Vehicle Drive Motor Control via Gear Stage Adjustment
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Solution Overview
Problem
Environmentally-friendly vehicles face reduced drivability and marketability due to motor overheating issues, which limit the use of electric vehicle mode and degrade fuel economy, as conventional systems protect against overheating by reducing motor output or stopping the motor at high temperatures.
Innovation Solution
A system and method for controlling a drive motor in vehicles that includes a vehicle controller to detect state data, set motor demand power and gear stage, generate motor demand torque, and adjust the gear stage based on motor temperature, thereby preventing overheating by reducing motor torque and operating the engine when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If motor output is reduced or motor is stopped to prevent overheating, then motor temperature is controlled, but drivability and fuel economy are degraded
Solution Approach 1:
The system changes the gear ratio parameter dynamically based on motor temperature. When motor temperature exceeds the reference temperature, the controller switches to a lower gear stage, which alters the torque and speed characteristics of the motor, thereby reducing motor temperature while maintaining vehicle drivability and fuel economy.
2Temperature
If gear ratio is not adjusted, then motor structure is simple, but motor temperature increases causing thermal degradation
Solution Approach 1:
The system implements a feedback control mechanism where the controller continuously monitors motor temperature and adjusts the gear stage accordingly. When motor temperature exceeds the reference temperature, the controller switches to a lower gear stage, creating a closed-loop feedback system that automatically regulates motor temperature without requiring complex additional hardware.
Data Source
AI summary
A system and a method of controlling a drive motor for a vehicle is disclosed. The system of controlling a drive motor for a vehicle may include: an engine and the drive motor as power sources; a data detector detecting a state data for controlling the drive motor; and a vehicle controller setting a motor demand power and a gear stage based on the state data. In particular, the vehicle controller generates a motor demand torque based on the motor demand power and the gear stage, checks a motor temperature after driving the drive motor based on the motor demand torque, and changes the gear stage based on the motor temperature.