Phase-Shift DC/DC Converter With Active Overvoltage Clamping
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Solution Overview
Problem
High-power DC/DC converters face challenges with active overvoltage protection, as existing solutions require specialized power modules with two power semiconductors, which are costly and complex to cool.
Innovation Solution
The design incorporates a phase-shift type DC/DC converter with a single power module comprising two power switches connected in series, which provides active overvoltage protection and simplifies cooling by using a common heat sink.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power module with two power semiconductors is used for active overvoltage protection, then overvoltage protection is achieved, but device complexity and cooling requirements increase
Solution Approach 1:
The invention extracts the overvoltage protection function from the main power conversion circuit by using a separate active clamping circuit with a dedicated power semiconductor switch. This allows the protection function to be implemented independently without requiring a specialized two-switch power module, thereby reducing device complexity while maintaining protection capability.
Solution Approach 2:
The invention makes the existing power module universal by having it serve dual purposes: the first power semiconductor handles main power conversion while the second power semiconductor provides overvoltage protection through active clamping. This multi-functionality eliminates the need for specialized protection modules, reducing overall device complexity.
2Reliability
If a power module with two power semiconductors is used for active overvoltage protection, then overvoltage protection is achieved, but cooling system complexity increases
Solution Approach 1:
The invention merges the cooling systems by having both power semiconductors (the main power switch and the protection switch) mounted on a common heat sink. This consolidation allows both heat sources to be dissipated through a single cooling system, eliminating the need for separate cooling arrangements and reducing thermal management complexity.
3Device complexity
If a single power switch is used instead of a power module, then device complexity is reduced, but integration into cooling system becomes complex
Solution Approach 1:
The invention resolves the cooling integration issue by designing the circuit so that both power semiconductors (the main switch and the protection switch) are mounted on the same heat sink. This merging of thermal paths simplifies cooling integration despite using multiple switches, as both heat sources share a common thermal management solution.
4Reliability
If specialized power modules are produced, then overvoltage protection is achieved, but manufacturing cost increases
Solution Approach 1:
The invention achieves overvoltage protection using standard off-the-shelf power modules rather than specialized custom modules. The existing power module with two power semiconductors is made universal to serve both power conversion and protection functions, eliminating the need for expensive specialized production while maintaining protection capability.
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 manages overvoltages with reduced complexity and cost, while optimizing cooling efficiency by distributing heat across a common heat sink.
Implementation Method 1
a transformer (20), the series circuit being connected between the midpoints (17, 18) of the half-bridges of the full bridge (110)
Implementation Method 2
a bridge rectifier (23) connected to the secondary side (22) of the transformer (20)
Implementation Method 3
a common heat sink for the power modules that encompass the first to sixth power switches (11 . . . 14, 31, 34)
Data Source
AI summary
Various embodiments of the teachings herein include a DC/DC converter comprising: four power switches forming a full bridge; a resonant coil forming a series circuit with a primary side of a transformer, the series circuit connected between midpoints of two half-bridges of the full bridge; a bridge rectifier connected to a secondary side of the transformer; a control device for the four power switches; an overvoltage protection circuit connected in parallel with an output of the bridge rectifier, the overvoltage protection circuit comprising a capacitor and a fifth power switch connected in series; and a sixth power switch connected in parallel with the output of the bridge rectifier and in series with the fifth power switch.