7 Regenerative Breaking (Recupero in rete) Sinusoid in phase with line voltageand amplitude-modulatedwith DC-bus voltage error[vel][acc]PI[vel]Tensione DC bus lettaPIf0 = 256 freteRegenerative Breaking (Recupero in rete)50 o 60Hz1 sinusoid cover 256memory locations
11 Control Strategies Feed Forward and PID The Feed-Forward (open loop) is used to provide position, velocity, current profiles, to be followed by the PID (closed loop),…so to avoid to load the integral action,…so that I can keep it low and have high dynamics
12 Control Strategies (cont’d) Feed Forward and PIDpositionvelocityaccelerationHigher bandwidths
13 Control Strategies (cont’d) Vector Control (VC)(Controllo ad Orientamento di Campo o Vettoriale)
14 Control Strategies (cont’d) Vector Control (VC)
15 Control Strategies (con’d) Experimentally we would see… :wIqIdIaIbIc
18 Clark & Park TransformIt’s the matrix T that transforms from 3 to 2* vectorsand from fixed to rotary reference system.* Actually 3 currents id, iq and i0, remains, where i0 is the neutral wire (neutro) current (if there’s one).