A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 1997

Computer load has highly distorted current waveform that contains rich harmonics and it will become more in the world since it has some technology advance. The proliferation of the computer load may cause harmonic problem in power distribution system. This study is aimed to predict the harmonic distortion level caused by increasing computer load. Field measurement were conducted on one customer - official building which have considerable computer loads and one distribution feeder which mainly supply to these kind of customer and residential customer. The result of measurement is used to evaluate the present status of harmonic distortion and also to verify the harmonic model. Both official building and distribution feeder was analyzed by means of HI-WAVE computer simulations. Harmonic levels determined from field measurement on the customer and distribution feeder are compared with the results of HI-WA VE simulations to determine if this analysis tool can be expected to provide useful results. Based on the base case simulation, the harmonic distortion level due to increasing computer load was predicted. The results showed that computer load in 12% of total load can raise the current injection level to the national standard for official building, 5.7% of total load for distribution feeder can raise the voltage distortion at point of common coupling to the national standard (VTHD=4%).