Converter Arc Flash Protection With Zoned Fault Isolation

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Solution Overview

Problem

Current methods for mitigating arc faults in power systems are inadequate, as they either reduce redundancy in power schemes or are prohibited in certain distribution systems, and primarily focus on cutting power to affected areas, lacking comprehensive solutions for protecting complex systems like ships or manufacturing devices.

Innovation Solution

A smart protection system that integrates central and local controllers to detect and manage arc faults by modifying the voltage-ampere curve with a foldback mode, reducing power availability to arc faults, and utilizing energy storage units to smooth bus currents during pulsating arcs, thereby preventing fault propagation and equipment damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If power is cut to affected areas to mitigate arc faults, then arc fault current is reduced, but system redundancy is reduced and productivity is lost

Engineering Contradiction:
Improvearc fault currentVSAvoidsystem availability
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system divides the power system into multiple zones with local controllers that can independently manage arc faults in specific segments without shutting down the entire system. This allows selective isolation of fault areas while maintaining power supply to healthy segments, thus reducing arc fault current impact while preserving overall system productivity and redundancy.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If high-resistance grounding is employed to limit ground current, then arc fault current is reduced, but the method is prohibited in certain distribution systems with line-to-neutral connected loads

Engineering Contradiction:
Improveground current magnitudeVSAvoidapplicability to different distribution systems
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The control system is designed to be universally applicable across different distribution system configurations (grounded and ungrounded). It can detect and respond to arc faults through voltage and current measurements without requiring high-resistance grounding, thus limiting ground current magnitude while maintaining adaptability to various distribution system types including those with line-to-neutral connected loads.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If traditional arc fault mitigation methods are used, then arc flash energy is reduced, but they lack comprehensive protection for complex systems and may cause false alarms leading to unnecessary shutdowns

Engineering Contradiction:
Improvearc flash energyVSAvoidfalse alarm rate
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The system employs continuous monitoring of voltage, current, and power measurements with feedback control algorithms that analyze multiple parameters simultaneously. This comprehensive feedback mechanism enables accurate distinction between genuine arc faults and normal system variations, reducing false alarms while maintaining reliable detection of actual arc faults, thus protecting complex systems without causing unnecessary shutdowns.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3953791B1Arc flash protection of power systems
Publication Date: 2023.12.13 RAYTHEON CO
  • EP3953791B1 patent drawingFigure 1
  • EP3953791B1 patent drawingFigure 2A
  • EP3953791B1 patent drawingFigure 2B

AI summary

A computer-implemented method includes measuring, by a first local controller connected to a first converter, one or more characteristics of the first converter. The first converter belongs to a set of two or more converters in a power system configured to power equipment, and each of the two or more converters is connected to a respective local controller. An arc fault is detected based at least in part on the one or more characteristics of the first converter, and an indication of the arc fault is communicated to the central controller. The arc fault is remediated by performing one or more remedial operations determined by at least one of the first local controller and the central controller.