Power supply protection circuit and power supply system

Abstract

The invention discloses a power supply protection circuit and a power supply system. The power supply protection circuit comprises a voltage sampling module and a relay module. The voltage sampling module is used for collecting target voltage of a power supply and outputting a first control signal; the relay module controls a first coil in the relay module to be powered on or powered off according to the first control signal, a first common contact of the relay module is connected with a first end of a second coil of the contactor, and a second common contact of the relay module is connected with a second end of the second coil of the contactor; wherein when the first control signal is a first logic level, a first coil in the relay module is powered on, a first common contact of the relay module is connected with a first normally open contact, a second common contact of the relay module is connected with a second normally open contact, a power-down loop of a second coil of the contactor is formed, and discharging to the power supply is stopped. Through the mode, the power supply can be cut off under the condition that the system controller fails or the system controller is pulled out of the power supply system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit control, in particular to a power protection circuit and a power system. BACKGROUND

[0002] The power system generally contains a system controller to control the power-on or power-off of the entire system. That is, under normal AC conditions, the contactor is powered on to allow the mains to power the load, and at the same time, the battery (power supply) is charged. In the case of mains power failure, the contactor will first cut off some unimportant loads, and the battery (power supply) will discharge to power some important loads. After the battery discharges to a certain extent, the system controller will also disconnect the contactor corresponding to the battery to prevent the battery from being deeply discharged and damaged.

[0003] The disadvantage is that there may be a situation where the system controller fails or the system controller is unplugged from the power system. At this time, the system cannot disconnect the battery, and if the mains power fails, the battery will be in a discharging state, thereby affecting the battery life. SUMMARY

[0004] The present application provides a power protection circuit and a power system, which can disconnect the power supply in the case of system controller failure or system controller being unplugged from the power system.

[0005] In a first aspect, the present application provides a power protection circuit, comprising: a voltage sampling module connected to a power supply, configured to collect a target voltage of the power supply and output a first control signal according to the target voltage; wherein the power supply is discharged through a contactor; a relay module, a control end of the relay module being connected to the voltage sampling module, configured to control a first coil in the relay module to be powered on or powered off according to the first control signal, a first common contact of the relay module being connected to a first end of a second coil of the contactor, and a second common contact of the relay module being connected to a second end of the second coil of the contactor; wherein when the first control signal is a first logic level, the first coil in the relay module is powered on, the first common contact of the relay module is connected to a first normally open contact, and the second common contact of the relay module is connected to a second normally open contact, forming a power-off loop of the second coil of the contactor, and stopping discharging the power supply.

[0006] When the first control signal is a second logic level, the first coil is powered off, the first common contact of the relay module is connected to a first normally closed contact, and the second common contact of the relay module is connected to a second normally closed contact.

[0007] The voltage sampling module comprises: a comparison unit, a first input end of the comparison unit being connected to the power supply and used for collecting a target voltage of the power supply; a second input end of the comparison unit being used for inputting a reference voltage, an output end of the comparison unit being used for outputting a second control signal; and a first switch unit, a control end of the first switch unit being connected to the output end of the comparison unit, a first end of the first switch unit being connected to the power supply voltage end, a second end of the first switch unit being grounded, the first end of the first switch unit being used as an output end of the voltage sampling module and used for outputting a first control signal.

[0008] The comparison unit comprises: a voltage dividing unit, an input end of the voltage dividing unit being connected to the power supply; and a comparator, a non-inverting input end of the comparator being connected to an output end of the voltage dividing unit, an inverting input end of the comparator being used for inputting a reference voltage, an output end of the comparator being connected to a control end of the first switch unit.

[0009] The voltage dividing unit comprises: N resistors connected in series; N-1 switch devices, two ends of each of the N-1 switch devices being connected to two ends of one resistor, and the N-1 switch devices being used for setting the number of switch devices that are turned on according to a power-off requirement of the power supply.

