Harmonic analysis of an HVDC rectifier using Unified Harmonic Domain algorithm and time domain initialization approach

Harmonic distortion in power systems is a growing concern due to the increasing penetration of non-linear devices in the electricity grid. Numerous methods for the analysis of power system harmonics have been developed both in the time domain and frequency domain. The Unified Harmonic Domain algorithm is a frequency domain technique reported to be computationally effective and arrives at an accurate solution. In the characterization of this harmonic analysis technique, there was an opportunity to improve solution convergence by implementing its initialization stage in the time domain. The test system used for this research is the rectifier of the CIGRE HVDC Benchmark Model. Results obtained from the various initialization stage implementations were compared with each other, as well as to a set of results from a PSCAD/EMTDC simulation. Results show that a non-updating Jacobian initialization stage and time domain initialization are promising alternatives to the original implementation.