Active filter device, air conditioning device, and air conditioning system

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Solution Overview

Problem

Existing air conditioning systems and connected loads, such as inverter circuits, generate harmonic currents that are not adequately addressed by current technologies, necessitating a solution to reduce harmonic currents and improve fundamental power factors to reduce facility capacity and energy consumption.

Innovation Solution

An active filter device is integrated into air conditioners, comprising a current source and controller that detect and generate compensation currents to counteract harmonic currents and improve power factors, allowing for sinusoidal wave currents and reducing harmonic currents and enhancing fundamental power factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If only the harmonic current from the air conditioner is addressed, then the air conditioner's power quality is improved, but harmonic currents from other connected loads remain untreated

Engineering Contradiction:
Improveharmonic current from air conditionerVSAvoidability to handle multiple load sources
Core Design Contradiction:
Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The active filter device is designed to function not only for the air conditioner but also for other connected loads. The controller detects harmonic currents from multiple sources and the current source generates compensation currents that address harmonics from any connected load, making the device universal for multi-load environments.

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

Solution Approach 2:

The active filter device acts as an intermediary between the power system and multiple loads. It detects harmonic currents from various sources through the common power connection and injects compensation currents to cancel out harmonics from any connected load, serving as a mediator that protects the entire system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If facility capacity and energy consumption are reduced through power factor improvement, then operational efficiency is improved, but the system becomes more sensitive to power quality issues

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem sensitivity to power quality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The controller continuously detects the actual current waveform and power quality parameters, compares them with ideal values, and adjusts the compensation current generation accordingly. This feedback mechanism ensures that even with reduced facility capacity, the system maintains high reliability by dynamically responding to power quality variations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes operational parameters such as compensation current magnitude and phase angle based on detected power quality conditions. By adjusting these parameters in real-time, the system optimizes energy consumption while maintaining reliability under varying load conditions and power quality scenarios.

Inventive Principle:
Principle #35Parameter changes

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 active filter device effectively reduces harmonic currents and improves fundamental power factors in air conditioning systems, even when connected with other loads, thereby optimizing energy efficiency and facility capacity.

Implementation Method 1

an active filter device which includes a current source 30 and a controller 40. The controller 40 controls an output current of the current source 30 so as to compensate for a harmonic current appearing in a power receiving path 12

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP3511797B1Active filter device, air conditioning device, and air conditioning system
Publication Date: 2024.11.06 DAIKIN INDUSTRIES LTD
  • EP3511797B1 patent drawingFigure 1
  • EP3511797B1 patent drawingFigure 2
  • EP3511797B1 patent drawingFigure 3

AI summary

A current source (30) capable of generating a current of a first compensation portion (i1) for either or both reducing a harmonic current in an air conditioner (10) or improving a fundamental power factor in the air conditioner (10) is provided. If an excess (res) of the current source (30) is larger than a second compensation portion (i2) for either or both reducing a harmonic current in a power receiving path (61) of a distribution board (60) or improving a fundamental power factor in the power receiving path (61) of the distribution board (60), a current obtained through superimposition of a current of a second compensation component (i2) and a current of the first compensation component (i1) is generated in the current source (30).