JP2011069782A - Voltage monitoring circuit, and battery power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage monitoring circuit that can reduce the number of data transmitted to a control unit from a voltage detection unit than the number of secondary batteries in a battery pack wherein a plurality of secondary batteries are connected in series, and to provide a battery power supply device using the same. <P>SOLUTION: The voltage monitoring circuit includes a voltage measuring IC 22 for detecting terminal voltages Vc and total voltages Vt of secondary batteries 34 in each of battery blocks and a control unit 21. The control unit 21 includes: a voltage acquisition unit 211 for acquiring the respective terminal voltages Vc detected by the voltage measuring IC 22 via a transmission line L, a ratio calculation unit 212 for calculating respective ratios of the respective terminal voltages Vc to the total voltages Vt based on the terminal voltages Vc, a total voltage acquisition unit 213 for transmitting the total voltages Vt detected by the voltage measuring IC 22 to acquire the total voltages Vt, and a terminal voltage acquisition unit 214 for calculating and acquiring the respective terminal voltages Vc according to each of the ratios to the acquired total voltages Vt. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a voltage monitoring circuit for an assembled battery and a battery power supply device using the same.

  Conventionally, for example, a power source of an electric vehicle such as HEV (Hybrid Electric Vehicle), a non-stop power source device, or a battery power source device used for power adjustment in solar power generation or wind power generation, obtains a power source voltage of 100 V or more. Therefore, the battery pack is configured using an assembled battery in which a plurality of secondary batteries are connected in series. It is not uncommon for the number of secondary batteries included in such an assembled battery to exceed 100, for example.

  On the other hand, the secondary battery may be deteriorated or have a reduced safety depending on the state of charge thereof. Therefore, the secondary battery is included in the assembled battery in order to properly operate the battery power supply device as described above. It is necessary to monitor the terminal voltage of each secondary battery and grasp the state of each secondary battery.

  Therefore, a voltage detection unit for measuring the terminal voltage of each secondary battery is provided, and data indicating each terminal voltage measured by the voltage detection unit is transmitted to a control unit configured using a microcomputer or the like. A power supply device is known (for example, refer to Patent Document 1).

JP 2008-108591 A

  However, in the above-described power supply device, it is necessary to transmit data indicating the terminal voltage by the number of secondary batteries. Therefore, when a large number of secondary batteries are included, the amount of data indicating each terminal voltage increases, and the voltage detection unit There was a disadvantage that the communication load for transmitting data to the control unit increased.

  An object of the present invention is to provide a voltage monitoring circuit capable of making the number of data transmitted from the voltage detection unit to the control unit smaller than the number of secondary batteries in an assembled battery in which a plurality of secondary batteries are connected in series, and It is providing the battery power supply device using this.

  A voltage monitoring circuit according to the present invention includes an assembled battery including a battery block in which a plurality of secondary batteries are connected in series, an individual voltage detection process for detecting a terminal voltage of each secondary battery in the battery block, A voltage detection unit that performs a total voltage detection process for detecting a total voltage that is a terminal voltage between both ends of the battery block; and the individual voltage detection process, the total voltage detection process, and the secondarys by the voltage detection unit. A control unit that controls a transmission operation of information indicating a terminal voltage of the battery, and a transmission unit that transmits information between the voltage detection unit and the control unit, wherein the control unit includes the voltage detection unit The information indicating the terminal voltage of each secondary battery detected by the individual voltage detection processing by the voltage acquisition unit that acquires via the transmission unit, and each of the secondary batteries acquired by the voltage acquisition unit Terminal power The ratio calculation unit that calculates each ratio of the terminal voltage to the total voltage based on the information indicating the ratio, and after the ratio calculation unit calculates the ratio, the voltage detection unit periodically A total voltage acquisition unit that executes total voltage detection processing and transmits information indicating the detected total voltage from the voltage detection unit via the transmission unit, and acquires the total voltage; and the total voltage acquisition unit A terminal that executes a terminal voltage calculation process for calculating and acquiring a terminal voltage of each secondary battery according to each calculated ratio with respect to the acquired total voltage each time the total voltage is acquired by A voltage acquisition unit.

  According to this configuration, information indicating the terminal voltage of each secondary battery detected by the voltage detection unit is acquired by the voltage acquisition unit via the transmission unit. Then, each ratio of the terminal voltage to the terminal voltage across the battery block in which a plurality of secondary batteries are connected in series by the ratio calculation unit, that is, the total voltage equal to the sum of the terminal voltages of the secondary batteries. Is calculated.

  Here, in a battery block in which a plurality of secondary batteries are connected in series, the current flowing through each secondary battery is always equal. Therefore, even if the current flowing through the battery block changes, the ratio of the terminal voltage of each secondary battery does not change and is kept substantially constant.

  Then, after each ratio is calculated, the total voltage acquisition unit periodically detects the total voltage of the battery block by the voltage detection unit, and transmits information indicating the total voltage from the voltage detection unit via the transmission unit. The total voltage is acquired by the total voltage acquisition unit.

  Further, each time the total voltage is acquired by the total voltage acquisition unit, that is, periodically, the terminal voltage of the secondary battery is calculated by the terminal voltage acquisition unit according to the respective ratios to the acquired total voltage. Is obtained.

  In this case, since the ratio of the terminal voltage of each secondary battery is substantially constant, after each ratio is calculated, the terminal voltage of each secondary battery is not transmitted every period. Regardless, by periodically transmitting the total voltage of the battery block, the terminal voltage of each secondary battery can be calculated and acquired for each period according to each ratio to the total voltage. The number of data transmitted to the control unit can be made smaller than the number of secondary batteries.

  Further, the voltage detection unit includes a storage unit that stores a terminal voltage of each secondary battery detected by the individual voltage detection process, and the voltage acquisition unit performs the individual voltage detection process by the voltage detection unit. The terminal voltage of each secondary battery detected by execution is stored in the storage unit, and information indicating the terminal voltage of each secondary battery stored in the storage unit is sequentially and periodically transmitted through the transmission unit. To obtain the terminal voltage of each secondary battery over a plurality of periods, and the ratio calculation unit is configured to acquire the terminal voltage of all the secondary batteries by the voltage acquisition unit. The ratios are preferably calculated.

  If the terminal voltage of each secondary battery is detected sequentially and transmitted each time it is detected, the time difference between the timings at which each terminal voltage is detected increases depending on the communication time. And if the time difference of the timing at which each terminal voltage is detected increases, the current flowing through each secondary battery may change during that time. As described above, when the ratio calculation unit calculates each ratio based on each terminal voltage detected under different conditions of the flowing current, each ratio includes an error caused by a current change. There is a possibility that the calculation accuracy of each terminal voltage calculated based on the above will decrease.

  Therefore, according to this configuration, the terminal voltage of each secondary battery detected at one time by the individual voltage detection processing is stored by the storage unit before being transmitted to the control unit. Then, the information indicating each terminal voltage stored in the storage unit is sequentially and periodically transmitted to the control unit via the transmission unit, so that the voltage acquisition unit spans a plurality of cycles. The battery terminal voltage is obtained. In this case, the time difference in timing at which each terminal voltage is detected is shortened compared to the case in which each terminal voltage is transmitted each time it is detected. Therefore, there is a possibility that errors due to current changes are included in each terminal voltage. Reduced.

  Then, the ratio calculation unit calculates each ratio of each terminal voltage based on each terminal voltage in which the possibility of including an error due to the current change is reduced, so that an error caused by the current change is included in each ratio. As a result of the reduced possibility of being included, the possibility that the calculation accuracy of each terminal voltage is reduced is reduced. Moreover, since the information which shows each terminal voltage memorize | stored in the memory | storage part is transmitted sequentially periodically over several periods, possibility that the communication load by a transmission part will increase is reduced.

  In addition, the voltage acquisition unit, when the total voltage acquisition unit causes the voltage detection unit to periodically execute the total voltage detection process, at a timing corresponding to the number of secondary batteries, The storage unit newly stores the terminal voltage of each secondary battery detected by executing the individual voltage detection process by the voltage detection unit, and the total voltage acquisition unit stores the information indicating the total voltage. Synchronously with periodic transmission through the transmission unit, information indicating the terminal voltage of each secondary battery newly stored in the storage unit is sequentially and periodically transmitted through the transmission unit. By acquiring the terminal voltage of each secondary battery over a plurality of cycles, the ratio calculating unit obtains a new terminal voltage of all the secondary batteries every time the voltage acquiring unit acquires the terminal voltage. , Calculate each ratio Door is preferable.

