How Grounding Resistor Cabinets Protect Transformers?

In power systems, transformers, as core equipment, are critical to the safe operation of the entire grid. However, due to various reasons, transformers are often exposed to multiple threats. In such cases, the importance of grounding resistor cabinets becomes evident, as they provide indispensable protection for transformers.

Firstly, grounding resistor cabinets can effectively protect transformers from lightning strikes. The instantaneous high voltage caused by lightning can severely damage transformers. By slowing down the rate at which lightning current is discharged into the ground, the grounding resistor cabinet reduces the electromagnetic effects induced by lightning, thereby shielding the transformer from lightning-related hazards.

Secondly, grounding resistor cabinets mitigate the impact of switching overvoltages on transformers. In power systems, switching overvoltages frequently occur during operations such as disconnecting unloaded transmission lines or energizing/de-energizing unloaded transformers. The grounding resistor cabinet provides an additional layer of protection by limiting both the magnitude and duration of these switching overvoltages.

Furthermore, grounding resistor cabinets help prevent single-phase-to-ground faults in transformers. Single-phase-to-ground faults are a common type of fault in power systems. By limiting the fault current, the grounding resistor cabinet reduces the extent of damage to the transformer, thus ensuring its normal operation.