribute to load leveling and can receive the supply of surplus power, which can be purchased at a generally low cost.

  Further, the shared power system has a connection point with the commercial power system, and power can be supplied from the commercial power source to each consumer in the local area via this connection point. It becomes possible to purchase electric power from the electric power company in bulk. Therefore, it is possible to operate such that only the power that cannot be covered by the surplus power of the distributed power source among the total power demand of all the consumers in the local area is purchased in units of the local area from the linkage point.

  A collective power network system according to a second aspect of the present invention is the collective power network system according to the first aspect, wherein the shared power system is supplied from the electric power generated by the distributed power source provided in the first consumer group and / or the commercial power source. A power storage facility for storing electric power is connected. According to this configuration, it is possible to store the surplus power of the distributed power source, the midnight power from the commercial power system, and the like in the capacitor facility. In addition, since it is possible to appropriately supply power from the storage facility to the shared power system, it is possible to compensate for fine fluctuations in power demand and fluctuations in the voltage generated by the distributed power supply.

  A collective power network system according to claim 3 is the collective power network system according to claim 1, wherein the first consumer group and / or the second consumer group is provided with gas equipment using gas as a fuel source. A centralized fuel gas supply device is provided which collectively receives gas from a commercial gas supply source and supplies the gas individually to a customer having the gas equipment via a common gas system. According to this configuration, the source gas such as city gas is supplied from the commercial gas supply source to the centralized fuel gas supply device, and the predetermined gas equipment is provided from the centralized fuel gas supply device via the common gas system. Fuel gas will be supplied individually to consumers. The gas equipment here includes, in addition to general gas appliances, a fuel cell system or a gas engine that is a distributed power source that operates using gas as a fuel source.

  A collective power network system according to a fourth aspect includes a shared power monitoring unit according to any one of the first to third aspects for controlling a total amount of power generated by the distributed power source in accordance with a total amount of power demand in the consumer group. The shared power monitoring unit is a total demand monitoring unit that monitors a total power demand in a customer group existing in the local area, and a total power generation monitoring unit that monitors a total power generation amount in the first consumer group, And a comparison control unit that compares the total power demand with the total power generation and generates a control signal for controlling the total power generation so that the total power generation does not exceed the total power demand. According to this configuration, since the total power generation amount in the first consumer group is regulated by the comparison control unit, the total power generation amount exceeds the total power demand amount and surplus power is generated in the shared power system. Deterred.

  A collective power network system according to a fifth aspect of the present invention is the collective power network system according to the fourth aspect, wherein the distributed power source provided in the first consumer group includes a first distributed power source capable of controlling the generated power, and the generated power is controlled. In the case of being distinguished from the second distributed power source that is impossible, the comparison control unit is configured to generate a control signal for controlling the amount of power generated by the second distributed power source. Here, the first distributed power source that can control the generated power refers to a distributed power source such as a fuel cell or a gas engine. The second distributed power source whose generated power is uncontrollable is, for example, a solar power generation system or a wind power generation system. According to this configuration, it is possible to prevent surplus power from being generated in the shared power system by appropriately performing output control of the first distributed power supply.

  A collective power network system according to a sixth aspect is the collective power network system according to any one of the first to fifth aspects, wherein an output of each distributed power source in the first consumer group is connected to the shared power system. A feature is that all the generated power generated in each consumer of the consumer group is once supplied to the shared power system. According to this configuration, for example, when a fuel cell system with a hot water supply facility is introduced as a distributed power source, an operation corresponding to the heat demand of the consumer is performed without considering surplus power, and necessary Electricity can be operated by purchasing from a shared power system.

  A collective power network system according to a seventh aspect is the collective power network system according to any one of the first to fifth aspects, wherein an output of each distributed power source in the first consumer group is connected to the shared power system. Of the generated power generated at each consumer in the consumer group, the surplus that has not been consumed by the consumer is supplied to the shared power system. According to this configuration, it is relatively easy to calculate and manage the electricity rate for each consumer. In other words, the amount of supply to the shared power system as a surplus, that is, the amount that the distributed power source of the consumer contributed to the power demand in the shared power system (the power demand excluding the amount used by the consumer) becomes clear. For this reason, it becomes relatively easy to determine the amount of power sold and offset the purchase of insufficient power.

  The collective power network system according to claim 8 is a plurality of consumers existing in a predetermined local area including a first consumer group having a distributed power source and a second consumer group not having a distributed power source. Group, a shared power system that enables power supply between consumers, an individual connection point between each consumer and a commercial power system existing in the local area, and the first power via the shared power system. Individual control means for enabling power supply from a distributed power source provided to each consumer in the consumer group and for supplying power from a commercial power source via the individual linkage point It is characterized by.

  According to this configuration, each consumer first uses the power supplied from the shared power system, and when insufficient power occurs, power is supplied from the commercial power system to each consumer via the individual linkage points. It is possible to execute the operation of receiving.

  According to the collective power network system according to claim 1, the power (surplus power) generated by the distributed power source can be effectively used by a customer existing in a predetermined local area via the shared power system. . In particular, in a consumer having a distributed power source such as a fuel cell system that cannot reversely flow, a countermeasure for suppressing surplus power becomes unnecessary, and the operation efficiency can be improved. In addition, it is possible to purchase insufficient power from the linkage points in local area units, and it is possible to purchase power from a power company with a large power receiving contract that is advantageous in terms of price. .

