WO2017029756A1

WO2017029756A1 - Power supply system, output control device, output control method, and recording medium

Info

Publication number: WO2017029756A1
Application number: PCT/JP2015/073364
Authority: WO
Inventors: 佐藤　克彦; 梅本　哲正; 沖田　真大
Original assignee: シャープ株式会社
Priority date: 2015-08-20
Filing date: 2015-08-20
Publication date: 2017-02-23

Abstract

A power supply system 1 supplies power to a load 5 through connection between a first power supply section 2 and a plurality of second supply sections 3a-3c. The power supply system 1 is provided with a control unit 4, which is provided to be able to obtain a power value for the load 5 and the total output value for the plurality of second power supply sections 3a-3c, and to set the same output upper limit value for the plurality of second power supply section 3a-3c. The control section 4 sets, as the output upper limit value, a value obtained by adding an adjustment value obtained in accordance with the total output value to an output upper limit calculation value calculated on the basis of the power value for the load 5 and a first value derived from the first power supply section 2.

Description

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

The present invention relates to a power supply system, an output control device, an output control method, and a recording medium. The present invention relates to a technique suitable for a hybrid system in which a power generator using natural energy is linked to a diesel generator.

Conventionally, an inexpensive diesel generator is used as a main power source in a place where there is no power system. In recent years, hybrid systems have been proposed in which a power generator using natural energy is linked to a diesel generator for the purpose of reducing fuel. For example, Patent Document 1 discloses a self-supporting power supply device that includes a distributed power source and a diesel generator using natural energy and is disconnected from a commercial power source. Note that a distributed power source using natural energy is configured to use, for example, solar power generation or wind power generation.

In the self-supporting power supply device of Patent Document 1, the DC / AC converter whose DC side is connected to the power storage device always operates independently. The diesel generator is connected to the power storage device via an AC / DC converter. A start / stop command and a power command to be output from the generator are sent from the control device to the diesel generator. With this configuration, there is no frequency fluctuation at the output end, and the diesel generator can be easily operated.

JP 2013-13176 A

When a configuration in which a power storage device is included in a hybrid system as in Patent Document 1, the installation cost and operating cost of the system increase. For this reason, for example, when it is desired to reduce costs, the hybrid system preferably does not include a power storage device.

In the hybrid system, when the output of the diesel generator decreases, the power generation efficiency deteriorates or the diesel generator fails. For this reason, in a hybrid system or the like that does not include a power storage device, an output upper limit value may be set in a power conditioner (hereinafter referred to as PCS) so that the diesel generator does not become a light load.

In a hybrid system including a plurality of PCSs, the output upper limit value given to each PCS may be the same. With this configuration, for example, the signal line in the hybrid system can be prevented from becoming complicated. However, if the output upper limit value is uniformly set to the same value, the output is restricted more than necessary, and natural energy may not be effectively used.

In view of the above points, an object of the present invention is to improve energy utilization efficiency when power is supplied to a load by linking a first power supply unit and a plurality of second power supply units. Is to provide.

To achieve the above object, a power supply system of the present invention is a power supply system that supplies power to a load by linking a first power supply unit and a plurality of second power supply units, A control unit configured to be able to acquire a power value of the load and a total output value of the plurality of second power supply units, and to set the same output upper limit value to the plurality of second power supply units; The control unit is obtained according to the total output value to an output upper limit calculation value calculated based on a power value of the load and a first value derived from the first power supply unit. A value obtained by adding an adjustment value is used as the output upper limit value.

In order to achieve the above object, an output control device according to the present invention is an output control device that controls outputs of a plurality of second power supply units that supply power to a load in cooperation with a first power supply unit. A power management unit provided to be able to obtain a power value of the load and a total output value of the plurality of second power supply units, and an output upper limit value that is the same for the plurality of second power supply units An upper limit value setting unit that sets the output upper limit calculation value calculated based on a power value of the load and a value derived from the first power supply unit, A value obtained by adding an adjustment value obtained according to the total output value is used as the output upper limit value.

In order to achieve the above object, the output control method of the present invention is an output control method for controlling outputs of a plurality of second power supply units that supply power to a load in cooperation with the first power supply unit. Then, an output upper limit calculation value is calculated based on the step of obtaining the total output value of the plurality of second power supply units, and the power value of the load and the value derived from the first power supply unit. A step of adding an adjustment value obtained according to the total output value to the output upper limit calculated value as an output upper limit value, and the output upper limit that is the same for each of the plurality of second power supply units And a step of transmitting a value.

In order to achieve the above object, a recording medium of the present invention is a computer-readable recording medium in which a computer-executable program is recorded non-temporarily, and causes the computer to execute the output control method. It is characterized by the fact that a program is recorded.

According to the present invention, when the first power supply unit and the plurality of second power supply units are linked to supply power to the load, it is possible to improve energy use efficiency.

