The pump performance study can plot the SCADA (Supervisory Control and Data Acquisition) pump head and efficiency points on the pump head and efficiency curves for a selected pump. This enables the users to determine if a pump is operating on its intended curve and whether it is operating at an acceptable efficiency. The SCADA data is provided through SCADA Signals.

How to Start a Pump Performance Study

To start a new pump performance study, right-click the pump in your model and select “Performance Study” from the context menu presented.

Pump Head Curve

The pump head curve is already available for a pump. The pump element must have a valid pump definition assigned to it.

The pump performance study provides a way to overlay the SCADA data on top of the pump curve at the pump's full speed.

A good pump may display data similar to the above image.

The above image is an example of how a poorly operated pump may show.

Data Transformations

The SCADA data may vary from system to system. If the SCADA data provides only suction and discharge pressure points, this data can be transformed into head. The head is then used with the flow to plot on the graph.

When suction and discharge pressure are given, the head is calculated as:

H = 2.31 (P_d – P_s) + D_z - S_z

The elevations of the pressure sensors, D_z and S_z, are typically the same. However, the user can specify different elevations to account for the difference.

In other cases, the suction pressure may not be measured or available (especially for submersible pumps). Therefore, a tank water level is needed to calculate the suction head.

H = 2.31(P_d) + D_z - S_z

where S_z is the HGL of the suction tank, which is calculated as the elevation of the zero value for the water level gauge plus the water level.

Pump Efficiency Curves

the user also has the option of include a pump efficiency curve in the pump performance study. As with the pump head curve, the efficiency curve should be created before starting the performance analysis. The efficiency plotted is the wire-to-water efficiency. Therefore, motor efficiency (and variation with speed for variable speed pumps) should be specified in the pump definition.

It is unlikely that a SCADA system will record the efficiency of the pump. Instead, the pump performance study can use flow, head and power to calculate the efficiency using the following equation:

e = k Q h / P

Where k is a conversion factor, Q is flow, h is head, and P is input power.

System Head Curves

The user can also display system head curves corresponding to the current scenario in the model (and the selected time steps in case of an EPS scenario). To generate a system head cure, the scenario must be runnable. It is advised to run the scenario beforehand as a check.