  According to this configuration, after each ratio is once calculated by the ratio calculation unit, the voltage detection is performed periodically at a timing corresponding to the number of secondary batteries when the total voltage detection process is executed. Each terminal voltage detected by the unit is newly stored in the storage unit. Then, in synchronization with the information indicating the total voltage being periodically transmitted via the transmission unit (in parallel), the information indicating each terminal voltage newly stored in the storage unit is sequentially added to a plurality of pieces of information. It is transmitted via the transmission unit over a period. Then, in synchronization with the information indicating the total voltage in this way (in parallel), each time the terminal voltages transmitted over a plurality of periods are all acquired by the voltage acquisition unit, the ratio calculation unit Since each ratio is newly calculated, for example, even when the deterioration of each secondary battery progresses and the ratio of the terminal voltage of each secondary battery changes, each ratio is updated. The possibility that the calculation accuracy of each terminal voltage calculated based on the decrease will be reduced.

  In addition, a function unit for communicating with the control unit via the transmission unit is further provided, and the terminal voltage acquisition unit executes communication via the transmission unit between the control unit and the function unit. When the frequency is less than a preset reference frequency, each secondary battery detected by causing the voltage detection unit to periodically execute the individual voltage detection process without executing the terminal voltage calculation process When the terminal frequency detection process for acquiring the terminal voltage of the communication unit via the transmission unit is performed, and the frequency of communication via the transmission unit between the control unit and the functional unit is greater than the reference frequency It is preferable that the terminal voltage of each secondary battery is acquired by executing the terminal voltage calculation process.

  According to this configuration, when the execution frequency of communication via the transmission unit between the control unit and the function unit is less than the reference frequency, the communication load in the transmission unit can be reduced. Therefore, the terminal voltage acquisition unit actually acquires each terminal voltage periodically detected by the voltage detection unit by communication via the transmission unit, so that the voltage detection unit actually performs the transmission within the range of the communication capability of the transmission unit. Each detected terminal voltage can be acquired via the transmission unit. Further, when the execution frequency of communication between the control unit and the function unit via the transmission unit is higher than the reference frequency, the communication load in the transmission unit becomes heavy. Therefore, the terminal voltage acquisition unit calculates each terminal voltage from the total voltage detected by the voltage detection unit, thereby reducing the amount of data transmitted via the transmission unit, so that the communication data amount is the communication of the transmission unit. The possibility of exceeding the capacity can be reduced.

  The transmission unit can set a transmission rate of the information, and the control unit further includes an error rate detection unit that detects an error rate in information transmission using the transmission unit, and the terminal The voltage acquisition unit sets the transmission rate by the transmission unit to a preset first rate when the error rate detected by the error rate detection unit is less than a preset determination threshold, and the terminal voltage Without executing the calculation process, the terminal voltage detection process for acquiring the terminal voltage of each secondary battery detected by the voltage detection unit periodically executing the individual voltage detection process, and the error rate When the error rate detected by the detection unit exceeds the determination threshold, the transmission rate by the transmission unit is set to a second rate that is slower than the first rate, and the terminal voltage calculation process is executed. It may acquire a terminal voltage of each secondary battery.

  According to this configuration, when the error rate detected by the error rate detection unit is less than the determination threshold, that is, when the transmission of information is satisfactorily performed by the transmission unit, the terminal voltage acquisition unit transmits the transmission rate of the transmission unit. Is set to the first speed without lowering to the second speed. And each terminal voltage detected by the voltage detection part within the range of the communication capability of the transmission part by acquiring each terminal voltage periodically detected by the voltage detection part by communication via the transmission part. Can be obtained via the transmission unit. In addition, when the error rate detected by the error rate detection unit exceeds the determination threshold, that is, when the reliability of information transmission by the transmission unit is low, the terminal voltage acquisition unit makes the transmission rate by the transmission unit slower than the first rate. By setting the second speed to improve the reliability of information transmission and calculating each terminal voltage from the total voltage detected by the voltage detection unit, the amount of data transmitted through the transmission unit is reduced. Therefore, it is possible to reduce the possibility that the amount of communication data exceeds the communication capability of the transmission unit due to a decrease in transmission speed.

  The information processing apparatus further includes a functional unit for communicating with the control unit via the transmission unit, wherein the transmission unit can set a transmission speed of the information, and the control unit An error rate detection unit that detects an error rate in transmission of used information, and the terminal voltage acquisition unit presets an execution frequency of communication between the control unit and the functional unit via the transmission unit When the error rate detected by the error rate detection unit is less than a preset determination threshold, the transmission rate by the transmission unit is set to a preset first rate, Without executing the terminal voltage calculation process, the voltage detection unit periodically acquires the terminal voltage of each secondary battery detected by executing the individual voltage detection process, and the control unit and the function unit Between When the execution frequency of communication via the transmission unit is higher than the reference frequency, the terminal voltage calculation process is executed to obtain the terminal voltage of each secondary battery, which is detected by the error rate detection unit When the error rate exceeds the determination threshold, the transmission rate by the transmission unit is set to a second rate that is slower than the first rate, and the terminal voltage calculation process is performed, thereby It is preferable to obtain the terminal voltage.

  According to this configuration, when the communication frequency between the control unit and the function unit via the transmission unit is less than the reference frequency, and the error rate detected by the error rate detection unit is less than the determination threshold, When the communication load in the transmission unit is light and information transmission by the transmission unit is performed satisfactorily, the transmission speed of the transmission unit is set to the first speed without being reduced to the second speed. Then, the terminal voltage acquisition unit acquires each terminal voltage periodically detected by the voltage detection unit by communication via the transmission unit, so that the voltage detection unit actually performs the transmission within the range of the communication capability of the transmission unit. Each detected terminal voltage can be acquired via the transmission unit.

  And when the execution frequency of the communication via a transmission part between a control part and a function part is more than reference | standard frequency, the communication load in a transmission part becomes heavy. Therefore, the terminal voltage acquisition unit calculates each terminal voltage from the total voltage detected by the voltage detection unit, thereby reducing the amount of data transmitted via the transmission unit, so that the communication data amount is the communication of the transmission unit. The possibility of exceeding the capacity can be reduced.

  Further, when the error rate detected by the error rate detection unit exceeds the determination threshold, that is, when the reliability of information transmission by the transmission unit is low, the terminal voltage acquisition unit sets the transmission rate by the transmission unit to be slower than the first rate. By setting the second speed to improve the reliability of information transmission and calculating each terminal voltage from the total voltage detected by the voltage detection unit, the amount of data transmitted through the transmission unit is reduced. Therefore, it is possible to reduce the possibility that the amount of communication data exceeds the communication capability of the transmission unit due to a decrease in transmission speed.

  The function unit transmits temperature information indicating a temperature of the secondary battery to the control unit via the transmission unit, and the control unit transmits the temperature information transmitted from the function unit. A communication frequency adjusting unit that determines whether or not the secondary battery has a temperature abnormality based on the temperature, and increases the frequency at which the function unit transmits the temperature information more than the reference frequency when it is determined that the temperature abnormality is present. It is preferable to provide.

  According to this configuration, when it is determined that there is a temperature abnormality in the secondary battery based on the temperature information transmitted from the function unit, the frequency at which the temperature information is transmitted by the function unit by the communication frequency adjustment unit is higher than the reference frequency. Since it is increased, the real-time property of temperature monitoring when an abnormality occurs can be improved. At this time, since the execution frequency of the communication between the control unit and the function unit via the transmission unit is increased more than the reference frequency, the terminal voltage acquisition unit determines each terminal from the total voltage detected by the voltage detection unit. By calculating the voltage, as a result of reducing the amount of data transmitted through the transmission unit, the possibility that the communication data amount exceeds the communication capability of the transmission unit can be reduced.

  Further, the assembled battery is configured by connecting a plurality of the battery blocks in series, the plurality of voltage detection units are provided corresponding to the plurality of battery blocks, and the control unit includes the plurality of battery blocks. The voltage detection unit controls the individual voltage detection process, the total voltage detection process, and a transmission operation of information indicating the terminal voltage of each secondary battery, and the transmission unit includes the plurality of voltage detection units and the control. It is preferable to transmit the information to and from the unit.

