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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.

There is a worldwide need to amplify the usage of renewable energy in the manufacture of electrical energy. Thus, the integrated energy systems (IESs) have become a major part of today’s power systems. Wind and solar energies are intermittent power sources and may lead to voltage and power flow instabilities. The purpose of this paper is to use the interline power flow controller (IPFC) for limiting the overloading of the transmission lines and improving the voltage stability of the IES.

This paper deals with an integrated system consisting of wind and solar energies and conventional systems. An appropriate position for the IPFC in the IES is proposed based on the disparity line utilization factor. The IPFC is then tuned for decreasing the loss of power and lessening the voltage deviation using the grey wolf algorithm.

The method is implemented on a modified IEEE 30-bus system. Results from the study show that the mega volt ampere (MVA) loading of the overloaded lines is reduced for the IES. Also, the voltage stability and the voltage profile of the system are improved to a major extent. The real and reactive power loss of the system is also brought down.

The use of renewable energy sources is a need of the present world to overcome environmental problems. This research focuses on the use of flexible AC transmission system (FACTS) devices with renewable sources incorporated in the power system. Very limited research has been done in this field. The IPFC, which is one of the most advanced FACTS device, is used for the study.

The purpose of this paper is to present the simulation method of power plants and storage system capacity design.

Owing to solar irradiation, wind speed and water flow are highly and randomly changeable, time variation of the signals needs to be taken into consideration as well as some features of the power plants and storage system. A Matlab/Simulink model of the given system – DC microgrid has been developed. The model allows simulation of a few years static simulations of the power balance. Hence, it can be used to size the plants.

An effective method of the power system design has been developed. It allows sizing the plants taking into consideration resources and load profiles, year changes in profiles and future development of the system. The storage system can be optimized to avoid high power unbalance and power cost increasing.

The model describes only static power behaviour of the modelled power system. It does not allow simulating local voltage changes and dynamic properties of the plants and storage.

This technique helps to size the plants and, first of all, storage system taking into consideration several technical and economical issues.

The method gives opportunity to design a storage system's capacity and power and optimize them. The authors have not found similar methods in the literature.

The purpose of this paper is to present a practical method for computing contingency‐based reliability and quality indices in power systems and to answer questions related to how much the system is reliable, how robust it is in surviving random contingencies, how much it is costing to maintain appropriate system security and reliability levels and, finally, to what extent the desired balance is maintained between generation facilities, transmission capabilities and consumer demand levels in various zones of the electric power system.

The methodology adopted in this paper is based on a combined contingency analysis/reliability evaluation scheme. A three‐component system model is utilized, which can be used effectively for evaluation and sensitivity analysis of reliability and quality in power systems. The model is a reduced (equivalent) system representation that comprises generation, transmission and load components with multi‐state values. The computational scheme presented in the paper integrates both the contingency effect and its probability of occurrence into one routine of analysis while reducing the power system around the region of interest.

The computational scheme presented in the paper can effectively assess both service reliability and system quality. The practical applications presented demonstrated that lower service reliability levels would jeopardize energy supply continuity and increase the likelihood of additional maintenance and restoration costs due to the resulting higher rate of system outages. Poor system quality levels, on the other hand, imply either deficiency or excess in the overall system capabilities as designed by its planners.

The work of this paper contributes to the solution of the reliability and quality assessment problem in practical power systems. As part of the present work, an advanced computerized scheme for fast composite system reliability and quality assessment was developed and then applied to an equivalent system model of the Saudi electricity system. The results obtained are claimed to have far‐reaching implications on various planning and operation aspects of the power system.

Auxiliary power system is an indispensable part of the train; the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways, which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters. Powered by DC-link voltage of traction converters, the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking. Meanwhile, powered by traction transformers, the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.

Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied. Failure reasons why previous solutions cannot be realized are analyzed. An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper. The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive. This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.

This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid. Control objectives of uninterrupted power supply technology are proposed, which are no overvoltage, no overcurrent and uninterrupted power supply.

The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section. Furthermore, this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.

When will individuals accept or reject systems that subordinate them, when will they take actions that will challenge these status hierarchies, and when will such challenges be more intense, overt, and non-normative? Research suggests that individuals often justify and maintain systems that subordinate them, yet we suggest that there are certain boundary conditions that predict when individuals will no longer accept their place in such systems. We propose a model that examines how multiple factors: A sense of power, emotions associated with power, and perceptions of the system's legitimacy and stability – predict when those in low power will act against authority or when they will act to justify and maintain such systems. We also suggest that the level and type of action taken against a hierarchy changes as more of the elements (i.e., sense of power, emotions, perceptions of the status hierarchy) of our model are present. We predict that the actions taken against hierarchies become more overt and non-normative as more of these factors are present.

