blockZoneStates

Select the zone state
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Information

Block that outputs the zone state. It first checks if the zone is in heating state; if not, it checks if the zone is in cooling state; otherwise it is in deadband state.

These states are defined in Buildings.Controls.OBC.ASHRAE.G36.Types.ZoneStates.

The logic of the block is as follows.

  1. The zone state is heating when both of the following two conditions are satisfied: (i) The heating control signal satisfies uHea > uHigh, where uHigh is a parameter, and (ii) the following condition is satisfied uHea - uCoo > uLow, where uCoo is the cooling control signal and uLow is a parameter. The second condition is used to avoid errors when uHea > 0 and uCoo > 0 at the same time.
  2. The zone state is cooling when the zone state is not heating and the cooling control signal satisfies uCoo > uHigh, where uHigh is a parameter. If uCoo < uLow, then the zone state is not cooling.
  3. The zone state is deadband when it is neither in heating state nor in cooling state.

Parameters

TypeNameDefaultDescription
RealuLow0.01Hysteresis parameter uLow for heating and cooling control signals to avoid chattering
RealuHigh0.05Hysteresis parameter uHigh for heating and cooling control signals to avoid chattering

Connectors

TypeNameDefaultDescription
Buildings.Controls.OBC.CDL.Interfaces.RealInputuHeaHeating control signal
Buildings.Controls.OBC.CDL.Interfaces.RealInputuCooCooling control signal
Buildings.Controls.OBC.CDL.Interfaces.IntegerOutputyZonStaZone state

Revisions

  • March 13, 2020, by Jianjun Hu:
    Replaced multiSum block with two addition blocks to avoid vector related implementation.
    This is for #1709.
  • September 11, 2019, by Kun Zhang:
    Improved the implementation to avoid issues when heating and cooling controls occur at the same time.
  • October 24, 2018, by David Blum:
    First implementation.