Power device

Abstract

To provide an entire system which is miniaturized by miniaturizing an external power source.SOLUTION: A power unit 10 comprises a second power transmission path 20 which electrically connects a first power storage part 14 with an ECU 34, a second power conversion part 30 which is provided on the second power transmission path 20 and converts power, a second power storage part 16 which has a voltage lower than the first power storage part 14, and a third power transmission path 22 which is provided in parallel with the second power transmission path 20 with respect to the ECU 34 and electrically connects the second power storage part 16 with the ECU 34.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power device that controls a first power conversion unit provided on a first power transmission path that electrically connects a first power storage unit and an operation unit with a control unit.

Background Art

[0002] Patent Document 1 discloses a power supply device mounted on a vehicle, the power supply device including an auxiliary power supply having a storage battery and a BMU (Battery Management System).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in an EV (electric vehicle) system such as an electric vehicle or an electric motorcycle, in addition to a battery (first power storage unit) for driving a motor (operation unit), a sub-battery (for example, a 12V storage battery) for driving general electrical components and an ECU (electronic control unit) is mounted. In recent years, the battery for an EV system is a high-performance battery such as a lithium battery, but battery management is required. Therefore, the battery is equipped with a battery management function and a communication function using CAN (Controller Area Network) or the like, like a BMU. Therefore, in the battery for an EV system, in order to operate these functions, it is necessary to receive power supply from an external power source (for example, a sub-battery).

[0005] In addition, many batteries for EV systems are removable and replaceable batteries. Taking advantage of this feature, there has been an increasing number of efforts to divert such batteries to systems that operate with fixed power sources other than EVs. At that time, as described above, since an external power source is required to start the battery, there is a problem that the system becomes larger.

[0006] The present invention has been made in consideration of such problems, and an object thereof is to provide a power device capable of reducing the size of the entire system by reducing the size of an external power source.

Means for Solving the Problems

[0007] An aspect of the present invention relates to a power device including a first power storage unit, an operation unit electrically connected to the first power storage unit via a first power transmission path, a first power conversion unit provided on the first power transmission path for converting power, and a control unit for controlling the first power conversion unit. In this case, the power device includes a second power transmission path electrically connecting the first power storage unit and the control unit, a second power conversion unit provided on the second power transmission path for converting power, a second power storage unit having a voltage lower than that of the first power storage unit, and a third power transmission path provided in parallel with the second power transmission path for the control unit and electrically connecting the second power storage unit and the control unit.

Effects of the Invention

[0008] According to the present invention, the second power conversion unit converts the power of the first power storage unit and supplies it to the control unit, thereby functioning as a driving power source for the control unit. As a result, the power supply capacity of the second power storage unit as an external power source can be reduced, and the external power source can be reduced in size and output. As a result, the entire power device can be reduced in size. In addition, by diverting the first power storage unit and the control unit to a system other than a vehicle or the like, it becomes possible to share the control of the first power storage unit. Thereby, miniaturization and simplification of the diverted system can be realized.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the power device according to the present invention will be exemplified and described with reference to the accompanying drawings.

[0011] [1. Overall Configuration of Power Device 10] As shown in FIG. 1, the power device 10 according to this embodiment is applied to, for example, a vehicle 12, and includes a first power storage unit 14, a second power storage unit 16, a first power transmission path 18, a second power transmission path 20, a third power transmission path 22, a fourth power transmission path 24, a fifth power transmission path 26, a first power conversion unit 28, a second power conversion unit 30, a third power conversion unit 32, an ECU 34 (control unit), a motor 36 as an operation unit, a main switch 38, and a headlight 40, a brake lamp 42, and a meter 44 as other operation units.

[0012] The first power storage unit 14 is a rechargeable battery disposed at least one in the power device 10. The first power storage unit 14 may be a mobile battery detachable from the power device 10, or may be a battery fixed to the power device 10. When the first power storage unit 14 is a mobile battery, for example, a battery pack of a detachable lithium-ion battery is suitable.

[0013] The second power storage unit 16 has a lower voltage (output voltage) than the first power storage unit 14. The second power storage unit 16 is a rechargeable battery disposed at least one in the power device 10. The second power storage unit 16 may be detachable from the power device 10, or may be fixed to the power device 10. For the second power storage unit 16, for example, a dry battery or a lead battery is suitable.

[0014] The first power transmission path 18 electrically connects the first power storage unit 14 and the motor 36.

[0015] The first power conversion unit 28 is provided on the first power transmission path 18 and converts power. Specifically, the first power conversion unit 28 includes an inverter and converts the DC power supplied from the first power storage unit 14 into AC power. By supplying the converted AC power to the motor 36, the motor 36 is driven. When the motor 36 operates as a generator, the first power conversion unit 28 converts the AC power generated by the motor 36 into DC power and supplies (charges) the converted DC power to the first power storage unit 14.

[0016] Therefore, the motor 36 is a load (operating unit) that operates by the electric power supplied from the first power storage unit 14. In the power device 10, instead of the aforementioned motor 36, a power consumption unit that consumes the electric power supplied from the first power storage unit 14, a power generation unit that supplies electric power to the first power storage unit 14, or a power conversion unit that converts electric power can also be electrically connected to the first power transmission path 18.

