A redundant power supply system and control method thereof

Abstract

The present invention provides a redundant power supply system and a control method thereof, wherein the system includes a power battery, a DCDC converter, a main battery, a power isolation module and a backup battery, wherein a main circuit, a first circuit and a second circuit arranged in parallel are provided in the power isolation module, one end of the first circuit is connected to the main power supply circuit, and the other end thereof is connected to the main circuit; one end of the second circuit is connected to the backup battery, and the other end thereof is connected to the main circuit; MOSFET Q1 and MOSFET Q2 are arranged in series on the first circuit, and MOSFET Q3 and MOSFET Q4 are arranged in series on the second circuit; the power isolation module also includes a first monitoring circuit, a second monitoring circuit, a first driving circuit and a second driving circuit; and a battery power sensor connected to the power isolation module for communication is provided on the backup battery. The present invention can ensure the normal power consumption of the whole vehicle and the reliability and life of the backup battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle power supply systems, and in particular relates to a redundant power supply system and a control method thereof. Background Art

[0002] With the research on autonomous driving technology, autonomous driving and its related modules are required to have a higher level of functional safety. For example, braking and steering functions must have backup redundancy, and network communications must have backup redundancy. For the power supply system, L3 and above autonomous driving needs to have redundant power supply nodes. When the main power supply system fails, it is necessary to immediately switch to the backup power supply system to avoid single point failure in the traditional vehicle power supply system, which will cause multiple functions of the vehicle to fail. Therefore, the safety and reliability of the backup power supply system is extremely important.

[0003] The main power supply circuit in the existing redundant power supply system is a power supply composed of a DCDC converter and a low-voltage 12V battery, and the backup power supply uses a backup 12V battery. When the main power supply circuit fails, it is necessary to switch to the backup power supply. The reliability and safety of the backup power supply are very important. The existing technical solution does not protect the safety and reliability of the backup 12V battery. Therefore, how to design a redundant power supply system and its control method to realize the backup of the vehicle power system and improve the safety and reliability of the backup power supply has become a technical problem that technicians in this field urgently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a redundant power supply system and a control method thereof to solve the above technical problems in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A redundant power supply system comprises a power battery, a DCDC converter, a main storage battery, a power isolation module, a backup storage battery and a battery capacity sensor, wherein the power battery is electrically connected to the DCDC converter, and the DCDC converter is arranged in parallel with the main storage battery on a main power supply circuit; the power isolation module is provided with a main circuit for connecting to a redundant power supply load, a first circuit and a second circuit arranged in parallel, one end of the first circuit is connected to the main power supply circuit, and the other end of the first circuit is connected to the main circuit; the backup storage battery is connected to one end of the second circuit through a backup power supply circuit, and the other end of the second circuit is connected to the main circuit; MOSFET Q1 and MOSFET Q2 are arranged in series on the first circuit, and MOSFET Q3 and MOSFET Q4 are arranged in series on the second circuit; the power isolation module also comprises a first monitoring circuit for detecting the main power supply circuit, a second monitoring circuit for detecting the backup storage battery and the backup power supply circuit, a first driving circuit for controlling the on and off of MOSFET Q1 and MOSFET Q2, and a second driving circuit for controlling the on and off of MOSFET Q3 and MOSFET Q4; the battery capacity sensor is arranged on the backup storage battery, and the battery capacity sensor is communicatively connected to the power isolation module.

[0007] Preferably, it further comprises a distribution box, in which a plurality of fuses are arranged in parallel, and each of the redundant power supply loads is connected to a main line in the distribution box via each of the fuses, and the main line is connected to the main line.

