Effects Voltage Sag on Single-Phase Domestic and Office Loads

This paper presents the effects of voltage sags on domestic and office equipment and provides equipment sensitive curves for safe and reliable operation based on the experimental results.

With the increased usage of sensitive electronic equipments in various industries, offices and household appliances, it is important to protect them from any power quality disturbances to avoid unnecessary losses of any kind. From the several types of power quality disturbances, the most frequent and concerning for electric utilities from a customer point of view was voltage sag.

Though a lot of research has been done on voltage sag characteristics and its effects on industrial equipment, there is not much literature available on the effect of voltage sags on single-phase loads, especially office and home equipment. This project investigates the behavior of domestic and office appliances for different magnitude, duration and angle of incidence of voltage sag.

Studies were conducted to obtain the sag tolerance curves which might or might not comply with the voltage sag immunity standards. An industrial power corruptor was used to generate voltage sag on one phase to observe the effects on the test equipment. Experiments were conducted on common office and household appliances using Industrial Power Corruptor (IPC) to monitor the equipment function and performance before, during and after the sag. The current and voltage waveforms obtained from the IPC software were analyded and reported. The results seem to be useful and informative for OEMs, Utilities and Emergency Power Supply Manufacturers.