Dual-Inverter EV Motor Control for On-Drive Boost Charging
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Solution Overview
Problem
Electrified vehicles face efficiency challenges in maximizing power conversion efficiency and acceleration performance due to the limited voltage utilization rate, which affects fuel efficiency and torque generation, especially when trying to cover both low and high power sections with a single motor.
Innovation Solution
The implementation of a dual inverter motor system with a transfer switch and a charging switch that forms a boost charging path from an auxiliary battery to a main battery through the motor system during driving, allowing for pulse width modulation control to optimize voltage boosting and improve mileage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of coils of the motor is increased to raise the maximum torque of the motor, then the maximum torque is improved, but the section with a high voltage utilization rate becomes farther away from a low torque region, causing fuel efficiency to deteriorate
Solution Approach 1:
The patent divides the motor system into two separate motor units, each with different coil configurations optimized for different torque regions. The first motor unit has coils configured for high voltage utilization rate in low torque regions, while the second motor unit has coils configured for high maximum torque in high torque regions. This segmentation allows the system to select the appropriate motor unit based on the required torque level, resolving the contradiction between maximum torque and fuel efficiency.
2Use of energy by moving object
If the main driving point is designed to be included in the section having a high voltage utilization rate, then fuel efficiency is improved, but the maximum torque of the motor is limited, causing acceleration performance to be lowered
Solution Approach 1:
The patent segments the motor system into two specialized motor units: one optimized for fuel efficiency in low torque conditions and another optimized for acceleration performance in high torque conditions. The control system selectively activates the appropriate motor unit based on the driving requirements, thereby achieving both fuel efficiency improvement and adequate acceleration performance without compromise.
Solution Approach 2:
The patent implements dynamic switching between two motor units based on real-time driving conditions and torque requirements. The control system dynamically selects which motor unit to operate, allowing the system to adapt to varying acceleration demands while maintaining optimal fuel efficiency in steady-state driving 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
This solution enhances the mileage of electrified vehicles by efficiently charging the main battery through voltage boosting, improving power conversion efficiency and maintaining acceleration performance across various power sections.
Implementation Method 1
a motor system including a dual inverter connected to the main battery and driving a motor depending on a motor driving mode, and a transfer switch for switching between first and second driving modes included in the motor driving mode; and a charging switch connected between the motor system and the auxiliary battery, and configured to form a boost charging path connected from the auxiliary battery to the main battery through the motor system
Implementation Method 2
When the motor is driven, a switching element in the inverter is turned on/off by pulse width modulation control and applies a line-to-line voltage to the coil of the motor forming the Y-connection in order to generate an alternating current, thereby generating a torque
Data Source
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AI summary
An electrified vehicle may include: a main battery and an auxiliary battery; a motor system including a dual inverter connected to the main battery and driving a motor depending on a motor driving mode, and a transfer switch for switching between first and second driving modes included in the motor driving mode; and a charging switch connected between the motor system and the auxiliary battery, and configured to form a boost charging path connected from the auxiliary battery to the main battery through the motor system when the first driving mode switches to a charging mode while driving.