Posts Tagged ‘LinkedIn Group’

Latest news from the LinkedIn Digital Power Electronics Control Group

Monday, August 31st, 2015

What is the latest news from the Linkedin Digital Power Electronics Control group?

The group now has over 600 members. To join the group please click here.

In the group we have lively discussions with people contributing their knowledge and experience. To all who have contributed and made the group so much fun – a really big thank you.

In the group we have had discussions that cover

  • Digital PWM modulators
  • ADC (analogue to digital converters)
  • Choosing the number of bits in a digitally controller,
  • Implementing digital filters,
  • Processor choices and coding.

How many bits are required in digital control of power electronics

Recently the how many bits are required was brought up and addressed in this way by John S.

There are two aspects to selecting the number of bits: measurement resolution and control variable resolution. For measurement resolution, the ADC resolution is the deciding factor, and this can be increased by oversampling.

In a current control application I was recently working on, I required 14 bits of resolution to meet a target requirement of +-1% of ADC quantitization error at 10% current. This resolution was relatively simple to achieve by oversampling the 12 bit ADC in the uC.

The resolution of the control variable, e.g. uC timer resolution, is just as critical in fast systems. If the resolution is too coarse, jitter in the control variable will appear at the output. With slower system dynamics, e.g. in voltage controlled systems, jitter in the control variable causes less jitter in the output variable because of the smoothing effect of the output capacitor. Ideally the resolution of the control variable should match that of the measured variable.

Thanks John.

Thanks also to all the other contributors.

Other discussions cover measuring stability of power converters, what is the effect of PWM timer quantisation and what is the best converter for isolated bi-directional DC to DC.

 Join the group by clicking here.

The best integrator for digital control.

Look for this symbol to identify the group.

Digital Power Electronics Control Group on LinkedIn

Wednesday, February 25th, 2015

We have started a group where we can share questions and discuss Digital Power Electronics Control on LinkedIn.

The group’s name is Digital Power Electronics Control.

The link to the group is https://www.linkedin.com/groups?home=&gid=6677852.

Look out for the group identified with the z-transform image like that shown above.

Recent Group Discussions

Recent discussions have included one on the effects of precision limits for PWM timers

Another thread covers how to get started in Digital Control of Power electronics.

There are some well known and expert members in the group who share experience and insight.

The group is private to prevent the spam that has been increasing on Linkedin so please ask to join.

Where to begin with digital control

The discussion on where to begin with digital control is an ongoing and popular thread.  The thread has 49 replies from group members offering advice on what is important in digital control of power electronics

Slip Strike

Another discussion covering a very specific issue is on handling slip-strike problems.  Slip strike is what happens where the system output gets “stuck” and then suddenly moves.  This typically happens in mechanical or hydraulic systems where the friction coefficient falls as movement begins.  A relatively simple solution is to use a high derivative gain to reduce the effect.  Other solutions include linearising the system to allow higher controller gains and higher bandwidth.

Choosing the control processor

The discussion on choosing the processor for digital control is also still popular.  This covers which is the best micro controller or processor for digital control of power electronics.  This is an ongoing and recurring theme as more people  use digital control for their power electronics.  Other subjects in the thread include

  • analogue to digital converter choice
  • aperture time
  • settling time and
  • how to design a digital loop compensator

Numeric precision and the effect of limited PWM timer bit limits are also mentioned.

Join the community

We look forward to seeing you there.

Come and join the community at the Digital Power Electronics Control group on LinkedIn.

https://www.linkedin.com/groups?home=&gid=6677852.

Download the report ‘Your Digital Power Future – Roadblocks to Avoid’ to learn about the three key issues to watch out for in the Digital Control of Power electronics.


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