Vector Control Study for Cascade Brushless Doubly-Fed Machine

2012 ◽  
Vol 433-440 ◽  
pp. 7247-7252
Author(s):  
Zheng Wang ◽  
Mo Yong Yang

In this paper, the structure and principle of the cascade brushless doubly-fed machine are introduced and the mathematical model under rotor reference frame(d-q axis) is derived.The validity of the model has been verified by numerical simulation ,which provides the theoretical foundation for the study of control strategy and its implementation of this kind of machine in future.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yan Langtao ◽  
Tan Jiawan ◽  
Liu Yusheng ◽  
Yang Hui

The new type of marine asynchronous shaft generator has the advantages of adjustable excitation and power factor, compared to the traditional synchronous shaft generator, and has been widely used. However, the traditional synchronous shaft generator simulation system is still used in domestic ship power station simulators, which seriously restricts the renewal of crew training. In order to overcome the shortage of the simulation system of doubly fed shaft generator for ship power plant simulator, in this paper, the mathematical model of marine doubly fed shaft system is established for the first time, according to the characteristics of doubly fed machine and marine shaft generator. This paper realizes power decoupling by stator flux orientation and simulates and analyses the asynchronous shaft generator under subsynchronous working conditions. The changing trend of each physical quantity in the simulation waveform meets the mathematical relationships of the actual physical quantity, which proves the correctness of the mathematical model and lays a theoretical foundation for the development of the simulation system of asynchronous shaft generator.


2021 ◽  
Vol 330 ◽  
pp. 03008
Author(s):  
Viktor Ostrovlyanchik ◽  
Ivan Popolzin ◽  
Vasiliy Kubarev ◽  
Dabin Qi

One of the options for the modernization of existing hoist electric drives with a wound-rotor induction motor is its starting according to the scheme of a doubly-fed machine. For this purpose, a frequency converter with an adjustable amplitude, frequency and phase shift of the voltage at its output is connected to the motor rotor. At the same time, the problem of obtaining a mathematical model of both the double fed machine itself and the speed control system based on it is relevant due to the need to take into account the additional supply voltage in the differential equations drawn up in accordance with the Kirchhoff’s law for the stator and rotor windings. The paper proposes a structural diagram for the mathematical model of an induction motor drive of a hoist based on a doubly fed machine.


Author(s):  
Oluwafemi Temidayo J. ◽  
Azuaba E. ◽  
Lasisi N. O.

In this study, we analyzed the endemic equilibrium point of a malaria-hygiene mathematical model. We prove that the mathematical model is biological and meaningfully well-posed. We also compute the basic reproduction number using the next generation method. Stability analysis of the endemic equilibrium point show that the point is locally stable if reproduction number is greater that unity and globally stable by the Lasalle’s invariant principle. Numerical simulation to show the dynamics of the compartment at various hygiene rate was carried out.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shijie Dai ◽  
Shining Li ◽  
Wenbin Ji ◽  
Zhenlin Sun ◽  
Yufeng Zhao

Purpose This study aims to realize the constant force grinding of automobile wheel hub. Design/methodology/approach A force control strategy of backstepping + proportion integration differentiation (PID) is proposed. The grinding end effector is installed on the flange of the robot. The robot controls the position and posture of the grinding end actuator and the grinding end actuator controls the grinding force output. First, the modeling and analysis of the grinding end effector are carried out, and then the backstepping + PID method is adopted to control the grinding end effector to track the expected grinding force. Finally, the feasibility of the proposed method is verified by simulation and experiment. Findings The simulation and experimental results show that the backstepping + PID strategy can track the expected force quickly, and improve the dynamic response performance of the system and the quality of grinding and polishing of automobile wheel hub. Research limitations/implications The mathematical model is based on the pneumatic system and ideal gas, and ignores the influence of friction in the working process of the cylinder, so the mathematical model proposed in this study has certain limitations. A new control strategy is proposed, which is not only used to control the grinding force of automobile wheels, but also promotes the development of industrial control. Social implications The automatic constant force grinding of automobile wheel hub is realized, and the manpower is liberated. Originality/value First, the modeling and analysis of the grinding end effector are carried out, and then the backstepping + PID method is adopted to control the grinding end effector to track the expected grinding force. The nonlinear model of the system is controlled by backstepping method, and in the process, the linear system composed of errors is obtained, and then the linear system is controlled by PID to realize the combination of backstepping and PID control.


Author(s):  
Yu Zhao ◽  
Yingying Wang ◽  
Liwei Li ◽  
Chao Yang ◽  
Yang Du ◽  
...  

The sheave installation method (SIM) is an effective and non-conventional method to solve the installation of subsea equipment in deep water (>1000m), which has been developed to deploy the 175t Roncador Manifold I into 1,885 meters water depth in 2002. With the weight increment of subsea cluster manifold, how to solve its installation with the high reliability in the deep sea is still a great challenge. In this paper, the installation of the 300t subsea cluster manifold using the SIM is studied in the two-dimensional coordinate system. The mathematical model is established and the lumped mass method is used to calculate the hydrodynamic forces of the wireropes. Taking into account the complex environment loads, the numerical simulation of the lowering process is carried out by OrcaFlex. The displacement and vibration of the subsea cluster manifold in the z-axis direction and the effective tension at the top of the wireropes can be gotten, which can provide guidance for the installation of the cluster manifold in the South China Sea.


2021 ◽  
Vol 6 (2) ◽  
pp. 83-88
Author(s):  
Asmaidi As Med ◽  
Resky Rusnanda

Mathematical modeling utilized to simplify real phenomena that occur in everyday life. Mathematical modeling is popular to modeling the case of the spread of disease in an area, the growth of living things, and social behavior in everyday life and so on. This type of research is included in the study of theoretical and applied mathematics. The research steps carried out include 1) constructing a mathematical model type SEIRS, 2) analysis on the SEIRS type mathematical model by using parameter values for conditions 1and , 3) Numerical simulation to see the behavior of the population in the model, and 4) to conclude the results of the numerical simulation of the SEIRS type mathematical model. The simulation results show that the model stabilized in disease free quilibrium for the condition  and stabilized in endemic equilibrium for the condition .


2021 ◽  
Vol 2090 (1) ◽  
pp. 012049
Author(s):  
N V Kovalenko ◽  
A V Smirnov ◽  
O A Ryabushkin

Abstract The mathematical model that describes the local heating of biological tissues by optical radiation is introduced. Changes of the electric properties of biological tissues in such process can be used as a reliable tool for analyzing heating and damage degrees of tissues.


Sign in / Sign up

Export Citation Format

Share Document