WO2011114422A1

WO2011114422A1 - Power supply system, power supply method, program, recording medium, and power supply controller

Info

Publication number: WO2011114422A1
Application number: PCT/JP2010/054340
Authority: WO
Inventors: 信行江崎; 秀信二村; 藤本　健
Original assignee: 株式会社正興電機製作所
Priority date: 2010-03-15
Filing date: 2010-03-15
Publication date: 2011-09-22
Also published as: CN102474104B; JPWO2011114422A1; JP5414082B2; CN102474104A

Abstract

Provided is a power supply system etc. which can stabilize and supply power to a load while a power generation source which generates an unpredictable amount of power is used as a power generation means that is electrically connected to a commercial system. The power generation source is employed in a manner similar to a power generation source which uses natural energy such as sunlight or wind power for example. A first power generation source, which generates an unpredictable amount of power, is provided together with a storage means and a second power generation source, which is able to vary the power supplied, as a distributed power source unit. When the power supply value of the first power generation source is less than a standard power value, which is the power value that should be output by the distributed power source unit, the power storage means and the second power generation source supply the shortage in the power value. When the power of the commercial system stops, the distributed power source unit becomes the standard power source, the use of another independent power source becomes possible, and the stable supply of power is further facilitated.

Description

POWER SUPPLY SYSTEM, POWER SUPPLY METHOD, PROGRAM, RECORDING MEDIUM, AND POWER SUPPLY CONTROL DEVICE

The present invention relates to a power supply system, a power supply method, a program, a recording medium, and a power supply control device, and more particularly to a commercial power supply source and a distributed power supply unit, wherein one of the commercial power supply source and the distributed power supply unit Or a power supply system capable of supplying power from both sides.

For example, as a means for supplying power to a load such as a home load, a grid-connected system has been proposed in which an independent power source such as a solar cell is electrically connected to the commercial grid in addition to the commercial grid (see Patent Document 1) .

On the other hand, the applicant has researched and developed a technology for effectively utilizing the power obtained by solar power generation and the like by including the storage means in the power generation system connected to the commercial system (see

Patent Documents

2 and 3, etc.) ).

JP 2000-92720 A Patent No. 3759151 Utility model registration No. 3122815

However, power generation means using natural energy such as solar light and wind power, for example, can not predict the amount of power generation. Therefore, it could not be a stable power supply source. In particular, in order to use it as a power supply source at the time of a blackout of a commercial system, it was a serious subject that it could not become a stable power supply source continuously.

Therefore, the present invention uses a power generation source whose power generation amount can not be predicted as a power generation means electrically connected to a commercial grid, such as a power generation source using natural energy such as sunlight or wind power. It is an object of the present invention to provide a power supply system or the like that enables a load to be supplied with power continuously and stably.

The invention according to claim 1 is a power supply system including a commercial power supply source and a distributed power supply unit and capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load, The distributed power supply unit includes: a first power generation source whose change in power value to be supplied is difficult to predict; a second power generation source which is different from the commercial power supply source and the first power generation source; When the first determination means compares the determination power value with the supply power value of the first generation power source and determines that the supply power value of the first generation power source is smaller than the determination power value, the second Second power generation control means for generating a power of a difference between a reference power value, which is a power value to be output by the distributed power supply unit, and a power supply value of the first power supply, with respect to the power generation source; The power supply value of the power generation source and the second power generation source is the reference power value And a storage power supply control means for supplying a power value of a difference between at least the reference power value and the supply power value of the first and second power sources to the power storage means, .

The invention according to claim 2 is the power supply system according to claim 1, wherein the commercial power supply source supplies power to the load through a first power supply path and a common path connected to the load. The first power supply path includes a commercial power switching unit capable of disconnecting the commercial power supply source, and the distributed power supply unit is connected to the load by the second power supply path and the common path. A third power source for supplying power and generating power using the commercial power supply source or / and the dispersed power source unit as a reference power source is connected to the common path, and the third power source is the reference power source. If the commercial power supply source is disconnected, the load from the third power supply via the connection point to the common path using the distributed power supply unit as a reference power supply. Third power supply to Further comprising a source control means.

The invention according to claim 3 is the power supply system according to claim 2, wherein, in the dispersed power supply unit, the first power source, the second power source, and the storage means are coupled by direct current, and the storage power supply is provided. The control means causes the storage means to be supplied with electric power when the combined DC power value is smaller than the reference power value, and the combined DC power value is larger than the reference power value. The power storage means stores electric power, and the second power supply path includes an inverter for converting direct current generated by the distributed power supply unit into alternating current, and the third power source is a reference power source. It is a power supply operated with a predetermined output by increasing the power supplied.

The invention according to claim 4 is the power supply system according to

claim

2 or 3, wherein the power supplied by the commercial power supply source, the distributed power supply unit, and the third power supply is adjusted to obtain the load. Means for adjusting the power supplied to the

The invention according to claim 5 includes a commercial power supply source and a distributed power supply unit, and power supply control in a power supply system capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load. In the method, the distributed power supply unit stores a first power generation source whose change in power value to be supplied is difficult to predict, a second power generation source which is different from both the commercial power supply source and the first power generation source, and stores power. A first determination step of determining whether the supply power value of the first power source is smaller than the determination power value, the first determination means further comprising: a possible storage means, and the distributed power supply unit further comprising; A second power generation control unit further included in the distributed power supply unit may be configured for the second power generation when the first determination unit determines that the power supply value of the first power generation is smaller than the determination power value. Output from the distributed power supply unit A second power generation control step of generating a power value of a difference between a reference power value which is a power value to be supplied and a power supply value of the first power generation source; Supplying at least the reference power value and the first and second power sources to the storage means when the supply power values of the one power source and the second power source are smaller than the reference power value. And a storage power supply control step of supplying a power value that is a difference from the power value.

