Wayside Communication via Power Grid Return Path
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Solution Overview
Problem
Existing railway communication systems using rail-to-rail current transmission face significant signal degradation over long distances due to weather and rail conditions, leading to unreliable communication.
Innovation Solution
A communication system utilizing coded current signals transmitted through one or both running rails of a railroad track, with wayside control devices connected to both the rails and a power line, allowing signal exchange and return via the power line, thereby bypassing rail-to-rail current leakage issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rail-to-rail current transmission is used for communication, then communication between wayside installations is enabled, but signal degradation occurs over long distances due to current leakage
Solution Approach 1:
The patent introduces a third conductor (power line) as an intermediary to carry the return current, eliminating the need for rail-to-rail current flow. This mediator (power line) handles the return path, allowing the rails to be used solely for signal transmission without leakage issues, thus enabling reliable long-distance communication.
Solution Approach 2:
The power line serves dual functionality: it provides electrical power to wayside installations and simultaneously serves as the return path for communication signals. This multi-functionality eliminates the need for dedicated communication infrastructure while solving the signal degradation problem.
2Reliability
If rail-to-rail current transmission is used, then communication is possible, but signal leakage to earth and between rails degrades the signal
Solution Approach 1:
The power line acts as an intermediary that captures the return current before it can leak to earth or between rails. By providing a controlled return path through the power line, the system eliminates uncontrolled current leakage and associated energy losses.
3Reliability
If differential rail signals are used for communication, then signal transmission is achieved, but additional communication lines or insulated joints are required
Solution Approach 1:
The existing power line infrastructure is utilized for dual purposes: power delivery and signal return path. This eliminates the need for additional communication lines, insulated joints, or specialized infrastructure, thereby reducing system complexity while maintaining reliable signal transmission.
Solution Approach 2:
The power distribution network serves itself by simultaneously providing power and communication pathways. The existing power lines are repurposed to carry both electrical power and signal return currents, eliminating the need for separate communication infrastructure.
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 reliable long-distance signal transmission without relying on differential rail signals, using the AC power grid as a return path, reducing signal limitations to series inductance and eliminating the need for insulated joints or additional communication lines.
Implementation Method 1
transmitting the coded current signal from the first wayside control device to the second wayside control device via the running rail
Implementation Method 2
returning the decoded current signal back to the first wayside control device via the power supply connections and the power line thus closing the current signal flow loop
Data Source
AI summary
A wayside communication system for transmitting coded current signals through running rails of a railroad track between wayside control devices. A power line common to the wayside control devices is used as the return path for the current signals. The system features train and broken rail detection. The system allows sending signals long distances since rail to rail current leakage is no longer an issue.