scholarly journals A Novel Optimal Shunt Capacitors Placement and Sizing Technique for Cost Minimization

Author(s):  
Thomson Mtonga ◽  
Keren K. Kaberere ◽  
George Kimani Irungu

<div>The installation of shunt capacitors in radial distribution systems leads to reduced branch power flows, branch currents, branch power losses and voltage drops. Consequently, this results in improved voltage profiles and voltage stability margins. However, for efficient attainment of the stated benefits, the shunt capacitors ought to be installed in an optimal manner, that is, optimally sized shunt capacitors need to be installed at the optimum buses of an electrical system. This article proposes a novel approach for optimizing the placement and sizing of shunt capacitors in radial distribution systems with a focus on minimizing the cost of active power losses and shunt capacitors’ purchase, installation, operation and maintenance. To reduce the search space, hence the computation time, the prroposed approach starts the search process by arranging the buses of the radial distribution system under consideration in pairs. Thereafter, these pairs influence each other to determine the optimum total number of buses to be compensated. The proposed approach was tested on the 34- and 85-bus radial distribution systems and when the simulation results were compared with those obtained by other approaches, it was established that the developed approach was a better option because it gave the least cost.</div>

2022 ◽  
Author(s):  
Thomson Mtonga ◽  
Keren K. Kaberere ◽  
George Kimani Irungu

<div>The installation of shunt capacitors in radial distribution systems leads to reduced branch power flows, branch currents, branch power losses and voltage drops. Consequently, this results in improved voltage profiles and voltage stability margins. However, for efficient attainment of the stated benefits, the shunt capacitors ought to be installed in an optimal manner, that is, optimally sized shunt capacitors need to be installed at the optimum buses of an electrical system. This article proposes a novel approach for optimizing the placement and sizing of shunt capacitors in radial distribution systems with a focus on minimizing the cost of active power losses and shunt capacitors’ purchase, installation, operation and maintenance. To reduce the search space, hence the computation time, the prroposed approach starts the search process by arranging the buses of the radial distribution system under consideration in pairs. Thereafter, these pairs influence each other to determine the optimum total number of buses to be compensated. The proposed approach was tested on the 34- and 85-bus radial distribution systems and when the simulation results were compared with those obtained by other approaches, it was established that the developed approach was a better option because it gave the least cost.</div>


Author(s):  
Su Mon Myint ◽  
Soe Win Naing

Nowadays, the electricity demand is increasing day by day and hence it is very important not only to extract electrical energy from all possible new power resources but also to reduce power losses to an acceptable minimum level in the existing distribution networks where a large amount of power dissipation occurred. In Myanmar, a lot of power is remarkably dissipated in distribution system.  Among methods in reducing power losses, network reconfiguration method is employed for loss minimization and exhaustive technique is also applied to achieve the minimal loss switching scheme. Network reconfiguration in distribution systems is performed by opening sectionalizing switches and closing tie switches of the network for loss reduction and voltage profile improvement. The distribution network for existing and reconfiguration conditions are modelled and simulated by Electrical Transient Analyzer Program (ETAP) 7.5 version software. The inputs are given based on the real time data collected from 33/11kV substations under Yangon Electricity Supply Board (YESB). The proposed method is tested on 110-Bus, overhead AC radial distribution network of Dagon Seikkan Township since it is long-length, overloaded lines and high level of power dissipation is occurred in this system. According to simulation results of load flow analysis, voltage profile enhancement and power loss reduction for proposed system are revealed in this paper.


2021 ◽  
Vol 13 (18) ◽  
pp. 10224
Author(s):  
Sasan Azad ◽  
Mohammad Mehdi Amiri ◽  
Morteza Nazari Heris ◽  
Ali Mosallanejad ◽  
Mohammad Taghi Ameli

Considering the strong influence of distributed generation (DG) in electric distribution systems and its impact on network voltage losses and stability, a new challenge has appeared for such systems. In this study, a novel analytical algorithm is proposed to distinguish the optimal location and size of DGs in radial distribution networks based on a new combined index (CI) to reduce active power losses and improve system voltage profiles. To obtain the CI, active power losses and voltage stability indexes were used in the proposed approach. The CI index with sensitivity analysis was effective in decreasing power losses and improving voltage stability. Optimal DG size was determined based on a search algorithm to reduce active power losses. The considered scheme was examined through IEEE 12-bus and 33-bus radial distribution test systems (RDTS), and the obtained results were compared and validated in comparison with other available methods. The results and analysis verified the effectiveness of the proposed algorithm in reducing power losses and improving the distribution system voltage profiles by determining the appropriate location and optimal DG size. In IEEE 12 and 33 bus networks, the minimum voltage increased from 0.9434 p.u and 0.9039 p.u to 0.9907 p.u and 0.9402 p.u, respectively. Additionally, the annual cost of energy losses decreased by 78.23% and 64.37%, respectively.


