JP2005295674A - Power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily interconnect to two or more commercial systems having different power specifications, and inhibit an increase in an installation space and in an apparatus cost. <P>SOLUTION: A power supply apparatus comprises a fuel cell body 21 for receiving a supplied fuel, generating and outputting power, a first inverter 22 and a second inverter 23 for inputting the generated power, a first fuel cell breaker 24 connected between a connection point of the first commercial system 1 and an electric light panel 2 and the first inverter 22, a second fuel cell breaker 25 connected between a connection point of the second commercial system 4 and a power panel 5 and the second inverter 23, an auxiliary machine 26 and a controller 27 connected to a connection point between the first inverter 22 and the first fuel cell breaker 24. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power supply apparatus that interconnects power generated from a generator with a commercial system.

  Conventionally, it has been proposed that power generated from a generator such as a fuel cell be connected to a commercial system.

  FIG. 14 is a diagram illustrating a conventional configuration for connecting power generated from a generator such as a fuel cell to a commercial system.

In FIG. 14, power generated from a fuel cell main body that receives a supply of fuel and performs a power generation operation is converted into power by an inverter and connected to a commercial system via a fuel cell power panel, and the refrigeration air conditioner is powered. It is connected to the commercial system via the panel.
In this specification, the refrigeration air conditioner is used as a generic term for a refrigerator and an air conditioner.

  In the configuration shown in FIG. 14, the specifications of power to be output are determined by a commercial system that can be connected to the grid. For example, there are two or more commercial systems with different power specifications, such as a light system and a low-voltage power system in a small store. When it exists, it is necessary to install separately the structure shown in FIG. 14 corresponding to the commercial system of each electric power use.

As a result, the installation space is increased and the cost of the apparatus is increased.
The present invention has been made in view of the above problems, and can be easily interconnected with two or more commercial systems having different power specifications, and can suppress an increase in installation space and an increase in apparatus cost. An object of the present invention is to provide a power supply device capable of performing the above.

  The power supply device of the present invention includes one generator and a plurality of inverters that supply power to different power systems using the output power of the generator as an input.

With this power supply apparatus, the required number of generators can be minimized (one), and as a result, installation space, apparatus cost, installation work cost, and the like can be reduced. Moreover, since it is connected to a plurality of commercial systems, the operating rate of the generator can be improved.
In this case, it is preferable that the plurality of inverters include a single-phase inverter that outputs single-phase power and a three-phase inverter that outputs three-phase power.

  In small stores, etc., the commercial system is divided into a light system and a low-voltage power system. However, when the size of the consumer is small, the load fluctuation of each power system is larger than that of a large-scale consumer. If a generator is installed corresponding to each of these, the generator's operating rate will decrease, but a single generator (single-phase two-wire 100V, single-phase three-wire 200 / 100V, etc.) And three-phase power (three-phase three-wire 200V, etc.) can be output, the generator operating rate can be greatly improved.

  Also, if the generator requires an auxiliary power source, it is preferred that this auxiliary power source be derived from single phase power.

  Since the auxiliary power supply supplies the power of the control device and auxiliary equipment at start-up, it does not require a large capacity, and it is sufficient to obtain it from the single-phase commercial power supply side. Can do.

  Also, power supply amount detection means for detecting the amount of power supply from the commercial system side to each system to which the power supply device is connected, the generator capacity based on the detected power supply amount, and to each system It is preferable to further include a control means for performing the output capacity control of the generator, and the power generation capacity control of the generator, the output capacity control to each system can be appropriately performed, and the reverse power flow to the commercial system is prevented. Can do.

  In addition, the control means preferably controls the output to each system so as to preferentially output the generated power of the generator to the commercial system side having a higher electricity bill, and the running merit is expanded. can do.

  Preferably, the generator is a fuel cell, and the control means also controls output distribution to each system in order to prevent reverse flow of the generated power. For example, priority is given to generated power. If the load on the grid that was being output suddenly decreases and reverse power flow is about to occur, the output to other systems is increased, thereby avoiding reverse power flow and sudden changes in the power generation capacity of the fuel cell Can be avoided.

  In addition, it is preferable to further include a power storage unit such as a secondary battery or a capacitor connected in parallel with the generator. When fast load fluctuations occur in all output systems, output distribution control for each system can handle However, even in such a case, it is possible to absorb the imbalance between the load and the power generation amount of the fuel cell by charging and discharging the power storage unit.

