JP2009165205A - Secondary battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery pack with an information transmitting and control system that is free of limitation on breakdown strength and operates with low power consumption. <P>SOLUTION: The secondary battery pack has a secondary battery block 3 that is constituted by connecting a plurality of unit blocks 2 in series, battery regulators 5 that are arranged in every unit block 2 and have functions of monitoring the voltages of secondary batteries and adjusting the balance, a charge switch 8, and a discharge switch 9. The secondary battery pack includes a constant current transmitter, which has transmitting sections 17, into which information from each battery regulator 5 is to be input, and in which these transmitting sections are connected to one another on the foregoing stage or the subsequent stage and which is so set as to output at least one hand of the information input from the transmitting section on the foregoing stage and the information input from the battery regulator 5 to the transmitting section on the subsequent stage and performs the transmission by a constant current value, and a current detector, which can detect the constant current value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a secondary battery, and in particular, a secondary battery including a secondary battery block configured by connecting a plurality of secondary batteries in series and a control circuit for monitoring battery voltage, controlling charge / discharge, and the like. Regarding the pack.

  In recent years, secondary batteries such as lithium-ion batteries have been used in fields such as electric devices and power storage, and demands for multiplicity for high voltage are increasing. At the same time, there is a high demand for ensuring long-term reliability, safety and extending the service life. When configuring a battery pack by connecting multiple cells in series, from the viewpoint of reliability, safety, and life, ideally, all the constituent batteries are uniform in charge / discharge operation and storage until the end of life. It is desired that the voltage changes and the performance deteriorates uniformly. However, in reality, there is a case where the balance of the voltage is lost due to variations in the performance of the battery alone or deterioration. As one of the countermeasures, as disclosed in Patent Document 1, generally, the voltage of the constituent battery is monitored, and a countermeasure for performing an abnormality such as an overcharge during charging or a voltage balance control is performed. It has been. Usually, when a secondary battery block is configured by making batteries multiplicity, the secondary battery is divided into several unit blocks for each battery, and a battery adjustment unit is installed in each of the unit blocks. Information is transmitted to a control circuit that controls the charge / discharge switch and the secondary battery pack is controlled.

JP 2002-152982 A

  However, when the information transfer circuit of the battery adjustment unit is arranged for each unit block, the potential difference between the unit blocks becomes large, and thus a high voltage may be applied in the signal transmission system to the control circuit. In addition, a high-voltage component is required for the circuit component and detection element connected thereto, or a special insulation measure for the signal transmission system is required.

  FIG. 3 is a circuit diagram showing an example of a battery pack in which a secondary battery block is configured by making the above-described battery multiplicity, and shows a case where the battery pack is configured by taking measures against insulation. In FIG. 3, unit blocks 2 composed of several secondary batteries 1 are connected in series to form a secondary battery block 3, and each unit block 2 has a battery adjustment unit 25, and the battery adjustment unit 25 is a secondary battery block 3. It has a function of monitoring the voltage of the battery 1 and a function of adjusting the voltage balance between the secondary batteries 1. Further, several unit blocks 2 are combined into a composite block 4, and each slave block 4 has a slave control unit 12 that monitors the voltage of the unit block 2 and adjusts the voltage balance therebetween, and has a master control unit 14. Is based on information from the slave control unit 12 of each composite block and information on the current detection unit 6 inserted in the charge / discharge path of the secondary battery block 3, and the charge switch 8 inserted in the slave control unit and the charge / discharge path, and The discharge switch 9 is controlled. In addition, the temperature detection part 10 which monitors the temperature of the secondary battery block 3 is provided, and the output is input into a master control part.

  Here, in FIG. 3, the detailed information such as the voltage value output from the slave control unit 12 is converted into a digital signal so that it is insulated from each slave control unit and installed in the insulated communication unit 15 and is connected to a photocoupler or wireless communication Such information is transmitted from the insulation communication unit 15 to the master control unit 14.

  FIG. 4 is a circuit diagram showing an example of a configuration of a secondary battery pack in which the configuration of FIG. 3 is further simplified. In FIG. 4, similarly to FIG. 3, unit blocks 2 composed of several secondary batteries 1 are connected in series to form a secondary battery block 3, and each unit block 2 has a battery adjustment unit 35, and battery adjustment The unit 35 has a function of monitoring the voltage of the secondary battery 1 and a function of adjusting the voltage balance between the secondary batteries 1. In addition, the current detection unit 26 monitors the charge / discharge current of the secondary battery block 3, and the control unit 24 controls the battery adjustment unit 35 based on information from the battery adjustment unit 35 and the current detection unit 26. . Further, a temperature detection unit 10 that monitors the temperature of the secondary battery block 3, and a charge switch 8 and a discharge switch 9 that perform connection / disconnection of the charge / discharge path under the control of the control unit 24 are provided.

