Product description
Page 32
3.2.1.2
Behaviour during normal operation and control characteristics
During operation the PFC stage controls the power input of the item servo positioning controller C 1-Series from the supply.
Based on an analog closed-loop control the mains current is regulated to a sinusoidal waveform with a phase shift near to 0 °.
The effective amplitude is adjusted according to the demanded input power
A superimposed digital closed-loop control adjusts the DC bus voltage to an average value close to 380 VDC. To relieve the
voltage control that is relatively sluggish, during load changes (acceleration/deceleration of the drive) the output/input power
delivered from the item servo positioning controller C 1-Series to the motor is measured and used for the pre-control of the
PFC stage
+
-
~
~
3 phase
power
stage
M
3 ~
microcontroller
voltage
controller
motion controller
IC for power factor
correction
L
D
C
u_q
i_q
PWM
U_Zk
i_v
i_u
T8
I_in
U_in
100V ... 230V AC
+/- 10%
F
motor
feedback
Figure 2:
Schematic setup of PFC stage
The control system includes the following values:
digital control of the DC bus voltage to an average value of 380 VDC
analog control of the input mains current
Keeping of a sinusoidal mains current under stationary load conditions
cos
ϕ
> 0.97 at nominal operation (at rated output power of the PFC stage)
By use of the parameterisation program item Motion Soft
the PFC stage (Parameters/Device parameters/PFC) can be
switched on and off. With deactivated PFC the DC bus behaves like a normal DC bus with a rectifier bridge
Under stationary load conditions the DC bus voltage is regulated to a constant average value, which is independent from the
actual power transferred to the motor.
