Photovoltaic Coupler Test Module for Railway Signaling

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Solution Overview

Problem

Intrinsically safe systems for railway signaling and other critical applications face challenges due to high development and production costs, limited lifespan of electromechanical relays, and intrusive testing methods that can compromise device safety and accuracy.

Innovation Solution

A test module utilizing an isolated photovoltaic coupler to charge a storage capacitor, which powers the circuit under test with minimal disturbance, allowing for efficient diagnosis of current leaks and triggering safety measures, and is designed for both input and output testing with a network of interconnected switches for redundancy and control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromechanical relays are used to secure digital circuit outputs, then reliability is improved, but device complexity and maintenance requirements increase due to limited operating cycles

Engineering Contradiction:
Improvecircuit output securityVSAvoidrelay network complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces electromechanical relays with solid-state electronic components, specifically using a microcontroller unit and electronic switching elements to perform the same output securing function. This substitution eliminates the mechanical moving parts that limit relay lifespan, thereby maintaining reliability while reducing device complexity and maintenance requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention employs solid-state components with significantly longer operational lifespans compared to electromechanical relays. These electronic components can endure far more operating cycles without degradation, effectively replacing the 'short-living' relays with durable solid-state alternatives that reduce maintenance frequency and improve overall system reliability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If intrusive testing methods are used to diagnose component failures, then measurement precision is improved, but device operation stability deteriorates due to power supply disturbances

Engineering Contradiction:
Improvefailure diagnosis accuracyVSAvoiddevice operation stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent implements preliminary diagnostic actions that assess component health without fully activating test sequences. The system performs preliminary checks on power supply stability and component responsiveness before initiating comprehensive intrusive tests, thereby preventing unnecessary disturbances to device operation while still achieving accurate failure diagnosis when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention employs partial testing methods that apply test signals at reduced power levels or for limited durations, sufficient to detect failures without causing the full disturbances associated with complete intrusive testing. This partial action approach maintains measurement precision for failure detection while minimizing impact on device operation stability.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If periodic tests are conducted to diagnose component failures, then reliability is improved, but productivity deteriorates due to operational interruptions

Engineering Contradiction:
Improvecomponent failure diagnosisVSAvoiddevice operational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements periodic diagnostic testing with optimized intervals that balance reliability monitoring with productivity maintenance. The system performs tests at strategically determined intervals based on component criticality and historical failure data, ensuring adequate reliability monitoring while minimizing operational interruptions compared to more frequent testing schedules.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The invention enables the system to perform self-diagnosis during normal operation using spare capacity and idle periods. The diagnostic functions utilize existing operational signals and components to assess system health without requiring dedicated test time, thereby maintaining reliability monitoring while avoiding productivity loss from separate testing operations.

Inventive Principle:
Principle #25Self-service

4Reliability

If photovoltaic couplers are used for intrinsic safety, then safety characteristics are improved, but device complexity increases due to additional components

Engineering Contradiction:
Improveintrinsic safetyVSAvoidcircuit configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the photovoltaic coupler functionality with existing power supply and control circuitry in the device. By integrating the isolating function into already-present components rather than adding separate dedicated isolating modules, the system achieves intrinsic safety through photovoltaic coupling while minimizing the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention designs the photovoltaic coupler to serve multiple functions simultaneously: providing galvanic isolation for intrinsic safety, generating power for isolated circuit sections, and enabling bidirectional signal transmission. This multi-functionality reduces the need for additional separate components, thereby maintaining safety improvements while limiting complexity increases.

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

The solution provides a cost-effective, compact, and safe power supply for testing, enabling efficient diagnosis and optimal safety measures without disrupting the operation of the devices, with the ability to detect current leaks and trigger alerts or backup systems as needed.

Implementation Method 1

a power supply means comprising an isolated photovoltaic coupler which, during the test, charges a storage means of energy

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP2187227B1System with intrinsic safety and test module, in particular for use in a railway signalling system
Publication Date: 2018.09.12 THALES SA
  • EP2187227B1 patent drawingFigure 1~2
  • EP2187227B1 patent drawingFigure 3A~3B
  • EP2187227B1 patent drawingFigure 4

AI summary

The system (200) has a test module for a component i.e. switch, to be tested, where the switch is selected from one of a negative channel MOSFET and a positive channel MOSFET. The test module includes a power supply unit that includes an insulated photovoltaic coupler (101) to charge an energy storage capacitor (106) that discharges in a component under test, where the component is tested by charging the energy storage capacitor and discharging the energy storage capacitor. A measuring unit (207) measures a charge state of the energy storage capacitor. An independent claim is also included for a railway signaling system comprising an intrinsic safety system.