A Continuous Monitoring for Neutral Grounding Resistors and Reactors With Hardware Validation

Neutral grounding devices (NGDs) are used to limit ground overcurrents, control transient overvoltages, and overcome the consequent issues. Intactness of these apparatuses is vital to prevent the risk of ungrounded or solidly grounded neutral. As such, they should be continuously monitored as targeted here. This paper proposes a continuous monitoring technique that supervises the NGD impedance obtained via full-range voltage and current measurement. It benefits from a new and cost-effective voltage metering mechanism specifically designed for the studied problem. Its performance has been validated using a fabricated prototype. In contrast to existing methods, the application of the proposed technique is not limited to a specific configuration, system operation mode, or NGD. Furthermore, monitoring is performed without signal injection. This monitoring technique shows reliable operation under various conditions of the system and grounding apparatuses based on the analysis performed using PSCAD in conjunction with MATLAB.