[0010] The first switch unit comprises: a first resistor, a first end of the first resistor being connected to the power supply voltage end, a second end of the first resistor being connected to the output end of the comparison unit; a second resistor, a first end of the second resistor being connected to the second end of the first resistor; and a first switch device, a control end of the first switch device being connected to a second end of the second resistor, a first end of the first switch device being connected to the power supply voltage end through a third resistor, and a second end of the first switch device being grounded; wherein the first end of the first switch device is used as the output end of the voltage sampling module; wherein the first switch device is in an off state when the second control signal is a second logic level, and the first control signal output by the output end of the voltage sampling module is a first logic level; the first switch device is in an on state when the second control signal is a first logic level, and the first control signal output by the output end of the voltage sampling module is a second logic level; wherein the first logic level and the second logic level are opposite in logic level.

[0011] The relay module comprises: a relay, the relay comprising a first coil, a first common contact, a second common contact, a first normally open contact, a second normally open contact, a first normally closed contact and a second normally closed contact; a first end of the first coil being connected to the power supply voltage end; a first control unit, a control end of the first control unit being connected to the voltage sampling module, a first end of the first control unit being connected to a second end of the first coil, and a second end of the first control unit being grounded; the first control unit being in an on state when the first control signal is the first logic level, so as to power on the first coil; and the first control unit being in an off state when the first control signal is the second logic level, so as to power off the first coil.

[0012] The power supply protection circuit further includes a pulse generation module connected to the first normally open contact, configured to ground the first normally open contact when the first control signal is a first logic level.

[0013] The pulse generation module includes a pulse generation unit configured to generate a pulse signal, a coupling switch having a first end connected to the power supply voltage end, a second end connected to the pulse generation unit, and a third end connected to the second normally open contact, and a second control unit having a control end connected to a fourth end of the coupling switch, a first end connected to the first normally open contact, and a second end grounded.

[0014] The second control unit includes a fourth resistor having a first end connected to the fourth end of the coupling switch, a fifth resistor having a first end connected to the fourth end of the coupling switch and a second end grounded, a sixth resistor having a first end connected to a second end of the fourth resistor, a seventh resistor having a first end connected to the second end of the fourth resistor and a second end grounded, and a second switch device having a control end connected to a second end of the sixth resistor, a first end connected to the second normally open contact, and a second end grounded.

[0015] The pulse generation unit includes a logic device configured to generate a pulse signal, a first diode having a positive electrode connected to an output end of the logic device, an eighth resistor having a first end connected to a negative electrode of the first diode, a capacitor having a first end connected to a second end of the eighth resistor and a second end grounded, and a second diode having a negative electrode connected to the output end of the logic device, a ninth resistor having a first end connected to a positive electrode of the second diode and a second end connected to the first end of the capacitor.

[0016] In a second aspect, the present application provides a power supply system, which includes a power supply, a contactor arranged on an output line of the power supply, a system controller configured to control the contactor, and a power supply protection circuit as provided in the first aspect.

[0017] The beneficial effects of the present application are: different from the prior art, the power protection circuit and the power supply system provided by the present application, the power protection circuit comprises: a voltage sampling module connected to the power supply, used for collecting a target voltage of the power supply, and outputting a first control signal according to the target voltage; wherein the power supply is discharged through a contactor; a relay module, the control end of the relay module is connected to the voltage sampling module, used for controlling the power-on or power-off of the first coil in the relay module according to the first control signal, the first common contact of the relay module is connected to the first end of the second coil of the contactor, and the second common contact of the relay module is connected to the second end of the second coil of the contactor; wherein when the first control signal is a first logic level, the first coil in the relay module is powered on, the first common contact of the relay module is connected to the first normally open contact, the second common contact of the relay module is connected to the second normally open contact, forming a power-off loop of the second coil of the contactor, and the discharge of the power supply is stopped, so that the power supply can be protected from deep discharge in the case that the system controller of the power supply system fails or the system controller is pulled out of the power supply system. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor. Among them:

