Radial System Research Articles

New High-Speed Rail System Proposed by August Scherl. Passenger Traffic Improvement Project

We reproduce an article first published in 1910 that describes in detail engineering projects, that were not only being developed but widely discussed. Those projects were dedicated to development of rapid, and particularly high-speed transportation in Berlin. The developments of that time reflected broad engineering views. It seems to be an attempt to integrate into a single project all the promising ideas regarding technical advancements as well as optimal transport modelling, routing schemes, traffic organisation, urban spatial planning. The discussion touched upon radial and ring traffic system, integration of the urban transportation system into national and even global one, splitting of passenger and freight traffic and infrastructure, and engineering decisions have reminded about contemporary monorail, elevated railways, light metro, and even personal rapid transit systems… The article attracted attention in Germany, as well as in other countries, and was reproduced in Zheleznodorozhnoe Delo [Railway Business] journal. Probably, many described aspects besides historical ones might be of interest today as well.

Радиосвязь Сибири в годы Великой Отечественной войны

The article examines the technical modernization of Siberian radio communications and broadcasting during the war period. Under the conditions of a large-scale evacuation of industrial facilities and the population to the Siberian region as well as the organization of new telephone and telegraph highways in the eastern direction wire telecommunications worked at the limit of its capabilities and could not cope with the load. In these conditions radio communication was often the only means of communication. Among the evacuated enterprises deployed on the territory of Siberia most of them were the enterprises of the radio industry. One of the main problems faced by the Siberian radio communications, in addition to the shortage of qualified personnel, was the lack of backup equipment, which the front desperately needed. Another difficulty was the restructuring of the radial telecommunication system which entailed the modernization of the transmitters of the main radio communication. In the conditions of an acute shortage of material resources for civil radio communications radio communication activities had to be seriously limited. In general, it was necessary to temporarily abandon the program of continuous radio coverage of the country developed in the pre-war period. First of all, the radio stations were set up at enterprises, city and rural streets and squares, in clubs, libraries, etc. At the same time, as far as possible, the park of radio points was expanded and the operability of radio centers was maintained. Thanks to the mobilization of internal reserves and measures of an administrativerepressive nature in Siberian radio communications it was possible to strengthen the material and technical basis. The industrial production of radio products (mainly for military purposes) was launched in Siberia. However, the quality level of radio communication was low. Since the main efforts were aimed at meeting the needs of the front and the liberated regions the total power of the Siberian radio network has not yet been able to match a large territory of the region and the average power of broadcast transmitters has also remained low. Development of broadcast networks was primarily happened in cities. So, a significant disproportion between the density of radio coverage in urban and rural areas preserved and increased.

Hybrid Heuristic Technique for Optimal Distributed Generation Integration in Distribution Systems

Integration of Distributed Generations (DGs) in distribution systems receives great attention nowadays due to its numerous benefits, the most important of which are reducing the overall power losses and improving voltage profile in distribution systems. In order to enhance the performance of the network, the DG units must be installed at optimal placement and sizing. Solution techniques for DG placement rely on various optimization methods. In this paper, a hybrid heuristic technique is proposed to solve the optimization problem for a single DG unit using two heuristic tests performed in two stages. In the first stage, a sensitivity test is used to determine the candidate location for DG placement. Then in the second stage, the optimal size is identified using a curve fitting test. A comprehensive analysis is performed in order to validate the results of the proposed technique. Both techniques have been tested on IEEE 33-bus and 69-bus radial distribution test systems. The obtained results show that although the comprehensive analysis can achieve slightly greater power loss reduction and voltage profile improvement, it requires a large number of tests that is proportional to the size of the distribution system. On the other hand, the proposed technique can achieve comparable results using a small fixed number of tests for any system, which means that this technique reduces the solution search space i.e., the computational demand and convergence time, while maintaining satisfactory results.

