POWER QUALITY IMPROVEMENT BY VOLTAGE SAGS. CASE STUDY

Voltage sag is defined as a sudden reduction of supply voltage down 90% to 10% of nominal voltage, followed by a recovery after a short process time. A typical duration of sags, according to some standards, is 10 (msec) to 1 (min).Although more process equipments accept these voltage disturbances without notable consequences, there are sensible electronic schemes affected by voltage sags. The actual paper analyses the power quality delivered to an important manufacturer which uses some “critical equipment― and emphasizes the connections between voltage disturbances and difficult events registered by manufacturers. Because the “mitigation means― are expensive, the authors try to choose the optimal solution (price/quality).