[0019] Figure 1 is a structural schematic diagram of an embodiment of the power supply system provided by the present application;

[0020] Figure 2 is a structural schematic diagram of an embodiment of the power protection circuit provided by the present application;

[0021] Figure 3 is a structural schematic diagram of an embodiment of the voltage sampling module provided by the present application;

[0022] Figure 4 is a structural schematic diagram of an embodiment of the comparison unit provided by the present application;

[0023] Figure 5 is a structural schematic diagram of an embodiment of the voltage dividing unit provided by the present application;

[0024] Figure 6 is a structural schematic diagram of an embodiment of the first switch unit provided by the present application;

[0025] Figure 7 is a structural schematic diagram of an embodiment of the relay module provided by the present application;

[0026] Figure 8is a structural schematic diagram of another embodiment of the power supply protection circuit provided in the present application;

[0027] Figure 9 is a structural schematic diagram of an embodiment of the pulse generation module provided in the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, rather than all the structures. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. Those skilled in the art will understand that the embodiments described herein can be combined with one another.

[0030] The power supply system generally includes a system controller to control the power-on or power-off of the entire system. That is, the contactor is powered on under normal AC conditions to allow the mains to supply power to the load, and at the same time, the battery (power supply) is also charged. In the case of mains power failure, the contactor will first cut off a part of the unimportant load, and discharge the battery (power supply) to supply power to some important loads. After the battery discharges to a certain extent, the system controller will also disconnect the contactor corresponding to the battery for the purpose of protecting the battery, to prevent the battery from being deeply discharged and damaged.

[0031] The related art controls the power-on and power-off of the contactor through the system controller. A pulse of about 700 ms applied to the contactor coil contact A->B can power on the contactor, and a pulse of about 700 ms applied to the contactor coil contact B->A can power off the contactor. The generation of the pulse and the control of the pulse width time are generally completed by the processing unit in the system controller through a program.

[0032] The disadvantage is that the processing unit in the system controller may cause the program to run out of control under certain electromagnetic interference environment, affecting the service life of the battery, and the system controller (supporting hot plug) may be unplugged, resulting in a failure to control, and the entire system has a risk of control failure, thereby affecting the service life of the battery.

[0033] Therefore, referring toFigure 1 , Figure 1 is a structural schematic diagram of an embodiment of the power supply system provided by the present application. The power supply system comprises: a power supply 10, a contactor 20, a system controller 30 and a power supply protection circuit 40.

[0034] The power supply 10 can be a rechargeable power supply. For example, a power supply that can be charged and discharged, such as a standalone power supply, an energy storage power supply, etc.

[0035] The contactor 20 is arranged on the output line of the power supply 10.

[0036] The system controller 30 is used to control the power-on or power-off of the contactor 20, so as to control the charging or discharging of the power supply 10.

[0037] The power supply protection circuit 40 is used to collect the voltage of the power supply 10, and then control the power-off of the contactor 20 when the voltage is lower than the threshold voltage, so as to disconnect the discharging of the power supply 10. The specific working logic and structure of the power supply protection circuit 40 are described in any of the following embodiments, and will not be described here. The system controller 30 and the power supply protection circuit 40 are arranged on different hardware. That is, the system controller 30 and the power supply protection circuit 40 are two separate hardware. For example, the power supply protection circuit 40 is arranged on another circuit board. The circuit board is not arranged on the system controller 30, but is arranged separately.

[0038] The power supply system can be a communication power supply system. For example, the power supply system can be arranged in a server, an industrial device, a vehicle, etc.

[0039] Referring to Figure 2 , Figure 2 is a structural schematic diagram of an embodiment of the power supply protection circuit provided by the present application. The power supply protection circuit 40 comprises: a voltage sampling module 41 and a relay module 42.

[0040] The voltage sampling module 41 is connected to the power supply 10 for collecting the target voltage of the power supply 10, and outputs a first control signal according to the target voltage; wherein the power supply 10 is discharged through the contactor 20.

