JP4857301B2 - Voltage measuring device and electric vehicle - Google Patents

Description

  The present invention relates to a voltage measuring device for measuring a voltage between terminals of each battery block constituting an assembled battery.

  In a vehicle including a secondary battery including a plurality of battery blocks as a power source, an electrical state of each battery block is measured, and charging / discharging of the secondary battery is controlled based on the state. Are known.

  For example, in Patent Documents 1-3, a voltage detection unit is provided for each battery block, each voltage detection unit is connected in series to form one transmission path, and between each terminal detected by each voltage detection unit A voltage measuring device that transmits information indicating voltage (hereinafter referred to as “voltage information”) in a serial manner through the transmission path, and measures the voltage between terminals of the battery block in response to input of the transmitted voltage information. It is disclosed.

  Patent Document 4 discloses a system including a cell monitoring IC chip that monitors the voltage of a battery cell, a control IC chip that controls the battery cell, and a main controller that transmits and receives signals via the control IC and insulation. Yes. The cell monitoring IC chip monitors the abnormality of the control IC chip or the abnormality of the battery cell connected to the control IC by the first signal output from the main controller via the first insulation. When the abnormality is detected, the cell monitoring IC chip specifies the control IC chip by the second signal output from the main controller via the second insulation. Alternatively, the cell IC chip searches for abnormal contents of the control IC chip or the battery cell connected to the control IC by the second signal.

Japanese Patent Laid-Open No. 9-139237 JP 2003-70179 A JP 2006-29895 A JP 2005-318750 A

  By the way, as described above, when voltage information detected by each voltage detection means connected in series is serially transmitted through one transmission path, if any abnormality occurs in any voltage detection means or signal line. The transmission path is interrupted, and all voltage information may not be transmitted.

  In order to prevent voltage information from being transmitted even if an abnormality occurs in any of the voltage detection means, it is conceivable to duplicate each voltage detection means. However, duplication of each voltage detection means generally causes an increase in cost.

  On the other hand, for example, when controlling the charging / discharging of the secondary battery using the voltage information of each battery block as a parameter, the voltage information of several battery blocks is used even if the voltage information of all the battery blocks cannot be obtained. In some cases, it may be preferable to design the battery so that charging / discharging of the secondary battery can be controlled temporarily.

  The present invention provides a voltage measuring device that connects voltage detection units provided for each battery block in series to construct a relay path, and acquires voltage information detected by each voltage detection unit via the relay path. It is an object of the present invention to provide a voltage measuring device that can acquire voltage information of at least one battery block even if any voltage detection unit has a problem.

  The voltage measuring device according to the present invention is a group of voltage detection units that are arranged in parallel for each battery block constituting the assembled battery and detects a voltage between terminals of the battery block, and are connected in series via a relay signal line. A voltage detection unit group that sequentially relays voltage information indicating a voltage between terminals of the battery block via a relay signal line in a serial manner; a voltage detection unit on one end side of the voltage detection unit group; and a first output signal line Is connected to the voltage detection unit on the other end side via a first input signal line, and outputs a voltage request signal to the voltage detection unit group via the first output signal line, and the voltage A voltage information collection unit that receives voltage information relayed by the voltage detection unit group in a serial manner via a relay signal line in response to a request signal, and receives an input via the first input signal line, and the voltage The information collecting unit The output request group is connected to at least one other voltage detection unit other than the voltage detection units on both ends of the output unit group via a second output signal line, and the voltage request signal output via the first output signal line If the response from the voltage detection unit group is an error, a new voltage request signal is output via any one of the second output signal lines, and the other end is supplied from the voltage detection unit connected to the second output signal line. The voltage information input to the side voltage detector is received via the first input signal line.

