MODELING AND MONITORING OF THERMODYNAMIC PROCESSES IN SYNCHRONOUS ELECTRIC MOTORS

2020 ◽  
pp. 28-35
Author(s):  
O. V. Kryukov ◽  
S. E. Stepanov ◽  
A. B. Vasenin
Keyword(s):  
Steel Structure ◽  
Diagnostic Model ◽  
Synchronous Motors ◽  
Stator Windings ◽  
Monitoring Model ◽  
Phase Group ◽  
Simplifying Assumptions ◽  
Main Components ◽  
Electrodynamic Forces ◽  
Thermodynamic Processes

Methods are given for the mathematical description of thermodynamic processes in the insulation of drive motors of alternating current megawatt class. The paper presents the requirements for equipping monitoring systems of the main technological equipment and electric machines, in particular, which regulate the monitoring of working capacity, reliability and safety of equipment using reliable technical and software tools. The most appropriate when choosing a monitoring model for synchronous motors is a functional diagnostic model, when using which the input actions of elementary checks are determined in advance by the working algorithm of the object, and only the composition of the controlled parameters of the diagnostic object is subject to selection. For a predictive analysis of the temperature of the windings of a synchronous machine, a three-stage heating theory is used, in which the motor is divided into a stator winding, a steel structure of the stator and a rotor. In addition, the models take into account the mechanical loads acting on the insulation of the stator windings in various modes during operation: electrodynamic, vibrational and thermomechanical. The results of the analysis of the dynamics of thermodynamic processes in the stator windings of machines with refinements related to the effects of cooling methods, the finning of the external surface of the machine, the heat sink through the frame and bearing shields, as well as the influence of a significant amount of air inside the thermal circuits of synchronous motors. For engineering calculations, algorithms for determining electrodynamic forces are recommended, taking into account simplifying assumptions that do not affect the accuracy of the practical assessment of the forces acting on the isolation of powerful machines. The determination of only some of the main components of the effects, which include the forces caused by the interaction of currents of one phase and acting on the extreme rod of the phase group in the involute part of the rod along the corresponding curves, is also justified.

Study on Welding Deformation and Residual Stress of H-Section Beam Based on Finite Element Method

2017 ◽  
Vol 753 ◽  
pp. 305-309 ◽  
Author(s):  
Xu Lu
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Finite Element ◽  
Source Parameters ◽  
Welding Process ◽  
Steel Structure ◽  
Bottom Plate ◽  
Welding Deformation ◽  
Element Simulation ◽  
Main Components

The welding H-section beam has good mechanical properties with its superior structure. So they become the main components of steel structure and have been widely used. In this paper, the welded H-section beam is used as the research object. The finite element simulation model is established. The heat source parameters are determined. The deformation of the steel due to the welding process is studied. The results show that the bottom plate and the bottom plate inward bending is about 2.32mm cause by welding process. The residual stress can reach 400MPa.

STUDY OF THE COMPOSITE ACTION OF HOLLOWCORE PANELS USED IN GIRDER-SLAB SYSTEM

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Nathalie Roy ◽  
Serge Parent ◽  
Mélissa Barrière
Keyword(s):  
Prestressed Concrete ◽  
Large Scale ◽  
Steel Structure ◽  
Experimental Program ◽  
Steel Beams ◽  
Composite Action ◽  
Concrete Panels ◽  
Current Design ◽  
Main Components ◽  
Hot Rolled

Floor construction with precast hollowcore panels produced by Lafarge Precast Edmonton results in a commonly used girder-slab system. Continuity between the elements is ensured by bent rebars and shear studs. Once all these elements are installed, a structural concrete is poured between the reinforced concrete panels and over the entire floor. The extent of composite action between the rigid diaphragm and the steel beams is not known. Therefore, its potential benefit is not taken into account in the current design procedures for the steel structure. The main components of this research project are the following: an experimental program consisting of a series of 6 large-scale shear tests were carried out. The outcome of this research shows that there is a potential for a composite action between a hollowcore plank and a standard hot rolled W shape. It was found that there is enough confinement to develop the steel stud strength when the beam is connected to the precast prestressed concrete panels using a 1/2" shear stud embedded between the planks and under two to three inches of concrete topping.

