This thesis investigates and compares the performance of HVDC protection algorithms in terms of their sensitivity, selectivity, speed, and robustness. The threshold determination process for each algorithm has been described in detail as well. Each algorithm is tested under various fault resistances, and fault distances to test the sensitivity of the algorithm. The trip time for each case in each algorithm is monitored to analyze the speed of the algorithm. Various external faults have been simulated to test the selectivity of the algorithm. Lastly, the resilience of each algorithm against white noise has been tested. Furthermore, the effect of varying the sampling frequency and the inductance of the current limiting inductors on each algorithm is investigated. The HVDC protection algorithms discussed are - current differential deviation-based protection, ROCOV-based protection, ROCOC-based protection, and DC reactor voltage change rate-based protection. All protection algorithms have been implemented in the PSCAD environment. The noise resilience analysis for each algorithm has been performed in MATLAB.