JPH10322924A - Secondary battery power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use the residual quantity of a secondary battery effectively with its soundness maintained by receiving data of the secondary battery and a load group for control of a charging and discharging device. SOLUTION: This system involves a load 1 and a charging/discharging device 2 connected to a secondary battery 3, and a power storage device group 4 or a load group 5 which is connected in parallel to a charging/discharging device 2 and making a linkage to a power supply system. The secondary battery 3 is connected to the load 1 to be discharged, after its connection to the charging/discharging device 2 for charging the power of a night-rate time zone. After being discharged, the connection to the load 1 is interrupted, excess power is discharged in a daytime-rate time zone by its connection to the charging/discharging device 2, and a control device 6 discharges excess power, after charging to the load 1 in the daytime rate time zone under an optimum discharging condition. In the night-rate time zone, excess power discharging is stopped and charging is conducted. The controller 7 of the charging/ discharging device 2 measures the necessary power for the power storage device group 4 or for the load group 5, selects a place needed, and supplies the surplus power of the secondary battery 3. It is thus possible to conduct efficient charging and discharging of the battery with its soundness maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery power storage system and, more particularly, to a battery system for evaluating battery soundness and remaining power, distributing surplus power, and performing optimal charge / discharge control.

[0002]

2. Description of the Related Art Lead batteries have been mainly used as secondary batteries for automobiles and uninterruptible power supplies. However, demands for power leveling and global environmental protection have increased, and the spread of power storage power supplies and electric vehicles has been strongly desired.
Today, when high energy density secondary batteries are needed,
The appearance of new secondary batteries is expected. In the future, nickel-cadmium batteries, nickel-hydrogen batteries,
It is conceivable that various types of secondary batteries such as lithium batteries and sodium-sulfur batteries will become larger depending on the application and enter the market. The important thing in managing batteries is
In order to maintain the soundness of batteries, it is necessary to perform long-life and safe charging and discharging according to each battery. This is because each battery has its own charge / discharge characteristics, and the temperature characteristics, rate characteristics, self-discharge characteristics, and the like are different.

In consideration of the usability of a battery, it is necessary to know the remaining capacity of the battery as accurately as possible. Conventionally, for each of these batteries, a charging method, a temperature control, and a method of determining a remaining capacity have been considered. For example, a method of managing only the voltage to detect the remaining capacity (Japanese Patent Laid-Open No.
No. 85179, JP-A-61-135335, etc., a method of controlling by voltage and current (JP-A-52-32542), and a method of controlling by current and time (JP-A-50-2130, JP-A-56-13056) -26271, JP-A-59-28678), a method of measuring and managing capacitance (JP-A-2-301974), a method of managing by voltage, current and temperature (JP-A-2-170372), internal resistance (Japanese Unexamined Patent Publication No. 3-163375), a method of integrating current values and then taking into account charge efficiency, discharge efficiency, and temperature characteristics (Japanese Unexamined Patent Publication No. 63-208773). There are known methods (JP-A-56-24768, JP-A-57-88679, JP-A-57-210578).

Further, the capacity changes depending on the history of charge and discharge. For example, it is known that a nickel-cadmium battery, a nickel-hydrogen battery and the like have a memory effect in which the capacity of the battery is reduced when shallow charge / discharge is repeated.
In a lithium battery or the like, if the balance between charge and discharge is lost, lithium accumulates in the positive and negative electrode materials and causes deterioration, so that it is necessary to discharge after knowing the charge capacity. In the case of a battery pack, it is very important to know the charge capacity. Since the voltage change at the end of charging is not clear in a nickel-hydrogen battery or the like compared to a nickel-cadmium battery, if the battery is not charged after knowing the discharge capacity, it will be overcharged, causing liquid depletion and an increase in internal pressure, which is a safety problem. Furthermore, since the battery capacity varies greatly depending on the temperature, the charging rate, and the discharging rate, the charge / discharge history must be considered. From such a viewpoint, a charging method is also being studied. For example, in order to eliminate the memory effect (Japanese Unexamined Patent Publication No. 4-308429) or to prevent overcharging (Japanese Unexamined Patent Publication No. 61-81139), there is a method in which the battery is completely discharged and then charged by control using a final voltage or time.