scholarly journals Dynamic Analysis of Series-Connected and Mechanically-Coupled Twin Synchronous Motor Drive

2020 ◽  
Vol 17 (1) ◽  
pp. 33-39
Author(s):  
I.K. Onwuka ◽  
G.C. Diyoke ◽  
E.S. Obe
Keyword(s):  
Reduction Gear ◽  
Motor Drive ◽  
Stator Winding ◽  
Speed Reduction ◽  
Synchronous Motors ◽  
Stator Windings ◽  
Three Phase ◽  
On Line ◽  
Winding Machine ◽  
The Mathematical Model

Series-connection of the stator windings of electric motors could serve a number of purposes, including load balancing between two synchronous motors. This paper modeled and analyzed a drive system of two separate three-phase synchronous motors whose stator windings are series- connected by a unique stator winding scheme, and whose shafts are mechanically coupled to a common load shaft through a speed reduction gear driven through the pinions of the respective motors. The mathematical model is developed in detail, and the system is simulated using MATLAB/SIMULINK. It is observed that for the case of a balanced load on the respective shafts of the two motors, the dynamic behavior of the two motors are identical. It is further observed that with the particular stator winding arrangement giving rise to six-windings per motor unit, each motor is essentially a three-phase motor and may be operated direct on line (DOL). Keywords: Common load shaft; DOL; series-connected stator windings; synchronous motors, six-winding machine

scholarly journals The Cause of Mechanical Vibration of Palasher Synchronous Motors and its Removal

2020 ◽  
Vol 8 (4) ◽  
pp. 68-73
Author(s):  
Jiří Pavelka ◽  
Josef Šimek ◽  
Pavel Kobrle ◽  
Petr Kokeš
Keyword(s):  
Magnetic Flux ◽  
Mechanical Vibration ◽  
Variable Component ◽  
Font Size ◽  
Mechanical Vibrations ◽  
Synchronous Motors ◽  
Stator Windings ◽  
Before And After ◽  
Direct Compensation ◽  
The Russian Federation

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; -ms-layout-grid-mode: line; mso-fareast-font-family: 'MS Mincho'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">The paper describes the procedure and the result of the analysis of mechanical vibrations of mining machines at the Palasher mine in the Russian Federation. The cause of these vibrations was the change in the magnitude of the magnetic flux in the air gap. The simulations showed the possibility of eliminating these changes in magnetic flux by injecting suitable voltages into the stator windings. The implementation of this injection is further described by torque variable component feed-direct compensation. Finally, oscillography records are presented before and after injection.</span>

scholarly journals Virtual Prototyping Platform for Designing Mechanical and Mechatronic Systems

2020 ◽  
Author(s):  
Cătălin Alexandru
Keyword(s):  
Parametric Design ◽  
Block Diagram ◽  
Virtual Prototyping ◽  
Virtual Model ◽  
Mechatronic Systems ◽  
The Real ◽  
Whole Process ◽  
Simplifying Assumptions ◽  
Main Components

The chapter deals with the description of a virtual prototyping platform that facilitates the design process of the mechanical and mechatronic systems. The virtual prototyping stages are defined and then integrated in a block diagram, highlighting how the data are transferred between these stages in order to finally obtain a valid and optimal virtual model, close (as structure and functionality) to the real one. The whole process is guided by the basic principle for successful virtual prototyping: as complicated as necessary and as simple as possible. The real modeling case, the specific simplifying assumptions, and the validity (viability) fields of the simplifying assumptions are discussed with reference to the main components of a mechanical or mechatronic system (bodies, connections between bodies, actuating elements). The purpose is to manipulate the simplifying assumptions in a way that reduces the complexity of the virtual model, but without altering the accuracy of the results. The basic types of analysis/simulation are depicted by considering their particularities, highlighting their role in the process of designing mechanical/mechatronic systems, and then the optimization is conducted by the use of parametric design tools. Finally, a case study is developed following those mentioned above.

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