DC-voltage and cycling induced recovery of switched polarisation in fatigued ferroelectric thin films
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Electric motors consume over half of the electrical energy produced by power stations, almost the three-quarters of the electrical consumption in industry and almost the half of commercial electrical consumption in developed countries. Motors are by far th ...
In recent years the use of solid state frequency converters is rapidly increasing in the industrial and power plants where electric machines are installed, since it allows variable speed operations for the electric system, thus becoming a key factor which ...
The present paper investigates transient overvoltages on ac induction motors when connected through a cable of arbitrary length to IGBT-PWM inverters. Considering classical transmission line analysis, and traveling-wave analysis with zero initial charges o ...
Pure perovskite Pb(Sc1/2Nb1/2)O-3 thin films without pyrochlore phase were prepared by the sol-gel method on TiO2/Pt/TiO2/SiO2/Si substrates. Films exhibited (111) preferred orientation and columnar microstructure. Diffuse phase transitions with permittivi ...
This set-up is particularly simple and makes possible the use of a flexible cable that may be plugged to the instrument using connectors for easy field applications. Measurements of AC and DC currents are demonstrated. ...
The brushless DC motors are normally built with rotor mounted PMs, which create the necessary back EMF voltage to produce a mechanical power. The shape of this back-EMF voltage is very important compared to the phase voltage supply one. Indeed, the electro ...
In many applications, industry has tried to develop sinusoidal supply for brushless DC (BLDC) motors. This paper describes a method that still keeps a simple 2 phases-on sensorless method and achieves sinusoidal supply, which is needed to avoid speed oscil ...
With brushless DC Motor (BLDC), current regulators in dq axes are very appreciated for sinusoidal supply. As the set current is constant, the regulator works properly. When the back-EMF is not sinusoidal, current oscillations appear in the dq regulator. A ...
Usually, each phase of the direct reluctance motor is fed separately by its own inverter producing a squarewave phase current depending on the rotor position. In the present work, a star-connection of the three stator phases is used and the direct reluctan ...
