AC-Coupling PV - Using Existing PV

There are two primary methods of installing the 16K hybrid with an existing PV system. AC-coupled PV (ACPV) can be connected either to the Smart Port of the inverter or on the Grid Port. It does not connect directly to the Grid Port but what we call “on the grid-side of the system” denoting that it is on the side of the inverter that is not supported by the inverter when the grid fails. 

Scenario 1: AC Coupling via the Smart Port 

This setup involves landing the grid-tied inverter (Solis or third-party) directly on the hybrid's AC-Gen port.

• Hard Constraint: The rated power of the grid-tied inverter must be less than or equal to the rated AC power of the S6 hybrid, and it must be a three-phase inverter.

• On-Grid Operation: The S6 cannot actively throttle the output of a third-party grid-tied inverter in this scenario. To prevent grid export, you must enable "Max Export Control" (based on Export Power & SOC) in the Smart Port settings. If export exceeds a set limit (currently 100W for 30 seconds), the S6 will simply open the smart port relay to cut off the grid-tied inverter entirely.

  
  

• Off-Grid Operation: The system uses frequency shifting to regulate power. The third-party inverter must be configured with a grid code that supports over-frequency load shedding. Once the battery state of charge (SOC) reaches 85% or higher, the S6 will ramp up the frequency to physically force the grid-tied inverter to stop producing.

  
  

Scenario 2: AC Coupling on the Grid Side (Dual Meter Setup)

This scenario is for when the grid-tied inverter is connected on the main AC grid side rather than the Gen port. It requires a two-meter configuration so the S6 can accurately monitor the external generation.

• Hardware Setup: You must install two Eastron smart meters.

  • Meter 1 (Grid): Placed at the grid connection, configured to Modbus ID 001.

  • Meter 2 (PV Inverter): Placed at the grid-tied inverter's output, configured to Modbus ID 002.

  • Note: Both meters use the default password "1000" for configuration.

• Wiring: The meters communicate back to the S6 via RS485 (pins A and B) using standard RJ45 terminals.

• Commissioning: During setup, the installer must go into the S6's "Device Setting," navigate to "Meter/CT Setting," and explicitly change the "Meter/CT Installation Location" to "Grid+PV Inverter" so the DSP knows to look for two separate telemetry streams.

The attached PPT slide deck was created for non-US products, but the steps remain the same. Instead of Eastron meter, it will be CHINT DTSU666, which is compatible with the 16K hybrid series.