Variable Frequency Drive for a larger factory fan

[chy_farm]

Last year we had a very hot Summer and Autumn so had a presumption that we should need a very big fan in our shed to get our job easier this year.
This motivation gave me a way to build a single phase Variable Frequency Drive for a bigger fan motor!

Fortunately or unfortunately we have cool Summer now, so not yet get a new big fan yet, nor have a chance to run this VFD...

[chy_farm]

Inside: Triangle and rectangle generators are analogue unit.

[chy_farm]

Started from these;






Making shifts to the frequency is to be done with a couple of white dials, an obsolete analogue way.




Chy

[chy_farm]

But on the way of assembling I found this handmade case was a tad small, so added some more rooms ;



Main power board with magnetic contactor and a transformer;


Placed a noise filter right after the main contactor;


Temperature sensors are placed onto five different part,
1: Bridge diode (50A),
2: Short cut unit,
3: Isolated Gate Bipolar Transistor unit,
4: High speed diodes for return current re-circulation unit,
5: Double 2mH filter coils right before the output terminal;


Output frequency monitor;


Output current monitor, and its detector (HAS-50);




Chy

[chy_farm]

Schematic for power units is;


Chy

please note there may be a wrong design in above drawing.

[chy_farm]

A couple of logic units of this type is known as noise-fragile to electro-magnetic noises. This part was one of the complexities to me.


Units in the right half (marked yellow) are electrically shielded with copper plate around them, they are a triangle wave generator and a wave form comparator, and a sine wave generator.

These in the left half are also shielded with so called shield wire (black wires), they make up a Pulse Width Modulation logic unit.

Chy

[nova_robotics]

That's great. Well done.

Why three Arduinos?

[chy_farm]

Good morning Nova, Why? ,,, only because I did not know other ways, lol. Do you make them in one Uno?
Chy

p.s. Glad to know you are a specialist of robotics, Nova!

[nova_robotics]

Good morning Nova, Why? ,,, only because I did not know other ways, lol. Do you make them in one Uno?
Chy

p.s. Glad to know you are a specialist of robotics, Nova!

Shoot me your code. I can have a look at it if you want. Are you bit-banging the Arduino functions? Interrupts and PWM outputs are very, very nice when you get them set up. If you swapped the three Arduino Unos out for one Arduino Due you can definitely monitor current, frequency and temperature with a single board, but you could probably also generate your sine waves. Arduino Dues are very fast. There are also lots of other (and much faster) boards to choose from as well. If you're having frequency and noise issues driving it directly from a microcontroller might solve some oscillator problems.

Again, awesome project and great work.

[chy_farm]

Shoot me your code. I can have a look at it if you want. Are you bit-banging the Arduino functions? Interrupts and PWM outputs are very, very nice when you get them set up. If you swapped the three Arduino Unos out for one Arduino Due you can definitely monitor current, frequency and temperature with a single board, but you could probably also generate your sine waves. Arduino Dues are very fast. There are also lots of other (and much faster) boards to choose from as well. If you're having frequency and noise issues driving it directly from a microcontroller might solve some oscillator problems.

Again, awesome project and great work.

Nova, thank you very much for your kindness.
This information is very big for me, for years I have been learning C, but not yet graduate from a first grade though, lol.
When I got to know Arduino, was a bit disappointed that it uses C++, which uses 'Class', this makes me mixed up and still I am loosing my way to restart learning.

So this offer is very great to me! Perhaps you make me stand again and start again Nova. Will try posting the code and ask you for your information.
Many thanks!!

Chy