JP6041216B2 - Power feeding system and power feeding method - Google Patents

Description

  The present invention relates to a power supply system and a power supply method for supplying power generated by using energy harvest or power from a storage battery to a load.

  In recent years, energy harvesting that recovers energy that exists in the natural environment (for example, solar energy, wind energy, hydraulic energy, etc.), converts it into electrical energy, and feeds (supplies) the electrical energy generated by this conversion to a load. Thoughts are attracting attention.

  As an example of energy harvesting, it is known that solar energy is collected and converted into electric energy using a solar cell panel. In recent years, solar cell panels have become more important from the viewpoint of effective use of energy, such as supplying power generated by solar cell panels to household or industrial power systems or backflowing surplus power, etc. A wide range of solar cell panels are expected in combination with secondary batteries.

  Conventionally, for example, Patent Document 1 is known as a solar power generation system that supplies a load using a power generation output from a solar battery panel and a discharge output from a secondary battery. The solar power generation system of Patent Document 1 includes a solar cell string including a solar cell and a secondary battery, converts the output of the solar cell string into AC power via a power converter, and detects the state of the secondary battery. To do.

  Furthermore, the solar power generation system detects the output of the power converter, and controls the output power value based on the state of the secondary battery and the output of the power converter. The solar power generation system controls the power conversion device so that the output of the power conversion device is smaller than the total value of the output power of the secondary battery. Thereby, the photovoltaic power generation system can realize smoothing of output or time shifting of output with an inexpensive system.

  In Patent Document 2, when charging power to a plurality of secondary batteries, the secondary batteries to be charged are switched in a time-sharing manner, and at the moment when charging of any secondary battery is stopped, It is disclosed to start charging the secondary battery. Thereby, when stopping charging of any secondary battery, all the secondary batteries can be fully charged quickly without interrupting the charging current.

  Japanese Patent Application Laid-Open No. 2003-228561 discloses that when power is supplied to a load using a plurality of secondary batteries, the secondary battery to be supplied to the load is switched at an appropriate interval. Thereby, the power supply unit can supply power to the load for a long time.

Japanese Laid-Open Patent Publication No. 2008-48544 Japanese Unexamined Patent Publication No. 2001-212558 Japanese Unexamined Patent Publication No. 5-111169

  However, in conventional energy harvesting, for example, when supplying electric energy generated by power generation of a solar cell panel to a load, it may be difficult to supply constantly and stably. For example, the amount of power generated by a solar panel fluctuates according to the daily weather. For example, if it is raining or if it is raining for several consecutive days, it does not reach the amount of power necessary for load operation. There was a thing. Accordingly, in energy harvesting, it is required to constantly and stably supply power necessary for load operation.

  The present invention has been made in view of the above-described conventional circumstances. The power generated in the energy harvest is supplied to the secondary battery preferentially over the load to charge the secondary battery. It is an object of the present invention to provide a power feeding system and a power feeding method that constantly and stably supplies power necessary for load operation.

  The present invention is the above-described power feeding system, which is a solar cell panel that converts solar energy into electrical energy to generate DC power, and a plurality of storage battery blocks that charge the DC power generated by the solar cell panel. And a plurality of charge / discharge control units that are provided for each of the storage battery blocks and control charging and discharging of the DC power to the storage battery block, the storage battery block used for charging or discharging, and information on whether or not to generate power by natural energy, or Based on information relating to the combination of storage battery blocks, a central control management unit that determines which storage battery block to use for charging the DC power and discharging to the load, and the determined storage battery block was discharged Based on DC power, supply DC power of the amount of power necessary for the operation of the load to the load Provided that the load output control unit.

  Further, the present invention is the above-described power feeding method, wherein the solar battery panel converts solar energy into electrical energy to generate DC power, and any one of the plurality of storage battery blocks has a storage battery block, Charging the DC power generated by the solar battery panel, and controlling charging and discharging of the DC power to the storage battery block by a charge / discharge control unit provided for each storage battery block And, by the central control management unit, based on the information on the possibility of power generation by natural energy and the information on the combination of the storage battery block or the storage battery block used for charging or discharging, the charging of the DC power and the discharging to the load, A step of determining whether to use the storage battery block; Ri, based on the DC power discharged from the determined storage battery block, and a step of supplying DC power of electric energy necessary for the operation of the load to the load.

  According to the above-described configuration, the electric power generated in the energy harvest is supplied to the secondary battery with priority over the load to charge the secondary battery, and the electric power necessary for the operation of the load is obtained using the charged electric power. It can be supplied constantly and stably.

  According to the present invention, the power generated in the energy harvest is supplied to the secondary battery with priority over the load to charge the secondary battery, and the charged power is used to constantly supply the power necessary for the operation of the load. And it can supply stably.

The figure which shows the system configuration example of the electric power feeding system of 1st Embodiment. The figure which shows the other system configuration example of the electric power feeding system of 1st Embodiment. (A) Characteristic diagram of output current and output voltage according to the sunlight intensity of the solar cell panel, (b) Characteristic diagram of output current and output voltage according to the temperature of the solar cell panel (A) Charging characteristic diagram of lithium ion storage battery, (b) Charging characteristic chart of lead storage battery The table which shows the operation example of charging / discharging of the storage battery block at the time of continuous fine weather of the electric power feeding system of 1st Embodiment The table which shows the operation example of charging / discharging of a storage battery block in the non-sunshine 1 date and time of the electric power feeding system of 1st Embodiment The table which shows the operation example of charging / discharging of the storage battery block in the non-sunshine 2 date and time of the electric power feeding system of 1st Embodiment The flowchart explaining operation | movement in the central control management part of the electric power feeding system of 1st Embodiment. The figure which shows the system configuration example of the electric power feeding system of 2nd Embodiment. The figure which shows the other system configuration example of the electric power feeding system of 2nd Embodiment.

