Electromagnetic systems such as AC machines have to support supply voltages containing a DC component which induces both an increase of the total magnetic losses and the premature saturation of the magnetic core. In the present paper, we present an approach for predicting the hysteresis loop of a magnetic material such as non oriented FeSi 3% which is subjected to a DC bias. The measurements ar...

Renewable energy sources like wind, sun, and hydro are considered as a reliable alternative to the traditional energy sources such as oil, natural gas, or coal. This paper describes modeling and simulations to determine a method for the power performance evaluation of autonomous wind turbine system. A speed control regulator is utilized to control the DC bus voltage. The inverter gate’s signals...

In this paper, a new structure for cascade multilevel inverter is presented which consists of a series connection of several sub-multilevel units. Each sub-multilevel unit comprises of eight unidirectional switches, two bidirectional switches, and six DC voltage sources. For the proposed cascade topology, two algorithms are presented to produce all possible levels at the output voltage waveform...

Due to the widespread impact of renewable energy resources on high power density grids, transmission at DC regime has been considered more useful than AC systems. The findings this study suggest application a ripple-free input current resonant DC-DC converter possessing voltage gain and efficiency as being suitable for Applying variable switching frequency control systems, proposed discussed he...

in this paper, a new cascaded multilevel inverter by capability of increasing the number of output voltage levels with reduced number of power switches is proposed. the proposed topology consists of series connection of a number of proposed basic multilevel units. in order to generate all voltage levels at the output, five different algorithms are proposed to determine the magnitude of dc volta...

This paper aims to explore a viable solution for a doubly-fed induction generator (DFIG)-based wind farm to meet the reactive support requirement of the low voltage ride-through (LVRT) grid code with safe grid-connected operation during asymmetrical grid faults. First, the control scheme for the DFIG-based wind energy conversion system (WECS) is designed. Then, the controllability issue is anal...

During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG) are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive ...

Received Feb 3, 2017 Revised Mar 18, 2017 Accepted May 5, 2017 Dual input dc-dc converters have two input voltage sources or one input source and an energy storage system like ultra capacitor, PV, battery, super capacitors and a single output load. In order to process the power in hybrid energy systems using reduced part count, researchers have proposed several multi-input dc-dc power converter...

Power transformers are facing different stress factors during service. Usually, the effects of DC components superimposing AC phase currents are not taken into consideration. Nevertheless, DC can occur in transmission grids due to different sources. This contribution presents ongoing field measurements which show DC in the range of serval Amperes. Different superimposing DC sources are identifi...

In this paper, a new cascaded multilevel inverter by capability of increasing the number of output voltage levels with reduced number of power switches is proposed. The proposed topology consists of series connection of a number of proposed basic multilevel units. In order to generate all voltage levels at the output, five different algorithms are proposed to determine the magnitude of DC volta...