A contribution to the rationalization of grounding impedance measurement in medium voltage substations

Abstract

In this paper, a method for grounding impedance measurement is proposed. The method is experimentally validated in five substations rated voltage 35/10 kV. Compared to a standard measuring method, the basic benefits of the proposed method are: (a) the current probe is realised in the form of a ground drill (a drill-type electrode designed to be driven into the earth) instead of being used the grounding grid of a next substation, (b) proposed method does not use an overhead line (or a cable line) for purposes to connect remote current probe, (c) the proposed method requires a test signal source whose output power may be in the order 100 W (instead of 1 kW in standard method), and (d) measuring accuracy of the proposed method is the same as in the case when standard method is used.

Keywords

• grounding
• grounding impedance
• ground drill
• FOP
• TCRM
• FSM