High-voltage backup power supply starting circuit, power supply system and vehicle

Abstract

The invention relates to the technical field of power electronics, and discloses a high-voltage backup power supply starting circuit, a power supply system and a vehicle. Reference voltage provided by a low-voltage power supply through a second voltage division circuit during normal work is compared with voltage of a high-voltage backup power supply through a first voltage division circuit through a first comparator; only when the high-voltage backup power supply is in a normal power-on state, the first controlled switch is switched on, the control circuit for triggering the high-voltage backup power supply is switched on, and the high-voltage backup power supply supplies power to the electric load, so that safe starting of the high-voltage backup power supply is realized through simple circuit components, additional control chips and other power supplies do not need to be arranged, and the cost is reduced. The high-voltage backup power supply is simple in structure and low in cost, the power supply stability is prevented from being influenced by self control delay of the control chip, the starting response speed of the high-voltage backup power supply is improved, the problem that an electric load is damaged due to abnormal power-on operation of the electric load when the electric load is not charged with high voltage but is charged reversely is solved, and the power supply safety is improved.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a high-voltage backup power supply starting circuit, a power supply system and a vehicle. Background Art

[0002] In electric vehicles, the electric drive controller is typically powered by a low-voltage power supply. However, to improve power supply stability and redundancy, a high-voltage backup power supply is often added. This ensures the basic safety functions of the electric drive system should the low-voltage power supply fail. This high-voltage backup power supply typically starts directly after high-voltage power is applied. This method poses a risk of reverse charging when the vehicle is towed in reverse, causing the electric drive controller to operate abnormally without high-voltage power, potentially damaging the controller or the electric drive system. Summary of the Invention

[0003] In view of this, the present invention provides a high-voltage backup power supply starting circuit, a power supply system and a vehicle to solve the problem in the related art that when the whole vehicle is towed in reverse, the high-voltage backup power supply starting method is not supplied with high voltage power but reverse charging causes the electric drive controller to power on and operate abnormally, resulting in damage to the controller or the electric drive system.

[0004] In a first aspect, the present invention provides a high-voltage backup power supply startup circuit, comprising: a first voltage divider circuit, a second voltage divider circuit, a first comparator and a first controlled switch, wherein the high-voltage backup power supply is connected to the positive input terminal of the first comparator through the first voltage divider circuit; the low-voltage power supply is connected to the reverse input terminal of the first comparator through the second voltage divider circuit, and the high-voltage backup power supply is a backup power supply for the low-voltage power supply; the output terminal of the first comparator is respectively connected to the control terminal of the first controlled switch and the low-voltage power supply; the output terminal of the first controlled switch is connected to the control circuit of the high-voltage backup power supply, and when the first controlled switch is turned on, the control circuit of the high-voltage backup power supply is triggered to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit.

[0005] The high-voltage backup power supply in the present invention is provided in order to improve the power supply stability and redundancy performance during the normal operation of the low-voltage power supply, so as to avoid the abnormal failure of the low-voltage power supply in the power supply system during the power supply process. The low-voltage power supply is used to provide a reference voltage through the second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared through the first comparator. Only when the high-voltage backup power supply is in a normal power-on state, the first comparator outputs a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit. When the high-voltage backup power supply is not powered on, the first comparator outputs a low-level signal, the first controlled switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby achieving safe startup of the high-voltage backup power supply through simple circuit components. There is no need to set up additional control chips and other power supplies, which is low-cost and avoids the startup delay of the high-voltage backup power supply due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, avoiding the problem of abnormal power-on and operation of the power load due to reverse charging without high voltage power supply, resulting in damage to the power load, and further improving the safety of power supply of the high-voltage backup power supply.

[0006] In an optional embodiment, the high-voltage backup power supply startup circuit also includes: a low-voltage power supply verification circuit, and the low-voltage power supply verification circuit includes: a third voltage divider circuit, a fourth voltage divider circuit and a second comparator, wherein the high-voltage backup power supply is connected to the reverse input terminal of the second comparator through the third voltage divider circuit; the low-voltage power supply is connected to the positive input terminal of the second comparator through the fourth voltage divider circuit, and the low-voltage power supply is connected to the input terminal of the second voltage divider circuit through the output terminal of the second comparator.

[0007] The present invention sets a low-voltage power supply verification circuit, and uses the high-voltage backup power supply to provide a reference voltage through the third voltage-dividing circuit after powering on, and compares the voltage of the low-voltage power supply through the fourth voltage-dividing circuit through the second comparator. Only when the power supply voltage of the low-voltage power supply is in a stable state, the second comparator outputs a high-level signal. At this time, the low-voltage power supply can provide a reference voltage to the first comparator, ensuring the stability of the reference voltage input to the first comparator, so that only when the low-voltage power supply and the high-voltage backup power supply are both stably supplied, the control circuit of the high-voltage backup power supply can be activated and started, so as to further ensure the stability of the output voltage of the high-voltage backup power supply, avoid the problem that the high-voltage backup power supply will provide a voltage lower than its power supply voltage requirement to the power load due to insufficient power supply of the low-voltage power supply, making the power load unable to work normally or even damaged, thereby further improving the stability and safety of the power supply of the high-voltage backup power supply.

