JPWO2011114422A1 - Power supply system, power supply method, program, recording medium, and power supply control device - Google Patents

Abstract

For example, a power generation unit that uses a natural energy source such as solar power or wind power, and a power generation unit that is electrically connected to a commercial power system and whose power generation amount is unpredictable is used. An object of the present invention is to provide a power supply system and the like that can stably supply power. The distributed power supply unit includes a first power generation unit whose power generation amount is unpredictable and a second power generation unit that can vary the power storage means and the power to be supplied. When the power value is smaller than the reference power value, which is the power value, the power storage means and the second power generation source supply the insufficient power value. At the time of a power failure in a commercial system, the distributed power supply unit becomes a reference power supply, so that another independent power supply can be used, and the stable supply of power is further facilitated.

Description

  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 in particular, includes a commercial power supply source and a distributed power supply unit, and one of the commercial power supply source and the distributed power supply unit for a load. Alternatively, the present invention relates to a power supply system that can supply power from both sides.

  For example, as a means for supplying electric power to a load such as a household load, a grid-connected system that electrically connects an independent power source such as a solar battery to a commercial system in addition to the commercial system has been proposed (see Patent Document 1). .

  On the other hand, the applicant has researched and developed a technique for effectively using electric power obtained by solar power generation or the like by including power storage means in a power generation system connected to a commercial system (see Patent Documents 2 and 3, etc.). ).

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

  However, for example, power generation means using natural energy such as sunlight and wind power cannot predict the power generation amount. Therefore, it could not be a stable power supply source. In particular, in order to use as a power supply source at the time of a power failure in a commercial system, it has been a serious problem that the power supply source is not continuously stable.

  Therefore, the present invention uses a power generation source whose power generation amount is unpredictable as a power generation means electrically connected to a commercial system, such as a power generation source using natural energy such as sunlight and wind power. An object of the present invention is to provide a power supply system or the like that can stably and stably supply power to a load.

  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 source that is difficult to predict a change in power value to be supplied; a second power source that is different from both the commercial power source and the first power source; and a power storage unit that can store power. The second determination unit 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 generation control means for generating a difference power between a reference power value, which is a power value to be output by the distributed power supply unit, and a supply power value of the first power generation, with respect to the power generation; The power supply value of the power generation source and the second power generation source is the reference power value. If also small, relative to said storage means, and a power storage supply control means to supply the electric power value of the difference between at least the power reference value and the supply power value of the first power source and the second power source.

  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. In the first power supply path, there is a commercial power switching means 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 that generates power using the commercial power supply source and / or the distributed power source unit as a reference power source is connected to the common path, and the third power source is connected to the common power source. If the commercial power supply source is disconnected, the load is connected to the third power source via the connection point to the common path with the distributed power source as a reference power source. Power generation to supply power to Further comprising a control means.

  The invention according to claim 3 is the power supply system according to claim 2, wherein in the distributed power supply unit, the first power generation power source, the second power generation power source, and the power storage means are coupled with each other in a direct current, The control means causes the power storage means to supply power when the combined DC power value is smaller than the reference power value, and when the combined DC power value is larger than the reference power value. Is for storing power in the power storage means, and the second power supply path includes an inverter for converting the direct current generated by the distributed power source into alternating current, and the third power source is a reference power source. This is a power source that increases the power to be supplied and operates at a predetermined output.

  The invention according to claim 4 is the power supply system according to claim 2 or 3, wherein the load supplied by adjusting the power supplied from the commercial power supply source, the distributed power supply unit, and the third power generation source is adjusted. Adjusting means for adjusting the power supplied to.

