This Paper Presents development of solar may shunt switching unit with a fully regulated Power regulation for Geostationary Earth Orbit(GEO) satellite. This shunt switching unit comprises the solar may shunt modules that regulate the solar array power. These solar array shunt modules connect/disconnect the solar array segments to/from the bus through switching actions. And that is also possible simply extension to an existing design by FPGA control logic changing. In order to verify the proposed design, the control logic and worst case analysis are analyzed and the simulation and experimental results we shown.