JP7675307B2 - Battery Control Device - Google Patents

Description

The present invention relates to a battery control device.

The battery control device determines whether or not there is an abnormality in the secondary battery consisting of multiple battery cells, and charges and discharges the battery. For example, the battery control device has a battery state detection unit that detects state information such as the voltage and temperature of each battery cell, a battery control unit that controls the secondary battery, a communication circuit (first communication circuit) for communicating between the battery state detection unit and the battery control unit, and a power supply circuit that supplies power to the battery control unit.

The battery control unit has a normal state in which it operates using power supplied from the power supply circuit and transmits and receives information with the battery status detection unit via the first communication circuit, and a sleep state in which the power supply from the power supply circuit is stopped.

The battery status detection unit periodically self-starts even when the battery control unit is in a sleep state, and monitors the status information of the secondary battery. If the battery status detection unit detects an abnormal voltage or temperature of the secondary battery through monitoring of the status information, it may start the power supply from the power supply circuit and start the battery control unit from a sleep state.

JP 2015-42084 A

In such a case, a dedicated communication circuit (second communication circuit) is required to transmit a signal (hereinafter referred to as the "start-up signal") for starting the power supply from the power supply circuit from the battery status detection unit to the power supply circuit (see, for example, Patent Document 1). However, providing a dedicated communication circuit (second communication circuit) solely for transmitting the start-up signal leads to a reduction in product cost and an increase in size, so there is room for improvement. Note that this problem is not limited to cases where the battery status detection unit detects an abnormality in the secondary battery, but is a common problem when some trigger is used to start up a battery control unit in a sleep state.

The present invention was made in consideration of these circumstances, and its purpose is to provide a battery control device that can start up the battery control unit without using a communication circuit solely for transmitting a start-up signal.

(1) One aspect of the present invention includes a battery state detection unit connected to a secondary battery and detecting the state of the secondary battery, a battery control unit controlling the secondary battery, a power supply circuit that supplies power to the battery control unit, and a communication circuit for communicating between the battery state detection unit and the battery control unit, the battery control unit having a normal state in which it operates using the power supply and communicates with the battery state detection unit via the communication circuit, and a sleep state in which the power supply from the power supply circuit is stopped, the communication circuit is electrically connected to the power supply circuit, and the battery control unit outputs a wake-up signal to the power supply circuit when the battery state detection unit performs the communication in the sleep state, and the power supply circuit may supply power to the battery control unit upon receiving the wake-up signal.

(2) In the battery control device of (1) above, the communication circuit may include a switch between the communication circuit and the power supply circuit, and the switch may be controlled to an on state when the battery control unit is in the sleep state, and may be controlled to an off state when the battery control unit is in the normal state.

(3) In the battery control device of (1) or (2), the communication circuit includes a communication IC for establishing communication between the battery state detection unit and the battery control unit, an insulating element connected between the battery state detection unit and the communication IC, and a communication line connecting the communication IC and the insulating element, the communication line being electrically connected to the power supply circuit, and the start-up signal may be transmitted from the side communication line to the power supply circuit.

(4) In the battery control device of (3) above, the communication circuit may further include a waveform shaping unit that performs at least one of rectification and smoothing of the startup signal transmitted from the communication line to the power supply circuit.

(5) In the battery control device of (3) or (4), the insulating element may be a pulse transformer.

(6) In any of the battery control devices described in (1) to (5) above, when the battery state detection unit detects at least one of a voltage abnormality and a temperature abnormality of the secondary battery, the battery state detection unit may cause the communication circuit to transmit the activation signal to the power supply circuit by communicating with the battery control unit.

As described above, the present invention provides a battery control device that can start up a battery control unit without using a communication circuit solely for transmitting a start-up signal.

1 is a diagram showing an example of a schematic configuration of a vehicle equipped with a battery control device according to an embodiment of the present invention. 1 is a schematic configuration diagram of a battery control device according to an embodiment of the present invention; FIG. 4 is a diagram illustrating an example of a startup process of the battery control device according to the embodiment. 5A to 5C are diagrams illustrating an example of processing in a waveform shaping unit according to the embodiment. FIG. 11 is a configuration diagram showing an example of a battery control device in which a dedicated communication circuit is provided only for transmitting a start-up signal.

