Hybrid Vehicle SOC Control via Virtual Center Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid electric vehicles face challenges in maintaining a stable state of charge (SOC) due to varying engine operation modes, leading to inefficient fuel use and difficulty in adapting to different driving conditions, such as expressways, national highways, and congested areas.
Innovation Solution
An apparatus and method that detect vehicle data to calculate a virtual center SOC, adjusting engine on/off states based on engine and motor efficiency maps, and driving conditions to optimize SOC control, ensuring flexible charging efficiency across different driving modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the engine is controlled to be turned on or off based on fixed SOC references divided by driving state (expressway, national highway, downtown area), then the engine operation can be simplified, but the SOC cannot be flexibly changed according to actual charging efficiency variations, leading to fuel efficiency deterioration
Solution Approach 1:
The patent implements dynamic adjustment of the virtual center SOC value based on real-time charging efficiency calculations. Instead of using fixed SOC references, the system continuously updates the virtual center SOC according to actual charging conditions, allowing the SOC target to adapt flexibly to varying driving states and charging efficiency levels, thereby resolving the contradiction between operational simplicity and adaptability
Solution Approach 2:
The system changes the SOC reference parameter dynamically by introducing a virtual center SOC that is calculated based on charging efficiency. This parameter transformation allows the engine control to respond to actual charging conditions rather than relying on predetermined fixed SOC values, enabling flexible adaptation while maintaining controlled operation
2Productivity
If the engine operates primarily in HEV mode to charge the battery on expressways and national highways, then charging efficiency is improved, but the SOC control becomes rigid and cannot respond to varying engine operation conditions, causing difficulty in maintaining predetermined SOC levels
Solution Approach 1:
The system employs feedback control by calculating charging efficiency based on actual engine operation and SOC changes, then using this feedback to adjust the virtual center SOC dynamically. This closed-loop approach ensures that high charging efficiency is maintained while the SOC control remains responsive to varying conditions, resolving the contradiction between productivity and reliability
Solution Approach 2:
The system performs preliminary calculation of the virtual center SOC based on expected charging efficiency before actual engine operation. This allows the control system to prepare appropriate SOC targets in advance, ensuring both high charging efficiency and stable SOC maintenance by anticipating operational conditions
3Device complexity
If the SOC is simply set to normal, charge, and discharge sections without considering charging efficiency variations, then the control logic is simplified, but fuel efficiency deteriorates due to entering idle charge state, full load state, and frequent departures from normal SOC section
Solution Approach 1:
The patent transforms the simple three-section SOC control logic into a more sophisticated system by introducing virtual center SOC as a dynamic parameter. This parameter change enables the system to optimize fuel efficiency by adjusting the SOC target based on charging efficiency, while the underlying control structure remains relatively simple and manageable
Data Source
AI summary
An apparatus for controlling a SOC of a hybrid vehicle comprises a data detector for detecting data including a SOC of a battery, a vehicle speed, an amount of operating of a brake pedal sensor, an amount of operating of an acceleration pedal sensor, and a driving state of a vehicle to control a SOC of a hybrid vehicle. Included are a correction value calculating unit configured for calculating a correction value of the SOC based on the data; a SOC calculating unit configured for calculating a virtual center SOC based on the correction value of the SOC and an actual SOC; and an engine-on/off determining unit configured for determining whether an engine is turned on or turned off based on the virtual center SOC.