Source voltage, frequency and impedance variation effects on the harmonics generated from a Personal Computer

The penetration of harmonics in residential power system networks due to the widespread use of nonlinear loads such as Personal Computers (PCs) can cause severe problems including voltage and current distortion. Almost all residential customers are subjected to variations in the system voltage and frequency. Also, the source impedance is different for different customers depending on their distance from the utility transformers and distribution cabinets and the system loading. Hence, the purpose of this paper is to investigate the effects of the voltage amplitude, source impedance and system frequency on the harmonics produced by a single PC for variations within practical limits. Experimental measurements and computer simulations are performed to confirm the observations.