Power control system

Abstract

The present invention provides a power control system that can suitably perform program rewriting of an electronic control unit using an external power supply. [Solution] A power control system comprising: a first relay that connects a first on-board battery to an electronic control unit so that it can supply power when the program is not being rewritten; a second relay that connects an external power supply to an electronic control unit so that it can supply power when the program is being rewritten; and a control unit that controls the connection state of the first relay and the second relay, wherein the control unit controls the first relay to a unidirectional conducting state with the current direction restricted from the first on-board battery to the electronic control unit, after the external power supply is connected to the second relay which is controlled to be in an off state, and before starting the program rewriting, controls the second relay to a unidirectional conducting state with the current direction restricted from the external power supply to the electronic control unit, controls the first relay to an off state, and controls the second relay to a bidirectional conducting state with the current direction not restricted.

Description

Technical Field

[0001] The present disclosure relates to a power control system used when executing program rewriting of an electronic control device using an external power source.

Background Art

[0002] Patent Document 1 discloses a system for rewriting a program of an electronic control device mounted on a hybrid vehicle including a main battery and an auxiliary battery. In this Patent Document 1, it is described that when specific conditions are satisfied, an electronic control device powered from the auxiliary battery rewrites its own program to a program transmitted from a device outside the vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When it is not possible to execute program rewriting of an electronic control device only with the power capacity of the auxiliary battery, it is conceivable to execute program rewriting of the electronic control device using an external power source (such as a power supply facility or a charger outside the vehicle). However, in this case, if the external power source is connected to the vehicle without considering the electrical connection state of the auxiliary battery, overcharging or overcurrent of the auxiliary battery may occur due to the external power source (when the voltage of the external power source > the voltage of the auxiliary battery), or current may flow from the auxiliary battery to the external power source and the power of the auxiliary battery may be wasted (when the voltage of the external power source < the voltage of the auxiliary battery).

[0005] Therefore, when executing program rewriting of an electronic control device using an external power source, consideration regarding power control is necessary.

[0006] This disclosure has been made in view of the above-mentioned problems, and aims to provide a power control system that can suitably perform program rewriting of an electronic control unit using an external power supply. [Means for solving the problem]

[0007] To solve the above problems, one aspect of the disclosed technology is a power control system used when rewriting the program of an electronic control device using an external power supply, comprising: a first relay that connects a first on-board battery to the electronic control device so as to be able to supply power when program rewriting is not performed; a second relay that connects an external power supply to the electronic control device so as to be able to supply power when program rewriting is performed; and a control unit that controls the connection state of the first relay and the second relay, wherein the control unit controls the first relay to a unidirectional conducting state with the current direction restricted from the first on-board battery to the electronic control device after the external power supply is connected to the second relay which is controlled to be in an off state, and before program rewriting is started, controls the second relay to a unidirectional conducting state with the current direction restricted from the external power supply to the electronic control device, controls the first relay to an off state, and controls the second relay to a bidirectional conducting state with the current direction not restricted. [Effects of the Invention]

[0008] According to the power control system of the present disclosure described above, since the first on-board battery (auxiliary battery) and the external power supply do not conduct electricity, the program rewriting of the electronic control unit can be suitably performed even when an external power supply is used. [Brief explanation of the drawing]

[0009] [Figure 1] Functional block diagram of a power control system and its peripheral parts according to one embodiment of the present disclosure. [Figure 2] Diagram illustrating a relay constructed using field-effect transistors. [Figure 3]This flowchart illustrates the pre-reprogramming control performed by the power control system before the electronic control unit's program is rewritten. [Figure 4] A flowchart illustrating the post-reprogramming control performed by the power control system after the electronic control unit's program has been rewritten. [Figure 5A] This diagram illustrates the connection status of the power control system in pre-reprogramming control. [Figure 5B] This diagram illustrates the connection status of the power control system in pre-reprogramming control. [Figure 6A] This diagram illustrates the connection status of the power control system in post-reprogramming control. [Figure 6B] This diagram illustrates the connection status of the power control system in post-reprogramming control. [Modes for carrying out the invention]

[0010] The power control system disclosed herein, when using an external power supply to rewrite the program of an electronic control unit, performs transition control that prevents electrical conduction between the auxiliary battery and the external power supply during the process of switching the power supply source of the electronic control unit from the auxiliary battery to the external power supply. This control prevents undesirable overcharging of the auxiliary battery and unnecessary power consumption. The embodiments of this disclosure will be described in detail below with reference to the drawings.