  The voltage measuring device according to the present invention is a group of voltage detection units that are arranged in parallel for each battery block constituting the assembled battery and detects a voltage between terminals of the battery block, and are connected in series via a relay signal line. A voltage detection unit group that sequentially relays voltage information indicating a voltage between terminals of the battery block via a relay signal line in a serial manner; a voltage detection unit on one end side of the voltage detection unit group; and a first output signal line Is connected to the voltage detection unit on the other end side via a first input signal line, and outputs a voltage request signal to the voltage detection unit group via the first output signal line, and the voltage A voltage information collection unit that receives voltage information relayed by the voltage detection unit group in a serial manner via a relay signal line in response to a request signal, and receives an input via the first input signal line, and the voltage The information collecting unit A response from the voltage detection unit group via the first input signal line is connected to at least one other voltage detection unit other than the voltage detection units on both ends of the output unit group via the second input signal line. Is an error, it receives voltage information input from the voltage detection unit on one end side to the voltage detection unit to which the one second input signal line is connected via any one second input signal. It is characterized by that.

  In one aspect of the voltage measuring apparatus according to the present invention, the assembled battery is configured by stacking a plurality of battery blocks, and is adjacent to each other in the stacking direction among the voltage detecting units constituting the voltage detecting unit group. The voltage detectors corresponding to the matching battery blocks are connected via relay signal lines so as not to be adjacent in the relay order of the voltage information.

  In one aspect of the voltage measurement device according to the present invention, the assembled battery is configured by stacking a plurality of battery blocks, and among the voltage detection units constituting the voltage detection unit group, an odd number in the stacking direction. Alternatively, each voltage detection unit corresponding to an even-numbered battery block is connected via a relay signal line in ascending or descending order, and then each voltage detection unit corresponding to an even-numbered or odd-numbered battery block is stacked in ascending or descending order in the stacking direction. It is connected through a relay signal line.

  The electric vehicle according to the present invention includes the voltage measuring device, and a control unit that controls charging / discharging of the assembled battery based on voltage information of at least one battery block measured by the voltage measuring device, An assembled battery is used as a drive source.

  According to the present invention, since the signal line for configuring the detour path is provided, the voltage information of at least one of the battery blocks is acquired even if a failure occurs in any of the voltage detection units. be able to.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an electric vehicle (PEV) equipped with a secondary battery that supplies electric power to a drive source. In this embodiment, an electric vehicle (PEV) will be described as an example. However, if the system measures the battery voltage of a secondary battery, a hybrid electric vehicle (HEV) having an engine and a secondary battery, a fuel cell, and a battery The present invention can also be applied to an electric vehicle such as a hybrid vehicle having a secondary battery.

  The electric vehicle includes a secondary battery 10, a battery electronic control unit (hereinafter referred to as a battery ECU) 20, a relay 30, an inverter 40, a motor generator 50, and a vehicle electronic control unit (hereinafter referred to as a vehicle ECU) 60.

  The battery ECU 20 includes a voltage measurement unit 22 (voltage measurement device) therein, and measures the battery voltage V of the secondary battery 10. Further, the battery ECU 20 calculates the state of charge of the secondary battery 10 (hereinafter referred to as SOC (State Of Charge)) based on information such as the battery voltage V, the charge / discharge current I, and the battery temperature T. Transmits battery information such as the SOC and battery temperature of the secondary battery 10 to the vehicle ECU 60. Further, the battery ECU 20 controls the opening and closing of the switch element of the relay 30 based on the battery voltage V. The charging / discharging of the secondary battery 10 is controlled by controlling the inverter 40 based on the battery information.

  The electric vehicle configured as described above runs under the control of the battery ECU 20 and the vehicle ECU 60 by converting DC power from the secondary battery 10 into AC power via the inverter 40 and driving the motor generator 50.

  FIG. 2 is a diagram mainly showing a voltage measuring unit 22 used for measuring the battery voltage of the secondary battery 10 among the functional blocks provided in the battery ECU 20.

  In FIG. 2, the secondary battery 10 is configured by electrically connecting six battery blocks B <b> 1 to B <b> 6 (hereinafter simply referred to as “battery block B” when collectively referring to each battery block). Assembled battery. Each of the battery blocks B is configured by electrically connecting two battery modules in series, and each battery module is configured by electrically connecting six unit cells in series. As each single battery, a nickel metal hydride battery, a lithium ion battery, or the like can be used. In addition, the number of battery blocks, battery modules, and single cells is not particularly limited. The configuration of the secondary battery is not limited to the above example. In addition, the unit cell is not limited to a specific shape such as a square shape or a cylindrical shape.