  According to this configuration, even when the number of secondary batteries included in the assembled battery is increased, each secondary battery is distributed to a plurality of battery blocks, and a plurality of voltage detection units corresponding to each battery block. Since each voltage detection unit can perform an individual voltage detection process and a total voltage detection process, respectively, by increasing the number of voltage detection units according to the increase in the number of secondary batteries, It is easy to enhance the processing capability of the individual voltage detection process and the total voltage detection process.

  Moreover, the battery power supply device which concerns on this invention is provided with the voltage monitoring circuit in any one of the above-mentioned, and the said assembled battery.

  According to this configuration, in the battery power supply device including the assembled battery in which a plurality of secondary batteries are connected in series, the number of data transmitted from the voltage detection unit to the control unit can be made smaller than the number of secondary batteries. .

  The voltage monitoring circuit and the battery power supply device having such a configuration include an assembled battery in which a plurality of secondary batteries are connected in series, and a voltage detection unit that detects a terminal voltage of each secondary battery. The number of data transmitted to the control unit can be made smaller than the number of secondary batteries.

It is a block diagram which shows an example of a structure of the battery power supply device using the voltage monitoring circuit which concerns on one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is a flowchart which shows an example of operation | movement of the battery power supply device shown in FIG. It is explanatory drawing for demonstrating the terminal voltage detection process shown in FIG. It is explanatory drawing for demonstrating the terminal voltage calculation process shown in FIG.4, FIG.5, FIG.6.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted. FIG. 1 is a block diagram showing an example of a configuration of a battery power supply device using a voltage monitoring circuit according to an embodiment of the present invention. The battery power supply device 1 shown in FIG. 1 is a power supply for various battery-equipped devices such as an uninterruptible power supply device, a portable personal computer, a digital camera, an electronic device such as a mobile phone, a vehicle such as an electric vehicle and a hybrid car, It is used for various purposes such as power adjustment of power generators.

  A battery power supply device 1 shown in FIG. 1 includes a voltage monitoring circuit 2, connection terminals 31 and 32, switching elements Q1 and Q2, an assembled battery B, and temperature sensors 35a and 35b. The voltage monitoring circuit 2 includes a control unit 21, voltage measurement ICs (Integrated Circuits) 22a and 22b (voltage detection units), temperature measurement ICs 23a and 23b (functional units), and a transmission line L.

  The connection terminal 31 is connected to the positive electrode of the assembled battery B via the switching elements Q1 and Q2, and the negative electrode of the assembled battery B is connected to the connection terminal 32. As a result, a current path from the connection terminal 31 to the connection terminal 32 via the switching elements Q1 and Q2 and the assembled battery B is configured.

  The connecting terminals 31 and 32 are connected to a charging unit such as a charger or a power generation device that supplies a charging current to the assembled battery B, a load circuit that operates by supplying power from the assembled battery B, and the like. Charging / discharging is performed.

  The charging unit connected to the connection terminals 31 and 32 may be, for example, a power supply circuit that generates a charging current for the assembled battery B from a commercial power supply voltage, and generates power based on natural energy such as sunlight, wind power, or hydraulic power. It may be a power generation device or a power generation device that generates electric power using power from an internal combustion engine or the like.

  The load circuit connected to the connection terminals 31 and 32 is an assembled battery in battery-equipped devices such as electronic devices such as portable personal computers, digital cameras, and mobile phones, and vehicles such as electric vehicles and hybrid cars. It may be a load circuit that operates by supplying power from B, or may be a load circuit that operates by supplying power from an uninterruptible power supply or a power generator.

  The connection terminals 31 and 32 may be wiring patterns such as lands and pads in addition to the terminal block and the connector.

  As the switching elements Q1 and Q2, for example, p-channel FETs (Field Effect Transistors) are used. In the switching element Q1, the cathode of the parasitic diode is directed to the connection terminal 31. When the switching element Q1 is turned off, only the current in the charging direction of the assembled battery B is cut off. In the switching element Q2, the cathode of the parasitic diode is directed to the assembled battery B. When the switching element Q2 is turned off, only the current in the discharge direction of the assembled battery B is cut off.

  As the switching elements Q1 and Q2, various switching elements such as contactors and relay switches can be used. Moreover, it is not restricted to the example divided into the switching element for charge directions, and the switching element for discharge directions.

  The assembled battery B is configured by connecting a battery block 33a and a battery block 33b in series. Each of the battery blocks 33a and 33b includes a plurality of, for example, seven secondary batteries 34 connected in series.

  As the secondary battery 34, various secondary battery cells such as a lithium ion secondary battery and a nickel hydride secondary battery are used. The secondary batteries 34 included in the battery blocks 33a and 33b have the same configuration, and in principle, batteries having the same characteristics such as full charge capacity and internal resistance value are used.

  The number of battery blocks included in the assembled battery B may be one or three or more. In addition, the assembled battery B may be an assembled battery in which a plurality of battery blocks are connected in parallel, or may be an assembled battery connected in combination of series and parallel.

  The secondary battery 34 is not necessarily a unit cell (cell). For example, a plurality of unit cells may be connected in series or in parallel, and the series and parallel are combined and connected. It may be.

  The temperature sensors 35a and 35b are temperature sensors configured using, for example, a thermistor or a thermocouple. The temperature sensors 35a and 35b are disposed in close contact with, for example, the battery blocks 33a and 33b or in the vicinity of the battery blocks 33a and 33b, respectively. And temperature sensor 35a, 35b detects the temperature of battery block 33a, 33b, and outputs the voltage signal which shows the temperature value to temperature measurement IC23a, 23b, respectively.

  The voltage measurement ICs 22a and 22b (voltage detection units) include individual voltage detection units 221a and 221b, total voltage detection units 222a and 222b, storage units 223a and 223b, and communication units 224a and 224b. The temperature measurement ICs 23a and 23b (functional units) include temperature detection units 231a and 231b and communication units 232a and 232b.

  In addition, although the voltage measurement IC 22a, the temperature measurement IC 23a, the voltage measurement IC 22b, and the temperature measurement IC 23b are illustrated as examples of separate integrated circuits, the voltage measurement IC 22a (voltage detection unit) and the temperature measurement IC 23a (functional unit) are illustrated. Each of the voltage measurement IC 22b (voltage detection unit) and the temperature measurement IC 23b (functional unit) may be configured as one integrated circuit.

  The control unit 21 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores a predetermined control program, and a RAM (Random Access Memory) that temporarily stores data. And a communication circuit and peripheral circuits thereof.

  Then, the control unit 21 executes a control program stored in the ROM, thereby performing a voltage acquisition unit 211, a ratio calculation unit 212, a total voltage acquisition unit 213, a terminal voltage acquisition unit 214, a protection control unit 215 (communication frequency adjustment) Function), an error rate detection unit 216, and a communication unit 218.

  The voltage measurement IC 22a and the voltage measurement IC 22b, the temperature sensor 35a and the temperature sensor 35b, and the temperature measurement IC 23a and the temperature measurement IC 23b are configured similarly. The voltage measurement IC 22a, the temperature sensor 35a, and the temperature measurement IC 23a are provided corresponding to the battery block 33a, and the voltage measurement IC 22b, the temperature sensor 35b, and the temperature measurement IC 23b are provided corresponding to the battery block 33b. Yes.

  The communication units 218, 224 a, 224 b, 232 a, and 232 b are communication interface circuits connected to each other by a bus type transmission line L. The communication units 218, 224a, 224b, 232a, 232b allow data transmission / reception by performing communication via the transmission line L between the control unit 21 and the voltage measurement ICs 22a, 22b and the temperature measurement ICs 23a, 23b. Has been.

  In this case, the communication units 218, 224a, 224b, 232a, 232b, and the transmission line L correspond to an example of the transmission unit.

  The communication units 218, 224a, 224b, 232a, and 232b can use various communication methods such as synchronous or asynchronous serial communication. The communication units 224a, 224b, 232a, and 232b transmit the transmission data with a parity bit and a cyclic code added thereto, and the reception-side communication unit 218 uses the parity bit and the cyclic code added to the transmission data. The transmission error is detected.

  The communication units 218, 224a, 224b, 232a, and 232b can set the data transmission speed. Specifically, for example, when a synchronous communication method is employed, the communication unit 218 changes the frequency of the synchronous clock signal transmitted to the communication units 224a, 224b, 232a, and 232b, so that the data The transmission speed may be changed. For example, when an asynchronous communication method is employed, the communication unit 218 changes the data transmission rate by notifying and setting the transmission rate to the communication units 224a, 224b, 232a, and 232b. You may make it make it.

