KStar EASTRON SDM630MCT 40mA, User Manual, Page: 2 / 5

01
Three-Phase Power Meter For Kstar Three phase inverter
Solution:
KSTAR three phase inverters can fulfil the requirement of zero export function with a
smart meter and three CTs. The system can implement data-driven decisions to
control the inverter’s output. Three are two different methods of achieving zero export
function, which are phase-level zero export and system-level zero export.
The system configuration diagram below illustrates these two different methods and
how it works.
Method 1(phase-level zero export): The inverter’s three phase outputs are balanced,
and the output will be determined based on the phase which has the minimum power
flowing through among the three phases. For example, if the load is 10kW/20kW/30kW
for phase A/B/C respectively, then the limit power for the inverter is 10kW each phase.
The rest of required power will be drawn from the grid.
Method 2(system-level zero export): The inverter’s three phase outputs are balanced,
and the output will be determined based on the total load. For example, if the load is
10kW/20kW/30kW for phase A/B/C respectively, then the limit power for the inverter is
20kW each phase. For phases that requires less power than 20kW, there will be phase-
level injections to the grid. For phases that requires more power than 20kW, there will
be power drawn from the grid to support the load.
L1: 10kW
L1: 10kW L1: 0kW
L2: 10kW
L3: 20kW
L2: 10kW
L3: 10kW
L2: 20kW
L3: 30kW
L1: 10kW
L1: 20kW L1: 10kW
L2: 10kW
L3: 0kW
L2: 20kW
L3: 20kW
L2: 30kW
L3: 20kW