  The voltage measurement unit 22 includes voltage detection units 24-1 to 24-6 (hereinafter referred to as “voltage detection unit 24” when collectively referred to as each voltage detection unit) provided for each battery block, and each voltage detection unit. And a voltage information collecting unit 26 that collects voltage information indicating the inter-terminal voltage measured by the unit 24.

  The voltage information collection unit 26 outputs a first output signal line So1 for outputting a command signal to the voltage detection unit 24, and a first input signal line Si1 for receiving a response signal input to the command signal from the voltage detection unit 24. And are connected. Furthermore, the voltage information collection unit 26 in the present embodiment is also connected to a second output signal line So2 for outputting a command signal to the voltage detection unit 24. The role of the second output signal line So2 will be described later.

  Each voltage detection part 24 is connected to the positive electrode side terminal and the negative electrode side terminal of each battery block B, and measures the voltage between terminals. The voltage detectors 24 are connected in series with each other via the first relay signal line Sb1, and the voltage detector 24-1 on the highest potential side (frontmost stage side) connects the first output signal line So1. The voltage information collecting unit 26 is connected. Further, the voltage detection unit 24-6 on the lowest potential side (last stage side) is connected to the voltage information collection unit 26 via the first input signal line Si1.

  That is, the voltage information collection unit 26 and each voltage detection unit 24 are connected in series (in a ring shape) via the signal lines So1, Sb1, and Si1 to form one closed circuit (loop circuit).

  The voltage information collection unit 26 acquires the voltage information of each battery block B from each voltage detection unit 24 through the signal lines So1, Sb1, Si1 in the following procedure.

  That is, the voltage information collection unit 26 outputs a start signal to the highest potential side voltage detection unit 24-1 via the first output signal line So1. The voltage detection unit 24-1 receives an activation signal and starts measuring the voltage across the terminals of the battery block B, and the voltage detection unit is connected to the activation signal at a lower potential side (rear stage side) than itself. The data is output to 24-2 via the first relay signal line Sb1-1. The voltage detector 24-1 temporarily holds the measured voltage across the terminals of the battery block B in its own memory.

  When the voltage detection unit 24-2 receives an activation signal input via the first relay signal line Sb1-1, the voltage detection unit 24-2 performs the same operation as the voltage detection unit 24-1. As described above, each voltage detection unit 24 receives the activation signal from the higher potential side of itself, measures the terminal voltage of the battery block B, and transfers the activation signal to the lower potential side of itself.

  When receiving the activation signal, the voltage detection unit 24-6 on the lowest potential side transfers the activation signal to the voltage information collecting unit 26 via the first input signal line Si1.

  The voltage information collection unit 26 outputs the activation signal to the voltage detection unit 24-1 on the highest potential side via the first output signal line So1, and then the activation signal is transferred from the voltage detection unit 24-6 on the lowest potential side. After waiting, the voltage request signal is output to the highest potential side voltage detector 24-1 via the first signal line So1 in a serial manner.

  The voltage detection unit 24-1 receives the input of the voltage request signal, adds the voltage information between the terminals measured by itself to the voltage request signal, and performs a first relay to the voltage detection unit 24-2 on the low potential side in a serial manner. The signal is output via the signal line Sb1.

  When the voltage detection unit 24-2 receives the input of the voltage request signal, the voltage detection unit 24-2 performs the same operation as the voltage detection unit 24-1. In this way, each voltage detection unit 24 receives a voltage request signal from the higher potential side than itself, adds the voltage information obtained by measuring itself to the voltage request signal, and sends a voltage request to the lower potential side in a serial manner. Transfer the signal.

  When the voltage information collection unit 26 receives a voltage request signal input in a serial manner from the voltage detection unit 24-6 on the lowest potential side, the voltage information collection unit 26 checks whether the voltage request signal is normal by a parity check or the like.

  With this configuration, voltage information is transmitted from the high potential side voltage detection unit 24 to the low potential side voltage detection unit 24, and the transmitted voltage information is collected by the voltage information collection unit 26.