[0011] <Embodiment> [composition] Figure 1 is a functional block diagram of a power supply control system and its peripheral components according to one embodiment of the present disclosure. The functional block illustrated in Figure 1 includes a high-voltage battery 10, a DC-DC converter 20, an auxiliary battery 30, an external power supply 40, a relay unit 50, an electronic control device 60, and a control unit 70.

[0012] The configuration shown in Figure 1 can be installed, as an example, in electric vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs).

[0013] The high-voltage battery 10 is a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery (the first in-vehicle battery). The high-voltage battery 10 can supply the power it stores to the electronic control unit 60 (and the auxiliary battery 30) via the DCDC converter 20 and the relay unit 50. In an electric vehicle, for example, the drive battery corresponds to the high-voltage battery 10.

[0014] The DCDC converter 20 is a voltage converter provided between the high-voltage battery 10 and the relay unit 50. This DCDC converter 20 converts the input voltage of the high-voltage battery 10 into the voltage required for the electronic control unit 60 (and the auxiliary battery 30) and outputs it to the electronic control unit 60 (and the auxiliary battery 30) via the relay unit 50. For the DCDC converter 20, for example, a step-down type DCDC converter that steps down the input voltage and outputs it can be used.

[0015] The auxiliary battery 30 is a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery (the second in-vehicle battery). This auxiliary battery 30 can supply the power it stores to the electronic control unit 60 via the relay unit 50. Also, the auxiliary battery 30 can store the power output from the high-voltage battery 10 via the DCDC converter 20 and the relay unit 50. This auxiliary battery 30 includes a battery 31 for storing power and a relay (RLY) 32 that can switch the electrical connection state between this battery 31 and the relay unit 50. The circuit configuration described later is used for the relay 32.

[0016] The external power source 40 is a power source that can be connected to an external power source connection terminal (or rescue terminal) provided in the vehicle in advance so as to be able to supply power. Examples of this external power source 40 include power supply facilities such as a charging stand and a portable charger.

[0017] The relay unit 50 is configured to connect the DC-DC converter 20, the auxiliary battery 30, and the external power source 40 in parallel and output the power of each component to the electronic control unit 60. This relay unit 50 includes at least a relay (RLY) 51 whose one end is connected to the auxiliary battery 30, a relay (RLY) 52 whose one end is connected to the external power source 40, a relay (RLY) 53 whose one end is connected to the DC-DC converter 20, and a relay (RLY) 54 whose one end is connected to the electronic control unit 60. The other ends of these relays 51 to 54 are connected to each other. When there are multiple electronic control units 60, relays may be provided for connection to each electronic control unit 60. Among these relays 51 to 54, at least the relay 52 uses the circuit configuration described later.

[0018] The electronic control unit 60 is an in-vehicle device (auxiliary load) that operates with the power supplied from the high-voltage battery 10 via the DC-DC converter 20 or the power supplied from the auxiliary battery 30. The number of electronic control units 60 mounted on the vehicle is not limited to the number shown in FIG. 1.

[0019] When the control unit 70 rewrites the program of the electronic control unit 60 using the external power source 40, it is a configuration for controlling the electrical connection state among the high-voltage battery 10, the auxiliary battery 30, the external power source 40, and the electronic control unit 60. This control unit 70 controls at least the DC-DC converter 20, the relay 32 of the auxiliary battery 30, and the relay 52 of the relay unit 50. The control performed by the control unit 70 by instructing the DC-DC converter 20, the relay 32, and the relay 52 will be described later.

