Systems and methods for inductive overvoltage protection of PFC bulk capacitors in power supplies
View Patent ↗Systems and methods are provided that may be implemented for overvoltage protection of bulk capacitors employed in power factor correction (PFC) circuitry components of switched mode power supply units (PSUs) using one or more inductive overvoltage feedback protection paths (OVPs) to monitor a voltage indicative of a PFC bulk capacitor by sensing the real time voltage at one or both of the primary and/or secondary side windings of a PSU transformer, and/or using an auxiliary windings of a PSU transformer.
1. A switched mode power supply unit (PSU) system, comprising:
transformer circuitry having a primary side winding and a secondary side winding;
a primary side including at least one bulk capacitor configured to receive a power input and coupled to maintain an output voltage on the primary side winding;
a secondary side including DC secondary side circuitry and the secondary side winding of the transformer, the DC secondary side circuitry being configured to receive power from the primary side through the transformer and to produce a DC power output therefrom;
at least one PSU processing device coupled to control the primary side of the PSU to provide DC power to the primary side winding of the transformer; and
at least one inductive overvoltage protection (OVP) feedback path coupled to the PSU processing device, the inductive OVP path being inductively coupled to the primary winding of the transformer to receive a voltage from the primary winding that is indicative of a real time voltage on the bulk capacitor.
2. The system of claim 1 , where the primary side includes AC primary side switcher circuitry and the primary side winding of the transformer, the AC primary side switcher circuitry configured to receive the power input as an AC power input; where the DC secondary side circuitry is configured to receive power from the AC primary side switcher circuitry through the transformer and to produce the DC power output therefrom; and where the at least one PSU processing device is coupled to control the primary side switcher circuitry to provide DC power to the primary side winding of the transformer.
3. The system of claim 1 , where the inductive OVP feedback path comprises a sense winding provided on the secondary side of the PSU system, the sense winding being inductively coupled to the primary winding of the transformer.
4. The system of claim 1 , where primary side of the PSU includes the PSU processing device; and where the inductive OVP feedback path is coupled between the secondary side sense winding and the PSU processing device across an isolation barrier element.
5. The system of claim 1 , where the inductive OVP feedback path comprises a sense winding provided on the primary side of the PSU system, the sense winding being inductively coupled to the primary winding of the transformer.
6. The system of claim 1 , where the inductive OVP feedback path further comprises a sense winding inductively coupled to the primary winding of the transformer.
7. The system of claim 6 , where the inductive OVP feedback path further comprises an OVP sense capacitor coupled in parallel with the sense winding.
8. The system of claim 7 , where the inductive OVP feedback path further comprises OVP sense circuitry coupled between the sense winding and the PSU processing device, the OVP sense circuitry including the OVP sense capacitor; and
where the OVP sense circuitry is configured to:
compare an OVP trigger voltage threshold value to a value of voltage that is based on the real time voltage induced on the OVP sense capacitor from the primary winding of the transformer through the sense winding,
provide an OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed to exceed the OVP trigger voltage threshold value, and
not provide the OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed not to exceed the OVP trigger voltage threshold value; and
where the PSU processing device is configured to control the primary side of the PSU to:
provide DC power to the primary side winding of the transformer in the absence of an OVP control signal provided from the OVP sense circuitry, and
stop providing DC power to the primary side winding of the transformer upon receipt of the OVP control signal provided from the OVP sense circuitry.
9. The system of claim 1 , further comprising at least one resistive OVP feedback path coupled to the PSU processing device, the resistive OVP feedback path being electrically coupled to the bulk capacitor to receive a voltage indicative of the real time voltage on the bulk capacitor.
10. The system of claim 9 , where the resistive OVP feedback path is configured to provide a voltage signal indicative of the real time voltage on the bulk capacitor to the PSU processing device; and where the PSU processing device is configured to control the primary side of the PSU to:
provide DC power to the primary side winding of the transformer when the voltage signal is indicative of a real time voltage on the bulk capacitor that does not exceed a trigger voltage threshold value; and
stop providing DC power to the primary side winding of the transformer when the voltage signal is indicative of a real time voltage on the bulk capacitor that exceeds a trigger voltage threshold value.
