HVAC system with on-off control

1. A controller for HVAC equipment of a plant, the controller comprising a processing circuit configured to:

predict an impact of a time delay of the plant on a performance variable received as feedback from the plant, wherein the time delay is an amount of time that elapses between:

a first time at which the HVAC equipment performs a transition between an on state and an off-state; and

a second time at which the performance variable begins to change as a result of the transition or changes by an amount exceeding a threshold as a result of the transition;

artificially increase or decrease a value of the performance variable using an adjustable time delay parameter to at least partially negate the impact of the time delay on the performance variable; and

use the artificially increased or decreased value of the performance variable in on-off feedback control to operate the HVAC equipment, wherein the on-off feedback control comprises transitioning the HVAC equipment or a stage of the HVAC equipment between the on-state and the off-state based on a setpoint value.

2. The controller of claim 1 , wherein the on-off feedback control comprises deadband control and the controller is configured to transition the HVAC equipment or the stage of the HVAC equipment between the on-state and the off-state based on the setpoint value and a deadband value.

3. The controller of claim 1 , wherein the controller is configured to artificially increase or decrease the value of the performance variable using a filter based on an exponential expansion of a transfer function that at least partially negates the impact of the time delay on the performance variable.

4. The controller of claim 3 , wherein the controller is configured to artificially increase or decrease the value of the performance variable using a plurality of filters in series that at least partially negate the impact of the time delay of the plant on the performance variable.

5. The controller of claim 1 , wherein the controller is configured to obtain the adjustable time delay parameter based on samples of the performance variable received over a time period.

6. The controller of claim 5 , wherein the controller is configured to obtain the adjustable time delay parameter by perturbing an input to the plant and observing a dynamic response of the plant to the perturbed input.

7. The controller of claim 1 , wherein the controller is configured to increase or decrease the adjustable time delay parameter in response to the time delay of the plant changing.

8. The controller of claim 1 , wherein the controller is configured to obtain the adjustable time delay parameter based on at least one of a type of the HVAC equipment, one or more parameters of a space of the plant, or one or more parameters of the plant.

9. A method for performing on-off control for a plant, the method comprising:

predicting an impact of a time delay of the plant on a performance variable received as feedback from the plant, wherein the time delay is an amount of time that elapses between:

a first time at which HVAC equipment performs a transition between an on-state and an off-state; and

a second time at which the performance variable begins to change as a result of the transition or changes by an amount exceeding a threshold as a result of the transition;

artificially increasing or decreasing a value of the performance variable using an adjustable time delay parameter to at least partially negate the impact of the time delay on the performance variable; and

using the artificially increased or decreased value of the performance variable in on-off feedback control to operate the HVAC equipment, wherein the on-off feedback control comprises transitioning the HVAC equipment or a stage of the HVAC equipment between the on-state and the off-state based on a setpoint value.

10. The method of claim 9 , further comprising increasing or decreasing the adjustable time delay parameter in response to a change in the time delay of the plant.

11. The method of claim 9 , wherein the performance variable is artificially increased or decreased using one or more filters and one or more samples of the performance variable, wherein each of the filters correspond to a portion of an exponential expansion of a transfer function that at least partially negates the impact of the time delay.

12. The method of claim 9 , further comprising selecting the adjustable time delay parameter based on at least one of a type of the HVAC equipment, one or more parameters of a space of the plant, or one or more parameters of the plant.

13. The method of claim 9 , further comprising:

perturbing an input to the plant;

observing a dynamic response of the plant to the perturbed input; and

obtaining the adjustable time delay parameter based on the dynamic response of the plant.

14. A system for controlling a plant, the system comprising:

HVAC equipment that operates to affect a performance variable of a plant; and

a controller comprising a processing circuit configured to:

predict an impact of a time delay of the plant on the performance variable received as feedback from the plant, wherein the time delay is an amount of time that elapses between:

a first time at which the HVAC equipment performs a transition between an on-state and an off-state; and

a second time at which the performance variable begins to change as a result of the transition or changes by an amount exceeding a threshold as a result of the transition;

artificially adjust a value of the performance variable using an adjustable time delay parameter to at least partially negate the impact of the time delay on the performance variable; and

use the artificially adjusted value of the performance variable in on-off feedback control to operate the HVAC equipment, wherein the on-off feedback control comprises transitioning the HVAC equipment or a stage of the HVAC equipment between the on-state and the off-state based on a setpoint value.

15. The system of claim 14 , wherein the controller is configured to increase or decrease the adjustable time delay parameter to account for a change in the time delay of the plant.

16. The system of claim 14 , wherein the controller is configured to artificially increase or decrease the value of the performance variable using a filter based on an exponential expansion of a transfer function that at least partially negates the impact of the time delay on the performance variable.