In this paper we give the definition of 1/2-harmonic maps u : D → N , where D is an open set of IR and N is a k dimensional submanifold N of IRm as critical points of the functional ∫ Ω |∆ 1/4u|2dx . We write the Euler-Lagrange equation satisfied in a weak sense by the 1/2-harmonic maps, which is a nonlocal partial differential equation involving the 1/2-Laplacian operator . We prove the local ...

Transformers are the basic and valuable equipment of electricity network. Transformers correct function has important role in reliability of network .distribution transformers are designed for work at nominal frequency and full sinus current. Application of nonlinear loads in recent decades, such as power electronic loads, caused higher levels of harmonic. This kind of load can lead to creating...

This paper proposes an output current ripple reduction algorithm using a proportional-integral (PI) controller for an energy storage system (ESS). In single-phase systems, the DC/AC inverter has a second-order harmonic at twice the grid frequency of a DC-link voltage caused by pulsation of the DC-link voltage. The output current of a DC/DC converter has a ripple component because of the ripple ...

The benefits of applying multiple alternatives for mock-up and compression of helicopter harmonic motion are analyzed. Multiple mock-up approaches, along with a weighted-average mechanism, are approximated so that quicksand affiliated with only applying alone better alternate for the rotor blade vibration-reduction dilemma are bypassed. A harmonic motion external function matching to a flight c...

A new output structure for class E power amplifier (PA) is proposed in this paper. A series LC resonator circuit, tuned near the second harmonic of the operating frequency is added to the output circuit. This resonator causes low impedance at the second harmonic. The output circuit is designed to shape the switch voltage of the class E amplifier and lower the voltage stress of the transistor. T...

Model reduction is a new numerical technique [1, 2] that allows us to obtain an accurate low-dimensional representation of high-dimensional finite elements models. Additionally, in the case of linear models the time to perform model reduction is comparable to the solution time of a stationary problem. Hence model reduction can be employed as a fast solver for a transient or harmonic problem dur...

Alternating current (AC) electrical drives mainly require smaller (or torque) ripples and lower total harmonic distortion (THD) of voltage for excellent drive performances. Normally, in practice, to achieve these requirements, the inverter needs be operated at high switching frequency. By operating frequency, size filter can reduced. However, which oftenly employs insulated gate bipolar transis...