The invention according to claim 6 includes a commercial power supply source and a distributed power supply unit, and power supply control in a power supply system capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load. In the method, the distributed power supply unit includes: a first power supply whose change in power value to be supplied is difficult to predict; a second power supply which is different from both the commercial power supply source and the first power supply; When the supply power value of the power generation source is smaller than the determination power value, a reference power value which is a power value to be output by the distributed power supply unit with respect to the second generation power source and a supply power value of the first generation power source A second power generation control means for generating power of a difference between the two, a storage means capable of storing power, and the supply power values of the first and second power sources are smaller than the reference power value, The storage means is at least A storage power supply control means for supplying a power value of a difference between the quasi power value and the power supply value of the first power source and the second power source, the commercial power supply source comprising: Power is supplied to the load through a common path connected to the load, and the first power supply path includes a commercial power switching unit capable of disconnecting the commercial power supply source, and the distributed power supply unit , The second power supply path and the common path to supply power to the load, and the common path includes a third power generation source using the commercial power supply source or / and the dispersed power source unit as a reference power source When the power supply is connected, and the third power supply control means included in the power supply system disconnects the commercial power supply source, the distributed power supply unit is used as a reference power supply for the third power supply. Connection point to the common route as Via a third generation source control step of supplying electric power to the load.

The invention according to claim 7 is a program for causing a computer to execute the power supply control method according to claim 5 or 6.

The invention according to claim 8 is a computer readable recording medium having the program according to claim 7 recorded thereon.

The invention according to claim 9 includes a commercial power supply source and a distributed power supply unit, and power supply control in a power supply system capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load. In the apparatus, the distributed power supply unit stores a first power generation source whose change in power value to be supplied is difficult to predict, a second power generation source which is different from both the commercial power supply source and the first power generation source, and stores power. And the first determination means compares the determination power value with the supply power value of the first generation power source and determines that the supply power value of the first generation power source is smaller than the determination power value A second power source that generates, to the second power source, a power of a difference between a reference power value, which is a power value to be output by the dispersed power source unit, and a supplied power value of the first power source. Control means, the first power source and the second power generation When the supplied power value is smaller than the reference power value, a power value of the difference between at least the reference power value and the supplied power value of the first and second power sources is supplied to the storage means. And an electric storage supply control means for supplying electric power.

The invention according to claim 10 includes a commercial power supply source and a distributed power supply unit, and power supply control in a power supply system capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load. It is an apparatus, The said distributed power supply part is the 1st generation power source whose change of the electric power value to supply is hard to predict, the 2nd generation power source which is different from the said commercial power supply source and also the said 1st generation power, When the supply power value of the power generation source is smaller than the determination power value, a reference power value which is a power value to be output by the distributed power supply unit with respect to the second generation power source and a supply power value of the first generation power source Second power generation control means for generating power of the difference between the first and second power generation means, storage means capable of storing electric power, and the supply power values of the first and second generation power sources are smaller than the reference power value. , For the storage means at least A storage power supply control means for supplying a power value of the difference between the reference power value and the power supply value of the first and second power sources, the commercial power supply source including a first power supply path and Power is supplied to the load through a common path connected to the load, and a commercial power switching unit capable of disconnecting the commercial power supply source exists in the first power supply path, and the distributed power supply unit Power is supplied to the load through the second power supply path and the common path, and power is generated on the common path using the commercial power supply source or / and the distributed power supply unit as a reference power source; A power source is connected, and the third power source is for stopping power generation when reverse power flow to the commercial power supply source is detected, and the commercial power supply source is disconnected. With respect to the third power source Source unit via the connection point to the common pathway as the reference power source to a third power source control means for supplying electric power to the load.

The first power source uses, for example, natural energy such as solar power generation or wind power generation, and is a power source whose power generation amount can not be predicted. Further, the second power source is, for example, a power generator capable of output adjustment in order to obtain a stable output in total according to the output of the first power source as a power supply system.

In addition, the output of the first power source may change rapidly, and the response speed of the second power source may not catch up. The storage means is capable of supplying stored power, for example, in quicker response than the second generator. The power value of the storage means supplied by the storage supply control means may directly output one equal to the reference power value, and the supply power of the first and second power sources may be stored in the storage means. . Further, the power supply value of the first power source or / and the second power source may be compensated by the power supply of the storage means to supply a reference power value as a whole.

Furthermore, the disconnection of the commercial power supply source is not only in the case where the commercial power supply source has an abnormality such as a blackout of the commercial power supply source, for example, the detection means reverses the distributed power supply unit to the commercial power supply source. It may be performed in consideration of the influence on the commercial power supply source, as in the case where it is detected that the power flow has occurred and the voltage has risen. This is because, when a large amount of natural energy such as solar power generation and fuel cells are introduced as distributed power sources, it is assumed that the parallel power supply source is decentralized to protect the commercial power supply source. In addition, even if the storage means switching means is provided which can disconnect the storage means, and the detection means detects reverse power flow from the storage means to the commercial power supply source, the storage means may be disconnected. Good.

Furthermore, the determination power value may be the same value as the reference power value. Also, the value may be higher or lower than the reference power value. For example, it is set to a value higher than the reference power value, and the determination power value is also changed according to the magnitude of the fluctuation of the power value of the first power source, and the power value of the first power source is decreased than the reference power value. It may be made to generate power of the 2nd generation power source before. In addition, it is set to a value lower than the reference power value, continuously measures the difference between the reference power value and the power value of the first generator, and changes the determination reference value according to the difference power. The determination reference value may be changed according to the remaining amount of the storage means. Furthermore, even if an output adjustable power generator is used for the second power source, there is usually a fixed adjustment range for the adjustment. The determination power value may be set in consideration of such an adjustment range of the second power source.

