Adaptive Distance Protection for Smart Grids with Infeed Compensation using Synchronized Phasor Measurements

Distance protection is one of the widely adopted schemes for the protection of transmission lines. This scheme provides a zone based protection and has inherent backup capabilities. But the scheme is prone to mal-operations under conditions where the network configurations is such that an infeed source is present within the reach of the relay. These infeeds affect the backup protection capability of distance relays. This paper shows the impact of infeed on existing distance protection scheme and proposes a new algorithm for distance relays that adaptively compensates for the effect of infeed using synchronized phasor measurements. The proposed work is specially designed for direct implementation in Smart Grid environment which has sophisticated communication infrastructure and advanced measuring devices such as the Phasor Measurement Units (PMUs). The newly proposed scheme is tested using simulation in MATLAB/Simulink. The relay algorithm is also implemented using Raspberry Pi microprocessor development kit with IOT based communication.