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The performance analysis and evaluation of a real grid-connected photovoltaic system operating under mild continental climate condition of Kosovo is conducted in this paper. The PV system is installed on a flat roof of the laboratory building at Faculty of Electrical and Computer Engineering. With fixed monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) module types with an installed capacity of 1.76 kWp and 2.16 kWp respectively, inclined at an angle of 45 • C, facing south and through two solar inverters, the latter feds the low voltage distribution grid with electricity. Performance and meteorological data for each type of modules were collected and analyzed for the period between December 2014 to November 2015. The m-Si PV modules have shown higher performance compared with p-Si PV modules. Electricity production during the monitoring period was 1286.57 kWh/kWp from p-Si modules and 1328.21 kWh/kWp from m-Si modules. The annually average daily final yield (Y f ), the annual average value of performance ratio (PR) and system efficiency (η sys ), for the p-Si PV modules were found to be 3.53 kWh/kWp/day, 80% and 11.67% respectively. In addition, corresponding values for the m-Si modules were 3.64 kWh/kWp/day, 84% and 12.78% respectively. Furthermore, a comparative analysis of the performance of the photovoltaic system under study with other photovoltaic systems installed in various countries worldwide was carefully investigated and presented in this paper.

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Flexible alternating current transmission systems (FACTS) technology opens up new opportunities for controlling power flow and enhancing the usable capacity of present, as well as new lines. The Unified Power Flow Controller (UPFC) is a most complex power electronic device, which can simultaneously control a local bus voltage and optimization power flows in electrical power transmission system. This paper presents real and reactive power flow control through a 400 kV transmission line by connected the UPFC at the sending and receiving end. The objective are to determine control and performance of UPFC who is intended for installation on that transmission line to control active and reactive power flow. When no UPFC is installed, active and reactive power through the transmission line can not be controlled. Simulations are carried out in Matlab/Simulink environment to evaluate the performance of the UPFC. Index Terms-Flexible AC Transmission Systems (FACTS), Matlab/Simulink, Active and Reactive Power, transmission line, Unified Power Flow Controller (UPFC).V. Komoni is with the