Technical And Economic Evaluation Of Voltage Sag

With the fast development of electric and electronic technique, problems of transient power quality, especially voltage sags, are brought to public attention. Voltage sags are systematically analyzed from the views of technique and economy. As viewed from technique, methods of sag exposed areas and sag monitor are introduced. The theoretical basis and control strategy of dynamic voltage restorer is thoroughly studied. Emulation tests by PSCAD are carried out. As viewed from economy, the probabilistic method is put forward to analyze the cost of voltage sag. The effects of remaining voltage and sag duration are mainly taken into account. The costs using different compensation methods are compared. And the optimization compensation method is obtained considering economic factors. Finally, reasonable suggestions of industry standard about voltage sag are proposed.