Parallel Charging Switch Units for Balanced High-Power Vehicle Charging

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Solution Overview

Problem

Conventional charging systems for heavy vehicles, such as trucks and buses, struggle with high power requirements and extended charging times, which can lead to imbalances in current paths and potential damage to charging components.

Innovation Solution

A charging system comprising multiple parallelly arranged charging switch units, each with a contactor, measurement device, and variable resistor, controlled by a charging control unit to balance current paths by adjusting resistance and preventing overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If multiple parallel charging switch units are used to increase charging power, then charging time is reduced, but current imbalance between paths may cause damage to charging components

Engineering Contradiction:
Improvecharging timeVSAvoidcharging component safety
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The control unit continuously monitors the resistance values of each current path through measurement devices and dynamically adjusts the variable resistors to balance the current distribution, preventing overheating and damage while maintaining high charging power

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the resistance parameter of variable resistors in real-time based on the measured current path conditions, optimizing current distribution to prevent imbalance while maintaining high charging power across parallel paths

Inventive Principle:
Principle #35Parameter changes

2Reliability

If variable resistors are added to balance current paths, then component safety is improved, but device complexity increases

Engineering Contradiction:
Improvecharging component safetyVSAvoidcharging system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The charging system is divided into multiple independent charging switch units, each with its own variable resistor and measurement device, allowing modular assembly and independent control of each parallel current path

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Variable resistors are introduced as intermediary components in each current path to actively balance current distribution, preventing direct damage to charging components while maintaining system manageability through distributed control

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If resistance is increased in low-resistance paths to balance current, then current distribution is improved, but energy loss increases

Engineering Contradiction:
Improvecurrent distribution balanceVSAvoidenergy loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The variable resistors are adjusted only to the extent necessary to balance current distribution between parallel paths, applying minimal resistance increase needed to prevent current imbalance while avoiding excessive energy loss

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The resistance parameter of variable resistors is dynamically adjusted based on real-time measurements to achieve current balance with minimal energy loss, optimizing the trade-off between reliability and energy efficiency

Inventive Principle:
Principle #35Parameter changes

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 effectively balances current paths, reduces the risk of damage to charging components, and minimizes charging time by allowing higher power transfer, thus improving the operational efficiency and availability of heavy vehicles.

Implementation Method 1

a variable resistor configured to control the resistance in the current path

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

a measurement device configured to determine a parameter indicative of a resistance in a current path through the charging switch unit

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 3

each charging switch unit comprises a contactor configured to control a flow of current from the charging port to the energy storage

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentEP4015287B1A charging system for an energy storage in a vehicle and a method for controlling the charging system
Publication Date: 2025.01.22 VOLVO TRUCK CORP
  • EP4015287B1 patent drawingFigure 1~2
  • EP4015287B1 patent drawingFigure 3~4
  • EP4015287B1 patent drawingFigure 5

AI summary

The invention relates to a charging system (100) for an energy storage (102) in a vehicle comprising: a plurality of parallelly arranged charging switch units (104a-d), each having an input terminal (106a-d) configured to be connected to a common charging port (108), and an output terminal (110a-d) configured to be connected to the energy storage, wherein each charging switch unit comprises a contactor (200) configured to control a flow of current from the charging port to the energy storage; for each charging switch unit, a measurement device (202) configured to determine a parameter indicative of a resistance in a current path through the charging switch unit, and a variable resistor (204) configured to control the resistance in the current path; and a charging control unit (116) connected to each of the charging switch units and configured to, if an estimated difference in resistance between any two of the plurality of current paths through a charging switch unit is higher than a predetermined difference threshold value, control the variable resistor of a charging switch unit in the current path having the lowest resistance to increase the resistance of that current path.