JP4861043B2 - Battery pack, energy remaining amount monitoring method and secondary battery module - Google Patents

Description

  The present invention relates to a battery pack having a built-in secondary battery and a method for monitoring the remaining amount of energy, and in particular, allows the remaining amount of energy to be monitored with high accuracy while using a simple control circuit. .

  The conventional method for monitoring the remaining amount of energy in a battery pack includes a current integration circuit unit in the battery pack, detects charge / discharge current flowing through the battery, integrates the detection signal, and monitors the charge / discharge integrated value. When the battery voltage reaches the upper limit set value or the lower limit set value by detecting the voltage, the charge / discharge integrated value is reset and the remaining energy is monitored (for example, see Patent Document 1).

There has also been proposed a method for monitoring the remaining amount of energy by creating a database of the open circuit voltage of the battery and calculating the remaining energy from the open circuit voltage of the battery (see, for example, Patent Document 2 and Patent Document 3).
JP 11-072544 A JP 2003-157912 A Japanese Patent Laid-Open No. 2-170372

  However, in the method of Patent Document 1, there is no means for correcting the charge / discharge integrated value until the battery voltage reaches the upper limit voltage or the lower limit voltage, and the charge / discharge integrated value obtained by integrating the charge / discharge current is the current detector. Due to the offsets and detection errors, there will be a deviation from the actual energy used.

  In addition, the methods of Patent Document 2 and Patent Document 3 make the actual energy remaining amount accurate by making the open circuit voltage of the battery a database and increasing the number of detection points such as voltage, current, and temperature to enlarge the database. However, the battery pack requires a high-performance computing microcomputer and a large-scale database, which increases the cost of the battery pack.

The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to achieve a small size and low speed by a simple control circuit that does not require a high-performance arithmetic processing microcomputer or the like. An object of the present invention is to provide a battery pack capable of detecting the remaining amount of energy with high accuracy and not requiring a high-speed communication means and a method for monitoring the remaining amount of energy.

In order to achieve the above object, a battery pack according to the present invention includes a secondary battery, voltage detection means for detecting a cell voltage of the secondary battery, and current detection means for detecting a charge / discharge current of the secondary battery. A protection switch that protects the secondary battery, and a control circuit having a protection switch controller that turns on and off the protection switch by inputting voltage information output from the voltage detection means and current information output from the current detection means. In the battery pack provided, the control circuit obtains voltage information output by the voltage detection means, and determines communication residual energy information of the secondary battery based on the voltage information, the communication means, a remaining energy level information acquisition unit that acquires an energy remaining amount information of the secondary battery by the external device is determined via the communication means, the charge and discharge of the secondary battery based on the detected value of the current detecting means A charging and discharging current integrating unit that integrates the flow, that have a monitoring data calculator for calculating the monitoring data is the remaining energy level at the charge-discharge state of the secondary battery from the energy remaining amount information and the charge-discharge integration value Features.

The battery pack energy remaining amount monitoring method of the present invention includes a secondary battery, voltage detection means for detecting a cell voltage of the secondary battery, current detection means for detecting a charge / discharge current of the secondary battery, A battery pack comprising a protection switch for protecting a secondary battery, and a control circuit for turning on / off the protection switch by inputting voltage information output from the voltage detection means and current information output from the current detection means in the control circuit comprises means for communicating with an external device for determining on the basis of the energy remaining amount information of the secondary battery acquires voltage information output from said voltage detecting means to the voltage information, wherein the external device is determined and secondary energy remaining amount information of the battery acquired via the communication unit, the energy remaining amount information and the secondary battery charge and discharge current secondary batteries to charge and discharge integration value obtained integrating the Characterized by calculating the monitoring data is the remaining energy level at the charge-discharge state.

  The battery pack of the present invention and the method for monitoring the remaining amount of energy of the present invention separate the battery open circuit voltage database from the battery pack to the external device, and the battery pack receives the energy remaining from the external device when the battery operates. Get quantity information. The control circuit of the battery pack monitors the remaining energy of the battery pack by adding the charge / discharge integrated value obtained by integrating the charge / discharge current to the remaining battery information.

  In the method for monitoring the remaining amount of energy of the battery pack of the present invention having the above-described configuration, it is possible to reduce the cost of the control circuit by omitting a high-performance arithmetic processing microcomputer and database from the battery pack, and to charge and discharge the battery. By accumulating the charge / discharge current in accordance with the operation, it is possible to monitor the remaining energy with high accuracy and achieve high functionality.

