Combined Power and Communication Cable with Segmented Shielding

Solution Overview

Problem

Current industrial control systems require multiple cables for power delivery and communication with motors, leading to increased cost and complexity, while attempts to combine these in a single cable are limited by electrical noise and interference, affecting signal integrity and system reliability.

Innovation Solution

A combined power and communications cable design that groups power delivery and communication conductors, uses electrical shielding and specific fillers to minimize noise and interference, ensuring high voltage power delivery with low voltage data communication over the same cable, maintaining signal integrity and system durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate cables are used for power delivery and communication, then signal integrity and system reliability are maintained, but device complexity and installation cost increase due to doubled cables and connectors

Engineering Contradiction:

Improvesignal integrityVSAvoidnumber of cables and connectors

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines power delivery conductors and communication conductors into a single cable assembly. The cable includes three insulated conductors for three-phase power and two insulated conductors for differential communication signals, all contained within one jacket. This merging reduces the number of cables and connectors while maintaining signal integrity through strategic conductor grouping and shielding.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The cable is segmented into distinct functional groups: power conductors are grouped together in a power triad, communication conductors are grouped in a communication pair, and a ground conductor is separated. Each group is twisted together and provided with separate shielding. This segmentation allows each group to be optimized for its specific function while reducing electromagnetic interference between groups.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If power and communication conductors are combined in a single cable, then device complexity is reduced, but electrical noise and interference increase affecting signal integrity

Engineering Contradiction:

Improvenumber of cablesVSAvoidelectrical noise and interference

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The cable is segmented into distinct functional groups: power conductors are grouped together in a power triad, communication conductors are grouped in a communication pair, and a ground conductor is separated. Each group is twisted together and provided with separate shielding. This segmentation allows each group to be optimized for its specific function while reducing electromagnetic interference between groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical shields act as intermediaries between the power conductors and communication conductors. The shields are positioned to block electromagnetic fields from the high-voltage power conductors from coupling onto the low-voltage communication conductors, thereby minimizing noise and interference while allowing both functions to coexist in the same cable.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If communication conductors are placed near power conductors to reduce cable size, then device complexity is reduced, but capacitive coupling and signal integrity loss increase

Engineering Contradiction:

Improvecable structureVSAvoidsignal integrity loss

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The cable is segmented into distinct functional groups: power conductors are grouped together in a power triad, communication conductors are grouped in a communication pair, and a ground conductor is separated. Each group is twisted together and provided with separate shielding. This segmentation allows each group to be optimized for its specific function while reducing electromagnetic interference between groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical shields act as intermediaries between the power conductors and communication conductors. The shields are positioned to block electromagnetic fields from the high-voltage power conductors from coupling onto the low-voltage communication conductors, thereby minimizing noise and interference while allowing both functions to coexist in the same cable.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Device complexity

If high voltage power is delivered through the same cable as low voltage communication, then device complexity is reduced, but electrical interference and system reliability decrease

Engineering Contradiction:

Improvecable configurationVSAvoidsystem reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The cable is segmented into distinct functional groups: power conductors are grouped together in a power triad, communication conductors are grouped in a communication pair, and a ground conductor is separated. Each group is twisted together and provided with separate shielding. This segmentation allows each group to be optimized for its specific function while reducing electromagnetic interference between groups.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Electrical shields act as intermediaries between the power conductors and communication conductors. The shields are positioned to block electromagnetic fields from the high-voltage power conductors from coupling onto the low-voltage communication conductors, thereby minimizing noise and interference while allowing both functions to coexist in the same cable.

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

The solution effectively reduces the number of cables needed, minimizing electrical noise and interference, thereby enhancing signal integrity and system reliability while maintaining the durability of the industrial control system.

Implementation Method 1

grouping and electrically shielding communications conductors minimizes capacitive coupling effects and resulting signal integrity loss

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

grouping power delivery conductors together into a power triad minimizes their inductive coupling effects onto grouped, neighboring communications conductors

Methodology Applied

Scientific EffectInductive coupling: Electromagnetic Induction

Implementation Method 3

first, second and third insulated conductors twisted together around a common center... fourth and fifth insulated conductors twisted together around a common center

Methodology Applied

Scientific EffectElectromagnetic interference: Electromagnetic Induction

Data Source

PatentUS9018529B2Single motor power and communication cable

Publication Date: 2015.04.28 ROCKWELL AUTOMATION TECH INC

AI summary

A combined power and communications cable for use with a motor and drive unit in an industrial control system is provided. The cable may comprise first, second and third insulated conductors twisted together and covered by a cable jacket (first group); fourth and fifth insulated conductors twisted together and covered by an electrical shield (second group); and a sixth insulated conductor for delivering a protective ground (third group). The first, second and third groups are twisted together, covered by an electrical shield and covered by a cable jacket. Filler may be formed around the fourth and fifth insulated conductors, and may be formed around the first, second and third groups, to substantially maintain round geometric shapes.