Electrical Power Distribution

This paper investigates the concept of network reconfiguration by considering the seasonal load changeon feeders. The author tried to establish that the reconfiguration of networks can be carried out for load balancing during the seasonal change in loads depicted by the chronological load curves of the feeders. In electrical power distribution systems, some feeders supply consumers with the same type of loads in particular areas. Like thefeeders dedicated to supply residential areas, the dominated loads are domestic and commercial. While somefeeders may be dominated with industrial loads, some with agriculture etc. By examining the chronological loadcurves the possibilities of feeder reconfiguration are identified. Seasonal reconfiguration will increase thereliability of supply, reduce line losses and improve voltage profile.

The framework outlines three tiers of resilience which enable stakeholders to assess and improve their system’s resilience throughout its lifecycle:

Top level: The stages of resilience, which represent different times in a system’s lifecycle and different means of evaluating and executing resilience.
Middle level: The core functions of resilience, which span across the time stages.
Lower level: The process steps that correspond to implementing practices for resilience in each of the core functions.
While the concept of resiliency is not new, its application to the electric grid is neither standardized nor well-defined, and there is little to no guidance on how to evaluate resilience specifically for distributed wind systems. This paper provides a framework for evaluating the resilience of any electric energy delivery system, and provides a detailed example centered on distributed wind. Because different assets can operate in a variety of applications and at different scales, there is no one-size-fits-all approach for evaluating resiliency.

The present work deals with a renewable energy based microgrid (MG) with ANFIS controller for standalone operation. The places where renewable energy sources such as wind, solar, hydro etc. are in abundance, use them to generate electricity by developing wind-hydro based MG. The main control unit of MG is VSI (Voltage Source Inverter) in which an indirect current control is applied. This VSI is used for power quality improvements through harmonics suppression of nonlinear loads; voltage regulation during contingencies such as load unbalance; reactive power compensation at PCC (Point of Common Coupling) according to the system requirement. It is capable of providing power balance under various changes among the generation, storage and demand units. For appropriate functioning of VSI, a reweighted zero attractor least mean square (RZALMS) control algorithm is applied to generate PWM switching pulses for VSI. A model of MG with ANFIS controller is developed in MATLAB/ Simulink environment to simulate its performance in normal and dynamic conditions at linear and nonlinear loads. A renewable wind-hydro based microgrid has been developed. The performance of MG has been demonstrated using RZALMS control approach to provide power quality solutions i.e. harmonics suppression, reactive power compensation, load balancing and voltage control. It has also managed the power balance in the microgrid during various states such as high wind power generation, load unbalancing and peak load demand. Such MG provides energy independence in rural areas and contributes in reducing the fossil consumption and its bad impact on the environment. A single voltage source inverter has performed power quality improvement and power balancing. The PMBLDCG does not require speed sensor, position sensor and wind speed sensor for MPPT control. Individual inverters and converters are not being used on various units viz. wind, hydro, battery bank etc. Therefore, the overall system cost and maintenance is reduced. The performance of the proposed controller with ANFIS and PI controller results were evaluated by using Matlab/Simulink software.

A generalized macroscopic representation of electrical steels used in transformer manufacturing industry is developed. The proposed representation is specifically formulated for integration in the finite element method. Usage of the specific technique enables the accurate evaluation of electromagnetic field distribution of transformer cores under heavily saturated conditions. Advantages over conventional techniques include numerical stability, numerical accuracy, and reduction of iterations of the Newton–Raphson method.

Intensive economic development in recent years, as well as growing amounts of electricity consumption in the Municipality of Tešanj, indicate the need for a systematic approach in defining the ways of meeting growing electricity demands. Taking into account the expected increase in load (through the year 2025), and using the appropriate mathematical models, this paper presents the results of an impact assessment of the interpolation of the new 110/x kV Jelah substation into the medium voltage Tešanj distribution network — specifically regarding the Jelah area. The results of the analysis of power flows, voltage conditions and losses, with respect to the expected increases in energy consumption in 2020 and 2025 in the analyzed area, indicate that the problem of overload to the existing 35/10 kV substations requires special attention when planning the development of distribution networks, and that inadequate development and untimely investments into the electricity grid could lead to significant changes in voltage and active power losses in the network, thus compromising standardized limits.

