[SOLVED] Algorithm MPPT (P&O )

[delo]

Hello,I am the student of electronics.The P & O algorithm :

When will the MPP is reached in practice? And what is the value of D (expression) ?
Thank you in advance for the answer.

 

[max.wangxin.sh]

maybe you can get some clues from LT8490, one IC from LTC for MPPT and battery charger.

 

[kappa_am]

it reaches the optimum value when P-P(n-1)=0.
Value of D is depend on the system for which you are implementing if D is large it has high dynamic but you may have oscillation around optimum point. If it is small you reach the optimum point more precisely but in longer time.

 

[Warpspeed]

And what is the value of D (expression) ?
.

D is the small difference you either add to, or subtract from, V ref.

D causes Vref to step up, or step down. The size of D sets the size of the steps.

 

[delo]

Thank you. And what is the initial value of Vref and D?

 

[Warpspeed]

Vref can be any starting off point you choose, perhaps the specified MPPT voltage for the panels you are using, or maybe half the control range. It probably does not matter all that much.

D is something you choose by experience. If its made too large the control point may jump around excessively. If its made very small, correction may be very slow.