Air-Conditioning Demand Control With Grouped Shut-Off Scheduling

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Solution Overview

Problem

Existing air-conditioning control methods using intermittent shut-off operations struggle to balance power reduction with maintaining a comfortable indoor environment, especially when external and internal conditions change constantly, leading to potential comfort deterioration.

Innovation Solution

A demand control device that groups indoor units, estimates reducible power based on low power operations, predicts power consumption, and calculates targeted power reductions to distribute evenly among groups, ensuring air-conditioning control without exceeding target demand power while minimizing comfort loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If intermittent shut-off operation is performed to reduce power consumption, then power consumption amount is reduced, but indoor environmental comfort deteriorates

Engineering Contradiction:

Improvepower consumption amountVSAvoidindoor environmental comfort

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent divides indoor units into multiple groups and performs intermittent shut-off operations on a per-group basis rather than shutting off all units simultaneously. This segmentation allows different groups to operate at different times, ensuring that at least some units continue to provide cooling while others are shut off to reduce overall power consumption, thus balancing energy reduction with comfort maintenance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic intermittent shut-off operations where groups of indoor units are cyclically shut off and restarted. By calculating appropriate shut-off periods and distributing operations across multiple groups over time, the system reduces average power consumption while ensuring that cooling is periodically restored to maintain acceptable indoor environmental comfort.

Inventive Principle:

Principle #19Periodic action

2Device complexity

If constant is used for calculation expression of power amount to be reduced, then calculation is simplified, but prediction accuracy deteriorates when external conditions change

Engineering Contradiction:

Improvecalculation complexityVSAvoidpower consumption prediction accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces static constant values in power consumption calculations with dynamic parameters that adapt to changing external conditions. Specifically, it uses current outdoor temperature, humidity, and other environmental factors that are updated in real-time, allowing the power consumption prediction and shut-off calculation to automatically adjust when weather conditions change, thereby maintaining high prediction accuracy without excessive calculation complexity.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If solar radiation amount measured N hours before demand time limit is used, then calculation is simplified, but prediction accuracy deteriorates when weather conditions change constantly

Engineering Contradiction:

Improvedata processing complexityVSAvoidpower consumption prediction accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary calculations of power consumption and shut-off timing at the start of each demand time limit period rather than relying on outdated historical data. By calculating the required power reduction and shut-off schedule in advance based on current weather conditions and predicted load, the system ensures accurate predictions even when weather changes constantly, while keeping data processing complexity manageable through efficient algorithms.

Inventive Principle:

Principle #10Preliminary action

4Object-affected harmful factors

If indoor temperature setting is changed according to number of persons, then comfort is optimized, but control complexity increases

Engineering Contradiction:

Improveindoor environmental comfortVSAvoidcontrol system complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements automatic detection of occupancy conditions and automated adjustment of temperature settings and shut-off schedules without requiring manual intervention. The system self-adjusts by detecting the number of persons in each room and automatically optimizing temperature settings and group shut-off timing, thereby maintaining high comfort levels while avoiding the complexity of manual control configurations.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10180672B2Demand control device and computer readable medium

Publication Date: 2019.01.15 MITSUBISHI ELECTRIC CORP

AI summary

There is provided air-conditioning control in a low power operation so as not to exceed a target demand power amount in a predetermined measurement period while preventing deterioration of comfortableness of a living space. There include a reducible-power-amount estimation unit configured to calculate, for each group, a reducible power amount by making indoor units perform, for each group, a shut-off operation for a minimum shut-off time in the first half of a demand time limit, and a reduced-power-amount determination unit configured to distribute, when a power consumption amount predicted by a power consumption amount prediction unit exceeds a target demand power amount after the first half of the demand time limit passes, the exceeding power amount to each zone, evenly distribute, in each zone, the distributed power amount to each group, and calculate, based on the reducible power amount of each group, a shut-off time of each group when each group performs the shut-off operation to reduce the distributed power amount.