Impact of Voltage Variation on Domestic and Commercial Loads

This Thesis studies the impact of variations in supply voltage on various loads representing different types of loads. The scope of Thesis is analysis of active and reactive power used by appliances at different supply voltages varying from 90% up to 110% of rated value, as well as other factors that these variations influence. Previous studies showed that power consumption of certain device varies with changing of supply voltage, but most of them were dealing with 120V networks, and the other ones are outdated. This study provides ZIP models (polynomial of 2nd power with coefficients Z, I and P standing for constant impedance, current and power correspondingly) for typical house appliances, also results of induction motor heating test and analysis of typical household appliances mix. Results show, which of appliances can withstand voltage variations better, as well as give an idea what is power-voltage curve of the household and what is the percentage of economical losses. Also studies show that almost every device is able to maintain its operation during critical voltage deviations of 10% Using that data, it is possible to optimize energy usage and decrease losses. The results encourage continuing further investigation of devices with higher power and show the necessity of dynamic seasonal household model