Author Archive

Precision Correction for Digital PWM

Friday, August 30th, 2019

Precision Correction in Digital PWM Modulators – Free Webinar

Get the best digital PWM modulator performance.

Register here

Tuesday October 1 at 12 noon PDT (3pm EDT)

Register here

Digital Modulators have precision limits that arise from the limited timer clock rate of microprocessors and digital signal processors.  Possible effects on the control of the power converter includes

  • Poor steady state tracking
  • Limit cycle oscillation from slip-strike 
  • Reduced stability margins and possible instability
Get the best digital PWM modulator performance
Get the best digital PWM modulator performance

Get the best digital PWM modulator performance

In the webinar these topics are explained

  • Timer precision
  • PWM Quantization
  • Variable Period Oscillator Quantization
  • Precision extension as a solution to digital modulator issues
  • Designing the digital modulator

The webinar will explain how to get the best performance from your digital PWM for you converter designs. Take a look at our Power Control IP Blocks

Register here

As always there will be 10 minutes of questions and answers after the webinar.

Register here

Choosing you power electronics processor effectively in Digital Power Electronics Development – Free Webinar

Thursday, May 16th, 2019

Tuesday June 4 at 12 noon PDT (3pm EDT)

How do you choose your processor.

Your Digital Power Electronics Processor Choice power electronics processor is crucial to success in Digital Power. And the key to choosing in a way that doesn’t end up creating delays in the project delivery.

So what are the most important issues to consider

Processing latency

Delays in the digital processor add phase lag and so can make getting stable operation at reasonable target bandwidth. Estimating accurately the delay that is acceptable and possible with possible target processors ensures that the processor will not run out of time during the development.

How to manage the limited number of bits

The limited number of bits in a processor means that there is a trade off between precision and dynamic range. The natural instinct is often to have larger dynamic range and lower precision. Best practice is to choose the opposite. Joins us in the webinar to see why.

Timer resolution

Likewise timer precision limits the available resolution in PWM and variable frequency modulators.

ELMG Digital Power are offering you the opportunity to attend our regular webinar on Digital Power Electronics. The next webinar is

Tuesday June 4 at 12 noon PDT (3pm EDT)

This is an hour webinar on that details the accumulated ELMG Digital Power experience with processor choices for power electronics control

Join ELMG Digital Power’s regular monthly Digital Power Webinar and expand your Digital Power knowledge and expertise. 

The webinar will be hosted and presented by Dr. Hamish Laird  ELMG Digital Power’s CTO  Hamish has 25 years experience the design and implementation of varied digital control systems and IP for power electronics.

This exciting opportunity is free and includes a 15 minute Q&A session with Dr. Hamish.

Dr Hamish Laird

The webinar is scheduled for

Tuesday June 4 at 12 noon PDT (3pm EDT)

Click the link below to sign up for the webinar

http://info.elmgdigitalpower.com/choosing-your-digital-power-processor

In-house course digital power electronics

Wednesday, May 30th, 2018

We recently ran our digital control course in-house for a power electronics company.

Great group of guys and this is what they said.

“Everybody enjoyed the course, and it’s given us a lot of food for thought!”

Why choose in-house course digital power electronics training?

  1. Keep know-how in-house.
  2. Minimal disruption to your team.
  3. Everyone gets the same exposure.
  4. It’s team building.
  5. In house means no travel and travel can be hard to get approved.
  6. Have the teacher all to yourself.
  7. Great value when you add it all up.
  8. Emphasis on material specifically for you.

When can we have it?

Send us an e-mail and we’ll work a time out.

Is it the same as the publicly available course?

Yes – we use

  • #Teledyne #Lecroy scopes
  • AP 300 analysers
  • Boost coverters
  • Fyfe digital power platforms

It’s run by the same team

We also do the same workshop practical experiments to reinforce the learning.

Can you tell us who had the recent in-house course?

No. It is covered by an NDA so we won’t disclose which company it was.