  1 shows an example in which the communication units 218, 224a, 224b, 232a, and 232b form a bus topology by the transmission line L, but various topologies such as a daisy chain may be used. it can.

  First, the voltage measurement ICs 22a and 22b will be described. The individual voltage detection units 221a and 221b and the total voltage detection units 222a and 222b are configured using, for example, a multiplexer, an analog digital converter, or the like. Then, the individual voltage detection units 221a and 221b execute individual voltage detection processing for detecting the cell voltage Vc that is the terminal voltage of each secondary battery 34 in the battery blocks 33a and 33b.

  Specifically, the individual voltage detectors 221a and 221b, for example, select each end of each secondary battery 34 in the battery blocks 33a and 33b sequentially by using, for example, a multiplexer and connect it to an analog-digital converter. An individual voltage detection process for converting the 34 cell voltage Vc into a digital value and detecting it is executed.

  The individual voltage detection units 221a and 221b store the data indicating the cell voltages Vc thus obtained in the storage units 223a and 223b, or are controlled by the communication units 224a and 224b via the transmission line L. To be transmitted to the unit 21.

  The total voltage detection units 222a and 222b execute total voltage detection processing for detecting each total voltage Vt that is a terminal voltage between both ends of the battery blocks 33a and 33b.

  Specifically, the total voltage detectors 222a and 222b, for example, select terminals at both ends of the battery blocks 33a and 33b by using, for example, a multiplexer and connect them to the analog-digital converter, whereby each of the battery blocks 33a and 33b. A total voltage detection process for converting the total voltage Vt into a digital value and detecting it is executed. Note that the total voltage detection units 222a and 222b, for example, sum the cell voltages Vc of the respective secondary batteries 34 detected by the individual voltage detection units 221a and 221b, respectively, thereby calculating the total voltages Vt of the battery blocks 33a and 33b. May be detected.

  The storage units 223a and 223b are configured using, for example, a RAM (Random Access Memory) or a register.

  Next, the temperature measurement ICs 23a and 23b will be described. The temperature detection units 231a and 231b are configured using, for example, an analog-digital converter. And according to the request | requirement from the control part 21, the voltage signal which shows the temperature value output from the temperature sensors 35a and 35b is converted into a digital signal, and the digital data which shows the said temperature is transmitted to the transmission line by the communication parts 232a and 232b. The data is transmitted to the control unit 21 via L.

  Next, the control unit 21 will be described. The voltage acquisition unit 211 transmits a request signal for requesting each cell voltage Vc in the battery blocks 33a and 33b and the total voltage Vt to the voltage measurement ICs 22a and 22b via the transmission line L by the communication unit 218. The cell voltage Vc and the total voltage Vt are transmitted from the voltage measurement ICs 22a and 22b.

  The voltage acquisition unit 211 normally transmits the request signal for requesting each cell voltage Vc to the voltage measurement ICs 22a and 22b periodically, for example, once every 10 msec, so that the individual voltage detection units 221a and 221a, The individual voltage detection process is executed by 221b. Each cell voltage Vc obtained in this way is transmitted via the transmission line L by the communication units 224a and 224b, so that a communication frequency set in advance between the voltage acquisition unit 211 and the voltage measurement ICs 22a and 22b. The communication is executed with.

  As a result, the voltage acquisition unit 211 uses the delay time required for monitoring each cell voltage Vc in the battery pack B in the normal state, for example, a delay time within 10 msec. It can be acquired.

  Here, as described above, the control unit 21 and the temperature measurement ICs 23a and 23b are separately provided within a range not exceeding the communication capability of the communication unit 218 in parallel with the individual voltage detection process being periodically executed. The communication frequency at which communication can be performed between the two is preset as a reference frequency.

  The ratio calculation unit 212 sums the cell voltages Vc of the secondary batteries 34 in the battery blocks 33a and 33b acquired by the voltage acquisition unit 211, for example, for each battery block, so that the total voltages of the battery blocks 33a and 33b. Vt is calculated, and each ratio of the cell voltage Vc of each secondary battery 34 to the total voltage Vt is calculated for each battery block.

  The total voltage acquisition unit 213 causes the voltage measurement ICs 22a and 22b to periodically transmit a request signal for the total voltage Vt through the communication unit 218, whereby the total voltage detection units 222a and 222b periodically perform total voltage detection processing. Is executed. The total voltage acquisition unit 213 acquires the total voltage Vt by causing the communication units 224a and 224b to transmit the total voltage Vt of the battery blocks 33a and 33b detected by the total voltage detection units 222a and 222b.

  The protection control unit 215 sends a request signal for requesting temperature data to the temperature measurement ICs 23a and 23b by the communication unit 218 at a communication frequency of the first frequency set to once per second, for example, at normal times. Send it. Then, in the temperature measurement ICs 23a and 23b, the request signals are received by the communication units 224a and 224b, and the temperature detection units 231a and 231b receive the temperatures ta and tb of the battery blocks 33a and 33b based on the output signals of the temperature sensors 35a and 35b. Is detected. The temperatures ta and tb obtained in this way are transmitted to the control unit 21 by the communication units 224a and 224b and received by the communication unit 218, respectively.

  In this case, data transmission / reception is executed between the control unit 21 and the temperature measurement ICs 23a and 23b via the transmission line L at a first frequency of once per second.

  Then, for example, when at least one of the temperatures ta and tb received by the communication unit 218 exceeds a preset determination temperature tj, the protection control unit 215 determines that a temperature abnormality has occurred and performs switching. The elements Q1 and Q2 are turned off, and charging / discharging of the assembled battery B is prohibited. For example, 60 ° C. is set as the determination temperature tj.

  Furthermore, when the protection control unit 215 determines that a temperature abnormality has occurred, the protection control unit 215 increases the transmission frequency of the temperature data request signal to the temperature measurement ICs 23a and 23b, for example, to the second frequency set once every 100 msec. Let

  Here, the above-described reference frequency is set as, for example, once every 200 msec. When a temperature abnormality occurs, the communication frequency between the control unit 21 and the temperature measurement ICs 23a and 23b exceeds the reference frequency. .

  Further, for example, when any of the cell voltages Vc detected by the terminal voltage acquisition unit 214 exceeds the full charge voltage of the secondary battery 34, the protection control unit 215 turns off the switching element Q1 to perform charging. By prohibiting, overcharge of the secondary battery 34 is prevented.

  In addition, the protection control unit 215, for example, the discharge prohibition voltage Voff that is set in advance in order to prevent the secondary battery 34 from being overdischarged, for example, of each cell voltage Vc detected by the terminal voltage acquisition unit 214. In the following cases, the switching element Q2 is turned off to inhibit discharge, thereby preventing the secondary battery 34 from being deteriorated due to overdischarge.

  The error rate detection unit 216 detects an error rate Er in information transmission using the transmission line L. Specifically, the error rate detection unit 216 counts, for example, the number N of times data is received by the communication unit 218 and the number Ne of times when a transmission error is detected by the communication unit 218 when the data is received. Then, the error rate Er is calculated by dividing the number Ne by the number N.

  The terminal voltage acquisition unit 214 normally sets the transmission rate by the communication unit 218 to a first rate of 50 kbps, for example, and the cell voltage Vc is supplied to the voltage measurement ICs 22a and 22b by the voltage acquisition unit 211 at a cycle of, for example, 10 msec. The cell voltage Vc is acquired by executing a terminal voltage detection process for transmitting the cell voltage Vc from the voltage measurement ICs 22a and 22b. The cell voltage Vc for one cell is represented by 2 bytes, for example.

  On the other hand, for example, when the protection control unit 215 determines that a temperature abnormality has occurred, as described above, the communication frequency between the control unit 21 and the temperature measurement ICs 23a and 23b exceeds the reference frequency. .

  Therefore, when the terminal voltage acquisition unit 214 determines that the temperature abnormality has occurred, for example, by the protection control unit 215, the communication frequency between the control unit 21 and the temperature measurement ICs 23a and 23b exceeds the reference frequency. Instead of periodically requesting transmission of each cell voltage Vc, the cell voltage Vc of each secondary battery 34 in the battery blocks 33a and 33b is calculated and acquired by the terminal voltage calculation process described below.

  In the terminal voltage calculation process, the battery block 33a is obtained by multiplying the total voltage Vt of each battery block acquired by the total voltage acquisition unit 213 by each ratio in each battery block calculated by the ratio calculation unit 212. , 33b, the cell voltage Vc of each secondary battery 34 is calculated.

