Any way to use power flow tool with one bus represented as ideal inverter with 3 separate controlled voltage sources?

I am modeling a microgrid power system with one synchronous generator (SimPowerSystems non-linear block) and one 3-phase inverter-based source. The inverter is modeled as 3 individual controlled voltage sources. I would like to use the power flow tool to generate initial conditions to initialize the controllers for the generator and the inverter. However, I can't use the power flow tool with the 3-phase inverter represented by individual controlled voltage sources. How can I specify the inverter bus as a PV bus without using a 3ph controlled voltage source? (a 3ph voltage source block isn't available where I can manipulate voltage magnitude and frequency) Can I somehow use the single-connector Load Flow Bus block for this? Or is that block type only to display power flow values from buses falling under machine or 3ph controlled source category?