JP5685624B2 - Battery system - Google Patents

Description

  The present invention relates to a battery system for a vehicle or a power supply system for general industry, a circuit board for the system, and an integrated circuit used in an electric vehicle, a hybrid vehicle, and a vehicle equipped with an electric drive device such as a train. About.

  In a conventional battery system, for example, as described in Patent Document 1, a plurality of battery groups in which a plurality of battery cells are connected in series are connected to form one battery module, and the state of the battery cell for each battery group A subordinate control device for monitoring the above is provided. These lower-level control devices are configured to receive commands from the higher-level control device via a signal transmission path. In the signal transmission path, an insulating circuit such as a photocoupler is provided so as not to be affected by a potential difference between the lower control device and the upper control device.

JP 2003-70179 A

The body of a vehicle represented by an automobile or a train is easily in contact with the human body, and in order to enhance safety, when the battery system is mounted on a vehicle, the battery system is electrically insulated from the body. It has become. This is not limited to vehicles, for example, the same applies to industrial machines, and the machine itself and the housing are also easily in contact with the human body, and when the battery system is used for industrial purposes, to improve safety to the human body, The power system of the battery system is electrically insulated from the machine itself and the housing. On the other hand, other power systems with a low power supply voltage, such as a power supply for a control circuit, do not adversely affect the human body, so the vehicle body or housing may be used as a reference potential. May be used as part of the system. Especially in automobiles, the low voltage power supply system uses the vehicle body as part of the low power system. As described above, in order to enhance safety, the battery system is insulated from other power supply systems. In consideration of system inspections and repairs, and in some cases, traffic accidents, it is desirable that battery systems be connected in series via a switchable connector in order to enhance safety. In such a structure, the DC supply current from the battery system is interrupted by opening the connector, and safety can be further improved.
The battery system includes a plurality of battery cells connected in series, and the battery cells connected in series are further connected in series via the connector. The battery cell has a plurality of integrated circuits that function as a battery cell controller for measuring or diagnosing the terminal voltage of the battery cell or controlling the state of charge, and collectively describing these functions as battery cell processing. Each of a plurality of integrated circuits that process a plurality of battery cells has a transmission circuit. The transmission circuits included in each integrated circuit are also connected in series with each other, and a transmission path is formed by the serial connection.
Each of the integrated circuits is electrically connected to the battery cells connected in series, and each of the integrated circuits is affected by the potential of the battery cells. On the other hand, the integrated circuit has a problem that it is difficult to increase the withstand voltage. For this reason, if for some reason a high voltage generated by the series connection is applied to the series-connected integrated circuits, the withstand voltage of the integrated circuit may be exceeded and the integrated circuits may be damaged. When the connector connected in series with the battery cell is opened, the battery cells at both ends of the connector are insulated from each other, so that the potential state of the battery cell changes, and thus a part of the integrated circuit. There is a possibility that a voltage exceeding the withstand voltage will be applied. A highly reliable system that is not easily affected by changes in the potential state of the battery cell due to opening and closing of the connector is desired.
An object of the present invention is to provide a highly reliable battery system.

A battery system according to the present invention includes a battery module configured by connecting a plurality of battery cells in series, a plurality of battery cells grouped, a plurality of integrated circuits performing processing on the battery cells in units of groups, and a plurality of battery cells A first transmission line for transmitting a command signal from the upper control circuit for controlling the integrated circuit to the highest integrated circuit of the integrated circuit via the first insulating circuit, and a data signal collected by the plurality of integrated circuits being integrated at the highest level. A second transmission line for transmitting from the circuit to the lowest integrated circuit, and a second insulation circuit for driving data signals collected by the plurality of integrated circuits from the lowest integrated circuit to the higher control circuit by the power of the total voltage of the battery module a third transmission path for transmitting via the first isolator to the driving state by the activation signal output from the host control circuit when the command signal is output, the command signal is output Characterized in that it and a current supply control circuit for the serial first isolator and non-driven state when not.

According to the present invention, it is possible to improve the reliability of the battery system. For example, when the present invention is applied to a lithium battery system, there is a large effect, and when it is applied to a lithium battery system for a vehicle, there is a very large effect.
In a lithium battery system, for example, it is desirable to constantly monitor the state of each lithium battery cell with high accuracy based on detection by a lithium battery cell controller. If a part of the lithium battery cell controller is damaged, accurate detection of the condition or diagnosis based on the detection result, information transmission may be difficult, or erroneous detection result or judgment result may be sent. There is. It is desirable to be able to prevent such problems. For example, in a lithium battery system for a vehicle, there is a possibility of being related to human life, and in particular, improvement in safety is desired. In addition, there is a high possibility of encountering an accident with movement, which is an attribute of the vehicle, and the accident is likely to cause a circuit damage. For this reason, high safety is desired. Furthermore, automobiles are likely to be used for many years under changing environmental conditions, and high safety is also desired in this respect.

It is a figure which shows one Embodiment of the battery system for vehicles. It is a figure which shows the drive system of the rotary electric machine for vehicles carrying the vehicle battery system shown in FIG. 2 is a perspective view showing an external appearance of a battery unit 900. FIG. 4 is an exploded perspective view of a battery unit 900. FIG. It is a figure which shows the board | substrate 81 with which the cell controller 80 was provided. 6 is a diagram illustrating another example of a transmission path 60. FIG. It is a figure which shows the modification of the battery system shown in FIG. It is a figure which shows the modification of the battery system shown in FIG. It is a figure which shows connection with each battery cell of the battery cell group corresponding to battery cell controller CC3N. It is a figure explaining the internal structure of battery cell controller CC3N. It is a figure which shows the transmission output circuit 140 of the battery cell controller CCM of a transmission side, and the transmission input circuit 138 of the battery cell controller CCN of a receiving side. It is a figure which shows a signal waveform. It is a figure explaining the function of control terminal CT2. It is a figure which shows the waveform of signal AD of FIG. 2 is a diagram showing a start input circuit 147, a timer circuit 150, and a main constant voltage power supply 134. FIG. FIG. 16 is a diagram illustrating a signal input to the reception terminal RX of FIG. 15, an output of the differential trigger circuit 253, a counter operation, an output of the timer circuit 150, and an operating state of the main constant voltage power supply 134. It is a figure which shows the transmission output circuit 140 of the battery cell controller CCM of a transmission side, and the transmission input circuit 138 of the battery cell controller CCN of a receiving side. It is a figure which shows the signal waveform of the information transmitted. It is a figure which shows the signal waveform of the information transmitted. It is a figure which shows other embodiment explaining the internal structure of each battery cell controller which is an integrated circuit.

