PoE System Using AC Voltage for Automation

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Solution Overview

Problem

The existing Power over Ethernet (PoE) technology in automation technology is limited by DC power losses and complicates galvanic isolation and safety measures, requiring two independent cables for power and data transmission.

Innovation Solution

A system using an Ethernet-enabled field device with an Ethernet cable capable of transmitting data and power over Ethernet, and power sourcing equipment that transforms alternating voltage to supply power, allowing longer cable lengths and simplified galvanic isolation by using AC voltage instead of DC voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If DC voltage is used for Power over Ethernet, then power can be supplied over Ethernet cable, but power losses increase and cable length is limited

Engineering Contradiction:

Improvepower lossesVSAvoidcable length

Core Design Contradiction:

Loss of energyVSLength of stationary object

Solution Approach 1:

The patent changes the voltage parameter from DC to AC, which fundamentally alters the power transmission characteristics. AC voltage enables longer cable lengths and reduces power losses compared to DC voltage in PoE systems.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If DC voltage is used for Power over Ethernet, then power supply is simplified, but galvanic isolation becomes complicated

Engineering Contradiction:

Improvegalvanic isolation complexityVSAvoidpower losses

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If two independent cables are used (one for power, one for data), then power and data transmission are reliable, but installation costs increase and installation difficulty increases

Engineering Contradiction:

Improveinstallation costVSAvoidpower and data transmission reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent merges power transmission and data transmission into a single Ethernet cable. By using AC voltage on the Ethernet infrastructure, the system combines both functions in one cable while maintaining reliability through the transformer-based galvanic isolation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The Ethernet cable is made multi-functional by enabling it to carry both data signals and AC power simultaneously. This universal cable performs multiple functions that previously required separate dedicated cables.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Length of stationary object

If AC voltage is used instead of DC voltage, then cable length can be extended and galvanic isolation is simplified, but compatibility with standard PoE devices is reduced

Engineering Contradiction:

Improvecable lengthVSAvoidPoE device compatibility

Core Design Contradiction:

Length of stationary objectVSAdaptability or versatility

Solution Approach 1:

The transformer acts as an intermediary device that enables AC voltage transmission over Ethernet cables. It provides galvanic isolation and voltage transformation, serving as a mediator between the AC power source and the Ethernet infrastructure.

Inventive Principle:

Principle #24Intermediary (Mediator)

5Loss of energy

If AC voltage transformation is implemented in power sourcing equipment, then power delivery efficiency improves, but device complexity increases

Engineering Contradiction:

Improvepower delivery efficiencyVSAvoidpower sourcing equipment complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #24Intermediary (Mediator)

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 reduces power losses and simplifies galvanic isolation, enabling efficient power delivery over Ethernet cables, reducing installation costs and improving safety in automation technology.

Implementation Method 1

said power sourcing equipment being arranged so that an input alternating voltage is transformed to a first alternating output voltage, which is provided at said first output port to supply power to the field device over said Ethernet cable

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9838212B2PoE-system for use in automation technology

Publication Date: 2017.12.05 ENDRESS & HAUSER GMBH & CO KG

AI summary

A system for use in automation technology comprising: an Ethernet-enabled field device configured to measure a physical variable, and to generate data representative of the measured physical variable; an Ethernet cable connectable/connected to said field device, wherein said Ethernet cable having PoE (Power over Ethernet) capability so as to both transmit the data from the field device as well as supply power to the field device over the Ethernet cable; and a power sourcing equipment with at least a first output port to which the Ethernet cable is connectable/connected, wherein the power sourcing equipment is arranged so that an input alternating voltage is transformed to a first alternating output voltage, which is provided at the first output port to supply power to the field device over the Ethernet cable.