EV Power Supply Dynamic SOC Control for Battery Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric vehicles, maintaining the state of charge of the auxiliary battery below 100% to enhance charging efficiency leads to reduced cooling capability, causing the primary battery's temperature to rise and accelerating its degradation.
Innovation Solution
A power supply device with a primary and secondary electric storage device, a DC/DC converter, a cooler, detectors, and an electronic control unit that adjusts the charging mode based on temperature and actual drive value to limit the state of charge of the secondary battery when the cooler is driven, and sets it above the maximum value when not driven, thereby enhancing cooling capability and charging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the state of charge of the auxiliary battery is maintained below 100% to enhance charging efficiency, then charging efficiency of the secondary electric storage device is improved, but cooling capability of the cooler becomes deficient
Solution Approach 1:
The patent implements dynamic switching between two charging modes (first charging mode with SOC limit below 100% for high efficiency, and second charging mode with SOC limit at 100% for maximum cooling capability) based on real-time temperature conditions of the primary battery. This dynamic adaptation allows the system to optimize charging efficiency under normal conditions while ensuring adequate cooling capability when temperature thresholds are exceeded.
2Productivity
If the state of charge of the auxiliary battery is maintained below 100% to enhance charging efficiency, then charging efficiency of the secondary electric storage device is improved, but degradation of the primary electric storage device is promoted
Solution Approach 1:
The patent employs feedback control by continuously monitoring the temperature of the primary battery and adjusting the charging mode of the auxiliary battery accordingly. When temperature exceeds a predetermined threshold, the system switches to the second charging mode that prioritizes cooling capability, thereby preventing excessive temperature rise and reducing degradation of the primary battery while maintaining high charging efficiency during normal operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves the cooling capability of the primary battery, reducing its degradation and maintaining high charging efficiency of the secondary battery by dynamically controlling the charging modes based on temperature and drive value.
Implementation Method 1
The direct current/direct current converter is configured to step down a voltage of the primary electric storage device and to supply the voltage to the secondary electric storage device to charge the secondary electric storage device
Implementation Method 2
The cooler is configured to be supplied with a source voltage from the secondary electric storage device and to be driven depending on a target drive value to cool the primary electric storage device
Data Source
AI summary
An ECU of an electric vehicle supplies a target rotation speed RT having a value corresponding to the temperature TB of a main battery to a cooler, controls a main DC/DC converter such that the SOC of an auxiliary battery is in a predetermined range SOCL to SOCH less than 100% when a cooling fan in the cooler is driven at the target rotation speed (RT), and controls the main DC/DC converter such that the SOC of the auxiliary battery is 100% when the cooling fan is not driven at the target rotation speed (RT).