[0005]

With respect to the method of determining the remaining capacity of the battery, the method of determining from the specific gravity of the electrolyte is limited to a lead battery. The method of controlling by voltage is considered to be effective for a battery having a relatively large voltage change accompanying charge / discharge, such as a lead battery or a lithium battery.
It is not suitable for batteries such as cadmium batteries or nickel-metal hydride batteries whose remaining capacity cannot be determined only by voltage. Also, in the case where the discharge current value (rate) is different from that in the case where the discharge current value (rate) is managed in addition to the voltage, it is difficult to accurately predict the remaining capacity under the operating conditions. Even when measuring and managing the internal resistance and capacitance, if the deterioration mode of the battery is not clearly understood, it is difficult to determine whether the internal resistance is increased due to the deterioration of the battery or because there is no remaining capacity. When the current value is integrated and then managed in consideration of charging efficiency, discharging efficiency, and temperature characteristics, the remaining capacity becomes fairly accurate. However, for a battery with a large decrease in capacity or a large self-discharge, the capacity of the battery is reduced. It is difficult to judge if you do not always know. As described above, conventionally known methods for determining the remaining capacity differ depending on each battery, and at present, it is necessary to control each battery individually.

[0006] Further, in order to eliminate the memory effect (Japanese Patent Laid-Open No. 4-308429) and to prevent overcharge (Japanese Patent Application Laid-Open No.
No. 61-81139) aims at suppressing battery deterioration and simplifying the charging method when used as a power source for portable equipment and the like. As described above, a method of controlling charging and discharging in consideration of the characteristics and history of the battery has not been considered so far.

Furthermore, the difference between nighttime and daytime power demands has been increasing in recent years, and summertime daytime power demands are approaching the upper limit of total power generation capacity. There is an electric power storage technology to solve this. For example, a large secondary battery is installed in a substation to store (recharge) surplus power during the night and discharge (discharge) it during the peak power demand during the day (Electronics magazines p185-188, 111). Vol. 3, 1991). However, there is no specific means for maintaining soundness when the secondary battery is used or for effectively using the remaining amount.

[0008] It is an object of the present invention to provide a distributed power storage system that can effectively use the remaining amount while maintaining the soundness of the secondary battery.

[0009]

According to the present invention, there is provided a secondary battery connected to a load, and a charging / discharging device connected to the secondary battery and interconnected to a power supply system. In a secondary battery power storage system to which a group is connected, a control device that receives information on the secondary battery and the load group and controls a charge / discharge device is provided.

Further, the load group, at least one of the secondary batteries, and the control device are connected by information transmission means.

Alternatively, there is provided a signal line for transmitting operation status information of the load group to the control device, and a signal line for transmitting surplus power information of the secondary battery to the control device.

[0012] At least one of means for measuring operation status information linked to the load group and means for measuring surplus power information linked to the secondary battery can be provided.
As the measuring unit, a commonly used measuring unit (sensor) can be used according to the measurement purpose.

Further, a power storage device group is connected to the charging / discharging device, and the power storage device group and the control device are connected by information transmission means.

[0014] The power storage device group may be provided with means for measuring the power storage status. The measuring means used here may be a commonly used measuring means (sensor) depending on the purpose of measurement.

Examples of the present invention include buildings, factories, and condominiums having power supply facilities for secondary batteries for electric vehicles, secondary batteries for hot water supply facilities, secondary batteries for lighting, secondary batteries for air conditioners, emergency power supplies, and the like. It can be applied to general household use as well as cities. Furthermore, the present invention can be applied to transportation using electric energy.

It is preferable that the control device includes a clock or a timer.

The present invention also provides a secondary battery connected to a load, a charging / discharging device connected to a power supply system and connecting the secondary battery, a load group and a power storage device connected to the charging / discharging device. In a secondary battery power storage system to which at least one of the groups is connected, surplus power after the secondary battery supplies power to a load, and information from the secondary battery, the load group, and the power storage device group. Based on this, a power supply destination and a capacity are selected and power is supplied to the selected destination.

Further, a power supply destination and a capacity are selected based on at least one of surplus power information of the secondary battery, operation status information of the load group, and power storage status information of the power storage device. Power is supplied to the selected destination.

The power storage system of the present invention uses a power storage system for a secondary battery as described below, for example, when controlling charging and discharging of power stored in a power supply system or a group of secondary batteries and power storage devices. Can be.

A charging / discharging device connected to a power supply system and connected to at least one of a load group and a power storage device group, a control device for controlling the charging / discharging device is provided, and connection means for connecting to a secondary battery; And the control device that controls the charge / discharge device based on information from one or more of the load group, the power storage device group, and the connection unit.

Further, there is provided a power storage system for a secondary battery, comprising information transmission means between one or more of the group of loads, the group of power storage devices, and the connection means and the control device. To this, a secondary battery is connected to perform charging and discharging, and electric power can be used effectively.

At least one of the group of loads, the group of power storage devices, and the connecting means is provided with various kinds of measuring means linked to the information transmitting means. The information measured by the measuring means can be transmitted by the information transmitting means.

