Control of Solar Tracker Motor

Thread Starter

Yussef Ait

Joined Feb 5, 2019
4
Hello,
I want to control my single phase motor, that allows me to turn the tracker in Z axis,
So I am confused in what type of control i should use, because the motor is moving slowly to track the sun position.
Should i use a simple circuit with a relay connected to uC to turn ON/OFF moving it with small angles,
or its better to use PWM command or others !!
 

Thread Starter

Yussef Ait

Joined Feb 5, 2019
4
I didn't choose the motor characteristics yet,
for sensors i want to use a gyroscope that will serve to determine the solar panel position, and based on this data the motor will rotate.
I just found that in solar tracking DC motor are more used, it's simple to control. what do u think ?
 

Dodgydave

Joined Jun 22, 2012
9,912
I would use a DC motor and a Window Comparator looking at photocells, Whichever is giving more output the motor turns that way.
 

Thread Starter

Yussef Ait

Joined Feb 5, 2019
4
I would use a DC motor and a Window Comparator looking at photocells, Whichever is giving more output the motor turns that way.
actually i am using SPA algorithm and photo sensor what makes my system in hybrid loop control,
but the problem is i dnt know what type of motor will be useful in this application !
 

dendad

Joined Feb 20, 2016
3,733
I was going to make one of these too.
The motors I was thinking of using were windscreen wiper motors. They are readily available and come with a built in worm drive reduction.
This would be further geared down.
Position tracking was to be either with encoder, or an accelerator/compass module if it would work.
And the position was to be calculated, not sensed.
But I have not done it as yet.
Still, the windscreen motors should work ok. The only mod would be to remove the connection to the case that some do have, so both ends of the motor are floating.
 

oz93666

Joined Sep 7, 2010
737
Trackers are a solution to yesterdays problem ... when solar panels were 10 times the cost they are today ...

It's an interesting exercise , but has no practical value , for the cost of all the motors etc. you could double up on your solar panels and get much more output .... and of course the tracker will certainly break down before a year has passed ...

Even orientation of static panels is not as important as you would think , since such a big component comes from scattered light..

It may just be sensible on solar farms (in countries where labor is cheap) , to have a guy go around every week to slightly adjust orientation ... the support frame would have to be especially designed for adjustment ... I've never heard of this being done , so even this may not be economically viable.
 
Last edited:

dendad

Joined Feb 20, 2016
3,733
I think you are correct oz93666. More panels are easier. That is probably why I did not go ahead.
It could be fun to have 2 panels and log the power.
One fixed and one tracking.
Then swap the panels to cancel out variations. the extra power from the tracking would have to at least offset the motor power, but I do doubt it would be worth it other than just a fun project.
 

MisterBill2

Joined Jan 23, 2018
8,033
The solar tracking motors control task is simple because the sun moves at a known slow pace. So a small correction every few minutes will be adequate. Then after sunset the system needs to move back to the morning position, which is quite predictable. all the controller needs to do is activate when the error exceed some small value and then switch off when the error is reduced below some smaller value. And it only needs to track in one direction because the sun motion is fairly predictable. So a single-speed is all that you need to correct the error every few minutes. The return to start move can be handled by a pair of limit switches.
 

MisterBill2

Joined Jan 23, 2018
8,033
Actually the Sun does not move! :p:D
Max.
The sun does not move in a coordinate system that includes the sun as a fixed point. That is true. But in a coordinate system that includes the spots where we stand watching, it certainly does move. We learned that in the second week of our dynamics class, Max. And likewise with industrial robots, where the reference is some imaginary point within the grasp of the gripper.
 

mvas

Joined Jun 19, 2017
537
Use a motor that will survive the weather
Outdoor Antenna Rotors are weatherproof

P.S.
And our Milky Way Galaxy is moving,
All while the Universe is expanding ...
 

MaxHeadRoom

Joined Jul 18, 2013
22,403
And likewise with industrial robots, where the reference is some imaginary point within the grasp of the gripper.
Industrial robots have always typically used absolute encoders which retain position when powered down, as opposed to any of the other typical CNC machines that generally require re-refencing at power up.;)
Max.
 
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