  The control means includes a charge output means for outputting at least a power charge and a fuel charge, and a capacity output control means for performing power generation capacity control and output control to each system based on the output power charge and fuel charge. Furthermore, it is preferable to include this, and by performing the control based on the fee, it is possible to perform fine priority output control for each season and to maximize the running merit.

  In addition, it is preferable that the charge output means is one in which unit price data or charge calculation software can be rewritten by communication from a remote place, so that it is possible to save the trouble of inputting by the customer, and incur disadvantages due to forgetting to update, etc. Can be prevented.

  In addition, it is preferable to supply the commercial system side of the three-phase power through the electrical wiring to the refrigeration air conditioner, among the power panel of the generator, the three-phase system power panel or breaker can be made unnecessary, Reduction of space and initial cost can be achieved.

  Moreover, it is preferable that the said generator and an inverter are integrated with the said refrigeration air conditioner, and an installation space and apparatus initial cost can be reduced.

  Since the power supply apparatus of the present invention does not require the installation of a plurality of generators, there is no need for overlapping portions, and it is possible to reduce costs, installation space, construction costs, etc. On the other hand, in order to generate electricity with one generator, there is a specific effect that the operating rate of the generator can be improved.

Embodiments of a power supply apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an embodiment of a power supply apparatus of the present invention.

  This power supply device is connected to a first commercial system 1 through a lighting board 2 for lighting, an outlet 3 and the like, and is connected to a second commercial system 4 through a power panel 5 for a refrigeration air conditioner 6. Connected.

  In addition, the fuel cell main body 21 that receives the supply of fuel and outputs generated power, the first inverter 22 and the second inverter 23 that receive the generated power, the first commercial system 1 and the lamp board 2 The first fuel cell breaker 24 connected between the connection point and the first inverter 22, the connection point between the second commercial system 4 and the power panel 5, and the second inverter 23. The second fuel cell breaker 25, the auxiliary device 26 connected to the connection point between the first inverter 22 and the first fuel cell power panel 24, and the control device 27. .

  The first commercial system 1 is, for example, a single-phase 100V, and the second commercial system 4 is, for example, a three-phase 200V. However, it is not limited to these. Accordingly, the first inverter 22 is configured to output a single-phase 100V, and the second inverter 23 is configured to output a three-phase 200V.

  In the embodiment of FIG. 1, the fuel cell main body 21 is adopted as a generator, but other generators such as a gas engine generator can be adopted.

  The power supply apparatus having the above configuration can link the power generated by one generator with the first commercial system 1 and the second commercial system 4 by the first inverter 22 and the second inverter 23. it can.

  Accordingly, it is not necessary to install a plurality of generators, so that an overlapping portion is unnecessary, and costs, installation space, construction costs, and the like can be reduced.

  Moreover, since the power is generated by a single generator for a plurality of power loads, the operating rate of the generator can be improved.

  As can be seen from the above, since the operating rate of the generator is high with a small space and low initial cost, it is possible to realize an electric power supply device that is quickly depreciated and has a high economic effect.

  In small stores, etc., the system is divided into a light system and a low-voltage power system. However, when the size of the customer is small, the load fluctuation of each power system is larger than that of a large-scale customer. Although the operating rate of the generator is significantly reduced, in this embodiment, since both single-phase power and three-phase power can be output, the operating rate of the generator can be significantly improved.

  Further, since the auxiliary power supply supplies the power of the control device 27 and the power of the auxiliary machine 26 at the time of start-up, it does not require a large capacity, and it is sufficient to obtain it from the first commercial system 1 side. The wiring cost can be reduced because of the phase.

  FIG. 2 is a block diagram showing another embodiment of the power supply apparatus of the present invention.

This power supply device is different from the power supply device of FIG. 1 in that a first inflow current value detection unit 28 is provided between the first commercial system 1, the lamp panel 2, and the first fuel cell power supply panel 24. The second inflow current value detection unit 29 is provided between the second commercial system 4 and the power panel 5 and the second fuel cell power panel 25, the first inverter 22 and the first inverter 22 The first output detection unit 30 is provided between the fuel cell power supply panel 24 and the second output detection unit 31 is provided between the second inverter 23 and the second fuel cell power supply panel 25. The output from the first inflow current value detector 28, the output from the second inflow current value detector 29, the output from the first output detector 30, and the output from the second output detector 31 To the control device 27, and control signals from the control device 27 are sent to the fuel cell body 21, the first inverter 22, and the second inverter. Converter 23, and only points supplied to the auxiliary machine 26.
Instead of the inflow current value detection units 28 and 29, one that actually detects the amount of electric power may be employed.

