I have here an FOC controller with encoder and a 2200kv, 40A, 324W motor. I can run the motor just fine and I limited the current to 4A and the motor spins up to around 1400rmp. When I now increase the current limit, I would expect the motor to turn faster, since it allows higher voltage across the phases, but this seems not to work at all and the motor turns maybe around 1450rmp at 10A, where also the PWM on timings are changed only a small amount. I run the motor not in the speed control mode, just in the current control mode, which will spin the motor to the maximum possible rmp.
What could cause the problem here? Is it possible, that the FOC with encoder somehow goes into saturation?
Edit: Here is a plot of (Iq,Id,Vq,Vd) for this motor, with a reference quadrature current Iq=-3A, where I first let the motor run full speed, then I slowly put a load on it with my hand until stall. Is it possible, that if |Vq|<|Vd|, the motor cannot accelerate anymore? Since this is the case here, when the motor holds the speed.
Edit 2 I made now some new measurements, where also the speed is included and the phase currents. Iq_ref is set to 2A and I hold the motor and release it with my hands. I really don't know what really does limit my speed here. Id grows, when the motor reaches the current limit Iq_lim of 2A. The plotter is not the fastest, so that the phase currents could only be truly depicted at very low speeds.