The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. In the drawings, the same reference numerals may be used to denote identical or similar parts, and duplicate explanations may be omitted. In addition, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

The "connection" described below is an electrical connection. An electrical connection is a connection that allows electrical signals to be transmitted directly or indirectly. The electrical connection may be a connection via components such as a cable, resistor, capacitor, diode, or switch.

Figure 1 is a diagram showing an example of a schematic configuration of a vehicle 100 equipped with a battery control device 300 according to this embodiment. The vehicle 100 is, for example, a hybrid vehicle or an electric vehicle. As an example, the vehicle 100 is an electric vehicle that uses a motor as a driving power source.

As shown in FIG. 1, the vehicle 100 includes a secondary battery 110, a motor 120, and a power conversion device 130.

The secondary battery 110 is mounted on the vehicle 100 and is a nickel-metal hydride battery, a lithium-ion battery, or the like. For example, the secondary battery 110 is used as a battery inside the vehicle 100. For example, the power of the secondary battery 110 is used as driving power for the motor 120 and operating power for devices mounted on the vehicle 100.

The secondary battery 110 comprises multiple battery cell groups G (G-1 to G-n) connected in series. n is an integer of 2 or more. Multiple battery cells C are connected in series to each of the battery cell groups G-1 to G-n. The number of battery cells C in each of the battery cell groups G-1 to G-n (hereinafter also referred to as the "number of battery cells") depends on factors such as the body size of the vehicle 100 in which the secondary battery 110 is mounted, and therefore the number of battery cells may differ depending on the vehicle 100.

In each of the battery cell groups G-1 to G-n, the positive terminal of the battery cell (top cell) C located at the top is the positive terminal P1 of the secondary battery 110, and the negative terminal of the battery cell (bottom cell) C located at the bottom is the negative terminal P2 of the secondary battery 110. The positive terminal P1 and negative terminal P2 of each battery cell C are each connected to the power conversion device 130. When there is no need to distinguish between the multiple battery cell groups G-1 to G-n, they will simply be referred to as "battery cell group G."

The motor 120 is an electric motor driven by power from the power conversion device 130. For example, the motor 120 is a driving motor for the vehicle 100. For example, the motor 120 is a three-phase (U, V, W) brushless motor. The motor 120 may be a motor generator. That is, the motor 120 may be used as a generator driven by the engine of the vehicle 100, and may also be used as an electric motor for starting the engine. The motor 120 of this embodiment operates mainly as an electric motor to drive the wheels of the vehicle 100.

The power conversion device 130 manages the secondary battery 110 and controls the driving of the motor 120. The power conversion device 130 includes a power converter 200 and a battery control device 300.

The power converter 200 boosts the output voltage VBAT output from the secondary battery 110 and converts the boosted voltage to AC. The power converter 200 then outputs the converted AC voltage to the motor 120 to drive the motor 120. The power converter 200 may also have a function of stepping down the regenerative voltage from the motor 120 at a predetermined step-down ratio and outputting it to the secondary battery 110.

The battery control device 300 controls the secondary battery 110, which is the object of control, and manages the state of the secondary battery 110. The control over the secondary battery 110 may be, for example, control to keep the voltage of the secondary battery 110 within a normal range (e.g., cell balance control), control to keep the temperature of the secondary battery 110 within a normal range, or control to eliminate an abnormality in the secondary battery 110 if one occurs.

Below, an example of the schematic configuration of the battery control device 300 will be described with reference to FIG. 2. FIG. 2 is a schematic configuration diagram of the battery control device 300 according to this embodiment. Note that, in the example shown in FIG. 2, a case where there are four battery cell groups G is described, but the number of battery cell groups G is not particularly limited.

The battery control device 300 includes a battery state detection unit 10, a battery control unit 20, a power supply circuit 30, and a communication circuit 40.

The battery state detection unit 10 is connected to the secondary battery 110 and detects the state of the secondary battery 110 (hereinafter referred to as "state information"). The state information of the secondary battery 110 is, for example, at least one of the voltage of each battery cell C (hereinafter referred to as "cell voltage") and the temperature of the secondary battery 110. The temperature of the secondary battery 110 may be the temperature of each battery cell C or the temperature of each battery cell group G. However, it is not limited to this, and the state information of the secondary battery 110 may be the current flowing through the secondary battery 110. The battery state detection unit 10 periodically starts up by itself even when the battery control unit 20 is in a sleep state, and monitors the state information of the secondary battery.

