Control Examples; Better Control; Smart Logic Control; Smart Logic Control Programming - Danfoss VLT DriveMotor FCM 106 Design Manual

Application Examples
Energy savings
P =P
shaft shaft output
4 4
Illustration 4.9 Flow Distribution over 1 Year
H
(mwg)
60
50
40
30
20
10
0
P
(kW)
shaft
60
50
40
30
20
10
0
Illustration 4.10 Pump Performance
3 Distri-
m /
bution
h
% Hours
350 5 438
300 15 1314
250 20 1752
200 20 1752
150 20 1752
100 20 1752
Σ
100 8760
Table 4.5 Pump Performance
40
s
B
A
1650rpm
1350rpm
C
1050rpm
750rpm
100 200 300
A 1
1650rpm
1350rpm
B 1
1050rpm
C 1
750rpm
100 200 300
Valve regulation Frequency converter
Power Consump- Power
tion
A - B kWh A - C
1 1 1
42.5 18.615 42.5
38.5 50.589 29.0
35.0 61.320 18.5
31.5 55.188 11.5
28.0 49.056 6.5
23.0 40.296 3.5
275.064
®
VLT DriveMotor FCP 106 and FCM 106 Design Guide

4.3 Control Examples

4.3.1 Better Control

When a frequency converter is used for controlling the
flow or pressure of a system, improved control is obtained.
A frequency converter can vary the speed of the fan or
pump, obtaining variable control of flow and pressure.
Furthermore, a frequency converter can quickly adapt the
speed of the fan or pump to new flow or pressure
conditions in the system.
Achieve simple control of process (Flow, Level or Pressure)
using the built-in PI control.

4.3.2 Smart Logic Control

A useful facility in the frequency converter is the smart
logic control (SLC).
In applications where a PLC is generates a simple
sequence, the SLC can take over elementary tasks from the
main control.
SLC is designed to act from events sent to or generated in
the frequency converter. The frequency converter then
performs the pre-programmed action.

4.3.3 Smart Logic Control Programming

( 3 )
m /h
400
The smart logic control (SLC) comprises a sequence of
user-defined actions (see 13-52 SL Controller Action)
executed by the SLC when the associated user-defined
event (see 13-51 SL Controller Event) is evaluated as TRUE
by the SLC.
Events and actions are each numbered and are linked in
pairs called states. This means that when event [1] is
fulfilled (attains the value TRUE), action [1] is executed.
After this, the conditions of event [2] is evaluated, and if
evaluated TRUE, action [2] is executed and so on. Events
and actions are placed in array parameters.
( )
400 m 3 /h
Only one event is evaluated at any time. If an event is
evaluated as FALSE, nothing happens (in the SLC) during
the present scan interval and no other events are
evaluated. This means that when the SLC starts, it
evaluates event [1] (and only event [1]) each scan interval.
control
Only when event [1] is evaluated TRUE, the SLC executes
Consump-
action [1] and starts evaluating event [2].
tion
kWh
1
It is possible to program from 0 to 20 events and actions.
18.615
When the last event/action has been executed, the
38.106
sequence starts over again from event [1]/action [1].
32.412
Illustration 4.11 shows an example with 3 events/actions:
20.148
11.388
6.132
26.801
MG03M102 - 08/2015