  According to the collective power network system according to the second aspect, surplus power of the distributed power source can be used effectively, and inexpensive midnight power can be used, so that the power cost in the shared power system can be suppressed. In addition, since the power storage facility can compensate for small fluctuations in power demand and fluctuations in the voltage generated by the distributed power supply, it is possible to stabilize the power of the shared power system. Further, there are advantages such as prevention of reverse power flow when many distributed power sources that do not allow reverse power flow are included, or effective use of a solar power generation system that can generate power only during the daytime.

  According to the collective power network system according to claim 3, since a large-scale gas purchase contract is concluded with a city gas supply company that supplies commercial gas in local area units, it is advantageous in terms of fuel gas procurement costs. It becomes.

  According to the collective power network system according to claim 4, it is possible to prevent generation of surplus power in the shared power system because the total power generation amount exceeds the total power demand amount. Occurrence can be prevented in advance.

  According to the collective power network system according to claim 5, generation of surplus power in the shared power system is suppressed by appropriately performing output control of the first distributed power source capable of controlling generated power. Can improve the efficiency when viewed with.

  According to the collective power network system according to the sixth aspect, for example, in a customer who has introduced a fuel cell system, it is possible to operate freely following a thermal load. The benefits will become more apparent.

  According to the collective power network system according to the seventh aspect, since it is relatively easy to determine the amount of power sold and offset the purchase of insufficient power, the operation of the collective power network system can be relatively simplified. It becomes like this.

  According to the collective power network system according to claim 8, since it has an individual connection point with the commercial power system, the purchase amount of insufficient power in each consumer is clarified individually, and is insufficient in the local area. The process of apportioning and subtracting the purchase amount of electricity is unnecessary, and the payment system can be simplified.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications.
(First embodiment)
FIG. 1 is a block diagram showing a basic configuration of a collective power network system according to the present invention. Here, the consumers A to H are a plurality of small consumers existing in a predetermined local area L, for example, each household of an apartment house, a single-family house in a predetermined area, or a small business consumer. . The consumers A and B have a polymer electrolyte fuel cell (PEFC) system 20, the consumer C has a solid oxide fuel cell (SOFC) system 30, the consumer E has a gas engine 50, and the customer F. , G are each provided with a photovoltaic (PV) system 60 as a distributed power source. That is, consumers A, B, C, E, F, and G are a first consumer group provided with distributed power sources.

  On the other hand, the consumers D and H are not equipped with a distributed power supply, the consumer D is equipped with a general gas appliance 40 (and a general power load), and the consumer H is equipped with an all-electric power load 70. . That is, consumers D and H are the 2nd consumer groups which are not provided with a distributed power supply, respectively. In addition, although illustration is abbreviate | omitted, the general gas appliance and the general electric power load are installed also in the consumers A, B, C, E, F, and G which are the 1st consumer groups.

  A power and fuel gas (city gas) supply system for the consumers A to H in the local area L will be described. In the collective power network system, the power receiving system from the commercial power supply source 80G to the consumers A to H existing in the local area L is unified, and the power supply systems to the consumers A to H are mutually connected. It is characterized in that a shared power system 81 to be connected is provided. In addition to this, a common gas system 12 for a plurality of consumers is also provided for the fuel gas supply system.

  First, with respect to the fuel gas supply system, PEFC system 20, which is a distributed power source that operates using gas as a fuel source, SOFC system 30, consumers A, B, C, E including gas engine 50, and predetermined general gas appliance 40 The structure which purchases gas from the commercial gas supply source 10G collectively and supplies each gas with respect to the consumer D provided with this is employ | adopted. That is, a source gas such as city gas is supplied to the centralized fuel gas supply device 11 from the commercial gas supply source 10G via the commercial gas supply system 10 and the common gas meter 10M, and the common gas system is supplied from the centralized fuel gas supply device 11. 12, the fuel gas is individually supplied to the consumers A to E. The consumers A to E are provided with individual gas meters 13A to 13E, and the amount of gas supplied from the common gas system 12 is measured for each of the consumers A to E.

  On the other hand, the consumers F and G are not connected to the common gas system 12 and are supplied with gas from the commercial gas supply source 10G by an unillustrated individual gas system. Of course, the consumers F and G may also be connected to the common gas system 12. In addition, about the consumer H provided with the electric load 70 of all electrification, since all the loads are covered with electric power, gas supply is unnecessary.

  According to such a configuration, the common gas meter 10M is installed on the upstream side of the centralized fuel gas supply apparatus 10, and the amount of gas used in each consumer A to E existing in the local area L is comprehensively measured. Since a large gas purchase contract is concluded with a city gas supply company that supplies commercial gas in a predetermined local area L unit, etc., this is advantageous in terms of fuel gas procurement costs. In addition, since the gas amount used by each consumer A-E is measured by each individual gas meter 13A-13E as above-mentioned, according to the fuel gas amount used by each consumer A-E, gas It becomes possible to determine the share of the fee.

  Next, with respect to the power supply system, first, the shared power system 81 enables power supply between consumers, and in the local area L, a certain amount of power can be procured from a distributed power source provided by each consumer. ing. Further, the shared power system 81 is provided with a connection point J with the commercial power system 80. From the commercial power system 80 and the connection point J to the shared power system 81 (ie, from the commercial power supply source 80G). Electric power can be supplied to each consumer A to E). That is, each of the consumers A to E includes a double power supply system including a supply system that uses the distributed power supply in the local area L and a supply system that receives commercial power. Thereby, when the electric power by the distributed power supply is insufficient in the shared power system 81, the commercial power is instantaneously supplied from the commercial power system via the linkage point J.