In the embodiment described below, various aspects desirable as a product are improved, and not only the above-mentioned problem specialized in improving reliability but also various other problems are solved. The following is a brief description of typical issues and solutions.
[Uniform battery cell power consumption]
The invention described below is devised so that the power consumption of the lithium battery cells mounted on the vehicle connected in series does not become unbalanced. That is, the power consumption of each lithium battery cell mounted on the vehicle, in other words, the power load of each lithium battery cell is made uniform. The following description will be described with a vehicle installation having a particularly large effect as a representative example. However, the solution to this problem is not limited to the vehicle installation represented by a train or an automobile, but an industrial battery system, particularly a lithium battery system. When applied to, good effects can be obtained.
The electric power generated by the lithium battery cell mounted on the vehicle has a higher voltage than other power systems mounted on the vehicle, and is electrically insulated from other power systems of the vehicle in order to increase safety. Therefore, the plurality of integrated circuits for controlling the lithium battery cell are electrically insulated from the other power systems. Since the control circuit or other information transmission system of the other party that transmits information to or from the plurality of integrated circuits is operated by another power system, the plurality of integrated circuits and the control circuit or other information transmission system Is transmitted through an insulating circuit having an input / output terminal that is electrically isolated. Here, the insulating circuit is a circuit including, for example, a photocoupler, and the insulating circuit converts an input signal input to the input terminal into light by a photodiode built in the photocoupler, and further includes a phototransistor that incorporates the light. The signal is converted again into an electrical signal and output from the output terminal. Since information is transmitted inside the insulating circuit using light as a medium, information can be transmitted, but the input terminal and the output terminal are electrically insulated.
Electric power is required to operate the above-described insulating circuit. In particular, relatively large electric power is required to drive the photodiode. In addition, a photocoupler that transmits information at a high speed has higher power consumption than a photocoupler that transmits information at a low speed.
In the following embodiments, the information transmission terminals of the integrated circuits that control the lithium battery cells are electrically connected in series with each other, and information is transmitted through the transmission path constituted by the series connection. Reception for information transmission with other transmission lines and other control circuits is performed by a state-of-the-art integrated circuit (also referred to as the highest level in the following embodiments) that constitutes the serially connected transmission lines. Is called. On the other hand, transmission from the transmission line is performed by an integrated circuit at the final stage (also referred to as the lowest order in the following embodiments) constituting the transmission line constituted by the series connection. As described above, relatively large power is required for information transmission via the photocoupler which is an insulating circuit. Therefore, if only the lithium battery cell supplying power to the final stage integrated circuit is charged with the power for transmitting the information, the power load among the plurality of lithium battery cells becomes unbalanced. It is desirable to reduce this imbalance.
In the following embodiments, the power load is balanced as follows. That is, the lithium battery module is configured by further connecting a plurality of lithium battery cell groups configured by connecting a plurality of lithium battery cells in series. Furthermore, in order to perform the process regarding each said lithium battery cell group, the some integrated circuit provided corresponding to each said lithium battery cell group is provided. Each integrated circuit has a transmission terminal for outputting information and a reception terminal for receiving information, and the transmission terminal of the integrated circuit is connected to the reception terminal of the adjacent integrated circuit, respectively. Thus, a transmission path constituted by series connection is formed. The power consumption of the insulating circuit that outputs information from the integrated circuit at the last stage of the transmission path is not borne only by the lithium battery cell group corresponding to the integrated circuit at the last stage, but a plurality of lithium battery cell groups It is configured to bear. Thereby, it is possible to prevent the power consumption of the insulating circuit from being biased to one lithium battery cell group, and to reduce the power load imbalance between the lithium battery cells. In the following embodiments, in order to obtain a greater effect, the power consumption of the insulation circuit is integrated from the lithium battery cell group corresponding to the first integrated circuit constituting the transmission line in the final stage of the integration of the transmission line. The electric load of the entire lithium battery cell up to the lithium battery cell group corresponding to the circuit is set. With this configuration, the power load imbalance between lithium battery cells can be greatly reduced. As a specific circuit configuration, as a power source of a drive circuit that drives a photodiode included in the insulation circuit, a final stage that configures the transmission path from a lithium battery cell group corresponding to a leading integrated circuit that configures the transmission path. The voltage of the entire lithium battery cell up to the lithium battery cell group corresponding to the integrated circuit is supplied.
[Reduction of power consumption of lithium battery cells]
[Reduction of power consumption 1]
It is desirable that the power consumption of the power source composed of the lithium battery cells connected in series be saved as much as possible. In particular, in an automobile, it is desirable to cover the electric power related to the running of the automobile with a lithium battery power source as small as possible, and it is desirable to save power consumption as much as possible. In a car, the parking state may last for a long time, and it is particularly important to reduce power consumption during parking. In the following embodiment, the circuit configuration is such that the drive current of the insulating circuit used for the output from the transmission line configured by connecting the transmission / reception terminals of the integrated circuit in series is not flowing in a state where the power source is not used. Power consumption is saved. The transmission path uses a digital signal to transmit information, and it is desirable that the drive current does not flow in a digital value “0” state where no signal exists. That is, it is desirable that the drive current flows in the state of the digital value “1”. The integrated circuit includes a circuit for selecting a relationship between whether the voltage of the output terminal for transmission is “high” or “low” and the digital value “1” or “0”. The above relationship can be selected in response to the instruction signal. By selecting the above relationship, it is possible to prevent the drive current from flowing when the digital value is “0”. For example, in the following embodiment, when the power source composed of lithium battery cells is not used because the vehicle operation is stopped, the output of the transmission line becomes “0”, and the driving current of the photodiode is reduced. Is automatically shut off. Such a circuit configuration saves power consumption.
[Reduction of power consumption 2]
In the following embodiments, there are at least two types of transmission lines constituted by the integrated circuits. One is a first transmission line, which plays a role of transmitting a terminal voltage and a command of a lithium battery cell measured by an integrated circuit, and has a large power consumption of the insulating circuit. The other is a second transmission line that simply transmits only the state and has a function of transmitting 1-bit information. The second transmission line has a lower transmission frequency than the first transmission line, and the power consumption of the insulating circuit is low. In this transmission system, power supply to the photocoupler of the first transmission path is stopped when the transmission path is not used due to parking or the like. When transmission is necessary for starting a car, the upper control circuit sends a signal indicating a state of “1” to the second transmission path. When the second transmission path receives the signal “1”, based on this reception, the power supply to the photocoupler of the first transmission path is started, and the transmission operation of the first transmission path can be started. Since the power supply to the photocoupler of the first transmission path is automatically maintained in a state where the transmission operation is performed on the first transmission path, the second transmission path is an operation for transmitting original information. Even if it moves to, the electric power supply to the photocoupler of the said 1st transmission line is maintained. With such a circuit configuration, power consumption in a transmission stop state is saved.
[Reduction of applied voltage associated with communication]
In the following embodiments, each integrated circuit that is a battery cell controller uses at least two kinds of power supply voltages, that is, a high power supply voltage VCC and a low power supply voltage VDD. The multiplexer for selecting the terminal voltage of each lithium battery cell constituting the lithium battery cell group operates in response to the high power supply voltage VCC, and the analog-digital converter or various storage devices or the transmission circuit for data transmission has a low power supply voltage. Operates at VDD. In the following embodiments, a transmission path is formed by connecting transmission / reception circuits of each battery cell controller in series. Moreover, the electric potential of each battery cell controller is different, and the electric potential of the battery cell controller rises or falls in order according to the order of the series connection. In such a transmission line constituted by series connection of circuits having different potentials, when information is transmitted from the higher potential to the lower potential, the reception circuit operates at the high power supply voltage VCC, and the transmission circuit is operated at the low power supply voltage VDD. As a result, the voltage between the transmission / reception circuits of adjacent battery cell controllers can be reduced, and the reliability is improved. In the case of transmitting information from a lower potential to a higher potential, the potential difference between the transmission and reception circuits can be reduced by operating the reception circuit or the transmission circuit with the low power supply voltage VDD, and the reliability is improved. Further, the power consumption can be saved by operating the circuit with the low power supply voltage VDD in both the above systems.
[High-speed startup from sleep mode]
In the following embodiments, a plurality of transmission circuits of each integrated circuit, which is a battery cell controller, are connected in series to form a transmission path, thereby reducing the number of necessary insulation circuits. Furthermore, in order to reduce power consumption, the battery cell controller is set to a sleep state. In a vehicle, it is necessary to make the plurality of battery cell controllers connected in series in an operable state in a short time. For this reason, in the following embodiments, each battery cell controller has a startup output circuit that transmits a rising signal “wake up”, and each battery cell controller performs an operation of rising when it receives the rising signal. And a rising signal is simultaneously transmitted from the start-up output circuit to the next battery cell controller regardless of the completion of the rising operation of itself. Thus, even before the own rising is completed, the rising signal can be transmitted to the next battery cell controller, and the rising signal can be quickly transmitted to each battery cell controller connected in series. Compared with the case where each battery cell controller completes the rising operation and then transmits a rising signal to the next battery cell controller, the rising operation of the entire system is much faster. In particular, when the following embodiment is used in an automobile, even if the driver wants to operate the system in a hurry and wants to start quickly, the entire system can be started up quickly so that the above-mentioned desire can be met. It becomes possible.
Other problems and solutions will be described in the description using the drawings.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIGS. 1-5 is a figure explaining one Embodiment of the battery system for vehicles which concerns on this invention. FIG. 1 is a view showing a main part of a vehicle battery system, FIG. 2 is a view showing a drive system for a vehicular rotating electrical machine equipped with the vehicle battery system, and FIGS. 3 to 5 are views for explaining a battery unit 900. First, the drive system for the vehicular rotating electrical machine shown in FIG. 2 will be described. Here, an automobile is the optimum vehicle, but good results can be obtained even when applied to a train. Although it can be applied to an industrial machine, an application example to a vehicle will be described below as a representative example.

  FIG. 2 is a circuit diagram when the vehicle battery system of the embodiment is applied to a drive system for a vehicular rotating electrical machine. The drive system includes a battery unit 900 including a battery system, an inverter device 220 that converts DC power from the battery unit 900 into three-phase AC power, a vehicle drive motor 230, a battery unit 900, and a host controller that controls the inverter device 220. 110 is provided. Motor 230 is driven by the three-phase AC power from inverter device 220.

  The battery unit 900 includes two battery modules 9A and 9B, a cell controller 80, and a battery controller 20. The battery module 9A and the battery module 9B are connected in series via a switch 6 that functions as a service disconnect for maintenance and inspection in which a switch and a fuse are connected in series. When the switch 6 is opened, the direct circuit of the electric circuit is cut off, and no current flows even if a one-point connection circuit is formed between the battery modules 9A and 9B and the vehicle. With such a configuration, high safety can be maintained.

  The battery module 9A is configured by connecting a plurality of battery cell groups in which a plurality of battery cells are connected in series. The battery module 9B is configured similarly. The positive electrode of the battery module 9A is connected to the positive electrode of the inverter device 220 via the positive high voltage cable 81 and the relay RLP. The negative electrode of the battery module 9B is connected to the negative electrode of the inverter device 220 via the negative high voltage cable 82 and the relay RLN. A series circuit of a resistor RPRE and a precharge relay RLPRE is connected in parallel with the relay RLP. Between the relay RLP and the inverter device 220, a current sensor Si such as a hall element is inserted. The current sensor Si is built in the junction box, and its output line is led to the battery controller 20.

  For example, a relay RLP or a relay RLN having a rated current of about 80 A can be used, and a precharge relay RLPRE having a rated current of about 10 A can be used. For example, a resistor RPRE having a rated capacity of 60 W and a resistance value of about 50Ω can be used, and a current sensor Si having a rated current of about ± 200 A can be used. The negative high voltage cable 82 and the positive high voltage cable 81 described above are connected to the inverter device 220 that drives the motor 230 via the relay RLP, the relay RLN, and the output terminals 810 and 820. With such a configuration, high safety can be maintained.

  The inverter device 220 includes a power module 226, an MCU 222, a driver circuit 224 for driving the power module 226, and a large-capacity smoothing capacitor 228 of about 700 μF to about 2000 μF. The power module 226 converts the DC power supplied from the battery modules 9 </ b> A and 9 </ b> B into three-phase AC power for driving the motor 230.

  The smoothing capacitor 228 can obtain desirable characteristics of the film capacitor than the electrolytic capacitor. The smoothing capacitor 228 mounted on the vehicle is influenced by the environment where the vehicle is placed, and is used in a wide temperature range from a low temperature of minus tens of degrees Celsius to about 100 degrees Celsius. When the temperature drops below zero degree, the electrolytic capacitor suddenly deteriorates in characteristics and the ability to remove voltage noise decreases. For this reason, a large noise may be added to the integrated circuit provided in the cell controller 80. The film capacitor is less susceptible to temperature degradation and voltage noise applied to the integrated circuit can be reduced.

  The MCU 222 changes the negative relay RLN from the open state to the closed state at the start of driving of the motor 230 in accordance with a command from the host controller 110, then changes the precharge relay RLPRE from the open state to the closed state, and charges the smoothing capacitor 228. Thereafter, the positive relay RLP is changed from the open state to the closed state, and supply of power from the battery modules 9A and 9B of the battery unit 900 to the inverter device 220 is started.

  The inverter device 220 controls the phase of the AC power generated by the power module 226 with respect to the rotor of the motor 230, and operates the motor 230 as a generator during braking of the hybrid vehicle, that is, performs regenerative braking control, thereby operating the generator. The battery module 9A, 9B is charged by regenerating the power generated by the battery module 9A, 9B. When the state of charge of the battery modules 9A and 9B is lower than the reference state, the inverter device 220 operates using the motor 230 as a generator. The three-phase AC power generated by the motor 230 is converted into DC power by the power module 226 and supplied to the battery modules 9A and 9B. As a result, the battery modules 9A and 9B are charged.

  When powering the motor 230, the MCU 222 controls the driver circuit 224 to generate a rotating magnetic field in the advance direction with respect to the rotation of the rotor of the motor 230 in accordance with a command from the host controller 110, and the switching operation of the power module 226. To control. In this case, DC power is supplied to the power module 226 from the battery modules 9A and 9B. On the other hand, when the battery modules 9A and 9B are charged by regenerative braking control, the MCU 222 controls the driver circuit 224 so as to generate a rotating magnetic field in a delay direction with respect to the rotation of the rotor of the motor 230, and the power module. The switching operation of H.226 is controlled. In this case, electric power is supplied from the motor 230 to the power module 226, and DC power of the power module 226 is supplied to the battery modules 9A and 9B. As a result, the motor 230 acts as a generator.

  The power module 226 of the inverter device 220 conducts and cuts off at high speed and performs power conversion between DC power and AC power. At this time, since a large current is interrupted at a high speed, a large voltage fluctuation occurs due to the inductance of the DC circuit. In order to suppress this voltage fluctuation, a large-capacity smoothing capacitor 228 is provided in the DC circuit. In the inverter device 220 for in-vehicle use, heat generation of the power module 226 is a big problem, and in order to suppress this heat generation, it is necessary to increase the operation speed of conduction and interruption of the power module 226. When this operation speed is increased, the voltage jump due to the inductance increases as described above, and a larger noise is generated. For this reason, the capacity of the smoothing capacitor 228 tends to be larger.

  When the inverter device 220 starts operating, the charge of the smoothing capacitor 228 is substantially zero, and a large initial current flows into the smoothing capacitor 228 when the relay RLP is closed. The large current may cause the negative main relay RLN and the positive main relay RLP to be fused and damaged. In order to solve this problem, the MCU 222 changes the resistance of the precharge relay RLPRE from the open state to the closed state while the positive side relay RLP is kept open after the negative side relay RLN is changed from the open state to the closed state. The smoothing capacitor 228 described above is charged while limiting the maximum current via RPRE.

