Instability and Imbalance Response of Large Induction Motor Rotor by Unbalanced Magnetic Pull

2004 ◽  
Vol 10 (3) ◽  
pp. 447-460 ◽  
Author(s):  
Bo-Suk Yang ◽  
Yong-Han Kim ◽  
Byung-Gu Son
Keyword(s):  
Induction Motor ◽  
Transfer Matrix Method ◽  
Analytical Method ◽  
Electromagnetic Force ◽  
Matrix Method ◽  
Evaluation Method ◽  
Induction Motors ◽  
Practical Application ◽  
Time Transfer ◽  
Second Order Differential Equations

This paper deals with a general analytical method for analyzing the instability and mechanical imbalance response of induction motors considering unbalanced electromagnetic forces produced in the induction motors with rotor eccentricity and phase unbalance. The equations to be solved are a set of second-order differential equations that give matrices with periodic coefficients that are a function of time due to the unbalanced electromagnetic force. The evaluation method of rotor instability zones is presented by a time transfer matrix method. The Newmark β method is adapted to solve for an imbalance response. A practical application is given for a large induction motor. The results show that the proposed method is satisfactory.

scholarly journals Fluid-Structure Interaction Analysis of Aircraft Hydraulic Pipe with Complex Constraints Based on Discrete Time Transfer Matrix Method

2021 ◽  
Vol 11 (24) ◽  
pp. 11918
Author(s):  
Haihai Gao ◽  
Changhong Guo ◽  
Lingxiao Quan
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Equation Model ◽  
Pipe Conveying Fluid ◽  
Time Transfer ◽  
Boundary Constraints ◽  
Structure Interaction ◽  
Complex Constraints ◽  
Conveying Fluid

Fluid-structure interaction (FSI) is prevalent in aircraft hydraulic pipes due to high-pressure fluid pulsation, complex pipe path routing and boundary constraints, which pose a serious threat to the safety and reliability of the aircraft hydraulic system. This paper focuses on the FSI response of aircraft hydraulic pipes with complex constraints. A comprehensive fourteen-equation model for describing the FSI of pipe conveying fluid with wide pressure and Reynolds number range is proposed. The excitation models and complex boundary constraints of liquid-filled pipes are established. Moreover, based on the transfer matrix method (TMM), combined with the time discreteness and analytical integral method, a discrete time transfer matrix method (DTTMM) for solving the FSI fourteen-equation model in time domain is presented. Then, the numerical solution and experiment of an ARJ21-700 aircraft hydraulic pipe with complex constraints is carried out with four working conditions. The obtained results verify the correctness of the proposed model and solution method, and reveal the universal laws of the FSI response about aircraft hydraulic pipes, which can also provide theoretical and experimental references for modeling, solutions and verification in the FSI analysis of pipe conveying fluid.

Discrete Time Transfer Matrix Method for Launch Dynamics Modeling and Cosimulation of Self-Propelled Artillery System

2012 ◽  
Vol 80 (1) ◽  
Author(s):  
Bao Rong ◽  
Xiaoting Rui ◽  
Ling Tao
Keyword(s):  
Transfer Matrix ◽  
Discrete Time ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Mechanical Systems ◽  
Coupled Systems ◽  
Order System ◽  
Time Transfer ◽  
Integration Algorithm ◽  
Complex Mechanical Systems

In many industrial applications, complex mechanical systems can often be described by multibody systems (MBS) that interact with electrical, flowing, elastic structures, and other subsystems. Efficient, precise dynamic analysis for such coupled mechanical systems has become a research focus in the field of MBS dynamics. In this paper, a coupled self-propelled artillery system (SPAS) is examined as an example, and the discrete time transfer matrix method of MBS and multirate time integration algorithm are used to study the dynamics and cosimulation of coupled mechanical systems. The global error and computational stability of the proposed method are discussed. Finally, the dynamic simulation of a SPAS is given to validate the method. This method does not need the global dynamic equations and has a low-order system matrix, and, therefore, exhibits high computational efficiency. The proposed method has advantages for dynamic design of complex mechanical systems and can be extended to other coupled systems in a straightforward manner.

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