The block diagram which shows schematic structure of the electric power supply system which concerns on embodiment of this invention The schematic diagram for demonstrating the subject which the electric power supply system which concerns on embodiment of this invention solves The block diagram which shows the structure of the electric power supply system which concerns on 1st Embodiment of this invention. The block diagram which shows the structure of the solar power generation device with which the electric power supply system which concerns on 1st Embodiment of this invention is provided. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 1st Embodiment of this invention is provided. The flowchart which shows the setting flow of the output upper limit in the electric power supply system which concerns on 1st Embodiment of this invention. Schematic diagram showing numerical examples that facilitate understanding of the output upper limit setting flow shown in FIG. The block diagram which shows the structure of the electric power supply system which concerns on 2nd Embodiment of this invention. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 2nd Embodiment of this invention is provided. The flowchart which shows the setting flow of the output upper limit in the electric power supply system which concerns on 2nd Embodiment of this invention. Schematic diagram showing a numerical example that facilitates understanding of the output upper limit setting flow shown in FIG. The block diagram which shows the structure of the solar power generation device with which the electric power supply system which concerns on 3rd Embodiment of this invention is provided. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 3rd Embodiment of this invention is provided. The flowchart which shows the setting flow of the output upper limit in the electric power supply system which concerns on 3rd Embodiment of this invention. The flowchart which shows the process B added in the electric power supply system which concerns on 3rd Embodiment of this invention. The block diagram which shows the structure of the solar power generation device with which the electric power supply system which concerns on 4th Embodiment of this invention is provided. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 4th Embodiment of this invention is provided. The flowchart which shows the setting flow of the output upper limit in the electric power supply system which concerns on 4th Embodiment of this invention. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 5th Embodiment of this invention is provided. The figure which shows an example of the table memorize | stored in the PCS management data storage part with which the electric power supply system which concerns on 5th Embodiment of this invention is equipped. The block diagram which shows the structure of the electric power supply system which concerns on 6th Embodiment of this invention. The block diagram which shows the function structure of the controller with which the electric power supply system which concerns on 6th Embodiment of this invention is provided. The flowchart which shows the setting flow of the output upper limit in the electric power supply system which concerns on 6th Embodiment of this invention.

Hereinafter, a power supply system, an output control device, an output control method, and a recording medium according to embodiments of the present invention will be described in detail with reference to the drawings. Note that in the drawings showing the block diagrams, a solid line indicates a power line, and a broken line indicates a signal line.
<Outline of power supply system>

First, an outline of a power supply system according to an embodiment of the present invention will be described. FIG. 1 is a block diagram showing a schematic configuration of a power supply system 1 according to an embodiment of the present invention. As shown in FIG. 1, the power supply system 1 includes a first power supply unit 2, a plurality of second power supply units 3a to 3c, and a controller 4. The first power supply unit 2 and the plurality of second power supply units 3a to 3c cooperate to supply power to the load 5.

The controller 4 includes a computer and functions as an output control device for the plurality of second power supply units 3a to 3c. The controller 4 performs output control of the plurality of second power supply units 3a to 3c in accordance with an output control program executed by the computer. The output control program may be stored in a storage unit provided in the controller 4. As another configuration, for example, the output control program may be recorded on the recording medium 6 that non-temporarily records a program executable by the computer. The recording medium 6 may be an optical disk, a magnetic disk, a flash memory, or the like, for example. The controller 4 is an example of a control unit of the present invention.

The power supply system 1 may be a system that supplies power in a single phase or a system that supplies power in three phases. Further, the controller 4 may control the first power supply unit 2. The control unit that controls the first power supply unit 2 may be provided separately from the controller 4.

The same output upper limit value is set for each of the plurality of second power supply units 3a to 3c. As a reason for adopting such a configuration, for example, avoiding a situation where a signal line in the system becomes complicated. In FIG. 1, the number of second power supply units is three, but this is only an example. The number of the second power supply units may be plural, and the number may be changed as appropriate.

FIG. 2 is a schematic diagram for explaining a problem to be solved by the power supply system 1 according to the embodiment of the present invention. Here, the case where the first power supply unit 2 is a diesel power generation device and the second power supply units 3a to 3c are solar power generation devices will be described as an example. The diesel generator 2 includes a diesel generator and operates as a main power source. The diesel power generator 2 may include a plurality of diesel generators. Each of the solar power generation devices 3a to 3c includes a solar panel and a PCS. The PCS converts DC power generated by the solar panel into AC power and outputs the AC power to the load 5.

When the diesel generator 2 is operated with a light load of about 50% or less of the rated value, unburned gas is likely to be generated. As a result, oil that has not burned from the exhaust pipe may drip or a large amount of black smoke may be generated. In order to prevent such a situation from occurring, a generator having a smaller rated output is selected. Moreover, in order to avoid a light load driving | operation, the minimum output (output lower limit) is set to the diesel generator 2. In the example shown in FIG. 2, the rated output of the diesel power generator 2 is 500 kW, and the minimum output is 40% (200 kW) of the rated output.

The PCS of each of the solar power generation devices 3a to 3c normally outputs the maximum power generated by sunlight by MPPT (Maximum Power Point Tracking) control. In the PCS, an output upper limit value is set by an external signal. When it is necessary to suppress the output by the output upper limit value, the PCS can prevent the output in accordance with the MPPT control. In the example shown in FIG. 2, the rated output of each PCS (the maximum output of the solar power generation device) is 100 kW.

In FIG. 2, the plurality of solar power generation devices 3a to 3c are installed with different installation angles (directions). When installed in this way, the peak time of power generation differs for each photovoltaic power generation device. In the example shown in FIG. 2, if the output is not suppressed, the first PCS outputs 70 kW, the second PCS outputs 40 kW, and the third PCS outputs 20 kW.

In the example shown in FIG. 2, the power required by the load 5 is 320 kW. When the output suppression of each PCS is not performed, the total output of the three PCSs is 130 kW. In this case, the output of the diesel generator 2 is 190 kW, which is lower than the minimum output (200 kW). Therefore, an output upper limit value is given to the three PCSs so that the output is suppressed. In this example, the output upper limit value is given so that the total output value of the three PCSs is 120 kW (= 320 kW−200 kW) or less.

As described above, the output upper limit values of the three PCSs are set to be the same. Therefore, it is conceivable to simply divide the total output value (120 kW) allowed for the three PCS into three equal parts and set the output upper limit value of each PCS to 40 kW. When the output upper limit value is set in this way, actually, the first PCS outputs 40 kW, the second PCS outputs 40 kW, and the third PCS outputs 20 kW. That is, the total output value of the three PCSs is 100 kW. Although the total output value of the three PCSs is allowed up to 120 kW, the limit is more than necessary. The controller 4 controls the output of each PCS so that such an unnecessary limit is not added. Thereby, solar power generation can be used effectively. Hereinafter, the power supply system of the present invention will be described in more detail by dividing it into a plurality of embodiments.
<First Embodiment>

FIG. 3 is a block diagram showing the configuration of the power supply system according to the first embodiment of the present invention. In the power supply system of the first embodiment, the first power supply unit shown in FIG. In the power supply system of the first embodiment, the plurality of second power supply units shown in FIG. 1 are realized as a plurality of solar power generation devices 3a to 3b.