  After the smoothing capacitor 228 is charged to a predetermined voltage, the initial state is released. That is, initial charging to the smoothing capacitor 228 via the precharge relay RLPRE and the resistor RPRE is stopped, and as described above, the negative-side relay RLN and the positive-side relay RLP are closed and the power supply system 1 transfers to the power module 226. Supply DC power. By performing such control, the relay circuit can be protected, and the maximum current flowing through the lithium battery cell and the inverter device 220 can be reduced to a predetermined value or less, and high safety can be maintained.

  Since reducing the inductance of the DC side circuit of the inverter device 220 leads to suppression of the noise voltage, the smoothing capacitor 228 is disposed close to the DC side terminal of the power module 226. The smoothing capacitor 228 itself is also configured to reduce inductance. When the initial charging current of the smoothing capacitor 228 is supplied in such a configuration, a large current flows instantaneously, and there is a possibility that high heat is generated and damaged. However, the damage can be reduced by limiting the charging current by the precharge relay RLPRE and the resistor RPRE. Although control of the inverter device 220 is performed by the MCU 222, as described above, control for initially charging the smoothing capacitor 228 is also performed by the MCU 222.

  The connection line between the negative electrode of the battery module 9B of the battery unit 900 and the relay RLN on the negative electrode side, and the connection line between the positive electrode of the battery module 9A and the relay RLP on the positive electrode side have a case ground (the same potential as the vehicle chassis). Capacitors CN and CP are inserted between the two. These capacitors CN and CP remove noise generated by the inverter device 220 to prevent malfunction of the weak electric system circuit and destruction due to the surge voltage of the IC constituting the cell controller 80. Although the inverter device 220 has a noise removal filter, these capacitors CN and CP further enhance the effect of preventing malfunction of the battery controller 20 and the cell controller 80, and improve the noise resistance reliability of the battery unit 900. Inserted to further enhance.

  In FIG. 2, the high-power circuit of the battery unit 900 is indicated by a thick line. For these wires, rectangular copper wires having a large cross-sectional area are used. The blower fan 17 is a fan for cooling the battery modules 9A and 9B, and is operated via a relay 16 that is turned on by a command from the battery controller 20.

  3 and 4 are diagrams showing an example of a specific configuration of the battery unit 900, FIG. 3 is a perspective view showing an external appearance of the battery unit 900, and FIG. 4 is an exploded perspective view. The battery unit 900 includes a substantially rectangular parallelepiped battery case 900 a including a metal upper lid 46 and a lower lid 45. The lower lid 45 is provided with output terminals 810 and 820 for supplying DC power or receiving DC power.

  A plurality of battery packs (battery cell groups) 19 composed of a plurality of battery cells are housed and fixed in the battery case 900a. The parts constituting the battery unit 900 have many wires for detecting voltage and temperature, but are covered with a battery case 900a which is a metal case, and thus are protected from external electrical noise. Further, as described above, the battery cell is protected by the battery case 900a and the outer container, and the safety of the power supply system is maintained even if a traffic accident occurs.

  In the present embodiment, the battery cell is a cylindrical lithium secondary battery in which the positive electrode active material is lithium manganese complex oxide, the negative electrode active material is amorphous carbon, and is covered with a casing having high thermal conductivity. The battery cell of this lithium secondary battery has a nominal voltage of 3.6 V and a capacity of 5.5 Ah, but when the state of charge changes, the terminal voltage of the battery cell changes. For example, when the charge amount of the battery cell decreases, it decreases to about 2.5V, and when the charge amount of the battery cell increases, it increases to about 4.3V.

  As shown in FIGS. 3 and 4, a plurality of assembled batteries 19 are arranged and fixed to the lower lid 45 in two rows in the case longitudinal direction. The plurality of assembled batteries 19 in one row constitute a battery module 9A, and the plurality of assembled batteries 19 in the other row constitute a battery module 9B. A cell controller box 79 is fixed to one end of the lower lid 45 with screws. In the cell controller box 79, a substrate 83 provided with the cell controller 80 shown in FIG. 5 is fixed by screws.

  The substrate 83 is screwed to the cell controller box 79 in an upright state through round holes formed at four locations on the upper and lower sides. Due to such a structure, the entire battery unit 900 can be stored in a relatively small space. Moreover, the complexity of wiring between each assembled battery 19 and the cell controller 80 can be eliminated. Connectors 48 and 49 are provided at the left and right ends of the board 83 at a distance from each other. The connectors 48 and 49 are connected to the battery cells of the battery modules 9A and 9B via the detection harness.

  A communication harness 50 for communicating with the battery controller 20 is led out from the substrate 83, and the communication harness 50 has a connector at the tip thereof. This connector is connected to a connector (not shown) on the battery controller 20 side. Note that chip elements such as resistors, capacitors, photocouplers, transistors, and diodes are mounted on the substrate 83, but these elements are omitted in FIG. 5 to avoid complications. On the board 83, connectors 48 and 49 are provided for the two battery modules 9A and 9B, respectively, and the communication harness 50 for communicating with the battery controller 20 is provided separately. Thus, by providing the connectors 48 and 49 and the communication harness 50 separately, wiring work becomes easy and maintenance becomes easy.

  One of the connectors 48 and 49 connects the battery cell on the high voltage side connected in series with the substrate 83, and the other connector 48 and 49 connects the battery cell on the low voltage side connected in series with the substrate 83. As a result, the voltage difference within the range of each connector can be reduced. A partial connection state in which only a part of the connectors is connected momentarily occurs when the connector is connected or opened. However, since the voltage difference within the range of each connector can be reduced, adverse effects caused by the partial connection state can be reduced.

  The battery modules 9A and 9B fixed in parallel to the lower lid 45 are connected in series by a switch 6 serving as a service disconnection (not shown). Output terminals 810 and 820 for supplying the power of the positive high voltage cable 81 and the negative high voltage cable 82 to the outside or receiving power from the outside are provided on the front portion of the lower lid 45.

(Description of transmission line)
Details of the communication transmission path between the cell controller 80 shown in FIG. 2 and the battery controller 20 operating as a host control circuit will be described. The cell controller 80 shown in FIG. 2 includes a plurality of integrated circuits CC3A, CC3B,..., CC3N, CC4A, CC4B,..., CC4N shown in FIG. It will be called battery cell controllers CC3A to CC4N.

  FIG. 1 shows battery modules 9A and 9B, battery cell controllers CC3A to CC4N, a transmission path 60, and a battery controller 20. As described above, the battery module 9A and the battery module 9B are connected in series by the switch 6. The positive side of the battery module 9A is connected to the high voltage cable 81, and the negative side of the battery module 9B is connected to the high voltage cable 82.

  Each of the battery modules 9A and 9B is composed of a plurality of battery cell groups. Each battery cell group is composed of six lithium battery cells BC1 to BC6 in this embodiment, but may be composed of four lithium battery cells, or a mixture of four and six lithium battery cells. It may be. In some cases, the power to be supplied cannot be configured by a combination of four or six battery modules. In this embodiment, a different number of battery modules, such as four or six, can be connected to the integrated circuit, and the number of lithium battery cells can be set to an optimum value according to the state of power to be supplied. It becomes.

  Battery cell controllers CC3A, CC3B,..., CC3N are provided corresponding to the battery cell groups of the battery module 9A, and battery cell controllers CC4A, CC4B,. Is provided. That is, the battery module 9A is provided with a battery cell controller group CCG1 including battery cell controllers CC3A, CC3B,..., CC3N, and the battery module 9B includes a battery cell controller group including battery cell controllers CC4A, CC4B,. CCG1 is provided.

  In FIG. 1, there are further battery cell controllers between the battery cell controller CC3B and the battery cell controller CC3N and between the battery cell controller CC4B and the battery cell controller CC4N. However, the configuration is the same and the explanation is complicated. Omitted to avoid. Further, in FIG. 1, the battery module 9A, the battery cell controller group CCG1 and the transmission path 60 shown on the upper side of the figure are the same as the battery module 9B, the battery cell controller group CCG2 and the transmission path 60 shown on the lower side of the figure. . Hereinafter, details will be described with reference to the configuration on the upper side of the figure related to the battery module 9A.

  Signal transmission and reception between the battery controller 20 and each of the battery cell controllers CC3A, CC3B,..., CC3N are performed via a transmission path 60 including a signal harness 50. The battery cell controllers CC3A, CC3B,..., CC3N are connected in series by transmission lines 602 and 604. The command signal transmitted from the transmission terminal TX1 of the battery controller 20 is transmitted to the battery cell controllers CC3A, CC3B,..., CC3N via the loop communication path, and data corresponding to the command is transmitted to the battery cell controller CC3A, The signal is received by the receiving terminal RX1 of the battery controller 20 via a loop communication path composed of CC3B,..., CC3N.

  That is, the command signal transmitted from the transmission terminal TX1 of the battery controller 20 is received by the reception terminal RX of the battery cell controller CC3A via the transmission path 60, and data corresponding to the command signal from the transmission terminal TX of the battery cell controller CC3A. Or a command is sent. The command signal received at the reception terminal RX of the battery cell controller CC3B is transmitted from the transmission terminal TX. The reception and transmission are sequentially performed in this way, and the transmission signal is transmitted from the transmission terminal TX of the battery cell controller CC3N and received by the reception terminal RX1 of the battery controller 20. Serial communication is performed through such a loop communication path. Each of the battery cell controllers CC3A, CC3B,..., CC3N starts detection and diagnosis of the terminal voltages of the battery cells BC1 to BC6 constituting the corresponding battery cell group according to the received command signal, and based on the command signal Data collected or detected by each battery cell controller is transmitted to the battery controller 20 by serial communication as described above.

  Each of the battery cell controllers CC3A, CC3B,..., CC3N further performs abnormality diagnosis and transmits a 1-bit signal via the transmission line 604 when there is an abnormality. When each battery cell controller CC3A, CC3B,..., CC3N determines that it is abnormal or when it receives a signal (abnormal signal) indicating an abnormality from the previous battery cell controller at the reception terminal FFI1, Send an abnormal signal. On the other hand, the abnormal signal transmitted from the transmission terminal FFO1 changes to a normal signal when the abnormal signal that has already been sent to the receiving terminal FFI1 does not come or the abnormality determination of itself changes to a normal determination. .

  The battery controller 20 normally does not transmit an abnormal signal to the integrated circuit, but transmits a test signal that is a pseudo abnormal signal from the transmission terminal FFOUT1 of the battery controller 20 in order to diagnose that the transmission path of the abnormal signal operates correctly. To do. A test signal that is a pseudo-abnormal signal is transmitted from the transmission terminal FFOUT1 of the battery controller 20 to the reception terminal FFI of the battery cell controller CC3A via the transmission path 604. In response to this test signal, the test signal is transmitted from the transmission terminal FFO of the battery cell controller CC3A to the reception terminal FFI of the next battery cell controller CC3B. This test signal is sequentially transmitted to the next battery cell controller, and is transmitted from the transmission terminal FFO of the battery cell controller CC3N to the reception terminal FFIN1 of the battery controller 20 via the transmission path 604.

