electrical Power Systems

Abstract   
                With A Critical Analysis and research on the Said subject, observation have pulled my attention, that Many have concentrated on the root causes, Some focus more on the consequences and others on the Solution. Generating, transmitting, distributing and utilizing Electricity with Environmental Sustainability and Affordability will tackle the three facets {the problem, the cause and the Solution}. 
Looking at the current state of the world globally, Electricity Generation in a greater measure is produced from fusil fuels sources, irrespective of its increase of carbon emission to our atmospheres. Whereas there are abundant natural sources which electricity can be harnessed? It seems to me that attention need to draw now to Governmental Authority, Generating companies, Scientific/engineering communities and to the entire human race on the suffice of the earth about the impacts of such electrical generating sources to Environmental sustainability and affordability. 
The contamination of Carbon dioxide in the atmosphere in the past was 250ppm and presently it is estimated at about 411.97 ppm. As per the ―US Energy Information Administration‖ {EIA}, 2008 release; it will reach 450ppm by 2030. The spurt in the growth of Co2 is attributed to growing of fossil fuels –coal, oils and gas. The major consumers of these fossil fuels are electricity and automobiles. Electricity generation top the list. 
In this project I will be critically analyze how generating electricity from fusil-fuel had been destructive to our environment and how generating, transmitting and utilizing clean-green renewable electrical energies, smart Grid, promoting IEEE Smart village goals and UNESCO development sustainability Vision number ―Seven‖ can help reduce the effect of Global Warming and improve electricity generation, transmission, distribution and utilization with environmental sustainability, cheap and affordable energy.

Electrical energy is the most convenient form of energy since it can be converted to almost all other forms of energy in the cheapest and most efficient way. Electrical power must be delivered to consumers in a safe, efficient, economical and reliable way. This makes it necessary to have power systems which will guarantee all these requirements. Currently the Tanzania electric supply company (TANESCO) lacks a proper method of fault location in the distribution level and more so in the underground lines. The company has a limited length of underground and marine power lines but plans to employ underground power lines in distribution level especially in urban areas and a major product is on-going at Ilala area in Dar-Es-Salaam. Fault detection and location is most difficult in underground lines. This project was aimed at designing an accurate, cost effective and on-line fault detection and location system for underground distribution power cable. This was achieved through reviewing the available literature on fault location techniques to reveal drawbacks, gathering useful information from TANESCO and application of Electrical Engineering skills grasped during the four years of study. Numerical and descriptive data obtained from TANESCO were analyzed and used in designing a system that meets the specified technical requirements. Programming and simulation software known as Atmel studio 7 and proteus were used during design and simulation. Finally physical prototype was assembled and tested.

Nigeria is facing an acute shortage of electric power that drives economic activities. Consequently, all sectors of the economy are facing a retrogression in productivity. Besides, even much of the power made available either from the grid or self-generation is wasted due to poor installation design and use of inefficient devices and equipment such as filament bulbs, and fluorescent lamps (among others). This work examines the present common practice of electrical services that wastes energy with the viewing to advancing the best practice that minimises overall energy / power loss. A three-bedroom flat and an eatery in Nigeria were used as a case study. Load audit, analysis and calculations were made to assist in making vital decisions as to the types and sizes of luminaires, cables and protective devices (among others) to be used in accordance with known standards and regulations. The results show that 71.8% and 69.1% respectively of energy is saved for lighting in three-bedroom flat and eatery; 37.4% and 30.8% in other loads used in three bedroom and eatery respectively. All this is as a result of use of frugal design and energy saving-saving devices. This further implies a saving in absolute cost of energy consumed in a particular situation.

In the proposed paper power generation from photovoltaic array is used to connect the grid. DFCM
Inverter control with PSPWM technique is used in order to control active and reactive power injected into grid. FLC
MPPT technique is proposed for maximum power point tracking and is compared with Constant voltage MPPT
technique. The simulation results of proposed system and Constant voltage MPPT technique are compared by using
MATLAB/SIMULINK software.

