Mechatronics

Drives(Azionamenti )

Mechatronics

PWMPWMModulation (Pulse Width Modulation)

Mechatronics

AC brushless drive

[velocita’] [accelerazione]

oscillatore

Sincos encoder o

Mechatronics

50 o 60Hz

Tensione DC bus letta

f0 = 256 frete

PI

PI

Regenerative

Breaking(Recupero

in rete)

1 sinusoid cover 256 memory locations

[acc][vel]

[vel]

Sinusoid in phase with line voltage and amplitude-modulatedwith DC-bus voltage error

Mechatronics

Control Strategies

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

Feed Forward and PID

Mechatronics

Control Strategies (cont’d)

positionvelocityacceleration

Higher bandwidths

Feed Forward and PID

Mechatronics

Control Strategies (cont’d)

Vector Control (VC) (Controllo ad Orientamento di Campo o

Vettoriale)

Mechatronics

Control Strategies (cont’d)

Vector Control (VC)

Mechatronics

Control Strategies (con’d)

Iq

Id

Ia

Ib

Ic

Experimentally we would see… :

Mechatronics

…and indeed we actually see:

Mechatronics

and:

Mechatronics

Clark & Park Transform

It’s the matrix T that transforms from 3 to 2* vectors and 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).