Power Conversion Device Switching Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional power conversion devices experience increased switching noise due to the proximity of drive circuits on a substrate, constrained by the size of the power supply transformer, which limits the gap between them and affects the efficiency of switching operations.

Innovation Solution

The power conversion device features a substrate with drive circuits and power supply circuits electrically isolated from a control circuit, where power supply transformers are placed across isolating regions to transform voltage, allowing for a wider gap between drive circuits and reducing switching noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single power supply transformer is disposed between upper arm and lower arm semiconductor modules, then the transmission distance of control power is shortened and voltage variation is reduced, but the interval between drive circuits is constrained by the transformer dimension which increases switching noise

Engineering Contradiction:
Improvecontrol power supply stabilityVSAvoidswitching noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention divides the single power supply transformer into multiple separate power supply transformers, with each transformer dedicated to a specific drive circuit. This segmentation allows each transformer to be positioned immediately adjacent to its corresponding drive circuit, minimizing the interval between drive circuits and reducing switching noise, while still providing stable power supply to each module independently

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the power supply transformer dimension constrains the interval between drive circuits, then the transformer can be positioned between upper and lower arms, but this increases switching noise induced when driving semiconductor modules

Engineering Contradiction:
Improvetransformer positioningVSAvoidswitching noise
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the power supply transformer from the central position between upper and lower arms and relocates it to be positioned immediately adjacent to each specific drive circuit. This extraction eliminates the constraint that the transformer dimension imposed on the interval between drive circuits, allowing minimal spacing and reduced switching noise while maintaining manufacturing simplicity

Inventive Principle:
Principle #2Taking out (Extraction)

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 effectively suppresses switching noise, reduces inductance, and miniaturizes the substrate by providing independent power supply transformers for each arm, enhancing the flexibility in arranging drive circuits and improving power output accuracy.

Implementation Method 1

power supply transformers for transforming a voltage supplied from the control circuit to a driving voltage are provided across the isolating regions for the respective power supply circuits

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3229361B1Power conversion device
Publication Date: 2019.06.19 NISSAN MOTOR CO LTD
  • EP3229361B1 patent drawingFigure 1
  • EP3229361B1 patent drawingFigure 2
  • EP3229361B1 patent drawingFigure 3

AI summary

Provided is a power conversion device in which the effect of switching noise generated when drive circuits drive switching elements can be reduced. The power conversion device is mounted with a control circuit (CNT), drive circuits (DR1-DR6) for driving switching elements in response to control signals from the control circuit (CNT), and power supply circuits (P1-P6) for supplying power to the drive circuits (DR1-DR6) on a substrate (11). The power conversion device is characterized in that drive-circuit/power supply-circuit placement and wiring regions (UP, UN, VP, VN, WP, WN) of a high current system in which the drive circuits (DR1-DR6) and the power supply circuits (P1-P6) are disposed on the substrate (11) are provided for the respective switching elements with isolating regions (AR11-AR16) interposed between the drive-circuit/power supply-circuit placement and wiring regions and the control circuit (CNT) of a low current system; a gap L is formed between the pairs of the drive-circuit/power supply-circuit regions; and then power supply transformers (T1-T6) for transforming a voltage supplied from the control circuit (CNT) are provided for the respective power supply circuits (P1-P6) in-between the isolating regions (AR11-AR16).