Split Battery Charging Circuit for High-Voltage EV Packs

Solution Overview

Problem

Conventional charging circuits for electric vehicles with high battery voltages face inefficiencies and high costs due to the need for complex DC voltage conversion to match the rated voltage of the energy store, leading to significant electrical losses.

Innovation Solution

A charging circuit with a DC-DC converter that supplies a portion of the energy store directly from the charging station and uses a smaller converter to adjust the voltage for the remaining portion, reducing overall energy conversion needs and losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a DC-DC converter is used to convert the charging voltage to match the rated voltage of the energy store, then the charging voltage can be adapted to high voltage energy stores, but significant electrical losses occur and the converter becomes large and complex

Engineering Contradiction:

Improvecharging voltage adaptationVSAvoidelectrical losses

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The energy store is divided into two portions: a first portion connected directly to the charging station and a second portion connected through a DC-DC converter. This segmentation allows only the necessary voltage conversion for the second portion, reducing overall energy losses while maintaining adaptability to high voltage energy stores.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different connection configurations are applied to different portions of the energy store based on local requirements. The first portion uses direct connection for efficiency, while the second portion uses voltage conversion. This local differentiation optimizes the balance between adaptability and energy efficiency.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If a DC-DC converter is used to convert the charging voltage to match the rated voltage of the energy store, then the charging voltage can be adapted to high voltage energy stores, but the converter size and complexity increase significantly

Engineering Contradiction:

Improvecharging voltage adaptationVSAvoidconverter complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The energy store is divided into two portions: a first portion connected directly to the charging station and a second portion connected through a DC-DC converter. This segmentation allows only the necessary voltage conversion for the second portion, reducing overall energy losses while maintaining adaptability to high voltage energy stores.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different connection configurations are applied to different portions of the energy store based on local requirements. The first portion uses direct connection for efficiency, while the second portion uses voltage conversion. This local differentiation optimizes the balance between adaptability and energy efficiency.

Inventive Principle:

Principle #3Local quality

3Loss of energy

If the entire energy store is connected directly to the charging station, then charging efficiency is maximized, but the charging voltage must exactly match the energy store rated voltage

Engineering Contradiction:

Improvecharging efficiencyVSAvoidvoltage compatibility

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The energy store is divided into two portions: a first portion connected directly to the charging station and a second portion connected through a DC-DC converter. This segmentation allows only the necessary voltage conversion for the second portion, reducing overall energy losses while maintaining adaptability to high voltage energy stores.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different connection configurations are applied to different portions of the energy store based on local requirements. The first portion uses direct connection for efficiency, while the second portion uses voltage conversion. This local differentiation optimizes the balance between adaptability and energy efficiency.

Inventive Principle:

Principle #3Local quality

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 approach enhances charging efficiency by minimizing energy losses and reducing the size and complexity of the DC-DC converter, allowing for cost-effective and efficient charging of electric vehicles with higher rated voltages.

Implementation Method 1

The DC-DC converter (14) is set up to convert an electrical voltage at its input to a further electrical voltage at its output

Methodology Applied

Scientific EffectDC-DC voltage conversion: Electromagnetic Induction

Data Source

PatentUS20240308364A1Charging circuit and method for charging an electrical energy store, and electric vehicle

Publication Date: 2024.09.19 ROBERT BOSCH GMBH

AI summary

The present invention relates to charging an electrical energy store, in particular a traction battery of an electric vehicle, wherein the electrical energy store has a rated voltage which is higher than an electrical voltage provided for charging. For this purpose, one portion of the electrical energy store is directly charged by the electrical voltage provided, and a further portion of the electrical energy store is charged by means of an electrical voltage which is converted by a DC-DC converter from the voltage provided for charging. In this way, only some of the energy required for charging the electrical energy store has to be converted by means of a voltage converter.