  The battery controller 20 is configured to operate at a low voltage such as 5 volts generated from a 14V system power supply with the chassis potential of the vehicle as ground (GND). On the other hand, the power supply system composed of lithium battery cells is a power supply system that is electrically isolated from the 14V power supply, and each battery cell controller CC3A, CC3B,. It operates by receiving a potential difference, that is, a voltage between the highest potential and the lowest potential of the corresponding battery cell group. As described above, the power supply system of the battery controller 20 and the power supply system of the cell controller 80 have different potential relationships, and the voltage values are also greatly different. Therefore, the transmission path 60 connecting the battery controller 20 and the cell controller 80 is provided with an insulating circuit (photocouplers PH1 to PH4) for electrically insulating both controllers, thereby improving reliability. In FIG. 1, photocoupler PH1 and photocoupler PH2 are the same, and photocoupler PH3 and photocoupler PH4 are also the same.

  The entire battery cell of the battery module 9A is used as the power source for the photocouplers PH3 and PH4 for transmission from the battery cell controller group CCG1 to the battery controller 20, and the voltage VCC of the entire battery module 9A is supplied to the photocouplers PH3 and PH4. Added. The photocoupler cannot communicate at high speed unless a certain amount of current is passed. In this case, the photocouplers PH3 and PH4 are driven by the total voltage of the battery module 9A, and power is supplied from the battery cells of the entire battery module 9A to the photocouplers PH3 and PH4. It is possible to prevent some of the battery cells from being biased, and it is possible to suppress variation in the charge amount of each battery cell in the battery module 9A.

  In this case, the voltage obtained by combining all the battery cell groups of the battery module 9A is applied to the photocouplers PH3 and PH4. However, power may be supplied from a plurality of battery cell groups instead of all of them. The variation in the charge amount between the battery cells of the corresponding battery cell group can be suppressed. For example, a voltage between the GND terminal of the battery cell controller group CC3N and the VCC terminal of the battery cell controller group CC3B may be applied to the photocouplers PH3 and PH4.

  The photocoupler PH3 is driven via a constant current circuit 613. The photocoupler PH3 that performs data transmission needs to pass a certain amount of current as described above, and the current needs to be constant in order to have a lifetime under such conditions. If the current is small, the light emission amount of the LED of the photocoupler PH3 is reduced, the output is lowered, and the reliability of signal transmission is lowered. Conversely, if the current amount is too large, the life of the photocoupler PH3 is shortened. On the other hand, when the voltage of the battery module 9A changes, the current flowing through the photocoupler PH3 also changes, causing the above-described problems.

  Therefore, by providing the constant current circuit 613, a constant current is supplied to the photocoupler PH3 regardless of the voltage. By providing the constant current circuit 613 in this way, it is possible to prevent a decrease in signal transmission reliability and a decrease in the lifetime of the photocoupler. Furthermore, since the current flowing through the photocoupler is determined by the connected resistance, the current flowing when there is a voltage difference between the battery module 9A and the battery module 9B is different, resulting in a difference in power consumption. However, by providing the constant current circuit 613 and making the current value supplied to the photocoupler PH3 the same, it is possible to equalize the power consumption related to signal transmission between the battery module 9A and the battery module 9B.

  On the other hand, electric power for driving the light receiving element output circuits of the photocouplers PH1 and PH2 that receive signals from the battery controller 20 is supplied from the battery cell group related to the battery cell controller CC3A. A switch SW01 is provided in the transmission path between the photocoupler PH1 for data transmission reception and the battery cell controller CC3A, and the operating voltage of the photocoupler PH1 is supplied via the switch SW01. An OR circuit OR01 is provided on the base side of the switch SW01. The switch SW01 is used when a signal is transmitted from the flag transmission terminal FFOUT1 of the battery controller 20, or when the battery cell controller CC3A generates the internal voltage VDD. Operate.

  The photocoupler PH1 for data transmission / reception has a large dark current during standby, resulting in a problem of wasteful power consumption. Therefore, when the cell controller 80 is in the sleep state and does not use the transmission line, the above-described OR circuit OR01 turns off the switch SW01 and stops the power supply to the photocoupler PH1. As a result, useless power consumption can be prevented.

  When the operation of the battery cell controller groups CCG1 and CCG2 is started, a start signal is output from the flag transmission terminals FFOUT1 and FFOUT12 of the battery controller 20. The photocoupler PH2 is driven by the start signal, the switch SW01 is turned on by the OR circuit OR01, and the light receiving element circuit of the photocoupler PH1 is enabled. Thereafter, the battery controller 20 outputs a transmission signal including data and instructions from the transmission terminal TX1. The transmission signal is input to the reception terminal RX of the battery cell controller CC3A via the photocoupler PH1, and the battery cell controller CC3A operates. When the battery cell controller CC3A starts operating, a voltage VDD described later is output from the terminal VDD of the battery cell controller CC3A, a base current flows through the switch SW01, and the power supply of the photocoupler PH1 is maintained.

  The battery module 9A and the battery module 9B are detachably connected by the switch 6 as described above. The outer case of the battery unit 900 described above has a structure that cannot be opened unless the lock by the switch 6 is removed. When the switch 6 is unlocked, an electrical switch circuit between the battery modules 9A and 9B connected in series is opened, and a switch for opening / closing detection provided in the switch 6 is opened.

  When a pulse signal is output from the terminal PORTOUT of the battery controller 20, the pulse signal is input from the terminal PORTIN if the open / close detection switch provided in the switch 6 is closed. If the switch 6 is open and the open / close detection switch is open, transmission of the pulse signal is interrupted. Since the line connecting the terminal PORTIN and the open / close detection switch is connected to the ground via the resistor 620, the input potential of the terminal PORTIN is held at the ground potential in a state where transmission of the pulse signal is interrupted.

  The battery controller 20 can detect the open / close state of the open / close detection switch of the switch 6 based on the input potential of the terminal PORTIN. When the battery controller 20 detects the opening of the switch 6, the battery controller 20 transmits the open state of the switch 6 to a related control device, for example, the inverter device 220, and controls the safety of the entire system to be maintained. For example, when the switch 6 is opened, charging of the battery modules 9A and 9B by the inverter device 220 is prohibited. In the above description, the configuration related to the battery module 9A has been described, but the same effect can be achieved with respect to the transmission path 60 of the battery module 9B having the same configuration.

The effects of the battery system shown in FIG. 1 are summarized as follows.
(A) Since an insulation circuit (photocouplers PH1 to PH4) for electrical insulation is provided in the transmission line 60 connecting the battery controller 20 and the cell controller 80, reliability can be improved.
(B) Since power is supplied to the photocouplers PH1 and PH2 from the battery cells of the entire battery module 9A, it is possible to prevent the power consumption of the photocoupler from being biased to some of the battery cells of the battery module 9A. . Therefore, it is possible to suppress the variation in the charge amount of each battery cell in the battery module 9A.
(C) By providing the constant current circuit 613, a constant current is supplied to the photocoupler PH3 regardless of the total voltage of the battery module 9A as a whole, thereby preventing a decrease in signal transmission reliability and a decrease in the lifetime of the photocoupler. In addition, power consumption associated with signal transmission can be made uniform between the battery module 9A and the battery module 9B.
(D) When the cell controller 80 is in the sleep state and does not use the transmission line, the switch SW01 is turned off to stop the power supply to the photocoupler PH1, thus preventing unnecessary power consumption. can do.
(E) The open / close state of the open / close detection switch of the switch 6 can be detected, and the safety of the entire system can be improved.

  FIG. 6 shows another example of the transmission line 60. In the system shown in FIG. 1 described above, signals output from the transmission terminals TX and FFO of the battery cell controller CC3N of the battery module 9A are input to the reception terminals RX1 and FFIN1 of the battery controller 20 via the photocouplers PH3 and PH4. Further, the signals output from the transmission terminals TX and FFO of the battery cell controller CC4N of the battery module 9B are input to the reception terminals RX2 and FFIN2 of the battery controller 20 via the photocouplers PH3 and PH4. That is, the battery cell controller group CCG1 and the battery cell controller group CCG2 are configured to form separate communication loops.

  On the other hand, in the example shown in FIG. 6, signals output from the transmission terminals TX and FFO of the battery cell controller CC3N of the battery module 9A are input to the corresponding reception terminals RX and FFI of the battery cell controller CC4A of the battery module 9B, respectively. I did it. In this case, the transmission paths 602 and 604 connected to the transmission terminals TX and FFO of the battery cell controller CC3N of the battery module 9A are connected to the receiving photocouplers PH1 and PH2 of the battery module 9B. In other words, the transmission terminals TX and FFO of the battery cell controller CC3N of the battery module 9A and the reception terminals RX and FFI of the battery cell controller CC4A of the battery module 9B are connected via the photocouplers PH1 and PH2 which are insulating circuits. .

  In the case of the configuration shown in FIG. 1, a communication loop on the battery module 9A side and a communication loop on the battery module 9B side are provided separately. On the other hand, in the case of the configuration shown in FIG. 6, the battery cell controller group CCG1 and the battery cell controller group CCG2 are connected in series to form one communication loop. There is an advantage that the number of input / output terminals of the battery controller 20 may be small. In the case of the configuration shown in FIG. 6, the battery cell controller group CCG1 and the battery cell controller group CCG2 related to the battery modules 9A and 9B that are detachably connected by the switch 6 are signaled via an insulation circuit (photocouplers PH1 and PH2). Therefore, the reliability can be improved as in the case of FIG. That is, in the embodiment shown in FIG. 6, when the switch 6 is opened, the connection between the lithium battery cell BC6 constituting the battery module 9A and the lithium battery cell BC1 constituting the battery module 9B is released, and the battery module 9A and the battery module are opened. The circuit of the current flowing through 9B is cut off, and safety is improved.

  However, when the switch 6 is closed, the GND terminal of the integrated circuit CC3N and the VCC terminal of the integrated circuit CC4A are electrically connected, and the potentials of the integrated circuit CC3N and the integrated circuit CC4A are predetermined. The value is kept stable. When the switch 6 is opened, the GND terminal of the integrated circuit CC3N and the VCC terminal of the integrated circuit CC4A are electrically opened, and the potential between the integrated circuits is not determined. In this state, electrical transmission is performed between the transmission terminals “RX”, “RT”, “FFI”, “FFO” of the integrated circuit CC3N and “RX”, “RT”, “FFI”, “FFO” of the integrated circuit CC4A. If there is a general connection relationship, a potential difference between the integrated circuit CC3N and the integrated circuit CC4A is applied to the connection portion. Since the integrated circuit CC3N and the integrated circuit CC4A do not have a high withstand voltage, a potential difference occurs between the integrated circuits when the switch 6 is opened due to a leak circuit or the like occurring somewhere. There is a risk of damage. In FIG. 6, since the transmission path of the integrated circuit CC3N and the integrated circuit CC4A related to both ends of the switch 6 is connected via an insulating circuit, the reliability is improved.

  In the example shown in FIG. 1 and FIG. 6, the transmission direction is a method of transmitting from a high potential to a low potential, but a method of transmitting from a low potential to a high potential, A method that wraps data using both methods is also possible. A circuit for transmitting from a low potential to a high potential will be described later.

