Study of inverter and rectifier substations islanding fault in HVDC system, and comparison between different control-protective methods

In this paper Islanding fault of rectifier and inverter substations are studied in HVDC system both in back to back and long transmission line systems. The effect of system short circuit ratio (SCR), are studied too. System's controller action, pulse blocking of faulty converter and rectifier changing operation to inversion mode are three control schemes that studied here. Finally the results compared with each other and with system that has no control action and the best method for each fault are determined. All of these simulations are done using MATLAB- SIMULINK.