Function overview
Page 53
5.2
Functions of the item Servo Positioning Controller C 3-Series
5.2.1
Compatibility
For reasons of compatibility, the control structure of the item Servo Positioning Controller C 3-Series has more or less the
same characteristics, interfaces, and parameters as the previous item C Series.
PWM
M
Positioning
controller
Speed
controller
Current
controller
Power
stage
Motor
Angle encoder 1
and 2
Actual value management
X2A
X2B
X10
Setpoint management:
- analogue inputs
- fixed values
- synchronization
- ramp generator
Positioning and interpolation
for trajectory calculation:
- position setpoint
- speed feedforward
- current feedforward
E1
E2
Figure 2:
Control structure of the item C 3-Series
Figure 2
shows the control structure of the item C 3-Series. The current controller, speed controller, and positioning controller
are arranged in a cascade. Due to the rotor-oriented control principle, the current can be set separately as active current (i
q
)
and reactive current (i
d
). Therefore, there are two current controllers, both of them PI controllers. However, to provide a better
overview, the i
d
controller is not included in
Figure 2
.
The basic operating modes are torque control, speed control, and positioning.
Other functions, such as synchronisation, "flying saw", etc., are variants of these basic operating modes. Furthermore,
individual functions of these operating modes can be combined, e.g. torque control with speed limitation.
5.2.2
Pulse width modulation (PWM)
The item Servo Positioning Controller C 3-Series can vary the clock frequency in the current controller circuit. In most cases,
the clock frequency can be set via the item Motion Soft
parameterisation software. In order to minimise switching losses, the
clock frequency of the pulse width modulation can be reduced by half compared to the frequency in the current controller
circuit.
The item Servo Positioning Controller C 3-Series also features a sine modulation or alternatively a sine modulation with third
harmonic. This increases the effective converter output voltage. The type of modulation can be selected via the item Motion
Soft
parameterisation software. Sine modulation is the default setting.
Table 30:
Output voltage at the motor terminals in the case of a DC bus circuit voltage (U
ZK
) of 560 V