New proposed fractional-polynomial functions: new recommendation for overcome the imbalance in three-phase systems

Non-linear loads or load imbalances, etc., are the typical causes of asymmetric operation of three-phase systems. The appearance of inverse (positive) and homopolar (zero) symmetric components cause damage to the systems and electrical equipment and increase the power losses on the transmission lines. Reactive power compensation is one of the solutions that can overcome this asymmetry. The difficulty that exists in many different methods is the optimal calculation of the value of the compensator. In this paper, a new method to overcome these problems is proposed and investigagted. The proposed method is based on the fundamental electrical quantities (voltages and currents) on the controllable values of the static compensation devices and overcoming of the asymmetric operation regime in the three-phase systems.

OBTAINING NEW THIN WALLED TUBULAR STRUCTURES THROUGH MATRIX MORPHOLOGICAL RESEARCH

New products based on a structure that represents a combination of known elements in a higher quality set, as well as products that refer to new shapes, new curves, new surfaces can be obtained logically - analytically - deductively or by methods specific to the optimal calculation. The present paper focuses on the method of analyzing tridimensional morphology, some possible solutions being evaluated on value criteria. Of course, these methods can be applied in the field of engineering with very good results. The focus of this study is to obtain new thin walled tubular structures - such as car crash members - which in the case of axial shock loads have a higher predictable behavior compared to those already used in various technical fields. Following the study, it can be said that depending on the amount of absorbed energy in the case of axial collisions and the absorption of kinetic energy developed at the time of impact, the optimal crashworthiness solution could be tubular structures with a circular support base and rectangular deformable area for impact.

Finding the Optimal Size of Permanent Magnets for a Transverse Magnetic Flux Generator with a Disk Rotor

Based on the analysis of the transverse flux machine designs, they were found to have a relative design simplicity and a high-power density. The purpose of this work is to determine the optimal height of a permanent magnet and to define its effect on the induced EMF value in the stator coils and the cogging torque, as well as to define the picture of the magnetic flux leakage between the stator poles. To achieve these goals, the 3D model of a low speed generator was studied. The electromagnetic analysis was carried out using a modern software, which allows us to determine the magnetic field distribution in the 3D, as well as the induced EMF value and the rotor cogging torque. The criterion for the optimal calculation is the highest EMF value at the minimum value of the rotor cogging torque. The parameters of the permanent magnets, such as the width and length, remained unchanged, whereas, the height varied from 1 to 8 mm at a 1-mm step. The corresponding dependencies are obtained for each height. The most significant result of the work is the conclusion that the height of the permanent magnet should not exceed the 3-mm value. The significance of the obtained results is that the used methodology allowed finding the optimal height of the permanent magnet, since a further increase in its height leads to no growth in the EMF value, but rather significantly enhances the negative effect from the rotor cogging torque. In addition, the simulation results were supported experimentally.

Building the controler for differential diving modes of VIAM-AUV2000

This paper presents a new form of the autonomous underwater vehicle with a built-in subsystem of cylinder and counterbalance to support floating and diving, the electrical and mechanical system is built-in a modular form for easy integration and disassembly - mounting and expanding the system. In particular, show optimal calculation for diving robot's profile, simulating stress, deformation impact on the profile of the robot to select the hull's material and thickness to make sure the robot is durable and steady at a depth of 50m. The paper also presents advantages of hybrid design between traditional AUV which uses propeller and rudder to turn and glider using counterbalance and cylinder to dive. In addition, the design of the control system for the robot is also mentioned and clarified through the selection of sensors, actuators, designing electrical circuit, designing 600W thruster and tri-axis rotation angles estimator for stable operation of the robot at a depth of 50m. In addition, the paper also presents the dynamic model of the diving robot VIAMAUV2000, from which, builds, simulates and applies controller for diving robot in two main forms: using thruster (AUV mode) and not using thruster (Glider mode).

Determining the possibility of placing turbine systems for hydraulic regulation and production of electrical energy in the District Heating Network in Krakow

This article presents the methods of specifying the potentiality of energy recovery in the turbine installations projected to hydraulic regulation of the heating medium in the Krakow District Heating System. To achieve this, creating hydraulic calculations enabling to indicate the best places to install turbines in District Heating System is necessary. For this reason, a great amount of work - like choosing a methodology and optimal calculation program, creating an actual database for calculations - has to be done. Hydraulic calculations will also help to determine optimal parameters of future instalments, select the most suitable devices necessary for the proper working of turbine installations and create the future impact assessment to District Heating System.

Sensitivity analysis of truck structure based on CA algorithm

With the continuous improvement of modern CAE technology, structural reanalysis algorithm has gradually come into people’s vision and developed rapidly. The structure reanalysis algorithm introduced in this paper is an accelerated calculation method. The core idea of this algorithm is to avoid the complete analytical calculations after the structure modification, and reduce the calculation scale, save the calculation time, improve the efficiency of CAE simulation effectively on the premise of meeting the requirements of structure accuracy. The objective of this paper that is based on the initial third-order modal information of the truck structure is to control the overall quality of the structure. And it has important guiding significance for practical production. In this paper, different design variables are set in combination with the structural reanalysis algorithm. While the parameters of design variables are modified, sensitivity information analysis and Taylor expansion theorem are used to verify the feasibility and accuracy of the structural reanalysis method in optimal calculation

MATHEMATICAL AND ALGORITHMIC DESCRIPTION OF THE OPTIMAL PLACEMENT OF PRODUCTS ON THE VEHICLE

The principles of the optimal calculation of the distribution of the volume of products on the vehicle platform, the mathematical and algorithmic description of the optimal placement of products on the TS platform, as well as mathematical models for the description of the optimal placement of products in the truck body, the description of calculation algorithms and the structure of the program development are considered.

On the Optimal Calculation of the Rice Coding Parameter

In this article, we design and evaluate several algorithms for the computation of the optimal Rice coding parameter. We conjecture that the optimal Rice coding parameter can be bounded and verify this conjecture through numerical experiments using real data. We also describe algorithms that partition the input sequence of data into sub-sequences, such that if each sub-sequence is coded with a different Rice parameter, the overall code length is minimised. An algorithm for finding the optimal partitioning solution for Rice codes is proposed, as well as fast heuristics, based on the understanding of the problem trade-offs.