The power supply system of the first embodiment includes a first wattmeter 7 that measures the power of the load 5 and a second wattmeter that measures the total of output values output from the three solar power generation devices 3a to 3c. 8 and. Instead of the

wattmeters

7 and 8, an ammeter and a voltmeter may be arranged. Further, instead of the second wattmeter 8, a wattmeter that measures the output of the diesel power generator 2 may be provided. Further, the second wattmeter 8 is not disposed, and the total output of the three solar power generation devices 3a to 3c (three PCS) is obtained by using signals from the PCS included in the solar power generation devices 3a to 3c. A value may be obtained.

FIG. 4 is a block diagram showing a configuration of the solar power generation device 3a included in the power supply system according to the first embodiment of the present invention. The three solar power generation devices 3a to 3c have the same configuration. Therefore, here, the solar power generation device 3a will be described as a representative example, and description of the other solar

power generation devices

3b and 3c will be omitted. The solar power generation device 3 a includes a solar panel 31 and a PCS 32. The PCS 32 includes an output upper limit value acquisition unit 321 that acquires an output upper limit value from the outside. The PCS 32 includes an output control unit 322 that controls the output of the PCS based on an output upper limit value acquired from the outside.

FIG. 5 is a block diagram showing a functional configuration of the controller 4 included in the power supply system according to the first embodiment of the present invention. The controller 4 includes a power management unit 41. The power management unit 41 acquires the load power value (Pld) from the first wattmeter 7 and the total output value (Ppv) of the three PCSs 32 from the second wattmeter 8.

The controller 4 includes an upper limit setting unit 42 that sets the same output upper limit for each PCS 32. The upper limit setting unit 42 includes an upper limit calculated value calculation unit 421, an adjustment value calculation unit 422, and an output upper limit value transmission unit 423. The upper limit calculation value calculation unit 421 is provided so that information can be acquired from the power management unit 41. The adjustment value calculation unit 422 is provided so that information can be acquired from the power management unit 41 and the upper limit calculation value calculation unit 421. The output upper limit value transmission unit 423 is provided so that information can be acquired from the upper limit calculation value calculation unit 421 and the adjustment value calculation unit 422. Detailed functions of the respective functional units will be clarified in the contents described later.

FIG. 6 is a flowchart showing an output upper limit setting flow in the power supply system according to the first embodiment of the present invention. FIG. 7 is a schematic diagram illustrating a numerical example that facilitates understanding of the output upper limit value setting flow illustrated in FIG. 6. Hereinafter, in the description of the flowchart of FIG. 6, specific numerical examples will also be described with reference to FIG. 7. Note that an initial value of an adjustment value (P_offset) described later is 0.

In setting the output upper limit value, the controller 4 acquires the load power value (Pld) from the first wattmeter 7 and the total output value (Ppv) of the three PCSs 32 from the second wattmeter 8 ( Step S1). In the example shown in FIG. 7, Pld = 320 kW and Ppv = 100 kW.

Next, the controller 4 calculates the power value (Pld-Pdg_min) that can be output by the three PCSs 32 from the power value (Pld) of the load and the minimum output value (Pdg_min) of the diesel power generator 2. The minimum output value (Pdg_min) of the diesel power generator 2 may be stored in a storage unit (not shown) included in the controller 4, for example. As another configuration, when a control unit (not shown) of the diesel power generator 2 is provided separately from the controller 4, the minimum output value (Pdg_min) is transmitted from the control unit to the controller 4. Also good. Moreover, when the diesel generator 2 is comprised with the several diesel generator, the minimum output value (Pdg_min) changes according to the total rated capacity of the generator in operation. The controller 4 compares the magnitude relationship between the power value (Pld-Pdg_min) that can be output by the three PCSs 32 and the total value (Ppv_rtd × N) of the rated output values of the three PCSs 32 (step S2). In the example shown in FIG. 7, (Pld−Pdg_min) = (320 kW−200 kW) = 120 kW, (Ppv_rtd × N) = (100 kW × 3) = 300 kW.

The minimum output value (Pdg_min) of the diesel power generator 2 is an example of the first value and the output limit value of the present invention. A value (Pld-Pdg_min) obtained by subtracting the minimum output value (Pdg_min) of the diesel power generator 2 from the power value (Pld) of the load is an example of the second value of the present invention.

When the power value (Pld-Pdg_min) that can be output by the three PCSs 32 is equal to or greater than the total value (Ppv_rtd × N) of the rated output values of the three PCSs 32 (No in step S2), it is necessary to suppress the output of each PCS 32 There is no. For this purpose, the controller 4 sets the upper limit calculation value (Ppv_max) = the rated output value (Ppv_rtd) of each PCS 32 and the adjustment value (P_offset) = 0 (step S3).

On the other hand, when the power value (Pld-Pdg_min) that can be output by the three PCSs 32 is smaller than the total value (Ppv_rtd × N) of the rated output values of the three PCSs 32 (Yes in step S2), the output of each PCS 32 is suppressed. There is a need. The example shown in FIG. 7 corresponds to this case. The controller 4 calculates, as an upper limit calculation value (Ppv_max) of each PCS 32, a value obtained by dividing the power value (Pld-Pdg_min) that can be output by the three PCSs 32 into three equal parts (step S4). The upper limit calculation value (Ppv_max) is an example of the output upper limit calculation value of the present invention. In the example shown in FIG. 7, Ppv_max = (Pld−Pdg_min) / N = 120/3 = 40 kW.

