JP2014209826A - Independent power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an independent power supply using a solar cell capable of solving a problem in conventional secondary batteries which are repeatedly used from a full-charged state to a point immediately before the charged quantity of electricity runs out resulting in unsatisfactory service life by means of a float charging.SOLUTION: The independent power supply sequentially calculates the current amount flowing in/out a secondary battery. After charging the secondary battery to a certain level in a manner of bulk charge, the charging is continued up so as to replenish the discharged electric quantity. After the discharged electric quantity becomes equal to the charged electric quantity, the charging mode enters into a zero-charge mode to stop the charging. If the secondary battery cannot get full by the electricity from a solar cell module during day-time, the electric power generation of the solar cell module can be effectively used according to how to use a commercial power supply that fully charges the secondary battery as a night-time commercial power supply.

Description

  The present invention relates to an independent power supply device combining a solar cell module and a secondary battery.

  A solar cell is a battery that generates power using sunlight. Because it uses sunlight, which can be said to be inexhaustible, it is attracting attention as a clean and safe energy. However, there was a problem that power generation could not be performed during the time when there was no sunlight at night. Therefore, an independent power source that stores the electricity generated by the solar cell in a secondary battery, uses the electricity generated by sunlight during the daytime, and supplies the secondary battery electricity that was charged during the daytime to the load. An apparatus has been proposed (Patent Document 1).

  Moreover, regarding the charging method of the secondary battery, methods such as trickle charging and float charging have been proposed (Patent Document 2). Here, trickle charging refers to a method of continuing charging with a minute current so as to charge only the self-discharge of the secondary battery. In this charging method, although it takes time to recharge the largely discharged power, it is not necessary to worry about overcharging.

  On the other hand, the float charging is a method of reducing a burden on the secondary battery by flowing current to another (load or the like) by a bypass circuit after charging until the battery is fully charged. Since the voltage remains applied to the secondary battery, power is supplied to the load while charging. In order to charge by such a method, it is said that float charging can make a secondary battery last longer.

Japanese Patent Laid-Open No. 05-074499 Japanese Patent Laid-Open No. 08-017473

  The independent power supply device using a solar cell outputs power from the solar cell module to a load. Therefore, when the night solar cell module does not generate power, the power of the secondary battery is supplied to the load. That is, in an independent power supply device using a solar battery, it can be said that the secondary battery repeatedly discharges and charges at night and daytime, and thus has a heavy burden.

  When charging such a secondary battery, bulk charging for charging the discharged power up to a predetermined voltage at maximum power, absorption charging for performing constant voltage charging for a predetermined time to prevent overcharging, and then self-discharge Float charging is performed to charge and supply power to the load with a voltage that compensates for the amount.

  However, although float charging is effective in extending the life of secondary batteries that are always used in a state close to full charge, the independent power supply using solar cells depletes the stored power from full charge. Since the period until immediately before is repeated every day, there is a problem that the life of the secondary battery cannot be extended as is usually said.

  Moreover, there has been no knowledge in the past about how to efficiently use the solar cell module while extending the life of the secondary battery.

  The present invention has been conceived in view of the above problems. The inventor of the present invention, in a secondary battery that repeats a full charge and a large amount of power discharge, when the voltage between the terminals of the secondary battery reaches a predetermined value in the bulk charge, and charge and discharge electricity by the constant voltage charge When the time difference when the amount becomes zero reaches a predetermined time, it has been found that there is an effect in extending the battery life by performing the overcharge process. Moreover, it discovered that the solar cell module could be used efficiently by using a commercial power source.

More specifically, the independent power supply device of the present invention is:
A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, when the secondary battery is the solar battery module and the charge / discharge electricity amount cannot be charged to zero, the secondary battery is charged from a commercial power source at night.

Moreover, in the independent power supply device according to the present invention,
A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, when the secondary battery is used to the execution depth, the secondary battery is charged from a commercial power source.

Moreover, in the independent power supply device according to the present invention,
A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, when the secondary battery is used up to the execution depth, the secondary battery is charged from a commercial power source at night.

In the above independent power supply,
The charge / discharge control means uses the generated power only for power supply to the load when the secondary battery is charged until the charge / discharge electricity amount reaches zero from a negative value.

Moreover, in the independent power supply device according to the present invention,
The charge / discharge control means resets the value of the charge / discharge electricity amount when overcharged until the charge / discharge electricity amount reaches a predetermined amount or more.

  The independent power supply according to the present invention records the amount of charge / discharge electricity used from the fully charged state of the secondary battery to be used, and when charging, the amount of electricity to be charged and the amount of charge / discharge electricity used It was decided to charge at a constant voltage until. Therefore, there is no possibility of overcharging.

  In addition, after charging the discharged amount of electricity, the zero charge mode is entered in which no charging is performed. Therefore, even if it is the secondary battery of the independent power supply device using a solar cell module which repeats full charge and a large amount of discharge, the lifetime of a secondary battery can be extended.

  Also, in the charge / discharge cycle, the time difference between when the voltage between the terminals of the secondary battery becomes a predetermined value in the bulk charge and when the charge / discharge electricity amount becomes zero by the constant voltage charge becomes the predetermined time. Sometimes, overcharging can extend battery life without considering the history of secondary batteries used.

  In addition, when the secondary battery is used up to the effective depth, or when the solar battery module cannot be fully charged, the commercial power supply is used. It can be kept below a certain ratio, and the life of the secondary battery can be extended.

  Moreover, since a commercial power source is used as appropriate, the electricity generated by the solar cell module can be used without wasting it.

It is a figure which shows the structure of the independent power supply device which concerns on this invention. It is a figure which shows the detailed structure of a charging / discharging control means. It is a figure which shows the flow of a charging / discharging electric quantity calculating means. It is the graph which showed the charging process of the independent power supply device which concerns on this invention on the time-axis. It is a figure which shows the flow of a charging process. In FIG. 4, it is a figure which shows the state in which the secondary battery deteriorated and t2 and t3 became equal. It is a figure which shows the processing flow of an immediate charge type independent power supply device. It is a figure which shows the processing flow charged using a solar cell module. It is a figure which shows the processing flow charged using a commercial power source. It is a figure which shows the processing flow of a night charge type independent power supply device. It is a figure which shows the processing flow of an undercharge type independent power supply device. It is a figure which shows the structure of the independent power supply with backup. It is a figure which shows the detailed structure of the charging / discharging control means in FIG. It is a figure which shows the processing flow of the independent power supply with backup.