[0008] In an optional embodiment, the low-voltage power supply verification circuit also includes: a fifth voltage-dividing circuit and a first voltage-stabilizing circuit, wherein the high-voltage backup power supply is connected to the input end of the third voltage-dividing circuit through the fifth voltage-dividing circuit; the first voltage-stabilizing circuit is arranged at the output end of the fifth voltage-dividing circuit to stabilize the voltage output by the fifth voltage-dividing circuit.

[0009] The present invention reduces the voltage of the high-voltage backup power supply to near the output voltage of the low-voltage power supply by setting a fifth voltage-dividing circuit, thereby facilitating the verification of the output voltage of the low-voltage power supply, and stabilizes the voltage input to the third voltage-dividing circuit through the first voltage-stabilizing circuit, thereby ensuring the stability of the voltage input to the third voltage-dividing circuit, and further providing a stable reference voltage for the second comparator, so as to further improve the accuracy of the stability verification of the output voltage of the low-voltage power supply, further ensure the stability of the output voltage of the high-voltage backup power supply, and further improve the stability and safety of the power supply of the high-voltage backup power supply.

[0010] In an optional embodiment, the control circuit includes: a second controlled switch, a sixth voltage-dividing circuit, and a second voltage-stabilizing circuit, wherein the high-voltage backup power supply is connected to the input end of the first voltage-dividing circuit and the first end of the second controlled switch respectively through the sixth voltage-dividing circuit; the control end of the second controlled switch is connected to the output end of the first controlled switch, and the second end is connected to the power load; and the second voltage-stabilizing circuit is arranged at the output end of the sixth voltage-dividing circuit to stabilize the voltage output by the sixth voltage-dividing circuit.

[0011] The present invention realizes the switching of the control circuit on and off by setting a second controlled switch in the control circuit, utilizes the hardware fast response characteristics of the controlled switch, improves the response speed of the control circuit, and reduces the voltage of the high-voltage backup power supply to near the power supply voltage required by the power load by setting a sixth voltage-dividing circuit, and stabilizes the voltage input to the first voltage-dividing circuit and the power load by the second voltage-stabilizing circuit, thereby ensuring the stability of the voltage input to the first voltage-dividing circuit, and further ensuring the accuracy of the output result of the first comparator, and ensuring the stability of the power supply voltage output by the high-voltage backup power supply to the power load, further improving the stability and safety of the power supply of the high-voltage backup power supply.

[0012] In an optional implementation, the first controlled switch is an NMOS transistor, and the second controlled switch is a triode.

[0013] The present invention sets the first controlled switch as an NMOS tube and the second controlled switch as a triode, thereby utilizing the characteristics of the NMOS tube and triode switches, such as fast response speed, low loss, flexible control, and low cost, to further improve the startup response speed of the high-voltage backup power supply, save energy loss, and reduce the hardware cost of the high-voltage backup power supply startup circuit.

[0014] In a second aspect, the present invention provides a power supply system, comprising: a low-voltage power supply, a high-voltage backup power supply, a control circuit of the high-voltage backup power supply, and a high-voltage backup power supply startup circuit provided by the above-mentioned first aspect or any corresponding embodiment thereof, wherein the high-voltage backup power supply is connected to the power supply end of the power load through the control circuit; the high-voltage backup power supply startup circuit is connected to the control circuit for triggering the conduction or shutdown of the control circuit; the power supply end of the power load is also connected to the low-voltage power supply.

[0015] The power supply system provided by the present invention is configured so as to improve the power supply stability and redundancy performance during the normal operation of the low-voltage power supply in order to avoid the abnormal failure of the low-voltage power supply during the power supply process. The low-voltage power supply provides a reference voltage through a second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared with the voltage of the first comparator. Only when the high-voltage backup power supply is in a normal power-on state does the first comparator output a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit. When power is not supplied, the first comparator outputs a low-level signal, the first controlled switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby achieving safe startup of the high-voltage backup power supply through simple circuit components. There is no need to set up additional control chips and other power supplies, which is low-cost and avoids the startup delay of the high-voltage backup power supply due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, and avoiding the problem of abnormal power-on and operation of the power load when the high-voltage power is not supplied but reverse charging, resulting in damage to the power load. This further improves the safety of the high-voltage backup power supply and improves the power supply stability and safety of the entire power supply system.