Next, the controller 4 determines whether or not the total output value (Ppv) of the current three PCSs 32 is smaller than the total value (Ppv_max × N) of the upper limit calculation value (step S5). If the total output value (Ppv) of the current three PCSs 32 is smaller than the total value (Ppv_max × N) of the upper limit calculation value (Yes in step S5), there is room to increase the current output upper limit value. Increases the adjustment value (P_offset) (step S6). In the example shown in FIG. 7, Ppv = 100 kW and (Ppv_max × N) = (40 kW × 3) = 120 kW. For this reason, the adjustment value (P_offset) is increased.

The adjustment value (P_offset) may be increased by a predetermined value such as 1% of the rated output value of each PCS 32 (corresponding to 1 kW in the example of FIG. 7). As another example, the adjustment value (P_offset) is the difference between the total value (Ppv_max × N) of the upper limit calculation value and the current total output value (Ppv) of the three PCSs 32 in the number of PCSs 32 (N). It may be increased by the divided value. In the example of FIG. 7, the amount by which the adjustment value (P_offset) is increased is (Ppv_max × N−Ppv) / N = (40 kW × 3-100 kW) / 3≈6 kW.

If the total output value (Ppv) of the current three PCSs 32 is equal to or greater than the total value (Ppv_max × N) of the upper limit calculation value (No in step S5), the current output upper limit value may be too large. The controller 4 determines whether or not the adjustment value (P_offset) is greater than 0 (step S7). When the adjustment value (P_offset) is greater than 0 (Yes in step S7), the controller 4 decreases the adjustment value (P_offset) (step S8). If the adjustment value (P_offset) is not greater than 0 (No in step S7), the controller 4 sets the adjustment value (P_offset) to 0 (step S9). Note that, when the adjustment value (P_offset) is decreased, the determination method of the value is not particularly limited. For example, it may be reduced by 1% of the rated output value.

When the upper limit calculation value (Ppv_max) and the adjustment value (P_offset) are determined, the controller 4 sets the output upper limit value (Ppv_lmt) = the upper limit calculation value (Ppv_max) + the adjustment value (P_offset). The output upper limit value (Ppv_lmt) is notified to each PCS 32 (step S10). In the example illustrated in FIG. 7, for example, an output upper limit value 41 kW (or 46 kW) is transmitted. After performing the process of step S10, the controller 4 returns to step S1 and repeats the above process. Each PCS 32 that has acquired the output upper limit value controls the output so as not to exceed the acquired output upper limit value. The output upper limit (Ppv_lmt) is updated as appropriate.

In the output upper limit setting flow shown above, the adjustment value (P_offset) is immediately increased or decreased after the determination in step S5. However, this is only an example. For example, the adjustment value (P_offset) may be increased or decreased when the state determined in step S5 continues for a certain period of time. Further, instead of the determination in step 5, for example, the following configuration may be employed. When the difference between the total output value (Ppv) of the current three PCSs 32 and the total value (Ppv_max × N) of the upper limit calculation value is within a predetermined range, the adjustment value (P_offset) is not changed, The configuration may be such that the adjustment value (P_offset) is changed when it is outside the predetermined range.

According to the power supply system of the first embodiment, the output upper limit value is not simply set according to the power value of the load 5, the minimum output set in the diesel power generator 2, and the number of PCSs 32. In the power supply system of the first embodiment, the output upper limit value is set in consideration of the total output value of the three PCSs 32. For this reason, according to the power supply system of 1st Embodiment, it can prevent that the electric power output from each PCS32 is suppressed more than necessary, for example. For this reason, according to the electric power supply system of 1st Embodiment, the electric power of solar power generation can be used effectively.

Further, according to the power supply system of the first embodiment, for example, if there is no change in the power that can be generated by the solar power generation devices 3a to 3c and the power of the load 5, the total output value of the plurality of PCSs 32 is targeted. It can be close to the power value. For this reason, according to the electric power supply system of 1st Embodiment, the electric power of solar power generation can be used effectively. The target power value is a value obtained by subtracting the minimum output of the diesel generator 2 from the power value of the load 5.

Further, according to the power supply system of the first embodiment, for example, even when the total output value of the plurality of PCSs 32 suddenly increases due to solar radiation fluctuations, the output upper limit value can be immediately corrected. For this reason, it is easy to cope with solar radiation fluctuations.
Second Embodiment

FIG. 8 is a block diagram showing a configuration of a power supply system according to the second embodiment of the present invention. The power supply system of the second embodiment has generally the same configuration as the power supply system of the first embodiment. The difference from the first embodiment is that three second wattmeters 8a to 8c are arranged so that output values of the three solar power generation devices 3a to 3c can be separately measured. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted unless particularly necessary.

FIG. 9 is a block diagram showing a functional configuration of the controller 4 included in the power supply system according to the second embodiment of the present invention. The configuration of the first embodiment is different in that the output value (Ppvi) of each PCS 32 is input to the power management unit 41 separately. The power management unit 41 can sum the output values of the PCSs 32 to obtain a total output value (Ppv) of the three PCSs 32.

FIG. 10 is a flowchart showing an output upper limit setting flow in the power supply system according to the second embodiment of the present invention. FIG. 11 is a schematic diagram illustrating a numerical example that facilitates understanding of the setting flow of the output upper limit value illustrated in FIG. 10. Hereinafter, in the description of the flowchart of FIG. 10, specific numerical examples will also be described with reference to FIG. 11. Also in the second embodiment, the initial value of the adjustment value (P_offset) is zero.

