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PQ issues are very much important for utilities, customers and end users and it is essential to be known by the concerned authorities or users for reduction of economic losses due to the poor PQ. The cost of poor PQ is high and rising. The paper gives insights on global economical losses due to poor PQ. The business risk posed by PQ problems is a real one with even ‘low tech’ industries exposed to serious financial losses. The global economic meltdown is not the only factor that is pulling down the revenues of Asian countries. A study released said Indian industries lost more than $ 9.6 billion in 2008–09 due to power outages. According to 2008 reports, poor power quality costs European business more than 150 billion dollars a year. In this paper, a comprehensive survey on different power quality related problems as experienced by customers in different countries are highlighted. Summary of PQ costs are given. As the consequence of poor PQ might have large financial impacts on a country's economy, more initiatives are expected from the concerned parties and regulating bodies to take corrective measures for maintaining better power quality from utility and at end users. Smart grid requires intelligent PQ monitoring to solve different PQ related problems. Authors proposed an intelligent power quality monitoring system that will help to detect different PQ disturbances and consequently assist in employing or implementing appropriate mitigation techniques. [ABSTRACT FROM PUBLISHER]

Modern world is under tremendous pressure for alternative sources of energy and the trends are towards sustainable energy. Present power systems are facing heavy economic losses for poor power qualities. Efficiency of sustainable energy depends on the power quality of the supply. Presently, Power Quality issues are major problems for utilities, customers and end users. The cost of poor PQ is high and gradually rising. The paper gives insights on global economical losses due to poor PQ. The business risk posed by PQ problems is a real one with even low tech industries exposed to serious financial losses. It has been observed that the consequences of poor PQ would have large financial impacts on a country's economy, and more initiatives are required from the concerned parties and regulating bodies to take corrective measures for maintaining better power quality. Especially for successful sustainable energy programme, Power Quality Monitoring can help identify the cause of power system disturbances and the problem conditions on a system before they cause interruptions or disturbances. In an environment of sustainable energy and modern grid, intelligent PQ monitoring is essentially required to solve different PQ related problems. Authors proposed an intelligent power quality monitoring system using virtual instrumentation and appropriate data acquisition system to detect different PQ disturbances. The system is user friendly due to its graphical user interface. The tests were done in the Energy Laboratory of NIT, Silchar (India) and Research Lab, Electrical Engineering Department, AMU, Aligarh (India). The available energy in both the labs was solar energy. The qualities monitored include voltage fluctuations, sag, swell, interruptions, harmonics etc. The huge amount of acquired data has been analyzed using quadratic discriminant analysis technique to determine the condition of the waveforms. The system shows fast response with accuracy in monitoring desired power qualities. [ABSTRACT FROM PUBLISHER]

A synchro and a fast rotating magnetic field (RMF) based technique is developed in this paper for the measurement of machine vibrations. The RMF is used to measure the velocity of these vibrations with high resolution. A new strategy is applied by transmitting the machine vibrations to the rotor of a synchro and measuring them in terms of pulses of different pulse widths. A broad spectrum of pulses is obtained corresponding to instantaneous velocities of vibrations. The effectiveness of the developed vibration measurement technique is verified by experimental tests on a dc motor. Test results show that the developed method measures all possible instantaneous velocities and peaks of machine vibrations accurately within millisecond range which are missed by conventional methods. Hence the technique is very useful for an early fault diagnosis and overall condition monitoring of the machines. [ABSTRACT FROM PUBLISHER]