A time-domain approach for characterizing harmonic currents generated by a cluster of adjustable speed drives

This paper presents an efficient time-domain algorithm to characterize harmonic currents generated by a cluster of adjustable speed drives operated under either balanced or imbalanced supply voltages and asymmetrical source impedances, where the Poincare map-based approach is adopted as the solution method. An actual industrial rolling mill system with several dc motor drives operating in parallel is under test to show the usefulness of the proposed method. Simulation results are compared with those obtained by actual measurements. It shows that the harmonic currents determined by the proposed method well agree with those obtained by actual measurements. The proposed algorithm is relatively accurate, computationally efficient, and robust in characterizing harmonic currents generated by the multiconverter loads.