Exxelia introduces the CCM family at ESA / SPCD 2022

Magnetic components for space applications, optimized for multi output Flyback transformers


SUMMARY


  • Introduction : evolution of magnetic components in space

Definition – How to satisfy it?

  • Part 1 : Family qualification by ESA/CNES

Why choose Technology Flow over QPL products?

Qualification steps.

  • Part 2 : Performance characterization of CCM technology

Thermal behavior.

Frequency response and Current saturation (standard CCM inductors).

  • Part 3 : Optimization for multi output Flyback transformers

The cross regulation problem or voltage deviations on some outputs.

PhD thesis definition – Different stages of work – Present and future results.

  • Conclusion

Components that meet present and future customer needs

 

WHAT IS A CCM?

 

CCM family : INTRODUCTION

 

What are the new technical needs and constraints for specific transformers?

 

First : Applications with more outputs.

Need for more In/Out pins.

More different voltages and power levels.

 

Second : Increase in the power to volume and power to weight ratios.

We can no longer take large safety margins.

  →  need to know all the technical limitations of the product.

Reliability, internal heating, frequency response, current saturation.

 

Third : Development time is getting shorter

Breadboards/Prototypes must work the first time  →  design method must be accurate.

Even specific products must avoid qualification time.

  →  have to be already qualified before BreadBoard/Prototype step.

 

Part 1 : ESA qualification 

 

 

  • CCM family : What is this, and what is it for?

1 technology for 5 shapes

Ferrite circuit around windings wound in a bobbin, cabled on a leadframe and moulded.

For both standard and custom components

Different types of functions : inductors (DMC, CMC), pulse/SMPS/measurement transformers

  →  QPL qualification not adapted  Technology Flow is better

 

  • What is a Technology Flow?

Exxelia must prove that CCM technology is space compliant.

1st step Evaluation (Exxelia), 2d step Qualification (ESA/CNES).

Exxelia has to define : bill of materials / manufacturing process / design rules and list of tests to be performed.

 

Bill of materials

3 key raw materials : Bobbin, leadframe and magnetic circuit.

Other materials : wires, solid insulation, glue/resin/varnish, weld, ink, package.

 

Manufacturing process

3 key steps : winding, cabling, moulding.

Other steps : gluing, assembling, marking, testing, packaging.

 

Design rules

All theoretic actions the designer has to do upstream to prevent surprises downstream.

 

Test campaigns

All those in Charts F4 SG1, SG2 and SG3.

Thermal shocks, Temperature rise, Overload, Soldering heat, Vibrations, Mechanical shocks Operating life, Permanence of marking, Solderability, Terminal strength, Dielectric, Moisture.

 

  • Summary of work carried out

- More than 100 components designed, manufactured, and tested

  many configurations of  functions / shapes / tests.

- Some components destroyed to identify security margins

  on thermal, mechanical, dielectric aspects.

- Evaluation took several years to complete

 Result :  Qualification was successful on first try.

 

  • Conclusion

Respecting BOM, process and design rules qualified  ... Exxelia has the right to offer any function in CCM shapes without any mandatory testing for customer.

 

Part 2 : CCM technology performances

 

 

  • Security margins must be reduced

Maximum permissible loss value  →  leads to internal heating (Tmax <  125 °C).

Maximum operating frequency  →  above resonant frequency component is no more inductive.

Saturation curve  →  which inductor value at which excitation current?

 

  • How can these characteristics be determined ?

We decided to carry out 3 experimental campaigns :

  1. Thermal resistance determination for each of 5 shapes.
  2. Inductance versus frequency curves for standard inductors.
  3. Inductance versus current curves for standard inductors.

 

  • Thermal resistance Rth of CCM4, CCM5, CCM6, CCM20 and CCM25

  • Definition of test conditions

Use of inductors with one winding connected to all pins one side.

 

Measurements in vacuum are very complex.

  →  in natural convection in the air first.

Copper losses (heating source) only.

  →  DC current excitation / measurement of Rwind.

Component on PCB / all pins soldered  / no glue / no copper except for large current paths.

