Ultra Fast Solid State Ground Fault Isolator

Authors: I Made Darmayuda, Zhou Jun, Krishna Mainali, Simon Ng Sheung Yan, Saisundar S, Eran Ofek

Abstract:

Personnel protection devices are cardinal in safety hazard applications. They are widely used in home, office and in industry environments to reduce the risk of lethal shock to human being and equipment safety. This paper briefly reviews various personnel protection devices also describes the basic working principle of conventional ground fault circuit interrupter (GFCI) or ground fault isolator (GFI), its disadvantages and ways to overcome the disadvantages with solid-state relay (SSR) based GFI with ultrafast response up on fault implemented in printed circuit board. This solid state GFI comprises discrete MOSFET based alternating current (AC) switches, linear optical amplifier, photovoltaic isolator and sense resistor. In conventional GFI, current transformer is employed as a sensing element to detect the difference in current flow between live and neutral conductor. If there is no fault in equipment powered through GFI, due to insulation failure of internal wires and windings of motors, both live and neutral currents will be equal in magnitude and opposite in phase.

Keywords: current transformer, electrocution, GFCI, GFI

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1081463

References:

[1] Robert L. LaRocca, "Personnel Protection Devices for Use on Appliances,” IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 28, NO. 1, JANUARY/FEBRUARY 1992
[2] Guenter B. Finke, Bao-Min Ma, A NEW TYPE OF DIFFERENTIAL TRANSFORMER CORE FOR GROUND FAULT CIRCUIT INTERRUPTERS, IEEE TRANSACTIONS ON MAGNETICS, VOL. MAG-17, NO. 6, NOVEMBER 1981
[3] Jaebok Lee, Sughun Chang, Sungho Myung, Yuengue Cho I. S. Jacobs and C. P. Bean, "Transient False Tripping Characteristic Analysis of Ground Fault Circuit Interrupter," International Conference on Power System Technology, November 2004.
[4] Nosh K. Medora, S.M. P.E, Alexander Kusko, Sc.D., P.E. "Fault Sensing with an Artificial Reference Potential Provided by an Isolated Capacitance Effect, IEEE Symposiim on product safety engineering society, October- 2006.
[5] Arnold W. Smoot, , IEEE Senior Member, "GFCI-Applications and Alternatives”, IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. IA-1 l, NO. 1, January/Februaryj 1975.
[6] Jonathan Kimball, Senior Member, IEEE, Compatibility Between GFCI Breakers and Household Adjustable Speed Drives.