11. The system of claim 1 , where the PSU is an AC-DC adapter system.
12. A DC-powered information handling system, comprising:
a DC-powered system load; and
an AC-DC adapter system having AC primary side switcher circuitry configured to receive an AC power input, and a DC secondary side that receives power from the AC primary side switcher circuitry to produce a DC power output;
where the DC-powered information handling system is configured to be coupled by a DC power connection to receive DC power from the DC power output of the AC-DC adapter system; and
where the AC-DC adapter system comprises:
transformer circuitry having a primary side winding and a secondary side winding,
a primary side including the AC primary side switcher circuitry and the primary side winding of the transformer, the AC primary side switcher circuitry configured to receive the AC power input and including at least one bulk capacitor coupled to maintain an output voltage on the primary side winding,
a secondary side including the DC secondary side circuitry and the secondary side winding of the transformer, the DC secondary side circuitry being configured to receive power from the AC primary side switcher circuitry through the transformer and to produce the DC power output therefrom,
at least one PSU processing device coupled to control the primary side switcher circuitry to provide DC power to the primary side winding of the transformer, and
at least one inductive overvoltage protection (OVP) feedback path coupled to the PSU processing device, the inductive OVP path being inductively coupled to the primary winding of the transformer to receive a voltage from the primary winding that is indicative of a real time voltage on the bulk capacitor.
13. The system of claim 12 , where the inductive OVP feedback path further comprises a sense winding inductively coupled to the primary winding of the transfoimer, the sense winding being provided on either the primary or secondary side of the AC-DC adapter system; where the inductive OVP feedback path further comprises an OVP sense capacitor coupled in parallel with the sense winding; and where the inductive OVP feedback path further comprises OVP sense circuitry coupled between the sense winding and the PSU processing device, the OVP sense circuitry including the OVP sense capacitor; and
where the OVP sense circuitry is configured to:
compare an OVP trigger voltage threshold value to a value of voltage that is based on the real time voltage induced on the OVP sense capacitor from the primary winding of the transformer through the sense winding,
provide an OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed to exceed the OVP trigger voltage threshold value, and
not provide the OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed not to exceed the OVP trigger voltage threshold value; and
where the PSU processing device is configured to control the primary side switcher circuitry to:
provide DC power to the primary side winding of the transformer in the absence of an OVP control signal provided from the OVP sense circuitry, and
stop providing DC power to the primary side winding of the transformer upon receipt of the OVP control signal provided from the OVP sense circuitry.
14. The system of claim 12 , where the DC-powered information handling system is a notebook computer.
15. A method of operating a switched-mode power supply unit (PSU) system including a primary side and a secondary side that are separated by a transformer, the method comprising:
receiving a power input in the primary side of the PSU, the primary side of the PSU including a primary side winding of the transformer, and at least one bulk capacitor coupled to maintain an output voltage on the primary side winding;
using the PSU processing device to control the primary side to provide DC power to the primary side winding of the transformer;
receiving power in the secondary side of the PSU from the primary side of the PSU through the transformer, the secondary side of the PSU including a secondary side winding of the transformer and DC secondary side circuitry, the power being received in the secondary side of the PSU from the secondary winding of the transformer;
producing a DC power output from the DC secondary side circuitry; and
using at least one inductive overvoltage protection (OVP) feedback path to inductively receive a voltage from the primary winding of the transformer that is indicative of a real time voltage on the bulk capacitor and to provide a signal to the PSU processing device based at least in part on the value of the received voltage that is indicative of the real time voltage on the bulk capacitor.
16. The method of claim 15 , where the primary side of the PSU further comprises AC primary side switcher circuitry; and where the method further comprises:
receiving the power input as an AC power input in the AC primary side switcher circuitry;
using the PSU processing device to control the primary side switcher circuitry to provide DC power to the primary side winding of the transformer; and
receiving the power in the secondary side of the PSU from the AC primary side switcher circuitry through the transformer.
