Siemens SIMATIC ET 200SP Manual page 15

Product overview
2.2 Functions
PC mode (PowerControl) operating principles
Phase control
The load voltage is reduced through phase control and raised from the starting voltage up to
mains voltage in the zero crossing.
Depending on the application, phase control offers advantages compared to wave packet
control, such as even heating or prevention of radiation source flickering in case of low
setpoints.
You can configure the following during each half wave:
● For phase control - phase-angle proportional: The switch-on duration in proportion to the
process value.
● For phase control - power-proportional: The output power.
The following graphic schematically shows the principle of phase control:
①
②
Figure 2-2
Note
Use of filters
To observe the EMC guidelines, you must filter the faults caused by phase control in the
plant. A suitable filter, for example, is EPCOS SIFI-C B84113C.
For additional information about electromagnetic compatibility of the module, see the section
Technical specifications (Page 44).
Phase control - power-proportional
This control type enables you to control the output power in the phase control in proportion to
the maximum power.
This means, for example, that a 500 W heating element ideally consumes about 50 W of its
maximum power at a process value of 10.0%.
Note that infrared sources may consume more power. The deviation from the setpoint is at
its lowest in case of a linear and purely ohmic load.
14
Average power 80%, corresponds to a process value of 800 (power proportional)
Average switch-on duration 67%, corresponds to a process value of 670 (phase angle propor-
tional)
Principle of phase control
DQ 4x24..230VAC/2A HF digital output module (6ES7132-6FD00-0CU0)
Manual, 02/2018, A5E42404845-AA