The battery status detection unit 10 is connected to the battery control unit 20 via the communication circuit 40. The battery status detection unit 10 communicates with the battery control unit 20 via the communication circuit 40 to send and receive status information and other information. The battery status detection unit 10 determines whether or not there is an abnormality in the secondary battery based on the status information, and if it determines that there is an abnormality, it communicates with the battery control unit 20 via the communication circuit 40.

Next, the general configuration of the battery state detection unit 10 of this embodiment will be described.

For example, the battery status detection unit 10 includes multiple battery monitoring integrated circuits IC (hereinafter referred to as "battery monitoring ICs") 11.

The multiple battery monitoring ICs 11 (11-1 to 11-4) are electrically connected to the multiple battery cells C, and monitor the state of each battery cell C and each battery cell group, thereby monitoring the state of the secondary battery 110. For example, a battery monitoring IC 11 is provided corresponding to each of the battery cell groups _G1 to _G4 , and monitors the state of each battery cell C and each battery cell group. Note that the multiple battery monitoring ICs 11-1 to 11-4 each have the same configuration, and when there is no need to distinguish between the multiple battery monitoring ICs 11-1 to 11-4, they will simply be referred to as "battery monitoring IC 11."

For example, the battery monitoring IC 11 is provided corresponding to the battery cell group G, and has a number of input terminals corresponding to the output terminals (positive or negative terminals of the battery cell C) of each battery cell C in the battery cell group G. The output terminals (positive or negative terminals) of each battery cell C are connected one-to-one with the multiple input terminals of the battery monitoring IC 11, for example, by connection lines. This electrically connects both ends of each battery cell C to the battery monitoring IC 11. The battery monitoring IC 11 monitors the potential difference (hereinafter referred to as the "cell voltage value") Vcell between both ends of each battery cell C, and determines whether or not the cell voltage value Vcell of each battery cell C is abnormal. As an example, when the cell voltage value Vcell falls outside a predetermined voltage range, the battery monitoring IC 11 determines that the cell voltage value Vcell is abnormal.

The battery monitoring IC 11 monitors the temperature Tcell of the corresponding battery cell group G and determines whether or not there is an abnormality in the temperature Tcell. For example, the battery control device 300 has one or more temperature sensors (not shown) that measure the operating temperature of each battery cell group G. The battery monitoring IC 11 is connected to this temperature sensor, obtains the temperature Tcell measured by the temperature sensor, and determines whether or not there is an abnormality in the temperature Tcell. As an example, if the temperature Tcell falls outside a predetermined temperature range, the battery monitoring IC 11 determines that the temperature Tcell is abnormal.

The temperature sensor may detect the temperature Tcell in a non-contact or contact manner. For example, the temperature sensor is an infrared sensor that detects the temperature Tcell in a non-contact manner. This temperature sensor is placed, for example, in a position facing all the battery cell groups G arranged on one surface, while being supported by a scanning device or the like, and detects the temperature Tcell of each battery cell group G.

In this way, the battery monitoring IC 11-k (k is an integer from 1 to n) of this embodiment acquires the cell voltage value Vcell of each battery cell C-k and the temperature Tcell of the battery cell group G-k as status information. The battery monitoring IC 11-k determines the presence or absence of an abnormality in the battery cell group G-k by determining the presence or absence of an abnormality in the cell voltage value Vcell or the temperature Tcell based on the status information, and if it determines that the battery cell G-k is abnormal, it transmits an arbitrary signal to the communication circuit 40.

In the example shown in FIG. 2, multiple battery monitoring ICs 11-1 to 11-4 are daisy-chained and connected to each other by a communication line L1. This communication line L1 is a communication line capable of two-way communication. In other words, each battery monitoring IC 11 can communicate two-way with an adjacent battery monitoring IC 11.

