Integrated series active filter for aerospace flight control surface actuation

The paper investigates integrated series active filters to satisfy aircraft power quality benchmarks and underlying design compromises. Advantages include reduced component count and retrofitting capability. Further insights into the merits of the proposed solution are included, along with representative results from a prototype system

Identifying the information for the visual perception of relative phase

The production and perception of coordinated rhythmic movement are very specifically structured. For production and perception, 0° mean relative phase is stable, 180° is less stable, and no other state is stable without training. It has been hypothesized that perceptual stability characteristics underpin the movement stability characteristics, which has led to the development of a phase-driven oscillator model (e.g., Bingham, 2004a, 2004b). In the present study, a novel perturbation method was used to explore the identity of the perceptual information being used in rhythmic movement tasks. In the three conditions, relative position, relative speed, and frequency (variables motivated by the model) were selectively perturbed. Ten participants performed a judgment task to identify 0° or 180° under these perturbation conditions, and 8 participants who had been trained to visually discriminate 90° performed the task with perturbed 90° displays. Discrimination of 0° and 180° was unperturbed in 7 out of the 10 participants, but discrimination of 90° was completely disrupted by the position perturbation and was made noisy by the frequency perturbation. We concluded that (1) the information used by most observers to perceive relative phase at 0° and 180° was relative direction and (2) becoming an expert perceiver of 90° entails learning a new variable composed of position and speed

Rapid design of LCC current-output resonant converters with reduced electrical stresses

The paper presents and validates a straightforward design methodology for realising LCC current-output resonant converters, with the aim of reducing tank currents, and hence, electrical stresses on resonant components. The scheme is ideally suited for inclusion in a rapid iterative design environment e.g. part of a graphical user interfac

A study of superstitious beliefs among bingo players

This study was conducted in order to examine the beliefs players have regarding superstition and luck and how these beliefs are related to their gambling behaviour. A self-completion questionnaire was devised and the study was carried out in a large bingo hall in Nottingham, over four nights. 412 “volunteer” bingo players completed the questionnaires. Significant relationships were found in many areas. Many players reported beliefs in luck and superstition; however, a greater percentage of players reported having “everyday” superstitious beliefs, rather than those concerned with bingo

Integrated multilevel converter and battery management

A cascaded H-bridge multilevel converter is proposed as a BLDC drive incorporating real-time battery management. Intelligent H-bridges are used to monitor battery cells whilst simultaneously increasing their performance by reducing the variation between cells and controlling their discharge profiles

Improved rotor position estimation by signal injection in brushless AC motors, accounting for cross-coupling magnetic saturation

The paper presents an improved signal injection- based sensorless control method for permanent magnet brushless AC (BLAC) motors, accounting for the influence of cross-coupling magnetic saturation between the d- and q-axes. The d- and q-axis incremental self-inductances, the incremental mutual-inductance between the (d-axis and q-axis, and the cross-coupling factor are determined by finite element analysis. A method is also proposed for measuring the cross-coupling factor which can be used directly in the sensorless control scheme. Both measurements and predictions show that a significant improvement in the accuracy of the rotor position estimation can be achieved under both dynamic and steady-state operation, compared with that which is obtained with the conventional signal injection method

Novel battery model of an all-electric personal rapid transit vehicle to determine state-of-health through subspace parameter estimation and a Kalman Estimator

Abstract--The paper describes a real-time adaptive battery model for use in an all-electric Personal Rapid Transit vehicle. Whilst traditionally, circuit-based models for lead-acid batteries centre on the well-known Randles’ model, here the Randles’ model is mapped to an equivalent circuit, demonstrating improved modelling capabilities and more accurate estimates of circuit parameters when used in Subspace parameter estimation techniques. Combined with Kalman Estimator algorithms, these techniques are demonstrated to correctly identify and converge on voltages associated with the battery State-of-Charge, overcoming problems such as SoC drift (incurred by coulomb-counting methods due to over-charging or ambient temperature fluctuations). Online monitoring of the degradation of these estimated parameters allows battery ageing (State-of-Health) to be assessed and, in safety-critical systems, cell failure may be predicted in time to avoid inconvenience to passenger networks. Due to the adaptive nature of the proposed methodology, this system can be implemented over a wide range of operating environments, applications and battery topologies

Improved rotor position estimation in extended back-EMF based sensorless PM brushless AC drives with magnetic saliency

An improved extended back-EMF based sensorless control method is proposed for a brushless AC motor equipped with an interior permanent magnet rotor. It accounts for dq-axis cross-coupling magnetic saturation by introducing an apparent mutual winding inductance. The error which results in the estimated rotor position when the influence of cross-coupling magnetic saturation is neglected is analyzed analytically, predicted by finite element analysis, and confirmed experimentally, for various d- and q-axis currents. It is shown that a significant improvement in the accuracy of the rotor position estimation can be achieved by the proposed method, as confirmed by measurements

Modeling of cross-coupling magnetic saturation in signal-injection-based sensorless control of permanent-magnet brushless AC motors

An improved brushless AC motor model is proposed for use in signal-injection-based sensorless control schemes by accounting for cross-coupling magnetic saturation between the - and -axes. The incremental self- and mutual-inductance characteristics are obtained by both finite-element analysis and measurements, and have been successfully used to significantly reduce the error in the rotor position estimation of sensorless control