Explain the concept of 'touch potential' and 'step potential' in grounding, and how are they mitigated in substation design?

Touch potential is the voltage a person could be exposed to when touching a grounded object in a substation during a ground fault. It's the potential difference between the grounded object (e.g., equipment enclosure) and the point where the person is standing. Step potential is the voltage a person could be exposed to by stepping across the ground during a ground fault. It is the potential difference between a person's feet, typically assumed to be one meter apart. Both touch and step potentials pose a significant elect....