  Here, with regard to the commercial power supply system, a large-scale power purchase contract is concluded with a power supply company that supplies commercial power in consideration of economy, and the entire local area L is received by the commercial power system 80. One common electric power meter 80M is installed, and electric power is supplied from the commercial electric power supply source 80G to each consumer A to H through the common electric power system 81 from the common electric power meter 80M. . In the shared power system 81, individual power meters 82A to 82H are attached to the consumers A to H, respectively. That is, the amount of electric power used by the electric devices of the consumers A to H is measured by the individual power meters 82A to 82H.

  The shared power system 81 can be supplied with the generated power of the distributed power source provided by the first consumer. That is, the PEFC system 20 installed in the consumers A and B, the SOFC system 30 installed in the customer C, the gas engine 50 installed in the customer E, and the customers F and G. The generated power output of the solar power generation system 60 is connected to the shared power system 81. Thereby, it is set as the structure which the electric power generated with the distributed power supply of the 1st consumer can be supplied to the other consumers in the local area L via the shared power grid | system 81. FIG. Furthermore, depending on a contract with a power company that supplies commercial power, it is possible to reversely flow the power generated by the distributed power source to the commercial power grid 80 (so-called power sale) via the linkage point J. Yes.

  A power control device 90 (control means) is interposed between the shared power system 81 and the shared power meter 80M. The power control device 90 performs power reception control from the commercial power supply source 80G, power distribution control for each consumer A to H, and the like.

  At present, the sale of privately generated power is not allowed except for solar power generation and wind power generation. Therefore, in the embodiment shown in FIG. 1, the power generated by the PEFC system 20 of the consumers A and B, the SOFC system 30 of the customer C, etc. cannot flow backward to the commercial power supply system 81. Therefore, in the control unit (not shown) of each fuel cell system, it is necessary to predict the electric power and heat load demand of the consumer and to operate by commanding the power generation output so as not to generate surplus power. In some cases, the heat demand could not be sufficiently met. However, by making it possible to supply the generated power of the fuel cell system provided by each consumer to the shared power system 81 as in this embodiment, for example, surplus power is sent to the shared power system 81, and this surplus power is Operation that other consumers use is possible. As a result, the fuel cell system is operated according to the heat demand, and when surplus power is generated, it may be flowed to the shared power system 81, and the convenience of the fuel cell system is further improved.

  In the above configuration, it is desirable to connect a power storage facility to the shared power system 81 so that the system is economical and the power supply is stabilized. FIG. 2 is a block diagram showing a configuration in which a storage battery facility SB is added to the collective power network system shown in FIG. As this electrical storage equipment SB, what was equipped with storage batteries, such as a sodium sulfur battery, a redox flow battery, a lead battery, and the control part which performs charge / discharge control of this storage battery, for example is applicable.

  The electric storage (charging) operation for the electric storage device SB is performed by electric power generated by a distributed power source provided in the first consumer group, by electric power supplied from a commercial power supply source 80G, or by both electric powers. It can be set as the structure performed. The discharging operation of the storage battery facility SB can be configured to be performed on the shared power system 81. According to this configuration, it is possible to store the surplus power of the distributed power source, the midnight power from the commercial power system, and the like in the capacitor facility. In addition, since power can be supplied (discharged) from the storage facility to the shared power system as appropriate, it is possible to compensate for fine fluctuations in power demand in the local area L (see FIG. 13) and fluctuations in the voltage generated by the distributed power supply. You can do it. Therefore, the collective power network is capable of reducing the power cost in the shared power system 81 and stabilizing the power of the shared power system 81 by effectively using surplus power of the distributed power source and using inexpensive midnight power. The convenience of the system can be further improved.

  Next, various distributed power sources provided in the first consumer group will be briefly described. FIG. 3 is a block diagram illustrating a configuration example of the PEFC system 20 provided in the consumers A and B. The PEFC system 20 includes a PEFC battery stack 210, a radiator 220, a heat exchanger 230, a hot water tank 240, an air supply device 250, an inverter 260, an output control unit 262, and the like. The PEFC battery stack 210 includes a fuel electrode 211, an air electrode 212, an electrolyte 213, and a cooling plate 214. Fuel gas is supplied to the fuel electrode 211 from the centralized fuel gas supply device 11 shown in FIG. Actually, a hydrogen-rich reformed gas having a carbon monoxide concentration of 10 to 100 ppm or less is introduced into the fuel electrode 211 through an unillustrated individual reformer and carbon monoxide remover.

  Thereafter, most of the hydrogen component in the introduced reformed gas is ionized at the fuel electrode 211, and the hydrogen ions are transferred to the air electrode 212 through the electrolyte 213. Air is introduced into the air electrode 212 from an air supply device 250 including a blower 251 and a drive motor 252, and oxygen in the air is taken in and ionized. The oxygen ions and hydrogen ions moved from the fuel electrode 211 chemically react to generate water and generate power. Since the electric power generated by such a chemical reaction is a direct current, it is output as an alternating current output 261 after being subjected to direct current to alternating current conversion by the inverter 260.