In setting the output upper limit value, the controller 4 acquires the output value (Pvi) of each PCS 32 using the second wattmeters 8a to 8c together with the load power value (Pld). Further, the controller 4 adds the output values (Pvi) of the PCSs 32 to obtain the total output value (Ppv) of the three PCSs 32 (step S11). In the example shown in FIG. 11, first, Pld = 320 kW, Ppv1 = 70 kW, Ppv2 = 40 kW, Ppv3 = 20 kW, and Ppv = 130 kW.

After Step S11, Steps S2 to S5 are executed as in the first embodiment. In the example shown in FIG. 11, (Pld−Pdg_min) = 120 kW, Ppv_max = 40 kW, and (Ppv_max × N) = 120 kW. For this reason, first, Ppv> (Ppv_max × N) is satisfied in the determination in step S5 (No in step S5). For this purpose, the controller 4 performs process A (step 12). The process A specifically corresponds to steps S7 to S9 of the first embodiment (FIG. 6). Then, the controller 4 transmits (Ppv_max + P_offset) = (40 kW + 0 kW) = 40 kW as an output upper limit value (Ppv_lmt) to each PCS 32 (step S10). Each PCS 32 performs output according to the output upper limit value.

If power is acquired again in step S11, Pld = 320 kW, Ppv1 = 40 kW, Ppv2 = 40 kW, Ppv3 = 20 kW, and Ppv = 100 kW. For this reason, in the determination of the next step S5, Ppv <(Ppv_max × N) is satisfied (Yes in step S5), and the process proceeds to step S13.

Step S13 is a loop process, and the controller 4 repeats the processes of steps S14 and 15 until i becomes N while increasing i by 1. That is, the controller 4 determines whether or not the output value (Ppvi) is smaller than the output upper limit value (Ppv_lmt) for each PCS (step S14). The output upper limit (Ppv_lmt) is a value obtained by adding Ppv_max obtained in step S4 and the initial value of P_offset when the output upper limit is determined for the first time. When the flow for determining the output upper limit value is performed first, the output upper limit value (Ppv_lmt) is the value obtained in the most recent step S10. When the output value (Ppvi) is not smaller than the output upper limit value (Ppv_lm) (No in step S14), the controller 4 increases the count value (P_lmt_cnt) by one (step S15). When the output value (Ppvi) is smaller than the output upper limit value (Ppv_lmt) (Yes in step S14), the count value (P_lmt_cnt) does not increase. The count value (P_lmt_cnt) indicates the number of PCSs 32 that can possibly output larger than the current output upper limit value (Ppv_lmt). In the example shown in FIG. 11, the current output upper limit value (Ppv_lmt) = 40 kW. Then, P_lmt_cnt = 2.

When the processing of steps S14 and 15 is completed for all the PCSs 32, the controller 4 determines whether or not the count value (P_lmt_cnt) is 0 (step S16). If the count value (P_lmt_cnt) is 0 (Yes in step S16), it is determined that each PCS 32 cannot increase the output any more. For this purpose, the controller 4 maintains the adjustment value (P_offset) at the current value (step S17), and proceeds to step S10.

If the count value (P_lmt_cnt) is not 0 (No in step S16), the controller 4 determines that there is a PCS 32 that can output an output larger than the current output upper limit value by the number of count values (P_lmt_cnt). To do. Then, the controller 4 increases the adjustment value (P_offset) by the value obtained by dividing the output (Ppv_max × N-Ppv) to be increased by the count value (P_lmt_cnt). The example shown in FIG. 11 corresponds to this case. P_offset = 0 kW + (40 × 3-100) / 2 = 10 kW. The controller 4 transmits an output upper limit value (Ppv_lmt) = (Ppv_max + P_offset) = (40 kW + 10 kW) = 50 kW to each PCS 32 (step S10). Thereafter, the flow starting from step S11 is repeated.

In the flow shown above, the PCS 32 compares the output value of each PCS 32 with the output upper limit value when determining whether the PCS 32 can output an output larger than the current output upper limit value. However, this is only an example. For example, it is determined whether or not the PCS 32 can output an output larger than the current output upper limit value depending on whether or not the output value of each PCS 32 is within a certain range set based on the output upper limit value. Also good.

The power supply system of the second embodiment can obtain the same effects as those of the first embodiment, for example. Further, in the power supply system of the second embodiment, when obtaining the adjustment value (P_offset), the number of PCSs 32 that are determined to be output-suppressed is determined, and the adjustment value (P_offset) is determined using the determination result. Have decided. For this reason, in the power supply system of the second embodiment, for example, the power generated by the solar power generation device can be more appropriately used than in the case of the first embodiment. Moreover, in the electric power supply system of 2nd Embodiment, the electric power generated by the solar power generation device can be used effectively, for example, following quickly the load fluctuation and the solar radiation fluctuation.
<Third Embodiment>

The power supply system of the third embodiment is generally the same as the power supply system of the second embodiment. For this reason, description about the same content as 2nd Embodiment is abbreviate | omitted. FIG. 12 is a block diagram illustrating a configuration of a solar power generation device 3a included in the power supply system according to the third embodiment of the present invention. The three solar power generation devices 3a to 3c have the same configuration. For this reason, the solar power generation device 3a is shown here as a representative example, and illustration of the other solar

power generation devices

3b and 3c is omitted. FIG. 13 is a block diagram illustrating a functional configuration of the controller 4 included in the power supply system according to the third embodiment of the present invention.

As shown in FIG. 13, in the third embodiment, the controller 4 includes a PCS management unit 43 that manages each PCS 32. This point is different from the second embodiment. The PCS management unit 43 instructs each PCS 32 to stop operation and resume operation. For this purpose, the power supply system according to the present embodiment includes a signal line for instructing the output control unit 322 of each PCS 32 to stop operation and resume operation, as shown in FIGS. 12 and 13. It has been. In the present embodiment, the adjustment value calculation unit 422 determines whether to stop the operation of the PCS 32 and restart the operation.

The operation stop may be commanded by setting the output upper limit value to 0 kW, for example. In this configuration, the operation restart command may be determined when the output upper limit value is set to a value larger than 0 kW.