  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 electric power, a first power supply in which a change in power value to be supplied is difficult to predict, a second power supply different from both the commercial power supply source and the first power supply, and power A first determination step of determining whether or not a power supply value of the first generation power source is smaller than a determination power value; The second power generation control means further provided in the distributed power supply unit, when the first determination means determines that the supply power value of the first power generation power is smaller than the determination power value, with respect to the second power generation Output from the distributed power supply A second power generation control step of generating a difference power value between a reference power value that is a power supply value and a power supply value of the first power generation, and a power storage control means further provided in the distributed power supply unit, Supply of at least the reference power value and the first power source and the second power source to the power storage means when the supplied power values of the one power source and the second power source are smaller than the reference power value A power storage 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 source unit includes a first power source in which a change in power value to be supplied is difficult to predict, a second power source different from the commercial power source and the first power source, and the first power source. When the supply power value of the power generation source is smaller than the determination power value, a reference power value that is a power value to be output by the distributed power supply unit and a supply power value of the first power generation source with respect to the second power generation source A second power source control means for generating the difference power, a power storage means capable of storing power, and a power supply value of the first power source and the second power source is smaller than the reference power value, At least the group with respect to the power storage means Power storage control means for supplying a power value that is a difference between a power value and a power value supplied from the first power source and the second power source, and the commercial power supply source includes a first power supply path and the load. Power is supplied to the load by a common path connected to the first power supply path, the commercial power switching means capable of disconnecting the commercial power supply source is present in the first power supply path, A third power source that supplies power to the load through a second power supply path and the common path, and generates power using the commercial power supply source and / or the distributed power source as a reference power source in the common path And when the commercial power supply source is disconnected, the third power generation control unit included in the power supply system uses the distributed power supply unit as a reference power supply when the commercial power supply source is disconnected. The connection point to the common route Derived to includes a third power 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 on which the program according to claim 7 is recorded.

  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. The distributed power supply unit stores power by a first power source in which a change in a power value to be supplied is difficult to predict, a second power source different from both the commercial power source and the first power source, and The first power generation unit compares the determination power value with the power supply value of the first power generation unit and determines that the power supply value of the first power generation unit is smaller than the determination power value. In such a case, the second power source that generates the difference power between the reference power value, which is the power value to be output by the distributed power source, and the power value supplied from the first power source. Control means, the first power source and the second power source When the supplied power value is smaller than the reference power value, at least a power value of a difference between the reference power value and the supplied power value of the first power source and the second power source is supplied to the power storage unit. Storage power supply control means.

  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. The distributed power supply unit includes: a first power source in which a change in power value to be supplied is difficult to predict; a second power source that is different from both the commercial power source and the first power source; When the supply power value of the power generation source is smaller than the determination power value, a reference power value that is a power value to be output by the distributed power supply unit and a supply power value of the first power generation source with respect to the second power generation source A second power generation control means for generating the difference power, a power storage means capable of storing power, and a supply power value of the first power generation and the second power generation is smaller than the reference power value. , At least before the power storage means A power supply control means for supplying a power value of a difference between a reference power value and a power value supplied from the first power source and the second power source; and the commercial power supply source includes a first power supply path and the power source 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. A second power supply path and the common path to supply power to the load, and the common path generates power using the commercial power supply source and / or the distributed power supply unit as a reference power source. A power source is connected, and the third power source stops power generation when a reverse power flow to the commercial power supply source is detected, and when the commercial power supply source is disconnected, For the third power source, the distributed power Part 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 generation source uses natural energy such as solar power generation or wind power generation, and is a power generation source whose power generation amount cannot be predicted. Further, the second power source is, for example, a generator whose output can be adjusted in order to obtain a total and stable output 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. For example, the power storage means can respond more quickly than the second generator and supply the stored power. The power value of the power storage means supplied by the power storage supply control means may directly output the power value equal to the reference power value, and the power supplied to the first power source and the second power source may be stored in the power storage means. . Further, the reference power value may be supplied as a whole by supplementing the power supply value of the first power generation source and / or the second power generation source with the power supply of the power storage means.

  Further, the disconnection of the commercial power supply source is not only performed when an abnormality occurs in the commercial power supply source, such as a power failure of the commercial power supply source, but the detection means is reversed from 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 or a fuel cell is introduced as a distributed power source, a situation in which they are disconnected to protect the commercial power supply source is sufficiently assumed. Further, the power storage means switching means capable of disconnecting the power storage means is provided, and when the detection means detects a reverse power flow from the power storage means to the commercial power supply source, the power storage means may be disconnected. Good.

  Further, the determination power value may be the same value as the reference power value. 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 in accordance with the fluctuation of the power value of the first power source, so that the power value of the first power source decreases from the reference power value. You may make it make electric power generation of a 2nd power generation generate | occur | produce before. Also, set a value lower than the reference power value, continuously measure the difference between the reference power value and the power value of the first power source, change the determination reference value according to the power of the difference, The determination reference value may be changed according to the remaining amount of the power storage means. Further, even if a generator capable of adjusting the output is used for the second power generation, there is usually a certain adjustment range for the adjustment. The determination power value may be set in consideration of the adjustment range of the second power generation.

