Allocation and Sizing of Dispersed Photovoltaic Generation in Diesel Isolated Electrical Systems Using an Analytical Approach

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Claudio Goncalves ◽  
J. Paulo A. Vieira ◽  
Dione J. A. Vieira ◽  
M. Emilia L. Tostes ◽  
Bernard C. Bernardes ◽  
...  

This paper proposes an analytical methodology to allocate and size active power photovoltaic generation (PVG) units with embedded DC/AC inverter (PVGI) to be integrated as concentrated or dispersed generation in isolated medium voltage electrical grids. The methodology considers multiple objectives: improving the electrical grid voltage profile; reducing active power losses and the diesel generation participation. To validate the proposed methodology, the IEEE 33 and 69 buses networks and an isolated real electrical system were simulated. The results obtained demonstrated that the proposed methodology is effective in providing a solution with improvement in voltage profile, active power losses reduction, diesel generation participation reduction.

Author(s):  
Shah Mohazzem Hossain ◽  
Abdul Hasib Chowdhury

<span lang="EN-US">Large amount of active power losses and low voltage profile are the two major issues concerning the integration of distributed generations with existing power system networks. High </span><em><span lang="EN-US">R</span></em><span lang="EN-US">/</span><em><span lang="EN-US">X</span></em><span lang="EN-US"> ratio and long distance of radial network further aggravates the issues. Optimal placement of distributed generators can address these issues significantly by alleviating active power losses and ameliorating voltage profile in a cost effective manner. In this research, multi-objective optimal placement problem is decomposed into minimization of total active power losses, maximization of bus voltage profile enhancement and minimization of total generation cost of a power system network for static and dynamic load characteristics. Optimum utilization factor for installed generators and available loads is scaled by the analysis of yearly load-demand curve of a network. The developed algorithm of N-bus system is implemented in IEEE-14 bus standard test system to demonstrate the efficacy of the proposed method in different loading conditions.</span>


Author(s):  
Wan Iqmal Faezy Wan Zalnidzam ◽  
Hasmaini Mohamad ◽  
Nur Ashida Salim ◽  
Hazlie Mokhlis ◽  
Zuhaila Mat Yasin

The increasing penetration of electric vehicle (EV) at distribution system is expected in the near future leading to rising demand for power consumption. Large scale uncoordinated charging demand of EVs will eventually threatens the safety operation of the distribution network. Therefore, a charging strategy is needed to reduce the impact of charging. This paper proposes an optimal centralized charging schedule coordination of EV to minimize active power losses while maintaining the voltage profile at the demand side. The performance of the schedule algorithm developed using particle swarm optimization (PSO) technique is evaluated at the IEEE-33 Bus radial distribution system in a set time frame of charging period. Coordinated and uncoordinated charging schedule is then compared in terms of active power losses and voltage profile at different level of EV penetration considering 24 hours of load demand profile. Results show that the proposed coordinated charging schedule is able to achieve minimum total active power losses compared to the uncoordinated charging.


2019 ◽  
pp. 41-52
Author(s):  
Nikolaus M. Tana ◽  
Frans Likadja ◽  
Wellem F. Galla

The 20 kV medium Voltage overhead lines of Naioni feeder on PT. PLN (Persero) ULP Kupang system has a feed length of ± 79.825 kms and is the longest of all feeders installed in the ULP Kupang. To minimize the voltage drop and power losses on the Naioni Feeder 20 kV medium Voltage overhead lines (SUTM), network reconfiguration needs to be done including changing the diameter of the conductor, installing a transformer insert and installing a capacitor bank using the help of ETAP software. From the results of the study, before reconfiguration, the voltage drop at the end of the Bus_Trafo KB 082 channel was 0.967 kV and the voltage drop percentage was 4.68% while the total power losses at Naioni Feeder were 20 kV, which were active power losses of 48.062 kW and loss reactive power loss of 25,689 kVAR. Furthermore, after reconfiguring the carrying diameter on the channel that still uses a small diameter of 35 mm2, it will be converted to 70 mm2 on cable 17 that connects the KB 119 Transformer Bus channel to the KB 074 Transformer Bus which is a fairly long distance from all other channels. So that after carrying out the reconfiguration of the conductor diameter, the voltage drop at the end of the Bus Trafo KB 082 channel is 0.844 kV and the voltage drop percentage is 4.24%, while the total power losses in the Naioni Feeder are 20 kV which are active power losses of 41.142 kW and conductor reactive power loss of 25.53 kVAR. Furthermore, after installation of the transformer insert and changing the conductor diameter on cable 17 of 35 mm2 will be changed to 70 mm2 connecting the Transformer Bus Channel KB 119 to the KB 074 Transformer Bus, then the voltage drop at the end of the Bus Trafo KB 082 channel is 0.826 kV and the voltage drop percentage amounting to 4.15% while the total power losses at Naioni Feeder are 20 kV, namely active power losses of39.292 kW and reactive power losses of 24.467 kVAR. And then, if the capacitor bank is installed on the Bus Transformer KB 119 channel bus point to the Bus Trafo KB 074 channel, then the voltage drop at the Bus Trafo KB 082 channel end is 0.891 kV and the voltage drop percentage is 4.47%, while the total power losses are The 20 kV Naioni Feeder is an active power loss of 43.714 kW and a reactive power loss of 22.888 kVAR.


Designs ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 53
Author(s):  
Dumitru Toader ◽  
Marian Greconici ◽  
Daniela Vesa ◽  
Maria Vintan ◽  
Claudiu Solea ◽  
...  

