Drives
(Azionamenti )
Mechatronics
PWM
Modulation
(Pulse
Width
Modulation)
Mechatronics
AC brushless drive
Sincos encoder o
[velocita’]
[accelerazione]
oscillatore
Mechatronics
Sinusoid in phase with line voltage
and amplitude-modulated
with DC-bus voltage error
[vel] [acc]
PI
[vel]
Tensione DC
bus letta
PI
f0 = 256 frete
50 o 60Hz
1 sinusoid cover 256
memory locations
Regenerative
Breaking
(Recupero
in rete)
Mechatronics
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
Mechatronics
Control Strategies (cont’d)
Feed Forward and PID
position
velocity
acceleration
Higher bandwidths
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)
Experimentally we would see… :
w
Iq
Id
Ia
Ib
Ic
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).
Mechatronics