scholarly journals Frequency-current method of controlling an asynchronous three-phase motor

2020 ◽  
Vol 4 (394) ◽  
pp. 129-136
Author(s):  
Anatoly I. Korshunov ◽  
Khomyak A. Valentin ◽  
Irina D. Vasilyeva
Keyword(s):  
Mathematical Model ◽  
Asynchronous Motor ◽  
Current Method ◽  
Current Control ◽  
Computer Hardware ◽  
Motor Speed ◽  
Stator Current ◽  
Three Phase ◽  
The Mathematical Model ◽  
Frequency Current

Object and purpose of research. This paper discusses the method for controlling an asynchronous motor (AM), based on maintaining the optimal frequency of the rotor currents, which corresponds to the maximum electromagnetic moment of the rotor, and controlling its value by regulating the stator currents. Materials and methods. The mathematical model of asynchronous motor adopted in this study assumed the stator to be powered by a controlled three-phase AC generator. The functional diagram of motor speed control system and its digital model in the Matlab Simulink system have been developed. Main results. The constructed mathematical model of AM is correct under condition of smooth changes in set frequency and amplitude of stator currents governed by three-phase stator current control loop practically without error. Conclusion. The proposed method for controlling AM does not require complex calculations and is not too demanding in terms of computer hardware resources.

Modeling of the Three-Phase Asynchronous Motor Based on MATLAB/Simulink

2013 ◽  
Vol 313-314 ◽  
pp. 1042-1045 ◽  
Author(s):  
Hai Jun Liu ◽  
Jin Long Wang ◽  
Fang Di Bao
Keyword(s):  
Mathematical Model ◽  
Simulation Model ◽  
Asynchronous Motor ◽  
Quick Response ◽  
Matlab Simulink ◽  
Three Phase ◽  
Response Flexibility ◽  
Frame Transformation ◽  
The Mathematical Model

On the basis of the mathematical model of asynchronous motor combined with two-axis theory of revolving frame transformation simulating model was established under the environment of MATLAB/Simulink. At the same time, by using this simulation model, the analysis of the starting procedure of asynchronous motor was presented to demonstrate its correctness and such merits as quick response, flexibility, convenience, intuition and so on.

Research on Application of UPQC in Electric Vehicle Charging Equipment

2015 ◽  
Vol 734 ◽  
pp. 852-857
Author(s):  
Cheng Gong ◽  
Rui Shi ◽  
Zhong Jun Chi ◽  
Bao Qun Zhang ◽  
Long Fei Ma ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Electric Vehicle ◽  
Power Quality ◽  
Control Unit ◽  
Current Control ◽  
Electric Vehicle Charging ◽  
Vehicle Charging ◽  
Reference Parameters ◽  
Research On Application ◽  
The Mathematical Model

In order to improve the power quality problems caused by electric vehicle charging equipment, this paper put forward the research on Application of Unified Power Quality Controller (UPQC) in the charging field. Based on the mathematical model of UPQC, current control unit with state feedback single loop PI controller and voltage control unit based on dual PI loop controller are designed. Based on the mathematical model, the design reference parameters are derived. Finally, a UPQC prototype is developed and experiment is carried out, results show that UPQC has good application prospect in the field of electric vehicle charging.

Transfer Heat Mechanism of Oil-Gas-Water Three-Phase Flow in Pipeline

2011 ◽  
Vol 199-200 ◽  
pp. 1609-1612
Author(s):  
Qian Jun Mao
Keyword(s):  
Mathematical Model ◽  
Soil Temperature ◽  
Phase Flow ◽  
Fundamental Theory ◽  
Three Phase ◽  
Three Phase Flow ◽  
The Mathematical Model ◽  
Oil Gas ◽  
Flow Transfer ◽  
Heat Mechanism

It is well known that the oil-gas-water three-phase flow belongs to the field of multiphase flow,transfer heat mechanism of which is very complicated.Transfer heat mechanism is affected not only by different buries in oil gathering pipeline, but also by soil temperature periodicity change. Both domestic and oversea scholars have already studied on the transfer heat mechanisms of oil-gas-water three phase,but they are still in the level of fundamental theory and laboratory.This paper establishes transfer heat models of the oil-gas-water three-phase flow in buried oil gathering pipeline, including the physical model and the mathematical model,and testing in experiment .The purpose of this paper is to analyze value between the calculation and the testing . The results show that the mathematical model of this paper is accurate , and the relative error is ≤ 10%.

