Norton Based Modelling Techniques for Assessing the Harmonic Emissions of Inverter Based Resources

The proliferation of Inverter Based Resources (IBRs) connected to high voltage (HV) transmission networks can have detrimental impacts on waveform distortion. This is caused by the power electronic interface, with voltage source converter (VSC) technology being by far the most prevalent. As such, proper emission models, which can account for the non-linear operation of VSCs, must be developed and investigated for the assessment of harmonic distortion in HV networks. Norton based modelling techniques for assessing the harmonic emissions of inverter base resources are compared in this paper. Some recalls about the frequency domain modelling of IBRs are firstly given. Then, Monte Carlo simulations on two case-studies based on a PV plant and a Type IV wind turbine show quantitatively the performances of four Norton based models characterised by different levels of approximation.