JP2013207900A - Battery control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power while securing safety and the like.SOLUTION: A battery management unit 21 includes communication units (61, 62) which perform communication with battery units and receive battery state data, and transmit signals (for example, signals related to permission or prohibition of charging or discharging) on the basis of the battery state data to a power conversion control unit 11 performing charging and discharging control. The battery management unit 21 is able to operate in a normal operation mode to continuously perform communication in the communication units (61, 62) or in an intermittent operation mode to intermittently stop communication in the communication units (61, 62). When transition to the intermittent operation mode has been requested from the power conversion control unit 11 via the communication units, an operation mode setting unit in a main control unit 60 refers to the battery state data and the like, and prohibits transition to the intermittent operation mode if a battery current value is larger than a prescribed threshold value or abnormality such as overcharging has occurred.

Description

  The present invention relates to a battery control device.

  As shown in FIG. 16A, a system in which a power controller 903 including a power conversion circuit and a power conversion control unit is interposed between a power block 901 that outputs power and a power block 902 that receives power input. 900 (solar cell system etc.) has been put into practical use. In order to add a power storage function to this type of system 900, it is conceivable to connect a battery unit 904 made of a secondary battery to a power controller 903 as shown in FIG. A technique has also been proposed in which the host system control unit performs charge / discharge control while communicating with a part that manages the assembled battery (see Patent Document 1 below).

JP 2011-205827 A

  In the system as shown in FIG. 16B, in order to ensure the safety of the battery unit 904, the battery state should be monitored by performing communication for obtaining the battery state (battery current value, temperature, etc.). On the other hand, power saving is also important. In this regard, power saving can be achieved by using control that intermittently stops the battery state monitoring communication. When a battery management unit that mediates them is provided between the power controller 903 and the battery unit 904, an instruction regarding intermittent communication stop may be sent from the upper power controller 903 to the battery management unit. It is not always optimal to follow instructions from the system. Uniform intermittent communication stop according to an instruction from the host side may compromise the safety of the battery unit 904 or cause other problems.

  Therefore, an object of the present invention is to provide a battery control device capable of realizing power saving while ensuring safety and the like.

  A battery control device according to the present invention is a battery control device that monitors charge / discharge control of a battery unit including a secondary battery by a charge / discharge control unit and protects the battery unit, the battery unit and the charge / discharge The target operation mode is either a communication unit that communicates with each of the control units, a normal operation mode in which communication is continuously performed in the communication unit, or an intermittent operation mode in which communication in the communication unit is intermittently stopped. A control unit configured to perform communication in the communication unit according to the target operation mode, wherein the control unit satisfies the transition from the normal operation mode to the intermittent operation mode during the normal operation mode. When requested by the discharge control unit, the transition is prohibited under a predetermined prohibition condition.

  According to the present invention, it is possible to provide a battery control device capable of realizing power saving while ensuring safety and the like.

1 is a schematic overall configuration diagram of a power system according to an embodiment of the present invention. It is an internal block diagram of one battery unit. It is a figure which shows the structure of battery state data. It is a figure which shows the example of a connection method of the several battery unit which concerns on embodiment of this invention. It is a figure which shows the internal structural example of the battery management part and breaker part which concern on embodiment of this invention. It is a figure which shows the example of a procedure of communication using a battery management part. It is a figure for demonstrating the content of the response signal from a battery management part to a power conversion control part. FIGS. 5A and 5D for explaining the mode request signal, FIGS. 2B and 2E for explaining the mode notification signal, and FIG. 2C showing the operation mode setting unit. It is a figure which shows a mode that an active area and a sleep area come alternately in intermittent operation mode. It is a figure which shows the mode of the transition between normal operation | movement and intermittent operation | movement. It is a figure which shows the outline | summary of the exchange of the signal in connection with the 2nd application example of intermittent operation, and the transition prohibition to intermittent operation. It is a figure which shows a mode that software is hold | maintained in each of the main control part and the unit control part. It is an operation | movement flowchart of the battery management part which concerns on the 2nd application example of intermittent operation | movement. It is a figure which shows the outline | summary of the exchange of the signal in connection with the 3rd application example of intermittent operation | movement regarding the forced return to normal operation | movement. It is an operation | movement flowchart of the battery management part which concerns on the 3rd application example of intermittent operation | movement. It is a schematic block diagram of the conventional system which performs power conversion.

  Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to the drawings. In each of the drawings to be referred to, the same part is denoted by the same reference numeral, and redundant description regarding the same part is omitted in principle. In this specification, for simplification of description, a symbol or reference that refers to information, signal, physical quantity, state quantity, member, or the like is written to indicate information, signal, physical quantity, state quantity or Names of members and the like may be omitted or abbreviated.

  FIG. 1 is a schematic overall configuration diagram of a power system 1 according to an embodiment of the present invention. The power system 1 includes a power conversion control unit 11, a power conversion circuit 12, a battery management unit 21, a breaker unit 22, a battery block BB including one or more battery units BU, and a power block PB1 that outputs power. And a power block PB2 that receives power input. The power blocks PB1 and PB2 are connected to the power conversion circuit 12. The number of power blocks connected to the power conversion circuit 12 may be any number as long as it is 1 or more, and one power block may perform bidirectional power input / output with the power conversion circuit 12. FIG. 2 is an internal configuration diagram of one battery unit BU. Each battery unit BU is provided with a battery module 31 made of a secondary battery. In the present embodiment, discharging and charging means discharging and charging of the battery module 31 (more specifically, discharging and charging of each secondary battery in the battery module 31) unless otherwise specified. Therefore, for example, discharging and charging of the battery unit BU means discharging and charging of the battery module 31.

  The power conversion circuit 12 includes a plurality of switching elements such as field-effect transistors or insulated gate bipolar transistors, and performs power conversion processing under the control of the power conversion control unit 11. Run. The power conversion process includes a charging process and a discharging process.

  In the charging process, the power conversion circuit 12 converts the output power of the power block PB1 into desired DC power, and supplies the obtained DC power to each battery unit BU via the breaker unit 22. The power block PB1 is a power source that outputs AC power or DC power, and includes, for example, a commercial AC power supply and a solar cell unit. When each battery unit BU receives DC power based on the output power of the power block PB1, the battery unit BU is charged.

  In the discharge process, the power conversion circuit 12 receives the discharge power of each battery unit BU through the breaker unit 22, converts the received discharge power into desired DC power or AC power, and outputs it to the power block PB2. The power block PB2 is, for example, a load that consumes power, and is driven by output power from the power conversion circuit 12. The power conversion circuit 12 can also output the output power of the power block PB1 to the power block PB2 without going through the battery unit BU (at this time, predetermined power conversion can be performed).

  The power conversion control unit 11 performs operation control of the power conversion circuit 12 including control of power conversion processing. It can be said that the power conversion control unit 11 includes a charge / discharge control unit that controls charging and discharging of the battery unit BU.

The battery management unit 21 communicates with the power conversion control unit 11 via the communication line CL _S communicates with the respective battery units BU via the communication line CL _B. The battery management unit 21 receives battery state data (see FIG. 2) representing the state of the battery module 31 in each battery unit BU from each battery unit BU, and uses the received battery state data for the power conversion control unit 11. The data format is converted and transmitted to the power conversion control unit 11 (details of the battery state data will be described later).

The breaker unit 22 is a breaker (current breaker) interposed in series between the battery module 31 and the power conversion circuit 12 of each battery unit BU, and takes an on or off state. When the breaker unit 22 is on, each battery module 31 is connected to the power conversion circuit 12, and charging and discharging of each battery module 31 via the power conversion circuit 12 becomes possible. When the breaker unit 22 is turned off, the electric circuit between each battery module 31 and the power conversion circuit 12 is cut off, and charging and discharging of each battery module 31 via the power conversion circuit 12 becomes impossible. Instead of the breaker, the breaker portion 22 may be formed of a component capable of interrupting the electric circuit by an external signal such as a self-control protector (SCP) or a mechanical relay. The electric circuit between each battery module 31 and the power conversion circuit 12 includes a power line PL _B that is an electric circuit between each battery module 31 and the breaker unit 22, and a power line PL _S that is an electric circuit between the power conversion circuit 12 and the breaker unit 22. . The breaker unit 22 is turned on in principle. In the present embodiment, the breaker unit 22 is kept on unless otherwise specified.

The configuration of one battery unit BU will be described with reference to FIG. The battery unit BU is provided with each part referred by the codes | symbols 31-36. The battery module 31 includes one or more secondary batteries. The secondary battery forming the battery module 31 is any type of secondary battery, such as a lithium ion battery or a nickel metal hydride battery. The number of secondary batteries forming the battery module 31 may be one, but in this embodiment, the battery module 31 is composed of a plurality of secondary batteries connected in series. However, some or all of the secondary batteries included in the battery module 31 may be a plurality of secondary batteries connected in parallel. In the battery module 31, among the plurality of secondary batteries connected in series, the positive electrode of the secondary battery located on the highest potential side and the negative electrode of the secondary battery located on the lowest potential side are a pair in the battery unit BU. is connected to the power output terminal P _OUT, charging and discharging of the battery module 31 is made via the power output terminal P _OUT pair.

