Hybrid DC Disconnect Switch Arc Energy Commutation
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Solution Overview
Problem
Existing disconnecting apparatuses for direct current interruption between a photovoltaic generator and an inverter face issues such as rapid wear of mechanical switching contacts due to arcs, power losses with semiconductor switches, and lack of galvanic disconnection for safety.
Innovation Solution
A hybrid disconnecting apparatus with a mechanical switching contact and semiconductor electronics in parallel, where the semiconductor electronics become current-conductive to commutate arc current, using arc energy for operation and charging an energy storage device to control the switches, ensuring a short arc duration and reliable extinguishing without external energy sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical switching contact is used for direct current interruption, then galvanic disconnection is achieved, but the switching contact becomes worn out quickly due to arc
Solution Approach 1:
The patent introduces semiconductor electronics as an intermediary component between the mechanical switching contact and the direct current source. The semiconductor switch is connected in parallel with the mechanical contact and is activated by arc voltage to commutate the current away from the mechanical contact during arc occurrence, thereby protecting the mechanical contact from rapid wear while maintaining galvanic disconnection capability
Solution Approach 2:
The patent replaces the purely mechanical switching system with a hybrid system that uses semiconductor electronics for current commutation during arc events. The semiconductor switch substitutes for the mechanical contact's current-interruption function during critical arc periods, reducing the mechanical wear burden
2Reliability
If an extinguishing chamber is added to protect the mechanical switching contact, then contact wear is reduced, but additional expense and complexity are required
Solution Approach 1:
The patent replaces the mechanical extinguishing chamber with an electronic solution using semiconductor switches. The semiconductor electronics detect arc conditions and actively commutate current away from the mechanical contact through electronic control, eliminating the need for complex mechanical arc containment structures
Solution Approach 2:
The semiconductor electronics are controlled automatically by the arc voltage itself, which triggers the semiconductor switch to activate and commutate current. This self-activating mechanism eliminates the need for external control systems or complex mechanical actuation mechanisms
3Duration of action of moving object
If powerful semiconductor switches are used for load disconnection, then no mechanical wear occurs, but unavoidable power losses occur at the semiconductors
Solution Approach 1:
The patent uses the semiconductor switch for partial action - only during critical arc events when the mechanical contact opens. The semiconductor handles only the commutation of arc current, not the full continuous load current, thereby minimizing power losses while providing protection where most needed
Solution Approach 2:
The semiconductor switch operates periodically or intermittently during arc events rather than continuously. The arc voltage periodically triggers the semiconductor to activate and commutate current, creating a periodic action pattern that reduces overall energy consumption compared to continuous semiconductor operation
4Loss of energy
If semiconductor electronics are used without external energy source, then power losses are minimized, but control of semiconductor switches requires energy
Solution Approach 1:
The patent converts the harmful arc voltage into a beneficial control signal for the semiconductor switch. The arc voltage, which indicates problematic conditions, is used to trigger the semiconductor's current commutation function, turning a harmful phenomenon into the activation mechanism for protection
Solution Approach 2:
The semiconductor electronics are self-powered by the arc voltage they detect. The energy storage device is charged from the arc voltage itself, creating a self-sufficient system that draws control energy from the very condition it is designed to address, eliminating the need for external power sources
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 provides a reliable, shockproof, and energy-efficient direct current interruption with minimal power losses and galvanic disconnection, suitable for high-voltage direct current ranges, using the arc energy to power the semiconductor electronics and ensure safe arc extinguishing.
Implementation Method 1
the arc current is commutated from the switching contact to the semiconductor electronics
Implementation Method 2
charging an energy storage device to control the switches
Data Source
AI summary
A disconnecting apparatus for direct current interruption between a direct current source and an electrical device, in particular between a photovoltaic generator and an inverter, has a current-conducting mechanical switching contact and semiconductor electronics connected in parallel with the switching contact. The semiconductor electronics are non-conducting when the switching contact is closed, wherein a control input of the semiconductor electronics is wired with the switching contact in such a way that, when the switching contact opens, an arc voltage generated as a result of an arc via the switching contact switches the semiconductor electronics to become conducting.