[0008] A redundant power supply control method based on the redundant power supply system described above, comprising:

[0009] Under normal circumstances, MOSFET Q1, MOSFET Q2, MOSFET Q3, and MOSFET Q4 in the power isolation module are all turned on, and the vehicle is powered by the power battery through the DCDC converter; when a short-term heavy load occurs, the main battery and the backup battery will participate in the short-term discharge;

[0010] When the first monitoring circuit in the power isolation module detects that the main power supply circuit is in a failed state, the first drive circuit turns off MOSFET Q1 and MOSFET Q2, and the second drive circuit controls MOSFET Q3 and MOSFET Q4 to be turned on. At this time, the whole vehicle is powered only by the backup battery; when the first monitoring circuit detects that the main power supply circuit recovers from a failed state to a normal state, the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on to restore the main power supply circuit to supply power to the redundant power supply load;

[0011] When the second monitoring circuit in the power isolation module detects that the backup battery or the backup power supply circuit is in a failure state, the second drive circuit turns off MOSFET Q3 and MOSFET Q4, and the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on. At this time, the entire vehicle is powered only by the main power supply circuit; when the second monitoring circuit detects that the backup power supply circuit recovers from a failure state to a normal state, the second drive circuit controls MOSFET Q3 and MOSFET Q4 to be turned on to restore the backup battery to supply power to the redundant power supply load.

[0012] Preferably, when both the main power supply circuit and the backup power supply circuit are normal, when the backup battery is discharged through an external load, the battery power sensor monitors the power of the backup battery in real time and sends the power information of the backup battery to the power isolation module. When the power isolation module receives the backup battery SOC sent by the battery power sensor and it is less than the first set threshold, the second drive circuit disconnects MOSFET Q4, and the backup battery stops discharging; after the battery is charged, when the backup battery SOC is greater than the second threshold, the second drive circuit controls MOSFET Q4 to resume conduction, allowing the backup battery to discharge and be charged.

[0013] Preferably, the first set threshold is 69% to 71%; the second set threshold is 84% ​​to 86%.

[0014] Preferably, when both the main power supply circuit and the backup power supply circuit are normal, the DCDC converter continues to charge the backup battery. When the backup battery SOC is greater than a third set threshold, the MOSFET Q3 is disconnected through the second drive circuit to stop charging the backup battery. After the backup battery is discharged to the outside, when the backup battery SOC is less than the second set threshold, the MOSFET Q3 is turned on through the second drive circuit to allow the backup battery to discharge to the outside and be charged.

[0015] Preferably, the third set threshold is 94% to 96%.

[0016] Preferably, after the vehicle is powered off, the second drive circuit directly disconnects MOSFET Q3 and MOSFET Q4, and the entire vehicle is powered only by the main battery.

[0017] The beneficial effects of the present invention are:

[0018] The redundant power supply system and control method thereof of the present invention can better realize the switching of the main power supply circuit and the backup power supply circuit, so that the main power supply circuit and the backup power supply circuit back up each other. When the main power supply circuit or the backup power supply circuit fails, that is, is in a failed state, the power consumption of the entire vehicle can be effectively guaranteed; at the same time, the charging and discharging of the backup battery can be controlled to avoid overcharging and over-discharging of the backup battery, thereby ensuring the safety, reliability and life of the backup battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0020] Figure 1 An architectural diagram of a redundant power supply system provided in an embodiment of the present invention.

[0021] Markings in the accompanying drawings:

[0022] 11. Backup power supply circuit, 12. Main power supply circuit;

[0023] 21. main circuit, 22. first circuit, 23. second circuit, 24. first drive circuit,

[0024] 25. A second driving circuit;

[0025] 31. Main line, 32. Fuse. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solution of the present invention, the solution will be further described in detail below in conjunction with specific embodiments.