Between the battery module 31 and the pair of power input / output terminals P _OUT , a current sensor 33 that measures the value of the current flowing through the battery module 31 (hereinafter referred to as a battery current value), and a fuse 36 such as a self-control protector. And are interposed in series. A voltage sensor 34 is connected in parallel to both terminals of the battery module 31. The voltage sensor 34 measures a voltage value of the battery module 31 (hereinafter referred to as a battery voltage value). The battery voltage value is a terminal voltage value of the battery module 31, that is, a potential difference between the positive electrode of the secondary battery located on the highest potential side in the battery module 31 and the negative electrode of the secondary battery located on the lowest potential side. is there. However, the potential difference between the positive electrode and the negative electrode of each secondary battery of the battery module 31 (that is, the voltage value for each cell in the battery module 31) may also be measured and included in the battery state data. The battery module 31 is provided with a temperature sensor 35. The temperature sensor 35 measures the temperature of the battery module 31 (hereinafter referred to as battery temperature). The battery temperature is, for example, a surface temperature of a pack that wraps a plurality of secondary batteries in the battery module 31 or a temperature at a specific part in the battery module 31.

  The battery current value, battery voltage value, and battery temperature measured by the sensors 33, 34, and 35 are sent to the unit controller 32. The unit controller 32 generates battery state data (battery state information) based on the measured battery current value, battery voltage value, and battery temperature, and transmits the battery state data to the battery management unit 21. Battery state data is generated for each battery unit BU and transmitted to the battery management unit 21.

  FIG. 3 is a diagram illustrating a structure of battery state data transmitted from one battery unit BU. The battery state data in FIG. 3 is an example of the state data of the battery module 31 (data representing the state of the battery module 31), and includes information indicating the battery current value, the battery voltage value, and the battery temperature, It includes a remaining capacity data representing a remaining capacity or SOC (state of charge) of the battery module 31 that can be derived from the battery voltage value, and a battery state flag group including a plurality of flags. In the battery status flag group, a charge prohibition flag indicating whether or not charging of the battery module 31 should be prohibited, a discharge prohibition flag indicating whether or not discharging of the battery module 31 should be prohibited, and the battery module 31 is in an overcharged state. An overcharge flag indicating whether the battery module 31 is in an overdischarge state, an overcurrent flag indicating whether the battery module 31 is in an overcurrent state, or a battery temperature. Any of the inappropriate charging temperature flag indicating whether or not the temperature is not suitable for charging, the inappropriate discharging temperature flag indicating whether or not the battery temperature is not suitable for discharging, and any of the sensors 33, 34, and 35 are abnormal. A sensor error flag indicating whether or not a communication error has occurred, and a signal error flag indicating whether or not a communication abnormality has occurred. Each flag forming the battery state flag group takes a digital value (logical value) of 1 or 0.

  The initial value of each flag in the battery state flag group is zero. Processing for setting a value of 1 or 0 to a flag in the battery state flag group is referred to as flag setting processing for convenience of explanation. In each battery unit BU, the unit controller 32 performs flag setting processing for each flag in the battery state flag group based on the battery current value, battery voltage value, and battery temperature from the sensors 33, 34, and 35. However, the battery management unit 21 may perform flag setting processing for each flag in the battery state flag group. In this case, the battery management unit 21 applies to each flag in the battery state flag group for the battery unit BU based on the battery current value, the battery voltage value, and the battery temperature in the battery state data from a certain battery unit BU. Thus, flag setting processing can be performed.

When the battery block BB includes a plurality of battery units BU, a connection method between the plurality of battery units BU is arbitrary. However, in the following, as shown in FIG. 4, the battery block BB is provided with n battery units BU (hereinafter also referred to as battery units BU [1] to BU [n]) and n battery units BU. It is assumed that the battery units BU are connected in parallel to each other through the power line PL _B, and as a result, the parallel connection circuit of the n battery modules 31 is connected to the power conversion circuit 12 through the breaker unit 22. n is an integer of 2 or more. In FIG. 4, illustration of the sensor 33 and the like is omitted. Power line PL _B, the power output terminal P _OUT of the positive side of the battery unit BU is common-connected by the power line PL _B (+), the power output terminal P _OUT of the negative side of the battery unit BU is commonly connected Power line PL _B (−). The connection method of the n battery units BU via the power line PL _B is not limited to this, and a series connection circuit of a plurality of battery modules 31 can be included in the battery block BB.

The battery management unit 21 is connected via a communication line CL _B to each unit control section 32. At this time, it is preferable that n unit control units 32 in the battery units BU [1] to BU [n] are connected to the battery management unit 21 after being connected to each other by a daisy chain method or the like. By adopting such a connection configuration, the battery states of the plurality of battery units BU constituting the battery block BB can be handled as a set of battery state groups, so that more precise control is possible. However, the battery block BB may be formed so that the plurality of unit control units 32 are combined into one. In this case, even when a plurality of battery units BU are used, there is an advantage that the control is simplified because the battery management unit 21 has one communication target.

  FIG. 5 shows an internal configuration example of the battery management unit 21 and the breaker unit 22. The breaker part 22 is provided with each site | part referred by the codes | symbols 51-58. The battery management unit 21 includes each part referred to by reference numerals 60 to 68.

The power line PL _S includes a high-potential side power line PL _S (+) and a low-potential side power line PL _S (−). Power lines PL _B (+), PL _B (−), PL _S (+), and PL _S (−) are connected to breaker terminals 53, 54, 55, and 56, respectively. A breaker switch 51 is interposed in series between the breaker terminals 53 and 55, and a breaker switch 52 is interposed in series between the breaker terminals 54 and 56. The on-breaker unit 22, refers to the state in which the breaker switch 51 and 52 is a power line PL _B and PL _S turned on is connected, and the off-breaker 22, the breaker switch 51 and 52 is turned off The power lines PL _B and PL _S are not connected. The main control unit 60 can turn off the breaker switches 51 and 52 by applying a voltage V [12] described later to the coil 57 using a breaker trip circuit (not shown) under a predetermined condition. In addition, the unit control unit 32 of each battery unit BU can output a STOP signal when the degree of abnormality is large when an abnormality (overcharge or the like) occurs, and the breaker unit 22 is also turned off when the STOP signal is output. It is said. The main control unit 60 can recognize the on / off state of the breaker unit 22 by observing the state of the three-terminal switch 58 whose state is switched in conjunction with the on / off of the breaker switches 51 and 52. The switch 52 may be omitted, and the breaker terminals 54 and 56 may be directly connected without the breaker switch 52 being interposed.

The power line PL _S is connected to the converter 63 via a switch 66 including breaker terminals 55 and 56 and a field effect transistor. The main controller 60 controls the on / off state of the switch 66. When the switch 66 is on, the voltage between the terminals 55 and 56 is applied to the converter 63 as the input voltage V _IN , but when the switch 66 is off, the voltage between the terminals 55 and 56 is not supplied to the converter 63 (that is, V _IN = 0). When both the breaker unit 22 and the switch 66 are on, the converter 63 converts the input voltage V _IN into a voltage V [12] having a predetermined voltage value (for example, 12 VDC), and supplies the communication power supply circuit 64 with the voltage. Output. The communication power supply circuit 64 converts the voltage V [12] into a communication power supply voltage and outputs it to the communication units 61 and 62. The communication units 61 and 62 are driven using the communication power supply voltage as a drive voltage. In the example of FIG. 5, the communication power supply voltage includes a power supply voltage V [3.3] having a predetermined first voltage value (eg, 3.3 VDC) and a predetermined second voltage value (eg, 5 VDC). ) Having a power supply voltage V [5]. The regulator 65 is directly connected to the power line PL _S (that is, the breaker terminals 55 and 56) without going through the switch 66, and the voltage V _MAIN having a desired voltage value (for example, DC 5V) from the voltage between the breaker terminals 55 and 56. Is generated.

The main control unit 60 includes a CPU (Central Processing Unit) and the like, and is driven using the voltage V _MAIN as a drive voltage. The main control unit 60 controls the operation of the battery management unit 21 in addition to controlling the communication operation in the communication units 61 and 62. Communication unit 61, the battery unit BU connected to itself via the communication line CL _B (i.e., the unit controller 32) communicates with. The communication unit 62 communicates with the power conversion control unit 11 connected to itself via the communication line CL _S. Each battery unit BU notifies the main control unit 60 of an ID number unique to each battery unit BU, and the communication unit 61 can communicate with a desired battery unit BU using the ID number. Further, the output voltage V [12] of the converter 63 is supplied from the battery management unit 21 to each battery unit BU for driving each unit control unit 32.

  The temperature sensor 67 measures the temperature at a predetermined position in the battery management unit 21 (for example, the temperature of the board on which the main control unit 60 is mounted or the surface temperature of the casing of the battery management unit 21), and the measured temperature is measured by the main control unit. 60. The non-volatile memory 68 includes an EEPROM (Electrically Erasable Programmable Read-Only Memory) or the like.

[About communication]
Communication by the communication unit 61 (that is, communication between the battery management unit 21 and the battery unit BU) and communication by the communication unit 62 (that is, communication between the battery management unit 21 and the power conversion control unit 11) are independent from each other in full-duplex communication. However, in the present embodiment, it is assumed that they are half duplex communications independent of each other. Under the control of the main control unit 60, half-duplex communication by the communication unit 61 and half-duplex communication by the communication unit 62 are performed independently. As is well known, when half-duplex communication is performed between two blocks, transmission and reception cannot be performed simultaneously in each block. When one block is transmitting a signal, the other block is Be sure to be the signal receiver. Half-duplex communication by the communication units 61 and 62 can be made compliant with, for example, the RS-485 communication standard. In the half-duplex communication by the communication units 61 and 62, a master / slave method is adopted. Specifically, in communication by the communication unit 61, the battery management unit 21 (that is, the communication unit 61) is set as a master while the battery unit BU (that is, the unit control unit 32) is set as a slave, and the communication unit In communication by 62, the power conversion control unit 11 is set as a master, while the battery management unit 21 (that is, the communication unit 62) is set as a slave.