Wavelet Transform for Starting Characteristics of Three-Phase Cage Asynchronous Motor

2011 ◽  
Vol 347-353 ◽  
pp. 2987-2990
Author(s):  
Yuan Yuan Li ◽  
Qi Zhong Liu ◽  
Chao Gang Yu
Keyword(s):  
Wavelet Transform ◽  
Performance Test ◽  
Harmonic Wave ◽  
Asynchronous Motor ◽  
Time Frequency ◽  
First Order ◽  
Stator Current ◽  
Electric Machinery ◽  
Three Phase ◽  
Starting Characteristics

In electric machinery performance test, tooth harmonic time-frequency characters of first order of three-phase cage asynchronous motor are most important. The MATLAB software is used to make model and simulate the starting characteristic of asynchronous motor in this article, while the stator current signal of starting motor is de noised by wavelet transform. Through decomposition and reconstruction of wavelet transform, the amplitude of fundamental and harmonic wave in de noising stator current can be reduced, and then the tooth harmonic of first order of starting rotor is extracted. Using the excellent time-frequency analyzing characters of wavelet package transform, the tooth harmonic time-frequency curve is fitted.

Mathematical Model of Three-Phase Boost Converter

2012 ◽  
Vol 507 ◽  
pp. 96-100
Author(s):  
Zhong Zhang ◽  
Wei Ming Tong
Keyword(s):  
Mathematical Model ◽  
Nonlinear Control ◽  
Control Strategy ◽  
Boost Converter ◽  
Analysis Method ◽  
Topology Structure ◽  
Conservation Of Energy ◽  
Three Phase ◽  
Converter Topology ◽  
The Mathematical Model

Now the nonlinear control strategy used by a lot of power electronic converters is not dependent on the mathematical model of the system. They are only based on the error of control variables to control the output voltage or other variables, and this leads to the shortcomings of poor control and not easy to optimize. The fundamental reason is that they are not based on the mathematical model of converter topology structure. This paper presents a new way to build mathematical model. The paper established the unified mathematical model of the three-phase Boost converter topology structure by studied the three-phase Boost converter topology structure deeply and based on the law of conservation of energy and combined with small-signal modeling analysis method, and done the systematic analysis for it. The analysis method is also applicable to other converter topology, such as the buck, buck-boost, etc., and the model not only can be used in the controller design, can also provide a theoretical basis for the applications of a new nonlinear control strategy.

scholarly journals MATHEMATICAL MODELING OF A THREE-PHASE TRANSFORMER TAKING INTO ACCOUNT A MAGNETIC CORE ASYMMETRY

2021 ◽  
Vol 295 (2) ◽  
pp. 165-171
Author(s):  
O. KIMSTACH ◽  
◽  
I. ILLIASHENKO ◽  
A. ZHEZHELO ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Magnetic System ◽  
Short Circuit ◽  
Magnetic Core ◽  
Transient Processes ◽  
Three Phase ◽  
Significant Difference ◽  
The Asymmetry ◽  
High Level ◽  
The Mathematical Model

The paper analyses the aspects of modelling the operation of a three-phase core-type transformer. The features of the magnetic system construction of the transformer, which generate asymmetry, are disclosed. The fundamentals and methods for modelling a transformer in dynamic modes are considered. The main purpose of the paper is to research the influence of taking into account the asymmetry of the transformer magnetic core on its dynamic model. The paper proposes the mathematical model of a three-phase planar core-type transformer, which takes into account the asymmetry of the magnetic core. The mathematical model is based on the model of a generalized electric machine in the ABC axes, which is widely recognized and characterized by a high level of adequacy. A refined model, which takes into account the power losses in the magnetic core, has used. As is well known, such a model is characterized by higher accuracy and adequacy in the calculation of transient processes. For the proposed mathematical model, a comparative analysis of the calculated curves of transient processes for a 63 kVA transformer with a voltage of 6 / 0.4 kV is made. To disclose the effect of taking into account the magnetic core asymmetry of the transformer in the mathematical model, the current differences were calculated in pu for the modes of switching on at full power and three-phase short circuit. These modes are the most common and indicative in the analysis of the operability and stability of transformers. It was found that the most significant difference, which is obtained by taking into account the magnetic system asymmetry of the transformer, is 5…6% when it is switched on at full load. Thus, the relatively simple transformations and updating of the mathematical model of the transformer allow significantly increase its adequacy. The proposed mathematical model can be more effectively used when the non-typical design of three-phase transformers or reactors with significant asymmetry of the magnetic core is considered.

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