Nodal harmonic impedance derivation of AC network in PSS/E

A load flow based superposition method is presented to derive the nodal harmonic impedance of an AC network using PSS/E (Power System Simulator for Engineering) through an IPLAN (PSS/E Internal Programming Language) program. Using the CIGRE and IEEE guidelines for assessing the network harmonic impedance, harmonic models of the AC network element impedances, e.g. shunt capacitors and reactors, system load, generator, transmission lines, power cables and grid transformers, are implemented in the IPLAN program. The IPLAN program is validated with an IEEE 14Bus Test System Benchmark (supplied by The University of Alberta (UofA), Canada). Therefore, it can be efficiently used to compute the nodal harmonic impedance of the AC network to enable AC harmonic filter design studies to be performed, without the need for any network reduction studies to be performed. A practical application of the method is presented for the Gulf Cooperation Council Interconnection Authority (GCCIA) HVDC project. This scheme links the 60Hz Saudi Arabian system to the 50Hz Gulf States and required extensive investigation of the network harmonic impedance on both sides of the HVDC link.