  The battery system shown in FIG. 7 is a modification of the battery system shown in FIG. 6, and is formed by connecting battery modules 9C and 9D connected in series to the battery modules 9A and 9B shown in FIG. . The battery modules 9C and 9D are detachably connected by the switch 6. The battery modules 9C and 9D are connected to the battery cell controller groups CCG3 and CCG4 having the same configuration as the battery cell controller groups CCG1 and CCG2 shown in FIG. Is provided.

  The reception terminals RX and FFI of the battery cell controller group CCG3 are connected to the transmission terminals TX3 and FFOUT3 provided in the battery controller 20 via the insulation circuit 630, respectively, and the transmission terminals TX and FFO of the battery cell controller group CCG4 are insulated. The circuit 630 is connected to receiving terminals RX4 and FFIN4 provided in the battery controller 20, respectively. In addition, the transmission terminals TX and FFO of the battery cell controller group CCG3 are connected to the reception terminals RX and FFI of the battery cell controller group CCG4 via the insulation circuit 630, respectively. The insulation circuit 630 in FIG. 7 corresponds to the photocouplers PH1 and PH2 shown in FIG. Note that the photocoupler PH1 and the photocoupler PH3 in FIG. 6 are the same, and the photocoupler PH2 and the photocoupler PH4 are the same. By configuring the transmission line in this way, reliability is improved.

  The battery system shown in FIG. 8 is a modification of the battery system shown in FIG. 1, and battery modules 9A and 9D having the same structure as the battery modules 9A and 9B are arranged in parallel with the battery modules 9A and 9B shown in FIG. Connected. The battery cell controller groups CCG1 and CCG2 of the battery modules 9A and 9B are connected to the battery controller 20 through separate communication loops, and the transmission paths 602 and 604 of the battery cell controller groups CCG3 and CCG4 of the battery modules 9C and 9D are also included. Each forms a separate communication loop. Each transmission path 602, 604 is connected to the battery controller 20 via an insulation circuit 630. As described above, since the transmission between the integrated circuit on both sides of the switch 6 and the host control circuit is performed via the photocoupler 630, the reliability when the switch 6 is opened is improved and the parallel transmission path is used. High-speed transmission can be realized.

  In the transmission paths shown in FIGS. 1 and 8, transmission using terminals [TX] and terminals [RX] that require high-speed transmission is performed as shown in FIG. 1 and FIG. 20] is connected to each other by an insulating circuit, and transmission using terminals [FFI] and terminals [FFO], which are relatively low-speed transmissions, are integrated circuits at both ends of the switch 6 as shown in FIGS. The transmission terminals can be connected via an insulating circuit. In this case, the number of terminals used in the host control circuit [20] can be reduced while ensuring reliability and high-speed transmission.

(Measures against short-circuit current and noise)
FIG. 9 is a diagram showing a connection between the battery cell controller CC3N and each battery cell of the battery cell group corresponding to the battery cell controller CC3N. In FIG. 1 and FIG. 6, in order to simplify the explanation, a filter circuit that reduces noise generated by the inverter device 220 and the like, and a discharge resistance for equalizing the stored electric energy of the Li battery cell are not shown. However, FIG. 9 shows them in detail. The battery cell controllers other than the battery cell controller CC3N have the same connection, and here, the battery cell controller CC3N will be described as a representative.

  The battery cell controller CC3N includes voltage detection terminals CV1 to CV6 and GND in order to detect terminal voltages of the battery cells BC1 to BC6 constituting the corresponding battery cell group. The terminals CV1 to CV6 and the terminal GND are connected to the positive and negative electrodes of the battery cells BC1 to BC6, respectively. Also, resistors R30 are provided on the input lines of the terminals CV1 to CV6, respectively. The battery cell controller CC3N operates by receiving a potential difference between the highest potential and the lowest potential of the battery cell group corresponding to the battery cell controller CC3N, that is, the total voltage of the battery cell group.

  The battery cell controller CC3N includes a circuit related to voltage detection of the battery cells BC1 to BC6 (a differential amplifier 262, an analog-digital converter 122, a data holding circuit 125 described later), and a circuit that performs overcharge diagnosis and overdischarge diagnosis. . Each voltage of the battery cells BC1 to BC6 is input to the circuit that detects the voltage. However, since the voltage is input to each terminal via the resistor R30, for example, the terminal voltage of the battery cells BC1 to BC6 Even if an abnormal short circuit occurs in the detection line that leads to the battery cell controller CC3N, the short circuit current is limited for these circuits.

  When the inverter device 220 of FIG. 1 performs DC-AC power conversion, a large noise is generated. Further, as described above, automobiles are used in a wide range of environmental conditions from low temperature to high temperature. The smoothing capacitor 228 and the like included in the inverter device 220 have a reduced capability as a capacitor at a low temperature. Therefore, when an electrolytic capacitor is used, the capability is extremely reduced as compared with a film capacitor. In this way, not only the capacity degradation state of the capacitor but also a large noise is always added to the battery cells BC1 to BC6, and a countermeasure is desirable. In this embodiment, as shown in FIG. 9, since capacitors C10 and C20 and resistor R30 are provided, the noise removal function is provided for these noises.

  As described with reference to FIG. 1, the circuit for driving the photocouplers PH3 and PH4 at the final stage of the transmission line 60 is driven by the power supplied from the lowest potential terminal and the highest potential terminal of each battery cell controller group CCG1 and CCG2. Circuit configuration. For example, when the circuit operates with the voltage VCC of the battery cell controller CC3N in the final stage, there is an abnormality such as disconnection in the voltage detection line of the battery cell controller CC3M on the one stage high potential side of the battery cell controller CC3N. When this occurs, an unexpectedly high voltage may be applied to the photocoupler drive circuit. However, such a malfunction can be prevented by adopting a circuit configuration that is driven by the power supplied from the lowest potential terminal and the highest potential terminal of the battery cell controller groups CCG1 and CCG2.

(Explanation of battery cell controller)
FIG. 10 is a diagram illustrating an internal configuration of the battery cell controller CC3N that is an integrated circuit. The other battery cell controllers have the same configuration, and here, the battery cell controller CC3N will be described as an example. The terminal voltages of the lithium battery cells BC1 to BC6 are input to the multiplexer 120 via the terminals CV1 to CV6. The multiplexer 120 selects any one of the terminals CV 1 to CV 6 and inputs it to the differential amplifier 262. The output of the differential amplifier 262 is converted into a digital value by the analog-digital converter 122A. The inter-terminal voltage converted into a digital value is sent to the IC control circuit 123 and held in the internal data holding circuit 125. These voltages are used for diagnosis or transmitted to the battery controller 20 shown in FIG. The terminal voltage of each lithium battery cell input to the terminals CV1 to CV6 is biased with a potential based on the terminal voltage of the lithium battery cells connected in series to the ground potential of the battery cell controller that is an integrated circuit. The influence of the bias potential is removed by the differential amplifier 262, and an analog value based on the terminal voltage of each lithium battery cell is input to the analog-digital converter 122A.

  The IC control circuit 123 has an arithmetic function, a data holding circuit 125, a timing control circuit 126 for periodically detecting various voltages and diagnosing conditions, and a diagnostic flag holding in which a diagnostic flag from the diagnostic circuit 130 is set. Circuit 128. The diagnosis circuit 130 performs various diagnoses, for example, overcharge diagnosis and overdischarge diagnosis, based on the measurement value from the IC control circuit 123. The data holding circuit 125 is composed of, for example, a register circuit, stores the detected voltages between the terminals of the battery cells BC1 to BC6 in association with the battery cells BC1 to BC6, and stores other detection values. It is held so that it can be read out at a predetermined address.

  Each battery cell controller described as a representative example of the battery cell controller CC3N includes a balancing semiconductor switch for adjusting the amount of charge (also referred to as a charged state) of each of the lithium battery cells BC1 to BC6 constituting the corresponding lithium battery cell group. (NMOS, PMOS) are provided. For example, the charge amount of the battery cell BC1 is adjusted by a PMOS switch provided between the terminal CV1 and the terminal BR1. Similarly, an NMOS switch for adjusting the charge amount of the battery cell BC2 is provided between the terminal BR2 and the terminal CV3, and a PMOS for adjusting the charge amount of the battery cell BC3 is provided between the terminal CV3 and the terminal BR3. A PMOS switch for adjusting the charge amount of the battery cell BC4 between the terminals BR4 and CV5, and a PMOS for adjusting the charge amount of the battery cell BC5 between the terminals CV5 and BR5. An NMOS switch for adjusting the amount of charge of the battery cell BC6 is provided between the terminal BR6 and the terminal GND, respectively.

  Opening and closing of these balancing semiconductor switches is controlled by a discharge control circuit 132. The discharge control circuit 132 is supplied with a command signal for conducting the balancing semiconductor switch corresponding to the battery cell to be discharged from the IC control circuit 123. The IC control circuit 123 receives a discharge time command corresponding to each of the battery cells BC1 to BC6 from the battery controller 20 of FIG. 1 through communication, and executes the discharge operation.

  In charging the battery modules 9A and 9B, current is supplied from the electric load to the whole of a large number of battery cells connected in series. When a large number of battery cells connected in series are in different charging states, the supply of current to the electric load is limited by the state of the battery cell in the most discharged state among the large number of battery cells. On the other hand, when a current is supplied from an electric load, the supply of current is limited by the most charged battery cell among many battery cells.

  For this reason, among a plurality of battery cells connected in series, for example, for a plurality of battery cells in a charged state exceeding the average state, the balancing semiconductor switch connected to these battery cells is made conductive, A discharge current is passed through the connected resistors R30 and R20. Thereby, the charged state of the plurality of battery cells connected in series is controlled in a direction approaching each other. As another method, there is a method in which the battery cell in the most discharged state is used as a reference cell, and the discharge time is determined based on the difference in charge state from the reference cell. There are various other methods for adjusting the state of charge. The state of charge can be obtained by calculation based on the terminal voltage of the battery cell. Since the charge state of the battery cell and the terminal voltage of the battery cell are correlated, the charge state of each battery cell can be made closer by controlling the balancing semiconductor switch so that the terminal voltage of each battery cell is made closer. .

(Power supply voltage VCC and power supply voltage VDD)
At least two types of power supply voltages VCC and VDD (3 V) are used in the internal circuit of the battery cell controller CC3N. In the example shown in FIG. 10, the voltage VCC is the total voltage of the battery cell group including the battery cells BC1 to BC6 connected in series, and the voltage VDD is a constant voltage for starting the main constant voltage power supply 134 and the start output circuit 135. Generated by power supply 136. The multiplexer 120 and the transmission input circuits 138 and 142 for signal transmission operate at a high voltage VCC. The analog-digital converter 122A, the IC control circuit 123, the diagnostic circuit 130, and the transmission output circuits 140 and 143 for signal transmission operate at a low voltage VDD (3 V).

