Power quality (PQ) is becoming increasingly important owing to the increasing use of power electronic devices, coupled with the increasing penetration of loads, which are sensitive to voltage disturbances. As a result of the problems caused by the confluence of these two trends, there is an increasing need for PQ to be monitored in order to diagnose its nature and locate the source of the disturbance, allowing remedial measures to be taken. While automated systems for diagnosis of PQ events have been developed, identifying the location of the source of a disturbance is a problem, which has not been fully addressed to date; in particular the question of locating a non-stationary disturbance. In this study, a novel approach to identify the location of the source of a PQ disturbance is described, using a form of artificial neural network known as a self-organising map. The proposed technique is verified via simulation of the IEEE 14-bus model in PSCAD and an experimental system based on the IEEE 6-bus model. This approach provides a mean of locating the source of PQ events, including transient disturbances.

Actuators for more electric aircraft are predominantly based on permanent magnet machines for the best power to weight ratio. However, permanent magnet machines can give rise to drag torque under short circuit conditions. This paper explains the concept of permanent magnet assistance in switched reluctance machines and sets out a topology which maximizes the benefits of permanent magnet assistance without compromising fault tolerance. The problem of demagnetization in this topology is explored and a revised design proposed. The increased torque from permanent magnet assistance is demonstrated, and laboratory tests on a prototype machine evidence the fault tolerant nature of the proposed machine by comparison with a baseline permanent magnet machine design. It is suggested that the permanent magnet assisted segmental rotor switched reluctance machine could achieve similar torque to a permanent magnet machine in this application with much improved fault tolerance and with much reduced magnet mass.

The use of information intermediaries has been shown to undermine the effect of brand in online markets. In this paper, the effect of consumer search on the relationship between brand advertising and pricing strategies is analysed. Price data are taken from the leading UK motor insurance comparison website, with the advantage that prices can be related to the search characteristics of consumers and to the advertising expenditure of firms. The paper finds that more-advertised firms have lower price rankings at the comparison site, indicating that advertising is informative in this market. The main result is that consumer search weakens the relationship between advertising and pricing. An implication is that increased usage of price comparison sites will make informative brand advertising less important.