Basically the overall efficiency of the solar cell refers to the sunlight-to-electricity conversion process. On the other hand, the solar cell is better modeled as a current source since for the largest loads the current drawn is independent of load. In this respect the paper defines solar cell efficiency related only to the electrical parameters, as a ratio between the output power and the power generated by current source. Numerical algorithm is implemented in order to obtain the electrical parameters and to calculate the efficiency of the solar cell for different environmental conditions. Also the solar cell sensitivity of efficiency is calculated when the temperature and irradiance levels are changed separately and/or simultaneously. The examples presented prove the correctness and the accuracy of the proposed method.

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This paper analysis the Dynamic Voltage Restorer response provided for voltage sags mitigation in the electrical distribution networks with connection substation topology. Most often the voltage sags are caused by severe faults on the lines adjacent to main feeder and by faults on main feeder of connection substation. A realistic configuration of the electricity distribution network, similar to the distribution networks with connection substation that had been developed in Bucharest area is modeled. A DVR topology was chosen and implemented in Matlab/Simulink. The DVR performances are compared for different fault conditions. The results obtained during this study proves that the use of DVR for voltage sags mitigation on connection substation bus bars is a good solution for this type of distribution networks. Keywords-dynamic voltage restorer (DVR), electricity distribution networks, custom power devices, voltage sags.

This paper presents the Dynami (DVR) response study in cases of voltage sag electrical distribution networks with con topology. Usually, these voltage disturban faults that can occur on the lines connected t as the main feeder or even on main fee substation. A DVR that uses a diode based voltage source, supplied by the back-up fe substation, has been modeled in Matlab/Sim on the lines adjacent to main feeder and back faults on main feeder, with real impact for voltage supplied to end-users connected to th downstream of the connection substation b simulated. The DVR response has been stud conditions. The obtained results prove the chosen topology of this series Custom Power magnitude disturbances mitigation in distribu Keywords: dynamic voltage restorer (D rectifier, series custom power device, v disturbances.

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