Electric Vehicle Drive Controller Torque Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vehicle drive units fail to sufficiently generate drive motor torque, leading to inadequate output requested by drivers due to uniform torque limitation based on temperature and speed, which reduces the efficiency and characteristics of drive motors and generators.
Innovation Solution
An electrically operated vehicle driving controller that detects temperature and speed to calculate a dynamic limit ratio, allowing for increased torque as speed decreases and decreased torque as speed increases, enabling the drive motor to approach its maximum torque in low-speed conditions, thereby enhancing output generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uniform torque limitation is applied based on temperature and speed, then drive motor characteristics are protected from degradation, but driver requested output cannot be sufficiently generated
Solution Approach 1:
The patent applies dynamics by transitioning from uniform torque limitation to dynamic torque limitation. The controller now calculates limit ratios that vary with rotating speed, allowing the torque limitation to adapt dynamically to operating conditions. This enables the drive motor to operate closer to its maximum torque capability across different speed ranges while still protecting against characteristic degradation.
Solution Approach 2:
The patent implements parameter changes by modifying the torque limitation parameters based on rotating speed. The limit ratio is no longer uniform but changes as a function of speed, allowing optimization of torque output at different operating points. This parameter adaptation enables sufficient driver requested output while maintaining reliability.
2Reliability
If drive motor torque is limited uniformly, then temperature-induced characteristic degradation is prevented, but torque generation efficiency is reduced
Solution Approach 1:
The patent applies dynamics by implementing dynamic torque limitation that adapts to rotating speed. The limit ratio varies with speed, allowing the system to optimize torque generation efficiency at different operating points while maintaining protection against temperature-induced characteristic degradation.
Solution Approach 2:
The patent changes the limitation parameters dynamically based on rotating speed. By adjusting the limit ratio as a function of speed, the system improves torque generation efficiency across the operating range while maintaining reliability protection.
3Reliability
If limit ratio is applied to constrain torque, then drive motor and generator characteristics are protected, but driver requested output is insufficient
Solution Approach 1:
The patent applies dynamics by making the limit ratio dynamic rather than static. The controller calculates speed-dependent limit ratios that allow the system to protect characteristics while maximizing torque output at each operating point, thereby satisfying driver requested output.
Solution Approach 2:
The patent implements parameter changes by adjusting the limit ratio based on rotating speed. This parameter adaptation enables the system to maintain characteristic protection while generating sufficient driver requested output across different operating conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The controller effectively generates the required driver output by dynamically adjusting torque limits based on temperature and speed, preventing characteristic degradation of drive motors and generators, and ensuring adequate torque production, especially in low-speed scenarios.
Implementation Method 1
the drive motor is conventionally operated by receiving a direct electric current from a battery at a power applying (driving) time and generates the drive motor torque
Implementation Method 2
the drive motor generates the direct electric current by receiving torque by inertia of the electric automobile and supplies this electric current to the battery
Implementation Method 3
As the electric generator, the drive motor, etc. are operated, the coil of a stator is heated and the temperatures of the electric generator, the drive motor, etc. are raised
Data Source
AI summary
An electrically operated vehicle driving controller has an electrically operated machine driving section for operating an electrically operated machine; a driving section temperature detecting section for detecting the driving section temperature of the electrically operated machine driving section; a limit ratio calculating processor for calculating a limit ratio for limiting the torque of the electrically operated machine on the basis of the driving section temperature; a rotating speed calculating processor for calculating the rotating speed of the electrically operated machine; and a limit torque calculating processor for calculating an electrically operated machine limit torque corresponding to an electrically operated machine maximum torque set corresponding to the rotating speed on the basis of the limit ratio. Because the torque of the electrically operated machine is limited in a limit ratio corresponding to the temperature of the electrically operated machine, it is possible to prevent the characteristics of the electrically operated machine from being reduced.