In substations in power systems, there are two basic types of system grounding: solidly grounding and high resistance grounding. Solidly grounding is the most diverse and can handle 3 phase, line to line, and line to neutral loads. Unfortunately, it has high line to ground fault currents and can cause large feeders to trip in line to ground fault conditions. This makes it hard to troubleshoot and may cause reliability issues.
With high resistance grounding, it only supports 3 Phase and line to line loads, but it is highly reliable compared to solidly grounding. During ground fault conditions, the ground fault current is reduced to 5 amps. According to the IEEE Gold Book, 98% of all system faults originate as a line to ground fault conditions which means in 98% of system faults can be controlled by HRG. This creates a system that is more reliable, safer, and allows you to address the problem without having to experience an unplanned shutdown.
If you are looking at system grounding approaches, consider leveraging high resistance grounding.
