Electric power control device for a vehicle

Abstract

To solve the above problem, an IPU (3) of a vehicle (1) includes a storage battery (30) that supplies electric power to a drive unit (2) of the vehicle (1), a current sensor (33) that detects a current of the storage battery (30), a temperature sensor (31) that detects a temperature of the storage battery (30), contactors (34b), (34c) that block a flow of the current from the storage battery (30) and a flow of the current toward the storage battery (30), and a storage battery ECU (35) that, when a current detection function of the current sensor (33) is damaged, measures a time for which the temperature detected by the temperature sensor (31) reaches from a first specific value to a second specific value, and causes the contactors (34b), (34c) to act to block the flow of the current from the storage battery (30) and the flow of the current toward the storage battery (30) when the measured time is shorter than a specific time.

Description

Technical Field

[0001] This invention relates to an electrical control device for a vehicle. Background Technology

[0002] In recent years, research and development related to batteries that help improve energy efficiency has been carried out in order to ensure that more people have access to suitable, reliable, sustainable and advanced energy.

[0003] For example, a system is disclosed that detects an overcurrent internal short circuit in a battery pack in a vehicle equipped with a battery (e.g., see Patent Document 1).

[0004] [Previous Technical Documents]

[0005] (Patent Documents)

[0006] Patent Document 1: U.S. Patent Application Publication No. 2013 / 0179012 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] However, the Automotive Safety Integrity Level (ASIL) has introduced new provisions related to battery overcurrent. Even if the current detection function fails, it is necessary to detect battery overcurrent to protect the battery. Therefore, in vehicles equipped with a system like that in Patent Document 1, if the current detection function fails, battery charging must be stopped, and the vehicle must be stopped from operating.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a vehicle power control device that can continue to charge the battery and drive the vehicle even when the current detection function is damaged.

[0010] [Technical means to solve the problem]

[0011] (1) The power control device (e.g., the Intelligent Power Unit (IPU) 3) of the vehicle (e.g., vehicle 1) of the present invention includes: a battery (e.g., battery 30) that supplies power to the drive unit of the vehicle (e.g., drive unit 2); a current sensor (e.g., current sensor 33) that detects the current of the battery; a temperature sensor (e.g., temperature sensor 31) that detects the temperature of the battery; a blocking means (e.g., contactors 34b, 34c) that blocks the flow of current from the battery and the flow of current toward the battery; and a control means (e.g., the Electronic Control Unit (ECU) 35) that, when the current sensor is damaged, measures the time it takes for the temperature detected by the temperature sensor to reach a second specific value from a first specific value, and when the measured time is shorter than the specific time, activates the blocking means to block the flow of current from the battery and the flow of current toward the battery.

[0012] According to the vehicle power control device of the invention in (1), when the current sensor is damaged, the control means measures the time it takes for the temperature detected by the temperature sensor to rise from a first specific value to a second specific value. When the measured time is shorter than the specific time, it is assumed that the heating is caused by overcurrent, and the blocking means is activated to block the flow of current from the battery and the flow of current toward the battery. Thus, even when the current sensor is damaged, the battery overheating can be prevented, so there is no need to stop the charging of the battery and the driving of the vehicle to avoid overheating. Therefore, the vehicle power control device according to the invention in (1) can continue to charge the battery and drive the vehicle even when the current detection function is damaged.

[0013] (2) The electric control device of the vehicle of the invention of (1) may also include a cooling means (for example, the water cooling mechanism described below (illustration omitted)), which cools the aforementioned battery, and the aforementioned specific time is set based on the heating characteristics of the aforementioned battery and the cooling characteristics of the aforementioned cooling means.

[0014] The vehicle power control device according to (2) is able to effectively prevent excessive heating of the battery because the specific time for the blocking means to operate is set based on the heating characteristics of the battery and the cooling characteristics of the cooling means.

[0015] (The effect of the invention)

[0016] According to the present invention, a vehicle power control device can be provided that allows for continued battery charging and vehicle operation even when the current detection function is damaged. Furthermore, the present invention further contributes to improving energy efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the structure of a vehicle equipped with an IPU according to an embodiment of the present invention.

[0018] Figure 2 This is a flowchart illustrating the high-voltage blocking process in the IPU.

[0019] Figure 3 This is a diagram illustrating the conditions that cause the contactor to operate. Detailed Implementation

[0020] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0021] First, use Figure 1 The structure of a vehicle 1 equipped with an IPU (Intelligent Power Unit) 3 according to an embodiment of the present invention will be described. Figure 1 This is a schematic diagram showing the structure of a vehicle 1 equipped with an IPU3 according to an embodiment of the present invention.

