Vacuum-Interrupter Hybrid Circuit Breaker for Fast Fault Commutation
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Solution Overview
Problem
Hybrid circuit breakers become bulky and costly when conducting larger nominal currents due to the need for massive semiconductor circuits to handle high over and fault currents, leading to increased electrical stress and thermal energy absorption, which is challenging to cool effectively.
Innovation Solution
Employing a vacuum interrupter as the electro-mechanical bypass switch, which requires minimal stroke for dielectric strength, combined with an electrodynamic actuator and capacitor banks to facilitate fast commutation and reduce electrical stress on semiconductor components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hybrid circuit breaker uses a semiconductor circuit to handle high over and fault currents, then the breaker can protect the power line, but the semiconductor circuit becomes massive and the device becomes bulky and costly
Solution Approach 1:
A vacuum interrupter is introduced as an intermediary component between the power line and the semiconductor circuit. The vacuum interrupter handles the initial fault current interruption, allowing the semiconductor circuit to be smaller since it only needs to handle the commutation process, not the full fault current magnitude.
Solution Approach 2:
The patent replaces the traditional purely mechanical circuit breaker with a hybrid system combining vacuum interrupter (electro-mechanical) and semiconductor switch. This substitution allows for faster switching speeds and reduced contact wear while maintaining fault current handling capability.
2Power
If the semiconductor circuit is made massive to withstand high over and fault currents, then the breaker can handle higher currents, but the device becomes more expensive
Solution Approach 1:
The vacuum interrupter serves as a cost-effective intermediary that handles the expensive part of fault current interruption, allowing the use of smaller, cheaper semiconductor circuits while maintaining the ability to handle high currents.
Solution Approach 2:
The patent changes the operating parameters of the circuit breaker by using a vacuum environment for the interrupter, which allows for faster arc extinction and reduced semiconductor ratings, thereby reducing overall system cost while maintaining power handling capability.
3Reliability
If the electro-mechanical bypass switch uses a long stroke to achieve dielectric strength, then the switching reliability is improved, but the switching time increases and commutation to semiconductor circuit is delayed
Solution Approach 1:
The patent changes the medium parameter from air to vacuum, which fundamentally alters the dielectric strength characteristics. Vacuum provides sufficient dielectric strength at much smaller contact separations, reducing the stroke length and switching time while maintaining reliability.
Solution Approach 2:
By using vacuum as an inert environment, the patent eliminates air molecules that would otherwise sustain arcs and require larger clearance distances. The vacuum environment enables rapid arc extinction and faster commutation to the semiconductor circuit.
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 solution allows hybrid circuit breakers to handle higher currents without increasing size or cost, shifting the technical and economic limits for their use, and enabling faster switching operations.
Implementation Method 1
the electro-mechanical bypass switch is embodied as a vacuum interrupter, which comprises a switching contact and an actuator being designed to drive the switching contact of the vacuum interrupter
Implementation Method 2
combined with an electrodynamic actuator and capacitor banks to facilitate fast commutation
Implementation Method 3
combined with an electrodynamic actuator and capacitor banks to facilitate fast commutation
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A hybrid circuit breaker (1 ) is disclosed, which comprises an input connector (2a, 2b) for a power grid, an output connector (3a, 3b) for a load (RL) and a current path (4a, 4b) in-between. Furthermore, the hybrid circuit breaker (1 ) comprises an electro-mechanical bypass switch (5) being arranged in the current path (4a, 4b) and a semiconductor circuit (6) in parallel with the electro-mechanical bypass switch (5). Further on, the hybrid circuit breaker (1 ) comprises a control unit (CTRL) being capable of controlling a commutation from the current path (4a, 4b), in which the electro-mechanical bypass switch (5) is arranged, to the semiconductor circuit (6) in case of a switch off operation. The electro-mechanical bypass switch (5) is embodied as a vacuum interrupter, which comprises a switching contact (S1) and an actuator (7) being designed to drive the switching contact (S1).