Modeling and position-sensorless control of a dual-airgap axial flux permanent magnet machine for flywheel energy storage systems

This paper presents the modeling and position-sensorless vector control of a dual-airgap axial flux permanent magnet (AFPM) machine optimized for use in flywheel energy storage system (FESS) applications. The proposed AFPM machine has two sets of three-phase stator windings but requires only a single power converter to control both the electromagnetic torque and the axial levitation force. The proper controllability of the latter is crucial as it can be utilized to minimize the vertical bearing stress to improve the efficiency of the FESS. The method for controlling both the speed and axial displacement of the machine is discussed. An inherent speed sensorless observer is also proposed for speed estimation. The proposed observer eliminates the rotary encoder, which in turn reduces the overall weight and cost of the system while improving its reliability. The effectiveness of the proposed control scheme has been verified by simulations and experiments on a prototype machine.

Modeling and analysis of a novel variable-speed cage induction generator

This paper introduces a novel cage induction generator and presents a mathematical model, through which its behavior can be accurately predicted. The proposed generator system employs a three-phase cage induction machine and generates single-phase and constant-frequency electricity at varying rotor speeds without an intermediate inverter stage. The technique uses any one of the three stator phases of the machine as the excitation winding and the remaining two phases, which are connected in series, as the power winding. The two-series-connected-and-one-isolated (TSCAOI) phase winding configuration magnetically decouples the two sets of windings, enabling independent control. Electricity is generated through the power winding at both sub- and super-synchronous speeds with appropriate excitation to the isolated single winding at any frequency of generation. A dynamic mathematical model, which accurately predicts the behavior of the proposed generator, is also presented and implemented in MATLAB/Simulink. Experimental results of a 2-kW prototype generator under various operating conditions are presented, together with theoretical results, to demonstrate the viability of the TSCAOI power generation. The proposed generator is simple and capable of both storage and retrieval of energy through its excitation winding and is expected to be suitable for applications, such as small wind turbines and microhydro systems.

Practice and procedure - Motor Accident Insurance Act 1994 s45 - duty of claimant to cooperate with insurer

In Suncorp Metway Insurance Limited v Brown [2004] QCA 325 the Queensland Court of Appeal considered the extent of the duty of cooperation imposed on a claimant under s45 of the Motor Accident Insurance Act 1994 (Qld). The issue is an important one because it affects virtually all claims made under the Act.

Mandatory offers under the Motor Accident Insurance Act 1994 - with interest please!

In Windon v Edwards [2005] QDC 029 Robin QC DCJ considered the cost consequence of mandatory final offers under the Motor Accident Insurance Act 1994 (Qld)

Unidentified vehicle in multi-vehicle accident - failure to notify Nominal Defendant no bar to proceedings against it

In Kumar v Suncorp Metway Insurance Limited [2004] QSC 381 Douglas J examined s37 of the Motor Accident Insurance Act 1994 (Qld) in the context of an accident involving multiple insurers when a notice of accident had not been given to the Nominal Defendant

Practice and Procedures - Motor Accident Insurance Act 1994 ss 39 and 57

In Bermingham v Priest [2002] QSC 057 jones J considered the position of persons seeking to claim damages where the Motor Accident Insurance Act 1994 applies prior to its amendment by the Motor Accident Insurance Amendment Act 2000, and where proceedings are brought close to expiration of the statutory limitation period.

Motor Accident Insurance Act 1994 - obligation to disclose

In Turpin v Allianz Australia Insurance Ltd (unreported, Supreme Court of Queensland, S5216 of 2001), Mullins J, 17.10.2001) the plaintiff applied for a declaration that the respondent disclose pursuant to s47 of the Motor Accident Insurance Act 1994 copies of three statements referred to in a loss assessor's investigation report as "attached". The issue involved determination of whether the statements must be disclosed under s48(2) even though protected by legal professional privilege. The Court applied the decision of the Queensland Court of Appeal in James v Workcover Queensland.

Personal injury in motor accident in NSW - procedural requirements under Motor Accidents Insurance Act 1988 (NSW)

In Hooper v Robinson [2002] QDC 080 (District Court of Queensland, D 4841 of 2001, McGill DCJ, 19.4.2002) McGill DCJ considered the application of the decision in John Pfeiffer Pty Ltd v Rogerson [2000] 203 CLR 503 to notice requirements such as in s42 of NSW Motor Accident Insurance Act 1988 and concluded such provisions are now substantive.

Motor Accident Insurance Act 1994 - whether vehicle in question a vehicle "for which registration is required"

In Gideona v Nominal Defendant [2005] QCA 261, the Queensland Court of Appeal reconsidered the question of what is the material time for determining whether registration of a motor vehicle is required. The Court declined to follow the decision in Kelly v Alford [1988] 1 Qd R 404; deciding that the material time was the time when the accident occurred.

Motor Accident Insurance Act 1994 s45 - whether obligation to co-operate may authorise order requiring commencement of proceedings by minor prior to expiration of limitation period

In Australian Associated Motor Insurers Ltd v McPaul; Council of the City of Gold Coast v McPaul [2005] QSC 278 the applicant insurer sought an order requiring a claimant who had been injured in a motor vehicle accident some years earlier when he was five years old to commence a proceeding to determine the question of the applicant's liability to him. The applicant's interest in seeking the order was to avoid the prejudice which could follow from further delay, particularly delay until the respondent became obliged to commence proceedings to avoid a limitations bar.

Motor Accident Insurance Act 1994 - reasonable excuse for delay in giving notice under s37

The decisions in Perdis v The Nominal Defendant [2003] QCA 555, Miller v the Nominal Defendant [2003] QCA 558 and Piper v the Nominal Defendant [2003] QCA 557 were handed down contemporaneously by the Queensland Court of Appeal on December 15 2003. They consider important issues as to the construction of key provisions of the Motor Accident Insurance Act 1994 (Qld)

Motor Accident Insurance Act 1994 - compulsory conferences and offers to settle

In Lindsay v Aumaali [2004] QDC 028 the Court considered whether it could, in effect, postpone the requirement for a compulsory conference under s51A of the Moror Accident insurance Act 1994 (Qld) or the exchange of final offers under s51C of the Act until after the start of proceedings.

Limitation of Actions - incorrect date of accident advised to solicitor

The decision of the Queensland Court of Appeal in Cormie v Orchard [2003] QCA 236 involved consideration of whether the respondent solicitor was liable in negligence for failing to commence proceedings within the applicable limitation period in circumstances where the solicitor had relied on the advice as to the date of injury nominated incorrectly but unequivocally by the client.

Graphene and carbon nanotubes from arc plasmas : experiment and plasma modeling

Graphene and carbon nanotubes are the most promising nanomaterials for application in various modern nanodevices. The successful production of the nanotubes and graphene in a single process was achieved by using a magnetically enhanced arc discharge in helium atmosphere between carbon and metal electrodes. A 3-D fluid model has been used to investigate the discharge parameters.