Furthermore, as the determination power value, another determination power value (start determination power value) for activating the second power source and another determination power value (stop determination power value) for stopping the second power source It may be provided as By doing this, it is possible to suppress the energy consumption by frequently starting and stopping the second power source when the power value supplied by the first power source fluctuates sharply.

According to the invention of each claim of the present application, a power generation source whose power generation amount can not be predicted because it uses natural energy such as solar power generation or wind power generation as the first power generation source electrically connected to the commercial power system Also in the case of using the second power source and the storage means, it is possible for the second power source and the storage means to supply power corresponding to the shortage of the reference power value. Therefore, it becomes possible to provide a high quality power supply power generation system capable of stably and continuously supplying electric power, and it becomes possible to plan a normal load peak cut etc. with certainty. In addition, it becomes possible to effectively utilize so-called zero emission power source utilizing natural energy, and it becomes easy to contribute to CO2 reduction.

Here, if only the second power source is configured to compensate the first power source, power shortage will occur during the time lag from when the second power source starts generating power until when the power is supplied. sell. When using a power source that uses natural energy as the first power source, such a situation is expected to occur naturally and frequently. However, when the storage means that does not need to generate power newly supplies power quickly, power can be stably supplied to the load regardless of the time lag until the second power supply supplies power. It becomes. In addition, since the second power source generates power, it is possible to continuously and stably supply power to the load before the power stored in the storage means reaches the bottom. That is, by the coexistence of the storage means and the second power source, unstable power supply of the first power source can be quickly and stably compensated.

On the contrary, for example, even when the powers supplied by the first power source and the second power source become excessive because the power source of the first power source generates an excessive amount of power, the storage means stores the extra power. Thus, power can be stably supplied to the load. Therefore, it becomes possible to equalize the unstable power supply of the first power source.

In the event of a commercial power outage, it is prohibited to supply power to the commercial grid for security reasons. According to the inventions of claims 2 and 6 of the present application, it is possible to continuously and stably supply power from the distributed power supply unit to the load after disconnecting the commercial system even when the commercial system fails. It becomes.

Further, according to the invention of claims 2 and 6 of the present application, the third power source is provided separately from the distributed power source unit. For example, fuel cells are mainly operated with a commercial power supply. As such, there is a power source that can not operate in the absence of another power source such as a commercial power source (referred to herein as a "reference power source"). According to the inventions of claims 2 and 6 of the present application, by connecting the third power source which is such a power source to the common path, the commercial power supply source is disconnected, and the power generation of the third power source is achieved. Even when stopped, the distributed power source unit can be restarted as a reference power source to continue power generation. This makes it possible to continuously supply a more stable power supply to the load.

Furthermore, according to the invention of claim 3 of the present application, it is possible to supply an alternating current to the load even when using a power supply coupled by direct current as the distributed power supply unit and the third power supply. It becomes. Therefore, even when the commercial system is disconnected, it is possible to stably supply alternating current to the load.

Furthermore, according to the invention of claim 4 of the present application, the adjustment means can adjust the power supplied from the plurality of power supply sources to the load. Therefore, it is possible to adjust the amount of power supplied from each power supply source, in consideration of the remaining charge amount of the storage means, the load on each power generation source, and the like. This makes it possible to realize a practical energy management system (EMS).

FIG. 1 is a block diagram showing the configuration of a power supply system 1 according to an embodiment of the present invention. It is a flowchart which shows the operation example at the time of the normal time of the power supply system 1 which concerns on embodiment of this invention. 5 is a graph showing an example of the relationship between the fluctuation of the power supply value of the photovoltaic power generation panel 25 and the power supply by the distributed power supply unit 5. In the electric power supply system 1 which concerns on embodiment of this invention, it is a flowchart which shows the operation example at the time of the power failure of the commercial power supply source 3. FIG.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an outline of a configuration of a power supply system 1 according to an embodiment of the present invention.

The power supply system 1 includes a commercial power supply source 3 (an example of “commercial power supply source” in the claims of the present application) which is a commercial system, and a distributed power supply unit 5 (an example of the “distributed power supply unit” in the claims of the present application). It is possible to supply power from one or both of the commercial power supply source 3 and the distributed power supply unit 5 to the load 11 (an example of the “load” in the present application).

The commercial power supply source 3 is common to the first power supply path 13 from the commercial power supply source 3 to the connection point 14 and the connection point 14 to the load 11 shown in FIG. Power is supplied by path 15. The first power supply path 13 includes a switch 17 as a commercial power switching unit capable of disconnecting the commercial power supply 3. Furthermore, the switch 17 is not only used when there is an abnormality in the commercial power supply 3 such as a blackout of the commercial power supply 3, for example, but it is detected by the detecting means not shown. As in the case where it is detected that the reverse power flow has occurred to 3 and that the voltage has risen, it may be performed in consideration of the influence on the commercial power supply 3 as well. This is because, when a large amount of natural energy such as solar power generation is introduced as the distributed power supply unit 5, it is assumed that the parallel power supply source can be disconnected to protect the commercial power supply source.

In addition, the distributed power supply unit 5 supplies power to the load 11 through the second power supply path 19 and the common path 15 from the DC coupling 31 to the connection point 14 shown in FIG. The second power supply path 19 includes a switch 21 capable of disconnecting the distributed power supply unit 5.

The power supply system 1 controls the fuel cell 7 (an example of the “third power source” in the claims of the present application) that generates power using the commercial power supply source 3 and / or the distributed power supply unit 5 as a reference power source. Control device 9 (an example of "third power generation control means" in the claims of the present application).

Fuel cells are generally power sources operated at constant output. This is because if the output is fluctuated, the elements to be adjusted such as the amount of heat release and the amount of hydrogen are diverse, and the efficiency becomes worse. In addition, a generator such as a fuel cell or a gas engine generator that does not allow reverse power flow has a problem that the power generation needs to be narrowed down when the power used by the load 11 is low, which also contributes to poor operation. Fuel cells are mainly used to supply power by linking to a commercial power system, and in order to supplement the commercial power supply source 3 focusing only on the relationship with the power of the commercial power supply source 3 , And are connected in parallel to the photovoltaic panel 25.