  The AC output 261 is supplied as drive power to various power devices existing in the consumer (in-house supply mode), or supplied to other customers to the shared power system 81 (shared supply) Mode). The output control unit 262 appropriately performs switching operation between the home supply mode and the shared supply mode. The mode switching operation is performed by, for example, individual determination of the PEFC system 20 according to the degree of generation of surplus power in the PEFC system 20. In addition to being executed, it is also configured to be executed by a predetermined load increase / decrease command signal given from an overall control unit provided in the collective power network system.

  In the PEFC battery stack 210, heat is generated because hydrogen and oxygen chemically react as described above. Therefore, although it is necessary to cool the PEFC battery stack 210 so as not to be overheated, the heat at the time of cooling is recovered to generate hot water or the like, thereby effectively utilizing the heat. In the example shown in FIG. 3, a cooling water circulation path 222 and a radiator 220 that pass through the cooling plate 214 of the PEFC battery stack 210 are provided, and the cooling water is circulated in the circulation path 222 by the pump 221, thereby Is kept at a constant temperature (cooled).

  On the other hand, the circulation path 222 is a piping path that also passes through the heat exchanger 230. One of the heat absorbed by the cooling plate 214 into the tap water introduced into the heat exchanger 230 through the water pipe path 231. Department (surplus heat) is exchanged. By such a heat exchange operation, warm water of about 60 ° C. is generated in the heat exchanger 230. Such hot water is sent to the hot water storage tank 240 through the output piping 232 and stored therein, and is used for a kitchen, a washroom, and a bath (heat demand equipment) as necessary.

  FIG. 4 is a block diagram illustrating a configuration example of the SOFC system 30 provided in the customer C. The SOFC system 30 includes an SOFC battery stack 310, a high-temperature water heat exchanger 320, a low-temperature water heat exchanger 330, a combustion chamber 340, an air supply device 350, an inverter 360, an output control unit 362, and the like. The SOFC battery stack 310 includes a fuel electrode 311, an air electrode 312, and an electrolyte 313. A hydrogen-rich reformed gas is introduced into the fuel electrode 311 from the centralized fuel gas supply device 10 through the shared gas system 12, an unillustrated individual reformer, and the like.

  After that, most of the hydrogen component (and carbon monoxide component) in the introduced reformed gas reacts with oxygen ions sent from the air electrode 312 in the fuel electrode 311 to generate electricity. Air is introduced into the air electrode 312 from an air supply device 350 including a blower 351 and a drive motor 352, and oxygen in the air is taken in and ionized. Such oxygen ions move to the fuel electrode 311 through the electrolyte 313, and chemically react with the hydrogen component (and carbon monoxide component) as described above to generate electricity. Similarly, since the generated electric power is direct current, it is output as alternating current output 361 after DC-AC conversion by inverter 360. Similar to the output control unit 262 shown in FIG. 3, the output control unit 362 appropriately performs the switching operation between the home supply mode and the shared supply mode.

  Generally, the hydrogen utilization rate at the fuel electrode 311 is 70 to 80%, and the remainder is discharged as surplus (fuel electrode exhaust gas). The oxygen utilization rate in the air at the air electrode 312 is 50 to 60%, and the remainder is discharged as surplus (air electrode exhaust air). In order to utilize such surplus energy, the fuel electrode exhaust gas and the air electrode exhaust air are introduced into the combustion chamber 340 disposed on the outlet side of the SOFC battery stack 310 and burned. The heat generated by this combustion is used for heat retention of the SOFC battery stack 310 and is recovered by a heat exchanger.

  That is, an exhaust gas recovery pipe 341 is connected to the combustion chamber 340, and the exhaust gas recovery pipe 341 is configured to pass through the high temperature water heat exchanger 320 and the low temperature water heat exchanger 330. The high temperature combustion exhaust gas generated by the combustion reaction in the combustion chamber 340 is sequentially guided to the high temperature water heat exchanger 320 and the low temperature water heat exchanger 330 through the exhaust gas recovery pipe 341, and the high temperature water heat exchanger 320 and the low temperature water heat exchange are conducted. Heat is transferred to and from the tap water introduced into the vessel 330 via the water pipe line 332. By such a heat transfer operation, the high-temperature water heat exchanger 320 generates high-temperature water of about 90 ° C., and the low-temperature water heat exchanger 330 generates low-temperature water of about 60 ° C. Such high-temperature water and low-temperature water are used for heat demand equipment in the consumer through output piping lines 321 and 331, respectively.

  The gas engine 50 provided in the consumer E includes, for example, an engine unit that generates power by rotating a gas turbine using city gas or the like as fuel gas, and heat recovery that generates hot water or the like by using exhaust heat of the engine unit. And a unit. Furthermore, the solar power generation system 60 provided in the consumers F and G has a configuration including, for example, a rooftop type solar cell panel. The above is an example of the distributed power supply, and various package type power generation devices, wind power generation systems, and the like are applicable in the present invention.

  Next, a specific operation mode of the collective power network system according to the present embodiment will be described. In the collective power network system, for example, the following operation modes (1) to (3) can be adopted.

  (1) Power is generated by distributed power sources (PEFC system 20, SOFC system 30, gas engine 50, and solar power generation system 60) of consumers A, B, C, E, F, and G, which are the first consumer group. All the electric power is once sent to the shared power grid 81, and each consumer A to H purchases the amount of power to be used individually from the shared power grid 81. In this case, each of the consumers A to H existing in the local area L receives electric power generated by the distributed power sources owned by the consumers A, B, C, E, F, and G from the shared power system 81. In addition to receiving power, the shortage is received from the commercial power system 80 that is contracted collectively. The latter received power amount is measured by the common power meter 80M, and the individual received power amounts including the former and the latter are measured by the individual power meters 82A to 82H. For customers A, B, C, E, F, and G who have distributed power sources, a power generation meter is also installed, and the amount of power supplied to the shared power system 81 is measured and offset. Is desirable.