The secondary battery used in the present invention is characterized by comprising means for measuring the charge / discharge amount of the secondary battery and a computer for calculating the remaining amount.

More specifically, there is provided a means for measuring data for obtaining measurement data of the secondary battery, a memory capable of storing information including the measurement data, an arithmetic program, and data on battery characteristics, and a memory which is stored in the memory. It is desirable to have a computer equipped with a control device for controlling the received information and information inputted from the outside, and that the information stored in the secondary battery can be transmitted through the information transmitting means.

The following are examples of the secondary battery used in the present invention.

The battery includes at least one of secondary batteries such as a lead battery, a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium battery, or all of the combinations thereof. The secondary battery includes a memory unit that stores at least measurement data and a calculation program.

The power storage device group includes at least one of a secondary battery such as a lead battery, a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium battery, a regenerative power storage device, and a superconducting power storage device. Includes all combinations.

The charging / discharging device has orthogonal transform means and connection switching means. Orthogonal transformation means such as thyristors enable control of the power factor. The connection switching means can switch the connection between the power supply system and the secondary battery, the load group, or the power storage device group by grasping the surrounding load condition. If necessary, means for measuring the amount of electric power transferred via the charge / discharge device, for example, means for measuring the charge / discharge amount, and means for communicating the measured value to a control device for controlling the charge / discharge device are provided. The secondary battery or the power storage device group may be provided with a unit for measuring a charge / discharge amount.

As means for measuring the charge / discharge amount, for example, sensors such as an ammeter and a voltmeter coulomb meter can be used.

The control device for controlling the charging / discharging device determines the power supply destination of the secondary battery or the power storage device from information such as the surplus power of the secondary battery, the operation status of the load group, and the storage status of the power storage device group. Can be selected. Further, means for calculating the charge / discharge amount based on information from the secondary battery, the load group, and the power storage device group, and a storage means may be provided.

The operating status information is information such as electric power or the like that is necessary or necessary at the time of operating the load group. Further, it is preferable to use schedule information and the like such as a scheduled operation time in the future.

The information transmitting means is, for example, a signal line.
Also, information may be transmitted via radio waves.

The surplus power information is, for example, a measured value of the surplus power amount, data relating to an optimal charge / discharge characteristic (charge / discharge mode), a charge / discharge operation history, and the like.

The load group and the power storage device group include one or more loads or power storage devices. The power storage system used in the present invention is, for example, a charge / discharge system in which a secondary battery installed in a load such as an electric vehicle and a secondary battery connected to a power supply system such as a charging station are connected. A power storage device group connected to the power supply system and connected in parallel with the secondary battery via the charging / discharging device at the destination, a load group connected to the power storage device group, and a load group connected to the charging / discharging device It is provided.

Further, a charging / discharging device connected to a power supply system may be provided, and a secondary battery, a load group, and a power storage device group may be connected to the charging / discharging device.

According to the present invention, a load group, a power storage device group,
Based on information from the secondary battery, load groups, power storage devices,
Charge and discharge of the secondary battery can be controlled.

More specifically, the measurement is performed using a means for measuring the required electric power based on the operating conditions of the load group and the like. And
Surplus power of secondary batteries, power storage status of power storage devices,
After grasping the discharge characteristics and dischargeable capacity of the battery and selecting a power supply destination capable of supplying power from the load group or the power storage device group, it is possible to supply surplus power via the charge / discharge device. it can.

As a matter of course, the power may be temporarily stored in the power storage device and then supplied to the load group.

Thus, surplus power can be effectively distributed,
Since the discharge can be performed by grasping the remaining power and evaluating the discharge amount, efficient discharge control can be performed while maintaining the soundness of the battery.

In charging, the remaining capacity of the secondary battery can be ascertained, and whether charging or discharging can be performed can be determined based on the magnitude of the remaining capacity.

The power supply destination is selected by measuring the optimum charge / discharge characteristics unique to the secondary battery and the power required for the load group or the storage status of the power storage device group. When the load group includes a plurality of loads, it is preferable to measure the required power for each load. Similarly, when the power storage device group has a plurality of power storage devices, it is preferable to grasp the storage status of each power storage device.

For example, a power supply destination and a supply capacity are selected based on a judgment as to whether the secondary battery can supply the power or whether the output density (whether or not a large current discharge is performed) is appropriate for the secondary battery. In the charging / discharging device, the secondary battery and the power supply destination can be switched so as to be connected to each other to supply power.

Further, by using the timer, the battery can be charged during the nighttime charge period and discharged during the daytime charge period to reduce the cost of using electric power. Electric power can be used efficiently.