  Hereinafter, embodiments of a power feeding system and a power feeding method according to the present invention will be described with reference to the drawings. The power supply system and the power supply method according to the present invention use a solar battery panel that generates solar power as electric energy by converting solar energy into electric energy as an example of energy harvesting that converts energy existing in the natural environment into electric energy. explain. However, the energy harvest is not limited to a solar cell panel that converts solar energy into electrical energy, and may be, for example, a wind power generation facility or a hydroelectric power generation facility that generates direct-current power by converting wind energy or hydraulic energy into electrical energy. Good.

  Note that the present invention can also be expressed as a power feeding method including each process (step) for the power feeding method executed by the power feeding system. Furthermore, the central control management unit, the charge / discharge control unit, or the load output control unit (see later) constituting the power supply system according to the present invention can be expressed as a device or a program for operating the device as a computer. is there.

(First embodiment)
FIG. 1 is a diagram illustrating a system configuration example of a power feeding system 100 according to the first embodiment. Power supply system 100 shown in FIG. 1, the solar cell panel 1, MPPT (Maximum Power Point Tracking ) section 2, a central control management unit 3, a plurality of charging and discharging control unit _a 1 ~a _n, a plurality of battery blocks _b 1 ~b _n and the load output control unit 6.

FIG. 2 is a diagram illustrating another system configuration example of the power supply system 100 according to the first embodiment. Power supply system shown in FIG. 2 100, the solar cell panel 1, MPPT unit 2, the central control management unit 3, a plurality of charging and discharging control unit _a 1 ~a _n, a plurality of battery blocks _b 1 ~b _n, load output control unit 6 and a DC / AC inverter 8.

In the power feeding system 100 shown in FIG. 1 or 2, a load 7 is connected to the load output control unit 6. Discharge control unit _a 1 ~a _n is provided for each battery block _b 1 ~b _n, the charge and discharge control unit _a 1 ~a _n and battery blocks _b 1 ~b _n provided in a one-to-one correspondence ing. In the power feeding system 100 shown in FIG. 2, a load 9 is connected to the DC / AC inverter 8.

  The solar cell panel 1 converts solar energy into electric energy to generate DC power. The solar cell panel 1 is formed by combining a plurality of solar cells formed on a silicon semiconductor or compound semiconductor substrate in series on a plane, in parallel, or in series and in parallel, as shown in FIG. It has the characteristics of output current and output voltage shown in 3 (b).

  The electric energy converted from the solar energy by the solar cell panel 1 is input to the MPPT unit 2 as an output current and an output voltage. FIG. 3A is a characteristic diagram of an output current and an output voltage corresponding to the sunshine intensity of the solar cell panel. FIG. 3B is a characteristic diagram of output current and output voltage according to the temperature of the solar cell panel.

  In addition, when the planar solar panel 1 is fixed in one direction and installed on the ground or a building, the intensity of sunlight irradiating the solar cells due to the change in position of the sun due to the rotation of the earth is time. Changes over time. Thereby, the electric energy based on the electric power generation of the solar cell panel 1 changes with progress of time by the characteristic of the output current and output voltage shown to Fig.3 (a). Hereinafter, the electric energy based on the electric power generation of the solar cell panel 1 is referred to as “PV (Photovoltaic) electric power generation”.

  The MPPT unit 2 is a processor such as an MPU (Micro Processing Unit) or a CPU (Central Processing Unit) for performing overall control of the MPPT unit 2 by exchanging signals with the central control management unit 3, and a solar cell panel 1 includes a current sensor capable of measuring an output current from 1, and a voltage sensor capable of measuring an output voltage from the solar battery panel 1.

  The MPPT unit 2 is a maximum for maximizing the PV power generation amount of the DC power generated by the solar cell panel 1 based on the output current and output voltage from the solar cell panel 1 measured by the current sensor and the voltage sensor. Performs power point tracking control (Maximum Power Point Tracking). The MPPT unit 2 notifies the central control management unit 3 of current and voltage information when the PV power generation amount is maximized by the maximum power point tracking control. Note that the maximum power point follow-up control by the MPPT unit 2 can be configured by a known technique that has already been known, and therefore a specific description of the operation of the MPPT unit 2 is omitted.

Central control management unit 3 controls the entire power supply system 100 performs exchange of signals between the one of the MPPT unit 2, one of the charging and discharging control unit a ₁ ~a _n and load output control section 6 For example, a processor such as an MPU or CPU and a memory capable of storing data. The central control management unit 3 generates an MPPT control notification and outputs the MPPT control notification to the MPPT unit 2 to perform the maximum power point tracking control for maximizing the PV power generation amount of the DC power generated by the solar cell panel 1. Let me do it.

The central control management unit 3 stores in memory a maximum amount of charge in each of the storage battery blocks b _{1 to} b _n in advance, and stores information on the maximum amount of charge in each battery block b _{1 to} b _n. and it notifies the discharge control unit _a 1 ~a _n. Each charging maximum electric energy may be different for each storage battery block, or may be the same value. The maximum amount of charge is the maximum amount of power that can be charged in the storage battery block.

