WO2012090709A1

WO2012090709A1 - Power control apparatus and distributed power supply system

Info

Publication number: WO2012090709A1
Application number: PCT/JP2011/078927
Authority: WO
Inventors: 正寛牧野; 渉堀尾; 俊之平田
Original assignee: 三洋電機株式会社
Priority date: 2010-12-28
Filing date: 2011-12-14
Publication date: 2012-07-05
Also published as: JP2014045527A

Abstract

Provided is a power control apparatus for restricting the output of a plurality of distributed power supply systems to control the total output power, wherein the restriction of output can be executed more appropriately. The power control apparatus is configured so that priority is set for each of a plurality of distributed power supply systems connected to a power grid, and the output of each of the plurality of distributed power supply systems is restricted so that the total output of the plurality of distributed power supply systems will not exceed a threshold value, that is, the output of the plurality of distributed power supply systems is restricted one-by-one, starting from a power supply system having low priority, until a state wherein the total output does not exceed the threshold value is achieved.

Description

Power control device and distributed power supply system

The present invention relates to a power control apparatus that controls a distributed power supply system and a distributed power supply system including the power control apparatus.

In recent years, there is an increasing number of cases in which each customer uses a distributed power supply system linked to a power system (for example, see Patent Document 1). As an example of the distributed power supply system, as an example, a solar cell system in which a solar cell is used, a secondary battery system in which a secondary battery is used, and a cogeneration in which a fuel cell or a gas engine is used System (cogeneration system).

The output power of various distributed power systems can be configured to reversely flow to the power system via the linkage point for the amount exceeding the load consumption. In particular, in the solar cell system, the power reversely flowed to the power system can be sold to the power company.

However, in the operation of the power system, there is a case where it is necessary to suppress the power that flows backward from the distributed power system to the power system.

For this reason, some distributed power supply systems prevent output power from flowing backward, and an example thereof will be described below with reference to FIG.

In FIG. 2, the left side and the right side of the dotted line represent the power system side and the customer side (the power system formed in one consumer), respectively. As shown in FIG. 2, the power system includes a power transmission line L (portion indicated by a thick line) connected to the power system at a cooperation point. The power transmission line L includes one or a plurality of power transmission lines L. A load is connected. The total power consumption of each load is defined as power consumption _PLOAD .

Further, in the power system, as the distributed power system, the solar cell system 101 and the cogeneration system 102 are respectively connected to the power system via the power transmission line L.

The solar cell system 101 converts DC power generated by the solar cell 111 into AC power and outputs the AC power to the power transmission line L. The solar cell power conditioner 112 (power conditioner) converts the DC power obtained by the power generation of the solar cell 111 into AC and outputs it to the power transmission line L.

The cogeneration system 102 converts the DC power obtained by the fuel cell 121 into AC power and outputs it to the power transmission line L. Cogeneration for power conditioner 122, a DC power obtained by power generation of the fuel cell 121 is converted into AC power, and outputs to the power transmission line L as the output power P _FC. In addition, the cogeneration system 102 uses the exhaust heat in the power generation of the fuel cell 121 as a heat source of a heat pump water heater or a heat source of an air conditioner when performing a heating operation. These devices are referred to as exhaust heat utilization equipment 123.

In addition, regarding the connection point with the power transmission line L of each distributed power supply system, the connection point of the cogeneration system 102 (point B shown in FIG. 2) is downstream from the connection point of the solar cell system 101 (point A shown in FIG. 2). On the side (the side far from the power system). A power detection point 104 is provided at a position downstream of the point A in the power transmission line L and upstream of the point B.

Information on the power P _BUY that is the power (detected value) at the power detection point 104 is transmitted to the power generator 122 for cogeneration. Moreover, the threshold value TFC is set in the power generator 122 for cogeneration, and when the power P _BUY becomes equal to or less than the threshold TFC, the output power P _FC is reduced so that this state is eliminated.

The power P _BUY here is expressed by the following formula (1).

