Dual Three-Phase EV Drive With Harmonic Compensation Bridges

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Solution Overview

Problem

Existing electric drive systems in electric vehicles face challenges in reconciling performance and cost, with silicon devices offering low cost but high loss and harmonics, and silicon carbide devices providing high performance but high cost.

Innovation Solution

A dual three-phase motor system is employed, where a silicon-based three-phase bridge handles primary power transmission and a silicon carbide-based bridge compensates harmonics, using a non-equal power dual three-phase motor with isolated windings to optimize performance and reduce cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If silicon-based three-phase bridge is used for primary power transmission, then cost is reduced, but harmonic performance deteriorates

Engineering Contradiction:
ImprovecostVSAvoidharmonic performance
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The converter is segmented into two independent three-phase bridges: a silicon-based bridge for primary power transmission and a silicon carbide-based bridge for harmonic compensation. This segmentation allows each bridge to be optimized for its specific function, with the silicon bridge handling cost-effective bulk power conversion and the silicon carbide bridge eliminating harmonics generated by the silicon bridge

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The non-equal power dual three-phase motor acts as an intermediary coupling mechanism between the two three-phase bridges. The motor's isolated windings allow independent control of each bridge while maintaining electrical isolation, enabling the silicon carbide bridge to compensate harmonics without interfering with the primary power transmission function of the silicon bridge

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If silicon carbide-based bridge is used for harmonic compensation, then harmonic performance is improved, but cost increases

Engineering Contradiction:
Improveharmonic performanceVSAvoidcost
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

Silicon carbide devices are applied locally and selectively only in the second three-phase bridge dedicated to harmonic compensation, rather than throughout the entire converter system. This localized application of high-performance (and high-cost) materials optimizes harmonic performance while containing costs by using cheaper silicon devices for primary power transmission where high-performance materials are not critical

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If dual three-phase motor with isolated windings is employed, then performance and cost are optimized, but device complexity increases

Engineering Contradiction:
Improvecost-performance ratioVSAvoiddevice complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The non-equal power dual three-phase motor serves multiple functions simultaneously: it acts as the primary load, provides electrical isolation between the two three-phase bridges through its isolated windings, enables independent control of each bridge, and facilitates harmonic compensation. This multi-functionality reduces the need for additional isolation components or complex control architectures

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 improved harmonic performance and reduced cost by leveraging silicon devices for primary power and silicon carbide devices for harmonic compensation, achieving efficiency comparable to silicon carbide-only systems at a lower cost.

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

Methodology Applied
Scientific EffectElectrical Energy Conversion:

Implementation Method 2

the motor includes a first winding and a second winding; 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

Methodology Applied
Scientific EffectElectromagnetic Energy Conversion: Electromagnetic Induction

Implementation Method 3

a control unit, which is configured to superpose 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

Methodology Applied
Scientific EffectWaveform Superposition:

Data Source

PatentEP4583399A1Electric drive system, method, apparatus, storage medium, electronic device, and electric vehicle
Publication Date: 2025.07.09 CRRC ZHUZHOU ELECTRIC LOCOMOTIVE RESEARCH INSTITUTE CO LTD
  • EP4583399A1 patent drawingFigure 1~2
  • EP4583399A1 patent drawingFigure 3~4
  • EP4583399A1 patent drawing

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.