This thesis presents a new d-q based control of single phase grid connected inverters. The inverters are capable of delivering active and reactive power based on the reference set points and/or demand from the load. Also, an on-grid and off-grid control strategy for the single phase inverter has been proposed, that can seamlessly transition from from an "on-grid" state to the "off-grid" state and vice-versa. In this context, a Synchronous Frame PLL has been developed that can help the controller to retain a frequency set point in both the on-grid and off-grid states. Further, a methodology has been proposed for inverter re-synchronization with the grid.In order to support unbalance power distribution grid, a methodology has been designed for single phase load management that takes into account of the size of the inverter and the local load balance required at each phase where the inverter is connected. Both active and reactive power balance are simultaneously introduced with this architecture. As some load changes may be too large for the inverter to supply, an Apparent power limiter is also proposed, such that the active and reactive power reference remains within the operating capacity of the inverter. Finally, a simple droop control model has been proposed for the single phase inverter that can work in grid connected mode. The approach supports active power sharing between inverters by measuring the change in frequency and voltage.