Independent photovoltaic system

Abstract

The paper presents an independent photovoltaic system. The photovoltaic installation is divided into two parts: the stationary and the follow up one. The stationary pall of the system is composed of twelve modules, having a power of 660 Wp, turned towards the south and set rip at an angle of 45 degrees. The mechanic construction let a periodic change of the elevation angle of about 20 degrees -75 degrees The follow rip part of the system is composed of two identical mechanisms following the sun movement. Working in the a azimuth-elevation scheme, those gears let the use of any sun-tracking system (in one ol two axis). On each mechanism three modules have been installed. Total power of the follow rip part in 330 Np. Because of searching and didactic character of the installation a parallel connection of the modules into aggregates of 165 Wp has been made. Each aggregate contains a separate cable system driven to the control chamber: It allows observation and comparison between several system elements (charge controllers and regulators, batteries, inverters, etc.). Observation can be made at the same lighting and temperature conditions. In the control chamber there are some measuring and control devices. They are in charge of supervising, the correct loaning of the accumulator batteries protect them om over-loading and assure proper division of power between several loads. For the goals mentioned above, Neste mid Siemens products have been used. To convert 12 VDC tension of batteries to 220 VAC special inverters we use. Monitoring of the whole system has been built rising equipment and software of the Advantech Company. During the research work it has been found that for monitoring of installation of this value the industrial DA&C modules (like the ADAM4000 family) are the best ones. According to them, a diffused control system related to a bus RS485 and working under the GENIE program has been elaborated. This system, apart from the main controlling functions, has to steer the move of the systems following the sun movement. Thanks to the constant measurement of the level and direction of the sun radiance, it was possible to rise intelligent decision algorithms improving operation of the following systems.