Large PV plant grounding

[h1986]

Hello everyone
I've been working on a 10 MW PV system grounding. I've got some questions. I was wondering if somebody could help.
This farm is really large and I don't know how to do it. How can I design a ground grid for it? how can I analyze it in ETAP.
Please help me.
Thanks in advance

 

[ggunn]

Hello everyone
I've been working on a 10 MW PV system grounding. I've got some questions. I was wondering if somebody could help.
This farm is really large and I don't know how to do it. How can I design a ground grid for it? how can I analyze it in ETAP.
Please help me.
Thanks in advance

I mean no offense, but how is it that someone who doesn't thoroughly understand this stuff get to be the designer of a 10MW PV system?

 

[electrofelon]

Hello everyone
I've been working on a 10 MW PV system grounding. I've got some questions. I was wondering if somebody could help.
This farm is really large and I don't know how to do it. How can I design a ground grid for it? how can I analyze it in ETAP.
Please help me.
Thanks in advance

I would just follow the NEC. This is often just two ground rods. You won't gain any thing by doing something more elaborate. Put your money into some SPD's instead.

 

[jaggedben]

I mean no offense, but how is it that someone who doesn't thoroughly understand this stuff get to be the designer of a 10MW PV system?

I would just follow the NEC.

Note: He is in Iran.

This is often just two ground rods. You won't gain any thing by doing something more elaborate. Put your money into some SPD's instead.

Especially if it's ground mount with structural metal going into the ground everywhere.

 

[electrofelon]

Especially if it's ground mount with structural metal going into the ground everywhere.

Yeah. The dirt worshipping gets out of hand. Had one several meg ground mount. The head designer couldn't believe that two ground rods were all the utility used. Behind him was probably 3500 driven I beams, and 6 in front of him at the disco bank. Another job, had to drive ground rods every 200 feet along the fence to "ground the fence" :slaphead:

 

[pv_n00b]

There's a big difference between a grounding electrode system and a ground grid. A ground grid is a grid of conductors put in under high voltage substations to control step and touch voltages. I have not heard of anyone putting one under a PV array in the USA but they would put them under the HV substations on the AC side.

So I can't help with the question. If they require a ground grid under the array where you are it's going to be larger than anything I have ever seen. Best check with others in your area to see how they are doing it. My thought is that you do not need a ground grid, just a simple grounding electrode system.

 

[pv_n00b]

I mean no offense, but how is it that someone who doesn't thoroughly understand this stuff get to be the designer of a 10MW PV system?

It's not unusual in other parts of the world for a company's first PV project to be 10MW. I have worked with several hydropower companies in Latin America who were getting into PV by bidding a 10MW project as their first project. There is no residential or C&I PV in many countries, utility scale is the starting point. And yes it's crazy, I've been asked by people working on utility-scale projects how to size strings.