Investigation On Protection Schemes Of Generator Transformer Units During Power System Black-Start

Black-start is an effective measure to restore the power system when blackout occurs. During black-start, the special switching manipulation and operating state of the power system have a great impact on the security and dependability of protective system. By analyzing the features of power system black-start, the impacts imposed on various types of protective devices and their action during fault in the process of black-start are analyzed. MATLAB/Simulink simulation software is used to simulate the initial stage of black-start for the operation mode of the partial or total loss of excitation protection and excessive excitation protection. The basic principles of how to arrange the protective devices are presented. The protection schemes with the partial or total loss of excitation and excessive excitation are proposed for the radial system with a single power source during the initial stage of black-start. The simulation results demonstrate the reliability of the proposed protection scheme.