Tongwei · Growatt
Tongwei TNC 2.0 TWMNH-48HW470 + Growatt MAX 100KTL3-X LV: how many panels per string
From 7 to 25 Tongwei TNC 2.0 TWMNH-48HW470 panels per string on an MPPT input of the Growatt MAX 100KTL3-X 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
- 7–25pcs
- Input V_max
- 1,100V
- MPPT window
- 180–1,000V
- Panel I_sc
- 15.95A
- MPPT input I_sc
- 40.0A
- Panel V_mp in heat
- 26.2V
Ground frame designer
A ground plant with Tongwei TNC 2.0 TWMNH-48HW470
The builder opens with this panel and the Growatt MAX 100KTL3-X 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 = 1.16 (α -0.24 %/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 | 42.25 | 7 | 26 | 1,098.6 |
| Region II | -42 °C | 42.43 | 7 | 25 | 1,060.7 |
| Region IIIA | -38 °C | 42.08 | 7 | 26 | 1,094.0 |
| Region IIIB | -32 °C | 41.55 | 7 | 26 | 1,080.3 |
| Region IV | -20 °C | 40.50 | 7 | 27 | 1,093.4 |
| Region V | -27 °C | 41.11 | 7 | 26 | 1,068.9 |
The minimum per string keeps the string voltage in heat (panel V_mp 26.2 V) above the MPPT window (180 V).
Input currents
| Panel I_sc / MPPT input I_sc, A | 15.95 / 40.0 |
|---|---|
| Panel I_mp / MPPT input I_mp, A | 15.26 / 32.0 |
| Parallel strings per MPPT | 2 |
| MPPT inputs | 10 |
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 | 11 | 5.17 | 1 | 11 pan. × 1 — inv. 1, MPPT 1 | 0.05 |
| ≈ 10 kW | 22 | 10.34 | 1 | 22 pan. × 1 — inv. 1, MPPT 1 | 0.10 |
| ≈ 15 kW | 32 | 15.04 | 1 | 16 pan. × 2 — inv. 1, MPPT 1 | 0.15 |
- DC/AC 0.05 — inverter oversized
- DC/AC 0.10 — inverter oversized
- DC/AC 0.15 — inverter oversized
A preliminary calculation; a design needs an engineer's check. Solispec engine 0.12.0.