Load flow analysis of low voltage dc networks with photovoltaic

2014 ◽  
Author(s):  
Chathuranga Jayarathna ◽  
Prabath Binduhewa ◽  
Janaka Ekanayake ◽  
Jianzhong Wu
Keyword(s):  
Low Voltage ◽  
Flow Analysis ◽  
Load Flow ◽  
Load Flow Analysis

scholarly journals Analisis Pemasangan Filter Pasif Untuk Mengurangi Harmonisa Pada Transformator Rectifier Di PT. Indah Kiat Pulp And Paper Perawang

SainETIn ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 59-68
Author(s):  
Rido Rahmadani
Keyword(s):  
Power Factor ◽  
Low Voltage ◽  
Flow Analysis ◽  
Harmonic Distortion ◽  
Chloride Ion ◽  
Load Flow ◽  
Electrolysis Process ◽  
Pulp Industry ◽  
Load Flow Analysis ◽  
Power Load

The chlor-alkali process is an electrolysis process which plays an important role in the chemical industry such as the pulp industry. The process produces a product in the form of H2 gas, CL2 gas and NaOH (where the source of chloride ion used is NaCl). This electrolysis process requires a dirrect current with a large current  and a low voltage. In this electrolysis process a three phase controlled 12 pulse rectifiers are used which a connected with multi-winding transformers. In the rectifiers process there will be harmonic distortion on the source side of the transformer which can reduce the power quality of the system. To overcome the harmonic problems that occur in the system, an installation analysis of the equipment in the form of a passive single tuned  filter is aimed at reducing harmonic distortion of current and voltage and increasing the power factor (cos φ). From the result of harmonic analysis using ETAP software, after the installation of harmonic filters orde 11, 13 and 23, the harmonic current value (THDI) and harmonic voltage (THDV) has decreased, namely, before the filter installation, THDI value is 6,5% whereas after installation of filters, THDI value becomes 0,98%, thus there is a THDI decrease of 5,52%. Furthermore, for the voltage harmonic value (THDV) before filter installation is 1,48% while after filtering, THDV value becomes 0,26%, thus there is a THDV decrease of 1,22%. From the results of the simulation of the flow of power (load flow analysis), after installation of filters there is an increase in the value of the power factor (cos φ). Namely, before the filter installation, the value of power factor (cos φ) is 0,8 while after the filter installation the value of the power factor (cos φ) to 0,96, thus an increase in the power factor (cos φ) of 16%.   Keywords : harmonic filter, single tuned filter, power factor, transformer rectifier

scholarly journals A Virtual Tool for Load Flow Analysis in a Micro-Grid

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3173 ◽  
Author(s):  
Giovanni Artale ◽  
Giuseppe Caravello ◽  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Dario Di Cara ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Low Voltage ◽  
Flow Analysis ◽  
Load Flow ◽  
Measurement Instruments ◽  
Voltage Measurement ◽  
Parameter Uncertainties ◽  
Load Flow Analysis ◽  
Micro Grid ◽  
Power Measurements

This paper proposes a virtual tool for load flow analysis in energy distribution systems of micro-grids. The solution is based on a low-cost measurement architecture, which entails low-voltage power measurements in each secondary substation and a voltage measurement at the beginning of the medium voltage (MV) feeder. The proposed virtual tool periodically queries these instruments to acquire the measurements. Then, it implements a backward–forward load flow algorithm, to evaluate the power flow in each branch and the voltage at each node. The virtual tool performances are validated using power measurements acquired at the beginning of each MV feeder. The uncertainties on each calculated quantity are also evaluated starting from the uncertainties due to the used measurement instruments. Moreover, the influence of the line parameter uncertainties on the evaluated quantities is also considered. The validated tool is useful for the online analysis of power flows and also for planning purposes, as it allows verifying the influence of future distributed generator power injection. In fact, the tool is able to off-line perform the load flow calculation in differently distributed generation scenarios. The micro-grid of Favignana Island was used as a case study to test the developed virtual tool.

scholarly journals Analisis Pengaruh Harmonisa terhadap Rugi-Rugi Daya pada Sistem Tegangan Rendah dan Transformator GR088 di Penyulang Menjangan

2018 ◽  
Vol 5 (2) ◽  
pp. 1
Author(s):  
Salim Afif ◽  
I W. Sukerayasa ◽  
W. G. Ariastina
Keyword(s):  
Direct Measurement ◽  
Low Voltage ◽  
Flow Analysis ◽  
Harmonic Distortion ◽  
Load Flow ◽  
Network System ◽  
Harmonic Load ◽  
Medium Voltage ◽  
Load Flow Analysis ◽  
Harmonic Distortions

Menjangan feeder is a medium-voltage network system which distributes electricity throughout Gilimanuk and some areas in Buleleng. It has 69 distribution substations, which one of them, substation GR088, contributes to the highest value of the total harmonic distortion (THDi). In this research, the effect of harmonic distortions on losses at low voltage system of substation GR088 will be evaluated.The method used in this study is direct measurement of harmonic distortions at each low-voltage costumer whose electricity is generated by substation GR088 at Menjangan Feeder. Software is also used to perform harmonic load flow analysis and simulations. The total value of losses on transformer and low voltage system of substation GR088 Menjangan feeder, in a no-harmonic condition is 1481,7 Watt. On under-harmonic condition, the total value of losses is 1552,5 Watt. Therefore there is a 70,8 Watt difference between the two conditions. At this case, beside the heat created by the harmonic distortion that can affect the performance of transformers, it also cause a quite great value of losses, which is 1,7 kWh per day, or approximately 620 kWh per year. It means the harmonic distortion in substation GR088 can cause PT PLN (Persero) lose Rp.910.018,8 per year.

Operation Characteristics of Zone 3 Distance Protection in Wind Power Systems with Fixed-Speed Induction Generators

2011 ◽  
Vol 12 (4) ◽  
Author(s):  
Shenghu Li
Keyword(s):  
Power Systems ◽  
Wind Power ◽  
Reactive Power ◽  
Flow Analysis ◽  
Load Flow ◽  
Synchronous Generators ◽  
Induction Generators ◽  
Load Flow Analysis ◽  
Wind Power Systems ◽  
Operation Characteristics

The induction generators (IGs) are basic to wind energy conversion. They produce the active power and consume the reactive power, with the voltage characteristics fragile compared with that of the synchronous generators and doubly-fed IGs. In the stressed system states, they may intensify var imbalance, yielding undesirable operation of zone 3 impedance relays.In this paper, the operation characteristics of the zone 3 relays in the wind power systems is studied. With the theoretical and load flow analysis, it is proved that the equivalent impedance of the IGs lies in the 2nd quadrature, possibly seen as the backward faults by the mho relays, i.e. the apparent impedance enters into the protection region from the left side. The undesirable operation may be caused by more wind power, larger load, less var compensation, and larger torque angle.

Load Flow Analysis for Micro Grid

2021 ◽  
pp. 177-196
Author(s):  
P. Sivaraman ◽  
C. Sharmeela ◽  
S. Elango
Keyword(s):  
Flow Analysis ◽  
Load Flow ◽  
Load Flow Analysis ◽  
Micro Grid
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