  Hereinafter, the period in which the terminal voltage detection process is executed, the period in which the total voltage Vt is acquired by the total voltage acquisition unit 213, and the period in which the terminal voltage calculation process is executed are each referred to as a communication cycle.

  In addition, although the terminal voltage acquisition part 214 showed the example which calculates each cell voltage Vc by a terminal voltage calculation process, when it determines with the temperature abnormality having generate | occur | produced by the protection control part 215, for example, the communication part 218 was shown. The cell frequency Vc may be calculated by the terminal voltage calculation process when the communication frequency exceeds the reference frequency.

  In addition, when the error rate Er detected by the error rate detection unit 216 exceeds a preset determination threshold value Ej, the terminal voltage acquisition unit 214 determines the transmission rate by the communication units 218, 224a, 224b, 232a, 232b, For example, the cell voltage Vc of each secondary battery 34 in the battery blocks 33a and 33b is calculated and acquired by setting the second speed of 20 kbps, which is slower than the first speed, and executing the terminal voltage calculation process.

  Next, the operation of the battery power supply device 1 configured as described above will be described. 2-6 is a flowchart which shows an example of operation | movement of the battery power supply device 1 shown in FIG. First, the error rate detection unit 216 detects the error rate Er of communication via the transmission line L (step S1).

  Specifically, for example, a request signal for requesting data transmission for testing is transmitted from the communication unit 218 to the voltage measurement ICs 22a and 22b and the temperature measurement ICs 23a and 23b, and communication is performed from the communication units 224a, 224b, 232a, and 232b. Test data is transmitted to the unit 218. When receiving data, the communication unit 218 detects a communication error using, for example, a parity bit or a cyclic code.

  Then, the error rate detection unit 216 counts the number N of times that the data is received by the communication unit 218 and the number Ne that the transmission error is detected by the communication unit 218, and the number Ne is divided by the number N of times to obtain an error. The rate Er is calculated.

  Next, the terminal voltage acquisition unit 214 compares the error rate Er with the determination threshold value Ej (step S2). If the error rate Er does not exceed the determination threshold value Ej (NO in step S2), the communication state is good. And the transmission rate by the communication units 218, 224a, 224b, 232a, 232b is set to the normal first rate (step S3), while if the error rate Er exceeds the determination threshold value Ej (YES in step S2) ), For example, the communication state is judged to be bad due to the influence of noise, and the transmission speed by the communication units 218, 224a, 224b, 232a, 232b is lower than the first speed in order to improve the reliability of communication. Two speeds are set (step S4).

  Thus, since the transmission rate is set according to the detection result of the error rate Er, it is possible to improve noise resistance and improve communication reliability.

  Next, the protection control unit 215 causes the communication unit 218 to transmit a request signal for requesting temperature data to the temperature measurement ICs 23a and 23b. Then, the temperatures ta and tb of the battery blocks 33a and 33b are transmitted from the temperature measurement ICs 23a and 23b, and the temperatures ta and tb are received by the communication unit 218 (step S5).

  Next, the protection control unit 215 compares the temperatures ta and tb with the determination temperature tj (step S6), and if both the temperatures ta and tb are equal to or lower than the determination temperature tj (NO in step S6), the battery block 33a. 33b are in the normal temperature range, the switching elements Q1 and Q2 are turned on so that the assembled battery B can be charged and discharged (step S7).

  The temperature change of the battery blocks 33a and 33b is moderate when normal. Therefore, it is not necessary to detect the temperatures ta and tb frequently. Therefore, when both the temperatures ta and tb are equal to or lower than the determination temperature tj (NO in step S6), the protection control unit 215 sets the frequency at which the data indicating the temperatures ta and tb are transmitted from the temperature measurement ICs 23a and 23b, for example, for 1 second. The first frequency is set to a low frequency that does not exceed the reference frequency, such as once (step S8), and the process proceeds to step S9.

  As a result, the transmission frequency of the data indicating the temperatures ta and tb is reduced to reduce the communication load of the communication unit 218, which is necessary for monitoring each cell voltage Vc within a range not exceeding the communication capability of the communication unit 218. The cell voltage Vc can be transmitted by the voltage measurement ICs 22a and 22b within the delay time.

  Hereinafter, unless the communication frequency is changed in step S13, the acquisition of the temperatures ta and tb at the first frequency by the protection control unit 215 in step S8 is repeated in parallel with the subsequent processing.

  On the other hand, in step S6, if at least one of the temperatures ta and tb exceeds the determination temperature tj (YES in step S6), the battery blocks 33a and 33b are hot beyond the normal temperature range. The protection control unit 215 turns off the switching elements Q1 and Q2 and inhibits charging / discharging of the assembled battery B (step S12).

  As described above, when the battery blocks 33a and 33b are at a high temperature exceeding the normal temperature range, the temperature of the battery blocks 33a and 33b is closely monitored to notify the temperature ta and tb to the outside, or even higher. When it becomes, it is necessary to issue a warning.

  Therefore, when at least one of the temperatures ta and tb exceeds the determination temperature tj (YES in step S6), the protection control unit 215 transmits the frequency indicating that the temperature ta and tb are transmitted from the temperature measurement ICs 23a and 23b. For example, it is set to the second frequency having a high frequency exceeding the reference frequency, such as once every 100 msec (step S13).

  In this case, the cell voltage Vc is transmitted by the voltage measurement ICs 22a and 22b within a delay time required for monitoring each cell voltage Vc in parallel within a range not exceeding the communication capability of the communication unit 218. Therefore, the process proceeds to step S14 in order to reduce the amount of communication data necessary to acquire each cell voltage Vc.

  Hereinafter, unless the communication frequency is changed in step S8, the acquisition of the temperatures ta and tb at the second frequency by the protection control unit 215 in step S13 is repeated in parallel with the subsequent processing.

  In step 9, the terminal voltage acquisition unit 214 compares the error rate Er with the determination threshold value Ej (step S9), and if the error rate Er does not exceed the determination threshold value Ej (NO in step S9), the communication unit 218. , 224a, 224b, 232a, and 232b, the transmission speed is set to the normal first speed, so that the delay required to monitor each cell voltage Vc within a range not exceeding the communication capability of the communication unit 218 It is possible to transmit data indicating the temperatures ta and tb at the first frequency by the temperature measurement ICs 23a and 23b while transmitting the data indicating the cell voltages Vc by the voltage measurement ICs 22a and 22b within the time. Therefore, the process proceeds to step S10 in order to execute transmission of data indicating each cell voltage Vc by the voltage measurement ICs 22a and 22b.

  On the other hand, if the error rate Er exceeds the determination threshold value Ej (YES in step S9), the transmission rate by the communication units 218, 224a, 224b, 232a, 232b is set to a second rate that is slower than the first rate in step S4. Therefore, the communication capability of the communication unit 218 is reduced. Then, the voltage measurement ICs 22a and 22b transmit data indicating each cell voltage Vc within a delay time required for monitoring each cell voltage Vc, and the temperature measurement ICs 23a and 23b perform the transmission at the first frequency. It becomes difficult to execute transmission of data indicating the temperatures ta and tb.

  Therefore, the process proceeds to step S14 in order to reduce the amount of communication data necessary to acquire each cell voltage Vc.

  In step S10, the terminal voltage acquisition unit 214 causes the voltage acquisition unit 211 to execute the terminal voltage detection process illustrated in FIG. 3 for each communication cycle described above, for example, every 10 msec. FIG. 7 is an explanatory diagram for explaining the terminal voltage detection process shown in FIG. 3.

  In the terminal voltage detection process shown in FIG. 3, first, the voltage acquisition unit 211 causes the communication unit 218 to transmit a request signal for requesting the cell voltages Vc of the battery blocks 33a and 33b to the voltage measurement ICs 22a and 22b (step). S21).

  Hereinafter, it is assumed that the cell numbers 1 to n are assigned to the secondary batteries 34 of the battery blocks 33a and 33b, and the cell voltages of the secondary batteries 34 having the cell numbers 1 to n are expressed as cell voltages Vc1 to Vc1. Vcn is described, and the ratio of the cell voltages Vc1 to Vcn is described as ratios R1 to Rn. Here, “n” indicates the number of secondary batteries 34 included in the battery blocks 33a and 33b. In the examples shown in FIGS. 1, 7, and 8, n = 7.

  Then, individual voltage detection processing is executed by the individual voltage detection units 221a and 221b, and cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are detected, respectively, and cell voltages Vc1 to Vcn in the battery block 33a are detected from the communication unit 224a. The cell voltages Vc1 to Vcn in the battery block 33b are transmitted from the communication unit 224b (step S22).