In the power system shown in FIG. 2 Therefore, the output power _{P FC} is the power consumption _{P LOAD} threshold value corresponding to that time - so as not to exceed (power _{P LOAD} threshold TFC), said to be limited.

Japanese Patent No. 4164050

By the way, if secondary batteries become widespread for the use of late-night power, the use of both cogeneration systems and secondary battery systems as a distributed power system is expected to increase in the same consumer. It is expected that more cases will be provided.

Here, even when a plurality of distributed power supply systems are provided, it is possible to adopt a form according to the above-described power system and control the outputs of these distributed power supply systems. That is, it is possible to control the power generation capability of the distributed power supply system so that the sum of the outputs of these distributed power supply systems does not exceed the threshold value.

However, in this case, unless the distributed power supply system in which the output restriction is executed first (the execution order of the output restriction) is not determined, confusion is likely to occur during the execution of the output restriction, and the operation of the output restriction is complicated. There is concern about becoming. In addition, characteristics related to ease of output restriction differ depending on the type of distributed power supply system, so if the execution order of output restriction is determined in consideration of this, output restriction can be performed more efficiently. It becomes.

In view of the problems described above, the present invention is intended to provide a power control apparatus and a distributed power supply system that perform output restriction of a distributed power supply system and can perform the output restriction more appropriately.

In order to achieve the above object, a power control apparatus according to the present invention uses the common coordination point as the power for each of a plurality of distributed power systems connected to a power system via a common interconnection point. In order to prevent the power flowing to the system from exceeding the threshold value, the output of the distributed power supply system is limited in order from the preset lower priority order.

According to this configuration, regarding the output restriction of a plurality of distributed power supply systems, it is determined in advance which distributed power supply system this output restriction is executed first, so that the output restriction can be performed more appropriately. .

In addition, as the power control device having the above configuration in which one of the plurality of distributed power systems is a secondary battery system, more specifically, the priority order of the secondary battery system is set to the lowest priority order. It is good also as composition to do.

Further, in the above configuration, the priority order may be updated according to predetermined reference information. According to this configuration, it is easy to set the priority setting contents to be adapted to the situation at that time.

Further, as one of the plurality of distributed power supply systems, the power control apparatus having the above configuration in which the secondary battery system is configured, more specifically, the priority is based on information on a remaining charge of the secondary battery. It is good also as a structure set based on.

Moreover, as one of the plurality of distributed power systems, a power control device having the above configuration in which a cogeneration system having a power generation device is used. More specifically, the priority is a power that can be generated by the power generation device. A configuration may be set with reference to any one of the amount of hot water in the hot water storage tank in which hot water heated by the exhaust heat of the power generation device is stored and the temperature of the hot water storage tank.

More specifically, as the power control device having the above configuration, in which one of the plurality of distributed power supply systems is a cogeneration system having a power generation device that generates power using supplied fuel, the priority order is more specifically described. May be configured with reference to information on the remaining amount of fuel supplied to the power generation device.

In the above configuration, when the amount of hot water in the hot water tank does not reach a predetermined reference value, the cogeneration system may be set to the highest priority.

In addition, the power control apparatus according to the present invention stores the priorities assigned to a plurality of distributed power supply systems that are linked so as to be able to superimpose AC power on the power system, and superimposes them on the power system from the plurality of distributed power supply systems. It is good also as a structure which outputs the signal which restrict | limits the quantity of the alternating current power superimposed on the said electric power system according to the said priority based on the magnitude of the sum total of the alternating current power performed, and a predetermined threshold value.

In the above configuration, the distributed power supply system may be configured to convert at least DC power output from any one of the generated power of the solar battery or the discharged power of the storage battery into AC power and superimpose it on the power system.

Moreover, the distributed power supply system according to the present invention is a distributed power supply system that is linked so that AC power can be superimposed on the power system. A control unit is provided that suppresses the amount of AC power to be superimposed on the power system when a signal that regulates the amount of AC power to be superimposed is input.

The distributed power supply system according to the present invention regulates the amount of AC power superimposed on the power system in the distributed power system connected to the power system via a connection point and capable of superimposing AC power. A control unit that suppresses the amount of AC power superimposed on the power system when a signal to be input is input.

