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Development of a cost-effective op-amp based digital power factor meter

Kok , Boon Ching and Tan, C. S. and Sulaiman, E. (2007) Development of a cost-effective op-amp based digital power factor meter. In: 1st Engineering Conference (EnCon 2007), 28 December 2007, Universiti Malaysia Sarawak, Sarawak.


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Conventional power factor meter uses analogue system to read the power factor of an AC electric power system which is defined as the ratio of the real power to the apparent power. In the modern life, an easy-captured data yet cost effective power factor measurement device is vital in the electrical power engineering studies. The unstable reading of the analogue based power factor meter especially in the disturbance situations emerged the development of digital based power factor meter (PFM) to replace the conventional electro-dynamic types. The major advantage of using the digital based PFM is the data read by the meter can be stored easily for other applications or studies. This paper presents the development of a cost effective digital PFM which is based on an analogue-to-digital converter (ADC) provided with ratiometric facilities. Generally, the digital power factor meter consists of four main parts which are power supply, inputs circuit, signal processing, and the display part. A signal proportional to the peak voltage (Vm) is applied to the reference input voltage of the ADC, while another signal proportional to the product of the peak voltage (Vm) and power factor is applied to the analogue input. Both signals are processed through various operational amplifier based circuits such as averager, zero detector, and differentiator. The developed digital PFM has been tested and performed for single phase laboratory measurements with three decimal digits display on a liquid crystal display (LCD) unit. The results achieved validate the functionality of the developed digital PFM.

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: power factor; phase detection; op-amp; ADC
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK3001-3521 Distribution or transmission of electric power
Divisions: Faculty of Electrical and Electronic Engineering > Department of Electrical Power Engineering
Depositing User: Normajihan Abd. Rahman
Date Deposited: 03 Sep 2013 00:54
Last Modified: 21 Jan 2015 07:39
URI: http://eprints.uthm.edu.my/id/eprint/4156
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