One important problem in the operation of medium voltage networks is the detection of a single-line-to-ground fault in its incipient state, when the fault resistance values are very high. In a medium voltage (MV) distribution network with a neutral grounding resistor (NGR), one of the methods employed to discriminate a single line-to-ground fault is the use of an overcurrent relay with an operating characteristic adjusted according to the effective value of the current flowing through the limiting resistor. In case of a single line-to-ground fault with a high fault resistance value, the correct tripping settings of the protective relay require the precise computation of this current. In comparison to the assumptions made by the models from the literature—the three-phase voltage system of the medium voltage busbars is symmetrical and there are no active power losses in the network insulation—the model proposed in this paper considers the pre-fault zero-sequence voltage of the medium voltage busbars and the active power losses in the network insulation, which is necessary in certain fault conditions where the use of the former leads to unacceptable errors.


Tehnika ◽  
2020 ◽  
Vol 75 (6) ◽  
pp. 749-755
Author(s):  
Stevan Rakočević ◽  
Martin Ćalasan ◽  
Tatjana Konjić

In this paper, CONOPT solver, embedded in program GAMS, is proposed for optimal power flow analysis in distribution network with renewable energy sources. CONOPT solver possibilities have been tested on IEEE 33 test system solving a problem o f minimizing active power losses in the network. Locations and sizes o f renewable energy sources were taken form available literature. The results obtained using CONOPT solver have been compared with results obtained by using metaheuristic and hybrid algorithms. It is shown that the CONOPT solver gives better results in terms o f minimum values o f active power losses.


Electrician ◽  
2019 ◽  
Vol 13 (3) ◽  
pp. 61-68
Author(s):  
Christopher Theophilus Prayogo ◽  
Osea Zebua ◽  
Khairudin Hasan

Intisari — Jarak yang jauh antara sisi penyuplai energi listrik dan sisi konsumen (beban) pada jaringandistribusi menimbulkan permasalahan seperti meningkatnya rugi-rugi daya di sepanjang saluran dan jatuhtegangan. Pemasangan kapasitor adalah salah satu solusi untuk meminimalkan rugi-rugi daya sekaligusmemperbaiki profil tegangan. Tujuan dari penelitian ini adalah mencari nilai kapasitas optimal daribeberapa bank kapasitor yang dipasang pada jaringan distribusi untuk meminimisasi rugi-rugi daya aktifmenggunakan metode Grey Wolf Optimizer (GWO). Lokasi penempatan bank kapasitor ditentukan denganmenggunakan metode faktor sensitivitas rugi-rugi atau Loss Sensitivity Factor (LSF). Studi kasus yangdigunakan adalah jaringan distribusi 20 kV Penyulang Wortel, di Gardu Induk Menggala, ProvinsiLampung. Simulasi penentuan lokasi penempatan dan optimasi kapasitas bank kapasitor dilakukan denganmenggunakan perangkat lunak MATLAB. Hasil simulasi menunjukkan bahwa lokasi optimal penempatanempat bank kapasitor menggunakan metode LSF adalah pada bus 42, 51, 58 dan 60 dan kapasitas optimalbank kapasitor pada bus-bus tersebut yang diperoleh dengan menggunakan metode GWO masing-masingadalah sebesar 0,15 MVAR, 0,45 MVAR, 0,15 MVAR, dan 0,15 MVAR. Rugi-rugi daya aktif yang diperolehsetelah pemasangan bank kapasitor adalah sebesar 0,1041 MW atau berkurang sebesar 23% dari nilai rugirugi daya aktif sebelum pemasangan bank kapasitor yakni 0,1352 MW. Nilai tegangan minimum yangdiperoleh setelah pemasangan bank kapasitor adalah 0,944 pu dan memperbaiki profil tegangan dari nilaitegangan minimum sebelum pemasangan bank kapasitor yakni sebesar 0,916 pu.Kata-kata kunci - optimasi kapasitas, capacitor bank, Grey Wolf Optimizer, rugi-rugi daya aktif, faktorsensitivitas rugi-rugi.Abstract — Long distance between the electricity supply side and the consumer side (load) on the distributionnetwork can cause problems such as increasing power losses along the line and voltage drop. Installingcapacitors is one solution to minimize power losses while improving the voltage profile. The aim of this researchis to find the optimal capacity value of several capacitor banks installed in the distribution network to minimizeactive power losses using the Grey Wolf Optimizer (GWO) method. The location of the capacitor bank placementis determined by using the Loss Sensitivity Factor (LSF) method. The case study used is a 20 kV distributionnetwork of Wortel Feeders, in Menggala substation, Lampung Province. Simulation of determining theplacement location and optimization of capacitor banks capacity is performed using MATLAB software. Thesimulation results show that the location of four capacitor banks using the LSF method is on buses 42, 51, 58and 60 and the optimal capacitor bank capacity on those buses obtained using the GWO method are 0.15 MVAR,0.45 MVAR, 0.15 MVAR, and 0.15 MVAR, respectively. The active power losses obtained after the installation ofcapacitor bank are equal to 0.1041 MW or reduced by 23% from the value of active power losses before theinstallation of capacitor bank which is 0.1352 MW. The minimum voltage value obtained after the installation ofcapacitor bank is 0.94 pu and improves the voltage profile of the minimum voltage value before the installationof capacitor bank which is equal to 0.916 pu.Keywords— capacity optimization, capacitor bank, Grey Wolf Optimizer, active power losses, Loss SensitivityFactor.


2017 ◽  
Vol 2017 (3) ◽  
pp. 65-70
Author(s):  
A.F. Zharkin ◽  
◽  
V.A. Novskyi ◽  
N.N. Kaplychnyi ◽  
A.V. Kozlov ◽  
...  

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