  Here, in the secondary battery pack of FIG. 4, the information of the battery adjustment unit 35 is sent to the transmission unit 27 provided with an insulation communication means such as a high voltage level conversion circuit or a photocoupler, and controlled there. Is transmitted to the unit 24. In addition, since the battery adjustment part 39 arrange | positioned at the unit block nearest to a charging / discharging path | route has the same reference potential as the control part 24, the output is directly input into the control part 24 without passing the transmission part 27. .

  As described above, in the secondary battery pack shown in FIG. 3, by providing the insulated communication unit that is insulated from the battery adjustment unit and the slave control unit, the secondary battery pack shown in FIG. The high voltage problem described above is addressed by providing a conversion circuit or an insulated communication means.

  However, in general, there is a problem that the withstand voltage is limited in the high voltage countermeasure using the high withstand voltage component. That is, there is a problem that the cascade connection of the control ICs accompanied by the level conversion is required in accordance with the increase in the number of conversions. there were. On the other hand, the insulation method generally has a problem of high power consumption and high cost. Further, in the insulation method, the steady power consumption tends to further increase due to a large leak or the like, so that the battery energy is lost inside the battery pack.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to divide a secondary battery block configured by connecting a plurality of secondary batteries in series into a plurality of unit blocks. In a secondary battery pack that is provided with a battery adjustment unit for each unit block and is controlled according to the information, the secondary battery pack is provided with an information transmission and control system that operates with low power consumption without a withstand voltage limitation. is there.

  In order to achieve the above object, a secondary battery pack according to the present invention includes a secondary battery block formed by connecting a plurality of unit blocks configured by connecting a plurality of secondary batteries in series, and the unit block. A battery adjustment unit connected to each secondary battery in the unit block and having a function of monitoring the voltage of the secondary battery; and a charging path inserted into the charging / discharging path of the secondary battery block. In a secondary battery pack having a charge switch for cutting off and a discharge switch for cutting off a discharging path, a transmission unit arranged for each unit block and connected to each of the battery adjustment units to receive information from the battery adjustment unit And the transmission unit is connected to a transmission unit arranged in a unit block at the front stage or the rear stage, so that a small amount of information is input from the transmission unit at the front stage and a small amount of information is input from the battery adjustment unit. And it is configured to output one to the subsequent transmission unit also.

  Also, the secondary battery pack of the present invention is a secondary battery in which a plurality of composite blocks formed by connecting a plurality of unit blocks connected in series are connected in series. A block, a battery adjustment unit arranged for each unit block, connected to each secondary battery in the unit block and having a function of monitoring the voltage of the secondary battery, and the composite block arranged for each composite block A slave control unit having a function of monitoring the voltage of each unit block in the battery, a charge switch for cutting off a charge path inserted in a charge / discharge path of the secondary battery block, and a discharge switch for cutting off the discharge path The secondary battery pack includes a transmission unit that is arranged for each of the composite blocks and that is connected to the slave control unit and receives information from the slave control unit. Connected to the transmission unit arranged in the preceding or subsequent composite block and set to output at least one of information input from the previous transmission unit and information input from the slave control unit to the subsequent transmission unit May be.

  In addition, the transmission unit may include a constant current transmission function that performs transmission at a constant current value and a current detection function that detects the constant current value.

  Further, the transmission unit is detection information from the battery adjustment unit of the unit block in which the transmission unit is arranged or detection information from the transmission unit in the previous stage, or a slave control unit of the composite block in which the transmission unit is arranged An OR function unit that outputs detection information when there is at least one of detection information from may be provided.

  Moreover, at least one of the charge switch or the discharge switch may be controlled by an output from a transmission unit arranged in a unit block closest to the charge / discharge path.

  A current detection unit that monitors a charge / discharge current of the secondary battery block, and an output of the current detection unit is input to a battery adjustment unit disposed in a unit block closest to the charge / discharge path; The adjustment unit or the transmission unit connected to the battery adjustment unit may include means for determining whether or not the output of the current detection unit is in an abnormal state.