Author(s):  
Cihan Katar ◽  
Cengiz Polat Uzunoglu

In the near future, the digitalizing world will continue to improve and the need for DC based devices will be increased beyond doubt. Today’s electrical grid is strictly dependent on AC-DC rectifiers. Each conversion process means additional power losses and signal quality deteriorations for the network. In addition, networks which are fed by batteries and renewable sources such as solar panels, and wind turbines are suffering from conversion-based power losses. In this respect, the idea of switching to DC on the low voltage side of the networks has become an intriguing subject. In this study, the applicability and efficiency of the low voltage direct current (LVDC) concept for low voltage distribution systems is discussed and a sample LVDC distribution system is analyzed. In this operational residential application electrical transient analyzer program (ETAP) is employed for comparison of different voltage levels such as 110 V<sub>DC</sub>, 250 V<sub>DC</sub>, 320 V<sub>DC</sub> and conventional 220/380 V<sub>AC</sub>. As a novel approach different DC voltage levels are compared with typical AC system in detail. Comparative analysis is conducted for safety regulations, voltage drops, current carrying capacities, power consumption and harmonic calculation of the proposed system. In this respect applicability, possible drawbacks and future aspects of LVDC systems are interpreted.


2020 ◽  
Vol 10 (4) ◽  
pp. 1384
Author(s):  
Rabea Jamil Mahfoud ◽  
Nizar Faisal Alkayem ◽  
Yonghui Sun ◽  
Hassan Haes Alhelou ◽  
Pierluigi Siano ◽  
...  

In this paper, an improved hybridization of an evolutionary algorithm, named permutated oppositional differential evolution sine cosine algorithm (PODESCA) and also a sensitivity-based decision-making technique (SBDMT) are proposed to tackle the optimal planning of shunt capacitors (OPSC) problem in different-scale radial distribution systems (RDSs). The evolved PODESCA uniquely utilizes the mechanisms of differential evolution (DE) and an enhanced sine–cosine algorithm (SCA) to constitute the algorithm’s main structure. In addition, quasi-oppositional technique (QOT) is applied at the initialization stage to generate the initial population, and also inside the main loop. PODESCA is implemented to solve the OPSC problem, where the objective is to minimize the system’s total cost with the presence of capacitors subject to different operational constraints. Moreover, SBDMT is developed by using a multi-criteria decision-making (MCDM) approach; namely the technique for the order of preference by similarity to ideal solution (TOPSIS). By applying this approach, four sensitivity-based indices (SBIs) are set as inputs of TOPSIS, whereas the output is the highest potential buses for SC placement. Consequently, the OPSC problem’s search space is extensively and effectively reduced. Hence, based on the reduced search space, PODESCA is reimplemented on the OPSC problem, and the obtained results with and without reducing the search space by the proposed SBDMT are then compared. For further validation of the proposed methods, three RDSs are used, and then the results are compared with different methods from the literature. The performed comparisons demonstrate that the proposed methods overcome several previous methods and they are recommended as effective and robust techniques for solving the OPSC problem.


2021 ◽  
Vol 13 (6) ◽  
pp. 3199
Author(s):  
Laith Shalalfeh ◽  
Ashraf AlShalalfeh ◽  
Khaled Alkaradsheh ◽  
Mahmoud Alhamarneh ◽  
Ahmad Bashaireh

An increasing number of electric vehicles (EVs) are replacing gasoline vehicles in the automobile market due to the economic and environmental benefits. The high penetration of EVs is one of the main challenges in the future smart grid. As a result of EV charging, an excessive overloading is expected in different elements of the power system, especially at the distribution level. In this paper, we evaluate the impact of EVs on the distribution system under three loading conditions (light, intermediate, and full). For each case, we estimate the maximum number of EVs that can be charged simultaneously before reaching different system limitations, including the undervoltage, overcurrent, and transformer capacity limit. Finally, we use the 19-node distribution system to study these limitations under different loading conditions. The 19-node system is one of the typical distribution systems in Jordan. Our work estimates the upper limit of the possible EV penetration before reaching the system stability margins.


Author(s):  
Sayed Mir Shah Danish ◽  
Mikaeel Ahmadi ◽  
Atsushi Yona ◽  
Tomonobu Senjyu ◽  
Narayanan Krishna ◽  
...  

AbstractThe optimal size and location of the compensator in the distribution system play a significant role in minimizing the energy loss and the cost of reactive power compensation. This article introduces an efficient heuristic-based approach to assign static shunt capacitors along radial distribution networks using multi-objective optimization method. A new objective function different from literature is adapted to enhance the overall system voltage stability index, minimize power loss, and to achieve maximum net yearly savings. However, the capacitor sizes are assumed as discrete known variables, which are to be placed on the buses such that it reduces the losses of the distribution system to a minimum. Load sensitive factor (LSF) has been used to predict the most effective buses as the best place for installing compensator devices. IEEE 34-bus and 118-bus test distribution systems are utilized to validate and demonstrate the applicability of the proposed method. The simulation results obtained are compared with previous methods reported in the literature and found to be encouraging.


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