# Grid tie with difference in grid voltage

Registered Users Posts: 1
Hi friends.. .

I am new here..

I am working on a solar project.that too grid tied..

But the issue with me is that

My solar grid tied inverter is a 380v 3 phase inverter and my grid is 220v 3 phase system.

As my grid will be changed into 380v 3 phase later after an year or so.. I selected 380v 3 phase inverter though my grid is 220v 3 phase system..

So now as I am having a 220v 3phase as grid.. is there any option by which I can connect it to my 3 phase 380v inverter?

Can I use a 220v 3 phase to 380v 3 phase transformer in between the grid and inverter?

Also I am not having a netmeter right now... Will it be matter?

First of all, what you do with your utility connection is very much based on local laws and utility regulations. I guess you are somewhere around Riyadh Saudi Arabia?

Regarding your incoming line voltage... AC (Alternating Current) is actually quite a complex set of math, and 3 phase power is an order of magnitude more complex.

First, I would guess that your 220/380 VAC (60 Hz?) is actually not going to change your actual pole transformer and home wiring (other than perhaps going up to ~230/400 VAC as a standard).

Some information I could find:

https://www.ashleyedisonuk.com/voltage-saudi-arabia-994/

Single Phase:
127V 2 wire
220V 2 wire

3 phase:
220V 4 wire
380v 4 wire

Frequency:
60 Hz

The country currently utilises a dual-voltage power distribution system. In residential and light commercial buildings the Kingdom uses 127 volts, whereas 220 volts is required in for larger commercial and industrial applications. With more than 70% of the world now using a 230/400 volt distribution system, the government approved plans in August 2010 to move the country to a 230/400 volts system.
I guess that you have a 4 wire 3 Phase which is a Wye Connection ("Y" or "Star") to the utility. There are "high leg Delta" or 3 phase Delta with a "stinger" (basically a 3 phase Delta with a ground bonded center tap in one of the three transformers)--But in any case, I doubt that any of that is changing for you.

To be clear, you presently have 220 VAC single phase (Line to Neutral--In Wye chart below, White/Blue is "Neutral"; XYZ are "Line") and 380 VAC 3 phase power (Line to Line). That is not changing. It is just in 1 year, when you measure Line to Neutral voltage, it will now be 230 VAC. And when you measure Line to Line it will be 400 VAC. You do not need any "extra transformers" or changes to your home power system (or GT Inverters).

http://forum.solar-electric.com/discussion/353274/grid-tie-with-difference-in-grid-voltage#latest

More or less, it appear that your utility is simply jacking up the voltage to your home by ~5% (220 to 230 VAC). That is usually something that the average user can ignore. For example, the "legal" line voltage In North America is (roughly) ~210 to ~264 VAC. It used to be ~220 Volts nominal but now, it it is ~240 VAC (over the last many decades).

For your Grid Tied solar power system, your change in utility/line voltage should not affect your system (it will operate with the old or new voltage standard). You may notice your electric stove heats a little bit faster, your tools (like arc welders) may work a little bit hotter/faster/more power.

Check with your GT Solar System installer (or your GT inverter supplier) and double check that they will support the change in grid voltage in the coming years.

Regarding a "net meter"--That depends on your utility's requirements. A typical net power meter runs "forwards" if you are using more power than solar is generating (at night for example). And runs "backwards" during the day when you have lots of sun.

But there are lots of variations in meters and utility requirements. Without detailed knowledge from your utility, I cannot really begin to guess what they require and what would happen if you installed GT Solar without informing the utility (not "fire bad", but depending on the meter, you may have some "billing surprises").

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 3,127 ✭✭✭✭✭
I was curious, and found:

I could most definitely be reading this wrong, but my understanding is that the currently supplied power is 127v/220v, with 127v being line-neutral, and 220v being line-line.  Both voltages are currently supplied to most (all?) residential and smaller business buildings.

The new system does involve a transition to new transformers providing 230v/400v with 230v being supplied line->neutral, and 400v line-line.  It appears to me from the Q&A in the above that most (all?) residential and smaller businesses will be supplied with only 230v line-neutral service, and only larger industrial users supplied with 230/400v.

If I'm understanding this properly, the OP might want to check to see if 230/400v will actually be available to him.  I also noticed reference elsewhere to a July 2018 projected start date for grid-tied solar, and there is a provisional application process in place now.
Off-grid.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter

Anyway, some quick clips:

4
Electric Voltage Change
Saudi Electricity Company
Introduction:
The cabinet’s decision to change the electricity distribution voltage from 127/220
volts to 230/400 volts for residential and commercial purposes in the new areas
and for new customers in existing areas is in support of the company’s efforts in
providing a safe and reliable electric services. The change in voltage shall facilitate
the standardization of electrical devices in accordance with the electrical standards
in the GCC countries. It will bring several positive aspects to the Kingdom and the
customers, importers, and providers of electric services. The change shall bring
about a reduction in low energy losses in the distribution network and in the wirings
in buildings. It shall also overcome the problem of voltage decline in the distribution
networks and equipment. Moreover, the change in the electricity distribution
voltage shall reduce the number of cables used, as well as the cross-sectional areas
of the cables for the same power capacity; thus reducing the cost of establishing
distribution networks and wiring installations in buildings

It appears from the document, that homes will continue to be supplied by single phase power. If your home where to have 3 phase equipment--That did not seem to be addressed (don't know if 3 phase power is "common" in Saudi homes).

In terms of what will happen... More or less it appears a minor increase in base voltage (230 VAC vs 220 VAC) and the "elimination" of the "neural" connection that we have in 120/240 VAC "split phase" North American homes.

New connections will simply be a Line to Line of 230 VAC, and all breakers/switches will be changed to double pole devices (not Hot/Neutral distribution). I am not sure if this is done so they do not need to "track" Line vs Neutral, or both Lines will truly be hot?

A typical 3 phase Wye system has the center connection ground referenced--Which would mean that one of the "Line" connections would be ground referenced.

For our original poster, Moosairshad, do you have 3 phase power in your place now? Or do you have single phase power only (110/220 VAC service is "split phase" power, not 3 phase power)?

If you have 3 phase power, then the "Voltages" become much more "interesting".

In the US, we have 120/240/277 VAC single phase power (277 vac single phase is a large building/industrial voltage from 3 phase 480 VAC Wye--Typically, from what little experience I have, used for factory lighting).

For three phase power, we have 208 VAC Wye (common in small office parks in California--Line to neutral voltage is 120 VAC for standard appliance and lighting voltage), 240 VAC Delta and 480 VAC Wye (and higher voltages for large installations).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 3,127 ✭✭✭✭✭
Off-grid.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
• Solar Expert Posts: 5,123 ✭✭✭✭
Just watch out for the men in Black suits and Dark sunglasses to knock on your doors...

KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
• Registered Users Posts: 3,127 ✭✭✭✭✭
Being in Canada, I suspect both our MIBs are female, likely wearing jeans and a Roots sweatshirt (no black suits cuz after years of effort and billions spent, the feds still haven't figured out how to write an accurate paycheque)
Off-grid.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
• Solar Expert Posts: 1,132 ✭✭✭✭

2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

• Solar Expert Posts: 5,123 ✭✭✭✭
OOPS! Too late, they have already got to LittleHabour2....     .....    ......  they are here too?

KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep