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brushless-doubly-fed-machine
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Analysis of Brushless Doubly-Fed Motor under Various Operating Modes
, M.Sc. Thesis Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor)
Abstract
The Brushless Doubly-Fed Machine (BDFM) is a machine which incorporates the robustness of the squirrel cage induction machine and the speed and power factor control of a synchronous machine. All of these advantages are obtainable from a relatively low rating power electronic converter (e.g. 30% of the machine’s rating). The stator of a BDFM is furnished with two balanced three phase windings of conventional design (power and control winding). These windings differ in pole number and are often excited at different frequencies. Hence, there is no direct magnetic coupling between them. The power winding is connected to a constant-voltage, constant-frequency source and the control winding is...
Design, modeling and analysis of a single phase Brushless Doubly-Fed Generator
, M.Sc. Thesis Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor)
Abstract
In this thesis, we consider design, modeling, and analysis of a single-phase Brushless Doubly-Fed Machine (BDFM). Generally, this type of machine is called the Brushless Doubly-Fed Induction Machine (BDFIM), that is a new class of induction machines. BDFM is a type of AC machines that requires two alternative power sources. One of the stators windings, called Power Winding, is connected to the network grid and the other one, which is called Control Winding, is connected via a converter, which is in the order of one-third of the nominal power of the machine, to the grid. Like the other types of induction machines, BDFM can also work as a generator or motor. The important criteria of this...
Optimal Design and Control of Brushless Doubly Fed Machines
, M.Sc. Thesis Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor) ; Barati, Farhad (Supervisor)
Abstract
Doubly fed machines require lower converter rating in comparison to single fed machines, and this is the most important advantage of doubly fed machines. Among them, Brushless Doubly Fed Machines (BDFMs) have some advantages, including higher reliability and longer maintenance period. Determination of the converter rating is an important issue that has been not sufficiently investigated. Determination of the minimum converter rating, or in other words, converter current and voltage, in order to minimize the cost to commercialize the BDFM is mandatory. In this thesis, the problem is presented properly, and the optimal voltage and current of each machine side and grid side converters are...
Study on Brushless Doubly-Fed Machine during Network Unbalanced Conditions and Present Compensating Approaches
, M.Sc. Thesis Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor)
Abstract
The Brushless Doubly-Fed Machine (BDFM) is a new kind of doubly-fed machines which incorporates the robustness of the squirrel cage induction machine and the speed and power factor control of a synchronous machine. All of these advantages are obtained from a relatively low rating power electronic converter. The stator of a BDFM is furnished with two balanced three phase windings of conventional design. At this thesis the effects of an unbalanced grid on the operation of a BDFM has been studied. A balanced grid contains three phases with the same amplitude and the phase angle of 120 degrees between each two phases. The unbalanced grid is defined by any turbulent grid. There are some kinds of...
Reliability Model of Wind Turbine System with BDFG
, Ph.D. Dissertation Sharif University of Technology ; Oraee, Hashem (Supervisor) ; Fotuhi Firouzabad, Mahmud (Supervisor)
Abstract
Considerable attention has been given in recent years to renewable energy sources due to concerns about dwindling fuel reserves and the potential impact of conventional energy systems on the environment. Wind power is one form of renewable energy resources and also considered as Dispersed Generation (DG). Widespread utilization of wind power imposes many effects on planning and operation of power system. In other side, reliability evaluation and enhancement is an important factor in modern power system planning and operation. So, reliability assessment of wind turbines is of great importance and will receive more attention in the future according to increase of WT utilization. The...
An improved dynamic model for simulation and stability analysis of brushless doubly fed machines
, Article 2016 18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe, 5 September 2016 through 9 September 2016 ; 2016 ; 9789075815245 (ISBN) ; Tahami, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This paper presents a dynamic model for brushless doubly fed machine including core loss. Using the space vector notation, the conventional equivalent circuit model of the machine is modified to take the core loss effect into account. The proposed method introduces resistances corresponding to stator/rotor core loss components designated to the power/control windings. This model can be used for enhanced time-domain simulations, design of high performance control strategies with core loss detuning effect compensation and also as a tool for stability analysis of the machine drive under different control methods. The dynamic model of a prototype machine is simulated with and without...