  In the voltage measurement unit 22 according to the present embodiment, the three voltage detection units 24-4 to 24-4 on the low potential side of the voltage detection unit 24 via the second output signal line So 2 instead of the first output signal line So 1. 24-6 and the voltage information collection part 26 are comprised by another closed circuit.

  When the voltage information collecting unit 26 has not successfully collected the voltage information when collecting the voltage information from each voltage detecting unit 24 via the first output signal line So1, the second output signal A voltage request signal is output toward the voltage detection unit 24-4 via the line So2. Even when the voltage detection unit 24-4 receives the input of the voltage request signal via the second output signal line So2, the voltage detection unit 24-4 adds the voltage information obtained by measuring itself to the voltage request signal, and the serial method. The voltage request signal is output to the voltage detection unit 24-5 on the lower potential side than itself. The voltage detectors 24-5 and 24-6 add the voltage information obtained by measuring itself to the input voltage request signal, and output the voltage request signal in a serial manner.

  By adding the second output signal line So2 in this way, even if any malfunction occurs in any of the three voltage detection units 24 on the high potential side, the voltage information collection unit 26 has at least three of the low potential side. Voltage information can be collected from the voltage detectors 24-4 to 24-6.

  Therefore, according to the embodiment, for example, when the battery ECU 20 controls charging / discharging of the secondary battery using the voltage information of each battery block as a parameter, even if the voltage information of all the battery blocks cannot be acquired, the battery ECU 20 is low. The charging / discharging of the secondary battery can be provisionally controlled using the voltage information of the three battery blocks on the potential side.

  The wiring location of the second output signal line So2 is not limited to the voltage detection unit 24-4, and the second output signal line So2 may be wired to another voltage detection unit. However, if the second output signal line S2 is wired on the high potential side, the closed circuit configured via the second output signal line So2 may include the defective voltage detection unit 24. As compared with the case of wiring near the middle potential, it becomes higher. Further, if the second output signal line So2 is wired too low, the voltage detecting unit 24 included in the closed circuit configured via the second output signal line So2 is reduced, and the voltage information collecting unit 26 can collect it. Voltage information is reduced. Therefore, the second output signal line So2 is preferably wired to the voltage detection unit 24 near the intermediate potential, for example, the voltage detection unit 24-4.

  In the above embodiment, the example in which one second output signal line So2 is used as a detour path for transmitting voltage information has been described.

  However, for example, as shown in FIG. 3, a plurality of second output signal lines So2-1 to So2-3 are wired to different voltage detectors 24, and an output signal from which the voltage information collecting unit 26 outputs a voltage request signal. Lines may be switched. For example, when an error occurs in the voltage request signal output via the first output signal line So1, the voltage information collection unit 26 selects the second output signal line So2 one by one in order from the high potential side, for example. Then, a new voltage request signal is output via the selected second output signal line So2. In this way, a plurality of detour paths can be configured by connecting a plurality of second output signal lines So2 to different voltage detection units 24. Therefore, it is possible to increase the probability that a closed circuit excluding the voltage detection unit 24 in which a problem has occurred can be configured.

  In the above embodiment, the example in which the detour path is configured by providing the second output signal line So2 has been described. However, for example, as shown in FIG. 4, the detour path may be configured by adding the input signal line Si2.

  FIG. 4 shows an example in which the voltage detection unit 24-3 and the voltage information collection unit 26 are connected via the second input signal line Si2.

  When using the second input signal line Si2 as a bypass path, for example, the voltage information collection unit 26 adds a flag to the voltage request signal, and when using the bypass path, sets the flag to “1”. When the normal path is used, the voltage request signal is output through the first output signal line So1 with “0”.

  When receiving a voltage request signal, the voltage detector 24 first determines whether the flag is “1” or “0”. Further, in the case of “1”, it is determined whether or not the second input signal line Si2 is connected to itself. In FIG. 4, since the second input signal line Si2 is connected to the voltage detection unit 24-3, the voltage detection unit 24-3 adds the voltage information of its own when the flag is “1”. Is output to the voltage information collecting unit 26 via the second input signal line Si2.