As described above, according to the power control device or the distributed power supply system of the present invention, the distributed power supply system is ordered with respect to the output restriction of the distributed power supply system, and the output restriction can be performed more appropriately.

Explanatory drawing which shows the form of the electric power system which concerns on this embodiment Explanatory drawing about an example of a conventional power system

Embodiments of the present invention will be described below with reference to the drawings.

[About power system configuration]
FIG. 1 is an explanatory diagram showing a form of a power system 9 according to the present embodiment. In FIG. 1, the left side and the right side of the dotted line represent the power system side (the power system provided by the power company) and the customer side (the power system 9 formed in one consumer), respectively. The consumer is a household or a business entity that has a power sales contract with an electric power company. Electricity trading with electric power companies will be performed separately for each consumer.

As illustrated in FIG. 1, the power system 9 includes a power transmission line L (a portion indicated by a thick line in FIG. 1) connected to a power system (system power supply). The power transmission line L is connected to one or a plurality of loads, for example, electric devices used in the customer. These loads operate using power supplied through the power transmission line L, that is, power supplied from a power system or a distributed power system connected to the power transmission line L as a power source. In the following description, the total power consumption of each load may be expressed as power consumption _PLOAD .

The power system 9 includes a solar cell system 1, a cogeneration system (cogeneration system) 2, and a secondary battery system 3 as distributed power supply systems (systems that output power using a distributed power supply). As shown in FIG. 1, these distributed power supply systems are each connected to a power transmission line L and connected to a power system via a common connection point.

The solar cell system 1 outputs electric power obtained by the solar cell 11 which is one of the distributed power sources to the power transmission line L. The solar cell 11 is formed of a solar cell panel or the like, and is a device that generates electric power by photoelectrically converting received sunlight. Further, the solar cell system 1 is provided with a solar cell power conditioner 12. The solar cell power conditioner 12 is connected to the power transmission line L, converts the DC power obtained by the power generation of the solar cell 11 into AC, and outputs the AC power toward the power transmission line L. Of this AC power, the power not consumed by the load flows backward to the power system. The amount of power flowing backward can be measured using a power detector (not shown) provided between point A on the power transmission line L and the power system.

The cogeneration system 2 outputs electric power obtained by the fuel cell 21 that is one of the distributed power sources to the power transmission line L. The fuel cell 21 is a power generation device included in the cogeneration system 2, and generates power in a power generation possible range using fuel supplied in advance.

In addition, the cogeneration system 2 is provided with a power generator 22 for cogeneration. Cogeneration for power conditioner 22 is connected to a power transmission line L, the DC power obtained by power generation of the fuel cell 21 is converted into AC power and outputs toward the power transmission line L as the output power P _FC.

In addition, the cogeneration system 2 is provided with a waste heat utilization facility 23. The waste heat utilization facility 23 can be utilized as a part of a heat source such as hot water supply or air conditioning by utilizing the waste heat in the power generation of the fuel cell 21. According to the exhaust heat utilization facility 23, for example, hot water heated using the exhaust heat of the fuel cell 21 as an auxiliary heat source can be stored in a hot water storage tank 23a provided as one of the facilities.

The secondary battery system 3 converts the DC power discharged by the secondary battery 31 that is one of the distributed power sources into AC power and outputs the AC power to the power transmission line L. The secondary battery 31 can be charged and discharged, and has superior output controllability (responsiveness) compared to the fuel cell 21 and the like. That is, according to the secondary battery 31, a quicker response can be made to a situation where a sudden output change is required.

The secondary battery system 3 includes a secondary battery power conditioner 32. The secondary battery power conditioner 32 is connected to the power transmission line L, converts the DC power output from the secondary battery 31 to AC, and outputs the output power P _BAT toward the power transmission line L. The secondary battery power conditioner 32 converts the alternating current power supplied from the power transmission line L into direct current and sends the secondary battery 31 to the secondary battery 31 when the secondary battery 31 is charged.

