Induction Loop for Low-Ohm Wheel-Rail Connection

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Solution Overview

Problem

Existing rail vehicle track occupancy detection systems face reliability issues due to high impedance between wheels and rails, especially when vehicles are parked for long periods, as they require continuous power supply and maintenance to ensure low-impedance connections, which is not feasible without external power and leads to unreliable detection.

Innovation Solution

The implementation of an intermittently fed induction loop with alternating current, which breaks through corrosion layers between wheels and rails, allowing for a low-impedance connection to be maintained with minimal energy consumption, enabling reliable track occupancy detection even when vehicles are stationary for extended periods without external power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous power supply is provided to maintain low-impedance connection, then reliability of track occupancy detection is improved, but energy consumption increases and maintenance requirements increase

Engineering Contradiction:
Improvereliability of track occupancy detectionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by intermittently applying alternating voltage to the induction loop at specific intervals rather than continuously. This periodic voltage application breaks through corrosion layers on wheel-rail contact surfaces, maintaining low-impedance connections while significantly reducing energy consumption compared to continuous power supply.

Inventive Principle:
Principle #19Periodic action

2Reliability

If continuous power supply is provided to maintain low-impedance connection, then reliability of track occupancy detection is improved, but maintenance requirements increase

Engineering Contradiction:
Improvereliability of track occupancy detectionVSAvoidmaintenance requirements
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent implements self-service by using the induction loop system to automatically break through corrosion layers on the wheel-rail contact surfaces through intermittent voltage application. This self-maintaining mechanism keeps the contact surfaces conductive without requiring external maintenance interventions, reducing maintenance requirements while ensuring reliable detection.

Inventive Principle:
Principle #25Self-service

3Reliability

If high current is applied to overcome contact resistance, then track occupancy detection reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvetrack occupancy detection reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of applying high current continuously, the patent uses periodic application of alternating voltage to the induction loop. This periodic action generates sufficient current at specific intervals to break through corrosion layers and establish low-impedance connections, achieving reliable detection with significantly reduced overall energy consumption.

Inventive Principle:
Principle #19Periodic action

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 ensures a reliable low-impedance connection between wheels and rails, allowing for effective track occupancy detection with reduced energy consumption and minimal maintenance, enabling vehicles to be parked or towed without continuous power supply, thus enhancing safety and operational efficiency.

Implementation Method 1

by induction of an electrical voltage in a through the wheels, through sections of at least one of the rails and through electrical connections between wheels formed secondary current loop

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an intermittently fed induction loop with alternating current, which breaks through corrosion layers between wheels and rails, allowing for a low-impedance connection to be maintained

Methodology Applied
Scientific EffectElectrical breakdown of insulating layers: Electrical Discharge Machining

Data Source

PatentEP2380796B1Guarantee of a low-ohm electric connection between wheels of a rail vehicle and rails
Publication Date: 2012.05.23 BOMBARDIER TRANSPORTATION GMBH
  • EP2380796B1 patent drawingFigure 1~2
  • EP2380796B1 patent drawingFigure 3
  • EP2380796B1 patent drawingFigure 4

AI summary

The railway vehicle has an induction loop (1) for verification of low resistive electric connection between wheels (115a-115d,116a-116d) of the railway vehicle and running rails (101,102). A feeder is provided, which connects the electric alternating current voltage to the induction loop in an intermittent manner such that the induction loop is supplied with temporal interruptions with the alternating current. The duration of the temporal interruption of the supply is longer than the duration of the supply of the induction loop occurred before the interruption. An independent claim is also included for a method for operating a railway vehicle.