Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage

The doubly fed induction machine (DFIM)-based DC voltage generator is equipped with a stator-connected diode rectifier. The six-pulse diode rectifier as a nonlinear circuit introduces harmonics in the stator and rotor current and distorts the machine stator voltage, as well as the stator flux. This...

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Main Authors: Grzegorz Iwański, Mateusz Piwek, Gennadiy Dauksha
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/16/2/814
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author Grzegorz Iwański
Mateusz Piwek
Gennadiy Dauksha
author_facet Grzegorz Iwański
Mateusz Piwek
Gennadiy Dauksha
author_sort Grzegorz Iwański
collection DOAJ
description The doubly fed induction machine (DFIM)-based DC voltage generator is equipped with a stator-connected diode rectifier. The six-pulse diode rectifier as a nonlinear circuit introduces harmonics in the stator and rotor current and distorts the machine stator voltage, as well as the stator flux. This causes electromagnetic torque oscillations and instantaneous power components oscillations. The torque oscillations adversely impact the mechanical parts of the drive-train and oscillations of the <i>p</i> component of instantaneous power influence DC-bus voltage oscillations. The oscillations can be somewhat cancelled by control methods. However, cancellation of electromagnetic torque is not strictly coupled with cancellation of oscillations of the <i>p</i> component of instantaneous power. The paper presents an analysis of influence of the control methods aimed at a reduction of torque oscillations on the output voltage oscillations level in the stand-alone DFIM-based DC voltage generator. Field-oriented control FOC with current controllers and space vector modulation-based direct torque control DTC-SVM with flux module regulation have been compared with control in which electromagnetic torque is one of the commanded variables, whereas the second variable is the dot product of stator flux and rotor current space vectors. The contributions of this paper are the introduction of a new variable in the second control path in the DTC-SVM method instead of flux vector length and the proof that it can reduce torque and DC-bus voltage oscillations in the DFIG-DC system. Additionally, this paper reveals that for proper stator-to-rotor-turns ratio of a doubly fed machine necessary for reduction of the rotor converter power, lower DC-bus voltage can be obtained than is required for full realization rotor side voltage requested by rotor current controllers. This is the reason why, regardless of the control method, torque oscillations cannot be always fully cancelled, and a comparative study of the methods at these conditions has been conducted in simulation and in laboratory tests.
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spelling doaj.art-a69ffe0d0fb04f46865720396b0a36a62023-11-30T22:04:26ZengMDPI AGEnergies1996-10732023-01-0116281410.3390/en16020814Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output VoltageGrzegorz Iwański0Mateusz Piwek1Gennadiy Dauksha2Faculty of Electrical Engineering, Warsaw University of Technology, 75 Koszykowa St., 00-662 Warszawa, PolandFaculty of Electrical Engineering, Warsaw University of Technology, 75 Koszykowa St., 00-662 Warszawa, PolandFaculty of Electrical Engineering, Warsaw University of Technology, 75 Koszykowa St., 00-662 Warszawa, PolandThe doubly fed induction machine (DFIM)-based DC voltage generator is equipped with a stator-connected diode rectifier. The six-pulse diode rectifier as a nonlinear circuit introduces harmonics in the stator and rotor current and distorts the machine stator voltage, as well as the stator flux. This causes electromagnetic torque oscillations and instantaneous power components oscillations. The torque oscillations adversely impact the mechanical parts of the drive-train and oscillations of the <i>p</i> component of instantaneous power influence DC-bus voltage oscillations. The oscillations can be somewhat cancelled by control methods. However, cancellation of electromagnetic torque is not strictly coupled with cancellation of oscillations of the <i>p</i> component of instantaneous power. The paper presents an analysis of influence of the control methods aimed at a reduction of torque oscillations on the output voltage oscillations level in the stand-alone DFIM-based DC voltage generator. Field-oriented control FOC with current controllers and space vector modulation-based direct torque control DTC-SVM with flux module regulation have been compared with control in which electromagnetic torque is one of the commanded variables, whereas the second variable is the dot product of stator flux and rotor current space vectors. The contributions of this paper are the introduction of a new variable in the second control path in the DTC-SVM method instead of flux vector length and the proof that it can reduce torque and DC-bus voltage oscillations in the DFIG-DC system. Additionally, this paper reveals that for proper stator-to-rotor-turns ratio of a doubly fed machine necessary for reduction of the rotor converter power, lower DC-bus voltage can be obtained than is required for full realization rotor side voltage requested by rotor current controllers. This is the reason why, regardless of the control method, torque oscillations cannot be always fully cancelled, and a comparative study of the methods at these conditions has been conducted in simulation and in laboratory tests.https://www.mdpi.com/1996-1073/16/2/814stand-alone generatorDC voltage generatordirect torque controldoubly fed induction machine
spellingShingle Grzegorz Iwański
Mateusz Piwek
Gennadiy Dauksha
Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
Energies
stand-alone generator
DC voltage generator
direct torque control
doubly fed induction machine
title Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
title_full Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
title_fullStr Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
title_full_unstemmed Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
title_short Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
title_sort doubly fed induction machine based dc voltage generator with reduced oscillations of torque and output voltage
topic stand-alone generator
DC voltage generator
direct torque control
doubly fed induction machine
url https://www.mdpi.com/1996-1073/16/2/814
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AT gennadiydauksha doublyfedinductionmachinebaseddcvoltagegeneratorwithreducedoscillationsoftorqueandoutputvoltage