[0022] like Figure 1 As shown, vehicle 1 includes a drive unit 2, an IPU 3, a charger 4, and a plug 5, etc. That is, vehicle 1 in this embodiment is a plug-in hybrid electric vehicle.

[0023] Drive unit 2 uses the electricity supplied by IPU3 to propel vehicle 1. Drive unit 2 includes, for example, an engine and motor as power sources, as well as a fuel injection electronic control unit (FI-ECU) and a power control unit (PCU) that control them.

[0024] IPU3 includes the drive battery pack for drive unit 2 and functions as the power control device for vehicle 1. Specifically, IPU3 includes multiple batteries 30, multiple temperature sensors 31, multiple voltage sensors 32, current sensors 33, multiple contactors 34a, 34b, 34c, battery ECU 35, and water cooling mechanism (not shown).

[0025] The storage battery 30 is a high-voltage storage battery that is charged by the charger 4 and supplies power to the drive unit 2 by discharging. In this embodiment, the storage battery 30 is, for example, a large-capacity storage battery composed of multiple battery cells made of lithium-ion secondary batteries connected in series.

[0026] Temperature sensor 31 functions as a temperature sensor to detect the temperature of battery 30. In this embodiment, multiple temperature sensors 31 are provided, for example, one is provided in each stack of multiple battery cells to detect the temperature of each stack.

[0027] The voltage sensor 32 functions as a voltage sensor for detecting the voltage of the battery 30. In this embodiment, the voltage sensor 32 is, for example, a cell voltage sensor (CVS). One voltage sensor 32 is provided in each of the plurality of stacks included in the battery 30 to detect the voltage of each stack.

[0028] The current sensor 33 functions as a current sensor for detecting the current of the battery 30. In this embodiment, the current sensor 33 is, for example, composed of an initial state of charge (ISOC) sensor.

[0029] Contactor 34a operates during startup, while contactors 34b and 34c operate during vehicle operation and battery charging, in addition to startup. Contactors 34b and 34c are the positive and negative contactors, respectively, blocking the flow of current from and towards the battery 30. Specifically, contactors 34b and 34c, with high voltage, block the power supply from the battery 30 to the drive unit 2, and also block the supply of regenerative power from the drive unit 2 to the battery 30. Furthermore, contactors 34b and 34c, with high voltage, block the power supply from the charger 4 (not shown), which is connected to an external power supply device via plug 5, to the battery 30.

[0030] The battery ECU 35 centrally controls the IPU 3. This battery ECU 35 determines whether the current detection function of the current sensor 33 is damaged. Specifically, when the current sensor 33 detects an abnormal value, the battery ECU 35 detects a fault in the current sensor 33 and determines that the current sensor 33's current detection function is damaged. Whether the current sensor 33's detection value is abnormal can be determined based on factors such as the charging and discharging history of the battery 30.

[0031] In addition, when the current detection function of the current sensor 33 is damaged, the battery ECU 35 measures the time it takes for the highest temperature among the temperatures detected by multiple temperature sensors 31 to reach a second specific value (e.g., 40°C) from a first specific value (e.g., 45°C). When the measured time is shorter than a specific time (e.g., 200 seconds), the contactors 34b and 34c are activated to block the flow of current from the battery 30 and the flow of current toward the battery 30.

[0032] The specific timing at which the battery ECU 35 actuates contactors 34b and 34c is appropriately set based on the heating characteristics of the battery 30 and the cooling characteristics of the water-cooling mechanism (not shown). This specific timing will be described in detail below.

[0033] The charger 4 is connected to an external power supply device (not shown) via a plug 5, thereby charging the battery 30.

[0034] The water-cooling mechanism (not shown) functions as a cooling means to cool the heated battery 30. The water-cooling mechanism is, for example, located below the battery 30 to cool the battery 30.

[0035] Next, use Figure 2 The high-voltage blocking process in IPU3 is explained. Figure 2 This is a flowchart illustrating the high-voltage blocking process in IPU3.

[0036] like Figure 2 As shown, the high-voltage blocking process in IPU3 includes a current detection function failure determination step S1, a high-voltage blocking determination step S2, and a high-voltage blocking step S3. This high-voltage blocking process in IPU3 is executed simultaneously with the IG-ON (automotive ignition) setting of vehicle 1.