As described above, the following effects can be obtained by using the two power supply voltages VCC and VDD.
(A) By driving the analog-digital converter 122A, the IC control circuit 123, the diagnostic circuit 130, and the transmission output circuits 140 and 143 with the power supply of the low voltage VDD, the withstand voltage required for these circuits can be lowered and the reliability is improved. Improvement, cost reduction, and the like. Further, a high-accuracy voltage can be supplied to the analog-digital converter 122A, which leads to an improvement in measurement accuracy.
(B) By reducing the power supply voltage, the power consumption of the battery cell controller can be suppressed, and the power consumption of the battery modules 9A and 9B can be reduced.
(C) The battery cell controllers CC3A to CC3N are connected in series by driving the transmission input circuits 138 and 142 for signal transmission with a high voltage power supply (VCC) and driving the transmission output circuits 140 and 143 with a low voltage VDD. (Daisy chain connection) has the following major advantages. That is, by driving the transmission output circuits 140 and 143 at the low voltage VDD, the peak value of the signal input to the transmission destination battery cell controller is lowered, and the withstand voltage of the transmission destination battery cell controller can be lowered. . Further, even when the withstand voltage of the battery cell controller at the transmission destination is not lowered, the margin for the withstand voltage is increased and the reliability is increased.
(D) Driving the transmission input circuits 138 and 142 with a high voltage power supply (VCC) and driving the transmission output circuits 140 and 143 with a low voltage VDD, that is, changing the drive voltages of the transmission input circuit and the transmission output circuit. Thus, the stability of the operation is increased.

(Explanation of signal waveform)
11 and 12 are diagrams for explaining the relationship between the drive voltage of the transmission output circuit 140 and the peak value of the signal transmission destination. FIG. 11 shows the transmission output circuit 140 of the battery cell controller CCM on the transmission side and the transmission input circuit 138 of the battery cell controller CCN on the reception side. The transmission output circuit 140 is shown with a part of the transmission output circuit 140 shown in FIG. 10 omitted. FIG. 12 is a diagram showing signal waveforms.

  As shown in FIG. 11, the transmission output circuit 140 outputs a signal having a waveform as shown in the upper left of FIG. 12 from the transmission terminal TX by controlling the opening and closing of the switches 244 and 245 by the control circuit 246. As shown in FIG. 1, the terminal GND (ground) of the battery cell controller in the upper transmission direction is connected to the terminal VCC of the battery cell controller in the lower transmission direction. Therefore, the transmission output circuit 140 outputs a signal having an amplitude of the voltage VDD with reference to the ground of the battery cell controller CCM, that is, the VCC of the battery cell controller CCN. When the switch 245 is opened and the switch 244 is closed, a high level (potential VCC + VDD) signal is output. Conversely, when the switch 245 is closed and the switch 244 is opened, a low level (potential VCC) signal is output (left side 12L in FIG. 12). (Refer to the waveform of).

  The signal output from the transmission terminal TX of the battery cell controller CCM is input to the reception terminal RX of the lower battery cell controller CCN in the transmission direction, and then input to the differential amplifier 231 of the transmission input circuit 138. The differential amplifier 231 outputs a signal corresponding to the difference between the input battery cell controller CCM signal and the battery cell controller CCN voltage VCC. The signal shown in the center 12C of FIG. 12 indicates the output signal of the differential amplifier 231 (the signal at the point P in FIG. 11). The low level of the signal becomes the ground level of the battery cell controller CCN, and the high level of the signal. Becomes a potential of the ground level + VDD. The signal output from the differential amplifier 231 is compared with the threshold value VDD / 2 by the comparator 232 to obtain [1] and [0] signals.

  Each battery cell controller has a circuit 231 that receives a signal from another adjacent battery cell controller and a circuit 234 that receives a signal from a photocoupler. Which of these circuits is used is determined by: The switch 233 selects the control signal applied to the terminal CT1 shown in FIG. When the battery cell controller CCN is the highest cell controller in the transmission direction of the battery cell controller group CCG1, that is, when a signal from the photocoupler PH1 is input to the reception terminal RX of the battery cell controller CCN, the switch 233 is The lower contact is closed, and the output signal of the comparator 234 is output from the transmission input circuit 138. On the other hand, when the signal from the adjacent battery cell controller is input to the reception terminal RX of the battery cell controller CCN, the upper contact of the switch 233 is closed, and the output signal of the comparator 232 is output from the transmission input circuit 138. In the case of the battery cell controller CCN shown in FIG. 11, since the signal from the adjacent battery cell controller CCM is input to the transmission input circuit 138, the upper contact of the switch 233 is closed.

  When the battery cell controller CCN is the uppermost battery cell controller, a signal as shown on the right side 12R in FIG. 12 is input from the photocoupler PH1 to the reception terminal RX. The high level of the input signal in this case is the potential VCC with reference to the ground level of the battery cell controller. The comparator 234 compares the signal from the photocoupler PH1 input to the reception terminal RX with the threshold value VCC / 2, and outputs [1] and [0] signals.

  The transmission input circuit 142 and the transmission output circuit 143 shown in FIG. 10 have the same circuit configuration as the transmission input circuit 138 and the transmission output circuit 140 described above, and the signal transmission between the terminal FFI and the terminal FFOUT is also described above. Since it is the same as that of a thing, description is abbreviate | omitted here.

(Control terminals CT1 to CT3)
The battery cell controller CC3N shown in FIG. 10 includes control terminals CT2 and CT3 for switching operations in addition to the control terminal CT1 described above. As described above, the control terminal CT1 is a terminal for selecting whether to receive a transmission signal from the photocouplers PH1 and PH2 or from an adjacent battery cell controller. Since the output waveform peak value differs between the output from the photocoupler and the output from the terminal TX and terminal FFO of the adjacent battery cell controller, the determination threshold value is different. Therefore, the switches 233 and 252 of the transmission input circuit 138 and the activation input circuit 147 are switched based on the control signal of the control terminal CT1. Switching of the switch 233 is performed as described above, and switching of the switch 252 will be described later.

  The control terminal CT2 is a control terminal for selecting whether to transmit a signal to an adjacent battery cell controller or to transmit to a photocoupler when a signal is output from the transmission terminals TX and FFOUT. Although details will be described later, the relationship (polarity) of the signal waveform [H / L] corresponding to the signal [1] / [0] differs between when transmitting to the adjacent battery cell controller and when transmitting to the photocoupler. .

  The control terminal CT3 is a control terminal for selecting the number of cells in the battery cell group associated with the battery cell controller CC3N. For example, 6 cells or 4 cells are selected. Then, the control in the terminal voltage measurement or the like is switched to an optimum one according to the selected number of cells. As a result, by combining the battery cell group of 4 cells and the battery cell group of 6 cells, it becomes possible to easily configure the battery modules 9A and 9B having various numbers of cells.

  13 and 14 are diagrams for explaining the function of the control terminal CT2. As described above, the control terminal CT2 is a control terminal for selecting whether the signal transmission destination is an adjacent battery cell controller or the photocouplers PH3 and PH4, and a control signal indicating the transmission destination is input thereto. The switch 241 of the transmission output circuits 140 and 143 switches the inversion or non-inversion of the transmission signal based on the control signal from the control terminal CT2. As will be described later, when the transmission destination is the photocouplers PH2 and PH4 in FIG. 1, the transmission signal is inverted to reduce the power consumption of the photocouplers PH2 and PH4. The transmission system between the terminal RX1 and the terminal TX1 and the transmission line system between the terminal FFOUT1 and the terminal FFIN1 have the same basic operation and effect, and the RX1-TX1 transmission system will be described as an example below as a representative.

  A signal A of the transmission line 602 in FIG. 13 is an output of the battery controller 20 which is a host controller, and the signal corresponding to [1] is “high level” as shown in FIG. It is “low level” when no signal is present and at [0]. Therefore, when there is no signal, the output from the transmission terminal TX1 of the battery controller 20 does not drive the photocoupler PH1, so that the power consumption of the photocoupler PH1 is reduced. Further, since the photocoupler PH1 is not driven, the circuit that receives light is not driven, and the circuit that receives light is cut off and no current flows, which contributes to reduction in power consumption.

  In such a cut-off state, the reception terminal RX of the battery cell controller CC3A is at a high level. Therefore, in the signal B of the transmission line 602 connected to the reception terminal RX, [0] is “high level” and [1] is “low level” as shown in FIG. The processing of the battery cell controller CC3A is performed in this relationship, and a signal is transmitted to the next battery cell controller CC3B while maintaining this relationship. Hereinafter, signals are successively transmitted to the battery cell controllers connected in series in such a relationship.

  The output of the battery cell controller CC3N that drives the photocoupler PH3 (output of the transmission terminal TX) is the above relationship, that is, [0] is “high level” and [1] is “low level”. In this case, the output level (output voltage) becomes “high level” not only in the [0] state of the signal but also in the period when the transmission signal is not output. In this case, the output is at a high level not only in the [0] state of the signal but also in the period when the transmission signal is not output. As a result, the photocouplers PH3 and PH4 on the output side are driven even during a period in which no transmission signal is output, and wasteful power is consumed.

  In the present embodiment, as shown in FIG. 10, the transmission output circuits 140 and 143 are provided with a switch 241 and an inverter 242. Switching of the switch 241 is performed based on the control signal from the control terminal CT2, and when transmitting to the photocouplers PH3 and PH4, the signal is inverted by the inverter 242 and output, and the transmission signal is transmitted to the adjacent battery cell controller. When transmitting, the transmission signal is output without inversion. Thus, by inverting the transmission signal and outputting it from the transmission terminals TX and FFO, the signal C of the transmission line 602 connected to the transmission terminal TX of the battery cell controller CC3N of FIG. 13 is as shown in FIG. It will be a thing. In the signal C, the signal [0] and the signal during the period when the transmission signal is not output are inverted to the “low level” (low voltage) state, and the photocouplers PH3 and PH4 are not driven. As a result, the power consumption of the photocoupler in this state can be reduced to substantially zero. Further, since the semiconductor that receives light is also cut off, the power consumption is reduced in this respect as well.

  Since the output side of the photocouplers PH3 and PH4 is pulled up by a resistor, when the photocouplers PH3 and PH4 are driven, the potential on the output side becomes a low level (ground level), and the driving of the photocouplers PH3 and PH4 is stopped. Then, it becomes high level (VCC). Therefore, the signal D of the transmission line connecting the photocoupler PH3 and the reception terminal RX of the battery controller 20 has a waveform as shown in FIG.

  In FIG. 10, when the constant voltage VDD (3 V) is output from the main constant voltage power supply 134, the battery cell controller CC3N rises from the sleep state and enters the operation state. 15 and 16 are diagrams for explaining operation stop and operation start of the main constant voltage power supply 134. FIG. 15 shows the start input circuit 147, the timer circuit 150, and the main constant voltage power supply 134, and FIG. 16 shows FIG. The signal output from each circuit is shown. When the activation input circuit 147 receives a signal transmitted from the adjacent battery cell controller or the photocoupler, the timer circuit 150 operates and supplies the voltage VCC to the main constant voltage power supply 134. By this operation, the main constant voltage power supply 134 is in an operating state, and the constant voltage generation circuit 153 outputs the constant voltage VDD.

  Since the signal received at the receiving terminal RX always has high and low levels (potential level), the change is captured by the differential trigger circuit 253 including a capacitor or the like, and the trigger signal is transmitted to the timer circuit 150. The timer circuit 150 stops the drive output and stops the operation of the main constant voltage power supply 134 when a trigger signal is not input for a predetermined period, for example, 10 seconds. The timer circuit 150 is configured by a preset type down counter 152, for example, and can be realized by a circuit in which a count value is set every time a trigger signal is input. As shown in FIG. 16, when the count value reaches a predetermined value (eg, zero), the signal output is stopped and the VCC voltage supplied to the constant voltage generation circuit 153 is cut off.

