Output regulation with dynamic digital control loop compensation
View Patent ↗A digital compensator detects time-varying or periodic variations in the input voltage and, via the use of an iterative-learning control (“ILC”) system, a repetitive-control (“RC”) system, or a run-to-run control (“R2R”) system, generates a compensating signal based on prior behavior of the time variance.
1. A system for regulating an output voltage or current given an input voltage, the system comprising:
an analog-to-digital converter for sampling a signal representing a load current or voltage;
a digital controller for:
i. detecting a time-varying disturbance in the input voltage; and
ii. generating a compensating signal based at least in part thereon; and
a modulator for varying the load current or voltage based at least in part on the compensating signal to thereby substantially remove effects of the time-varying disturbance therefrom.
2. The system of claim 1 , wherein the digital controller comprises at least one of a repetitive controller, an iterative-learning controller, or run-to-run controller.
3. The system of claim 1 , wherein the digital controller implements a transfer function for generating the output signal.
4. The system of claim 1 , further comprising a current-sense resistor for translating the output current to a voltage.
5. The system of claim 1 , further comprising a filter for removing high-frequency components of the signal representing the load current or voltage.
6. The system of claim 1 , further comprising an amplifier for amplifying the signal representing the load current or voltage.
7. The system of claim 1 , wherein the modulator is a pulse-width modulator in an inverted floating Buck regulator circuit.
8. The system of claim 7 , further comprising a switch for varying the load current or voltage based on an output of the pulse-width modulator.
9. The system of claim 1 , wherein a source of the time-varying disturbance comprises a power transformer or a rectifier.
10. The system of claim 1 , further comprising an LED light source for generating light, the output voltage or current being applied thereto.
11. The method of claim 10 , wherein the compensating signal varies a duty cycle of a pulse-width modulator that varies the load voltage or current.
12. A system for regulating an output voltage or current, the system comprising:
inverting floating Buck regulator circuitry for controlling the voltage or current through a load;
a pulse-width modulator for operating the Buck regulator circuitry; and
a digital controller for:
i. detecting a time-varying disturbance in the input voltage; and
ii. varying a duty cycle of the pulse-width modulator to substantially remove effects of the time-varying disturbance from the output voltage or current.
13. A method for regulating an output voltage or current given an input voltage, the method comprising:
sampling a signal representing a load current or voltage;
detecting a time-varying disturbance in the input voltage;
generating a compensating signal based at least in part thereon; and
varying the load current or voltage based at least in part on the compensating signal to thereby remove effects of the time-varying disturbance therefrom.
14. The method of claim 13 , wherein a source of the time-varying disturbance comprises a power transformer or a rectifier.
15. The method of claim 13 , wherein the time-varying disturbance repeats periodically.
16. The method of claim 13 , wherein generating the compensating signal comprises synthesizing an actuation sequence in a current repetition based on a tracking error detected in a prior repetition.
17. The method of claim 13 , wherein generating the compensating signal comprises generating a model of the time-varying disturbance.