Abstract
The AC-DC transfer measurement system constitutes a primary establishment for AC voltage, power and energy measurements. This is achieved by comparing the RMS of an AC signal with a DC reference using a thermal converter. The mathematical modelling was developed for a better description of the thermal RMS-DC converter’s operation and performance. The theoretical and simulation analysis was carried out to outline the factors influencing the transfer characteristics of the converter in AC and DC regimes. Since any system of electric and/or electronic instruments can experience undesired electrical signals ground currents resulting in annoying and often subtle measurement errors, remedial measures of controlling electromagnetic interference (EMI) are desired and essential. The generation and emission of unwanted electrical noise often result in performance degradation and failures of electronic systems. It is then necessary to find a mitigation technique to overcome this problem and avoid costly systems failures in industry.
A literature review of the EMI modelling research was carried out as the main foundation for understanding noise management in AC measurement systems. EMI generation and propagation paths have been outlined. The AC-DC transfer measurement system was analysed for possible EMI sources. Based on the analysis, a microcontroller-driven GPIB isolator device was designed and prototyped to prevent the ground loops occurrence between the measurement circuit and the control-plane circuit of the AC-DC transfer measurement system. Various methods of reducing and controlling unwanted signals in the measurement circuit have been explained.
M.Phil. (Electrical and Electronic Engineering)