  The independent power supply apparatus according to the present invention will be described below with reference to the drawings. The following description exemplifies several embodiments of the independent power supply device of the present invention, and modifications can be made without departing from the spirit of the present invention.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of an independent power supply device 1 according to the present invention. The independent power supply device 1 of the present invention includes a solar cell module 10, a secondary battery 12, a charge / discharge control means 11, a voltage sensor 13, a charge / discharge current sensor 14, an output terminal 15, and a commercial power input terminal 31. Have. Further, an inverter 34 may be provided immediately before the output terminal 15. The solar cell module 10 is connected to the charge / discharge control means 11 by the wiring L1.

  The charge / discharge control means 11 is connected to the secondary battery 12 via a wiring L2, and is connected to the output terminal 15 via a wiring L3. The output terminal 15 is connected to the load 19 through the wiring L4. These wirings are indicated by bold lines in FIG. A current supplied to the load 19 or charged to the secondary battery 12 flows through the wirings L1 to L4.

  The commercial power input terminal 31 connected to the commercial power supply 30 via the wiring L5 is connected to the charge / discharge control means 11 by the wiring L6. Further, the AC-DC converter 32 may be disposed on the wiring L6.

  The solar cell module 10 is a device that extracts electricity from solar rays by the photovoltaic effect, and is not particularly limited to silicon, a compound semiconductor, and a dye-sensitized type. The secondary battery 12 is not particularly limited as long as it is a secondary battery such as a lead battery, nickel metal hydride, or lithium ion, but a lead battery can be preferably used.

  The voltage sensor 13 is not particularly limited as long as it detects the voltage of the secondary battery 12. The voltage sensor 13 is connected to the charge / discharge control means 11 by a signal line SL1. The voltage sensor 13 transmits the measured voltage value SV to the charge / discharge control means 11 through the signal line SL1.

  The charge / discharge current sensor 14 is a current sensor that can determine whether the current flowing is a current for charging (charging current) or a discharging current (discharge current). The charge / discharge current sensor 14 is connected to the charge / discharge control means 11 by a signal line SL2. The charge / discharge current sensor 14 transmits the measured current value SA to the charge / discharge control means 11 through the signal line SL2.

  Based on the output (SA) of the charge / discharge current sensor 14, the charge / discharge control means 11 calculates an amount of electricity such as a charge / discharge amount ΣC described later. The charge / discharge control means 11 can be realized by, for example, a combination computer such as an MPU (Micro Processor Unit) and a memory.

  Moreover, the solar cell module 10 has an electromotive force monitor 16, and is connected to the charge / discharge control means 11 by a signal line SL3. The electromotive force monitor 16 can send out the current electromotive force value SPv of the solar cell module 10 as an output. The electromotive force monitor 16 may not be incorporated in the solar cell module 10. This is because the charge / discharge control means 11 only needs to be able to know the electromotive force of the solar cell module 10 and may be a voltmeter disposed between the solar cell module 10 and the charge / discharge control means 11.

  FIG. 2 shows a detailed view of the charge / discharge control means 11. The charge / discharge control means 11 includes at least a control unit (MPU) 20, a memory 24, a power control unit 22, and a timer 25. The control device 20 is connected to the memory 24, the electromotive force monitor 16 of the solar cell module 10, the power control unit 22, the charge / discharge current sensor 14, the voltage sensor 13, and the timer 25.

  The power control unit 22 is connected to the solar cell module 10, the secondary battery 12, the commercial power supply input terminal 31, and the output terminal 15 through wirings L1 to L3 and L6. A commercial power supply 30 is connected to the commercial power input terminal 31. A load 19 is connected to the output terminal 15 (see FIG. 1).

  The electric power control part 22 adjusts the electric power supplied to the secondary battery 12 and the output terminal 15 (load 19) among the electric power generated in the solar cell module 10. In addition, it has voltage conversion means (not shown) such as a DC-DC converter inside, and the charging voltage to the secondary battery 12, the supply voltage to the output terminal 15 (load 19), etc. Can be output as a value.

  Further, at night when the solar cell module 10 does not generate electricity, control is performed to supply the amount of electricity stored in the secondary battery 12 to the output terminal 15 (load 19), and the current from the secondary battery 12 is transferred to other than the output terminal 15. Has a circuit or the like for preventing flow. In addition, the power control unit 22 is also connected to the commercial power source 30, and flows power from the commercial power source 30 to the secondary battery 12 and the load 19 as necessary. Note that these functions of the power control unit 22 are activated, changed, or stopped by an instruction Cov from the control device 20.

  Next, functions of the charge / discharge control means 11 will be described. At least the charge / discharge control means 11 according to the present invention realizes the function of charge / discharge electricity quantity calculation means. The charge / discharge electricity amount calculating means calculates a charge / discharge electricity amount ΣC, which is the sum of the amount of electricity charged to the secondary battery 12 and the amount of electricity discharged from the secondary battery 12. As described above, the independent power supply device 1 according to the present invention manages the electricity stored in the secondary battery 12 by converting it into the amount of electricity (Ah).

  The charge / discharge control means 11 realizes charge / discharge electricity calculation means for calculating the charge / discharge electricity ΣC from the signal (SA) from the charge / discharge current sensor 14. This is calculated | required when the control apparatus 20 calculates | requires the amount of electricity from the product of the electric current which flowed through the secondary battery 12, and the flow time, and integrates sequentially. FIG. 3 shows a flow of the charge / discharge electric quantity calculation means.

  Referring to FIG. 3, when this process starts (step S1000), an initial value is set. The initial value is ΔC, which is the amount of electricity during a minute time, and the accumulated charge / discharge amount of electricity ΣC. These values are set to zero (step S1010). Next, end determination is performed (step S1020). When the process is to be ended, the flow is shifted to the end process (step S1070).

  The end determination can be ended if there is an operation stop signal or an action even during this processing or other processing. In other words, the process is not returned from anywhere in step S1020, which is an end determination process, but this indicates that the end determination can be returned from any subsequent flow.

  Next, the control device 20 acquires the current value SA and the current direction from the charge / discharge current sensor 14 (step S1030). At this time, for example, it is preferable that the current to be acquired be handled with a positive sign if the current flows for charging and with a negative sign if the current flows toward the load 19. At this time, the voltage value SV may be acquired from the voltage sensor 13.