  By adding the second input signal line Si2 in this way, even if any malfunction occurs in any of the three voltage detection units 24 on the low potential side, the voltage information collection unit 26 has at least three voltage detection units on the high potential side. Voltage information can be collected from the voltage detectors 24-1 to 24-3.

  In addition, as shown in FIG. 5, a plurality of second input signal lines Si2-1 to Si2-3 are wired to different voltage detectors 24, and the voltage signal collector 26 receives input of voltage requests. May be switched. In this case, when an error occurs in the voltage request signal input via the first input signal line Si1, the voltage information collection unit 26 sets the second input signal line Si2 one by one in order from the low potential side, for example. select. The voltage information collection unit 26 outputs a new voltage request signal via the first output signal So1 so as to receive the voltage request signal input via the selected second input signal line Si2. For example, the voltage information collection unit 26 adds the identification information indicating any one input signal line Si to the voltage request signal and outputs it. If the identification information indicated by the voltage request signal is the input signal line Si connected to itself, the voltage detection unit 24 outputs the voltage request signal to which the voltage information is added via the input signal line Si. The information is output to the information collecting unit 26.

  Thus, by connecting the plurality of second input signal lines Si2 to the different voltage detectors 24, a plurality of detour paths can be configured. Therefore, it is possible to increase the probability that a closed circuit excluding the voltage detection unit 24 in which a problem has occurred can be configured.

  By the way, in said embodiment, the example which connects each voltage detection part 24 via 1st relay signal wire | line Sb1 in the connection order of the battery block B was demonstrated. Here, when the secondary battery 10 is configured by stacking the battery blocks B, the connection order of the battery blocks B corresponds to the stacking order of the battery blocks B. In the present embodiment, the two-dimensional or three-dimensional arrangement in the direction perpendicular to the length direction of the battery module is referred to as a stacked arrangement. In such a connection order, the voltage information collected by the voltage information collection unit 26 via the detour path may be biased toward one end side in the stacking direction. However, when the battery blocks B are stacked, the temperature characteristics may differ depending on the arrangement of the battery blocks. For example, since the battery blocks at both ends in the stacking direction have a wide heat dissipation surface, they easily radiate heat. On the other hand, the battery block near the center in the stacking direction has a narrow heat radiating surface and is unlikely to radiate heat. In general, a secondary battery is more likely to deteriorate at a high temperature, and a difference in battery characteristics is likely to occur between the battery block near the center and the battery blocks at both ends. For this reason, for example, voltage information collected via a detour path uses only voltage blocks with biased temperature characteristics, only for battery blocks that are biased to one end in the stacking direction, or for battery blocks near the center in the stacking direction. As a result, charging / discharging of the secondary battery 10 may be controlled.

  Therefore, for example, as shown in FIG. 6, the relay order of the voltage detectors 24 is determined in the order in which the voltage characteristics of the battery blocks B are considered in consideration of the temperature characteristics of the battery blocks B. May be.

  In FIG. 6, the voltage detection units 24 are connected via the first relay signal line sb <b> 1 so that the voltage detection units corresponding to the battery blocks adjacent in the stacking direction are not adjacent in the relay order. In other words, the voltage detectors corresponding to the odd (or even) number are connected in ascending order from one end in the stacking direction, and the voltage detectors corresponding to the even (or odd) number are connected in ascending order. More specifically, the voltage detector 24 is connected so that the relay order is the order of the voltage detectors 24-1, 24-3, 24-5, 24-2, 24-4, 24-6. Yes.

  In this way, by determining the relay order of each voltage detection unit 24 in consideration of the temperature characteristics, the voltage information collection unit 26 temporarily provisions the battery block from some voltage detection units 24 using a detour path. Even when the voltage information is collected, the voltage information can be collected from the battery blocks distributed in the stacking direction without being biased only to the battery blocks disposed on one end side in the stacking direction. Therefore, the battery ECU 20 can control charging / discharging of the secondary battery using the voltage information of the battery blocks having different temperature characteristics.