FIG. 14 is a flowchart showing an output upper limit setting flow in the power supply system according to the third embodiment of the present invention. The output upper limit setting flow in the third embodiment is substantially the same as in the second embodiment. However, in the second embodiment, in steps S2, S4, S5, and S18, the number of PCSs is not the number (N) of PCSs included in the system but the number (n) of operating PCSs. Is different. Another difference is that process B is added after steps S17 and S18. Note that n is a value of N or less. The number (n) of operating PCSs 32 is managed by the PCS management unit 43.

FIG. 15 is a flowchart showing the added process B in the power supply system according to the third embodiment of the present invention. As shown in FIG. 15, in the third embodiment, after calculating the adjustment value (P_offset) in step S18, the controller 4 determines whether or not to stop the PCS 32 having the smallest output value. In the previous procedure, it is determined that there is at least one PCS 32 that may be able to produce an output that is larger than the current output upper limit. When the output can be supplemented by the at least one PCS 32, the PCS 32 having a small output value is stopped.

Specifically, the controller 4 determines whether or not to stop the PCS 32 having the smallest output by the following equation (1) (step S19).
(Ppv_max + Ppv_x) / (n−1) <Pth (1)
Ppv_x: the output value of the Xth PCS 32 with the smallest output Pth: the constant threshold value Pth can be determined, for example, by experiment or simulation.

If the expression (1) is satisfied (Yes in step S19), the controller 4 stops the operation of the Xth PCS 32 and decreases n by 1 (step S20). From the next loop, the new n value is used. On the other hand, if the expression (1) is not satisfied (No in step S19), the controller 4 does not stop the operation of any PCS 32.

As shown in FIG. 15, in the third embodiment, after determining that the adjustment value (P_offset) is maintained in step S17, the controller 4 determines whether there is a PCS 32 that is stopped (step S17). S21). Specifically, it is determined whether N = n. If N = n is not satisfied (No in step S21), it is determined that there is a stopped PCS 32, and therefore one stopped PCS 32 is restarted (step S22). At this time, n is increased by one. From the next loop, the new n value is used. On the other hand, if N = n, it is determined that there is no PCS 32 that is stopped, so the operation resumption process is not performed.

Note that it is not necessary to use Equation (1) to determine whether to stop the PCS 32 having the smallest output. For example, the determination may be made based on whether or not the output value (Ppv_x) of the PCS 32 having the smallest output is equal to or less than a certain output value.

The power supply system of the third embodiment can obtain the same effects as those of the second embodiment, for example. Further, in the power supply system of the third embodiment, for example, the operation of the PCS in the solar power generation device with extremely low output can be stopped, and the solar power generation device can be maintained. Moreover, in the electric power supply system of 3rd Embodiment, the solar power generation device with a big output can be selected appropriately, for example, and the electric power generated with the solar power generation device can be used efficiently.
<Fourth embodiment>

The power supply system of the fourth embodiment has generally the same configuration as the power supply system of the first embodiment (see, for example, FIG. 3). The description of the same configuration as in the first embodiment is omitted. FIG. 16: is a block diagram which shows the structure of the solar power generation device 3a with which the electric power supply system which concerns on 4th Embodiment of this invention is provided. The three solar power generation devices 3a to 3c have the same configuration. For this reason, the solar power generation device 3a is shown here as a representative example, and the illustration of the other solar

power generation devices

3b and 3c is omitted. FIG. 17 is a block diagram illustrating a functional configuration of the controller 4 included in the power supply system according to the fourth embodiment of the present invention.

As shown in FIG. 16, in the fourth embodiment, each of the solar power generation devices 3a to 3c includes a solar radiation meter 33. This point is different from the configuration of the first embodiment. The pyranometer 33 is arranged in parallel with the solar panel 31 so as to coincide with the light receiving surface of the solar panel 31. Due to the presence of the pyranometer 33, the maximum output power of each PCS 32 can be predicted. The pyranometer 33 is an example of the measurement unit of the present invention.

As shown in FIGS. 16 and 17, the amount of solar radiation measured by the solar radiation meter 33 is transmitted to the adjustment value calculation unit 422 of the controller 4. The adjustment value calculation unit 422 calculates the maximum output power predicted value in each PCS 32 by the following equation (2).
P_est_i = H (i) × Ppv_rtd × K (2)
P_est_i: Maximum output power predicted value of i-th PCS 32 H (i): Solar radiation amount [kW / m ² ] of i-th PCS 32
K: Efficiency (constant value)
Ppv_rtd: Maximum rated output value of PCS 32 In this embodiment, Ppv_rtd has the same value for all PCSs 32.

FIG. 18 is a flowchart showing an output upper limit value setting flow in the power supply system according to the fourth embodiment of the present invention. The output upper limit setting flow in the power supply system according to the fourth embodiment is generally the same as the output upper limit setting flow of the second embodiment shown in FIG. However, in the fourth embodiment, the total output value of the three PCSs 32 can be measured, but the output value of each PCS 32 cannot be measured. In the fourth embodiment, a pyranometer 33 is provided. Due to the difference of these matters, the following points are different from the flowchart of the second embodiment.

Step 11 in the second embodiment is the same as step S1 (FIG. 6) in the first embodiment. Moreover, step S14 of the second embodiment is changed to step S23.

In the flowchart shown in FIG. 18, in steps S13, S23, and S15, the number of PCSs 32 that may be able to output larger than the current output upper limit value is counted. In the second embodiment, the number of PCSs 32 is counted based on the output value of each PCS 32 measured by the second wattmeters 8a to 8c. In the fourth embodiment, unlike this, the number of PCSs 32 that may be able to output larger than the current output upper limit value is counted based on the predicted maximum output power value (P_est).

