Cascaded Bridge Drive Power Supply Using Shared Bootstrap Circuits
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Solution Overview
Problem
The complexity and high cost associated with the complementary half-bridge topology in electronic power systems due to each bridge topology requiring its own bootstrap and driving power supply.
Innovation Solution
A bridge cascade system with N bridge topologies cascaded on AC sides, utilizing a single driving power supply circuit and multiple bootstrap power supply circuits, where the bootstrap power supply circuits are connected in various configurations such as parallel, series, or hybrid, to power the driving circuits, reducing the need for multiple isolated power supplies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If each bridge topology uses its own bootstrap power supply and driving power supply, then the high-voltage side switch transistor can be properly powered, but the system complexity and hardware cost increase
Solution Approach 1:
The patent merges multiple driving power supply circuits into a single shared driving power supply circuit that can power multiple bridge topologies. The bootstrap power supply circuits are also shared across bridge topologies. This combining approach reduces the number of isolated power supplies while maintaining reliable power delivery to each high-voltage side switch transistor through the shared infrastructure.
Solution Approach 2:
The driving power supply circuit is designed with universal functionality to power multiple bridge topologies simultaneously. The bootstrap power supply circuits serve multiple purposes by supporting different bridge topologies through shared connections. This multi-functionality eliminates the need for dedicated power supplies for each bridge topology, reducing overall system complexity.
2Reliability
If each bridge topology uses its own bootstrap power supply, then the high-voltage driving circuit can be isolated when the neutral point potential changes, but the hardware cost increases
Solution Approach 1:
Multiple bootstrap power supply circuits are merged into a shared configuration where they can be selectively activated based on the neutral point potential of different bridge topologies. The bootstrap diodes and capacitors are shared across bridge topologies, reducing component count and hardware cost while maintaining the isolation function when needed.
Solution Approach 2:
Instead of creating completely separate bootstrap power supply circuits for each bridge topology, the patent uses a copied/shared approach where the same bootstrap circuitry serves multiple topologies through selective activation. This reduces hardware cost by avoiding redundant components while preserving the functional isolation capability.
3Manufacturing precision
If multiple isolated power supplies are used for each bridge topology, then proper voltage levels can be maintained, but the system design becomes more complex
Solution Approach 1:
The driving power supply circuit is designed as a universal power source that can provide appropriate voltage levels to multiple bridge topologies through the shared bootstrap power supply circuits. By controlling which bootstrap circuits are activated based on neutral point potentials, the system maintains precise voltage levels without requiring multiple isolated power supplies, thus simplifying the overall design.
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 simplifies the design of the driving power supply and reduces costs by sharing power supply components across multiple bridge topologies, enhancing efficiency and reducing hardware complexity.
Implementation Method 1
A bootstrap power supply circuit includes a bootstrap capacitor Cboot and a bootstrap diode Dboot
Implementation Method 2
A bootstrap power supply circuit includes a bootstrap capacitor Cboot and a bootstrap diode Dboot
Data Source
AI summary
Provided is a bridge cascade system, which includes at least one phase unit and a driving unit for the phase unit. The phase unit includes N bridge topologies cascaded on alternating current AC sides. The driving unit includes one driving power supply circuit, multiple bootstrap power supply circuits and 2N driving circuits. In the phase unit, the driving circuits are powered by the driving power supply circuit directly or through corresponding bootstrap power supply circuits. The driving circuits are configured to provide driving signals for corresponding switch transistors in the phase unit. In this way, one driving power supply is matched with multiple bootstrap power supply circuits, realizing power supply to the driving circuits corresponding to the switch transistors of all bridge topologies, which reduces the difficulty in designing the driving power supply for the bridge cascade system and reduces cost for the system.