Selective protection circuit and method, and power supply system

• US 10,177,561 B2
• Filed: 08/14/2017
• Issued: 01/08/2019
• Est. Priority Date: 02/15/2015
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Zhang, Zhenxing, Xu, Jiansheng
• Primary Examiner(s): Ghulamali, Qutbuddin
• Application Number:
  US15/676,196
• Publication Number:
  US 20170346275A1
• Time in Patent Office: 512 Days
• Field of Search: 340638, 340292, 340635
• CPC Class Codes: G05F 3/205 Substrate bias-voltage generators for static stores G11C5/146
• CPC Class Codes: H01H 73/18 Means for extinguishing or suppressing arc magnet coil acting as blow-out device H01H71/38
• CPC Class Codes: H01H 83/10 operated by excess voltage, e.g. for lightning protection
• CPC Class Codes: H02H 3/07 and with permanent disconnection after a predetermined number of reconnection cycles
• CPC Class Codes: H02H 7/267 for parallel lines and wires
• CPC Class Codes: H02J 9/00 Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H02M 1/088 for the simultaneous control of series or parallel connected semiconductor devices

Abstract

A selective protection circuit includes a current-limiting module and a control module, where the current-limiting module includes a switch unit, and the switch unit includes a first end, a second end, and a control end; the first end is connected to a positive electrode of a bus voltage of an HVDC power supply, and the second end is connected to a positive electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting module; the control end is connected to the control module; and the control module is configured to output a control signal to the control end when a value of a total current flowing through the switch unit is greater than or equal to a preset threshold, so as to switch off the switch unit.

Claims

1. A selective protection circuit, comprising:

a current-limiting circuit; and

a control circuit,

wherein the selective protection circuit is included in a power supply that supplies power to at least two parallel load branches, wherein each load branch of the at least two parallel load branches comprises one voltage pre-regulator circuit;

wherein the current-limiting circuit comprises a switch unit, and the switch unit comprises a first end, a second end, and a control end;

wherein the first end is connected to a positive electrode of a bus voltage of the power supply, and the second end is connected to a positive electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting circuit;

or the first end is connected to a negative electrode of a bus voltage of the power supply, and the second end is connected to a negative electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting circuit;

wherein the control end is connected to the control circuit; and

wherein the control circuit is configured to output a control signal to the control end when a value of a total current flowing through the switch unit is greater than or equal to a preset threshold, so as to switch off the switch unit, wherein the preset threshold is greater than a maximum value of an operating current flowing through the switch unit.

2. The selective protection circuit according to claim 1, wherein:

the current-limiting circuit is located in a first load branch of the at least two parallel load branches, and a load branch connected to the current-limiting circuit is the first load branch;

or

the at least two parallel load branches are connected to the power supply by using at least two power distribution units (PDUs), the current-limiting circuit is located in a first PDU of the at least two PDUs, and a load branch connected to the current-limiting circuit is the load branch connected to the first PDU.

3. The selective protection circuit according to claim 1, wherein

the current-limiting circuit further comprises a unidirectional conduction unit and an inductor, and when the unidirectional conduction unit is on, a current flowing through the unidirectional conduction unit flows in a direction from a positive electrode of the unidirectional conduction unit to a negative electrode of the unidirectional conduction unit;

the positive electrode of the unidirectional conduction unit is connected to the negative electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit;

the negative electrode of the unidirectional conduction unit is connected to the positive electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit; and

one end of the inductor is connected to the negative electrode of the unidirectional conduction unit, and the other end is connected to the positive electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit.

4. The selective protection circuit according to claim 3, wherein the current-limiting circuit is located in a first load branch of the at least two parallel load branches, and when the voltage pre-regulator circuit is a boost circuit, the inductor is integrated with an inductor of the voltage pre-regulator circuit.

5. The selective protection circuit according to claim 3, wherein:

the control circuit is further configured to output another control signal to the control end after a first preset time period after the switch unit is switched off, so that the switch unit enters a hiccup current-limiting state, wherein the first preset time period is less than or equal to a time period in which the inductor supplies, when the switch unit is switched off and by using electric energy stored in the inductor, power to a load in the load branch connected to the current-limiting circuit.

6. The selective protection circuit according to claim 1, wherein:

a bus of the power supply supplies power to the control circuit.

7. The selective protection circuit according to claim 1, wherein the switch unit is a field effect transistor or a power transistor.