[0016] In an optional embodiment, the power supply system further includes: a backup power supply drive circuit and an isolation transformer, wherein the input end of the backup power supply drive circuit is connected to the high-voltage backup power supply start-up circuit, and the output end is connected to the input end of the isolation transformer; the power supply end of the isolation transformer is connected to the high-voltage backup power supply, and the output end is connected to the power load.

[0017] The present invention achieves electrical isolation between the power supply system and the power load by using a backup power drive circuit to drive the isolation transformer, suppresses interference between the power supply system and the power load, avoids mutual influence of faults, and further improves the safety of the power supply system.

[0018] In an optional embodiment, the isolation transformer includes a first secondary coil and a second secondary coil, the first secondary coil is connected to the power supply end of the power load, and the second secondary coil is connected to the input end of the backup power drive circuit.

[0019] The present invention utilizes an isolation transformer with two secondary coils, so that one output is used to supply power to the power load and the other is used to supply power to the backup power drive circuit, thereby realizing self-circulating power supply of the power drive circuit after the high-voltage backup power supply is started. Even if the low-voltage power supply power is abnormally powered off and completely disconnected, it will not affect the high-voltage backup power supply to the power load, thereby further improving the power supply stability of the entire power supply system.

[0020] In a third aspect, the present invention provides a vehicle comprising: an electrical load and a power supply system provided by the second aspect or any corresponding embodiment thereof.

[0021] The vehicle provided by the present invention is provided with a high-voltage backup power supply in order to improve the power supply stability and redundancy performance during the normal operation of the low-voltage power supply, so as to avoid the abnormal failure of the low-voltage power supply in the power supply system during the power supply process. The low-voltage power supply is used to provide a reference voltage through the second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared through the first comparator. Only when the high-voltage backup power supply is in a normal power-on state, the first comparator outputs a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit. When the high-voltage backup power supply is not powered on, the first comparator outputs a low-level signal. The first controlled switch The switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby realizing the safe startup of the high-voltage backup power supply through simple circuit components, without the need to set up additional control chips and other power supplies, low cost, and avoiding the high-voltage backup power supply startup delay due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, avoiding the problem of abnormal power-on and operation of the power load due to reverse charging without high voltage power, resulting in damage to the power load, further improving the safety of the high-voltage backup power supply, improving the power supply stability and safety of the entire power supply system, ensuring that the basic safety functions of the power load of the entire vehicle can be normally realized during driving, and improving the safety of vehicle driving.

[0022] In an optional embodiment, the high-voltage backup power source in the power supply system is a power battery of the vehicle, and the low-voltage power source in the power supply system is a storage battery of the vehicle.

[0023] The present invention improves the power supply stability and safety of the vehicle's electrical loads by utilizing the vehicle's power battery as a backup power source for the vehicle's storage battery. When the storage battery fails abnormally, it can ensure the basic safety functions of the vehicle and improve vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 2 is a schematic structural diagram of a high-voltage backup power supply startup circuit according to an embodiment of the present invention;

[0026] Figure 2is a schematic structural diagram of a power supply system according to an embodiment of the present invention;

[0027] Figure 3 This is a structural example diagram of a power supply system in the related art;

[0028] Figure 4 is a structural example diagram of another power supply system in the related art;

[0029] Figure 5 is a schematic diagram of a working strategy of a power supply system according to an embodiment of the present invention;

[0030] Figure 6 2 is a schematic structural diagram of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0032] In electric vehicles, the power supply for their electric drive controllers is generally provided by a low-voltage power supply. However, in order to improve power supply stability and redundancy, a high-voltage backup power supply is often added so that when the low-voltage power supply fails abnormally, the high-voltage backup power supply can be used to ensure the basic safety functions of the electric drive system. This high-voltage backup power supply starting method is generally to start directly after the high voltage is turned on. This method has the problem that when the entire vehicle is towed in reverse, the high voltage is not turned on but reverse charging occurs, causing the electric drive controller to power on abnormally and operate, resulting in damage to the controller or the electric drive system. Therefore, there is an urgent need for a high-voltage backup power supply starting circuit that can prevent unexpected starting problems caused by reverse high-voltage charging.

[0033] In this embodiment, a high-voltage backup power supply startup circuit is provided. Figure 1 FIG. 1 is a schematic diagram of a high-voltage backup power supply startup circuit according to an embodiment of the present invention. Figure 1 As shown, the high-voltage backup power supply startup circuit includes:

[0034] A first voltage divider circuit 101, a second voltage divider circuit 102, a first comparator U2 and a first controlled switch Q2, wherein the high-voltage backup power supply 1 is connected to the positive input terminal of the first comparator U2 through the first voltage divider circuit 101; the low-voltage power supply 2 is connected to the negative input terminal of the first comparator U2 through the second voltage divider circuit 102, and the high-voltage backup power supply 1 serves as the backup power supply for the low-voltage power supply 2; the output terminal of the first comparator U2 is respectively connected to the control terminal of the first controlled switch Q2 and the low-voltage power supply 2; the output terminal of the first controlled switch Q2 is connected to the control circuit of the high-voltage backup power supply 1, and when the first controlled switch Q2 is turned on, the control circuit of the high-voltage backup power supply 1 is triggered to turn on, so that the high-voltage backup power supply 1 supplies power to the electrical load through the control circuit.

