Emin Meral, MehmetCelik, Dogan2025-05-102025-05-1020201752-14161752-142410.1049/iet-rpg.2019.13252-s2.0-85097949963https://doi.org/10.1049/iet-rpg.2019.1325https://hdl.handle.net/20.500.14720/6840Meral, Mehmet Emin/0000-0003-0841-4630The increasing penetration of distributed generation (DG) inverters supplying power to the networks bring challenges to the power system under the grid faulty and harmonic grid since negative sequence components lead to double oscillations. Reference current generation (RCG)-based flexible control strategies ensure solutions to mitigate oscillations on the control signals and to maintain a more stable, secure and reliable power system operation. In this direction, this study proposes an RCG-based optimal control strategy that reduces oscillations of active and reactive power at optimal control parameter values and ensures minimum harmonic contents at the grid side under an unbalanced and harmonic distortion grid. The main cause of the power oscillations is comprehensively demonstrated, optimised and examined with numerical studies and theoretically. Control parameters are accurately selected by the courtesies of optimisation function to minimise power oscillations. A fast and robust third-order sinusoidal signal integrator (TOSSI) extracts positive-negative sequence components for the calculation of the RCG. To provide a fast transient response and achieve almost current tracking errors at a zero level, proportional complex integral (PCI) current regulation controller is selected. Various case studies have been performed to show the validity and availability of the proposed entire system, including flexible control, optimisation, TOSSI and PCI.eninfo:eu-repo/semantics/openAccessOptimal ControlOptimisationPower Generation ControlPower GridsDistributed Power GenerationElectric Current ControlTransient ResponseHarmonic DistortionPower Distribution ControlPi ControlInvertorsPower OscillationsNovel Optimal Control StrategyDistributed Generation InverterGrid FaultyHarmonic NetworksHarmonic GridDouble OscillationsReference Current Generation-Based Flexible Control StrategiesControl SignalsStable Power System OperationSecure Power System OperationReliable Power System OperationRcg-Based Optimal Control StrategyActive PowerReactive PowerOptimal Control Parameter ValuesMinimum Harmonic ContentsUnbalanced Distortion GridHarmonic Distortion GridControl ParametersPositive-Negative Sequence ComponentsProportional Complex Integral Current Regulation ControllerConference Object1415Q3Q230103022WOS:000599951400025