  With reference to FIG. 6, an example of a communication procedure using the communication units 61 and 62 will be described. In FIG. 6, the direction from the top to the bottom corresponds to the traveling direction of time. In the description of the communication procedure using FIG. 6, it is mainly assumed that the number of battery units BU is two for concrete explanation, but of course, the number may be other than two. Further, it is assumed that the ID number assigned to the battery unit BU [i] is “i” (i is an integer).

  The communication unit 61 sequentially transmits a command including a data request command to the plurality of battery units BU and executes basic communication processing for sequentially receiving response signals to the commands from the plurality of battery units BU. The basic communication process functions as a communication process for acquiring battery state data, and includes transmission of a command 311, reception of a response signal 312, transmission of a command 313, and reception of a response signal 314 as shown in FIG. 6.

More specifically, the basic communication process, first, sends a command 311 added with the ID number from the communication unit 61 "1" to the communication line CL _B. Of the battery units BU [1] to BU [n], only the battery unit BU [1] corresponding to the ID number “1” responds to the command 311, and the unit controller 32 of the battery unit BU [1] A response signal 312 including the latest battery state data in the battery unit BU [1] is returned. After receiving the response signal 312, the communication unit 61 sends a command 313 to which the ID number “2” is added to the communication line CL _B. Of the battery units BU [1] to BU [n], only the battery unit BU [2] corresponding to the ID number “2” responds to the command 313, and the unit control unit 32 of the battery unit BU [2] A response signal 314 including the latest battery state data in the battery unit BU [2] is returned. In the case of n = 2, the communication unit 61 receives the response signal 314 and ends the basic communication process for one time. However, when there is another battery unit BU, similar communication processing for other battery units BU is also included in the basic communication processing.

The communication unit 61 periodically and repeatedly executes basic communication processing at a predetermined interval INT _B (for example, every 1 second to several seconds). The main control unit 60 stores the battery state data received by the communication unit 61 in a buffer memory 70 including a DRAM (Dynamic Random Access Memory) provided in the battery management unit 21 (for example, the main control unit 60). To do. At this time, the battery state data stored in the buffer memory 70 may be updated each time reception is performed so that only the latest battery state data for each battery unit BU is held in the buffer memory 70.

The communication unit 62 receives a command 321 including a data request command from the power conversion control unit 11 independently of the communication of the communication unit 61. In response to receiving the command 321, the communication unit 62 transmits a response signal 322 including processed battery state data to the power conversion control unit 11. The processed battery state data (contents of the response signal 322) is generated by the main control unit 60 based on the latest battery state data stored in the buffer memory 70. The processed battery state data is data obtained by performing a predetermined data format conversion on the latest battery state data for n battery units BU, but the latest battery state data for n battery units BU itself. It may be. If no communication abnormality has occurred, the command 321 is periodically transmitted from the power conversion control unit 11 at a predetermined interval INT _S (for example, 1 second to several seconds interval) and received by the communication unit 62. The response signal 322 is periodically transmitted from the communication unit 62 to the power conversion control unit 11 at the same interval INT _S.

[Abnormality monitoring and protection]
The main control unit 60 monitors whether or not an abnormality has occurred in the battery block BB, the battery management unit 21, and the breaker unit 22 of the power system 1. Abnormalities monitored by the main controller 60 include occurrences of overcharge, overdischarge, overcurrent, temperature, sensor, and communication, all of which are battery unit BU. Alternatively, it may be regarded as belonging to an abnormality in the battery management unit 21.

The abnormality due to overcharging refers to a state in which the battery voltage value of any battery unit BU exceeds a predetermined reference voltage value V _THU for a predetermined time or more. The abnormality due to overdischarge refers to a state in which the battery voltage value of any battery unit BU has been below a predetermined reference voltage value V _THL for a predetermined time or more (V _THU > V _THL ). The abnormality due to overcurrent refers to, for example, a state in which the battery current value of any battery unit BU exceeds a predetermined reference current value I _THU for a predetermined time or more. The temperature abnormality refers to, for example, a state in which the battery temperature of any battery unit BU or the temperature measured by the temperature sensor 67 deviates from a predetermined temperature range for a predetermined time or more.

  The sensor abnormality includes abnormality of the sensors 33, 34, and 35 in any battery unit BU, and may include abnormality of the temperature sensor 67. For example, a state in which the battery current value, battery voltage value, or battery temperature measured by the sensor 33, 34, or 35 deviates from a predetermined current range, voltage range, or temperature range belongs to an abnormality of the sensor 33, 34, or 35. . Further, for example, a state where the measured temperature of the temperature sensor 67 deviates from a predetermined temperature range belongs to the abnormality of the temperature sensor 67.

  The communication abnormality includes a first communication abnormality that is a communication abnormality between the battery management unit 21 (that is, the communication unit 61) and the battery unit BU, and a communication between the power conversion control unit 11 and the battery management unit 21 (that is, the communication unit 62). And a second communication abnormality that is abnormal. The first communication abnormality includes, for example, a state where a response signal (for example, 312 or 314) from the battery unit BU with respect to a command (for example, 311 or 313) from the communication unit 61 is not received by the communication unit 61. The second communication abnormality includes, for example, a state in which a command 321 scheduled to be periodically transmitted from the power conversion control unit 11 is not received by the communication unit 62 for a predetermined time or longer.

  Based on the battery state data received from each battery unit BU, the measured temperature of the temperature sensor 67, and the communication state of the communication units 61 and 62, the main control unit 60 converts the request or notification regarding the charging or discharging of the battery module 31 into power conversion. It is included in the response signal 322 transmitted to the control unit 11. Specifically, based on the battery state data received from each battery unit BU and the temperature measured by the temperature sensor 67, the main control unit 60 detects an abnormality due to overcharge, an abnormality due to overdischarge, an abnormality due to overcurrent, a temperature abnormality and a sensor. Determine whether an abnormality has occurred. Further, the main control unit 60 determines whether or not the first or second communication abnormality has occurred based on the signal reception state by the communication units 61 and 62. The main control unit 60 generates a charge permission / prohibition signal 341 and a discharge permission / prohibition signal 342 reflecting these determination results, and includes the signals 341 and 342 in the response signal 322 (see FIG. 7). However, only one of the signals 341 and 342 may be included in the response signal 322. Further, a battery state data signal 343 representing the latest battery state data for each battery unit BU can be further included in the response signal 322 (see FIG. 7).

  Each of the signals 341 and 342 is a flag that takes a digital value (logical value) of 0 or 1. The signal 341 having a value of 0 functions as a charge permission signal for permitting charging of the battery module 31, and the signal 341 having a value of 1 functions as a charge prohibition signal indicating the necessity of prohibiting charging of the battery module 31. To do. The signal 342 having a value of 0 functions as a discharge permission signal that permits discharge of the battery module 31, and the signal 342 having a value of 1 functions as a discharge inhibition signal that indicates the necessity of prohibiting discharge of the battery module 31. To do. For example, when a charge prohibition flag having a value of 1 (see FIG. 3) indicates that charging should be prohibited, the main control unit 60 calculates the logical sum of n charge prohibition flags for n battery units BU. The value of the signal 341 can be set. When the discharge prohibition flag having a value of 1 (see FIG. 3) indicates that the discharge should be prohibited, the main control unit 60 outputs the logical sum of the n discharge prohibition flags for the n battery units BU as a signal 342. Value can be set.

  If the battery unit BU is overcharged, overdischarged, overcurrent or abnormal temperature, the charging process and / or the discharging process should be stopped from the viewpoint of protection of the battery unit BU. In addition, when a sensor abnormality or a communication abnormality occurs, there is a problem that the state of the battery unit BU to be protected is not accurately known. For this reason, it is not preferable in terms of safety to continuously execute the charging process and / or the discharging process. Therefore, when an abnormality occurs, the main control unit 60 substitutes 1 for either or both of the signals 341 and 342 in accordance with the type of abnormality that has occurred, thereby prohibiting charging or discharging from being performed by power conversion control. Seek to part 11. The power conversion control unit 11 controls the power conversion circuit 12 so that the charging process is immediately stopped when the received response signal 322 includes a charge prohibition signal (that is, a signal 341 having a value of 1). When the received response signal 322 includes a discharge inhibition signal (that is, a signal 342 having a value of 1), the power conversion circuit 12 is controlled so that the discharge process is immediately stopped.

  It can be said that the generation and transmission of the charge prohibition signal or the discharge prohibition signal by the battery management unit 21 correspond to the first protection operation for the battery unit BU. When the charge prohibition signal is transmitted in a state where the charging process is performed, or when the discharge prohibition signal is transmitted in a state where the discharge process is performed, the battery current value is quickly zero (or substantially includes zero) However, if there is a failure in the power conversion circuit 12 or the power conversion control unit 11 is not operating correctly, it will not be zero.

