Electrocaloric Device Voltage Modulation for Adaptive Temperature Lift

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Solution Overview

Problem

Existing electrocaloric systems face efficiency decreases when the target temperature lift is reduced, as they are often optimized for specific conditions and lack the ability to modulate temperature lift, leading to inefficient operation when conditions change.

Innovation Solution

An electrocaloric system that determines the internal temperature lift and modulates the voltage applied to the electrocaloric device based on the difference between the current and heat rejection temperatures, allowing for efficient operation across varying target temperature lifts by adjusting the voltage and switching frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electrocaloric device operates at a fixed voltage optimized for a specific temperature lift, then it achieves high efficiency at that specific condition, but efficiency decreases when the target temperature lift changes

Engineering Contradiction:
Improveenergy efficiencyVSAvoidadaptability to varying temperature lifts
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic voltage modulation to the electrocaloric device based on real-time temperature differential feedback. The controller adjusts the voltage level according to the difference between the heat rejection temperature and the desired space temperature, enabling the system to adapt to varying temperature lift requirements while maintaining optimal energy efficiency across different operating conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the electrical parameter (voltage) applied to the electrocaloric device in response to changing thermal conditions. By modulating the voltage based on the calculated temperature lift requirements, the system optimizes the electrocaloric effect to match the actual cooling or heating demand, thereby maintaining high efficiency across a range of temperature lifts

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the voltage applied to the electrocaloric device is increased to achieve higher temperature lift, then the temperature difference increases, but energy consumption increases

Engineering Contradiction:
Improvetemperature liftVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The system employs feedback control by continuously monitoring the heat rejection temperature and the desired space temperature, calculating the actual temperature lift required, and adjusting the voltage applied to the electrocaloric device accordingly. This feedback mechanism ensures that voltage is increased only to the extent necessary to achieve the required temperature differential, minimizing energy consumption while maintaining the needed temperature lift

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system applies partial voltage modulation rather than maximum voltage continuously. By applying only the necessary voltage to achieve the required temperature lift and using modulation to match the actual demand, the system avoids excessive energy consumption while still achieving the required temperature difference when needed

Inventive Principle:
Principle #16Partial or excessive 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

Maintains high efficiency by varying the voltage and switching frequency in response to changing temperature demands, ensuring effective cooling or heating while maintaining a target temperature band.

Implementation Method 1

several technologies have been investigated for heat pump, air conditioning, and/or other energy conversion applications. These technologies include the use of electrocaloric energy conversion

Methodology Applied
Scientific EffectElectrocaloric effect: Electrocaloric Effect

Data Source

PatentEP3805669B1Electrocaloric device and control system thereof
Publication Date: 2023.05.24 PALO ALTO RESEARCH CENTER INC
  • EP3805669B1 patent drawingFigure 1A
  • EP3805669B1 patent drawingFigure 1B
  • EP3805669B1 patent drawingFigure 2

AI summary

A method for operating an electrocaloric system includes determining an internal temperature lift of an electrocaloric device. A current temperature of a space to be cooled is determined. A heat rejection temperature is determined. A difference between the current temperature and the heat rejection temperature is determined. A target temperature lift is determined based on the difference and a target temperature for the space. A voltage applied to the electrocaloric device is modulated based on the internal temperature lift and the target temperature lift.