[0020] [Relay Circuit] As shown in FIG. 2(a), the relay 32 of the auxiliary battery 30 and the relay 52 of the relay unit 50 described above use a circuit configured by connecting two field effect transistors (FETs) in series with the rectification direction of the body diode reversed.

[0021] In this configuration, if both field-effect transistors are ON (gate voltage: ON), current can flow in either direction, resulting in a "bidirectional conduction state" (Figure 2(b)). Also, in this configuration, if both field-effect transistors are OFF (gate voltage: OFF), current cannot flow in either direction, resulting in a "blocked state" (Figure 2(d)). Furthermore, in this configuration, if one field-effect transistor is ON (gate voltage: ON) and the other field-effect transistor is OFF (gate voltage: OFF), current can flow only in one direction, from the ON transistor to the OFF transistor, resulting in a "unidirectional conduction state (DiOR)" (Figure 2(c)).

[0022] [control] Next, with further reference to Figures 3 to 6B, the control performed in the power control system according to this embodiment will be described.

[0023] (1) Control before program rewriting Figure 3 is a flowchart illustrating the processing procedure for pre-reprogramming control, which is the control performed by the control unit 70 of the power supply control system before the program of the electronic control unit 60 is rewritten. Figures 5A and 5B illustrate the connection status of the power supply control system over time during pre-reprogramming control.

[0024] The pre-reprogramming control illustrated in Figure 3 is initiated by receiving a request or instruction to rewrite the program of the electronic control unit 60 from a predetermined configuration. When this pre-reprogramming control is initiated, the state of each configuration is the normal state with the vehicle powered on, the DCDC converter 20 is in operation (ON), the relay 32 of the auxiliary battery (auxiliary LiB) 30 (hereinafter referred to as "first relay 32") is in a bidirectional conductive state, and the relay 52 of the relay unit 50 (hereinafter referred to as "second relay 52") is in a disconnected state (state shown in Figure 5A(a)). Furthermore, the relays 51, 53, and 54 of the relay unit 50 are always in a bidirectional conductive state during the pre-reprogramming control.

[0025] (Step S301) The control unit 70 stops the operation of the DC-DC converter 20. This electrically disconnects the high-voltage battery 10 from the relay unit 50 (state shown in Figure 5A(b)). Once the DC-DC converter 20 stops, the process proceeds to step S302.

[0026] (Step S302) The control unit 70 determines whether the voltage at the vehicle's external power connection terminal is normal or abnormal. This determination is made to determine whether the external power supply 40 is correctly connected to the external power connection terminal, and in addition to determining whether the external power supply 40 is physically connected to the terminal, it also determines whether an external power supply 40 with the correct voltage is connected to the terminal. Therefore, errors such as overvoltage application or reverse polarity connection can be eliminated. A voltage sensor or the like, which is pre-installed at the external power connection terminal, can be used for this determination. If the control unit 70 determines that the voltage at the external power connection terminal is normal (step S302, normal), the process proceeds to step S304. On the other hand, if the control unit 70 determines that the voltage at the external power connection terminal is abnormal (step S302, abnormal), the process returns to step S303.

[0027] (Step S303) The control unit 70 determines whether a predetermined time has elapsed since the DC-DC converter 20 stopped. This determination is made to allow sufficient time for the determination in step S302, as connecting the external power supply 40 to the external power supply connection terminal is a manual operation. The predetermined time is set to any amount of time sufficient for making the determination. If the control unit 70 determines that the predetermined time has elapsed (step S303, yes), the process proceeds to step S309. On the other hand, if the control unit 70 determines that the predetermined time has not elapsed (step S303, no), the process proceeds to step S302.

[0028] (Step S304) The control unit 70 controls the first relay 32 to a unidirectional conducting state. This causes the first relay 32 to be in a state where current flows only from the auxiliary battery 30 to the relay unit 50 (state shown in Figure 5A(c)). Once the first relay 32 is controlled to a unidirectional conducting state, the process proceeds to step S305.

