JP3824228B2 - Control method of cell energy amount adjusting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an energy distribution circuit for setting a ratio of the energy storage amount of each cell to a target value with respect to the energy amount stored in an electric energy storage device constituted by electric energy storage cells connected in series. It is related with the control method of the cell energy amount adjusting device provided with.
[0002]
[Prior art]
Conventionally, electric energy storage cells are connected in series to form an energy storage device having a higher terminal voltage and a larger energy storage capacity than a single cell. However, each cell constituting the device stores the energy storage device. The amount of energy that is being managed has hardly been managed.
[0003]
Therefore, for example, as disclosed in Patent Document 1, regardless of charging, discharging, or standby, the energy amount of a cell is transferred from any cell to any cell using a transformer. There has been proposed a cell energy amount adjusting device that can maintain an optimum target value by performing the above.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-136660
[Problems to be solved by the invention]
Patent Document 1 shows the circuit configuration of the apparatus, but does not specifically show how to determine the optimum target value. This technology proposes a method of transferring energy from an arbitrary cell to an arbitrary cell or the entire energy storage device, but it is important how to determine the optimal (energy amount) target value. It is a difficult issue.
[0006]
Accordingly, an object of the present invention is to provide a control method of a cell energy amount adjusting device that can set a target value of energy amount and can control a voltage value in one cell within a withstand voltage.
[0007]
[Means for Solving the Problems]
The present invention has a function of measuring an energy storage amount of each cell of an energy storage device configured by connecting a plurality of capacitor cells or secondary battery cells in series, and energy stored in an arbitrary cell. A control method of a cell energy amount adjusting device having a function of transferring an arbitrary amount of energy to an arbitrary cell or the entire energy storage device.
[0008]
According to the present invention, in an energy storage device in which a plurality of cells are connected in series to form one unit, information on the energy capacity of each cell in the energy storage device is held and the energy storage of each measured cell is stored. The energy storage amount of the entire energy storage device is calculated from the amount, and the target value of the energy storage amount of each cell so that the difference between the energy storage amount of each cell and the energy capacity of the cell corresponds to the magnitude of the energy capacity. Is set, and the control method of the cell energy amount adjusting device is obtained.
[0009]
That is, the present invention has a function of measuring the energy storage amount of each cell of an energy storage device configured by connecting a plurality of capacitor cells or secondary battery cells in series, and is stored in an arbitrary cell. A method for controlling a cell energy amount adjusting device having a function of transferring a certain amount of energy to an arbitrary cell or the entire energy storage device, holding information on the energy capacity of each cell, The maximum energy storage amount of each cell when energy is stored in the cell, the energy storage amount of each cell and the energy storage amount of the entire energy storage device at the arbitrary time are measured, and the maximum energy storage amount of each cell From the ratio of the difference between the energy storage amount of each cell at an arbitrary time and the energy capacity of each cell, the energy storage device at the arbitrary time Calculate the ratio of the energy storage amount of each cell to the total energy storage amount, and transfer the energy from the cell requiring energy transfer to another cell, multiple cells, or the entire energy storage device with the calculated ratio as a target. By doing so, the control method of the cell energy amount adjusting device for adjusting the ratio of the energy storage amount of each cell.
[0010]
According to the present invention, the cell constituting the energy storage device is a capacitor cell, holds information on the capacitance of each cell, measures the voltage of each capacitor cell at an arbitrary time, and determines the energy of the energy storage device. The amount of energy stored in the energy storage device is calculated by calculating the storage amount, and the difference between the target voltage of each capacitor cell and the withstand voltage of each capacitor cell is proportional to the reciprocal of the capacitance of each capacitor cell, and can be calculated by the target voltage. The target voltage of each capacitor cell is set so that the storage amount is equal to the calculated energy storage amount of the actual energy storage device, and the energy from the capacitor cell having a voltage higher than the target voltage becomes the target voltage. Cell energy that regulates the voltage of each capacitor cell by sampling and redistributing to other capacitor cells A method of controlling a regulating device.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a control method of a cell energy amount adjusting apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0012]
A case where the present invention is applied to an energy storage device using an electric double layer capacitor as an energy storage cell will be described. Since the energy storage of the electric double layer capacitor is performed by the accumulation of electric charges, the terminal voltage increases / decreases as the energy storage amount increases / decreases.
[0013]
Here, a case where six electric double layer capacitors are connected in series will be described. Of course, any number of electric double layer capacitors to be connected may be used for convenience. FIG. 1 is a diagram showing an example of a cell energy amount adjusting device to which the control method of the cell energy amount adjusting device of the present invention is applied.
[0014]
FIG. 1 is a circuit example when a flyback converter is used in the energy recovery circuit, and any one of the switches SW1 to SW6 selected in accordance with an instruction from the central control unit 5 is set at a specific time by a switching signal of the switch drive circuit 6. Turn on. The corresponding coil of the energy transfer transformer T1 or T2 corresponding to the corresponding switch is excited, and a voltage according to the voltage of the corresponding electric double layer capacitor is generated in the coils L7 and L9 according to the winding ratio of the coil. To do.
[0015]
This voltage is stored in the cell voltage memory 4 via the voltage input circuits 3a and 3b, and the voltages of all the electric double layer capacitors C1 to C6 are measured by sequentially storing the cell voltages of the remaining electric double layer capacitors. I can do it.
