New overall efficiency formula for analyzing power systems containing multiple harmonic sources

This research paper looks at developing a new formula and method for investigating and analyzing overall efficiency of a power system containing multiple harmonic sources. Traditionally, the power generated and consumed due to harmonics is ignored in overall efficiency studies. However, in the modern world, power systems contain levels of harmonics which can no longer be ignored. In this paper, five case studies that increase the number of harmonic sources (Adjustable Speed Drives) from one to five are conducted. A computer based simulation methodology is developed for overall efficiency analysis using the DIgSILENT software package. The grid was assumed as sinusoidal source as DIgSILENT software package cannot perform the efficiency investigation using a non-sinusoidal source. Investigations were conducted at full and half-loads. An example on the application of the new formula and the results of the case studies analyzed are also included in this paper. The developed formula and methodology was found to be effective and its use is recommended.