Description
ABSTRACT
Effectiveandefficient electricpower transmission isamajor concernin Nigeria. Electricpower transmission is the link between the generating companies and the distribution companies in Nigeria. This research work is to ascertain the status of Owerri 132kV/33kV Transmission Network for better performance with Newton Raphson method using Static VARCompensators tosolve the problem ofunder voltage, optimize the systemforbetterpowerdelivery by placing Static VAR Compensators to minimize PowerSystem losses and maximize powertransferby its equivalent model using ETAP 7.0.The data used forthis research work were obtained from the Transmission Company of Nigeria TCN (Owerri 132kV/33kV T/S) in Imo State.The Network consist of132kV lines, ALAOJI I and ALAOJI 2 with the Six (6) 33kV Feeders: Mbaise 33kV,Owerri main 33kV, Owerri line 2, 332kV, Oguta 33kV, Okigwe 33kV and Orlu 33kV with a total load 152.42 MVA; The 132kV Substation has two (2) 60MVA transformers and one (1) 45MVA transformer called Mobitra.. Theresult of the simulation showed that transformers buses were over loaded beyond their capacities. The introduction of Static VAR Compensators at the 132kV Buses showed that there was an increase of Load MW by 3% and a reduction of Load MVAR by 49.37% when a capacity 52.9MVAR from the VAR Compensator was introduced at the 132kV buses. The simulated result showed an optimization of existing Network from the enhanced voltage, adequate power supply and a reduction ofthe total power loss from 22.0MW to 21.181MW representing a 4% reduction in load MW as seen from the simulation of the modeled 132kV/33kV Network.
CHAPTER ONE
INTRODUCTION
BACKGROUND OF THE STUDY
Efficient and reliable power supply systems must be maintained by the power supply companies. The increasing amount of electrical load and the location of the substations away from the power plants bring about a significant drop in voltage and power losses along the transmission lines. The voltage drop greatly affects the quality of power provided, and may cause the damage of connected electrical equipment if the voltage drop is not compensated or optimized.
There is an issue ofpower qualityfor developingnations where the load keeps increasingrapidlymore than the generated powerwhich is not up to the level of load demand. Electrical transient analyzer program (ETAP 7.0)was used to carry out load flow analyses and also ascertain the effect of Static VAR Compensators for voltage optimization of the 132/33kV transmission network under review
The Aim of thisresearch work isto use a FACT Controller (Static VAR Controllers) inload flow analysis of a 15 Bus Owerri 132kV/33kV Network to better utilized theNetwork, reduce power system under voltages, Line loses and increase the voltage profile of the existing Network.
The objective seeks to achieve detailed analyses by using modern software ETAP Version 7.0, to perform Load flow calculations showing voltage magnitudes at various buses, real and reactive power in each line of the transmission line when its equivalent single line diagram ismodeled in ETAP for optimal power transfer.
This scope of this work is limited to the 67km Owerri 132/33kV Transmission network from Alaoji to Owerri. The single line diagram of Owerri 132/33kV Transmission Station is Modeled and simulated in ETAP based upon actual data of the 132kV and 33kV bus/feeders loads. Static VAR Compensators was used to maintain System Stability and improve voltage profile.
Thus, load flow problem provide insight into the calculations of real and reactive power in the buses and its voltage and phase angle and load flow across each line and the solution provides the ability of the system to Operate within its static stability limits from one Transmission Station to the other without over loading linesand by the using VAR Compensators and correct tapping of transformers.
STATEMENT OF THE PROBLEM
Due to tremendous industrial growth and rapid population, requirement of power has increased manifold. Thus, it is pertinent to transmit power from the source to load centres down to consumers with minimum possible losses and disturbances.This objective can be achieved only if the transmission systems are so designed and constructed in such that they are efficient, technically sound and reliable(Uche et al., 2013).
The lines should have sufficient current carrying capacity so as to transmit the required power over agiven distance without an excessive voltage drop andoverheating.Linelossesshouldbesmallandinsulationofthelinesshouldbeadequatetocopewiththesystemvoltage.Thereshouldbesufficientmechanical strength to cope with the worst probable(not worst possible due to economic factor) weatherconditionsandprovidesatisfactoryserviceoveralongperiodoftimewithouttoomuchmaintenancenecessity.
Transmission lines vary according to distances and are classified as such, known as short lines, medium lines and long lines(Muhtazaruddin et al., 2014).Transmission network forms the vital links between generating stations and the consumers via distribution systems. As we all know, electricity,unlike water cannot be stored in large quantities, as such should be used as the productions go on. Transmission network therefore is the medium through which the bulk power can be conveyed from one place to another over long distances. Transmission voltage varies from 132KV,220KV, 330KV, 400KV and above (Gupta, 2015). In Nigeria however, the transmission levels are mainly132KV and 330KV, while distribution levels fall into 33KV and 11KV respectively(Muhtazaruddin et al., 2014).
Due totremen do us industrial growth and rapid population,requirement of power has increased manifold. Thus, it is pertinent to transmit power from the source to load centers down to consumers withminimumpossiblelossesanddisturbances.Thisobjectivecanbeachievedonlyifthetransmission systems are so designed and constructed in such that they are efficient, technically sound and reliable (Uche et al., 2013).
AIM AND OBJECTIVES OF THE STUDY
The aim of this work is to ascertain the status of farin gada 132kV/33kV Transmission Network for better performance.
The objectives of this study are:
- To solve the problem of under voltage, optimize the system for better power delivery
- To minimize Power System losses and maximize power transfer
- To ensure that power transmit is consumed with minimum possible losses and disturbances
- To ensure effective and efficient electric power transmission
1.4 SIGNIFICANCE OF THE STUDY
In transmission lines receiving end voltage and power factor are two very important aspects to be considered. optimizing power transmission network is important in that it used to keep voltage within tolerable limit and to improve power factor, transmission line compensation is done.
1.5 APPLICATION OF THE STUDY
Power flow is used for line loading, generation adequacy, economic dispatching and unit commitment, all for planning and stability of power system. The implementation of this work would be beneficial to the following group of people.
- Power holding company of Nigeria,
- The Research students
- The ministry of power and energy for policy formulation
It will also offer some economic benefits by way of reducing fault level and improve steady state performance for expansion alternative.
1.6 SCOPE OF THESTUDY
Power system control and line compensation are essential for the effective working of power system. Voltage, frequency and power factor are the main items to be controlled. To get the desired voltage at the distribution end voltage control is necessary. The scope of this work covers to ascertaining farin gada 33kV Transmission Network for better performance using Static VAR Compensators to solve the problem of under voltage, optimize the system for better power delivery by placing Static VAR Compensators to minimize Power System losses and maximize power transfer.
