Dual-Inverter Motor Drive With Y/Open-End Winding Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motor driving technologies face challenges in maximizing power conversion efficiency of inverters for eco-friendly vehicles, particularly in balancing low-torque and high-torque regions, which affects fuel efficiency and acceleration performance.
Innovation Solution
A motor driving apparatus that switches between Y-connection and open end winding motor driving modes using two inverters, with a controller managing switching states to optimize voltage vector synthesis and minimize switching losses, employing SiC FETs and Si IGBTs for efficient power conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the number of windings of the motor is increased to increase the maximum torque of the motor, then the maximum torque is improved, but the section where the voltage use rate is high moves away from a low-torque region, causing fuel efficiency to deteriorate
Solution Approach 1:
The patent applies dynamics by enabling the motor to switch between two operational modes (Y-connection mode and open-end winding mode) depending on the torque demand. This dynamic switching allows the system to adapt to varying operating conditions, achieving high torque when needed while maintaining high voltage use rate and fuel efficiency during normal operation.
Solution Approach 2:
The patent changes the connection configuration parameter of the motor windings between Y-connection and open-end winding modes. This parameter change enables the system to achieve different operational characteristics: Y-connection for high voltage use rate and fuel efficiency, and open-end winding for high torque output, thereby resolving the contradiction between torque and fuel efficiency.
2Use of energy by moving object
If the vehicle is designed so that the main operating point is included in the section where the voltage use rate is high, then fuel efficiency is improved, but the maximum torque of the motor is limited, causing acceleration start performance to deteriorate
Solution Approach 1:
The patent makes the motor system universal by designing it to perform multiple functions through two operational modes. The Y-connection mode handles normal operation with high fuel efficiency, while the open-end winding mode provides high torque for acceleration. This multi-functionality allows the single motor to satisfy both fuel efficiency requirements and acceleration performance requirements.
Solution Approach 2:
The system dynamically switches between operational modes based on torque demand. During acceleration requiring high torque, the system switches to open-end winding mode. During normal operation, it operates in Y-connection mode for high fuel efficiency. This dynamic adaptation resolves the contradiction between fuel efficiency and maximum torque capability.
3Force
If switching elements are increased in size to handle high torque, then maximum torque is improved, but device complexity and cost increase
Solution Approach 1:
The patent segments the inverter system into two separate inverters: a main inverter operating in Y-connection mode for normal operation, and an auxiliary inverter operating in open-end winding mode for high torque applications. This segmentation allows each inverter to be optimized for its specific operating range, avoiding the need for oversized switching elements that would be required if a single inverter had to handle both low and high torque requirements.
Solution Approach 2:
The system dynamically selects which inverter configuration to use based on torque demand. The controller switches between Y-connection and open-end winding modes, enabling the use of appropriately sized switching elements for each mode rather than requiring oversized elements to handle peak torque continuously. This reduces overall device complexity and cost.
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
Improves efficiency across the entire torque range, enhances fuel efficiency, and reduces switching losses by optimizing the switching pattern of pulse width modulation control, allowing for better acceleration performance without increasing the size of switching elements.
Implementation Method 1
as a switching element in the inverter is turned ON/OFF by a pulse width modulation control, a line voltage is applied to the windings of the Y-connected motor to generate an alternating current to generate a torque
Implementation Method 2
to synthesize a voltage vector corresponding to a voltage command when the motor is driven in an open end winding mode in which the first switching elements and the second switching elements are switched in a spatial vector pulse width modulation mode
Data Source
AI summary
A motor driving apparatus includes: a first inverter including: a plurality of first switching elements and connected to a first end of each of the windings; a second inverter including: a plurality of second switching elements and connected to a second end of each of the windings; and a controller configured to control a switching state of the plurality of first switching elements and the plurality of second switching elements based on a driving mode of the motor in one sampling period.