The output power of each distributed power supply system (1 to 3) is supplied to the load via the power transmission line L. Moreover, when the sum total of the output power is excessive with respect to the load, the surplus part flows backward to the power system.

In order to control the amount of this reverse power flow, the connection points in the cogeneration system 2 and the secondary battery system 3 (points B and C shown in FIG. 1) with respect to the connection points with the power transmission lines L of the respective distributed power systems. Is provided on the downstream side (the side far from the power system) from the connection point (point A shown in FIG. 1) of the solar cell system 1. In the power transmission line L, power detection points (4a, 4b) are provided at positions downstream of the point A and upstream of the points B and C. An electric power detection point (not shown) is provided between the point A and the system power supply so that the entire current flowing from the customer side to the electric power system can be detected. The electric power sales power can be obtained from the entire current, and is usually attached to the building as a power sales meter.

Information on the power P _BUY that is the power (detected value) at the power detection point 4a (the direction from the upstream side to the downstream side is positive) is transmitted to the power generator 22 for cogeneration, and the power at the power detection point 4b (similarly, The information on the power P _BUY ) is transmitted to the secondary battery power conditioner 32. The power P _BUY represents the purchased power (the magnitude of the purchased power) in the power system 9 when the solar cell system 1 is not generating power.

Here, if the power P _BUY has a negative value, it can be said that the output power of the cogeneration system 2 or the secondary battery system 3 is flowing backward in the power system. Therefore, the amount of electric power in the reverse power flow can be controlled by changing the conversion amounts of the power generator 22 for cogeneration and the power converter 32 for the secondary battery. The fuel cell 21 is suitable for long-period adjustment because it requires time to change the amount of power generation, and the secondary battery 31 is suitable for short-period adjustment because it does not require time to change the amount of power generation. The power output to the power transmission line L is limited with a margin of.

More specifically, a threshold TFC corresponding to the cogeneration system 2 is set in the cogeneration power conditioner 22 by the controller 5 described later. The power generator 22 for cogeneration outputs power P so that this state is canceled when the power P _BUY becomes equal to or less than the threshold value TFC (so that the power P _BUY exceeds the threshold value TFC almost without excess or shortage). Restrict _FC .

Further, a threshold value TBAT corresponding to the secondary battery system 3 is set in the secondary battery power conditioner 32 by the controller 5 described later. Then, the secondary battery power conditioner 32 outputs power P _BAT so that this state is canceled when the power _PBUY is equal to or less than the threshold value TBAT (so that the power P _BUY exceeds the threshold value TBAT substantially without excess or shortage). To limit.

In addition, the power system 9 is provided with a controller 5. The controller 5 is connected to each power conditioner of the distributed power supply system (in this embodiment, the cogeneration power conditioner 22 and the secondary battery power conditioner 32). The controller 5 can recognize which power conditioner itself has the priority order for setting the power output limit.

The controller 5 determines the priority order for each of the cogeneration system 2 and the secondary battery system 3 based on the predetermined information, and sets the priority order for each power conditioner (22, 32). This "priority order" is an order set from the viewpoint of the importance or controllability of each distributed power supply system in the present situation, and it is set to a higher order as it is undesirable to limit the output. is there. It should be noted that various forms can be adopted as to what information the controller 5 determines the priority based on what information. Some specific examples of the form will be described again.

Various forms can be adopted as the form for setting the priority order. In this embodiment, the priority order is set by setting the above-described threshold values (TFC, TBAT) to each power conditioner (22, 32). It has come to be. That is, the controller 5 sets a higher threshold value in order from the distributed power supply system with the lowest priority. For example, when the priority order of the secondary battery system 3 is lower than that of the cogeneration system 2, the threshold value TFC for the cogeneration system 2 is set to 100W, and the threshold value TBAT for the secondary battery system 3 is set to 200W.

As described above, the reason why the priority order can be set by setting the threshold value will be clarified by the following description. The controller 5 may have a function of adjusting the output power of the cogeneration system 2 or the secondary battery system 3 in accordance with a user instruction or the like in addition to the function of setting a threshold value for each distributed power supply system.

