Archive for the ‘Control’ Category

Frequency Responses for Control

Monday, September 25th, 2017

ELMG Digital Power are offering you the opportunity to attend our regular webinar on Digital Control in Power Electronics.  This month’s webinar is titled “Frequency Responses for Control”.

This is an hour webinar covers

  • understanding frequency responses for control
  • how to use frequency responses for control in design of power converters

Thursday 12th October at 12 noon California time (3pm Eastern).

Webinar – Frequency Responses for 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. Hamish is ELMG Digital Power’s CTO and presenter and teacher of the Digital Control of Power Electronics Workshop. He 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.

Frequency Responses for Control

Converter Frequency response from Analyzer Measurement

 

 

 

 

 

 

 

 

The webinar is scheduled for Thursday 12th October at 12 noon California time (3pm Eastern).

Click the link below to register.  Spaces are limited.

http://info.elmgdigitalpower.com/frequency_responses_for_control

Frequency Responses for Control

Converter Frequency Response from Self Measurement

DIGITAL CONTROL OF POWER ELECTRONICS – A FOUR DAY TRAINING WORKSHOP

Monday, January 16th, 2017

ELMG Digital Power invites you to register for our tailored training course, ‘Introduction to the Digital Control of Power Electronics’ to be held in Camarillo, California on January 30th – February 2nd 2017.

ELMG Digital Power INC – Empowering you to achieve the Digital Control advantage

Register here

Hands on Course

This hands-on course aims to provide engineers with solutions to the key issues in digital signal processing, using microcontrollers, microprocessors, DSP and FPGA. These solutions can then be employed effectively in the control of power electronics.

Over the four-day course, split into morning and afternoon sessions, participants will be provided with targeted training on digital power electronics control covering the detail of both digital control and power electronics and how they go together.  They will gain the ability to close a digital power converter feedback loop in a stable fashion by following repeatable easily understood steps, as well as techniques to understand what the effect digital control’s limited bandwidth, processing power, number of bits and dynamic range have in digital power electronic control.

What you get from the course?

Engineers who attend the course will gain in-depth knowledge of the interaction of power electronics and digital control; this includes sampling and aliasing in the context of fixed and variable frequency switching power converters. There will be take away methods and steps to solve design issues such as one sample noise, precision limits in filters and controllers, non-linearity, quantization and other digital effects.  A copy of the slide slide presentation course booklet covering the material presented and lunch each day will be provided.

Introduction to Digital Control of Power Electronics

The 30 engineers who completed the Digital Control of Power Electronics Course August 2016

Who is the course for?

The course has been specifically designed to meet the learning needs of engineers, regardless of whether you are:

  • a practicing power electronics engineer,
  • an experienced engineer moving into the area of digital control of power electronics,
  • a software engineer working in digital power control teams,
  • a firmware engineer involved in FPGA development in digital power control teams,
  • a mid-career engineer transitioning from analogue control to digital control, or
  • a recent graduate with some experience (<5 years) and looking to up skill in the area of digital control.

Register here

The course will be presented and led by Dr. Hamish Laird, Principal Engineer at ELMG Digital Power. An extremely well-regarded teacher, engineer, researcher and public speaker, Hamish works in developing digitally controlled power converters and controllers for converters. He is the author of seventeen academic papers on digital power electronics and power quality and has taught previous digital power courses at Camarillo.

Introduction to Digital Control of Pwoer Electronics - Four Day Training Workshop

Dr. Hamish Laird at the Camarillo Ridley Engineering Design Center

Advanced Digital Control Power Electronics Course

Wednesday, October 19th, 2016

Digital Control Power Electronics course – January 30 to February 2

The next Advanced Digital Control of Power Electronics training course is running in

Camarillo, California

January 30 to February 2

Registrations open now – click here or on the button below


Register now


Course outline is here.

Four days

The course has been expanded to four days and includes lab sessions each day to reinforce the learning on

  • Precision extension of Digital Modulators
  • Digital Loop closing
  • The effects of delay
  • Loop measurement using the control processor.

What people who have attended say about the course?

“Had very high expectations of this course. Hamish delivered. Excellent for power engineers who are starting digital power. Thanks for putting this on…I only regret it is a 3 day course. I could sit here for 3 more days”

“This course was full of critical material not found in the app notes.  Very enjoyable and well taught.”

