JP-2026075922-A - Electric vehicles

Abstract

[Problem] To provide an electric vehicle that can detect the operation of the safety valve of a battery mounted on the vehicle using a detection method that is less susceptible to external environmental influences, thereby suppressing the risk of failure to detect the operation of the battery's safety valve. [Solution] The electric vehicle 1 comprises a plurality of batteries 45 restrained in the stacking direction H by a restraining device 41, and a control unit 20. Each of the plurality of batteries 45 has a safety valve 48. The control unit 20 acquires battery characteristic information for each of the plurality of batteries 45, external environment information, and information on the initial load F0, which is the measured value of the restraining load that restrains the plurality of batteries 45 and is the restraining load when the ignition power is turned on. Based on the battery characteristic information for each of the plurality of batteries 45 and the external environment information, the control unit 20 acquires an estimated load Fes, which is an estimated value of the restraining load that restrains the plurality of batteries 45. Based on the initial load F0 and the estimated load Fes, the control unit 20 detects the opening of the safety valve. [Selection Diagram] Figure 1

Inventors

• 岡田 昂樹

Assignees

• トヨタ自動車株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (1)

1. The system comprises multiple batteries constrained in the stacking direction by a restraining device, and a control unit. Each of the plurality of batteries has a safety valve, and the control unit acquires battery characteristic information of each of the plurality of batteries, external environment information, and information on the initial load which is the actual value of the restraining load that restrains the plurality of batteries and is the restraining load when the ignition power is turned on. The control unit obtains an estimated load, which is an estimated value of the constraint load that restrains the plurality of batteries, based on the battery characteristic information of each of the plurality of batteries and the external environment information. The control unit detects the opening of the safety valve based on the initial load and the estimated load in an electric vehicle.

Description

This disclosure relates to electric vehicles. Electric vehicles utilize numerous batteries as their power source. These batteries are, for example, rechargeable batteries such as lithium-ion batteries. When batteries are subjected to abnormally high temperatures or overcharge, a large amount of gas is generated inside the battery. Batteries are equipped with safety valves that activate to release gas to the outside when the internal pressure rises abnormally due to the gas. When the safety valve activates, the current must be cut off to prevent further use. Therefore, systems for detecting the activation of safety valves have been proposed. International Publication No. 2011/101942 (Patent Document 1) describes a detection system that detects the sound emitted during safety activation and determines whether the safety valve has activated based on the magnitude of the detected sound. International Publication No. 2011/101942 This is a schematic diagram of an electric vehicle according to an embodiment of the present disclosure.This is a schematic diagram of a battery pack and energy storage cell according to an embodiment of the present disclosure.This is a control flow diagram of an electric vehicle according to an embodiment of the present disclosure. Embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated. <Overall configuration of electric vehicles> Figure 1 is a diagram showing a schematic configuration of an electric vehicle according to an embodiment of the present disclosure. The electric vehicle 1 is, for example, an electric car. The electric vehicle 1 comprises a motor generator (MG) 11 (a rotating electric machine), drive wheels 12, a power control unit (PCU) 13, a system main relay (SMR) 14, an ECU 20, an HMI device 30, a battery pack 40, and a monitoring unit 50. The ECU 20 is communicated with the PCU 13, SMR 14, HMI device 30, and monitoring unit 50. MG11 is, for example, an embedded permanent magnet synchronous motor (IPM motor) that has both motor and generator functions. The output torque of MG11 is transmitted to the drive wheels 12 via a power transmission system that includes a reduction gear and a differential gear. During braking of the electric vehicle 1, the MG 11 is driven by the drive wheels 12, and the MG 11 operates as a generator. As a result, the MG 11 also functions as a braking device that performs regenerative braking, converting the kinetic energy of the electric vehicle 1 into electrical energy. The regenerative power generated by the regenerative braking force in the MG 11 is stored in the battery pack 40. The PCU 13 is a power conversion device that converts power bidirectionally between the MG 11 and the battery pack 40. The PCU 13 includes, for example, an inverter and a converter that operate based on a control signal from the ECU 20. When the battery pack 40 is discharged, the converter boosts the voltage supplied from the battery pack 40 and supplies it to the inverter. The inverter converts the DC power supplied from the converter into AC power to drive the MG 11. Note that the PCU 13 may also be configured without the converter. The SMR14 is electrically connected to the power line connecting the battery pack 40 and the PCU 13. When the SMR14 is closed (ON) (i.e., conducting) in response to a control signal from the ECU 20, power can be exchanged between the battery pack 40 and the PCU 13. Conversely, when the SMR14 is open (OFF) (i.e., disconnected) in response to a control signal from the ECU 20, the electrical connection between the battery pack 40 and the PCU 13 is interrupted. The HMI device 15 is mounted on the electric vehicle 1 and displays various information (e.g., map information and video content) on a display screen (not shown), and also notifies the user of various information (e.g., traffic information and weather information) by voice. The HMI device 15 includes a display with a touch panel and a speaker. The HMI device 15 is configured to notify the user of the electric vehicle 1 of signals corresponding to the output from the ECU 20. The ECU 20 includes a processor 21, a memory 22, and a storage 23. The processor 21 is a computing device such as a CPU (Central Processing Unit) or MPU (Micro-Processing Unit). The memory 22 is volatile memory (working memory) such as RAM (Random Access Memory). The storage 23 is rewritable non-volatile memory such as flash memory. The storage 23 stores a system program including an OS (Operating System) and a control program including computer-readable code necessary for control calculations. The processor 21 performs various processes by reading the system program and control program, loading them into the memory 22, and executing them. The ECU 20 may be divided into multiple ECUs according to function. Note that the ECU 20 is an example o