A current inverter fed synchronous motor is affected by torque ripple and suffers damping losses. These limitations can be overcome either by increasing the number of phases or by fitting several shifted armatures to the synchronous machine. This results in the reduction of the torque ripple...

We consider the use of a computer algebra system to carry out the symbolic computations needed in thermodynamics. A package for Maple is described and illustrated with several examples involving the creation and manipulation of thermodynamic derivatives.

The conjugate pairing rule states that for Hamiltonian systems to which a Gaussian or Nosé–Hoover thermostat is applied, the spectrum of Lyapunov exponents should exhibit a simple symmetry: that the sum of conjugate pairs of exponents should be a constant independent of the pair index. This...

For interior or buried permanent magnet motors, the back emf and inductances are usually non-sinusoidal functions of time which causes torque pulsations in operation at low speed. This paper presents an instantaneous torque control scheme of interior PM motor drive for both constant torque and...

A method to characterise and to model the hysteresis phenomenon of magnetic material is proposed. It is based on the Preisach model taking a normal distribution law for the switching field density. The using of this model needs the identification of five parameters. The characterisation of a...

In this paper, the instantaneous space vector method is presented as synthesis tool for the determination of the sequential command of a three phase/single phase PWM converter which can operate as an inverter or a rectifier, with a current or a voltage DC source. Though the PWM patterns...

In this article, a technique for the identification of a nonlinear compressor performance model exhibiting bifurcation phenomena is presented. The approach consists of employing the modal form of the compressor flow equations along with derived linear and nonlinear stability results. When the...

This paper presents Norton transmission line (TL) models and equivalent circuits for the simulation of reactive circuit components. These models, not only retain the obvious physical concepts of Thevenin-TL models, but also allow the nodal analysis technique to be used, overcoming the inherent...

Electronic protoyping is becoming a part of every scientific inquiry and product design, and is the focus of research in the new scientific field of Computational Science and Engineering. The new grand challenge here is the rapid prototyping of manufactured artifacts and the rapid solution to...

We are concerned with a problem of scheduling a flexible manufacturing cell with random time operations. A job-shop production section comprises a set of n jobs (orders) and a set of m machines (processors). Each order consists of a chain of operations, each of which needs to be executed during...