I am using the OPAL-RT platform to do inverter testing now.
I connected a PV inverter (GFL) with OP8110 of the OPAL-RT platform.
OP8110 (Power Amplifer )is operated in Voltage Source mode.
If I want to connect GFM inverter with OP8110, OP8110 needs to operated in Current Source (see the following reference).
My question is can OP8110 operate in current source mode? If yes, how can I change it to current source mode?
Ref: “Power Hardware-in-the-Loop (PHIL): A Review to Advance
Smart Inverter-Based Grid-Edge Solutions”
Annette von Jouanne 1,*, Emmanuel Agamloh 1 and Alex Yokochi 2
@Vincent_Jiang
Hello,
Thank you for reaching out to the OPAL-RT Community!
Can the OP8110 operate in Current Source Mode?
By default, the OP8110 4-Quadrant Power Amplifier is factory-configured to operate natively in Voltage Source Mode (Voltage Control Mode), providing a high-bandwidth, low-latency voltage output to emulate the grid for standard Grid-Following (GFL) inverters.
While the OP8110 hardware topology supports current control, operating it in Current Source Mode typically requires specific controller/firmware configurations and model-level interfacing depending on your simulator model and firmware package.
Interfacing Grid-Forming (GFM) Inverters in PHIL
When testing a Grid-Forming (GFM) inverter (which acts as an AC voltage source), connecting it directly to an amplifier in Ideal Transformer Model (ITM) voltage mode creates a direct parallel connection between two stiff voltage sources. To achieve stable closed-loop PHIL operation with GFM inverters, there are two common approaches:
Voltage-Type PHIL with Virtual / Coupling Impedance (Recommended & Most Common):
Keep the amplifier in Voltage Mode.
In your real-time simulation model (RT-LAB / HYPERSIM), include the physical/virtual grid impedance or use interface stabilization algorithms such as the Damping Impedance Method (DIM) or Transmission Line Model (TLM).
The simulator measures the feedback current from the OP8110, calculates the voltage drop across the simulated grid/line impedance, and commands the reference voltage to the amplifier accordingly.
Current-Type PHIL Interface (Current Source Mode):
The simulator measures the terminal voltage generated by the physical GFM inverter.
The real-time simulation calculates the resulting current drawn by the simulated power system and commands the amplifier to inject that exact current into the GFM inverter.
How to Configure Your Setup
Because changing the amplifier’s low-level control mode or deploying specialized GFM PHIL interface templates depends on your specific hardware revision, firmware version, and simulator package (RT-LAB / HYPERSIM / eHS):
Next Step: We recommend opening a ticket with the OPAL-RT Support Center.
Please provide your system serial number / target ID, your current RT-LAB/HYPERSIM version, and the specific ratings/specifications of your GFM inverter.
Our application support team will be happy to provide the appropriate PHIL interface model examples, stability guidelines, or firmware instructions tailored to your test bench.
@Parija Thank you. I will use Imperix RCP as a three phase grid forming inverter (model name: TPI8032). And I will connect Imperix RCP GFM inverter with OP8110. The max power of Imperix RCP grid forming inverter I will set at 5kW or below.