  Further, the determination power value (startup determination power value) for starting the second power source and the determination power value (stop determination power value) for stopping the second power source are different values as the determination power value. You may provide as. By doing in this way, when the electric power value which a 1st generating power supply supplies rises and falls violently, it becomes possible to suppress the energy consumption by starting and stopping a 2nd generating power frequently.

  According to the invention according to each claim of the present application, the first generation power source electrically connected to the commercial system uses a natural energy such as solar power generation or wind power generation, and therefore the power generation amount cannot be predicted. Even when the second power source and the power storage unit are used, it is possible to supply the power that is insufficient for the reference power value. Therefore, it is possible to provide a high-quality power supply power generation system that can supply power stably and continuously, and normal load peak cuts can be reliably planned. In addition, the so-called zero-emission power source using natural energy can be effectively used, and it is easy to contribute to CO2 reduction.

  Here, if only the second power source is configured to supplement the first power source, there will be a shortage of power during the time lag from when the second power source starts generating power until it supplies power. sell. Such a situation is expected to occur naturally and frequently when a power source that uses natural energy is used as the first power source. However, it is possible to supply power stably to the load despite the time lag until the second power source supplies power, as the power storage means that does not require power generation supplies power quickly. It becomes. In addition, when the second power generation unit generates power, the power stored in the power storage means can be continuously and stably supplied to the load before the power reaches the bottom. In other words, the coexistence of the power storage means and the second power source makes it possible to quickly and stably compensate for the unstable power supply of the first power source.

  Conversely, for example, when the power generated by the first power source generates excessive power and the power supplied from the first power source and the second power source becomes excessive, the power storage means stores the excess power. Thus, it is possible to stably supply power to the load. Therefore, the unstable power supply of the first power source can be leveled.

  In the event of a power failure in the commercial system, it is prohibited to supply power to the commercial system for security reasons. According to the inventions according to 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 in the event of a power failure of the commercial system. It becomes.

  According to the inventions according to 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 and the like are mainly operated with a commercial power supply source. As described above, there is a power source that cannot be operated when there is no other power supply source (referred to as “reference power supply” in the present application) such as a commercial power supply source. According to the invention according to claims 2 and 6 of the present application, by connecting the third power source as 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 performed. Even when the operation is stopped, the distributed power supply unit can be used as a reference power supply to restart and continue power generation. This makes it possible to continuously supply more stable power to the load.

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

  Further, according to the invention of claim 4 of the present application, it is possible for the adjusting means to adjust the power supplied to the load from a plurality of power supply sources. Accordingly, it is possible to adjust the power supply amount from each power supply source in consideration of the remaining amount of power stored in the power storage means, the burden on each power generation source, and the like. As a result, a practical energy management system (EMS) can be realized.

It is the block diagram which showed the structure of the electric power supply system 1 which concerns on embodiment of this invention. It is a flowchart which shows the operation example at the normal time of the electric power supply system 1 which concerns on embodiment of this invention. 5 is a graph showing an example of the relationship between fluctuations in the power supply value of the photovoltaic power generation panel 25 and power supply by the distributed power supply unit 5. FIG. 4 is a flowchart showing an operation example of the commercial power supply source 3 during a power failure in the power supply system 1 according to the embodiment of the present invention.

  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 the 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) and a distributed power supply unit 5 (an example of “distributed power supply unit” in the claims of the present application). The power can be supplied 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 “load” in the claims of the present application).

  The commercial power supply source 3 is common to the load 11 from the commercial power supply source 3 to the connection point 14 shown in FIG. Power is supplied through the path 15. In the first power supply path 13, there is a switch 17 as commercial power switching means capable of disconnecting the commercial power supply source 3. Further, the switch 17 is used not only when an abnormality occurs in the commercial power supply source 3 such as a power failure of the commercial power supply source 3, but also from the distributed power supply unit 5 by a detection unit (not shown). 3 may be performed in consideration of the influence on the commercial power supply source 3 as in the case where it is detected that a reverse power flow has occurred in 3 and the voltage has increased. This is because, when a large amount of natural energy such as solar power generation is introduced as the distributed power supply unit 5, a situation where it is disconnected to protect the commercial power supply source is sufficiently assumed.