[0041] The control end of the relay module 42 is connected to the voltage sampling module 41, for controlling the power-on or power-off of the first coil in the relay module 42 according to the first control signal (such as the subsequent RELAYB), the first common contact of the relay module 42 is connected to the first end of the second coil of the contactor 20, and the second common contact of the relay module 42 is connected to the second end of the second coil of the contactor 20; wherein when the first control signal is a first logic level, the first coil in the relay module 42 is powered on, the first common contact of the relay module 42 is connected to the first normally open contact, the second common contact of the relay module 42 is connected to the second normally open contact, forming a power-off loop of the second coil of the contactor 20, and the discharging of the power supply 10 is stopped.

[0042] In some embodiments, the first end of the second coil of the contactor 20 is A, and the second end of the second coil of the contactor 20 is B. When the current flows from A to B, the second coil of the contactor 20 is powered on, and the corresponding contacts of the contactor 20 are connected, forming a discharge circuit of the power supply 10, and the power supply 10 is discharged. When the first control signal is the first logic level, the first coil in the relay module 42 is powered on, the first common contact and the first normally open contact of the relay module 42 are connected, the second common contact and the second normally open contact of the relay module 42 are connected, at this time, the current flows from B to A, the second coil of the contactor 20 is powered off, the corresponding contacts of the contactor 20 are disconnected, forming a power-off circuit of the second coil of the contactor 20, and the discharge circuit of the power supply 10 is disconnected, and the discharge of the power supply 10 is stopped.

[0043] In some embodiments, the second common contact of the relay module 42 can be connected to the corresponding positive pole, i.e., to provide current. The first common contact of the relay module 42 can be connected to the corresponding negative pole, and when the first common contact and the first normally open contact of the relay module 42 are connected, and the second common contact and the second normally open contact of the relay module 42 are connected, the current on the second coil of the contactor 20 flows from B to A, and the second coil of the contactor 20 is powered off.

[0044] In some embodiments, when the first control signal is the second logic level, the first coil is powered off, the first common contact and the first normally closed contact of the relay module 42 are connected, and the second common contact and the second normally closed contact of the relay module 42 are connected.

[0045] In this embodiment, when the system controller 30 is normal, or the target voltage of the power supply 10 is greater than the threshold value, the first control signal is the second logic level, the first coil in the relay module 42 is in a powered-off state, the first common contact and the first normally closed contact of the relay module 42 are connected, and the second common contact and the second normally closed contact of the relay module 42 are connected.

[0046] When the target voltage of the power supply 10 is less than the threshold value, the first control signal is the first logic level, the first coil in the relay module 42 is in a powered-on state, the first common contact and the first normally open contact of the relay module 42 are connected, the second common contact and the second normally open contact of the relay module 42 are connected, forming a power-off circuit of the second coil of the contactor 20, and the discharge of the power supply 10 is stopped.

[0047] In some embodiments, referring to Figure 3 , the voltage sampling module 41 includes a comparison unit 411 and a first switching unit 412.

[0048] A first input terminal of the comparison unit 411 is connected to the power supply 10 for collecting a target voltage of the power supply 10; a second input terminal of the comparison unit 411 is used for inputting a reference voltage Vref, and an output terminal of the comparison unit 411 is used for outputting a second control signal. For example, when the target voltage is greater than the reference voltage Vref, the first control signal is a high level. When the target voltage is less than the reference voltage Vref, the first control signal is a low level. Based on this, the reference voltage Vref can be used as the threshold value mentioned above.

[0049] A control terminal of the first switch unit 412 is connected to the output terminal of the comparison unit 411, a first terminal of the first switch unit 412 is connected to the power supply voltage terminal, a second terminal of the first switch unit 412 is grounded, and the first terminal of the first switch unit 412 is used as an output terminal of the voltage sampling module 41 for outputting the first control signal.