17. The method of claim 15 , where the inductive OVP feedback path comprises a sense winding provided on the secondary side of the PSU system; where the primary side of the PSU includes the PSU processing device; and where the method further comprises:
using the sense winding to inductively receive the voltage from the primary winding of the transformer that is indicative of a real time voltage on the bulk capacitor; and
providing an OVP control signal to the PSU processing device across an isolation barrier element.
18. The method of claim 17 , where the inductive OVP feedback path further comprises an OVP sense capacitor coupled in parallel with the sense winding; where the inductive OVP feedback path further comprises OVP sense circuitry coupled between the sense winding and the PSU processing device, the OVP sense circuitry including the OVP sense capacitor; and where the method further comprises:
using the OVP sense circuitry to:
compare an OVP trigger voltage threshold value to a value of voltage that is based on the real time voltage induced on the OVP sense capacitor from the primary winding of the transformer through the sense winding,
provide an OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed to exceed the OVP trigger voltage threshold value, and
not provide the OVP control signal to the PSU processing device when the value of voltage that is based on the real time voltage induced on the OVP sense capacitor is sensed not to exceed the OVP trigger voltage threshold value; and
using the PSU processing device to control the primary side of the PSU to:
provide DC power to the primary side winding of the transformer in the absence of an OVP control signal provided from the OVP sense circuitry, and
stop providing DC power to the primary side winding of the transformer upon receipt of the OVP control signal provided from the OVP sense circuitry.
19. The method of claim 15 , further comprising:
using at least one resistive OVP feedback path electrically coupled to the bulk capacitor to receive a voltage indicative of a real time voltage on the bulk capacitor;
using the resistive OVP feedback path to provide the voltage signal indicative of the real time voltage on the bulk capacitor to the PSU processing device; and
using the PSU processing device to control the primary side of the PSU to:
provide DC power to the primary side winding of the transformer when the voltage signal is indicative of a real time voltage on the bulk capacitor that does not exceed a trigger voltage threshold value, and
stop providing DC power to the primary side winding of the transformer when the voltage signal is indicative of a real time voltage on the bulk capacitor that exceeds a trigger voltage threshold value.
20. The method of claim 15 , where the PSU is an AC-DC adapter system; and where the method further comprises providing the DC power output from the DC secondary side circuitry to a DC-powered information handling system across a DC power connection to power a DC-powered system load of the DC-powered information handling system.
21. The method of claim 20 , where the DC-powered information handling system is a notebook computer.
22. The system of claim 1 , where the inductive OVP feedback path and the PSU processing device are together configured to protect the primary side bulk capacitor by controlling the primary side of the PSU based on the received voltage from the primary winding of the transformer to limit the real time voltage on the bulk capacitor.
23. The system of claim 1 , further comprising at least one resistive OVP feedback path coupled to the PSU processing device, the resistive OVP feedback path being electrically coupled to the bulk capacitor to receive a voltage indicative of the real time voltage on the bulk capacitor; where the inductive OVP feedback path comprises a sense winding provided on the secondary side of the PSU system, the sense winding being inductively coupled to the primary winding of the transformer; and where the inductive sense winding is provided on the same side of a printed circuit board (PCB) as are the primary side and secondary side transformer windings and that is opposite from a side of the PCB on which resistors of the resistive OVP feedback path are provided.
24. The system of claim 12 , where the inductive OVP feedback path and the PSU processing device are together configured to protect the primary side bulk capacitor by controlling the primary side of the PSU based on the received voltage from the primary winding of the transformer to limit the real time voltage on the bulk capacitor.
25. The method of claim 15 , further comprising using the inductive OVP feedback path and the PSU processing device to protect the primary side bulk capacitor by controlling the primary side of the PSU based on the received voltage from the primary winding of the transformer to limit the real time voltage on the bulk capacitor.