Accurate radial boundary loading and measuring methods for optical components

The two main fixing methods in the assembly process of optical components are adhesive bonding and thread fastening. For both methods, boundary loading effect is generated on optical component, which results in stress distribution in it. The quantitative prediction and control of the stress distribution in optical component is not available because the boundary load induced by adhesive or thread is difficult to control and test quantitatively. Up to now, the interrelationship and variation between the boundary load and the internal stress in optical component have not been effectively studied. Based on the above requirements, quantitative radial boundary loading and real-time measuring methods for optical component are proposed in this paper. Quantitative interrelationship between the boundary load and the stress distribution and surface form in optical component can be obtained by integrating the stress and surface measurement devices with radial boundary loading system. This innovative loading and measuring device is suitable for various sizes of optical components, and it solves the quantitative application and control problems during loading, measuring, and real-time detection of adhesive curing force.

Hybrid swarm evolutionary programming for optimal distributed generation in distribution system

This paper discusses the incorporation of the Hybrid Swarm Evolutionary Programming (SEP) for optimal distributed generation (DG) in the distribution system. High load demand will result in unstable control power distribution due to power transmission loss. The compensation process can be implemented by installing a compensation device to prevent this from happening. It is required the optimal sizing and location for the devices to achieve the objective and this can be done by using an optimization technique. Thus, this project aims to develop a hybrid computational intelligence technique is called hybrid SEP for loss minimization. The proposed method embedded the element of Particle Swarm Optimization (PSO) into traditional Evolutionary Programming (EP) to improve precision of traditional EP algorithm. The purpose of this study is to investigate the maximum benefits of DG integration to be gained. The proposed techniques are validated on IEEE-69 bus radial system with multiple units of DG. The results showed that the most effective type of DG inject to IEEE-69 bus radial system is with DG Type III, with 95% of active power loss reduction and the best on voltage profile improvement. Hybrid SEP shows superior to EP in term of loss minimization.

Becoming more polycentric: public transport and location choices in the Munich Metropolitan Area

ABSTRACT The Munich Metropolitan Area (MMA) is embarking on becoming a more polycentric urban region. For long, the monocentric city model has provided strong explanatory power in understanding the location decisions of private households and firms. However, this model has been challenged by the emergence of large, polycentric city-regions. Increasing commute ranges and the spatial reorganization of economic activities show patterns of concentration and deconcentration at the same time but on different spatial scales. This paper gives an overview of and theorizing about the spatial driving forces and development within recent years. We use the interplay of agglomeration and network advantages to describe the spatial evolution of the MMA where new secondary centers emerge. Publicly available data and a large-scale web-survey provide the basis for descriptive and multivariate statistical analyses. We find – maybe not surprisingly that still the same driving forces of the monocentric city model – accessibility and economic competition – are at work: the MMA’s public transport rail network still forms a radial and monocentric system, while the present use of space by inhabitants shows an increasingly polycentric pattern with explicit tangential relations. We then discuss the future spatio-functional development path of the MMA by pitching the current strong population and employment growth with its tendency toward metropolisation against an alternative development path with competing driving forces. We conclude with visualizing and discussing the alternative spatial development that simultaneously projects concentration, deconcentration, and dispersion dynamics.

Behavioural imprint of the Ordovician Radiation: Evidence from Middle–Upper Ordovician deep-sea trace fossils in western Inner Mongolia, North China

