This paper presents an active disturbance rejection control (ADRC) approach for three-phase four-legs voltage source inverters (FL-VSIs) in a standalone renewable energy resources (RES)-based islanded microgrid. The key purpose of the proposed approach is to improve the control robustness against load-side disturbances, power supply parameters uncertainties, and faulty operating conditions. Indeed, a notable benefit of ADRC is its ability to operate effectively without the need for precise knowledge of disturbance characteristics or accurate modeling and FL-VSI parameters.
View Article and Find Full Text PDFUnder the presence of nonlinear load, the most existing virtual impedance (VI) methods-based control solution performs poorly in reactive power sharing among droop-operated VSIs in microgrids (MGs). This may be due to the involved estimation techniques for extracting the current harmonics at selected frequencies, which suffer from either poor accuracy of the harmonic estimation and/or the effect of DC offset in the measurements. Such an issue may affect the performance of the virtual impedance control, hence, the system stability.
View Article and Find Full Text PDFSolitary myofibroma or infantile myofibroma is a rare spindle cell neoplasm that generally affects infants before the age of 2 years but cases in young children and adults have been described. Although the location of infantile myofibroma in the oral and maxillofacial region has been described, the intramasseteric location of the lesion is very uncommon. A thorough assessment of histopathological and immunohistochemical characteristics is necessary to have a correct diagnosis.
View Article and Find Full Text PDFModel predictive control (MPC) is an outstanding control method which can achieve superior dynamic response, nonlinear control and multi-objective collaborative control. However, because of unfixed switching frequency, the harmonic spectrum of the output current is dispersed, which would make it difficult to design the output filter. In this work, a double voltage vector model predictive control (DVV-MPC) algorithm for grid-connected cascade H-bridge (CHB) multilevel inverter is presented.
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