International Conference on Science and Engineering for Sustainable Development (icsesd-2017)
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| International Conference on Science and Engineering for Sustainable Development (ICSESD-2017) ( www.jit.org.in ) International Journal of Advanced Engineering, Management and Science (IJAEMS) Special Issue-2 https://dx.doi.org/10.24001/ijaems.icsesd2017.95 ISSN : 2454-1311 www.ijaems.com Page | 333 Load-flow Analysis of Distribution systems using ETAP Chandan S. Kamble 1 , Prof. Rajni Rewatkar 2
Assistant Professor, Priyadarshini College of Engineering, Nagpur 1 E-mail: chandan41086@gmail.com
development of any country. To maintain the generation of electric power at adequate level the power has to be transmitted in proper form and quality to the consumer. Open access transmission has created a deregulated power market and brought new challenges to system planning. This paper proposes a new method to compute a probabilistic load flow in extensive power systems for the purpose of using it as a quick screening tool to determine the major investment on improving transmission system inadequacy. This research paper deals with the simulation of 132 kV substation in Electrical Transient Analyzer Program (ETAP) with detailed load flow analysis and also to overcome the problem of an under voltage. The results are based on actual data received from 132 kV Hingna II substation. Keyword— Load Flow,ETAP software, reactive power , Buses, voltage profile. I. INTRODUCTION The Power Station Load Flow Analysis program calculates the bus voltages, branch power factors, currents, and power flows throughout the electrical system. The program allows for swing, voltage regulated, and unregulated power sources with multiple utility and generator connections. It handles both radial and loop systems.
The Display Options section explains what options are available for displaying some key system parameters and the output results on the one-line diagram, and how to set them. The Load Flow Calculation Methods section shows formulations of different load flow calculation methods. Comparisons on their rate of convergence, improving convergence based on
different system
parameters and
configurations, and some tips on selecting an appropriate calculation method are also found in this section. The Required Data for Calculations section describes what data is necessary to perform load flow calculations and where to enter them. Finally, the Load Flow Study Output Report section illustrates and explains output reports and their format.
ETAP Load Flow software performs power flow analysis and voltage drop calculations with accurate and reliable results. Built-in features like automatic equipment evaluation, alerts and warnings summary, load flow result analyzer, and intelligent graphics make it the most efficient electrical power flow analysis tool available today.
ETAP load flow calculation program calculates bus voltages, branch power factors, currents, and power flows throughout the electrical system. ETAP allows for swing, voltage regulated, and unregulated power sources with unlimited power grids and generator connections. This load flow calculation software is capable of performing International Conference on Science and Engineering for Sustainable Development (ICSESD-2017) ( www.jit.org.in ) International Journal of Advanced Engineering, Management and Science (IJAEMS) Special Issue-2 https://dx.doi.org/10.24001/ijaems.icsesd2017.95 ISSN : 2454-1311 www.ijaems.com Page | 334 analysis on both radial and loop systems. ETAP allows to select from several different load flow calculation methods in order to achieve the most efficient and accurate results. The following two tables describe how these factors are used in these cases:
Motor load includes induction motor and generator, synchronous motor, MOV, and motor load portion of lumped load.
Static load includes static load, capacitor, and static load portion of lumped load.
Table 2.1:-Factors Used for Motor Load Calculation
Input to Studies Results from Studies Bus Editor Load Loss Vd Load Loss Load Loss Vd Bus Nominal kV
x
x x x X x X Bus Operating V
x x
x X x Demand Factor X x
x x x X x X Loading % X x x x x x X x X Service Factor
App. Factor
*
Load Quantity X x
x x x X
X Bus Diversity Factor
* * * * * Global Diversity Factor
* * * * *
Table 2.2:-Factors Used for Static Load Calculation
Input to Studies Results from Studies Bus Editor Load Loss Vd Load Loss Load Loss Vd Bus Nominal kV X x
x x x X x X Bus Operating V
x
x X x Demand Factor X x
x x x X x X Loading % X x x x x x X x X App. Factor
Load Quantity X x x x x X
X Bus Diversity Factor
* * * * *
Global Diversity Factor
* * * * * * Indicates the factor is used in calculation if specified by the user in the related load editor or study case.