The brushless doubly-fed machine vector model in the rotor flux oriented reference frame
, Article 34th Annual Conference of the IEEE Industrial Electronics Society, IECON 2008, Orlando, FL, 10 November 2008 through 13 November 2008 ; January , 2008 , Pages 1415-1420 ; 9781424417667 (ISBN) ; Oraee, H ; Abdi, E ; Shao, S ; Mc Mahon, R ; Sharif University of Technology
IEEE Computer Society
2008
Abstract
The paper presents the vector model of the Brushless Doubly-Fed Machine (BDFM) in the rotor flux oriented reference frame. The rotor flux oriented reference frame is well known in the standard AC machines analysis and control. Similar benefits can be sought by employing this method for the BDFM The vector model is implemented in MATLAB/SIVIULINK to simulate the BDFM dynamic performance under different operating conditions. The predictions from the vector model are compared to those from the coupled circuit model in simulation. The results are shown for the cascade mode of operation. © 2008 IEEE
Investigation of core loss effect on steady-state characteristics of inverter fed brushless doubly fed machines
, Article IEEE Transactions on Energy Conversion ; Volume 29, Issue 1 , March , 2014 , Pages 57-64 ; ISSN: 08858969 ; Tahami, F ; Oyarbide, E ; Sharif University of Technology
Abstract
Brushless doubly fed machine (BDFM) shows promising results for wind power and adjustable-speed drive applications. Due to poor rotor magnetic coupling and relatively high value of slip, core loss is an important factor which can affect the steady-state and dynamic performance of BDFM. Specifically, core loss plays a major role when evaluating the efficiency of the machine. By now, there is no comprehensive study on core loss effect on performance characteristics of BDFM in the literature. In this paper, based on the derived relations and applying transformation of parameters from one winding to another one, the steady-state equivalent circuit model of BDFM without core loss is modified in...
Experimental investigations on the core loss effects in an inverter fed brushless doubly fed machine
, Article IECON Proceedings (Industrial Electronics Conference) ; 2013 , Pages 2821-2826 ; 9781479902248 (ISBN) ; Tahami, F ; Oyarbide, E ; Sharif University of Technology
2013
Abstract
Brushless doubly fed machine (BDFM) shows promising results for wind power and adjustable-speed drive applications. Due to poor rotor magnetic coupling and relatively high value of slip, core loss is more emphasized in this machine than the conventional machines. By now, there are few comprehensive researches on core loss effect on performance characteristics of BDFM in the literature. In this paper, based on the derived relations and by applying suitable rules for transformation of parameters from one winding to another one, the steady state equivalent circuit model of BDFM referred to power winding stator side is obtained. Comparison between simulation and experimental results verifies the...
Steady-state analysis and performance of a brushless doubly fed machine accounting for core loss
, Article IET Electric Power Applications ; Volume 7, Issue 3 , 2013 , Pages 170-178 ; 17518660 (ISSN) ; Tahami, F ; Tavner, P ; Tohidi, S ; Sharif University of Technology
2013
Abstract
In this study a steady-state equivalent circuit for a brushless doubly fed machine (BDFM), based upon earlier work, is introduced which takes account of core losses. Based upon some loss approximations, simple relationships have been derived, which show that the synchronous mode operation, in terms of core loss, of the BDFM is similar to the cascaded doubly fed machine. The slip-dependence of core loss resistances in the equivalent circuit has been investigated by applying energy conservation to derive machine steady-state torque-speed relations in the presence of core loss. Experimental speed measurements of the BDFM in the simple induction mode were used to identify the core loss...