Considering this, the battery management unit 21 performs a second protection operation, which may be referred to as an additional protection process, after transmitting the charge inhibition signal or the discharge inhibition signal. The second protection operation will be described. In the second protection operation, the main controller 60 monitors the target current value I _TG, charge inhibition by the communication unit 62 the signal or the discharge prohibition signal target current value I _TG from the transmission timing by a predetermined time TH _TIME has passed the The breaker unit 22 can be switched from on to off when the magnitude of is not below the positive predetermined value I _TH . When the target current value I _TG is equal to or lower than the predetermined value I _TH after the elapse of the predetermined time TH _TIME from the transmission timing, the main control unit 60 can keep the breaker unit 22 on. In the case where the charge prohibition signal is transmitted from the communication unit 62, the target current value I _TG is a battery current value in charging for any one of the battery units BU, and the battery units BU [1] to BU [n] It may be a total value, an average value, or a maximum value of the battery current values in the measured charging. In the case where the discharge prohibition signal is transmitted from the communication unit 62, the target current value I _TG is the battery current value in the discharge for any one of the battery units BU, and the battery units BU [1] to BU [n] It may be a total value, an average value, or a maximum value of battery current values in the measured discharge.

  The main control unit 60 stores the latest battery state data received from each battery unit BU in the non-volatile memory 68 immediately before the switching when the breaker unit 22 is switched from on to off by the second protection operation or the like. It is good to keep. By using the stored data, it becomes easy to investigate the cause of the breaker unit 22 being turned off, and the recovery work is facilitated.

  As can be understood from the above description, the battery unit BU does not have a charge / discharge control function, and the charge / discharge control is mainly left to the power conversion control unit 11 and the power conversion circuit 12. The power conversion control unit 11 and the power conversion circuit 12 may be mounted on a device called a power controller, and a solar cell system is formed by the power controller and a solar cell unit that is an example of the power block PB1. (In this case, the power block PB2 is, for example, a load or a power system). A usage form such as forming a solar cell system with a power storage function by adding a battery unit to this type of solar cell system is conceivable. In such a usage form, a new solar cell system prepared separately is newly added. A form in which the battery unit BU is additionally connected to the battery is one practical example. When considering a solar cell system with a power storage function, power conversion control including charge / discharge control, power generation control and reverse power flow control for the solar cell unit is important for the entire system. Protection is also important. In particular, for example, when considering a mode in which the battery unit BU is connected to an existing solar cell system, there is still anxiety about the stability of protection simply by leaving the protection of the battery unit BU to the existing solar cell system side. In consideration of this, in this embodiment, the battery management unit 21 is provided as an intermediary between the power conversion control unit 11 and the power conversion circuit 12 and the battery unit BU, and the battery management unit 21 is mainly used for communication. A protection function (first and second protection operations) is realized.

[Normal operation mode and intermittent operation mode]
By the way, the battery management unit 21 (main control unit 60) operates in any one of a plurality of operation modes, and the operation mode actually used in the battery management unit 21 is referred to as a target operation mode. As shown in FIG. 8A, the command 321 for the battery management unit 21 includes a mode request signal for requesting which operation mode is set as the target operation mode (in other words, the operation mode to be the target operation mode). Mode designation signal) 361 for designating. The main control unit 60 selects and sets a target operation mode from among a plurality of operation modes according to the mode request signal 361 received from the power conversion control unit 11 via the communication unit 62. An operation mode setting unit 101 that performs this selection and setting is included in the main control unit 60 (see FIG. 8C). As shown in FIG. 8B, the communication unit 62 sends a mode notification signal 362 to the response signal 322 for notifying which operation mode is the current target operation mode under the control of the main control unit 60. And can be transmitted to the power conversion control unit 11.

  The plurality of operation modes that are candidates for the target operation mode include at least the normal operation mode and the intermittent operation mode, and the execution state of communication differs depending on the operation mode.

When the normal operation mode is set to the target operation mode, the battery management unit 21 executes the normal operation. In normal operation, communication is continuously performed by the communication units 61 and 62. The communication operation of the communication units 61 and 62 described with reference to FIG. 6 corresponds to a normal operation. That is, in the normal operation, the basic communication process in the communication unit 61 is periodically and repeatedly executed at a predetermined interval INT _B (for example, 1 second to several seconds), and at a predetermined interval INT _S (for example, 1 second to several seconds). ), The command 321 is periodically transmitted from the power conversion control unit 11 and received by the communication unit 62. As a result, the response signal 322 is periodically transmitted from the communication unit 62 to the power conversion control unit 11 at the same interval INT _S.

When the intermittent operation mode is set to the target operation mode, the battery management unit 21 executes the intermittent operation. In the intermittent operation, communication in the communication units 61 and 62 is intermittently stopped. More specifically, when the target operation mode is the intermittent operation mode, as shown in FIG. 9, an active period in which communication is performed in the communication units 61 and 62 and a sleep period in which communication in the communication units 61 and 62 is stopped. Visited alternately. The time length of one active section is called active time, and the time length of one sleep section is called sleep time. The sleep time is at least longer than the transmission interval of two commands (for example, commands 311 and 313 in FIG. 6) transmitted from the communication unit 61 in the normal operation mode. Furthermore, the sleep time may be set longer than the interval INT _B (and INT _S ). All sections in which the target operation mode is the normal operation mode belong to the active section.

  The main control unit 60 causes the execution state of communication in the communication units 61 and 62 to follow the target operation mode. Specifically, when the target operation mode is the normal operation mode, the main control unit 60 maintains the switch 66 (see FIG. 5) on to turn on the communication power supply voltages (V [3.3] and V [3.3]. 5]) is continuously generated. On the other hand, when the target operation mode is the intermittent operation mode, the main control unit 60 maintains the switch 66 on during the active period and turns off the switch 66 during the sleep period. As a result, in the active period, communication similar to that in the normal operation mode is performed by the communication units 61 and 62, but in the sleep period, the communication power supply voltage as the drive voltage is not supplied to the communication units 61 and 62. The transmission and reception operations by the communication units 61 and 62 do not function at all.

For example, the power conversion control unit 11 performs battery management so that intermittent operation is performed using transmission of the mode request signal 361 in a time zone in which the battery unit BU is expected to be completely or hardly discharged or not charged. The unit 21 can be instructed. As shown in FIG. 8D, the mode request signal 361 includes a normal operation request signal REQ _NOR requesting that the normal operation mode is set to the target operation mode, and an intermittent operation mode set to the target operation mode. It can be either the intermittent operation request signal REQ _INT requesting the above. As shown in FIG. 8E, the mode notification signal 362 includes a normal operation notification signal REP _NOR for notifying that the normal operation mode is set to the target operation mode, and the intermittent operation mode is set to the target operation mode. It can be either an intermittent operation notification signal REP _INT that notifies that the For example, when the signal 361 is a 1-bit signal, the signal 361 having the value “0” functions as the signal REQ _NOR , and the signal 361 having the value “1” functions as the signal REQ _INT (also for the signal 362). The same). FIG. 10 shows an outline of signal exchange related to transition between the normal operation mode and the intermittent operation mode. In the normal operation, the signals REQ _NOR and REP _NOR are exchanged. When the communication unit 61 receives the signal REQ _INT , the communication unit 61 returns to the notification signal REP _INT and shifts to the intermittent operation. Thereafter, when the communication unit 61 receives the signal REQ _NOR , the communication unit 61 returns to the normal operation while returning the notification signal REP _NOR . A mode request signal 361 (REQ _NOR or REQ _INT ) that can be transmitted from the power conversion control unit 11 during the sleep period is ignored by the power management unit 21.

  The plurality of operation modes may include operation modes other than the normal operation mode and the intermittent operation mode, and may include a sleep mode, for example. When the sleep mode is set to the target operation mode, main control is performed until a specific input is given to the battery management unit 21 from the outside (for example, until a specific signal is given from the power conversion control unit 11 to the main control unit 60). Unit 60 keeps switch 66 off.

  In the configuration example of FIG. 5, it can be said that the converter 63 and the communication power supply circuit 64 form a communication voltage generation unit that generates a drive voltage for the communication units 61 and 62 based on the discharge power of the battery unit BU. The main control unit 60 stops communication of the communication units 61 and 62 by stopping supply of discharge power to the communication voltage generation unit in the sleep period. In the intermittent operation, the power consumption of the converter 63 and the communication power supply circuit 64 itself in the sleep period and the power consumption of the parts driven by the generated voltages are eliminated, so that power saving can be achieved.

  Even during the execution period of the intermittent operation, the communication function and the protection function (first and second protection operations) of the battery management unit 21 are effective in the active period, as in the normal operation. However, in the sleep section, the communication function of the battery management unit 21 is disabled, and as a result, the protection function realized using the communication function is also disabled. For this reason, it is important to control the content of the intermittent operation and the feasibility of execution according to the situation in consideration of ensuring the safety of the battery unit BU.

  Hereinafter, some application examples related to the intermittent operation will be described. As long as there is no contradiction, the above items apply to each application example described below. As long as there is no contradiction, any of a plurality of application examples shown below can be combined with each other.