[0017] The ECU 34 is electrically connected to the first power storage unit 14 via the second power transmission path 20. The ECU 34 can receive the supply of DC power from the first power storage unit 14 via the second power transmission path 20. A second power conversion unit 30 that converts electric power is provided on the second power transmission path 20.

[0018] The second power conversion unit 30 is a DC / DC converter provided in the ECU 34. The second power conversion unit 30 converts (steps down) the DC voltage (DC power) supplied from the first power storage unit 14 to a DC voltage lower than the DC voltage, and supplies the converted DC voltage (DC power) to the ECU 34. The ECU 34 operates by the DC voltage (DC power) supplied from the second power conversion unit 30 when an on signal is output from the main switch 38 provided in the vehicle 12. That is, the second power conversion unit 30 functions as a drive power source for the ECU 34. Note that the on signal refers to a high-level signal output from the main switch 38. Also, the off signal described later refers to a low-level or zero-level signal output from the main switch 38.

[0019] Further, the ECU 34 is electrically connected to the second power storage unit 16 via the third power transmission path 22. In this case, the second power transmission path 20 and the third power transmission path 22 are electrically connected in parallel to the ECU 34. As will be described later, when the first power storage unit 14 is in a non-operating state where its operation has stopped and an on signal is output from the main switch 38, the ECU 34 operates by the DC power (DC voltage) supplied from the second power storage unit 16 via the third power transmission path 22. Note that in the present embodiment, the power supply from the second power storage unit 16 to the ECU 34 via the third power transmission path 22 is performed to start the first power storage unit 14 and is limited to a power supply for a relatively short period of time.

[0020] In addition to the ECU 34, the headlight 40, the brake lamp 42, and the meter 44, which are auxiliary devices of the vehicle 12, are electrically connected to the third power transmission path 22. These auxiliary devices operate by the DC power supplied from the second power storage unit 16 via the third power transmission path 22.

[0021] The fourth power transmission path 24 is a power supply line that extends from the second power storage unit 16 to the first power storage unit 14 via the third power transmission path 22 and the ECU 34. That is, the third power transmission path 22 constitutes a part of the fourth power transmission path 24. Based on the DC power supplied from the second power storage unit 16 via the third power transmission path 22, the ECU 34 generates an activation signal (starting power) for starting the first power storage unit 14 and supplies the generated activation signal to the first power storage unit 14 via the fourth power transmission path 24, thereby starting the first power storage unit 14.

[0022] When the first power storage unit 14 is in the activated state, it is in a state where it can exchange DC power with the outside. As a result, it becomes possible to supply DC power from the first power storage unit 14 to the ECU 34 and the like. On the other hand, when the supply of the activation signal from the ECU 34 to the first power storage unit 14 via the fourth power transmission path 24 stops, the first power storage unit 14 switches from the activated state to the non-activated state and stops operating. As a result, the first power storage unit 14 is in a state where it cannot exchange DC power with the outside.

[0023] Therefore, the ECU 34 operates by receiving the supply of DC power from the second power storage unit 16 only during the time period when the first power storage unit 14 is in the non-activated state, and operates with the DC power supplied from the activated first power storage unit 14 during other time periods.

[0024] The fifth power transmission path 26 electrically connects the first power storage unit 14 and the second power storage unit 16. The third power conversion unit 32 is a DC / DC converter provided in the fifth power transmission path 26. The third power conversion unit 32 converts (steps down) the DC voltage (DC power) supplied from the first power storage unit 14 into a DC voltage lower than the DC voltage, and supplies (charges) the converted DC voltage (DC power) to the second power storage unit 16.

[0025] The ECU 34, the first power conversion unit 28, the first power storage unit 14, and the third power conversion unit 32 can transmit and receive signals or information via a communication line 46 such as a CAN. Thereby, the ECU 34 can control the first power conversion unit 28, the first power storage unit 14, and the third power conversion unit 32 via the communication line 46.

[0026] Note that the power device 10 is applicable to the power supply systems of various vehicles 12 such as motorcycles, bicycles, and four-wheeled vehicles. Further, the power device 10 is applicable not only to the vehicle 12 but also to various power supply systems that supply power from the first power storage unit 14 to operating parts such as the motor 36 or charge the first power storage unit 14. Therefore, the power device 10 can be installed not only in the vehicle 12 but also in houses, offices, public facilities, etc.

[0027] In addition, the power device 10 is also applicable to the power supply systems of various moving bodies such as vehicles, aircraft, flying objects, and ships that can be occupied by people or cannot be occupied by people. In this case, as the power supply system of the vehicle, it is applicable to the power supply system of an electric vehicle or the power supply system of a vehicle equipped with a drive motor such as a hybrid vehicle.

