Zero-current-transition, discontinuousconduction-mode (ZCT-DCM) converters are introduced in this paper. Compared to hard-switching (PWM) converters in DCM, the ZCT-DCM converters have similar current stresses and conduction losses, and much reduced turn-off switching losses. At the expense of increased voltage stresses, zerocurrent/zero-voltage switching is maintained for a wide range of loads...

The estimation of harmonic components of power voltage signals is one of the measurements prescribed by the power quality (PQ) standards (IEC 61000-4-30, 2008). In general, the harmonic components originate from non-linear elements connected to the power system such as non-linear loads (e.g., switched-mode power supplies) or transformers. An example of a distorted voltage measured in an office ...

Modern wireless communication systems are based on microwave technologies. Ferroelectric devices with the electric field dependent dielectric properties and low dielectric losses at microwave frequencies are very promising. Capacitance tunability nc, defined as the ratio of the capacitance at zero applied bias voltage to the capacitance at some desired applied voltage, is the key functional pro...

Due to the deregulation trend in electric power system networks, many factors have to be taken into consideration such as lack of supplying electric power, system reliability, power quality, electric system losses and voltage disturbance and profile problems. The excessive growing needs for electricity force electrical researchers to implement new approaches through the electric system. Introdu...

In this paper, several optimum structures of a cascaded multilevel inverter is proposed. This optimization is based on generation a constant number of output voltage levels by using minimum number of power switches or dc voltage sources or minimum amount of blocked voltage by power switches. In addition, the optimum structure for a constant number of dc voltage sources by using minimum number o...

This paper presents a new method which applies the application of Genetic Algorithm as meta-heuristic optimization method for power system problems in distribution substations. With increase in load, any power system model suffers from disturbances. These disturbances effect the overall stability of the system. Criterias like voltage profile, power flows, losses tell us about the state of the s...

This paper represents an effective method for optimal placement of DG and capacitor in distribution system. The main objective is to reduce the power losses in the system by placing capacitor and DG of optimal size and at optimal location. Distribution system connects the high voltage transmission system and low voltage side, hence it is necessary to keep the system at minimum losses for making...

Due to the increased importance of DFIGs in optimization of real and reactive power losses and the maintenance of voltage profile, the general methods of DG placement and sizing in the existing literature cannot be of practical importance in DFIG .In this paper a pure PSO method used in general DG is compared with a HGAPSO in the siting and sizing of DFIG with the objective of minimizing power ...

In this paper, a DC-DC resonant converter with high voltage gain and small size is studied. To reduce the size and weight of this converter, the operating frequency should be as high as possible. In this research, the frequency changes from 120 to 200 kHz. Due to the high operating frequency, it is necessary to reduce the switching losses using soft switching methods. Resonant converters are su...