JP2011211793A - Discharge control system for electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge control system capable of operating a load for predetermined time in accordance with the power storage amount of an electric double layer capacitor (EDLC) and setting various operation patterns depending on the load.SOLUTION: The discharge control system includes: the EDLC; a load such as an LED illuminator to be operated by discharge energy from the EDLC; a discharge control section 13 for controlling a discharge amount to be supplied from the EDLC to the load; a detecting section 12 for detecting the power storage amount in the EDLC; and an inputting/setting section 14 of operation time and the operation patterns of the load to be operated by the EDLC. The discharge control section 13 determines the discharge amount from the EDLC per each operation time on the basis of the operation time and operation patterns, which are inputted into the inputting/setting section 14, and the power storage amount of the EDLC, which is obtained from the detecting section 12. During discharge control, the power storage amount in the EDLC is always monitored so that the operation pattern (discharge schedule) can be corrected.

Description

  The present invention stores electric power generated by a natural energy power generation device such as a solar power generation device or a wind power generation device in an electric double layer capacitor (hereinafter referred to as EDLC), and operates a load such as an LED lighting device by discharging from the EDLC. The present invention relates to a discharge control system for EDLC.

  In a solar system using a natural energy power generation device, for example, a solar power generation device, a secondary battery such as a lead storage battery or an EDLC is used to level the generated power. In particular, since the EDLC has a smaller internal resistance than a lead storage battery, it is possible to monitor an accurate amount of electricity stored by capacitance and voltage without being influenced by external factors such as the amount of discharge current. For this reason, this EDLC is used as a power source for lighting such as emergency lights. When the amount of electricity stored is low during normal operation, the light is turned off, and when an emergency such as an earthquake occurs in the off state, the amount of electricity stored is small. An EDLC discharge control system has also been proposed (see Patent Document 1).

JP 2010-51109 A

  However, the invention described in Patent Document 1 only controls lighting on and off based on a certain level of the amount of electricity stored in the EDLC, and continues for a predetermined time even when the amount of electricity stored is small. Therefore, it cannot cope with a lighting device that is required to light up. For example, when supplying electric current from an EDLC charged with a solar power generation device to an evacuation lamp that is required to be continuously turned on for 14 hours at night, even if the amount of electricity stored in the EDLC is small due to cloudy or rainy weather, A fixed 14-hour lighting must be performed.

  However, the invention of Patent Document 1 is not suitable for this type of application because it does not light from the beginning when the amount of stored electricity is less than the reference. Further, in Patent Document 1, in an emergency such as an earthquake, the lighting is forcibly turned on even if the amount of power storage is small. However, if the lighting is forcibly performed with normal lighting, the power consumption is large. The required lighting time cannot be obtained.

  Such a problem occurs not only in lighting but also in other loads operated by the EDLC, and appropriately discharges from the EDLC depending on the storage amount of the EDLC and the operation time and pattern of the load. It was desired to provide a controllable technology.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to store the EDLC storage amount and the required load operating time (lighting time in the case of lighting), An object of the present invention is to provide an EDLC discharge control system capable of obtaining an optimal discharge schedule according to a pattern.

  In order to achieve the above object, an EDLC discharge control system according to the present invention includes an EDLC, a load operated by the discharge energy of the EDLC, and a discharge control unit that controls a discharge amount supplied from the EDLC to the load. And an EDLC storage amount detection unit, an operation time of a load operated by the EDLC, and an input / setting unit for an operation pattern, wherein the discharge control unit includes an operation time input to the input / setting unit and The discharge amount from the EDLC for each operation time is determined based on the operation pattern and the amount of EDLC charge obtained from the detection unit.

  The load is a lighting device having a dimming function, and the discharge control unit determines a discharge amount from the EDLC supplied to the dimming device, and the operation pattern is from the start to the stop of the load. The discharge amount from the EDLC is changed linearly or non-linearly, and the storage amount detection unit detects the storage amount during the discharge control from the EDLC by the discharge control unit. It is also an aspect of the present invention that the discharge control unit corrects the set operation pattern based on the amount of electricity newly obtained during the discharge control.

