scholarly journals Index-based optimal DG allocation for voltage quality improvement in an unbalanced network

2021 ◽  
Vol 6 (2) ◽  
pp. 090-103
Author(s):  
Ahmadreza Eslami
Keyword(s):  
Distribution Systems ◽  
Intermediate Stage ◽  
Voltage Regulation ◽  
Voltage Profile ◽  
Distributed Generations ◽  
Voltage Unbalance ◽  
Voltage Variation ◽  
Voltage Quality ◽  
Three Phase ◽  
Unbalanced Network

Voltage quality is a one of the major concerns in distribution systems. Distributed Generations (DGs) have the potential to improve voltage quality, if optimally planned and operated. Considering the problem of DG siting and sizing, this paper aims at integrating technical factors, particularly voltage quality, in planning of DGs. Hence, a methodology is proposed which optimizes voltage quality in the presence of DGs and can be used as one of the objectives in a multi-objective problem or as an intermediate stage in usual DG planning. Modified voltage quality indices are proposed which consider factors including voltage profile, voltage variation due to DG disconnection, voltage regulation and voltage unbalance. The indices are defined in such a manner suitable for three-phase unbalanced networks. The system voltage quality is assessed by a new comprehensive voltage quality index. By applying this index, the DGs locating and penetration problem is formulated to improve system voltage quality. The method is tested on IEEE 13-bus feeder which is an inherently unbalanced network.

scholarly journals Strategies Comparison for Voltage Unbalance Mitigation in LV Distribution Networks Using EV Chargers

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 289
Author(s):  
Jorge Nájera ◽  
Hugo Mendonça ◽  
Rosa de Castro ◽  
Jaime Arribas
Keyword(s):  
Distribution System ◽  
Single Phase ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Voltage Unbalance ◽  
Voltage Quality ◽  
Three Phase ◽  
Charging Control ◽  
Local Measurements ◽  
Network Simulations

The increasing penetration of Electric Vehicles (EVs) in LV distribution networks can potentially cause voltage quality issues such as voltage unbalance and under-voltage conditions. According to the EV charger characteristics, some strategies can be adopted to mitigate the aforementioned effects. Smart decentralized charging controls seem to be a more practical solution than centralized controls, since there is no need for communication because they rely only on local measurements. The four most relevant decentralized charging strategies, two for single-phase and two for three-phase EV chargers, have been implemented in a typical three-phase four-wire European LV distribution network. Simulations have been carried out for scenarios with single-phase EV chargers, three-phase EV chargers, and a combination of both. Single-phase controls are aimed at under-voltage regulation, while three-phase controls are focused on mitigating voltage unbalance. Results show that the implementation of a decentralized EV charging control is an adequate solution for Distribution System Operators (DSOs) since it improves the reliability and security of the network. Moreover, even though decentralized charging control does not use any communication, the combination of three-phase and single-phase controls is able to mitigate voltage unbalance while preventing the under-voltage condition.

scholarly journals Impact of voltage unbalance on the performance of three-phase induction motor

2006 ◽  
Vol 24 (1) ◽  
pp. 45 ◽  
Author(s):  
P Giridhar Kini ◽  
R C Bansal ◽  
R S Aithal
Keyword(s):  
Power System ◽  
Induction Motor ◽  
Process Industries ◽  
Voltage Unbalance ◽  
Voltage Variation ◽  
Three Phase ◽  
Generating Capacity ◽  
Working Performance ◽  
Performance Variations

Availability of quality power has become an important issue for industrial utilities due to frequent performance variations in process industries. Increase in the generating capacity has not kept up pace of power demand, which results into shortage of power supply and power system network is normally subjected to varying and unequal loads across the three phases. Continuous variation of single-phase loads on the power system network leads to voltage variation and unbalance, most importantly; the three-phase voltages tend to become asymmetrical in nature. Application of asymmetrical voltages to induction motor driven systems severely affects its working performance. This paper presents the effects of voltage variation and unbalance on the performance of an induction motor driven centrifugal pump with a case study.

