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This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components.

The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions.

Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems.

The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems.

The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP.

The purpose of this paper is to introduce a method based on the fuzzy correlation for modelling of active and reactive powers from the substations of the electrical distribution systems, at the peak load.

Based on the correlation theory, the fuzzy models of the loads can be obtained using a new algorithm. If in the case of the principal/connection station there is sufficient database information for a good forecasting of the load, then for those substations where data are missing (there is no continuous monitoring or the measuring system can be broken for a while) the forecasting of the load can be performed using the correlation studies. The starting point of the algorithm is statistical analysis of the active and reactive curves of the substations and utilization of a fuzzy linear regression model. This can be made for different time windows (window 24 h, window 7 h, etc). The window 24 h can be used successfully to estimate the hourly load on any substation. The other time window (7 h) can be used in the peak load estimation of the substations, using the maximum value of the active power recorded in a reference substation.

The numerical data show that the fuzzy correlation models can be used with very good results for determination of the peak load corresponding distribution substations, and further with the state estimation of the system. In this study, the influence of the time window size is presented in detail, and the fuzzy correlation models for the peak loads from the distribution substations are obtained.

Starting from the correlation theory, a method of fuzzy modelling of active and reactive powers from the substations of an electrical distribution system is proposed.

Classic models for distribution systems design have usually considered only basic aspects such as power capacity limits, power demand requirements and the minimization of a single‐objective function that represents the total system expansion cost. However, multiobjective design models include aspects such as reliability evaluations, the optimal voltage profile in the network, social amenity values and geographical conditions of the study area, as well as the basic design aspects. In this paper, a multiobjective model is presented for optimal design of distribution systems by finding the best reliability of the network and the least expensive system expansion simultaneously. A multiobjective method used in applications of the model to practical distribution systems design problems is outlined. The computer results indicate that multiobjective models achieve satisfactory solutions, which consider multiple objectives simultaneously. These solutions, preferred by the planner, are advantageous compared with the classic design solutions.

Electrical energy distribution systems must be low losses systems in order to enhance the system efficiency. Therefore, it is preferred to distribute electrical energy by bus-ducts in the place of cables over all energy levels and decrease the losses. The purpose of this paper is to focus on a comprehensive survey of various aspects of bus-ducts design including electromagnetic, mechanical and thermal. Advantages and disadvantages of different available design techniques are reviewed.

Different works on various bus-based power transmission and distribution systems are reviewed. Generally these are done in three categories including systems modeling methods, heat transfer in the systems, short circuit and electromagnetic force. The attempt is made to provide geometrical and materials specifications in order to present the analyzed system well.

Different types of bus-ducts from used materials, voltage level and insulation types are reviewed. Bus-duct modeling techniques are introduced which can be easily applied for bus-ducts design. Electromagnetic field distribution, thermal pattern inside and outside of the bus-duct in normal and short circuit modes and finally mechanical considerations are dominant factors which must be taken into account in the bus-ducts design. This leads to an optimal design of bus-ducts which prolong the life span of the bus-ducts fixed in the installations.

This paper for the first time systematically reviews the latest state of arts in the design of bus-ducts for efficient electrical energy distribution. It summarizes a variety of design techniques applicable to bus-ducts design.

This paper aims to automatically generate load shedding sequences due to insufficient power supply, to ensure flight safety and complete flight task.

In this paper, a power allocation and load management model, including logical and physical submodels of the distribution system, is first established according to different requirements of the loads in different flight phase and the current total power supply. Then, an optimal load management scheme based on an improved ant colony algorithm is proposed to automatically generate load shedding sequences for both safety-critical and nonsafety critical loads, to achieve a reliable and safe power supply.

To verify the efficiency and feasibility of the algorithm, the proposed method is verified in a virtual simulation platform. Simulation result illustrates that the proposed algorithm is efficient and feasible.

The proposed method can provide guidance on load power supply when the civil aircraft is under abnormal power supply situation.

An optimal load management scheme is proposed by considering different requirements of the loads in different flight phase and the current total power supply.

The results of a study of the reliability of the Los Alamos National Laboratory electrical system are discussed and an assessment of the risk arising from power interruptions is made. The study was intended to provide a current status of the system and to rank modifications to improve the system. Fault‐tree analysis, cause‐consequence analysis, and directed graphs were used. The study resulted in a ranking of the relative importance of the consequences of power loss to various Los Alamos technical sites and facilities, sets of equipment whose failure will lead to loss of power to the sites, and statistical estimates of the frequency of power loss to sites and facilities.

The purpose of this paper is to analyze annual energy expenditure in the presence of non-linear load and substation voltage harmonics in distribution systems. Economic assessment of non-sinusoidal energy is a challenging task that involves complex computations of harmonic load powers and harmonic line losses.

The paper evaluates fundamental and non-sinusoidal components of electrical energy by applying backward/forward sweep technique in distorted distribution systems. This work involves harmonic power computations at the substation by including harmonic losses occurring in various lines of the distribution system.

The paper found that annual energy expenditure significantly depends upon the non-linear load, supply voltage harmonics and type of tariff structure considered in the distribution system. Impact of individual harmonic orders on the energy billing is also assessed.

The paper concludes that considering harmonic distortions in the distribution system analysis would help electricity regulators formulate adequate pricing structures, which would further generate appropriate economic signals for electricity utility and the consumers.

Identify a new methodology for fault characterization, identification and location in electrical distribution systems, based on the use of matrix algebra.

The developed diagnostic methodology is based on a high precision analytical model of the network using a distributed parameters representation.

Test results have proved the approach to be efficient and precise, while providing a generalized quadripolar model of a line affected by the most common kinds of fault.

Generalization to a greater number of fault cases, experimental tests.

Utilities are quite interested in such items, since the new required quality standards put severe constraints on faults management and clearance. On the other hand, the system requires a rather complete measurement equipment of secondary substations.

The paper presents a new diagnostic technique for faults identification, location and characterization in distribution systems.

The purpose of this paper is to address the issue of power quality through a case study in an IT‐intensive modern office building.

This paper presents results from a power quality audit conducted last year. Firstly, the power site inspection included: (a) a walk‐down of the facility's electrical system to inspect the condition of equipment and becoming familiar with the electrical system; (b) interviewing facility electrical personnel and end‐users on failure of equipment; (c) identifying and collecting the electronic equipment that is most sensitive to power disturbances; (d) requesting and reviewing equipment literature and electromagnetic compatibility characteristics; (e) after that, in the power quality monitoring, voltage and current were measured at various floors.

It was found that the main problems for the equipment installed were harmonics and leakage currents. The paper examines the causes and effects of power disturbances that affect computer or any other microprocessor based equipment and analyses the disadvantages of modern power supplies.

This provides useful information for facilities managers on the current state of power disturbances. The convenience of “enhanced power supply” is also discussed. Finally, it is addressed the role of standards on the protection of IT and the implications for the final costumer.

This paper has provided empirical data from a power site survey developed in a high tech building. This case study demonstrates the impacts of generalized electronic devices on the power quality of the buildings and the implications on energy uses.