  The central control manager 3 determines which storage battery block is used for charging the DC power generated by the solar battery panel 1 and discharging the loads 7 and 9. For example, which storage battery block is used may differ from day to day, and information regarding the storage battery block or combination of storage battery blocks used for charging or discharging may be stored in advance in the memory of the central control management unit 3. Information regarding the storage battery block or the combination of storage battery blocks used for charging or discharging may be arbitrarily changed by the system administrator of the power feeding system 100.

The central control management unit 3 generates and outputs a charge start notification to a charge / discharge control unit (for example, the charge / discharge control unit a ₁ ) corresponding to the storage battery block (for example, the storage battery block b ₁ ) determined to be used for charging. , the DC power at the maximum power supplied from the MPPT unit 2 based on the MPPT control notification is supplied from the MPPT unit 2 to the charge and discharge control unit _{a 1.} It is assumed that the central control management unit 3 constantly or regularly acquires information on the PV power generation amount from the processor of the MPPT unit 2.

Central control management unit 3, the discharge start notification generates and outputs to be determined is used to discharge the battery blocks (e.g. battery block b _n) charge-discharge control unit corresponding to (e.g., charging and discharging control unit a _n) , the charge and discharge control unit via a _n, is supplied to the load output control unit 6 to discharge the DC power charged in the battery block b _n corresponding to the charge and discharge control unit a _n.

When the DC power generated by the solar battery panel 1 exceeds a predetermined maximum charging power amount and is charged in the storage battery block, the central control management unit 3 generates a charge stop notification and corresponds to the storage battery block b ₁ obtained from the charging and discharging control unit a ₁ to.

  The central control management unit 3 generates a load supply notification and outputs it to the load output control unit 6 when the direct current power generated by the solar battery panel 1 is directly supplied to the loads 7 and 9. Then, the MPPT unit 2 is caused to supply the load output control unit 6 with the direct-current power generated by the solar cell panel 1 during the maximum power generation. The other operations of the central control manager 3 will be described later with reference to the flowchart of FIG.

Operation of the charge and discharge control unit a ₁ ~a _n and accumulators block b ₁ ~b _n are each similar, in a production example of a feed system 100, each charging target battery block discharge target different in one day It is assumed (see FIGS. 5 to 7). Hereinafter, it is determined that the storage battery block b ₁ is used for charging by the central control management unit 3, and the storage battery block b _n is determined to be used for discharging by the central control management unit 3, and the charge / discharge control units a ₁ , a _The configuration and operation will be described by exemplifying _n and the storage battery blocks b ₁ and b _n .

Discharge control unit a _1, a _n is charging the battery blocks b _1, b _n of the DC power generated by the solar cell panel 1, to control the discharge. Discharge control unit a _1, a _n is the battery blocks b ₁ performs exchange of signals between the central control management unit 3 or the load output control unit 6 charges, the discharge of the MPU or CPU, etc. for controlling the A processor, a current sensor capable of measuring an output current from the solar panel 1, a voltage sensor capable of measuring an output voltage from the solar panel 1, a temperature sensor capable of measuring the ambient temperature of the storage battery blocks b ₁ and b _n , and This is a configuration including a DC / DC converter that transforms an input voltage from the MPPT unit 2 into a predetermined voltage suitable for charging or discharging in accordance with a switching control signal from the processor.

Discharge control unit a ₁ acquires the charging start notification output from the central control management unit 3 in the processor outputs a charging start notification receiving notification of the acquired charging start notification to the central control management unit 3, It is determined whether or not the ambient temperature of the storage battery block b ₁ measured by the temperature sensor is a temperature suitable for charging the storage battery block b ₁ . It is assumed that the ambient temperature suitable for charging the storage battery block b ₁ is determined in advance.

Discharge control unit a _1, when the ambient temperature of the battery block b ₁ is determined to be a temperature suitable for charging the battery blocks b _1, based on the charging start notification from the central control management unit 3, a DC power The charging mode is determined, and charging of DC power supplied from the MPPT unit 2 during maximum power generation is started. Note that the charging start notification acknowledgment as described above, may contain information about the charging mode determined by the charging and discharging control unit a _1.

  The charging mode of DC power is determined in advance according to the type of storage battery block that is a secondary battery. For example, a constant current charging mode, a constant voltage charging mode, a multistage constant current charging mode, and the like are known. The constant current charging mode, constant voltage charging mode, and multi-stage constant current charging mode will be described with reference to FIGS. 4 (a) and 4 (b). Fig.4 (a) is a charge characteristic view of a lithium ion storage battery. FIG.4 (b) is a charge characteristic view of a lead storage battery.

Fig.4 (a) has shown the charging current and charging voltage with respect to the elapsed time of charge of a lithium ion storage battery. As shown to Fig.4 (a), in the charge first term (time 0- _tf1 ) after a charge start, the constant current charge which charges with a fixed electric current value (charge current) is performed (constant current charge mode), In the second half of charging (t _{f1 to} t _f2 ), constant voltage charging is performed in which charging is performed at a constant voltage value (charging voltage) (constant voltage charging mode).

At the time of constant current charging (time 0 to t _f1 ), the charging voltage increases with time. In the constant voltage charging (time _t f1 _{~t f2),} the charging current decreases with time. Time t _f1 is a timing for shifting from the constant current charging mode to the constant voltage charging mode. Time _tf2 is the time when the state of charge of the lithium ion storage battery becomes fully charged and the state of charge completion is reached.