FIG. 3 is a flowchart for explaining the operation of the power supply apparatus of FIG.
In the following description, the subscript i indicates the single-phase side or the three-phase side, i = 1 on the single-phase side, and i = 3 on the three-phase side.

  In step SP1, the current value ICi flowing from the commercial system side is detected. In step SP2, it is determined whether or not the current value ICi is smaller than the first threshold value ICLi, and the current value ICi is smaller than the first threshold value ICLi. If not, it is determined in step SP3 whether or not the current value ICi is smaller than the second threshold value ICHi.

  If the current value ICi is smaller than the first threshold value ICLi, the inverter output control target value WSi is set to 0 in step SP4.

When the current value ICi is a value between the first threshold value ICLi and the second threshold value ICHi, in step SP5, the inverter output control target value WSi is set to WRi × (ICi−ICLi) / (ICHi−ICLi). Set to. Note that WRi is an inverter rated output.
If the current value ICi is greater than or equal to the second threshold value ICHi, the inverter output control target value WSi is set to WRi in step SP6.

  After the processing from step SP1 to step SP6 is performed for each system (I = 1, 3), in step SP7, the sum ΣWSi of the inverter output control target value WSi is set as the fuel cell output control target value WFCs.

  Next, in step SP8, the magnitude of the fuel cell output control target value WFCs and the fuel cell rated output WFCR is determined. If WFCs> WFCR, the fuel cell rated output WFCR is converted to the fuel cell output control target value in step SP9. WFCs, WS1 is the smaller of WS1 and WFCs {min (WS1, WFCs)}, and WS3 is WFCs-WS1.

  If it is determined in step SP8 that WFCs ≦ WFCR, or if the processing in step SP9 is performed, in step SP10, the difference ΔWFCs between the previous fuel cell output control target value and a predetermined threshold value ΔWFC is determined. If ΔWFCs> ΔWFC, in step SP11, the previous fuel cell output control target value WFCsp and the difference ΔWFCs are added to obtain the fuel cell output control target value WFCs. The smaller one {min (WFCs-WS1, WS3)}.

  When it is determined in step SP10 that ΔWFCs ≦ ΔWFC, or when the process of step SP11 is performed, in step SP12, each inverter output is controlled so that the electric output Wi becomes the inverter output control target value WSi, In step SP13, the flow rate of fuel and air in the fuel processor (a device for processing fuel and supplying it to the fuel cell body 21, not shown) is controlled so as to meet the output W = WFCs of the fuel cell body.

Then, after the process of step SP13 is performed, the process of step SP1 is performed again.
For example, the threshold ICL is determined such that the threshold ICL is a current value corresponding to 30% of the fuel cell rated output, and the threshold ICH is a current value corresponding to the fuel cell rated output.

  In this way, as shown in FIG. 4, the fuel cell power generation output control target value WS can be set according to the current value ICi.

  In this embodiment, the capacity control of the fuel cell can be performed appropriately, and a reverse power flow to the commercial system can be prevented.

  In addition, the generated power can be preferentially output to a commercial system with a higher electricity bill, and the running merit can be expanded.

  In addition, in order to prevent the reverse power flow of the generated power, output distribution to each system can be controlled. In this case, for example, the load on the system that preferentially outputs the generated power suddenly increases. When the power flow decreases and the reverse power flow is likely to occur, a sudden change in the power generation capacity of the fuel cell can be avoided while avoiding the reverse power flow by increasing the output to another system.

FIG. 5 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.
The power supply device differs from the power supply device in FIG. 2 only in that a power storage unit 33 is provided in parallel with the fuel cell main body 21 via the charge / discharge relay 32.

  If fast load fluctuations occur in all output systems, output distribution control for each system cannot be used, but in this case, the power storage unit can be charged and discharged to generate power from the load and the fuel cell. Can absorb imbalance with quantity.

FIG. 7 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.
The power supply device is different from the power supply device of FIG. 2 in that the control device 27 outputs a charge output means (not shown) for outputting at least a power charge and a fuel charge, and the output power charge and fuel charge. Unit capacity data for charge calculation by a remote monitoring computer 35 via a communication network 34 such as the Internet, and a capacity output control means (not shown) for controlling the power generation capacity and output to each system. Or it is only the point which rewrites the software for charge calculation.