[0035] For example, Figure 1 As shown, the first voltage divider circuit 101 is composed of a first resistor R15 and a second resistor R18, and the second voltage divider circuit 102 is composed of a third resistor R16 and a fourth resistor R17. The resistance value model of each resistor can be flexibly set according to needs, as long as the voltage comparison function between the high-voltage backup power supply 1 and the low-voltage power supply 2 can be achieved, and no further details will be given here.

[0036] The high-voltage backup power supply in the embodiment of the present invention is provided in order to improve the power supply stability and redundancy performance during the normal operation of the low-voltage power supply, so as to avoid the abnormal failure of the low-voltage power supply in the power supply system during the power supply process. The low-voltage power supply is used to provide a reference voltage through the second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared through the first comparator. Only when the high-voltage backup power supply is in a normal power-on state, the first comparator outputs a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit. When the high-voltage backup power supply is not powered on, the first comparator outputs a low-level signal, the first controlled switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby achieving safe startup of the high-voltage backup power supply through simple circuit components. There is no need to set up additional control chips and other power supplies, which is low-cost and avoids the startup delay of the high-voltage backup power supply due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, avoiding the problem of abnormal power-on and operation of the power load when the high-voltage power is not supplied but reverse charging, resulting in damage to the power load, and further improving the safety of power supply of the high-voltage backup power supply.

[0037] In some optional embodiments, such as Figure 1As shown, the above-mentioned high-voltage backup power supply startup circuit also includes: a low-voltage power supply verification circuit, and the low-voltage power supply verification circuit includes: a third voltage divider circuit 103, a fourth voltage divider circuit 104 and a second comparator U1, wherein the high-voltage backup power supply 1 is connected to the reverse input terminal of the second comparator U1 through the third voltage divider circuit 103; the low-voltage power supply 2 is connected to the positive input terminal of the second comparator U1 through the fourth voltage divider circuit 104, and the low-voltage power supply 2 is connected to the input terminal of the second voltage divider circuit 102 through the output terminal of the second comparator U1.

[0038] For example, Figure 1 As shown, the third voltage-dividing circuit is composed of a fifth resistor R5 and a sixth resistor R8, and the fourth voltage-dividing circuit is composed of a seventh resistor R6 and an eighth resistor R7. The resistance value model of each resistor can be flexibly set according to needs, as long as the voltage comparison function between the high-voltage backup power supply 1 and the low-voltage power supply 2 can be achieved, and no further details will be given here.

[0039] The embodiment of the present invention sets a low-voltage power supply verification circuit, and uses the third voltage-dividing circuit to provide a reference voltage after the high-voltage backup power supply is powered on, and the voltage of the low-voltage power supply through the fourth voltage-dividing circuit is compared with the voltage of the low-voltage power supply through the second comparator. Only when the power supply voltage of the low-voltage power supply is in a stable state, the second comparator outputs a high-level signal. At this time, the low-voltage power supply can provide a reference voltage to the first comparator to ensure the stability of the reference voltage input to the first comparator, so that only when the low-voltage power supply and the high-voltage backup power supply are both stably supplied, the control circuit of the high-voltage backup power supply can be activated and started, so as to further ensure the stability of the output voltage of the high-voltage backup power supply, avoid the problem that the high-voltage backup power supply will provide a voltage lower than its power supply voltage requirement to the power load due to insufficient power supply of the low-voltage power supply, so that the power load cannot work normally or even is damaged, thereby further improving the stability and safety of the power supply of the high-voltage backup power supply.

[0040] In an optional embodiment, the low-voltage power supply verification circuit also includes: a fifth voltage divider circuit 105 and a first voltage stabilizing circuit 106, wherein the high-voltage backup power supply 1 is connected to the input end of the third voltage divider circuit 103 through the fifth voltage divider circuit 105; the first voltage stabilizing circuit 106 is arranged at the output end of the fifth voltage divider circuit 105 to stabilize the voltage output by the fifth voltage divider circuit 105.