  As described above, in the present invention, the information of the battery adjustment unit of each unit block or the slave control unit of each composite block is input to the transmission unit, and the transmission unit transmits the information to the transmission unit of the next stage. By sequentially passing through the subsequent transmission unit, the information of the battery adjustment unit of each unit block or the information of the slave control unit of each composite block is transmitted to the control unit or the charge / discharge switch.

  By adopting a configuration in which the output of the transmission unit is output as a constant current by a minute current and is received by the current detection unit using a high resistance body, it is possible to transmit input information with different voltage levels as a constant current.

  In addition, by transmitting the output sequentially as a constant current output and setting the current output value so that the charge / discharge switch can be driven, it can be stored in any information of the battery adjustment unit or slave control unit arranged in each stage. Based on this, the charge / discharge switch can be directly driven, and the drive function can be performed simultaneously with the transmission of information.

  As described above, according to the present invention, a secondary battery block configured by connecting a plurality of secondary batteries in series is divided into a plurality of unit blocks, and a battery adjustment unit is provided for each unit block. The secondary battery pack to be controlled can be a secondary battery pack provided with an information transmission and control system that operates with low power consumption without a withstand voltage limitation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a circuit diagram showing an embodiment of a secondary battery pack according to the present invention. In FIG. 1, a secondary battery block 3 formed by connecting a plurality of unit blocks 2 configured by connecting a plurality of secondary batteries 1 in series, and a unit block 2 arranged for each unit block 2. A battery adjustment unit 5 connected to each secondary battery and having a function of monitoring the voltage of the secondary battery and a function of adjusting the voltage balance between the secondary batteries, and inserted into the charge / discharge path of the secondary battery block 3 In the secondary battery pack having the charging switch 8 that cuts off the charging path and the discharging switch 9 that cuts off the discharging path, the information from the battery adjustment unit 5 is arranged for each unit block 2 and connected to the battery adjustment unit 5 respectively. The transmission unit 17 is connected to a transmission unit disposed in the preceding or subsequent unit block, and the information input from the previous transmission unit and the battery adjustment unit 5 are input. That at least one of information are set so as to output to the subsequent transmission unit.

  The transmission unit 17 includes a constant current transmission unit that performs transmission with a constant current value and a current detection unit that can detect the constant current value.

  Furthermore, the charge switch 8 and the discharge switch 9 are directly controlled by the output from the transmission unit 21 that is disposed in the unit block 19 that is the unit block closest to the charge / discharge path and connected to the battery adjustment unit 20 of the unit block 19. Is set to be.

  In addition, the present embodiment includes a current detection unit 6 that monitors the charge / discharge current of the secondary battery block 3, and the output of the current detection unit 6 is a battery adjustment unit disposed in the unit block 19 that is closest to the charge / discharge path. 20, the battery adjustment unit 20 has means for determining whether the output of the current detection unit 6 is in an abnormal state, and sends the information to the transmission unit 21 together with the information of the unit block 19.

  Here, in the present embodiment, all the battery adjustment units monitor the voltage of the secondary battery in the unit block connected thereto, adjust the balance of the voltage values, and further, the unit block and the unit block It has a function of judging an abnormal state such as overcharge and overdischarge of the secondary battery in the unit block and outputting the abnormal information as detection information to a transmission unit connected thereto.

  FIG. 2 is a diagram illustrating an example of a specific circuit configuration of the transmission unit 17. In FIG. 2, when there is abnormality information from the previous transmission unit, the information is sent as a constant current from the constant current transmission circuit of the previous transmission unit and input to the high resistance circuit 41. The voltage across the high resistance circuit 41 is detected by the voltage detection circuit 42, and the information is input to the OR circuit 43. Here, abnormality information from the battery adjustment unit 5 is also input to the OR circuit 43, and when there is at least one of abnormality information from the battery adjustment unit or abnormality information from the previous transmission unit, the OR circuit 43 outputs abnormality information. To do. This abnormality information is input to the constant current transmission circuit 44, and is sent as a constant current to the transmission unit at the next stage.

  As described above, the abnormality information is transmitted one after another through the transmission unit 17, and when there is abnormality information from the battery adjustment unit 5, the information is also transmitted and input to the final-stage transmission unit 21, and the charge switch 8 and the discharge switch 9 are controlled.

  As described above, since the transmission units are sequentially connected by the transmission of information by constant current, the potential difference at the boundary between the transmission units arranged in each unit block becomes zero. Information can be transmitted without using an insulation method that requires electric power, and information can be transmitted without causing the conventional problems even when the number of series stages of secondary batteries and unit blocks increases.