As described above, the controller 5 has a function of controlling the cogeneration system 2 and the secondary battery system 3 together with the cogeneration power conditioner 22 and the secondary battery power conditioner 32. That is, the controller 5, the cogeneration power conditioner 22, and the secondary battery power conditioner 32 form a power control device 6 that controls the cogeneration system 2 and the secondary battery system 3 as a whole. Further, the controller 5 is configured to be able to exchange signals with the outside of the power system 9 and can set respective threshold values from the outside. In addition, for easy explanation, the threshold value is set by the controller 5 in the cogeneration system 2 and the secondary battery system 3, but the threshold value may be set in the AC output of the solar cell power conditioner 12 of the solar cell system 1. The AC output is controlled at a power detection point between the point A and the system power supply. In this case, the controller 5 stores the priorities assigned to the plurality of distributed power systems linked so that the AC power can be superimposed on the power system, and the AC power to be superimposed on the power system from the plurality of distributed power systems. Based on the magnitude of the sum and a predetermined threshold, a signal for limiting the amount of AC power to be superimposed on the power system according to the priority order is output. Furthermore, this distributed power supply system further includes a configuration in which DC power output from at least one of the generated power of the solar battery or the discharged power of the storage battery is converted into AC power and superimposed on the power system.

[Specific examples of output restrictions]
The controller 5 performs output restriction on these distributed power supply systems so that the output power in the cogeneration system 2 and the secondary battery system 3 does not exceed the threshold value and is supplied to the power transmission line L. Moreover, output limitation is performed so that the output power in the solar cell system 1 does not exceed the threshold and is supplied to the power system. Here, in order to make it easier to understand the mechanism of the output limitation, a specific example will be described below.

Here, it is assumed that the threshold TFC is set to 100 W and the threshold TBAT is set to 200 W. From this, it can be said that the secondary battery system 3 has a lower priority than the cogeneration system 2. In a state where the output power P _FC is 500 W, the output power P _BAT is 500 W, and the power consumption P _LOAD (sum of power consumption of each load) is 2000 W (for convenience, the “initial state”), the power consumption P _LOAD Suppose the case of decrease.

The following formula (2) is established for the power P _BUY .

Therefore, in the initial state, the power P _BUY is 1000 W, which exceeds the threshold value TFC and the threshold value TBAT, so that the output of the cogeneration system 2 and the secondary battery system 3 is not limited.

First, as a first example, a case where the power consumption P _LOAD decreases from 2000 W to 1000 W will be given. In this case, as is clear from Equation (2), when the power consumption P _LOAD is reduced to 1200 W, the power P _BUY is reduced to the threshold value TBAT. Therefore, when the power consumption P _LOAD further decreases from this state, the output power P _BAT is limited so that the power P _BUY does not become equal to or less than the threshold value TBAT.

As a result, the output power P _BAT is finally limited to less than 300 W (for example, 299 W), and the state where the power P _BUY exceeds the threshold value TBAT is maintained. Note that the output power P _FC is not particularly limited, and remains in the initial state of 500 W.

Next, as a second example, a case where the power consumption P _LOAD decreases from 2000 W to 500 W will be given. Also in this case, as in the first example, when the power consumption P _LOAD further decreases from 1200 W, the output power P _BAT is limited so that the power P _BUY does not become equal to or less than the threshold value TBAT. However, as this limitation proceeds, the output power P _BAT is finally limited to substantially zero, and the output power P _BAT cannot be reduced any further.

When the power consumption P _LOAD further decreases from this state, the power P _BUY decreases to the threshold value TFC. Therefore, as the power consumption P _LOAD further decreases, the output power P _FC is limited so that the power P _BUY does not become equal to or less than the threshold value TFC. As a result, finally, the output power P _BAT is limited to substantially zero, the output power P _FC is limited to less than 400 W (for example, 399 W), and the state where the power P _BUY exceeds the threshold TFC is maintained.

As is clear from the above description, in the case of the first case, the output of the secondary battery system 3 is limited until the sum of the output powers of the cogeneration system 2 and the secondary battery system 3 does not exceed the threshold value. Yes.