  According to such an operation mode, for example, in the consumers A, B, and C that have introduced fuel cell systems such as the PEFC system 20 and the SOFC system 30 that are usually accompanied by a hot water supply facility or the like as a distributed power source, The operation according to the heat demand in the consumer is performed, and the necessary power can be purchased from the shared power system 81. Therefore, the control of suppressing the generation of surplus power is unnecessary, and the merit of introducing the fuel cell system can be further realized.

  (2) Of the electric power generated by each of the distributed power sources of the consumers A, B, C, E, F, and G, which are the first consumer group, the consumers A, B, C, E, F, and G Only surplus power excluding consumed power is supplied to the shared power grid 81, and other consumers purchase the amount of power to be used from the shared power grid 81. According to such an operation mode, it is relatively easy to calculate and manage a power rate for each consumer. That is, the power supplied to the shared power system 81 as a surplus, that is, the distributed power sources of the consumers A, B, C, E, F, and G are the power demands in the shared power system (the power demand excluding the amount used by the consumers). ) Will be clear, and it will be relatively easy to determine the amount of power sold and offset the purchase of insufficient power.

  (3) The total surplus of power generated by each of the distributed power sources of the consumers A, B, C, E, F, and G, which are the first consumer group, is transmitted via the shared power system 81 and the linkage point J. In addition to selling power, the insufficient power is purchased in bulk by consumers A to H in the local area. This is an operation based on the premise that the generated power can be sold by the distributed power source. In this case, the power control apparatus 90 also performs the operation of determining whether to sell or receive power.

  Among these operation modes, specific device configuration examples and operations will be described for the operation modes (1) and (2). FIG. 5 is a block diagram showing a configuration for realizing the operation mode (1). In this example, a shared power monitoring unit 91 is added to the collective power network system, and the total power generation amount by the distributed power source is controlled according to the total power demand amount in the consumer group. The shared power monitoring unit 91 includes a total demand monitoring unit 911, a total power generation monitoring unit 912, and a comparison control unit 913.

  FIG. 5 also shows an example of the functional configuration of the customer A. In this example, the power usage meter Um and the power supply meter Gm as the individual power meter 82A and the output (power generation amount) of the PEFC system are controlled. The example provided with the output control part 262 and the consumer electric power equipment 27 which consists of general household appliances etc. is shown. Other customers also have the same functional configuration, but only the power usage meter Um is used as the individual power meters 82D and 82H for the customers D and H, which are the second consumer group not provided with the distributed power source. Is provided. Further, for the customers F and G including the photovoltaic power generation system 60 that cannot substantially perform system drive control, a functional unit corresponding to the output control unit 262 is not provided.

  The total demand monitoring unit 911 of the shared power monitoring unit 91 monitors the total power demand in the customer group existing in the local area L. That is, the measured value of the power usage meter Um of each consumer A to H is input to the total demand monitoring unit 911, whereby the total demand monitoring unit 911 causes the total amount of power used in the power equipment of the consumers A to H. Is grasped by addition processing.

  The total power generation monitoring unit 912 monitors the total power generation in the first consumer group. That is, the measured value of the power generation amount meter Gm of each of the consumers A, B, C, E, F, and G of the first consumer group is input to the total power generation amount monitoring unit 912, whereby the total power generation amount monitoring unit 912 The total amount of electric power generated in one consumer group is grasped by addition processing.

  The comparison control unit 913 compares the total power demand calculated by the total demand monitoring unit 911 and the total power generation calculated by the total power generation monitoring unit 912, and controls the total power generation so that the total power generation does not exceed the total power demand. A control signal is generated. In the case of this embodiment, the comparison control unit 913 is the consumers A, B, C, E, that is, the PEFC system 20, the SOFC system 30, and the gas that are distributed power sources (first distributed power sources) capable of controlling the generated power. A control signal (load increase / decrease command) for controlling the output is output to each output control unit (the output control unit 262 in FIG. 5) of the engine 50 so that surplus power is not generated in the shared power system 81. In addition, a control signal is not output to the photovoltaic power generation system 60 which is a distributed power source (second distributed power source) that cannot control the generated power. Further, the comparison control unit 913 outputs a discharge (or charge) command to the storage battery facility SB as necessary, and performs control for stabilizing the power of the shared power system 81.

  On the other hand, for example, the output control unit 262 provided in the consumer A outputs a predetermined drive signal to the PEFC system 20 according to the control signal when the output control signal is given from the comparison control unit 913. . For example, when the total amount of power generation is expected to exceed the total amount of power demand, the comparison control unit 913 transmits a command signal “load reduction”, but in response to this, the output control unit 262 receives a PEFC. A drive signal for suppressing a predetermined amount of power generated by the system 20 is output. When the total power generation amount is insufficient with respect to the total power demand, the comparison control unit 913 transmits a command signal for “load increase”, and the output control unit 262 receives this command from the PEFC system 20. A drive signal for increasing the generated power by a predetermined amount is output.