  The voltage information collection unit 26 according to the present embodiment can obtain voltage information from each voltage detection unit 24. However, the voltage information includes not only the voltage information but also abnormality of the battery and the presence / absence of a failure of the voltage detection unit. You can also get

It is a figure which shows schematic structure of the electric vehicle carrying the secondary battery which supplies electric power to a drive source. It is the figure which showed centering on the voltage measurement part used in order to measure the battery voltage of a secondary battery among the functional blocks with which the inside of battery ECU is equipped. It is a figure which shows the modification of the voltage measurement part which concerns on this embodiment. It is a figure which shows the modification of the voltage measurement part which concerns on this embodiment. It is a figure which shows the modification of the voltage measurement part which concerns on this embodiment. It is a figure which shows the modification of the voltage measurement part which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Secondary battery, 20 Battery ECU, 22 Voltage measurement part, 24 Voltage detection part, 26 Voltage information collection part, 30 Relay, 40 Inverter, 50 Motor generator, 60 Vehicle ECU.

Claims (5)

A group of voltage detectors that are arranged in parallel for each battery block constituting the assembled battery and detect the voltage between the terminals of the battery block, and are connected in series via a relay signal line, and the voltage between the terminals of the battery block is Voltage detection unit group that sequentially relays the voltage information shown through the relay signal line in a serial manner;
The voltage detection unit group is connected to a voltage detection unit on one end side via a first output signal line, connected to a voltage detection unit on the other end side via a first input signal line, and the first output signal line The voltage request signal is output to the voltage detection unit group via the voltage information, and the voltage information relayed in a serial manner by the voltage detection unit group via the relay signal line in response to the voltage request signal is output to the first input. A voltage information collection unit that receives input via a signal line;
With
The voltage information collection unit
A voltage request signal connected to at least one other voltage detection unit other than the voltage detection units on both ends of the voltage detection unit group via a second output signal line, and output via the first output signal line When the response from the voltage detection unit group is an error, a new voltage request signal is output via any one of the second output signal lines, and the voltage detection unit connected to the second output signal line Receiving voltage information input to the voltage detection unit on the other end side via the first input signal line;
A voltage measuring device characterized by that. A group of voltage detectors that are arranged in parallel for each battery block constituting the assembled battery and detect the voltage between the terminals of the battery block, and are connected in series via a relay signal line, and the voltage between the terminals of the battery block is Voltage detection unit group that sequentially relays the voltage information shown through the relay signal line in a serial manner;
The voltage detection unit group is connected to a voltage detection unit on one end side via a first output signal line, connected to a voltage detection unit on the other end side via a first input signal line, and the first output signal line The voltage request signal is output to the voltage detection unit group via the voltage information, and the voltage information relayed in a serial manner by the voltage detection unit group via the relay signal line in response to the voltage request signal is output to the first input. A voltage information collection unit that receives input via a signal line;
With
The voltage information collection unit
The voltage detection unit group is connected to at least one other voltage detection unit other than the voltage detection units on both ends via a second input signal line,
If the response from the voltage detection unit group via the first input signal line is an error, any one of the second inputs from the voltage detection unit on the one end side via any one of the second input signals. Receives voltage information input to the voltage detector connected to the signal line.
A voltage measuring device characterized by that. In the voltage measuring device according to claim 1 or 2,
The assembled battery is configured by stacking a plurality of battery blocks,
Among the voltage detection units constituting the voltage detection unit group, each voltage detection unit corresponding to each battery block adjacent in the stacking direction is connected via a relay signal line so as not to be adjacent in the voltage information relay order. To be
A voltage measuring device characterized by that. In the voltage measuring device according to claim 1 or 2,
The assembled battery is configured by stacking a plurality of battery blocks,
Among the voltage detection units constituting the voltage detection unit group, the voltage detection units corresponding to the odd-numbered or even-numbered battery blocks in the stacking direction are connected via relay signal lines in ascending or descending order, and then in the stacking direction. Each voltage detection unit corresponding to an even or odd numbered battery block is connected via a relay signal line in ascending or descending order,
A voltage measuring device characterized by that. A voltage measuring device according to any one of claims 1 to 4,
Control means for controlling charging / discharging of the assembled battery based on voltage information of at least one battery block measured by the voltage measuring device;
An electric vehicle using the assembled battery as a drive source.

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