Hybrid Arc Flash Interruption Using Solid-State Fault Commutation
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Solution Overview
Problem
Current electrical power protection systems have a slow response time to interrupt hazardous currents during arc flash events, causing thermal and mechanical stress to equipment and potentially harming personnel, especially when the fault is caused by low-level overcurrents.
Innovation Solution
A hybrid arc flash mitigation system that includes an arc flash sensor and a mitigation device with a bypass power switch device and an electro-mechanical switch, which can quickly interrupt fault currents by switching to an open-circuit condition upon detection, using a solid-state circuit interrupter and an ultra-fast actuator to commutate the fault current within 0.5 milliseconds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional circuit breakers and fuses are used for protection, then the system provides basic fault protection, but the response time is relatively long causing thermal and mechanical stress to equipment
Solution Approach 1:
The protection system is segmented into multiple functional components: arc flash sensors (optical and current sensors) for detection, a controller for processing, and a bypass power switch device with solid-state circuit interrupter for execution. This segmentation allows each component to specialize in its function, enabling faster overall response while maintaining reliable protection.
Solution Approach 2:
The patent replaces traditional mechanical circuit breakers and fuses with a solid-state circuit interrupter system. The bypass power switch device uses solid-state electronics and magnetic field-based actuation instead of mechanical moving parts, eliminating mechanical response delays and enabling microsecond-level fault interruption.
2Loss of time
If upstream bolted short circuit is created to transfer fault current, then the fault current is transferred quickly, but significant thermal and mechanical stress is caused to electrical system components
Solution Approach 1:
The bypass power switch device acts as an intermediary between the fault location and the upstream power source. Instead of directly creating a bolted short circuit that subjects components to extreme stress, the device provides a controlled low-impedance path that rapidly transfers fault current while limiting the stress on electrical system components through its solid-state protection mechanisms.
Solution Approach 2:
The system changes the impedance parameter of the fault path by switching in the bypass power switch device. This creates a controlled low-impedance path that directs fault current away from the arc flash location while maintaining parameters that prevent excessive thermal and mechanical stress on system components.
3Loss of time
If arc flash elimination response is provided within 2 milliseconds, then the response is faster, but the commutation is limited by the distance and impedance between protection system and arc flash location
Solution Approach 1:
The bypass power switch device is pre-positioned and pre-configured in the electrical system before a fault occurs. The solid-state circuit interrupter and associated components are ready in advance, eliminating the need for complex real-time commutation calculations based on distance and impedance. When a fault is detected, the pre-positioned device can immediately act without being limited by measurement or calculation delays.
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 reduces the risk of arc flash damage and personnel injury by rapidly interrupting fault currents, providing a faster response than traditional systems and minimizing thermal and mechanical stress on electrical equipment.
Implementation Method 1
an arc flash sensor to detect an arc flash event
Implementation Method 2
an electro-mechanical switch between the path input and the path output... activate the actuator to generate the open-circuit condition of the electro-mechanical switch
Implementation Method 3
a bypass power switch device that includes a solid-state circuit interrupter and that is configured to conduct current between the path input and the path output in response to an open-circuit condition of the switch
Implementation Method 4
generate a trigger signal to activate the actuator to generate the open-circuit condition
Data Source
AI summary
A system including an arc flash sensor that detects an arc flash event and an arc flash mitigation device in communication with the sensor. The mitigation device includes a path of least resistance having a path input and a path output. The arc flash sensor is located downstream the output. The mitigation device includes an electro-mechanical switch between the input and the output and an actuator. The mitigation device also includes a bypass power switch device that includes a solid-state circuit interrupter and that conduct current between the input and the output in response to an open-circuit condition of the switch. A system controller is provided to generate a trigger to activate the actuator to generate the open-circuit condition of the switch, which causes the power switch device to interrupt a fault current associated with a fault event in response to detection of the arc flash event.