Dynamic modeling and simulation of brushless doubly fed induction machine in consideration of core loss
, Article IECON Proceedings (Industrial Electronics Conference) ; 2012 , Pages 1753-1757 ; 9781467324212 (ISBN) ; Tahami, F ; The Institute of Electrical and Electronics Engineers (IEEE); IEEE Industrial Electronics Society (IES) ; Sharif University of Technology
2012
Abstract
Brushless doubly fed induction machine has recently attracted attention in variable speed generators and motor drives. In order to have a high performance control, a precise dynamic model is required. This paper aims at introducing a model of brushless doubly fed induction machine taking core loss into account. The details of model derivation are outlined and the torque relation is expressed in the general reference frame. The model is then used for simulation of the dynamic performance of the machine. The error introduced by neglecting core loss effect is also shown
Steady state analysis of brushless doubly fed induction machine taking core loss into account
, Article IECON Proceedings (Industrial Electronics Conference) ; 2012 , Pages 2030-2035 ; 9781467324212 (ISBN) ; Tahami, F ; Sharif University of Technology
2012
Abstract
Brushless doubly fed induction machines show promising results for wind power applications. Due to their poor rotor magnetic coupling and relatively high value of slip, core loss is an important factor which affects the steady state and dynamic performance. The core loss effect on performance of brushless doubly fed induction machines has not been extensively studied in the literature. In this paper, a steady state equivalent circuit taking core loss into account is introduced. Simple relationships are derived which show that the brushless doubly-fed induction machine is similar to the cascaded doubly-fed induction machine in terms of core loss. The energy conservation principle is applied...
Performance of the brushless doubly-fed machine under normal and fault conditions
, Article IET Electric Power Applications ; Volume 6, Issue 9 , Volume 6, Issue 9 , 2012 , Pages 621-627 ; 17518660 (ISSN) ; Zolghadri, M. R ; Oraee, H ; Tavner, P ; Abdi, E ; Logan, T ; Sharif University of Technology
2012
Abstract
In this study, the steady-state operation of the brushless doubly-fed machine (BDFM) in various modes is physically elaborated and the active power flow and torque analysis are presented for each operating mode alongside confirmatory experimental results on a 4/8 pole D160 size machine. The machine behaviour in asynchronous operating modes is described similar to the conventional induction machines with corresponding pole numbers. Moreover, its performance in synchronous mode is shown to be similar to synchronous machines. On the basis of the above, the BDFM performance is further analysed under two possible fault conditions: first, a controller or converter fault leading to loss of...
An equivalent circuit model for brushless doubly fed induction machine considering core loss
, Article 2012 3rd Power Electronics and Drive Systems Technology, PEDSTC 2012, 15 February 2012 through 16 February 2012 ; February , 2012 , Pages 348-353 ; 9781467301114 (ISBN) ; Tahami, F ; Sharif University of Technology
2012
Abstract
Brushless doubly fed induction machines show promising results for wind power applications. Due to their poor rotor magnetic coupling and relatively high value of slip, core loss is an important factor which affects the steady state and dynamic performance. The core loss in brushless doubly fed induction machines has not been extensively studied in the literature. In this paper, a steady state equivalent circuit taking core loss into account is introduced. Simple relationships are derived which show that the brushless doubly-fed induction machine is similar to the cascaded doubly-fed induction machine in terms of core loss. The proposed equivalent circuit is simulated to derive the steady...
