EFFECT OF THE DC CONTROL ON RECOVERY FROM COMMUTATION FAILURES IN AN HVDC INVERTER FEEDING A WEAK AC NETWORK

Recovery from commutation failures after inverter side faults can be problematic. This paper explores the effect of the DC control on recovery from commutation failures in an HVDC inverter, due to AC system fault in line commutated thyristor inverter connected to a weak AC network. The AC system fault is a single phase ground fault. MATLAB Simulink is used for the simulation studies. K e y w o r d s: HVDC transmission, commutation failures, recovery, voltage dependent current order limits (VDCOL), short circuit ratio (SCR)