[0028] Furthermore, the power device 10 is also applicable to the power supply systems of various general-purpose devices not occupied by people, specifically, (1) various chargers, (2) various dischargers, (3) various working machines such as general-purpose working machines, lawn mowers, cultivators, and blowers, (4) electrical devices without electric motors such as floodlights and lighting devices, and (5) various devices installed in houses and buildings. In this case, as an example of the above (5), there are (A) devices that operate with direct current power such as acoustic devices like clocks and radio cassette recorders, (B) devices that operate with alternating current power such as fans, juicers, mixers, and incandescent lamps, (C) devices that operate with direct current power converted from alternating current power such as televisions, radios, stereos, and personal computers, and (D) devices that operate with alternating current power further converted from direct current power once converted from alternating current power, such as washing machines, refrigerators, air conditioners, microwave ovens, and inverter-type devices including fluorescent lamps.

[0029] [2. Internal Structure of ECU34] As shown in FIG. 2, the ECU 34 is composed of a computer having a microprocessor and a memory (not shown). The ECU 34 has a plurality of terminals 50, the aforementioned second power conversion unit 30, a diode 52, a step-up / down circuit 54, and an internal circuit 56. The internal circuit 56 has a low-voltage power supply 58 and an activation signal generation unit 60.

[0030] The plurality of terminals 50 include a signal terminal 50a to which an on signal or an off signal from the main switch 38 is input, a positive terminal 50b and a negative terminal 50c connected to the second power transmission path 20, and a power terminal 50d connected to the third power transmission path 22. The signal terminal 50a is electrically connected to the internal circuit 56. The power terminal 50d is electrically connected to the internal circuit 56 via the diode 52 and the step-up / down circuit 54. The input side (primary side) of the second power conversion unit 30 is electrically connected to the positive terminal 50b and the negative terminal 50c. The output side (secondary side) of the second power conversion unit 30 is electrically connected to the internal circuit 56.

[0031] In this case, the ON signal or OFF signal from the main switch 38 is supplied to the internal circuit 56 via the signal terminal 50a. The step-up / down circuit 54 steps down the DC voltage supplied from the second power storage unit 16 via the power terminal 50d and the diode 52, and supplies the stepped-down DC voltage to the internal circuit 56. The second power conversion unit 30 steps down the DC voltage supplied from the first power storage unit 14 via the positive terminal 50b and the negative terminal 50c, and supplies the stepped-down DC voltage to the internal circuit 56.

[0032] In FIG. 2, the step-up / down circuit 54 and the second power conversion unit 30 are electrically connected in parallel to the internal circuit 56. Therefore, among the DC voltage output from the step-up / down circuit 54 and the DC voltage output from the second power conversion unit 30, the DC voltage with the higher voltage level is supplied to the internal circuit 56. Accordingly, when the first power storage unit 14 is in the non-activated state, the DC voltage output from the second power conversion unit 30 becomes a low level, so the DC voltage output from the step-up / down circuit 54 is supplied to the internal circuit 56. Also, when the first power storage unit 14 is in the activated state, if the DC voltage output from the step-up / down circuit 54 is higher than the DC voltage output from the second power conversion unit 30, the DC voltage output from the step-up / down circuit 54 is supplied to the internal circuit 56. Further, when the first power storage unit 14 is in the activated state, if the DC voltage output from the second power conversion unit 30 is higher than the DC voltage output from the step-up / down circuit 54, the DC voltage output from the second power conversion unit 30 is supplied to the internal circuit 56. Note that the diode 52 functions as a reverse current prevention diode to prevent the DC voltage output from the step-up / down circuit 54 or the second power conversion unit 30 to the internal circuit 56 from being output to the outside via the power terminal 50d.

[0033] When an on-signal is input to the internal circuit 56 from the main switch 38 via the signal terminal 50a, the internal circuit 56 operates with the DC voltage supplied from the step-up / down circuit 54 or the second power conversion unit 30. In this case, the internal circuit 56 executes various control processes by reading and executing a program stored in a memory (not shown). The low-voltage power supply 58 of the internal circuit 56 steps down the DC voltage supplied from the step-up / down circuit 54 or the second power conversion unit 30 to a lower DC voltage. The stepped-down DC voltage is supplied to a processor (not shown) that constitutes the internal circuit 56.

[0034] The activation signal generation unit 60 generates an activation signal for activating the first power storage unit 14 based on the DC voltage supplied from the step-up / down circuit 54 or the second power conversion unit 30. The activation signal generation unit 60 supplies the generated activation signal to the first power storage unit 14, thereby switching the first power storage unit 14 from the non-activated state to the activated state, or maintaining the activated state of the first power storage unit 14. When a plurality of first power storage units 14 are electrically connected to the ECU 34, the activation signal generation unit 60 can individually generate and supply activation signals to the plurality of first power storage units 14. Thereby, the activation signal generation unit 60 can individually control the switching between the non-activated state and the activated state for each of the plurality of first power storage units 14.

[0035] [3. Specific Configuration of Power Device 10] FIG. 3 and FIG. 4 show the specific configuration of the power device 10 of FIGS. 1 and 2. Note that FIG. 4 also shows the configuration of the ECU 34 other than the generation of the activation signal. FIGS. 3 and 4 illustrate the case where it is applied to the power device 10 for vehicle drive. In FIGS. 3 and 4, for the components also shown in FIGS. 1 and 2, the description is simplified or omitted. Also, in FIGS. 3 and 4, as in FIGS. 1 and 2, the case where the power device 10 includes the first battery 14a and the second battery 14b as the first power storage unit 14 will be described.