In the case of the second case, the output of the secondary battery system 3 is first limited until the sum of the output powers of the cogeneration system 2 and the secondary battery system 3 does not exceed the threshold, and then the cogeneration is performed. System 2 output is limited.

Thus, the power control device 6 has a low priority until the sum of the output powers of the cogeneration system 2 and the secondary battery system 3 does not exceed a threshold value (which varies depending on the power consumption P _{LOAD at} that time). In this order, the output of the distributed power supply system is limited. This threshold value is power consumption P _LOAD -threshold value TBAT until the output power P _BAT becomes substantially zero, and thereafter power consumption P _{LOAD -threshold} value TFC.

In other words, the controller 5 advances the output restriction for only one distributed power supply system. When the output power of this distributed power supply system is limited to approximately zero, the output restriction is similarly applied to only one distributed power supply system with the next lowest priority while maintaining this restricted state. Will continue. The power control device 6 performs such an operation until the total output power does not exceed the threshold value. Thereby, output restriction of a plurality of distributed power supply systems is not advanced at the same time (the severity of restriction changes), and it is avoided that the operation of output restriction becomes complicated.

Also, the output power is controlled so that the AC output of the solar cell system 1 does not exceed the set threshold value. The generated power of the solar cell system 1 is supplied to the power system until this threshold is reached, and at the same time, the generated power of the cogeneration system 2 and the secondary battery system 3 is not supplied to the power system. Therefore, by changing the threshold value set in the solar cell system 1, it is possible to control the AC power that is reversely flowed to the power system. If a signal for setting the threshold value is sent from the outside to the controller 5, this reverse power flow is externally transmitted. The amount of power can be changed. For example, a distributed power system including such a solar cell system 1 is linked to an electric power system so that AC power can be superimposed, and is superimposed on the electric power system according to the amount of electric power superimposed on the electric power system from a plurality of distributed power systems. When a signal for regulating the amount of AC power to be input is input, a control unit that suppresses the amount of AC power superimposed on the power system is provided. Furthermore, the distributed power supply system including such a solar cell system 1 is connected to the power system via a connection point so that AC power can be superimposed, and regulates the amount of AC power superimposed on the power system. When a signal is input, it has a control unit that suppresses the amount of AC power superimposed on the power system.

[Types related to priority setting]
As described above, the controller 5 sets priority for each of the distributed power supply systems based on the predetermined information. With regard to the mode in which the controller 5 sets the priority order (or the setting content is updated), the mode will be described below by taking the first to fourth modes as examples.

<First form>
The first form can be adopted when one of the plurality of distributed power supply systems is a secondary battery system (a secondary battery is used as a distributed power supply). The first form is a form in which the priority order of the secondary battery system is fixedly set to the lowest priority order. That is, in the power system 9, the controller 5 of the first form fixedly sets the priority order of the secondary battery system 3 to a lower order than the cogeneration system 2. The solar cell system 1 is not limited.

As already described, the secondary battery 31 is superior in output controllability (responsiveness) compared to the fuel cell 21 and the like. That is, according to the secondary battery 31, even when a situation in which a sudden output change is required (for example, a situation in which the power consumption P _LOAD suddenly decreases), a quicker response can be made. ing. Therefore, according to the first embodiment, the secondary battery system 3 is first subjected to output restriction, and the characteristics of the secondary battery 31 can be utilized. Furthermore, it is possible to extend the life of the fuel cell 21 by preventing the cogeneration system 2 from being subject to output restriction as much as possible and reducing the burden on the fuel cell 21.

Note that the power control device 6 can moderately suppress the output of the fuel cell 21 while the priority order of the secondary battery system 3 is set to a lower order than the cogeneration system 2. Also good. In this way, the output of the fuel cell 21 can be gradually changed while allowing the secondary battery system 3 to respond quickly to fine fluctuations in the power consumption of the load. As a result, it is possible to extend the life of the fuel cell 21 by reducing the burden on the fuel cell 21.