[0050] When the second control signal is a low level, the first switch unit 412 is in a cut-off state, and at this time, the first control signal is a high level signal (a first logic level). When the second control signal is a high level, the first switch unit 412 is in a cut-off conduction state, and the first control signal is a low level signal (a second logic level).

[0051] In some embodiments, referring to Figure 4 , the comparison unit 411 includes a voltage dividing unit 4111 and a comparator 4112.

[0052] An input terminal of the voltage dividing unit 4111 is connected to the power supply 10.

[0053] A non-inverting input terminal of the comparator 4112 is connected to an output terminal of the voltage dividing unit 4111, an inverting input terminal of the comparator 4112 is used for inputting the reference voltage Vref, and an output terminal of the comparator 4112 is connected to a control terminal of the first switch unit 412.

[0054] The voltage dividing unit 4111 includes N resistors and N-1 switch devices connected in series. Wherein, N is an integer greater than or equal to 2.

[0055] The N-1 switch devices, two ends of each switch device are connected to two ends of one resistor respectively, are used for setting the number of switch devices turned on according to the power-off requirement of the power supply 10.

[0056] Referring to Figure 5The voltage dividing unit 4111 is described as follows: if N is 5, five resistors (resistor R1, resistor R2, resistor R3, resistor R4 and resistor R5) are connected in series. Four switching devices (K1, K2, K3 and K4) are connected. The switching device K1 connects both ends of the resistor R2. The switching device K2 connects both ends of the resistor R3. The switching device K3 connects both ends of the resistor R4. The switching device K4 connects both ends of the resistor R5. The number of switching devices that are turned on can be set according to the power-off requirement of the power supply 10. For example, if the switching device K1 is turned on, the voltage dividing unit 4111 is composed of the resistor R1, the resistor R3, the resistor R4 and the resistor R5. In this way, different specifications of the power supply 10 or different power-off requirements of the power supply 10 can be adapted. The number of switching devices that are turned on can be set according to the power-off requirement of the corresponding power supply 10. For example, if the switching device K1 and the switching device K2 are turned on, the voltage dividing unit 4111 is composed of the resistor R1, the resistor R4 and the resistor R5. In this way, different specifications of the power supply 10 or different power-off requirements of the power supply 10 can be adapted. The number of switching devices that are turned on can be set according to the power-off requirement of the corresponding power supply 10. That is, the voltage dividing level can be set by using N-1 switching devices and N resistors connected in series, so that different power-off voltages can be set for different types of power supply 10.

[0057] In some embodiments, the N-1 switching devices can be composed of a code switch. For example, a 4-bit code switch, a 6-bit code switch, etc.

[0058] Referring to Figure 6 The first switching unit 412 includes a first resistor R6, a second resistor R7, a third resistor R9 and a first switching device Q1.

[0059] The first end of the first resistor R6 is connected to the power supply voltage terminal VCC, and the second end of the first resistor R6 is connected to the output terminal of the comparison unit 411.

[0060] The first end of the first resistor R6 is connected to the power supply voltage terminal VCC, and the second end of the first resistor R6 is connected to the output terminal of the comparison unit 411.

[0061] The control terminal of the first switching device Q1 is connected to the second end of the second resistor R7, the first end of the first switching device Q1 is connected to the power supply voltage terminal VCC through the third resistor R9, and the second end of the first switching device Q1 is grounded. The first end of the first switching device Q1 serves as the output terminal of the voltage sampling module 41. Further, the control terminal of the first switching device Q1 can also be connected to the capacitor C1 and the resistor R8. The first switching device Q1 can be a MOS tube, a triode or other device with switching capability.

[0062] In some embodiments, the first switching device Q1 is in an off state when the second control signal is at the second logic level, and the first control signal RELAYB output by the output terminal of the voltage sampling module 41 is at the first logic level.