“Good course. Hamish knows his material. I’ll be able to apply this coursework to my work.”

 

“I would highly recommend the ELMG digital control course to all power electronics engineers.  What makes this course particularly valuable is in the practical approach and relevance to the control of power electronics.  The topic of digital control is a very broad subject and hence the specific challenges and applicable tools are very different depending on the application details. Many digital control / DSP courses try to approach the topic from a very generic broad approach, treating all applications in the same way.  The classic approach involves starting from a conventional analog control model and then adding ADC and DAC blocks to change between the analog and digital domains with a digital controller replacing the traditional analog controller. The problem with this classic approach is that it is not a practical or applicable method for designing high bandwidth controllers for use for the control of power converters. The ELMG digital control course specifically focuses on the control of power electronics and hence the course only considers concepts and techniques that are applicable to the control of power electronics.  The course covers a wide range of digital control theory and introduces the power electronics engineer to all of the state of the art digital control concepts.  This course is a must for any power electronics engineer who is involved in the digital control of power converters.”

Michael Harrison – Director of Power Conversion, Enphase.

Register by clicking below





Register now





 

Latching digital PWM – good feature or bad feature

Sunday, August 7th, 2016

 

This from a discussion in the Digital Power Electronics Control Group on Linkedin 

‘I was wondering if you could explain what you mean by “…ensuring that the PWM does not latch at the switching speed (very important for wide bandwidth)”. Isn’t the PWM comparator by nature a latch? Are you implying for best performance one should not use PWM shadow registers but rather do ” immediate” PWM updates?’

Latching digital PWM – good feature or bad feature?

Hamish from ELMG Digital Power

‘D. – I am not implying that latching is necessarily completely bad. Latching does have some uses as it provides another place in the system where you can reduce the effect of “aliasing in time” on transients. That said if you use a latching PWM then it is clear that you add delay. Whether this matters for your control depends on the bandwidth aim you have and whether you have designed a system that has low margin due to its power converter. But generally we always use our PWMs wide open with no latching delay to minimise the phase we get. We sample faster than the switching frequency and use the PWM as a down sampler. It means you need to take care of the “aliasing in time” elsewhere and be careful about intermod product magnitude from other non linearities in the loop – low pass filters are required along with a bit of modulation know how. Very doable and looks like magic when you need more bandwidth.’

Come join the discussion on all things Digital Power in the Digital Power Electronics Control Group

Latching digital PWM - good feature or bad feature

Look for the LinkedIn Group with this identifying z domain function.

On the course do you address the issues that occur in digital control teams between software engineers and power electronics hardware engineers

Tuesday, August 2nd, 2016

How do hardware and software engineers talk to each other?

This is the extract from a recent conversation on LinkedIn between power electronics engineers of all different flavors.  It sums up beautifully the issues between hardware and software engineers in digital power electronics control developments. (Names shortened to protect the innocent.)

D. H.

‘Y. & A., I have no idea what half of the acronyms are which you (software) guys are using but, I get the feeling from A.  that optimized C (whatever that is) is slower for a multiplication than assembly. Y. seems to be saying that a particular version of C he likes creates a faster multiplication.
So, I’m just left confused. Which is it?
I’m from the 80’s. This is when a multiply was a simple, understandable add-shift, add-shift,….repeat 8 times and you’re done. Many modern processors have one command – MUL AxB. Nowadays, digital guys are telling me that this method is so complicated. Why? Why is a simple multiply so complicated now when 30 yrs ago it was routine and easy to understand?’

Hamish from ELMG Digital Power

‘D. H. – there is a really big disconnect between the software able guys like Y. and the non software able guys ( I am guessing you – sorry if I am wrong). It is often that sort of cultural mis-alignment that causes lots of issues in the development. We fix the cultural alignment for companies sometimes. And its a process and there isn’t really an easy road and, I hate to say it, some teams go under doing it. We created our digital training course as the result of a customer R and D manager asking us when we were in the middle of a fix up “How could we have avoided this?” ‘

D. H.

‘Hamish, You’re right about the cultural mismatch. (Yes, I’m not a software guy). My post a few days back concerned a software guy who had trouble communicating to me why his code was lengthy and complex, and I had trouble communicating with him as to why my view of a simple look-up table isn’t valid anymore. Maybe D. E. was correct, a “good” programmer should know how to deal with math.
Are these type of issues going to be addressed in your course?’