The purpose of this paper is to present a new system frequency response model with participation of wind-hydro-thermal units to overcome frequency deviations.

The extracted minimum frequency equation is considered as a constraint in security-constrained unit commitment calculations. Because of high-order polynomials in the frequency transfer function and high degree of nonlinearity of minimum frequency constraint, Routh stability criterion method and piecewise linearization technique are used to reduce system order and linearize the system frequency response model, respectively.

The results of this paper indicate that by using this model, the hourly minimum frequency is improved and is kept within defined range.

This combined model can be used to evaluate the frequency of the power system following unexpected load increase or generation disturbances. It also can be used to investigate the system frequency performance and ensure power system security which are caused by peak load or loss of generation in presence of renewable energies.

The paper aims to present a grid-connected multi-inverter for solar photovoltaic (PV) systems to enhance reliability indices after selected the placement and level of PV solar.

In this study, the associated probability is calculated based on the solar power generation capacity levels and outages conditions. Then, based on this probability, dependability indices like average energy not supplied (AENS), expected energy not supplied and loss of load expectations (LOLE) are computed, also, another indices have been computed such as (customer average interruption duration index (CAIDI), system average interruption frequency index (SAIFI) and system average interruption duration index (SAIDI)) addressing by affected customers with distribution networks reliability assessment, including PV. On the basis of their dependability indices and active power flow, several PV solar modules installed in several places are analyzed. A mechanism for assessing the performance of the grid's integration of renewable energy sources is also under investigation.

The findings of this study based on data extracted form a PV power plant connected to the power network system in Diyala, Iraq 132 kV, attempts to identify the system's weakest points in order to improve the system's overall dependability. In addition, enhanced reliability indices are given for measuring solar PV systems performance connected to the grid and reviewed for the benefit of the customers.

The main contributions of this study are two methods for determining the reliability of PV generators taking into consideration the system component failure rates and the power electronic component defect rates in a PV system which depend on the power input and the power loss using electrical transient analysis program (ETAP) program.

Green energy as a transportation supply trend is irreversible. In this paper, a highway energy supply system (HESS) evolution model is proposed to provide highway transportation vehicles and service facilities with a clean electricity supply and form a new model of a source-grid-load-storage-charge synergistic highway-PV-WT integrated system (HPWIS). This paper aims to improve the flexibility index of highways and increase CO₂ emission reduction of highways.

To maximize the integration potential, a new energy-generation, storage and information-integration station is established with a dynamic master–slave game model. The flexibility index is defined to evaluate the system ability to manage random fluctuations in power generation and load levels. Moreover, CO₂ emission reduction is also quantified. Finally, the Lianhuo Expressway is taken as an example to calculate emission reduction and flexibility.

The results show that through the application of the scheduling strategy to the HPWIS, the flexibility index of the Lianhuo Expressway increased by 29.17%, promoting a corresponding decrease in CO₂ emissions.

This paper proposed a new model to capture the evolution of the HESS, which provides highway transportation vehicles and service facilities with a clean electricity supply and achieves energy transfer aided by an energy storage system, thus forming a new model of a transportation energy system with source-grid-load-storage-charge synergy. An evaluation method is proposed to improve the air quality index through the coordination of new energy generation and environmental conditions, and dynamic configuration and dispatch are achieved with the master–slave game model.

The earlier methods are more resilient to improvements such as load shift and path change. This results in problems such as a voltage drop and a high reactive flux. In addition, due to the delay, congestion or interruption of the transmission, the system cannot receive all phasor measurement unit (PMU) measurements at the relevant time as well as the presence of noise in the received data.

With the development of wide area measurement system technologies, it seems to be possible to track voltage stability online via time-stamped PMUs. As the voltage instability causes a voltage decomposition, voltage instability is one of the most important problems when monitoring the power supply.

This harmonic distortion significantly decreases the data quality in the grid. As a result, instability ascertainment based on PMU has been suggested as a method for detecting voltage instability in power systems monitored with PMU. In addition, a technique called instability amendment via load dropping has been proposed to keep the device from collapsing due to voltage failure.

To improve the power output, the power prominence melioration technique was developed. This proposed system has been implemented in MATLAB Simulink and compared with the recent researches.