[0036] In FIGS. 3 and 4, the first power conversion unit 28 is a PDU (Power Drive Unit) 62. A series circuit of a first battery 14a and a second battery 14b as the first power storage unit 14 is electrically connected to the PDU 62. A contactor 64 is disposed between the first battery 14a and the PDU 62. In this case, the third power conversion unit 32 and the ECU 34 receive power supply from a wiring that electrically connects the first battery 14a and the contactor 64. That is, the second power transmission path 20 and the fifth power transmission path 26 are connected to a wiring that electrically connects the first battery 14a and the contactor 64.

[0037] The first battery 14a and the second battery 14b have the same configuration. That is, the first battery 14a includes a battery body 66a, a BMU 68a, a switch 70a, an insulating part 72a, a transceiver 74a, a power supply part 76a, and a connector 78a. The second battery 14b includes a battery body 66b, a BMU 68b, a switch 70b, an insulating part 72b, a transceiver 74b, a power supply part 76b, and a connector 78b.

[0038] The battery bodies 66a and 66b constitute a secondary battery including a plurality of cells connected in series. The switches 70a and 70b are provided in series with the battery bodies 66a and 66b, and their conduction states are determined by control from the BMUs 68a and 68b. The BMUs 68a and 68b detect the states of the battery bodies 66a and 66b and notify the detected states to the ECU 34 or the like. In this case, the operating states of the BMUs 68a and 68b are determined by control from the ECU 34 or the like, and the BMUs 68a and 68b control the conduction states of the switches 70a and 70b according to the determined operating states.

[0039] The insulating parts 72a and 72b are optical couplers or the like provided between the BMU 68a, 68b and the transceivers 74a, 74b, and electrically insulate the signals between the BMU 68a, 68b and the connectors 78a, 78b on the BMU 68a, 68b side and the connectors 78a, 78b side. For example, the insulating parts 72a and 72b electrically insulate and convert the activation signals supplied from the A terminals 80a, 80b of the connectors 78a, 78b toward the BMU 68a, 68b and supply them to the BMU 68a, 68b. Therefore, the BMU 68a, 68b and the transceivers 74a, 74b are electrically insulated via the insulating parts 72a and 72b. Note that the A terminals 80a, 80b are connected to the ECU 34 via the activation signal transmission lines 82a, 82b.

[0040] The transceivers 74a, 74b are provided between the connectors 78a, 78b and the insulating parts 72a, 72b, and convert and relay bidirectionally the signals used for communication between the BMU 68a, 68b and the ECU 34. In this case, the B terminals 84a, 84b and the C terminals 86a, 86b of the connectors 78a, 78b connected to the transceivers 74a, 74b are connected to the communication line 46. The power supply parts 76a, 76b receive power supply from the battery bodies 66a, 66b and supply a part of the power to the BMU 68a, 68b, the insulating parts 72a, 72b, etc. In this case, the power supply parts 76a, 76b are provided on the battery body 66a, 66b side rather than the insulating parts 72a, 72b and are electrically insulated from the connectors 78a, 78b side.

[0041] As described above, the connectors 78a, 78b include a plurality of signal terminals for exchanging signals for controlling the first battery 14a and the second battery 14b. For example, the signals exchanged via the connectors 78a, 78b include an activation signal for activating the first power storage part 14 and a signal for the BMU 68a, 68b to communicate with the ECU 34. In addition to the terminals for these signals, the connectors 78a, 78b include ground terminals 88a, 88b, etc. The above connectors 78a, 78b are an example of exchanging electrical signals and are not limited thereto, and signals may be exchanged optically.

[0042] The BMU 68a and 68b monitor the charging and discharging status of the first battery 14a and the second battery 14b, the power storage amounts of the battery bodies 66a and 66b, the temperature, etc. The monitoring results are shared with the ECU 34. Also, the BMU 68a and 68b control the charging and discharging of the battery bodies 66a and 66b, etc. by controlling switches 70a, 70b, etc. based on control commands from the ECU 34 or the above-described monitoring results.

[0043] The ECU 34 further includes a transceiver 90 and a contact driver 92. In FIGS. 3 and 4, the management unit 94 of the ECU 34 corresponds to the functional blocks of the processor that constitutes the aforementioned internal circuit 56.

[0044] The activation signal generation unit 60 generates an activation signal for making the first battery 14a and the second battery 14b available. The activation signal generation unit 60 supplies the generated activation signal to the first battery 14a and the second battery 14b via the activation signal transmission lines 82a and 82b. In this case, the activation signal transmission lines 82a and 82b are made as different wirings for the first battery 14a and the second battery 14b. Thereby, the activation signal generation unit 60 can individually activate (start up) the first battery 14a and the second battery 14b.

[0045] The activation signal generation unit 60 sets the voltage of the activation signal to be equivalent to the DC voltage supplied from the buck-boost circuit 54 or the second power conversion unit 30 to the management unit 94 when the activation signal indicates a significant state. That is, when the activation signal indicates a significant state, the activation signal generation unit 60 outputs a voltage equivalent to the DC voltage supplied from the buck-boost circuit 54 or the second power conversion unit 30 as the activation signal. For example, the activation signal generation unit 60 may include a switch (not shown) and generate the activation signal by controlling the conduction state of this switch. The activation signal generation unit 60 generates an activation signal for each of the first battery 14a and the second battery 14b. Thereby, it becomes possible to individually control the startup states of the first battery 14a and the second battery 14b.

