Isaac Samuel

Soil layer resistivity modelling is a vital component of grounding system design. Grounding system for facility, equipment, power station and general system protection purposes must be designed to be able to handle the anticipated level of fault current. To achieve this; the earth rods, mats and any other equivalent alternatives deployed must be adequately sized in terms of the physical dimensions and the number of such rods required in order to achieve the desired low, overall grounding system resistance. The resistance to earth of a grounding system is a function of the resistivity of the soil in concern, and to ensure appropriate design, the resistivity profile of the soil must be determined via appropriate soil modelling. This paper presents a Monte Carlo simulation approach to two layer soil modelling using the square error as an optimization function. The result of the simulation shows an improvement in model accuracy, and it also conforms significantly with the results of published works that applied genetic algorithm.

In industries, electric motors contribute a major percentage of electrical loads, and by implication, a major portion of the generated electrical energy is consumed by electric motors, and it is therefore vital to ensure that these motors operate with negligible energy loss. In operational environment, many factors can be responsible for a reduction in motor performance. One of the major factors is a regime of voltage unbalance that affects the motor, the load and supply network. Three phase induction motor studies can be carried out using methods such as real load test, finite element analysis, flux linkage-current relations etc. A new model based on phase frame analysis has been developed for easy computation of sequence components. This paper seeks to explore the performance of a 3-phase induction motor operating under unbalance voltage conditions using the phase frame analysis. The results of this study established that there are negative impacts of supply imbalance on the performance of three phase motor.

—Noise pollution happens to be a menace that the world is currently fighting hence, a way of controlling such pollution is needed so that in the event of passing information to a particular individual or group such information will land on the table of the recipient without constituting a menace to those around. The application of Information and Communication Technology ICT is therefore envisaged in solving this problem especially in environment where ICT is the order of the day. This paper, therefore, proposes a technological approach to solving this problem; the design and implementation of a Voice over Inter-Protocol VoIP as a means of sending voice messages from one android application to another, over a wireless network to individual, groups etc. The android platform was chosen because of its merit in portability and been able to connect to the internet easily. The VoIP has been designed, implemented and tested within the halls of residence of Covenant University, Nigeria and the result was satisfactory hence, acceptability of this work will show a great reduction in noise pollution in tertiary institutions, places of worships, and every other open spaces, events where messages need to be sent but to the specific recipients.

The numerous power system blackouts in the past decade and in recent times attest to the fact that more work still needs to be done to tackle the problem of voltage instability and the resultant voltage collapse. This research work proposes a new line stability index that is suitable for the prediction of voltage collapse in Power System Networks (PSNs). This index code-named the New Line Stability Index-1 (NLSI_1) was obtained by deriving from first principles equivalent expressions for the Line Stability Index (Lmn) and the Fast Voltage Stability Index (FVSI) and combining them through a switching logic based on the voltage angle difference since it can signal the imminence of voltage collapse. This new index (NLSI_1) was tested on the IEEE 14-bus system and it gives the same results as the other indices (Lmn and FVSI). For the base case, the IEEE 14-bus test system was found to be stable with all the three indices having approximately equal values (< 1) for all the lines. The contingency case reveals that bus 14 ranks as the weakest bus in the system with the smallest maximum permissible reactive load of 74.6 Mvar and the critical line with respect to bus 14, is the line connecting bus 13 to bus 14. The values of the three indices, Lmn, FVSI and NSLI_1, are approximately equal thereby further validating the accuracy of the new line stability index-1 (NLSI_1).

Forecasting of electrical load is very crucial to the effective and efficient operation of any power system. This is achieved by obtaining the most accurate forecast which help in minimizing the risk in decision making and reduces the costs of operating the power plant. Therefore, the comparative study of time series and artificial neural network methods for short term load forecasting is carried out in this paper using real time load data of Covenant University,with the moving average, exponential smoothing (time series method) and the Artificial Neural Network (ANN) models. The work was done for the day-today operation of the soon-to-be-completed power station of the university. For each of the methods, models were developed for the load forecast. The Artificial Neural Network proved to be the best forecast method when the results are compared in terms of error measurements with a mean absolute deviation(MAD) having 0.225, mean squared error (MSE) having 0.095 and the mean absolute percent error(MAPE)having 8.25.

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 the over dependence o n  fossil-fuel based energy, there is
an exponential rise in carbon dioxide (CO
2
) emissions into the atmosphere,  thereby causing severe environmental degradation
and ozone layer depletion. This paper seeks to apply the 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  only  when  there  is
insufficient radiant energy.  A case study is reported to show the importance of the ASWHS for domestic water heating. The
maximum design efficiency and the expected energy output of the 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 the ASWHS with  a  high payback period of 15 years; and  a lower  unit cost  (US$0.01/kWh)
of the ASWHS makes it more economically viable as compared to the unit cost (US$0.18/kWh) of the grid supply for the same
amount of energy consumed.
Keywords-  ASWHS, CO2 emissions, microcontroller, solar energy, solar collector, unit cost.