Power quality indices are being developed that attempt to quantify certain aspects of service quality. There has been considerable amount of work on the characterization of individual types of power quality disturbances and corresponding indices. However, there does not exist in the literature a standard approach that allows one to quantify the overall power quality. This paper proposes a unified power quality index (UPQI) as a useful tool for ranking sites as to their overall power quality. Absfrod-Power quality indices are being developed that attempt to quantify certain aspects of senire qualih. There has been considerable amount of work on the characterization of individual types of power qualie disturbances and correspanding indices. However, there does not exist in the literature a standard approach that allows one to quantify the overall power quality. This paper propares B Unified Power Quality Index (WQI) as a useful tool for ranking sites as to their overall power quality. Disciplines Physical Sciences and Mathematics

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The rotor saliency of the axially laminated synchronous reluctance motor (SynRM) produces a square airgap flux density distribution. If a square current distribution interacts with this flux the SynRM generates its optimal torque. This paper extends previous work on the magnetic modelling of the SynRM. A design model is proposed which incorporates all rotor and stator dimensions. Saturation effects have also been included in the model. The key dimensions affecting SynRM performance are identified as rotor radius, rotor pole pitch, rotor steel : steel + fibre ratio, airgap, stator current density and stator slot opening. An iterative algorithm is determined for the design optimisation process. This algorithm is simple enough to be implemented in a spreadsheet environment. The model is used to design a 5kW motor with an optimal torque / unit mass ratio. The designed motor has a nine phase concentrated winding to approximate the ideal square current excitation. Finite element analysis and a static load test on the constructed machine confirm the model's predictions, In addition, optimal values for the key motor dimensions, over a range of motor sizes, are determined and discussed. NOM EN C LATU R E Average surface area of rotor laminations (m2) Average surface area of stator slot pitch (m2) Airgap flux density (T) Effective airgap (m) Rotor magnetic field intensity (Alm) Stator magnetic field intensity (Alm) Stator current density distribution (Nm) Motor stack length (m) Mean direct axis length (m) 279 Stator slot pitch (rn) Airgap radius (m) Quadrature axis reluctance per metre (ANVblm) Rotor steel : steel + fibre ratio Yoke depth (m) Angular displacernent from direct axis of rotor (rad) Rotor pole pitch (cad) Permeability of free space, 471 x IO-' (H/m) Quadrature axis flux (Wb)

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This paper reports on a simple method to identify problem areas with relation to harmonic distortion within radial distribution systems at the planning stage. The purpose of the work is to produce a simple method of establishing harmonic distortion levels throughout a study distribution system when only limited system data and load information is available. The preliminary work presented in this paper is aimed at establishing useful planning guidelines for utilities to help with the analysis of harmonics in medium voltage (MV) distribution systems during the design phase. Harmonic analysis during the design of a distribution system is seen as an important step in controlling harmonic distortion levels. Abstract: This paper reports on a simple method to identify problem areas with relation to harmonic distortion within radial distribution systems at the planning stage. The purpose of the work is to produce a simple method of establishing harmonic distortion levels throughout a study distribution system when only limited system data and load information is available. The preliminary work presented in this paper is aimed at establishing useful planning guidelines for utilities to help with the analysis of harmonics in Medium Voltage (MV) distribution systems during the design phase. Harmonic analysis during the design of a distribution system is seen as an important step in controlling harmonic distortion levels. Disciplines Physical Sciences and Mathematics