  Then, each cell voltage Vc1 to Vcn in the battery blocks 33a and 33b is received by the communication unit 218, and all the cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are acquired by the terminal voltage acquisition unit 214 (step S23). The voltage detection process ends and the process proceeds to step S11.

  Then, as shown in FIG. 7, individual voltage detection processing is executed for each communication cycle (showing a cycle executed by a circle), and cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are detected, Since the cell voltages Vc1 to Vcn are transmitted and acquired by the terminal voltage acquisition unit 214, the terminal voltage acquisition unit 214 can acquire the latest cell voltages Vc1 to Vcn for each communication cycle, and the cell voltage Vc1. The monitoring accuracy of ~ Vcn is improved.

  Next, in step S11, the protection control unit 215 controls on / off of the switching elements Q1 and Q2 based on the cell voltages Vc1 to Vcn of the battery blocks 33a and 33b acquired by the terminal voltage acquisition unit 214, and again in step S6. The subsequent processing is repeated after returning to step S2.

  Next, the terminal voltage calculation process in step S14 will be described. In step S <b> 14, the voltage acquisition unit 211, the ratio calculation unit 212, the total voltage acquisition unit 213, and the terminal voltage acquisition unit 214 execute the terminal voltage calculation process illustrated in FIGS. 4, 5, and 6. FIG. 8 is an explanatory diagram for explaining the terminal voltage calculation processing shown in FIGS. 4, 5, and 6.

  First, the voltage acquisition unit 211 confirms whether the ratios R1 to Rn in the battery blocks 33a and 33b have already been calculated (step S31). If the ratios R1 to Rn have already been calculated (YES in step S31), the process proceeds to step S51 to start the calculation of each cell voltage Vc immediately, while the ratios R1 to Rn are still calculated. If not (NO in step S31), the process proceeds to step S32 to calculate the ratios R1 to Rn.

  In step S32, the voltage acquisition unit 211 causes the communication unit 218 to transmit a request signal requesting the cell voltages Vc of the battery blocks 33a and 33b to the voltage measurement ICs 22a and 22b, and the individual voltage detection units 221a and 221b individually A voltage detection process is executed (step S32).

  Then, the cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are detected by the individual voltage detection units 221a and 221b, respectively, and stored by the storage units 223a and 223b (step S33).

  Next, the voltage acquisition unit 211 assigns 1 to a variable i indicating the cell number of each secondary battery 34 in the battery blocks 33a and 33b (step S34).

  Next, the voltage acquisition part 211 requests | requires transmission of the cell voltage Vci of the secondary battery 34 of the cell number i memorize | stored in the memory | storage parts 223a and 223b by communication with voltage measurement IC22a, 22b (step S35). .

  Then, the individual voltage detection units 221a and 221b cause the communication units 224a and 224b to transmit the cell voltage Vci stored in the storage units 223a and 223b to the control unit 21 (step S36).

  Then, the cell voltage Vci in the battery blocks 33a and 33b is received by the communication unit 218 and acquired by the voltage acquisition unit 211 (step S37). As described above, steps S32 to S37 correspond to the communication cycle 1 shown in FIG.

  Next, the voltage acquisition unit 211 compares the variable i with the cell number n (step S38). If the variable i does not satisfy the cell number n (NO in step S38), 1 is added to the variable i ( Step S39), steps S35 to S38 are repeated until the variable i is equal to or greater than the number of cells n (YES in step S38) (corresponding to communication cycles 2 to 7 in FIG. 8).

  When the variable i is greater than or equal to the number of cells n (YES in step S38), since all the cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are acquired by the voltage acquisition unit 211, the ratios R1 to Rn are calculated. If necessary, the process proceeds to step S40.

  In step S40, the ratio calculation unit 212 calculates the ratios R1 to Rn of the battery block 33a with respect to the total voltage Vt based on the all cell voltages Vc1 to Vcn in the battery block 33a acquired by the voltage acquisition unit 211 (step S40). S40).

  Next, the ratio calculation unit 212 calculates the ratios R1 to Rn of the battery block 33b with respect to the total voltage Vt based on the all cell voltages Vc1 to Vcn in the battery block 33b acquired by the voltage acquisition unit 211 (step S41). ).

  In steps S40 and S41, the total voltage Vt of the battery blocks 33a and 33b is obtained as the total value of the cell voltages Vc1 to Vcn in each battery block, and the ratio Ri of the secondary battery 34 of the cell number i in each battery block is Is given by the following equation (1).

Ri = Vci / Vt (1)
Steps S40 and S41 are executed at the timing after the end of the communication cycle 7 shown in FIG.

  Next, in step S51, the voltage acquisition unit 211 causes the communication unit 218 to transmit a request signal for requesting the cell voltages Vc of the battery blocks 33a and 33b to the voltage measurement ICs 22a and 22b, and the individual voltage detection units 221a and 221a. The individual voltage detection process is executed by 221b (step S51).

  Then, cell voltages Vc1 to Vcn in battery blocks 33a and 33b are detected by individual voltage detection units 221a and 221b, respectively, and stored by storage units 223a and 223b (step S52).

  Next, the voltage acquisition unit 211 assigns 1 to a variable i indicating the cell number of each secondary battery 34 in the battery blocks 33a and 33b (step S53).

  Next, the total voltage acquisition unit 213 causes the communication unit 218 to transmit a request signal requesting execution of the total voltage detection process and transmission of the total voltage Vt to the voltage measurement ICs 22a and 22b (step S54).

  Furthermore, the voltage acquisition part 211 requests | requires transmission of the cell voltage Vci of the secondary battery 34 of the cell number i memorize | stored in the memory | storage parts 223a and 223b by communication with voltage measurement IC22a, 22b (step S55).

  Then, the total voltage detection units 222a and 222b execute a total voltage detection process, and the communication units 224a and 224b transmit the obtained total voltage Vt of the battery blocks 33a and 33b to the control unit 21 (step S56).

  Furthermore, the individual voltage detection units 221a and 221b cause the communication units 224a and 224b to transmit the cell voltage Vci stored in the storage units 223a and 223b to the control unit 21 (step S57).

  Then, the total voltage Vt and the cell voltage Vci in the battery blocks 33a and 33b are received by the communication unit 218, the total voltage Vt is acquired by the total voltage acquisition unit 213, and the cell voltage Vci is acquired by the voltage acquisition unit 211. (Step S58).

  Next, the terminal voltage acquisition unit 214 multiplies the total voltage Vt in the battery block 33a by the ratios R1 to Rn of the battery block 33a calculated by the ratio calculation unit 212, respectively, and the cell voltages Vc1 to Vcn in the battery block 33a. Is calculated (step S59).

  Next, the terminal voltage acquisition unit 214 multiplies the total voltage Vt in the battery block 33b by the ratios R1 to Rn of the battery block 33b calculated by the ratio calculation unit 212, respectively, and the cell voltages Vc1 to Vcn in the battery block 33b. Is calculated (step S60).

  As described above, steps S51 to S60 correspond to the communication cycle 8 shown in FIG.

  Next, the voltage acquisition unit 211 compares the variable i with the cell number n (step S61). If the variable i does not satisfy the cell number n (NO in step S61), 1 is added to the variable i ( Step S62), Steps S54 to S61 are repeated (corresponding to communication cycles 9 to 14 in FIG. 8) until the variable i becomes n or more (YES in Step S61).

  As described above, according to steps S51 to S61 (communication cycles 8 to 14), the data transmitted from the voltage measurement ICs 22a and 22b to the control unit 21 via the transmission line L in one communication cycle are the total voltage Vt and the cell voltage Vci. As shown in FIG. 7, the amount of communication data can be reduced as compared with the case where n (seven in FIG. 7) cell voltages Vc1 to Vcn are transmitted in each communication cycle. .

  On the other hand, since all cell voltages Vc1 to Vcn are calculated based on the total voltage Vt and the ratios R1 to Rn in each communication cycle, communication within a delay time required for monitoring each cell voltage Vc. All cell voltages Vc1 to Vcn can be obtained for each cycle.

  As a result, by reducing the amount of communication data related to the cell voltage Vc, the transmission rate can be reduced in order to improve the reliability of communication while reducing the decrease in monitoring accuracy (monitoring frequency) of each cell voltage Vc. Even when the communication frequency of the temperature data is increased, these data can be transmitted and received within a range not exceeding the communication capability of the communication unit 218.

