A Real-Time Digital Protection Scheme for VSCHVDC System with LR Type Solid State Current Limiter Controller

The major problems in a voltage source converter high voltage direct current (VSC-HVDC) system are power oscillation, voltage fluctuation, and high-level fault currents. The reason for this is because current flows via the VSC’s antiparallel diodes as well as the discharge current of DC capacitors during disturbances. At present time, DC protection measures are likewise insufficient to protect such systems. Based on an inductor-resistor (LR) type solid state fault current limiter (LR-SSFCL), this work provides an effective real-time digital protection solution for VSC-HVDC. During contingencies, the suggested technique uses adequate limiting impedance, but during normal conditions, the impedance is bypassed, resulting in essentially minimal impact. The VSCHVDC system is implemented using a real-time digital simulator (RTDS) device in conjunction with the proposed LRSSFCL based controller. As per the findings, the proposed method can reduce oscillation in both active power and voltage. According to the numerical results, the proposed technique dampens voltage variation by 69.9 percent and power oscillation by 73.06 percent. The new LR-SSFCL based technique is compared to the current method in the literature, with the proposed one ensuring real-time application applicability.