PV Module Simulink models ECEN 2060

Transcription

1 P Module Simulink models ECEN 060

2 Simulink models of P modules Current-input P module nputs: P P current P [A] [W/m ] Outputs: P voltage P [] P output power [W] This model is well suited for the case when modules are connected in series and share the same current oltage input P module P module () P nputs: P voltage P [] [W/m ] Outputs: P current P [A] P output power [W] This model is well suited for the case when modules are connected in parallel and share the same voltage Model parameters, in both cases, are the standard P module data-sheet parameters: short-circuit current sc open-circuit voltage oc rated current R at maximum power point (MPP) rated voltage R at MPP under standard test conditions (kw/m,.5 AM, 5 o C). A bypass diode (a single diode across the entire module) can be included. Temperature effects are not modeled.

3 P cell circuit model and equations SC R s + KCL: SC R p P = 0 R p iode characteristic: P cell _ ( / ) e T = o KL: Pcell = R s P 3

4 Simulink mplementation Both P module models are implemented as masked subsystems in Simulink Look Under Mask (right-click or Edit menu) reveals details of the model implementation etails of the current-input P module model: P Saturation -t*log((u/o)+) By-pass diode max MinMax iode Constant Product G to current gain sc f (z) Solve f(z) = 0 Algebraic Constraint z d cell Switch nputs: P current and insolation d o*(exp(u/t)-) PN-junction characteristic d/rp /Rp /Rp Outputs: P voltage and P power 4

5 nside the current-input P module model Saturation -t*log((u/o)+) By-pass diode max MinMax iode Constant Product G to current gain sc f (z) Solve f(z) = 0 Algebraic Constraint z d cell Switch d o*(exp(u/t)-) PN-junction characteristic d/rp /Rp /Rp N s = P N s Pcell = number of cells in series SC R p P KCL solved for using Algebraic Constraint block = 0 / ( ) e T = o Pcell = R S P 5

6 nside the current-input P module model Saturation -t*log((u/o)+) max Bypass diode current cannot be negative By-pass diode MinMax iode Constant Product G to current gain sc f (z) Solve f(z) = 0 Algebraic Constraint z d cell Switch d o*(exp(u/t)-) PN-junction characteristic d/rp /Rp /Rp bypass bypass = t ln + o Bypass diode voltage (if forward biased) Select P with bypass diode ( iode = ) or without bypass diode ( iode =0) 6

7 Model Mask: Parameters Edit Mask (right-click or Edit menu), click on Parameters This is where the masked subsystem model parameters are defined 7

8 Model Mask: nitialization Edit Mask (right-click or Edit menu), click on nitialization The MATLAB code computes model parameters o, R s, R p based on the model parameters (short-circuit current sc, circuit voltage oc, rated voltage r, and rated current r ) 8

9 Application Example: P Array P array consisting of 6 P modules connected in series 000 P 6-module P Array P + P P To Workspace P3 XY - P P4 Product XY power _ P5 P6 Add Simulink model pv_array.mdl Ramp 9

10 nside the voltage-input P module P module () P f (z) Solve f(z) = 0 Algebraic Constraint z nputs: P voltage and insolation Current-input P model Algebraic Constraint block solves for P that results in P Outputs: P voltage and P power 0

11 Application Example: P Module Characteristics Simulink model: pv_characteristic.mdl P power - characteristic P module () P = 00, 400, 600, 800, 000 W/m P P P P P