FIG. 8 is a flowchart for explaining the operation of the power supply apparatus of FIG.
In the following description, the subscript i indicates the single-phase side or the three-phase side, i = 1 on the single-phase side, and i = 3 on the three-phase side.

  In step SP1, the target power generation output WSoi is calculated based on the energy unit price. In step SP2, the current value ICi flowing from the commercial system side is detected. In step SP3, the current value ICi is greater than the first threshold value ICLi. It is determined whether or not the current value ICi is smaller than the first threshold value ICLi. In step SP4, it is determined whether or not the current value ICi is smaller than the second threshold value ICHi.

  If the current value ICi is smaller than the first threshold value ICLi, the inverter output control target value WSi is set to 0 in step SP5.

When the current value ICi is a value between the first threshold value ICLi and the second threshold value ICHi, in step SP6, the inverter output control target value WSi is set to WRi × (ICi−ICLi) / (ICHi−ICLi). Set to. Note that WRi is an inverter rated output.
If the current value ICi is greater than or equal to the second threshold value ICHi, the inverter output control target value WSi is set to WRi in step SP7.

  After the processing from step SP2 to step SP7 is performed for each system (I = 1, 3), in step SP8, the sum ΣWSi of the inverter output control target value WSi is set as the fuel cell output control target value WFCs.

Next, in step SP9, the magnitude of the fuel cell output control target value WFCs and the fuel cell rated output WFCR is determined. If WFCs> WFCR, the fuel cell rated output WFCR is converted into the fuel cell output control target value in step SP10. WFCs, WS1 is the smaller of WS1 and WFCs {min (WS1, WFCs)}, and WS3 is WFCs-WS1.
If it is determined in step SP9 that WFCs ≦ WFCR, or if the processing in step SP10 is performed, in step SP11, the difference ΔWFCs between the previous fuel cell output control target value and a predetermined threshold value ΔWFC is determined. If ΔWFCs> ΔWFC, in step SP12, the previous fuel cell output control target value WFCsp and the difference ΔWFCs are added to obtain the fuel cell output control target value WFCs, and WS3 is set between WFCs−WS1 and WS3. The smaller one {min (WFCs-WS1, WS3)}.

  If it is determined in step SP11 that ΔWFCs ≦ ΔWFC, or if the processing in step SP12 is performed, in step SP13, each inverter output is controlled so that the electric output Wi becomes the inverter output control target value WSi. In step SP14, the flow rate of fuel and air in the fuel processing device (device for processing fuel and supplying it to the fuel cell main body 21, not shown) is controlled so as to meet the output W = WFCs of the fuel cell main body.

  Then, after the processing of step SP14 is performed, the processing of step SP1 is performed again.

The process in step SP1 is performed as follows, for example.
First, the electricity rate CE [yen / kWh] is calculated as follows.
If from 8:00 to 22:00, CE1 = 28, CE3 = 13
From 12:00 to 18:00, CE1 = 6, CE3 = 13
Further, the calculation of the gas charge CG [yen / kWh] is performed as follows.
CG = 4.5
The maintenance cost CM [yen / kWh] is calculated as follows.
CM = 2
Further, the power generation efficiency E [−] is calculated.
E = 0.5
Based on these, the target power generation output WSo [kW] is calculated as follows.
From 8:00 to 22:00 When CG / E + CM <CE1, WSo1 = WFCR, WSo3 = 0
22:00 to 8 o'clock When CE1 <CG / E + CM <CE3, WSo1 = 0, WSo3 = WFCR
If CE3 <CG / E + CM, WSo1 = 0, WSo3 = 0
Therefore, as shown in (A) of FIG. 9, the electric power system load purchases commercial power at night and supplies most of it from the fuel cell main body 21 during the day.
As for the low-voltage power system load, as shown in FIG. 9B, the supply from the fuel cell main body 21 and the purchase of commercial power are used together without distinction between day and night.

As shown in FIG. 9C, the power generation amount of the fuel cell main body 21 and its distribution are distributed only to the low-voltage power system at night and to the lamp system and low-voltage power system during the day.
In this case, by controlling based on the fee, it is possible to perform fine priority output control according to the time by season and maximize the running merit. In addition, maintenance costs and service life can be considered.

  In addition, unit price data or calculation software for calculating power charges and fuel charges can be rewritten remotely by communication, so that it is possible to eliminate the trouble of customer input and prevent disadvantages due to forgetting to update. .

FIG. 10 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.
This power supply device is different from the power supply device in FIG. 1 in that the second fuel cell power supply panel 25 is omitted, the auxiliary device 26 and the control device 27 are omitted, and the output of the second inverter 23 is directly set. It is only the point supplied to the refrigeration air conditioner 6.