  In this case, the output control unit 262 may perform output control of the PEFC system 20 (power generation unit) in response to the load increase / decrease command signal given from the comparison control unit 913 as described above. Even when a command signal indicating “load reduction” is transmitted from the control unit 913, the power generated by the PEFC system 20 is not suppressed to satisfy the heat demand of the customer A, and the output of the power generation equipment at other consumers It is also possible to perform control for further reducing the power consumption or storing the power in the battery storage facility SB.

  Further, even when a command signal for “load increase” is transmitted from the comparison control unit 913, whether or not the PEFC system 20 (power generation unit) has an output margin, and further, the heat demand accompanying the increase in output It is desirable to perform control to increase the output within a predetermined range (within a range in which the generated heat is not wasted) after determining whether the consumer A can expect it in light of the past heat load pattern or the like. Even if such control is performed and, as a result, power is insufficient in the shared power system 81, commercial power is supplied through the linkage point J, or in the example of FIG. Therefore, no particular problem occurs.

  Next, FIG. 6 is a block diagram showing a configuration for realizing the operation mode (2). Also in this example, the point that the shared power monitoring unit 91 is added to the collective power network system is the same as the example shown in FIG. 5, but the functional configuration of each consumer is different. FIG. 6 shows an example of the functional configuration of the customer A, and shows an example in which two-stage measurement meters are attached on the power receiving side and the power output side. That is, on the power receiving side, power is supplied from the shared power system 81 to the consumer power device 27 through the power purchase meter Um1 and the power usage meter Um2. Then, the measured values of both the power purchase meter Um1 and the power usage meter Um2 are input to the total demand monitoring unit 911.

  In addition, the generated power of the PEFC system 20 can be supplied through two routes: a route P1 that is supplied to the customer A's premises and a route P2 that supplies power to the shared power system 81 via the power generation amount meter Gm1. Has been. And the electric power by the said route P1 is supplied to the consumer electric equipment 27 via the electric power use meter Um2. Further, the electric power by the route P2 is supplied to the shared power system 81 via the power supply meter Gm2. The measured values of both the power generation amount meter Gm1 and the power usage meter Um2 are input to the total power generation amount monitoring unit 912.

  With this configuration, the customer A primarily uses the power generated by the PEFC system 20 at home, and purchases power from the shared power system 81 when shortage occurs. Conversely, when surplus power is generated, it is possible to transmit power to the shared power system 81. The purchase amount of the insufficient power is measured by the power purchase meter Um1, and the surplus power is measured by the power supply meter Gm2, and the power purchase meter Um1, the power usage meter Um2, and the power generation amount meter Gm1 and the power usage. From each measured value of the meter Um2, the total demand amount and the total power generation amount can be grasped.

  In this case, the output control unit 262 may control the output of the PEFC system 20 (power generation unit) according to the power demand in the customer A, but whether or not the PEFC system 20 has a margin for output. Further, after determining whether the heat demand accompanying the increase in output can be expected in the customer A in light of the past heat load pattern, etc., the output is within a predetermined range (in a range where the generated heat is not wasted). It is desirable to perform control to increase the value. This is the same even when a command signal for “load increase” is transmitted from the comparison control unit 913. Even if such control is performed and as a result, the electric power is short in the consumer A, the commercial power (or the interchanged power in the local area L) is supplied from the shared power system 81, or the electric power is supplied from the capacitor facility SB. Since the supply is made, no particular problem occurs.

  A schematic operation flow of the system including the shared power monitoring unit illustrated in FIG. 5 or 6 will be described based on the flowchart illustrated in FIG. When the predetermined sampling period arrives (Yes in Step S1), the total demand amount V1 in the consumer group A to H existing in the local area L is calculated by the total demand monitoring unit 911 (Step S2) and power generation The total power generation amount V2 generated in the first consumer group (distributed power source) is calculated by the total amount monitoring unit 912 (step S3).

  Then, the comparison control unit 913 compares the total power demand amount V1 and the total power generation amount V2 (step S4), and if they do not match (No in step S4), both are within the range where the total power generation amount does not exceed the total power demand amount. Control signals (specifically, load increase / decrease command signals for the first distributed power supply) are generated (step S5) so that the power generation total amount substantially follows the power demand total amount. ). When both are substantially the same (Yes in step S4), power is supplied only by the distributed power supply (step S6). Then, it returns to step S1 and a process is repeated.

  After step S5, the power supply form to the shared power system 81 changes depending on whether the total power demand is equal to or less than a predetermined threshold (whether it is within the range of the power generation capacity of all distributed power sources). . That is, when the total power generation capacity is exceeded (Yes in step S7), commercial power is introduced into the shared power system 81 via the linkage point J (step S8). On the other hand, even when the total power generation capacity is not exceeded (No in step S7), as described above, when the operation according to the heat demand of each consumer is performed (the power is not generated according to the command signal from the comparison control unit 913). When the total amount of power demand cannot be covered by the power actually output from the distributed power supply (No in step S9), commercial power is introduced into the shared power system 81 via the linkage point J. (Step S8). Conversely, when the total amount of power demand can be covered by the power actually output from the distributed power supply (Yes in step S9), power is supplied only by the distributed power supply (step S6).

(Second Embodiment)
In the above configuration, city gas supplied in advance from the commercial gas supply source 10G is intensively refined into reformed gas, and this reformed gas is distributed to the PEFC system 20, the SOFC system 30, the gas appliance 40, and the gas engine 50. It is good also as a structure to supply. FIG. 8 is a block diagram showing a configuration of a collective power network system including such a centralized reforming type gas supply system. In addition, since the structure regarding the shared power grid | system 80 is the same as that of 1st Embodiment demonstrated previously, description is abbreviate | omitted.