  In the EDLC discharge control system of the present invention having the above-described configuration, even when the amount of electricity remaining in the EDLC is small, the discharge control according to the amount of electricity stored is performed for a predetermined time. Can continue to drive. In addition, the discharge amount for each elapsed time can be easily determined on the basis of the expression representing the operation pattern required for the load, the variable operation time such as the load operation time that determines the expression, and the amount of electricity stored in the EDLC. Can handle patterns.

  When the amount of electricity stored is constantly monitored during discharge and the operation pattern set based on this is corrected, a more accurate discharge schedule can be obtained, and other loads connected to the EDLC can suddenly operate. Thus, even when the amount of stored electricity calculated at the start of operation changes abruptly, it is possible to ensure the required operation time according to the new discharge schedule.

The block diagram which shows the Example of the discharge control system of EDLC of this invention. The flowchart explaining operation | movement of the Example of FIG. The flowchart explaining the EDLC discharge control process in the flowchart of FIG. The graph which shows the example of the discharge pattern set in this invention. The graph which shows the discharge pattern in the other Example of this invention.

(1) Configuration of Embodiment Hereinafter, the configuration of the embodiment of the present invention will be specifically described with reference to the block diagram of FIG.
In the figure, reference numeral CU denotes a controller constituting the discharge control system of this embodiment. In this embodiment, the electric power from the photovoltaic power generator PV connected to the controller CU is charged to the capacitor EDLC, and this EDLC The amount of discharge with respect to the illumination device LED connected to the controller CU is controlled according to the amount of stored electricity (remaining power amount).

  The controller CU includes a charge control unit 10 that controls charging of the EDLC from the solar power generation device PV. This charging control unit 10 is connected to the day / night determination unit 11, and charges the EDLC from the photovoltaic power generation device PV during the day according to the day and night determined by the day / night determination unit 11 using an optical sensor, a timer, and the like. Stop charging for. The charging control unit 10 includes a detection unit for the output voltage of the photovoltaic power generation device PV, a detection unit for a charging current to the EDLC, and a detection unit for a terminal voltage of the EDLC. The charging current is controlled in accordance with the charging allowable current amount.

Under the control of the charging control unit 10, the amount of electricity stored in the EDLC is detected by the amount of electricity detecting unit 12 provided in the controller CU based on the amount of charge Q stored in the EDLC. The charged amount detection unit 12 sets the capacitance C of the EDLC in the controller CU in advance and calculates Q = C · V from the capacitance C and the terminal voltage V of the EDLC. The day / night determination unit 11 detects the charging current I every second from the time of switching from night to day (the charging start time by the charging control unit 10), and calculates Q = I · s. As a result, if two points are obtained from the stored charge Q, EDLC capacitance C, and terminal voltage V, the discharge amount becomes energy E. Therefore, the discharge energy E is obtained from E = 1/2 · C · V ^2. This energy E becomes the amount of electricity stored in the EDLC used to drive the load.

  The controller CU includes a discharge control unit 13. The discharge control unit 13 controls the discharge energy from the EDLC supplied to the illumination device LED, which is a load, according to the stored amount of EDLC detected by the stored power amount detection unit 12. A data input / setting unit 14 is connected to the discharge control unit 13, and discharge control is performed based on the continuous lighting time (operation time of the load) and the operation pattern of the lighting device LED input to the data input / setting unit 14. The unit 13 controls the discharge amount (discharge current) for each time.

  Examples of the operation time and operation pattern set in the data input / setting unit 14 are shown in FIGS. FIG. 4A shows a case where the lighting device LED as a load is linearly dimmed as a discharge pattern. In the data input / setting unit 14, the MAX, MIN value, and lighting time of the LED discharge current are set. Here, MAX400 mA, MIN50 mA, and lighting for 14 hours. Further, the discharge pattern is a straight line connecting two points of the discharge start time (time t = 0, 400 mA) and the discharge duration time (time t = 14, 0 mA) in the graph of (A). That is, in the coordinates of the figure, the x-axis is time t, the y-axis is discharge current (mA), and the triangular area surrounded by the straight line and the x-axis and y-axis is the residual energy E of EDLC.

At this time, the linear discharge pattern set in the data input / setting unit 14 is expressed by the following equation.
(a) y = ax + b
(b) When x = 0, E / 14/2 = b
(c) When t = 14, 0 mA = a

  Further, when the discharge pattern to be set is linear and the capacity of the EDLC is large, the discharge current at the start of discharge becomes a set maximum value MAX400 mA or more on the basis of the charged amount when calculated. However, in the present embodiment, the discharge control unit 13 supplies a discharge current with the set maximum value as an upper limit to the load, so that the remaining remaining portion hatched in the figure is discharged at 400 mA.

