Power Converter Fault Isolation Using Controlled Switch Burnout
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Solution Overview
Problem
Failure of a single semiconductor switch in a power converter with parallel connections leads to a complete shutdown, rendering the system unusable.
Innovation Solution
A power system with a controller that switches off the faulty semiconductor switch intermittently and guides current through healthy switches to burn out the faulty switch, using existing components without additional units, and employs high-frequency pulse modulation to safely remove the fault.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple semiconductor switches are connected in parallel to meet power requirements, then power density is improved, but failure of one switch leads to complete shutdown of the power converter
Solution Approach 1:
The patent segments the semiconductor switches into individually controllable units within switching units. Each semiconductor switch can be independently switched off when a fault is detected, while other switches continue to operate. This segmentation allows the system to maintain partial functionality rather than complete shutdown, resolving the contradiction between using parallel switches for high power and maintaining reliability.
Solution Approach 2:
The patent changes the operational state parameter of individual semiconductor switches from all-on to selectively on/off based on fault detection. When a fault is detected in one semiconductor switch, the controller switches off only that specific switch while keeping others operational. This parameter change enables the system to maintain power delivery through healthy switches, resolving the reliability issue without sacrificing power density.
2Reliability
If current is provided to burn out a faulty semiconductor switch, then the faulty switch is removed, but there is risk of damaging other components
Solution Approach 1:
The patent applies preliminary action by detecting faults and switching off the faulty semiconductor switch before attempting to burn it out. The controller first identifies the faulty switch through fault detection circuits, then selectively switches off only that specific switch using individual control signals. This preliminary isolation prevents current from flowing through healthy switches during the burn-out process, eliminating the risk of damaging other components while still enabling removal of the faulty switch.
Solution Approach 2:
The patent uses switching units as intermediaries between the controller and individual semiconductor switches. The switching unit structure with individual control signals acts as a mediator that can isolate the faulty switch before the burn-out process. This intermediary mechanism ensures that when current is applied to burn out the faulty switch, only that specific switch is affected, protecting other components from damage.
3Reliability
If semiconductor switches are controlled individually to remove faults, then system reliability is improved, but control complexity increases
Solution Approach 1:
The patent implements multi-functionality in the controller that can perform both normal power conversion control and fault detection/isolation functions using the same hardware structure. The switching units are designed to handle both operational switching and fault isolation tasks. This universal design enables individual control of semiconductor switches for fault tolerance without requiring separate dedicated control circuits, thus managing complexity while improving reliability.
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
The system effectively removes faulty semiconductor switches without damaging other components, allowing the power system to resume operation.
Implementation Method 1
A current is provided that burns the faulty semiconductor switch or an element arranged in series with the faulty semiconductor switch, thereby removing the faulty semiconductor switch from the power converter
Data Source
AI summary
A power system includes a power converter that includes switching units that form at least two legs. Each of the at least two legs includes a top switching unit and a bottom switching unit. Each of the switching units includes semiconductor switches arranged in parallel. A controller is configured to receive information or determine that one of the semiconductor switches of the switching units has a fault condition. The controller is further configured to control the switching units such that the semiconductor switches of the switching unit that includes the faulty semiconductor switch are switched off at least intermittently, and the semiconductor switches of at least one of the further switching units are switched on. A current is guided through the faulty semiconductor switch and the semiconductor switches of the at least one of the further switching units to remove the faulty semiconductor switch.