Compressor Power Factor Correction to Reduce Grid Harmonic Content

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Solution Overview

Problem

Existing HVAC systems using refrigeration circuit systems face challenges in maintaining grid compliance due to harmonic content in current drawn from the grid, which is inefficient and requires additional inductive elements that are costly and space-consuming.

Innovation Solution

A method and system that utilizes an active power factor correction filter to control the compressor system, determining current characteristics of additional loads to compensate for harmonics without modifying the loads, using an inverter and power factor correction filter to manage current drawn from the grid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional inductive elements are used to damp current and reduce harmonic content, then grid compliance is improved, but energy losses increase and installation space is consumed

Engineering Contradiction:

Improvegrid complianceVSAvoidenergy losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The invention changes the operating parameters of the compressor system by using an inverter to control the compressor motor, enabling variable speed operation and soft switching that inherently reduces harmonic content in the current drawn from the grid, eliminating the need for additional inductive damping elements

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical/passive approach of using inductive elements for current damping with an electronic control system (inverter) that actively manages current characteristics through electronic switching and control algorithms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If additional inductive elements are used to damp current and reduce harmonic content, then grid compliance is improved, but device complexity and installation space increase

Engineering Contradiction:

Improvegrid complianceVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inverter serves multiple functions simultaneously: it controls the compressor motor speed, manages power factor correction, and actively reduces harmonic content in the grid current, eliminating the need for separate inductive damping components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the functions of motor control, power factor correction, and harmonic reduction into a single integrated inverter system, simplifying the overall device architecture and reducing installation space requirements

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If additional inductive elements are used to damp current and reduce harmonic content, then grid compliance is improved, but cost increases

Engineering Contradiction:

Improvegrid complianceVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The inverter performs multiple functions including motor control, power factor correction, and harmonic reduction, providing grid compliance capabilities without requiring additional expensive inductive damping elements

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 approach maintains grid compliance while reducing energy losses and installation space, allowing flexible operation under varying conditions without additional components.

Implementation Method 1

a power factor correction filter (PFC) for power factor compensation, which supplies the inverter with direct current

Methodology Applied

Scientific EffectRectification:

Implementation Method 2

an inverter, which supplies the electric motor with single- or multi-phase alternating current

Methodology Applied

Scientific EffectInversion:

Implementation Method 3

an electric motor for providing a mechanical movement for compressing the working medium

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 4

via which the working medium is compressed in order to increase the pressure thereof

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS20260063348A1Method for controlling a compressor system, compressor for compressing a working medium, compressor system and refrigeration circuit system for carrying out a refrigeration cycle process

Publication Date: 2026.03.05 VIESSMANN HOLDING INTERNATIONAL GMBH

AI summary

A method for controlling a compressor system includes an electrically operated compressor for compressing a working medium, and a further electrical load. The compressor includes an electric motor for compressing the working medium, an inverter supplying the electric motor with single- or multi-phase alternating current, a power factor correction filter (PFC) supplying the inverter with direct current and whose current input for supplying power to the compressor connects to a grid current source providing alternating current. For supplying power thereto the further electrical load connects to the same grid connection point as the power factor correction filter. The method includes operating the compressor system with electrical current from the grid current source, determining at least one current characteristic value of the further load, and controlling the power factor correction filter of the compressor at least in dependence of the determined at least one current characteristic value of the further load.