Bidirectional DC-Isolated Transmission Channel for Hazardous Areas

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Solution Overview

Problem

Existing methods for transmitting direct and alternating current signals between two systems require multiple galvanically isolated channels, which are expensive and space-consuming, and often cannot support simultaneous transmission of current and voltage signals due to power interference and amplifier saturation.

Innovation Solution

A bidirectional, galvanically isolated transmission channel using a direct current transformer with an isolating converter and an electronic I/I or I/U converter, allowing simultaneous transmission of direct and alternating current signals over a single two-wire channel, with an alarm signal generator for detecting voltage changes as notification signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two galvanically isolated channels are used for transmitting measurement and status signals, then signal transmission reliability is improved, but device complexity and space requirements increase

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidchannel configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate galvanically isolated channels into a single two-wire channel that can simultaneously transmit both measurement signals and status signals bidirectionally. The isolating converter with primary and secondary circuits enables this merging while maintaining galvanic isolation, thereby reducing device complexity and space requirements while preserving transmission reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single two-wire channel is designed to perform multiple functions: transmitting measurement signals from the first system to the second system, transmitting status signals from the second system to the first system, and providing galvanic isolation. This multi-functionality eliminates the need for separate dedicated channels for each signal type.

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

2Area of stationary object

If a voltage converter is used for galvanic isolation in a two-line channel, then space requirements are reduced, but active current outputs cannot be connected due to power interference

Engineering Contradiction:
Improvechannel space occupationVSAvoidcompatibility with active current outputs
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The isolating converter dynamically adapts its operation based on the connected load requirements. It can operate in different modes to accommodate both passive and active current outputs, adjusting its power conversion characteristics to prevent interference while maintaining compatibility with various device types.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the isolating converter to enable compatibility with active current outputs. By adjusting voltage and current parameters dynamically and implementing bidirectional power flow capability, the system can connect active current outputs without power interference issues.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If control and feedback signals follow each other sequentially in a two-wire channel, then device complexity is reduced, but simultaneous transmission of current and voltage signals is not possible

Engineering Contradiction:
Improvesignal transmission structureVSAvoidsignal transmission speed
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements periodic switching action in the isolating converter to enable simultaneous bidirectional signal transmission. By using pulse-width modulation and periodic switching of the primary and secondary circuits, the system can transmit control signals and feedback signals concurrently in different time slots or frequency bands, achieving both reduced complexity and high transmission speed.

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

Enables efficient, space-saving transmission of both measurement and notification signals between systems without the need for additional isolated channels, supporting active current outputs and preventing power interference, thus facilitating effective communication in hazardous and non-hazardous areas.

Implementation Method 1

a direct current transformer (4) including an isolating converter (3) with a primary circuit (45) and a secondary circuit (46), which is operated for signal transmission with direct current signals in short circuit, the direct current transformer converting direct current signals into alternating current signals and converting them back into direct current signals

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2002413B1Bidirectional, DC-isolated transmission channel
Publication Date: 2012.08.08 PHOENIX CONTACT GMBH & CO KG
  • EP2002413B1 patent drawingFigure 1
  • EP2002413B1 patent drawingFigure 2
  • EP2002413B1 patent drawingFigure 3

AI summary

Arrangement and method for the electrically isolated transmission of DC and AC signals. The signals can be transmitted in both directions using the same and only available DC-isolated channel. The arrangement comprises a first transmission and reception system (1), a DC transformer (4) in shorted mode, an operation amplifier arrangement (5) and a second transmission and reception system (2) with an event signal generator (9).