In recent years, both Europe and America have experienced a significant number of major blackouts. This report specifically focuses on events that affected Europe and North America during 2003 and provides a detailed analysis by critical comparison, where available, of diverse and authoritative information sources. The main information sources used include UCTE, Eurelectric, national and international investigation committees like the joint US-Canada investigation committee on the North East blackout, the UCTE Investigation Committee on the 28 September blackout in Italy, the British, Danish, Italian, French, Swedish and Swiss authorities reports, etc).

Abstract—The field of power system reliability is dominated by the use of homogenous Markov models. The negative exponential distributions in these models, however, are unrealistic in the case of repair or switching times. The use of homogenous Markov models is often justified ...

-The 132 KV High Voltage (HV) transmission lines in Nigeria cover a total distance of 7780km and have 132 / 33 / 11 kV substations with an installed transformation capacity of 11,660 MVA. These lines convey power not only to Nigeria but also to Niger and Benin Republicsrespectively. Unfortunately, these lines are fragile (technically weak) and could wheel out a maximum of 8238 MW of power. Besides, they are mainly radial by construction, thus making voltage control even more challenging. It is very important that the outages on these HV lines are kept to a minimum to ensure sustainable economic activities in Nigeria and in those other countries. This work studies and evaluates the outages on 132 kV transmission system from 2008 to 2017. The data were analysed using descriptive statistics. The results show that a total of 11,062 outages occurred in the years under study. Out of this number, 9823 (88.8%) was as a result of forced outages while the remaining 1239 (11.2%) accounted for planned outages. The highest number of outages (1116) was recorded in 2016 while the least (689) occurred in 2010. Effective measures have been suggested to reduce the intensity and frequency of occurrence of forced outages on the transmission network.

This paper provides a review of the research conducted on complex network analysis (CNA) in electric power systems. Moreover, a new approach is presented to find optimal locations for microgrids (MGs) in electric distribution systems (EDS) utilizing complex network analysis. The optimal placement in this paper points to the location that will result in enhanced grid resilience, reduced power losses and line loading, better voltage stability, and a supply to critical loads during a blackout. The criteria used to point out the optimal placement of the MGs were predicated on the centrality analysis selected from the complex network theory, the center of mass (COM) concept from physics, and the recently developed controlled delivery grid (CDG) model. An IEEE 30 bus network was utilized as a case study. Results using MATLAB (MathWorks, Inc., Nattick, MA, USA) and PowerWorld (PowerWorld Corporation, Champaign, IL, USA) demonstrate the usefulness of the proposed approach for MGs placement.

This paper summarizes harmonic distortion test results for typical home load mixes which use various combinations of common linear loads, voltage controlled loads, and nonlinear rectifier/converter loads. The harmonic distortion produced by these load mixes are compared to IEEE-519 limits for both voltage and current distortion at the primary and secondary points of common coupling with a 10 kVA, 7,200-120/240 V, single phase, pole mount distribution transformer. The results are expressed using a per unit system based on a 10 kVA per home 12 month average maximum 15 minute demand. Typical current time domain waveforms of common nonlinear loads which are associated with residential use are also documented for comparison. In an effort to aid utility distribution power quality planning, the harmonic current produced by typical nonlinear loads is summarized on a per-device and a per-home basis.

Co-authors:
J. K. Phipps
C. A. Riggio
D. J. Pileggi
R. J. Schneider

Publications:
https://www.academia.edu/34490201/Residential_Harmonic_Current_Injection_in_Distribution_Feeders_An_IEEE-519_Evaluation

International Journal of Electrical and communication engineering (IJECE) is an open access peer-reviewed journal that publishes quality articles contributing new results in all areas of Applied Control Systems, Electrical Engineering and Electronics Engineering. The Journal of Electrical and communication engineering (IJECE) is an abstracted and indexed international journal of high quality devoted to the publication of original research papers from Control Systems, Electrical Engineering, Power Systems, Automation, Electronics Engineering, Networks and Communication Systems and their broad range of applications.

