Inverter Module Insulating Through Hole Noise Interference

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Solution Overview

Problem

Existing inverter integrated electric compressors face insufficient protection against electromagnetic noise interference between the high voltage and low voltage circuits, leading to potential malfunctions despite enhanced moisture-proof and vibration-proof properties.

Innovation Solution

An insulating through hole is provided between the frame ground connected to the high voltage system and the low voltage circuit on the control circuit board, increasing the insulating distance and allowing the resin gel material to fill and cover the area, effectively blocking electromagnetic noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a shield plate is provided between the control circuit board and high voltage circuit, then noise interference between the control circuit board and high voltage circuit is prevented, but electromagnetic noise can still propagate from the frame ground to the low voltage circuit

Engineering Contradiction:
Improveelectromagnetic noise interferenceVSAvoidcontrol circuit stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The control circuit board is segmented into distinct high voltage and low voltage regions, with the frame ground physically divided into separate high voltage ground and low voltage ground areas. This segmentation prevents noise propagation by creating isolated electrical zones on the same board.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A resin gel material is introduced as an intermediary substance filling the space between high voltage and low voltage circuits. This gel acts as an electromagnetic shielding medium that blocks noise propagation while allowing the compact inverter module design to be maintained.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the inverter apparatus is compactly integrated in the inverter accommodating part, then space efficiency is improved, but sufficient noise blocking and electrical insulating performance becomes difficult to achieve

Engineering Contradiction:
Improveinverter apparatus sizeVSAvoidelectromagnetic noise propagation
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The inverter module merges the power system circuit board and control circuit board into a single integrated unit housed together in one inverter accommodating part. This consolidation achieves compact space utilization while maintaining noise isolation through proper circuit board layout and grounding segmentation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Different regions of the control circuit board are assigned different electrical characteristics - high voltage areas use one grounding scheme while low voltage areas use another. This local differentiation of electrical properties allows compact integration while preventing noise propagation between different voltage zones.

Inventive Principle:
Principle #3Local quality

3Reliability

If resin gel material is used for filling, then moisture-proof and vibration-proof properties are enhanced, but electromagnetic noise blocking performance is insufficient without additional shielding structures

Engineering Contradiction:
Improvemoisture-proof and vibration-proof propertiesVSAvoidelectromagnetic noise interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The inverter module employs a composite protection approach combining resin gel material with electromagnetic shielding structures. The resin gel provides moisture and vibration protection while the shielding structures (frame ground segmentation and low voltage circuit shielding) provide electromagnetic noise blocking, creating a multi-functional protection system.

Inventive Principle:
Principle #40Composite materials

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 configuration enhances electrical insulating performance, prevents noise interference, and ensures reliable operation by blocking electromagnetic noise from propagating to the low voltage circuit, thereby improving the overall reliability of the inverter apparatus and compressor.

Implementation Method 1

the inverter apparatus is also required to have high vibration-proof properties, moisture-proof properties, and electrical insulating properties

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

it is necessary to block electromagnetic noise to thereby improve the stability of the control circuit

Methodology Applied
Scientific EffectElectromagnetic noise blocking: Absorption (EM radiation)

Implementation Method 3

the power system circuit board is sealed with a thermosetting resin that fills the resin case up to a position at which the thermosetting resin covers an upper surface of the power system circuit board

Methodology Applied
Scientific EffectThermosetting:

Data Source

PatentEP2629412B1Inverter module and inverter integrated motor-driven compressor
Publication Date: 2020.02.26 MITSUBISHI HEAVY IND LTD
  • EP2629412B1 patent drawingFigure 1
  • EP2629412B1 patent drawingFigure 2
  • EP2629412B1 patent drawingFigure 3~4

AI summary

The present invention has an object to provide an inverter module and an inverter integrated electric compressor capable of reliably suppressing noise interference on a control circuit board and facilitating filling with a resin gel material. Provided is an inverter module including a power system circuit board and a control circuit board (30) that are integrated through a resin case, in which an insulating through hole (47) is provided in a region between: a frame ground (42) connected to a high voltage system formed on the control circuit board (30); and a low voltage circuit (46) adjacent to the frame ground (42).