Disclaimer
This document, prepared by Sungrow Australia Group Pty. Ltd. (ABN 76 168 258 679), serves as a guideline for solar installers for troubleshooting. It is not a statement or advice on Electrical or Solar Industry standards or guidelines. All OH&S regulations must be observed when working on Sungrow equipment.
Introduction to Retrofitting
The Sungrow hybrid inverter is compatible with any 3-phase PV grid-connected inverter. Existing PV systems can be retrofitted to become a PV Energy Storage System (ESS) by adding the hybrid inverter. Power generated by the existing PV inverter will first supply loads, then charge the battery. The hybrid inverter's energy management function significantly improves the self-consumption of the new system.
There are two primary methods to retrofit an existing PV system:
- To parallel the PV inverter and hybrid inverter at the grid connection point.
- To connect the PV inverter to the back-up circuit of the hybrid inverter.
1. Grid Connect Port to Retrofit the Existing PV System
In this configuration, the AC terminal of the PV inverter and the GRID terminal of the hybrid inverter are connected in parallel. A meter must be connected to the hybrid inverter, and the hybrid inverter must be configured for the existing system.
To configure the system, navigate in the Local Access interface: Tap "More ➔ Settings ➔ Power Regulation Parameters ➔ Rated Power of Original Power Generation System" and enter the power of the existing system.
Diagram Description (Figure 1): The diagram illustrates the grid connect port setup. It shows a PV inverter connected via AC to the GRID terminal of a Sungrow SH10RT hybrid inverter. Optional components are also indicated.
2. Back-up Circuit Port to Retrofit the Existing PV System
This method utilizes the back-up circuit port to retrofit the existing PV system, enabling the PV inverter to operate even when the grid is off. The AC terminal of the PV inverter is connected in parallel with the BACK-UP terminal of the hybrid inverter.
Important Power Limitation: The PV inverter's power output CANNOT exceed the nominal power of the hybrid inverter. For single-phase PV inverters, this limit also applies to the single-phase nominal power of the three-phase hybrid inverter.
Before retrofitting to an off-grid port, the "Frequency Shift Power Control" parameter must be enabled.
Frequency Shift Power Control
When a PV inverter is connected to the hybrid inverter's back-up circuit during battery-backup operation, the hybrid inverter must be capable of limiting the PV inverter's output power to protect the battery and loads from overcharging or damage due to excessive power.
In off-grid mode, the hybrid inverter adjusts the AC output frequency. The PV inverter detects this frequency change. When the battery-backup grid frequency exceeds the value set in "Set Test Frequency", the PV inverter automatically limits its output power.
It is crucial that connected PV inverters limit their AC output power via the hybrid inverter in response to frequency changes. The frequency-dependent active power limitation (PF) must be configured within the PV inverter.
To access these settings, navigate in the Local Access interface: Tap "More ➔ Settings ➔ Operation Parameters ➔ Other Parameters".
Configuration Table:
| Parameter | Default Value | Range |
|---|---|---|
| Frequency Shift Power Control | OFF | ON/OFF |
| Frequency Shift Test | OFF | ON/OFF |
| Set Test Frequency | 50.00 Hz | 50.00~55.00 Hz |
Existing system settings must also be enabled.
Diagram Description (Figure 2): The diagram shows the back-up circuit port setup. It depicts PV inverters connected via AC to the BACK-UP terminal of a Sungrow SH10RT hybrid inverter, which is then connected to loads and the grid.
3. Communication Cable Connection
For standard data synchronization, the hybrid inverter and PV inverter can be added separately to the same plant on iSolarCloud using individual WiFi dongles (V31 for SH_RT, WiNet for SG_RT).
For enhanced data synchronization, the PV inverter and hybrid inverter can be daisy-chained. This configuration requires an EyeM4 dongle.
Diagram Description: The diagram illustrates the communication cable connections. It shows an EyeM4 dongle connected to an SG10RT inverter, which is then connected via RS485 to an SH10RT hybrid inverter. A DTSU666 meter is also shown connected to the SH10RT via RS485. Pin assignments for COM2 of SG10RT and COM terminal of SH10RT are detailed.
Important Notes
- The ESS system is not a UPS. Do NOT connect critical equipment requiring continuous and stable power supply to the back-up circuit.
- When retrofitting the PV inverter on the back-up circuit, if the battery State of Charge (SOC) is above 85%, the system may not seamlessly shift from grid-connect to off-grid mode. The hybrid inverter may enter a fault mode and shut down before restarting, which can take 2-3 minutes.
- Retrofitting configurations are limited to one PV inverter and one hybrid inverter. For systems with three or more inverters, a logger might be necessary. Consult Sungrow for optimal solutions.
- All inverters and dongles must be updated to the latest firmware version.
- In a zero-export scenario, the hybrid inverter ensures its own zero export to the grid but does not guarantee zero export for the PV inverter. Contact the PV inverter manufacturer for their zero-export solution.
- PV modules for the hybrid inverter are optional.
Contact Information
For inquiries, please contact the Sungrow Service Department:
- Phone: 1800 786 476
- Email: service@sungrowpower.com.au
- Hours: Monday - Friday, 9am - 5pm (AEDT)