[0029] (Step S305) The control unit 70 controls the second relay 52 to a unidirectional conducting state. This causes the second relay 52 to be in a state where current flows only from the external power supply 40 to the relay unit 50 (state shown in Figure 5B(d)). Once the second relay 52 is controlled to a unidirectional conducting state, the process proceeds to step S306.

[0030] (Step S306) The control unit 70 controls the first relay 32 to an off state. This electrically disconnects the auxiliary battery 30 from the relay unit 50 (state shown in Figure 5B(e)). Once the first relay 32 is controlled to an off state, the process proceeds to step S307.

[0031] (Step S307) The control unit 70 controls the second relay 52 to a bidirectional conductive state. As a result, current flows through the second relay 52 from both the external power supply 40 and the relay unit 50 (state shown in Figure 5B(f)). Once the second relay 52 is controlled to a bidirectional conductive state, the process proceeds to step S308. (Step S308) The control unit 70 determines that it is possible to rewrite the program of the electronic control unit 60 and terminates this pre-reprogramming control. In response to this determination, the program rewriting process of the electronic control unit 60 is executed by a predetermined device.

[0032] Examples of processes for rewriting the program of the electronic control unit 60 include wired reprogramming, which is performed by connecting a cable to the vehicle, and wireless reprogramming, which is performed wirelessly via OTA (On The Air) by connecting the vehicle to the internet or the like. (Step S309) The control unit 70 determines that it is impossible to rewrite the program of the electronic control unit 60 and terminates this pre-reprogramming control. In response to this determination of impossibility, a predetermined action (such as aborting, waiting, or retrying) is taken against the program rewriting process of the electronic control unit 60 by a predetermined device.

[0033] (2) Control after program rewriting Figure 4 is a flowchart illustrating the processing procedure for post-reprogramming control, which is the control performed by the control unit 70 of the power supply control system after the program of the electronic control unit 60 has been rewritten. Figures 6A and 6B illustrate the connection status of the power supply control system over time during post-reprogramming control.

[0034] The post-reprogramming control illustrated in Figure 4 is initiated after the program rewriting process of the electronic control unit 60 is performed by a predetermined device. When this post-reprogramming control is initiated, the state of each configuration is as follows: the DC-DC converter 20 is stopped (OFF), the first relay 32 of the auxiliary battery (auxiliary LiB) 30 is disconnected, and the second relay 52 of the relay unit 50 is in a bidirectional conductive state (state shown in Figure 6A(a)). Furthermore, the relays 51, 53, and 54 of the relay unit 50 are assumed to always be in a bidirectional conductive state during the pre-reprogramming control.

[0035] (Step S401) The control unit 70 controls the second relay 52 to a unidirectional conducting state. This causes the second relay 52 to be in a state where current flows only from the external power supply 40 to the relay unit 50 (state shown in Figure 6A(b)). Once the second relay 52 is controlled to a unidirectional conducting state, the process proceeds to step S402.

[0036] (Step S402) The control unit 70 controls the first relay 32 to a unidirectional conducting state. This causes the first relay 32 to be in a state where current flows only from the auxiliary battery 30 to the relay unit 50 (state shown in Figure 6A(c)). Once the first relay 32 is controlled to a unidirectional conducting state, the process proceeds to step S403.

[0037] (Step S403) The control unit 70 controls the second relay 52 to the off state. This electrically disconnects the external power supply 40 from the relay unit 50 (state shown in Figure 6B(d)). Once the second relay 52 is controlled to the off state, the process proceeds to step S404.

[0038] (Step S404) The control unit 70 controls the first relay 32 to a bidirectional conductive state. As a result, current flows through the first relay 32 from both the auxiliary battery 30 and the relay unit 50 (state shown in Figure 6B(e)). Once the first relay 32 is controlled to a bidirectional conductive state, the process proceeds to step S405.

