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.
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.
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;
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.
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.
We are pleased to announce the 2018 power electronics digital control webinar schedule for ELMG Digital Power.
These free webinars are the best chance to be among the best digital power electronics control engineers in the world.
The sessions cover the need to know details of Digital Control of Power Electronics and include a question and answer session after the webinar.
Make a note of the dates.
|Tuesday May 1||Digital Control of Power Electronics using Zynq …[sign up here]|
|Tuesday June 5||What you need in a development platform for Digital Power Electronics…[Sign up here]|
|Tuesday July 3||Designing and Implementing Digital Integrators|
|Tuesday August 7||Using Simulation Tools effectively in Digital Power Electronics Development.. [Sign up here]|
|Tuesday September 4||Measuring Power Converter Control Transfers|
|Tuesday October 2||Basics of Digital Power Electronics Control – Where to Start|
|Tuesday November 6||How to choose your control processor for Digital Power Electronics|
|Tuesday December 4||Frequency Domain Control Design for Digital Power Using SciLab|
|Tuesday January 8 2019||Precision Correction in Digital PWM Modulators|
|Tuesday February 5 2019||Filter Structures for Digital Power Electronics Control|
|Tuesday March 5 2019||Fractional Step Digital Filters|
|Tuesday April 2 2019||Development Structures for Firmware and Software in Digital Power Electronics|
|Tuesday May 7 2019||Grid Synchronization with PLLs|
We’ll remind you of the time, dates and where to sign up by e-mail.
The webinars will be presented by ELMG Digital Power CTO, Dr Hamish Laird.
Is there a student discount for the Digital Power Electronics Control Course?
In short the answer is no.
That said graduate students can benefit immensely from the course.
In the past students have attended and one of the students asked Dr.Laird to help with supervision in her PhD project on partial step filters for grid connected power converters. Dr Laird helped until her graduation in 2017.
The intention of the course is to provide industry training and to enable industry people. This means these attendees are the priority.
ELMG Digital Power invites you to register for our tailored training course, ‘Introduction to Advanced Digital Control of Power Electronics’
The workshop is in Camarillo, California.
Be among the best digital power electronics control engineers and get the best digital control of power electronics training.
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 digital 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.
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.
The course has been specifically designed to meet the learning needs of engineers, regardless of whether you are:
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.
ELMG Digital Power are continuing in the Xilinx Alliance Program.
After meeting the requirement to have Xilinx certified engineers we successfully completed the application for the program.
When asked about this Dr Laird said
“As part of ELMG Digital Power’s continuing commitment to providing fantastic service and products we are privileged in continuing our Xilinx Alliance Program membership. We see great things happening with Xilinx All Programmable FPGAs and Zynq SoCs. It was great to see the capability of the SDSoC tools and to see the progress and extension of the Vivado Suite. We are really pleased to continue our Xilinx Alliance Program commitment and are please to be part of the Xilinx community.”
Dr Laird continues
“We are very pleased and proud of our Xilinx Alliance Program membership and for the value that it lets us bring to our customers. Training for key people in our organization is essential for us to continue to help our customers with FPGA and other All Programmable solutions. Our IP blocks, power electronics know how and ability to deliver solutions are our key areas of focus.”
See you at APEC 2018 next week. Here is the ELMG Digital Power APEC 2018 Presentation Schedule. Join us and Ridley Engineering at Booth #1025 at APEC.
Monday March 5th
5:00pm Show opening
6:00 pm Running RidleyWorks
7:00 pm Beyond Small-Signal Models
7:30pm Digital Control – What goes Wrong?
Tuesday March 6th
12:00pm Show opening
12:30pm Proximity Loss Models
1:30pm Rapid prototyping with SwitchBit
2:30pm Precision extension in digital integrators – how and why?
4:30pm Dead time compensation in DC to DC converters
Wednesday March 7th
10:00am Show opening
10:30am Ridley Engineering Hands-on Workshop
11:30am Designing your converter so you can control it with digital control
12:30am Ridley Engineering Internship Program
1:00pm RidleyWorks Game Final
See you at APEC in San Antonio, Texas.