| A photovoltaic array is an important component of the photovoltaic system.It determines the cost of photovoltaic system and rational power capacity of the system.Thus the reasonable configuration of photovoltaic arrays is the key problem of reseach.In this paper, variable electronic load testing method is adopted and a photovoltaic array tester prototype is designed,which is based on the Philips'LPC2214.The main aspects of the paper are as follows:1. There are four sampling channels that cover different scales for each sampling volatage and current respectively in the hardware circuit of the controller based on LPC2214.During sampling,the system can automatically select the most suitable scale to improve the large-scale measurement accuracy.2. The suitable voltage and current sampling range could be chosen by a pre-sampling to determine the photovoltaic array open circuit voltage and short circuit current.The pre-sampling method is done by changing the equivalent resistance of the variable electronic load from zero to unlimited.3. The tested voltage data was resorted ascending.The correspording tested current data will be processed by the digital filter that use lagrange method.4. The auxiliary power supply,testing-control circuit and LCD are integrated together so that the characteristics of the solar arrays can be measured and displayed at the same time by the prototype tester.5. Both the mathematical model of the photovoltaic array and the measured data can be used to estimate and analysis characteristic curve of the solar array.The experiment results of testing the actual solar arrays show that the testing system operates stabely, easily to carry,has the higher measurement accuracy.A complete testing will take about 14ms, and the measured characteristics of photovoltaic arrays can displayed on LCD directly in the form of a curve that made the characteristics of photovoltaic arrays more illustratable and comprehensible.It can meet the needs of engineering.
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