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The penetration of distributed generation (DG) has recently been increased worldwide. These DG units have excessive effects on voltage profile and losses in distribution systems. In this paper, an optimization model for active distribution systems is constructed with considering voltage deviation index and active losses. An adaptive algorithm is proposed for optimizing the weighting factors of the...
In some countries, electrical distribution lines have to cross areas where the installation cost could be very high and carrying out maintenance could become extremely difficult (e.g. desert areas). As a result, frequent power disconnections and blackout heavily affect the quality of supply of end-users. Oppositely, the renewable energy sources exploitation in supplying portions of the distribution...
The immense deployment of renewable energy resources (RES) have gained significant interest in distribution networks, which creates great challenges for distribution network planners and operators. One way of mitigating such challenges is to combine the integration of RES with energy storage systems (ESS). However, appropriate combination of both RES and ESS requires new planning methodologies in...
In this paper two active anti-islanding methods are evaluated and compared according to the ABNT NBR 62116 and IEEE STD 929-2000 standards. These standards specify voltage and frequency trip time settings and trip magnitudes. The first method is the active frequency drift with positive feedback and the second one is the active frequency jump that is based on phase-locked loop perturbation. The latter...
The amount of distributed generators connected to the utility grid has been growing every year. With this in mind, it is necessary to use methods that can detect islanding conditions in a faster way and that do not decrease the quality of the energy provided by the utility grid. This paper focuses on the design and simulation of a single phase grid-tied photovoltaic system using an active frequency...
The number of photovoltaic distributed generators introduced into electricity distribution systems is increasing worldwide. Safety measures must be taken for the correct operation of these new distributed generators so as to prevent uncontrolled and undesired power injections into the grid and possible damages to equipment and personnel. This paper describes an anti-islanding detection method used...
A low voltage (LV) distribution level unified power flow controller (UPFC) is shown capable of regulating the positive sequence voltage with a network while simultaneously correcting phase unbalance voltages that can be produced by high levels of distributed photovoltaic (PV) generation. Instantaneous reactive power theory shows that DC-bus capacitor power will fluctuate at twice mains frequency during...
Conventional anti-islanding techniques used in grid-tied photovoltaic (PV) systems pose many disadvantages at high levels of PV deployment. One such issue is the inability of these systems to ride-through grid disturbances. In this paper, the use of a Power Line Carrier Communications (PLCC) Permissive anti-islanding scheme is investigated as a means of safely enabling ride-through operation of grid-tied...
The use of Distributed Generation (DG) units for grid ancillary services, in particular for smart grid applications, has been deeply considered in the last few years. It has been demonstrated that DG units can produce not only active power, which is obviously the principal role, but also they can provide ancillary services such as: voltage control, spinning reserve, backup supply, harmonic compensation,...
Projections indicate photovoltaic (PV) electric power generation can be a significant grid resource in the future. The reliability and power quality of the grid can suffer if this resource has detrimental characteristics, or if this resource fails to do its part and support the grid through the range of possible system contingencies. This paper describes and evaluates grid support functions implemented...
Based on conventional current hysteresis band control, an adaptive hysteresis band control algorithm featuring dynamically modulate hysteresis band width was presented in this paper, and will be used in the application of photovoltaic grid-connected inverter. In the platform environment of Matlab/Simulink, the simulation modules of photovoltaic array, hysteresis band calculator, adaptive hysteresis...
The many different islanding detection methods for anti-islanding protection in power system are discussed. Passive, active and remote techniques are reviewed. Most of the ldquoactive methodsrdquo discussed are developed for photovoltaic (PV) as a distributed energy resource. Some recent methods can be use for any type of distributed generation. A final comparison of active islanding detection methods...
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