Of the multiple battery monitoring ICs 11-1 to 11-4 connected in a daisy chain, only the battery monitoring IC 11-4 on the lowest potential side (one end side) is connected to the communication circuit 40 via the communication line L2. The communication line L2 is a communication line capable of two-way communication. This allows the multiple battery monitoring ICs 11-1 to 11-4 connected in a daisy chain and the battery control unit 20 to communicate via the communication circuit 40, allowing them to send and receive information to and from each other.

In the multiple communication lines L1, each first communication line t1 is an electric wire that transmits an upstream communication signal output from each battery monitoring IC 11-1 to 11-4 to the battery control unit 20. In addition, in the multiple communication lines L1, each first coupling capacitor C1 is provided in the middle of each first communication line t1 and blocks the transmission of DC components between each battery monitoring IC 11-1 to 11-4.

In the multiple communication lines L1, each second communication line t2 is an electric wire that transmits downstream communication signals output from the battery control unit 20 to each of the battery monitoring ICs 11-1 to 11-4. In addition, in the multiple communication lines L1, each second coupling capacitor C2 is provided in the middle of each second communication line t2 and blocks the transmission of DC components between each of the battery monitoring ICs 11-1 to 11-4.

That is, the first coupling capacitor C1 and the second coupling capacitor C2 in each communication line L1 are circuit elements that ensure electrical isolation in each of the battery monitoring ICs 11-1 to 11-4. Since each of the battery monitoring ICs 11-1 to 11-4 is daisy-chained to each other by multiple communication lines equipped with such first coupling capacitors C1 and second coupling capacitors C2, mutual interference can be suppressed.

The battery control unit 20 has a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). In addition to the processor, the battery control unit 20 may also include a non-volatile or volatile semiconductor memory (e.g., a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (Electrically Erasable Programmable Read Only Memory)). For example, the battery control unit 20 may be a microcontroller such as an MCU.

The battery control unit 20 communicates with each of the battery monitoring ICs 11-1 to 11-4 via the communication circuit 40 and controls the secondary battery 110. The battery control unit 20 has at least two states: a normal state and a sleep state. In the normal state, the battery control unit 20 operates with power supplied from the power supply circuit 30 and communicates with the battery state detection unit 10 (each of the battery monitoring ICs 11-1 to 11-4) via the communication circuit 40. In the sleep state, the power supply from the power supply circuit 30 is stopped. When the battery control unit 20 is in the sleep state, the battery control unit 20 cannot communicate with the battery state detection unit 10 via the communication circuit 40. Therefore, if the battery control unit 20 is in the sleep state when the battery state detection unit 10 communicates with the battery control unit 20, it is necessary to supply power from the power supply circuit 30 to the battery control unit 20 and transition the battery control unit 20 from the sleep state to the normal state.

When the battery control unit 20 receives information indicating an abnormality in the secondary battery 110 (e.g., an abnormality in the cell voltage Vcell or an abnormality in the temperature Tcell) from the battery state detection unit 10 via the communication circuit 40 in the normal state, the battery control unit 20 executes processing for turning on or blinking a warning light or hazard lights provided in the vehicle 100. In this way, when the battery control unit 20 receives information indicating an abnormality in the secondary battery 110, it executes processing to be taken in response to the abnormality (hereinafter referred to as "abnormality response processing"), such as notifying the abnormality or executing processing to resolve the abnormality. However, as described above, when the battery control unit 20 is in the sleep state, it cannot receive information indicating an abnormality in the secondary battery 110 from the battery state detection unit 10 in the first place, and therefore cannot execute the abnormality response processing. Therefore, in order to execute the abnormality response processing, when the battery state detection unit 10 detects an abnormality in the secondary battery 110, it is necessary to wake up the battery control unit 20, which is in the sleep state, from the sleep state to the normal state.

The power supply circuit 30 supplies power to the battery control unit 20. For example, the power supply circuit 30 operates using a DC power supply B in the battery control device 300, and generates a voltage to be supplied to the battery control unit 20 from the DC power supply B. The power supply circuit 30 supplies power to the battery control unit 20 by outputting the generated voltage to the battery control unit 20. However, when the battery control unit 20 is shifted from a normal state to a sleep state, the power supply circuit 30 stops the power supply to the battery control unit 20. Note that when the battery control unit 20 is in a sleep state, the power supply to the battery control unit 20 remains stopped. The power supply to the battery control unit 20 by the power supply circuit 30 may be stopped based on an instruction signal from the battery control unit 20, based on an instruction signal from a processor higher than the battery control unit 20, or based on the judgment of the power supply circuit 30 itself.

