Graetz Bridge Rectifier Architecture for High Power

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Solution Overview

Problem

High-power rectifiers face challenges in delivering high currents and voltages efficiently due to current balancing issues and prohibitive imbalances when increasing the number of monodirectional components in parallel, limiting the power that can be rectified without excessive imbalance.

Innovation Solution

The architecture is modified by splitting each component bar and fuse bar into multiple parallel bars, allowing for a larger number of components in parallel while maintaining a limited imbalance, typically between 20% and 30%, by creating multiple sets of functional groups that can be balanced independently and globally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the number of monodirectional components in parallel is increased to deliver higher power, then the rectified current and voltage increase, but the current imbalance becomes prohibitive

Engineering Contradiction:
Improverectified powerVSAvoidcurrent balance
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The invention divides the single component bar into multiple parallel component bars (at least two), with monodirectional components distributed across these separate bars. Each bar carries a subset of the total current, and the bars are connected to the same busbar. This segmentation reduces the current imbalance on each individual bar while maintaining the total power capacity, as the imbalance accumulates more slowly across multiple distributed components rather than concentrating on a single bar.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multiple monodirectional components are connected in parallel on a single component bar, then the power handling capacity increases, but the current distribution becomes unbalanced

Engineering Contradiction:
Improvepower handling capacityVSAvoidcurrent distribution uniformity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The component bar is segmented into multiple parallel bars, distributing the monodirectional components across these separate physical structures. This segmentation allows each bar to handle a portion of the total current with better balance, while the collective array of bars provides the necessary power handling capacity. The mathematical relationship shows that imbalance grows with the square root of the number of components rather than linearly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a one-dimensional arrangement (single component bar) to a two-dimensional array (multiple parallel component bars connected to a common busbar). This dimensional change allows current to be distributed across multiple parallel paths, reducing the imbalance on each individual path while maintaining the total current handling capability.

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

3Device complexity

If a single component bar structure is used, then the device complexity is low, but the maximum power is limited due to imbalance constraints

Engineering Contradiction:
Improvestructural complexityVSAvoidmaximum rectified power
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The component bar structure is segmented into multiple parallel bars, each carrying a subset of monodirectional components. This segmentation enables the system to achieve higher power capacity while keeping each individual bar's current load manageable and balanced. The overall structure remains relatively simple, with each bar independently connected to the common busbar.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple parallel component bars are merged at their connection point to the common busbar, creating a combined current-carrying structure. This merging allows the individual balanced currents from each bar to sum together, achieving high total power capacity while maintaining the balance benefits of the segmented architecture.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2638572B1Compact diode/thyristor rectifier architecture allowing high power
Publication Date: 2015.04.08 ALSTOM TECH LTD
  • EP2638572B1 patent drawingFigure 1~2
  • EP2638572B1 patent drawingFigure 3~4
  • EP2638572B1 patent drawingFigure 5

AI summary

The invention relates to a Graëtz bridge converter rectifier, wherein at least one rectifier arm, located between a single AC terminal and a single DC terminal, comprises multiple unidirectional electronic components (5), connected in parallel, connected on one side to the DC terminal by means of a conductive assembly, referred to as the component assembly, and on another side to the AC terminal. The invention is characterized in that for at least one rectifier arm, the component assembly comprises a plurality of separate component bars (9A, 9B) each having at least one end connected to the DC terminal, the unidirectional components (5) being distributed between the component bars (9A, 9B) in as many parallel-connected component assemblies (71, 72) as there are component bars (9A, 9B).