(1) First Embodiment Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a circuit diagram showing the configuration of the battery pack of this embodiment, FIG. 2 is a functional block diagram of the battery pack of this embodiment, and FIG. 3 is an operation flowchart showing a method for monitoring the remaining energy in this battery pack. It is.

(1-1) Configuration of First Embodiment In FIGS. 1 and 2, 1 is a battery pack, 2 is a secondary battery, 3 is voltage detection means for detecting the voltage of the secondary battery 2, and 4 is a secondary battery. Current detection means 5 for detecting the charge / discharge current is a protection switch for protecting the secondary battery.

  6 is a control circuit for turning on / off the protection switch 5 and monitoring the remaining energy of the secondary battery based on the information of the voltage detection means 3 and the current detection means 4. Reference numeral 7 denotes a communication means for exchanging information on the remaining amount of energy between the battery pack 1 of the present embodiment and the external device 8 configured separately from the battery pack 1. is there. 9 is a battery pack energy monitoring data display means, 10 is a remaining energy reset switch, 11 is a power supply for the control circuit 6, and 12 is a power switch for the control circuit 6.

  The battery pack 1 includes a secondary battery 2 that can be charged or discharged, and the terminal voltage of the secondary battery 2 is detected by the voltage detection means 3 and output to the control circuit 6. The charging / discharging current of the secondary battery 2 is detected by the current detection means 4 and a signal is output to the control circuit 6.

  Here, the secondary battery 2 may be a single battery cell, or a plurality of battery cells may be connected in series or in parallel. Further, a secondary battery module may be configured by connecting a plurality of secondary batteries in series or in parallel, and the secondary battery modules may be connected in series or in parallel.

  The voltage detection means 3 may detect the voltage of a secondary battery cell separately, and may detect the secondary battery voltage of several cells. The current detection means 4 may be a current detection device that detects a magnetic flux such as Hall CT, or may be connected to an impedance element such as a shunt resistor to detect a current from a change in terminal voltage.

  The control circuit 6 includes an over / under voltage state determination unit 61 and a protection switch control unit 62. That is, the over / under voltage state determination unit 61 determines from the signal of the voltage detection means 3 that the secondary battery 2 is not in an over voltage state or under voltage state, and if the secondary battery 2 is over voltage state or low When it is determined that the voltage state has been reached, the protection switch 5 is turned off by the command from the protection switch control unit 62 to protect the secondary battery 2.

  Further, when the over / under voltage state determination unit 61 of the control circuit 6 determines that the secondary battery is in an over current state from the signal of the current detection means 4, the protection switch is in response to a command from the protection switch control unit 62. 5 is turned off to protect the secondary battery 2. Further, when the control circuit power switch 12 is off and the power supply 11 is not connected to the control circuit 6, the terminal voltage of the battery pack 1 is prevented from being applied by turning off the protection switch 5. It also has a function to prevent electric shock disasters.

  The control circuit 6 has an energy remaining amount information acquisition unit 65. When the power supply 11 of the control circuit 6 is turned on by turning on the power switch 12, the energy remaining amount of the secondary battery is transmitted from the external device 8 via the communication means 7. Information is input to the remaining energy information acquisition unit 65.

  The external device 8 is a converter that connects the battery pack 1 and the electrode terminal to charge or discharge the secondary battery 2 and includes a high-performance microcomputer for controlling the converter. That is, the external device 8 stores the open terminal voltage detection unit 81 of the battery pack 1 and the database 82 in which the correspondence relationship between the voltage and the remaining energy necessary for confirming the remaining energy information from the detected voltage is stored. And, based on these voltage values and the database, an energy remaining amount information confirmation unit 83 for confirming the remaining energy in the battery pack 1 is provided. In addition, as this database, the thing of the said patent document 2 and the patent document 3 can be used.

  The remaining energy information obtained by the remaining energy checking unit 83 is output to the remaining energy information acquiring unit 64 provided in the control circuit 6 of the battery pack 1 via the communication unit 7 as described above. Further, the secondary battery charge / discharge control unit 84 outputs a charge / discharge command for the battery pack 1 based on the remaining energy information.