[0041] For example, Figure 1As shown, the fifth voltage divider circuit 105 is composed of a ninth resistor R1, a tenth resistor R2, an eleventh resistor R3, and a twelfth resistor R4. The high-voltage backup power supply 1 is stepped down by the fifth voltage divider circuit 105. In practical applications, the number of resistors set in the fifth voltage divider circuit 105 and the resistance model of each resistor can be flexibly set as needed, as long as the voltage comparison function between the high-voltage backup power supply 1 and the low-voltage power supply 2 can be achieved. No further details will be given here. The above-mentioned first voltage stabilizing circuit 106 is composed of a first voltage stabilizing diode D1 and a first capacitor C1 connected in parallel, wherein the first voltage stabilizing diode D1 is connected in parallel with the twelfth resistor R4. For example, the voltage stabilizing value of the first voltage stabilizing diode D1 is the power supply voltage of the load at the power end, such as a voltage stabilizing value of 12V, etc. This is only an example, and the present invention is not limited to this. The voltage stabilizing function is achieved by the first voltage stabilizing diode D1, and the interference in the output voltage is filtered out by the first capacitor C1.

[0042] The embodiment of the present invention facilitates the verification of the output voltage of the low-voltage power supply by setting a fifth voltage-dividing circuit to reduce the voltage of the high-voltage backup power supply to near the output voltage of the low-voltage power supply, and stabilizes the voltage input to the third voltage-dividing circuit through the first voltage-stabilizing circuit, thereby ensuring the stability of the voltage input to the third voltage-dividing circuit, and further providing a stable reference voltage for the second comparator, so as to further improve the accuracy of the stability verification of the output voltage of the low-voltage power supply, further ensure the stability of the output voltage of the high-voltage backup power supply, and further improve the stability and safety of the power supply of the high-voltage backup power supply.

[0043] In an optional embodiment, the control circuit includes: a second controlled switch Q1, a sixth voltage-dividing circuit 107, and a second voltage-stabilizing circuit 108, wherein the high-voltage backup power supply 1 is connected to the input end of the first voltage-dividing circuit 101 and the first end of the second controlled switch Q1 respectively through the sixth voltage-dividing circuit 107; the control end of the second controlled switch Q1 is connected to the output end of the first controlled switch Q2, and the second end is connected to the power load; the second voltage-stabilizing circuit 108 is provided at the output end of the sixth voltage-dividing circuit 107 to stabilize the voltage output by the sixth voltage-dividing circuit 107.

[0044] For example, Figure 1As shown, the sixth voltage divider circuit 107 is composed of a thirteenth resistor R11, a fourteenth resistor R12, a fifteenth resistor R13, and a sixteenth resistor R14. The high-voltage backup power supply 1 is stepped down by the sixth voltage divider circuit 107. In actual applications, the number of resistors set in the sixth voltage divider circuit 107 and the resistance model of each resistor can be flexibly set as needed, as long as the voltage comparison function between the high-voltage backup power supply 1 and the low-voltage power supply 2 can be achieved. No further details will be given here. The above-mentioned second voltage stabilizing circuit 108 is composed of a second voltage stabilizing diode D2 and a second capacitor C2 connected in parallel, wherein the second voltage stabilizing diode D2 is connected in parallel with the sixteenth resistor R14. For example, the voltage stabilizing value of the second voltage stabilizing diode D2 is the power supply voltage of the load at the power end, such as a voltage stabilizing value of 12V, etc. This is only an example, and the present invention is not limited to this. The voltage stabilizing function is achieved by the second voltage stabilizing diode D2, and the interference in the output voltage is filtered out by the second capacitor C2.

[0045] The embodiment of the present invention realizes the switching of the control circuit between on and off by setting a second controlled switch in the control circuit, utilizes the hardware fast response characteristics of the controlled switch, improves the response speed of the control circuit, and reduces the voltage of the high-voltage backup power supply to near the power supply voltage required by the power load by setting a sixth voltage-dividing circuit, and stabilizes the voltage input to the first voltage-dividing circuit and the power load by the second voltage-stabilizing circuit, thereby ensuring the stability of the voltage input to the first voltage-dividing circuit, and further ensuring the accuracy of the output result of the first comparator, and ensuring the stability of the power supply voltage output by the high-voltage backup power supply to the power load, thereby further improving the stability and safety of the power supply of the high-voltage backup power supply.

[0046] In some optional embodiments, such as Figure 1 As shown, the first controlled switch Q2 is an NMOS transistor, and the second controlled switch Q1 is a triode. Figure 1 The seventeenth resistor R20, the eighteenth resistor R21, the nineteenth resistor R22, and the twentieth resistor R23 constitute the peripheral circuit corresponding to the first controlled switch and the second controlled switch. The specific values ​​can be flexibly set according to needs and will not be described in detail here. Figure 1 The twenty-first resistor R9 constitutes a peripheral circuit of the second comparator, the twenty-second resistor R19 constitutes a peripheral circuit of the first comparator, and the twenty-third resistor R10 and the twenty-fourth resistor R24 ​​are current limiting resistors.

[0047] It should be noted that, in practical applications, the first controlled switch Q2 and the second controlled switch Q1 may also be other switch devices, such as IGBT switches, and corresponding peripheral circuits may be designed adaptively, and the present invention is not limited thereto.

