This study presents the performance analysis and testing of a 250 kW medium‐speed brushless doubly‐fed induction generator (DFIG), its associated power electronics control systems. The experimental tests confirm design, show system's steady‐state dynamic grid low‐voltage ride‐through capability. DFIG in combination with simplified two‐stage gearbox promises low‐cost low‐maintenance reliable drivetrain for wind turbine applications.

This paper presents analytical methods to calculate the equivalent circuit parameters for large-scale brushless doubly fed machines (BDFMs) with magnetic wedges utilized closing stator open slots. The use of reduces magnetizing currents in machine, reflected values inductances, but also increases leakage fluxes affecting value series inductances circuit. Though such effects can be modeled by numerical models, proposed are particularly helpful optimizing machine design, inverter rating,...

The brushless doubly fed machine (BDFM) is an alternative to the induction generator, widely used in wind turbines without use of brush gear and slip ring. Rotor design important for achieving optimal multi-MW BDFM. To date, nested-loop rotors have been exclusively various BDFMs, although they may not be ideal larger machines. This paper studies, both analytically experimentally, different D160 D400 frame size BDFMs. An optimization on rotor equivalent circuit parameters carried out verified...

This paper presents an optimized design method for the magnetic circuit of brushless doubly fed machines (BDFMs). The BDFM is attractive electrical machine, particularly wind power applications, as a replacement slip-ring generators. study shows that conventional methods stator and rotor back iron can be modified, leading to lighter smaller machine. proposed concepts are supported by analytical methods, their practicality verified using two-dimensional finite-element modeling analysis. Two...

The brushless doubly fed induction generator (BDFIG) is an alternative to the (DFIG), widely used in wind turbines which avoids need for brush gear and slip rings. choice of pole numbers two stator windings present BDFIG sets operating speed, typically medium speed range eliminate a gearbox stage. This paper focuses on how both total number poles assignment between affect machine performance. Analytical expressions have been developed parameters including pull-out torque, magnetizing current...

This paper studies the unbalanced magnetic pull in brushless doubly fed machine (BDFM) caused by both static and dynamic rotor eccentricities. Several parallel winding designs for two stator windings are proposed, practicality of such is discussed with respect to direct coupling between undesirable harmonic fields. Once practical established, their effects on reducing deflection as a result eccentricities shown compared series wound stator. study has been carried out prototype D400 250-kW BDFM.

In this work, an analytical study has been performed on the Brushless Doubly Fed Machine's (BDFM) vibration due to interaction of its fundamental magnetic fields, exerting bending forces in back iron. The effects rotor eccentricity exacerbating machine's have considered by assessing stator iron displacement function presence eccentricity. Finite element analysis is carried out for a 250 kW BDFM built frame size D400 validate methods. determined ideally-constructed machine as well when static...

The brushless doubly-fed machine (BDFM) has two stator windings with different pole numbers, supplied frequencies. Therefore, the distribution of magnetic fields in and rotor iron is complex. In addition, flux density non-sinusoidal a DC offset at natural speed. This makes use conventional hysteresis models utilised for sinusoidal impractical BDFM. this paper new model proposed BDFM based on scalar Preisach model. rotational characteristics are also considered their effects generating losses...

A procedure has been established for obtaining equivalent circuit parameters the brushless doubly fed machine, also known as induction by transforming a reduced coupled‐circuit model into sequence component form. This approach takes advantage of reduction procedure's ability to reduce complex rotor structure single loop without significant loss accuracy. An alternative method based on winding factors developed and includes coupling via harmonic fields. Parameters determined in both ways are...

Recent advancement in design and control of brushless doubly-fed induction machine (BDFIM) has substantially improved its performance. In this article, two high efficient vector schemes are proposed for the BDFIM drive based on Lyapunov nonlinear techniques. The first scheme aims speed with a one-level structure without an inner loop controller, rotor error is delivered to backstepping controller. second two-level controller model reference torque control, respectively. To enhance...

In this study, a large-scale brushless doubly fed machine (BDFM) built in frame size D400 is tested at different operating conditions order to examine its noise and vibration levels. A series of measurements were conducted on the establish main modes excitation developed by machine. The harmonic spectrums amplitudes are presented two rotor speeds which level highest, determine components frequencies existed spectrum. analysis BDFM then proposed assess sources

The brushless doubly fed induction generator (BDFIG) with a partially rated converter has characteristics of squirrel cage and conventional synchronous generator. Its control is challenging due to the machine's complicated structure, which requires an effective controller stabilize it within its normal speed range under various steady state dynamic operations. In this paper, comprehensive nonlinear vector scheme proposed for BDFIGs, where achieved through model reference adaptive (MRAC),...

