Using SWMM Control Sets in SewerGEMS and CivilStorm

Product(s): SewerGEMS, CivilStorm
Version(s): V8i, CONNECT Edition
Area: Modeling

Problem

Can SWMM Control Sets be used in Bentley's storm and sewer products? How is the data inputted and utilized?

Solution

SWMM Control Sets allow a SewerGEMS or CivilStorm user to control the behavior of elements based on the condition in some other element using control rules set based on the SWMM program. These control rules are based on the syntax rules presented below and are used only by the Explicit (SWMM) solver. SWMM Control Sets can be used to turn pumps on and off. They can also be used to adjust the weir height and orifice opening for conduit control structures. Additional information on these can be found in the SewerGEMS and CivilStorm Help documentation.

if you are using a pond and pond outlet structure, set the pond outlet node's "has control structure?" to "No", then define a start control structure in the downstream conduit, to define your orifice or weir. SWMM controls currently only apply to conduit control structures, not pond composite outlet structure components.

The following screenshot shows the objects that can be used in SWMM Control Sets:

The meaning of SETTING depends on the object being controlled:

  • for Pumps it is a multiplier applied to the flow computed from the pump curve,
  • for Orifices it is the fractional amount that the orifice is fully open (orifice control is accomplished by lowering or raising a horizontal gate from the top of the orifice),
  • for Weirs it is the fractional amount of the original freeboard that exists (i.e., weir control is accomplished by moving the crest height up or down),
  • for Outlets it is a multiplier applied to the flow computed from the outlet's rating curve. 

Node (depth, head, inflow), link (flow, depth), pump flow, and simulation time are typically used in the condition part of the Control Set. The pump status and orifice and weir settings are used in the action statement. The formatting of this statement is similar to the logical control statement that users of WaterGEMS, WaterCAD, and SewerCAD may be familiar with: IF condition THEN action ELSE action2. Priorities can also be added that will make it so a given control takes precedence over another control.

Creating Control Sets

As SWMM Control Sets are used with pumps or control structures on conduits, these elements will need to be present in the model. Go to Components > SWMM Extensions > Control Sets to open the SWMM Control Sets dialog. This is where you can create and edit your control sets. To create a new control set, click the New button in the upper left.

The Control Editor Pane on the right side of the dialog allows you to define SWMM controls. Each control rule is a series of statements of the form:

RULE ruleID
IF condition_1 AND condition_2 OR condition_3 AND condition_4 Etc.
THEN action_1 AND action_2 Etc. ELSE action_3 AND action_4 Etc.
PRIORITY value

where keywords are shown in all caps, ruleID is an ID label assigned to the rule, condition_n is a Condition Clause, action_n is an Action Clause, and value is a priority value (e.g., a number from 1 to 5).

NOTE:

  • Only the RULE, IF and THEN portions of a rule are required; the other portions are optional.
  • Blank lines between clauses are permitted and any text to the right of a semicolon is considered a comment.
  • ELSE statements may need to be placed on a separate line.
  • Units are not entered in the control set text box. Instead, they are specified using the dropdown above the box. For example when set to  "US Units - CFS, ft, cubic ft" then the "10" in the below example represents a flow of 10 CFS. 

For example, suppose you wanted to create a control where a weir fraction open changes based on the flow on a given conduit. A zero could be used for closed and a 1.0 for open, plus values in between. The control would be formatted like this:

RULE 1A
IF LINK CO-1 FLOW > 10
THEN WEIR W1 SETTING = 0.5

Note: Starting with SewerGEMS and CivilStorm CONNECT Edition Update 3 (version 10.03.03.04), SWMM Time Series Control Data can now be used with SWMM Control Sets. For more information on creating these and applying them to a control set, see this link: Using SWMM Time Series Control Data.

In this case, you would enter "LINK" before the conduit label so that the control knows what type of element it is. In the action statement (THEN), you include the element type as well as a label. In the example above the label is "W1". This is the label of the weir as seen in the Conduit Control Structures dialog:

Note: older versions had a "SWMM Label" field where the label would be entered. 

The next step for using SWMM Control Sets is to open the calculation option properties. Set the property field Apply SWMM Control Set to "True." For the property SWMM Control Set, click the pulldown menu and select the name.

Note: if you are using a pond and pond outlet structure, set the pond outlet node's "has control structure?" to "No", then define a start control structure in the downstream conduit, to define your orifice or weir. SWMM controls currently only apply to conduit control structures, not pond composite outlet structure components.

Keep in mind that your SWMM Control Set will typically have more than one entry. For instance, you will have controls for the pump turning on and off. For conduit control structures, you would have different weir or orifice settings for different simulation times or flow values.

Examples

The following are examples of control rules that can be used in SWMM Control Sets:

Simple time-based pump control

RULE R1
IF SIMULATION TIME > 8
THEN PUMP 12 STATUS = ON
ELSE PUMP 12 STATUS = OFF ;

Multi-condition orifice gate control

RULE R2A
IF NODE 23 DEPTH > 12 AND LINK 165 FLOW > 100
THEN ORIFICE R55 SETTING = 0.5

RULE R2B
IF NODE 23 DEPTH > 12 AND LINK 165 FLOW > 200
THEN ORIFICE R55 SETTING = 1.0

RULE R2C IF NODE 23 DEPTH <= 12 OR LINK 165 FLOW <= 100
THEN ORIFICE R55 SETTING = 0 ;

Pump station operation (as in a SWMM4 Type5 pump)

RULE R3A
IF NODE N1 DEPTH > 5
THEN PUMP N1A STATUS = ON

RULE R3B
IF NODE N1 DEPTH > 7
THEN PUMP N1B STATUS = ON

RULE R3C
IF NODE N1 DEPTH <= 3
THEN PUMP N1A STATUS = OFF AND PUMP N1B STATUS = OFF

Important Notes

  • It is best to only specify either a SWMM control set or on/off controls for a model. Using both types of controls can lead to conflicts.
  • If you run into an error 217 about an invalid format when using an AND or an OR function, but moving the AND/OR portion to a new line.
  • Not all modulated controls are currently available for use in SewerGEMS and CivilStorm. 
  • As of 10.00.00.45, SWMM Curves and Time Series cannot be referred to in controls. For example to have a pump follow a time series pattern where you want to control the speed of the pump over time, you would not be able to create a SWMM control with action like "THEN PUMP PMP-1 SETTING = TIMESERIES TS101". Reference # 772418.

See Also

Modeling gate valve opening and closing based on pressure transducer reading

Conduit start/stop control structures

Creating Controls - Conditions, Actions, and Control Sets 

Creating Controls - Conditions, Actions, and Control Sets for WaterGEMS and WaterCAD SELECTSeries 6 

  • Created by Bentley Colleague
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