  The control circuit 6 includes a charge / discharge current integrating unit 64 that calculates a charge / discharge integrated value by integrating the charge / discharge current when the secondary battery 2 starts a charge / discharge operation. Based on the integrated current value obtained by the charge / discharge current integrating unit 64 and the remaining energy information obtained from the external device 8, the monitoring data calculating unit 66 indicates the remaining energy level for each time point of the battery pack 1. The monitoring data is calculated, and the protection operation of the battery pack 1 and the charge / discharge timing are grasped based on the calculation result. The calculation result by the monitoring data calculation unit 66 is displayed on the display means 9 provided in the battery pack 1.

  Further, the external device 8 is provided with an energy arithmetic calculation result acquisition unit 85 that acquires the calculation result obtained by the monitoring data calculation unit 66 of the control circuit 6 via the communication means 7. Further, the external device 8 includes an energy remaining amount information acquisition unit 65 of the battery remaining amount information acquired by the external device 8 at regular intervals when the charging / discharging operation of the secondary battery 2 is stopped. A timer 86 is provided for transmission to the.

(1-2) Operation of the First Embodiment The operation of the battery pack of the present embodiment having the above-described configuration will be described with reference to the flowcharts shown in FIGS. In each figure, reference numerals S1 to S10 denote individual steps constituting the flowchart.

  FIG. 3 shows the basic operation of the present embodiment. When the power switch 12 of the control circuit 6 is turned on (step 1), the battery pack 1 receives energy from the external device 8 via the communication means 7. The remaining amount information is acquired (step 2). That is, the external device 8 detects the terminal voltage of the battery pack 1 by the open terminal voltage detection unit 81, and the energy remaining amount from the relationship between the detected voltage value and the voltage-energy remaining amount stored in the database 82. The information confirmation unit 83 determines the remaining energy level of the battery pack 1 when the control circuit power switch 11 is turned on, and transmits the value to the remaining energy acquisition unit 65 of the battery pack 1.

  In this state, when the charge / discharge operation is started (step 3), the current detection means 4 detects the charge / discharge current, and the charge / discharge current is integrated by the integration unit 64 (step 4). Based on this integrated value and the remaining energy information acquired from the external device by the remaining energy acquisition unit 65, the monitoring data calculation unit 66 calculates the remaining energy at each time point during the charge / discharge period (step 5) The calculation result is output to the display means 9 as monitoring data (step 6). At the same time, the monitoring data is sent to the monitoring data acquisition unit 85 provided in the external device 8 via the communication unit 7 and output to a display unit such as a liquid crystal display of the external device 8.

  The calculation process of the monitoring data calculation 66 is performed by adding the integrated value of the charge / discharge current integrating unit 64 to the initial value using the remaining energy information acquired from the external device 8 as an initial value. For example, when the charging current is large and the integrated value is +, it is added to the initial value, so that the remaining energy increases, so that the increased remaining energy is output as monitoring data. In this way, accurate monitoring data can be sequentially generated by a simple calculation process of adding the integrated value of the charge / discharge current to the initial value acquired from the external device 8, and the battery pack 1 itself is complicated. This eliminates the need for a built-in microcomputer for monitoring data.

  On the other hand, the monitoring data obtained as described above is transmitted from the monitoring data acquisition unit 85 of the external device 8 to the secondary battery charge / discharge control unit 84, which controls the battery pack 1 based on the monitoring data. The charge / discharge operation can be controlled.

  During the charge / discharge operation as described above, based on the voltage value detected by the voltage detection means 3, the over / under voltage state determination unit 61 of the control circuit 6 determines that the battery pack 1 is in the over voltage state or under voltage state. In this case, charging / discharging of the battery pack 1 is stopped by opening the protection switch 5 according to a command from the protection switch control unit 62. Similarly, when the overcurrent state determination unit 63 of the control circuit 6 determines that the battery pack 1 is in an overcurrent state based on the current value detected by the current detection unit 4, a command from the protection switch control unit 62 is provided. Thus, by opening the protection switch 5, charging / discharging of the battery pack 1 is stopped. Even when the user manually turns off the control circuit power switch 12, the power supply device to the control circuit 6 is interrupted, and the protection switch 5 is opened to stop charging / discharging of the battery pack 1.

(1-3) Effects of the First Embodiment According to the first embodiment having the above-described configuration, as a result of the external device 8 sharing the function for calculating the remaining energy, the battery pack 1 itself is While simplifying the control circuit 6 to reduce the size and cost, the accumulated charge / discharge value can be accurately calculated by accumulating the current only when the battery is charged / discharged. In addition, since there is little data to send and receive and only the initial values required for computation need to be transmitted, the need for high-speed communication means is also a factor in cost reduction, and high-performance energy even if the cost is reduced The remaining amount can be monitored.

