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{{Menu_Photovoltaic_installations}}
{{Menu_Photovoltaic_installations}}__TOC__
== Grid connected PV system ≤ 10kW (Residential)  ==


'''''(page to be completed)'''''
=== One single phase inverter ===


== Grid connected PV system <= 10kW (Residential)  ==
* Typically, a 5kW grid-connected single-phase inverter. with UOC MAX &le; 600V. One or two strings – Isctc < 25A, IAC < 32A. In this design there is no string protection.
* A PV main switch is necessary. When the inverter is indoors, an additional remote controlled switch at the DC cable entry point is recommended for emergencies services.


'''<big> ==> One single phase inverter </big>'''
{{FigImage|DB422723_EN|svg|P22|Grid connected <{{=}} 10kW}}


*Typically, a 5kW grid-connected single-phase inverter. with UOC MAX  600V.
== 10 to 100kW grid connected PV system (Small building) ==
*One or two strings – Isctc &lt; 25A, IAC &lt; 32A.
*In this design there is no string protection.
*A PV main switch is necessary. When the inverter is indoors, an additional remote controlled switch at the DC cable entry point is recommended for emergencies services.


[[Image:Fig P22.png|none]]
=== One three phase inverter with one string combiner box ===


{| width="800px" valign="top" border="1"
* Typically, 30kW to 60kW grid-connected inverters. U<sub>OC max</sub> is generally higher than 600V (up to 1000V), Isctc does not exceed 200A, Iac does not exceed 100A.
|-
* This design has more than 2 strings.
! align="left"  width="180px" | Needs
* Reverse current protection is therefore necessary.  
! align="center" width="110px" | String junction box
* A main PV switch is required. When an inverter is inside, additional remote-controlled switch at DC cable entry point is recommended for emergencies.
! align="center" width="170px" | PV array main switch
! align="center" width="170px" | Inverter
! align="center" width="170px" | AC box (400V)
|- bgcolor="#79C68C" align="center"
| align="left" colspan="5" | '''Switchgears and control (Q)'''
|- bgcolor="#79C68C" align="center"
| align="left" | - Isolation || • || • (d) || (a) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Switching<br>(Making & breaking<br>rated current || •<br>DC21B || • (d)<br>DC21B || (a) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Control || • (b) || • (d) || (e) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Over-current protection || (c) ||  ||  || • (f)
|- bgcolor="#79C68C" align="center"
| align="left" | - Protection against<br>Insulation fault ||  ||  || (h) || (h)<br>RCD type B or A SI
|- bgcolor="#A6D6AE" align="center"
| align="left" | '''Surge protection (SPD)''' ||  || • type 2 ||  || • type 1 or 2
|- bgcolor="#D1D3D4" align="center"
| align="left" | '''Enclosure (E)''' || Outdoor<br>Double insulation || Indoor<br>Double insulation || || Standard AC requirement +<br>grid code requirement
|- bgcolor="#FFFFFF" align="center"
| align="left" | '''Metering''' || ||  || Inverter relevant parameters || Energy
|}
(a) PV array main switch could be included in the inverter. This solution makes inverter service or replacement more difficult.<br>
(b) Remote switching for emergency services located as closely as possible to the PV modules or to the point of entry of DC cables in the building.<br>
(c) No protection is required when the number of string does not exceed 2.<br>
(d) Service and emergency switching<br>
(e) Inverter shall include a protection for anti-islanding (in accordance with VDE 0126 for example)<br>
(f) Overload and short-circuit protection B curve recommended.<br>
(g) This SPD could be unnecessary if there is another SPD in the AC installation at a distance of less than 10 metres.<br>
(h) If the inverter provides no galvanic separation a RCD protection is necessary on AC side. IEC 60364-712 specifies RCD type B. Some local regulations require RCD type A SI<br>


'''''Fig. P22 :''''' ''10-100kW single multi MPPT inverter''
{{FigImage|DB422725_EN|svg|P23|10-100kW single MPPT inverter}}


=== Multi single phase inverters design ===


* Typically, 6x5 to 20x5kW grid-connected inverters.
* The design used for residential building can be duplicated as often as necessary.
* In that case, the DC system is very simple and the AC system is very similar to usual AC systems.


== 10 to 100kW grid connected PV system (Small building)==
{{FigImage|DB422726_EN|svg|P24|10-100kW multi single MPPT inverter}}


'''<big> ==> One three phase multi input inverter without array box </big>'''
== 150kW to 500kW Grid connected PV system (Large building and farm)  ==


* Typically, 10kW to 36kW grid-connected inverters, UOC MAX probably higher than 600V (i.e. 800V or 1000V), Isctc < 125A, Iac < 63A.
=== Three phase inverter with more than two string combiner boxes ===
* In this range of power, inverters usually have between 2 and 4 maximum power point tracking (MPPT) inputs, so the number of strings in the same DC sub-network is equal to one or two.
* There is no need for string protection.
* A PV main switch for each MPPT input is necessary.
* When an inverter is indoors, additional remote-controlled switches at DC cable entry point are recommended for emergencies services.


