Large scale integration of distributed generating sources challenges the conventional protection schemes in the distribution networks. The response of inverter interfaced sources to network faults are different from the conventional generators and hence need special protection systems. A new protection methodology for distribution networks with inverter based sources is discussed in the present work. The proposed interface protection relay algorithm uses instantaneous symmetrical voltage components for fault detection. The effectiveness of proposed relay algorithm is evaluated by conducting simulation studies using PSCAD/EMTDC software. © 2017 IEEE.