Inspection

Why including measurements?

Visual inspections is not enough!

Andreas Iliou - shading and measurements analysis

1 Module Circuit Design

2 Mismatch Effects

3 Hot-Spot Heating

4 Bypass diode, temperature

01Module Circuit Design

19 modules per string

4 Module Circuit Design – Shading

Some strings are shaded , flowers / Pylones

5 Module Circuit Design – Shading

Some strings are shaded , flowers / Pylones

6 Module Circuit Design – Shading

Some strings are shaded , flowers / Pylones

7Modules shaded via transmissionlines

PV Plant with similar shadings from a Transmission line

8 Module Circuit Design -Shading

Modules performance less in substrings shadedduring the whole day

Could be regrouped easily as place is available

shadingshade

Soft shade

9 Module Circuit Design -Shading

„Noise “measured on site during Shading e.g M9 O1 U3.2 G8 2,38 Ohm / 245 mA AC leakage current !!!

Rows shaded

shaded

10Module Circuit Installation

1 module was dismantled from the wind, therefore shading another 5 modules in different strings – future hotspot possible !!

11Module Circuit Installation

Mountain/ Valley installation so different values as module strings have different angles towards the sun

02Mismatch Effects

13 Mismatch Effects

M9.O1 U3.2 C36 –G8

6,8 A 13,3 mA7,4 A 14,7mA

6,5 A 15,9 mA7,6 A 14,8mA7,1 A 13,6mA

7,0 A 13,5 mA

AC leakage current

M9.O1 U3.2 –G82,38 Ohm / 245 mA

at earthing point

Different angles towards the sunSee more details sep. excel sheets

14 Mismatch- what can be achieved with measurements on site ?

A 1 / G 10

0,3mA 7,2 7,7 7,6 6,9 7,1 7,6 A1

2Ohm /3,8mA

44,7

44,3

44,2

45,4

44,2

51,6 G10

Shaded row , or burned busbars will show deviations

Shaded array

Here 51,6 A instead normally 44,7 – 45 A

Due to contact problems increasing resistance

15 Mismatch Effects

See more details sep. excel sheets

Instead of normal values 44- 45 A

this substring is over the limit

After investigation it shows

Burned current sensors

We need to do Visual andMeasurements on sites

One alone is not enough

03Hot-Spot Heating

17Field Observation

This results have been caused by the shading permanently of some

substrings via transmission lines/ or –and Pylons

Hotspots are not accumulated right now- future ?!

Siemens Les Mees

( see page 7)

04Bypass Diodes

19 Bypass Diodes

Normal picture with bypassdiodes getting cooled

20 Bypass Diodes

Bypass diodes getting hotter, heating up -> shading