[0048] In the embodiment of the present invention, by configuring the first controlled switch as an NMOS transistor and the second controlled switch as a triode, the characteristics of the NMOS and triode switches, such as fast response speed, low loss, flexible control, and low cost, are utilized to further improve the startup response speed of the high-voltage backup power supply, save energy loss, and reduce the hardware cost of the high-voltage backup power supply startup circuit.

[0049] The following will be combined with Figure 1 The circuit structure shown is used to describe in detail the working principle and working process of the high-voltage backup power supply startup circuit provided by the embodiment of the present invention.

[0050] like Figure 1 As shown, DC+ is the input terminal of the high-voltage backup power supply 1, which is connected in series with resistors R1, R2, R3, and R4. R1, R2, R3, and R4 are voltage-dividing resistors, and their number can be adjusted according to the actual voltage conditions and is not limited to the number shown in the example. The high-voltage power supply is divided by R1, R2, R3, and R4. R4 is connected in parallel with D1 and C1 to stabilize and clamp the stepped-down voltage. This subcircuit can divide the voltage input of the high-voltage backup power supply 1 and clamp it to approximately 12V (the subsequent power supply voltage range). C1 is connected to R5, which is connected to R8 and pin 2 of U1. The 12V power supply after the high-voltage backup power supply 1 is stepped down can be further divided to approximately 4.5V through R5 and R8, facilitating comparison with the voltage of the divided 5V power supply, and then input to pin 2 of U1. P5V is the 5V output from low-voltage power supply 2. It is connected to R6, U1's pins 1 (connected in series with R10), and 5. R6, R7, and U1's pin 3 are connected. P5V, the output voltage of low-voltage power supply 2, is divided by R6 and R7 and input to U1's pin 3. When the voltage at pin 3 is higher than that at pin 2, pin 1 outputs a high level, and P5V outputs the VCC1 voltage through R10. This prevents the output of a power supply voltage below 12V due to unstable 5V power supply. Excessive low voltage can cause damage to subsequent circuits and loads due to abnormal operation.

[0051] VCC1 is connected to U2's pins 1 and 5. It is also connected to R16, U2's pins 1 (with R24 in series), and 5. R16 is connected to R17 and U2's pin 2. The VCC1 voltage is divided by R16 and R17 and then connected to U2's pin 2. DC+ is connected in series with R11, R12, R13, and R14. These resistors act as voltage dividers and their number can be adjusted based on actual voltage conditions, not limited to the example. R13 is connected in parallel with D2 and C2. C2 is connected to R15, which is then connected to R18 and U2's pin 3. The DC+ voltage is divided by R11, R12, R13, and R14, and then stabilized to 12V by D2 and C2. It is then divided again by R15 and R18, and input to pin 3 of U2. When the voltage at pin 3 is higher than that at pin 2, pin 1 outputs a high level, and VCC1 drives Q2 to turn on. Q2 is connected to R22, which is connected to Q1, turning on Q1. Q1 is connected to D2 and C2. When Q1 turns on, the 12V power supply is output to VCC2. This ensures a voltage output of approximately 12V; starting will not be possible if the voltage is lower than 12V.

[0052] This makes it possible to inspect the quality of the low-voltage P5V power supply, confirm that the low-voltage power-up is successful, and that the supply voltage meets the requirements. At the same time, the confirmed P5V voltage is used as a reference to calibrate the other high-voltage supply voltage, confirming that the output power supply VCC2 meets the design requirements. This ensures reliable startup of the high-voltage backup power supply while avoiding abnormal operation or damage to the power load due to the low supply voltage.

[0053] The embodiment of the present invention also provides a power supply system, such as Figure 2 As shown, the power supply system includes: a low-voltage power supply 2, a high-voltage backup power supply 1, a control circuit of the high-voltage backup power supply 1 ( Figure 2 The high-voltage backup power supply 1 is connected to the power supply end of the power load 5 through the control circuit; the high-voltage backup power supply startup circuit 8 is connected to the control circuit for triggering the control circuit to be turned on or off; the power supply end of the power load 5 is also connected to the low-voltage power supply 2.

[0054] For the specific circuit structure, working principle and working process of the high-voltage backup power supply startup circuit 8, please refer to the above-mentioned Figure 1 The description of the high-voltage backup power supply startup circuit shown will not be repeated here.

[0055] The power supply system provided by the embodiment of the present invention is provided with a high-voltage backup power supply in order to improve the power supply stability and redundancy performance during the normal operation of the low-voltage power supply, so as to avoid the power supply system from failing to supply power due to abnormal failure of the low-voltage power supply during the power supply process. Therefore, the low-voltage power supply is utilized to provide a reference voltage through the second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared through the first comparator. Only when the high-voltage backup power supply is in a normal power-on state, the first comparator outputs a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit, and when the high-voltage backup power supply is turned on, the high-voltage backup power supply is turned on. When the power source is not powered on, the first comparator outputs a low-level signal, the first controlled switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby achieving safe startup of the high-voltage backup power supply through simple circuit components. There is no need to set up additional control chips and other power supplies, which is low-cost and avoids the startup delay of the high-voltage backup power supply due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, and avoiding the problem of abnormal power-on and operation of the power load when the high-voltage power is not supplied but reverse charging, resulting in damage to the power load, further improving the safety of the high-voltage backup power supply, and improving the power supply stability and safety of the entire power supply system.

