Photovoltaic By-Pass Diodes (LTspice IV) All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 Contents Solar Module Model and Specification Bypass Diode Model Modules without the Bypass Diodes Modules with the Bypass Diodes Solar Module Field with the Bypass Diodes Library Files and Symbol Files Location Simulation Index All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

1. Solar Module Model and Specification No. SC75-RT-A Maximum power(Pmax) 75(W) Voltage at Pmax(Vmp) 40.5(V) Current at Pmax(Imp) 1.85(A) Short-circuit current(Isc) 2.20(A) Open-circuit voltage(Voc) 55.5(V) Parameter, SOL is added as normalized incident radiation, where SOL=1 for AM1.5 conditions Fig.1 A single solar module part number SC75-RT-A The specification of Showa Shell's solar module SC75-RT-A are shown in the table. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 2. Bypass Diode Model IF-VF Characteristic: .model Dbypass D + IS=10.134E-6 N=1.1371 RS=12.648E-3 Bypass Diodes Fig.2 A bypass diode is connected to the solar module. Fig.3 Shottky diode I-V characteristics. Shottky diode is used as a bypass. I-V characteristic of the diode is shown in the graph. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

3. Modules without the Bypass Diodes Simulation Circuit Simulation Result Current is limited by an inactive module Current SOL=1 SOL=0.2 (under shade) Power Under shade, incident radiation drops to 20% SOL=1 SOL=0.2 (under shade) Simulate 3 solar modules that are connected in series without bypass diode when one module is in shade. the simulation result shows how the power and current are lowered. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

4. Modules with the Bypass Diodes Simulation Circuit Simulation Result Current flow past an inactive module Current SOL=1 SOL=0.2 (under shade) Power Under shade, incident radiation drops to 20% SOL=1 SOL=0.2 (under shade) With the bypass diode when one module is in shade. the simulation result shows that the output of the active modules can flow past an inactive module. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

5. Solar Module Field with the Bypass Diodes Activated Bypass Diode Current Flow Under shade, incident radiation drops to 20% Simulate solar field that’s built from 30 solar modules in series with bypass diode across group of 10 modules when one group is in shade. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

5. Solar Module Field with the Bypass Diodes Current SOL=1 SOL=0.2 (under shade) Power SOL=1 SOL=0.2 (under shade) The graphs show I-V and P-V with bypass diodes across groups of 10 modules. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

Library Files and Symbol Files Location …\Photovoltaic By-Pass Diodes Copy/Paste into C:\Program Files\LTC\LTspiceIV\lib\sub Copy/Paste into C:\Program Files\LTC\LTspiceIV\lib\sym Copy the library files (.lib) from the folder …\Photovoltaic By-Pass Diodes\.sub\, then paste into the folder C:\Program Files\LTC\LTspiceIV\lib\sub Copy the symbol files(.asy) from the folder …\Photovoltaic By-Pass Diodes\.asy\, then paste into the folder C:\Program Files\LTC\LTspiceIV\lib\sym All Rights Reserved Copyright (C) Bee Technologies Corporation 2011

All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 Simulation Index Simulations Folder name Bypass Diode Model............................................ Modules without the Bypass Diodes..................... Modules with the Bypass Diodes.......................... Solar Module Field with the Bypass Diodes.......... ...\Simulation\Bypass-Diode ...\Simulation\Case1\Type-A ...\Simulation\Case1\Type-B ...\Simulation\Case2 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011