PV

Question 1

What is the nominal power of PV modules?

Answer 1

100-350W

Question 2

PV cells & modules in series…

Answer 2

Increase total voltage

Question 3

PV cells and modules in parallel..

Answer 3

Increase total current

Question 4

What is the difference between indirect and direct MPPT methods?

Answer 4

Indirect: relies on prior knowledge of PV module characteristics & measurements of irradiance and temp. Real MPP cannot be achieved

Direct: based on iterative algorithm ma that measure current and/or voltages at the PV array terminals. The voltage applied to the PV arrays is changed to achieve MPP. Real MPP can be achieved

Question 5

Name 2 indirect MPPT methods

Answer 5

Open-circuit method
Short-circuit method

Question 6

Name 2 direct MPPT methods

Answer 6

Perturbation & observation (P&O)
Incremental Conductance (IncCond)

Question 7

Explain the open-circuit method

Answer 7

An indirect mppt method.

An linear relationship between MPP and open circuit voltage is defined:
V_mpp = k_vmpp * Voc

Open-circuit voltage can be estimated based on temp and irr measurements:

Voc = Voc,n + K_v (T-Tn)

Constants can be obtained from STC parameters

Question 8

Explain the short-circuit method

Answer 8

Indirect MPPT method

Similarly to the open-circuit method but we use the short-circuit current.

I_mpp = k_impp Isc

Isc = (Isc,n + K_I (T-Tn)) G/Gn

Constants obtained from STC parameters