This paper discusses the inverter ratings of BrushIt can be shown (Appendix A) that for an ideal BDFM less Doubly-Fed Machine (BDFM) adjustable speed drive (ASD) operating at constant torque the control winding rating, S2, is or generator (ASG) systems. Based on the per phase equivalent related to the machine rating, Smn, by circuit model, the ratings of the two inverters in a bidirectional converter are evaluated individually. An approach to minimise the total inverter rating is presented, taking into account power = 2 factor constraints of the power grid. The effects of speed S m-f2 7-3 deviation and control winding excitation on the inverter ratings I i 3 are discussed. Predictions of inverter ratings are presented with Equation (3) has been conventionally used to determnine the experimental verification. A design example is also provided in covreraig3] 4.Hwe,asaeulofteeiwhich the total inverter rating is minimised for a practical BDFM tacnerte ragntiing [3],u[].aHoevras an resulkoate rnutnesis-a based ASG system. tne,mgeiigidcacsadlaaeidcacsi Index Terms-BDFM, inverter rating, ASD, ASG practical BDFM, calculations based on an ideal BDFM need to be modified for a full evaluation of the converter rating.

The paper presents the design and performance analysis of a 6 MW medium-speed Brushless Doubly-Fed Induction Generation (Brushless DFIG) for a wind turbine drivetrain. Two machines with different frame sizes have been designed to show the flexibility of the design procedure. The mediumspeed Brushless DFIG in combination with a two stage gearbox offers a low-cost, low-maintenance and reliable drivetrain for wind turbine applications.

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Details of a lumped parameter thermal model for studying thermal aspects of the frame size 180 nested loop rotor BDFM at the University of Cambridge are presented. Predictions of the model are verified against measured end winding and rotor bar temperatures that were measured with the machine excited from a DC source. The model is used to assess the thermal coupling between the stator windings and rotor heating. The thermal coupling between the stator windings is assessed by studying the difference of the steady state temperatures of the two stator end windings for different excitations. The rotor heating is assessed by studying the temperatures of regions of interest for different excitations.

Detailed materials properties of silicon on insulator films produced by dual electron‐beam recrystallization of polysilicon films are reported. By scanning a line electron beam parallel to the edges of an array of narrow seeding windows, large areas (several square centimeters) of precisely oriented single‐crystal silicon have been formed. The optimum beam conditions and substrate geometry to achieve the best recrystallization have been investigated, and it has been found that using a fast scan speed (∼ 35 cm/s) allows seeded regrowth without melting the substrate below the isolating oxide. Using these conditions, complete wafers may be recrystallized in around 30s without introducing strain or wafer warping. Remaining crystallographic defects include dislocations midway between seeding windows and an occasional twinning of the regrowth when the windows are aligned along <110>.

The aim of this paper is to demonstrate the benefits of squarewave excited integrated drives as a replacement for standard single-phase motors. To overcome the adverse effects of squarewave excitation on induction motor performance the motor phase number is sufficiently increased. Although the threephase PWM drive is an industry standard in power electronic drives and offers good motor performance, it's higher switching frequency leads to higher inverter losses, making this type of drive less suitable as the basis of an integrated drive. The thermal constraints in an integrated drive require low inverter losses which can be achieved with squarewave excitation. To verify this, the PWM drive has been compared against the squarewave excited multiphase drive.

Free-standing wire samples have been fabricated that enable low dimensional conducting wires to be examined by transmission electron microscopy (TEM). These structures have been fabricated using a combination of gas-assisted ion beam etching and electron beam lithography, and have cross-sectional dimensions between 70 nm and 1 µm, and lengths of up to 50 µm. The free-standing wires have been examined by TEM before and after ion implantation and annealing. The results indicate that no extended defects are created in the wires, even for high doses (1016cm-3) or high beam energies (>50 keV). The reason for this is not fully understood. In addition, the fabrication process has been extended so that low temperature electrical measurements can be performed on the TEM samples. In this way it is hoped eventually to study the role of specific crystalline defects in limiting the electronic and phonon transport.