In this paper, the concept of secondary control is applied for voltage unbalance compensation in an islanded microgrid. The aim of the proposed control approach is to enhance the voltage quality at the point of common coupling (PCC). Unbalance compensation is achieved by proper control of distributed generators (DGs). The DGs control structure mainly consists of active and reactive power contro...

We study transport properties of two Josephson junctions coupled by an external shunt resistance. One of the junctions (say, the first) is driven by an unbiased ac current consisting of two harmonics. The device can rectify the ac current yielding a dc voltage across the first junction. For some values of coupling strength, controlled by an external shunt resistance, a dc voltage across the sec...

The proliferation of compensators, due to their nonlinear characteristics raises concern over the distortion levels they cause in voltages and currents at the transmission level. In this paper, series compensation by Thyristor Controlled Series Capacitor (TCSC) and shunt compensation by STATCOM are investigated in terms of power quality and their effects on protective relays behavior. For each ...

The use of non-linear loads critically affects the quality of supply by drawing harmonic currents and reactive power from the electrical distribution system. Active power filters are the most viable solution for solving such power quality problems in compliance with the harmonic standards. This article presents a digital signal processor (DSP) based fundamental-tuned-filter (FTF) algorithm for ...

These impedance conditions correspond to the class F operating condition, the ideal voltage and current shapes for which are shown in Figure 1. Here a sum of odd harmonics produces a square voltage waveform and a sum of even harmonics approximates a half-sinusoidal current shape. In reality, both extrinsic and intrinsic transistor parasitic elements have a substantial effect on the efficiency, ...

this paper presents the new topology of three phase on line uninterruptible power supply (ups) by employing t-source inverter (tsi) with maximum constant boost pulse width modulation (pwm) control and the results are compared with the conventional uninterruptible power supply (ups). the conventional ups consists of voltage source inverter (vsi) with step up transformer or dc-dc booster which de...

Voltage-Sourced Converter (VSC) is the main component in a VSC-based High Voltage Direct Current (HVDC) system. In addition to the characteristic harmonics, the inter-harmonics could be originated from the characteristic of each converter working at different modulation frequencies, or from a distorting frequency on one or both ac (or dc) systems. The space vector representation of VSC’s switch...

–A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a mis-operation of end user equipments. Utility distribution networks, sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial losses. With the restructuring of p...

High-Voltage Direct Current (HVDC) systems are a feasible solution that allows the transmission of energy between several power networks. As consequence use HVDC systems, renewable sources can be integrated more easily into distribution grids and smart grids. Furthermore, contribute to improving quality (PQ) which they connected. This paper presents multiterminal system not only controls flows ...

Numerical methods for the computation of harmonic propagation and distortion differ in the manner in which they represent the harmonic sources and the system impedance. Iterative methods (e.g. harmonic load flow) use a phasor representation of these parameters. Time domain methods, on the other hand, use a time representation of the system elements and the harmonic sources. Thus, they are gener...