[0037] In the current detection function failure determination step S1, the battery ECU 35 determines whether the current detection function of the current sensor 33 is damaged. When the current detection function of the current sensor 33 is damaged (if "yes" in step S1), the process proceeds to the high voltage interruption determination step S2. When the current detection function of the current sensor 33 is not damaged (if "no" in step S1), the current detection function failure determination step S1 is repeated.

[0038] In the high-voltage blocking determination step S2, the battery ECU 35 measures the time it takes for the temperature detected by the temperature sensor 31 to rise from a first specific value (e.g., 40°C) to a second specific value (e.g., 45°C), and determines whether the measured time is shorter than a specific time (e.g., 200 seconds). If the time measured by the battery ECU 35 is shorter than the specific time (e.g., 200 seconds) ("Yes" in step S2), the process proceeds to the high-voltage blocking step S3. If the time measured by the battery ECU 35 is not shorter than the specific time (e.g., 200 seconds) ("No" in step S2), the high-voltage blocking determination step S2 is repeated.

[0039] here, Figure 3 This diagram illustrates the conditions that cause contactors 34b and 34c to operate. Figure 3 In the diagram, the line indicating a temperature rise caused by overcurrent corresponds to the condition "Yes" in step S2. On the other hand, the line indicating a temperature rise caused by normal current corresponds to the condition "No" in step S2.

[0040] Return to Figure 2 In the high-voltage blocking step S3, the battery ECU 35 actuates contactors 34b and 34c to block the flow of current from and toward the battery 30 with a high voltage (e.g., a voltage of 12kW or higher). After blocking, the process ends.

[0041] According to this embodiment, the following effects are achieved.

[0042] According to IPU3, when the current detection function of current sensor 33 fails, battery ECU 35 measures the time it takes for the temperature detected by temperature sensor 31 to rise from a first specific value to a second specific value. If the measured time is shorter than the specified time, it is assumed that the heating is caused by overcurrent, and contactors 34b and 34c are activated to block the flow of current from and toward battery 30. Therefore, even when current sensor 33 fails, overheating of battery 30 can be prevented, and thus, there is no need to stop charging battery 30 or driving vehicle 1 to avoid overheating. Therefore, according to IPU3 of vehicle 1 in this embodiment, even when the current detection function fails, charging of battery 30 and driving of vehicle 1 can continue.

[0043] Furthermore, according to IPU3, the specific time for activating contactors 34b and 34c is set based on the heating characteristics of the battery 30 and the cooling characteristics of the water-cooling mechanism (not shown). Therefore, according to this embodiment, overheating of the battery 30 can be reliably prevented.

[0044] Furthermore, the present invention is not limited to the above-described embodiments, and all variations and improvements within the scope of achieving the objectives of the present invention are included in the present invention.

[0045] For example, the above embodiments apply the invention to plug-in hybrid electric vehicles, but it is not limited thereto. It can be widely applied to vehicles that include high-voltage batteries that supply power to the vehicle's drive unit.

[0046] Figure Labels

[0047] 1 vehicle

[0048] 2 drive units

[0049] 3IPU (Power Control Unit)

[0050] 30 storage batteries

[0051] 31 Temperature sensor

[0052] 32 Voltage Sensor

[0053] 33 Current Sensor

[0054] 34a, 34b, 34c contactors (interception method)

[0055] 35 Battery ECU (Control Method)

[0056] 4 Chargers

[0057] 5 plugs

[0058] S1 Current Detection Function Fault Determination Steps

[0059] S2 High Voltage Interruption Judgment Steps

[0060] S3 High Voltage Interception Procedure

Claims

1. An electrical control device for a vehicle, comprising: The battery supplies power to the vehicle's drive unit; A current sensor detects the current of the aforementioned battery; A temperature sensor is used to detect the temperature of the aforementioned battery. Interception measures, which block the flow of current from the aforementioned battery and the flow of current toward the aforementioned battery; and, The control means, when the aforementioned current sensor is damaged, measures the time it takes for the temperature detected by the aforementioned temperature sensor to rise from a first specific value to a second specific value, and when the measured time is shorter than the specific time, causes the aforementioned blocking means to operate, so as to block the flow of current from the aforementioned battery and the flow of current toward the aforementioned battery.

2. The vehicle power control device according to claim 1, wherein, Includes cooling means, which cool the aforementioned battery. The aforementioned specific time is set based on the heating characteristics of the aforementioned battery and the cooling characteristics of the aforementioned cooling method.

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