Dual Three-Phase EV Drive With Si-SiC Harmonic Compensation
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Solution Overview
Problem
The challenge of reconciling the performance and cost of electric drive systems in electric vehicles is difficult due to the trade-off between silicon devices, which are low-cost but high-loss, and silicon carbide devices, which are high-cost but high-performance.
Innovation Solution
A dual three-phase motor system is employed, where a first three-phase bridge with silicon-based devices handles primary power transmission, and a second three-phase bridge with silicon carbide-based devices addresses harmonic compensation, optimizing performance while reducing costs by using a non-equal power dual three-phase motor with isolated windings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If silicon-based devices are used in the three-phase bridge, then the cost is reduced, but the loss increases and performance deteriorates
Solution Approach 1:
The patent divides the three-phase bridge into two separate bridges: a first three-phase bridge using low-cost silicon-based devices and a second three-phase bridge using high-performance silicon carbide-based devices. This segmentation allows each bridge to be optimized for its specific function, with the silicon-based bridge handling cost-sensitive applications and the silicon carbide bridge handling performance-critical tasks, thereby resolving the contradiction between cost and loss.
Solution Approach 2:
Different portions of the power conversion system are assigned different device types based on their specific requirements. The first three-phase bridge uses silicon-based devices where cost is the primary concern, while the second three-phase bridge uses silicon carbide devices where low loss and high performance are critical. This local differentiation of quality resolves the contradiction by matching device characteristics to functional requirements.
2Loss of energy
If silicon carbide-based devices are used in the three-phase bridge, then the performance and efficiency are improved, but the cost increases
Solution Approach 1:
The patent segments the power conversion system into two functional bridges, allowing silicon carbide-based devices to be used only in the second three-phase bridge where high efficiency and low loss are critical, rather than deploying them throughout the entire system. This selective application maintains high performance where needed while controlling overall system cost.
Solution Approach 2:
Silicon carbide-based devices are applied locally in the second three-phase bridge where their superior efficiency and low-loss characteristics provide the greatest benefit, while silicon-based devices are used in the first bridge where cost considerations dominate. This localized application of high-performance materials resolves the contradiction between efficiency and cost.
3Device complexity
If a single three-phase bridge is used, then the device complexity is low, but the harmonic performance is poor
Solution Approach 1:
The patent divides the power conversion system into two separate three-phase bridges with distinct functions: the first bridge handles primary power conversion while the second bridge specifically addresses harmonic compensation. This segmentation eliminates harmonics generated by the first bridge through the coordinated operation of the second bridge, resolving the contradiction between structural simplicity and harmonic performance.
Solution Approach 2:
The second three-phase bridge acts as an intermediary component that compensates for harmonics generated by the first bridge. By introducing this intermediate stage with silicon carbide-based devices, the system achieves superior harmonic performance while maintaining relative structural simplicity through the modular two-bridge architecture.
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 system achieves performance comparable to silicon carbide-only systems at a lower cost, with improved harmonic performance and efficiency, while maintaining electrical isolation and magnetic coupling between the two sets of devices.
Implementation Method 1
the converter includes a first three-phase bridge and a second three-phase bridge; an input end of the first three-phase bridge is connected to a power source, and an output end of the first three-phase bridge is connected to the first winding of the motor
Implementation Method 2
an input end of the second three-phase bridge is connected to the power source, and an output end of the second three-phase bridge is connected to the second winding of the motor
Implementation Method 3
the motor is a unit that transforms the electric energy into the mechanical energy
Implementation Method 4
superposing a waveform of the first three-phase bridge and a waveform of the second three-phase bridge to eliminate a sawtooth wave of the first three-phase bridge and obtain a waveform containing only a sawtooth wave of the second three-phase bridge
Data Source
AI summary
The present disclosure relates to the technical field of electric vehicle engineering, and in particular to an electric drive system, a method, an apparatus, a storage medium, an electronic device, and an electric vehicle. A motor and a converter are provided; the motor is configured to comprise a first winding and a second winding; the converter is configured to comprise a first three-phase bridge and a second three-phase bridge; an input end of the first three-phase bridge is configured to be connected to a power source, and an output end of the first three-phase bridge is configured to be connected to the first winding of the motor; and an input end of the second three-phase bridge is configured to be connected to the power source, and an output end of the second three-phase bridge is configured to be connected to the second winding of the motor.