  On the other hand, when an activation signal is output from the transmission terminal FFOUT of the battery controller 20, which is the host controller in FIG. 1, the switch SW01 is turned on and power is supplied to the photocoupler PH1 that transmits the TX signal. As a result, the signal is transmitted to the reception terminal RX of the uppermost battery cell controller CC3A and is input from the reception terminal RX to the activation input circuit 147. In the start input circuit 147, a switch 252 is provided. In a battery cell controller connected to receive a signal from the photocoupler PH1, the lower contact of the switch 252 is always set by a signal applied to the control terminal CT1. Closes. In such a battery cell controller, the input signal is compared with a threshold value (VCC + 1.5 V) by the comparator 250. On the other hand, in a battery cell controller that receives a signal from an adjacent battery cell controller, the switch 252 always closes the upper contact by a signal applied to the control terminal CT1, and the input signal is set to a threshold value (1.5V) by the comparator 251. Compare.

  The start input circuit 147 outputs a [0] / [1] signal based on the comparison result to the timer circuit 150 and the start output circuit 135 via the differential trigger circuit 253. The startup output circuit 135 includes switches 254 and 255 connected to the startup constant voltage power supply 136 having an output voltage of 3 V, and a control circuit 256 that controls the opening and closing thereof, and the signal from the startup input circuit 147 is amplified. The signal is changed to a 3V signal and transmitted to the switch 243 of the transmission output circuit 140. The switch 243 performs switching depending on whether it is activated or not, and the lower contact is closed before activation. Therefore, the signal transmitted from the activation output circuit 135 is transmitted from the transmission terminal TX to the reception terminal RX of the next battery cell controller.

  As described above, since the signal is sent from the activation output circuit 135 to the reception terminal RX of the next battery cell controller separately from the rising operation (activation operation) of the battery cell controller that has received the signal from the reception terminal RX, the battery cell controller Compared with the case where a signal is sent to the next battery cell controller after starting up, the operation start of the entire system is accelerated.

  In the embodiment described with reference to FIG. 1 and FIGS. 6 to 13, the information transmission direction of the transmission line is not limited to the direction from the higher potential to the lower direction, but information is transmitted from the higher potential to the lower direction as an example. The circuit to be described is described. As in the embodiments described in FIG. 1 and FIGS. 6 to 13, there are various advantages in that information is transmitted from a higher potential to a lower direction, but the above effect can be obtained even in the reverse direction. . Hereinafter, an embodiment in which information is transmitted from a lower potential to a higher potential will be described with reference to FIGS. However, the basic operation is the same as that of the embodiment described in FIG. 1 and FIGS. 6 to 13, and the basic operation and common effects are omitted. In addition, the transmission line formed by connecting the terminal RX or the terminal TX and the transmission line formed by connecting the terminal FFI or the terminal FFO have almost the same operation regarding the relationship between the potential change and the transmission / reception of the battery cell controller. There will be described as a representative transmission line formed by connecting the terminal RX and the terminal TX.

(Description of other embodiment of transmission circuit and signal waveform)
FIGS. 17, 18, and 19 are other embodiments relating to the embodiment described with reference to FIGS. 11 and 12 for explaining the relationship between the drive voltage of the transmission output circuit 140 and the peak value of the signal transmission destination. In the present embodiment, unlike FIGS. 1, 6, 7, and 8, information is transmitted from the transmission terminal RX having a low potential to the reception terminal TX having a high potential. FIG. 17 shows the transmission output circuit 140 of the battery cell controller CCM on the transmission side and the transmission input circuit 138 of the battery cell controller CCN on the reception side. The transmission output circuit 140 corresponds to the transmission output circuit 140 shown in FIG. 11 described above, and a part of the transmission output circuit 140 described in FIG. 10 is omitted. 18 and 19 are diagrams showing signal waveforms of information to be transmitted.

  In FIG. 17, the transmission output circuit 140 includes a circuit in which opening and closing of the switches 244 and 245 shown in FIG. 11 are controlled by the control circuit 246, but these circuits are omitted. The transmission output circuit 140 of the battery cell controller CCM outputs a signal having a waveform indicated by 18L in FIG. 18 from the transmission terminal TX. In the present embodiment, the terminal VCC of the upper battery cell controller CCM in the transmission direction is connected to the terminal GND (ground) of the lower battery cell controller CCN in the transmission direction. Therefore, the transmission output circuit 140 outputs a signal having an amplitude of the voltage (VCC + VDD) with reference to the ground of the battery cell controller CCM.

  The signal output from the transmission terminal TX of the battery cell controller CCM is input to the reception terminal RX of the lower battery cell controller CCN in the transmission direction, and then input to the comparator 232 of the transmission input circuit 138. Since the comparator 232 has the ground level at the VCC potential of the battery cell controller CCM and further uses the VDD / 2 voltage as a threshold in addition to the ground potential, the output signal of the battery cell controller CCM is compared with the voltage (VCC + VDD / 2). Is done. This state is indicated by a signal 18C in FIG.

  As shown in FIG. 11, each battery cell controller shown in FIG. 17 has a comparator 232 that receives a signal from another adjacent battery cell controller, and a comparison circuit 234 that receives a signal from a photocoupler. Which of these comparison circuits is used is selected by a switch 233 that operates based on a control signal applied to the terminal CT1. When the battery cell controller CCN is the highest cell controller in the transmission direction of the battery cell controller group CCG1, that is, when the signal from the photocoupler PH1 is input to the receiving terminal RX of the battery cell controller CCM or CCN, switching is performed. The lower contact of the device 233 is closed, and the output signal of the comparator 234 is used as a transmission input signal.

  In the case of the battery cell controller CCN of FIG. 17, since the output terminal TX of the adjacent battery cell controller CCM is connected to the reception terminal RX of the battery cell controller CCN, the switch 233 is based on the control signal received by the terminal CT1. The upper contact is closed, and the output signal of the comparator 232 is output as the output signal of the transmission input circuit 138.

  FIG. 19 shows an operation when the battery cell controller receives a signal from a photocoupler that is an electrical insulation circuit. When the battery cell controller receives a signal from the photocoupler, the switch 233 selects the comparator 234 based on the control signal applied to the terminal CT1. As described above with reference to FIG. 12, the amplitude of the signal input from the photocoupler to the reception terminal RX changes with the voltage VCC with reference to the ground level of the battery cell controller. Therefore, in this embodiment, the threshold value of the comparator 234 that compares the signals from the photocoupler is set to the voltage VCC / 2, which is a voltage higher than the threshold value of the comparator 232, as in the case described with reference to FIG. The comparator 232 compares the input signal with the threshold value VCC / 2, and outputs the result [1] and [0] signals which are digital values.

  Note that the transmission input circuit 138 and the transmission output circuit 140 shown in FIG. 17 are the same in the transmission path using the terminal FFO and the terminal FFI described below, and the description thereof is omitted here.

(Description of another embodiment of the battery cell controller)
FIG. 20 is a diagram of another embodiment for explaining the internal configuration of each battery cell controller that is an integrated circuit described above with reference to FIG. 10. The configuration shown in FIG. Is the difference. The other battery cell controllers have the same configuration, but here, the battery cell controller CC3N will be described as an example.

  As described in FIG. 10, the terminal voltages of the lithium battery cells BC1 to BC6 are input to the multiplexer 120 via the terminals CV1 to CV6. The multiplexer 120 selects any one of the terminals CV 1 to CV 6 and inputs it to the differential amplifier 262. The output of the differential amplifier 262 is converted into a digital value by the analog-digital converter 122A. The inter-terminal voltage converted into a digital value is sent to the IC control circuit 123 and held in the internal data holding circuit 125. These voltages are used for diagnosis or transmitted to the battery controller 20 shown in FIG.

  Similar to the description of FIG. 10, the IC control circuit 123 has an arithmetic function, a data holding circuit 125, a timing control circuit 126 that periodically detects various voltages and performs state diagnosis, and a diagnostic flag from the diagnostic circuit 130. And a diagnostic flag holding circuit 128 in which is set. The diagnosis circuit 130 performs various diagnoses, for example, overcharge diagnosis and overdischarge diagnosis, based on the measurement value from the IC control circuit 123. The data holding circuit 125 is composed of, for example, a register circuit, stores the detected voltages between the terminals of the battery cells BC1 to BC6 in association with the battery cells BC1 to BC6, and stores other detection values. It is held so that it can be read out at a predetermined address.

  As described above with reference to FIG. 10, each battery cell controller includes a balancing semiconductor for adjusting the amount of charge (also referred to as a charged state) of each of the lithium battery cells BC <b> 1 to BC <b> 6 constituting the corresponding lithium battery cell group. Switches (NMOS, PMOS) are provided. For example, the charge amount of the battery cell BC1 is adjusted by a PMOS switch provided between the terminal CV1 and the terminal BR1. Similarly, an NMOS switch for adjusting the charge amount of the battery cell BC2 is provided between the terminal BR2 and the terminal CV3, and a PMOS for adjusting the charge amount of the battery cell BC3 is provided between the terminal CV3 and the terminal BR3. A PMOS switch for adjusting the charge amount of the battery cell BC4 between the terminals BR4 and CV5, and a PMOS for adjusting the charge amount of the battery cell BC5 between the terminals CV5 and BR5. An NMOS switch for adjusting the amount of charge of the battery cell BC6 is provided between the terminal BR6 and the terminal GND, respectively.

  Opening and closing of these balancing semiconductor switches is controlled by a discharge control circuit 132. The discharge control circuit 132 is supplied with a command signal for conducting the balancing semiconductor switch corresponding to the battery cell to be discharged from the IC control circuit 123. The IC control circuit 123 receives a discharge time command corresponding to each of the battery cells BC1 to BC6 from the battery controller 20 of FIG. 1 through communication, and executes the discharge operation.

  As described above with reference to FIG. 10, each battery cell controller CC3N uses at least two types of power supply voltages VCC and VDD (3V). Here, the voltage VCC is a voltage higher than VDD, and in the present embodiment, the voltage VCC is a total voltage of a battery cell group composed of battery cells BC1 to BC6 connected in series, and the voltage VDD is the main constant voltage power supply 134. And a voltage generated by the starting constant voltage power source 136 of the starting output circuit 135. Multiplexer 120 operates at high voltage VCC. On the other hand, transmission input circuits 138 and 142 for signal transmission or transmission output circuits 140 and 143 for signal transmission, or analog-digital converter 122A, IC control circuit 123, diagnostic circuit 130, and transmission output circuit 140 for signal transmission. , 143 operate at a low voltage VDD (3 V).

As described above, the following effects can be obtained by using the two power supply voltages VCC and VDD.
(A) By driving the analog-digital converter 122A, the IC control circuit 123, the diagnostic circuit 130, and the transmission output circuits 140 and 143 with the power supply of the low voltage VDD, the withstand voltage required for these circuits can be lowered and the reliability is improved. Improvement, cost reduction, and the like. Further, a high-accuracy voltage can be supplied to the analog-digital converter 122A, which leads to an improvement in measurement accuracy.
(B) By reducing the power supply voltage, the power consumption of the battery cell controller can be suppressed, and the power consumption of the battery modules 9A and 9B can be reduced.
(C) By driving the transmission input circuits 138 and 142 or the transmission output circuits 140 and 143 for signal transmission with the low voltage VDD, the peak value of the signal input to the battery cell controller at the transmission destination is reduced, and transmission is performed. The withstand voltage of the previous battery cell controller can be lowered. Further, even when the withstand voltage of the battery cell controller at the transmission destination is not lowered, the margin for the withstand voltage is increased and the reliability is increased.

