One of the currently investigated problems in power electronics-based electrical energy conversion is proper operation of electronic converters during grid voltage imbalance and harmonics. In classic control methods, it introduces oscillations of variables, resulting in the necessity to improve control systems with signals filtration and usually by application of resonant terms as part of current controllers. The paper presents a new approach to grid-connected inverter control based on transformation to a non-Cartesian frame, the parameters of which are correlated with grid voltage asymmetry. The proposed method results in resignation from resonant terms used as controllers and their replacement with proportional–integral terms for which anti-wind-up structures are significantly simpler than for oscillatory terms. The paper presents new transformation principles, features and some simulation results showing the waveforms of signals transformed to the new non-Cartesian frame.
Abdeltawab, H. H. and Mohamed, Y. A. R. I. (2016). Robust Energy Management of a Hybrid Wind and Flywheel Energy Storage System Considering Flywheel Power Losses Minimization and Grid-Code Constraints. IEEE Transactions on Industrial Electronics, 63(7), pp. 4242–4254.
Abdel-Khalik, A. S., Hamad, M. S., Massoud, A. M. and Ahmed, S. (2018). Postfault Operation of a Nine-Phase Six-Terminal Induction Machine Under Single Open-Line Fault. IEEE Transactions on Industrial Electronics, 2, pp. 1084–1096.
Afshari, E., Moradi, G. R., Rahimi, R., Farhangi, B., Yang, Y., Blaabjerg, F. and Farhangi, S. (2017). Control Strategy for Three-Phase Grid-Connected PV Inverters Enabling Current Limitation Under Unbalanced Faults, IEEE Transactions on Industrial Electronics, 64(11), pp. 8908–8918.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.