[0046] The transceiver 90 converts signals used for communication between the BMUs 68a, 68b and the ECU 34 and relays them bidirectionally. The management unit 94 associates the activated first battery 14a and second battery 14b with the identification information of the first battery 14a and second battery 14b, and assigns the identification information to the first battery 14a and second battery 14b, respectively. The management unit 94 sends the identification information of the first battery 14a and second battery 14b to the BMUs 68a, 68b via the transceivers 74a, 74b activated by the activation signal.

[0047] Furthermore, output request information from a throttle sensor 96 (accelerator sensor) provided in the vehicle 12 is input to the ECU 34. After the management unit 94 finishes the initialization process of the first battery 14a and second battery 14b by supplying the activation signal, based on the output request information input to the ECU 34, the management unit 94 controls the contactor 64, the first battery 14a, the second battery 14b, the PDU 62, etc. The ECU 34 controls the charging and discharging of the first battery 14a and second battery 14b by controlling the first battery 14a and second battery 14b. The contactor drive unit 92 switches the contactor 64 to a connected state or a disconnected state according to the control from the management unit 94.

[0048] The BMUs 68a, 68b include activation processing units 100a, 100b, battery control units 102a, 102b, and communication processing units 104a, 104b.

[0049] Based on the activation signal supplied from the ECU 34, the activation processing units 100a, 100b set the states of the first battery 14a and second battery 14b to an activated state in which DC power can be output. For example, the activation processing units 100a, 100b detect that the activation signal is in a valid state and set the states of the first battery 14a and second battery 14b to an activated state in which DC power can be output. The activation processing units 100a, 100b detect that the activation signal has become an invalid state and set the states of the first battery 14a and second battery 14b to a non-activated state in which power is not output.

[0050] The battery control units 102a and 102b detect changes in the states (such as voltage and SOC) of the respective cells of the battery bodies 66a and 66b, for example, and adjust them so that the charge states of the respective cells become uniform. Further, the battery control units 102a and 102b control the switches 70a and 70b by control from the ECU 34 or the like to make the first battery 14a and the second battery 14b available.

[0051] The communication processing units 104a and 104b communicate with the ECU 34 according to a predetermined protocol. For example, the communication processing units 104a and 104b communicate information for controlling the charge and discharge of the first battery 14a and the second battery 14b with the ECU 34. The communication processing units 104a and 104b include identification information for the ECU 34 to identify the first battery 14a and the second battery 14b in the above information and communicate it. The communication processing units 104a and 104b store the identification information notified from the ECU 34 in a storage area (not shown) in the BMU 68a and 68b.

[0052] [4. Operation of the power device 10] The power device 10 according to the present embodiment is configured as described above. Next, its operation will be described with reference to FIGS. 5 and 6. Here, the description will be made with reference to FIGS. 1 to 4 as necessary. This operation is an operation for switching the first power storage unit 14 (for example, the first battery 14a or the second battery 14b) to an activated state or a non-activated state.

[0053] FIG. 5 is a timing chart showing the time change of the operation of the power device 10. Further, FIG. 6 is a flowchart corresponding to the timing chart of FIG. 5.

[0054] When the user turns on the main switch 38 (see FIGS. 1, 2, and 4) at time t1 (step S1), an on signal is supplied from the main switch 38 to the internal circuit 56 via the signal terminal 50a of the ECU 34 (see FIGS. 1 to 4).

[0055] In the next step S2, the second power storage unit 16 starts supplying a DC voltage to the buck-boost circuit 54 via the third power transmission path 22, the power terminal 50d, and the diode 52.

[0056] In the next step S3, the buck-boost circuit 54 steps down the DC voltage supplied from the second power storage unit 16. The stepped-down DC voltage is supplied to the internal circuit 56. As a result, the internal circuit 56 starts operating by the DC voltage supplied from the buck-boost circuit 54, triggered by the supply of the on-signal of the main switch 38. As a result, the management unit 94 and the activation signal generation unit 60 are activated.

[0057] In the next step S4, the activation signal generation unit 60 outputs an activation signal to the first power storage unit 14 via the fourth power transmission path 24. The BMU68a (BMU68b) constituting the first power storage unit 14 receives the supply of the activation signal, starts up at time t2, and starts communicating with the ECU34 via the transceiver 74a (transceiver 74b). That is, the first power storage unit 14 switches from the non-activated state to the activated state. As a result, the management unit 94 performs a numbering process of associating the first power storage unit 14 that has received the activation signal with the identification information of the first power storage unit 14 and assigning the identification information to the first power storage unit 14. As a result, the management unit 94 sends the identification information of the first power storage unit 14 to the BMU68a (BMU68b) via the transceiver 74a (transceiver 74b) of the first power storage unit 14 that has been switched to the activated state by the activation signal.

