Bootstrap Supply Circuits for Multi-Level Converter Startup Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power converters, particularly multi-level power converters, face challenges in supplying adequate power to level-shifter/driver (LS/D) circuits, especially at startup, due to the high voltage requirements of power FETs.
Innovation Solution
The implementation of linear regulators and bootstrap capacitors, as well as floating charge circuits and bootstrap capacitors, provides a bootstrap power supply for LS/D circuits in each tier of a multi-level FET-based power converter, ensuring efficient power delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional power supply methods are used for LS/D circuits in multi-level power converters, then the circuit structure remains simple, but the power supply reliability is insufficient especially at startup due to high voltage requirements
Solution Approach 1:
The patent introduces bootstrap capacitors as intermediary energy storage elements and floating charge circuits as mediator components to transfer and regulate voltage between different tiers. These intermediaries enable reliable power supply to LS/D circuits without requiring direct connection to high voltage sources, thus improving reliability while managing complexity through functional decomposition
Solution Approach 2:
The power converter is divided into multiple tiers, each with its own bootstrap capacitor and floating charge circuit. This segmentation allows independent power management for each tier's LS/D circuits, enabling startup reliability at each level while maintaining overall system functionality through modular architecture
2Power
If adequate power is supplied to LS/D circuits at high voltage levels, then the power delivery capability is sufficient, but the power loss increases due to the high voltage requirements
Solution Approach 1:
The patent dynamically changes voltage parameters through the charging and discharging of bootstrap capacitors. During startup, capacitors charge to required voltage levels; during operation, they maintain appropriate voltage differences across LS/D circuits. This parameter modulation enables sufficient power delivery at each tier while avoiding continuous high voltage exposure that would cause excessive power loss
Solution Approach 2:
The floating charge circuits periodically transfer charge between bootstrap capacitors of adjacent tiers. This periodic charge redistribution ensures that each tier receives adequate power when needed while allowing voltage levels to settle at optimal values during non-transfer periods, thereby reducing average power loss while maintaining peak power delivery 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 addresses the power supply challenges for LS/D circuits, enhancing the efficiency and reliability of multi-level power converters by minimizing power loss and ensuring stable operation across varying voltage conditions.
Implementation Method 1
The implementation of linear regulators and bootstrap capacitors, as well as floating charge circuits and bootstrap capacitors, provides a bootstrap power supply for LS/D circuits
Data Source
AI summary
Circuits and methods for providing a “bootstrap” power supply for level-shifter/driver (LS/D) circuits in a FET-based power converter. In a first embodiment, linear regulators and a bootstrap capacitor provide a bootstrap power supply for level-shifter/driver circuits in each tier of a multi-level FET-based power converter. In a second embodiment, floating charge circuits and bootstrap capacitors provide an improved bootstrap power supply for level-shifter and driver circuits in each tier of a multi-level FET-based power converter. More particularly, a floating charge circuit configured to be coupled to an associated bootstrap capacitor includes a first sub-circuit configured to pre-charge the associated bootstrap capacitor when coupled and a second sub-circuit configured to transfer charge between the bootstrap capacitor and a bootstrap capacitor coupled to an adjacent floating charge circuit.