More specifically, for example, electric power is supplied (charged) to a secondary battery from a charging / discharging device having a secondary battery connected thereto during a night charge period, and the power of the secondary battery is charged during a day charge period. The surplus power after charging is supplied (discharged) from a secondary battery to a charge / discharge device connected to the secondary battery, and from there, a power storage device group, a load connected to the power storage device group via the charge / discharge device. Power is supplied (discharged) to the load group connected to the group and the charging / discharging device. Thereby, after charging and using cheap electric power at night, electric power can be sold during the day through a charge / discharge device to which a secondary battery can be connected to another electric power consumer. In order to sell power, a control device provided in a charge / discharge device connected to a secondary battery, measures the power required for a load group by operating status information from a plurality of power storage device groups or load groups, It is preferable that the power supply destination is selected in consideration of the dischargeable capacity of the secondary battery and the like, and the surplus power of the secondary battery supplied from the secondary battery to the charging / discharging device is supplied to the power supply destination.

By discharging the surplus power, the soundness of the battery and the original capacity of the battery can be known. The capacity of the battery can be known from the charge capacity after the battery has been discharged close to 100% (to almost empty state). Also, in order to know the soundness of the battery, it is desirable to know the capacity of the battery every time it is charged and discharged.

The secondary battery used in the present invention includes, for example, a means (sensor) for measuring various data, an A / D converter for taking the data into a computer, various charge / discharge history data, and calculation and display. It is desirable to have a memory unit storing a program and further storing a standard characteristic data array, and a control device for processing information described in the memory unit or information input from outside the memory. These can be integrated with the battery.

For example, the calculation and display programs include a calculation program for calculating the discharge capacity by integrating the discharge current data, a calculation program for calculating the charge capacity by integrating the charge current data, Calculation program for calculating the discharge rate at the time of taking in the discharge current data and the dischargeable capacity under the temperature condition from the temperature characteristics and the temperature characteristic, and calculating the surplus power discharge capacity by integrating the surplus power discharge current data. And a program for displaying it. The discharge operation history when the secondary battery discharges to the load is the discharge current data,
Measured using a means (sensor) that measures as discharge voltage data and discharge temperature data, and through an A / D converter,
Import to a computer equipped with a memory unit and a control device. Further, the secondary battery measures charging operation history as charging current data, charging voltage data, and charging temperature data when charging nighttime electric power from a charging / discharging device to which the secondary battery is connected. Through the computer. In addition, the surplus power discharge operation history when the surplus power is discharged through the charging / discharging device connected to the rechargeable battery includes the surplus power discharge current data, the surplus power discharge voltage data, and the surplus power discharge temperature data. Is measured using a sensor, and this is taken into the computer via an A / D converter. The health of the battery can be known using these pieces of information. That is, using the discharge current data and the surplus power discharge current data, the discharge capacity to the load and the surplus power discharge capacity of the surplus power to the charge / discharge device can be known, and the discharge voltage data and the surplus power discharge voltage data are used. Thereby, it is possible to control a sound discharge that does not discharge below the lower limit of the battery voltage, that is, does not cause overdischarge. Further, the charging capacity from the charging / discharging device can be known from the charging current data. Using the charge voltage data, overcharging can be suppressed by charging to the upper limit of the battery voltage in the case of a lithium battery, and in the case of a nickel-cadmium battery, it is determined from the voltage change at the end of charging so that overcharging does not occur. Charging can be terminated. Unlike a nickel-cadmium battery, a nickel-hydrogen battery has a small voltage change at the end of charging, so it is desirable to consider a temperature change in addition to the voltage change. Other types of batteries can also be used to detect battery abnormalities when the temperature rises abnormally. Furthermore, since the charging efficiency and the discharging efficiency vary depending on the temperature, it is preferable to use the temperature data for correcting the charging capacity and the discharging capacity.

It is desirable that the above data be corrected based on the charging rate, discharging rate, and temperature. First, in the secondary battery, a standard characteristic data array such as a charge rate characteristic, a discharge rate characteristic, and a temperature characteristic which the secondary battery originally has is stored in the memory unit. A / D
The discharge current data and the charge current data taken into the converter are respectively integrated to determine the discharge capacity and the charge capacity. The charge rate characteristics, discharge rate characteristics,
From the temperature characteristics, a converted charge capacity is calculated by converting the charge capacity into a dischargeable capacity at the time of taking in the discharge current data and a dischargeable capacity under the temperature condition in real time. The real-time remaining capacity is obtained by subtracting the real-time discharging capacity from the real-time converted charging capacity. As a result, the remaining capacity can be displayed according to the temperature at that location and the discharge rate. For example, in an electric vehicle or the like, the remaining traveling distance differs depending on whether the vehicle is traveling on a slope or a downhill. Therefore, when traveling on a slope, the remaining traveling distance corresponding to the traveling distance can be evaluated and displayed based on the discharge rate characteristics. Further, since the discharge efficiency differs depending on the temperature in winter and summer, the remaining mileage in consideration of the temperature characteristics can be displayed.

