Analysis of noncharacteristic harmonics of a large HVDC transmission system and comparison with site tests

The authors describe the analysis of harmonic currents on the DC line of an HVDC transmission system. For this purpose, extensive measurements were carried out on a system having a high rating. The basic parameters influencing the currents on the DC side have been theoretically studied and computer models described. The results of the measurements are compared with the results of the simulation. Recommendations and conclusions for analysis of the interference caused by HVDC systems are discussed.