FIG.4 (b) has shown the charging current and charging voltage with respect to the elapsed time of charge of a lead storage battery. As shown in FIG. 4 (b), in the charging year after start of charging (time 0 to t _f3) constant current charging for charging at a constant current value (charging current) is performed (constant current charging mode), charge late (t _{f3 ~t f5)} multistage constant current charging to charge down by ΔI charging current every time the charging voltage of the lead storage battery reaches the predetermined switching voltage V _c in is performed (multi-stage constant current charging mode) .

At the time of constant current charging (time 0 to t _f3), the charging voltage increases with time. In multi-stage constant-current charging (time _{t f3 ~t f5),} the charging voltage of the lead storage battery is lowered ΔI charging current every time reaching the switch voltage V _c, charged at the charging current is lowered ΔI is performed. At time t _f4 when the charging current lowered by ΔI becomes smaller than the predetermined charging end current value I _cf , the charging current I is set to the charging end current value I _cf. Thereafter, charging is performed with the charging current I _cf , and the multi-stage constant current charging ends when the charging voltage of the lead storage battery reaches the charging maximum voltage V _t that defines a predetermined maximum charging power amount at time t _f5 .

The charge / discharge control unit a ₁ monitors the charge amount of the DC power charged in the storage battery block b ₁ with a current sensor and a voltage sensor, and the maximum charge power amount of the storage battery block b ₁ notified from the central control management unit 3 It is determined whether or not the battery is charged beyond the limit. When the charge / discharge control unit a ₁ determines that the storage battery block b ₁ is charged exceeding the maximum charge power amount, the charge / discharge control unit a ₁ stops the charge in the storage battery block b ₁ and generates a charge stop notification to perform central control. Output to the management unit 3.

Discharge control unit a _n acquires the discharge start notification output from the central control management unit 3 in the processor, and outputs the same discharge start notification to the load output control section 6. Further, the charge and discharge control unit a _n, together with the discharge start notification receiving notification of the acquired discharge start notification from the central control management unit 3 outputs to the central control management unit 3, based on the discharge start notification, battery block b _The DC power charged to _n is discharged and supplied to the load output control unit 6.

The storage battery block b ₁ is composed of a rechargeable secondary battery such as one or a plurality of lithium ion storage batteries or lead storage batteries. The storage battery block b ₁ charges the direct-current power at the maximum power generation supplied from the MPPT unit 2 under the control of the charge / discharge control unit a ₁ . Battery block b _n, under the control of the charge and discharge control unit a _n, to discharge the DC power charged is supplied to the load output control section 6 via the discharge control unit a _n.

Battery blocks _b 1 ~b _n is excellent in cycle charge-discharge characteristics, by charging and discharging control unit _a 1 ~a _n provided in correspondence with the battery block _b 1 ~b _n, and the other battery blocks Control of charging and discharging is performed independently.

The number of storage battery blocks b _{1 to} b _n can be optimally adjusted based on the energy harvest according to the demand in the area where the power supply system 100 shown in FIG. In accordance with the number of battery blocks _b 1 ~b _n, the number of charging and discharging control unit _a 1 ~a _n is also determined.

Load output control unit 6 supplies the DC power supplied from the battery block b _n through the charging and discharging control unit a _n to the load 7. In the power supply system 100 shown in FIG. 1 or FIG. 2, the value of the electric energy necessary for the operation of the load 7 is known, and the electric energy necessary for the operation of the load 7 is preset in the load output control unit 6. And

Load output control unit 6, MPU for controlling the DC power supplied from the battery block b _n performs exchange of signals between the central control management unit 3 or the charge and discharge control unit a ₁ ~a _n or CPU processor etc., the solar photovoltaic panel 1 or accumulator block b ₁ measurable current sensor output current from ~b _n, the solar photovoltaic panel 1 or accumulator block b ₁ measurable voltage sensor output voltage from ~b _n, This is a configuration including a DC / DC converter that transforms an input voltage from the solar battery panel 1 or the storage battery blocks b _{1 to} b _n to a voltage necessary for the operation of the load.

Load output control section 6 acquires the are discharge start notification output from the discharge control unit a _n in the processor, and outputs a discharge start notification receiving notification of the acquired discharge start notification to the charge and discharge control unit a _n. Furthermore, the load output control section 6 receives a supply of DC power charged in the battery block b _n from the charging and discharging control unit a _n. Load output control section 6, a DC power supplied from the charging and discharging control unit a _n, transforms the voltage required for operation of the load 7 in the DC / DC converter, it supplies DC power to a load 7.

  When the load output control unit 6 acquires the load supply notification output from the central control management unit 3 in the processor, the load output control unit 6 outputs a load supply notification reception notification indicating that the load supply notification has been acquired. Furthermore, the load output control unit 6 receives supply of DC power from the MPPT unit 2 at the time of maximum power generation in the solar cell panel 1. The load output control unit 6 transforms the direct current power at the maximum power generation supplied from the MPPT unit 2 into a voltage necessary for the operation of the load 7 in the DC / DC converter, and supplies the direct current power to the load 7. The load 7 operates based on a DC voltage (DC power).

