Coordinating Numerical Relays with Voltage-Time-Current Characteristics in DG Integrated Power Networks and Implementation using FPGA

This paper presents the coordination of numerical relays having voltage-current-time characteristics in distributed generation (DG) connected power system networks. The nonstandard numerical relay settings are complex to formulate as the relay operating time equation is nonlinear with voltage and current variables. Hence, the coordination framework becomes a nonlinear constrained optimization problem. To solve this coordination problem, a new naturally inspired optimization algorithm named, the Chaotic Coyote Optimization Algorithm (CCOA) is employed. The coordination model is employed on the 8 bus system which is designed in DIGSILENT integrated with a 40 MW PV-DG. The numerical relay settings are validated from the fault data extracted from DIGSILENT in field-programmable gate array (FPGA) using MATLAB SIMULINK interface.