Harmonic severity analysis at the hospital

Abstract

Harmonic is one of the power quality issues that affecting the critical electrical power system especially at the hospital. Due to high consumption of electricity usage and a lot of equipment breakdown every month, the harmonic is suspected to be one of the main causes. The purposes of this project are to determine the cause of the harmonic, to identify the harmonic severity and to propose the harmonic mitigation technique at the hospital. The measurement of Total Harmonic Distortion (THD) had been done to measure and analyse the harmonic severity at main intake of electrical supply and several critical departments in the hospital by using Fluke 435 Power Quality and Energy Analyser. This study had shown that major causes of harmonic at the hospital were from the computers, fluorescent lamps, split unit air-conditioning, and portable medical devices. The current THD at the low voltage (LV) side of the main intake had shown the reading of 49.64% which had exceeded 5% of harmonic current limit based on the IEEE Std 519-1992 at PCC. Hence, this implied that the harmonic problem at the hospital is severe. Therefore, harmonic mitigation technique was introduced in order to improve the electrical system at the hospital. This technique including proposing harmonic filters and requirement of low THD (< 10 %) in the new equipment procurement. The result of this study suggests awareness for the maintenance staff, doctors and others to cater the harmonic issues at the hospital