  Here, when a plurality of secondary batteries 34 are connected in series as in the assembled battery B (battery blocks 33a and 33b), the cell voltage Vc of each secondary battery 34 is the internal resistance of each secondary battery 34. Is determined by the voltage generated by the current flow and the electromotive force of each secondary battery 34. Further, the electromotive force of each secondary battery 34 is determined by the amount of stored charge of each secondary battery 34.

  When each secondary battery 34 is connected in series, the current flowing through each secondary battery 34 is the same. Therefore, if each secondary battery 34 has no characteristic variation, the internal resistance value and the charge If the characteristics such as efficiency are the same, the voltage generated by the current flowing through the internal resistance of each secondary battery 34 becomes equal. In addition, since the charge / discharge current of each secondary battery 34 is also equal, the amount of electric charge stored in each secondary battery 34 is also equal. As a result, the electromotive force of each secondary battery 34 is also equal.

  Then, in the ideal state where the characteristics of the secondary batteries 34 are equal, the ratios R1 to Rn that are the ratios of the cell voltages Vc of the secondary batteries 34 are equal to each other. However, in actuality, characteristics such as the internal resistance value of each secondary battery 34 vary due to manufacturing variation and subsequent characteristic deterioration, and the voltage and power storage caused by current flowing through the internal resistance of each secondary battery 34. There are also variations in the amount of charge. Variation in the amount of stored charge appears as variation in electromotive force.

  As a result, a difference occurs between the cell voltages Vc of the secondary batteries 34, and a difference also occurs between the ratios R1 to Rn.

  However, as described above, the difference between the ratios R <b> 1 to Rn is caused by the manufacturing variation of each secondary battery 34 and the characteristic variation due to deterioration. Variations in characteristics caused by manufacturing variations do not change afterwards. Further, the characteristic variation caused by the deterioration changes gradually. For example, no significant change occurs unless the charging / discharging cycle is repeated about 10 times or the period of about 1 month is elapsed.

  Therefore, the ratios R1 to Rn are substantially not changed in a period of about 1 hour, for example, and are hardly changed in a period of about 1 minute. On the other hand, the cell voltage Vc itself of each secondary battery 34 changes in real time according to the charge / discharge current flowing through the assembled battery B.

  Therefore, in the battery power supply device 1 shown in FIG. 1, in steps S31 to S62 shown in FIGS. 4 and 5, the ratio calculation unit 212 calculates the ratios R1 to Rn in the battery blocks 33a and 33b, and the voltage measurement ICs 22a and 22b. However, in each communication cycle, instead of the cell voltages Vc1 to Vcn, the total voltage Vt that is the total value of the cell voltages Vc1 to Vcn is transmitted in real time, and the terminal voltage acquisition unit 214 changes the total voltage Vt that changes in real time to Real-time cell voltages Vc1 to Vcn are calculated and acquired by multiplying ratios R1 to Rn that hardly change.

  Thereby, the possibility that the real time property of the cell voltages Vc1 to Vcn is impaired is reduced while reducing the communication data amount.

  In FIG. 4, FIG. 5, and FIG. 8, the individual voltage detectors 221a and 221b detect the cell voltages Vc1 to Vcn at the same time (within one communication cycle) and store them in the storage units 223a and 223b. In addition, although the example in which the cell voltages Vc1 to Vcn stored in the storage units 223a and 223b are transmitted across a plurality of communication cycles is shown, the cell voltages Vc1 to Vcn are sequentially detected in each communication cycle. You may make it transmit.

  However, the cell voltages Vc1 to Vcn change in real time according to the current flowing through the assembled battery B. For example, the cell voltage Vc1 is detected while charging the assembled battery B, and the cell voltage Vcn is detected while discharging the assembled battery B. Thus, if the currents flowing through the battery pack B when the cell voltages Vc1 to Vcn are detected are different, the ratios R1 to Rn of the cell voltages Vc1 to Vcn thus obtained include currents Includes errors caused by changes.

  Therefore, as shown in FIGS. 4, 5, and 8, the cell voltages Vc1 to Vcn are collectively detected at the same time (within one communication cycle) and stored in the storage units 223a and 223b. By transmitting cell voltages Vc1 to Vcn stored in 223a and 223b, that is, cell voltages Vc1 to Vcn detected at the same time, over a plurality of communication cycles, errors in cell voltages Vc1 to Vcn are reduced. Errors in the ratios R1 to Rn are reduced, and as a result, the accuracy of the cell voltages Vc1 to Vcn calculated by the terminal voltage acquisition unit 214 in each communication cycle can be improved.

  In addition, according to the battery power supply device 1 shown in FIG. 1, as shown in FIG. 8, until all the cell voltages Vc <b> 1 to Vcn are completely transmitted, the ratio calculation unit 212 can calculate the ratios R <b> 1 to Rn. In the communication cycles 1 to n, the terminal voltage acquisition unit 214 cannot calculate the cell voltages Vc1 to Vcn. However, normally, when the battery power supply device 1 is manufactured, since the battery power supply device 1 is operated for the shipping inspection, the communication cycles 1 to n are executed at the time of the shipping inspection, and the ratios R1 to Rn are already calculated in the market. In this state, the battery power supply device 1 is circulated. Accordingly, the fact that the cell voltages Vc1 to Vcn cannot be calculated in the communication cycle before the ratios R1 to Rn are calculated does not cause any trouble.

  Returning to FIG. 5, in step S61, the voltage acquisition unit 211 compares the variable i with the number of cells n (step S61). If the variable i does not satisfy the number of cells n (NO in step S61), the variable 1 is added to i (step S62), and steps S54 to S62 are repeated (corresponding to communication cycles 9 to 14 in FIG. 8) until the variable i becomes equal to or greater than the number of cells n (YES in step S61).

  When the variable i is greater than or equal to the number of cells n (YES in step S61), all the cell voltages Vc1 to Vcn in the battery blocks 33a and 33b are acquired by the voltage acquisition unit 211, so that the ratios R1 to Rn are newly added. The process proceeds to step S71 to calculate and update.

  Next, based on the all cell voltages Vc1 to Vcn in the battery block 33a newly acquired in step S58 by the voltage acquisition unit 211 in step S71 by the ratio calculation unit 212, for example, using the above-described formula (1), the battery Ratios R1 to Rn of the block 33a with respect to the total voltage Vt are calculated (step S71).

  Next, based on the all cell voltages Vc1 to Vcn in the battery block 33b newly acquired in step S58 by the voltage acquisition unit 211 by the ratio calculation unit 212, for example, using the above formula (1), Ratios R1 to Rn with respect to the total voltage Vt are calculated (step S72), the terminal voltage calculation process is terminated, and the process proceeds to step S11.

  Next, in step S11, the protection control unit 215 controls on / off of the switching elements Q1 and Q2 based on the cell voltages Vc1 to Vcn of the battery blocks 33a and 33b calculated by the terminal voltage acquisition unit 214, and again in step S6. The subsequent processing is repeated after returning to step S2.

  Steps S71 and S72 are executed, for example, at a timing after the end of the communication cycle 14 shown in FIG.

  When the terminal voltage calculation process is executed again, since the ratios R1 to Rn have already been calculated (YES in step S31), steps S51 to S72 (communication cycle 15 and after in FIG. 8) are executed. Will be.

  As described above, in steps S71 and S72, the ratios R1 to Rn are updated based on the cell voltages Vc1 to Vcn newly received from the voltage measurement ICs 22a and 22b. Therefore, for example, the deterioration of each secondary battery 34 proceeds and the cell voltage Vc1 is increased. Even when the variation in .about.Vcn changes, the ratios R1 to Rn are updated in accordance with the change, and as a result, the terminal voltage acquisition unit 214 can suppress a decrease in calculation accuracy of the cell voltages Vc1 to Vcn. .

  In addition, although temperature measurement IC23a, 23b was described as an example of a function part, the function part should just communicate with the control part 21 via the transmission line L, and detects the temperature of battery block 33a, 33b It is not limited to what you do. In this case, when an event that triggers the functional unit to increase the communication frequency occurs in step S6, the process may proceed to step S12.

  Further, the temperature measurement ICs 23a and 23b and the steps S5, S6, S8, S12, and S13 may be omitted. The error rate detection unit 216 and steps S1, S2, S4, and S9 may be omitted.

  Moreover, it is good also as a structure which always reduces the communication data amount between the control part 21 and voltage measurement IC22a, 22b by performing the terminal voltage detection process of step S31-S72 always.

