Adaptive PID control for chilled water CRAC units
AssigneeVertiv Corporation
InventorCraig A. Brunstetter
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to a proportional, integral, derivative (PID) control system for controlling a cooling component of a cooling unit. The system may make use of a PID actuator position controller, a memory in communication with the PID actuator position controller, and a plurality of look-up tables. The look-up tables may be stored in the memory and may set forth different proportional “P”, integral (“I”) and derivative (“D”) gains based on an operating variable associated with operation of the cooling component of the cooling unit. The PID actuator position controller uses the lookup tables together with determination of projected data and historical data, to adjust at least one of the P, I and D gains in real time.
Claims15
A computer room air conditioning (CRAG) unit incorporating a proportional, integral, derivative (PID) control system for controlling a cooling component of a cooling unit to assist in controlling a supply air temperature of air discharged from the CRAC unit, the system including:
- a supply air temperature sensor;
- a PID controller in communication with the supply air temperature sensor;
- a memory in communication with the PID controller;
- a plurality of look-up tables stored in the memory and setting forth different proportional “P”, integral (“I”) and derivative (“D”) gains based on an operating variable associated with operation of the cooling component of the cooling unit;
- the cooling component including an electrically adjustable component being in communication with the PID controller and helping to control performance of the CRAG unit at least in part in response to the supply air temperature;
- and
- wherein the PID controller uses the look-up tables together with a limited slope calculation which defines projected behavior of the operating variable, to adjust at least one of the P, I and D gains in real time, in controlling the cooling component to modify performance of the CRAC unit.
A computer room air conditioning (CRAC) unit incorporating a proportional, integral, derivative (PID) control system for controlling a cooling component of the CRAC unit to assist in controlling a supply air temperature of air being discharged from the CRAC unit, the system including:
- a PID controller;
- a sensor configured to sense a temperature of air associated with operation of the CRAC unit and to provide an electrical signal to the PID controller;
- a memory in communication with the PID controller;
- a plurality of look-up tables stored in the memory and setting forth different proportional (“P”), integral (“I”) and derivative (“D”) gains based on an operating variable associated with operation of the cooling component;
- a plurality of algorithms stored in the memory to help determine the gains to be used in controlling the cooling component;
- the cooling component including at least one of a motor driven unit fan and an electrically adjustable chilled water (CW) valve, and being in bi-directional electrical communication with the PID controller and responsive to electrical signals from the PID controller such that the PID controller controls the cooling component to control performance of the CRAC unit in accordance with the air temperature;
- and
- wherein the PID controller uses the look-up tables together with a limited slope calculation, wherein the limited slope calculation defines projected behavior of the operating variable to determine different P, I and D gains to be used by the PID controller in controlling performance of the CRAC unit, within a plurality of different operating regions of the operating variable.
A method for controlling a computer room air conditioner (CRAC) unit in a manner such that operation of a cooling component of the CRAC unit is modified to assist in controlling a supply air temperature of air being discharged by the CRAC unit, the method including:
- using a PID controller of the CRAC unit to control a proportional gain (P), an integral gain (I) and a derivative gain (D), wherein the proportion gain, the integral gain and the derivative gain are used to modify operation of the CRAC unit;
- using a memory to communicate with the PID controller;
- storing a plurality of look-up tables in the memory;
- using the look-up tables to hold different proportional, integral and derivative gains based on an operating variable associated with operation of the cooling component;
- and
- causing the PID controller to access the look-up tables and a limited slope calculation to determine projected operating data for the cooling component, wherein the cooling component includes at least one of a motor driven unit fan and an electrically adjustable chilled water (CW) supply valve, and to adjust at least one of the P, I and D gains for the cooling component in real time in response to evaluations of at least the projected operating data, to control the CRAC unit.
Dependencies are inferred from the claim text.