Specifically, for each PCS 32, the predicted maximum output power value (P_est) and the current output upper limit value (Ppv_lmt) are compared. As a result of the comparison, if the predicted maximum output power value (P_est) is smaller than the current output upper limit value (Ppv_lmt), the count value of the number is not increased. On the other hand, if the predicted maximum output power value (P_est) is equal to or greater than the current output upper limit value (Ppv_lmt), the count value of the number is increased.

In this embodiment, the solar power generators 3a to 3c are provided with the solar radiation meter 33, but this is only an example. The pyranometer 33 may be shared by a plurality of solar power generation devices. For example, the solar radiation meter 33 may be shared by a plurality of solar power generation devices in which the solar panels 31 face the same direction.

In the power supply system of the fourth embodiment, for example, the same effects as those of the second embodiment can be obtained. For example, since the pyranometer 33 is used, it is easy to perform output control reflecting the actual weather condition. In addition, it is good also as a structure provided with the wattmeter which measures the output of each PCS32 similarly to 2nd Embodiment. In this case, for example, the output measurement result of each PCS 32 may be added to the measurement result of the pyranometer 33 to determine the number of PCSs 32 that can possibly output larger than the current output upper limit value.
<Fifth Embodiment>

The power supply system of the fifth embodiment has substantially the same configuration as the power supply system of the first embodiment (see, for example, FIG. 3). The description of the same configuration as in the first embodiment is omitted. FIG. 19 is a block diagram illustrating a functional configuration of the controller 4 included in the power supply system according to the fifth embodiment of the present invention.

As shown in FIG. 19, in the fifth embodiment, the controller 4 includes a PCS management data storage unit 44. This point is different from the configuration of the first embodiment. The PCS management data storage unit 44 stores, for example, direction information, number information, past solar radiation amount information, past use history information, and the like of the solar panel 31. Information stored in the PCS management data storage unit 44 can be transmitted to the adjustment value calculation unit 422. The PCS management data storage unit 44 is an example of the storage unit of the present invention.

The adjustment value calculation unit 422 predicts the output of each PCS 32 based on, for example, the current season and time, direction information and number information of the solar panels 31 obtained from the PCS management data storage unit 44, past solar radiation amount information, and the like. To do.

As another example, the adjustment value calculation unit 422 obtains an output predicted value (P_est) of each PCS 32 based on, for example, the current time, usage history information stored in the PCS management data storage unit 44, and the like. For example, the PCS management data storage unit 44 stores a table as shown in FIG. The table shown in FIG. 20 is a table created from the past usage history, and includes the predicted output value of each PCS 32 for each time. If the current time is 10:00, the predicted output value of each PCS 32 is 70 kW for the first PCS, 40 kW for the second PCS, and 20 kW for the third PCS.

The output upper limit setting flow in the power supply system according to the fifth embodiment can be the same as the output upper limit setting flow of the fourth embodiment shown in FIG. However, the method of acquiring the predicted output value (P_est) used in step S23 is different. In the fourth embodiment, the predicted output value is obtained using the measurement value of the pyranometer 33. On the other hand, in the fifth embodiment, an output predicted value is obtained using information obtained from the PCS management data unit 44.

For example, it is assumed that the current time is 10:00 and the output upper limit value of each PCS 32 is 40 kW and the allowable value (Pld-Pdg_min) of the total output value of three PCS 32 is 120 kW. In this case, while using the table of FIG. 20, the controller 4 appropriately updates the output upper limit value to approach 60 kW.

In the power supply system of the fifth embodiment, for example, the same effects as those of the second embodiment can be obtained. Further, for example, since past history information stored in the PCS management data storage unit 44 is used, appropriate output control can be performed while reducing the number of power meters, pyranometers, and the like.
<Sixth Embodiment>

FIG. 21 is a block diagram showing a configuration of a power supply system according to the sixth embodiment of the present invention. In the power supply system of the sixth embodiment, the first power supply unit shown in FIG. 1 is realized as a power system 2 configured by a power company. In the power supply system of the sixth embodiment, a plurality of second power supply units shown in FIG. 1 are realized as a plurality of solar power generation devices 3a to 3b.

The power supply system of the sixth embodiment includes a first wattmeter 7 that measures the power of the load 5 and a second wattmeter that measures the sum of output values output from the three solar power generation devices 3a to 3c. 8 and. This is the same as the power supply system of the first embodiment. The configuration of the solar power generation devices 3a to 3c of the sixth embodiment is the same as that of the first embodiment.

FIG. 22 is a block diagram showing a functional configuration of the controller 4 included in the power supply system according to the sixth embodiment of the present invention. The configuration of the controller 4 is substantially the same as that of the power supply system of the first embodiment. However, the controller 4 includes a system command acquisition unit 45. This point is different from the first embodiment.

The system command acquisition unit 45 acquires a system command value (Pgrd) issued by the power system 2. In the present embodiment, the system command value (Pgrd) is a command value for purchased power. System command value (Pgrd) = 0 means that reverse power flow is impossible. Further, when the system command value (Pgrd) is a negative value, the value indicates the allowable power value of reverse power flow.

FIG. 23 is a flowchart showing an output upper limit value setting flow in the power supply system according to the sixth embodiment of the present invention. The output upper limit value setting flow of the sixth embodiment is generally the same as the output upper limit value setting flow of the first embodiment. The difference is that steps S2 and S4 of the first embodiment are changed to steps S24 and S25, respectively. Specifically, the difference is that Pdg_min in the first embodiment is replaced with Pgrd. Since it is the same except for the point, detailed description is abbreviate | omitted.

In the power supply system of the sixth embodiment, for example, similarly to the first embodiment, it is possible to prevent the power output from each PCS 32 from being suppressed more than necessary. For this reason, according to the electric power supply system of 6th Embodiment, the electric power of solar power generation can be used effectively.
<Others>

The configuration of each embodiment described above is merely an example of the present invention. The configuration of each embodiment may be changed as appropriate without departing from the technical idea of the present invention. Each embodiment and the fine modification in embodiment can also be implemented combining in the possible range.

