Instantaneous Power-Based Busbar Protection for Multi-terminal HVDC Network

Busbar is an essential part of power system which needs to be precisely protected. So, in this paper, we present a new Direct Current (DC) busbar differential protection algorithm for High Voltage Direct Current (HVDC) system. It uses instantaneous power concept instead of using the traditional current-based concept of differential protection. Hence, the power is calculated for each branch connected to the busbar from the measured values of currents and voltage memory. The scheme has been tested using dynamic simulation in Matlab and proven to be highly sensitive, discriminative, rapid and reliable for all types of faults. It assures security and stability in case of external faults and even during severe disturbance conditions. Besides, the scheme ensures continuity of power by seamless switching of branches to a healthy busbar, if available, restoring the pre-fault conditions.