EV Charging Control with SOC Thresholds for Fire Prevention
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Solution Overview
Problem
Electric vehicle fires pose a significant risk due to battery-related issues, particularly during rapid charging, and existing fire extinguishing methods are inadequate, while battery aging and overcharging lead to reduced lifespan and increased fire risk.
Innovation Solution
An electric vehicle charging device equipped with a fire prevention function that switches from constant current to constant voltage charging modes based on battery state, monitors charging cycles, and evaluates battery health to prevent overcharging and optimize charging conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid charging (DC) is used to charge the electric vehicle battery, then charging speed and productivity are improved, but the risk of battery fire and thermal runaway increases due to high current and temperature
Solution Approach 1:
The charging device dynamically adjusts charging parameters (current, voltage, power) in real-time based on battery state monitoring. The system transitions from static charging rates to dynamic control that adapts to battery temperature, charge level, and health status, enabling fast charging while preventing thermal runaway through continuous parameter optimization
Solution Approach 2:
The system implements multi-parameter feedback monitoring including battery temperature, voltage, current, and charge level. This feedback mechanism detects abnormal conditions and automatically adjusts or terminates charging to prevent fire hazards, creating a closed-loop safety system that responds to real-time battery state
2Use of energy by moving object
If continuous charging at high capacity is performed to maximize energy intake, then charging efficiency is improved, but battery aging accelerates and lifespan decreases due to overcharging and thermal stress
Solution Approach 1:
The system optimizes charging parameters (current, voltage, temperature thresholds) based on battery state of health (SOH) and charge level. By dynamically changing these parameters rather than maintaining constant high-rate charging, the system maximizes energy intake while preventing the thermal and electrical stress that causes battery aging
Solution Approach 2:
The system implements controlled charging termination before reaching 100% capacity under certain conditions, and uses pulse charging techniques that apply intermittent high current followed by rest periods. This partial action approach prevents excessive charging stress while still achieving high energy intake efficiency over time
3Object-affected harmful factors
If traditional fire extinguishing methods (water cooler, suffocation cover, portable water tank) are used, then fire suppression capability is provided, but effectiveness is reduced due to battery embeddedness, gas leakage, or excessive response time
Solution Approach 1:
The system performs preliminary detection and warning before thermal runaway occurs, identifying early signs of battery failure through monitoring parameters. This preliminary action enables preventive measures or controlled shutdown before fire develops, making fire suppression unnecessary in many cases and improving overall safety reliability
Solution Approach 2:
The system extracts and monitors key diagnostic parameters (temperature, voltage, current, impedance) separately from the battery pack itself. By taking out these measurement functions and analyzing them externally, the system can detect fire risks early and respond appropriately without being constrained by the physical limitations of traditional extinguishing methods
4Device complexity
If constant current charging mode is used to maintain simple charging control, then device complexity is reduced, but charging precision and battery safety are compromised due to inability to respond to changing battery conditions
Solution Approach 1:
The system transitions from static constant current control to dynamic charging control that continuously adjusts parameters based on battery state. This dynamic approach maintains manageable device complexity through modular architecture while achieving high charging precision through real-time adaptation to battery conditions
Data Source
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AI summary
Disclosed are: a method for safely and efficiently charging an electric vehicle using an electric vehicle charging device equipped with an electric vehicle battery fire prevention function and performance evaluation function; and an electric vehicle charging device. The method comprises the steps in which: (a) after an electric vehicle is connected to an electric vehicle charging device, the electric vehicle charging device starts charging a battery of the electric vehicle in a constant current charging mode in which charging is carried out in a state where a charging current is maintained at a constant; and (b) the electric vehicle charging device repeats the process, while increasing t, of measuring, from time point t to time point (t+1), the voltage value at time t which is the charging voltage at both ends of the battery of the electric vehicle, and a current value at time t which is the charging current flowing in the battery of the electric vehicle, and in consideration of the voltage value at time t, current value at time t, and time points t and (t+1) to acquire power amount information at time t, wherein, in step (b), if the electric vehicle charging device detects that, during the repetition while increasing t from k to k+z, the state of charge (SOC) of the battery of the electric vehicle has reached a preset first critical capacity when t equals k+m where m is an integer from 0 to z inclusive, the electric vehicle charging device detects that the charging mode has been switched from the constant current charging mode to a constant voltage charging mode in which charging is carried out in a state where the charging voltage is maintained at a predetermined constant voltage or is varied within a predetermined critical range with respect to the predetermined voltage.