Hello. I am new to this forum and have just joined after browsing for a while. I would like to build a PV diverter using a Raspberry PI. I am a retired electronics/computing person and can see my way to programming and doing the electronics side. I have the following questions( which may have already been answered- apologies if that is the case)
1) Can I buy a commercial backend to do PWM on my immersion heater. This is so I and my house insurer can sleep at night :-)
2) I have followed the talk on phase and burst control but a lot of the commercial devices say they use PWM to keep harmonics down and to provide more efficient control.
3) If anyone else has used a Raspberry Pi is Python fast enough for the control or is it better to use a C compiler
4) Is there a good source of CT transformers and interface electronics that are both cheap and reliable.( born in Yorkshire)
5) has anyone an algorithm that uses PWM
many thanks in advance
Geoff
Re: New to the group
Hello, Geoff, and welcome.
When you write PWM, you mean like this? I'm not aware that anyone has done it. You still need some high voltage switching and filtering components, albeit the filter will be a lot smaller than the phase control equivalent.
The shop will sell you a split-core 100 A c.t., there have been very few reported failures of these. There are reports of cheap SSR's that have failed, so the advice there is to buy a quality one from a reputable supplier, (i.e. not fleabay); but as you seem to know about electronic construction you might be happier doing it yourself. We've had one report of a problem - this is where the constructor had tinned the high current wires and then used screw terminals. Of course, the solder flowed, the contact pressure was gone and the chocolate block melted! We put him right.
I can't answer the other points.
Re: New to the group
Welcome Geoff.
Python may be slow for intensive calculations, but I don't think it could be a limit for "control". Or perhaps am I mistaken on what you refer to as "control". Perhaps if you had mathematically complicated regulation filters, you'd end up reaching a limit, but I don't see that coming.