<Second form>
The second form can be adopted when one of the plurality of distributed power supply systems is a secondary battery system (a secondary battery is used as a distributed power supply). In the second form, information on the remaining charge of the secondary battery is acquired as reference information, and the setting contents of the priority order are updated according to this reference information.

For example, in the power system 9, the controller 5 of the second form monitors the remaining charge of the secondary battery 31. The controller 5 sets the priority order of the secondary battery system 3 to a lower order than the cogeneration system 2 while the remaining charge amount is less than or equal to the predetermined reference amount. The priority order of the battery system 3 is set higher than the cogeneration system 2. The solar cell system 1 is not limited.

Thereby, when the remaining charge of the secondary battery 31 is relatively small (usually, the importance of the secondary battery 31 is considered low), the secondary battery system 3 is first subjected to output restriction, It is possible to prevent the cogeneration system 2 from being subject to output restriction as much as possible. On the other hand, when the remaining charge of the secondary battery 31 is relatively large (usually, the importance of the secondary battery 31 is considered high), the secondary battery system 3 should not be subject to output restriction as much as possible. Is possible.

<Third form>
The third mode may be employed when one of the plurality of distributed power supply systems is a cogeneration system (a power generation device such as a fuel cell or a gas engine is used as a distributed power supply). The third mode is information on the cogeneration system (for example, the power that can be generated by the power generator, the amount of hot water in the hot water tank in which hot water warmed by the exhaust heat of the power generator is stored, and the temperature of the hot water tank) Is set as reference information, and the priority setting content is updated according to the reference information.

For example, in the power system 9, the controller 5 of the third form monitors the amount (or temperature) of hot water in the hot water tank 23a. The controller 5 sets the priority order of the cogeneration system 2 to a higher or higher order than the secondary battery system 3 while the amount of hot water (or temperature) is below a predetermined reference amount, and exceeds the reference amount. During the operation, the priority order of the cogeneration system 2 is set lower than that of the secondary battery system 3. The solar cell system 1 is not limited.

Thereby, when the amount of hot water (or temperature) in the hot water storage tank 23a is relatively small, that is, when the necessity of supplying hot water to the hot water storage tank 23a is high and the importance of the fuel cell 21 is considered to be high, the cogeneration system It is possible to prevent 2 from being subject to output restriction as much as possible.

On the other hand, when the amount of hot water (or temperature) in the hot water storage tank 23a is relatively large, that is, a sufficient amount of hot water is secured in the hot water storage tank 23a (therefore, it is less necessary to supply hot water to the hot water storage tank 23a from now on). When the importance of the battery 21 is considered to be low, it is possible to make the cogeneration system 2 subject to output restriction first and to prevent the secondary battery system 3 from being subject to output restriction as much as possible.

<4th form>
The fourth mode can be employed when one of the plurality of distributed power systems is a cogeneration system (a power generation apparatus that generates power using fuel supplied in advance is a distributed power source). In the fourth mode, information on the remaining amount of fuel supplied to the power generation apparatus is acquired as reference information, and the priority setting content is updated according to this reference information.

For example, in the power system 9, the controller 5 of the fourth form monitors the remaining amount of fuel supplied to the fuel cell 21. The controller 5 sets the priority of the cogeneration system 2 to a lower order than the secondary battery system 3 while the remaining amount is equal to or less than the predetermined reference amount, and the cogeneration system 2 while the remaining amount exceeds the reference amount. 2 is set higher than the secondary battery system 3. The solar cell system is not limited.

As a result, when the remaining amount of fuel is relatively small (usually, the importance of the fuel cell 21 is considered to be low), the cogeneration system 2 is first subjected to output restriction and the secondary battery system 3 can be formed. As a result, it is possible to prevent the output from being restricted. On the other hand, when the remaining amount of fuel is relatively large (usually, the importance of the fuel cell 21 is considered high), it is possible to prevent the cogeneration system 2 from being subject to output restriction as much as possible.