RESUMO A perspectiva de uma maior participação das fontes eólicas no Sistema Interligado Nacional aponta para a necessidade de incluir a previsão de curto prazo da geração eólica nos procedimentos da operação em tempo real e da programação diária da operação. No presente trabalho apresentam-se duas abordagens para previsão probabilística da geração eólica: regressão quantílica e uma metodologia híbrida que congrega processos gaussianos, estimador de densidade de probabilidade e simulação de Monte Carlo. Uma avaliação comparativa das duas abordagens propostas foi conduzida por meio de um experimento computacional com dados reais de um parque eólico localizado na Galícia, Espanha. PALAVRAS-CHAVE Energia eólica, Estimação de densidade, Previsão probabilística, Processo gaussiano, Regressão quantílica 1.0-INTRODUÇÃO O comportamento intermitente da velocidade do vento impõe desafios para a integração segura e econômica dos aproveitamentos eólicos aos sistemas de potência. Para viabilizar a integração da geração eólica os centros de operação demandam novas ferramentas de gerenciamento de energia elétrica, entre as quais se destaca a previsão da geração eólica [1]. Em geral, os métodos de previsão privilegiam a predição do valor esperado da geração eólica sem, contudo, quantificar e informar apropriadamente a incerteza associada à previsão. Em virtude do comportamento aleatório e intermitente do vento, a previsão do valor esperado da geração eólica sem uma quantificação adequada da incerteza não atende completamente as necessidades da operação. Por exemplo, em sistemas com grande participação de fontes eólicas a reserva operativa deve ser dimensionada de maneira a cobrir as incertezas nas previsões de carga e de geração eólica [2]. A densidade de probabilidade contém toda a informação de uma variável aleatória, portanto, para lidar com a incerteza deve-se considerar as previsões de densidade de probabilidade da geração eólica fornecidas por métodos de previsão probabilística [3]. O presente trabalho tem por objetivo descrever e comparar duas propostas para previsão probabilística da geração eólica: a regressão quantílica [4] e uma metodologia híbrida que congrega processos gaussianos [5], estimador de densidade de probabilidade [6] e simulação de Monte Carlo [7]. A implementação e análise comparativa das duas abordagens foi conduzida por meio de um programa em linguagem R [8] aplicado em um experimento computacional que contou com dados reais provenientes de um parque eólico localizado na Galícia, Espanha. A seguir, na seção 2 tem-se uma descrição da metodologia híbrida e na seção 3 uma breve introdução à regressão quantílica. Na sequência, na seção 4 apresentam-se algumas métricas para avaliação da qualidade de previsões probabilísticas. Os principais resultados são descritos na seção 5, em especial, as previsões probabilísticas das médias horárias da geração eólica até 48 horas à frente, ao longo de uma semana. Por fim, na seção 6 tem-se as conclusões do trabalho.

Power supply in Nigeria has degraded to a level that many residential buildings now have three or two power supply lines connected to each building(big or small) at the usual nominal 240V a.c supply. The standard practice in a developed country where there is stable and reliable power is to have one single phase line in a typical small building. Usually, a Nigerian consumer in this setting connected to three phase manually transfers the fuse to an active line or phase where there is quality power. This manual engagement, though unacceptable is dangerous to life and property. It is also time-wasting. A better work can be done by using a three phase automatic phase discriminator. The device displays the voltage level available on each of the phases connected to the house and then switches on to the one with high quality power output. A programmed intelligent microcontroller PIC16F877A was used. The device was also subjected to continuity test during which contactors and relay coils showed low resistances at their terminals. Finally, the circuit was simulated on Proteus and Electronics Software to further confirm its workability and efficiency. The overall performance was very good.

The performance evaluation of a power system can be
carried out through deterministic and probabilistic approaches. Deterministic methods presents the basic limitation of not considering the essentially stochastic nature of power systems behavior mainly due to random equipment outages and load. Therefore, the adequacy analysis of a power system should be performed by using stochastic methods such as probabilistic power flow and composite generation/transmission reliability. The performance indicators are based on the analysis of several
possible system operating states, including combination of
generator, transformer and line outages, load fluctuations, etc. To achieve a reasonable accuracy in estimating the probabilistic indices we may have to perform a great number of system contingencies. Therefore, in the contingency analysis process, specially in dealing with heavily stressed systems, there may be situations where the Newton-Raphson algorithm does not converge to a solution. These system solvability problems may be alleviated by calculating the minimum load shedding in order to bring solvability to an otherwise unsolvable power flow. In the considered approach, the process of computing the minimum load
shedding is carried out by an OPF solved by a direct interior point (IP) method based on the primal-dual logarithm barrier algorithm. This paper describes the adopted approach to calculate probabilistic indicators of power system performance by combining the nonlinear OPF solved by the IP algorithm and the Monte Carlo simulation method. Applications to a 1600-bus network derived from the Brazilian South/Southeast/Central West system are presented and discussed.