Trace fossils are unique evidence of the body plan and behavioural complexity of animals. Major radiation periods in the Phanerozoic were associated with not only changes in biodiversity, biomass, and ecosystems but also transformations in the relatively implicit, behavioural world. Here we report on a diverse ichnoassemblage from the Middle–Upper Ordovician deep-marine deposits of Inner Mongolia, North China, totalling 24 ichnogenera (including two undetermined forms). They include Alcyonidiopsis, Bifasciculus, Bifungites, Chondrites, Circulichnis, ?Cochlichnus, Dendrorhaphe, Diplocraterion, Halopoa, Gyrophyllites, Monofungites, Multina, Nereites, Paleodictyon, Phymatoderma, Ptychoplasma, Rhizocorallium, Sinusichnus, Taenidium, Thalassinoides, Trichichnus, Zoophycos, bag-like trace, and closed ring trace. Highly regular and complex burrow systems have been discovered, i.e., the branched circular pattern of Circulichnis sinensis, elaborate radial graphoglyptid tunnel system Dendrorhaphe racemosa ichnosp. nov., sinusoid mazework Sinusichnus sinuosus, and the boxwork bag-like trace consisting of highly symmetric horizontal galleries and numerous semi-equidistant vertical shafts. The occurrence of these complex trace fossils suggests distinct behavioural complication and novelty in deep-sea communities during the Middle–Late Ordovician. We speculate that along with the onshore–offshore displacement of ichnofauna and significant expansion of deposit-feeding structures possibly driven by accelerated competition in the shallow-marine niches and aided by ameliorated deep-sea benthic food level, there was underlying behavioural evolution towards more delicate, geometric, and efficient feeding patterns. The Late Ordovician may represent the early peak not only in ichnodiversity but also in ichnodisparity and behavioural complexity of deep-sea ichnofauna, which probably reflect the complex interplay of biodiversity, biomass, and ecological changes during the Ordovician Radiation.

DESIGN AND TECHNOLOGICAL PROPOSALS FOR IMPROVING A SINGLE-PHASE TRANSFORMER WITH LAMINATED MAGNETIC CORE

Goal. The purpose of the work is to analyze the features and substantiate the advantages of the spatial radial electromagnetic system of a single-phase transformer with rectangular sections of the rods of a charged magnetic circuit. Methodology. Improvement of single-phase transformers is possible by structural-geometric transformations of active elements. The justification of the advantages of such transformations is achieved by the method of invariant objective functions with dimensionless optimization components and universal relative controlled variables. Results. Replacing the rectangular contours of the variants of a planar magnetic circuit with a hexagonal circuit leads to a decrease in the volume of steel and the loss of three angular zones of changes in the direction of the magnetic flux relative to the texture compared to planar counterparts. The separation of the windings into sections with an arrangement on three rods leads to a decrease in the average length of the coil. Originality. A three-core magnetic core can consist of rod and jugular-angular parallelogram plates of anisotropic and isotropic electrical steel. It is advisable to combine a combination of steels by integral welding of billets with subsequent separation into chevron jugular-rod elements. The method called on has developed mathematical models of the mass, cost, and active power losses of variants of a single-phase electromagnetic system of a transformer with rod and armor planar and spatial radial three-core magnetic cores. Practical significance. It was found that the decrease in the extrema of the mass and cost indicators, as well as the calculated decrease, under the condition that the coefficients of additional losses are identical, the extrema of the losses of the single-phase radial three-rod system of the transformer relative to the planar analogue with a bar stocked magnetic wire from anisotropic steel, respectively 13,0-12,3 %, 15,3-10,1 % and 15,1-18,1 % with copper windings and 10,8-10,2 %, 12,8-13,7 % and 12,6-12,3 % with aluminum windings. The main indicators of traditional single-phase systems with rod and armored magnetic circuits differ insignificantly, which is consistent with early known optimization and calculation data of transformers.

Model order reduction for reliability assessment of flexible power networks

Model order reduction (MOR) has demonstrated its robustness and wide applicability in simulating large-scale mathematical models in the engineering research domain. In this paper, MOR techniques are applied to quantify relevant reliability metrics of power distribution systems and the impact associated with the integration of different smart grid technologies. To the best of the authors’ knowledge, this is the first application of MOR techniques of balanced truncation to derive reliability models of electricity networks, which exhibit a reduced number of equivalent components and thus simplify the complexity for network analysis. The extensive case studies presented, based on both radial and meshed systems, demonstrate that the proposed technique allows for a faster reliability assessment through Monte Carlo simulation while preserving high accuracy. The proposed methodology can also be applied to systems endowed with photovoltaic and energy storage technologies, emphasising that this approach represents a promising starting point for reliability analysis of more complex systems, which are normally characterised by a large penetration of these distributed energy resources.

