Python‐Based Integration of Harmonic Domain Models of Grid‐Connected Switched Systems for Power Flow Analysis

This paper presents a new Python‐based methodology that combines the advantages of two established techniques for analysing electrical power systems (i.e., (i) harmonic domain (HD) modelling and (ii) PSS/E software tool). By integrating these two approaches, the Python‐based program enhances the accuracy of the solution while maintaining computational resources. The proposed methodology primarily employs the harmonic domain admittance matrix (HDAM) that describes the system's behaviour in terms of harmonics. PSS/E can then analyse the system's power flow while considering the effects of harmonics. The paper showcases the proposed algorithm when using two specific scenarios (i.e., (i) integrating high‐voltage direct current (HVDC) systems into the grid and (ii) integrating photovoltaic (PV) solar power systems into the grid). The proposed model was validated on the IEEE 39‐bus system incorporating HVDC and PV connections. Benchmarking against detailed PSCAD time‐domain simulations demonstrated high accuracy, with maximum voltage magnitude errors maintained below 1.5 × 10 −3 pu and power mismatches not exceeding 2.5 × 10 −3 pu. Furthermore, the proposed method significantly improved computational efficiency, reducing simulation time by over 98% (e.g., from 1760 s in PSCAD to 5.94 s with the proposed method) while achieving strict convergence (10 −6 ) in fewer than 18 iterations.