  Next, the current value SA is multiplied by a predetermined minute time ΔT to obtain a minute charge / discharge amount of electricity ΔC (step S1040). Then, the small charge / discharge electricity amount ΔC is added to the charge / discharge electricity amount ΣC to obtain a new charge / discharge electricity amount ΣC (step S1050). And it waits as it is until minute time (DELTA) T passes (step S1060). And it returns to step S1030 again and acquires electric current value SA. By doing in this way, the control apparatus 20 can always hold | maintain charging / discharging electricity amount (SIGMA) C (total amount of electricity as a result of discharging or charging from the secondary battery 12).

  Next, the operation of the independent power supply device 1 of the present invention will be described. Here, the full charge capacity FC is determined. The full charge capacity FC is the amount of electricity from when the secondary battery 12 is fully charged until it is fully discharged, and is expressed as current × time (A · hr: written as “Ah”). This can be obtained from a characteristic curve of the battery, usually called a discharge curve.

  In FIG. 4, the graph explaining the basic operation | movement of charging / discharging using only the solar cell module 10 of the independent power supply device 1 is shown. The commercial power supply 30 is not used. FIG. 5 shows a flow of operations for FIG. In FIGS. 4A, 4B, and 4C, the horizontal axis represents time. From time t1 to t4 is a time zone in which sunlight can be obtained, and is a chargeable time zone. The vertical axis in FIG. 4A is the terminal voltage (V) of the secondary battery 12. The voltage V1 is a nominal voltage. For example, in the case of a lead storage battery, it is about 13.0V.

  V2 is the maximum voltage allowed at the time of charging and is a constant voltage setting value. The constant voltage set value is a value that serves as a guide when shifting from bulk charging (described later) to absorption charging. In the case of a lead storage battery, it is about 14.9V.

  In FIG. 4B, the vertical axis represents the charge / discharge current (A) flowing through the secondary battery 12. When the current value is positive, the current flows into the secondary battery 12, that is, the charged current. When the current value is negative, the current flows out from the secondary battery 12. In FIG. 4C, the vertical axis represents the charge / discharge electricity amount ΣC (Ah) of the secondary battery 12.

  Referring to the flow of FIG. 5, when this process starts (step S300), initial setting is performed (step S302), and an end determination is performed (step S304). In the case of termination (Y branch of step S304), the independent power supply device 1 is terminated (step S340).

  In order to simplify the explanation, it is assumed that the nighttime secondary battery 12 supplies power to the load 19 and is at time t0 in FIG. At this time, the integration of the charge / discharge electricity amount ΣC is continued (step S306), and it is determined whether or not the electromotive force of the solar cell module 10 is generated (step S308). In FIG. 5, “panel on (Vth)” is displayed.

  This is performed by referring to the value SPv from the electromotive force monitor 16. More specifically, the determination is made based on whether or not the value SPv is greater than a predetermined voltage Vth. Here, the voltage Vth is a threshold value for determining whether or not the power generated by the solar cell module 10 can be used.

  At this time, in FIG. 4, the time is between t0 and t1, the voltage of the secondary battery 12 (FIG. 4A) gradually decreases, and the flowing current (FIG. 4B) is loaded from the secondary battery 12 to the load. It flows toward 19 (the sign is negative). Therefore, the charge / discharge electricity amount ΣC (FIG. 4C) is integrated with minus values, and the absolute value of the minus value increases. That is, it can be said that the secondary battery 12 is decreasing toward a depleted state. When the charge / discharge electricity amount ΣC becomes “−FC (Ahr)”, the electricity amount of the secondary battery 12 is all discharged.

  At time t1, the sun rises and the solar cell module 10 starts generating power. When it is confirmed that the value SPv from the electromotive force monitor 16 exceeds a predetermined value (Vth) (Y branch in step S308), the process proceeds to bulk charging (step S310). Bulk charging refers to a charging mode in which charging of the secondary battery 12 is performed by MPPT (Maximum Power Point Tracker) control.

  Here, all the power generated by the solar cell module 10 other than the power required by the load 19 is used for charging the secondary battery 12. The control device 20 instructs the power control unit 22 to perform such charging with an instruction Cov. It should be noted that the charge / discharge electricity calculation means performs processing even during bulk charging, calculates the flow of electricity, and integrates the charge / discharge electricity ΣC.

  In bulk charging, current flows into the secondary battery 12, so that the charge / discharge current is positive (see FIG. 4B). In addition, the terminal voltage of the secondary battery 12 increases (see FIG. 4A). Bulk charging is continued until the terminal voltage of the secondary battery 12 reaches the constant voltage set value V2 (N branch in step S312). During this time, since a current flows to the secondary battery 12, the charge / discharge electricity amount ΣC increases from a negative value toward zero (see FIG. 4C).

  When the terminal voltage value (SV) of the secondary battery 12 reaches the constant voltage set value V2 (Y branch of step S312), the mode shifts to a constant voltage charging mode (also called absorption charging) in which charging is performed with a constant charging voltage (also called absorption charging) ( Step S318). In the constant voltage charging mode, the power control unit 22 performs adjustment so that the voltage between the terminals of the secondary battery 12 becomes a predetermined value (here, the constant voltage setting value V2). On the other hand, the charge / discharge current gradually decreases (see FIG. 4B).

  Even during this time, the charge / discharge control means 11 supplies necessary power to the load 19. In addition, the charge / discharge electricity calculation means continues to calculate the charge / discharge electricity ΣC. The charge / discharge electricity amount ΣC increases from a negative value toward zero because a current flows into the secondary battery 12.

  In the constant voltage charging mode, the control device 20 detects whether or not the charge / discharge electricity amount ΣC has reached the target value TC (step S320). Here, TC is set to zero.

  When the charge / discharge electricity amount ΣC is changed from the negative value to the target value TC (here, “zero”), the constant voltage charging mode is terminated (Y branch of step S320). That is, in the independent power supply device 1 of the present invention, the charge / discharge electricity amount ΣC discharged from the secondary battery 12 is accumulated as a negative value, and the secondary battery 12 is charged until the charge / discharge electricity amount ΣC returns to zero. . In other words, it is not determined that the battery is fully charged based on the voltage between the terminals of the secondary battery 12 as conventionally performed.

  When the constant voltage charging mode ends (time t3 in FIG. 4), the process proceeds to the zero charging mode (step S322). The zero charge mode is a mode in which the secondary battery 12 is not charged at all. Of the power generated by the solar cell module 10, electricity required by the load 19 is supplied from the power control unit 22. Therefore, the charge / discharge current becomes zero (see time t3 to t4 in FIG. 4B). Further, the value of the charge / discharge current amount ΣC does not change.