[[Image:Fig P23.png|none]]
* Typically, 150kW to 500kW single inverter.
* This design is very similar to the three phase inverter with one string combiner box except that it has more arrays, which requires array cable protection.
* Istc <= 400A, IAC <= 600A.


{| width="800px" valign="top" border="1"
{{FigImage|DB422728_EN|svg|P25|150-500kW single MPPT inverter with N arrays > 2}}
|-
! align="left"  width="170px" | Needs
! align="center" width="145px" | String junction box
! align="center" width="165px" | PV array main switch
! align="center" width="130px" | Inverter
! align="center" width="190px" | AC box (400V)
|- bgcolor="#79C68C" align="center"
| align="left" colspan="5" | '''Switchgears and control (Q)'''
|- bgcolor="#79C68C" align="center"
| align="left" | - Isolation || • || • (d) || (a) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Switching<br>(Making & breaking<br>rated current || •<br>DC21B || • (d)<br>DC21B || (a) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Control || • (b) || • (d) || (e) || • (d)
|- bgcolor="#79C68C" align="center"
| align="left" | - Over-current protection || (c) ||  ||  || • (f)
|- bgcolor="#79C68C" align="center"
| align="left" | - Protection against<br>Insulation fault ||  ||  || (h) || (h)<br>RCD type B or A SI
|- bgcolor="#A6D6AE" align="center"
| align="left" | '''Surge protection (SPD)''' ||  || • type 2 ||  || • type 1 or 2
|- bgcolor="#D1D3D4" align="center"
| align="left" | '''Enclosure (E)''' || Outdoor IP5x<br>Double insulation || Indoor IP5x<br>Double insulation || || Standard AC requirement +<br>grid code requirement
|- bgcolor="#FFFFFF" align="center"
| align="left" | '''Metering''' || ||  ||  || Energy
|}
(a) PV array main switch could be included in the inverter. This solution makes inverter service or replacement difficult.<br>
(b) Remote switching for emergency services located as closely as possible to the PV modules or to the point of entry of DC cables in the building.<br>
(c) No protection is required when the number of string does not exceed 2.<br>
(d) Service and emergency switching<br>
(e) Inverter shall include a protection for anti-islanding (in accordance with VDE 0126 for example)<br>
(f) Overload and short-circuit protection (B curve recommended).<br>
(g) If there is no SPD in the inverter or if the distance between DC box and inverter exceeds 10m a SPD is necessary in this box.<br>
(h)
*If the inverter provides no galvanic separation a RCD protection is necessary on AC side. IEC 60364-712 specifies RCD type B. Some local regulations require RCD type A SI
*If the inverter provides at least simple separation
** Without functional earthing: insulation monitoring is necessary, it's usually done by the inverter in this range of power.
** With functional earthing: the earthing shall be done with a DC MCB breaker (C60PV 4P series 2 – 10A) or a fuse.
 
'''''Fig. P23 :''''' ''10-100kW single multi MPPT inverter''

Latest revision as of 17:52, 20 December 2019

Grid connected PV system ≤ 10kW (Residential)

One single phase inverter

  • Typically, a 5kW grid-connected single-phase inverter. with UOC MAX ≤ 600V. One or two strings – Isctc < 25A, IAC < 32A. In this design there is no string protection.
  • A PV main switch is necessary. When the inverter is indoors, an additional remote controlled switch at the DC cable entry point is recommended for emergencies services.
Fig. P22 – Grid connected <= 10kW

10 to 100kW grid connected PV system (Small building)

One three phase inverter with one string combiner box

  • Typically, 30kW to 60kW grid-connected inverters. UOC max is generally higher than 600V (up to 1000V), Isctc does not exceed 200A, Iac does not exceed 100A.
  • This design has more than 2 strings.
  • Reverse current protection is therefore necessary.
  • A main PV switch is required. When an inverter is inside, additional remote-controlled switch at DC cable entry point is recommended for emergencies.
Fig. P23 – 10-100kW single MPPT inverter

Multi single phase inverters design

  • Typically, 6x5 to 20x5kW grid-connected inverters.
  • The design used for residential building can be duplicated as often as necessary.
  • In that case, the DC system is very simple and the AC system is very similar to usual AC systems.
Fig. P24 – 10-100kW multi single MPPT inverter

150kW to 500kW Grid connected PV system (Large building and farm)

Three phase inverter with more than two string combiner boxes

  • Typically, 150kW to 500kW single inverter.
  • This design is very similar to the three phase inverter with one string combiner box except that it has more arrays, which requires array cable protection.
  • Istc <= 400A, IAC <= 600A.
Fig. P25 – 150-500kW single MPPT inverter with N arrays > 2
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