What is a solar substation grounding guide?

Abstract: This guide is primarily concerned with the grounding system design for photovoltaic solar power plants that are utility owned and/or utility scale (5 MW or greater). The focus of the guide is on differences in practices from substation grounding as provided in IEEE Std 80.

What is the purpose of the grounding system design guide?

Scope: This guide is primarily concerned with the grounding system design for ground-mount photovoltaic (PV) solar power plants (SPPs) that are utility owned and/or utility scale (5 MW or greater). The focus of the guide is on differences in practices from substation grounding as provided in IEEE Std 80.

Does this guide cover small scale solar power plants?

Similarly, this guide does not directly cover small scale solar power plants (such as rooftop type systems), substation grounding, or lightning protection.

What ohms should a grounding bank be?

The following is the design guide used by IEEE p1547.8 recommended practice to design the grounding bank and associated protection. As shown in the xls table of Figure 4, the grounding impedance should be 105 ohms. Consider a grounding transformer using 3 x 30kVA standard distribution transformers in a wye-grounded to delta configuration.

What is the standard earthing system of a solar farm?

The standard earthing system of a solar farm is as follows: The DC and AC sides of the system are galvanically (functionally) isolated. The DC side of the PV system may be either grounded or ungrounded. When it is grounded it is done at the ground fault protection device of the inverters.

Can a substation interconnect a solar plant?

The focus of the guide is on differences in practices from substation grounding as provided in IEEE Std 80. This guide is not intended for the substations to interconnect the solar plant; however, if the substation is included within the plant, portions of this guide may be applicable.