[0016]
Immediately after the turned-on switches SW1 to SW6 are turned off, the energy obtained by magnetizing the transformer T1 or T2 is sent between the input / output terminals 1 and 2 via the rectifier D1 or D2. The energy is recovered throughout the energy storage device, and the energy is distributed to each electric double layer capacitor in inverse proportion to its capacitance.
[0017]
By repeatedly turning on and off the switch, it is possible to extract an arbitrary amount of energy from a specific electric double layer capacitor and redistribute the energy to each electric double layer capacitor.
[0018]
FIG. 2 shows a flowchart of the basic operation of the cell energy amount adjusting apparatus. If the capacitance of each electric double layer capacitor is grasped in advance, the energy storage amount of each electric double layer capacitor cell can be measured by measuring the voltage of each electric double layer capacitor cell.
[0019]
Even if characteristics such as capacitance and leakage current fluctuate from the initial state, the learning function in the flowchart can recognize how much the fluctuation is based on the voltage variation and amount of change in each electric double layer capacitor. It becomes possible to always grasp the capacitance and leakage current of each electric double layer capacitor.
<0020
Here, the learning function refers to a function of measuring a variation in voltage of each electric double layer capacitor and predetermining a secular change in capacitance of each electric double layer capacitor.
[0021]
2, the set value of the energy storage amount of each electric double layer capacitor is determined by the control method of the present invention, and the energy storage amount of each electric double layer capacitor cell is set to the set value. Energy transfer is performed as follows.
[0022]
FIG. 3 is an explanatory diagram of a flowchart of the control method of the cell energy amount adjusting apparatus of the present invention. Here, only the operation of the part for determining the set voltage of (1) in FIG. 2 is shown. If the capacitances of the electric double layer capacitors are all uniform, all the voltages need to be uniform. However, if there is variation in the capacitance, the voltages are uniform when fully charged. That is, the voltage may be set so as to store energy to the maximum.
[0023]
When the energy storage device is charged, the voltage of each electric double layer capacitor increases in inverse proportion to the value of the respective capacitance, so that the voltage of each electric double layer capacitor and the resistance of the electric double layer capacitor are increased. What is necessary is just to set so that the ratio of the difference with a voltage may become equal to the ratio of the reciprocal of an electrostatic capacitance.
[0024]
Also, assuming that the efficiency during energy transfer is 100%, there is no increase or decrease in energy before and after energy transfer, so the energy storage amount of the energy storage device measured by the sum of the energy storage amount of each electric double layer capacitor is What is necessary is just to set it as the voltage which becomes equal.
[0025]
Actually, once the ratio of the energy storage amount is made equal to the target value, it takes time to vary during operation. Therefore, energy transfer may be performed slowly with a small amount of energy. Then, since the converter which transfers energy should just be designed to transfer energy with small electric power, it is possible to make the efficiency of energy transfer close to 100%. Even if the efficiency is somewhat lowered, the sum of the energy storage amounts of the electric double layer capacitors may be equal in consideration of the efficiency before and after the energy transfer.
[0026]
In the present invention, the cell energy amount adjusting device is configured by using the electric double layer capacitor, but the cell energy amount adjusting device may be configured by using any energy storage cell.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a control method for a cell energy amount adjusting device that provides an algorithm for determining a target value for setting the voltage of each cell by the cell energy amount adjusting device.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a cell energy amount adjusting device to which a control method of a cell energy amount adjusting device of the present invention is applied.
FIG. 2 is a flowchart of a basic operation of the cell energy amount adjusting apparatus.
FIG. 3 is an explanatory diagram of a flowchart of a control method of the cell energy amount adjusting device of the present invention.
[Explanation of symbols]
1, 2 Input / output terminal 3 (of large-capacity energy storage device) Voltage input circuit 4 Cell voltage memory 5 Central control unit 6 Switch drive circuit 7 Controller A Address flow in the controller C C1 to C6 Capacitance C1, C2, C3, C4, C5, C6 Energy storage cell (electric double layer capacitor)
D Data flow in the control device D1, D2 Rectifiers L1, L2, L3, L4, L5, L6 Energy transfer transformer primary side coils L7, L9 Energy transfer transformer voltage measuring coils L8, L10 Energy transfer transformer secondary side coils SW1, SW2, SW3, SW4, SW5, SW6 Switching FET
SC1, SC2, SC3, SC4, SC5, SC6 Gate drive capacitors SD1, SD2, SD3, SD4, SD5, SD6 Gate drive diodes SR1, SR2, SR3, SR4, SR5, SR6 Gate drive resistors T1, T2 Energy transfer Transformer U Energy storage device overall energy V1, V2, V3, V4, V5, V6 Electric double layer capacitor voltage Vr Electric double layer capacitor withstand voltage

Claims (1)

It has a function of measuring the amount of energy stored in each cell of an energy storage device configured by connecting a plurality of capacitor cells in series, and the energy stored in any cell can be stored in any cell or the entire energy storage device In the control method of a cell energy amount adjusting device having a function of transferring an arbitrary amount of energy to a cell, information on the capacitance of each cell is held, and the voltage of each cell at an arbitrary time is measured to measure the energy storage device. The energy storage amount is calculated, and the difference between the target voltage of each cell and the withstand voltage of each cell is proportional to the reciprocal of the electrostatic capacity of each cell, and the calculated energy of the actual energy storage device The target voltage of each cell is set so that the energy storage amount of the energy storage device that can be calculated by the storage amount and the target voltage is equal, and from the target voltage Sampling extent that becomes the energy to the target voltage from the high voltage of the cell, by redistributing the other cells, the control method of the cell energy amount adjusting apparatus characterized by adjusting the voltage of each cell.

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