<< First application example of intermittent operation >>
A first application example regarding intermittent operation will be described. In intermittent operation, if the sleep interval is made longer, the power saving effect is enhanced. However, if the sleep interval in which the communication function and the protection function are invalidated is made too long, there is a high possibility that the control for securing the safety will be neglected. Considering this, the main control unit 60 according to the first application example variably sets at least one of the active time and the sleep time based on the battery state data when the intermittent operation mode is set to the target operation mode ( That is, it can be changed). Hereinafter, for simplification of description, a process of variably setting at least one of the active time and the sleep time by the main control unit 60 is referred to as a variable setting process. The battery state data used for the variable setting process may be the latest battery state data acquired by the main control unit 60 via the communication unit 61 at the timing when the variable setting process is performed. The main control unit 60 can perform the variable setting process at the start of the intermittent operation, and may perform the variable setting process at an arbitrary timing during the execution period of the intermittent operation.

A reference time REF _ACT (for example, 5 seconds) is defined for the active time, and a reference time REF _SLP (for example, 25 seconds) is defined for the sleep time. The reference times REF _ACT and REF _SLP may be times designated by the power conversion control unit 11. For example, when transmitting the intermittent operation request signal REQ _INT (see FIG. 8D), the power conversion control unit 11 may include a signal designating the reference times REF _ACT and REF _SLP in the command 321. Alternatively, the main control unit 60 may set the reference times REF _ACT and REF _SLP in advance. The main control unit 60 can perform variable setting processing according to the battery state data by setting the state in which the active time and the sleep time are matched with the reference times REF _ACT and REF _SLP , respectively, as an initial state. Hereinafter, the variable setting process will be described mainly assuming that n ≧ 2. However, n = 1 may be used (the same applies to other application examples described later). The active time and the sleep time may be set within a certain time (for example, 30 seconds), which is set as the total time of the active section 1 and the sleep section 1.

-Variable setting processing based on battery current value-
As the battery state data, the battery current value of each battery unit BU may be used. The battery current value represents a current value in charging or discharging the battery module 31 and has a zero value, a positive value (charging), or a negative value (discharging) (the same applies to other application examples described later). When the battery current value is used as the battery state data, the main control unit 60 sets the evaluation current value based on the battery current value of each battery unit BU. When n = 1, the evaluation current value is an absolute value of the battery current value of the battery unit BU [1]. When n ≧ 2, the evaluation current value is, for example, the total value, the average value, the maximum value, or any of the absolute values of the battery current values of the battery units BU [1] to BU [n].

The main control unit 60 compares the evaluation current value with a predetermined threshold value I _THA1 (I _THA1 ≧ 0). If the evaluation current value is _{equal to} or less than the threshold value I _THA1 , the reference times REF _ACT and REF _SLP are maintained as in the initial state. Is set to active time and sleep time. On the other hand, when the evaluation current value is larger than the threshold value I _THA1 , the main control unit 60 increases only the active time, decreases only the sleep time, or increases the active time and sleep time based on the initial state. Decrease. At this time, the increase amount of the active time and the decrease amount of the sleep time can be increased as the evaluation current value increases. Needless to say, increasing the active time based on the initial state means increasing the active time from the reference time REF _ACT , and decreasing the sleep time based on the initial state means the reference time REF _SLP. It means to reduce the sleep time.

When the evaluation current value is _{equal to} or greater than a predetermined threshold value I _THA2 (I _THA2 > I _THA1 ), the main control unit 60 may set the sleep time to zero. That is, even if the intermittent operation request signal REQ _INT is received by the communication unit 62, the target operation mode may be set to the normal operation mode to perform the normal operation.

-Variable setting processing based on battery temperature-
As the battery state data, battery temperatures of the battery units BU [1] to BU [n] (hereinafter also referred to as n battery temperatures) may be used.

The main control unit 60 determines whether or not each battery temperature belongs to a predetermined temperature range TMP _RNG . If all n battery temperatures belong to the temperature range TMP _RNG , as in the initial state, The reference times REF _ACT and REF _SLP are set to the active time and the sleep time. On the other hand, when there is a battery temperature that deviates from the temperature range TMP _RNG (hereinafter referred to as a deviation temperature) among the n battery temperatures, the main control unit 60 sets the active time based on the initial state. Increase only, decrease only sleep time, or increase active time and decrease sleep time. At this time, the amount of increase in the active time and the amount of decrease in the sleep time can be increased as the departure temperature moves away from the temperature range TMP _RNG . That is, when the departure temperature is higher than the upper limit temperature of the temperature range TMP _RNG , as the difference between the departure temperature and the upper limit temperature increases, the main control unit 60 increases the increase amount of the active time and the decrease amount of the sleep time. Can be enlarged. Similarly, when the departure temperature is lower than the lower limit temperature of the temperature range TMP _RNG , as the difference between the departure temperature and the lower limit temperature increases, the main control unit 60 increases the increase amount of the active time and the decrease of the sleep time. The amount can be expanded. In the case of n ≧ 2, the deviation temperature that determines the increase amount of the active time and the decrease amount of the sleep time is the maximum value or the minimum value of the n battery temperatures, and the temperature range TMP _RNG among the n battery temperatures. Is the battery temperature farthest from.

The temperature range TMP _RNG is, for example, a part (center portion) of a predetermined operable temperature range of the battery module 31. For example, when there is a battery temperature that deviates from the predetermined temperature range TMP _RNG2 among n battery temperatures, the main control unit 60 may set the sleep time to zero. That is, even if the intermittent operation request signal REQ _INT is received by the communication unit 62, the target operation mode may be set to the normal operation mode to perform the normal operation. The temperature range TMP _RNG2 includes the temperature range TMP _RNG and is wider than the temperature range TMP _RNG . The temperature range TMP _RNG2 may coincide with the above operable temperature range, or may be a part of the above operable temperature range.

-Variable setting processing based on remaining capacity data-
As the battery state data, remaining capacity data (hereinafter also referred to as n remaining capacity data) of the battery units BU [1] to BU [n] may be used. As described above, the remaining capacity data is data representing the remaining capacity or SOC of the battery module 31. As is well known, the SOC of the battery module 31 is the ratio of the remaining capacity to the full charge capacity of the battery module 31. When the remaining capacity data represents the value of the remaining capacity, the capacity range described later is a range in units of “A · h (ampere hour)”, and when the remaining capacity data represents the SOC value, the capacity described later. The range is a range having “%” as a unit.

The main control unit 60 determines whether or not each remaining capacity data belongs to a predetermined capacity range CP _RNG , and when all the n remaining capacity data belong to the capacity range CP _RNG , the initial state As described above, the reference times REF _ACT and REF _SLP are set to the active time and the sleep time. On the other hand, when there is remaining capacity data that deviates from the capacity range CP _RNG (hereinafter, referred to as deviated remaining capacity data) among the n remaining capacity data, the main control unit 60 uses the initial state as a reference. Thus, only the active time is increased, only the sleep time is decreased, or the active time is increased and the sleep time is decreased. At this time, the increase amount of the active time and the decrease amount of the sleep time can be increased as the deviation remaining capacity data moves away from the capacity range CP _RNG . That is, when the deviation remaining capacity data is larger than the upper limit value of the capacity range CP _RNG , the main control unit 60 increases the increase amount of the active time and the sleep time as the difference between the deviation remaining capacity data and the upper limit value increases. The amount of decrease can be increased. Similarly, when the deviation remaining capacity data is smaller than the lower limit value of the capacity range CP _RNG , the main control unit 60 increases the amount of increase in active time and sleep as the difference between the deviation remaining capacity data and the lower limit value increases. The amount of time reduction can be expanded. In the case of n ≧ 2, the deviation remaining capacity data defining the increase amount of the active time and the decrease amount of the sleep time is the maximum value or the minimum value of the n remaining capacity data, and among the n remaining capacity data, This is the remaining capacity data farthest from the capacity range CP _RNG .

Also, for example, when there is remaining capacity data that deviates from the predetermined capacity range CP _RNG2 in n remaining capacity data, the main control unit 60 may set the sleep time to zero. . That is, even if the intermittent operation request signal REQ _INT is received by the communication unit 62, the target operation mode may be set to the normal operation mode to perform the normal operation. The capacity range CP _RNG2 includes the capacity range CP _RNG and is wider than the capacity range CP _RNG . The SOC converted values of the upper limit and the lower limit of the capacity range CP _RNG2 are, for example, 100% (or 100% −Δ) and 0% (or 0% + Δ), respectively (Δ is “0 <Δ <0.5”) Satisfying a predetermined value).

-Variable setting processing based on battery voltage value-
As the battery state data, battery voltage values (hereinafter, also referred to as n battery voltage values) of the battery units BU [1] to BU [n] may be used. Since the battery voltage value, which is the terminal voltage value, changes depending on the remaining capacity data, the same processing as the variable setting process based on the remaining capacity data is possible.

That is, the main control unit 60 determines whether each battery voltage value belongs to a predetermined voltage range V _RNG , and when all n battery voltage values belong to the voltage range V _RNG , As in the initial state, the reference times REF _ACT and REF _SLP are set to the active time and the sleep time. On the other hand, when there are battery voltage values that deviate from the voltage range V _RNG (hereinafter referred to as deviation voltage values) among the n battery voltage values, the main control unit 60 uses the initial state as a reference. Increase only the active time, decrease only the sleep time, or increase the active time and decrease the sleep time. At this time, the increase amount of the active time and the decrease amount of the sleep time can be increased as the deviation voltage value moves away from the voltage range V _RNG . That is, when the deviation voltage value is higher than the upper limit value of the voltage range V _RNG , as the difference between the deviation voltage value and the upper limit value increases, the main control unit 60 increases the increase amount of the active time and the sleep time. The amount can be expanded. Similarly, when the deviation voltage value is lower than the lower limit value of the voltage range V _RNG , as the difference between the deviation voltage value and the lower limit value increases, the main control unit 60 increases the increase amount of the active time and the sleep time. The amount of reduction can be expanded. In the case of n ≧ 2, the deviation voltage value that determines the increase amount of the active time and the decrease amount of the sleep time is the maximum value or the minimum value of the n battery voltage values. This is the battery voltage value farthest from the range V _RNG .