  In this case, among the power supply panels of the generator, a three-phase power supply panel or breaker is not required, and space saving and initial cost reduction can be realized.

FIG. 11 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.
This power supply device is different from the power supply device of FIG. 10 only in that the fuel cell main body 21 and both inverters 22 and 23 are integrated with the refrigeration air conditioner 6.

  In this case, installation space and device initial cost can be reduced.

  FIG. 12 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.

  This power supply device is different from the power supply device of FIG. 11 in that heat exchange is performed between the exhaust heat of the fuel cell main body 21 and the refrigerant in the refrigerant flow path of the refrigeration air conditioner 6 in parallel with the outdoor heat exchanger 35. It is only the point which provided the waste heat utilization heat exchanger 34 which performs this.

  Note that 36 is a compressor, 37 is an indoor heat exchanger, 38 is a condenser, 39 is an evaporator, and 40 is a four-way valve.

  In this case, by using the exhaust heat in the same system, it can be used appropriately, so that energy saving can be improved.

  FIG. 13 is a block diagram showing still another embodiment of the power supply apparatus of the present invention.

  This power supply device is different from the power supply device of FIG. 10 in that an exhaust heat utilization heat exchanger (for example, a boiler or the like) that supplies hot water by exchanging heat between the exhaust heat of the fuel cell main body 21 and water. Only 41 is provided.

However, the exhaust heat utilization heat exchanger 41 may further have a heating source.
In this case, the energy saving performance can be enhanced by preferentially using the boiler having low energy use efficiency compared to the refrigerator.

It is a block diagram which shows one Embodiment of the electric power supply apparatus of this invention. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a flowchart explaining the effect | action of the electric power supply apparatus of FIG. It is a figure explaining the change of the inverter output control target value corresponding to the inflow current value from a commercial system. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a figure explaining the effect | action of an electrical storage part. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a flowchart explaining the effect | action of the electric power supply apparatus of FIG. It is a figure explaining the electric power feeding by the electric power supply apparatus of FIG. 7, the purchase from a commercial system, and distribution of the electric power generation amount. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a block diagram which shows other embodiment of the electric power supply apparatus of this invention. It is a block diagram which shows the conventional electric power supply apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st commercial system 4 2nd commercial system 6 Refrigeration air conditioner 21 Fuel cell main body 22 1st inverter 23 2nd inverter 27 Control apparatus 28 1st inflow current value detection part 29 2nd inflow current value detection Unit 33 Power storage unit

Claims (11)

It includes one generator (21) and a plurality of inverters (22) and (23) that supply power to different power systems (1) and (4) using the output power of the generator (21) as an input. A power supply device. The power supply according to claim 1, wherein the plurality of inverters (22) and (23) include a single-phase inverter (22) that outputs single-phase power and a three-phase inverter (23) that outputs three-phase power. apparatus. The power supply device according to claim 2, wherein the generator (21) requires an auxiliary power source, and the auxiliary power source is obtained from single-phase power. Based on the detected power supply amount and power supply amount detection means (28) (29) for detecting the power supply amount from the commercial system (1) (4) side to each system to which the power supply device is connected. The power supply device according to any one of claims 1 to 3, further comprising a control means (27) for controlling the power generation capacity of the generator and the output capacity to each system. The said control means (27) also performs output control to each system in order to preferentially output the generated power of the generator (21) to the commercial system side having a higher electricity bill. The power supply device described. The said generator (21) is a fuel cell, and the said control means (27) also controls the output distribution to each system | strain in order to prevent the reverse power flow of the generated electric power. 5. The power supply device according to 5. The power supply device according to any one of claims 1 to 6, further comprising a power storage unit (33) connected in parallel with the generator (21). The control means (27) includes a charge output means for outputting at least a power charge and a fuel charge, and a capacity output control means for performing power generation capacity control and output control to each system based on the output power charge and fuel charge. The power supply device according to any one of claims 4 to 7, further comprising: 9. The power supply apparatus according to claim 8, wherein the fee output means (27) is configured to rewrite unit price data or fee calculation software by communication from a remote place. The power supply device according to any one of claims 2 to 9, wherein the three-phase power is supplied to the commercial system (4) side through electric wiring to the refrigeration air conditioner (6). The power supply device according to claim 10, wherein the generator (21) and the inverter (22) (23) are integrated with the refrigeration air conditioner (6).

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