Photovoltaic 1-5 curve measurement techniques

Performance evaluation of photovoltaic (PV) arrays under actual field conditions provides important feedback to the module design process. One of the principal methods for assessing an array's performance is to plot its current, I, versus voltage, V, curve. Following a brief review of techniques for measuring the I-V curve, a new, capacitive-based approach is presented. It use a rapid sweep of the I-V curve that substantially reduced the average power transfer between array and load, and in turn, substantially reduced the size and weight of the curve tracer. Both theoretical and practical aspects of the approach are presented for a 10-kW unit. Performance is verified by comparison with I-V curves obtained by using a conventional load. The agreement is found to be excellent. Approximately an order of magnitude reduction in size, weight and power consumption over conventional units was realized with the experimental I-V curve tracer.