Impact of hybrid FACTS devices on the stability of the Kenyan power system

<p>Flexible alternating current transmission system (FACTS) devices are deployed for improving power system’s stability either singly or as a combination. This research investigates hybrid FACTS devices and studies their impact on voltage, small-signal and transient stability simultaneously under various system disturbances. The simulations were done using five FACTS devices-static var compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensators (SSSC), thyristor controlled series compensator (TCSC) and unified power flow controller (UPFC) in MATLAB’s power system analysis toolbox (PSAT). These five devices were grouped into ten pairs and tested on Kenya’s transmission network under specific contingencies: the loss of a major generating machine and/or transmission line. The UPFC-STATCOM pair performed the best in all the three aspects under study. The settling times were 3 seconds and 3.05 seconds respectively for voltage and rotor angle improvement on the loss of a major generator at normal operation. The same pair gave settling times of 2.11 seconds and 3.12 seconds for voltage and rotor angle stability improvement respectively on the loss of a major transmission line at 140% system loading. From the study, two novel techniques were developed: A performance-based ranking system and classification for FACTS devices.</p>

Design and Static Stress Analysis of Double Wishbone Suspension

Double Wishbone suspension systems are by far the best choice of suspension systems recommended for sports vehicles. It is more stable and stiffer when compared to the other suspension geometries. In this report a brief study of how a double-wishbone suspension system acts under loading conditions when traveling at high speeds is presented, also the forces acting on its components are analysed, and post-processed results are discussed. The geometry of the whole suspension is designed on SolidWorks and analysis is performed on Ansys software. Further the results from the analysis are studied based on material selection and various analysis methods. Finally, the proposed suspension system is concluded safe to use when the values of Equivalent stress, Total Deformation, and Factor of Safety were measured and under threshold limits. Keywords: double wishbone suspension, static structural, suspension system, analysis, deformation, Ansys, stress analysis, FOS, FEA, structural analysis.

Large-Scale System Analysis Under Uncertainty

Discover a comprehensive set of tools and techniques for analyzing the impact of uncertainty on large-scale engineered systems. Providing accessible yet rigorous coverage, it showcases the theory through detailed case studies drawn from electric power application problems, including the impact of integration of renewable-based power generation in bulk power systems, the impact of corrupted measurement and communication devices in microgrid closed-loop controls, and the impact of components failures on the reliability of power supply systems. The case studies also serve as a guide on how to tackle similar problems that appear in other engineering application domains, including automotive and aerospace engineering. This is essential reading for academic researchers and graduate students in power systems engineering, and dynamic systems and control engineering.

System analysis of the sequencing quality of human whole exome samples on BGI NGS platform

Human exome sequencing is a classical method used in most medical genetic applications. The leaders in the field are the manufacturers of enrichment kits based on hybridization of cRNA or cDNA biotinylated probes specific for a genomic region of interest. Recently, the platforms manufactured by the Chinese company MGI Tech have become widespread in Europe and Asia. The reliability and quality of the obtained data are already beyond any doubt. However, only a few kits compatible with these sequencers can be used for such specific tasks as exome sequencing. We developed our own solution for library pre-capture pooling and exome enrichment with Agilent probes. In this work, using a set of the standard benchmark samples from the Platinum Genome collection, we demonstrate that the qualitative and quantitative parameters of our protocol which we called “RSMU_exome” exceed those of the MGI Tech kit. Our protocol allows for identifying more SNV and indels, generates fewer PCR duplicates, enables pooling of more samples in a single enrichment procedure, and requires less raw data to obtain results comparable with the MGI Tech's protocol. The cost of our protocol is also lower than that of MGI Tech's solution.

Frother Characterization Using a Novel Bubble Size Measurement Technique

Bubble size measurement is a vital part of flotation system analysis and diagnostics. This work evaluates a commercial camera probe as a novel method for in situ bubble size measurement. This device is compared to the conventional Anglo Platinum Bubble Sizer (Stone Three TM). It was found that, in laboratory applications, the in situ bubble size analysis technology appears to be a more user-friendly and reliable option for determining bubble size in flotation, whereas the Anglo Platinum Bubble Sizer is more applicable for full scale industrial work. This probe was then used to conduct a rigorous comparison of the behavior of different frother chemistries at a variety of background solution ionic strength conditions. The critical coalescence concentrations and the minimum Sauter mean bubble diameters were determined. Five frothers were compared in terms of their ability to reduce bubble size and sensitivity to salinity. In order to adjust plant recipe and control strategy accordingly, it is recommended that the plant would need to use less frother during periods of the high salinity of process water to achieve the minimum Sauter mean bubble size.