  The DC / AC inverter 8 converts the direct current voltage corresponding to the direct current power supplied from the load output control unit 6 into an alternating current voltage corresponding to the amount of electric power necessary for the operation of the load 9. The DC / AC inverter 8 supplies the converted AC voltage to the load 9. The load 9 operates based on AC voltage (AC power).

  FIG. 5 is a table showing an operation example of charging / discharging of the storage battery block during continuous fine weather of the power supply system according to the first embodiment. FIG. 6 is a table showing an operation example of charging / discharging of the storage battery block at the date and time of non-sunshine 1 of the power supply system according to the first embodiment. FIG. 7 is a table showing an operation example of charging / discharging of the storage battery block in the non-sunshine 2 date and time of the power supply system according to the first embodiment.

  In the description of the tables in FIGS. 5 and 6, the number of storage battery blocks and the number of charge / discharge control units corresponding to the storage battery blocks are three, respectively. In the description of the table in FIG. 7, the number of charge / discharge control units corresponding to the storage battery block and the storage battery block is 4, respectively. In the description of the tables in FIGS. 5 to 7, it is assumed that all the storage battery blocks are fully charged before the first day, and the amount of power necessary for the operation of the load 7 is one storage battery that is fully charged. It is assumed that the amount of DC power charged in the block is less than the amount of power.

  In the table of FIG. 5, since the first day to the fourth day are all sunny and the weather is good, the solar cell panel 1 can generate power on the first day to the fourth day. In the case of the weather of such a condition, three storage battery blocks are used, and further, the direct current charged in one of the three storage battery blocks is discharged, and the PV power generation amount of the discharged storage battery block is reduced. By charging DC power, it is possible to stably supply power to the load 7 (see the shaded portion in FIG. 5). Similarly, power can be stably supplied to the load 7 on the second to fourth days.

  In the table of FIG. 6, since the weather is bad due to rain on the odd-numbered day and clear and the weather is good on the even-numbered day, power generation in the solar panel 1 is possible only on the even-numbered day. In the case of the weather of such a condition, three storage battery blocks are used, and further, the direct current charged in one of the three storage battery blocks is discharged, and the storage battery block after discharging while waiting for charging. By charging the DC power of the PV power generation amount, it becomes possible to stably supply power to the load 7 (see the shaded portion in FIG. 6). Similarly, power can be stably supplied to the load 7 on the second to ninth days.

  In the table of FIG. 7, an example relating to a multiple of 3 is shown. Specifically, in the table of FIG. 7, the weather is bad due to rain on days other than the multiple of the third day and the weather is fine and fine on the multiple of the third day. Power generation is possible. In the case of the weather of such conditions, four storage battery blocks are used, and a direct current charged in one of the four storage battery blocks is discharged to charge one or two storage battery blocks. By charging the storage battery block after discharge with DC power of the amount of PV generated while waiting, the power can be stably supplied to the load 7 (see the shaded portion in FIG. 7). Similarly, the power can be stably supplied to the load 7 on the second to twentieth days.

Figure 5 As shown in Figure 7 of the table, can be controlled independent charging and discharging of the charging and discharging control unit _a 1 ~a _n corresponding to a plurality of battery blocks _b 1 ~b _n and each battery block _b 1 ~b _n By providing the power to the power supply system 100 shown in FIG. 1 or FIG. 2, power can be permanently and stably supplied to the load 7 and the load 9 (see the shaded portions in FIGS. 5 to 7).

FIG. 8 is a flowchart for explaining the operation in the central control manager 3 of the power feeding system 100 of the first embodiment. In the description of FIG. 8, the PV power generation amount is parameter A, the charge amount of DC power charged in the storage battery block b ₁ is parameter B, the discharge amount of DC power discharged from the storage battery block b _n is parameter C, and the load The amount of power required for the operation of No. 7 is set as parameter D.

  In FIG. 8, the central control manager 3 determines whether the PV power generation amount, that is, the DC power generation amount of the solar cell panel 1 is zero (S1). It is assumed that the central control management unit 3 constantly or regularly acquires information on the PV power generation amount from the processor of the MPPT unit 2. When it is determined that the PV power generation amount is not zero (S1, NO), the process proceeds to step S4.

On the other hand, when it is determined that the PV power generation amount A is zero (S1, YES), the central control management unit 3 has a dischargeable storage battery block among the plurality of storage battery blocks b _{1 to} b _n . It is determined whether or not (S2). That is, the central control management unit 3 determines a storage battery block that can be discharged and a charge / discharge control unit that can control the discharge of the storage battery block.

  The central control management unit 3 defines a table in which storage battery blocks used for each day are determined in advance based on an operation example of the power supply system 100 according to the weather, as shown in the tables of FIGS. Based on weather conditions of multiple days, it is possible to create (generate) a charge / discharge plan. In this case, the central control management unit 3 grasps the presence of the dischargeable storage battery block, and proceeds to the process of step S3.

Further, it is assumed that the contents of the table are not stored in the central control management unit 3 in the determination in step S2. In this case, the central control management section 3 inquires whether dischargeable battery block exists in KakuTakashi discharge controller a ₁ ~a _n, a response result indicating that dischargeable battery block is present If it is obtained from any of the charge / discharge control units, the presence of a dischargeable storage battery block is grasped. In this case, the process proceeds to step S3.

  When it is determined that there is no dischargeable battery block (S2, NO), the flowchart of FIG. 8 ends.

