LONGi · Growatt
LONGi Hi-MO 5 LR5-72HBD-545M + Growatt MAX 50KTL3 LV: how many panels per string
From 6 to 18 LONGi Hi-MO 5 LR5-72HBD-545M panels per string on an MPPT input of the Growatt MAX 50KTL3 LV inverter — in any climatic region of Ukraine. Below: the window for each region, the input currents and example plants laid out by the Solispec engine.
- Panels per string
- 6–18pcs
- Input V_max
- 1,100V
- MPPT window
- 200–1,000V
- Panel I_sc
- 13.92A
- MPPT input I_sc
- 32.0A
- Panel V_mp in heat
- 35.6V
Ground frame designer
A ground plant with LONGi Hi-MO 5 LR5-72HBD-545M
The builder opens with this panel and the Growatt MAX 50KTL3 LV inverter: Solispec lays out the strings itself.
- No sign-up
- Snow and wind check
- Drawings and estimate
String by climatic region
T_min per ДСТУ-Н Б В.1.1-27:2010, табл. 1; open-circuit voltage at T_min: K_U = 1 + α·(T_min − 25)/100 = 1.18 (α -0.265 %/K, T_min -42 °C; Annex B).
| Region | T_min | Panel U_oc at T_min, V | Min per string | Max per string | String U_oc at max, V (≤ 1,100) |
|---|---|---|---|---|---|
| Region I | -40 °C | 58.20 | 6 | 18 | 1,047.6 |
| Region II | -42 °C | 58.47 | 6 | 18 | 1,052.4 |
| Region IIIA | -38 °C | 57.94 | 6 | 18 | 1,042.9 |
| Region IIIB | -32 °C | 57.15 | 6 | 19 | 1,085.8 |
| Region IV | -20 °C | 55.57 | 6 | 19 | 1,055.8 |
| Region V | -27 °C | 56.49 | 6 | 19 | 1,073.3 |
The minimum per string keeps the string voltage in heat (panel V_mp 35.6 V) above the MPPT window (200 V).
Input currents
| Panel I_sc / MPPT input I_sc, A | 13.92 / 32.0 |
|---|---|
| Panel I_mp / MPPT input I_mp, A | 13.04 / 26.0 |
| Parallel strings per MPPT | 1 |
| MPPT inputs | 6 |
No cautions about the currents.
Example plants
The Solispec engine laid out the strings for plants of several sizes with this inverter at the lowest T_min; only those that pass the checks with every panel placed are shown.
| Plant | Panels | kW DC | Inverters | Strings | DC/AC |
|---|---|---|---|---|---|
| ≈ 5 kW | 10 | 5.45 | 1 | 10 pan. × 1 — inv. 1, MPPT 1 | 0.11 |
| ≈ 10 kW | 20 | 10.90 | 1 | 10 pan. × 1 — inv. 1, MPPT 1; 10 pan. × 1 — inv. 1, MPPT 2 | 0.22 |
| ≈ 15 kW | 28 | 15.26 | 1 | 14 pan. × 1 — inv. 1, MPPT 1; 14 pan. × 1 — inv. 1, MPPT 2 | 0.31 |
- DC/AC 0.11 — inverter oversized
- DC/AC 0.22 — inverter oversized
- DC/AC 0.31 — inverter oversized
A preliminary calculation; a design needs an engineer's check. Solispec engine 0.12.0.