Investigating the harmonic characteristics of household appliances and the harmonic compensation scheme of the residential distribution system using power electronic interface DGs

This article focuses on the electrical characteristics of household appliances and their effects on the power grid. With the change of the load landscape and the introduction of equipment based on power electronics and low consumption loads, it is increasingly important to have complete knowledge of power quality and their harmonic characteristics in addition to conventional load models. This is critical for accurate load representation, especially for bottom-up full load models, in assessing voltage stability, determining possible interactions at harmonic frequencies, the effect of system impedance, as well as possible voltage sags and swells and unbalance conditions. For this study, household appliances are classified into five categories: lighting, power electronics, resistive, motor, and cumulative loads. The effect of voltage change on load current characteristics is also studied. The results of laboratory tests including most of the common household appliances are analyzed in the range of +۱۰%/-۵% of the rated supply voltage and in the range of +/-۳ Hz of the rated source frequency, followed by a selected harmonic compensation plan based on modal analysis. It is developed to assign compensation priorities on DGs working in different distribution system nodes to improve the compensation performance. A modeled residential distribution system including distribution components such as distribution line, PFC capacitors, transformers and appliances along with DG units is used to verify the improvement of compensation performance