Mathemathical modeling of a synchronous generator with combined excitation

Bazenov

Tymoshchuk

et al. 2021

Self Cite

The paper presents the results of testing and research of the characteristics of a controlled autonomous magnetoelectric synchronous generator with a magnetic shunt. Structurally, the studied generator is a modified asynchronous machine in which the rotor is made with permanent magnets and an additional system in the form of a magnetic shunt. By adjusting the winding current of the magnetic shunt, the output voltage of the generator is regulated. The following characteristics were investigated: the no-load characteristic during operation with permanent magnets and when the winding current of the magnetic shunt changes with forward and reverse polarity. Also, the external characteristic for active and active-inductive loads; the control characteristic when the load current changes at a constant generator voltage. Analysis of the obtained characteristics makes it possible to determine the limits of regulation of the external characteristic, which is ≈40 % relative to the main magnetic flux. The obtained regulation depth allows maintaining the stability of the external characteristic for power factors not exceeding 0.9, which is the usual passport value for autonomous power plants based on synchronous generators. Comparison of the data of research conducted on the experimental setup shows sufficient convergence for engineering and practical tasks. The maximum quantitative difference is 9.3 %, which suggests the adequacy of the previously developed mathematical model. The control characteristic, constructed experimentally at constant generator voltage, is the control law of the magnetic shunt winding for the studied generator. The investigated version of a synchronous generator with a magnetic shunt should be used for autonomous power plants, renewable energy systems, and autonomous power supply systems.

Section: No-load Characteristic With the Direct And Reverse Polarity Of The Power Supply Of The Magnetic Shunt Windingmentioning

confidence: 90%

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Voltage stabilization of a controlled autonomous magnetoelectric generator with a magnetic shunt and permanent magnet excitation

Bazenov

Tymoshchuk

et al. 2021

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“…To control the magnetic flux of a synchronous generator, synchronous generators with hybrid excitation can be used. The excitation system consists of permanent magnets on the rotor and an electric excitation winding located on a fixed stator [12]. The main magnetic flux is created by permanent magnets, and on average about 20 % -by the excitation winding.…”

Section: The Study Materials and Methodsmentioning

confidence: 99%

“…The magnetic flux of the generator is controlled by changing the current of the excitation winding. Of particular note are designs with an axial magnetic flux [12], which provide low synchronous speeds of rotation. This makes it possible to obtain a direct (gearless) connection between the windmill and the generator.…”

Section: The Study Materials and Methodsmentioning

confidence: 99%

Development of the control system for taking off the maximum power of an autonomous wind plant with a synchronous magnetoelectric generator

Ostroverkhov

Kovalenko

et al. 2022

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The object of this study is electromechanical processes in an autonomous wind power plant with a magnetoelectrical generator. Under actual conditions, the wind speed is constantly changing. The wind turbine works as efficiently as possible only at the rated value of wind speed. When the wind speed changes, the efficiency of converting mechanical wind energy into electrical energy decreases. Controlling the power of the electric generator when the wind speed changes is a relevant scientific and technical task. A maximum power selection control system based on the parameters of an experimental sample of a synchronous magnetoelectric generator has been designed and investigated. A feature of the synthesized control system is that it was developed on the basis of the concept of inverse dynamics problems in combination with minimization of local functionals of instantaneous energy values. The control law provides weak sensitivity to parametric perturbations of the object and carries out dynamic decomposition of the interdependent nonlinear system, which predetermines its practical implementation. Transient processes of the power, voltage, and current of the stator, as well as the voltage and excitation current were established when the wind speed changes from 3 to 8 m/s, as well as when the active electrical resistance of the load changes. The results of this study confirm the effectiveness of the maximum power take-off control system when wind speed and load change. When the wind speed changes within 3–8 m/s and the load by 50 %, the efficiency of converting mechanical wind energy into electrical energy increases by 15–40 % compared to the traditional magnetoelectric system. The findings of the current study are recommended for practical use in autonomous power plants based on wind turbines with generators with permanent magnets.

“…The implementation of mathematical calculations of the electromagnetic field was carried out in the software package COMSOL Multiphysics by the method of finite elements [10].…”

Section: Construction Of a Field Mathematical Model Of A Magnetoelect...mentioning

confidence: 99%

Designing a voltage control system of the magnetoelectric generator with magnetic flux shunting for electric power systems

Ostroverkhov

Tymoshchuk³

et al. 2022

The object of research in this work is a three-phase magnetoelectric generator with magnetic flux shunting based on industrial induction electric motors. The presence of a magnetic shunt makes it possible to control the voltage of the generator by changing the excitation current in the non-contact electrical winding of the magnetic shunt, which is powered by direct current. Thus, the problem of stabilization of the output voltage of the generator with permanent magnets is solved when the speed of rotation and load change. This paper reports the construction of a three-dimensional field mathematical model of the generator, which allows for electromagnetic calculations of the generator with specified parameters, taking into consideration the influence of final effects, magnetic scattering fields, as well as their radial-axial nature. The results of the calculation of the electromagnetic field are the initial parameters for building a simulation model in the MATLAB-Simulink environment. A simulation model of a magnetoelectric generator with magnetic flux shunting under conditions of changing rotational speed and load has been constructed in the MATLAB-Simulink environment. On the basis of the built models, the performance characteristics of a magnetoelectric generator with magnetic flux shunting were established, which show the limits of control of the output voltage. Adjusting characteristics were determined at zero and rated shunt current for different types of load. The adjusting characteristics of the generator are presented at the rated voltage of the generator for different types of load and with an increase to 150 % of the rated value. The study's results show the high efficiency of the voltage control system of a magnetoelectric generator with a magnetic shunt at different speeds of rotation and load