  After shifting to the zero charge mode, it is monitored whether or not it has become nightfall (step S324). This can be realized by the control device 20 monitoring the value SPv of the electromotive force monitor 16. As in step S308, the threshold value compared with the value SPv is replaced with Vss, which is lower than the threshold value Vth in step S308. In other words, the zero charge mode is continued until the sunset and the power supply from the solar cell module 10 is completely eliminated (Y branch in step S324).

  When the sun sets and the electromotive force of the solar cell module 10 disappears (N branch in step S324), the secondary battery 12 starts discharging the load 19 from the stored amount of electricity. At this time, the secondary battery 12 and the load 19 are connected by the power control unit 22 according to an instruction Cov from the control device 20. The process flow increments the date DL (step S326) and returns to step S304. In step S304, after the end determination (N branch in step S304), electricity is supplied to the load 19 while adding a negative value to the charge / discharge electricity amount ΣC, and the solar cell module 10 is activated (Y branch in step S308). Wait for.

  As described above, the independent power supply device 1 using the solar cell module 10 repeats daytime charging and nighttime discharging. By the way, it is known that the secondary battery 12 deteriorates while charging and discharging are repeated. However, by performing overcharge processing such that the charge / discharge electricity amount ΣC becomes zero or more at a predetermined timing, the cell balance is recovered, and deterioration of the secondary battery 12 is suppressed. Here, zero or more is about 0.2 times the full charge capacity FC.

  The inventor according to the present invention, when the secondary battery 12 repeats charging and discharging, the time when the constant voltage set value (V2) is reached by bulk charging, and then the charging / discharging electricity amount ΣC becomes zero by constant voltage charging. It has been found that the time interval of the time is gradually shortened, and when the time interval reaches a predetermined value, the life of the secondary battery 12 can be extended by performing an overcharge process.

  For example, referring to FIG. 4, the constant voltage set value (V2) is reached at time t2 in bulk charging. Further, the charge / discharge electricity amount ΣC becomes zero by the constant voltage charge thereafter at time t3. This time interval t3-t2 (hereinafter, this time interval is referred to as “degradation index time”) is shortened each time charging and discharging are repeated. FIG. 6 shows a case where time t2 and time t3 overlap.

  The secondary battery 12 to be used is preferably overcharged when the “deterioration index time” reaches a predetermined value. For example, the “deterioration index time” shown in FIG. 6 is zero. However, if the “deterioration index time” is a fixed time, it is not particularly limited to zero. If this “degradation index time” is long, the time interval for performing the overcharge process is shortened. Therefore, the “degradation index time” can be determined depending on the characteristics of the secondary battery 12 to be used, the usage environment, and the like.

  Further, from the viewpoint of always recovering the secondary battery 12 to the same state, it is desirable that the overcharge process is performed when the “deterioration index time” always becomes a predetermined value. However, when the solar cell module 10 is used, the timing for charging depends on the weather. Therefore, if this “degradation index time” is equal to or shorter than a predetermined time, the overcharge process may be performed.

Now, in the independent power supply device 1 which concerns on this invention, the commercial power supply 30 is also used besides the solar cell module 10. FIG. Below, three types of independent power supply devices 1 using a commercial power supply 30 are shown. The characteristics of each type are shown.
(1) When the secondary battery is used to the execution depth, it is charged to full charge with a commercial power source.
(2) When the secondary battery has been used up to the working depth, wait until night and fully charge with commercial power.
(3) If the secondary power supply is not fully charged, fully charge it with commercial power supply on the night of the day.

  (1) is called immediate charge type, (2) is called night charge type, and (3) is called undercharge type. These are referred to as independent power supply devices 1a, 1b, and 1c, respectively. Each hardware configuration is the same as that shown in FIGS. 1 and 2 and is the same, but the software executed by the charge / discharge control means 11 is different. That is, the method of charging the secondary battery 12 and the method of using the commercial power source 30 are different. In addition, it is common for each independent power supply device 1 to detect the “degradation index time” described above and perform an overcharge process. The processing flow of each of the following types of independent power supply devices 1 will be described in detail.

<Instantaneous charging type independent power supply 1a>
When the secondary battery 12 is used up to the execution depth, the immediate charge type independent power supply 1a charges the commercial power supply 30 until it is fully charged. Here, full charge means charging until the charge / discharge electricity amount ΣC becomes zero. FIG. 7 shows a processing flow.

  When the process starts (step S100), initialization is performed (step S102). In the immediate charge type independent power supply 1a, several variables are used, and these values are set to predetermined values. Specifically, the charging / discharging electricity amount ΣC, the target value TC for charging, the predetermined time Tth compared with the “deterioration index time”, S as the index for full charge, and the like.

  Next, an end determination is made (step S104), and in the case of end (Y branch of step S104), it stops (step S101). When continuing (N branch of step S104). Next, it is determined whether or not nightfall has come (step S106). This may be determined by the control device 20 using the timer 25 to know the current time. Moreover, you may perform the same process as step S324 of FIG.

  If one day has passed (Y branch of step S106), the variable DL is incremented (step S116). DL is a variable representing a date. However, DL assumes one day from nightfall to nightfall. This is because the night when the solar cell module 10 does not operate is treated as one continuous time.

  Next, it is determined whether power can be supplied to the load 19 (step S108). Of course, when the sun does not come out at night, even if it is the time when the sun goes out, there are cases where power generation cannot be performed when the angle with the solar cell module 10 is shallow or when the weather is extremely bad. Therefore, it may be said here that it is determined whether the solar cell module 10 is generating power.

  If it is determined that there is enough power to be supplied to the load 19 (Y branch in step S108), it is next determined whether or not charging is possible (step S110). At this time, it is determined that the solar cell module 10 is generating power. Therefore, the amount of electricity from the solar cell module 10 after the Y branch in step S110 becomes the “total power generation amount”. Since the purpose of the independent power supply 1 is to supply power to the load 19, the generated electricity is first supplied to the load 19, and then surplus electricity is charged to the secondary battery 12.

  If power is being generated and there is power to be supplied to the load 19 but not enough electricity to charge (N branch in step S110), the electricity generated by the solar cell module 10 is supplied to the load 19 (step S128). ). In the figure, it was described as “solar load supply”.

  On the other hand, if the power generation amount has room to be charged (Y branch in step S110), it is checked whether or not this full charge has been performed (step S112). This is determined based on whether or not the variable S is DL (a variable representing a date). That is, when full charge is executed within the day, the date of the day is input to the variable S.

