Dual Motor Power System Torque Distribution for Electric Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pure electric vehicles with single or dual motors face limitations in dynamic performance and economic optimization due to restricted torque and power characteristics, leading to potential power interruptions and suboptimal driving comfort.
Innovation Solution
A dual motor power system with a single motor outputting power via a single gear ratio and the second motor via two gear ratios, controlled by a system that optimizes torque distribution and synchronizer engagement to achieve maximum synchronized efficiency, determining optimal working points through ergodic optimization considering torque thresholds, motor efficiencies, and vehicle speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single motor with one or two gears is used, then the transmission system is simple, but the dynamic performance is limited by the peak torque and power characteristic of the single motor
Solution Approach 1:
The power system is segmented into two independent motors (first motor and second motor), each capable of providing power through different gear ratios. This segmentation allows the system to overcome the limitations of a single motor by distributing the power delivery across multiple independent power sources, thereby achieving higher peak torque and power output while maintaining relatively simple individual transmission paths.
2Productivity
If a two-gear transmission system is used to optimize dynamic performance and economics, then power interruption occurs which affects driving comfort
Solution Approach 1:
The patent merges two motor-transmission systems into a unified power delivery system where the first motor with single gear ratio and the second motor with two gear ratios work cooperatively. This combination allows seamless power delivery during gear transitions, as one motor can compensate while the other transitions gears, thereby eliminating power interruptions and improving driving comfort while maintaining economic optimization capabilities.
3Reliability
If dual motors are used with gears selected based on vehicle speed and acceleration pedal degree, then gear switching without power interruption is achieved, but optimal economics is difficult to obtain
Solution Approach 1:
The control system implements feedback mechanisms that continuously monitor vehicle operating conditions, motor performance parameters, and transmission state. Based on this feedback, the system dynamically adjusts the torque distribution between the two motors and selects the optimal gear ratio for the second motor, thereby achieving both seamless gear switching and optimal economic efficiency through real-time adaptive control.
Solution Approach 2:
The system dynamically adjusts the torque distribution ratio between the first and second motors based on real-time operating conditions. The control system can flexibly vary the contribution of each motor and select the appropriate gear ratio for the second motor, transforming a static gear selection approach into a dynamic optimization process that simultaneously achieves smooth gear transitions and optimal fuel economy.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A dual motor power system for a pure electric vehicle and a control method thereof are disclosed, wherein within a range defined between upper and lower torque thresholds for the operations of one of the two motors under current vehicle speed, the torque of this motor is changed stepwise with a certain torque step; the required torque of the other motor is determined based on the torque distribution relation of the first and second motors; and the synchronized efficiency of the power system is determined based on the torques of the first and second motors so that the optimal synchronized efficiency of the power system is ergodically searched out, and the optimal working points of the two motors and the corresponding gear of the second motor are determined then.