There are two main 132kv bus incoming for the substation. These buses are:- 1.132kv kalmeshwar 2.132kv Ambazari Now the transmission line first parallel connected with lightning arrester to diverge surge, followed by CVT connected parallel.CVT measures voltage and steps down from 132kv to 63.5 volts A.C for control panel, at the location a wave trap is connected to carrier communication at higher frequencies. Switchgear equipment is provided, which is the combination of circuit breaker having an isolator at each end. Two transformers are connected to main bus . In addition to the main bus, Transfer bus is also provided in substation in International Conference on Science and Engineering for Sustainable Development (ICSESD-2017) ( www.jit.org.in ) International Journal of Advanced Engineering, Management and Science (IJAEMS) Special Issue-2 https://dx.doi.org/10.24001/ijaems.icsesd2017.95 ISSN : 2454-1311 www.ijaems.com Page | 335 case any maintenance work is to be carried out on the main bus. After the main bus, lightning arresters, current transformers, isolators and circuit breakers before the transformers are provided. Then transformers step downs voltage from 132kv to 33kv & 11kv respectively. The main bus is then again provided with switchgear equipment & a current transformer. Capacitor bank is connected to main bus. It is provided to improve power factor & voltage profile.
The details of the equipment are taken from 132KV Hingna II substation of Nagpur ring main EHV system.
•
It comprises of 4 transformers out of which 2 are of 50MVA rating & other 2 are of 25MVA each. •
The 132KV substation consists of 35 buses,out of which there is 1 generating bus & 2 load bus. •
transformers of rating 33 kv/0.4 kv and 11kv/0.4KV of 0.2 MVA each for distribution purpose.
Following table explains the load calculation done by manually at each feeder with considering primary line current. Table 3.1 Manual load calculation
IV. ETAP SIMULATION RESULTS Fig. 4.1 Simulation Diagram of Hingna II 132kv Substation International Conference on Science and Engineering for Sustainable Development (ICSESD-2017) ( www.jit.org.in ) International Journal of Advanced Engineering, Management and Science (IJAEMS) Special Issue-2 https://dx.doi.org/10.24001/ijaems.icsesd2017.95 ISSN : 2454-1311 www.ijaems.com Page | 336 Fig. 4.1 Load flow of Hingna II 132kv Substation after simulation V. CONCLUSION The load flow calculation results are reported both on the one-line diagram and in the Crystal Reports format. The graphical one-line diagram displays the calculated bus voltages, branch flows and voltage drops, load power consumption, etc. It also flags abnormal operating conditions, such as overloaded cables and over- or under voltage buses, in different colors. The Crystal Reports format provides with detailed information for a load flow analysis. Load Flow Report Manager can be utilize to help the view of output report.
Fig. 5.1 Load flow Report International Conference on Science and Engineering for Sustainable Development (ICSESD-2017) ( www.jit.org.in ) International Journal of Advanced Engineering, Management and Science (IJAEMS) Special Issue-2 https://dx.doi.org/10.24001/ijaems.icsesd2017.95 ISSN : 2454-1311 www.ijaems.com Page | 337 Fig. 5.1 Load load summary
The above result shown in fig. 4.1 is of the load summary to view. Some portions of the summary are available only when specific options in the study case, such as Critical and Marginal Voltage.
software is carried out with an approach to overcome the problem of an under voltage. Load Flow Studies using ETAP software is an excellent tool for system planning. A number of operating procedures can be analyzed such as the loss of generator, a transmission line, a transformer or a load. Load flow studies can be used to determine the optimum size and location of capacitors to surmount the problem of an under voltage. Also, they are useful in determining the system voltages under conditions of suddenly applied or disconnected loads. Load flow studies determine if system voltages remain within specified limits under various contingency conditions, and whether equipment such as transformers and conductors are overloaded. After carrying work in the load-flow analysis of distribution systems, the following guidelines seem to be worth pursuing this area: (i)Load-flow analysis for unbalanced network. (ii)Fuzzy load-flow analysis. (iii)Uncertainty in branch impedance.
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