Power Conversion Device Compact Layout

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Solution Overview

Problem

Conventional power conversion devices face challenges in downsizing while maintaining stability and reliability, as increased wiring inductance due to longer connections between smoothing capacitors and gate drive boards can lead to surge voltages, affecting circuit operation.

Innovation Solution

A power conversion device design where smoothing capacitors are arranged on both sides of a heat radiating plate with power semiconductors, and gate drive boards are positioned under the semiconductors and capacitors, utilizing a water-cooling or air-cooling method, with insulating members and connectors to reduce inductance and enhance insulation reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If smoothing capacitors and gate drive boards are arranged away from the power semiconductor to facilitate replacement, then ease of repair is improved, but wiring inductance increases leading to surge voltage that adversely affects circuit operation

Engineering Contradiction:
Improveease of repairVSAvoidcircuit operation stability
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The patent transitions from a one-dimensional linear arrangement to a two-dimensional planar arrangement on the heat radiating plate. Multiple smoothing capacitors are positioned at different locations (both sides of the plate) and multiple gate drive boards are arranged underneath, creating a distributed spatial configuration that reduces wiring length while maintaining accessibility for repair.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of stationary object

If the unit including the power semiconductor is downsized, then the power conversion device volume is reduced, but wiring inductance increases when other devices are arranged away from the power semiconductor

Engineering Contradiction:
Improvepower conversion device volumeVSAvoidcircuit operation stability
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The patent merges multiple devices (power semiconductors, smoothing capacitors, gate drive boards) onto a single heat radiating plate structure. This consolidation reduces the overall device volume while keeping wiring paths short by positioning all components in close proximity on the same mounting surface.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes the two-dimensional surface area of the heat radiating plate to arrange components efficiently. By distributing capacitors on both sides and placing gate drive boards underneath, the design maximizes spatial utilization within a compact footprint, reducing wiring lengths while maintaining component accessibility.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple smoothing capacitors and gate drive boards are arranged on the heat radiating plate, then wiring inductance is reduced improving circuit operation, but device complexity increases

Engineering Contradiction:
Improvecircuit operation stabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heat radiating plate serves multiple functions simultaneously: it provides thermal management for the power semiconductors, acts as a mounting structure for capacitors and gate drive boards, and serves as a mechanical support framework. This multi-functionality reduces the need for separate structural components, simplifying the overall device complexity despite the increased number of active components.

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 configuration stabilizes circuit operations, improves insulation reliability, and reduces manufacturing costs, enabling a compact and efficient power conversion device.

Implementation Method 1

a water-cooling method of circulating cooling water to radiate heat

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 2

an air-cooling method of supplying cooling air to a cooling fin to radiate heat

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Data Source

PatentEP3579396B1Power conversion device
Publication Date: 2022.10.19 HITACHI LTD
  • EP3579396B1 patent drawingFigure 1
  • EP3579396B1 patent drawingFigure 2
  • EP3579396B1 patent drawingFigure 3

AI summary

In order to miniaturize an entire power conversion device having built therein a power semiconductor, a smoothing capacitor, and a gate drive substrate, inside a casing of this power conversion device, a plurality of smoothing capacitors are disposed on both sides of a heat radiating plate having a plurality of power semiconductors mounted on both sides thereof, and a gate drive substrate for inputting and outputting controls signals to and from the plurality of power semiconductors, is disposed below the power semiconductors, the heat radiating plate, and the smoothing capacitors, whereby a compact power conversion device is provided in which circuit operations are stabilized, insulation reliability is made more reliable, and manufacturing costs are reduced.