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Distributed solar photovoltaic (PV) generation market continues to grow with increasing operational challenges for distribution network operators. In South Africa, residential solar PV system projects have also been implemented in low voltage distribution networks, and there are plans for future projects at municipal level. Residential solar PV growth introduces more technical and economic concerns...
This paper presents a novel concept for combining network and market or system service-orientated functions in grid storage systems. For this, a network service consisting in local phase balancing for power flows or voltages is considered. This service can be combined with further system or market — orientated services. A theoretical formulation of the converter set-points is provided for the use-case...
Presently, the quality of power supplied is essential to many customers. Power quality (PQ) is a valued utility service where many customers are prepared to pay and get it. In the future, distribution system operators ought to decide, to provide their customers with distinct PQ ranges at different prices. Here, in this paper, a new control action to improve and maintain and enhance the power quality...
There is a considerable increase in exploiting renewable energy resources in generating electrical energy during past 20 years. One of these renewable energy resources is wind power. This flaw is compounded in the cases of taking error in the grid, changes in the magnitude of wind, which in turn cause the generation of unfavorable electrical voltage and current harmonic waves, especially when high-voltage...
Since last decade, due to advancement in technology and increasing in the electrical loads and also due to complexity of the devices the quality of power distribution is decreases. A Power quality issue is nothing but distortions in current, voltage and frequency that affect the end user equipment or disoperation; these are main problems of power quality so compensation for these problems by DPFC...
This paper presents a comprehensive review on various impacts of DG integration on PQ and importance of proper grid-integration planning in light of maintaining PQ at the levels compliant with grid code requirements. It also focusses on the effective utilization of DGs for power quality enhancement in the utility grids. The proposed solutions essential for PQ enhancement in electricity networks with...
According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, Enhancement of power quality by using fuzzy based multilevel power flow controller (DPFC) is proposed. The DPFC is a new FACTS device, which its structure is similar to unified power flow controller (UPFC). In spite of...
The Power quality issues like voltage variations and current variations presented in the electrical networks are due to the consumer's utilities. Which are non — linear in nature. These non — linear loads inject increased flow of currents and reduced voltages with distortions. These voltage and current variations cause adverse effect on the consumer utilities. To overcome this problem we are using...
The spreading of electrical vehicles leads to a positive impact on the mobility field from the ecological, economical and efficiency point of view. Unfortunately this diffusion is also potentially capable of negative reverberations on distribution and transmission networks, since EVs can be considered as a new load category. Rather than preventing this virtually negative situation, it is possible...
This paper presents a model for a MV/LV bidirectional solid state transformer (SST) for distribution system studies. A multilevel converter configuration is used in the MV side for voltage and current harmonic reduction. The model has been implemented in the ATP version of the EMTP. Several case studies have been carried out in order to evaluate the behavior of the SST model under different operating...
Voltage unbalance is one of the main concerns in power quality studies. In the work here three-phase transmission system analysis is used to simulate voltage unbalance. Distributed Series Reactors (DSRs) are employed to improve voltage unbalance due to asymmetry in line parameters, unbalanced loading, and other causes, such as transmission line sending end voltage unbalances. The main advantage of...
This paper proposes a new topology for a three-phase AC/AC converter without DC. The presented topology is based on an direct AC/AC ĆukB2 bipolar matrix-reactance chopper. The considered solution is intended to control power flow and compensate voltage perturbations in the modern AC power grid with active loads (two-source system). The main difference in the proposed solution in comparison to a conventional...
This paper deals with the analysis of active and reactive power flows between the distribution and transmission network in the Czech Republic when operation of renewable energy sources can influence power relations in the network.
Utilities are developing new ways to manage the connection of increasing amounts of distributed generation (DG) on the electric grid. Among other issues, DG can lead to high voltage and other power quality problems. This paper describes a field trial by Greater Sudbury Hydro of a new low voltage control device, the LV-IPR. The device controls voltage directly by way of a series voltage injection,...
The objective of this paper is to propose a dc-bus voltage regulation and power control strategy for the three-phase back-to-back active power conditioner (APC). The proposed three-phase back-to-back APC is able to control the power flow between micro-grids. The demanded active and reactive power via droop control regulates the frequency and voltage, which contributes the power quality and stability...
This work aims at the optimal siting and sizing of distributed generation (DG) in distribution feeders. It is used an objective function which computes a penalty for voltage deviation in each bus coupled with the active power losses of the system. In this way, it is considered the equality and inequality constraints concerning the power flow, total apparent power of DG, number of installed DGs, fixed...
According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, voltage sag and swell of the power quality issues are studied and distributed power flow controller (DPFC) is used to mitigate the voltage deviation and improve power quality. The DPFC is a new FACTS device, which its...
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...
Small- and large-scale wind and solar photovoltaic (PV) generation systems are interconnecting to the distribution system at a rapid pace. Penetration limits are often imposed due to the impact these additional distributed resource can have on voltage. In order to accommodate high penetration scenarios without impacting power quality or reliability, additional control functions must be utilized. A...
This paper presents a Single-Phase Active Conditioner, which primal function is regulate load voltage, thus protecting the most sensitive loads from sags, swells, flicker and voltage harmonics. It is constituted by two back-to-back H-bridge converters. One regulates load voltage, the other DC-link voltage. This paper will focus essentially on the active power flow during sag and swell events, in a...
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