Dual Battery Power Supply System for Catenary-Free Trains

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Solution Overview

Problem

Power supply systems for trains without catenary face challenges in achieving sufficient autonomy due to the heavy and expensive nature of power batteries, which require oversizing to maintain lifespan, increasing weight and cost, or reducing distance.

Innovation Solution

A power supply system comprising power batteries and energy batteries arranged in parallel, with a control block that distributes energy based on power density differences, limiting energy discharge from energy batteries when maximum power is required and using power batteries to balance the load, while storing excess braking power mechanically or thermally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If power batteries are used to supply trains without catenary, then the power supply system can provide high power density, but the system becomes heavy and expensive

Engineering Contradiction:
Improvepower densityVSAvoidweight of power supply system
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The power supply system is segmented into two distinct battery subsystems: power batteries (high power density) and energy batteries (high energy density). This segmentation allows each subsystem to specialize in its strength, with power batteries providing peak power and energy batteries providing sustained energy, thereby reducing the total weight compared to using only power batteries

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual-battery system provides multi-functionality by combining the high power capability of power batteries with the high energy capacity of energy batteries. The control block enables the system to dynamically switch between different battery combinations based on power demand, achieving both high power and long autonomy without requiring excessive weight from a single battery type

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

2Reliability

If power batteries are oversized to maintain lifespan, then the battery lifespan is extended, but the weight and cost increase

Engineering Contradiction:
Improvebattery lifespanVSAvoidweight of power supply system
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

Instead of oversizing power batteries to handle both peak power and long-duration energy storage, the invention applies partial action by using power batteries only for peak power delivery and energy batteries for sustained energy supply. This prevents the need to oversized power batteries, extending their effective lifespan while reducing weight

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The control block acts as an intermediary that manages the interaction between power and energy batteries. It dynamically distributes power demands between the two battery types based on their respective capabilities and state of charge, optimizing lifespan usage patterns and preventing excessive discharge cycles that would require oversizing

Inventive Principle:
Principle #24Intermediary (Mediator)

3Weight of moving object

If the distance in autonomy is reduced, then the power supply system size and weight are decreased, but the operational range is limited

Engineering Contradiction:
Improveweight of power supply systemVSAvoiddistance in autonomy
Core Design Contradiction:
Weight of moving objectVSDuration of action of moving object

Solution Approach 1:

The invention merges power batteries and energy batteries in parallel configuration, combining the high power density advantage of power batteries with the high energy density advantage of energy batteries. This merging creates a hybrid system that achieves both reduced weight and extended autonomy distance, overcoming the trade-off between system size and operational range

Inventive Principle:
Principle #5Merging (Combining)

4Quantity of substance

If energy batteries are used for high power delivery, then the energy density advantage is utilized, but the power delivery capability is insufficient

Engineering Contradiction:
Improveenergy densityVSAvoidpower delivery capability
Core Design Contradiction:
Quantity of substanceVSPower

Solution Approach 1:

The system segments the power delivery function between two battery types: energy batteries provide sustained energy supply with high energy density, while power batteries provide peak power bursts with high power density. This segmentation allows energy batteries to operate within their optimal power range while supplementing with power batteries when high power is needed

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4043270A1Power supply system, associated method and computer program
Publication Date: 2022.08.17 ALSTOM HOLDINGS SA
  • EP4043270A1 patent drawingFigure 1
  • EP4043270A1 patent drawingFigure 2
  • EP4043270A1 patent drawing

AI summary

This power supply system (10) includes: - a set of power battery(ies) (1) and a set of energy battery(ies) (2), such that the set of power battery(ies) (1) has a higher power density than the set of energy battery(ies) (2) and the set of energy battery(ies) (2) has a higher energy density than the set of power battery(ies) (1); - a control block (8, 3, 6) adapted to control the distribution of energy between the set of power battery(ies) (1) and the set of energy battery(ies). The control block is adapted to, if the current power P to be supplied by the power supply system is greater than PmaxEnergie_décharge, limit the part of the power delivered by the energy battery set (2) to PmaxEnergie_décharge and to have the balance of power, P - PmaxEnergie_décharge, delivered by the power battery set (1).