System and method for a closed-loop bake-out control
AssigneeWatlow Electric Manufacturing Company
InventorsLincoln KIRCHOFF, Lukas THENMAIER
Life of this patent
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Abstract
A control system for operating a heater includes a controller configured to determine an operational power level based on a measured performance characteristic of the heater, a power set-point, and a power control algorithm, determine a bake-out power level based on a measured leakage current at the heater, a leakage current threshold, and a moisture control algorithm, and select a power level to be applied to the heater. The selected power level is the lower power level from among the operational power level and the bake-out power level.
Claims20
A control system for operating a heater, the control system comprising:
- a controller configured to:
- determine an operational power level based on a measured performance characteristic of the heater, a power set-point, and a power control algorithm,
- determine a bake-out power level based on a measured leakage current at the heater, a leakage current threshold, and a moisture control algorithm, and
- select a power level to be applied to the heater, wherein the selected power level is the lower power level from among the operational power level and the bake-out power level.
A method for controlling a heater comprising:
- measuring a performance characteristic of the heater;
- measuring a leakage current;
- determining an operational power level based on the measured performance characteristic, a power set-point, and a power control algorithm;
- determining a bake-out power level based on the measured leakage current, a leakage current threshold, and a moisture control algorithm;
- and
- applying one of the operational power level or the bake-out power level as a selected power level to the heater.
A method for controlling moisture within a heater, the method comprising:
- operating the heater in a primary operation mode to heat a workpiece, wherein in the primary operation mode, an operational power level is applied to the heater;
- measuring, by a leakage current sensor, a leakage current of the heater, wherein the leakage current is indicative of moisture within the heater;
- determining a bake-out power level based on the measured leakage current, a leakage current threshold, and a moisture control algorithm, wherein the moisture control algorithm is defined as a proportional-integral-derivative (PID) control;
- operating the heater in a bake-out mode in response to the bake-out power level being less than the operational power level;
- and
- operating the heater in the primary operation mode in response to the bake-out power level being greater than the operational power level.
Dependencies are inferred from the claim text.