  If the full charge is achieved (Y branch of step S112), the process proceeds to "Solar load supply" of step S128. Here, although there is more power generation than is supplied to the load 19, there is no room for charging on the secondary battery 12 side. Therefore, the remaining electricity supplied to the load 19 is discarded as it is. This is called “invalid power generation”.

  When full charge is not achieved (N branch of step S112), the secondary battery 12 is charged (step S114). In FIG. 7, “solar charge” is described. The contents of this processing include bulk charging, constant voltage charging, and overcharging processing based on the “degradation index time” described above. Details of the contents of this processing will be described later with reference to FIG.

  Now, returning to step S108, when electricity cannot be supplied to the load 19 (N branch of step S108), electricity is supplied from the secondary battery 12 to the load 19 (step S118). In FIG. 7, “battery load supply” is described. The charge / discharge control means 11 controls to supply electricity from the secondary battery 12 to the load 19. Then, the charge / discharge control means 11 determines whether or not the target value TC is 0.2 (step S120). This is a process for determining whether or not to perform an overcharge process. Here, 0.2 is 0.2 times the full charge capacity FC. Hereinafter, it is abbreviated as “0.2”.

  In this process, when the target value TC is 0.2 (Y branch in step S120), it may be considered that power generation is stopped when the solar cell module 10 is overcharged. In that case, in order to continue an overcharge process, it transfers to the process in the commercial power source 30 (step S124). When the overcharge process is not performed (N branch of step S120), it is determined whether the usage state of the secondary battery 12 has reached the execution depth (step S122).

  The execution depth is a limit amount of the discharge amount of the secondary battery 12. When the secondary battery 12 is repeatedly charged and discharged to release all of the battery capacity, the life of the secondary battery 12 is rapidly shortened. Therefore, the amount of electricity to be charged and discharged is stopped at a part of the battery capacity. Specifically, the charge / discharge control means 11 determines how much the charge / discharge electricity amount ΣC has decreased. The execution depth is appropriately determined at the time of designing the system, and is usually determined with reference to about 70% of the full charge capacity FC.

  When the charge / discharge amount ΣC of the secondary battery 12 has not reached the execution depth (N branch in step S122), electricity is continuously supplied from the secondary battery 12 to the load 19. The process flow returns to step S104. However, since the same determination as in steps S106 and S108 is repeated, the process returns to step S118 again, and electricity is continuously supplied from the secondary battery 12 to the load 19.

  When the amount of charge / discharge electricity ΣC has reached the execution depth (Y branch in step S122), the commercial power supply 30 is used to supply power to the load 19 and charge the secondary battery 12. The charge / discharge control unit 11 performs control so that predetermined electricity flows from the commercial power supply 30 to the load 19 in step S124. Then, the secondary battery 12 is charged using the commercial power supply 30 (step S126). In FIG. 7, “commercial charging” is described.

  In the charging of the secondary battery 12 using the commercial power source 30, charging is performed by substantially the same operation as “solar charging” in step S <b> 114 which is charging using the solar battery module 10. Therefore, bulk charging, constant voltage charging, and overcharge processing based on the “deterioration index time” described above are included. Details of this processing will be described later with reference to FIG.

  Next, the “solar charging” process in step S114 will be described with reference to FIG. This process includes a process for determining whether to perform bulk charge, constant voltage charge, overcharge process, and overcharge process. Referring to FIG. 8, when the process moves to step S <b> 114 “solar charge” (of FIG. 7), it is determined whether or not bulk charge is completed (step S <b> 152). This is because the bulk charge process is skipped at this time because the process passes through this step even when the bulk process is finished and the charge is shifted to the constant voltage charge process.

  If the bulk charge is not completed (N branch in step S152), the bulk charge is performed (step S154). The charge / discharge control means 11 adjusts the circuit so that the secondary battery 12 is bulk charged. Next, the end of bulk processing is confirmed. This is determined by whether or not the terminal voltage value SV of the secondary battery 12 is a constant voltage setting value (V2).

  If the bulk charging has not been completed yet (N branch in step S156), the process of the “solar charging” is exited. Then, returning to step 104 in FIG. 7, if the solar cell module 10 continues the predetermined power generation, the process returns to this step again.

  When the terminal voltage value SV of the secondary battery 12 reaches the constant voltage setting value (V2) (Y branch of step S156), it is assumed that the bulk charge is finished. Then, the time Tsa at that time is recorded (step S158). Next, a flag indicating that the bulk charging has ended is set (step S160), and it is determined whether or not the constant voltage charging has ended (step S162).

  This is determined based on whether or not the charge / discharge electricity amount ΣC exceeds the charge target value TC. If constant voltage charging has not ended (N branch in step S162), constant voltage charging is further performed (step S164). The charge / discharge control means 11 controls the secondary battery 12 to perform constant voltage charging. Then, the routine of “solar charge” is exited and the process returns to step S104 in FIG.

  From step S104, if the same determination is made and the process returns to "solar charge" (step S114) again, bulk charge has already been completed, and therefore, in step S152, the Y branch is entered. Then, the bulk charging (steps S154 and S156) is skipped, and the process returns to the constant voltage charging process from step S162 again. In this way, constant voltage charging continues.

  Thus, in the “solar charge” routine, the process returns to step S104 (see FIG. 7). This is because it is necessary to assume that power generation of the solar cell module 10 is interrupted by the weather. If a routine such as “solar charge” is used, when power generation stops, the process moves from step S108 to step S118 in FIG. 7 and power can be supplied from the secondary battery 12 to the load 19 (step S118). ).

  Referring to FIG. 8 again, when the constant voltage charging is completed (Y branch of step S162), the time Tec at that time is stored (step S170). Next, it is determined whether or not the target value TC is 0.2 (step S172). In this step, it is determined whether or not the constant voltage charging process performed in step S164 is an overcharge process. If it is an overcharge process (Y branch of step S172), each variable is reset (step S174). And in order to memorize | store that having fully charged, the date DL of the day is recorded on the variable S (step S176).

  If the constant voltage charging performed in step S172 is not an overcharge process (N branch in step S172), is the time interval ("deterioration index time") between time Tec and time Tsa shorter than the predetermined time Tth? It is determined whether or not (step S178). This corresponds to determining whether or not the time interval (“deterioration index time”) between times t2 and t3 described in FIGS. 4 and 6 is smaller than a predetermined value Tth.

  When the “deterioration index time” is not shorter than the predetermined time Tth (N branch in step S178), the process of recording that the battery is fully charged in step S176, assuming that the secondary battery 12 can still be used. (Substitute the date DL for the variable S), and go out of "solar charge" (step S114).