  Further, in the present embodiment, the remaining amount of energy of the battery pack 1 can be grasped at a glance by means of the remaining amount of energy display means 9 provided in the battery pack 1, and it is possible to easily enhance the functionality of the battery pack. Is possible.

  Furthermore, since the protection switch 5 is controlled by the control circuit 6 so as to cope with various situations in which the battery pack 1 may fall, there is an advantage of high safety. As a result, according to the present embodiment, a large number of battery packs are controlled by a single external device, and the battery pack 1 itself takes charge of safety functions necessary for each battery pack 1. With a simple configuration, it is possible to provide a battery pack with high functionality and excellent safety.

(2) Second Embodiment A second embodiment of the present invention will be described based on the flowchart of FIG. That is, it is conceivable that the remaining energy of the battery pack 1 decreases with time as the battery 1 self-discharges and the power is consumed by the protection circuit. The second embodiment considers such a situation.

  In the second embodiment, the energy remaining amount reset switch 8 is provided in the battery pack 1, and the energy remaining amount reset switch 8 is turned on when it is desired to check the remaining energy state of the battery pack 1. The remaining amount information is acquired (step 7). The following processing is the same as that of the first embodiment shown in FIG. Thereby, the remaining energy information can be reset according to the state of the battery pack 1, and the remaining energy can be monitored in accordance with the state of the battery pack.

  Similarly, the remaining amount of energy obtained by referring to the database from the open terminal voltage of the secondary battery varies depending on the environmental temperature and the elapsed time after completion of the charge / discharge operation. On the other hand, the external device 8 can sequentially check the remaining energy information for the open circuit voltage.

  Therefore, in the second embodiment, when the remaining energy information calculated thereafter with respect to the remaining energy information communicated from the external device 8 to the control circuit 6 of the battery pack 1 last time changes from the external device 8. An information update signal is communicated (step 7). Based on the signal, the battery pack updates the remaining energy information, and monitors the remaining energy of the battery pack 1 from the charge / discharge integrated value obtained by integrating the remaining energy information and the charge / discharge current.

(3) Third Embodiment A third embodiment of the present invention will be described based on the flowchart of FIG. The third embodiment focuses on the point that the external device 8 can control the timing of current flow through the battery pack 1 because the external device 8 controls the charging and discharging of the battery pack 1.

  In the third embodiment, immediately before the external device sends current to the secondary battery, the remaining energy information is communicated from the external device to the control circuit 6 of the battery pack 1, and the remaining energy information and the charge / discharge current are obtained. The remaining energy level of the battery pack 1 is monitored from the accumulated charge / discharge integrated value (step 8). Thereby, the battery pack can obtain the remaining energy information obtained from the open circuit voltage immediately before the charge / discharge operation, and can monitor the remaining energy with higher accuracy.

(4) Fourth Embodiment FIG. 5 shows a fourth embodiment of the present invention. FIG. 5 is an operation flowchart of the fourth embodiment. That is, in the fourth embodiment, the control circuit 6 or the external device 8 of the battery pack 1 is provided with a timer 86, and the charge / discharge operation of the secondary battery 2 is stopped at every time set by the timer 86. (Step 9), the remaining energy information from the external device is updated (Step 10), and the monitoring data that is the remaining energy of the battery pack 1 is obtained from the charge / discharge integrated value obtained by integrating the remaining energy information and the charge / discharge current. Calculate.

  Thereby, the battery pack can obtain the remaining energy information obtained from the open circuit voltage immediately before the charge / discharge operation, and can monitor the remaining energy with high accuracy with a simple configuration.

1 is a circuit diagram showing a configuration of a first embodiment of the present invention. The functional block diagram which shows the structure of 1st Embodiment of this invention. The operation | movement flowchart which shows 1st Embodiment of this invention. The operation | movement flowchart which shows 2nd Embodiment of this invention. The operation | movement flowchart which shows 3rd Embodiment of this invention. The operation | movement flowchart which shows 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery pack 2 ... Secondary battery 3 ... Voltage detection means 4 ... Current detection means 5 ... Protection switch 6 ... Control circuit 7 ... Communication means 8 ... External device 9 ... Display means 10 ... Energy remaining amount reset switch 11 ... Control circuit Power supply 12 ... Control circuit power switch 61 ... Over / under voltage state determination unit 62 ... Protection switch control unit 63 ... Overcurrent state determination unit 64 ... Charge / discharge current integration unit 65 ... Energy remaining amount information acquisition unit 66 ... Monitoring data calculation unit 81 ... Open terminal voltage detection unit 82 ... Database 83 ... Remaining energy information confirmation unit 84 ... Secondary battery charge / discharge control unit 85 ... Monitoring data acquisition unit 86 ... Timer