Hamish 

‘D. H. – In short yes. The slightly longer answer is. In the course we cover this culture issue both explicitly and implicitly. Team culture structure and organisation for digital power controllers are really important to success. And even more critical to sustained success when the “fix up” consultant has left the building. How we address this group culture issue in the course is by showing the attendees how to setup the conversation and documents so that the different types of people all can understand and contribute. Understanding and empathizing with the software engineers ethos, and what he values, is key to the power electronics converter engineer being able to do her job. And likewise. Engineers are technical people – which often speaks for itself in team dynamics. In the course we cover how matching the system partition to the team partition and to the system documents gives you a really good shot at success.’

Y.

‘D. H.  , It is a known problem where software get hard time from hardware and vice versa ,many project fell because of this issue
I solved this problem long time ago when I decided to learn software (computer science ) after a good career as a hardware designer and since then all the hardware and software issue solve internally :-)’

Hamish from ELMG Digital Power

‘Y. is right that you can just learn it all; hardware, software and control. The problem comes when you leave the job and the team have to do it without you. Super engineers are great until they leave the team. And not every company can employ one and most companies prefer a team to manage this risk.’

Come to the course in Camarillo, California,  August 22 through 24 and we’ll show you a good approach to dealing with this cultural mismatch.

Register here

 

Three Day Digital Control Course August 22-24 California

Friday, July 22nd, 2016

The ELMG Digital Power Electronics Control Course

Three days of focused unique training in digital control of power electronics!

Our Digital Power Electronics Control Course overs the essential knowledge and know-how for engineers to implement digital power electronic control!

Come to the Three Day Digital Control Course in Camarillo, California August 22-24, 2016.  Register here.

How did the course came about?

Essentially the course came about because we were asked by one of our customer’s to provide one. The story is we were in the middle of a “fix up” job where the power supply had shown some control instability at its final release testing. The testing that showed the problem was passing a short circuit test of parallel connected power supplies. When the short circuit was removed the supplies came out of current limit, however they did not come out of the limit at exactly the same time. This created an oscillation where individual power supplies came out of current limit and then returned to current limit.  It was possible for the oscillation to continue indefinitely.  This was an unacceptable and embarrassing problem.

Six months of expertise in a three day course

During the six month project to rework the control code we spent lots of time teaching the team about the underlying issues that had been missed when the controller had been designed, coded and tested.  And part way through the “fix-up” the R and D manager suggested we could put a course together covering all that the team needed to know.

And so the digital control course was born

The first course covered exactly what we had discovered during the fix up job.  This included lots of digital expertise targeted for power electronics.  The areas we covered were diverse from;

  • Numeric precision loss in filters
  • Improvement of modulation spectral performance
  • Stability
  • The effect of numeric precision on stability
  • Best filter forms
  • Direct digital control design
  • Linearising control loops

What is covered in our course?

The course was created at the request of a Power Electronics Research  and Development manager.  He asked that we make it specific his team’s needs.  And this is why the course has the unique structure that it has.  We have been through the pain and heartbreak of having digital control development go wrong and have seen clearly where the repeated problems lie; our course addresses those areas.

Digital PWM and VPO modulators

One of the big differences between digital power electronics control and conventional analog control is the timer precision in digital modulators. This difference can be corrected or made negligible and in some cases can be made an advantage.  Spectral control in digital modulators is a focus area in the course as it is so effective.

Digital Precision in control blocks

It is possible to use a digital system and adjust the coefficients of the filters so that small inputs result in no output from the filter. Such scaling issues often lead to a loss of precision in the digital control system. The resulting slip-strike behavior can create limit cycle oscillations in the power converter output.

Direct Digital design of controllers

The “design then translation” approach of taking analog controllers to digital form can be avoided by using the direct digital design approach. This simple but powerful method of digital control loop design is covered in the course.

