Integrated EV Power Converter for Torque-Free Three-Phase Charging
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Solution Overview
Problem
Existing electric vehicle (EV) architectures face inefficiencies and high costs due to separate charging and traction systems, which are not used simultaneously, leading to inflexibility, increased capital and operational expenditures, and issues with torque production, noise, and vibration during three-phase charging.
Innovation Solution
An integrated power converter with three legs, open-end stator windings, and a power switch that allows for flexible operation modes, including single-phase and three-phase charging without torque production, using existing traction system electronics to save space and increase efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate charging and traction systems are used, then functional independence is achieved, but system size and cost increase
Solution Approach 1:
The patent combines the charging converter and traction inverter into a single integrated power converter with three legs. The charging converter uses two legs while the traction inverter uses all three legs, sharing common power electronic components and control systems. This merging eliminates the need for physically separate charging and traction systems, reducing overall system size and cost while maintaining functional independence through software-based control modes.
Solution Approach 2:
The integrated power converter is designed to perform multiple functions: it can operate as a charging converter for single-phase or three-phase AC charging, as a traction inverter for motor drive, and even return energy to the grid. The same hardware platform supports different operational modes through configurable control strategies, making the system universal and adaptable to various EV application scenarios without requiring dedicated separate systems.
2Device complexity
If charging and drive functions are combined in the same hardware, then system size and cost are reduced, but functionality and operational flexibility are limited
Solution Approach 1:
The patent implements dynamic operational modes that allow the integrated power converter to switch between different functions based on real-time requirements. The system can dynamically transition between charging mode (single-phase or three-phase), traction mode, and grid-return mode through software control. This dynamic adaptability ensures that while hardware is consolidated, functional versatility is maintained through flexible, reconfigurable control strategies that adjust system behavior according to operational needs.
3Productivity
If three-phase charging is achieved using additional non-shared converters, then charging capability is improved, but system complexity and cost increase
Solution Approach 1:
The patent achieves three-phase charging capability by utilizing two legs of the three-legged integrated power converter as a charging converter, sharing the same hardware platform with the traction inverter. This merging eliminates the need for additional non-shared converters, reducing system complexity and cost while maintaining full three-phase charging capability. The shared power electronic components and control systems handle both charging and traction functions efficiently.
4Productivity
If charging from three-phase grid produces torque, then charging function is achieved, but efficiency and mechanical part lifetime are reduced
Solution Approach 1:
The patent extracts the torque-producing function from the charging operation by implementing a dedicated charging converter mode that connects only two legs of the power converter to the grid for charging, while isolating the motor from torque production during charging. This separation ensures that charging current flows through the power converter without inducing torque in the motor, eliminating energy losses and mechanical stress that would otherwise occur during charging, thereby improving efficiency and extending mechanical part lifetime.
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 solution enables a compact, efficient, and reliable EV system that can charge from single-phase or three-phase grids, produce torque, and return energy to the grid, while reducing complexity and costs.
Implementation Method 1
a power converter comprising three legs... The first ends of the stator windings are connected to respective legs of the three legs of the power converter
Implementation Method 2
an electric motor including three open-end stator windings... that can charge from single-phase or three-phase grids, produce torque
Data Source
AI summary
An arrangement for electric power conversion and an electric drive comprises a power converter that includes three legs, an electric motor including three open-end stator windings respectively having first and second ends, and a power switch. The first ends of the stator windings are coupled to respective legs of the three legs of the power converter, and the second ends of the stator windings are coupled together and have a same electric potential. The power switch is configured to selectively disconnect one of the second ends of the stator windings from all other second ends to establish at most two distinct electric potentials. The at most two distinct electric potentials are coupled to respective legs of a power grid interface coupled to the arrangement.