When the dischargeable battery block is determined to exist (S2, YES), the central control management unit 3, so as to discharge the DC power of the discharge amount C from which the determined eg battery block b _n in step S2 and it outputs a discharge start notification to the charge and discharge control unit _{a n} (S3). That is, the central control management unit 3 via the charging and discharging control unit a _n, the load output control section 6 DC power to discharge the discharge amount C of the charging and discharging control unit a _n battery blocks b _n corresponding to Supply. The load output control unit 6 receives the supply of the DC power of the charge amount C from the storage battery block b _n and supplies the load 7 with the DC power of the power amount D necessary for the operation of the load 7. After step S3, the process returns to step S1.

  Next, the central control management unit 3 determines whether or not the PV power generation amount A is greater than zero and less than or equal to the DC power charge amount B (S4). When it is determined that the PV power generation amount A is greater than the DC power charge amount B (S4, NO), the process proceeds to step S7.

On the other hand, when it is determined that the PV power generation amount A is greater than zero and less than or equal to the charge amount B of DC power (S4, YES), the central control management unit 3 includes a plurality of storage battery blocks b _{1 to} b _n . It is determined whether there is a dischargeable storage battery block (S5). That is, the central control management unit 3 determines a storage battery block that can be discharged and a charge / discharge control unit that can control the discharge of the storage battery block. Since the determination in step S5 is similar to the determination in step S2 described above, detailed description thereof is omitted.

  If it is determined that there is no dischargeable battery block (S5, NO), the flowchart of FIG. 8 ends.

When the dischargeable battery block is determined to exist (S5, YES), the central control management unit 3, a DC power of the discharge amount C of the charge amount B from which the determined eg battery block b _n in step S5 and outputs a discharge start notification to the charge and discharge control unit a _n so as to discharge (S6). That is, the central control management unit 3 via the charging and discharging control unit a _n, the charge and discharge control unit a _n while the discharge amount C DC power by discharging the load output of the charge amount B from the battery block b _n corresponding It is made to supply to the control part 6.

Further, the central control management unit 3 outputs a load supply notification to the MPPT unit 2, and causes the MPPT unit 2 to supply the DC power of the PV power generation amount A to the load output control unit 6 (S6). Load output control section 6 is supplied with the DC power of the DC power and the PV power generation amount A of the charged amount C from the battery block b _n and MPPT unit 2, based on the combined DC power charged amount C and PV generations A In addition, DC power having an electric energy D necessary for the operation of the load 7 is supplied to the load 7. Thus, the DC power consumption ratio of the charge amount C in step S6 is the combined DC power of the PV power generation amount A and the charge amount C because the direct current power that is the source of the direct current power of the load amount D is step S3. The charge amount C can be reduced more than the DC power consumption rate. After step S6, the process returns to step S1.

  Next, the central control management unit 3 determines whether or not the PV power generation amount A is greater than the DC power charge amount B and equal to or less than the sum (B + D) of the DC power charge amount B and the load amount D ( S7). When it is determined that the PV power generation amount A is greater than the sum (B + D) of the DC power charge amount B and the load amount D (S7, NO), the process proceeds to step S12.

On the other hand, if it is determined that the PV power generation amount A is greater than the DC power charge amount B and equal to or less than the sum (B + D) of the DC power charge amount B and the load amount D (S7, YES), the central control is performed. The management unit 3 determines whether there is a dischargeable storage battery block among the plurality of storage battery blocks b _{1 to} b _n (S8). That is, the central control management unit 3 determines a storage battery block that can be discharged and a charge / discharge control unit that can control the discharge of the storage battery block. Since the determination in step S8 is similar to the determination in step S2 described above, detailed description thereof is omitted.

  If it is determined that there is no dischargeable battery block (S8, NO), the flowchart of FIG. 8 ends.

When the dischargeable battery block is determined to exist (S8, YES), the central control management unit 3 outputs the charge start notification to the MPPT unit 2 and the charge and discharge control unit a _1, MPPT section 2 and The charge / discharge control unit a ₁ is charged with the DC power of the PV power generation amount A, for example, in the storage battery block b ₁ determined in step S8 (S9).

Specifically, for example, when the maximum charge power amount of the storage battery block b ₁ is set as the parameter B _max , the central control management unit 3 supplies the MPPT unit 2 and the charge / discharge control unit a ₁ with (B _The storage battery block b ₁ is charged with the amount of DC power of _max− B). As a result, the power supply system 100 can charge the storage battery block b ₁ to be charged with a sufficient amount of direct current power of the PV power generation amount A in the central control management unit 3, and as a result, the storage battery block b ₁ is brought into a fully charged state. can do.

In the case where when charged to the storage battery block b ₁ is completed or accumulator block b ₁ is fully charged state, the charging and discharging control unit a ₁ is to stop the charging of the battery blocks b _1, charge stop A notification is generated and output to the central control manager 3.

Central control management section 3, whether or not the remaining amount A _re of PV generations A after step S9, whether becomes zero, i.e., DC power of the PV power generation amount A is all consumed for charging the battery block b ₁ in step S9 Is determined (S10). When the DC power of the PV power generation amount A is determined to have been all consumed for charging the battery block b ₁ in step S9 is (S10, YES), the process proceeds to step S3. That is, the central control management unit 3 via the charging and discharging control unit a _n, the load output control section 6 DC power to discharge the discharge amount C of the charging and discharging control unit a _n battery blocks b _n corresponding to Supply. The load output control unit 6 receives the supply of the DC power of the charge amount C from the storage battery block b _n and supplies the load 7 with the DC power of the power amount D necessary for the operation of the load 7.