In the present embodiment, the fuel cell 7 is connected to the common path 15 at the connection point 20 via the switch 22. The fuel cell 7 generates power using the commercial power supply source 3 and / or the distributed power supply unit 5 as a reference power supply, and increases the supplied power. When the commercial power supply source 3 is disconnected, the fuel cell 7 supplies power to the load 11 via the connection point 20 to the common path 15 using the distributed power supply unit 5 as a reference power supply. The power supply system 1 includes a sensor 23 that monitors the reverse flow of power supplied from the fuel cell 7 to the commercial power supply 3 and notifies the control device 9 of the reverse flow. The sensor 23 is connected to the common path 15 at a connection point 24 closer to the commercial power supply 3 than the connection point 20. When the reverse flow is detected by the sensor 23, the fuel cell stops its operation in order to prevent the isolated operation. Therefore, in the present embodiment, the fuel cell 7 is connected not to the first power supply path 13 but to the common path 15 in order not to detect reverse power flow to the commercial power supply source 3 due to selling electricity or the like.

The distributed power supply unit 5 is a photovoltaic power generation panel 25 (one example of the “first power generation source” in the claims of the present application) that generates power using sunlight, and a battery 27 capable of storing power generation from at least the photovoltaic power generation panel 25. (An example of the "power storage means" in the claims of the present application), an output adjustable generator 29 (an example of the "second power source" in the claims of the present application) capable of changing the voltage and frequency of power generation A DC coupling 31 which is a set of connection points at which currents from a plurality of power supply sources merge, a junction box 33 which combines power supply paths from the plurality of solar panels 25 into one path, and a solar panel A switch 35 capable of demultiplexing 25, a PV D / D converter 37 for transforming the photovoltaic panel 25, a switch 39 capable of decoupling the battery 27, and a battery D / D co-converter for transforming the battery 27 The generator output command is given to the inverter 41, the switch 43 capable of disconnecting the output adjustable generator 29, the generator A / D converter 45 for transforming the output adjustable generator 29, and the output adjustable generator 29 A controller 47 is provided.

In this embodiment, it is assumed that the output of the photovoltaic panel 25 is 50 kW, the storage amount of the battery 27 is 50 kWh, and the output of the power adjustable generator 29 is 50 kVA. In addition, the thing of another specification may be used for the solar power generation panel 25, the battery 27, and the output adjustable generator 29. FIG.

The DC coupling 31 electrically connects the photovoltaic power generation panel 25, the battery 27, and the power adjustable generator 29 as direct current.

The photovoltaic panel 25 is connected to the DC coupling 31 via the junction box 33, the switch 35 and the PV D / D converter 37. The PV D / D converter 37 always matches the impedance between the photovoltaic panel 25 and the load connected to the photovoltaic panel 25 to maximize power tracking (MPPT: maximum power point tracking) function Have.

The battery 27 is connected to the DC coupling 31 via the switch 39 and the battery D / D converter 41. The battery D / D converter 41 has a function as storage control means for controlling the charging of the battery 27, a function as storage storage control means for controlling the discharge, and a function as storage charging buck-boost means for controlling the voltage of the battery 27. . The switch 39 capable of disconnecting the battery 27 disconnects the battery 27 when a detection means (not shown) detects a battery abnormality such as an abnormal rise of the discharge voltage from the battery 27.

The power adjustable generator 29 is connected to the DC coupling 31 via the switch 43 and the generator A / D converter 45. The generator A / D converter 45, like the PV D / D converter 37, has an MPPT function that maximizes the output of the output adjustable generator 29. Here, although the power adjustable generator 29 generates alternating current, it is converted to direct current by the AC / DC converter function of the generator A / D converter 45, and direct current is supplied to the DC coupling 31.

Further, the control device 47 ("second power generation control means" in the claims of this application) in this embodiment, as a second power generation control means, gives a generator output command to the output adjustable generator 29.

The direct current supplied to the DC coupling by the photovoltaic panel 25, the battery 27 and the power adjustable generator 29 is supplied to the load 11 by the second power supply path 19 and the common path 15. The second power supply path 19 connects the DC coupling 31 and the common path 15. On the second power supply path 19, a capacitor 49 for equalizing DC ripple, which is a fine wave type signal, a main inverter 51 for supplying power from the distributed power supply unit 5 at normal times, and a commercial power supply source 3 There is a stand-alone inverter 53 for supplying power from the distributed power supply unit 5 at the time of power failure, and switches 55 and 57 which are stationary switches and high-speed switches.

Under the current legal system, it is prohibited to sell power once charged from the commercial grid. Therefore, a configuration in which the solar power generation panel 25 is directly connected to the first power supply path 13 is also conceivable for the sale of electricity. However, since the output of the photovoltaic panel 25 utilizes natural energy, the power supplied depends on the natural environment and changes unpredictably. In order to stably supply power to the load 11, it is necessary to cover the point that the power supplied by the photovoltaic panel 25 is unpredictable. Therefore, in the present embodiment, the distributed power supply unit 5 is configured to include the photovoltaic panel 25. In the present embodiment, in order to realize the sale of electricity, for example, the switch 35 does not pass the power generated by the photovoltaic panel 25 to the commercial power supply source 3 via the converter via the DC coupling 31. It is possible to make it possible to sell electricity without passing through the DC coupling 31 by switching to be able to directly output to.

When the detection means (not shown) detects an abnormal rise in reverse flow and reverse flow voltage from the storage means to the commercial power supply source 3, the main inverter 51, stand-alone inverter 53, switch 55, switch The power supply from the distributed power supply unit 5 is stopped by the switch 57 or the switch 21.

