Rail Vehicle Battery-Traction Bus Control to Cut Chopper Losses

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Solution Overview

Problem

The existing railway vehicle systems experience reduced energy efficiency and shorter battery-powered distance due to the energy transfer through choppers when using battery power, as the chopper's energy transfer harms overall efficiency and limits the vehicle's range.

Innovation Solution

The railway vehicle incorporates a control unit that manages energy exchange between the electric motor and battery through a direct current bus, optimizing energy distribution from both the electrical supply network and the battery, using rheostats to control energy flow during braking and traction phases, ensuring efficient energy management based on battery state of charge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the chopper is used for energy transfer between the battery and the traction converter, then the battery can be recharged from the power supply network, but the overall energy efficiency is reduced

Engineering Contradiction:
Improveenergy efficiencyVSAvoidenergy loss through chopper
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The invention extracts the chopper from the energy path between the battery and the traction converter. The control unit now directly manages energy transfer between these components, eliminating the inefficient chopper intermediary and reducing energy losses during battery recharging and motor operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control unit is designed to perform multiple functions: it directly controls the traction converter for motor operation and also manages battery recharging from the power supply network, replacing the specialized chopper function. This multi-functional approach simplifies the system architecture and improves energy efficiency.

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

2Duration of action of moving object

If the chopper is placed between the power supply network and the battery, then the battery can be recharged, but the distance covered on battery power is reduced

Engineering Contradiction:
Improvebattery-powered distanceVSAvoidenergy loss in charging circuit
Core Design Contradiction:
Duration of action of moving objectVSLoss of energy

Solution Approach 1:

The chopper is removed from the charging circuit between the power supply network and the battery. The control unit now directly manages this energy transfer, eliminating the energy losses that previously reduced the amount of energy stored in the battery and thereby reducing the vehicle's battery-powered range.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If the same chopper is used for both battery charging and motor power supply, then the device complexity is reduced, but the energy efficiency during motor operation is compromised

Engineering Contradiction:
Improvenumber of choppersVSAvoidenergy efficiency during motor operation
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The chopper is extracted from the motor power supply path. The control unit now directly manages energy transfer from the battery to the traction converter and motor, eliminating the energy losses that would occur through the chopper and improving overall energy efficiency during motor operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control unit is designed to directly manage multiple energy transfer paths: from the power supply network to the battery, from the battery to the traction converter, and from the traction converter to the motor. This multi-functional control approach eliminates the need for intermediate choppers while improving energy efficiency.

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 enhances energy efficiency by prioritizing energy use from the electrical supply network during traction and battery use during braking, maintaining optimal battery charge levels for efficient energy absorption and extending the vehicle's range when powered by the battery.

Implementation Method 1

a chopper connectable from an input to the connection to the power supply network... connected for recharging to an output of the chopper via a DC bus

Methodology Applied
Scientific EffectElectrical energy conversion: Electromagnetic Induction

Implementation Method 2

a traction converter connected to the connection to the power supply network, an electric motor connected to the output of the traction converter for its power supply

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

an electric motor connected to the output of the traction converter for its power supply

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 4

an electrical energy storage battery connected for recharging to an output of the chopper... When driving on a non-powered section, the motors are powered by the vehicle's battery

Methodology Applied
Scientific EffectElectrochemical energy storage: Battery (electricity)

Data Source

PatentEP4406772A1Rail vehicle with electrical energy storage
Publication Date: 2024.07.31 ALSTOM HOLDINGS SA
  • EP4406772A1 patent drawingFigure 1
  • EP4406772A1 patent drawingFigure 2
  • EP4406772A1 patent drawing

AI summary

The railway vehicle comprises: - a chopper (50A, 50B) connectable to an electrical power supply network, - a battery (22) connected to the chopper (50A, 50B) via a current bus (54A, 54B), - a traction chain (20) comprising: - a traction converter (52A, 52B) connected to the network, - an electric motor (12A, 12B) connected to the output of the traction converter (52A, 52B), and - a control unit (56) for the chopper (50A, 50B) and the traction converter (52A, 52B). The traction converter (52A, 52B) is connected to the current bus (54A, 54B) for its supply through the chopper (50A, 50B) from the power supply network and/or from the battery (22), and - the control unit (56) is suitable for controlling the chopper (50A, 50B) for supplying the battery (22) and supplying the electric motor (12A, 12B) from the network.