  If the “deterioration index time” is smaller than the predetermined time Tth (Y branch of step S178), it is determined that the overcharge process needs to be performed, and the target value TC is changed to 0.2 (step S180). Then, the routine of “solar charge” is exited, and the process returns to step S104.

  If the solar cell module 10 is still generating power, the process returns from step S106 to step S112 to return to the “solar charge” routine in step S114. Since bulk charging has already been completed, steps S154 to S160 are skipped, and it is determined whether or not constant voltage charging has ended (step S162).

  Here, although the charge / discharge electricity amount ΣC is zero, since the target value TC is rewritten to 0.2 in step S180, it is determined that constant voltage charging has not ended. That is, constant voltage charging is continued and overcharge processing is executed.

  When the constant voltage charging is completed, the charge / discharge electric quantity ΣC is charged to 0.2, and the overcharge process is performed. The end time Tec is stored again (step S170). However, since the value is 0.2 in the determination of the target value TC in the next step S172, the overcharge process is performed and each variable is reset. (From the Y branch of step S172 to step S174).

  The variables to be reset are TC, which is the target value for charging the charge / discharge electricity amount ΣC, and ΣC, which is the charge / discharge electricity amount. These are reset by setting the value to zero.

  If the solar cell module 10 stops generating power during the overcharge process, it is determined in step S108 that the solar cell module 10 cannot supply power to the load 19 (N branch in step S108). Electricity is supplied from the secondary battery 12 to the load 19 (step S118). Of course, this control is performed by the charge / discharge control means 11. Then, in the next step S120, it is determined whether or not TC is 0.2.

  Therefore, it is detected that the overcharge process is unprocessed, and the overcharge process is continued with the commercial power source 30 while electricity is sent to the load 19 with the commercial power source 30 after step S124. That is, when the overcharge process starts, the overcharge process is completed by the commercial power supply 30 even if the solar cell module 10 does not generate power.

  Next, with reference to FIG. 9, “commercial charging” in step S126 will be described. The “commercial charging” routine is almost the same as the “solar charging” routine. Different steps from the “solar charge” routine were given different step numbers. Step S182 (S156), step S184 (S164), and step S186 (S174).

  The difference from the “solar charging” routine is that the “commercial charging” routine uses the commercial power source 30 and therefore does not require that charging be interrupted in the middle. Therefore, when the bulk charge starts (step S154), the process continues until the bulk charge ends (step S182).

  That is, as long as the terminal voltage value SV of the secondary battery 12 does not reach the constant voltage setting value (V2) in step S182 (N branch of step S182), the bulk charge is continued. Further, the constant voltage charging (step S184) is continued until the charge / discharge electric quantity ΣC reaches the target value TC for charging.

  The immediate charging independent power supply device 1a configured by the above processing distributes electricity to the load 19 by the daytime solar cell module 10, and accumulates electricity until the secondary battery 12 is fully charged. However, even if a full charge is not performed on that day, the commercial power supply 30 is not used for charging until the battery is fully charged.

  On the other hand, when the “degradation index time” is equal to or less than Tth, the solar cell module 10 or the commercial power source 30 is used for charging. This is performed by setting TC = 0.2 in “solar charge” (step S114) or “commercial charge” (step S126).

  Further, when the secondary battery 12 is used, when the execution depth is reached, a full charge (or overcharge) process is performed immediately. This is performed by “commercial charging” (step S126).

<Night-chargeable independent power supply 1b>
When the secondary battery 12 is used up to the execution depth, the night-charging independent power supply 1b waits until night and then charges the commercial power supply 30 until it is fully charged. The reason for waiting until night is that the solar cell module 10 may be used for charging during the daytime.

  FIG. 10 shows a processing flow of the night charge type independent power supply 1b. Compared with the process of the immediate charge type independent power supply 1a of FIG. 7, when the solar cell module 10 cannot supply electricity to the load 19 (step S108, branch N), it is determined whether or not the execution depth has been reached (step S122). After that, it is determined whether it is night (step S123).

  If the execution depth has not been reached (N branch in step S122), the secondary battery 12 supplies electricity to the load 19. On the other hand, even if the execution depth has been reached (Y branch of step S122), if it is not night (N branch of step S123), the process goes from step S104 to step S108 to the load 19 by the secondary battery 12. Is continued (step S118).

  When it is night (Y branch of step S123), the secondary battery 12 is charged while supplying electricity to the load 19 using the commercial power supply 30 (step S126). Whether or not it is night can be confirmed by accessing the timer 25 or the like included in the charge / discharge control means 11.

  Even if the secondary battery 12 supplies electricity to the load 19 (step S118), the weather may recover and the solar cell module 10 may generate power. In that case, from the Y branch of step S108, it passes through step S112, and charging by the solar cell module 10 is performed in step S114.

  As a result of the recovery of the weather and the charging by the solar cell module 10, the battery does not become fully charged, but if it is charged beyond the execution depth, no power is generated in the solar cell module 10 (N in step S 108). (Branch) Even if the secondary battery 12 supplies the load 19 with electricity, the commercial power source 30 is not charged (the process does not move to step S124). However, since the electric supply from the secondary battery 12 to the load 19 continues, the execution depth is reached at night, and charging by the commercial power source 30 is performed (step S126).

  In the night-charging type independent power supply 1b, even when the operating depth is reached in the daytime and the solar cell module 10 cannot be charged due to bad weather, the secondary battery 12 supplies electricity to the load 19 until the night. Will do.

<Insufficient charge type independent power supply 1c>
The undercharged independent power supply 1c is charged to the full charge with the commercial power supply 30 on the day when it cannot be fully charged. FIG. 11 shows a processing flow of the undercharged independent power supply 1c. Steps S107, S1071 and S200 are different from the immediate charge type independent power supply device 1a of FIG. In step S200, the content of the process is electricity supply to the load 19 by the secondary battery 12, and is the same as in the case of FIG. However, the destination of the next process is different.

  This will be described from step S107. In step S107, it is confirmed whether it is currently daytime. Daytime refers to the period from sunrise to sunset. That is, it is daytime if the solar cell module 10 can generate power. This can be confirmed by holding the sunrise and sunset times of the year on a table. If it is daytime (Y branch of step S107), it is determined whether the solar cell module 10 can supply electricity to the load 19 (step S108).

  If supply is possible (Y branch in step S108), the process proceeds to a process of determining whether the solar cell module 10 can be charged. The subsequent steps S110, S112, S114, and S128 are the same as in the case of the immediate charge type independent power supply 1a. Therefore, overcharge processing based on the “degradation index time” is also performed.