Here, both the main inverter 51 and the stand-alone inverter 53 may operate as the "first determination means" in the claims of the present application. As a first determination means, it is determined whether or not the supplied power value P1 of the photovoltaic panel 25 is equal to _one of two determination power values P _{size 1} and P _{size 2} (P _{size 1} > P _{size 2} ). Do. Further, as a second determination means, it may be determined whether or not the supplied power value P ₁ + P ₂ of the solar power generation panel 25 and the output adjustable generator 29 falls below a predetermined reference power value P _basis . Furthermore, as the third determination means, the main inverter 51 and the stand-alone inverter 53 may also determine whether or not the commercial power supply source 3 has a power failure.

In normal times, the direct current power of the distributed power supply unit 5 is converted into alternating current by the main inverter 51 through the path to which the capacitor 49 is connected, and passes through the switch 55. At the time of a power failure of the commercial power supply source 3, the

switches

55 and 57 switch the circuit, and the DC power supplied by the distributed power supply unit 5 is converted to AC by the stand-alone inverter 53 and passes through the switch 57 to supply the second power. It is supplied to the load 11 through the path. Here, the main inverter 51 controls the power by phase control. On the other hand, the stand-alone inverter 53 can use the distributed power supply unit 5 as a reference power supply for the power supply 7 by controlling the power by voltage control.

Moreover, the main inverter 51 and the stand-alone inverter 53 are both examples of the "adjustment means" of this-application claim. As the adjustment means, in cooperation with the control device 9 and the control device 47, the power supplied to the load 11 by the commercial power supply 3, the power adjustable generator 29 and the fuel cell 7 is adjusted. Under normal conditions, the main inverter 51 stably supplies the reference power value to the distributed power supply unit 5 according to the power supplied by the solar power generation panel 25, the battery 27 and the output adjustable generator 29 are supplied to the control device 47. Control the power supplied. At the time of a power failure of the commercial power supply source 3, the stand-alone inverter 53 responds to the power supplied by the photovoltaic power generation panel 25 and the power supplied by the fuel cell 7 which normally supplies a constant power to supply the power required by the load. Then, the control device 47 controls the power supplied by the battery 27 and the power adjustable generator 29.

Hereinafter, the normal operation of the power supply system 1 will be described with reference to FIG. FIG. 2 is a flow chart showing an example of normal operation of the power supply system 1 according to the embodiment of the present invention.

First, in step S1, whether the main inverter 51 or a stand-alone inverter 53 as a first determination unit, supplying electric power value P ₁ of the photovoltaic panel 25 is outputted adjustable generator 29 stops the determination power value _{P-size 1} or not Determine if When it is determined that P ₁ PP _{size 1} , in step S2, the main inverter 51 or the stand-alone inverter 53 causes the control device 47 to stop the output adjustable generator 29, and proceeds to step S5.

If it is not determined that P ₁ PP _{size 1} in step S1, the main inverter 51 or the stand-alone inverter 53 as the first determination means can adjust the output power value P ₁ of the photovoltaic panel 25 in step S3. It is determined whether or not the determined power value P _{size 2} for activating the generator 29 is less than or equal to _two . When it is determined that P ₁ ≦ P _{size 2} , in step S4, the control device 47 issues a generator output command to the output adjustable generator 29 to generate electric power. If it is not determined in step S3 that P ₁ ≦ P _{size 2} , the command is not issued to the output adjustable generator 29, and the process proceeds to step S5.

In step S5, whether or not the main inverter 51 or the stand-alone inverter 53 as the second determination means has the supplied power value P ₁ + P _{2 of} the solar power generation panel 25 and the output adjustable generator 29 smaller than the reference power value P _group. Determine if When it is determined that P ₁ + P ₂ <P _group , the main inverter 51 or the stand-alone inverter 53 causes the control device 47 to start discharging the battery 27 from the battery 27 in step S6 and the flow ends. Do. Here _release power value P _bar discharged from the battery 27, the power P _group supply power value of solar panels 25 and output adjustable generator 29 is insufficient to the reference power value - equal to (P ₁ + P _2). In step S5, if it is determined that P ₁ + P 2 _<P _group, the power from the battery 27 ends the flow without being supplied.

Since the battery 27 already stores the electric power supplied from the photovoltaic power generation panel 25 and / or the commercial power supply source 3, supplying the shortage of the reference electric power value more quickly than the power adjustable generator 29 Is possible. Therefore, it is possible to stably supply power to the load 11 regardless of the time lag until the power adjustable generator 29 supplies power. On the contrary, for example, when the solar power generation panel 25 and the power adjustable generator 29 excessively supply power by the solar power generation panel 25 generating an excessive amount of power, the storage means stores the extra power. Thus, the power can be stably supplied to the load 11. Moreover, when the power adjustable generator 29 generates power, the power can be stably supplied to the load 11 before the power stored in the battery 27 reaches the bottom. In other words, stable power supply is realized by the battery 27 for short cycle fluctuation with respect to unstable power supply of the solar power generation panel 25 and stable by the power adjustable generator 29 for long cycle fluctuation. It can be said that power supply has been realized.

As described above, even if the power supply from the photovoltaic panel 25 fluctuates to an unpredictable level, the battery 27 and the output adjustable generator 29 serve as the power supply source in steps S1 to S6 of FIG. 2. Adjust and supply the shortfall with the reference power value by making use of each feature of. As a result, the distributed power supply unit 5 can function as a stable power supply source for the load 11.

Here, the details of the operation of the power adjustable generator 29 will be described with reference to FIG. Figure 3 is a diagram showing a relationship between the supplied power value P ₁ and starting and stopping of the output adjustable generator 29 of solar panels 25. Four cases are shown in FIGS. 3A and 3B according to the relationship between the change with time of the power supply value of the photovoltaic power generation panel 25 and the determination power value. In FIGS. 3A and 3B, the horizontal axis represents time, and the vertical axis represents a power value.

