New post on our linkedin group
This new discussion in our the Digital Control LinkedIn group.
Come join the discussion at https://www.linkedin.com/groups/6677852 and get the best views from the industry.
Great question.
The next Advanced Digital Control of Power Electronics training course is running in
Registrations open now – click here or on the button below
Course outline is here.
The course has been expanded to four days and includes lab sessions each day to reinforce the learning on
“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
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?’
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
Look for the LinkedIn Group with this identifying z domain function.
Dr. Tim King presented the Digital Power Control on a Zynq webinar.
In the presentation Dr. King detailed how the programmable logic fabric of the Zynq was fantastic for low latency and high precision digital power control.
He also outlined how to make use of the ARM A9 cores
The slides are available here
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.
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.
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.
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;
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.
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.
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.
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.
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.
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.
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.
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.
The next course is being held August 22-24 in Camarillo, California, USA.
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 |
| Residence Inn by Marriott
2912 Petit Street, Camarillo |
2.8 mi.
805-388-7997 |
$185/night |
| Courtyard by Marriott
4994 Verdugo Way, Camarillo |
4.3 mi.
805-388-1020 |
$180/night |
| Hampton Inn & Suites
50 W Daily Drive, Camarillo |
1.1 mi.
805-389-9898 |
$175/night |
| Hilton Garden Inn
200 Solar Dr., Oxnard |
5.6 mi.
805-983-8600 |
$155/night |
| Embassy Suites Mandalay Beach Resort
2101 Mandalay Beach Rd., Oxnard |
15.4 mi.
805-984-2500 |
$200/night |
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:
Los Angeles International Airport (LAX)
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
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;
Dr. Laird has worked for;
Through ELMG Digital Power Dr. Laird has provided advice, services and products to;
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”.
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.
At APEC this year we presented High Performance Digital Control of Power Electronics. We then made the slides available and repeated the presentation as two webinars.
Click here to download the slides if you do not have them already https://info.elmgdigitalpower.com/high-performance-digital-control-presentation
Thanks to some good attention by a person who worked through the controller example, we have noticed an error in one of the coefficients on the slide as shown below.
The correct value for the b1 coefficient is 0.00625.
Thanks to the helpful person who found this.
APEC Presentation slide correction for b1 coefficient
