Global environmental changes, nuclear power risks, losses in the electricity grid, and rising energy costs are increasing the desire to rely on more renewable energy for electricity generation. Recently, most people prefer to live and work in smart places like smart cities and smart universities which integrating smart grid systems. The large part of these smart grid systems is based on hybrid energy sources which make the energy management a challenging task. Thus, the design of an intelligent energy management controller is required. The present paper proposes an intelligent energy management controller based on combined fuzzy logic and fractional-order proportional-integral-derivative (FO-PID) controller methods for a smart DC-microgrid. The hybrid energy sources integrated into the DC-microgrid are constituted by a battery bank, wind energy, and photovoltaic (PV) energy source. The source-side converters (SSCs) are controller by the new intelligent fractional order PID strategy to extract the maximum power from the renewable energy sources (wind and PV) and improve the power quality supplied to the DC-microgrid. To make the microgrid as cost-effective, the (wind and PV) energy sources are prioritized. The proposed controller ensures smooth output power and service continuity. Simulation results of the proposed control schema under Matlab/Simulink are presented and compared with the super twisting fractional-order controller.

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Variable speed wind turbine generators installation has been significantly increased worldwide in the last few years. Faults at the grid side may call for the disconnection of the wind turbine from the grid as under such events, wind turbine generator (WTG) may not comply with the recent developed grid codes for wind energy conversion systems (WECS). In this paper, a unified power flow controller (UPFC) is applied to improve the fault ride through (FRT) capability of doubly fed induction generator (DFIG)-based WECS during voltage swell and voltage sag at the grid side. Simulation is carried out using MATLAB/Simulink software. Results show that UPFC can effectively improve the FRT capability of DFIG-based WECS and hence maintaining wind turbine connection to the grid during certain levels of voltage fluctuation at the grid side.

A little attention has been paid to the faults within the converter switches of a wind energy conversion system (WECS). Solutions suggested in the literature to improve the performance of a WECS rely on compensating the reactive power at the point of common coupling (PCC) to maintain the PCC voltage within the limits specified by the grid codes. Recently, transmission line operators have expanded WECS codes to include active power support to the grid during fault conditions. Therefore, to maintain the connection of a wind turbine during various disturbance events, it is essential to fulfil grid codes. This paper introduces a new application for a static synchronous compensator (STATCOM) equipped with a high-temperature superconducting coil (HTS) to compensate both active and reactive powers at the PCC during short-circuit events within the insulated-gate bipolar transistor (IGBT) switches of the grid side converter (GSC) of a doubly-fed induction generator (DFIG)-based WECS. Compliance of the voltage profiles of the DFIG with the fault ridethrough (FRT) specified in the recent grid codes of the USA, andSpain, with and without the proposed controller, is examined. Simulation results show that the proposed controller can bring the active and reactive power at the PCC to their nominal steady-state levels during studied fault.