[0063] In some embodiments, the first switch device Q1 is in a conducting state when the second control signal is a first logic level, and the first control signal RELAYB outputted by the output end of the voltage sampling module 41 is a second logic level; wherein the logic levels of the first logic level and the second logic level are opposite.

[0064] Referring to Figure 7 , the relay module 42 comprises a relay 421 and a first control unit 422.

[0065] The relay 421 comprises a first coil RLY1, a first common contact 3, a second common contact 6, a first normally open contact 4, a second normally open contact 5, a first normally closed contact 2 and a second normally closed contact 7. The first end 1 of the first coil RLY1 is connected to the power supply voltage end VCC. The first common contact 3 is connected to the first end A (which can be represented by LOADA) of the second coil of the contactor 20, and the second common contact 6 is connected to the second end B (which can be represented by LOADB) of the second coil of the contactor 20. The second normally open contact 5 is connected to the positive electrode (which can be represented by VIN+L). The first normally open contact 4 is connected to the negative electrode (which can be represented by LOAD-).

[0066] The control end of the first control unit 422 is connected to the voltage sampling module 41 to receive the first control signal RELAYB, the first end of the first control unit 422 is connected to the second end 8 of the first coil RLY1, and the second end of the first control unit 422 is grounded. Further, a diode D1 is also connected between the first end 1 and the second end 8 of the first coil RLY1.

[0067] The first control unit 422 is in a conducting state when the first control signal RELAYB is a first logic level, so as to power on the first coil RLY1.

[0068] The first control unit 422 is in a cut-off state when the first control signal RELAYB is a second logic level, so as to power off the first coil RLY1.

[0069] Further, the first control unit 422 can comprise a resistor R10, a switch device Q2, a capacitor C2 and a resistor R11. The switch device Q2 can be a MOS tube, a triode or other device with switching capability.

[0070] Referring to Figure 8 , Figure 8 is a structural schematic diagram of another embodiment of the power supply protection circuit provided by the present application. The power supply protection circuit 40 comprises a voltage sampling module 41, a relay module 42 and a pulse generation module 43. The pulse generation module 43 is connected to the above-mentioned first normally open contact 4, and is used to ground the first normally open contact 4 when the first control signal RELAYB is a first logic level.

[0071] Referring to Figure 9 The pulse generation module 43 comprises a pulse generation unit 431, a coupling switch P1 and a second control unit 432.

[0072] The pulse generation unit 431 is configured to generate a pulse signal.

[0073] The first end 1 of the coupling switch P1 is configured to be connected to a power supply voltage terminal VCC, the second end 2 of the coupling switch P1 is connected to the pulse generation unit 431, and the third end 3 of the coupling switch P1 is connected to the second normally open contact 5. In some embodiments, the first end 1 of the coupling switch P1 is connected to the power supply voltage terminal VCC through a resistor R13. The third end 3 of the coupling switch P1 is connected to the second normally open contact 5 through a resistor R12.

[0074] The control end of the second control unit 432 is connected to the fourth end 4 of the coupling switch P1, the first end of the second control unit 432 is connected to the first normally open contact 4, and the second end of the second control unit 432 is grounded.

[0075] Further, the second control unit 432 comprises a fourth resistor R15, a fifth resistor R14, a sixth resistor R17, a seventh resistor R16 and a second switching device Q3.

[0076] The first end of the fourth resistor R15 is connected to the fourth end 4 of the coupling switch P1.

[0077] The first end of the fifth resistor R14 is connected to the fourth end 4 of the coupling switch P1, and the second end of the fifth resistor R14 is grounded.

[0078] The first end of the sixth resistor R17 is connected to the second end of the fourth resistor R15.

[0079] The first end of the seventh resistor R16 is connected to the second end of the fourth resistor R15, and the second end of the seventh resistor R16 is grounded.

[0080] The control end of the second switching device Q3 is connected to the second end of the sixth resistor R17, the first end of the second switching device Q3 is connected to the second normally open contact, and the second end of the second switching device Q3 is grounded. Further, the first end of the second switching device Q3 is also connected to a diode D2 and a capacitor C3. The capacitor C3 is grounded through a resistor R18.