  As described above, according to the present invention, it is possible to obtain a secondary battery pack including an information transmission and control system that operates with low power consumption without limitation of withstand voltage.

  Needless to say, the present invention is not limited to the above-described embodiment, and the design can be changed according to the application and purpose. For example, instead of providing the transmission unit directly connected to the battery adjustment unit, a slave control unit that adjusts the battery adjustment units of several unit blocks as shown in FIG. You may make it provide the transmission part connected to the control part, and may transmit the information of those slave control parts. Further, the object of the present invention can be obtained as long as the signal output from the transmission unit such as abnormality information is not a constant current but has a minute current value. Further, the number of signals transmitted between the transmission units is not necessarily one, and a plurality of information can be transmitted by a plurality of connection wirings. In addition, the drive of the charge switch and the discharge switch is not directly driven by the transmission unit at the final stage, but can be driven by the drive control unit connected to the transmission unit at the final stage. In addition, information is not transmitted through all the transmission units arranged in the unit blocks constituting the secondary battery block, but information is transmitted for each composite block composed of several unit blocks. It is also possible to output control information. In addition, although the voltage monitoring function is indispensable in the battery adjustment unit and the slave control unit, the voltage balance adjustment function may not be provided, and the present invention is also applicable to such a case.

The circuit diagram which shows one Embodiment of the secondary battery pack by this invention. The figure which shows an example of the specific circuit structure of the transmission part of this Embodiment. The circuit diagram which shows an example of the battery pack which increased the battery and comprised the secondary battery block. The circuit diagram which shows an example of a structure of the secondary battery pack which simplified the structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Secondary battery 2, 19 Unit block 3 Secondary battery block 4 Composite block 5, 20, 25, 39 Battery adjustment part 6 Current detection part 8 Charge switch 9 Discharge switch 10 Temperature detection part 12 Slave control part 14 Master control part 15 Insulation communication unit 17, 21, 27 Transmission unit 24 Control unit 41 High resistance circuit 42 Voltage detection circuit 43 OR circuit 44 Constant current transmission circuit

Claims (6)

  A secondary battery block formed by connecting a plurality of unit blocks configured by connecting a plurality of secondary batteries in series, and connected to each secondary battery arranged in each unit block. A battery adjustment unit having a function of monitoring the voltage of the secondary battery, a charge switch for cutting off a charge path inserted in a charge / discharge path of the secondary battery block, and a discharge switch for cutting off the discharge path. In the next battery pack, the battery pack has a transmission unit arranged for each unit block and connected to the battery adjustment unit to input information from the battery adjustment unit, and the transmission unit is arranged in a unit block at the front stage or the rear stage. Are connected to each other and are set to output at least one of information input from the previous transmission unit and information input from the battery adjustment unit to the subsequent transmission unit. The secondary battery pack according to claim Rukoto.   A secondary battery block formed by connecting in series a plurality of composite blocks formed by connecting a plurality of unit blocks configured by connecting a plurality of secondary batteries in series, and arranged for each unit block A battery adjustment unit connected to each secondary battery in the unit block and having a function of monitoring the voltage of the secondary battery, and a voltage of each unit block in the composite block arranged for each composite block In a secondary battery pack having a slave control unit having a function, a charging switch that cuts off a charging path inserted in a charging / discharging path of the secondary battery block, and a discharging switch that cuts off a discharging path, the arrangement is arranged for each composite block Each having a transmission unit connected to the slave control unit and receiving information from the slave control unit. The transmission unit is connected to each other, and is configured to output at least one of information input from the previous transmission unit and information input from the slave control unit to the subsequent transmission unit, Rechargeable battery pack.   3. The secondary battery pack according to claim 1, wherein the transmission unit includes a constant current transmission function that performs transmission at a constant current value and a current detection function that detects the constant current value. 4.   The secondary battery pack according to claim 1, wherein the transmission unit includes an OR function unit that outputs detection information when there is detection information input to the transmission unit. .   At least one of the charge switch or the discharge switch is controlled by an output from a transmission unit arranged in a unit block or a composite block closest to the charge / discharge path. The secondary battery pack according to item.   It has a current detection unit that monitors the charge / discharge current of the secondary battery block, and the output of the current detection unit is sent to a battery adjustment unit or slave control unit arranged in the unit block or composite block closest to the charge / discharge path The transmission unit connected to the battery adjustment unit or the slave control unit or the battery adjustment unit or the slave control unit has a means for determining whether the output of the current detection unit is in an abnormal state. The secondary battery pack according to claim 1, wherein the secondary battery pack is characterized in that

Images