Condition monitoring can diagnose the inception of fault mechanisms in induction motors, thus avoiding failure and expensive repairs. Therefore, there is a strong need to develop an efficient condition monitoring approach. The main aim is to achieve a relatively low cost and non-invasive system which is still powerful in terms of monitoring for online detection of developing faults. The paper addresses rotor eccentricity faults and studies conventional monitoring techniques for induction motors. The eccentricity-generated additional air-gap flux waves should be reduced in order to reduce the unbalanced magnetic pull when there is an eccentric rotor. The radial forces in an induction motor are calculated, and the characteristics of unbalanced magnetic pull are described.

This paper addresses the need to detect the rotor radial position in an electrical machine. When it is not centered, it is referred to as rotor eccentricity. Cage induction machines can use the detection of sideband currents, and this is studied extensively elsewhere. Wound rotor induction machines do not generate the same sidebands, so an alternative detection method is needed. These machines are now popular generators in wind turbines. A simple method using pole-specific search coils is introduced, and a theory is developed to illustrate that rotor eccentricity leads to the generation of air-gap flux waves with pole-pairs that are p _m ± 1. This is tested using search coils in a 4-pole wound rotor machine. The method is found to successfully indicate the presence of rotor eccentricity.

This paper puts forward a concept for measuring rotor eccentricity in a wound rotor induction machine. The analysis is fully developed in the theory section, then an experimental rig is described and measurements are taken. These are compared with the calculated values. Pole-specific search windings are necessary in a wound rotor machine, because standard sideband current measurement techniques are only valid for cage induction machines. The search coils can also be used to suppress unbalanced magnetic pull.

Due to the chronic shortage of energy-related analytical data and disintegration of building energy regulations, numerous existing residential buildings in Petra (Jordan) and many cities worldwide suffer from poor building energy design. This paper aims at investigating the potential of applying energy-saving standards in order to improve the whole-building energy consumption of low-rise residential buildings in mild and dry climate zones. Representative buildings were selected based on a field survey. Proposed strategies focused on applicable solutions such as envelope components, and energy-related systems were set. The models were created using Autodesk Revit, and then the results were generated by the EnergyPlus engine. The findings showed that the application of building energy standards greatly impacts the overall energy end-use, where up to 30% reduction can be achieved by applying the Jordanian code, and up to 45% by applying the American standard. This work provides guidance for the residential building industry and policymakers in Jordan and many other countries with similar building characteristics and climate zones.

Condition monitoring can diagnose the inception of fault mechanisms in induction motors, thus avoiding failure and expensive repairs. Therefore, there is a strong need to develop an efficient condition monitoring. The main target is to achieve a relatively low cost and/or non-invasive system which is still powerful in terms of monitoring for online detection of developing faults. The presented paper addresses rotor eccentricity faults and studies conventional monitoring techniques for induction motors. In order to reduce the unbalanced magnetic pull (UMP) in case of an eccentric rotor, the eccentricity-generated additional airgap flux waves should be reduced. The radial forces in an induction motor are calculated, and the characteristics of unbalanced magnetic pull are described.