  The collective power network system shown in FIG. 8 is configured to be individually supplied to each consumer A to E including gas equipment via the centralized reformed gas supply device 14 and the accumulator 15. That is, a source gas such as city gas is supplied to the centralized reformed gas supply device 14 from the commercial gas supply source 10G via the commercial gas supply system 10, and the reformed gas is supplied from the centralized reformed gas supply device 14 to the centralized reformed gas supply device 14. The refined gas is purified and supplied to the consumers A to E via the accumulator 15 and the common gas system 12. The fuel used in the centralized reformed gas supply apparatus 14 may be city gas, petroleum liquid fuel such as kerosene, light oil, naphtha, or biogas. Furthermore, hydrogen gas produced by water electrolysis using sunlight and midnight power can be mixed and supplied together with these reformed gases.

  The accumulator 15 is installed in order to store a certain amount of reformed gas and maintain the reformed gas pressure constant even when a sudden demand fluctuation of the reformed gas occurs. The reformed gas is supplied to each consumer A to E through the common gas system 12 (which may be an existing city gas pipe line or the like) connected to the accumulator 15, and the SOFC. Supplied to system 30, gas appliance 40 and gas engine 50.

  FIG. 9 is a block diagram showing an example of the internal configuration of the centralized reformed gas supply device 14. This centralized reformed gas supply apparatus 14 includes a desulfurizer 141 having a sulfur removing function, a steam supply unit 142 that generates steam and adds steam to raw fuel, and a reformer (modified) that performs a reforming reaction. 143), a carbon monoxide converter 144 for performing a shift reaction for generating hydrogen and carbon dioxide, a shunt 145, and a reformer burner 146 for heating the reformer 143. .

The operation of the concentrated reformed gas supply device 14 will be described. A raw fuel such as city gas (CH ₄ is used in this embodiment) supplied from the commercial gas supply source 10G is first introduced into the desulfurizer 141, and the sulfur component of the odorous material contained in the raw fuel. Is removed. Steam is added from the steam supply unit 142 to the desulfurized gas and introduced into the reformer 143. The reformer 143 is heated to an operating temperature of about 750 to 800 ° C. by the reformer burner 146, and the introduced CH ₄ and water are reformed in the reformer 143 using a Ni-based catalyst. , Separated into hydrogen and carbon monoxide. Thereafter, the separated gas is introduced into a carbon monoxide converter 144 maintained at a temperature of 350 to 200 ° C., and the carbon monoxide is converted into hydrogen and carbon dioxide using an Fe-based catalyst or a Cu-based catalyst. . Thereby, the carbon monoxide concentration in the fuel gas (reformed gas) is reduced to about several percent.

In this way, the reformed gas obtained by refining the city gas in the centralized reformed gas supply device 14 is appropriately sent to the consumers A to E via the accumulator 15. In the present embodiment, a flow divider 145 is provided in the outlet side piping path of the carbon monoxide transformer 144, and a part of the reformed gas purified in the centralized reformed gas supply device 14 is supplied to the reformer burner. 146. This makes it possible to reduce the amount of No _X generated by combustion of the reformer burner 146 to a lower concentration (about 10 ppm) than when using raw fuel such as city gas, LPG, or kerosene. There are advantages in that the improvement can be achieved and the residual gas can be effectively used.

  According to the collective power network system according to the second embodiment described above, the fuel cell system (PEFC system 20 and SOFC system 30), the general gas appliance 40, and the gas engine 50 that are distributed and installed in a plurality of small consumers. Since the fuel supply is performed by the centralized reformed gas supply device 14 common to each consumer, each fuel cell system does not require a reformer unit, and the device configuration can be simplified and downsized. . In addition, since the reformed gas can be constantly supplied, the startup time is shortened and the fuel cell system can be operated efficiently.

(Third embodiment)
In the above embodiment, the connection point J between the commercial power system 80 and the shared power system 81 is provided, and the commercial power is purchased collectively in units of the local area L. However, for the purchase of commercial power, each customer A ˜H may be performed individually. FIG. 10 is a block diagram showing a configuration of a collective power network system including individual linkage points (which may be ordinary power receiving facilities) between the consumers A to H existing in the local area L and the commercial power system 80. . The difference from the system shown in FIG. 1 (first embodiment) described above is that a route in which each consumer A to H individually purchases electric power from the commercial power system 80 via the individual linkage points, and the above-described system. The common power system 81 is provided with two power receiving routes including a route for receiving the power generated by the distributed power source included in the first consumer group.

  The power generation output by the distributed power source held by the consumers A, B, C, E, F, and G that are the first consumer group is connected to the shared power system 81, and the generated power is shared power system 81. Can be supplied. The mode of the shared power system 81 is the same as that of the first embodiment. Note that a power control device (not shown) is interposed in the shared power system 81 so that the power distribution operation is controlled. The amount of power used by each consumer A to H in the shared power system 81 is measured by the individual power meters 82A to 82H.

  On the other hand, the power purchased individually for each consumer from the commercial power supply system 80 is measured by the general power meters 83A to 83H provided in each consumer A to H. Thus, each consumer AH can procure electric power from the distributed power source in the local area L via the shared electric power system 81 and can individually procure electric power from the commercial electric power system 80 via individual connection points. It becomes like this. The power supply control from the shared power system 81 and / or the commercial power system 80 is controlled by individual control means (not shown) provided in each consumer A to H.