The reason for providing two determination power values separately for determining the start and stop of the power adjustable generator 29 is as follows. Since photovoltaic panel 25 that utilizes natural energy, the supply power value P ₁ is unpredictable. Of course, little by little touch situation around the reference power value P _groups or one determination power value _P-size value of P ₁ is changed also conceivable. In addition, frequent start / stop of the power adjustable generator 29 consumes a great deal of energy. Therefore, _two P- _{size 1} and P- _{size 2} are provided as determination power values. Thus, if was possible to prevent also frequently repeated starting and stopping of the output adjustable generator 29 as the value of P ₁ is changed in small steps.

First, large with reference to FIG. 3 (a), is smaller than _{P-size 2} decreases the supply power value P ₁ of the solar panels 25 were greater than the _{P-size 1,} then than _{P-size 1} again Think about the case. The output adjustable generator 29 is stopped at the time when P ₁ > P _size ₂ until time T ₂ . In time _{T 2,} where P ₁ is _P 1 = _{P-size 2} decreases, the output adjustable generator 29 is activated. After that, at time T ₄ at which P ₁ increases and P ₁ = P _{size 1} again, the available output generator 29 is stopped. In Case 1, the output adjustable generator 29 the reference power value P _based largely interrupted at time T ₃ after it supplies power. The battery 27 compensates for the shortfall to the reference power value P _group until the output adjustable generator 29 starts up, and stores an excess supply amount exceeding the reference power value P _group . On the other hand, for example, as shown in FIG. 3 (b), the supply power value P ₁ of the solar panels 25 were greater than the _{P-format 1} is reduced not reduced to _{P-size 2,} then than _{P-size 1} again If the increase is shortage of the reference power value P _group compensates the discharge from the battery 27, it is not necessary to start the output adjustable generator 29.

As described above, by setting two judgment power values, the battery 27 and the power adjustable generator 29 compensate for the unpredicted fluctuation of the power supply site of the photovoltaic power generation panel 25, and the power adjustable generator It becomes possible to control energy consumption by frequently starting and stopping 29.

Here, although the output adjustable generator 29 is adjustable in output, normally, the lowest supply power value exists as a lower limit of the output adjustable range, for example, about 30% of the maximum output. Therefore, if the output adjustable generator 29 is started to a level slightly below the reference power value or the judgment power value, the supplied power becomes significantly excessive. Therefore, by setting the value near the minimum supply power value of the output adjustable generator 29 to, for example, the determination power value P _{size 2} for activating the output adjustable generator 29, a significant excess of the supplied power can be obtained. It is possible to prevent.

Subsequently, a state in which the distributed power supply unit 5 stably supplies the reference power value P _group will be illustrated using FIG. 3 (c). Figure 3 (c) is a graph showing an example of the relationship between the power supply due to variations with distributed power supply unit 5 of the supply power value P ₁ of the solar panels 25. In FIG. 3 (c), the horizontal axis represents time, and the vertical axis represents the supplied power. The P _group is a reference power value that the distributed power supply unit 5 is required to stably supply. The P _{size 1} is a determination power value for stopping the output adjustable generator 29. The P _{size 2} is a determination power value for starting the output adjustable generator.

In FIG. 3 (c), the time t ₁ before the supply power value P ₁ of the photovoltaic panel 25 is below the _{P-size 1,} outputs adjustable generator 29 is started and outputs adjustable power The unit 29 supplies the electric energy S ₁ (indicated by a mesh area in FIG. 3C) for the shortage with the P _group . P ₁ increases, _{P-format 1} at time _{t 1,} P _group in time _{t 2, the} at time _{t 3} to reach the _{P-size 2.} Smaller than shortage minimum output of the output adjustable generator 29 of the P _group from the time t ₁ over the t _3, the excess power amount S ₂ caused by the supply of the output adjustable generator 29. The excess power amount S ₂ is stored in the battery 27.

At time _{t 3,} since _{the P 1} reaches the _{P-size 1,} the output adjustable generator 29 is stopped. Thereafter, P ₁ is started to decline after the P ₁ exceeds the _{P-size 1,} at time t ₈ until reduced to _{P-size 2,} output adjustable generator 29 remains stopped. The excess power amount _{S 3} exceeds the P _group _{P 1} from the time _{t 2} from to _{t 5} and time _{t 6} to _{t 7} is stored in the battery 27. From time _{t 5} from to _{t 6} and time _{t 7} to _{t 8} supplies a shortage of the electric energy _{S 4} of the battery 27 and P _group.

The output adjustable generator 29 to reach _{P-size 2} at time t ₈ is activated, the output adjustable generator 29 there is a time lag before it starts to power supply, in practice the power supply from the time t ₉ is Is started. There is also a need for some time until the output adjustable generator 29 even after the power supply has been started can supply the difference between the P _group and P _1. Therefore, among the amount of power less than P _group _{P 1} from time _{t 7} to the time _{t 11,} the output adjustable generator 29 supplies electric energy _{S 6} (indicated by hatching in FIG. 3 (c)) the amount of power S ₅ not in time, the battery 27 is supplied can be more quickly the power supply.

After time _{t 11,} _{P 1} at time _{t 12} is output adjustable generator 29 is stopped exceeds _{P-size 1.} The excess power amount _{S 7} from the time t10 to supply the output adjustable generator 29 to _{t 12} the battery 27 is a power storage.

After time t _12, P ₁ interrupt a very short time only P _group is surplus power battery 27 has been power storage by providing power higher than P _group, from the time t ₁₃ to t _14, P _{Suppose that the size} is smaller than ₂ . At this time, if the main inverter 51 or the stand-alone inverter 53 can not detect that the value of P ₁ has become small, the output adjustable generator 29 is not started. The electric energy S ₈ of the shortfall less than the P _group between t ₁₃ and t ₁₄ is supplied by the discharge from the battery 27. As described above, the detection accuracy is set as needed (for example, depending on whether short-periodic or long-periodic correspondence is necessary). Similarly, even if the main inverter 51 or the stand-alone inverter 53 detects, if P ₁ has a value larger than P _{size 1} before the controller 47 starts the output adjustable generator 29, the output adjustable generator 29 may stop the start.