When it is determined that the DC power of the PV power generation amount A is not completely consumed for charging the storage battery block b ₁ in step S9 (S10, NO), the central control management unit 3 notifies the MPPT unit 2 of load supply , And causes the MPPT unit 2 to supply the DC power of the surplus PV power generation amount _Are to the load output control unit 6 (S11).

Furthermore, the central control management unit 3 outputs a discharge start notification to the charge and discharge control unit a _n so as to discharge the DC power of the discharge amount C from battery block b _n charged in step S9 (S11). That is, the central control management unit 3 via the charging and discharging control unit a _n, the charge and discharge control unit a supply _n from the battery block b _n corresponding to the load output control section 6 DC power to discharge the discharge amount C Let Load output control section 6 is supplied with the DC power charged amount C and excess PV power generation amount _{A re} from the battery blocks _{b 1} and MPPT unit 2, the synthesis DC charge amount C and excess PV power generation amount _{A re} Based on the electric power, DC power of the electric energy D necessary for the operation of the load 7 is supplied to the load 7.

Thereby, the DC power consumption ratio of the charge amount C in step S11 is the combined DC power of the surplus PV power generation amount _Are and the charge amount C, which is the source of the DC power of the load amount D. In step S3, the charge amount C can be reduced from the DC power consumption rate. Further, in step S9, because it charges the DC power of the PV power generation amount A to the battery blocks b _1, it is possible to efficiently charge the battery blocks b _1.

Next, the central control management unit 3 determines whether or not the PV power generation amount A is greater than the sum (B + D) of the charge amount B and the load amount D of DC power (S12). When it is determined that the PV power generation amount A is larger than the sum (B + D) of the DC power charge amount B and the load amount D (S12, YES), the central control management unit 3 notifies the MPPT unit 2 of the load supply. Is output. Further, the central control management unit 3 causes the MPPT unit 2 to directly supply the DC power of the PV power generation amount A to the load output control unit 6 without discharging the DC power from the storage battery block b ₁ (S13).

The load output control unit 6 receives the supply of the DC power of the PV power generation amount A from the MPPT unit 2, and based on the DC power of the PV power generation amount A, supplies the DC power of the power amount D necessary for the operation of the load 7 to the load 7. To supply. Thus, in step S13, only the PV power generation amount A in can cover the DC power load D, it is possible to avoid the discharge of the DC power from the battery block b _1. After step S13, the process returns to step S1.

As described above, the power supply system 100 according to the first embodiment uses, as an energy harvest, for example, in this embodiment, the direct-current power generated in the solar cell panel 1 is a secondary battery that is a secondary battery preferentially over the loads 7 and 9. ₁ charges the battery block b ₁ ~b _n is supplied to ~b _n, using a DC power charged can supply the needed power at all times and stably the operation of the load.

In addition, the power supply system 100 sets the power amount of the load amount D of the loads 7 and 9 in the load output control unit 6 in advance before starting the operation, and sets the storage battery blocks b _{1 to} b _n that can supply the power amount of the load amount D. By installing, the power of the load amount D for one day (for 24 hours) using only a single storage battery block (for example, storage battery block b ₁ ) without switching the storage battery block to be discharged during the operation of the day. The amount can be supplied stably.

In addition, since the power supply system 100 can be expanded and parallelized in units of the storage battery blocks b _{1 to} b _n , the power supply system 100 has excellent maintainability such as replacement, and the load output control unit 6 has a variation in the amount of power D. Can be suppressed to a minimum. Furthermore, the power supply system 100 includes the MPPT in the solar cell panel 1, the charging of the DC power generated in the solar cell panel 1 to the storage battery block and the supply to the load output control unit 6 in the central control management unit 3, the storage battery block b. for controlling the supply to the load output control section 6 of the direct-current power by the discharge from ₁ ~b _n collectively, it is possible to reduce the circuit configuration of the power supply system 100.

Further, power supply system 100, by employing a lithium-ion battery or the like to the battery block _b 1 ~b _n, it is possible to reduce the size and weight of the battery block _b 1 ~b _n.

(Second Embodiment)
FIG. 9 is a diagram illustrating a system configuration example of a power feeding system 100a according to the second embodiment. FIG. 10 is a diagram illustrating another system configuration example of the power feeding system 100a according to the second embodiment. The power supply system 100a of the second embodiment shown in FIG. 9 or 10 is the power supply system of the first embodiment in that the DC / DC converter 10 is connected between the load output control unit 6 and the load 7. 100 and the configuration is different. Since the other configuration is the same as that of the power supply system 100 of the first embodiment, the description of the same configuration is omitted.

  The DC / DC converter 10 inputs a DC voltage corresponding to the DC power supplied from the load output control unit 6, and converts the input DC voltage into a DC voltage corresponding to the DC power necessary for the operation of the load 7. Then, the converted DC voltage (DC power) is supplied to the load 7.

As described above, in addition to the effects of the power supply system 100 of the first embodiment, the power supply system 100a of the second embodiment has a load in the DC / DC converter 10 even when the DC voltage fluctuates in the storage battery blocks b _{1 to} b _n . It is possible to stably supply DC power having an amount of power D to the loads 7 and 9.

  While various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is obvious for those skilled in the art that variations and modifications of various embodiments, and combinations of various embodiments can be conceived within the scope of the claims. Of course, it is understood that it belongs to the technical scope of the present invention.