Further, for example, when there are battery voltage values that deviate from the predetermined voltage range V _RNG2 among n battery voltage values, the main control unit 60 may set the sleep time to zero. . That is, even if the intermittent operation request signal REQ _INT is received by the communication unit 62, the target operation mode may be set to the normal operation mode to perform the normal operation. The voltage range V _RNG2 includes the voltage range V _RNG and is wider than the voltage range V _RNG . The upper limit of the voltage range V _RNG2 corresponds to a voltage level of overcharge or a voltage level close to overcharge, and the lower limit of the voltage range V _RNG2 corresponds to a voltage level of overdischarge or a voltage level close to overdischarge.

-Variable setting processing based on multiple indicators-
The variable setting process focusing on the battery current value, the battery temperature, the remaining capacity data, and the battery voltage value has been individually described. However, the main control unit 60 uses the battery current value as the first index and the battery as the second index. The variable setting process may be performed based on two or more of the temperature, the remaining capacity data as the third index, and the battery voltage value as the fourth index. For example, the main control unit 60 performs the variable setting process based on two or more indices out of the first to third indices or based on two or more indices out of the first, second, and fourth indices. It may be made. Even when the variable setting process is performed using two or more indices, the active time or the sleep time can be changed according to each index.

  In the first application example of intermittent operation and the second and third application examples described later, the battery state data is considered to include all of the first to fourth indices, but any of the first to fourth indices is arbitrary. May include only one, two, or three. The main control unit 60 can perform variable setting processing using an index included in the battery state data.

  Disabling the communication function and the protection function by setting the sleep period is not preferable from the viewpoint of protection, but if the charge / discharge current is zero or sufficiently small, even if the sleep time is long or active Even if the time is somewhat short, there are few problems. The same applies when the battery temperature is near the center of the operable temperature range or when the remaining capacity data or the battery voltage value is sufficiently far from the overcharge or overdischarge level. However, when the charge / discharge current is relatively large, or when the battery temperature is relatively close to the upper or lower limit of the operable temperature range, or the remaining capacity data or the battery voltage value is relatively close to the overcharge or overdischarge level. In some cases, the battery status should be monitored with high frequency while avoiding invalidation of the communication function and the protection function as much as possible. On the other hand, power saving by intermittent operation is very beneficial. The above-described variable setting process taking these into consideration makes it possible to maintain a good balance between battery protection and power saving (power saving can be achieved while ensuring the safety of the battery unit BU).

In the above example, the active time changes only in the increasing direction starting from the reference time REF _ACT , and the sleep time changes only in the decreasing direction starting from the reference time REF _SLP . If it is considered that there are few safety problems based on at least one of the indicators, the active time may be smaller than the reference time REF _ACT or the sleep time may be larger than the reference time REF _ACT. Also good. For example, when the evaluation current value is _{equal to} or less than the threshold value I _THA1 , the active time may be decreased from the reference time REF _ACT as the evaluation current value becomes smaller, or in addition to or in place of the decrease. The sleep time may be increased from the reference time REF _SLP .

<< Second application example of intermittent operation >>
A second application example regarding the intermittent operation will be described. All of the above items including the items described in the first application example of the intermittent operation are applied to the second application example as long as there is no contradiction. As described above, the target operation mode is set according to the mode request signal 361 in principle (see FIGS. 8A and 8D), but under circumstances where it is determined that the transition to the intermittent operation mode is not desirable. Then, it is better to ignore the transition instruction to the intermittent operation mode. In consideration of this, the operation mode setting unit 101 according to the second application example receives the intermittent operation request signal REQ _INT by the communication unit 62 during the normal operation mode, that is, the target operation by the mode request signal 361. When it is requested to shift the mode from the normal operation mode to the intermittent operation mode, it is determined whether or not a predetermined prohibition condition is satisfied. Then, when the prohibition condition is not satisfied, the operation mode setting unit 101 shifts the target operation mode from the normal operation mode to the intermittent operation mode according to the request signal REQ _INT . However, when the prohibition condition is satisfied, the operation mode setting unit 101 prohibits the transition of the target operation mode from the normal operation mode to the intermittent operation mode and maintains the target operation mode in the normal operation mode. Thus, for example, it is possible to recognize the transition to the intermittent operation only when it is determined that the intermittent operation is sufficiently safe, and the safety is increased. FIG. 11 shows an outline of signal exchange related to prohibition of transition to intermittent operation.

  Processing for determining whether or not a prohibited condition is satisfied is referred to as prohibited condition determination processing.

-Prohibition condition judgment processing based on battery status data-
The operation mode setting unit 101 can perform a prohibition condition determination process based on the battery state data. The battery state data used for the prohibition condition determination process may be the latest battery state data that the main control unit 60 acquires via the communication unit 61 at the timing when the prohibition condition determination process is performed. As the battery state data, a battery current value, a battery temperature, remaining capacity data, or a battery voltage value is used.

When the battery current value of each battery unit BU is used as the battery state data, the operation mode setting unit 101 compares the evaluation current value with a predetermined threshold value I _THB (I _THB ≧ 0) according to the method described above in the first application example. ). The operation mode setting unit 101 can determine that the prohibition condition is not satisfied when the evaluation current value is equal to or less than the threshold value I _THB , and can determine that the prohibition condition is satisfied when the evaluation current value is greater than the threshold value I _THB. .

When the battery temperatures (n battery temperatures) of the battery units BU [1] to BU [n] are used as the battery state data, the operation mode setting unit 101 determines whether each battery temperature belongs to a predetermined temperature range TMP _RNG. Determine whether. The operation mode setting unit 101 can determine that the prohibition condition is not satisfied when all n battery temperatures belong to the predetermined temperature range TMP _RNGB, and the temperature range TMP is _included in the n battery temperatures. _If there is a battery temperature that deviates from _RNGB , it can be determined that the prohibition condition is satisfied.

When the remaining capacity data (n remaining capacity data) of the battery units BU [1] to BU [n] is used as the battery status data, the operation mode setting unit 101 has each remaining capacity data belonging to a predetermined capacity range CP _RNGB . It is determined whether or not. The operation mode setting unit 101 can determine that the prohibition condition is not satisfied when all of the n remaining capacity data belong to the predetermined capacity range CP _RNGB, and the capacity is _included in the n remaining capacity data. If there is remaining capacity data that deviates from the range CP _RNGB , it can be determined that the prohibition condition is satisfied.

When the battery voltage values of the battery units BU [1] to BU [n] (n battery voltage values as n terminal voltage values) are used as the battery state data, the operation mode setting unit 101 determines each battery voltage value. Is in the predetermined voltage range V _RNGB . The operation mode setting unit 101 can determine that the prohibition condition is not satisfied when all of the n battery voltage values belong to the predetermined voltage range V _RNGB, and the voltage is _included in the n battery voltage values. When there is a battery voltage value that deviates from the range V _RNGB , it can be determined that the prohibition condition is satisfied.

The operation mode setting unit 101 is prohibited by using two, three, or four of the four indexes (first to fourth indexes) including the battery current value, the battery temperature, the remaining capacity data, or the battery voltage value. Condition determination processing may be performed. For example, when four indices are used, the evaluation current value is equal to or less than the threshold value I _THB , all n battery temperatures belong to the temperature range TMP _RNGB , and all n remaining capacity data Is in the capacity range CP _RNGB and all n battery voltage values belong to the voltage range V _RNGB. It is determined that the condition is satisfied.

  According to the prohibition condition determination process based on the battery state data described above, in a situation where it is better to continuously enable the communication function and the protection function, such as when the charge / discharge current is relatively large, the intermittent operation is started. Since the transition can be prohibited, the safety of the battery unit BU is ensured.

――Prohibition condition judgment process based on presence or absence of abnormality――
The operation mode setting unit 101 can perform a prohibition condition determination process based on whether there is an abnormality in the battery unit BU or the battery management unit 21. Specifically, when the intermittent operation request signal REQ _INT is received by the communication unit 62, the operation mode setting unit 101 is based on the battery state data received from each battery unit BU and the temperature measured by the temperature sensor 67. The presence / absence of occurrence of abnormality due to charging, abnormality due to overdischarge, abnormality due to overcurrent, temperature abnormality and sensor abnormality is determined, and the presence / absence of occurrence of the first communication abnormality is determined from the signal reception state by the communication unit 61. As described above, the temperature abnormality of the battery module 31 based on the temperature measured by the temperature sensor 35 (see FIG. 2) and the temperature of the battery management unit 21 based on the temperature measured by the temperature sensor 67 (see FIG. 5) are included in the temperature abnormality. There is an abnormality. Of the seven abnormalities consisting of an abnormality due to overcharge, an abnormality due to overdischarge, an abnormality due to overcurrent, a temperature abnormality in the battery module 31, a temperature abnormality in the battery management unit 21, a sensor abnormality and a first communication abnormality, any one or two Only three, four, five, or six abnormalities may be determined as to whether or not they have occurred.