 

Equivalent bits – a question from LinkedIn Group

Wednesday, May 23rd, 2018

“I was looking through ELMG’s tutorial “Three Key Issues to Watch out for in the Digital Control of Power Electronics” (https://www.elmgdigitalpower.com/power-electronics-digital-control-free-report-on-three-key-issues/) and am having some trouble understanding the relationship between frequency, register size, and equivalent bits.

An example given in the “2. Timer Precision” section of the document reads:

‘Consider the case where the timer clock runs at 40MHz. If the variable period oscillator register has 256 bits then the maximum frequency that the VPO can make is 10MHz and the minimum is 39.0625kHz. The example LLC resonant power converter needs a variable frequency of 500kHz to 210kHz to perform the control. This means the VPO count register has a usable range from 80 to 191. This is 111 counts which is 6.8 equivalent bits or almost seven bits.”

Equivalent bits are a great way to look at numeric precision.

Come join the discussion to see how equivalent bits is calculated.  https://www.linkedin.com/groups/6677852/6677852-6242781250545942530

 

 

For your Digital Control Workshop which Micro Controllers are taught?

Wednesday, May 16th, 2018

For your Digital Control Workshop which microcontrollers are taught in the class?

Texas Instruments?

Thanks John

 

Hi John,

The uniqueness of the Digital Control Workshop is that it is not focused on one microcontroller family.  We cover the key know how that ensures you and your team will get your digital power supply robust and reliable.

Here at ELMG Digital Power our platform is an FPGA based power converter controller that we have developed.  We sell power electronic specific FPGA IP blocks for PWM, filters, three to two blocks and all the other required power electronic blocks.

We have development experience in using processors for power electronics control from

  • Xilinx
  • Atmel
  • Microchip
  • STM
  • AD and
  • Ti

Our course came about when and R and D manager asked us why his team had knowledge gaps that we were now helping fix.  These gaps were common across a number of our OEM clients.  We address these key common knowledge gaps in the course.

Happy to have a netmeeting or skype call to talk through this at anytime.

Contact us

Inductor Go Round – Redux

Wednesday, May 9th, 2018

ELMG Redux from 2010

This post was originally published in 2010.  It is republished here because it looks like people are still doing the inductor-go-round.

So what is the inductor-go-round?  It is like a merry-go-round (carousel) except with inductors.  It can cost companies (or their startup backers) lots of time and money.  And usually when you are on the inductor-go-round it feels much like a carousel at a fair.  Round and round and sadly, not much progress.

Power Converters

Often the optimization of a power converter’s performance comes down to the optimization of the converter inductor. (It can also be optimization of the transformer but lets for the moment assume a non-isolated converter). For people with big and small inductors there is, it seems, an inductor go round.

What is a big inductor? At ELMG Electronics Design and Development we generally say that any inductor with mass more than 1 kg – and yes it says kilograms (1kg = 2.2 pounds) – is a big inductor. Some of you will say that until you have a 40kg inductor you don’t really have an inductor. Other inductors will be smaller.  I guess it is all a matter of what you are familiar with.

For the inductors for grid connected inverters people start with laminated iron or some other laminated material.  This is typically the  inexpensive choice.  Some others choose ferrite cores. Some start with another core material.

Air cored next

Then running first into core material problems they then move to air cored as the core is the cause of all the problems. They then either come up against either;

  • the magnetic field interference problem (the enclosure is now the core),
  • the fault rupture problems that occur with designing air cored mechanical restraints,
  • or the size constraint.

Powdered?

From here most people head to a modern core material such a powder core. These materials are not necessarily homogeneous and so they then realize that to get long life times requires careful consideration of the wear out mechanisms and to meet this requirement means using a quality core material vendor (See www.micrometals.com/thermalaging_index.html for a good first discussion on thermal aging). The lesson here is that not all core materials are the same.

Back again

At this point some people go back to iron or ferrite and others go to an alternative core material like an amorphous alloy. If they then cannot meet the price point then they may well go back to laminated iron.

At this stage the realization is that there is no magic answer. The optimization of power inductors becomes the requirement and there is usually a realization that the inductor vendors are not as able as they seem. In the defense of the inductor manufacturers it must be said that most power electronics companies struggle to correctly specify inductors.

Getting off the inductor go round means designing the inductor completely.