  According to such a collective power network system, each of the consumers A to H first uses the power supplied from the shared power system 81, and in the case where insufficient power is generated, the individual power points are connected via the individual linkage points. It becomes possible to execute the operation of receiving power supply from the commercial power system 80 for each consumer. In particular, the consumers A to C that have introduced the fuel cell unit do not need to predict the power consumption pattern in the customer, and constantly flow into the commercial power system while ensuring a stable power supply source. There is an advantage that surplus power of the fuel cell system (PEFC system 20 and SOFC system 30) can be effectively utilized.

  Although the embodiments of the present invention have been described above, various modifications can be made to the configuration exemplified above. For example, in the above-described embodiment, an example in which one of the PEFC system 20 and the SOFC system 30 is employed as the fuel cell unit has been shown. However, other fuel cell systems such as a phosphoric acid fuel cell (PAFC) system are used. Alternatively, it may be a mode of being distributed to consumers including a molten carbonate fuel cell (MCFC) system.

1 is a block diagram showing a configuration of a collective power network system according to a first embodiment of the present invention. It is a block diagram which shows the structure which added the electrical storage equipment to the collective power network system concerning 1st Embodiment. It is a block diagram which shows the structural example of a polymer electrolyte fuel cell (PEFC) system. It is a block diagram which shows the structural example of a solid oxide fuel cell (SOFC) system. It is a block diagram for demonstrating a specific operation form. It is a block diagram for demonstrating a specific operation form. It is a flowchart which shows an example of the operation | movement flow of a collective power network system. It is a block diagram which shows the structure of the collective power network system concerning 2nd Embodiment of this invention. It is a block diagram which shows an example of an internal structure of a concentrated fuel gas supply apparatus. It is a block diagram which shows the structure of the collective power network system concerning 3rd Embodiment of this invention. It is a block diagram which shows the supply method of the electric power with respect to the conventional general household, business facilities, etc. FIG. It is a graph which shows the fluctuation state of electric power load, Comprising: It is a graph which shows the load fluctuation state of a detached house. It is a graph which shows the fluctuation state of electric power load, Comprising: It is a graph figure which shows the load fluctuation state in apartment houses.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Commercial gas supply system 10G Commercial gas supply source 11 Centralized fuel gas supply apparatus 12 Common gas system 20 PEFC system (distributed power supply)
30 SOFC system (distributed power supply)
40 General gas appliances 50 Gas engine (distributed power supply)
60 Solar power generation system (distributed power supply)
70 All-electric power load 80 Commercial power system 80M Shared power meter 81 Shared power system 82A-H Individual power meter 90 Power control device (control means)
91 Total demand monitoring unit 92 Total power generation monitoring unit 93 Comparison control unit A to H Consumers A, B, C, E, F, G First consumer group D, H Second consumer group J Linkage point

Claims (8)

A plurality of consumer groups existing in a predetermined local area including a first consumer group having a distributed power source and a second consumer group not having a distributed power source can supply power between the consumers. A shared power system and
The shared power system and the linkage point of the commercial power system,
Power can be supplied to each consumer in the local area from a distributed power source provided to each consumer in the first consumer group via the shared power system, and the commercial power A collective power network system characterized in that power can be supplied from a commercial power supply via a grid and the linkage point.   A power storage facility for storing electric power generated by a distributed power source provided in the first consumer group and / or electric power supplied from a commercial power source is connected to the shared power system. Item 4. The collective power network system according to Item 1. In the case where the first consumer group and / or the second consumer group is provided with gas equipment using gas as a fuel source,
A centralized fuel gas supply device is provided that collectively receives gas from a commercial gas supply source and individually supplies gas to a customer having the gas equipment via a shared gas system. The collective power network system described. A shared power monitoring unit for controlling the total amount of power generated by the distributed power source according to the total amount of power demand in the consumer group,
The shared power monitoring unit
A total demand monitoring unit for monitoring the total power demand in a group of consumers existing in the local area;
A total power generation monitoring unit for monitoring the total power generation in the first consumer group;
A comparison control unit that compares the total power demand with the total power generation and generates a control signal for controlling the total power generation so that the total power generation does not exceed the total power demand. A collective power network system according to any one of the above. In the case where the distributed power source provided in the first consumer group is classified into a first distributed power source in which the generated power can be controlled and a second distributed power source in which the generated power cannot be controlled,
The collective power network system according to claim 4, wherein the comparison control unit is configured to generate a control signal for controlling an amount of power generated by the second distributed power source.   The output of each distributed power source in the first consumer group is connected to the shared power system, and the generated power generated in each consumer of the first consumer group is temporarily all in the shared power system. The collective power network system according to claim 1, wherein the collective power network system is configured to be supplied.   The output of each distributed power source in the first consumer group is connected to the shared power system, and the generated power generated in each consumer in the first consumer group is consumed by the consumer. The collective power network system according to any one of claims 1 to 5, wherein a surplus that does not exist is configured to be supplied to the shared power system. A plurality of consumer groups existing in a predetermined local area including a first consumer group having a distributed power source and a second consumer group not having a distributed power source can supply power between the consumers. A shared power system and
An individual linkage point between each consumer existing in the local area and the commercial power system,
It is possible to supply power from a distributed power source provided to each consumer of the first consumer group via the shared power system, and to supply power from a commercial power source via the individual connection point A collective power network system comprising: an individual control means.

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