  Then, the operation mode setting unit 101 is one of an abnormality due to overcharge, an abnormality due to overdischarge, an abnormality due to overcurrent, a temperature abnormality of the battery module 31, a temperature abnormality of the battery management unit 21, a sensor abnormality, and a first communication abnormality. When it is determined that the prohibition condition has occurred, it is determined that the prohibition condition is satisfied, and when it is determined that none of the abnormality has occurred, it can be determined that the prohibition condition is not satisfied.

  According to the prohibition condition determination process based on the presence / absence of an abnormality described above, it is possible to prohibit the transition to intermittent operation when an abnormality occurs, that is, in a situation where the communication function and the protection function should be enabled to prevent the progress of the abnormality. Therefore, the safety of the battery unit BU is ensured.

-Prohibition condition judgment processing related to software update processing-
As shown in FIG. 12A, software SFT _A that defines the operation content of the battery management unit 21 (particularly the main control unit 60) is stored in a program memory PM _{A including} a flash memory in the main control unit 60. . The main control unit 60 implements the operation and control of the main control unit 60 described above by executing the software SFT _A on an arithmetic processing device (CPU or the like) provided therein. Similarly, in each battery unit BU, software SFT _B defining the operation contents of the battery unit BU (in particular the unit control section 32) is stored in the program memory PM _B consisting of flash memory or the like in the unit control section 32. The unit control unit 32 executes the software SFT _B on an arithmetic processing device (CPU or the like) provided in the unit control unit 32, so that the operation and control of the unit control unit 32 described above (battery state data generation operation and battery (Including an operation of transmitting a signal including state data to the communication unit 61).

The power conversion control unit 11 transmits an update signal A _UPDATE that is a signal for updating the software SFT _A to the communication unit 62. Update signal A _UPDATE includes code signal and the updated software SFT _A requesting an update of the software SFT _A. When the update signal A _UPDATE is received by the communication unit 62, the main control unit 60 updates the software SFT _A using a predetermined boot loader program in accordance with the content of the update signal A _UPDATE . Similarly, the power conversion control unit 11 transmits an update signal B _UPDATE that is a signal for updating the software SFT _B to the communication unit 62. Of the update signal B _UPDATE, the update signal for the software SFT _B of the battery unit BU [i] is represented by the symbol B _UPDATE [i]. The update signal B _UPDATE [i] includes a signal for requesting the update of the software SFT _B of the battery unit BU [i] and the code of the updated software SFT _B. When the update signal B _UPDATE [i] is received by the communication unit 62, the main control unit 60 transmits the update signal B _UPDATE [i] to the battery unit BU [i] using the communication unit 61. To do. Unit control unit 32 of the battery unit BU [i] receives the update signal B _UPDATE [i], in accordance with the contents of the update signal B _UPDATE [i], using a predetermined boot loader program, own software SFT _B Update.

During the execution period of the software SFT _A update process (process for updating the software SFT _A ), the execution of the basic communication process is stopped, and the protection function using the basic communication process is disabled. Further, during the execution period of the update process of the software SFT _B of the battery unit BU [i] (the process for updating the software SFT _B ), the generation of the battery state data in the battery unit BU [i] and the battery unit BU [ i] to communication unit 61 (in other words, reception of battery state data from battery unit BU [i] by communication unit 61) stops, and battery state data of battery unit BU [i] The protection function corresponding to is disabled. In a state where the protection function is disabled in whole or in part, it is not desirable to recognize the transition to the intermittent operation that can cause further deterioration of the protection function.

Considering this, the operation mode setting unit 101 may perform the prohibition condition determination process based on whether the update process of the software SFT _A or SFT _B is being executed. More specifically, the operation mode setting unit 101 determines that the prohibition condition is satisfied during the execution period of the update process of the software SFT _A or SFT _B , and both of the update processes of the software SFT _A and SFT _B are performed. It may be determined that the prohibition condition is not satisfied during the non-execution period.

  According to the above, since the transition to the intermittent operation is prohibited during the execution period of the software update process in which the communication function should not be invalidated, the software can be correctly updated, and the battery unit The safety of BU does not deteriorate excessively.

-Operation flow-
FIG. 13 is an operation flowchart of the battery management unit 21 according to the second application example. When the intermittent operation request signal REQ _INT is received by the communication unit 62 during the normal operation (step S121) (Y in step S122), whether or not the prohibition condition is satisfied is determined (step S123). When the prohibition condition is not satisfied, the intermittent operation is started (step S124), but when the prohibition condition is satisfied, the normal operation is continued.

<< Third application example of intermittent operation >>
A third application example regarding the intermittent operation will be described. All of the above items including the items described in the first and second application examples of the intermittent operation are applied to the third application example as long as there is no contradiction. When the intermittent operation is performed according to the intermittent operation request signal REQ _INT, there is a possibility that the intermittent operation is not desired to be continued. Considering this, the operation mode setting unit 101 according to the third application example continuously determines and monitors whether or not a predetermined release condition is satisfied when the target operation mode is the intermittent operation mode. The operation mode setting unit 101 maintains the target operation mode in the intermittent operation mode when the predetermined release condition is not satisfied. However, when a predetermined release condition is satisfied, the operation mode setting unit 101 changes the target operation mode from the intermittent operation mode to the normal operation mode regardless of the reception state and contents of the mode request signal 361 in the communication unit 62. Transition. Accordingly, when the target operation mode is the intermittent operation mode and the predetermined release condition is satisfied, the mode request signal 361 (that is, the normal operation request signal REQ) instructing the transition to the normal operation mode of the target operation mode. _NOR ) is not received by the communication unit 62, the operation mode setting unit 101 shifts the target operation mode from the intermittent operation mode to the normal operation mode. As a result, for example, it becomes possible to forcibly return to normal operation in a situation where safety is a top priority, and safety is increased. Here, in a state where the communication unit 62 does not receive the mode request signal 361 (that is, the normal operation request signal REQ _NOR ) instructing the transition to the normal operation mode of the target operation mode, the intermittent operation request signal in the communication unit 62 is received. The communication unit 62 does not receive the mode request signal 361 itself due to the request that the target operation mode should be maintained in the intermittent operation mode by the reception of REQ _INT and the occurrence of the second communication abnormality. State. FIG. 14 shows an outline of signal exchange related to forced return to normal operation.

  The process for determining whether or not the release condition is satisfied (that is, the process for determining whether or not the release condition is satisfied) is referred to as a release condition determination process. The operation mode setting unit 101 may constantly monitor whether the release condition is satisfied or not during the intermittent operation execution period.

-Release condition judgment processing based on battery status data-
The operation mode setting unit 101 can perform a release condition determination process based on the battery state data. The battery state data used for the release condition determination process may be the latest battery state data that the main control unit 60 acquires via the communication unit 61 at the timing when the release condition determination process is performed. The operation mode setting unit 101 can perform a release condition determination process every time the latest battery state data is acquired via the communication unit 61.

The cancellation condition determination process based on the battery state data may be the same as the prohibition condition determination process based on the battery state data according to the second application example. The operation mode setting unit 101 can perform the release condition determination process based on at least one of the battery current value, the battery temperature, the remaining capacity data, and the battery voltage value included in the battery state data. The specific contents of the prohibition condition determination process based on the battery state data described in the second application example can be applied to the release condition determination process based on the battery state data. In this application, “prohibition condition” and “prohibition condition determination process” in the description of the second application example may be replaced with “cancel condition” and “cancel condition determination process” (that is, when the prohibition condition is satisfied, If the release condition is satisfied and the prohibition condition is not satisfied, it can be considered that the release condition is not satisfied). Therefore, when the above evaluation current value is larger than the threshold value I _THB, it may be determined that the release condition is satisfied.

  According to the release condition determination process based on the battery state data, in a situation where it is better to always monitor and protect the state of the battery unit BU, such as when the charge / discharge current is relatively large, the continuous execution thereof is not possible. Since it is forcibly shifted to a possible normal operation, the safety of the battery unit BU is ensured.

--Release condition judgment processing based on whether there is an abnormality--
The operation mode setting unit 101 can perform a release condition determination process based on whether there is an abnormality in the battery unit BU or the battery management unit 21. Specifically, during the execution of the intermittent operation, the operation mode setting unit 101 performs an overcharge abnormality, an overdischarge abnormality, an overdischarge based on the battery state data received from each battery unit BU and the temperature measured by the temperature sensor 67. The presence / absence of occurrence of abnormality due to current, temperature abnormality and sensor abnormality is determined. Then, the operation mode setting unit 101 determines whether or not the first and second communication abnormalities have occurred based on the signal reception state by the communication units 61 and 62. As described above, the temperature abnormality of the battery module 31 based on the temperature measured by the temperature sensor 35 (see FIG. 2) and the temperature of the battery management unit 21 based on the temperature measured by the temperature sensor 67 (see FIG. 5) are included in the temperature abnormality. There is an abnormality. Among eight abnormalities consisting of abnormality due to overcharge, abnormality due to overdischarge, abnormality due to overcurrent, temperature abnormality of battery module 31, temperature abnormality of battery management unit 21, sensor abnormality, first communication abnormality and second communication abnormality, Only one to seven abnormalities may be subject to determination as to whether or not they have occurred.