[0027] like Figure 1As shown, an embodiment of the present invention provides a redundant power supply system, which includes a power battery, a DCDC converter, a main battery, a power isolation module, a backup battery and a battery power sensor, wherein the power battery is electrically connected to the DCDC converter, and the DCDC converter is arranged in parallel with the main battery on the main power supply circuit; the power isolation module is provided with a main line 21 for connecting to a redundant power supply load, a first line 22 and a second line 23 arranged in parallel, one end of the first line 22 is connected to the main power supply circuit 12, and the other end of the first line 22 is connected to the main line 21; the backup battery is connected to one end of the second line 23 through the backup power supply circuit 11, and the other end of the second line 23 is connected to the main line 21; MOSFET Q1 and MOSFET Q2 are arranged in series on the first line 22, and MOSFET Q3 and MOSFET Q4 are arranged in series on the second line 23; the power isolation module also has a first monitoring circuit for detecting the main power supply circuit, a second monitoring circuit for detecting the backup battery and the backup power supply circuit, a first drive circuit 24 for controlling the on and off of MOSFET Q1 and MOSFETQ2, and a first drive circuit 25 for controlling the on and off of MOSFET Q1 and MOSFETQ2. The second driving circuit 25 controls the on and off of Q3 and MOSFETQ4; the battery power sensor is arranged on the backup battery, and the battery power sensor is communicatively connected with the power isolation module.

[0028] The redundant power supply system provided in the embodiment of the present invention can better realize the switching of the main power supply circuit and the backup power supply circuit, so that the main power supply circuit and the backup power supply circuit back up each other. When the main power supply circuit or the backup power supply circuit fails, the power consumption of the entire vehicle can be effectively guaranteed; at the same time, the charging and discharging of the backup battery can be controlled to avoid overcharging and over-discharging of the backup battery, thereby ensuring the safety, reliability and life of the backup battery.

[0029] Furthermore, the redundant power supply system also includes a distribution box, in which a plurality of fuses 32 are arranged in parallel, and each of the redundant power supply loads is connected to the main line 31 in the distribution box via each of the fuses, and the main line 31 is connected to the main line 21. With this scheme, each redundant power supply load is short-circuit protected by each fuse. Preferably, the battery power sensor (IBS for short) is communicatively connected to the power isolation module via the LIN bus. It can be understood that in the embodiment of the present invention, the power battery, the DCDC converter and the main battery serve as the main power supply, and the backup battery serves as the backup power supply. The power isolation module controls the charging and discharging of the backup battery according to the power information of the backup battery sent by the battery power sensor to avoid overcharging and over-discharging of the backup battery, thereby improving the reliability and life of the backup battery.

[0030] Among them, MOSFET, whose full English name is Metal-Oxide-Semiconductor Field-Effect Transistor, and whose full Chinese name is Metal-Oxide Semiconductor Field-Effect Transistor, is a controllable switch commonly used in the prior art.

[0031] The embodiment of the present invention further provides a redundant power supply control method based on the redundant power supply system described above, which includes:

[0032] Under normal circumstances, that is, when both the main power supply circuit and the backup power supply circuit are fault-free, that is, when both the main power supply circuit and the backup power supply circuit are in normal state, MOSFET Q1, MOSFET Q2, MOSFET Q3, and MOSFET Q4 in the power isolation module are all turned on, and the vehicle is powered by the power battery through the DCDC converter; when a short-term heavy load occurs, the main battery and the backup battery will also participate in short-term discharge;

[0033] When the first monitoring circuit in the power isolation module detects that the main power supply circuit 12 fails, that is, is in a failed state, the first drive circuit 24 turns off MOSFET Q1 and MOSFET Q2. When the second monitoring circuit detects that the backup battery and the backup power supply circuit are both in a normal state, the second drive circuit 25 controls MOSFET Q3 and MOSFET Q4 to be turned on, and the entire vehicle is powered only by the backup battery. When the first monitoring circuit detects that the main power supply circuit recovers from a failed state to a normal state, the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on, so as to restore the main power supply circuit to supply power to the redundant power supply load.

[0034] When the second monitoring circuit in the power isolation module detects that the backup battery or the backup power supply circuit 11 fails, that is, is in a failed state, the second drive circuit 25 turns off MOSFET Q3 and MOSFET Q4. When the first monitoring circuit detects that the main power supply circuit is in a normal state, the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on. At this time, the entire vehicle is powered only by the main power supply. When the second monitoring circuit detects that the backup power supply circuit recovers from a failed state to a normal state, the second drive circuit 25 controls MOSFET Q3 and MOSFET Q4 to be turned on to restore the backup battery to supply power to the redundant power supply load.