[0039] (Step S405) The control unit 70 activates the DC-DC converter 20, which had been stopped. This electrically connects the high-voltage battery 10 to the relay unit 50, enabling power supply to the electronic control unit 60 together with the auxiliary battery 30 (state shown in Figure 6B(f)). This returns the vehicle to its normal state with the power ON. Once the DC-DC converter 20 is activated, this post-reprogramming control is terminated.

[0040] <Effects and Actions> As described above, according to the power control system according to one embodiment of the present disclosure, before executing the process of rewriting the program of the electronic control unit 60 using the external power supply 40, the first relay 32 on the auxiliary battery 30 side is controlled to a unidirectional conducting state, and then the second relay 52 on the external power supply 40 side is controlled to a unidirectional conducting state. After that, the first relay 32 is controlled to an interrupted state, and then the second relay 52 is controlled to a bidirectional conducting state.

[0041] This relay switching control prevents electrical conduction between the auxiliary battery 30 and the external power supply 40, thus avoiding overcharging of the auxiliary battery 30 and unnecessary power consumption.

[0042] Furthermore, according to the power control system according to one embodiment of the present disclosure, the first relay 32 on the auxiliary battery 30 side and the second relay 52 on the external power supply 40 side are not switched simultaneously, thus eliminating the possibility of the vehicle's power supply being lost (momentary interruption).

[0043] Although one embodiment of the present disclosure has been described above, the present disclosure can be interpreted not only as the power control system described above, but also as a method executed by a power control system having a processor and memory, a program for such a method, a computer-readable non-temporary recording medium storing such a program, or a vehicle equipped with a power control system. [Industrial applicability]

[0044] The power control system disclosed herein can be used in vehicles that perform program rewriting of in-vehicle devices using an external power supply. [Explanation of Symbols]

[0045] 10 High-voltage batteries 20 DC-DC converters 30 Auxiliary battery 31 Batteries 32. First Relay (RLY) 40 External power supply 50 Relay Units 51, 53, 54 Relay (RLY) 52. Second Relay (RLY) 60 Electronic control unit 70 Control Unit

Claims

1. A power control system used when rewriting the program of an electronic control unit using an external power supply, When the aforementioned program rewriting is not performed, a first relay connects the first onboard battery to the electronic control unit so that it can supply power, When the program is rewritten, a second relay connects the external power supply to the electronic control unit so that it can supply power, The system comprises a control unit that controls the connection state of the first relay and the second relay, The control unit, after the external power supply is connected to the second relay which is controlled to be in the disconnected state, and before starting the program rewriting, The first relay is controlled to a unidirectional conductive state in which the current direction is restricted from the first on-board battery to the electronic control device. The second relay is controlled to a unidirectional conducting state, restricting the current direction from the external power supply to the electronic control device. The first relay is controlled to the tripped state, The second relay is controlled to a bidirectional conducting state without restricting the direction of current. Power control system.

2. After completing the program rewriting, the control unit, before disconnecting the external power supply from the second relay, The second relay is controlled to a unidirectional conducting state, restricting the current direction from the external power supply to the electronic control device. The first relay is controlled to a unidirectional conductive state in which the current direction is restricted from the first on-board battery to the electronic control device. The second relay is controlled to the tripped state, The first relay is controlled to a bidirectional conducting state without restricting the direction of current. The power control system according to claim 1.

3. When the electronic control unit is not performing the program rewriting, and is receiving power from the second on-board battery via a DC-DC converter, The control unit stops the DCDC converter before starting the program rewriting and before controlling the first relay to the one-way conducting state. The power control system according to claim 1.

4. When the electronic control unit is not performing the program rewriting, and is receiving power from the second on-board battery via a DC-DC converter, After completing the program rewriting, the control unit controls the first relay to the bidirectional conductive state and then operates the DC-DC converter. The power control system according to claim 2.

5. The first relay and the second relay are each configured by connecting two field-effect transistors in series with the rectification direction of the body diodes reversed. A power control system according to any one of claims 1 to 4.

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