[0058] Note that FIG. 5 illustrates the numbering process when four first power storage units 14 are electrically connected to the ECU34. In this case, the ECU34 performs the numbering process while switching the four first power storage units 14 between the activated state and the non-activated state by intermittently supplying activation signals to each of the four first power storage units 14 with a time shift in the time period from t2 to t3. As a result, the first power storage unit 14 that is first supplied with the activation signal at time t2 switches to the activated state.

[0059] Then, when the numbering process is completed at time t3, in the next step S5, the first power storage unit 14 starts to output a DC voltage. In this case, the first power storage unit 14 performs a pre-charge process for charging a capacitor (not shown) after the numbering process. As a result, the value of the DC voltage output from the first power storage unit 14 gradually increases over time. The second power conversion unit 30 steps down the DC voltage supplied from the first power storage unit 14 and outputs the stepped-down DC voltage to the internal circuit 56 (management unit 94) side.

[0060] In step S6, the ECU 34 determines whether to switch the drive power supply for generating the activation signal from the boost-buck circuit 54 to the second power conversion unit 30. In this case, at time t4, if the value of the DC voltage output from the second power conversion unit 30 to the internal circuit 56 (management unit 94) side is higher than the value of the DC voltage output from the boost-buck circuit 54 to the internal circuit 56 (management unit 94) side, the drive power supply automatically switches from the boost-buck circuit 54 to the second power conversion unit 30 (step S6: YES, step S7).

[0061] As a result, in step S8, the boost-buck circuit 54 stops operating. Therefore, the power supply from the second power storage unit 16 to the ECU 34 is cut off.

[0062] Thereby, after time t4, the ECU 34 operates with the DC power supplied from the first power storage unit 14. Also, the activation signal generation unit 60 generates an activation signal based on the DC voltage supplied from the first power storage unit 14, and supplies the generated activation signal to the first power storage unit 14 to maintain the startup state of the first power storage unit 14.

[0063] In the above steps S6 to S8, the case where the driving power supply is automatically switched from the buck-boost circuit 54 to the second power conversion unit 30 based on the output voltage difference between the buck-boost circuit 54 and the second power conversion unit 30 was described. In the present embodiment, a state switching switch is provided between the buck-boost circuit 54 and the second power conversion unit 30 and the internal circuit 56 (management unit 94), and by referring to information stored in a memory (for example, EEPROM) not shown, the driving power supply may be switched from the buck-boost circuit 54 to the second power conversion unit 30.

[0064] In step S9, the internal circuit 56 (management unit 94) determines whether the main switch 38 has been turned off. When the main switch 38 is turned off at time t5 and an off signal is input to the internal circuit 56 (management unit 94) from the main switch 38 via the signal terminal 50a (step S9: YES), the process proceeds to step S10, and the activation signal generation unit 60 stops generating the activation signal. As a result, the supply of the activation signal to the first power storage unit 14 stops.

[0065] As a result, in step S11, the BMU68a (BMU68b) of the first power storage unit 14 executes an operation stop process and reduces the value of the DC voltage output from the first power storage unit 14 to the 0 level. Thereby, at time t6, the first power storage unit 14 stops operating and switches to a non-activated state. Note that after time t5, the ECU 34 switches the driving power supply from the second power conversion unit 30 to the buck-boost circuit 54.

[0066] [5. Modification Example of Power Device 10] FIG. 7 shows a modification example of the power device 10 of FIGS. 1 to 6. For the same components as those of the power device 10 of FIGS. 1 to 6, the same reference numerals are given and detailed description is omitted, and the same applies hereinafter.

[0067] This modification example illustrates the case where the first power storage unit 14, the second power storage unit 16, the ECU 34, the second power conversion unit 30, the first power transmission path 18, the second power transmission path 20, the third power transmission path 22, and the fourth power transmission path 24 are diverted to a system other than the vehicle 12. In this case, the first power storage unit 14 is electrically connected to a power distribution system 110 including an inverter or the like via the first power transmission path 18. That is, the power distribution system 110 is an operating unit (load) including the aforementioned first power conversion unit 28. In this modification example, since the first power storage unit 14 and the ECU 34 etc. are diverted to a system other than the vehicle 12, it can be shared with the battery control for the vehicle 12. As a result, the system of the diverted destination can be simplified.

[0068] [6. Comparative Example] Figs. 8 to 11 show a power device 120 of a comparative example. Fig. 8 is a comparative example with respect to the power device 10 of Fig. 1. Fig. 9 is a comparative example with respect to the power device 10 of Fig. 7. Fig. 10 is a comparative example with respect to the power device 10 of Fig. 3. Fig. 11 is a comparative example with respect to the ECU 34 of Fig. 4.

[0069] In the power device 120 of the comparative example, the ECU 34 operates receiving the supply of DC power only from the second power storage unit 16. Therefore, in the comparative example, the ECU 34 does not receive the supply of DC power from the first power storage unit 14. For this reason, in the comparative example, the buck-boost circuit 54, the second power conversion unit 30, and the second power transmission path 20 do not exist.

