Auxiliary Winding Switching Circuit for Single-Phase Induction Motors

The most common practice for starting a single-phase induction motor is to connect a starting capacitor, in series, with the auxiliary winding. Here, the possibility of using an electronic switch in parallel with the starting capacitor, is discussed. This work relates particularly to a switching device for electrically connecting and removing the auxiliary winding and starting capacitor from the single-phase induction motor's circuitry. The starting capacitor with the auxiliary winding are disconnected by electronic means as the motor gains speed hence leaving only the main winding in the motor circuit for normal operation

Remote Monitor and Controller System for Power Generators

Stand-alone power generating sets have become a source of alternative power supply in Nigeria for decades now, especially for business owners, corporate bodies, industries, as well as individuals, due to the epileptic condition of the electric power utility. The proper management, as embodied in the control and maintenance of such systems, has remained a source of concern as power failures are critical to the productivity of such users, especially industries and businesses. In this paper, a Remote Monitor and Controller System (RMCS) for power generators is designed to improve the operation and maintenance of power generators. The RMCS, which includes both a hardware module and software, provides a functionality that allows a power generator to be controlled and monitored from a remote location

Automatic Transfer and Controller System for Standby Power Generator

An automatic transfer system (ATS) was developed to monitor the a.c. voltage coming from Power Holding Company of Nigeria (PHCN) line for power failure conditions. Upon detection of an outage for a predetermined period of time, the standby generator is started, once is up to speed, the load is transferred from the PHCN line to the local Generator. This ATS is capable of electrically monitoring fuel level, oil level, Battery strength, next maintenance schedule and then start or stop the unmanned Generator from the computer system located in the comfort of homes or offices outside the Generator site. In this paper therefore, an Automatic Transfer System (ATS) for Power Generator is designed to improve the operation and maintenance of power generators. The ATS which includes both hardware and software module, provides a functionality that allows a power generator to be controlled and monitored from a remote locatio

Fault Tree-Based Reliability Assessment of a 132-kV Transmission Line Protection Scheme

The reliability of a power system network depends greatly on the performance of the protection system. Improving the reliability of the protection scheme of the transmission lines will enhance the overall reliability of the power system network. The focus of this paper is the improvement of the reliability of a power system transmission line using fault tree analysis (FTA). The paper considers the development of fault tree diagrams for the protection scheme of the 150km-long 132-kV transmission line in Northern Nigeria. The existing protection scheme is analyzed and compared with a proposed scheme equipped with a redundancy arrangement. And the result shows that the new scheme offers significant improvement (about 51%) in the availability of the line

Power Sector Reforms-Effects on Electric Power Supply Reliability and Stability in Nigeria

This study seeks to examine the power sector reforms, effects on electric power supply reliability and stability in Nigeria. The methodology adopted was to review the power sector before and after the reform, effects of the reform on electricity supply, reliability and the expected impact of the proposed models on the Nation’s economy. The major problems affecting the model been pursued especially in a developing country like Nigeria were also examined. The Electric Power Sector has over the past 25 years witnessed a slow and steady decline leading to near complete failure of the system in 1999 at the beginning of the immediate past civilian government. The federal government of Nigeria using National Council on Privatisation (NCP) in 1998 had therefore, embarked on an electric power sector reform program, which gave birth to 18 companies under the auspices of Power Holding Company of Nigeria (PHCN). These companies unbundled from the defunct vertically integrated Nigeria Power Authority (NEPA) monopolistic utility are characterised with horizontal structure. In February 2007 government of Nigeria awarded contracts of about $875 million across the country in actualising some of the goals in the power sector reforms. The study opined that if all identified problems militating against NEPA meeting the energy demand of the country is met by the reformed energy sector, in no distant time Nigeria can boost of an Electric Power Industry (EPI) that can meet the needs of its citizen in the 21st century and place the nation as one of the industrialised country in the worl

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

A Comparative Study of Regression Analysis and Artificial Neural Network Methods for Medium-Term Load Forecasting

Load forecasting is an operation of predicting the future of load demands in electrical systems using previous or historical data. This paper reports the study on a medium-term load forecast carried out with load demand data set obtained from Covenant University campus in Nigeria and carry out comparative study of the two methods used in this paper. Methods/Statistical analysis: The regression analysis and Artificial Neural Network (ANN) models were used to show the feasibility of generating an accurate medium-term load forecast for the case study despite the peculiarity of its load data. The statistical evaluation methods used are Mean Absolute Percentage Error (MAPE) and root mean square error. Findings: The results from the comparative study show that the ANN model is a superior method for load forecast due to its ability to handle the load data and it has lower MAPE and RMSE of 0.0285 and 1.124 respectively which is far better result than the regression model. Application/Improvements: This result provides a benchmark for power system planning and future studies in this research domain

Analysis and Simulation of a Single Generator-Infinite Bus Power System under Linear Quadratic Regulator Control

The thrust of this article is to develop elaborate educational material on linear quadratic regulator (LQR)-based power system control for electrical engineering students, especially senior undergraduate and fresh graduate students. The paper considers a comprehensive description of a power system, which is represented by a network of a single generator connected to an infinite bus, highlighting modeling, analysis, and simulation of the system. Graphical outputs for various combinations of system state and input weighting matrices are presente

Development of a Prototype Robot Manipulator for Industrial Pick-and-Place Operations

In the industry today, continuous attempts to realize optimal efficiency and increased productivity have spawned much progress in the use of intelligent automated devices and machines to perform various operations and tasks. The thrust of this work is to present the development of a three-degree-of-freedom revolute robot manipulator amenable to pick-and-place operations in the industry. Appropriate kinematic equations of the manipulator are obtained, and then used to develop algorithms for locating predetermined positions of a small object in a customized workspace. An Arduino-based controller circuit is built to implement the algorithms, and servomotors are used to carry out independent joint control of the manipulator. The positions of the object are identified with the aid of light-dependent resistors (LDR). Besides, in order to aid easy fabrication of links and overall system assembly, a 3D model of the manipulator is designed. The results of the work, showing effective and satisfactory operation of the manipulator, are presented

A microcontroller-based Active Solar Water Heating System for Domestic Applications

A potential solution to adequate and sustainable electricity supply problems in most developing countries is dependent on proper harnessing of solar (radiant) energy. Owing to tbe over dependence on fossil-fuel based energy, tbere is an exponential rise in carbon dioxide (C02) emissions into tbe atmosphere, thereby causing severe environmental degradation and ozone layer depletion. This paper seeks to apply tbe readily available radiant energy source to solar water heating, and establish possible economic benefits to its use in domestic applications for residents of Covenant University campus. The microcontroller-based active solar water heating system (ASWHS) is designed to effectively absorb radiant energy using solar collectors, and store it as hot water in a water tank via a direct current (DC) circulation pump powered by a stand-alone photovoltaic (PV) system. The design also incorporates an auxiliary electric heater which is put to use ou!y when tbere is insufficient radiant energy. A case study is reported to show tbe importance of tbe ASWHS for domestic water heating. The maximum design efficiency and tbe expected energy output of tbe solar collector throughout its working life is 79.94% and 498,225kWh respectively. A reduced dependence on grid supply and/or fossil-fuel based generator sets during hot water demand periods is recorded using tbe ASWHS witb a high payback period of 15 years; and a lower unit cost (US$0.01/kWh) oftbe ASWHS makes it more economically viable as compared to tbe unit cost (US$0.18/kWh) oftbe grid supply fortbe same amount of energy consume