Compressor-Thermostat Power-Line Communication for Single-Cable Control

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Solution Overview

Problem

Current data communication systems between variable capacity compressors and electronic thermostats in cooling systems are inefficient and costly, often requiring multiple cables and complex hardware arrangements for bidirectional or unidirectional communication.

Innovation Solution

A data communication system utilizing a single electrical cable that modulates the alternating voltage source's voltage or current values to enable bidirectional data exchange between the electronic thermostat and frequency inverter, leveraging the electrical network as a reference for communication, thereby reducing the number of cables and hardware requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple cables and complex hardware arrangements are used for data communication between variable capacity compressor and electronic thermostat, then communication reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidhardware complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines power transmission and data communication functions into a single electrical cable. The power cable carries both the alternating voltage power supply and the modulated data signals, eliminating the need for separate communication cables and reducing hardware complexity while maintaining communication reliability through voltage modulation techniques

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The electrical cable is designed to serve multiple functions simultaneously: it provides power transmission to both the compressor and thermostat, and enables bidirectional data communication between them. This multi-functionality reduces the number of components needed and simplifies the overall system architecture

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

2Reliability

If multiple cables are used for data communication, then communication capability is improved, but quantity of components and stock items increases

Engineering Contradiction:
Improvecommunication capabilityVSAvoidnumber of cables
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges power transmission and data communication into a single cable infrastructure. By modulating the voltage of the power cable, the system achieves bidirectional communication without requiring additional communication cables, thereby reducing the quantity of components and stock items needed

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a single cable is used for both power and communication, then device complexity is reduced, but insulation requirements become more demanding

Engineering Contradiction:
Improvecable quantityVSAvoidinsulation requirements
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces voltage modulation as an intermediary mechanism to enable data communication through the power cable without compromising insulation requirements. By encoding data in voltage variations of the existing power signal, the system avoids the need for additional insulation layers or specialized high-voltage communication cables

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 allows for efficient and cost-effective data communication, reducing the number of connections and stock items needed, while enabling the use of a single cable with less demanding insulation characteristics, and supporting both complex command exchanges and simple on/off commands.

Implementation Method 1

the electronic transmitter device being capable of modulating a voltage value or a current value of the alternating voltage source

Methodology Applied
Scientific EffectVoltage modulation: Phase Modulation

Implementation Method 2

the electronic receptor device being capable of demodulating the voltage value or the current value of the alternating voltage source

Methodology Applied
Scientific EffectDemodulation: Phase Modulation

Data Source

PatentEP2491322B1Data and commands communication system and method between variable capacity compressor and electronic thermostat for a cooling system
Publication Date: 2016.06.08 WHIRPOOL SA
  • EP2491322B1 patent drawingFigure 1
  • EP2491322B1 patent drawingFigure 2
  • EP2491322B1 patent drawingFigure 3

AI summary

The present invention refers to a data and commands communication system between compressor and electronic thermostat, particularly applied to cooling systems having variable capacity compressor (VCC), with the purpose of providing an exchange of data between said equipment which is technically more efficient and less costly compared to the solutions available today. Accordingly, there is described a data communication system between variable capacity compressor and electronic thermostat for a cooling system, the compressor comprising at least a frequency inverter unit (100) electrically associated to an electrical motor of the compressor, the electronic thermostat (200) being electrically associated to the frequency inverter unit (100), the electronic thermostat (200) and the frequency inverter unit (100) being powered by an alternating voltage source (15), the data communication system comprising a data communication single highway (50) between the electronic thermostat (200) and the inverter unit (100), arranged to establish an exchange of data between the thermostat (200) and the inverter unit (100), the exchange of data between the thermostat (200) and the inverter unit (100) being provided by the modulation of an electrical magnitude (Snetwork) of the alternating voltage source (15), the modulation of the electrical magnitude (Snetwork) of the alternating voltage source (15) being capable of configuring a modulated information signal (Sx), the exchange of data between the thermostat (200) and the inverter unit (100) being provided by a demodulation of the modulated information signal (Sx).