[0070] Therefore, in the power device 120 of the comparative example, the ECU 34 always requires the supply of DC power from the second power storage unit 16 as an external power source. As a result, the power supply capacity of the second power storage unit 16 increases, and the system configuration of the power device 120 becomes larger. Also, when the power device 120 is diverted to a system other than the vehicle 12, the system of the diverted destination also becomes larger.

[0071] In contrast, in the power device 10 according to the present embodiment, as described above, when the first power storage unit 14 is in an activated state, the second power conversion unit 30 to which power is supplied from the first power storage unit 14 functions as a driving power source for the ECU 34. Thereby, the power supply capacity of the second power storage unit 16 as an external power source can be reduced. As a result, the system configuration of the power device 10 can be miniaturized. Further, when the first power storage unit 14, the ECU 34, etc. are diverted to a system other than the vehicle 12, the system to which they are diverted can also be simplified.

[0072] [7. Other Modification Examples of the Power Device 10] FIGS. 12 to 15 show other modification examples of the power device 10 of FIGS. 1 to 7. In another modification example, the second power conversion unit 30 is provided inside the first power conversion unit 28. In this case, the second power conversion unit 30 further steps down the DC voltage stepped down by the third power conversion unit 32 and supplies it to the ECU 34. Also in this other modification example, similar to the power device 10 of FIGS. 1 to 7, the power supply capacity of the second power storage unit 16 as an external power source can be reduced, and miniaturization of the system configuration of the power device 10 can be realized. Further, when diverted to a system other than the vehicle 12, the system to which it is diverted can also be simplified. In FIG. 13, the second power conversion unit 30 is electrically connected to the internal circuit 56 via a terminal 50 (terminal 50e).

[0073] [8. Effects of the Present Embodiment] As described above, the power device 10 according to the present embodiment includes a first power storage unit 14, a motor 36 (operating unit) electrically connected to the first power storage unit 14 via a first power transmission path 18, a first power conversion unit 28 provided on the first power transmission path 18 for converting power, and an ECU 34 (control unit) for controlling the first power conversion unit 28.

[0074] In this case, the power device 10 includes a second power transmission path 20 that electrically connects the first power storage unit 14 and the ECU 34, a second power conversion unit 30 that is provided on the second power transmission path 20 and converts power, a second power storage unit 16 that has a voltage lower than that of the first power storage unit 14, and a third power transmission path 22 that is provided in parallel with the second power transmission path 20 with respect to the ECU 34 and electrically connects the second power storage unit 16 and the ECU 34.

[0075] According to this configuration, the second power conversion unit 30 converts the power of the first power storage unit 14 and supplies it to the ECU 34, thereby functioning as a driving power source for the ECU 34. As a result, the power supply capacity of the second power storage unit 16 as an external power source can be reduced, and the second power storage unit 16 can be miniaturized and have a lower output. Consequently, the entire power device 10 can be miniaturized.

[0076] Note that this effect is the same even when an external power source other than the second power storage unit 16 or a power conversion unit such as an external DC / DC converter is used as the starting power source for the ECU 34. That is, it is possible to miniaturize the external power source and to miniaturize or omit the power conversion unit.

[0077] In addition, by diverting the first power storage unit 14 and the ECU 34 to a system other than the vehicle 12 or the like, it is possible to share the control of the first power storage unit 14. Thereby, miniaturization and simplification of the diverted system can be achieved.

[0078] In this case, the power device 10 includes a fourth power transmission path 24 that electrically connects the first power storage unit 14 and the second power storage unit 16 and enables power to be supplied from the second power storage unit 16 to the first power storage unit 14. The first power storage unit 14 can be switched between an activated state in which power can be exchanged with the outside by supplying external power and a non-activated state in which power exchange is not possible.

[0079] Thereby, the first power storage unit 14 can be easily switched between the activated state and the non-activated state.

[0080] Further, when in the non - activated state, the first power storage unit 14 is switched to the activated state by the power of the second power storage unit 16 being supplied via the fourth power transmission path 24, and supplies power to the ECU 34 via the second power transmission path 20.

[0081] Thereby, the first power storage unit 14 can be easily used as the driving power source of the ECU 34.

[0082] In addition, the power device 10 is provided in the ECU 34 and includes an activation signal generation unit 60 (starting power generation unit) that generates an activation signal (starting power) for activating the first power storage unit 14. The third power transmission path 22 is a part of the fourth power transmission path 24 and electrically connects the activation signal generation unit 60 and the second power storage unit 16. In this case, when the first power storage unit 14 is in the non - activated state, the activation signal generation unit 60 generates an activation signal based on the power of the second power storage unit 16 and supplies the generated activation signal to the first power storage unit 14 via the fourth power transmission path 24, thereby switching the first power storage unit 14 to the activated state. Next, when the power supply from the first power storage unit 14 to the second power conversion unit 30 via the second power transmission path 20 is started after being switched to the activated state, the activation signal generation unit 60 generates an activation signal based on the power converted by the second power conversion unit 30 and supplies the generated activation signal to the first power storage unit 14 via the fourth power transmission path 24, thereby maintaining the activated state. Then, the activation signal generation unit 60 stops the supply of the activation signal to the first power storage unit 14, thereby switching the first power storage unit 14 from the activated state to the non - activated state.