The surplus power discharge current data can also be integrated and calculated to obtain a surplus power discharge capacity, which can be displayed. Since the surplus power discharge capacity is the amount of power sold, the surplus power discharge capacity is transferred to a charging / discharging device, a power storage device group, a load group, or the like that is connected to a power system and connected to a secondary battery, or is charged or discharged. It is preferable to provide a function for measuring and displaying the capacity also on the device side.

When the secondary battery discharges surplus power, it is desirable to discharge the battery under optimal discharge conditions for maintaining the soundness of the battery and extending its life. Therefore, when discharging the surplus power to a charging / discharging device in which the secondary battery is connected to the power supply system and the secondary battery is connected, the optimal charging / discharging condition is stored in the memory unit, and the discharging is performed according to the condition. preferable. The optimum discharge conditions are as follows. In the case of discharging, the information is information on a discharging method that specifies at least one of a maximum discharging capacity, a discharging current, a discharging voltage, a discharging time, and a lower limit voltage. Specifically, the constant current discharge, the constant voltage discharge, the pulse discharge, a combination of these, the optimal current value, the voltage, the time cut, and the voltage cut are stored in advance in the memory as battery characteristic data. Keep it. In the case of charging, information defining similar conditions is used. In the case of an assembled battery, if there is at least one deteriorated battery, it is overdischarged, and the life of the battery is significantly shortened. It is desirable to take a control method that takes into account the type, scale, and safety of the battery, such as cutting the voltage while monitoring the time cut or the voltage change.

The rechargeable battery and the future (next) dischargeable capacity and battery life of the secondary battery can be predicted based on the past charge capacity of the battery and its change. Depending on the manner in which the capacity is reduced, it can be determined whether the electrolyte is dry or the anode or the cathode is deteriorated. Further, it is also possible to calculate the future dischargeable capacity and dischargeable time of the battery each time, and discharge the surplus power according to the calculated dischargeable capacity and dischargeable time to prevent overdischarge. Similarly,
Even when charging the nighttime power from the charging / discharging device, the charging is performed in accordance with the optimum charging conditions stored in the memory unit. Also in this case, the future dischargeable capacity and dischargeable time can be obtained each time, and the battery can be charged according to the calculated dischargeable capacity and overcharge to prevent overcharge.

It is desirable to set whether or not to perform surplus power discharge depending on a time zone. For example, if the surplus power discharge does not end during the daytime toll period, the surplus power discharge is stopped. The previous charge capacity is used as the charge capacity. Further, the surplus power discharge capacity may be defined by the remaining capacity in order to further maintain the soundness of the battery depending on the type of the battery. For example, a nickel-cadmium battery or a nickel-hydrogen battery has a large self-discharge and a memory effect. Therefore, if the remaining capacity is in the range of 0 to 85% of the charged capacity, the dischargeable capacity of the future battery will be considered. 9 of the discharge capacity within the optimum discharge condition
It is preferable to discharge 5 to 100% of surplus power. When the remaining capacity is 85% or more of the charged capacity, it is better not to perform surplus power discharging. Thereby, charging and discharging can be simplified, and the memory effect can be prevented. On the other hand, in a lithium battery or the like, the self-discharge is small, and when the depth of discharge is deep, the cycle life is shortened. It is desirable to discharge the surplus power from 80 to 95% of the discharge capacity within the optimum discharge condition rewritten to the available capacity. Remaining capacity is 5% of charging capacity
In the following cases, it is better not to perform surplus power discharge since further discharge shortens the cycle life. When the remaining capacity is 80% or more of the charged capacity, it is better not to perform surplus power discharge in order to simplify charging and discharging.

When the surplus power is discharged in consideration of the battery performance as in the present invention, the overall capacity of the battery can be known almost every time, and the remaining capacity can be accurately determined. Thereby, the life of the battery and the future battery capacity can be predicted. For this reason, charge / discharge control according to the change in the performance of the battery can be performed, and the soundness of the battery can be improved.

In addition, the battery is charged by using cheap electric power at night and the surplus electric power is used during the day, so that economy is good.

[0055]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 shows an embodiment according to the present invention. In this embodiment, the load 1 and the charging / discharging device 2 are connected to the secondary battery 3 and are connected to the power supply system and connected to the power storage device group 4 connected in parallel with the charging / discharging device 2 or the charging / discharging device. And a load group 5 connected to the device 2. The broken line 30 is a signal line, which is connected to the control device 6.

