The conventional approach for the integration of multiple renewable sources and energy storage elements involves using dedicated single-input converters for each source and requires more number of converter stages leading to considerable reduction in reliability and efficiency of the system. In order to address this issue, a power flow management control strategy of a PV-wind-battery based grid connected single phase power generating system with an efficient multi-input dc-dc converter is proposed. This system can supply load, maintain the power flow between different sources, inject surplus power into the grid and charge the battery as and when required. A bidirectional buck-boost converter is used for harnessing power from PV source with battery charging/discharging control, while a transformer coupled boost half-bridge converter is used for harnessing power from wind source. A single-phase full-bridge inverter is used for feeding ac loads and interaction with grid. The proposed converter configuration has reduced number of power conversion stages with less component count, and reduced losses compared to existing grid-connected hybrid systems. This improves the efficiency and reliability of the system. Simulation studies using MATLAB/Simulink are carried out to verify the viability of the proposed system under various modes of operation depending on availability of sources and change in load.