The power supply circuit 30 is, for example, an integrated circuit and has at least four terminals: a first control terminal EN0, a second control terminal EN1, a power supply terminal POW, and an output terminal OUT.

A signal indicating whether the ignition switch is on or off is input to the first control terminal EN0. The communication circuit 40 is electrically connected to the second control terminal EN1. A DC power source B is supplied to the power supply terminal POW. The battery control unit 20 is connected to the output terminal OUT.

The power supply circuit 30 supplies power to the battery control unit 20 when a signal indicating that the ignition switch is on is input to the first control terminal EN0. The power supply circuit 30 may stop supplying power to the battery control unit 20 when a signal indicating that the ignition switch is off is input to the first control terminal EN0. When the battery control unit 20 is in a sleep state and a signal (hereinafter referred to as a "start-up signal") is input to the second control terminal EN1, the power supply circuit 30 supplies power to the battery control unit 20 to start up the battery control unit 20 from the sleep state and transition to the normal state.

The communication circuit 40 is a communication circuit for communicating between the battery state detection unit 10 and the battery control unit 20. The communication circuit 40 is electrically connected to the power supply circuit 30, and outputs a wake-up signal to the power supply circuit 30 when the battery state detection unit 10 communicates with the battery control unit while the battery control unit 20 is in a sleep state. For example, the communication circuit 40 outputs a wake-up signal to the power supply circuit 30 when the battery state detection unit 10 communicates with the battery control unit while the battery control unit 20 is in a sleep state. An example configuration of the communication circuit 40 in this embodiment is described below.

The communication circuit 40 includes a communication IC 41, an insulating element 42, a communication line 43, a waveform shaping unit 44, and a switch 45.

The communication IC 41 establishes communication between the battery state detection unit 10 and the battery control unit 20. The communication IC 41 is connected to the battery control unit 20 via a communication line L3 (e.g., a serial bus such as an SPI (registered trademark) (Serial Peripheral Interface) bus).

The insulating element 42 is connected between the battery state detection unit 10 and the communication IC 41. For example, the insulating element 42 is connected to the communication IC 41 via a communication line 43. The insulating element 42 is also connected to the battery state detection unit 10, i.e., the battery monitoring IC 11-4, via a communication line L2. This allows the battery monitoring IC 11-4 and the communication IC 41 to communicate while being electrically insulated from each other.

The insulating element 42 shown in FIG. 2 is a pulse transformer, but is not limited to this and may be anything that insulates the electrical connection between the battery monitoring IC 11-4 and the communication IC 41, such as a photocoupler or magnetic coupler.

The communication line 43 is electrically connected to the power supply circuit 30. In the example shown in FIG. 2, the communication line 43 is connected to the second control terminal EN1 of the power supply circuit 30, and a start-up signal from the communication circuit 40 is input to the second control terminal EN1.

The waveform shaping unit 44 performs at least one of rectifying and smoothing the start-up signal transmitted from the communication line 43 to the power supply circuit 30. In the example shown in FIG. 2, the waveform shaping unit 44 includes a diode 51 and a capacitor 52, and rectifies and smoothes the start-up signal input to the second control terminal EN1.

The anode of the diode 51 is connected to the communication line 43 via the switch 45, and the cathode is connected to the second control terminal EN1.

One end of capacitor 52 is connected to the cathode of diode 51, and the other end is connected to ground (GND).

The switch 45 is provided between the anode of the diode 51 and the communication line 43. When the switch 45 is in the on state, the anode of the diode 51 and the communication line 43 are electrically connected. When the switch 45 is in the off state, the electrical connection between the anode of the diode 51 and the communication line 43 is cut off. The on or off state of the switch 45 may be controlled by the battery control unit 20 or may be controlled by the power supply circuit 30.

The switch 45 may be an electrical switch such as a transistor (including a contactless relay), or a mechanical switch such as a contact relay.

The process of activating the battery control unit 20 from a sleep state (hereinafter referred to as "activation process") will be described below with reference to FIG. 3. FIG. 3 describes an example of the activation process of the battery control device 300. Note that in describing FIG. 3, the initial state is that the battery control unit 20 is in a sleep state and the switch 45 is in an on state.

