Torque Control Threshold for Electric Motor Efficiency
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Solution Overview
Problem
In electric vehicles, when the motor is controlled to produce a small requested torque, the driving efficiency becomes low due to increased power consumption by the electric system, leading to reduced cruising distance.
Innovation Solution
The torque control method sets the requested torque to zero when it is below a predetermined threshold, controlling the motor to generate torque only when necessary, thereby reducing inefficient driving states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the motor is controlled to generate a small request torque, then the vehicle can respond to light acceleration requests, but the driving efficiency becomes low due to increased power consumption by the electric system
Solution Approach 1:
The patent changes the torque parameter from a small non-zero value to zero when the request torque falls below a predetermined threshold. This parameter change resolves the contradiction by eliminating the inefficient operating state where the motor consumes excessive power for small acceleration requests, while still allowing the vehicle to respond to light acceleration needs through coasting or momentum.
2Productivity
If the motor operates at small torque levels, then the vehicle can maintain responsiveness to driver input, but the cruising distance is reduced due to low driving efficiency
Solution Approach 1:
The patent applies parameter change by setting the torque to zero below a threshold value, which eliminates wasteful energy consumption during light acceleration phases. This extends the cruising distance by preventing the motor from operating in inefficient low-torque regions, while vehicle responsiveness is maintained through alternative means such as coasting control and momentum utilization.
Data Source
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AI summary
A torque control method for controlling torque of a motor, comprises detecting request of speed control requested from a driver by using a sensor, calculating a request torque based on the request, performing, controlling torque generated at the motor based on the request torque, when the request torque is smaller than a predetermined torque threshold value, a coast traveling control for setting the request torque to zero and controlling the motor based on the request torque which is set to zero.