Variable Shunt Current Splitter for Fault Limiters

Solution Overview

Problem

Conventional fault current limiters require significant physical size and energy consumption to handle steady state currents, making them costly and difficult to install, especially in high current applications, and they often necessitate large cooling systems and substantial superconductor material.

Innovation Solution

A fault current limiter system incorporating a variable shunt current splitting device with first and second conductive windings wound about a core, allowing for strong magnetic coupling that reduces steady state current load on the fault current limiter by distributing current through both windings in opposite directions during normal operation, and increasing impedance during fault conditions to limit fault currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional fault current limiter is configured to carry all steady state current, then fault current limiting capability is ensured, but physical footprint and energy consumption increase significantly

Engineering Contradiction:

Improvefault current limiting capabilityVSAvoidphysical footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The current path is segmented into two separate windings (first and second windings) wound about a common core. The first winding carries a portion of the steady state current while the second winding carries the remaining portion. This segmentation allows the fault current limiter to handle only the difference current, significantly reducing its required capacity, physical footprint, and associated cooling requirements while maintaining effective fault current limiting through the combined magnetic effect of both windings.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a conventional fault current limiter is configured to carry all steady state current, then fault current limiting capability is ensured, but energy consumption increases significantly

Engineering Contradiction:

Improvefault current limiting capabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The current path is segmented into two separate windings (first and second windings) wound about a common core. The first winding carries a portion of the steady state current while the second winding carries the remaining portion. This segmentation allows the fault current limiter to handle only the difference current, significantly reducing its required capacity, physical footprint, and associated cooling requirements while maintaining effective fault current limiting through the combined magnetic effect of both windings.

Inventive Principle:

Principle #1Segmentation

3Reliability

If a conventional fault current limiter is configured to carry all steady state current, then fault current limiting capability is ensured, but superconductor material quantity and cooling system capacity increase

Engineering Contradiction:

Improvefault current limiting capabilityVSAvoidsuperconductor material quantity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The current path is segmented into two separate windings (first and second windings) wound about a common core. The first winding carries a portion of the steady state current while the second winding carries the remaining portion. This segmentation allows the fault current limiter to handle only the difference current, significantly reducing its required capacity, physical footprint, and associated cooling requirements while maintaining effective fault current limiting through the combined magnetic effect of both windings.

Inventive Principle:

Principle #1Segmentation

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

This configuration reduces the physical size and energy consumption of the fault current limiter, enabling more compact designs and lower material and energy costs, while effectively limiting fault currents without the need for excessive superconductor material or cooling capacity.

Implementation Method 1

first and second conductive windings wound about a core, wherein the first conductive winding is electrically coupled in parallel with the fault current limiter and is configured to carry current in a first direction. The second conductive winding is electrically coupled in series with the fault current limiter and is configured to carry current in a second direction opposite to the first direction

Methodology Applied

Scientific EffectMagnetic coupling: Electromagnetic Induction

Data Source

PatentEP2697882B1Fault current limiter system with current splitting device

Publication Date: 2019.12.18 VARIAN SEMICON EQUIP ASSC INC

Figure 1A~1B
Figure 2A~2C
Figure 2D~2E

AI summary

A fault current limiter system including a fault current limiter and a variable shunt current splitting device. The current splitting device includes first and second conductive windings, wherein the first conductive winding is electrically connected in parallel with the fault current limiter and is configured to carry current in a first direction. The second conductive winding is electrically connected in series with the fault current limiter and is configured to carry current in a second direction opposite to the first direction so that the reactance of the first winding is negated by the reactance of the second winding during steady state operation of the fault current limiter system. Thus, a first portion of a steady state current is conveyed through the fault current limiter and a second portion of the current is conveyed through the current splitting device. The steady state current load on the fault current limiter is thereby reduced.