It is desirable to measure rotor quantities such as currents and temperatures in an electrical machine for design verification condition monitoring purposes. A Bluetooth module which sends data from the was previously reported literature, but this battery powered, therefore duration of tests limited. This study presents a solution problem by developing rotor-mounted power supply system can harvest energy magnetic field inside machine, fixing external loop making use induced voltage loop....

The brushless doubly fed machine (BDFM) is an alternative to the induction generator, widely used in wind turbines, without use of brush gears and slip rings. Rotor design important for designing optimal multi-MW BDFM. To date, nested-loop rotors have been extensively various BDFMs but they may not be suitable larger machines. In this paper, different methods BDFM rotor equivalent circuit parameters determination are presented validated by experimental tests. Then, a optimization proposed...

This paper presents an optimisation method for the converter rating a Brushless Doubly-Fed Induction Generator (Brushless DFIG) wind turbine, considering grid's requirements on reactive power and low voltage ride-through (LVRT) compatibility. Steady-state transient models of machine have been utilised management LVRT analyses. The effects parameters inverter are discussed adjusting leakage magnetising by appropriate design stator slot magnetic wedges is proposed. analyses preformed prototype...

This paper studies the effects of magnetic wedges on equivalent circuit parameters Brushless Doubly-Fed Machine (BDFM).Magnetic are used in slot openings large electrical machines to reduce magnetizing currents, but study their BDFM performance is not straightforward due complex fields BDFM.Equivalent and FE models have been developed for a 250 kW taking into account verified experimentally.

Abstract A new fault diagnosis method for detecting the rotor eccentricity faults including static, dynamic and mixed is proposed brushless doubly‐fed induction machines (BDFIMs). BDFIMs are attractive alternatives conventional generator (DFIG) offshore wind power generation; therefore, paying attention to their detection essential. Existing methods cannot be directly applied BDFIM due its special structure stator winding configurations as well complex magnetic field patterns. This article...

This paper studies the converter rating requirement of a Brushless Doubly-Fed Induction Generator for wind turbine applications by considering practical constraints such as generator torque-speed requirement, reactive power management and grid low-voltage ride-through (LVRT). Practical data have been used to obtain realistic system model DFIG using steady-state dynamic models. A optimization is performed based on given constraints. The current voltage requirements are examined resulting...

In this paper a new rotor eccentricity fault detection method is proposed for the first time brushless doubly-fed induction machines (BDFIMs). Due to fact that BDFIMs are attractive alternatives wind power generation, paying attention their essential. Existing methods conventional can not be directly applied BDFIM due its special structure and stator winding configurations as well complex magnetic fields. technique based on current harmonic analysis detect faults in BDFIM. The validity of...

This paper studies the effects of magnetic wedges used for closing stator open slots on Brushless Doubly Fed Machines' (BDFM) equivalent circuit parameters. The BDFM is an attractive generator solution offshore wind power and can replace doubly-fed slip-ring induction generators. It shown in this that use wedges, commonly large machines, reduces windings magnetising currents, reflected values inductances. But they also increase leakage flux hence change series inductance circuit....

This study studies, using experimentally verified finite element (FE) analysis, various performance measures of the brushless doubly fed induction generator (BDFIG) when magnetic wedges are used for closing stator open slots. The BDFIG is an attractive solution offshore wind power and can replace slip-ring generators. It shown in this that use wedges, commonly large machines, reduces windings magnetising currents a BDFIG, reflected values inductances. They also increase leakage flux slots,...

Satellite image segmentation is an important topic in many domains. This paper introduces a novel semi-supervised method for satellite segmentation. Unlike the semantic strategies, this requires only limited labelled data from small local patches of images. Due to complexity and large number land cover objects images, fixed-size square window used feature extraction 7 different areas. The features are extracted by spectral domain analysis. Then, classification performed based on similarity...

In this paper, a new optimized rotor design for Brushless Doubly Fed Machines (BDFMs) is proposed. The BDFM considered as an attractive generator particularly offshore wind power generation and also replacement doubly fed slip ring induction generators. This due to its higher reliability lower maintenance reported in the literature. It shown paper from study of magnetic field distribution core that conventional iron can be modified, leading lighter machine. proposed method supported by...

In this paper the rotational characteristics of magnetic field in Brushless Double Fed Induction Machines (BDFIM) iron circuit is studied. The BDFIM has a complex pattern which make its loss prediction difficult. This due to fact that two stator windings with different pole numbers supply at frequencies. addition, contains excessive higher order harmonics conventional formulations not applicable predictions. A new formulation proposed for takes and harmonic effects into account prediction....