System Analysis and Simulation of the Process of Destructive Hydrogenization of Deasphaltisate of Heavy Oil

The article presents a systematic analysis and simulation of the process of destructive hydrogenation of deasphalted oil. The process of thermoregeneration of spent zeolite and the surface - acid properties of CaA zeolite catalysts are also studied. It has been established that such patterns that allow predicting their influence and to regulate the quality of the hydrogenation obtained on one or another form of the catalyst obtained from the studied factors and catalysts. In addition, the obtained data can be used in the search for the optimal process modes of the process under consideration on the specific form of the catalyst.

Metrological Analysis of the Relationship Model between the Properties of Piezoelectric Materials

The properties of piezoelectric materials due to the effect of electrical, mechanical, thermal, radiation, and chemical parameters are systematized. On the basis of Maxwell's relations (obtained from expressions for thermodynamic functions) and the application of the system analysis methodology, it made it possible to develop an analytical model of the relationship between the parameters and properties of piezoelectrics in the form of a system of equations. The results of the metrological analysis of an analytical model, which made it possible to identify the sources of additional errors in the measurement of parameters, to derive formulas for their calculation, which in turn contributes to an increase in the accuracy of measurements of the piezoelectrics parameters and products based on them, are presented.

A diesel engine air path model with a WG and an ETV for exhaust temperature controller design and embedded control

In this paper a mean value model of a turbocharged diesel engine air path with an electric wastegate (WG) and an exhaust throttle valve (ETV) is presented. The model is designed with regard to system analysis, controller design, and real-time feasibility. That means, care is taken to ensure that the model contains the relevant dynamics on the one hand and that the requirements for computing power and memory (RAM) are kept as low as possible on the other hand. New approaches for modeling the ETV and the exhaust gas temperature are presented. The latter is formulated via an artificial neural network (ANN) computed outside the model. The ANN is integrated into the model in such a way that the differentiation of the model still provides meaningful results for controller design. Thus, this model may also be used for online computation of nonlinear model predictive controllers (MPC) or nonlinear state observers. The parameters of the model are determined using GT-Power simulation data covering the entire working range of the engine. Only measured variables that are also accessible on the engine test bench are used. All optimization problems to be solved within the parameter determination are presented. It is analyzed which sensors are suitable to support the model in an implementation on an electronic control unit (ECU), and the effect without and with sensor correction is shown in a dynamic test bench measurement. Furthermore, the properties of the generated C code are presented, which are the number of mathematical operations, the runtimes, and the stack size. An evaluation of the real time capability is given based on eigenvalue analyses and the properties of the C code .

RURAL TERRITORIES AS A SYSTEM OF INTERACTION OF ECONOMIC AND SOCIAL PROCESSES

The article deals with the problems of interaction of economic and social processes in rural municipal areas, which is a determining factor in the quality of life of the rural population. The aim is to study on the basis of constructive simplification of the territorial system the allocation of its subsystems for separate study. The criterion for such allocation is to take into account the main links considered by the economic and social subsystems with the structure of the system as a whole. Rural territory can be represented in the form of interconnected spatial subsystems of the following: agricultural production, household, service, transport and information communications. At the same time, the potential for consumption of material and spiritual goods can be considered from the standpoint of three types of social accessibility: material, spiritual and spatial-temporal. It is revealed that the main disproportions in the modern development of rural areas are the disproportions between the potential of consumption, on the one hand, and the level of actual availability of material and spiritual goods, on the other. To eliminate these imbalances, it is advisable to use system analysis tools that allow you to obtain the necessary information about the interaction of social and economic factors. At the same time, the study of current trends in the interaction of economic and social processes that determine the standard of living of the rural population shows that the placement of capital investments within a rural municipal district should be based on a comprehensive cost-effectiveness analysis, since the evaluation of the effectiveness of investments for individual objects does not take into account the interrelationships, interaction and synergetic effect of socio-economic factors affecting the qual