Pulse modulation adaptive control method for activating an electrical device

A method for controlling a device of a facility management system, the device producing a change of an environmental characteristic in a building, said method comprising:

• specifying a desired value for the environmental characteristic;
• defining a desired maximum amplitude of variation (D) in the measured value;
• receiving a control signal (u) representative of a deviation of a measured value from the desired value for the environmental characteristic;
• and
• producing a pulse train (h) that controls turning on and off the device, the pulse train being a pulse-width, pulse-frequency modulated signal having a cycle period during which occurs a pulse of a given duration (TON), wherein the cycle period and the given duration are dynamically varied in response to the control signal so that the cycle period is maximized while an amplitude of variation of the measured value is maintained no greater than the maximum amplitude of variation (D) when the system is in a steady state pulsing condition.

A method for controlling a device of a facility management system, wherein the device has a plurality of stages and produces a change of an environmental characteristic in a building, the method comprising:

• specifying a desired value for the environmental characteristic;
• defining a desired maximum amplitude of variation (D) within which the measured value is permitted to vary;
• receiving a control signal (u) representative of a difference in magnitude between a measured value for the environmental characteristic and the desired value for the environmental characteristic;
• determining, in response to the control signal (u), a number of first stages (R) that are to operate at full capacity;
• determining, in response to the control signal (u), a fractional amount (v) of full capacity that a second stage is to operate at;
• and
• producing a pulsed output signal (h) that controls turning on and off of the second state, wherein the output signal is a pulse-width, pulse-frequency modulated signal having a cycle period during which a pulse of a given duration occurs, the cycle period and the given duration of the pulse being varied in response to the fractional amount (v) so that the cycle period is maximized while variation of the measured value is maintained no greater than the maximum amplitude of variation D when the system is in a steady state pulsing condition.

An apparatus for controlling a device of a facility management system, wherein the device controls an operational parameter of a building, comprising:

• means for receiving a control signal (u) representative of a deviation in magnitude between a measured value of the operational parameter and a desired value of the operational parameter;
• means for defining a desired maximum amplitude of variation (D) for the measured value;
• and
• means for producing a pulsed output signal (h) that turns the device on and off, wherein the output signal is a pulse-width, pulse-frequency modulated signal having a cycle period during which a pulse of a given duration (TON) occurs, the cycle period and the given duration of the pulse being dynamically calculated in response to changes in the control signal to maximize the cycle period while maintaining the amplitude of variation of the measured value equal to or below the maximum amplitude of variation (D) when the system is in a steady state pulsing condition.