The battery state detection unit 10 detects state information of the secondary battery 110 and determines whether or not there is an abnormality in the secondary battery 110 based on the state information (step S101). For example, the battery state detection unit 10 acquires the cell voltage value Vcell of each battery cell C and the temperature Tcell of each battery cell group G as state information. Then, the battery state detection unit 10 determines that an abnormality has occurred in the secondary battery 110 when at least one of the following occurs: the cell voltage value Vcell is outside a predetermined voltage range (e.g., a drop in cell voltage) and the temperature Tcell is outside a predetermined temperature range (e.g., a rise in temperature).

If the battery status detection unit 10 determines that an abnormality has occurred in the secondary battery 110, it communicates using the communication circuit 40 (step S102).

For example, if the battery status detection unit 10 determines that an abnormality has occurred in the secondary battery 110, it starts communication with the battery control unit 20 in the same manner as when communicating with the battery control unit 20 in a normal state. Here, because the battery control unit 20 is in a sleep state, the battery status detection unit 10 cannot actually communicate with the battery control unit 20. However, a signal S is output from the battery status detection unit 10, i.e., the battery monitoring IC 11-4, to the communication circuit 40.

When the communication circuit 40 receives the signal S from the battery monitoring IC 11-4, it outputs a start-up signal to the power supply circuit 30 (step S103). For example, the signal S is input from the battery monitoring IC 11-4 to the communication circuit 40 by the communication in step S102, and the signal S is output to the communication line 43 via the insulating element 42. The communication line 43 is connected to the power supply circuit 30 via the switch 45. The switch 45 is in the on state. Therefore, the signal S output from the insulating element 42 to the communication line 43 is output to the power supply circuit 30 via the switch 45. This signal S is an example of a start-up signal.

In this way, the communication circuit 40 utilizes the power of the daisy communication by the battery status detection unit 10, generates a start-up signal from that power, and outputs it to the power supply circuit 30.

In this embodiment, a waveform shaping unit 44 is provided between the switch 45 and the power supply circuit 30. The waveform shaping unit 44 performs at least one of rectification and smoothing of the start-up signal transmitted from the communication line 43 to the power supply circuit 30. For example, assume that the signal S has a waveform shown in FIG. 4(a) (a daisy communication waveform as an example). In this case, the waveform shaping unit 44 rectifies the waveform shown in FIG. 4(a) to obtain the waveform shown in FIG. 4(b). Furthermore, the waveform shaping unit 44 smoothes the rectified electric waveform to obtain the waveform shown in FIG. 4(c). The signal S shaped to the waveform shown in FIG. 4(c) is input to the second control terminal EN1 as a start-up signal. Note that the example shown in FIG. 4 illustrates a case where the reference voltage is 0V, but is not limited thereto, and the reference voltage in this embodiment may be a voltage other than 0V, such as 2.5V.

When the power supply circuit 30 receives a start-up signal from the communication circuit 40 (step S104), it supplies power to the battery control unit 20 (step S105). In the example shown in FIG. 2, when the start-up signal is input to the second control terminal EN1, the power supply circuit 30 supplies power to the battery control unit 20 from the output terminal OUT. As an example, when the voltage of the second control terminal EN1 exceeds a threshold value Vth, the power supply circuit 30 determines that a start-up signal has been input to the second control terminal EN1. Therefore, the waveform shaping unit 44 may shape the waveform of the start-up signal so that the voltage waveform of the start-up signal exceeds the threshold value Vth.

When power is supplied from the power supply circuit 30, the battery control unit 20 starts up from the sleep state and transitions to the normal state (step S106). This enables the battery control unit 20 to communicate with the battery state detection unit 10 via the communication circuit 40, and the battery control unit 20 can receive information indicating an abnormality in the secondary battery 110 from the battery state detection unit 10.

When the battery control unit 20 transitions to the normal state, it controls the switch 45 from the on state to the off state (step S107). This allows the battery control unit 20 to prevent a startup signal from being input to the power supply circuit 30 in the normal state. When a startup signal is input to the power supply circuit 30 each time the battery state detection unit 10 and the battery control unit 20 communicate in the normal state, the battery control unit 20 may not be able to transition from the normal state to the sleep state. Therefore, when the battery control unit 20 transitions to the normal state, it switches the switch 45 from the on state to the off state, making it possible to transition from the normal state to the sleep state.

