Buried Inductive Power Transfer for Track-Bound Vehicles
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Solution Overview
Problem
Existing systems for transferring electric energy to track-bound vehicles, such as trams, face challenges in providing continuous energy supply while meeting electromagnetic compatibility (EMC) limits and ensuring safety, particularly in historic city areas where overhead lines are undesirable and conductor rails pose safety risks.
Innovation Solution
A system that uses an electric conductor arrangement along the track to produce an alternating current electromagnetic field, allowing for continuous energy transfer to vehicles without physical contact, with the conductor arrangement buried underground or alongside the track, utilizing a serpentine configuration of lines to minimize electromagnetic field intensity sideways and ensure compliance with EMC limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If inductive energy transfer is used to continuously supply power to the vehicle along the track, then continuous energy transfer is achieved, but electromagnetic field intensity increases causing EMC issues and exposure to pedestrians and animals
Solution Approach 1:
The conductor arrangement is divided into multiple sections along the track, with each section capable of being independently activated. Only the section currently occupied by a vehicle is energized, while other sections remain inactive. This segmentation allows continuous energy transfer to moving vehicles while minimizing the overall electromagnetic field exposure in any given location along the track.
Solution Approach 2:
The conductor sections are activated periodically as vehicles pass through different zones. Each section is energized only when needed (when a vehicle is present) and deactivated when not in use. This periodic activation pattern enables continuous energy supply to moving vehicles while reducing cumulative electromagnetic exposure to pedestrians and animals in the environment.
2Reliability
If overhead lines are used to supply power to track-bound vehicles, then reliable power transfer is achieved, but aesthetic and historical preservation concerns arise in historic city areas
Solution Approach 1:
The power supply system is extracted from the visible overhead space and relocated underground. The conductor arrangement is buried in the ground alongside or under the track, eliminating the visual impact of overhead lines while maintaining reliable power transfer through inductive coupling between the buried conductors and vehicle receivers.
Solution Approach 2:
The ground itself serves as an intermediary medium, concealing the conductor arrangement while allowing electromagnetic energy to pass through to the vehicles. The buried conductors transfer power through the earth without visible infrastructure, preserving historical aesthetics while ensuring reliable power delivery.
3Duration of action of moving object
If conductor rails are used for power supply, then continuous power transfer is achieved, but safety problems arise for pedestrians and animals
Solution Approach 1:
The conductive elements are extracted from the ground surface and relocated to underground positions. The conductor arrangement is buried alongside or under the track, eliminating exposed conductive rails that could pose electrocution risks to pedestrians and animals while maintaining continuous power transfer capability through inductive coupling.
Solution Approach 2:
The conductor arrangement is enclosed within the ground matrix, effectively using the earth as a protective shell. This burial approach isolates the conductive elements from direct contact with pedestrians and animals, eliminating safety hazards while preserving the continuous power transfer function.
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
Enables efficient and safe continuous energy transfer to vehicles, reducing wear on contactors, minimizing electromagnetic interference, and adhering to EMC standards, while allowing for high-power energy delivery with low electromagnetic field exposure to pedestrians and animals.
Implementation Method 1
energy is transferred from an electric conductor arrangement, which is arranged along the track, to the vehicle travelling on the track without having electric contact between the vehicle and the conductor arrangement. The conductor arrangement carries an alternating current which generates a respective electromagnetic field and the electromagnetic field is used to transfer the electric energy to the vehicle
Data Source
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AI summary
The invention relates to a system for transferring electric energy to a track bound vehicle, in particular to a light rail vehicle, such as a tram, wherein the system comprises an electric conductor arrangement (12) for producing an electromagnetic field and for thereby transferring the energy to the vehicle, the electric conductor arrangement (12) comprises at least one line (1, 2, 3) for carrying one phase of an alternating voltage or current, the line (1, 2, 3) extends along the track, the line (1, 2, 3) is arranged in such a manner that it produces - at each point in time while the alternating electric current is flowing through the line (1, 2, 3) - a row of successive magnetic poles (at sections 5) of an electromagnetic field, wherein the successive magnetic poles have alternating magnetic polarities, the row of successive magnetic poles extends in the travel direction of the vehicle which is defined by the track.