In the above description, the case where the second power supply unit is configured by a solar power generation device has been described, but this is only an example. For example, the second power supply unit may be a device that generates power using other natural energy such as a wind power generator.

DESCRIPTION OF SYMBOLS 1 Electric power supply system 2 1st electric power supply part, diesel power generator, electric power system 3a-3c 2nd electric power supply part, solar power generation device 4 Controller (control part, output control apparatus)
5 Load 6 Recording medium 33 Pyrometer (measurement part)
41 Power management unit 42 Upper limit setting unit 44 PCS management data storage unit (storage unit)

Claims

A power supply system that links a first power supply unit and a plurality of second power supply units to supply power to a load,
A control unit configured to be able to acquire a power value of the load and a total output value of the plurality of second power supply units, and to set the same output upper limit value to the plurality of second power supply units; Prepared,
The control unit adjusts an output upper limit calculated value based on the load power value and a first value derived from the first power supply unit according to the total output value. A power supply system in which a value obtained by adding is used as the output upper limit value.
The power supply system according to claim 1, wherein the first value is an output limit value set in the first power supply unit or a command value given by the first power supply unit.
The power supply system according to claim 1 or 2, wherein the control unit updates the output upper limit value to bring the total output value closer to a second value.
The power supply system according to claim 3, wherein the second value is a value obtained by subtracting the first value from the power value of the load.
When it is necessary to make each output value of the plurality of second power supply units smaller than a rated output value, the setting of the output upper limit value using the output upper limit calculation value and the adjustment value is executed,
5. The power supply system according to claim 1, wherein when the output values do not need to be smaller than the rated output value, the output upper limit value is set to the rated output value. 6.
The control unit determines the adjustment value according to a result of comparing the total output value and a multiplication value obtained by multiplying the output upper limit calculation value by the number of the second power supply units in operation. The power supply system according to any one of claims 1 to 5.
When the total output value is smaller than the multiplication value, the control unit increases the adjustment value,
The power supply system according to claim 6, wherein the control unit reduces or maintains the adjustment value when the total output value is equal to or greater than the multiplication value.
The control unit is provided to be able to acquire each output value of the plurality of second power supply units,
When the total output value is smaller than the multiplication value, the control unit can output a larger output than the current output upper limit value from each acquired output value. And calculating the adjustment value based on the number,
The power supply system according to claim 6, wherein the control unit reduces or maintains the adjustment value when the total output value is equal to or greater than the multiplication value.
The control unit determines that there is a possibility that the second power supply unit whose acquired output value is not smaller than the current output upper limit value can output an output larger than the current output upper limit value. Item 9. The power supply system according to Item 8.
The power supply system according to claim 8 or 9, wherein the control unit determines whether to stop operation and restart operation of the second power supply unit.
The controller is
When there is the second power supply unit that may be able to output larger than the current output upper limit value, the operation stop determination is performed,
The power supply system according to claim 10, wherein the operation restart determination is performed when there is no second power supply unit that has a possibility of outputting an output larger than the current output upper limit value.
A measuring unit that can predict each output value of the plurality of second power supply units;
The power supply system according to claim 6, wherein the adjustment value is determined based on the total output value and information obtained from the measurement unit.
When the total output value is smaller than the multiplication value, the control unit may output a larger output than the current output upper limit value from each measured output predicted value. Determine the number, calculate the adjustment value based on the number,
The power supply system according to claim 12, wherein the control unit reduces or maintains the adjustment value when the total output value is equal to or greater than the multiplication value.
A storage unit for storing data that makes it possible to predict each output value of the plurality of second power supply units;
The power supply system according to claim 6, wherein the adjustment value is determined based on the total output value and information obtained from the storage unit.
When the total output value is smaller than the multiplication value, the control unit may be able to output an output larger than the current output upper limit value from each output predicted value obtained by data stored in the storage unit. Determining the number of the second power supply units, calculating the adjustment value based on the number,
The power supply system according to claim 14, wherein the control unit reduces or maintains the adjustment value when the total output value is equal to or greater than the multiplication value.
The said control part judges that the said 2nd electric power supply part whose said output prediction value is not smaller than the said current output upper limit value can output larger than the said current output upper limit value. The power supply system according to 13 or 15.
The power supply system according to any one of claims 1 to 16, wherein the first power supply unit supplies power generated by a diesel generator to the load.
The power supply system according to any one of claims 1 to 16, wherein the first power supply unit is a power system.
The power supply system according to any one of claims 1 to 18, wherein the second power supply unit supplies power generated by using natural energy to the load.
An output control device that controls outputs of a plurality of second power supply units that supply power to a load in cooperation with a first power supply unit,
A power management unit provided to be able to acquire a power value of the load and a total output value of the plurality of second power supply units;
An upper limit setting unit that sets the same output upper limit value in the plurality of second power supply units;
With
The upper limit setting unit adds an adjustment value obtained according to the total output value to an output upper limit calculation value calculated based on a power value of the load and a value derived from the first power supply unit. An output control device in which the output value is the output upper limit value.
An output control method for controlling outputs of a plurality of second power supply units that supply power to a load in cooperation with a first power supply unit,
Obtaining a total output value of the plurality of second power supply units;
Calculating an output upper limit calculation value based on a power value of the load and a value derived from the first power supply unit;
A value obtained by adding an adjustment value obtained according to the total output value to the output upper limit calculated value as an output upper limit;
Transmitting the same output upper limit value to each of the plurality of second power supply units;
An output control method comprising:
A computer-readable recording medium in which a computer-executable program is recorded non-temporarily.
A recording medium on which an output control program for causing a computer to execute the output control method according to claim 21 is recorded.