[0056] In some optional embodiments, such as Figure 2 As shown, the above-mentioned power supply system also includes: a backup power supply driving circuit 3 and an isolation transformer 4, wherein the input end of the backup power supply driving circuit 3 is connected to the high-voltage backup power supply starting circuit 8, and the output end is connected to the input end of the isolation transformer 4; the power supply end of the isolation transformer 4 is connected to the high-voltage backup power supply 1, and the output end is connected to the power load 5.

[0057] The embodiment of the present invention achieves electrical isolation between the power supply system and the power load by using a backup power supply drive circuit to drive the isolation transformer, suppresses interference between the power supply system and the power load, avoids mutual influence of faults, and further improves the safety of the power supply system.

[0058] Furthermore, the isolation transformer 4 includes a first secondary coil and a second secondary coil. The first secondary coil is connected to the power supply end of the power load 5 , and the second secondary coil is connected to the input end of the backup power drive circuit 3 .

[0059] The embodiment of the present invention utilizes an isolation transformer with two secondary coils, so that one output is used to supply power to the power load and the other is used to supply power to the backup power drive circuit, thereby realizing self-circulating power supply to the power drive circuit after the high-voltage backup power supply is started. Even if the low-voltage power supply power supply is abnormally powered off and completely disconnected, it will not affect the high-voltage backup power supply to the power load, thereby further improving the power supply stability of the entire power supply system.

[0060] The working principle and working process of the power supply system provided by the embodiment of the present invention will be described in detail below with reference to specific application examples.

[0061] Figure 3 This is a structural example diagram of a power supply system in related technology, such as Figure 3 As shown, during the operation of this power supply system, when the high-voltage backup power supply 1 is powered on, it directly supplies power to the backup power drive circuit 3 and the isolation transformer 4, completing the startup operation of the high-voltage backup power supply 1. Whether the high-voltage backup power supply 1 is operational is solely dependent on whether it is powered on. If the vehicle experiences a low voltage power outage and reverse towing, the reverse charging caused by reverse towing will activate the backup power circuit 3, causing it to supply power to the entire electronic control system. Since this is an unexpected operating condition, it may cause abnormal damage to the electronic control system.

[0062] Figure 4 This is a structural example diagram of another power supply system in the related art, such as Figure 4 As shown, during the operation of the power supply system, when the high-voltage backup power supply 1 is powered on, the high-voltage backup power supply 1 directly supplies power to the backup power drive circuit 3 and the isolation transformer 4. Since the startup circuit 6 requires the low-voltage power supply 2 to provide the enable control 7 to trigger the backup power drive circuit 3 to turn on, the high-voltage backup power supply 1 will not Figure 3 However, since the enabling control 7 requires the low-voltage power supply 2 for power supply, there is a situation in which the low-voltage power supply 2 loses power quickly, resulting in the enabling control 7 not having time to send an enabling signal, which ultimately causes the high-voltage backup power supply 1 to fail to operate normally and fail to play the role of power backup.

[0063] In the embodiment of the present invention, Figure 2As shown, during the operation of the power supply system, when the high-voltage backup power supply 1 is powered on, the high-voltage backup power supply 1 supplies power to the high-voltage backup power supply startup circuit 8. However, at this time, the high-voltage backup power supply startup circuit 8 does not directly supply power to the backup power supply drive circuit 3. It also needs to be compared with the low-voltage power supply 2 to confirm that the voltage of the high-voltage backup power supply 1 after voltage division is higher than the voltage of the low-voltage power supply 2 (thus confirming that the low-voltage power supply is in the powered-on state) before it will supply power to the backup power supply drive circuit 3. After the backup power supply drive circuit 3 is running, the isolation transformer 4 will run and output voltage. The isolation transformer 4 will have two outputs, one for the power load 5 and one for the backup power supply drive circuit 3, so that the backup power supply drive circuit 3 can be separated from the influence of the high-voltage backup power supply startup circuit 8 and achieve self-circulation. This system architecture can avoid the problem of starting only when the high voltage is powered on, and it can also avoid the problem of requiring low-voltage power supply to enable. It only needs both high and low voltage power supply at the startup moment, and only high voltage power supply is sufficient after startup.