Then, the operation | movement at the time of the power failure of the electric power supply system 1 is demonstrated using FIG. FIG. 4 is a flowchart showing an operation example at the time of a power failure of the commercial power supply source 3 in the power supply system 1 according to the embodiment of the present invention.

In step SS1, the main inverter 51 or the stand-alone inverter 53 as determination means determines whether or not the commercial power supply source 3 has a power failure. If it is not determined that there is a power failure, the flow is ended. When it is determined that a power failure has occurred, the switch 17 disconnects the commercial power supply source 3 in step SS2, and the control device 9 stops the fuel cell 7 whose isolated operation is prohibited. Subsequently, in step SS3, the fuel cell 7 resumes the power supply using the dispersed power supply unit 5 as a reference power supply, and the flow ends. The restart of the fuel cell 7 further facilitates the stable supply of power to the load 11.

In the embodiment, as an example of the first power generation source whose power generation amount can not be predicted, a wind power generation device may be used other than the solar power generation panel 25, for example, or a combination of these power generation devices It may be

Also, as the third power source, other than fuel cell 7, as long as it is a distributed power source that supplies electric power stably, a power source by other power generation means may be used, and naturally, RDF (waste solidified fuel) is used A power generation system such as a conventional power generation system or a cogeneration system that reuses the waste heat of power generation may be used.

Furthermore, in steps S1 to S6 of the embodiment, it is sufficient that the power supply from the photovoltaic power generation panel 25 can be supplemented from other power supply sources, and the discharge from the battery 27 is more than the power generation start of the power adjustable generator 29. It may be started earlier, or power generation may be started at the same time. That is, steps S5 and S6 may be performed prior to steps S1 to S4.

Furthermore, the reference power value P _group which is the power to be supplied by the distributed power supply unit 5 may be a fluctuating value. As long stable power supply to the power supply system 1 a load 11 according to the present embodiment, for example, when the power from the utility power is supplied, the reference power value P _group is a value that varies commercial the sum of the power and the reference power value P _group supplied from the system may be a constant. Further, when the electric power from the utility power is supplied, the reference power value P _group may be a value that follows the power supply value P ₁ that varies the photovoltaic panel 25.

Furthermore, the determination power values P _{size 1} and P _{size 2} need not be fixed values, and may be variable values. For example, the reference power value P _group as a value to follow the power supply value P ₁ that varies the photovoltaic panel 25, may determine the two determination power value (for example ± 10% of the reference power value, etc.). By making the reference power value P _base , the judgment power value P _{size 1} and the P _{size 2} follow the power supply value P ₁ of the solar power generation panel 25 as described above, the system operation does not start the output adjustable generator 29 as much as possible. It becomes possible.

Furthermore, before the control device 9 stops the power supply 7, the

switches

55 and 57, which are high-speed switches, switch the power supply from the main inverter 51 to the power supply from the stand-alone inverter 53 to use the distributed power supply unit 5 as a reference power supply. In such a case, power may be supplied to the load 11 without stopping the power supply 7.

Furthermore, the main inverter 51 and the stand-alone inverter 53 may be physically integrated, and may be switched between normal time and power outage of the commercial system.

Furthermore, the functions of the first determination means, the second determination means, and the adjustment means may be borne by configurations other than the main inverter 51 and the stand-alone inverter 53.

Furthermore, the control device 9 and the control device 47 may be combined into one control device. In addition, the control device 47 may be configured to have a control function for the power supply means of the PV D / D converter 37, the battery D / D converter 41, or the generator A / D converter 45.

Furthermore, it is sufficient that the DC coupling 31 compensates for the power supplied by the photovoltaic panel 25 and the power is supplied from the power adjustable generator 29 instead of the power adjustable power generator 29 which is an AC power source. A direct current source may be used. At this time, the AC / DC converter function of the generator A / D converter 45 becomes unnecessary.

Furthermore, the DC coupling 31 may be connected as long as currents from the photovoltaic power generation panel 25, the battery 27, and the power adjustable generator 29 which are a plurality of power supply sources included in the distributed power supply unit 5 are connected at the same voltage level. The number of connection points and the connection location are not limited.

Furthermore, the position of the DC / AC inverter may be configured to convert the power supplied from, for example, the photovoltaic panel 25, the battery 27, and the power adjustable generator 29 into alternating current and collect it at one site.

Furthermore, the load 11 may be configured to supply power to the load 11 by direct current.

REFERENCE SIGNS LIST 1 power supply system, 3 commercial power supply source, 5 distributed power supply unit, 7 fuel cell, 9 control device, 11 load, 13 first power supply path, 15 common path, 19 second power supply path, 25 solar power generation panel , 27 battery, 29 output adjustable generator, 31 DC coupling, 47 controller, 51 main inverter, 53 stand-alone inverter

