Zigzag Transformer Igniting Odd Silicon Rod Counts

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Solution Overview

Problem

Existing circuit arrangements for igniting thin silicon rods are only suitable for numbers that are multiples of four or even, making them insufficient for igniting odd numbers of rods.

Innovation Solution

The secondary winding systems of a three-phase transformer are wound in a zigzag configuration, with auxiliary three-phase transformers connected to form a closed delta system, allowing the thin rods to be connected in series and ignited with a three-phase AC power source, enabling ignition of rods in any number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a three-phase transformer with star-connected winding systems is used, then the circuit arrangement can ignite an even number of thin silicon rods (multiples of four), but it cannot ignite an odd number of rods

Engineering Contradiction:
Improvecapability to ignite different numbers of rodsVSAvoidcircuit arrangement configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by transitioning from a symmetric star-connected winding system to an asymmetric zigzag-connected winding system. The zigzag connection creates unequal phase relationships that allow for flexible configuration of any number of rods (including odd numbers) by selectively connecting rods to different taps on the winding strands, thereby resolving the limitation of only accommodating multiples of four rods.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent implements dynamics by introducing controllable switches that can selectively connect to different taps on the winding strands. This dynamic switching capability allows the circuit arrangement to adapt its configuration based on the number of rods to be ignited, enabling versatile operation from 3 to 12 rods by dynamically reconfiguring the circuit topology.

Inventive Principle:
Principle #15Dynamics

2Reliability

If high voltage (greater than 2500 V) is applied to ignite thin silicon rods, then the rods can be successfully ignited, but expensive insulation is required in the reactor

Engineering Contradiction:
Improveignition capability of thin silicon rodsVSAvoidinsulation requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by utilizing the zigzag connection to create variable voltage distributions across different phases. By selectively tapping different points on the winding strands and using controllable switches, the system can optimize voltage allocation to achieve reliable ignition while reducing peak voltage stress on insulation, thereby maintaining ignition reliability with reduced insulation requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces controllable switches as intermediary components between the transformer windings and the thin silicon rods. These switches act as mediators that can selectively connect or disconnect phases, allowing for flexible voltage application that achieves reliable ignition while providing control over voltage distribution to reduce insulation demands on the reactor.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the secondary winding systems are connected in a star system, then the circuit arrangement is simple, but it cannot accommodate odd numbers of thin silicon rods

Engineering Contradiction:
Improvewinding system configurationVSAvoidnumber of ignitable rods
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the symmetric star connection into an asymmetric zigzag connection, which inherently provides greater flexibility in accommodating different numbers of loads. The zigzag topology creates multiple accessible taps with different voltage relationships, enabling the system to adapt to any number of rods from 3 to 12 by selective switching, thus resolving the adaptability limitation of the star system.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent segments the secondary winding systems into multiple strands with multiple taps along each strand. This segmentation creates discrete voltage levels and phase relationships that can be selectively combined through controllable switches, allowing the system to accommodate any number of rods by selecting appropriate combinations of segmented winding portions.

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 allows for the ignition of thin silicon rods in any number, including odd quantities, by providing a flexible and efficient voltage supply that cancels out voltages, reducing the need for expensive insulation and ensuring uniform heating.

Implementation Method 1

a three-phase transformer (2) having a primary side (10) and a secondary side (11)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the secondary winding systems (14) in the three winding strands (50, 51, 52) are wound in a zigzag system

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The thin silicon rods in the reactor are heated electrically, with the thin silicon rods being supplied or fed with voltage

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2765698B1Assembly for igniting thin rods made of electrically conductive material, in particular thin silicon rods
Publication Date: 2018.10.24 SIEMENS AG
  • EP2765698B1 patent drawingFigure 1
  • EP2765698B1 patent drawingFigure 2
  • EP2765698B1 patent drawingFigure 3

AI summary

The arrangement (1) has a three-phase transformer (2) provided with a primary side and a secondary side (11). Secondary-side windings of the three-phase transformer comprise a secondary winding system (15), and are interconnected with one another such that sum of AC voltage of the secondary-side windings comprises secondary voltage vectors (43-45) and cancels one another out in a three-phase closed vector triangle system (46), where the three-phase transformer has delta winding/connection on the primary side and star winding/connection on the primary side.