  If supply is not possible (N branch in step S108), electricity is supplied to the load 19 by the secondary battery 12 (step S200). The charge / discharge control means 11 performs control so that electricity flows from the secondary battery 12 to the load 19, and the process returns to step S104 again.

  If it is not daytime in step S107 (N branch in step S107), it is determined whether or not the full charge has been performed that day (step S1071). If the date DL is assigned to the variable S, it indicates that the battery is fully charged. If fully charged (Y branch of step S1071), it will transfer to step S108 which judges whether electricity can be supplied to the load 19 with the solar cell module 10. FIG. However, since it is already night, the process proceeds to the N branch of step S108, and the charge / discharge control means 11 supplies electricity to the load 19 with the secondary battery 12 (step S200).

  Returning to step S1071, if the full charge is not performed that day (N branch of step S1071), electricity is supplied to the load 19 using the commercial power supply 30 (step S124), and "commercial charging" (step S126). Then, the secondary battery 12 is charged. As already described with reference to FIG. 9, once the “commercial charging” is executed, the charging is performed until the charge / discharge electricity amount ΣC reaches the charging target value TC, and the variable DL indicating that the charging has been fully performed (Note that if the “degradation index time” is less than or equal to the predetermined value, the target value TC is replaced with 0.2, and the process proceeds to step S104 once and returns to step S126 again).

  Therefore, the process returns from step S126 to step S104. If it is determined in step S107 that it is not daytime, and if it is determined in step S1071 whether or not a full charge has been performed, the date DL is assigned to the variable S. Proceed to the Y branch because the battery is charged.

  In step S1071, it is determined in step S108 whether or not electricity can be supplied from the solar cell module 10 in step S108. Since it is already night, electricity is supplied to the load 19 in the secondary battery 12 in step S200. That is, the charging / discharging control unit 11 supplies electricity to the load 19 with the commercial power source 30 (step S124) and charges the secondary battery 12 (step S126). Next, electricity is supplied from the secondary battery 12 to the load 19. Change control to supply.

  As described above, in the undercharged independent power supply 1c, the battery is charged until it becomes fully charged once a day.

  It is not easy to analytically determine how effectively the independent power supply device 1 uses the solar cell module 10. Therefore, we performed a simulation based on the annual climate of the actual installation location. The places are Sapporo, Osaka and Naha. The simulation conditions are as follows.

  The weather data for each city is the weather data published by NEDO, and annual data such as sunshine hours and weather were used. The solar cell module 10 has a rating of 460 Wh. The secondary battery 12 is composed of a lead storage battery and has a capacity of 24 V, 180 Ah, and 4.32 kWh. The load 19 has a power consumption of 50 W and consumes 1200 Wh of electricity per day. In addition, the electricity from the secondary battery 12 or the solar cell module 10 is converted into an alternating current of 100 V by a DC-AC inverter.

  The simulation results are shown in Table 1. The total power generation amount is the total power generated by the solar cell module 10. This is the integrated power from the time when the Y branch is reached in step S108 in FIG. The effective power generation amount is electricity collected in the secondary battery 12 or passed through the load 19.

  The reactive power generation amount is electricity that cannot be stored in the secondary battery 12 and is not passed through the load 19. That is, even if the solar cell module 10 generates power, it cannot be stored or consumed and is discarded as it is. This is a value obtained by subtracting the power supplied to the load 19 from the power generation amount of the solar cell module 10 at the time of the Y branch in step S112 of FIG. The effective power generation rate is the ratio of the effective power generation amount to the total power generation amount.

  Looking at the total power generation, it decreases in the order of Naha, Osaka, and Sapporo. This is because the sunshine hours are different. In terms of the effective power generation rate, the undercharged independent power supply 1c has the highest effective power generation rate in any city such as Naha, Osaka, and Sapporo. And the next was the night charge-type independent power supply device 1b. The effective power generation rate of the immediate charge type independent power supply 1a was about 60% in any city. The immediate charging type independent power supply 1a is a method of charging immediately after the execution depth is reached.

  On the other hand, the undercharged independent power supply 1c is a system that allows a full charge to be experienced every day. That is, it is shown that the electricity generated by the solar cell module 10 can be effectively used with a high efficiency of about 90% of the effective power generation rate by performing charge control aiming at full charge every day.

  As described above, it can be said that the independent power supply device 1 according to the present invention has an effective power generation rate of about 60% and effectively uses sunlight regardless of the type.

(Embodiment 2)
In the present embodiment, a case will be described in which the undercharged independent power supply 1c has a backup function for a predetermined period in an emergency such as a large-scale earthquake. This is designated as an independent power supply with backup 1d. The independent power supply device 1 according to the present invention performs charging from the commercial power supply 30 in some form when charging from the solar cell module 10 is insufficient. However, when an emergency such as a large-scale earthquake occurs, the possibility that the commercial power supply 30 will be cut off is very high.

  Even in such a case, the operation of the independent power supply device 1 needs to be guaranteed for a predetermined number of days (a predetermined warranty period). This period is called an operation guarantee period during a power failure. More specifically, the operation guarantee period at the time of a power failure is an operation guarantee period when the commercial power source 30 is out of power and is not charged in the daytime from the solar cell module 10 due to rain or the like. The operation guarantee period during a power failure is displayed on the surface of the backup independent power supply 1d or described in the instruction manual.

  The independent power supply with backup 1d has a basic configuration of the undercharged independent power supply 1c. In other words, since it is fully charged every day, it experiences full charge the day before the power failure occurred. Therefore, if the operation of the n-day period is guaranteed after the commercial power supply 30 has failed, it is only necessary to install the secondary battery 12 for n + 1 days. For example, assuming that the operation guarantee period during a power failure is 3 days, the undercharged independent power supply device 1c may be equipped with the secondary battery 12 having a capacity of 4 days or more.

  As a more specific example, the daily power consumption at the load is 600 W. Assuming that the discharge efficiency is about 85%, the capacity of the secondary battery 12 needs to be (600 W × 4 days ÷ 0.85 =) 2824 Wh or more.

  Further, when this is constituted by a storage battery having a voltage between open terminals of 12 V and a capacity of 60 Ah, assuming that the storage rate during deterioration is 80%, the required amount of storage battery is 2824 Wh ÷ (60 Ah × 12 V × 0.8) = 4. Nine. Here, the storage rate at the time of deterioration takes into account the case where the rated capacity of 60 Ah cannot be exhibited even when the secondary battery 12 is deteriorated, even when fully charged. As can be seen from the above calculation, if a battery of the above-mentioned standard is installed, it has a backup function of the operation guarantee period at the time of power failure by installing five or more batteries.