  Further, 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 represented by (B) in FIG. The second power supply path 19 includes a switch 21 that can disconnect the distributed power supply unit 5.

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

  A fuel cell is generally a power source operated at a constant output. This is because, when the output is varied, there are various factors for adjusting the amount of exhaust heat and the amount of hydrogen, and the efficiency is deteriorated. In addition, a generator such as a fuel cell or a gas engine generator in which a reverse power flow is not recognized needs to narrow the generated power when the load 11 uses a small amount of power. In order to assist the commercial power supply source 3, focusing on only the relationship with the power of the commercial power supply source 3, the fuel cell mainly supplies power in conjunction with the commercial system. The solar power generation panel 25 is connected in parallel.

  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 electric 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 power flow of the power supplied from the fuel cell 7 to the commercial power supply source 3 and notifies the control device 9 of the reverse power flow. The sensor 23 is connected to the common path 15 at a connection point 24 that is closer to the commercial power supply source 3 than the connection point 20. When the reverse power flow is detected by the sensor 23, the fuel cell stops its operation in order to prevent an independent operation. Therefore, in the present embodiment, the fuel cell 7 is connected to the common path 15 instead of the first power supply path 13 in order not to detect a reverse power flow to the commercial power supply source 3 due to power sale or the like.

  The distributed power supply unit 5 includes a solar power generation panel 25 that generates power using sunlight (an example of “first power generation” in the claims of the present application), and a battery 27 that can store at least power generation from the solar power generation panel 25. (An example of “storage means” in the claims of the present application), an output-adjustable generator 29 (an example of “second power generation” in the claims of the present application) that can change the voltage and frequency of power generation, and the distributed power supply unit 5 A DC coupling 31 that is a set of connection points where currents from a plurality of power supply sources are combined, a connection box 33 that combines power supply paths from the plurality of solar power generation panels 25 into one path, and a solar power generation panel 25, a switch 35 that can disconnect the solar panel 25, a PV D / D converter 37 that transforms the photovoltaic panel 25, a switch 39 that can disconnect the battery 27, and a battery D / D converter that transforms the battery 27. Generator 41, a switch 43 that can disconnect the output adjustable generator 29, a generator A / D converter 45 that transforms the output adjustable generator 29, and a generator output command to the output adjustable generator 29. A control device 47 is provided.

  In the present embodiment, it is assumed that the output of the photovoltaic power generation panel 25 is 50 kW, the charged amount of the battery 27 is 50 kWh, and the output of the output adjustable generator 29 is 50 kVA. The solar power generation panel 25, the battery 27, and the output adjustable generator 29 may be of other standards.

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

  The photovoltaic power generation panel 25 is connected to the DC coupling 31 via a connection box 33, a switch 35, and a PV D / D converter 37. The PV D / D converter 37 is a maximum power point tracking (MPPT) function that always matches impedances of the photovoltaic power generation panel 25 and a load connected to the photovoltaic power generation panel 25 to extract the maximum output. Have

  The battery 27 is connected to the DC coupling 31 via a switch 39 and a battery D / D converter 41. The battery D / D converter 41 has a function as a power storage control unit that controls charging of the battery 27, a function as a power storage supply control unit that controls discharge, and a function as a power storage step-up / down unit that controls the voltage of the battery 27. . The switch 39 capable of disconnecting the battery 27 disconnects the battery 27 when detection means (not shown) detects a battery abnormality such as an abnormal increase in discharge voltage from the battery 27.

  The output adjustable generator 29 is connected to the DC coupling 31 via the switch 43 and the generator A / D converter 45. Similarly to the PV D / D converter 37, the generator A / D converter 45 has an MPPT function that maximizes the output of the output adjustable generator 29. Here, the output adjustable generator 29 generates alternating current, but is converted into 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 the present application) in this embodiment gives a generator output command to the output adjustable generator 29 as the second power generation control means.