[0081] Further, the pulse generation unit 431 comprises a logic device 4311, a first diode D3, an eighth resistor R19, a capacitor C4, a second diode D4 and a ninth resistor R20.

[0082] The logic device 4311 is configured to generate a pulse signal. The logic device 4311 can be a CMOS logic device. For example, the model of the logic device 4311 can be SN74HC14PWR.

[0083] The positive pole of the first diode D3 is connected to the output of the logic device 4311.

[0084] The first end of the eighth resistor R19 is connected to the negative pole of the first diode D3.

[0085] The first end of the capacitor C4 is connected to the second end of the eighth resistor R19, and the second end of the capacitor C2 is grounded.

[0086] The negative pole of the second diode D4 is connected to the output of the logic device 4311.

[0087] The first end of the ninth resistor R20 is connected to the positive pole of the second diode D4, and the second end of the ninth resistor R20 is connected to the first end of the capacitor C4.

[0088] In the pulse generating unit 431, a charging circuit is formed by the first diode D3, the eighth resistor R19 and the capacitor C4, and a discharging circuit is formed by the capacitor C4, the second diode D4 and the ninth resistor R20, etc., and the high and low level time of the pulse signal can be determined by different circuit parameters.

[0089] In summary, the power supply protection circuit and the power supply system provided by the present application can protect the power supply from deep discharge in the case that the system controller of the power supply system is disabled or is pulled out of the power supply system.

[0090] In several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the above-described device embodiments are merely illustrative, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0091] The integrated units in the above other embodiments, if implemented in the form of software function units and sold or used as independent products, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0092] The above is only the embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation made by using the content of the specification and drawings, or directly or indirectly applied to other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A power supply protection circuit, characterized by, The power supply protection circuit comprises: a voltage sampling module connected to a power supply, configured to collect a target voltage of the power supply and output a first control signal according to the target voltage; wherein the power supply is discharged through a contactor; a relay module, a control end of the relay module being connected to the voltage sampling module, configured to control power-on or power-off of a first coil in the relay module according to the first control signal, a first common contact of the relay module being connected to a first end of a second coil of the contactor, and a second common contact of the relay module being connected to a second end of the second coil of the contactor; wherein when the first control signal is a first logic level, the first coil in the relay module is powered on, the first common contact of the relay module is connected to a first normally open contact, the second common contact of the relay module is connected to a second normally open contact, and a power-off loop of the second coil of the contactor is formed, thereby stopping discharging the power supply.

2. The power supply protection circuit of claim 1, wherein, When the first control signal is a second logic level, the first coil is powered off, the first common contact of the relay module is connected to a first normally closed contact, and the second common contact of the relay module is connected to a second normally closed contact.

3. The power supply protection circuit of claim 1, wherein, The voltage sampling module comprises: a comparison unit, a first input end of the comparison unit being connected to the power supply, configured to collect the target voltage of the power supply; a second input end of the comparison unit being configured to input a reference voltage, and an output end of the comparison unit being configured to output a second control signal; a first switch unit, a control end of the first switch unit being connected to the output end of the comparison unit, a first end of the first switch unit being connected to a power supply voltage end, a second end of the first switch unit being grounded, and the first end of the first switch unit being used as an output end of the voltage sampling module, configured to output the first control signal.

4. The power supply protection circuit of claim 3, wherein, The comparison unit comprises: a voltage dividing unit, an input end of the voltage dividing unit being connected to the power supply; a comparator, a non-inverting input end of the comparator being connected to an output end of the voltage dividing unit, an inverting input end of the comparator being configured to input the reference voltage, and an output end of the comparator being connected to the control end of the first switch unit.

5. The power supply protection circuit of claim 4, wherein, The voltage dividing unit comprises: N resistors connected in series; wherein N is an integer greater than or equal to 2; N-1 switch devices, two ends of each of the switch devices being connected to two ends of one resistor, configured to set the number of switch devices turned on according to the power-off requirement of the power supply.