Next, the effects of this embodiment will be described with reference to FIG. 5. FIG. 5 is a diagram showing an example of a battery control device 400 in which a dedicated communication circuit (second communication circuit) is provided solely for transmitting the activation signal. Note that the configuration of the battery control device 400 may be distinguished from the configuration of the battery control device 300 by adding an "A" to the end of the reference numeral.

In the battery control device 400 that controls the secondary battery 110, a communication circuit having an insulating element may be required when communicating with the battery state detection unit 10A of the secondary battery 110. In the example shown in FIG. 5, the communication circuit 500A is a communication circuit for establishing communication between the battery state detection unit 10A and the battery control unit 20A, and has a pulse transformer 42A that is an insulating element. The communication circuit 600A is a communication circuit for establishing communication between the battery state detection unit 10A and the power supply circuit 30A, and has a photocoupler 610A that is an insulating element. When the battery control unit 20 is in a normal state, the battery state detection unit 10A communicates with the battery control unit 20A via the communication circuit 500A. When the battery control unit 20 is in a sleep state, the battery state detection unit 10A periodically starts up by itself, and when an abnormal state of the secondary battery 110 is detected, it outputs a start-up signal to the power supply circuit 30A via the communication circuit 600A. As a result, the power supply circuit 30A supplies power to the battery control unit 20A, waking up the battery control unit 20A from a sleep state.

However, components such as the insulating elements included in the communication circuit are expensive, and providing the communication circuit 600A solely for the purpose of transmitting the start-up signal to the power supply circuit 30A leaves room for improvement when considering the need to reduce product costs.

The battery control device 300 of this embodiment uses the communication circuit 40, which is for communicating between the battery state detection unit 10 and the battery control unit 20, for transmitting the start-up signal as well, eliminating the communication circuit 600A that is only for transmitting the start-up signal. This makes it possible to realize a low-cost product, and also to reduce the size of the product by reducing the number of parts.

The above describes an embodiment of the present invention in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and includes designs that do not deviate from the gist of the present invention.

For example, the battery monitoring IC 11 may obtain the current value Ix flowing through the secondary battery 110 as status information from a current sensor (not shown) in the battery control device 300, and determine whether or not there is an abnormality in the current value Ix. The current value flowing through each of the multiple battery cells C connected in series is the current value Ix. Therefore, it is sufficient for one battery monitoring IC 11 out of the multiple battery monitoring ICs 11-1 to 11-4 to detect the current value Ix flowing through the secondary battery 110.

When the battery state detection unit 10 detects an abnormality in the secondary battery 110, it is sufficient that the communication signal S from the battery state detection unit 10 to the battery control device 300 is used as a start-up signal, and there is no particular limitation on the type of information transmitted. For example, when the battery state detection unit 10 detects an abnormality in the secondary battery 110, it may transmit a signal of information indicating the abnormality from the battery state detection unit 10 to the battery control device 300, or it may be a signal of other information.

In the above embodiment, as an example, the battery control device 300 is started from a sleep state when the battery state detection unit 10 detects an abnormality in the secondary battery 110, but this is not limited to this. The present invention is applicable to all cases in which the battery control device 300 is started from a sleep state, and is not limited to cases in which an abnormality in the secondary battery 110 is detected.

As examples of abnormalities in the secondary battery 110 detected by the battery state detection unit 10, abnormalities in the cell voltage value Vcell and abnormalities in the temperature Tcell have been described, but this is not limited to these, and there is no particular limitation as long as it indicates an abnormality in the secondary battery 110.

As described above, the battery control device 300 of this embodiment is connected to the secondary battery 110 and includes a battery state detection unit 10 that detects the state of the secondary battery 110, a battery control unit 20 that controls the secondary battery 110, a power supply circuit 30 that supplies power to the battery control unit 20, and a communication circuit 40 for communication between the battery state detection unit 10 and the battery control unit 20. The battery control unit 20 has a normal state in which it operates by power supply and communicates with the battery state detection unit 10 via the communication circuit 40, and a sleep state in which the power supply from the power supply circuit 30 is stopped. The communication circuit 40 is electrically connected to the power supply circuit 30, and outputs a start signal to the power supply circuit 30 when the battery control unit 20 is in the sleep state and the battery state detection unit 10 communicates using the communication circuit 40. When the power supply circuit 30 receives the start signal, it supplies power to the battery control unit 20.

