Salman Abdi

• Lecturer at University of East Anglia

Fine-tuning the hyperparameters of the Support Vector Machine (SVM) is crucial to making it an accurate classifier in fault detection. The convergence rate of the optimiser and its simplicity are also vital for achieving the optimal boundary. Therefore, a highly accurate fault detection algorithm that combines SVM with a simple, easy-to-implement,...

This paper presents a method to estimate the BDFM equivalent circuit rotor current from rotor bar current measurements. Rotor currents are measured using a specially designed hardware that incorporates Rogowski coils and Bluetooth wireless transmission. The measurement of rotor currents enables the parameters in the BDFM's full equivalent circuit t...

This paper introduces a novel finite-element-method-based model designed to analyze the electromagnetic–thermal dynamics of resistance spot welding (RSW) transformers used in battery manufacturing. The RSW process, inherently multiphysics and sensitive to temperature fluctuations, involves phase changes within the metal materials. This complexity,...

A Brushless Doubly-Fed Induction Machine (BDFIM) has wide application potential in wind turbines, industrial drives, small hydro power plants, power supply of ships, aircraft starters, and electric vehicles. In electric vehicles, a BDFIM offers a robust structure without needing permanent magnet materials, slip-rings, and brushes, which makes it pa...

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 control schemes are proposed for the BDFIM drive based on Lyapunov nonlinear techniques. The first scheme aims for speed control with a one-level structure without an inner...

The brushless doubly-fed machine (BDFM) has two stator windings with different pole numbers, supplied with different frequencies. Therefore, the distribution of magnetic fields in stator and rotor iron is complex. In addition, the stator flux density distribution is non-sinusoidal and has a DC offset at the natural speed. This makes the use of conv...

Abstract A new fault diagnosis method for detecting the rotor eccentricity faults including static, dynamic and mixed eccentricity is proposed for brushless doubly‐fed induction machines (BDFIMs). BDFIMs are attractive alternatives for the conventional doubly‐fed induction generator (DFIG) for offshore wind power generation; therefore, paying atten...

In this work, an analytical study has been performed on the Brushless Doubly Fed Machine's (BDFM) vibration due to the interaction of its fundamental magnetic fields, exerting bending forces in the back iron. The effects of rotor eccentricity on exacerbating the machine's vibration have been considered by assessing the stator back iron displacement...

The brushless doubly fed induction generator (BDFIG) is an alternative to the doubly fed induction generator (DFIG), widely used in wind turbines which avoids the need for brush gear and slip rings. The choice of pole numbers for the two stator windings present in the BDFIG sets the operating speed range but also affects the torque capability, magn...

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 generator solution for offshore wind power and can replace doubly fed slip-ring induction generat...

It is desirable to measure rotor quantities such as currents and temperatures in an electrical machine for design verification and condition monitoring purposes. A Bluetooth module which sends data from the rotor was previously reported in literature, but this module was battery powered, and therefore the duration of the tests was limited. This stu...

In this study, a large-scale brushless doubly fed machine (BDFM) built in frame size D400 is tested at different operating conditions in order to examine its noise and vibration levels. A series of measurements were conducted on the machine to establish the main modes of excitation of vibration and noise developed by the machine. The harmonic spect...

In this study, a large‐scale brushless doubly fed machine (BDFM) built in frame size D400 is tested at different operating conditions in order to examine its noise and vibration levels. A series of measurements were conducted on the machine to establish the main modes of excitation of vibration and noise developed by the machine. The harmonic spect...

In order to perform experiments on electrical machines, it is desirable to measure rotor parameters such as currents and temperatures. A Bluetooth module have been developed which sends data from the rotor, however this module is battery powered, and therefore the duration of the tests is limited. This paper presents a solution to this problem, by...

This paper presents an optimized design method for the magnetic circuit of brushless doubly fed machines (BDFMs). The BDFM is an attractive electrical machine, particularly for wind power applications, as a replacement for doubly fed slip-ring generators. This study shows that the conventional design methods for the BDFM stator and rotor back iron...

This paper studies the unbalanced magnetic pull in the brushless doubly fed machine (BDFM) caused by both static and dynamic rotor eccentricities. Several parallel winding designs for the two stator windings are proposed, and the practicality of such designs is discussed with respect to direct coupling between the stator windings and with rotor und...

A procedure has been established for obtaining equivalent circuit parameters for the brushless doubly fed machine, also known as the brushless doubly fed induction machine, by transforming a reduced coupled-circuit model into a sequence component form. This approach takes advantage of the model reduction procedure's ability to reduce a complex roto...

The brushless doubly fed machine (BDFM) is an alternative to the doubly fed induction generator, widely used in wind turbines without use of brush gear and slip ring. Rotor design is important for achieving an optimal multi-MW BDFM. To date, nested-loop rotors have been exclusively used in various BDFMs, although they may not be ideal for larger ma...

This paper studies the unbalanced magnetic pull (UMP) in the Brushless Doubly-Fed Machine (BDFM). Analytical study is performed to derive the UMP, then, Finite element (FE) analysis, which has been verified experimentally, is used to verify the analytical method. The BDFM with different types of rotor eccentricities including static and dynamic ecc...

This paper presents analytical methods to calculate the equivalent circuit parameters for large-scale brushless doubly fed machines (BDFMs) with magnetic wedges utilized for closing stator open slots. The use of magnetic wedges reduces the magnetizing currents in the machine, reflected in the values of magnetizing inductances, but also increases le...

This paper presents an optimisation method for the converter rating for 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 and transient models of the machine have been utilised for the reactive power management a...

This study presents the performance analysis and testing of a 250 kW medium-speed brushless doubly-fed induction generator (DFIG), and its associated power electronics and control systems. The experimental tests confirm the design, and show the system's steady-state and dynamic performance and grid low-voltage ride-through capability. The medium-sp...

This paper studies the effects of magnetic wedges on the equivalent circuit parameters of the Brushless Doubly-Fed Machine (BDFM). Magnetic wedges are used in slot openings of large electrical machines to reduce magnetizing currents, but the study of their effects on the BDFM performance is not straightforward due to the complex magnetic fields in...

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 a realistic system model of a Bru...