Abstract: In this paper modified SEPIC converter is preferred and based on preferred converter two types of step-up converters with high static gain are presented. These preferred converters are required to obtain high output voltage for applications which are supplied by low input voltage sources .The preferred converters are modified SEPIC converter without magnetic and with magnetic coupling . These two converters increases static gain and efficiency keeping switch voltage low. Also to limit crises of overvoltage at the output diode in the preferred converter with magnetic coupling, voltage multiplier is included in secondary part. This voltage multiplier raises static gain and it also considered as non-dissipative clamping circuit. The preferred converter with magnetic coupling comprises of leakage inductance of transformer and voltage multiplier which reduces losses. Simulation of these two proposed converters are done using MATLAB/SIMULINK and output results are compared.

Keywords: SEPIC converter , static gain , magnetic coupling , non-dissipative clamping circuit.