modelControlLoop

Validate sequence of output head pressure control signal

Information

This example validates Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.HeadPressure.Subsequences.ControlLoop. It demonstrates how the head pressure control loop signal is generated.

  • Before 0.5 seconds, the head pressure control loop is not enabled (uHeaPreEna=false). The loop output is not valid and will not be used.
  • At 0.5 seconds, the head pressure control loop is enabled. The PID controller resets the output from 0.
  • From 0.5 seconds to 2.5 seconds, the difference between the condenser water return temperature and the chilled water supply temperature is 2 °K and it is less than the minimum LIFT (10 °K). The reverse acting PID controller gradually increases the output to 1.
  • From 2.5 seconds to 4 seconds, the difference between the condenser water return temperature and the chilled water supply temperature is 13 °K and it is greater than the minimum LIFT (10 °K). The reverse acting PID controller gradually decreases the output to 0.
  • After 4 seconds, the head pressure control loop becomes disabled (uHeaPreEna=false). The loop output is not valid and will not be used.

Components

TypeNameDefaultDescription
Buildings.Controls.OBC.ASHRAE.G36.Plants.Chillers.HeadPressure.Subsequences.ControlLoopchiHeaPreLooOutput chiller head pressure control loop signal
Buildings.Controls.OBC.CDL.Logical.Sources.PulsebooPulHead pressure control enabling status
Buildings.Controls.OBC.CDL.Reals.Sources.ConstantTChiWatSupMeasured chilled water supply temperature
Buildings.Controls.OBC.CDL.Reals.Sources.PulseTConWatRetMeasured condenser water return temperature

Revisions

  • March 22, 2019, by Jianjun Hu:
    First implementation.