Claims (10)

A secondary battery; voltage detection means for detecting a cell voltage of the secondary battery; current detection means for detecting a charge / discharge current of the secondary battery; a protection switch for protecting the secondary battery; and a voltage detection means. In a battery pack comprising a control circuit having a protection switch controller that turns on and off the protection switch by inputting voltage information to be output and current information output by the current detection means,
The control circuit includes:
Means for acquiring voltage information output by the voltage detecting means and determining energy remaining information of the secondary battery based on the voltage information ;
A remaining energy information acquisition unit that acquires the remaining energy information of the secondary battery determined by the external device via the communication unit ;
A charge / discharge current integrating unit that integrates the charge / discharge current of the secondary battery based on the detection value of the current detection means;
A monitoring data calculation unit that calculates monitoring data that is a remaining amount of energy in a charge / discharge state of the secondary battery from the remaining energy information and charge / discharge integrated value ;
A battery pack comprising:   2. The battery pack according to claim 1, wherein the monitoring data calculation unit sets the remaining energy information acquired by the remaining energy information acquisition unit as an initial value. The control circuit includes a power supply and a power switch,
The battery pack according to claim 1 or 2, wherein when the control circuit power supply is off, charging and discharging of the battery pack is stopped by turning off the protection switch. The battery pack includes a reset switch for remaining energy information stored in the remaining energy information acquisition unit,
The battery according to any one of claims 1 to 3, wherein the control circuit acquires new energy remaining amount information from an external device when the energy remaining amount information is reset by the reset switch. pack.   5. The control circuit according to claim 1, wherein the control circuit updates the remaining energy information at regular intervals while charging / discharging of the battery pack is stopped. Battery pack. Secondary battery, voltage detection means for detecting cell voltage of secondary battery, current detection means for detecting charge / discharge current of secondary battery, protection switch for protecting secondary battery, and output of voltage detection means In the battery pack energy remaining amount monitoring method including a control circuit that inputs voltage information and current information output from the current detection means to turn on and off the protection switch,
The control circuit includes a communication unit with an external device that acquires voltage information output by the voltage detection unit and determines energy remaining information of the secondary battery based on the voltage information .
Obtaining the remaining energy information of the secondary battery determined by the external device via the communication means ,
A battery pack that calculates monitoring data that is a remaining amount of energy in a charge / discharge state of the secondary battery from the remaining energy information and a charge / discharge integrated value obtained by integrating the charge / discharge current of the secondary battery Energy monitoring method.   The method for monitoring the remaining amount of energy of the battery pack according to claim 6, wherein the remaining energy information of the secondary battery is acquired from an external device immediately before the secondary battery is charged and discharged.   8. The battery pack according to claim 6, wherein the remaining energy information of the secondary battery is acquired from an external device at regular intervals during a period in which the secondary battery has stopped charging / discharging operation. Energy remaining amount monitoring method. The battery pack includes a remaining energy reset switch,
9. The method for monitoring the remaining amount of energy of a battery pack according to claim 6, wherein the remaining amount of energy information of the secondary battery is acquired from an external device in accordance with the turning on of the reset switch. A secondary battery module in which a plurality of secondary batteries are connected in series or in parallel; a voltage detection means for detecting a cell voltage of the secondary battery; a current detection means for detecting a charge / discharge current of the secondary battery; A protection switch that protects the secondary battery, and a control circuit having a protection switch controller that turns on and off the protection switch by inputting voltage information output from the voltage detection unit and current information output from the current detection unit. In the next battery module,
The control circuit includes:
Means for acquiring voltage information output by the voltage detecting means and determining energy remaining information of the secondary battery based on the voltage information ;
A remaining energy information acquisition unit that acquires the remaining energy information of the secondary battery determined by the external device via the communication unit ;
A charge / discharge current integrating unit that integrates the charge / discharge current of the secondary battery based on the detection value of the current detection means;
A monitoring data calculation unit that calculates monitoring data that is a remaining amount of energy in a charge / discharge state of the secondary battery from the remaining energy information and charge / discharge integrated value ;
A secondary battery module comprising:

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