Hybrid Torque Reduction Control via Motor-Engine Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional hybrid electric vehicles face challenges in performing complete torque reduction when demand torque from the traction control system (TCS) is low or battery state-of-charge (SOC) is high, as they rely solely on motor torque, which may not satisfy the demand or produce sufficient negative torque.
Innovation Solution
The method involves determining the demand torque of the TCS and comparing it with motor output torque, allowing torque reduction by using either motor torque or engine torque based on the comparison, with the motor torque command set as the demand torque when it's less than motor output and engine torque command set to zero, or vice versa, to ensure effective torque reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If torque reduction is performed by using motor only, then rapid control is achieved, but torque reduction cannot be performed completely when demand torque is too low or battery SOC is too high
Solution Approach 1:
The control system dynamically switches between motor-only torque reduction and combined engine-motor torque reduction based on real-time conditions including demand torque magnitude and battery SOC level. When demand torque is low or SOC is high, the system transitions from motor-only control to a hybrid control mode that incorporates engine torque reduction, ensuring complete torque reduction while maintaining rapid response when conditions are favorable.
Solution Approach 2:
The system changes control parameters (torque reduction strategy) based on operating conditions. When battery SOC is high or demand torque is low, the control parameter shifts from motor-only torque reduction to a mode that reduces engine torque command to zero while maintaining motor torque command, thereby achieving complete torque reduction under varying conditions.
2Speed
If motor torque is used for torque reduction, then rapid control is achieved, but motor cannot output sufficient negative torque when battery SOC is too high
Solution Approach 1:
The control system dynamically adjusts torque reduction strategy based on battery SOC levels. When SOC is high, the system transitions from motor-only torque reduction to a mode that incorporates engine torque reduction, ensuring sufficient total torque reduction capability is maintained across all operating conditions while preserving rapid motor-based control when conditions are favorable.
Solution Approach 2:
The torque reduction system becomes multi-functional by incorporating both motor torque reduction and engine torque reduction capabilities. This allows the system to achieve torque reduction through either or both power sources depending on conditions, ensuring sufficient negative torque output capability is maintained whether battery SOC is low (motor only) or high (combined engine and motor).
Data Source
AI summary
A method for controlling torque reduction of a hybrid electric vehicle including a motor and an engine includes determining whether a demand torque of a traction control system (TCS) is generated. When the demand torque of the TCS is generated, the demand torque of the TCS and a motor output torque is compared. Based on a result of the comparison, torque reduction is performed by using only one of a motor torque. Also disclosed are an apparatus configured to perform the method for controlling torque reduction and a computer readable storage medium causing performance of torque reduction through the use of only one of a motor torque and an engine torque.