Component in a (pierced) box inside a ventilated oven  / temperature controlled.

 

  • Measurement bench

Measurements realised for each of 5 shapes.

2 L values  /  5 Tenv : 25, 50, 75, 100, 125 and 150°C  / up to 15 meas. points for each Tenv.

 

  • Complements and further work

Results applied for all CCM components  /  We have a math model air convection → vacuum.

3D simulations in progress to validate these curves  …  1st results are promising.

Measurements in vacuum are planned.

 

  • Frequency behavior for CCM4, CCM5, CCM6, CCM20 and CCM25 standard inductors

 

  • Definition of test conditions

Use of inductors with one winding connected to all pins one side.

Constant excitation, between 100µT and 1mT.

Components soldered on a brass plate.

RLC meter calibrated after 1 hour functioning.

 

Measurement device

 

  • Measurements realised for each of 5 shapes

2 L values  / up to 15 meas. points for each inductor value.

 

 

  • Result overview
    • Majority of inductors are usable at least up to 1MHz.
    • All of inductors are usable at least up to 400kHz.

 

  • Saturation behavior for CCM4, CCM5, CCM6, CCM20 and CCM25 standard inductors

 

  • Definition of test conditions

Use of inductors with one winding connected to all pins one side.

0,5 phase shift full bridge DC supply.

DC+AC (300kHz) excitation with duty cycle > 0,5.

ΔI constant as long as no saturation.

Period nb controlled to achieve desired DC current.

L value measured with current rise slope.

 

  • Measurements realised for each of 5 shapes

2 L values  / 2 Tenv, ambiant and 125°C / up to 15 meas. points for each Tenv.

2 types of curves L function of Idc or Imax (Idc+ΔI/2).

 

  • Result overview

Big ≠ between 25 and 125 °C : taking account of thermal behavior of ferrite is mandatory.

Main interest : to detect the beginning of saturation.

 

Part 3 : multi Flyback optimization

 

 

  • What are voltage deviations also named cross regulation problem ?
  1. At nominal point of load, some output voltages are different from theoretical values.
  2. If power level at regulated output varies, some non-regulated output voltages values vary.
  3. Current waveform on some auxiliary outputs is very different from theoretical triangle shape.

 

  • Observation :

The more different output / voltage levels / power levels …

The greater the probability to have voltage deviations.

Actual solution : linear regulators.

  →  more volume/weight, less efficiency, more heating.

 

  • Charge :  Transformer is mostly responsible

Problem seriousness depends on application and even on piece inside a manufacturing batch.

Magnetic root cause (transformer), but power electronics consequence (converter).

  →  need to work in both electromagnetism and power electronics.

 

  • Exxelia decided to manage a PhD thesis on this subject

Aims :

  1. Understand scientific problem, Identify root causes (transformer, other components?),
  2. Find solutions, Take account of voltage deviations in design and manufacturing process

Partners : G2Elab laboratory, D. Motte Michellon student, CNES, Steel Electronique

 

  • PhD step 1 : Understanding the scientific problem, identify root causes

Study of magnetic behavior of several transformers

  →  use of FLUX finite element simulation software

Identification of a circuit model compliant with several softwares (Psim, Spice, other)

  →  extended Cantilever magnetostatic model

Calculation of all output voltages for different transformers/converters

  →  use of Psim circuit software

 

  • Result of analysis :
  •  3/4 problem comes from transformer : magnetic coupling between all secondaries
  •  1/4 problem comes from drawbacks of some other components of converter

 

  • Actions :
  1.   Creating an analytic model to take account of leakage inductances between secondaries,
  2.   Use this model to quick calculate all output voltages.

 

  • PhD step 2 :  Finding theoretical and industrial solutions

We identified relationship between   CCM winding process, couplings between secondaries and voltage deviations.

We identified which other components and which drawbacks are concerned.

For the moment, one method of winding CCM to avoid worst cases of voltage deviations and to minimize variations from one piece to another applied since 01/01/2022 for all designed Flyback in CCM.

In progress, a software to optimize (minimize) voltage deviations and to identify best cases of CCM winding processes.