  The direct current supplied to the DC coupling by the photovoltaic power generation panel 25, the battery 27, and the output adjustable generator 29 is supplied to the load 11 through 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 that equalizes a DC ripple, which is a fine wave signal, a main inverter 51 that supplies power from the distributed power supply unit 5 at normal times, and a commercial power supply 3 There are a stand-alone inverter 53 that supplies power from the distributed power supply unit 5 in the event of a power failure, and switches 55 and 57 that are stationary switches and are high-speed switches.

  Under the current legal system, it is prohibited to sell electric power once charged from the commercial grid. Therefore, the structure which connects the solar power generation panel 25 directly to the 1st electric power supply path | route 13 for power sale is also considered. However, since the output of the photovoltaic power generation panel 25 uses 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 power generation panel 25 is unpredictable. For this reason, in this embodiment, the distributed power supply unit 5 is configured to include the photovoltaic power generation panel 25. In this embodiment, in order to realize the power sale, for example, the switch 35 does not pass the DC power generation 31 to the commercial power supply source 3 via the converter. Therefore, it is possible to sell power without passing through the DC coupling 31.

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

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

  Normally, the DC power of the distributed power supply unit 5 is converted into AC by the main inverter 51 through a 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 circuits, and the DC power supplied from the distributed power supply unit 5 is converted into AC by the stand-alone inverter 53 and is supplied to the second power supply via the switch 57. It is supplied to the load 11 through the path. Here, the main inverter 51 controls electric 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 generation source 7 by controlling power by voltage control.

  The main inverter 51 and the stand-alone inverter 53 are both examples of “adjusting means” in the claims of the present application. As the adjusting means, in cooperation with the control device 9 and the control device 47, the power supplied from the commercial power supply source 3, the output adjustable generator 29 and the fuel cell 7 to the load 11 is adjusted. The battery 27 and the output-adjustable generator 29 are supplied to the control device 47 according to the power supplied by the solar power generation panel 25 so that the main inverter 51 stably supplies the reference power value to the distributed power supply unit 5 at normal times. The power to be supplied is controlled. 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 that normally supplies a constant power so that the power required by the load is supplied at the time of a power failure of the commercial power supply source 3. Thus, the control device 47 controls the power supplied from the battery 27 and the output adjustable generator 29.

  Hereinafter, the normal operation of the power supply system 1 will be described with reference to FIG. FIG. 2 is a flowchart 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 whether. If it is determined that P ₁ ≧ P _{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 in step S1 that P ₁ ≧ P _{size 1} , in step S3, the main inverter 51 or the stand-alone inverter 53 as the first determination means can adjust the output of the power supply value P ₁ of the photovoltaic power generation panel 25. It is determined whether or not the determination power value P for starting the generator 29 is ₂ or less. When it is determined that P ₁ ≦ P _{size 2} , in step S 4, the controller 47 issues a generator output command to the output adjustable generator 29 to generate power. If it is not determined in step S3 that P ₁ ≦ P _{size 2} , the output adjustable generator 29 is not instructed 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 supply power value P ₁ + P _{2 of} the photovoltaic power generation panel 25 and the output adjustable generator 29 smaller than the reference power value P _group. Determine whether. When it is determined that P ₁ + P ₂ <P _group , in step S6, the main inverter 51 or the stand-alone inverter 53 causes the control device 47 to start the battery D / D converter 41 to start discharging from the battery 27 and ends the flow. To 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). If it is not determined in step S5 that P ₁ + P ₂ <P _group , power is not supplied from the battery 27 and the flow ends.

  Since the power already supplied from the photovoltaic power generation panel 25 and / or the commercial power supply source 3 is stored in the battery 27, the shortage of the reference power value is supplied more quickly than the output adjustable generator 29. Is possible. Therefore, it is possible to stably supply power to the load 11 in spite of a time lag until the output adjustable generator 29 supplies power. On the other hand, for example, when the solar power generation panel 25 and the output-adjustable generator 29 supply excessive power due to excessive power generation by the solar power generation panel 25, the power storage means stores excess power. Thus, it is possible to stably supply power to the load 11. Moreover, the power adjustable generator 29 generates electric power, so that it is possible to stably supply electric power to the load 11 before the electric power stored in the battery 27 is exhausted. In other words, with respect to the unstable power supply of the photovoltaic power generation panel 25, a stable power supply is realized by the battery 27 for a short period fluctuation, and the output adjustable generator 29 is stable for a long period fluctuation. It can be said that power supply has been realized.