A Hybrid PPSOGSA Algorithm for Optimal Volt/VAr/THDv Control in Distorted Radial Distribution Systems

ABSTRACT This paper presents a new hybrid PPSOGSA algorithm based on the phasor particle swarm optimization (PPSO) and gravitational search algorithm (GSA) for solving the Volt/VAr/THDv control optimization problem in radial distribution systems with non-linear loads. The PPSOGSA’s performance is analyzed and evaluated using the standard IEEE 30-bus radial distribution test system. The optimal solutions are obtained based on the following three optimization criteria: minimization of total active power losses, minimization of the voltage deviation, and a simultaneous minimization of total active power losses and voltage deviation. The voltage total harmonic distortion levels (THDv) are estimated using the decoupled harmonic power flow (DHPF) algorithm. Simulation results, obtained using the proposed PPSOGSA-based approach, are compared with those obtained using the other optimization algorithms such as PSO, PPSO, GSA, and PSOGSA. It is shown that the PPSOGSA-based approach has better performance in comparison to the other optimization techniques.

Optimal Allocation and Economic Analysis of Battery Energy Storage Systems: Self-Consumption Rate and Hosting Capacity Enhancement for Microgrids with High Renewable Penetration

Recent advances in using renewable energy resources make them more accessible and prevalent in microgrids (MGs) and nano grids (NGs) applications. Accordingly, much attention has been paid during the past few years to design and operate MGs with high renewable energy sources (RESs) penetration. Energy storage (ES) is the crucial enabler for reliable MG operation to help MGs become more resistant to disruptions, particularly with the increased penetration of RESs. In this regard, this paper formulates a two-stage optimization framework to improve a grid-connected MG performance. Firstly, the optimal allocation decisions of the battery ES systems (BESSs) are provided to enhance the self-consumption rate of the RESs and the hosting capacity (HC) of the MG. Secondly, an operation strategy with the results (number, location, and capacity) of the BESSs obtained from the first stage is handled as an objective function to minimize the MG’s total operation cost. The IEEE 33-bus radial system is modified to act as the MG with high RESs penetration. The problem is solved using a recent swarm intelligence optimization algorithm called the Harris hawks optimization (HHO) algorithm. The proposed optimal operation strategy considers numerous constraints, such as the charge-discharge balance, number and capacity limitations of the BESSs, and the different technical performance constraints of the MG. The results obtained verify the proposed optimization framework’s effectiveness for grid-connected MGs and validate the benefits gained from the appropriate allocation of BESSs. The results also indicate that oversized storage or using many unneeded storage units may adversely influence the MG’s total power losses.

Optimal Location of EV-PV Charging Stations in a Radial Distribution System(Dept.E)

The increasing penetration of electric vehicles (EVs) will greatly affect the operation of distribution networks. On one hand, the EVs can benefit the electric distribution systems. On the other hand, the connection of EVs to the distribution networks poses a series of new challenges for electric utility operators. This paper proposes an algorithm for optimal location of a combined EV-PV charging station in a distribution network for minimizing the system losses. The proposed method depends on PSO for solving the optimization problem. The method is performed in Matlab/Simulink and is applied to a 33-bus radial distribution test system with and without integrating the PV system and the results are analyzed and compared. The obtained results show that the EV-PV charging station is a suitable solution for reducing the feeder losses rather than the charging stations without PV.

