This document presents an efficient proportional derivative (PD) position controller for three-phase motor drives. The regulator has been designed in frequency domain, employing the direct–quadrature (d–q) synchronous rotating reference frame and the indirect vector control. The presented position regulator is easy to tune and incorporates a feed forward (FF) term to compensate effectively the effect of the load disturbance. This position controller has been validated experimentally by using two industrial three-phase motors: an induction motor (IM) of 7.5 kW and a permanent magnet synchronous motor (PMSM) of 3.83 kW. The inner proportional integral (PI) current loops of both machines have also been designed in the frequency domain. Each machine has connected in its shaft an incremental encoder of 4096 pulses per revolution, to measure the position. Several simulations and experimental tests have been carried out with both motors, in favorable conditions and also with various types of adversities (parametric uncertainties, unknown load disturbance and measurement noise in the position and current loops), getting very good results and suggesting that this controller could be used in the research area and also in the industry.

This paper presents the design and implementation of a supervisory control and data acquisition (SCADA) system for automatic fault detection. The proposed system offers advantages in three areas: the prognostic capacity for preventive and predictive maintenance, improvement in the quality of the machined product and a reduction in breakdown times. The complementary technologies, the Industrial Internet of Things (IIoT) and various machine learning (ML) techniques, are employed with SCADA systems to obtain the objectives. The analysis of different data sources and the replacement of specific digital sensors with analog sensors improve the prognostic capacity for the detection of faults with an undetermined origin. Also presented is an anomaly detection algorithm to foresee failures and to recognize their occurrence even when they do not register as alarms or events. The improvement in machine availability after the implementation of the novel system guarantees the accomplishment of the proposed objectives.

In this article, a new strategy for switching control has been proposed with the aim of reducing oscillations in floating offshore wind turbines. Such oscillations lead to a shortage in the system’s efficiency, lifespan and harvesting capability of wind and wave energies. In order to study the decreasing of undesired oscillations in the system, particularly in pitch and top tower fore-aft movements, a square-shaped platform barge equipped with four symmetric oscillating water columns has been considered. The oscillating water columns’ air flux valves allow to operate the air columns so that to control the barge movements caused by oscillatory motion of the waves. In order to design the control scheme, response amplitude operators have been used to evaluate the performance of the system for a range of wave frequency profiles. These response amplitude operators analysis makes it possible to implement a switching control strategy to adequately regulate the valves opening/closing transition. The obtained results show that the proposed controlled oscillating water column-based barge present a better performance compared to the traditional barge one. In the case study with the period of 10 s, the results indicate the significant oscillation reduction for the controlled oscillating water column-based system compared to the standard barge system by 30.8% in pitch angle and 25% in fore-aft displacement.

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