  (B) of FIG. 4 shows the case where lighting device LED is lighted according to a non-linear discharge characteristic as a discharge pattern. In this case as well, as in (A) above, the x-axis is time and the y-axis is the discharge current in the coordinates of the figure. Further, a substantially triangular area surrounded by a graph showing the discharge pattern is the remaining energy E of EDLC.

In this discharge pattern, an arbitrary function y = F (x), for example, a value obtained by integrating a quadratic function of y = ax ² + by + c with time t and a residual energy E obtained in (A) are equal. Calculate from
(a) E = (y = ax ² + by + c) 0 to 14 hours integrated value
(b) y = ax ² + by + c when (x, y) = (400, 0)
(c) y = ax ² + by + c when (x, y) = (50, t), t = 14h

  In this non-linear discharge pattern, various discharge patterns can be obtained by adding various constants to the equation. For example, at the initial stage of discharge, the lighting device LED is turned on brightly by increasing the discharge current, and when the turn-off time (t = 14) approaches, the lighting device LED is turned on by reducing the discharge current. Can do. This is suitable when the lighting device is lit brightly at the start of lighting with a lot of traffic, such as a night light.

  As another example of the non-linear discharge pattern, as shown in FIG. 4 (C), the discharge current for only a part of the continuous lighting time is increased and constant according to the patrol time of the guard. It is also possible to light the illumination device LED brightly for the time.

(2) Operation of Embodiment The operation of the present embodiment having the above-described configuration will be described with reference to the flowcharts of FIGS. When the discharge control system starts, first, the controller CU checks the system status such as the connection status, operation status, and the presence / absence of failure of the solar power generation devices PV, EDLC, and illumination devices LED connected thereto (step 1). ). In this case, it is also checked whether the voltage value, current value, and the like of the solar power generation device PV and EDLC necessary for control are input to each unit of the controller CU.

  Next, an operation time (for example, t = 14) and an operation pattern are set for the data input / setting unit 14, and the discharge control unit 13 reads them (step 2). As the operation pattern, a mathematical expression that can draw a linear or non-linear pattern as shown in FIGS. 4A to 4C is directly input, or a desired one of a plurality of mathematical expressions prepared in advance is selected. This is done by selecting the expression to be performed. Furthermore, the maximum value and the minimum value of the discharge current are also set.

  When the reading of the set value is completed, it is determined whether the current day or night is based on information such as the optical sensor input to the day / night determination unit 11 (step 3). When the day / night judgment result is daytime, the daytime mode is selected (step 4), the discharge control by the controller CU is not performed, and the power generated by the photovoltaic power generation device PV by the charge control unit 10 is supplied to the EDLC to store the power. (Step 5). When the determination result is night, the night mode is selected (step 6), and the discharge control by the discharge control unit 13, that is, the dimming operation of the lighting device LED is performed by the discharge current of the EDLC (step 7).

  FIG. 3 is a flowchart showing the EDLC discharge control process in step 7. In the discharge control process shown in FIG. 3, the charged amount detection unit 12 detects the charged amount (remaining energy amount E) of EDLC (step 11). This detection method is based on the above-mentioned Q = C · V or Q = I · s. By substituting the amount of stored electricity and the load operation time (for example, t = 14) set in the data input / setting unit 14 into an expression indicating an operation pattern, a discharge schedule that determines the discharge current for each time is determined. (Step 12). The EDLC starts supplying the discharge current to the lighting device LED according to the discharge schedule (step 13).

  In this case, the load in the present invention performs a minimum operation of 20-30% from a maximum operation of 100% according to the amount of discharge current, like a dimmable lighting device LED, and the discharge current decreases. Even if the operation does not stop. Of course, even with this type of load used in the present invention, if the discharge current is too low, the operation becomes impossible. And the one whose driving ability changes according to the amount of current is used.