Claims

A power supply system comprising a commercial power supply source and a distributed power supply unit, wherein power can be supplied to a load from one or both of the commercial power supply source and the distributed power supply unit,
The distributed power supply unit
A first generation power source for which it is difficult to predict changes in the supplied power value;
A second generator different from the commercial power supply source and the first generator;
Storage means capable of storing electric power;
When the first determination means compares the determination power value with the supply power value of the first generation power source and determines that the supply power value of the first generation power source is smaller than the determination power value, the second generation power generation method Second power generation control means for generating a power of a difference between a reference power value which is a power value to be output by the distributed power supply unit and a power supply value of the first power supply to the power supply;
When the supply power values of the first and second power sources are smaller than the reference power value, at least the reference power value and the first and second power sources are stored in the storage unit. And a storage power supply control unit configured to supply a power value of a difference from the power supply value of the power supply system.
The commercial power supply source supplies power to the load through a first power supply path and a common path connected to the load,
In the first power supply path, there is a commercial power switching unit capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through the second power supply path and the common path,
The common path is connected to a third power source that generates power using the commercial power supply source or / and the dispersed power source unit as a reference power source,
The third power source does not generate power without the reference power source,
When the commercial power supply source is disconnected, the third power source is supplied with power to the load via the connection point to the common path, using the dispersed power source unit as a reference power source. The power supply system according to claim 1, comprising power supply control means.
In the distributed power supply unit,
The first power source, the second power source, and the storage means are coupled by direct current,
The storage power supply control means causes the power storage means to supply power when the combined DC power value is smaller than the reference power value, and the combined DC power value is higher than the reference power value. When it is large, the power is stored in the storage means,
In the second power supply path, there is an inverter that converts direct current generated by the distributed power supply unit into alternating current;
The power supply system according to claim 2, wherein the third power source is a power source which increases the power supplied by the reference power source and is operated at a predetermined output.
The power supply according to claim 2 or 3, further comprising: adjustment means for adjusting the power supplied to the load by adjusting the power supplied by the commercial power supply source, the distributed power supply unit, and the third power source. Power supply system.
A power supply control method in a power supply system comprising a commercial power supply source and a distributed power supply unit, wherein power can be supplied to a load from one or both of the commercial power supply source and the distributed power supply unit,
The distributed power supply unit
A first generation power source for which it is difficult to predict changes in the supplied power value;
A second generator different from the commercial power supply source and the first generator;
And storage means capable of storing electric power;
A first determination step of determining whether or not a first determination unit included in the distributed power supply unit determines whether a supplied power value of the first power source is smaller than a determination power value;
When the first determination unit determines that the second generation power control unit included in the distributed power supply unit has a supply power value of the first generation power is smaller than the determination power value, the second generation power unit A second power generation control step of generating a power value of a difference between a reference power value, which is a power value to be output by the distributed power supply unit, and a supplied power value of the first power supply;
When the storage power supply control means included in the dispersed power source unit is smaller than the reference power value when the supply power values of the first power source and the second power source are smaller than at least the reference power value. And a storage power supply control step of supplying a power value of a difference between the first power source and the power supply value of the second power source.
A power supply control method in a power supply system comprising a commercial power supply source and a distributed power supply unit, wherein power can be supplied to a load from one or both of the commercial power supply source and the distributed power supply unit,
The distributed power supply unit
A first generation power source for which it is difficult to predict changes in the supplied power value;
A second generator different from the commercial power supply source and the first generator;
When the supply power value of the first power source is smaller than the determination power value, a reference power value, which is a power value to be output by the distributed power supply unit, and a first power source of the second power source. Second power generation control means for generating power of a difference between the supplied power values;
Storage means capable of storing electric power;
When the supply power values of the first and second power sources are smaller than the reference power value, at least the reference power value and the first and second power sources are stored in the storage unit. Storage power supply control means for supplying a power value of a difference from the supplied power value of
The commercial power supply source supplies power to the load through a first power supply path and a common path connected to the load,
In the first power supply path, there is a commercial power switching unit capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through the second power supply path and the common path,
The common path is connected to a third power source that generates power using the commercial power supply source or / and the dispersed power source unit as a reference power source,
Third power generation control means included in the power supply system is connected to the common path using the distributed power supply unit as a reference power supply with respect to the third power generation when the commercial power supply source is disconnected. A power supply control method, comprising: a third power generation control step of supplying power to the load via a point.
The program for making a computer perform the electric power supply control method of Claim 5 or 6.
The computer-readable recording medium which recorded the program of Claim 7.
A power supply control device in a power supply system including a commercial power supply source and a distributed power supply unit and capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load,
The distributed power supply unit
A first generation power source for which it is difficult to predict changes in the supplied power value;
A second generator different from the commercial power supply source and the first generator;
And storage means capable of storing electric power;
When the first determination means compares the determination power value with the supply power value of the first generation power source and determines that the supply power value of the first generation power source is smaller than the determination power value, the second generation power generation method Second power generation control means for generating a power of a difference between a reference power value which is a power value to be output by the distributed power supply unit and a power supply value of the first power supply to the power supply;
When the supply power values of the first and second power sources are smaller than the reference power value, at least the reference power value and the first and second power sources are stored in the storage unit. And power storage control means for supplying a power value which is a difference between the power supply value and the power supply control value.
A power supply control device in a power supply system including a commercial power supply source and a distributed power supply unit and capable of supplying power from one or both of the commercial power supply source and the distributed power supply unit to a load,
The distributed power supply unit
A first generation power source for which it is difficult to predict changes in the supplied power value;
A second generator different from the commercial power supply source and the first generator;
When the supply power value of the first power source is smaller than the determination power value, a reference power value, which is a power value to be output by the distributed power supply unit, and a first power source of the second power source. Second power generation control means for generating a power difference with the supplied power value;
Storage means capable of storing electric power;
When the supply power values of the first and second power sources are smaller than the reference power value, at least the reference power value and the first and second power sources are stored in the storage unit. Storage power supply control means for supplying a power value of a difference from the supplied power value of
The commercial power supply source supplies power to the load through a first power supply path and a common path connected to the load,
In the first power supply path, there is a commercial power switching unit capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through the second power supply path and the common path,
The common path is connected to a third power source that generates power using the commercial power supply source or / and the dispersed power source unit as a reference power source,
The third power source is to stop power generation when reverse power flow to the commercial power supply source is detected,
When the commercial power supply source is disconnected, a third of the third power sources is supplied with power to the load via a connection point to the common path using the distributed power source unit as a reference power source. A power supply control device comprising a power generation control means.