  FIG. 12 shows a configuration example of the independent power supply with backup 1d. FIG. 13 shows the configuration of the charge / discharge control means 11. The configuration is almost the same as that of the first embodiment shown in FIGS. 1 and 2. The difference is that a signal line L10 is provided from the charge / discharge control means 11 to the outside, and a signal Sem is transmitted through the signal line L10. Referring to FIG. 13, this signal line L <b> 10 is wired from control device 20 of charge / discharge control means 11.

  In addition, the control device 20 receives a signal Scv indicating whether power is supplied from the power control unit 22 through the wiring L6. That is, the independent power supply with backup 1 d can send a signal to the control device 20 regarding the presence / absence of electricity supplied from the commercial power supply 30 (output of the AC-DC converter 32).

  FIG. 14 shows an operation flow of the independent power supply with backup 1d. Since the independent power supply with backup 1d is based on the undercharged independent power supply 1c, there is the same part as the processing flow of FIG. Therefore, the same parts as those in FIG.

  In the independent power supply with backup 1d, a series of cases in which the commercial power source 30 is in a power failure state after detecting the night in step S107 (N branch) and not detecting the full charge in step S1071 (N branch). Processing is inserted. First, the charge / discharge control means 11 determines whether or not there is an output from the AC-DC converter 32 (see FIG. 12) (step S140).

  More specifically, the control device 20 determines whether or not the power control unit 22 detects whether power is supplied to the connection end of the wiring L6 and notifies the control device 20 of the result by the signal Scv. If there is no output from the AC-DC converter 32 (Y branch), it is determined that a power failure has occurred, and the process proceeds to a power failure processing routine.

  After determining that a power failure has occurred, the charge / discharge control unit 11 may generate a signal Sem indicating that a power failure state has been detected to the outside, and transmit the signal Sem via the signal line L10 (the flow is omitted). This signal may be displayed on the panel display 35 provided in the independent power supply with backup 1d. Even if the commercial power supply 30 is not a power failure, a power failure state for the backup independent power supply 1d may occur due to the wiring to the backup independent power supply 1d and the failure of the AC-DC converter 32.

  That is, this signal Sem does not only indicate a power failure, but also serves as a signal notifying the outside that a failure may have occurred inside the backup independent power supply 1d.

  If there is an output from the AC-DC converter 32, it is determined that a power failure has not occurred, and a process of supplying power from the commercial power supply 30 that is the same as the undercharged independent power supply 1c to the load (step S124) is performed.

  On the other hand, in the power failure process, the charge / discharge control means 11 adjusts the circuit so as to supply electricity from the secondary battery 12 to the load (step S142). Then, the process returns to step S104. While a power failure occurs at night, the process returns to step S142 again from step S104 through steps S106, S107, and S1071. Therefore, the repetition of this process is continued until the power failure is restored, and electricity is supplied from the secondary battery 12 to the load during that time.

  If the power failure is restored during the night, the determination in step S140 is N branch, electricity is supplied from the commercial power supply 30 to the load (step S124), and the secondary battery 12 is also charged in step S126. .

  In addition, the backup independent power supply 1d performs the same operation as the undercharged independent power supply 1c in the daytime operation.

  As described above, the independent power supply with backup 1d ensures that electricity is sent to the load for a predetermined period even when a power failure occurs and power generation from the solar cell module 10 cannot be performed in the daytime due to weather. can do.

  The independent power supply device of the present invention can be widely used not only for a power supply device using a solar battery module but also for charging control of a secondary battery.

DESCRIPTION OF SYMBOLS 1 Independent power supply device 10 Solar cell module 11 Charging / discharging control means 12 Secondary battery 13 Voltage sensor 14 Charging / discharging current sensor 15 Output terminal 16 Electromotive force monitor 19 Load 20 Controller 22 Power controller 24 Memory 25 Timer 30 Commercial power supply 31 Commercial Power input terminal 32 AC-DC converter 34 Inverter 35 Display

Claims (7)

A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, when the secondary battery is the solar battery module and the charge / discharge amount of electricity cannot be charged to zero, the secondary battery is charged from a commercial power source after night. . A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, the independent power supply device is characterized in that the secondary battery is charged from a commercial power supply when the secondary battery is used to the execution depth. A solar cell module that generates power with solar energy;
An independent power supply that supplies generated power generated by the solar cell module to a load, charges surplus power to a secondary battery, and supplies insufficient power from the secondary battery to the load when the generated power is insufficient Because
Charge / discharge control means for controlling the amount of power generated by the solar cell module or the amount of power supplied from a commercial power source to the secondary battery and the amount of power supplied to the load;
A voltage sensor for measuring the voltage of the secondary battery;
A charge / discharge current sensor for measuring a charge current to the secondary battery and a discharge current from the secondary battery;
Charging / discharging electric quantity which calculates the charging / discharging electric quantity which is the sum total of the charging electric quantity to the said secondary battery, and the discharging electric quantity from the said secondary battery based on the measured value from the said voltage sensor and the said charging / discharging current sensor Having an arithmetic means;
When the charge / discharge control means charges the secondary battery,
When the time difference between the time when the secondary battery voltage reaches a constant voltage setting value (V2) and the time when the charge / discharge electricity amount becomes zero or more becomes a predetermined time or less, the charge / discharge electricity amount becomes a predetermined amount or more. Overcharge until
In addition, when the secondary battery is used up to the execution depth, the secondary battery is charged from a commercial power source after night.   The independent power supply device according to claim 1, wherein when the commercial power supply fails, a signal indicating that a power failure state has been detected is generated.   The secondary battery has a capacity equal to or more than the power consumption per day of the load multiplied by a period obtained by adding one more day to the operation guarantee period at the time of a power failure, and the commercial power supply was interrupted at night. In this case, the independent power supply device according to any one of claims 1 to 4, wherein electricity is supplied from the secondary battery to the load.   The charge / discharge control means uses the generated power only for power supply to the load when the secondary battery is charged until the charge / discharge electricity amount reaches zero from a negative value. The independent power supply device according to any one of claims 1 to 5.   The said charge / discharge control means resets the value of the said charge / discharge electric quantity, when it overcharges until the said charge / discharge electric quantity becomes more than predetermined amount, The claim of Claim 1 thru | or 6 characterized by the above-mentioned. The independent power supply device described in the section.