Hybrid EV Dual-Motor Torque Distribution Using Selective Efficiency Maps
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Solution Overview
Problem
Hybrid electric vehicles face inefficiencies in electric energy use due to the distance between high voltage utility factor sections and low torque regions, which affects acceleration performance and overall electric energy efficiency.
Innovation Solution
The implementation of efficiency maps for multiple motors in a hybrid electric vehicle, where requested torque is distributed based on applied efficiency maps, allowing for optimal torque distribution between motors to improve electric energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the number of windings of the motor is increased to increase maximum torque, then the maximum torque is improved, but the high voltage utility factor section becomes distant from the low torque region, causing electric energy efficiency to deteriorate
Solution Approach 1:
The patent segments the efficiency map into multiple regions based on motor operating conditions (low torque region, high torque region, etc.). Different efficiency maps are selectively applied to different regions, allowing the system to optimize for maximum torque in high torque regions while maintaining electric energy efficiency in low torque regions. This segmentation resolves the contradiction by enabling region-specific optimization rather than a single design compromise.
2Use of energy by moving object
If the design is performed to include the main operating point in the section having high voltage utility factor, then electric energy efficiency is improved, but the maximum torque of the motor is restricted, causing acceleration power generation performance to deteriorate
Solution Approach 1:
The patent dynamically selects and switches between different efficiency maps based on real-time motor operating conditions. The control system determines the current operating region and selectively applies the most appropriate efficiency map, enabling the system to adaptively optimize for either electric energy efficiency or acceleration performance depending on the driving situation, rather than being fixed to a single design compromise.
Solution Approach 2:
The patent changes the parameters of the efficiency map based on motor operating conditions. By selecting different efficiency maps with different conversion references and parameters suited for different operating regions, the system can optimize performance characteristics dynamically. This allows the same motor to achieve both high electric energy efficiency in normal operation and high acceleration performance when needed.
3Use of energy by moving object
If efficiency maps are selectively applied based on motor drive mode, then torque distribution is optimized, but the control system complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the control system continuously monitors motor operating conditions and drive mode, then selectively applies appropriate efficiency maps based on this feedback. The system determines the current drive mode, selects the corresponding efficiency map, and uses it for torque distribution optimization. This feedback-based approach systematically manages the complexity by providing clear decision logic based on operating conditions.
Data Source
AI summary
Proposed is a method of controlling motor driving of a hybrid electric vehicle. Sum torque of a first motor, which is directly connected to an engine, and a second motor, which is directly connected to an input end of a transmission, are determined based on request torque and torque distributed to the engine. One of a first synthetic efficiency map and a second synthetic efficiency map, to which different conversion references of the motor drive mode are set, are selectively applied to an efficiency map of the second motor, based on information about the motor drive mode applied to the second motor. The sum torque is distributed to each of the first motor and the second motor based on an efficiency map of the first motor and the efficiency map of the second motor.