Multi-Charge Ignition System Current Peak Reduction

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Solution Overview

Problem

Current multi-charge ignition systems experience high primary current peaks during initial charge, leading to increased copper losses, EMC emissions, and load on onboard power generation, which are undesirable and costly to mitigate without using a DC/DC converter.

Innovation Solution

A multi-charge ignition system with an additional auxiliary primary winding and switch, allowing current to flow through these windings during the initial energization phase, and a step-down converter stage to manage power distribution across coil stages, enabling controlled energization and de-energization to minimize primary current peaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a DC/DC converter is used to minimize the high primary current peak, then copper losses and EMC emissions are reduced, but device complexity and cost increase

Engineering Contradiction:
Improvecopper lossesVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent divides the single primary winding into two separate primary windings (L1 and L3) with different inductances. This segmentation allows the system to distribute the charging current across multiple windings, reducing the peak current in each individual winding and thereby reducing copper losses without requiring a DC/DC converter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the electrical parameters by using two primary windings with different inductance values (L1 and L3). This parameter differentiation enables optimized current distribution during the charging phase, reducing the overall current peak and associated copper losses while maintaining the required energy delivery to the spark plug.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If a DC/DC converter is used to minimize the high primary current peak, then EMC emissions are reduced, but device complexity and cost increase

Engineering Contradiction:
ImproveEMC emissionsVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

By segmenting the primary winding into two separate windings (L1 and L3), the patent reduces the peak current magnitude in each winding. This segmentation directly lowers the electromagnetic interference and EMC emissions generated during the charging phase, eliminating the need for an additional DC/DC converter and its associated complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The use of two primary windings with different inductance parameters allows for optimized current profiles that reduce electromagnetic emissions. The differentiated inductance values enable better control over the charging current characteristics, reducing EMC emissions without adding device complexity.

Inventive Principle:
Principle #35Parameter changes

3Power

If a DC/DC converter is used to minimize the high primary current peak, then load on onboard power generation is reduced, but device complexity and cost increase

Engineering Contradiction:
Improveload on onboard power generationVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent segments the primary winding into two windings (L1 and L3) that can be charged in a distributed manner. This segmentation reduces the instantaneous power demand from the onboard power generation system by spreading the charging current over a longer period and across multiple windings, thereby reducing the peak load without requiring a DC/DC converter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By using two primary windings with different inductance parameters, the system optimizes the charging current profile to reduce peak power demand. This parameter differentiation allows for a more gradual energy transfer from the power generation system, reducing the instantaneous load while maintaining overall system performance.

Inventive Principle:
Principle #35Parameter changes

4Volume of moving object

If multi-charge ignition systems are used to reduce ignition system size, then system size is reduced, but spark continuity is compromised during recharge periods

Engineering Contradiction:
Improveignition system sizeVSAvoidspark continuity
Core Design Contradiction:
Volume of moving objectVSDuration of action of stationary object

Solution Approach 1:

The patent segments the ignition system into two separate coil stages, each with its own primary and secondary windings. This segmentation allows for overlapping charging and discharge cycles, where one stage can be charged while the other delivers energy to the spark plug, thereby maintaining continuous spark output while using smaller individual components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs periodic switching between two coil stages, with each stage operating in alternating charge and discharge cycles. This periodic action ensures that while one stage is delivering energy to maintain the spark, the other stage is being charged, thus maintaining spark continuity while allowing for reduced component sizes.

Inventive Principle:
Principle #19Periodic action

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 solution reduces primary current peaks, minimizing copper losses and EMC emissions while maintaining continuous ignition, thus enhancing system efficiency and reducing wear on the onboard power generation without the need for a DC/DC converter.

Implementation Method 1

a first transformer (T1) including a first primary winding (L1) inductively coupled to a first secondary winding (L2); a second transformer (T2) including a second primary winding (L3) inductively coupled to a second secondary winding (L4)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a first transformer (T1) including a first primary winding (L1) inductively coupled to a first secondary winding (L2); a second transformer (T2) including a second primary winding (L3) inductively coupled to a second secondary winding (L4)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

including switch means Q3 adapted to selectively allow current to pass through said auxiliary windings

Methodology Applied
Scientific EffectElectromagnetic field control: Electromagnetic Induction

Data Source

PatentEP3374627B1Method and apparatus to control an ignition system
Publication Date: 2024.04.03 DELPHI INT OPERATIONS LUXEMBOURG SARL
  • EP3374627B1 patent drawingFigure 1
  • EP3374627B1 patent drawingFigure 2(a)~2(e)
  • EP3374627B1 patent drawingFigure 3

AI summary

A multi-charge ignition system including a spark plug control unit adapted to control at least two coil stages so as to successively energise and de-energise said coil stage(s) to provide a current to a spark plug, said two stages comprising a first transformer (T1) including a first primary winding (L1) inductively coupled to a first secondary winding (L2); a second transformer (T2) including a second primary winding (L3) inductively coupled to a second secondary winding (L4); characterised in including auxiliary primary winding (L5) connected from the common high side of the primary winding in series to an auxiliary secondary winding (L6), the other end of said auxiliary secondary winding (L6) electrically connected to ground/low side, and including switch means Q3 adapted to selectively allow current to pass through said auxiliary windings.