6. The power supply protection circuit of claim 3, wherein, The first switch unit comprises: a first resistor, a first end of the first resistor being connected to a power supply voltage end, and a second end of the first resistor being connected to the output end of the comparison unit; a second resistor, a first end of the second resistor being connected to the second end of the first resistor. A first switch device, a control end of the first switch device is connected with a second end of the second resistor, a first end of the first switch device is connected with a power supply voltage end through a third resistor, and a second end of the first switch device is grounded; wherein the first end of the first switch device serves as an output end of the voltage sampling module; wherein the first switch device is in an off state when the second control signal is a second logic level, and the first control signal output by the output end of the voltage sampling module is the first logic level; the first switch device is in an on state when the second control signal is a first logic level, and the first control signal output by the output end of the voltage sampling module is the second logic level; wherein the logic levels of the first logic level and the second logic level are opposite.

7. The power supply protection circuit of claim 1, wherein, The relay module comprises: a relay, the relay comprising a first coil, a first common contact, a second common contact, a first normally open contact, a second normally open contact, a first normally closed contact and a second normally closed contact; a first end of the first coil being connected with a power supply voltage end; a first control unit, a control end of the first control unit being connected with the voltage sampling module, a first end of the first control unit being connected with a second end of the first coil, and a second end of the first control unit being grounded; the first control unit being in an on state when the first control signal is a first logic level, and the first coil being powered on; the first control unit being in an off state when the first control signal is a second logic level, and the first coil being powered off.

8. The power supply protection circuit of claim 1, wherein, The power supply protection circuit further comprises: a pulse generation module, the pulse generation module being connected with the first normally open contact, and being used for grounding the first normally open contact when the first control signal is a first logic level.

9. The power supply protection circuit of claim 8, wherein, The pulse generation module comprises: a pulse generation unit, used for generating a pulse signal; a coupling switch, a first end of the coupling switch being used for connecting with a power supply voltage end, a second end of the coupling switch being connected with the pulse generation unit, and a third end of the coupling switch being connected with the second normally open contact; a second control unit, a control end of the second control unit being connected with a fourth end of the coupling switch, a first end of the second control unit being connected with the first normally open contact, and a second end of the second control unit being grounded.

10. The power supply protection circuit of claim 9, wherein, The second control unit comprises: a fourth resistor, a first end of the fourth resistor being connected with the fourth end of the coupling switch; a fifth resistor, a first end of the fifth resistor being connected with the fourth end of the coupling switch, and a second end of the fifth resistor being grounded; a sixth resistor, a first end of the sixth resistor being connected with a second end of the fourth resistor; a seventh resistor, a first end of the seventh resistor being connected with the second end of the fourth resistor, and a second end of the seventh resistor being grounded; a second switch device, a control end of the second switch device being connected with the second end of the sixth resistor, a first end of the second switch device being connected with the second normally open contact, and a second end of the second switch device being grounded.

11. The power supply protection circuit of claim 9, wherein, The pulse generation unit comprises: a logic device, used for generating the pulse signal; a first diode, a positive electrode of the first diode being connected to an output terminal of the logic device; an eighth resistor, a first terminal of the eighth resistor being connected to a negative electrode of the first diode; a capacitor, a first terminal of the capacitor being connected to a second terminal of the eighth resistor, and a second terminal of the capacitor being grounded; a second diode, a negative electrode of the second diode being connected to the output terminal of the logic device; a ninth resistor, a first terminal of the ninth resistor being connected to a positive electrode of the second diode, and a second terminal of the ninth resistor being connected to the first terminal of the capacitor.

12. A power supply system characterized by comprising: The power supply system comprises: a power supply; a contactor, arranged on an output line of the power supply; a system controller, configured to control the contactor; a power supply protection circuit according to any one of claims 1-11.

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