blockEnable

Plant enable

Information

The plant is enabled when it has been disabled for at least the duration dtRun and:

  • Number of plant requests > number of ignored requests nReqIgn, and
  • For cooling systems: outdoor air temperature > outdoor air lockout temperature TOutLck, and
  • For heating systems: outdoor air temperature < outdoor air lockout temperature TOutLck, and
  • The enable schedule is active.

The plant is disabled when it has been enabled for at least the duration dtRun and:

  • Number of plant requests ≤ number of ignored requests nReqIgn for at least the duration dtReq, or
  • For cooling systems: outdoor air temperature < outdoor air lockout temperature TOutLck minus hysteresis dTOutLck, or
  • For heating systems: outdoor air temperature > outdoor air lockout temperature TOutLck plus hysteresis dTOutLck, or
  • The plant enable schedule is inactive.

Parameters

TypeNameDefaultDescription
Buildings.Templates.Plants.Controls.Types.ApplicationtypType of application
Booleanhave_inpSchfalseSet to true to provide schedule via software input point
Real[:,2]sch[0, 1; 24*3600, 1]Enable schedule
RealTOutLckif typ == Buildings.Templates.Plants.Controls.Types.Application.Heating then 18 + 273.15 else 15 + 273.15Outdoor air lockout temperature
RealdTOutLck0.5Hysteresis for outdoor air lockout temperature
IntegernReqIgn0Number of ignored requests
RealdtRun15*60Minimum runtime of enable and disable states
RealdtReq3*60Runtime with low number of request before disabling

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.BooleanInputu1SchSystem enable via schedule
Buildings.Controls.OBC.CDL.Interfaces.IntegerInputnReqPlaNumber of plant requests
Buildings.Controls.OBC.CDL.Interfaces.RealInputTOutOutdoor air temperature
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutputy1Enable command

Components

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Logical.Sources.TimeTableschEnaEnable schedule
Buildings.Controls.OBC.CDL.Integers.GreaterThresholdgreIgnReturn true if number of requests > number of ignored requests
Buildings.Controls.OBC.CDL.Reals.GreaterThresholdgreLckReturn true if OAT > lockout temperature
Buildings.Controls.OBC.CDL.Reals.LessThresholdlesLckReturn true if OAT < lockout temperature
Buildings.Controls.OBC.CDL.Logical.PrepreEnaLeft limit (in discrete-time) of enable signal
Buildings.Controls.OBC.CDL.Logical.TimertimEnaReturn true if system has been enabled for specified duration
Buildings.Controls.OBC.CDL.Logical.NotdisReturn true if disabled
Buildings.Controls.OBC.CDL.Logical.TimerrunDisReturn true if system has been disabled for specified duration
Buildings.Controls.OBC.CDL.Logical.MultiAndmulAndCombine enable conditions
Buildings.Controls.OBC.CDL.Logical.MultiOrmulOrCombine disable conditions
Buildings.Controls.OBC.CDL.Logical.NotdisSchReturn true if disabled by schedule
Buildings.Controls.OBC.CDL.Integers.LessEqualThresholdlowIgnReturn true if number of requests ≤ number of ignored requests
Buildings.Controls.OBC.CDL.Logical.TimertimLowReqReturn true if low number of requests for specified duration
Buildings.Controls.OBC.CDL.Reals.LessThresholdlowLckHysReturn true if OAT < lockout temperature - hysteresis
Buildings.Controls.OBC.CDL.Reals.GreaterThresholdgreLckHysReturn true if OAT > lockout temperature + hysteresis
Buildings.Controls.OBC.CDL.Logical.AndandRunDisable conditions met AND enable minimum runtime exceeded
Buildings.Controls.OBC.CDL.Logical.LatchlatClear enable signal if disable conditions are met

Revisions

  • March 29, 2024, by Antoine Gautier:
    First implementation.