GoodWe GW20K-SDT-3020kW three-phase string inverter, 2 MPPT

Overview

The GW20K-SDT-30 is the largest model of GoodWe's SDT G3 4–20kW range. Its first MPP tracker takes two strings at up to 32A and the second one string at 22A, over a 140–1000V window. Rated at 20kW, it can deliver up to 22kW and 33.3A per phase. Smart fan cooling keeps noise below 45dB, and the housing measures 530×413×227mm. GoodWe recommends a 40A AC switch. CEI 0-21, VDE-AR-N 4105, EN 50549-1/-10 and G99 certificates list this model.

• Models from 4 to 20kW with two MPP trackers
• 1100V maximum input, 140–1000V MPPT range
• Up to 110% AC output on most models
• Fanless natural cooling up to 12kW, IP66
• Type III surge protection standard, Type II and AFCI optional
• Wi-Fi, LAN and Bluetooth with Modbus RTU (SunSpec) and Modbus TCP

How it works

The SDT G3 converts the DC power of up to two PV strings into three-phase AC for self-consumption and export. Both MPP trackers start at 160V and operate from 140 to 1000V, with a 600V nominal input, so strings of different length or orientation can be connected to separate trackers. Models up to 15kW take one string per tracker at 22A; the 17kW and 20kW models accept two strings on the first tracker (32A) and one on the second.

Most models can deliver 110% of their nominal AC power, for example 6.6kW on the 6kW unit and 22kW on the 20kW unit. The GW10K-SDT-EU30 is the exception: its output is capped at 10kW and 15.2A, which suits grids where the connection limit equals the rated power. All models connect to 220/380V, 230/400V or 240/415V grids, with or without neutral.

Key features

Protection includes string current monitoring, insulation and residual current monitoring, reverse polarity protection and an integrated DC switch. Type III surge protection is fitted on DC and AC as standard, with Type II available as an option. Options also cover AFCI arc detection, PID recovery and rapid shutdown with GoodWe RSD transmitters and receivers. Units up to 12kW are cooled by natural convection and stay below 30dB.

Installation and compatibility

Mount the inverter vertically or tilted back by no more than 15°, indoors or outdoors, ideally sheltered from direct sun, rain and snow. Each inverter needs its own AC switch: GoodWe suggests 20A up to 10kW, 32A for 12–17kW and 40A for 20kW. A residual current monitor is built in; where an external RCD is required, GoodWe recommends Type A with at least 300mA. PV strings connect with MC4 connectors (4–6mm²).

For export limitation a GMK330 or GM330 meter is connected over RS485; several inverters are networked through an EzLink3000 on the master unit or through an EzLogger or SEC1000 controller. CEI 0-21 and VDE-AR-N 4105 certificates cover the 8–20kW models, while the EN 50549-1/-10 and NC RfG certificates also include the 4–6kW versions.

Monitoring and settings

Configuration is done over Bluetooth or Wi-Fi with the SEMS+ app, and plant data are sent to the SEMS+ portal through Wi-Fi, LAN or an optional 4G module. With a meter at the grid connection point the inverter also records household consumption around the clock. RS485 with Modbus RTU (SunSpec compliant) and Modbus TCP is available for data loggers and energy managers.

Questions and answers