San Diego Gas & Electric Company

San Diego Gas & Electric

Girolamo Rosselli

Phil A Patton

William J Cook

Ground Potential Rise (GPR) systems and methods with depth sensing measure the GPR between the ground grid and the remote earth. Methods and systems described herein may provide a GPR measurement to an existing distance protection. A GPR system may comprise a set of potential transformers. The set of potential transformers may be coupled to different ground rods driven into the earth at different depths, respectively. One wire of the high voltage side of the potential transformer may be coupled to the ground grid of a substation, and the second wire of the potential transformer may be coupled to an insulated wire that is coupled to a ground rod or multiple of ground rods bonded together. The low voltage side of the potential transformer is used to connect Distance Relays, Voltage Relays, DFR or Alarms.

Ground potential rise with depth sensing

Ground Potential Rise (GPR) sensors measure the GPR between the ground grid and the remote earth. A GPR sensor may provide a GPR measurement to an existing distance protection, which may operate based on this measurement automatically. A GPR sensor may comprise a potential transformer configured such that one wire of the high voltage side of the potential transformer is coupled to the ground grid of a substation. The second wire of the potential transformer is coupled to an insulated wire which is coupled to a ground rod or multiple of ground rods bonded together, that is driven into the earth. The low voltage side of the potential transformer is used to connect Distance Relays, Voltage Relays, DFR or Alarms.

Ground potential rise sensors

Systems and methods for adaptive distance protection are provided. An adaptive ground distance protection system may be installed in a power system to provide an accurate measurement of the apparent impedance of the transmission lines thereby ensuring reliable and stable operations of the power system. The potential of a system ground in reference to the remote earth is measured and used in calculating the apparent impedance of a transmission line. An accurate assessment of the apparent impedance of a transmission line is therefore provided and reduces the risk of misoperation of relays. Existing protection systems of a power system may be augmented, for example, via a retrofitting process, to enhance reliability of the power system, reduce costs, reduce customer service interruption, and expand opportunities for deployment.

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Lakeside, CA, United States of America

Girolamo Rosselli