Variable voltage and frequency supply to ac drives is invariably obtained from a three-phase voltage source inverter (VSI). A number of Pulse width modulation (PWM) scheme is used to obtain variable voltage and frequency supply. The most widely used PWM schemes for three-phase VSI are carrier-based sinusoidal PWM and space vector PWM (SVPWM). There is an increasing trend of using space vector PWM (SVPWM) because of their easier digital realisation and better dc bus utilisation. This paper focuses on step by step development of MATLAB/SIMULINK model of SVPWM. Firstly model of a three-phase VSI is discussed based on space vector representation. Next simulation model of SVPWM is obtained using NIATLAB/SIMULINK. Simulation results are also provided.

Droplet-based microfluidics has emerged as an important subfield within the microfluidic and general analytical communities. Indeed, several unique applications such as digital assay readout and single-cell sequencing now have commercial systems based on droplet microfluidics. Yet there remains room for this research area to grow. To date, most analytical readouts are optical in nature, relatively few studies have integrated sample preparation, and passive means for droplet formation and manipulation have dominated the field. Analytical scientists continue to expand capabilities by developing droplet-compatible method adaptations, for example, by interfacing to mass spectrometers or automating droplet sampling for temporally resolved analysis. In this review, we highlight recently developed fluidic control techniques and unique integrations of analytical methodology with droplet microfluidics—focusing on automation and the connections to analog/digital domains—and we conclude by offering a perspective on current challenges and future applications. Expected final online publication date for the Annual Review of Analytical Chemistry, Volume 14 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

PQ issues are very much important for utilities, customers and end users and it is essential to be known by the concerned authorities and 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.

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