[0035] The redundant power supply control method provided in the embodiment of the present invention also has the above technical effects.

[0036] Furthermore, when both the main power supply circuit and the backup power supply circuit are normal, when the backup battery is discharged through an external load, the power of the backup battery will gradually decrease, and the battery power sensor monitors the power of the backup battery in real time. When the power isolation module receives the backup battery SOC sent by the battery power sensor and it is less than the first set threshold, the second drive circuit disconnects MOSFET Q4 (at this time MOSFET Q3 is still turned on), and the backup battery will stop discharging to avoid the backup battery from being in an over-discharge state and ensure the service life of the backup battery; after the battery is charged (at this time, the DCDC converter can charge the backup battery through the body diodes of MOSFET Q3 and MOSFET Q4), when the backup battery SOC is greater than the second threshold, the second drive circuit controls MOSFET Q4 to turn on, allowing the backup battery to discharge and be charged.

[0037] It can be understood that when the backup battery and the backup power supply circuit are in normal state: when MOSFET Q3 and MOSFET Q4 are both turned on, the backup battery can supply power to the redundant power supply load and can also charge the backup battery; when MOSFET Q4 is turned on but MOSFET Q3 is turned off, the current of the backup battery can also supply power to the redundant power supply load through the body diodes of MOSFET Q4 and MOSFET Q3; when MOSFET Q4 is turned off but MOSFET Q3 is turned on, the main power supply can charge the backup battery through the body diodes of MOSFET Q3 and MOSFET Q4.

[0038] Specifically, the first set threshold is 69% to 71%, preferably 70%; the second set threshold is 84% ​​to 86%, preferably 85%. It can be understood that SOC (full name of English: State Of Charge) is used to reflect the remaining power of the battery. Its numerical definition is the ratio of the remaining power to the battery capacity, usually expressed as a percentage.

[0039] Further, when both the main power supply circuit and the backup power supply circuit are normal, and the DCDC converter continues to charge the backup battery, when the power isolation module receives the backup battery SOC sent by the IBS that is greater than the third set threshold, the second drive circuit disconnects the MOSFET Q3 (the MOSFET Q4 is still turned on at this time), and stops charging the backup battery, so as to avoid the backup battery from being in an overcharged state, ensure the service life of the backup battery, and improve the reliability of the backup battery; at this time, if the backup battery needs to be discharged to the outside, the conduction state of the MOSFET Q4 remains unchanged, and the backup battery can supply power to the redundant power supply load through the body diodes of the MOSFET Q4 and the MOSFET Q3; if the backup battery does not need to be discharged to the outside, the MOSFET Q4 is controlled to be disconnected through the second drive circuit; after the backup battery is discharged to the outside, when the IBS detects that the backup battery SOC is less than the second set threshold, the second drive circuit turns on the MOSFET Q3, allowing the backup battery to be discharged to the outside and charged.

[0040] Specifically, the third set threshold is 94% to 96%, and may be preferably 95%.

[0041] Furthermore, when the vehicle is powered off, that is, the entire vehicle needs to enter a dormant state, the high voltage of the entire vehicle is powered off, that is, the DCDC converter will also stop working, and the entire vehicle is only powered by a low-voltage battery. At this time, in order to prevent the two batteries from charging each other due to inconsistent power levels between the main battery and the backup battery, resulting in power loss, and to ensure that the backup battery is in a high power state, after the vehicle is powered off, the second drive circuit directly disconnects MOSFET Q3 and MOSFET Q4, so that the entire vehicle is only powered by the main battery.

