Power quality considerations for embedded generation integration in Nigeria: A case study of ogba 33 kV injection substation

The deregulation of the Nigerian power sector has resulted in the quest to explore power generation options for power quality improvement. One of such options is the pattern shift from central power generation to embedded power generation. Network integration of embedded generators (EGs) causes several regulatory, technical and economic issues. This research focuses on power quality challenges that may arise as a result of network integration of embedded generation in a weak electricity networks using Ogba 33 kV injection substation as case study. The embedded generators considered comprised of gas turbine and diesel generators. NEPLAN software was used to perform the load flow analysis with and without EGs connection on the network. This was necessary so as to ascertain the healthiness of the existing distribution network for EGs integration. The power quality issues considered in the study were bus voltage profiles and the total line losses. Simulation results showed that EGs connection improved the voltage profile, for example, bus voltage at PTC 11 kV, improved from 0.881 pu to 0.958 pu while the total active power loss was reduced by 78.16%. The results obtained suggest that the grid is healthy enough to accommodate the EGs with no quality issues

Synchronous Generator Excitation Chatter-Free Sliding Mode Controller

A chatter-free sliding mode controller (SMC) for synchronous generator excitation is presented in this paper. A linearized model of a single machine connected to an infinite bus is employed to design a variable-structure controller which not only stabilizes the system, but also ensures that this is maintained in the face of system parameter variations. Validating the robustness feature of an SMC, simulation results that show the dynamic performance of the system under both constant excitation and SMC-controlled excitation are presented

Contingency Analysis for Assessing Line Losses in Nigeria 330-kV Power lines

Line losses ill transmission lilies constitute one of the llllljor problt!llls affecting power generation and distribution systems. Losses luwe beelt foulld to affect the overall ejJidency of a system. Therefore, to illcretUe the efficiency of any system, losses must be minimized, This paper carried out a comprehensive study alld analym of line losses associated with Nigeritz 330-kV power transmission lines. The work includes the power-flow analysis carrid out on the existilfg Mtwork using both the Newton-Rapltson (N-R)wrltten in code-btlsed MATLAB a1ld the model-based N-R ill Power World Simulator (PWS) environment. The power-flow analysis HillS further subjected to contingency analysis and silllukdion using the N-R in PWS. Two 101111-flows were performed to reveal voltage violated buses.The resulb showed that the bus voltages outsith the statutory limit of 0.95- 1.05p.u(i.e 313.5 - 346.5kV) occurred at buses2-Bimi1JKebbi (0.9183pu), bus 9 Akangba (0.937pu), bus 18-0nitslul (0.935pu), bus 20-New-Htn~e~~ (0.920pu), bus 25- Kaduna (0.9233pu), bus 26-Kano (0.776pu), bus 22-Jos (0.8192pu) and bus 28-Gombe (0. 7247pu) under normal uncompensated conditio11. CfiiHICitive shunt compensation was applkd on these buses and the results recorded appreciable loss rethlction (about 111.35%). The result of the 11ingk line contiiJgency analyllis for uncompeMated and compen~~ated indicates a total of 335 alld 25 voltage bus violl.ltions respectivel

Design And Development Of A Microcontroller Based Wireless Security Access System

Security can simply be protecting your equipment and files from unauthorized access, but there is much more. Computer security helps ensure that your computers, networks, and peripherals work as expected all the time, and that your dsta is safe in the event of hard disk crash or a power failure resulting from an electrical storm. Security makes sure no dsmage is done to your dsta and that no one is able to read it unless you want them to. This work focuses on security from the dimension of remote wireless access using password credential. In various industries, companies and even homes of today, the use of this means of security is very popular and various evolution over the years have been made to the first model that came out in the late 1800's. The main activities involved in this work are the research done on how the automatic gate works and the transfer of frequency modulated signals using the transmitter and receiver module

Technical challenges in connecting wind energy converter to the grid

Most developing nations of the world are looking towards renewable energy sources as a sustainable option. Among all the energy sources, the one that is matured to the level of connecting it to the grid (either distribution or transmission) is wind energy. As wind energy is increasingly integrated into power systems in some countries of the world, the stability of already existing power systems is becoming a concern and of utmost importance to the power system engineers and operators. This is because the connection of wind generators to the existing grid poses new challenges which have a significant impact on the system and equipment operations in terms of steady state, dynamic operation, reliability, power quality, stability and safety for both the utility and customers. These challenges are due to the fluctuating nature of the wind and the type of wind generator used. In order to supply quality voltage, SVC and STATCOM can be used to control the reactive power at the point of common coupling. Also the use of variable speed wind turbine generator can help in lowering the flicker level. This paper therefore gives the overview of the causes of these challenges, its effect on the existing power system and possible ways of improving the challenges

