EV Motor Torque Control for Uphill Thermal Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control methods fail to balance the restraint of excessive temperature increase and maintain desired traveling performance, particularly on uphill roads, due to unnecessary torque restrictions when the motor temperature is within an allowable range.
Innovation Solution
A motor control method that adjusts the torque restriction based on gradient and temperature parameters, setting a correction torque upper limit by determining a gradient torque and an acceleration torque to counteract uphill forces and manage temperature, using sensors and control units to dynamically adjust torque limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If torque restriction is applied to prevent motor temperature increase, then motor temperature is controlled, but traveling performance on uphill roads deteriorates
Solution Approach 1:
The patent applies dynamics by making the torque upper limit dynamically adjustable based on operating conditions. The correction torque upper limit is calculated by correcting the basic torque upper limit according to the gradient parameter and temperature parameter, allowing the system to adapt torque restrictions to actual road conditions and temperature states, thereby preventing unnecessary torque limitation on uphill roads while still protecting against overheating.
Solution Approach 2:
The patent changes parameters by introducing gradient parameter and temperature parameter to modify the torque upper limit. The correction torque upper limit is determined by correcting the basic torque upper limit based on these parameters, enabling the system to adjust torque restrictions according to actual operating conditions rather than applying fixed restrictions.
2Temperature
If basic torque upper limit is restricted to prevent overheating, then temperature increase is restrained, but acceleration performance on uphill roads is insufficient
Solution Approach 1:
The system dynamically adjusts the correction torque upper limit based on real-time gradient parameter and temperature parameter values. When the gradient parameter exceeds a threshold, the system calculates an appropriate correction value to maintain sufficient acceleration capability while still preventing overheating, thus resolving the contradiction between temperature control and acceleration performance.
Solution Approach 2:
The patent implements feedback by continuously monitoring the temperature parameter and gradient parameter, then using this information to adjust the correction torque upper limit. The control unit calculates the correction value based on feedback from these parameters, enabling the system to respond to changing conditions and maintain optimal balance between temperature control and performance.
Data Source
AI summary
A gradient parameter indicating a road surface gradient of the electric vehicle is acquired, a temperature parameter indicating a temperature in a motor control system including the electric motor is acquired, a torque restriction process is executed in which when at least one of the gradient parameter and the temperature parameter is equal to or larger than a corresponding one of predetermined threshold values respectively defined therefor, and the upper limit of the request torque is set to a correction torque upper limit smaller than a predetermined basic torque upper limit. In the torque restriction process, a first torque is determined based on the gradient parameter, a second torque for providing a predetermined acceleration to the electric vehicle is determined, and the correction torque upper limit is determined by correcting the basic torque upper limit with reference to the first torque and the second torque.