Although not shown in FIG. 1 or FIGS. 2 to 4, if necessary, the charging / discharging device 2 may be connected to the power supply system.
And a means for supplying power to the load group 5 or the power storage device group 4 without going through. At this time, it is desirable to provide a signal line for transmitting a measured value such as a power consumption amount to the control device 6.
Further, a device for measuring the incoming and outgoing power of the secondary battery 3 and the power storage device group 4 is provided, and the measurement data is sent to the control device 6 via a signal line.

The secondary battery 3, the power storage device group 4, and the load group 5 are provided with sensors (measuring means) and slave stations.

The secondary battery 3 is first connected to the charging / discharging device 2 and supplies (charges) electric power in the nighttime charge zone from this. After charging, the secondary battery 3 is connected to the load 1 and discharged. After discharging, the secondary battery 3 cuts off the connection with the load 1 and the charging / discharging device 2
To discharge excess power during the daytime toll hours. The control device 6 of the secondary battery 3 performs surplus power after charging the load 1, that is, surplus power of the remaining capacity, under optimal discharge conditions during the daytime charge time zone, and stops the surplus power discharge during the nighttime charge time zone. To charge. The charge capacity at this time does not indicate the capacity of the battery because the remaining capacity is still left. Therefore, the charge capacity used for displaying the remaining capacity is used in place of the previous charge capacity. The control device 7 of the charging / discharging device 2 measures the required power of the power storage device group 4 or the load group 5, selects a required destination, and supplies the surplus power of the secondary battery 3.

FIG. 2 shows an embodiment according to the present invention. In this embodiment, the load 1 and the charging / discharging device 2 are connected to the secondary battery 3,
It is composed of a charge / discharge device 2 connected to a power supply system and a power storage device group 4 connected in parallel.

FIG. 3 shows an embodiment according to the present invention. In this embodiment, the load 1 and the charging / discharging device 2 are connected to the secondary battery 3,
The charging / discharging device 2 is connected to a power supply system and includes a load group 5 connected to the charging / discharging device 2.

FIG. 4 shows an embodiment according to the present invention. In this embodiment, the load 1 and the charging / discharging device 2 are connected to the secondary battery 3,
The power storage device group 4 includes a power storage device group 4 connected to the power supply system and connected in parallel with the charge / discharge device 2 at the destination, and a load group 5 connected to the power storage device group 4.

[Embodiment 2] FIG. 5 is a flowchart showing a control portion relating to the control device 6 of the secondary battery 3 shown in FIGS. Hereinafter, a description will be given based on FIGS. 1 to 5. The secondary battery 3 includes a control device 6, an A / D converter 8, and a memory unit 9. The memory unit 9 can store standard characteristic data such as a charge rate characteristic 10, a discharge rate characteristic 11, a temperature characteristic 12, and an optimal charge / discharge condition 13 that the secondary battery 3 originally has. The optimum charging / discharging condition 13 defines a charging / discharging method such as constant current charging / discharging, constant voltage charging / discharging, or pulse charging / discharging, regulation of current value and voltage, cut voltage, charge / discharge capacity or charge / discharge time.

When the secondary battery 3 is connected to the charging / discharging device 2 to charge power, the secondary battery 3 is charged in accordance with the optimum charging / discharging condition 13,
Each time, the A / D converter 8 captures the charging operation history as charging current data 14, charging voltage data 15, and charging temperature data 16. The charging voltage data 15 is required to end charging at the cut voltage. The charging temperature data 16 is used to detect the end of charging in the case of a nickel-metal hydride battery. It can also be used to detect battery abnormalities when the temperature rises abnormally. The charge current data 14 is used for integrating and integrating to obtain a charge capacity.

Each time the secondary battery 3 is connected to the load 1 and discharges, the A / D converter 8 captures the discharge operation history as discharge current data 17, discharge voltage data 18, and discharge temperature data 19 every time. The discharge voltage data 18 is required to end the discharge at the cut voltage. Discharge current data 17
Is used to obtain the discharge capacity by integrating and integrating. The charge capacity is converted in real time to a discharge rate at the time of taking in the discharge current data 17 and a dischargeable capacity under the temperature condition of the discharge temperature data 19 and used as a converted charge capacity in evaluating the remaining capacity. That is, the discharge capacity is subtracted from the converted charge capacity, and the result is displayed as the remaining capacity.

Further, when the secondary battery 3 is connected to the charging / discharging device 2 to discharge surplus power, discharging is performed in accordance with the optimum charging / discharging condition 13, and the surplus power discharging operation history is stored every time using the surplus power discharging current data 20, surplus power discharging current data 20, The A / D converter 8 takes in the power discharge voltage data 21 and the surplus power discharge temperature data 22. The surplus power discharge current data 22 is used for integrating and integrating to obtain a surplus power discharge capacity, and displays the surplus power discharge capacity. The surplus power discharge capacity can be sent to the power storage device group 4 and the load group 5 via the charge / discharge device 2. In the case of selling power, since this is the power selling capacity, it is preferable to convert and display the amount as necessary.