Optimal Placement and Sizing of DGs in Distribution Networks Using MLPSO Algorithm

In today’s world, distributed generation (DG) is an outstanding solution to tackle the challenges in power grids such as the power loss of the system that is intensified by the exponential increase in demand for electricity. Numerous optimization algorithms have been used by several researchers to establish the optimal placement and sizing of DGs to alleviate this power loss of the system. However, in terms of the reduction of active power loss, the performance of these algorithms is weaker. Furthermore, the premature convergence, the precision of the output, and the complexity are a few major drawbacks of these optimization techniques. Thus, this paper proposes the multileader particle swarm optimization (MLPSO) for the determination of the optimal locations and sizes of DGs with the objective of active power loss minimization while surmounting the drawbacks in previous algorithms. A comprehensive performance analysis is carried out utilizing the suggested approach on the standard IEEE 33 bus system and a real radial bus system in the Malaysian context. The findings reveal a 67.40% and an 80.32% reduction of losses in the two systems by integrating three DGs with a unity power factor, respectively. The comparison of the results with other optimization techniques demonstrated the effectiveness of the proposed MLPSO algorithm in optimal placement and sizing of DGs.

Improvement of three-phase group transformers for powering the electric drive of submersible centrifugal pumps and comparison of their technical level indicators

The possibility of improving the power supply system of the electric drive of submersible pumps is indicated. The modernization is carried out by replacing the design of single-phase toroidal transformers composed into the group transformer, with spatial single-phase transformers with a radial electromagnetic system. The radial electromagnetic system is characterized by the convenience of embedding into shells of a limited diameter, by a shorter average turn length, and the absence of winding laying disadvantages. The main task is to determine and to analyze the technical level indicators for spatial twisted electromagnetic systems options. The objective function optimization method is used to solve the problem. The objective function contains technical condition dimensionless indicators as well as relative geometric controlled variables. The extremum of the objective function relative components is a function of the winding window, the conductive material of the winding and three universal identical geometric controlled variables which can be used for any of the existing electromagnetic systems variants. In accordance with the principle of electromagnetic equivalence, the same materials, the average values of the amplitudes of the magnetic flux induction in the rods and yokes, the filling factor of the magnetic circuit with steel, as well as cooling methods of the induction static devices are respectively used. The results of the comparative analysis of the technical level indicators (mass, active materials cost and active power losses) showed that the design of a twisted radial electromagnetic system with a rectangular cross-section of rods provides a significant reduction in mass, cost and losses, as compared to an equivalent analogue with a toroidal electromagnetic system

Thermodynamic and mathematical analysis of modified Luikov's equations for simultaneous heat and mass transfer

Interface thermodynamic and mathematical analysis of modified Luikov equations (MLEs) for simultaneous heat and mass transfer in solids were developed. The thermodynamic relations at interface show that air-(wet solid) equilibrium relation may be mathematically approximated by two linear segments. These linear relations conduced to the possibility that MLEs have analytical solution for 1D rectangular, 1D radial cylindrical and 1D radial spherical coordinates system; and, the existence of a topology between solutions. The implications of MLEs thermodynamic and mathematical analysis on lumped equations were discussed. Experimental evolution of moisture and temperature during potato drying were compared with MLEs analytical (for one single linear stage at interface) and numerical (for the 2 linear stages) solutions.

Spiral tool path generation method in a NURBS parameter space for the ultra-precision diamond turning of freeform surfaces

Abstract Spiral tool path generation methods for the ultra-precision diamond turning of freeform surfaces can significantly affect machining efficiency and surface quality. However, effective methods for freeform surfaces with a high slope, especially nonrotation symmetric surfaces and those determined by the recursive formula, are unavailable. Therefore, a new spiral tool path generation method based on a nonuniform rational B-spline (NURBS) parameter space is proposed for the ultra-precision diamond turning of freeform surfaces. The discrete points are used for NURBS global interpolation by discretizing the surface in a radial Cartesian coordinate system, thereby forming a NURBS surface. A more uniform spiral tool path of freeform surfaces with a higher calculation efficiency can be obtained by directly utilizing the parameters on the NURBS surface than by applying existing methods. In addition, a solution is provided for freeform surfaces determined by the recursive formula. Simulation and experiments are conducted to show the effectiveness and adaptability of our method.