[0042] It can be understood that the charge and discharge protection of the backup battery is considered in the present invention because when the main power supply circuit fails, only the backup battery can provide power, and the vehicle can only travel safely for a short time relying solely on the backup power supply because the battery power is very limited. Therefore, the power and life of the backup battery are extremely important to ensure that the vehicle can safely drive to the roadside and park. The charge and discharge protection of the main battery is not considered because if the backup power supply fails, the entire vehicle can still be powered by the DCDC converter and the main battery, and the DCDC converter can ensure that the vehicle can travel normally for a long time.

[0043] The present invention adopts a new redundant power supply scheme for the whole vehicle. When a main power supply circuit fails, the backup power supply can immediately and reliably supply power, thereby ensuring the driving safety of L3 and above autonomous driving vehicles. The present invention adopts a power supply scheme with a backup power supply protection function. The main control unit is a power isolation module. By judging the power information of the backup battery sent by the IBS, the charging and discharging of the backup power supply are protected, thereby ensuring the safety and reliability of the backup power supply. At the same time, the remaining power of the backup power supply is controlled to be no less than 70%, thereby avoiding deep discharge of the backup battery and greatly extending the life of the backup power supply.

[0044] The above are only preferred embodiments of the present invention. It should be pointed out that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, after reading the contents of the present invention, relevant technical personnel in the field may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A redundant power supply control method for a redundant power supply system, characterized in that: It includes: Under normal circumstances, MOSFET Q1, MOSFET Q2, MOSFET Q3, and MOSFET Q4 in the power isolation module are all turned on, and the vehicle is powered by the power battery through the DCDC converter; when a short-term heavy load occurs, the main battery and the backup battery will participate in the short-term discharge; When the first monitoring circuit in the power isolation module detects that the main power supply circuit is in a failed state, the first drive circuit turns off MOSFET Q1 and MOSFET Q2, and the second drive circuit controls MOSFET Q3 and MOSFET Q4 to be turned on. At this time, the whole vehicle is powered only by the backup battery; when the first monitoring circuit detects that the main power supply circuit recovers from a failed state to a normal state, the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on to restore the main power supply circuit to supply power to the redundant power supply load; When the second monitoring circuit in the power isolation module detects that the backup battery or the backup power supply circuit is in a failed state, the second drive circuit turns off MOSFET Q3 and MOSFET Q4, and the first drive circuit controls MOSFET Q1 and MOSFET Q2 to be turned on. At this time, the whole vehicle is powered only by the main power supply circuit; when the second monitoring circuit detects that the backup power supply circuit recovers from a failed state to a normal state, the second drive circuit controls MOSFET Q3 and MOSFET Q4 to be turned on to restore the backup battery to supply power to the redundant power supply load; When both the main power supply circuit and the backup power supply circuit are normal, when the backup battery is discharged through an external load, the battery power sensor monitors the power of the backup battery in real time and sends the power information of the backup battery to the power isolation module. When the power isolation module receives the backup battery SOC sent by the battery power sensor and it is less than the first set threshold, the second drive circuit disconnects MOSFET Q4, and the backup battery stops discharging; after the battery is charged, when the backup battery SOC is greater than the second threshold, the second drive circuit controls MOSFET Q4 to resume conduction, allowing the backup battery to discharge and be charged; The first set threshold is 69% to 71%; The second threshold is 84% ​​to 86%; When both the main power supply circuit and the backup power supply circuit are normal, the DCDC converter continues to charge the backup battery. When the SOC of the backup battery is greater than the third set threshold, the MOSFET Q3 is disconnected through the second drive circuit to stop charging the backup battery. After the backup battery is discharged to the outside, when the SOC of the backup battery is less than the second set threshold, the MOSFET Q3 is turned on through the second drive circuit to allow the backup battery to discharge to the outside and be charged. The third set threshold is 94% to 96%.

2. The redundant power supply control method according to claim 1, characterized in that: After the vehicle is powered off, the second drive circuit directly disconnects MOSFET Q3 and MOSFET Q4, and the entire vehicle is powered only by the main battery.

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