    →  Increase of know-how for customer benefit.

 

CCM family : CONCLUSION

 

 

  • Whatever the function you need

Component is already qualified  →  Reliability and security.

Many pins  ==  many input/output possibilities.

You know its thermal behavior  →  have a good idea of its energy/power limit.

 

  • For inductor applications

You can have standard or custom components.

You know frequency and current responses.

 

  • For multi output Flyback transformers

Design method focused on :

  1. meeting customer’s need as close as possible,
  2. volume and weight reductions.

 

Understanding voltage deviations  =  problem minimization + ability to assist customer.

 

                                                                CCM technology is well adapted for space   …  and we continue to improve it.

 

 

 

Autor : Bruno COGITORE  –  Jean PIERRE

Magnetic Expert / Innovation  –  Space product Manager  •  Exxelia Magnetics

 

Publié le 05 Oct 2021 par Stephane PERES

Boostez votre projet avec les condensateurs film Exxelia aux délais de livraison réduits !

Nous sommes heureux d&#39;annoncer que certains produits de nos gammes de condensateurs film RA, KM, ainsi que notre gamme spéciale PMR (pour les marchés du médical et ferroviaire), bénéficient désormais de délais de livraison réduits.  Des délais de livraison réduits pour les condensateurs film des familles RA (Polypropylene PP) et KM (Polysulfure de phénylène PPS) : En effet, les délais de livraison des condensateurs film des gammes RA et KM ont été considérablement réduits. Auparavant, ces produits avaient un délai de livraison moyen de 20 semaines. Désormais, grâce à des efforts d&#39;optimisation de notre chaîne d&#39;approvisionnement et de production, nous avons réussi à réduire ce délai à seulement 8 semaines en moyenne ! L&#39;un des produits phares de cette gamme est le KM 111 S/T. Ce condensateur film haute performance est idéal pour une large gamme d&#39;applications, telles que l&#39;électronique de puissance, les filtres, les onduleurs et bien d&#39;autres encore. Le KM 111 S/T permet d’obtenir une valeur de capacité précise nécessaire pour des applications électromécaniques précises et rigoureuses pour l’aviation. Avec sa tension de service et sa capacité de charge élevées, le KM 111 S/T offre des performances exceptionnelles. Et maintenant, avec un délai de livraison réduit à seulement 8 semaines, vous pouvez l&#39;intégrer plus rapidement dans vos conceptions, accélérant ainsi le développement de vos produits. Composants KM 111 KM 21 KM 311 KM 50 KM 501 KM 531 KM 601 KM 62 KM 7 T KM 7 C KM 711 KM 78 KM 78R KM 82 KM 82 KM 90 KM 90P KM 94 KM 97 KM 31 KM 511 KM 531 KM 90 KM 90P Composants RA 01 RA 02 RA 03 RA 04 RA 11 RA 12 RA 13 RA 14 RA 21 RA 22 RA 23 RA 24 RA 31 RA 32 RA 33 RA 34 RA 75     Une révolution dans les délais de livraison avec les condensateurs film de la famille PMR (Polysulfure de phénylène PPS): Notre gamme spéciale PMR, conçue pour les applications médicales et ferroviaire, connaît également une amélioration significative de ses délais de livraison. Dans certains cas, nous avons pu diviser par un facteur 10 les délais de livraison habituels pour ces produits spécifiques. Cela signifie que vous pouvez désormais obtenir les condensateurs film de la gamme PMR dont vous avez besoin en un temps record ! Les condensateurs film de la gamme PMR sont spécifiquement conçus pour répondre aux exigences strictes des applications médicales et ferroviaires. Leur fiabilité, leur stabilité et leur durée de vie prolongée en font des choix idéaux pour les équipements médicaux, les dispositifs de surveillance, les systèmes de transport ferroviaire et bien d&#39;autres encore. Grâce à nos délais de livraison réduits, vous pouvez désormais bénéficier de ces avantages sans attendre longtemps pour recevoir vos produits.   PMR EFCO PMR 4 PMR 64