scholarly journals MODELING AND SIMULATION OF STATCOM FOR POWER QUALITY IMPROVEMENT

2021 ◽  
Vol 9 (2) ◽  
pp. 217-229
Author(s):  
Ch. Umamaheswararao, Et. al.
Keyword(s):  
Power Quality ◽  
Distribution Systems ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Voltage Profile ◽  
Inductive Load ◽  
Linear Load ◽  
Three Phase ◽  
Quality Aspects ◽  
Wide Range

In power system, reactive power compensation is one of the important action to maintain better voltage profile, stability and decrease losses. STATCOM is feasible in terms of cost effective in wide range of problem solving capabilities among all Flexible AC Transmission system (FACTS) in both transmission and distribution levels. In this paper the synchronous rotating frame theory algorithm is used since it is easy to implement i.e. the rotating three phase quantities are converted into stationary components. So it requires less number of PI controllers and also calculations on the stationary quantities are easy than to do calculations on instantaneous quantities and the modeling of STATCOM is done.  This project focuses on improvement of power quality in a three phase three wire system with a non-linear load i.e., three phase bridge rectifier and a parallel inductive load. Some power quality aspects like reactive power compensation of linear load, better Total Harmonic Distortion (THD) performance and the power factor improvement are achieved. The result shows the THD of input current achieved as per the IEEE 519-1992 standard. It is observed that STATCOM gives effective compensation for reactive power variation and hence the power quality of distribution systems improved.

Voltage Control Methods in the MV Grid with a Large Share of PV

2019 ◽  
Vol 20 (4) ◽  
Author(s):  
Csaba Farkas ◽  
András Tóth ◽  
Imre Orlay
Keyword(s):  
Distribution Systems ◽  
Voltage Regulation ◽  
Voltage Regulator ◽  
Voltage Profile ◽  
Distribution Grid ◽  
Large Share ◽  
Photovoltaic Generation ◽  
Line Voltage ◽  
Medium Voltage

Abstract The traditional distribution grid is operated radially and has passive consumers that only draw power from the grid but feed nothing back This operation is already under change so the traditional voltage regulation methods currently used in distribution systems need major modifications if we are to uphold the proper quality of electricity supply. In our paper we present the possible impact photovoltaic generation will likely have on the medium voltage grid and the means to lessen these impacts: we investigate various control options for solar inverters and a line voltage regulator as well. Simulation results indicate that the voltage profile can be maintained within the allowed limits with these regulation methods.

Investigation of Voltage Unbalance Profile in Low Voltage Electrical Distribution Network with Normal Mode Operation Using MATLAB

2018 ◽  
Vol 35 ◽  
pp. 60-76 ◽  
Author(s):  
Patrick Taiwo Ogunboyo ◽  
Remy Tiako ◽  
Innocent E. Davidson
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Voltage Drop ◽  
Distribution Network ◽  
Voltage Profile ◽  
Voltage Unbalance ◽  
Voltage Quality ◽  
Distribution Line ◽  
Electrical Distribution Network ◽  
Statutory Limit

With ever increasing use of semiconductor devices and information technology (ICT) equipment in the industry, homes and offices, power quality is gaining attention to both industry and the electric utility. Power voltage quality cause huge economic losses to businesses all over the world. It is estimated to cost industry and commerce about €100 billion per annum in European Union, since voltage quality problem is one of the major power quality disturbances. This paper presents an investigative a study of the 11/0.4 kV, low voltage electrical distribution network and analyzes voltage unbalance. It recommends an effective method of improving the voltage profile and reducing the voltage unbalance to acceptable standard. The network was modelled using distribution network standard parameters for low voltage distribution network using MATLAB/Simulink sim power system tool box. The simulation results show that the percentage voltage unbalance, correct voltage profile and minimum voltage drop of 0.5 km distribution feeder line is of standard acceptable statutory limit, hence the distribution line operates at optimum performance. However, it is also established that the voltage profile for distribution network feeder lengths of 0.8 km to 5 km for balanced and unbalanced distribution lines from the beginning to the customer terminal of the distribution lengths are less than the acceptable allowable limit of – 5 %, of the nominal voltage value, hence voltages are inadmissible for customers use. Moreso, the percentage voltage unbalance, voltage profile and voltage drop on 0.8 km to 5 km distribution feeder line are all less than standard acceptable statutory limit, hence the distribution line operates below optimum performance. It was established that mitigating these problems require the electricity distribution company to install an effective voltage boosting devices along the network lengths in order provide admissible, permissible and normalize end users standard acceptable voltage.

