Switchable AC-DC Converter for Vehicle Charging

Solution Overview

Problem

Current DC charging systems for vehicles are limited by power constraints due to battery voltage and charging plug current capacity, requiring additional components like DC/DC converters for efficient charging, which increases costs and complexity.

Innovation Solution

A combined AC-DC charging device with parallel converter circuits and a switchable AC/DC converter configuration allows for increased charging power by optimizing power transformation and utilizing existing AC charging systems for DC charging with minimal modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a DC/DC converter is used to enable DC charging, then charging power is improved, but device complexity and cost increase

Engineering Contradiction:

Improvecharging powerVSAvoidcomponent complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent makes the AC/DC converter switchable to operate in two modes: AC charging mode and DC charging mode. By adding a switchable configuration, the same hardware infrastructure serves dual purposes, eliminating the need for a separate DC/DC converter while enabling DC charging capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the AC charging system and DC charging system into a single unified converter setup. The AC/DC converter is configured to handle both AC and DC input modes, merging what would traditionally be separate charging systems into one integrated solution, thereby reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Power

If a DC/DC converter is added for DC charging, then charging power is improved, but cost increases

Engineering Contradiction:

Improvecharging powerVSAvoidmanufacturing cost

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The patent makes the AC/DC converter switchable to operate in two modes: AC charging mode and DC charging mode. By adding a switchable configuration, the same hardware infrastructure serves dual purposes, eliminating the need for a separate DC/DC converter while enabling DC charging capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the AC charging system and DC charging system into a single unified converter setup. The AC/DC converter is configured to handle both AC and DC input modes, merging what would traditionally be separate charging systems into one integrated solution, thereby reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If direct battery connection is used for DC charging, then device complexity is reduced, but charging power is limited

Engineering Contradiction:

Improvesystem complexityVSAvoidcharging power

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The patent makes the AC/DC converter switchable to operate in two modes: AC charging mode and DC charging mode. By adding a switchable configuration, the same hardware infrastructure serves dual purposes, eliminating the need for a separate DC/DC converter while enabling DC charging capability.

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 solution enables higher charging power for vehicles without additional component costs, allowing for faster battery charging and reduced loading times while maintaining efficiency and cost-effectiveness for both AC and DC charging modes.

Implementation Method 1

a first and a second converter circuit for transforming a charging current from the power source into a charging current for the energy storage device

Methodology Applied

Scientific EffectElectrical energy transformation:

Data Source

PatentEP3189575B1Device for charging an energy store

Publication Date: 2020.01.01 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

Figure 1
Figure 2
Figure 3

AI summary

Disclosed is a device for charging an energy store, comprising a first terminal to be connected to a direct current source, a second terminal to be connected to the energy store, and a parallel circuit between the first and second terminals. The parallel circuit comprises an intermediate circuit, a first converter circuit for converting an input voltage and an input current into an output DC voltage and an output direct current, and a second converter circuit.