Increase in use of power electronics in power system addressed power quality problems. Converters are widely used in industrial area for different application. They are non-linear devices and degrade power quality of system. In this paper, 12 – pulse ac – dc power supply is taken as non-linear load example. Power supply, here discuss is use in low voltage, high dc current application. High dc current is generated by connecting four M3 converters in parallel. Phase-shifting transformer is also introduce for require phase displacement. Converter can affect power quality in terms of inject harmonics and decrease power factor. It can be used as dynamic load; therefore, it is necessary to evaluate active and reactive power for different loading condition. This paper represents assessment of power quality for such system.

Research on the integration of renewable distributed generators (RDGs) in radial distribution systems (RDS) is increased to satisfy the growing load demand, reducing power losses, enhancing voltage profile, and voltage stability index (VSI) of distribution network. This paper presents the application of a new algorithm called 'coyote optimization algorithm (COA)' to obtain the optimal location and size of RDGs in RDS at different power factors. The objectives are minimization of power losses, enhancement of voltage stability index, and reduction total operation cost. A detailed performance analysis is implemented on IEEE 33 bus and IEEE 69 bus to demonstrate the effectiveness of the proposed algorithm. The results are found to be in a very good agreement.

The theft of electrical energy is one of the main problems faced by electricity distribution utilities, especially in developing countries. Aware of the difficulties in combating non-technical losses (NTLs) in Brazil, the National Electric Energy Agency (ANEEL) established tolerable limits for the percentage of non-technical losses to each Brazilian distribution utility. Despite the notable progress made by ANEEL, when comparing public utility NTLs and their regulatory targets in the last decade, it was observed that the goals defined by this agency were not able to lead to a general reduction in NTLs in the country. Thus, the search for alternative methodologies to deal with the topic is necessary. A more attractive alternative to the ANEEL’s model is an efficient frontier model. This paper describes a stochastic frontier cost model for panel data whose equation is specified to provide the tolerable limits for the percentage of NTLs. The proposed model was applied to a panel of dat...

The accurate calculation of short-circuit currents is especially important for distribution protective relay setting and coordination. This paper presents a mutual comparison of distribution networks’ short-circuit calculation results, provided through three types of load approximations: 1) open circuits, 2) constant currents, and 3) constant impedances. This is done in order to determine how much different load modeling influence the calculation results. It is found that the level of influence is minor. Finally, an idea for the possible simplification of the protective relay current calculation is suggested.

In this paper a robust three-dimensional (3D) finite element (FE) anisotropy model is introduced based on a particular scalar potential formulation. The specific 3D FE model is suitable for the accurate evaluation of the peak flux density distribution and no load loss of one-phase and three-phase wound core distribution transformers. The accuracy of the proposed 3D FE anisotropy model is validated by local flux density and no load loss measurements.

An efficient analytical (EA) method is proposed for
optimally installing multiple distributed generation (DG) technologies
to minimize power loss in distribution systems. Different DG
types are considered, and their power factors are optimally calculated.
The proposed EA method is also applied to the problem
of allocating an optimal mix of different DG types with various
generation capabilities. Furthermore, the EA method is integrated
with the optimal power flow (OPF) algorithm to develop a new
method, EA-OPF which effectively addresses overall system constraints.
The proposed methods are tested using 33-bus and 69-bus
distribution test systems. The calculated results are validated using
the simulation results of the exact optimal solution obtained by an
exhaustive OPF algorithm for both distribution test systems. The
results show that the performances of the proposed methods are
superior to existing methods in terms of computational speed and
accuracy.

