KEPCO BOP 1KW QUICK START GUIDE

QUICK START GUIDE
An ISO 9001 Company.
SOLAR DEVICE TESTER
USING BOP 1KW
I — INTRODUCTION
SCOPE OF MANUAL. This Quick Start Guide covers
the description and operation of the Solar Device Tester demonstration application written in LabView.
DESCRIPTION. The Solar Device Tester demonstration application is a simple standalone application that uses the Kepco Solar Device Tester subvi to control the output of the BOP and to take the measurements needed to characterize a solar device. The subvi can be adapted to an overall Test application as needed.
The BOP 1KW is connected directly to the solar device and controlled by the computer. Because measurements are done by the BOP 1KW, external DVMs are not needed. The BOP 1KW changes the output and makes synchronized measurements, and goes on to the next point at a rate of up to 20mS per point. The Solar Device Tester demonstra­tion application uses a LabView subvi to produce an I-V curve that characterizes the solar device (such as solar cells, solar panels, etc.) under test. For accurate voltage measurements remote sensing is recommended (as detailed in the BOP 1KW Operator manual, Section 2).
BOP 1KW
SOLAR DEVICE
TESTER
Protection Limit ensures that the BOP output does not exceed the capacity of the solar device. The negative Pro­tection Limit is normally set close to zero to prevent the solar device from overheating.
II — OPERATION
The user interface included with the Solar Device Tester demonstration application is illustrated in Figure 1. The bot­tom of Figure 1 shows a typical I-V curve taken by the subvi.
USING THE DEMONSTRATION APPLICATION.
The Version OK indicator (at the top of the panel shown in Figure 1) lights green to verify that the BOP firmware sup­ports the demonstration application and the subvi, or red to indicate that the firmware does not support the demonstra­tion application. An upgrade kit to allow older units to sup­port the demonstration application may be purchased at
www.kepcopower.com/bophibuy.htm#upgrade.
The BOP Parameters display allows the user to select volt­age or current mode by clicking on the Mode switch. The switch is green for voltage and yellow for current.
The start and end points for the sequence of setpoints that will characterize the device are entered under Ramp Char­acteristics. The Start and End Point units are in Amperes for Current Mode and Volts for Voltage mode. The positive
FIGURE 1. Demonstration Application Interface Showing
User Inputs and Rendered I-V Curve Output
Once the Start and End points are chosen, the user enters the Number of Points, Milliseconds to Wait and whether to swap the sign of the measurements. The number of points
KEPCO, INC. " 131-38 SANFORD AVENUE " FLUSHING, NY. 11355 U.S.A. " TEL (718) 461-7000 " FAX (718) 767-1102
http://www.kepcopower.com " email: hq@kepcopower.com
©2009, KEPCO, INC 1 Data subject to change without notice 228-1684
determines the resolution or level of detail of the charac­terization and can be set to as few as 10 to as many as 40,000 points per I-V Curve. Clicking the Swap Voltage Sign or Swap Current Sign buttons to the left of the I-V curve allows rendering of the I-V curve as preferred for I-V Trace and I-V Dark type tests.
Clicking the Press to Take Sample button causes the application to invoke the subvi which changes the BOP output, creating a linear ramp. At each step, the BOP 1KW provides a measured voltage and current value. While the curve is being taken, the voltage and current values (displayed under BOP Parameters) change, pro­viding status to the user. When the ramp is completed, these measurements are provided as an array, which the application renders as the I-V curve shown in Figure 1. The subvi also provides measured Vmp and Imp, which is graphically marked on the curve with a cursor formed by intersecting vertical and horizontal lines.
SOLAR DEVICE TESTER SUBVI. The Solar Device Tester subvi, written in LabView, includes an operator panel (see Figure 2). The subvi may be used as is in an overall Test application. The overall application will typi­cally use the measurement data provided by the Solar Device Tester subvi to produce an I-V curve that charac­terizes the device, and includes the four key device char­acteristics: Voltage Maximum Power (Vmp), Current Maximum Power (Imp), Voltage Open Collector (Voc) and Current Short Circuit (Isc) as well as Maximum Power Point (Pmp). The calculated values of Vmp, Imp and Pmp appear under Real Time Output. Isc and Voc are the high­est values that appear in the Measured Current and Mea­sured Voltage Arrays, respectively. Figure 1 shows a typical I-V curve characterizing a solar device produced from the data accumulated by the Solar Device Tester subvi.
KEPCO, INC. " 131-38 SANFORD AVENUE " FLUSHING, NY. 11355 U.S.A. " TEL (718) 461-7000 " FAX (718) 767-1102
http://www.kepcopower.com " email: hq@kepcopower.com
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