Mar 6, 20213 min read

SMA Zero export device | SMA export limiter | 2021

Updated: Oct 14, 2021

SMA Grid Tie PV Inverters

SMA is a Germany based solar inverter manufacturing company founded in 1981, turns over billions and employs around 5000 people.

SMA has the following series of solar string inverters

1. Sunny Boy: Single phase solar inverter with a range from 3kW to 6kW.
2. Sunny Tripower: Three-phase solar inverter with a rating of 15kW, 20kW and 25kW.
Sunny Tripower Core 1: Three-phase solar inverter with a rating of 50kW.
Sunny Tripower Core 2: Three-phase solar inverter with a rating of 110kW with IP class of IP65.
Sunny Highpower peak 1: Three-phase solar inverter with a rating of 75kW.
Sunny Highpower peak 3: Three-phase solar inverter with a rating of 100kW and 150kW.

With Design Ambient temperature of -25 Degree C to + 60 Degree C and Ingress protection class of IP65. SMA make Solar string inverters are ideal for installation in harsh condition.

SMA is one of the top three manufacturers of solar inverters in the world.

Source: Wood Mackenzie

SMA Zero Export Device

On-gird solar power (PV) plant generates excess power when the connected load is lesser than the power generated by the solar power plant (Power generation > Power required).

This excess power is synchronized with grid power hence it can revere the power flow.

In simple words, power will flow from the PV plant owner’s home to the connected grid [when Solar power generation > Power required by connected load].

With ZED Advance SMA gird tie inverters can be programmed to restrict the excess power generation. Hence provide Zero Export solution to solar plant owners.

ZED Advance is a programmable controller with set points, which can detect reverse power flow (from home to the grid) and control the power generation of the solar power plant.

When ZED Advance detects reveres power [solar power generation > Load demand] it ramps down the power generation of the grid-connected PV plant.

To match, load demand = solar power generation

And when the load increases, the ZED Advance will ramp up the solar power production accordingly.

As long as solar power generation is lower than the load demand, ZED Advance won't affect any change is solar power generation. But it keeps monitoring the system.

Setpoints of ZED Advance can be set between 0% to 100%. Where 5% means that the minimum 5% of load will be served by the grid.

If the frequency of load variation is very high, we need to fix the setpoint above 0% the suitable setpoints are 5%, 10% and 15%.

Curious about ZED Advance? We make a whole page on “ZED Advance” go and checkout and it will help you will be able to select the correct solution for your need.

SMA Export Limiter

Export Limitation means limiting the amount of power exported to the grid. Export limiters limit the power generation from the SMA PV inverter so that amount of power to be exported to the grid can be limited.

ZED Advance can also work as an export limiter for SMA make a grid-connected solar inverter.

Circuit Diagram of connecting ZED Advance with SMA make gird tie inverter.

ZED Advance required a Current transformer along with 10 core, 1.5 Sqmm Cable at the incomer from the grid for the load the measurement and 3 core 1.5 Sqmm cable for self-power as shown in the above illustration.

And compares this with the adjustable setpoint of the controller.

ZED advance also required LAN cable (cat 6) to communicate with SMA Solar Inverter as well as web portal (for online monitoring).

When the consumption from GRID is above this set point, the solar energy will be increased, when the consumption is below this set point, the solar energy will be reduced.