Fault detection
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for fault detection in a power control system. In one aspect, a method includes measuring a plurality of values of a feedback voltage from a power control system over a period of time; determining a rate of feedback voltage change based on the measured values of the feedback voltage and a duration of the period of time; determining, with a controller, that the determined rate of feedback voltage change is smaller than a threshold rate of change; and in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting a fault indication signal to the power control system.
1. A method comprising:
measuring, by a controller, a plurality of values of a feedback voltage from a power control system over a period of time, the power control system being configured to provide an output voltage, the feedback voltage being associated with the output voltage, a response time being estimated for the feedback voltage varying from an initial lower voltage to a higher voltage at a stable level based on one or more properties of the power control system, the period of time being predetermined based on the estimated response time;
determining, by the controller, a rate of feedback voltage change based on the measured values of the feedback voltage and a duration of the period of time;
determining, by the controller, that the determined rate of feedback voltage change is smaller than a threshold rate of change; and
in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting, by the controller, a fault indication signal to the power control system.
2. The method of claim 1 , further comprising determining that the power control system is turned on at an initial time point,
wherein measuring a plurality of values of a feedback voltage over a period of time comprises:
measuring a first value of the feedback voltage at a first time point substantially close to the initial time point; and
after the period of time and at a second time point, measuring a second value of the feedback voltage.
3. The method of claim 2 , wherein determining a rate of feedback voltage change comprises calculating the rate of feedback voltage change by dividing a difference between the first and second values of the feedback voltage by the duration of the period of time.
4. The method of claim 1 , wherein the power control system includes a switch and a control integrated circuit (IC), the control IC being configured to control the switch to turn on or off the power control system.
5. The method of claim 4 , wherein the control IC is configured to receive the fault indication signal and to control the switch to turn off the power control system upon receiving the fault indication signal.
6. The method of claim 4 , wherein the switch includes a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or a bipolar junction transistor (BJT).
7. The method of claim 1 , wherein the power control system includes an RLC circuit, and wherein the period of time is predetermined based on a response time of the RLC circuit, the period of time being substantially shorter than the response time of the RLC circuit.
8. The method of claim 7 , wherein the period of time is about one percent of the response time of the RLC circuit.
9. The method of claim 7 , wherein the threshold rate of change is predetermined based on electrical characteristics of the RLC circuit.
10. The method of claim 1 , wherein the power control system includes a DC-to-DC power converter or an AC-to-DC power converter.
11. A controller coupled to a power control system and configured to perform operations including:
measuring a plurality of values of a feedback voltage from the power control system over a period of time, the power control system being configured to provide an output voltage, the feedback voltage being associated with the output voltage, a response time being estimated for the feedback voltage varying from an initial lower voltage to a higher voltage at a stable level based on one or more properties of the power control system, the period of time being predetermined based on the estimated response time;
determining a rate of feedback voltage change based on the measured values of the feedback voltage and a duration of the period of time;
determining that the determined rate of feedback voltage change is smaller than a threshold rate of change; and
in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting a fault indication signal to the power control system.
12. The controller of claim 11 , the operations comprising determining that the power control system is turned on at an initial time point,
wherein measuring a plurality of values of a feedback voltage over a period of time comprises:
measuring a first value of the feedback voltage at a first time point substantially close to the initial time point; and
after the period of time and at a second time point, measuring a second value of the feedback voltage.
13. The controller of claim 12 , wherein determining a rate of feedback voltage change comprises calculating the rate of feedback voltage change by dividing a difference between the first and second values of the feedback voltage by the duration of the period of time.
14. The controller of claim 11 , wherein the power control system includes a switch and a control integrated circuit (IC), the control IC being configured to control the switch to turn on or off the power control system.
15. The controller of claim 14 , wherein the control IC is configured to receive the fault indication signal and to control the switch to turn off the power control system upon receiving the fault indication signal.
16. The controller of claim 14 , wherein the switch includes a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or a bipolar junction transistor (BJT).
17. The controller of claim 11 , wherein the power control system includes an RLC circuit, and wherein the period of time is predetermined based on a response time of the RLC circuit, the period of time being substantially shorter than the response time of the RLC circuit.
18. The controller of claim 17 , wherein the period of time is about one percent of the response time of the RLC circuit.
19. The controller of claim 17 , wherein the threshold rate of change is predetermined based on electrical characteristics of the RLC circuit.
20. One or more non-transitory storage media embodying logic configured when executed to cause a controller to perform operations comprising:
measuring a plurality of values of a feedback voltage from a power control system over a period of time, the power control system being configured to provide an output voltage, the feedback voltage being associated with the output, a response time being estimated for the feedback voltage varying from an initial lower voltage to a higher voltage at a stable level based on one or more properties of the power control system, the period of time being predetermined based on the estimated response time;
determining a rate of feedback voltage change based on the measured values of the feedback voltage and the predetermined duration of the period of time;
determining that the determined rate of feedback voltage change is smaller than a threshold rate of change; and
in response to determining that the determined rate of feedback voltage change is smaller than the threshold rate of change, transmitting a fault indication signal to the power control system.
21. The method of claim 1 , wherein the duration of the period of time is substantially smaller than the estimation of the response time.
22. The method of claim 1 , wherein the power control system is configured to provide the output voltage to a load circuit, and
wherein the estimation of the response time is determined based on the one or more properties of the power control system and one or more properties of the load circuit.
23. The method of claim 22 , wherein the threshold rate of change is predetermined based on the one or more properties of the power control system and the one or more properties of the load circuit.
24. The method of claim 1 , wherein measuring the plurality of values of the feedback voltage over the period of time comprises:
measuring, by the controller, the plurality of values of the feedback voltage over the period of time at a sampling frequency, wherein the sampling frequency is predetermined based on the predetermined period of time.
25. The method of claim 24 , wherein the predetermined period of time and the predetermined sampling frequency are stored in the controller.
26. The method of claim 1 , wherein a varying curve is estimated for the feedback voltage to vary from the initial lower voltage to the higher voltage at the stable level over the response time.
27. The method of claim 26 , wherein the varying curve comprises a monotonically increasing curve.