The objective of this study is minimizing the frequency deviation due to the load variations and fluctuations of renewable energy resources. In this paper, a new type-2 fuzzy control (T2FLC) approach is presented for load frequency control (LFC) in power systems with multi-areas, demand response (DR), battery energy storage system (BESS), and wind farms. BESS is used to reduce the frequency deviations caused by wind energy, and DR is utilized to increase network stability due to fast load changes. The suggested T2FLC is online tuned based on the extended Kalman filter to improve the LFC accuracy in coordination of DR, BESS, and wind farms. The system dynamics are unknown, and the system Jacobian is extracted by online modeling with a simple multilayer perceptron neural network (MLP-NN). The designed LFC is evaluated through simulating on 10-machine New England 39-bus test system (NETS-39b) in four scenarios. Simulation results verifies the desired performance, indicating its superiority compared to a classical PI controllers, and type-1 fuzzy logic controllers (FLCs). The mean of improvement percentage is about 20%. INDEX TERMS Renewable energy, artificial intelligence, machine learning, type-2 adaptive neuro-fuzzy, extended Kalman filter, demand response.

The Persistent power outage in the country due to faults has become alarming to the government and the body responsible for electricity generation in the country. It also creates a major problem for electricity consumers in Nigeria, there must be an improvement in the reliability of the transmission system in Nigeria. This research work is predominantly concerned with the analysis of outages on 330kV and 132kV transmission system, and system disturbances on generation and transmission system for five (5) years. The result shows that the forced outages are the most occurred outages on the 330 kV line, while on 132 kV line, emergency outages have the highest number of outages in 2014 but decreases rapidly over the years, similarly, twenty-seven (27) major system disturbances occurred in 2016 with 31% against ten (10) with 11% disturbances in 2015, while 2014 and 2018 with the same number of system disturbances of thirteen (13) with 15%, it is apparent that more disturbances occur on the transmission system, and there should be a proper protection scheme to maintain stable grid network. Consequently, Mini-grid and off-grid solutions will prominently address the issue of power supply shortage and instability in Nigeria.

Solar Energy is the prime important source of energy, and it has continued to gain popularity globally. As of 2018, about 486 GW of solar PV was installed worldwide. One of the key requirements for socioeconomic improvement in any nation of the world is the provision of dependable electricity supply systems. Recently, there is a massive growth in access to solar electricity in several Africa countries, notably South Africa, Egypt, Morocco, and Algeria. As a result, it decreases the global population without access to electricity with an appreciable value. This paper review the present state of solar energy capacity in the world also identifies vital approaches of improving their functionality, reliability, and affordability as well as the essential method that policymakers may implement in the future. The result shows that there is a recurrent growth in solar energy annually and as at the end of 2018 Asia with the largest capacity of 56.58%, while Central America and the Caribbean have the lowest installed capacity of 0.36%. As the request for an uninterrupted supply increases in different regions, progressive builders are embracing solar photovoltaics (PV) renewable energy as an option for their customers.

Nigeria with a population of well over 170 million people derives her bulk electricity supply from both Hydro and Thermal power plants. The plants, located in different parts of the country should be such that power should be generated and delivered to consumers efficiently and appropriately. This calls for the need to evaluate the performance of these plants periodically to ensure that they are kept in top form. The Olorunsogo Thermal power plant with an installed capacity of 690MW was studied, analysed and evaluated using data covering 2013 to 2017.The results show that the maximum overall efficiency (32.01%) occurred in 2015 as against the expected value of 40-45%. The minimum overall efficiency (25.29%) was recorded in 2017. Similarly, the maximum and minimum overall thermal efficiencies were 32.66% and 25.81% and they occurred in 2015 and 2017 respectively. The reliability figures were 86.54% (maximum), attained in 2015 and 83.79% (minimum) scored in 2016. The international best practice recommends 60% and above for overall efficiency and 75% and above for thermal efficiency and 98% and above for reliability respectively. Comparatively, the calculated values of performance indices fell short of the international standard. Besides, the average overall efficiency in the years under study was 29.0%, the thermal equivalent was 29.6% and the reliability index was 85.6%. These calculated indices definitely vary from the standard, implying that the plant performance has to be improved upon. How this could be done has been suggested