Converter non-linearity correction

Certain converter topologies are non-linear either in the control input to the output or the conversion ration.  Dealing with the converter non-linearity to achieve high bandwidth is key to stable parallel connected converters.

Stability

The course covers the fundamentals of stability from a physical basis with a focus on measurements of power converter transfers.  This along with a simple framework for managing margins and robustness is an integral part of the course.

Why we offer the course?

Understanding and implementing digital control of power electronics offers great advantages for configuration and flexibility. However, this is not without road blocks and issues that need to be designed around. This course provides the know how to get digital control working robustly and reliably.

How do I get on the course?

The course is next being run in Camarillo, California USA August 22-24.  To register for the course, click and visit the information page here. Press the ‘Register’ button on the page and this will take you to the shopping cart for the course. Complete the purchase to register for the course.

Next course

The next course is being held August 22-24 in Camarillo, California, USA.

Hotels

HOTELS

There are several hotels a short distance from the Ridley Engineering Design Center. The prices below reflect their current prices for August 2016. The last hotel listed is a nice beachfront resort if you do not mind the 25-minute commute to the office. Regardless of your selection, we recommend arriving on Sunday evening and departing Wednesday evening or Thursday.

 

Best Western Inn

295 E Daily Drive, Camarillo

0.3 mi.

805-987-4991

$100/night

Book.western.com

Residence Inn by Marriott

2912 Petit Street, Camarillo

2.8 mi.

805-388-7997

$185/night

Marriott.com

Courtyard by Marriott

4994 Verdugo Way, Camarillo

4.3 mi.

805-388-1020

$180/night

Marriott.com

Hampton Inn & Suites

50 W Daily Drive, Camarillo

1.1   mi.

805-389-9898

$175/night

Hilton.com

Hilton Garden Inn

200 Solar Dr., Oxnard

5.6 mi.

805-983-8600

$155/night

Hilton.com

Embassy Suites Mandalay Beach Resort

2101 Mandalay Beach Rd., Oxnard

15.4 mi.

805-984-2500

$200/night

Hilton.com

Travelling to the course

Transportation

Airports: There are three options for airports. Bob Hope Airport in Burbank will be the least congested and is serviced by American, United, Delta, Southwest and JetBlue:

Bob Hope Airport (BUR)

Los Angeles International Airport (LAX)

Santa Barbara Airport (SBA)

Shuttle: The Roadrunner Shuttle is a Camarillo-based service that provides door-to-door service from the airport. www.rrshuttle.com

Driving:

Bob Hope Burbank Airport (BUR) via US 101

https://goo.gl/maps/caMGB9QSEqP2

Los Angeles International Airport (LAX) via US 101

https://goo.gl/maps/kRBDQifyVfM2

Los Angeles International Airport (LAX) via Pacific Coast Highway (PCH)

https://goo.gl/maps/XPbBhNQYTzj

Santa Barbara Airport (SBA) via US 101

https://goo.gl/maps/2fGP3K7FMZx

About the presenter

3 Day Digital Control Course

Dr. Hamish Laird

Dr. Hamish Laird is a well regarded digital power electronics control engineer, researcher, lecturer and teacher.  Hamish is Chief Technology Officer at ELMG Digital Pwoer and holds a visiting academic position at the University of Canterbury in Christchurch, New Zealand.

During his career Dr Laird has worked on the control for;

  • High Voltage Direct Current Transmission
  • Reactive Power Compensators
  • AC and DC Motor Drives
  • DC to DC converters including LLC and phase shifted bridges
  • Medium and low voltage AC motor starters

Dr. Laird has worked for;

  • Alstom Grid (GEC Alsthom)
  • Eurotherm Drives
  • University of Canterbury
  • Aucom

Through ELMG Digital Power Dr. Laird  has provided advice, services and products to;

  • ABB
  • Enphase
  • Comsys
  • Evashred
  • TNEI
  • Eaton

Dr Laird says

“In designing and presenting the course we aim to have engineers able to use digital control in power electronics to achieve robust and reliable results.  See you in Camarillo”.

 

How to Register

Click here to register.  

P.S. Please note that the ELMG Digital Power course is being hosted at the Ridley Engineering Centre in Camarillo, California.  Ridley Engineering are processing all course registrations viatheir webstore.  Click here to register.