8. A method, applied to a scenario in which a power supply is used to supply power, wherein the power supply supplies power to at least two parallel load branches, and each load branch of the at least two parallel load branches comprises one voltage pre-regulator circuit;

and the method comprises;

detecting a value of a total current flowing through a target channel, wherein the target channel refers to a channel between a positive electrode of a bus voltage of the power supply and a positive electrode of a power supply of a voltage pre-regulator circuit in one load branch of the at least two parallel load branches, or a channel between a negative electrode of a bus voltage of the power supply and a negative electrode of a power supply of a voltage pre-regulator circuit in one load branch of the at least two parallel load branches; and

in response to the value of the total current being greater than or equal to a preset threshold, controlling to shut down the target channel, wherein the preset threshold is greater than a maximum value of an operating current flowing through the target channel.

9. The method according to claim 8, wherein after the controlling to shut down the target channel, the method further comprises:

after a first preset time period, controlling to periodically conduct and shut down the target channel, wherein both the first preset time period and a time period in which the target channel is shut down during periodic conduction and shutdown of the target channel are less than or equal to a time period in which there is no power outage in a load in a load branch connected using the target channel, when the target channel is shut down.

10. The method according to claim 9, wherein after the controlling to periodically conduct and shut down the target channel, the method further comprises:

after a second preset time period, when the value of the total current is still greater than or equal to the preset threshold, controlling to shut down the target channel;

or

after a second preset time period, when the value of the total current is less than the preset threshold, controlling to conduct the target channel,

wherein the second preset time period is greater than or equal to duration of a power-on phase of the target channel.

11. The method according to claim 8, wherein the controlling to shut down the target channel comprises:

after a third preset time period, if the value of the total current is still greater than or equal to the preset threshold, controlling to shut down the target channel, wherein the third preset time period is greater than or equal to duration of a lightning current in the target channel.

12. A power supply system, comprising:

a selective protection circuit; and

a power supply, wherein the power supply supplies power to at least two parallel load branches, and each load branch of the at least two parallel load branches comprises one voltage pre-regulator circuit;

wherein the selective protection circuit comprises a current-limiting circuit and a control circuit, wherein the current-limiting circuit comprises a switch unit, and the switch unit comprises a first end, a second end, and a control end;

wherein the first end is connected to a positive electrode of a bus voltage of the power supply, and the second end is connected to a positive electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting circuit;

or the first end is connected to a negative electrode of a bus voltage of the power supply, and the second end is connected to a negative electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting circuit;

wherein the control end is connected to the control circuit; and

wherein the control circuit is configured to output a control signal to the control end when a value of a total current flowing through the switch unit is greater than or equal to a preset threshold, so as to switch off the switch unit, wherein the preset threshold is greater than a maximum value of an operating current flowing through the switch unit.

13. The power supply system circuit according to claim 12, wherein:

the current-limiting circuit is located in a first load branch of the at least two parallel load branches, and a load branch connected to the current-limiting circuit is the first load branch;

or

the at least two parallel load branches are connected to the power supply by using at least two power distribution units (PDUs), the current-limiting circuit is located in a first PDU of the at least two PDUs, and a load branch connected to the current-limiting circuit is the load branch connected to the first PDU.

14. The power supply system circuit according to claim 12, wherein

the current-limiting circuit further comprises a unidirectional conduction unit and an inductor, and when the unidirectional conduction unit is on, a current flowing through the unidirectional conduction unit flows in a direction from a positive electrode of the unidirectional conduction unit to a negative electrode of the unidirectional conduction unit;

the positive electrode of the unidirectional conduction unit is connected to the negative electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit;

the negative electrode of the unidirectional conduction unit is connected to the positive electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit; and

one end of the inductor is connected to the negative electrode of the unidirectional conduction unit, and the other end is connected to the positive electrode of the power supply of the voltage pre-regulator circuit in the load branch connected to the current-limiting circuit.

15. The power supply system circuit according to claim 12, wherein the current-limiting circuit is located in a first load branch of the at least two parallel load branches, and when the voltage pre-regulator circuit is a boost circuit, the inductor is integrated with an inductor of the voltage pre-regulator circuit.

16. The power supply system circuit according to claim 12, wherein:

the control circuit is further configured to output another control signal to the control end after a first preset time period after the switch unit is switched off, so that the switch unit enters a hiccup current-limiting state, wherein the first preset time period is less than or equal to a time period in which the inductor supplies, when the switch unit is switched off and by using electric energy stored in the inductor, power to a load in the load branch connected to the current-limiting circuit.

17. The power supply system circuit according to claim 12, wherein:

a bus of the power supply supplies power to the control circuit.

18. The power supply system circuit according to claim 12, wherein the switch unit is a field effect transistor or a power transistor.