  Then, the operation mode setting unit 101 includes an abnormality due to overcharge, an abnormality due to overdischarge, an abnormality due to overcurrent, a temperature abnormality of the battery module 31, a temperature abnormality of the battery management unit 21, a sensor abnormality, a first communication abnormality, and a second communication. When it is determined that any of the abnormalities has occurred, it is determined that the release condition is satisfied, and when it is determined that none of the abnormalities has occurred, it is determined that the release condition is not satisfied. Also good.

  According to the cancellation condition determination process based on the presence / absence of an abnormality described above, when an abnormality occurs, that is, in a situation where the communication function and the protection function should be enabled and the progression of the abnormality should be stopped, they are forced to a normal operation that is always effective. Therefore, the safety of the battery unit BU is ensured.

--Release condition judgment process for software update process--
The operation mode setting unit 101 monitors whether an update signal A _UPDATE or B _UPDATE [i] that can be transmitted from the power conversion control unit 11 is received by the communication unit 62 during the intermittent operation execution period. The cancellation condition determination process may be performed based on whether or not the reception has been performed. That is, the operation mode setting unit 101 determines that the release condition is satisfied when the update signal A _UPDATE or B _UPDATE [i] is received by the communication unit 62, and when the reception is not received, the release condition is satisfied. You may decide not to. The state in which the update signal A _UPDATE or B _UPDATE [i] is received by the communication unit 62 is the update process of the software SFT _A or the battery unit BU [i] according to the update signal A _UPDATE or B _UPDATE [i]. It may be considered that the update process of the software SFT _B includes a state where it is actually executed.

  As described in the description of the second application example, in the software update process, the communication function should be maintained effectively. By forcibly returning to the normal operation when the software update signal is received, the software can be correctly updated, and the safety of the battery unit BU is not excessively lowered.

-Operation flow-
FIG. 15 is an operation flowchart of the battery management unit 21 according to the third application example. While the intermittent operation is being performed (step S131), whether the release condition is satisfied / not satisfied is determined (step S132). If the release condition is satisfied (Y in step S132), the intermittent operation is stopped and the normal operation is performed. This is performed (step S134). Even when the release condition is not satisfied, whether or not the normal operation request signal REQ _NOR is received is checked (step S133), and when the signal REQ _NOR is received by the communication unit 62, a transition to the normal operation is performed. .

  When designing the entire system including the power conversion control unit 11, the power conversion circuit 12, and the battery unit BU collectively, the power conversion control unit 11 considers ensuring the safety of the battery unit BU and the like according to the situation. Thus, it is possible to control whether or not the intermittent operation can be executed. However, a mode in which the battery unit BU is additionally connected to the existing solar cell system or the like as described above is also assumed. In such a mode, for example, “the power conversion control unit 11 simply checks only the current time, It is undeniable that “intermittent operation is required in anticipation that charging and discharging are hardly performed in the midnight hours” (in reality, charging and discharging may be performed, and abnormalities such as overdischarge may occur. May be). Therefore, it is important to provide the battery unit BU with protection not limited only to the instruction of the power conversion control unit 11. The transition prohibition process to the intermittent operation according to the second application example and the cancellation process of the intermittent operation according to the third application example contribute to provision of such protection.

<< Deformation, etc. >>
The embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiment is merely an example of the embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the above embodiment. The specific numerical values shown in the above description are merely examples, and as a matter of course, they can be changed to various numerical values. As annotations applicable to the above-described embodiment, notes 1 to 5 are described below. The contents described in each comment can be arbitrarily combined as long as there is no contradiction.

[Note 1]
When the breaker unit 22 is on, the switch 66 can be omitted so that the voltage generated by the discharge of the battery unit BU is always supplied to the converter 63 as the input voltage V _IN . In this case, the main control unit 62 may control the communication units 61 and 62 so that the communication operations (transmission operation and reception operation) by the communication units 61 and 62 are stopped in the sleep period. However, it is preferable to use the switch 66 in order to enhance the power saving effect.

[Note 2]
All or part of the components of the power system 1 (see FIG. 1) according to the present embodiment can be mounted on various other systems, devices, etc., for example, driven using the discharge power of the battery module 31 It may be mounted on a moving object (electric vehicle, ship, aircraft, elevator, walking robot, etc.) or electronic device (personal computer, portable terminal, etc.), or may be incorporated in a power system of a house or factory.

[Note 3]
In the above-described embodiment (see FIG. 1), it is assumed that the power block PB1 is a power block that outputs power and the power block PB2 is a power block that receives power input, but the power blocks PB1 and PB2 Each of these may be a power block capable of inputting and outputting power. In this case, the power conversion circuit 12 may be a circuit capable of bidirectional power conversion. That is, the power conversion circuit 12 converts the output power of the power block PB1 into input power to the power block PB2 or the battery block, and converts the output power of the power block PB2 into input power to the power block PB1 or the battery block. You may have a function and the function which converts the output electric power of a battery block into the input electric power to electric power block PB1 or PB2.

[Note 4]
A device including the battery management unit 21 and the breaker unit 22 can also be referred to as a battery control device. A system including the battery management unit 21, the breaker unit 22, and the battery block BB can also be referred to as a battery system. The communication units 61 and 62 may be considered to form one communication unit that communicates with each of the power conversion control unit 11 and the battery unit BU. A device including the power conversion control unit 11 and the power conversion circuit 12 can also be referred to as a power conversion device.

[Note 5]
The present invention is also applicable to an electric power system in which a plurality of breaker units 22 and battery blocks BB are provided. At this time, a plurality of breaker units 22 and a plurality of battery blocks BB may be provided for one power conversion circuit 12. In an electric power system provided with a plurality of breaker units 22 and battery blocks BB, a battery management unit 21 may be provided for each set of one breaker unit 22 and one battery block BB, or a plurality of breaker units 22 and One battery management unit 21 may be provided for a plurality of battery blocks BB.

DESCRIPTION OF SYMBOLS 1 Power system 11 Power conversion control part 12 Power conversion circuit 21 Battery management part 22 Breaker part 31 Battery module 60 Main control part 61, 62 Communication part 101 Operation mode setting part BU Battery unit PB1, PB2 Power block

Claims (8)

A battery control device that monitors charge / discharge control of a battery unit including a secondary battery by a charge / discharge control unit and protects the battery unit,
A communication unit that communicates with each of the battery unit and the charge / discharge control unit;
Either a normal operation mode in which communication is continuously performed in the communication unit or an intermittent operation mode in which communication in the communication unit is intermittently stopped is set as a target operation mode, and the communication unit in accordance with the target operation mode A control unit for performing communication,
The control unit prohibits the transition under a predetermined prohibition condition when the charge / discharge control unit requests the transition from the normal operation mode to the intermittent operation mode during the normal operation mode. A battery control device. The communication unit acquires state data of the secondary battery from the battery unit,
The control unit determines whether the prohibition condition is satisfied or not based on state data of the secondary battery or based on presence or absence of abnormality in the battery unit or the battery control device. The battery control device according to claim 1. The status data includes a current value of charging or discharging of the secondary battery, a temperature of the secondary battery, a remaining capacity data that is a remaining capacity or SOC of the secondary battery, and a terminal voltage value of the secondary battery. Including at least one of
The control unit determines whether the prohibition condition is satisfied or not based on at least one of the current value, the temperature, the remaining capacity data, and the terminal voltage value. The battery control device described in 1. The battery control according to claim 3, wherein the control unit determines that the prohibition condition is satisfied when a current value of charging or discharging of the secondary battery based on the state data is larger than a predetermined threshold value. apparatus. The controller determines that the prohibition condition is satisfied when an abnormality is recognized in the battery unit or the battery control device,
The abnormality in the battery unit or the battery control device is:
Abnormality due to overcharge of the secondary battery, abnormality due to overdischarge of the secondary battery, abnormality due to overcurrent of the secondary battery, temperature abnormality of the secondary battery, temperature abnormality of the battery control device, the secondary battery 5. The apparatus according to claim 2, comprising at least one of an abnormality of a sensor for detecting the state of the communication and an abnormality of communication between the communication unit and the battery unit. The battery control apparatus described. The control unit determines that the prohibition condition is satisfied during an execution period of a software update process that defines an operation content of the battery control device or an execution period of a software update process that defines an operation content of the battery unit. The battery control device according to any one of claims 1 to 5, wherein A communication voltage generator that generates a drive voltage for the communication unit based on the discharge power of the battery unit;
The intermittent operation mode includes an active period in which communication is performed and a sleep period in which communication is stopped,
The said control part stops communication of the said communication part by stopping supply of the said discharge electric power with respect to the said voltage generation part for communication in the said sleep area, The any one of Claims 1-6 characterized by the above-mentioned. The battery control device described in 1. A battery unit including a secondary battery;
A power conversion device that includes a charge / discharge control unit that controls charging and discharging of the secondary battery, and performs power conversion of power input or output to the battery unit;
A battery control device that monitors charge / discharge control of the battery unit by the charge / discharge control unit and protects the battery unit;
The battery control device includes:
A communication unit that communicates with each of the battery unit and the charge / discharge control unit;
Either a normal operation mode in which communication is continuously performed in the communication unit or an intermittent operation mode in which communication in the communication unit is intermittently stopped is set as a target operation mode, and the communication unit in accordance with the target operation mode A control unit that executes communication,
The control unit prohibits the transition under a predetermined prohibition condition when the charge / discharge control unit requests the transition from the normal operation mode to the intermittent operation mode during the normal operation mode. And power system.

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