8/16/2019 The Cascade Control Architecture – Control Guru
1/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
2/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
3/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
4/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
5/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
6/9
8/16/2019 The Cascade Control Architecture – Control Guru
7/9
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
8/9
wo controllers – the outer primary level controller (LC) and inner secondary feed
flow controller (FC)
wo measured process variable sensors – the outer primary liquid level (PV1) and
inner secondary feed flow rate (PV2)
ne final control element (FCE) – the valve in the liquid feed stream
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
9 5/19/2016 11:32 PM
8/16/2019 The Cascade Control Architecture – Control Guru
9/9
The feed flow rate (PV2) responds b e f o r e the tank level (PV1) when the header
pressure disturbs the process or when the feed valve moves.
The output of the primary controller, CO1, is wired such that it becomes the set
point of the secondary controller, SP2.
Ultimately, level measurement, PV1, is our process variable of primary concern.
Protecting PV1 from header pressure disturbances is the goal of the cascade.
Cascade Control Architecture – Control Guru http://controlguru.com/the-cascade-control-architecture/
Top Related