ESE 435 Lab 5: Photovoltaic systems Report (combined with lab 4) I. Outside preparation for lab Review results from Lab 4 and reread Chapter 8 (primarily sections 8.4, From Cells to Modules to Arrays and 8.7 Shading Impacts on I-V Curves) from the online textbook: Masters, G.M. Renewable and Efficient Electric Power Systems, IEEE Press, 2004. II. Lab Exercises The objective of this lab is to investigate the characteristics of PV cells combined in series, parallel, or a combination to achieve higher voltage and current output. The Elvis DMM has a 2Amp limit on current measurements, so use an illumination at 1/3 of peak for all measurements. Set the illumination by varying the lamp distance and measuring output with the photometer. Verify current output with a single cell. Acquire I-V curves at this illumination for each of your 4 cells. Make sure to record short-circuit current as well. For each of the following configurations, devise an appropriate experimental arrangement. Before measuring, adapt the simulation model of Lab 4 to mimic your arrangement, and verify that the arrangement works as expected. Simulate shading of one of the cells and confirm resulting behavior. Have an instructor check your experimental setup before powering your circuit. Repeat for these configurations: a) 4 cells in series b) 4 cells in parallel c) 2 x 2 array (2 in series and 2 in parallel) Use your LabVIEW vi to measure I-V curves at constant illumination. Record the temperature on one of the cells during the measurement. Repeat these measurements with one of the cells shaded (or broken). For the series (x4) configuration, devise a correction scheme using bypass diodes as described in the reference above. Configure one of the cells in your array to use the bypass diode, and measure I-V characteristics of the entire array with and without shading. Verify your measurements with simulation including the bypass diode. III. Report Data: Include representative waveforms and measurements to document expected (and unexpected) results. Include schematics used for simulation and simulation results. Analysis: Estimate the efficiency, fill factor and MPP for each configuration. Discuss scalability of performance when combining cells into arrays.Consider the implications of shading on performance of a PV array. Based on the PV cell model, discuss the currents involved in each of the cells (IL versus ID). Comment on the effectiveness and tradeoffs involved in using a bypass diode to limit power loss due to shading. Conclusions: Consider the implications of your results for design and operation of photovoltaic power systems. As with previous experiments, comment on how we might improve the lab in any aspect you like, i.e., data taking, scope of circuit, equipment issues, etc. Also, please comment on aspects of the lab you enjoyed (so that we know what portions to keep and/or