A Case Study of Harmonics in Electrical Installations of Buildings

건축물 전기설비의 고조파에 관한 사례연구

This paper presents the result of survey of case study for Harmonics in electrical Installations of buildings. Recently, many power electronic equipments(power converter, computers, air conditioners electronic ballasts for fluorescent lamps and so on) are used in office buildings, and harmonic current from them influence the other equipments in a distribution line. Notably, voltage distortion or voltage harmonics may approach or exceed is allowable level in power distribution system. Individual electric power consumers and end-users and responsible for reducing current harmonics while companies or utilities are responsible for reducing voltage harmonics at the point of common coupling in distribution system. As for harmonics, which one of the electric power qualities, it becomes important to obtain harmonic voltage/current distribution of the power system precisely because the use of power electronic apparatus in increasing. However, there are some difficulties on evaluating the measured data in comparison with the simulated result. The primary cause was indentitied with the resonance of harmonics form many sources. To suppress harmonics in electrical installations of buildings, one of many methods suggest that resonance frequencies are controlled by modulating the capacities of high-voltage customer's capacitors.