With this configuration, it is possible to start up the battery control unit 20 in a sleep state without using a communication circuit solely for transmitting a start-up signal.

The communication circuit 40 may also include a switch 45 between the communication circuit 40 and the power supply circuit 30. The switch 45 may be controlled to be in an on state when the battery control unit 20 is in a sleep state, and may be controlled to be in an off state when the battery control unit 20 is in a normal state.

This configuration makes it possible to prevent the startup signal from being input to the power supply circuit 30 when the battery control unit 20 is in a normal state.

The communication circuit 40 may also include a communication IC 41 for establishing communication between the battery state detection unit 10 and the battery control unit 20, an insulating element 42 connected between the battery state detection unit 10 and the communication IC 41, and a communication line 43 connecting the communication IC 41 and the insulating element 42. In this case, the communication line 43 may be electrically connected to the power supply circuit 30. Then, the start-up signal may be transmitted from the communication line 43 to the power supply circuit 30.

The communication circuit 40 may further include a waveform shaping unit 44 that performs at least one of rectification and smoothing of the start-up signal transmitted from the communication line 43 to the power supply circuit 30.

This configuration allows the communication circuit 40 to more reliably transmit the startup signal to the power supply circuit 30.

In addition, when the battery state detection unit 10 detects at least one of a voltage abnormality and a temperature abnormality in the secondary battery 110, the battery state detection unit 10 may communicate with the battery control unit 20 to cause the communication circuit 40 to transmit a start-up signal to the power supply circuit 30.

The term "unit" in the specification means a unit that processes at least one function or operation, which may be embodied as hardware or software, or a combination of hardware and software.

100...vehicle, 110...secondary battery, 120...motor, 130...power conversion device, 200...power converter, 300...battery control device, 10...battery state detection unit, 11...battery monitoring IC, 20...battery control unit, 30...power supply circuit, 40...communication circuit, 41...communication IC, 42...insulation element, 43...communication line, 44...waveform shaping unit, 45...switch

Claims (6)

a battery state detection unit connected to a secondary battery and detecting a state of the secondary battery;
A battery control unit that controls the secondary battery;
a power supply circuit that supplies power to the battery control unit;
a communication circuit for communicating between the battery state detection unit and the battery control unit;
Equipped with
the battery control unit has a normal state in which it operates by the power supply and communicates with the battery state detection unit via the communication circuit, and a sleep state in which the power supply from the power supply circuit is stopped,
the communication circuit is electrically connected to the power supply circuit, and outputs a wake-up signal to the power supply circuit when the battery state detection unit performs the communication while the battery control unit is in the sleep state;
The power supply circuit supplies power to the battery control unit upon receiving the activation signal.
Battery control device. the communication circuit includes a switch between the communication circuit and the power supply circuit;
the switch is controlled to an on state when the battery control unit is in the sleep state, and is controlled to an off state when the battery control unit is in the normal state.
The battery control device according to claim 1 . The communication circuit includes:
a communication IC for establishing communication between the battery state detection unit and the battery control unit;
an insulating element connected between the battery state detection unit and the communication IC;
a communication line connecting the communication IC and the isolation element;
Equipped with
the communication line is electrically connected to the power supply circuit,
The activation signal is transmitted from the communication line to the power supply circuit.
The battery control device according to claim 1 or 2. The battery control device according to claim 3 , wherein the communication circuit further comprises a waveform shaping unit that performs at least one of rectification and smoothing of the start-up signal transmitted from the communication line to the power supply circuit. The battery control device according to claim 3 or 4, wherein the insulating element is a pulse transformer. When the battery state detection unit detects at least one of a voltage abnormality and a temperature abnormality of the secondary battery, the battery state detection unit causes the communication circuit to transmit the activation signal to the power supply circuit by performing the communication with the battery control unit.
The battery control device according to any one of claims 1 to 5.

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