MVDC is starting to be considered as an option for enhancing transfer capacity and providing increased power quality at distribution networks. There is a term starting to be used of “soft open-point” which can provide controlled power transfer between two 11kV or 33kV distribution groups, without affecting short-circuit levels, voltage differences, loop flows or limitations due to phase-angle differences. The 4-quadrant converters can provide reactive power support and voltage control at each end of the link and multi-terminal is also feasible. There are future technology opportunities including enhancement of existing corridors through the conversion of existing AC lines to DC.
This paper provides a technology overview as well as information on recently deployed projects ranging from linking of oil and gas platforms, through to an urban infeed. It will summarise the benefits of MVDC and the applications where it may provide a competitive or preferential alternative solution to conventional technology.

Biomass co-firing with lignite represents an attractive solution for operating lignite-fired thermal power plants (TPP) with the dual advantage of using local renewable resources and  imultaneously reducing emissions. The subject of this study is technical and environmental investigation of the feasibility of the cofiring of Soma lignite with some dried agricultural residues in the Soma thermal power plant from the exergy analysis perspective, using THERMOFLEX simulation software. The use of biomass cofiring with poor quality coal could allow Turkey to comply with Kyoto commitments while benefiting from using indigenous fuel resources and reducing biomass waste disposal problems. Two technologies are considered; (1) direct cofiring, in which biomass is mixed with lignite in the same mill and fed into the boiler furnace and (2) parallel cofiring method, in which biomass is fired in a separate circulating fluidized bed boiler and produced steam is supplemented into the steam network of the power plant. The investigations reveal that both direct and parallel co-firing of the biomass could result in a significant decrease in fuel consumption, emissions and exergy destruction and a slight increase in the exergy efficiency of the Soma TPP. Olive waste, in particular, has a positive effect on general performance and emissions of the TPP, with fuel consumption, CO2 , SO2
and dust emissions, in direct co-firing dropping by approximately 20, 4, 19 and 18 percent, respectively, and in parallel co-firing by 26, 3, 20 and 25 percent, respectively.

The paper presents an unbalanced three-phase power-flow model for wind turbine generating systems (WTGSs). The model takes into account voltage unbalance factor which exists at the point of common coupling. The developed model is integrated with the unbalanced forward/backward sweep power-flow method. The model comprises of three main components: they are the wind turbine, induction generator, and interface transformer to the grid. Due to their design symmetry, the generator and the transformer are modeled using symmetrical sequence networks. The results show that the developed model has robust convergence characteristics. The solution of the IEEE unbalanced radial feeders shows that the injected powers per phase due to the WTGS are not equal and strongly dependent on the voltage unbalance factor. The results also show that the simplified models based on positive sequence network lead to inaccurate overall power-flow solution.

Active power curtailment Reactive power capability A B S T R A C T The penetration of renewable distributed generations (DG) is recently being increased in distribution systems. Due to the intermittent nature of these generation units, several technical problems are expected based on the environmental conditions and load profiles, such as voltage rise and increasing losses. A traditional way to alleviate these technical problems is to oversize their interfacing inverters for releasing their capacities to inject/ absorb further reactive power. In the literature, the DG inverter is normally oversized by a certain percentage (e.g., 10%) for this purpose. In turn, an optimization-based method is proposed in this paper to calculate the optimal oversize of the interfaced inverter employed in various utility-owned DG types to regulate voltages and to reduce losses with minimum total costs. The proposed method considers the active power curtailment (APC) feature in the DG inverter and the transformer taps. Different control schemes of the interfaced inverter are considered and incorporated in the proposed optimization model. The simulation results demonstrate the effectiveness of the proposed method compared with existing methods.

Looking back from the year 2050, this article provides a retrospective snapshot of the U.S. electric system - how it looked in 2015, how it had changed so much by 2030, and how the drivers of change that were rampant and seemed so disruptive during the twenty-teens converged eventually to form a coherent, well-functioning, new electric system paradigm.