Modeling of a BDFM-based wind turbine under unbalanced grid voltage dips
, Article 2011 IEEE Power and Energy Conference at Illinois, PECI 2011 ; 2011 ; 9781424480500 (ISBN) ; Gorgin, H ; Oraee, H ; Sharif University of Technology
2011
Abstract
Brushless Doubly-Fed Machine (BDFM) is a machine which incorporates the robustness of the squirrel cage induction machine while having the speed and power factor control of a synchronous machine. A special kind of rotor called Nested-Loop rotor plays an important part in the BDFM, coupling the two stator fields. In future BDFM will share a large part in wind power market. This paper presents a mathematical model of Brushless Doubly-Fed Machine (BDFM) based on Stator Flux Orientation (SFO) in the positive and negative reference frames under unbalanced grid voltage conditions
Magnetic field harmonic analysis in brushless doubly fed machine
, Article Proceedings of the 2011 3rd International Youth Conference on Energetics, IYCE 2011, 7 July 2011 through 9 July 2011 ; July , 2011 , Page(s): 1 - 7 ; 9781457714948 (ISBN) ; Jandaghi, B ; Saket, M. A ; Oraee, A ; Oraee, H ; Sharif University of Technology
2011
Abstract
In this paper, harmonic sources in a BDFM are studied, and a method for specifying rotor and stator space harmonic components is established. A criterion for evaluating different rotor designs is introduced, based on space harmonics. Then the equivalent space and time harmonic circuits are obtained, using basic equivalent circuit. Finally, the effects of these harmonics on the torque-speed characteristic are studied
Eddy current losses in brushless doubly-fed machines
, Article Proceedings of the 2011 3rd International Youth Conference on Energetics, IYCE 2011, 7 July 2011 through 9 July 2011 ; July , 2011 , Page(s): 1 - 5 ; 9781457714948 (ISBN) ; Jandaghi, B ; Oraee, A ; Saket, M. A ; Gorginpour, H ; Oraee, H ; Sharif University of Technology
2011
Abstract
The application of the brushless doubly-fed machine (BDFM) is in wind power generation in harsh conditions, where reliability is important. In this paper, eddy current losses in a BDFM in four categories: a) the rotor classic eddy current losses, b) stator classic eddy current losses, c) rotor excessive eddy current losses, and d) stator excessive eddy current losses, are calculated for single frequency of the rotor and double frequency of the stator magnetic fields
Reduction of the torque ripple in brushless doubly-fed machine
, Article Proceedings of the 2011 3rd International Youth Conference on Energetics, IYCE 2011, 7 July 2011 through 9 July 2011 ; July , 2011 , Page(s):1 - 7 ; 9781457714948 (ISBN) ; Jandaghi, B ; Oraee, A ; Saket, M. A ; Ahmadian, M ; Oraee, H ; Sharif University of Technology
2011
Abstract
In this paper, a new structure for the rotor of the Brushless Doubly-Fed Machine (BDFM) is introduced to reduce the machine's torque ripple. The ripple has a considerable effect on the machine start up. At the first section of the paper, analytical expressions for the air gap permeance distribution, the air gap MMF distribution, cogging torque and back EMF are presented. Then, the effects of skewing the rotor loops are analyzed. Finally, the relation between non-skewed quantities and their values in skewed coordinate are introduced
A survey on rotor faults in brushless doubly fed machines
, Article Proceedings of the 2011 3rd International Youth Conference on Energetics, IYCE 2011, 7 July 2011 through 9 July 2011 ; July , 2011 , Page(s): 1 - 8 ; 9781457714948 (ISBN) ; Gorginpour, H ; Saket, M. A ; Oraee, A ; Ahmadian, M ; Oraee, H ; Sharif University of Technology
2011
Abstract
The cause of about 10% of faults in induction machines is related to the rotor part. In this paper, an analytical method for general modeling of brushless doubly-fed machines (BDFMs) with broken rotor loops and end ring is presented. The approach is based on calculation of resistance and inductance matrices through the winding function of the machine, so the assumption of sinusoidal MMF is not needed. It is also shown that a fault in a loop can lead to faults in other parts of the rotor. To validate the method a simulation in MATLAB/Simulink is performed based on the D180-frame prototype BDFM
Modeling and control of a grid-connected BDFM under unbalanced grid voltage conditions
, Article 2011 IEEE International Electric Machines and Drives Conference, IEMDC 2011, 15 May 2011 through 18 May 2011 ; May , 2011 , Pages 1647-1651 ; 9781457700613 (ISBN) ; Seyed Mahdi Izadkhast ; Khosravi, H ; Oraee, H ; Sharif University of Technology
2011
Abstract
This paper presents a mathematical model for Brushless Doubly-Fed Machine (BDFM) based on Stator Flux Orientation (SFO) in positive and negative reference frames under unbalanced grid voltage conditions. A negative controller is designed to eliminate the effects of unbalanced conditions on electrical torque. The model and controller performance during unbalanced conditions is validated by time domain simulation in MATLAB/Simulink