Optimum Location of Voltage Regulators in the Radial Distribution Systems

2016 ◽  
Vol 17 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Surender Reddy Salkuti ◽  
Young Hwan Lho
Keyword(s):  
Radial Distribution ◽  
Heuristic Algorithm ◽  
Distribution System ◽  
Distribution Systems ◽  
Voltage Regulation ◽  
Optimal Location ◽  
Voltage Regulators ◽  
Optimal Placement ◽  
Voltage Profile ◽  
Minimum Number

Abstract In this paper, a new heuristic algorithm is proposed for the optimum voltage control, which is applicable for the large Radial Distribution Systems (RDSs). In the RDSs, voltage levels at different buses can be maintained within the specified limits using the conductor grading or placing the Voltage Regulators (VRs) and capacitors at suitable locations. The proposed Back Tracking Algorithm (BTA) proposes the optimal location, number and tap positions of VRs to maintain the voltage profile within the desired limits and decreases losses in the system, which in turn maximizes the net savings in the operation of distribution system. In addition to BTA, an approach using the fuzzy logic called Fuzzy Expert System (FES) is also proposed, and the results of FES are compared with the results of BTA. This heuristic algorithm proposes the optimal location and tap setting of VRs, which contributes a smooth voltage profile along the network. It also used to access the minimum number of initially considered VRs, by moving them in such way as to control the network voltage at minimum possible cost. It is concluded that the FES also gives the optimal placement and the number along with the tap settings of VRs. The proposed FES contributes good voltage regulation, and decreases the power loss which in turn increases the net savings when compared to the BTA. The effectiveness of the proposed heuristic approaches are examined on practical 47 bus and 69 bus Radial Distribution Systems (RDSs).

scholarly journals Optimal Allocation of DGs with network reconfiguration using Improved Spotted Hyena Algorithm

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Distribution Systems ◽  
Optimal Allocation ◽  
Fitness Function ◽  
Spotted Hyena ◽  
Voltage Profile ◽  
Distributed Generations ◽  
System Reconfiguration ◽  
Optimal Subset ◽  
Spotted Hyenas ◽  
The Given

Several studies of distribution network enhancement focused only on the optimization of either the integration of distributed generations (DGs) or system reconfiguration (SRC). However, very few researches have been exerted for incorporating both where this merge represents further complexities in searching for maximizing their benefits and minimizing the investments. This paper sheds light on the simultaneous allocation of DGs with SRC in distribution systems. It suggests a multi-objective formulation considering multiple objectives: active power loss minimization, total cost reduction, and voltage profile improvement. For solving this problem, an improved spotted hyena optimizer (ISHO) is developed. The SHO demonstrates a good feature in finding the optimal or nearly optimal subset with simple structure to minimize the given fitness function. To support the exploration characteristics of the proposed ISHO, it augments a switch strategy in the updating mechanism of the spotted hyena’s positions and random positions are generated instead of the violated spotted hyenas. The simulations are investigated for the integration of a single and multiple DGs with SRC for two standard systems, which are IEEE 33 and 69-node test systems. The obtained results prove the efficiency of the suggested method for the network manager to find the optimal DGs allocation with SRC considering multiple criteria. These results are compared with previous literatures to demonstrate the effectiveness of the proposed algorithm.

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