The performance of a photovoltaic (PV) panel is affected by its orientation and its tilt angle with the horizontal plane. This is because both of these parameters change the amount of solar energy received by the surface of the PV panel. A mathematical model was used to estimate the total solar radiation on the tilted PV surface, and to determine optimum tilt angles for a PV panel installed in Sanliurfa, Turkey. The optimum tilt angles were determined by searching for the values of angles for which the total radiation on the PV surface was maximum for the period studied. The study also investigated the effect of two-axis solar tracking on energy gain compared to a fixed PV panel. This study determined that the monthly optimum tilt angle for a PV panel changes throughout the year with its minimum value as 13° in June and maximum value as 61° in December. The results showed that the gains in the amount of solar radiation throughout the year received by the PV panel mounted at monthly optimum tilt angles with respect to seasonal optimum angles and tilt angel equal to latitude were 1.1% and 3.9%, respectively. Furthermore, daily average of 29.3% gain in total solar radiation results in an daily average of 34.6% gain in generated power with two-axis solar tracking compared to a south facing PV panel fixed at 14° tilt angle on a particular day in July in Sanliurfa, Turkey.

ABSTRACT The modern Great Basin of the interior western United States is characterized by surface winds with considerable spatial and temporal variabilities. Wind records from the second half of the 20th century for 12 Great Basin localities, analyzed with standard aeolian-sediment transport methods developed elsewhere in the world, reflect this complexity. The drift potential (DP) for aeolian deposits is generally moderate (DP 200– 400) in the western Great Basin and weak (DP b 200) in the central Great Basin where winds are
predominantly west-southwesterly. DP is relatively high (DP N 300) at the eastern edge of the Great Basin where the dominant prevailing wind direction is south-southwesterly. Both DP and resultant drift direction (RDD) are consistent with synoptic meteorological observations of the evolution of cold fronts in the Great Basin. Meteorological observations show that effective winds to produce dunes are most commonly the result of late winter–early spring cyclogenesis. There has been considerable temporal variability of DP in the latter half of the 20th century. Most of the Great Basin has experienced decreasing wind strength since 1973, consistent with recent studies of wind strength in North America and elsewhere. Dune morphology matches both localized RDD and temporal variations in DP reasonably well in the Great Basin. The results demonstrate that local topography can have an important influence on wind directionality, thus providing a cautionary note on the interpretation of dune morphology in the paleoclimatic and stratigraphic record.

The basis of comprehension of power-flow problems obtained from lectures, lecture slides and subject book. Circuit built and simulated in the Power World program, and then the analytical solution obtained using the theoretical knowledge. Finally, both answers were compared with each other and the difference in the figures were deducted and discussed elaborately.

1. Overview of Indian Power Sector 6-9
2. Power System Operation Corporation Limited 10-12
3 Eastern Regional Load dispatch Centre 13-15
4. Frequency Management 16-20
5. Voltage Management 21-23
6. Outage Planning 24-25
7. Switching Coordination 26
8. Periodic Report and Event Information 27
9. Network Security and Congestion Management 28-29
10. Scheduling and Load Dispatch 30-33
11. SCADA/EMS System Operation 34-38
12. Synchrophasor Initiative 39-43
13. Metering and Settlement System 44-47
14. Conclusion 48
15. Bibliography 49
16. Project Report on “Islanding of Power Systems” 50-80

Phronetic organizational research is an approach to the study of management and organizations focusing on ethics and power. It is based on a contemporary interpretation of the Aristotelian concept phronesis, usually as ‘prudence’. Phronesis is the ability to think and act in relation to values, to deliberate about ‘things that are good or bad for humans’ in the words of Aristotle (1976:1140a24–b12). Phronetic organizational research effectively provides answers to the following four value-rational questions, for specific problematics in management and organization studies: 1. Where are we going with this specific management problematic? 2. Who gains and who loses, and by which mechanisms of power? 3. Is this development desirable? 4. What, if anything, should we do about it?