Frequency Domain Modelling of a Commercial Heat Pump for Harmonic Studies

Harmonic analysis is necessitated when there is presence of the non-linear equipment in an electrical system. Frequency domain modeling making use of Frequency Coupling Matrices is considered one of the most powerful techniques and is widely adopted when considering harmonic analysis. In this paper, the power-dependent frequency domain model of a commercial heat pump is analyzed considering six different output powers along with numerical validation. The main purpose of the paper is to study the sensitivity of different Norton-based models, characterized by different levels of approximation, to the operation point of the heat pump and to quantify their errors in terms of harmonic emission up to the 19{th} order. Average frequency coupling matrix, lookup table, and interpolation approaches are also compared. Monte Carlo simulations are performed to compare the performances of the considered Norton-based models.