One of the major problems in direct power-controlled grid-connected voltage source converters is that during dips, converter current increases to compensate for reduced grid voltage. The most common dips are unsymmetrical, and they cause unbalance distortion current. This paper introduces a new, simple but effective algorithm which limits dips. A positive-sequence virtual-flux based control sch...

the subject under investigation has been electronic learning (e-learning) or electronic education (e-education), specifically concentrating on virtual university. virtual university has been the subject of much debate in recent years. in short, the concept of virtual university denotes a learning/educational system/environment based on internet where higher education is promoted using tools and...

background : along with emersion of the internet, virtual education increasingly has been growing. many studies discussed this method and its impact on learning. present study investigated students’ attitude towards virtual education as well as its effect on learning. methods : this was a pretest-posttest quasi-experimental study. the nursing students, who had selected fluids and electrolyte di...