Parallel Power Switch Drive Inductors for Uniform Current Sharing
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Solution Overview
Problem
Conventional power semiconductor modules with multiple switches in parallel face nonuniform dynamic current division during switching operations due to parasitic emitter-side inductances, leading to reduced switching capacity and increased costs in compensating for these issues.
Innovation Solution
The electronic circuit employs common-mode rejection inductors in each pair of conductive connections between power semiconductor switches, synchronously driven by a common drive unit, to minimize dynamic circulating currents and ensure uniform current division, combining direct output-side connection with separate driving without requiring costly synchronization of control units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate driving with output-side decoupling components is used to compensate for different inductances, then uniform current division is improved, but space requirement and cost increase
Solution Approach 1:
The patent combines the decoupling function directly into the drive unit by providing separate drive units for each power semiconductor switch. This integration eliminates the need for additional external decoupling components, thereby reducing space requirements while maintaining uniform current division through individualized driving control.
Solution Approach 2:
The patent segments the driving control by providing separate drive units for each power semiconductor switch. This segmentation allows independent control of each switch, compensating for different parasitic inductances and achieving uniform current division without requiring additional decoupling components.
2Ease of manufacture
If hard direct connection of output sides with decoupling resistances is used, then cost is reduced, but current division uniformity deteriorates due to inability to achieve symmetry in modules with more than two switches
Solution Approach 1:
The patent applies segmentation by providing separate drive units for each power semiconductor switch. This allows independent optimization of each switch's driving parameters, achieving uniform current division in modules with any number of switches without requiring geometric symmetry or additional decoupling components.
Solution Approach 2:
The patent changes the driving parameters by providing individual drive units that can be independently optimized for each power semiconductor switch. This allows compensation for different parasitic inductances through parameter adjustment rather than requiring symmetric geometry or additional components.
3Manufacturing precision
If separate drive units with hard direct connection of output sides are used, then current division uniformity is improved, but production cost increases due to stringent synchronicity requirements
Solution Approach 1:
The patent introduces a common reference potential as an intermediary that all separate drive units share. This common reference potential serves as a mediator that synchronizes the drive units without requiring complex synchronization circuits, thereby maintaining current division uniformity while reducing production costs.
Solution Approach 2:
The patent merges the reference potential function across all drive units by connecting them to a common reference potential. This integration provides automatic synchronization of the separate drive units, achieving uniform current division without requiring complex synchronization mechanisms.
4Ease of manufacture
If common drive unit with direct parallel connection is used, then cost is reduced and simplicity is improved, but dynamic circulating currents increase due to different parasitic inductances
Solution Approach 1:
The patent segments the driving control by providing separate drive units for each power semiconductor switch instead of using a common drive unit. This segmentation allows independent control of each switch, compensating for different parasitic inductances and eliminating dynamic circulating currents while maintaining cost-effectiveness through direct parallel connection of output sides.
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 effectively suppresses oscillations and ensures uniform dynamic current division, optimizing direct-current behavior and reducing production costs by decoupling the conductive connections from the power circuit, allowing for cost-effective production and efficient switching operations.
Implementation Method 1
a first inductance LD1,1, LD1,2, LD1,3 being provided in each of the first electrically conductive connections and a second inductance LD2,1, LD2,2, LD2,3 being provided in each of the second electrically conductive connections, the first inductance LD1,1, LD1,2, LD1,3 being coupled to the second inductance LD2,1, LD2,2, LD2,3 for each of the power semiconductor switches
Data Source
AI summary
In the case of an electronic circuit, comprising a drive unit, which generates at least one drive signal, two or more power semiconductor switches each having a first and a second main terminal, which power semiconductor switches can be switched synchronously by the drive signal, the first and the second main terminals of the power semiconductor switches in each case being electrically connected in parallel among one another, for each of the power semiconductor switches a first and a second electrically conductive connection for connection to the drive unit, a uniform dynamic current division between the power semiconductor switches is achieved according to the invention by virtue of the fact that a first inductance is provided in each of the first electrically conductive connections, and a second inductance is provided in each of the second electrically conductive connections, the first inductance being coupled to the second inductance for each of the power semiconductor switches.