  Thus, even if the power supply from the photovoltaic power generation panel 25 fluctuates unpredictably, the battery 27 and the output adjustable generator 29 are used as the power supply source in steps S1 to S6 in FIG. Utilizing the features of each, adjust and supply the power shortage from the reference power value. As a result, the distributed power supply unit 5 can function as a stable power supply source for the load 11.

Here, details of the operation of the output adjustable generator 29 will be described with reference to FIG. FIG. 3 is a diagram showing the relationship between the power supply value P ₁ of the photovoltaic power generation panel 25 and the start and stop of the output adjustable generator 29. Three cases are shown in FIGS. 3A and 3B depending on the relationship between the change in the power supply value of the photovoltaic power generation panel 25 with time and the determination power value. 3A and 3B, the horizontal axis represents time, and the vertical axis represents the power value.

The reason why two determination power values for determining the start and stop of the output adjustable generator 29 are separately provided 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 activation and deactivation of the output adjustable generator 29 itself consumes a great deal of energy. Therefore, two judgment _sizes , P _{size 1} and P _{size 2} , were provided. 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, referring to FIG. 3A, the supply power value P1 of the photovoltaic power generation panel 25 that was larger than the P _{size 1} is decreased to be smaller than the P _{size 2} , and then again larger than the P _{size 1.} Consider the case. The output-adjustable generator 29 is stopped during the time period 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. Thereafter, at time T ₄ when P ₁ increases and P ₁ = P _{size 1} again, the outputable 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. Battery 27 compensates the shortage of the reference power value P _group until the output adjustable generator 29 starts to power storage oversupply 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 determination power values, the battery 27 and the output adjustable generator 29 compensate for unpredictable fluctuations in the power supply area of the photovoltaic power generation panel 25, and the output adjustable generator It becomes possible to suppress energy consumption by frequently starting and stopping 29.

Here, although the output adjustable generator 29 can adjust the output, there is usually a minimum supply power value 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 determination 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 starting the output adjustable generator 29, the supply power is significantly excessive. It becomes possible to prevent.

Subsequently, the manner in which the distributed power supply unit 5 stably supplies the reference power value P _group will be illustrated with reference to FIG. FIG. 3C is a graph showing an example of the relationship between the fluctuation of the power supply value P ₁ of the photovoltaic power generation panel 25 and the power supply by the distributed power supply unit 5. In FIG.3 (c), a horizontal axis represents time and a vertical axis | shaft represents the electric power supplied. P _group is a reference power value that the distributed power supply unit 5 is required to supply stably. P _{size 1} is a determination power value for stopping the output adjustable generator 29. 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 machine 29 supplies a power amount S ₁ (indicated by a net-like area in FIG. 3C) that is insufficient for 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.} From time t ₁ to t ₃ , the shortage with the P _group becomes smaller than the minimum output of the output adjustable generator 29, and surplus power S ₂ is generated by the supply of the output adjustable generator 29. This surplus power S ₂ is stored in the battery 27.

At time t ₃ , since P ₁ reaches P _{size 1} , the output adjustable generator 29 is stopped. Thereafter, P ₁ starts to decrease after P ₁ exceeds P _{size 1} , but output adjustable generator 29 remains stopped until it decreases to P _{size 2} at time t ₈ . The surplus power amount S ₃ exceeding the P _group of P ₁ from time t ₂ to t ₅ and from 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. Further, a certain amount of time is required until the output adjustable generator 29 can supply the difference between the P _group and P ₁ even after the power supply is started. Therefore, among the amount of power that does not satisfy the P _group of P ₁ from time t ₇ to time t ₁₁ , the amount of power S _{6 that} is supplied by the output adjustable generator 29 (displayed with diagonal lines in FIG. 3C) 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 it is smaller than _{size 2} . At this time, the main inverter 51 or the output adjustable generator 29 to be able to detect that the stand-alone inverter 53 the value of P ₁ is smaller is not activated. An insufficient amount of power S _{8 that} is less than the P _group between t ₁₃ and t ₁₄ is supplied by discharging from the battery 27. Thus, the accuracy of detection is set as necessary (for example, whether a short-period response is required or a long-period response is required). Similarly, as the main inverter 51 or stand-alone inverter 53 it has detected, if the value P ₁ is greater than _{P-size 1} by the control unit 47 activates the output adjustable generator 29, the output adjustable generator 29 may stop the activation.