The Persistent power outage in the country due to faults has become alarming to the government and the body responsible for electricity generation in the country. It also creates a major problem for electricity consumers in Nigeria, there must be an improvement in the reliability of the transmission system in Nigeria. This research work is predominantly concerned with the analysis of outages on 330kV and 132kV transmission system, and system disturbances on generation and transmission system for five (5) years. The result shows that the forced outages are the most occurred outages on the 330 kV line, while on 132 kV line, emergency outages have the highest number of outages in 2014 but decreases rapidly over the years, similarly, twenty-seven (27) major system disturbances occurred in 2016 with 31% against ten (10) with 11% disturbances in 2015, while 2014 and 2018 with the same number of system disturbances of thirteen (13) with 15%, it is apparent that more disturbances occur on t...

Part 1 defines network radiality, parameter, and performance heuristics that are employed in a three-level hierarchical rule base for optimization of power distribution system operations. A heuristic preprocessor module produces a list of switch closures that would seem to reduce total system losses. Network radiality rules are employed to assess if a particular search path has identified a switch that can be closed or if the path is worth pursuing further. Network parameter rules ensure the system operates within original design parameters. Network performance rules assess the reduction in total system losses of each proposed switching operation. Part 2 describes the fuzzification of the rule base. This is part of an intelligent optimization system for multiobjective performance optimization of power distribution operations.

In this paper, a new steady-state model of a three-phase asynchronous motor is proposed to be used in the studies of electrical power systems. The model allows for obtaining the response of the demand for active and reactive power as a function of voltage and frequency. The contribution of the model is the integration of the characteristics of the mechanical load that can drive motors, either constant or variable load. The model was evaluated on a 2500 kW and 6000 V motor, for the two types of mechanical load, in a wide range of voltage and frequency, as well as four load factors. As a result of the evaluation, it was possible to verify that, for the nominal frequency and voltage variation, the type of load does not influence the behavior of the powers and that the reactive power is very sensitive to the voltage variation. In the nominal voltage and frequency deviation scenario, it was found that the type of load influences the behavior of the active and reactive power, especially in the variable load. The results demonstrate the importance of considering the model proposed in the simulation software of electrical power systems.

This paper presents a tool capable of performing alarms processing to diagnose faults in electrical power systems. The purpose is to filter alarms generated during a shutdown and indicate which equipment is at fault. To solve this problem, it was proposed an integrated use between constructive heuristic methods (CH) and integer programming (IP) by establishing a methodology for its completion. Initially, CH method performs through alarms signaled by protective relays, an analysis with relation to direction of fault in each equipment of power system. Thus, CH in possession of as much information as possible, and signals coming from trip of each relay equipment (busbars, power transformers and transmission lines), can identify direction in which disturbance occurred. The final processing is done by IP, which analyzes the response of protection system as a whole, using signs of opening triggers of circuit breakers along with response of CH, indicating at fault section and possible fail...

Experts are varied in estimating the amount of power needed for national development. One expert estimated 297,900 MW by the year 2030 using a 13 percent Gross Domestic Product (GDP). The Power Sector Road Map's aspiration is 40,000 MW by the year 2020 while the preferred Vision 20:2020 target is 40GW (40,000 MW) available capacity. Vision 20:2020 further proposed that hydro sources contribute 10% of this value; thermal, 80%; coal, 6% and renewables, 4%. However, as at December 2017, Nigeria's total installed generating capacity was 12,324.40 MW. In order to assess the fundamentals and proffer solutions for the improvement of power generation to meet popular expectations, this work analyses the installed capacities of the nation from 1986-1995, on the one hand and from 2007-2016, on the other hand using graphical illustrations and tables. The gap between the two time phases was deliberate to create some effect. The results show that over the years, there has been an apparent, non-challance towards systematic development of Nigeria's power sector. To put a check to this deteriorating condition / trend, useful suggestions have been made.