  Moreover, although the cell voltage Vc1-Vcn acquired by the terminal voltage acquisition part 214 was shown for the on-off control (step S11) of switching element Q1, Q2 by the protection control part 215, the switching element Q1, Q2 was not necessarily shown. For example, the battery voltage Bc1 to Vcn acquired by the terminal voltage acquisition unit 214 is transmitted to a charging unit or a load circuit connected to the connection terminals 31 and 32, thereby charging and discharging the assembled battery B. It is good also as a structure utilized in order to control. For example, the cell voltages Vc1 to Vcn may be displayed or recorded so that only the cell voltages Vc1 to Vcn are monitored.

  A voltage monitoring circuit according to the present invention and a battery power supply device using the voltage monitoring circuit include electronic devices such as portable personal computers, digital cameras and mobile phones, vehicles such as electric vehicles and hybrid cars, hybrid elevators, solar cells and power generation devices. Can be suitably used in battery-mounted devices and systems such as a power supply system in which a secondary battery and a secondary battery are combined.

DESCRIPTION OF SYMBOLS 1 Battery power supply device 2 Voltage monitoring circuit 21 Control part 22a, 22b Voltage measurement IC
23a, 23b Temperature measurement IC
31, 32 Connection terminals 33a, 33b Battery block 34 Secondary battery 35a, 35b Temperature sensor 211 Voltage acquisition unit 212 Ratio calculation unit 213 Total voltage acquisition unit 214 Terminal voltage acquisition unit 215 Protection control unit 216 Error rate detection unit 218, 224a, 224b, 232a, 232b Communication unit 221a, 221b Individual voltage detection unit 222a, 222b Total voltage detection unit 223a, 223b Storage unit 231a, 231b Temperature detection unit B Battery assembly Ej Determination threshold Er Error rate L Transmission line Q1, Q2 Switching element R1 ~ Rn ratio Vc, Vc1 ~ Vcn Cell voltage Vt Total voltage tj Judgment temperature ta, tb Temperature

Claims (9)

In an assembled battery including a battery block in which a plurality of secondary batteries are connected in series, an individual voltage detection process for detecting a terminal voltage of each secondary battery in the battery block and a terminal voltage between both ends of the battery block A voltage detector that performs a total voltage detection process for detecting a certain total voltage;
A control unit that controls the individual voltage detection process, the total voltage detection process, and a transmission operation of information indicating a terminal voltage of each secondary battery by the voltage detection unit;
A transmission unit for transmitting information between the voltage detection unit and the control unit;
The controller is
A voltage acquisition unit that acquires information indicating the terminal voltage of each secondary battery detected by the individual voltage detection process by the voltage detection unit via the transmission unit;
Based on information indicating the terminal voltage of each secondary battery acquired by the voltage acquisition unit, a ratio calculation unit that calculates each ratio of the terminal voltage to the total voltage;
After each ratio is calculated by the ratio calculation unit, the voltage detection unit periodically executes the total voltage detection process, and information indicating the detected total voltage is transmitted from the voltage detection unit to the transmission unit. A total voltage acquisition unit for acquiring the total voltage by transmitting via
Each time the total voltage is acquired by the total voltage acquisition unit, a terminal voltage calculation that calculates and acquires the terminal voltage of each secondary battery according to each calculated ratio with respect to the acquired total voltage. A voltage monitoring circuit comprising: a terminal voltage acquisition unit that executes processing. The voltage detector is
A storage unit for storing a terminal voltage of each secondary battery detected by the individual voltage detection process;
The voltage acquisition unit
The terminal voltage of each secondary battery detected by executing the individual voltage detection process by the voltage detection unit is stored by the storage unit, and the terminal voltage of each secondary battery stored in the storage unit is indicated. By transmitting information sequentially and periodically through the transmission unit, the terminal voltage of each secondary battery is acquired over a plurality of periods,
The ratio calculation unit
The voltage monitoring circuit according to claim 1, wherein the respective ratios are calculated after the terminal voltages of all the secondary batteries are acquired by the voltage acquisition unit. The voltage acquisition unit
When the total voltage acquisition unit causes the voltage detection unit to periodically execute the total voltage detection process, the voltage detection unit further performs the voltage detection unit at a timing corresponding to the number of secondary batteries. The storage unit newly stores the terminal voltage of each secondary battery detected by executing the individual voltage detection process, and the total voltage acquisition unit periodically transmits information indicating the total voltage via the transmission unit. In synchronization with the transmission, information indicating the terminal voltage of each secondary battery newly stored in the storage unit is transmitted periodically through the transmission unit in a plurality of cycles. In addition, the terminal voltage of each secondary battery is acquired,
The ratio calculation unit
The voltage monitoring circuit according to claim 1, wherein the ratio is calculated each time a new terminal voltage of all the secondary batteries is acquired by the voltage acquisition unit. A functional unit for communicating with the control unit via the transmission unit;
The terminal voltage acquisition unit
When the execution frequency of communication between the control unit and the function unit via the transmission unit is less than a preset reference frequency, the voltage detection unit does not execute the terminal voltage calculation process. Periodically performing the terminal voltage detection process for acquiring the terminal voltage of each secondary battery detected by executing the individual voltage detection process via the transmission unit;
When the execution frequency of the communication between the control unit and the function unit via the transmission unit is higher than the reference frequency, the terminal voltage calculation process is executed to execute the terminal voltage of each secondary battery. The voltage monitoring circuit according to claim 1, wherein the voltage monitoring circuit is acquired. The transmission unit is
The transmission speed of the information is settable,
The controller is
An error rate detection unit for detecting an error rate in transmission of information using the transmission unit;
The terminal voltage acquisition unit
If the error rate detected by the error rate detection unit is less than a preset determination threshold, the transmission rate by the transmission unit is set to a preset first rate, and the terminal voltage calculation process is executed. Without performing a terminal voltage detection process to obtain the terminal voltage of each secondary battery detected by periodically executing the individual voltage detection process by the voltage detection unit,
When the error rate detected by the error rate detection unit exceeds the determination threshold, the transmission rate by the transmission unit is set to a second rate slower than the first rate, and the terminal voltage calculation process is executed. The terminal voltage of each said secondary battery is acquired. The voltage monitoring circuit of any one of Claims 1-3 characterized by the above-mentioned. A functional unit for communicating with the control unit via the transmission unit;
The transmission unit is
The transmission speed of the information is settable,
The controller is
An error rate detection unit for detecting an error rate in transmission of information using the transmission unit;
The terminal voltage acquisition unit
A determination threshold in which an execution frequency of communication between the control unit and the function unit via the transmission unit is less than a preset reference frequency, and an error rate detected by the error rate detection unit is preset. If not, the transmission rate by the transmission unit is set to a preset first rate, and the individual voltage detection processing is periodically executed by the voltage detection unit without executing the terminal voltage calculation processing. To obtain the terminal voltage of each secondary battery detected,
When the frequency of communication between the control unit and the function unit via the transmission unit is higher than the reference frequency, the terminal voltage calculation process is executed to obtain the terminal voltage of each secondary battery. Acquired,
When the error rate detected by the error rate detection unit exceeds the determination threshold, the transmission rate by the transmission unit is set to a second rate slower than the first rate, and the terminal voltage calculation process is executed. The terminal voltage of each said secondary battery is acquired by this. The voltage monitoring circuit of any one of Claims 1-3 characterized by these. The functional unit is
Temperature information indicating the temperature of the secondary battery is transmitted to the control unit via the transmission unit,
The controller is
Based on the temperature information transmitted from the function unit, the presence / absence of temperature abnormality of the secondary battery is determined, and when it is determined that the temperature abnormality exists, the frequency at which the function unit transmits the temperature information is the reference frequency. The voltage monitoring circuit according to claim 4, further comprising a communication frequency adjusting unit that increases the frequency more than the communication frequency adjusting unit. The assembled battery is
A plurality of the battery blocks are connected in series;
The voltage detector is
A plurality of battery blocks are provided corresponding to the plurality of battery blocks,
The controller is
Controlling the individual voltage detection processing, the total voltage detection processing, and the information transmission operation indicating the terminal voltage of each secondary battery by the plurality of voltage detection units,
The transmission unit is
The voltage monitoring circuit according to claim 1, wherein the information is transmitted between the plurality of voltage detection units and the control unit. The voltage monitoring circuit according to any one of claims 1 to 8,
A battery power supply device comprising: the assembled battery.