  Then, the operation | movement at the time of a power failure of the electric power supply system 1 is demonstrated using FIG. FIG. 4 is a flowchart showing an operation example of the commercial power supply source 3 during a power failure 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 the determination means determines whether or not the commercial power supply source 3 is out of power. If it is not determined that there is a power failure, the flow ends. If it is determined that there is a power failure, in step SS2, the switch 17 disconnects the commercial power supply source 3, and the control device 9 stops the fuel cell 7 for which the independent operation is prohibited. Subsequently, in step SS3, the fuel cell 7 resumes power supply using the distributed power supply unit 5 as a reference power supply, and the flow ends. By restarting the fuel cell 7, stable supply of power to the load 11 is further facilitated.

  In addition, in an Example, as an example of the 1st generating power source whose electric power generation amount is unpredictable, a wind power generator other than the solar power generation panel 25 may be used, for example, and these power generators are combined. It may be.

  In addition to the fuel cell 7, as the third power source, a power source by other power generation means may be used as long as it is a distributed power source that stably supplies power, and of course, RDF (solid waste fuel) is used. A power generation system such as a power generation system or a cogeneration system that reuses waste heat from 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, so that the discharge from the battery 27 can be performed more than the start of power generation by the output adjustable generator 29. It may be started early, 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.

Further, the reference power value P _group that 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 supplied from the grid and the reference power value P _group may be constant. Further, when power is supplied from a commercial system, the reference power value P _group may be a value that follows the power supply value P ₁ that fluctuates in the photovoltaic power generation 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 may determine two determination power values (for example, ± 10% of the reference power value) as values that follow the fluctuating power supply value P ₁ of the photovoltaic power generation panel 25. Thus, the system operation which does not start the output adjustable generator 29 as much as possible by making the reference power value P _group , the judgment power value P _{size 1} and the P _{size 2} follow the power supply value P ₁ of the photovoltaic power generation panel 25. It becomes possible.

  Further, before the control device 9 stops the power generation source 7, the switches 55 and 57, which are high-speed switches, switch from the power supply from the main inverter 51 to the power supply from the stand-alone inverter 53 to make the distributed power supply unit 5 a reference power source. In this case, power may be supplied to the load 11 without stopping the power generation source 7.

  Further, the main inverter 51 and the stand-alone inverter 53 may be configured to be physically integrated, and may be used by switching between the normal time and the power failure of the commercial system.

  Furthermore, each function of the first determination unit, the second determination unit, and the adjustment unit may be assumed to be performed by a configuration 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. 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, the DC coupling 31 may be configured so that the power supplied from the photovoltaic power generation panel 25 is supplemented to supply power from the output adjustable generator 29, and instead of the output adjustable generator 29 that is an AC power source. A DC power 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 only needs to be connected at the same voltage level with the current from the photovoltaic power generation panel 25, the battery 27, and the output adjustable generator 29, which are a plurality of power supply sources included in the distributed power supply unit 5. The number of connection points and the connection location are not limited.

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

  Furthermore, the structure which supplies electric power with respect to the load 11 by direct current | flow with respect to the load 11 may be sufficient.

  DESCRIPTION OF SYMBOLS 1 Power supply system, 3 Commercial power supply source, 5 Distributed power supply part, 7 Fuel cell, 9 Control apparatus, 11 Load, 13 1st power supply path, 15 Common path, 19 2nd 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 (10)

