Low-cost outdoor solar cells in-line measurement with Zigbee

With the explosive growth in the solar industry, it has intensified the need for test and measurement solutions that can quickly and accurately collected characteristics of solar cells and modules. A low-cost out-door solar cell in-line measurement is presented. It provides distributed working parameters collecting for solar cells in each node. And a Zigbee wireless network is imbedded for communicating between measuring node, central station and host computer. The measuring nodes collect working parameters of solar cell, such as short circuit current, open circuit voltage, max power point, shunt/series resistance and so on. In each node, 3-4 solar cells can be measured simultaneously. A Microchip PIC16F690 MCU is employed for I-V curve controlling and measuring by adjusting internal programmable voltage reference. The collected data is sent to central station by Zigbee wireless network. Solar illumination amplitude and ambient temperature are measured in central station, and data from measuring node is forward to host computer by central station too. Host computer get related data and compute fill factor and other important parameters of solar cells in long-term.