Hi Miodrag,
We'd love to have you join in on the discussion and participate in the planning & implementation! I think our envisioned mode of operation will dictate that the genset never run until its full output can be utilized. That means we will tune the genset to run at its optimum economy while producing output capable of most or all of the current demand of the EV while cruising along.
So in the long-range mode of operation, the vehicle could run as a true series hybrid with indefinite range. That's a worst-case scenario from an environmental standpoint but it's our design goal.
This also means that the genset will never run unless the battery is discharged to a level where it can begin to take the full genset output as a charging current. For example: you have 40 miles range on your battery alone and you have a 50 round-trip mile commute, with no opportunity charging at the turn. You would drive to work and start the genset at, say, the 15 mile mark. This way, no matter if you are cruising (consuming the full genset output) or stop-and-go (alternately charging or feeding the motor), none of the genset's output would be wasted. When you arrive at mile 25, the genset can continue running until the full charge is attained, then it will shut down automatically. On the return trip, the genset stays off and you plug in at home to recharge for tomorrow.
The reason for the long-winded example is that we don't envision throttling the output of the genset. Instead, we want to limit the draw of the motor on the genset to its actual output. If the genset can produce 20kW, then any demand by the motor/drive above 20kW would have to come from the battery pack (like during hard acceleration). Conversely, we would want the "coupling means" to be able to feed excess current not demanded by the motor into the batteries (like during a stop, deceleration, low speed driving).
The reason for all of this management of constant output of the genset is to make maximum/optimum use of every drop of (fossil) fuel. This can be best accomplished by tuning the ICE to the perfect RPM for efficiency/minimum emissions and then running it as little as possible in the various modes of operation.
Bottom line: we need your help in figuring out how to limit the motor's draw on the genset to its optimum output level!