  The storage battery block to be charged in step S9 in the flowchart of FIG. 8 is basically preferably a dischargeable storage battery block determined by the central control manager 3 in step S8. However, the storage battery block to be charged in step S9 in the figure is not limited to the storage battery block determined by the central control management unit 3 in step S8, and may be another storage battery block.

For example, in step S9, the central control management unit 3 compares the remaining charge in all the storage battery blocks b _{1 to} b _{n and} gives priority to the storage battery block with the least remaining charge or the storage battery block scheduled to be used on the next day. Then, the DC power of the PV power generation amount A may be charged.

  In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2011-217955) of an application on September 30, 2011, The content is taken in here as a reference.

  The present invention supplies the power generated in energy harvesting to the secondary battery with priority over the load to charge the secondary battery, and uses the charged power to constantly and stably maintain the power necessary for the operation of the load. It is useful as a power supply system and a power supply method for supplying power automatically.

DESCRIPTION OF SYMBOLS 1 Solar cell panel 2 MPPT part 3 Central control management part 6 Load output control part 7, 9 Load 8 DC / AC inverter 10 DC / DC converter a1, an charging / discharging control part b1, bn Storage battery block 100, 100a Feeding system

Claims (10)

A solar panel that converts solar energy into electrical energy to generate DC power; and
A plurality of storage battery blocks for charging the DC power generated by the solar cell panel;
A plurality of charge / discharge control units that are provided for each of the storage battery blocks and control charging and discharging of the DC power to the storage battery block;
Determination of which storage battery block to use for charging the DC power and discharging to the load based on information on whether or not to generate power by natural energy and information on the storage battery block used for charging or discharging or a combination of the storage battery blocks A central control manager,
And a load output control unit configured to supply, to the load, DC power necessary for the operation of the load, based on the determined DC power discharged from the storage battery block. The power supply system according to claim 1,
An MPPT unit that performs maximum power point tracking control for maximizing the DC power generated by the solar cell panel based on the output current and output voltage of the solar cell panel;
Each of the charge / discharge control units starts charging of the maximum DC power output from the MPPT unit based on a charge start notification from the central control management unit. The power supply system according to claim 1 or 2,
Each of the charge / discharge control units includes each current sensor capable of measuring an output current of the solar cell panel, and each voltage sensor capable of measuring an output voltage of the solar cell panel,
Each of the charging / discharging control units stops charging the storage battery block corresponding to the charging / discharging control unit when charged exceeding a predetermined maximum charging power amount determined by the central control management unit. A power supply system that outputs a charge stop notification to the central control manager. The power supply system according to claim 2 or 3,
Each of the charge / discharge control units discharges the direct-current power charged in the storage battery block corresponding to the charge / discharge control unit based on a discharge start notification from the central management control unit, and the load output control unit Supply system to supply to. The power supply system according to claim 4,
When the DC power generation amount of the solar battery panel is zero, the central control management unit outputs the discharge start notification to the determined charge / discharge control unit, and the storage battery corresponding to the charge / discharge control unit A power supply system that controls the charge / discharge control unit to discharge DC power of a DC power charge amount from a block. The power feeding system according to claim 4 or 5,
When the DC power generation amount of the solar battery panel is equal to or less than the DC power charge amount of the storage battery block corresponding to the determined charge / discharge control unit, the central control management unit discharges the discharge to the charge / discharge control unit. A start notification is output, and the charge / discharge control unit is controlled to discharge DC power of the DC power charge amount from the storage battery block, and the DC power generation amount of the solar battery panel is supplied to the load output control unit A power supply system for controlling the MPPT unit. It is the electric power feeding system as described in any one of Claims 4-6,
The central control management unit is configured such that the DC power generation amount of the solar cell panel is larger than the DC power charge amount of the storage battery block corresponding to the determined charge / discharge control unit, and the DC power charge amount and the operation of the load The power supply system that controls the charge / discharge control unit so as to charge the storage battery block with the DC power generation amount of the solar battery panel when the sum is equal to or less than the sum of the power required for the battery. The power supply system according to claim 7,
The central control management unit determines whether or not there is an excess power amount of DC power of the solar cell panel when the storage battery block is charged exceeding the predetermined maximum charging power amount, and the surplus power A power supply system that controls the MPPT unit so as to supply the load output control unit with DC power of the surplus power when it is determined that there is an amount. It is the electric power feeding system as described in any one of Claims 4-8,
The central control management unit has a DC power charge amount of the storage battery block corresponding to the charge / discharge control unit for which the DC power generation amount of the solar battery panel is determined, and a power amount of power necessary for the operation of the load. A power supply system that controls the MPPT unit so as to supply the load output control unit with DC power of a DC power generation amount of the solar cell panel. A step of generating direct-current power by converting solar energy into electric energy by a solar panel;
Charging one of the plurality of storage battery blocks with the DC power generated by the solar cell panel;
Controlling charging of the DC power and discharging of the DC power to the storage battery block by a charge / discharge control unit provided for each storage battery block;
Based on the information on the possibility of power generation by natural energy and the information on the combination of the storage battery block used for charging or discharging or the combination of the storage battery blocks by the central control management unit, any of the storage batteries can be charged to the DC power and discharged to the load. Determining whether to use a block;
Supplying a DC power necessary for the operation of the load to the load based on the DC power discharged from the determined storage battery block by a load output control unit.

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