This article presents an application of neural network-based Model Predictive Control (MPC) to improve the wind turbine control system’s performance in providing frequency control ancillary services to the grid. A closed-loop Hammerstein structure is used to approximate the behavior of a 5MW floating offshore wind turbine with a Permanent Magnet Synchronous Generator (PMSG). The multilayer perceptron neural networks estimate the aerodynamic behavior of the nonlinear steady-state part, and the linear AutoRegressive with Exogenous input (ARX) is applied to identify the linear time-invariant dynamic part. Using the specific structure of the Cascade Hammerstein design simplifies the online linearization at each operating point. The proposed algorithm evades the necessity of nonlinear optimization and uses quadratic programming to obtain control actions. Eventually, the proposed control design provides a fast and stable response to the grid frequency variations with optimal pitch and torque cooperation. The performance of the MPC is compared with the gain-scheduled proportional-integral (PI) controller. Results demonstrate the effectiveness of the designed control system in providing Frequency Containment Reserve (FCR) and frequency regulation in the future of power systems.

This paper describes a miniature thermoelectric power plant made with the boiler and the water pump from an old starch iron. It also uses a computer cooling fan, which serves as electric power generator. The boiler vaporizes the water it receives from the water pump. ...

This paper presents the power generation system reliability assessment using an advanced Markov process combined with blocks diagram technique. The effectiveness of the suggested methodology is based on HL-I of IEEE_EPS_24_bus. The proposed method achieved the generation reliability and availability of an electrical power system using the Markov chain which based on the operational transition from state to state which represented in matrix. The proposed methodology has been presented for reliability performance evaluation of IEEE_EPS_24_bus. MATLAB code is developed using Markov chain construction. The transition between probability states is represented using changing the failure and repair rates. The reduced number of generation system are used with Markov process to assess the availability, unavailability, and reliability for the generation system. Additionally, the proposed technique calculates the frequency, time duration of states, the probability of generation capacity state which get out of service or remained in service for each state of failure, and reliability indices. A considerable improvement in reliability indices is found with using blocks diagram technique which is used to reduce the infinity number of transition states and assess the system reliability. The proposed technique succeeded at achieving accurate and faster reliability for the power system.

Abstract Massive blackouts of electrical power systems over the past decade has focused increasing attention to cascading events that may lead to widespread network collapses. It is important to be able to identify places in the system where the cascading events are most ...

The radial distribution system is the most commonly used power distribution system, but lacks reliability because there is only one power source for a group of customers. A knowledge-based system is defined that ensures network radiality during reconfiguration of a power distribution system. Network radiality heuristics identify a pair of switching operations that will preserve radiality. A line section table specifies the line section identifier, start bus, end bus, and line section type for each line section in the network. A bus table identifies the line section that supplies the bus and those line sections that are fed by the bus for each bus in the network. A matrix-structured knowledge base with four distinct rule bases is used. Rule base A is used in considering whether to open a switch and rule base B is used during a breadth first search in finding a corresponding initially open switch to close to assume the load transfer that would be necessitated by the switch opening. Rule base C is used in considering whether to close a switch and rule base D is used during a breadth first search in finding a corresponding initially closed switch to open because of the load transfer that would be necessitated by the switch closing. In the interest of brevity, only rule bases A and B are described. The line section and bus tables must be updated after any switching operations are enacted. Extensive simulations of the knowledge-based system revealed that a solution was found in a time-efficient manner. This knowledge-based system enhances network reliability and hence prevents power outages. Also, the knowledge-based system can be used to preserve radiality during optimization of power distribution system operations for different objectives .

The paper presents a new method to break down, by subsystem and cause, power distribution losses in electrical systems where the share of nontechnical losses is important. In this type of system the traditional method has given rise to inaccuracies due to high unregistered load. The new method is based on the nature of the losses: resistive losses obtained from