Proportional harmonic current sharing among inverters is desired in ac microgrid with nonlinear loads. Usually, virtual impedance emulated to achieve good at the cost of increased voltage distortion system. Existing schemes overcome this issue by communicating and/or values inverters, thereby requiring significant data exchange. Further, some them suffer from single point failure because their ...

The inverse scattering problem of determining the boundary impedance from knowledge of the time harmonic incident wave and the far-field pattern of the scattered wave is considered. We solve the finite difference Helmholtz equation subject to the exact radiation condition for the discrete problem. The approach is decomposed into two steps. First, we reduce the problem to a well-posed system of ...

Harmonic resonance may cause abnormal operation and even damage of power facilities, further threatening normal and safe operation of power systems. For renewable energy generations, controlled loads and parallel reactive power compensating equipment, their operating statuses can vary frequently. Therefore, the parameters of equivalent fundamental and harmonic admittance/impedance of these comp...

A highly selective impedance transformation filtering technique suitable for tunable selective RF receivers is proposed in this paper. To achieve blocker rejection comparable to SAW filters, we use a two stage architecture based on a low noise trans-conductance amplifier (LNTA). The filter rejection is captured by a linear periodically varying (LPV) model that includes band limitation by the LN...

Original scientific paper This paper presents a set of rules for an intelligent algorithm of high impedance fault detection by observing the phase to ground voltage, phase to phase current and harmonics of fault current. Several techniques to detect high impedance faults already exist for example current injection in the neutral, superposing voltage signals, harmonic analysis, neural networks. ...

In a simply connected planar domain D a pair of Cauchy data of a harmonic function u is given on an accessible part of the boundary curve, and on the nonaccessible part u is supposed to satisfy a homogeneous impedance boundary condition. We consider the inverse problems to recover the non-accessible part of the boundary or the impedance function. Our approach extends the method proposed by Kres...

The inverse scattering problem of determining the boundary impedance from knowledge of the time harmonic incident wave and the far-field pattern of the scattered wave is considered. We use the finite-difference approximation for the Helmholtz equation along with the exact radiation condition for the discrete equation. The approach involves two steps. First, we reduce the problem to a well-posed...