Novel Method for Tower Grounding Resistance Measurement

摘要

The main problems of tower grounding resistance measurement are the unknown position of the tower grounding body caused by long-time buried span that affects measurement accuracy because of the imprecise electrode arrangement, the low efficiency achieved when measuring without a connected grounding lead, and the large error obtained when a tower grounding lead is connected. Hence, a novel method to measure tower grounding resistance is presented in this paper. In the proposed method, current of different frequency ranges is injected through the grounding lead on the premise of connecting a tower grounding lead. On the one hand, this method detects the buried position by analyzing the surface magnetic field intensity caused by exciting current. On the other hand, the method measures the tower grounding resistance value of different frequency ranges to obtain an accurate value through data processing. A measurement model with a connected grounding lead was constructed. The surface magnetic field distribution of the grounding body was analyzed. The accurate measurement condition was evaluated to determine the frequency range of exciting current and the data processing method. Finally, a simulation was performed to verify the method. Results showed that the method can identify the position of the tower grounding body and can measure the resistance accurately with a connected grounding lead.