[Others]
As described above, the power control device 6 sets priorities for each of the solar cell system 1, the cogeneration system 2, and the secondary battery system 3 (a plurality of distributed power supply systems) linked to the power system. A functional unit (priority setting unit), and a functional unit (power limiting unit) that limits the output of the distributed power supply system so that the sum of the outputs of the cogeneration system 2 and the secondary battery system 3 does not exceed the respective thresholds. It is equipped with. The power limiting unit limits the output of the distributed power supply system in order from the lowest priority until the output does not exceed the above threshold.

Therefore, according to the controller 5, regarding the output restriction of the solar cell system 1, the cogeneration system 2, and the secondary battery system 3, it is determined in advance which distributed power supply system this output restriction is executed first. Can be performed more appropriately. In the present embodiment, the present invention can be similarly applied even when the number of distributed power supply systems subject to output restriction is three or more.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the gist of the present invention.

This application is based on a Japanese patent application (Japanese Patent Application No. 2010-291572) filed on Dec. 28, 2010, the contents of which are incorporated herein by reference.

The present invention can be used for a power system having a plurality of distributed power supply systems.

DESCRIPTION OF SYMBOLS 1 Solar cell system 2 Cogeneration system 3

Secondary battery system

4a, 4b Electric power detection point 5 Controller 6 Electric power control apparatus 11 Solar cell 12 Solar cell power conditioner 21 Fuel cell 22 Cogeneration power conditioner 23 Waste heat utilization equipment 23a Hot water storage tank 31 Two Secondary battery 32 Power conditioner for secondary battery L Power transmission line

Claims

For each of a plurality of distributed power systems connected to a power system via a common connection point, the power is set in advance so that the power flowing to the power system through the common cooperation point does not exceed a threshold value. The power control apparatus that limits the output of the distributed power supply system in descending order of priority.
The power control apparatus according to claim 1,
One of the plurality of distributed power systems is a secondary battery system,
The power control apparatus, wherein the priority order of the secondary battery system is set to the lowest priority order.
The power control apparatus according to claim 1,
The power control apparatus, wherein the priority order is updated according to predetermined reference information.
The power control device according to claim 3,
One of the plurality of distributed power systems is a secondary battery system,
The power control apparatus according to claim 1, wherein the priority is set based on information on a remaining charge of the secondary battery system.
The power control device according to claim 3,
One of the plurality of distributed power systems is a cogeneration system having a power generation device,
The priority is determined by referring to any information of the power that can be generated by the power generator, the amount of hot water stored in the hot water tank that stores hot water heated by the exhaust heat of the power generator, and the temperature of the hot water tank. A power control device that is set.
The power control device according to claim 3,
One of the plurality of distributed power systems is a cogeneration system having a power generation device that generates electric power using supplied fuel,
The power control apparatus according to claim 1, wherein the priority is set with reference to information on a remaining amount of fuel supplied to the power generation apparatus.
The power control device according to claim 5,
When the amount of hot water in the hot water storage tank has not reached a predetermined reference value, the priority order of the cogeneration system is set to the highest priority order.
Stores the priorities assigned to a plurality of distributed power systems linked so that AC power can be superimposed on the power system, and sums the AC power to be superimposed on the power system from the plurality of distributed power systems and a predetermined threshold value And outputting a signal for limiting the amount of AC power to be superimposed on the power system according to the priority order.
The power control apparatus according to claim 8, wherein
The distributed power system includes a configuration in which DC power output from at least one of generated power of a solar battery or discharged power of a storage battery is converted into AC power and superimposed on the power system. apparatus.
A signal that regulates the amount of AC power superimposed on the power system in accordance with the amount of power superimposed on the power system from a plurality of distributed power systems in a distributed power system linked so that AC power can be superimposed on the power system A distributed power supply system comprising a control unit that suppresses an amount of alternating current power that is superimposed on the electric power system when the power is input.
In a distributed power supply system connected to a power system via a connection point and capable of superimposing AC power, when a signal for regulating the amount of AC power superimposed on the power system is input to the power system A distributed power supply system comprising a control unit that suppresses the amount of alternating-current power to be superimposed.