Investigation of the Performance of of Synchronous Generators Equipped with Nonlinear Excitation Controller

Investigation of the dynamic performance of a synchronous generator connected to an infinite bus (SMIB) system is carried out in this paper. The generator is equipped with a nonlinear excitation control law based on the concepts of geometric homogeneity and feedback linearization. A new positive parameter, called the dilation gain, is introduced in the control law for improved damping of oscillations and better dynamic performance. Two models of the system are employed for the study, and a disturbance in form of a network fault with varied durations is applied to test the performance of the system. Simulation results as well as MATLAB® code for testing for exact linearization of an affine nonlinear system are provided

Wind Energy Potential in Nigeria

Wind energy is one of the fastest growing technologies in energy generation industry nowadays. The erratic and epileptic state of power in this country and the concern about global warming should be a great concern for all and should drive us into strong demand for wind generation. The main advantages of electricity generation from wind are the absence of harmful emissions, very clean and the almost infinite availability of the wind that is converted into electricity. In Nigeria, where the wind power prospect is estimated to be high or moderate has not connected this renewable resources to the grid. It is not just enough to say that the wind turbines should be connected to the grid because there are sufficient wind speeds to drive the wind turbine. Mostly, the stability and reliability studies must be carried out whenever wind power is to be connected to power system to predict severe consequences on the power system to which the wind generators will be connected. This paper therefore describes the wind energy potential in Nigeria and specifies the conditions to be met before the wind generator can be connected to the existing grid and how it can be connected. The paper also shows that short-circuit power at Point of Common Coupling (PCC) is the crucial value for the permissible installed power ratings of the turbine

An Electronic Protection Unit for Diesel Engine Standby Generators

Today diesel engine-driven standby generators for backup power supply have been adopted for residential, commercial, and industrial use--especially in some developing countries where power from the utility company is highly erratic. Although many of these generators function well in operation, certain engine conditions, such as low oil pressure, high oil and water temperature, abnormally high speed, etc., could lead to malfunction, failure, or complete breakdown of the engine. Therefore, the focus of this work is to present the implementation of a simple, but effective electronic protection unit (EPU) capable of mitigating the adverse effect which may arise as a result of these conditions. It is composed of two major sub-circuits-the main protective sub-circuit and the timing sub-circuit-realized using a combination of passive and active components. Unlike the common electrical relay-based protection system, this unit has an additional advantage of being able to keep the faultindicating system of the generator working even after engine shutdown, thereby facilitating fault tracking. The unit has been tested on a diesel engine-driven generator and found to function satisfactorily. The test results are shown

Development of a software solution for solar-PV power systems sizing and monitoring

Power systems sizing and monitoring are very important design components in determining the overall performance of solar-photovoltaic (PV) systems. These design components represent the pre-installation and post-installation stages of solar-PV systems planning respectively, and paying adequate attention to them can go a long way to increasing the working life of solar-PV system installations. The SolarHelper developed in this work is a small software solution package that monitors and records vital system variables that will give the state and performance of an existing solar-PV installation at any given time; and it is able to accurately provide a simulated output of the required battery storage capacity, and PV array size based on load demands

DESIGN AND IMPLEMENTATION OF AN AUTOMATIC IRRIGATION SYSTEM BASED ON MONITORING SOIL MOISTURE

An automatic irrigation control system has been designed to facilitate the automatic supply of adequate of water from a reservoir to field or domestic crops in all agricultural seasons. One of the objectives of this work is to see how human control could be removed from irrigation and also to optimize the use of water in the process. The method employed is to continuously monitor the soil moisture level to decide whether irrigation is needed, and how much water is needed in the soil. A pumping mechanism is used to deliver the needed amount of water to the soil. The work can be grouped into four subsystems namely; power supply, sensing unit, control unit and pumping subsystems which make up the automatic irrigation control system. A moisture sensor was constructed to model the electrical resistance of the soil; a regulated 12 volts power supply unit was constructed to power the system; the control circuit was implemented using operational amplifier and timer; and the pumping subsystem consisting of a submersible low-noise micro water pump was constructed using a small dc-operated motor. System response tests were carried out to determine the time taken for the system to irrigate potted samples of different soil types having different levels of dryness. The results obtained showed that sandy soils require less water than loamy soils and clay soils require the most water for irrigation