FIG. 6 shows the charge / discharge cycle characteristics of the secondary battery at this time, and FIG. 7 shows a comparison between the display of the remaining capacity and the actual remaining capacity. Lead batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and lithium batteries all have a small capacity reduction and can be charged and discharged for 1000 cycles or more. Also,
The difference between the remaining capacity display and the actual remaining capacity is extremely small.

[Embodiment 3] When the secondary battery 3 is a nickel-cadmium battery or a nickel-hydrogen battery and the remaining capacity is in the range of 0 to 85% of the charged capacity, the battery is discharged in the future. The control device 6 controls so that the surplus power is discharged from 95 to 100% of the discharge capacity within the optimum discharge condition replaced by the available capacity. Remaining capacity is 85% of charging capacity
If the above remains, surplus power discharge is not performed. When the remaining capacity of the lithium battery is in the range of 5% to 80% of the charge capacity, the discharge capacity is replaced with the dischargeable capacity of the future battery, and 80 to 95% of the discharge capacity within the optimal discharge condition.
The control device 6 controls so as to discharge the excess power up to this point. When the remaining capacity is 5% or less of the charged capacity, no surplus power is discharged. When the remaining capacity is 80% or more of the charged capacity, the surplus power is not discharged. FIG. 8 shows the charge / discharge cycle characteristics of the battery under the above control. All of the nickel-cadmium battery, nickel-hydrogen battery and lithium battery have no capacity reduction and the cycle life is 1200 cycles or more.

Comparative Example 1 In the comparative example, the load 1 and the charging / discharging device 2 are connected to the secondary battery 3. The secondary battery 3 is first connected to the charging / discharging device 2 and supplies (charges) electric power in the nighttime time zone. After charging, the secondary battery 3 is connected to the load 1 and discharged. After the discharge, the secondary battery 3 disconnects from the load 1 and connects to the charging / discharging device 2 to perform charging during the night charge period. The remaining capacity was obtained by subtracting the discharge capacity from the initial capacity of the battery. FIG. 9 shows a comparison between the remaining capacity display value and the actual remaining capacity. As the cycle elapses, the difference is large, and accurate remaining capacity display cannot be performed. FIG. 10 shows charge / discharge cycle characteristics at this time. All of the lead batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and lithium batteries had large capacity reductions, and reached a life of 500 to 700 cycles.

[0070]

According to the present invention, efficient charging and discharging can be performed while maintaining the soundness of the battery. In addition, charging can be performed using inexpensive nighttime power, and surplus power can be supplied to other consumers in the daytime.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a secondary battery power storage system according to the present invention.

FIG. 2 is a configuration diagram of a secondary battery power storage system according to the present invention.

FIG. 3 is a configuration diagram of a secondary battery power storage system according to the present invention.

FIG. 4 is a configuration diagram of a secondary battery power storage system according to the present invention.

FIG. 5 is a flowchart of control of a secondary battery according to the present invention.

FIG. 6 is a charge / discharge cycle characteristic diagram of the secondary battery of Example 2.

FIG. 7 is a comparison diagram between the remaining capacity display and the actual remaining capacity according to the second embodiment.

FIG. 8 is a charge / discharge cycle characteristic diagram of the secondary battery of Example 3.

FIG. 9 is a comparison diagram between the remaining capacity display of Comparative Example 1 and the actual remaining capacity.

FIG. 10 is a charge / discharge cycle characteristic diagram of the secondary battery of Comparative Example 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Load, 2 ... Charge / discharge device, 3 ... Secondary battery, 4 ... Power storage device group, 5 ... Load group, 6 ... Secondary battery control device, 7 ... Charge / discharge device control device, 8 ... A / D converter , 9: memory unit, 10: charge rate characteristics, 11: discharge rate characteristics, 12: temperature characteristics, 13: optimum charge / discharge conditions, 14: charge current data, 15: charge voltage data, 16: charge temperature data, 1
7: discharge current data, 18: discharge voltage data, 19: discharge temperature data, 20: surplus power discharge current data, 21:
Surplus power discharge voltage data, 22 ... surplus power discharge temperature data, 30: signal line, A: nickel-hydrogen battery, B: lead battery, D: nickel-cadmium battery, E: lithium battery.