[0083] Thereby, the first power storage unit 14 can be efficiently switched between the activated state and the non - activated state.

[0084] In addition, the power device 10 includes a fifth power transmission path 26 that is provided in parallel with the fourth power transmission path 24 and electrically connects the first power storage unit 14 and the second power storage unit 16, and a third power conversion unit 32 that is provided on the fifth power transmission path 26 and converts power.

[0085] As a result, the second power storage unit 16 can be charged from the first power storage unit 14 via the third power conversion unit 32.

[0086] In addition, the power device 10 is electrically connected to the third power transmission path 22 and includes a headlight 40, a brake lamp 42, and a meter 44 (other operating parts) that have an operating voltage lower than that of the motor 36.

[0087] As a result, while supplying power from the second power storage unit 16 to the ECU 34, it becomes possible to operate auxiliary machines for the vehicle 12.

[0088] In addition, the second power conversion unit 30 is provided inside the ECU 34 or the first power conversion unit 28.

[0089] The effect of the power device 10 will be further described.

[0090] In the power device 120 of the comparative example, the activation signal is generated only by the power supply from the second power storage unit 16. On the other hand, in the power device 10 according to the present embodiment, after the first power storage unit 14 is activated, the activation signal is generated by the power supply from the second power conversion unit 30 provided inside the ECU 34 or the first power conversion unit 28. In this case, the second power conversion unit 30 provided in the ECU 34 is a starting power source independent of the control of the vehicle 12. Therefore, the power generated by the second power conversion unit 30 is used as the driving power source of the ECU 34 or as the activation signal.

[0091] In addition, in the power device 10, it is also possible to incorporate the miniaturized second power storage unit 16 into the second power conversion unit 30 inside the ECU 34.

[0092] In the power device 10 configured as described above, it is possible to reuse the first power storage unit 14, which is a battery pack for the vehicle 12. It is also possible to use it as a power source for general-purpose machines other than the vehicle 12, such as lighting devices. Furthermore, since the extraction of the power source of the ECU 34 is reduced, it is possible to miniaturize the second power storage unit 16.

[0093] Furthermore, since the operation required for activating the first power storage unit 14 can be completed in a short time, it becomes possible to reduce the voltage and size of the charging system required for charging the second power storage unit 16.

[0094] Furthermore, by performing switching with a state switching switch using an EEPROM, it becomes possible to use the same ECU 34 in the vehicle 12 and general-purpose machines. As a result, simplification and reuse of the system become possible.

[0095] Note that the present invention is not limited to the above-described embodiments, and it goes without saying that various configurations can be adopted based on the description in this specification.

Explanation of Reference Numerals

[0096] 10... Power device 14... First power storage unit 16... Second power storage unit 18... First power transmission path 20... Second power transmission path 22... Third power transmission path 28... First power conversion unit 30... Second power conversion unit 34... ECU (control unit) 36... Motor (operating unit)

Claims

1. In a power device including a first power storage unit, an operating unit electrically connected to the first power storage unit via a first power transmission path, a first power conversion unit provided on the first power transmission path for converting power, and a control unit for controlling the first power conversion unit, a second power transmission path electrically connecting the first power storage unit and the control unit; a second power conversion unit provided on the second power transmission path for converting power; a second power storage unit having a voltage lower than that of the first power storage unit; a third power transmission path provided in parallel with the second power transmission path with respect to the control unit and electrically connecting the second power storage unit and the control unit; a fourth power transmission path electrically connecting the first power storage unit and the second power storage unit and enabling power supply from the second power storage unit to the first power storage unit; comprising: the first power storage unit is switchable between an activated state in which power can be exchanged with the outside by supplying power from the outside and a non-activated state in which such exchange is not possible; in the non-activated state, power of the second power storage unit is supplied via the fourth power transmission path to switch to the activated state, and power is supplied to the control unit via the second power transmission path; the power device includes an activation power generation unit provided in the control unit for generating activation power for activating the first power storage unit; the third power transmission path is a part of the fourth power transmission path and electrically connects the activation power generation unit and the second power storage unit; the activation power generation unit when the first power storage unit is in the non-activated state, generates the activation power based on the power of the second power storage unit and supplies the generated activation power to the first power storage unit via the fourth power transmission path to switch the first power storage unit to the activated state; when power supply from the first power storage unit switched to the activated state to the second power conversion unit via the second power transmission path is started, generates the activation power based on the power converted by the second power conversion unit and supplies the generated activation power to the first power storage unit via the fourth power transmission path to maintain the activated state; a power device that switches the first power storage unit from the activated state to the non-activated state by stopping the supply of the activation power to the first power storage unit.

2. In the power device according to Claim 1, a fifth power transmission path provided in parallel with the fourth power transmission path and electrically connecting the first power storage unit and the second power storage unit; A third power conversion unit that is provided on the fifth power transmission path and converts power; A power device comprising the same. **Claim 3** In the power device according to claim 1 or 2, A power device, comprising another operating unit that is electrically connected to the third power transmission path and has an operating voltage lower than that of the operating unit. **Claim 4** In the power device according to any one of claims 1 to 3, The second power conversion unit is provided inside the control unit or the first power conversion unit. A power device.

Images