  The transmission output circuit 140 operates as described above with reference to FIG. 17. As shown in detail in FIG. 20, the transmission output circuit 140 generates a signal to be transmitted to the adjacent battery cell controller and a signal to be transmitted to the photocoupler. Switch circuits 244 and 245 are provided. Selection of these signals is performed by a switch 259 which is applied to the control terminal CT2 and operates based on the control signal. The inverter circuit 242 is a circuit that inverts the signal, and has a function of preventing the photocoupler photodiode from being driven by a signal whose signal value means “zero”. Because of this function, the power consumption of the photocoupler can be reduced. In particular, since the transmission operation is stopped while the car is parked, it is a great saving in power consumption that the driving current of the photodiode does not flow when the signal value is “zero”. The control circuit 246 has a function of driving the switch circuits 244 and 245 and operates the switch circuits 244 and 245 based on the output of the inverter circuit 242. The switch circuit 260 outputs a signal 18L shown in FIG. 18, and the switch circuits 244 and 245 output a signal 18R shown in FIG.

  The switch 243 is a switch circuit based on whether the battery cell controller is before or after starting, and after the start, the switch circuits 244 and 245 and the switch circuit 260 are selected, and signals from these are output from the terminal TX. Is done. The transmission output circuit 143 that outputs a signal from the terminal FFO has the same structure and operation as the transmission output circuit 140, and a description thereof will be omitted.

  The transmission input circuit 138 is as described in FIG. The transmission input circuit 142 related to the input signal from the terminal FFI is the same as the transmission input circuit 138, and a description thereof will be omitted. The signal received from terminal FFI is used to transmit an abnormal condition. When a signal indicating abnormality is received from the terminal FFI, the signal is input to the transmission output circuit 143 via the transmission input circuit 142 and the OR circuit 288, and is output from the transmission output circuit 143 via the terminal FFO. When an abnormality is detected by the diagnostic circuit 130, a signal indicating the abnormality is input from the diagnostic flag holding circuit 128 to the transmission output circuit 143 via the OR circuit 288 regardless of the content received at the terminal FFI, and the terminal is transmitted from the transmission output circuit 143 to the terminal. Output via FFO.

  As shown in FIG. 10, when a signal is received from the terminal RX, the reception of the signal is detected by the comparator 251 of the activation input circuit 147, and a trigger signal is sent to the timer circuit 140 by the differential trigger circuit 253 and also to the activation output circuit 125. The trigger signal is also sent from the start output circuit 135 via the switch 243 and the start signal is output from the terminal TX. The timer circuit 140 operates and then the main power supply circuit 134 operates to start up the battery cell controller. However, without waiting for this start-up, a start signal is sent from the start output circuit 135 to the next battery cell controller. The whole can stand up in a short time.

  The start output circuit of FIG. 20 can select either an output to a photocoupler or an output to an adjacent integrated circuit, similarly to the transmission output circuits 140 and 143, and an inverter circuit 242 for reducing the power consumption of the photocoupler. Have. An output circuit to the photocoupler is not necessarily required if only the rise control of the battery cell controller that is an adjacent integrated circuit is required, but it is more reliable that the host control circuit 20 can check whether the rise signal is correctly transmitted. Leads to improvement. Therefore, it is important that the startup output circuit has an output circuit to the photocoupler.

  Each of the embodiments described above may be used alone or in combination. This is because the effects of the respective embodiments can be achieved independently or synergistically. In addition, the present invention is not limited to the above embodiment as long as the characteristics of the present invention are not impaired.

  6: Switch, 9A, 9B, 9C, 9D: Battery module, 20: Battery controller, 60, 602, 604: Transmission path, 80: Cell controller, CC3A to CC3N, CC4A to CC4N: Battery cell controller, 134: Main Constant voltage power supply, 135: start output circuit, 138, 142: transmission input circuit, 140, 143: transmission output circuit, 147: start input circuit, 220: inverter device, 230: motor, 233, 241, 252: switch, 613: constant current circuit, 630: insulation circuit, 900: battery unit, BC1 to BC6: battery cell, CT1 to CT3: control terminal, OR01: OR circuit, PH1 to PH4: photocoupler, R20, R30, 620: resistance, SW01: Switch

Claims (12)

A battery module configured by connecting a plurality of battery cells in series;
A plurality of integrated circuits for grouping a plurality of the battery cells, and performing processing on the battery cells in units of each group;
A first transmission path for transmitting a command signal from a high-order control circuit that controls the plurality of integrated circuits to a top-level integrated circuit of the integrated circuit via a first isolation circuit;
A second transmission path for transmitting data signals collected by the plurality of integrated circuits from the highest-order integrated circuit to the lowest-order integrated circuit;
A third transmission line for transmitting data signals collected by the plurality of integrated circuits from the lowest-order integrated circuit to the higher-order control circuit via a second insulation circuit driven by power by the total voltage of the battery module ;
When the command signal is output, the activation signal output from the host control circuit causes the first insulation circuit to be driven, and when the command signal is not output, the first insulation circuit is not driven. And a control circuit . The battery system according to claim 1,
The battery system further comprising a constant current circuit that converts the electric power generated by the total voltage of the battery module into a constant current and supplies the power to the second insulation circuit. The battery system according to claim 1 or 2 ,
The energization control circuit has a circuit holding function for bringing the first insulating circuit into a driving state even when the activation signal disappears when the command signal is output and the uppermost integrated circuit is driven. Battery system characterized. The battery system according to any one of claims 1 to 3 ,
Each of the integrated circuits includes a constant voltage circuit that steps down the total voltage of the grouped battery cell group to a predetermined voltage;
And a signal generation circuit that generates the data signal with a peak value of the signal equal to or lower than the voltage by using a potential difference of the predetermined voltage with respect to a ground level of each integrated circuit as a drive voltage. system. The battery system according to claim 4 ,
An activation circuit for activating the constant voltage circuit by the activation signal;
A battery system comprising: an activation signal transmission circuit that transmits the activation signal to the second transmission line. The battery system according to claim 4 or 5 ,
The integrated circuit includes a first switching circuit that switches a level determination threshold for a signal received via the transmission line, and the switching by the first switching circuit is performed based on a control signal from the outside. Battery system characterized by the above. The battery system according to any one of claims 1 to 6 ,
The integrated circuit includes a second switching circuit that switches whether the waveform of the data signal is inverted and transmitted, and switching is performed by the second switching circuit based on a control signal from the outside. Battery system. The battery system according to any one of claims 1 to 7 ,
The said integrated circuit is provided with the control terminal into which the control signal which instruct | indicates whether the number of the battery cells processed with this integrated circuit is 4 or 6 is input. The battery system according to any one of claims 1 to 8 ,
A battery system, wherein a resistor is disposed between a terminal of the battery cell and a terminal voltage input unit of the integrated circuit. A plurality of integrated circuits controlled by a higher-level control circuit and performing processing on the battery cells in units of each group, dividing the battery cells of the battery module configured by connecting a plurality of battery cells in series;
A first transmission line for transmitting a command signal from the upper control circuit to the uppermost integrated circuit of the plurality of integrated circuits;
A second transmission path for transmitting data signals collected by the plurality of integrated circuits from the highest-order integrated circuit to the lowest-order integrated circuit;
A third transmission line for transmitting data signals collected by the plurality of integrated circuits from the lowest-order integrated circuit to the higher-order control circuit;
A first insulation circuit interposed in the first transmission line and driven by a predetermined power;
A second insulation circuit interposed in the third transmission line and driven by power by the total voltage of the battery module ;
When the command signal is output, the activation signal output from the host control circuit causes the first insulation circuit to be driven, and when the command signal is not output, the first insulation circuit is not driven. And a control circuit . A first battery module configured by connecting a plurality of battery cells in series;
  A plurality of battery cells connected in series, and a second battery module connected in series to the first battery module;
  A plurality of first integrated circuits that group a plurality of battery cells of the first battery module and perform processing on the battery cells in units of groups;
  A plurality of second integrated circuits for grouping a plurality of battery cells of the second battery module and performing processing on the battery cells in units of groups;
  A first transmission line for transmitting a command signal from a higher-order control circuit that controls the plurality of first and second integrated circuits to a first highest integrated circuit of the plurality of first integrated circuits via a first isolation circuit When,
  A second transmission path for transmitting data signals collected by the plurality of first integrated circuits from the highest first integrated circuit to the lowest first integrated circuit;
  Data signals collected by the plurality of first integrated circuits are transmitted from the lowest first integrated circuit to the upper control circuit via a second insulation circuit driven by power based on the total voltage of the first battery module. A third transmission line,
  A fourth transmission line for transmitting a command signal from the upper control circuit to the second highest integrated circuit of the second integrated circuit through a third insulating circuit;
  A fifth transmission line for transmitting data signals collected by the plurality of second integrated circuits from the second highest integrated circuit to the second lowest integrated circuit;
  A data signal collected by the plurality of second integrated circuits is transmitted from the lowest second integrated circuit to the upper control circuit via a fourth insulation circuit driven by electric power based on the total voltage of the second battery module. A sixth transmission line,
  A constant current circuit for making the electric power generated by the total voltage of the first battery module constant and supplying the electric power to the second insulation circuit;
  A battery system comprising: a constant current circuit that converts the electric power generated by the total voltage of the second battery module into a constant current and supplies the power to the fourth insulation circuit. A first battery module configured by connecting a plurality of battery cells in series;
  A plurality of battery cells connected in series, and a second battery module connected in series to the first battery module;
  A plurality of first integrated circuits that group a plurality of battery cells of the first battery module and perform processing on the battery cells in units of groups;
  A plurality of second integrated circuits for grouping a plurality of battery cells of the second battery module and performing processing on the battery cells in units of groups;
  A first transmission line for transmitting a command signal from a higher-order control circuit that controls the plurality of first and second integrated circuits to a first highest integrated circuit of the plurality of first integrated circuits via a first isolation circuit When,
  A second transmission path for transmitting data signals collected by the plurality of first integrated circuits from the highest first integrated circuit to the lowest first integrated circuit;
  A third signal is transmitted from the lowest first integrated circuit to the highest second integrated circuit of the plurality of second integrated circuits via a second isolation circuit. A transmission line;
  A fourth transmission line for transmitting data signals collected by the plurality of first and second integrated circuits from the second highest integrated circuit to the second lowest integrated circuit;
  A third insulation circuit driven by the power of the total voltage of the second battery module for the data signals collected by the plurality of first and second integrated circuits from the lowest second integrated circuit to the upper control circuit; A fifth transmission line for transmitting via
  A constant current circuit for making the electric power generated by the total voltage of the first battery module constant and supplying the electric power to the second insulation circuit;
  A battery system comprising: a constant current circuit that converts the electric power of the total voltage of the second battery module into a constant current and supplies the electric power to the third insulation circuit.

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