Electric Vehicle Control Device AC Power Conversion

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Solution Overview

Problem

Existing electric vehicle control devices with diesel engines require reduction in size and cost while maintaining efficient AC power control.

Innovation Solution

The electric vehicle control device incorporates an AC synchronous generator, a bidirectional converter, an inverter, and an auxiliary power unit, with a CVCF load, and includes features like AC reactors and an accumulator for power redundancy, allowing for optimized converter selection and reduced auxiliary power source capacity, thereby minimizing size and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a diesel engine with AC generator is used to generate AC power, then power supply capability is improved, but device size and cost increase

Engineering Contradiction:
Improvepower supply capabilityVSAvoiddevice size
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The patent extracts the auxiliary power source device from the traditional diesel engine system and replaces it with a compact configuration using an AC synchronous generator directly coupled with bidirectional converter and capacitor. This extraction eliminates the need for heavy diesel engine components while maintaining power supply capability through the generator-capacitor combination.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical diesel engine system with an electrical system comprising AC synchronous generator, bidirectional converter, and capacitor. This substitution eliminates mechanical combustion components and reduces device size while maintaining power generation capability through electromagnetic conversion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Power

If a diesel engine with AC generator is used to generate AC power, then power supply capability is improved, but device cost increases

Engineering Contradiction:
Improvepower supply capabilityVSAvoiddevice cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent extracts the expensive diesel engine component and replaces it with more cost-effective electrical components including AC synchronous generator, bidirectional converter, and capacitor. This extraction reduces manufacturing cost while maintaining power supply capability through the alternative electrical architecture.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The AC synchronous generator in the patent serves multiple functions: generating AC power for the inverter, providing power to auxiliary equipment, and enabling bidirectional energy flow through the converter. This multi-functionality reduces the need for separate dedicated components, thereby lowering overall device cost.

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

3Adaptability or versatility

If auxiliary power source device is added to convert DC to AC for auxiliary equipment, then power supply versatility is improved, but device complexity increases

Engineering Contradiction:
Improvepower supply versatilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the auxiliary power source function with the main inverter system by using the same AC synchronous generator and bidirectional converter for both primary propulsion and auxiliary power needs. This consolidation eliminates the need for separate auxiliary power conversion equipment, reducing device complexity while maintaining power supply versatility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inverter system in the patent is designed to serve dual purposes: driving the main propulsion motor and supplying power to auxiliary equipment. The AC synchronous generator and bidirectional converter operate in a multi-functional manner, providing both DC to AC conversion for propulsion and AC power for auxiliary loads, thereby reducing overall system complexity.

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

This configuration achieves a reduction in size and cost while maintaining efficient AC power control and performance, with improved current ripple reduction and power supply redundancy.

Implementation Method 1

an AC synchronous generator (2C), which performs CVCF operation

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a bidirectional converter (3D) connected with the AC synchronous generator (2C)

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 3

an inverter (8), which converts DC power supplied from a DC link into AC power

Methodology Applied
Scientific EffectInversion:

Implementation Method 4

AC reactors and an accumulator for power redundancy, allowing for optimized converter selection and reduced auxiliary power source capacity, thereby minimizing size and cost

Methodology Applied
Scientific EffectInductance: Inductor

Data Source

PatentEP2452848B1Electric vehicle control device
Publication Date: 2018.11.21 KK TOSHIBA
  • EP2452848B1 patent drawingFigure 1
  • EP2452848B1 patent drawingFigure 2
  • EP2452848B1 patent drawingFigure 3

AI summary

An electric vehicle control device wherein: AC power generated by an AC synchronous generator is converted to DC power by a converter; the DC power converted by the converter is converted to AC power by an inverter, and is supplied to a vehicle drive motor constituting a motive power source for driving an electric vehicle; the DC power converted by the converter is converted to AC power by an auxiliary power source device and supplied to a CVCF load, an auxiliary device capable of withstanding harmonics being connected in series with the AC synchronous generator.