A power supply system comprising 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 power source for which it is difficult to predict a change in the power value to be supplied;
A second power source different from the commercial power source and the first power source;
Power storage means capable of storing power; and
When the first determination means compares the determination power value with the supply power value of the first power source and determines that the supply power value of the first power source is smaller than the determination power value, the second generation power Second power generation control means for generating a difference power between a reference power value, which is a power value to be output by the distributed power supply unit, and a supply power value of the first power generation, with respect to the power supply;
When the power supply value of the first power source and the second power source is smaller than the reference power value, at least the reference power value, the first power source, and the second power source for the power storage unit A power supply system comprising: a storage power supply control unit that supplies a power value that is a difference from the supplied power value. 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 means capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through a 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 and / or the distributed power source 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 configured to supply power to the load via the connection point to the common path with the distributed power source unit serving as a reference power source. The power supply system according to claim 1, further comprising a power control unit. In the distributed power supply unit,
The first power source, the second power source and the power storage means are coupled with a direct current,
The power storage supply control means supplies power to the power storage means when the combined DC power value is smaller than the reference power value, and the combined DC power value is lower than the reference power value. If it is larger, the power storage means stores power,
The second power supply path includes 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 that increases power supplied from the reference power source and is operated at a predetermined output.   4. The adjusting device according to claim 2, further comprising an adjusting unit that adjusts power supplied to the load by adjusting power supplied from the commercial power supply source, the distributed power supply unit, and the third power generation unit. 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, 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 power source for which it is difficult to predict a change in the power value to be supplied;
A second power source different from the commercial power source and the first power source;
Power storage means capable of storing power,
A first determination step in which a first determination unit included in the distributed power supply unit determines whether or not a supply power value of the first power generation unit is smaller than a determination power value;
When the first power generation control means provided in the distributed power supply unit determines that the first power generation power supply power value is smaller than the determination power value, the second power generation control A second power generation control step of generating a power value of a difference between a reference power value that is a power value to be output by the distributed power supply unit and a power supply value of the first power generation;
The storage power supply control means included in the distributed power supply unit has at least the reference power value for the power storage means when supply power values of the first power generation power source and the second power generation power source are smaller than the reference power value. And a storage power supply control step of supplying a difference power value between the power supply value of the first power supply and the second power supply. A power supply control method in a power supply system comprising 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 power source for which it is difficult to predict a change in the power value to be supplied;
A second power source different from the commercial power source and the first power source;
When the supply power value of the first power source is smaller than the determination power value, a reference power value that is a power value to be output by the distributed power source unit with respect to the second power source and the first power source Second power generation control means for generating power of the difference between the supplied power values;
Power storage means capable of storing power; and
When the power supply value of the first power source and the second power source is smaller than the reference power value, at least the reference power value, the first power source, and the second power source for the power storage unit Power storage control means for supplying a power value that is the difference from the power supply 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 means capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through a 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 distributed power source as a reference power source,
When the commercial power supply source is disconnected, the third power generation control means included in the power supply system is connected to the common path with respect to the third power generation using the distributed power supply unit as a reference power supply. A power supply control method including a third power generation control step of supplying power to the load via a point.   A program for causing a computer to execute the power supply control method according to claim 5 or 6.   A computer-readable recording medium on which the program according to claim 7 is recorded. 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 power source for which it is difficult to predict a change in the power value to be supplied;
A second power source different from the commercial power source and the first power source;
Power storage means capable of storing power,
When the first determination means compares the determination power value with the supply power value of the first power source and determines that the supply power value of the first power source is smaller than the determination power value, the second generation power Second power generation control means for generating a difference power between a reference power value, which is a power value to be output by the distributed power supply unit, and a supply power value of the first power generation, with respect to the power supply;
When the power supply value of the first power source and the second power source is smaller than the reference power value, at least the reference power value, the first power source, and the second power source for the power storage unit A power supply control device comprising: a power storage control unit that supplies a power value that is a difference from the power supply value of the power supply. 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 power source for which it is difficult to predict a change in the power value to be supplied;
A second power source different from the commercial power source and the first power source;
When the supply power value of the first power source is smaller than the determination power value, a reference power value that is a power value to be output by the distributed power source unit with respect to the second power source and the first power source Second power generation control means for generating a power difference of the supplied power value;
Power storage means capable of storing power; and
When the power supply value of the first power source and the second power source is smaller than the reference power value, at least the reference power value, the first power source, and the second power source for the power storage unit Power storage control means for supplying a power value that is the difference from the power supply 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 means capable of disconnecting the commercial power supply source,
The distributed power supply unit supplies power to the load through a 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 distributed power source as a reference power source,
The third power source is configured to stop power generation when a reverse power flow to the commercial power supply source is detected;
When the commercial power supply source is disconnected, the third power source is configured to supply power to the load via the connection point to the common path with the distributed power source as a reference power source. A power supply control device comprising a power generation control means.