A Real-Time Alternating Direction Method of Multipliers Algorithm for Nonconvex Optimal Power Flow Problem

The high penetration rate of smart devices such as storage elements brings new challenges to the optimal power flow (OPF) problem in power systems, which is generally nonconvex and difficult to be solved in real time. This article proposes a set of two fully distributed algorithms by combining the alternating direction method of multipliers and proximal alternating minimization techniques. The first one is a basic distributed algorithm for offline scheduling of 24-h ahead OPF. The other extended one is the warm-starting algorithm by using the offline scheduling solution as the initial point, and the warm-starting algorithm can get converged faster than the basic algorithm. Both algorithms aim to provide a highly feasible solution for the nonconvex OPF problem, and simulation conducted on four radial power systems with batteries has validated the performance of these two algorithms.

Alternative method to determine the uniaxial-strain compressibility of cohesive sandstone

Compaction and subsidence risk related to hydrocarbon production are frequently assessed using Geertsma models. The underlying theory assumes linear poroelastic reservoir rock to compress by pore pressure depletion under uniaxial-strain conditions. Adequate mechanical testing techniques have been developed to measure the uniaxial-strain compressibility, although the execution of these methods is technically difficult and requires a significant level of experience. In this paper, a simplified technique is proposed to approximate the compressibility from triaxial strain data, which is different from earlier hydrostatic stress/uniaxial-strain conversion approaches. The method is applied to Berea outcrop sandstone and Groningen reservoir material, employing pore pressure depletion protocols under triaxial stress and uniaxial-strain boundary conditions. By interpolation of triaxial stress–strain data and adopting linear poroelastic theory, the uniaxial-strain compressibility required for the application of the Geertsma model is yielded. This does not require a priori information of elastic constants. Moreover, the interpolation technique allows for an independent check of the technical performance of the radial strain control system. The method holds for rocks that are close to linear poroelastic, subjected to stress conditions below the critical state line.

Determining optimal location and size of capacitors in radial distribution networks using moth swarm algorithm

In this study, the problem of optimal capacitor location and size determination (OCLSD) in radial distribution networks for reducing losses is unraveled by moth swarm algorithm (MSA). MSA is one of the most powerful meta-heuristic algorithm that is taken from the inspiration of the food source finding behavior of moths. Four study cases of installing different numbers of capacitors in the 15-bus radial distribution test system including two, three, four and five capacitors areemployed to run the applied MSA for an investigation of behavior and assessment of performances. Power loss and the improvement of voltage profile obtained by MSA are compared with those fromother methods. As a result, it can be concluded that MSA can give a good truthful and effective solution method for OCLSD problem.

Train probe for beam diagnostics of the SC200 superconducting cyclotron

The SC200 proton therapy system commissioned by the Hefei CAS Ion Medical and Technical Devices Co., Ltd. (HFCIM; Hefei, China) and the Joint Institute for Nuclear Research (JINR; Dubna, Russia) has made significant progress. A main radial beam diagnostic system (MRBDS) equipped with a new type of train probe was developed to satisfy the requirements of beam diagnosis. In this paper, the detailed design of the mechanical structure and electronics system of the MRBDS is presented. The electronics system, which includes hardware and software components, was tested and calibrated. The results show that measurement errors can be significantly reduced by the designed calibration procedures. The repeatability of the mechanical structure was also verified, and the experimental results indicate that the unidirectional repeatability of the positioning is better than 0.3 mm. Finally, the MRBDS was used to measure the phase lag of the particles in the beam, and the results showed a high degree of agreement with theoretical calculations, which proved the applicability and high efficiency of the MRBDS.