Voltage input PV module. Inputs: ⢠PV current IPV [A]. ⢠Insolation [W/m2]. Outputs: ⢠PV voltage VPV [V]. ⢠PV output power Ppv [W]. This model is well suited for ...
PV Module Simulink models
ECEN 2060 Spring 2008
Simulink models of PV modules Current-input PV module Ipv
PV module (I)
Insolation
Inputs:
Voltage input PV module Vpv
Vpv
Insolation
Ppv
PV1
• PV current IPV [A] • Insolation [W/m2]
Outputs: • PV voltage VPV [V] • PV output power Ppv [W]
This model is well suited for the case when modules are connected in series and share the same current
PV module (V)
Inputs:
Ipv Ppv
PV1
• PV voltage VPV [V] • Insolation [W/m2]
Outputs: • PV current IPV [A] • PV output power Ppv [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 PV module data-sheet parameters: • short-circuit current Isc • open-circuit voltage Voc • rated current IR at maximum power point (MPP) • rated voltage VR at MPP under standard test conditions (1kW/m2, 1.5 AM, 25oC). A bypass diode (a single diode across the entire module) can be included. Temperature effects are not modeled. ECEN2060
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PV cell circuit model and equations KCL:
I SC ISC
ID VD
Rs
+
Rp
Diode characteristic: _
PV cell
VD − ID − − I PV = 0 Rp
(
)
I D = I o eVD / VT − 1 KVL:
VPVcell = VD − Rs I PV ECEN2060
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Simulink Implementation • Both PV module models are implemented as masked subsystems in Simulink • Look Under Mask (right-click or Edit menu) reveals details of the model implementation PV module (I) • Details of the current-input PV module model: Ipv
Vpv
Insolation
Ppv
PV1
Saturation
-Vt*log((u/Io)+1)
max
By-pass diode
MinMax
Rs 1 Ipv
2
Rs
Ipv
Product
Ppv
Diode
Ipv
Constant
2 Insolation
G
Isc
Insolation to current gain
Inputs: PV current and insolation ECEN2060
f (z)
Solve f(z) = 0
z
Vd
Algebraic Constraint
Id
Io*(exp(u/Vt)-1)
PN-junction characteristic Vd/Rp
1/Rp 1/Rp
Vpv cell
1
Ns Switch
Vpv
Ns
Outputs: PV voltage and PV power
4
Inside the current-input PV module model Saturation
-Vt*log((u/Io)+1)
max
By-pass diode
MinMax
Rs 1 Ipv
2
Rs
Ipv
Product
Ppv
Diode
Ipv
Constant
2
G
Insolation
Isc
Insolation to current gain
f (z)
Solve f(z) = 0
z
Vd
Vpv cell
Algebraic Constraint
Id
Io*(exp(u/Vt)-1)
Vd/Rp
VPV = N sVPVcell
1/Rp
N s = number of cells in series
1/Rp
I SC
KCL solved for VD using Algebraic Constraint block ECEN2060
Switch
Vpv
Ns
PN-junction characteristic
V − I D − D − I PV = 0 Rp
1
Ns
VPVcell = VD − RS I PV
(
)
I D = I o eVD / VT − 1
5
Inside the current-input PV module model Saturation
1 Ipv
-Vt*log((u/Io)+1)
max
By-pass diode
Bypass diode current cannot be negative
MinMax
Rs 2
Rs
Ipv
Product
Ppv
Diode
Ipv
Constant
2 Insolation
G Insolation to current gain
Isc
f (z)
Solve f(z) = 0
z
Vd
Algebraic Constraint
Id
Vpv cell
1
Ns Switch
Vpv
Ns
Io*(exp(u/Vt)-1)
PN-junction characteristic Vd/Rp
1/Rp 1/Rp
I bypass + 1 VDbypass = Vt ln Io
Select VPV with bypass diode (“Diode” = 1) or without bypass diode (“Diode” =0)
Bypass diode voltage (if forward biased) ECEN2060
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Model Mask: Parameters • Edit Mask (right-click or Edit menu), click on Parameters • This is where the masked subsystem model parameters are defined
ECEN2060
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Model Mask: Initialization • Edit Mask (right-click or Edit menu), click on Initialization • The MATLAB code computes model parameters Io, Rs, Rp based on the model parameters (short-circuit current Isc, circuit voltage Voc, rated voltage Vr, and rated current Ir)
ECEN2060
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Application Example: PV Array PV array consisting of 6 PV modules connected in series
Ipv
1000
PV module (I)
Insolation
Vpv
ECEN2060 6-module PV Array
Ppv
PV1
Insolation
IPV
Ipv
PV module (I)
Insolation
Vpv Ppv
PV2
+ Ipv
PV module (I)
Insolation
PV To Workspace Vpv Ppv Vpv
PV3
Ipv
PV module (I)
Insolation
VPV
Vpv
XY V-I Vpv Ppv
PV4
Ppv Ppv
Ipv
PV module (I)
Insolation
Product
Vpv Ppv
PV5
Ipv
PV module (I)
Insolation
_
XY power
Vpv
Ipv
Simulink model pv_array.mdl
Ppv
PV6
Add
Ipv Ramp Ipv
ECEN2060
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Inside the voltage-input PV module Vpv
PV module (V)
Insolation
Ipv Ppv
PV1
1 Vpv
Ipv
2
Vpv
Insolation
Insolation
Ppv
f (z)
Solve f(z) = 0
z
Algebraic Constraint
PV module (I)
1 Ipv
2 Ppv
Inputs: PV voltage and insolation Current-input PV model ECEN2060
Algebraic Constraint block solves for IPV that results in VPV