The use of series injection to eliminate voltage distortion in low and medium voltage networks

Voltage distortion is seen as an interference on the nominal frequency, amplitude or shape of a voltage waveform. The most frequent voltage distortion is in the amplitude and shape of the voltage waveform. In this paper, the voltage distortion in a rural distribution network is investigated and some of the problems experienced in this area are discussed. An increasingly popular form of rural electrification is that of single wire earth return (SWER) lines. This is a low cost method of electrifying small and remote communities fairly economically. This form of distribution is however prone to voltage distortion due to its high regulation. The question is posed as to how the voltage quality supplied to these users can be economically controlled. Not only can this be a solution to the voltage quality problem, but it can possibly increase the load capacity per line in cases where the capacity is limited by voltage regulation. A closer look is taken at the use of series injection to supply the additional voltage required to compensate for voltage regulation. An experimental setup is made to evaluate the argument in a practical manner. The experiment also served to provide confirmation of the required capacity of the series voltage source used for the series injection