Investigation of Power Differential Concept for Line Protection

In this paper, investigation of a novel fault detection concept for line protection is presented. In this concept, the difference and average quantities for phase active and reactive power entering and leaving the line are compared. Performance of the developed detector is computed under sampling misalignment as compared with conventional current differential approach. This computation is carried out via simulating a tie line connecting two power system networks using the Electromagnetic Transient Program (EMTP). The detector sensitivity for internal fault and stability for external fault are examined for wide range of fault resistance and operating conditions. The test results show distinguished performance of the proposed power differential concept in detecting high impedance faults and remarkable stability during system severe power swings.