Inverter-Integrated Motor Compressor Noise Suppression

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Solution Overview

Problem

The integrated-inverter electric compressor faces issues with poor assemblability, increased size, and susceptibility to electromagnetic noise interference due to the co-location of power and control boards with high-voltage components, leading to structural complexity and reduced productivity.

Innovation Solution

Separating the inverter circuit and noise-suppression filter circuit into different accommodating portions with electrical connection via a single pair of busbars, reducing the number of components and welding positions, and optimizing busbar connections to improve layout flexibility and noise suppression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the inverter circuit and noise-suppression filter circuit are accommodated together in the same inverter-accommodating portion, then the structural complexity is reduced, but the electromagnetic noise interference increases and assemblability deteriorates

Engineering Contradiction:
Improvestructural complexityVSAvoidelectromagnetic noise interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the accommodating structure into two separate portions: an inverter-accommodating portion for the inverter circuit and a filter-accommodating portion for the noise-suppression filter circuit. This segmentation physically separates the high-voltage components that generate electromagnetic noise from the sensitive inverter circuit, thereby reducing electromagnetic interference while maintaining structural organization through dedicated housing sections.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the inverter circuit and noise-suppression filter circuit are accommodated together in the same inverter-accommodating portion, then the structural complexity is reduced, but the assemblability deteriorates

Engineering Contradiction:
Improvestructural complexityVSAvoidassemblability
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The patent divides the accommodating structure into two separate portions: an inverter-accommodating portion for the inverter circuit and a filter-accommodating portion for the noise-suppression filter circuit. This segmentation physically separates the high-voltage components that generate electromagnetic noise from the sensitive inverter circuit, thereby reducing electromagnetic interference while maintaining structural organization through dedicated housing sections.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the inverter circuit and noise-suppression filter circuit are separated into different accommodating portions, then the electromagnetic noise interference is reduced, but the device complexity increases

Engineering Contradiction:
Improveelectromagnetic noise interferenceVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the inverter-accommodating portion and filter-accommodating portion into a single integrated housing structure. The housing contains both separate accommodating portions as built-in features, merging the structural support function while maintaining the functional separation of circuits. This reduces overall structural complexity compared to using entirely separate housings for each circuit portion.

Inventive Principle:
Principle #5Merging (Combining)

4Object-affected harmful factors

If multiple pairs of busbars are used to electrically connect the filter circuit and inverter circuit in separate accommodating portions, then the electromagnetic noise interference is reduced, but the number of welded positions increases

Engineering Contradiction:
Improveelectromagnetic noise interferenceVSAvoidproductivity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent combines the electrical connection functions of multiple busbars into a single busbar structure. This single busbar provides both the electrical connection between the filter circuit and inverter circuit and serves as the housing for the filter-accommodating portion. By merging these functions, the number of welded positions is reduced from multiple connections to a single connection, thereby improving productivity while maintaining electromagnetic noise suppression through physical separation of circuits.

Inventive Principle:
Principle #5Merging (Combining)

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 simplifies the structure, reduces electromagnetic noise interference, and enhances productivity by allowing easier assembly and adaptation to specification changes while maintaining reliability.

Implementation Method 1

an inverter unit for converting DC power supplied from a power supply to AC power and applying it to the electric motor so that the rotational speed can be changed

Methodology Applied
Scientific EffectPower conversion (DC to AC):

Implementation Method 2

high-voltage components, such as a capacitor, normal mode coil, and common mode coil, constituting a noise-suppression filter circuit provided on a power line

Methodology Applied
Scientific EffectElectromagnetic noise suppression:

Data Source

PatentEP2461035B1Inverter-integrated motor-driven compressor
Publication Date: 2019.06.19 MITSUBISHI HEAVY IND LTD
  • EP2461035B1 patent drawingFigure 1
  • EP2461035B1 patent drawingFigure 2
  • EP2461035B1 patent drawingFigure 3~4

AI summary

Provided is an integrated-inverter electric compressor with suppressed self-noise interference in an inverter unit, simplified electrical connections between an inverter circuit and a filter circuit, and fewer welded positions. A housing (2) has, on the periphery thereof, an inverter box (5) accommodating the inverter circuit (21) and a junction box (6) communicating with the inverter box (5) and accommodating a plurality of high-voltage components constituting a noise-suppression filter circuit (27). The plurality of high-voltage components accommodated in the junction box (6) are electrically connected via a busbar (33). The busbar (33) includes branched busbars (34) branched off near connections with a high-voltage component installed close to the inverter circuit (21), and the branched busbars (34) are connected to P-N terminals (25) of the inverter circuit (21) in a communicating section (12) between the junction box (6) and the inverter box (5).