Claims (18)

[Claims] 1. A secondary battery power storage system comprising a secondary battery connected to a load, and a charge / discharge device connected to the secondary battery and a power supply system, wherein a load group is connected to the charge / discharge device. And a control device that receives information from at least one of the secondary battery and the load group and controls the charging / discharging device. 2. A secondary battery power storage system comprising a secondary battery connected to a load, and a charge / discharge device connected to the secondary battery and a power supply system, wherein a load group is connected to the charge / discharge device. A control device for controlling the charging / discharging device, and an information transmission unit for communicating at least one of the load group, the secondary battery, and the control device connected to the charging / discharging device with the control device. Secondary battery power storage system. 3. A secondary battery power storage system comprising a secondary battery connected to a load, and a charging / discharging device connected to the secondary battery and a power supply system, wherein a load group is connected to the charging / discharging device. A control line for controlling the charging / discharging device, a signal line for transmitting to the control device at least one of operating status information of the load group connected to the charging / discharging device and surplus power information of the secondary battery. A power storage system for a secondary battery, comprising: 4. A power storage device group according to claim 1, further comprising a power storage device group connected to said charging / discharging device, and a signal line connecting said power storage device group and said control device. Next battery power storage system. 5. The secondary battery power storage system according to claim 1, further comprising a computer for measuring a charge / discharge amount of said secondary battery and calculating a remaining amount. 6. A secondary battery power storage system according to claim 5, further comprising a display device for displaying a remaining amount of charge / discharge calculated by said computer. 7. The computer according to claim 5, wherein the computer processes the information stored in the memory or the information input from outside the memory, the memory storing the measurement data and the operation program information of the secondary battery. A secondary battery power storage system, comprising: a control device for performing the operation; and an A / D converter for taking in information from outside the memory into the computer. 8. The secondary battery power storage system according to claim 7, wherein said secondary battery, said computer, and said A / D converter are integrated. 9. The discharge current data according to claim 5, wherein
Means for measuring a discharge operation history consisting of discharge voltage data and discharge temperature data, and a charge operation history consisting of charge current data, charge voltage data and charge temperature data;
And a computer for taking in information from the measuring means. 10. The memory section according to claim 7, wherein the memory section has a charge rate characteristic, a discharge rate characteristic, and a temperature characteristic which the secondary battery originally has, and a maximum charge capacity, a charge current, About a charging method that specifies at least one of charging time, charging voltage, and upper limit voltage, and a discharging method that specifies at least one of maximum discharging capacity, discharging current, discharging time, discharging voltage, and lower limit voltage as optimal discharging conditions The secondary battery power storage system is characterized by storing the following information. 11. The memory according to claim 7, wherein the memory section integrates an arithmetic program for calculating discharge capacity by integrating discharge current data taken into the A / D converter, and integrates charge current data. A calculation program for calculating the charge capacity by using the discharge rate characteristic and the temperature characteristic stored in the memory unit. And a program for calculating and displaying a real-time remaining capacity obtained by subtracting a real-time discharge capacity from the real-time converted charge capacity. Storage system. 12. A power supply system, connected to a load group,
And a control device for controlling the charge / discharge device based on information from the load group, in a power storage system for a secondary battery including a charge / discharge device having a connection portion with the secondary battery. Power storage system for secondary batteries. 13. A power supply system, connected to a load group,
In a power storage system for a secondary battery including a charge / discharge device having a connection portion with a secondary battery, the power storage system includes a control device that controls the charge / discharge device, and the load group connected to the charge / discharge device. A power storage system for a secondary battery, comprising information transmission means for communicating between at least one of the connection means and the control device. 14. A power storage device group according to claim 12, further comprising a power storage device group connected to said charging / discharging device, and information transmission means for communicating between said power storage device group and said control device. Distributed power control system. 15. The secondary battery according to claim 1, further comprising a battery selected from at least one of a lead battery, a lithium battery, a nickel-cadmium battery, and a nickel-hydrogen battery as the secondary battery. Next battery power storage system. 16. The charging / discharging device according to claim 1, wherein the charging / discharging device includes orthogonal transforming means, and means for switching connection between the power supply system and the secondary battery and the load group or the power storage device group. A power storage system for a secondary battery, comprising: 17. The power storage device according to claim 4, wherein the power storage device group is a secondary battery selected from at least one of a lead battery, a lithium battery, a nickel-cadmium battery, and a nickel-hydrogen battery. A power storage system for a secondary battery, comprising at least one of a superconducting power storage device. 18. A secondary battery power storage system comprising a secondary battery connected to a load, and a charge / discharge device connected to the secondary battery and a power supply system, wherein a load group is connected to the charge / discharge device. The method for operating a secondary battery power storage system according to claim 1, wherein surplus power after power is supplied from said secondary battery to said load is supplied to said load group via said charging / discharging device.