  In this way, the discharge of the EDLC is controlled according to the operation schedule determined by the set operation pattern, operation time, and storage amount, and in that state, the day detection signal from the day / night determination unit 11 is input or set. When the operation time t elapses and the EDLC charge amount becomes 0, the EDLC discharge control ends (step 14). After that, it returns to the daytime mode (step 4), the charging control for the EDLC from the photovoltaic power generator PV (step 5) is performed, or the system state check (step 8) is performed, and new setting values and operation patterns are read. (Step 2). Note that the flowchart of FIG. 2 shows a case where a new set value is read.

(3) Effects of the embodiment According to this embodiment, even when the charge amount (remaining energy amount) of the EDLC decreases, the current supplied to the lighting device LED is reduced to continuously illuminate for a preset time. Can be lit. Therefore, even when the solar power generator is not fully charged during cloudy or rainy weather, the set lighting time can be secured, so lighting devices that require constant lighting, such as evacuation lights and night lights, can be used. Can be lit by.

  In the present invention, a plurality of operation patterns are set as equations, and the storage amount of the EDLC and the operation duration of the load are given as variables in the equation without changing the set equation itself. An operation schedule corresponding to the operation time can be obtained. Therefore, preparing a plurality of operation patterns, such as those performed in the discharge control of the conventional secondary battery, compared to a control system that selects the required operation pattern from among them according to the amount of stored electricity, Fine control according to the amount of power storage is possible. In particular, EDLC has less internal resistance than secondary batteries such as lead-acid batteries, and can accurately determine the amount of electricity stored based on terminal voltage and output current. Yes.

(4) Other Embodiments The present invention is not limited to the above-described embodiment. For example, as shown in FIG. 5, the once started operation schedule is corrected in accordance with the change in the charged amount of EDLC, and a new It is also possible to create an operation pattern. That is, in the embodiment of FIG. 5, the amount of EDLC stored (remaining amount) is always checked, and the current that can be lit is adjusted. That is, the discharged current I is subtracted from the remaining energy E at the start of discharge every 1 s, and the drawn remaining energy E ′ and the remaining lighting scheduled time (t ′) are always calculated. It is possible to obtain the discharge schedule obtained in (B) more accurately.

The calculation in this case is performed as follows.
(a) Correction when the discharge pattern is linear E = (y = ax + b)
E ′ = (y = ax + b), x = 14−t
(b) Correction when the discharge pattern is non-linear E = (y = ax ² + by + c)
E ′ = (y = ax ² + by + c) 0 to 14-t integrated value

  According to this embodiment, a load other than the lighting device that needs to be continuously operated is connected to the EDLC, and the set operation pattern is shown even when the amount of electricity stored in the EDLC changes rapidly due to the operation of the other load. A new operation schedule can be obtained by substituting an ever-changing power storage amount into the set formula without changing the formula, and the inconvenience that the required duration cannot be ensured as a result of following the original schedule. It will be resolved.

DESCRIPTION OF SYMBOLS 10 ... Charge control part 11 ... Day and night determination part 12 ... Electric power storage amount detection part 13 ... Discharge control part 14 ... Input and setting part PV ... Solar power generation device EDLC ... Electric double layer capacitor LED ... LED lighting apparatus C ... Controller

Claims (4)

An electric double layer capacitor;
A load such as an LED lighting device driven by the discharge energy of the electric double layer capacitor; and
A discharge controller for controlling the amount of discharge supplied to the load from the electric double layer capacitor;
A detection unit for a storage amount of the electric double layer capacitor;
An input / setting unit for an operation time and an operation pattern of a load operated by the electric double layer capacitor,
The discharge control unit is based on the operation time and operation pattern input to the input / setting unit, and the amount of electricity stored in the electric double layer capacitor obtained from the detection unit. A discharge control system for an electric double layer capacitor, wherein the discharge amount is determined.   The said load is an illuminating device which has a light control function, The said discharge control part determines the discharge amount from the electric double layer capacitor supplied to this light control device, The Claim 1 characterized by the above-mentioned. Electric double layer capacitor discharge control system.   3. The electricity according to claim 1, wherein the operation pattern changes the amount of discharge from the electric double layer capacitor linearly or non-linearly from the start to the stop of the load operation. Double layer capacitor discharge control system.   The storage amount detection unit detects the storage amount during discharge control from the electric double layer capacitor by the discharge control unit, and the discharge control unit obtains the newly stored storage amount during the discharge control. 4. The electric double layer capacitor discharge control system according to claim 1, wherein the set operation pattern is corrected on the basis of the operation pattern.

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