[0064] Figure 1 The output VCC2 is connected to the backup power drive circuit 3, activating the backup power drive circuit 3 to enable the isolation transformer 4 to operate and output power. The isolation transformer 4 can output two power supplies: one to reversely supply the backup power drive circuit 3, enabling it to achieve self-circulation (no longer relying on the low-voltage power supply for comparison), and one to output to the power load 5. The high-voltage backup power startup circuit 8 can verify the quality of the low-voltage P5V power supply, confirming that the low-voltage power is on and that the supply voltage meets the requirements. At the same time, this confirmed P5V voltage is used as a reference to calibrate the other high-voltage supply voltage to confirm that the voltage output to the backup power drive circuit 3 meets the design requirements, thereby preventing abnormal operation or damage to the backup power drive circuit 3 due to the low supply voltage.

[0065] With this power supply system design, the backup power circuit can only be activated when both the low-voltage power supply 2 and the high-voltage backup power supply 1 are providing stable power. Even if the low-voltage power supply unexpectedly loses power during the power-up process, the dual comparators can verify each other to avoid driving anomalies caused by insufficient low-voltage power supply or abnormal low-voltage power loss. Furthermore, after startup, the high-voltage backup power supply 1 can independently power the backup power drive circuit 3, and even if the low-voltage power supply 2 is completely disconnected, the backup power circuit's operation and output will not be affected.

[0066] Specifically, during the mutual verification process of the dual comparators, when the high voltage and low voltage (i.e., the high voltage backup power supply 1 and the low voltage power supply 2) are powered on for the first time, the following situations may occur:

[0067] 1. The high voltage may be insufficient, and the low voltage power supply is normal, then you can Figure 1 The circuit in the middle and lower part ensures that the voltage VCC2 lower than 12V after high voltage division will not be output to the subsequent backup power drive circuit 3.

[0068] 2. The low pressure may be insufficient and the high pressure may be normal. Figure 1 The circuit in the upper middle section ensures that a voltage VCC1 lower than approximately 4.5V will not be output to the circuit below.

[0069] 3. Only when the low voltage and high voltage are normal at the first power-on, will the backup power circuit be started to supply power to the electrical load 5.

[0070] Vehicle scene:

[0071] 1. The normal power-on process for the entire vehicle is to power on the low voltage first and then the high voltage. If the low voltage cannot be powered on normally, the high voltage will not be powered on either, the system will not operate normally, and there will be no need for a backup power supply.

[0072] 2. The low voltage is powered on normally, and then the high voltage is powered on. However, during the high voltage power-on process, the low voltage drops abnormally. If it is not checked at this time, the power supply input below 12V will be supplied to the backup drive circuit, causing the drive circuit to work abnormally or the hardware to be damaged.

[0073] 3. Both low voltage and high voltage are powered on normally, and then the low voltage drops abnormally. In this case, the backup power supply has already started during the previous normal power-on process and has achieved self-circulation. The low voltage drop does not affect the output function of the backup power supply.

[0074] Figure 5 This is a schematic diagram of the working strategy of the power supply system according to an embodiment of the present invention, which specifically includes the following processes:

[0075] Power-on identification:

[0076] After the vehicle is powered on and running normally, two comparison circuits are used to cross-compare the low voltage power-on and low voltage supply voltage, high voltage power-on and high voltage supply voltage. Confirm that the power-on status and supply voltage meet the requirements:

[0077] Low voltage power supply: ≥5V;

[0078] High voltage power supply: ≥200V;

[0079] Output and start the backup power drive circuit:

[0080] After the above power supply voltage conditions are met, power is supplied to the backup power drive circuit, which drives the isolation transformer to operate and output voltage.

[0081] Backup power self-circulation:

[0082] After the isolation transformer is running and outputting, one path is sent to the load, and the other path is reversely supplied to the backup power drive circuit, thereby replacing the high-voltage backup power start-up circuit at the start-up time.

[0083] Backup power supply access:

[0084] After the power supply circuit of the high-voltage power supply, i.e. the above-mentioned high-voltage backup power supply 1, operates normally, if the low-voltage power supply, i.e. the above-mentioned low-voltage power supply 2, is disconnected, the high-voltage power supply is connected to supply power to the electrical load to realize the backup function.

[0085] The embodiment of the present invention further provides a vehicle, such as Figure 6 As shown, the vehicle includes: an electrical load 5 and a power supply system 600 provided in another embodiment of the present invention. The power supply system 600 is used to supply power to the electrical load 5. For example, the vehicle is an electric vehicle, and the electrical load 5 is an electric drive controller of the vehicle.

[0086] In the vehicle provided by the embodiment of the present invention, the high-voltage backup power supply is provided during the normal operation of the low-voltage power supply in order to improve the power supply stability and redundancy performance, so as to avoid the power supply system from failing to supply power due to abnormal failure of the low-voltage power supply during the power supply process. Therefore, the low-voltage power supply provides a reference voltage through the second voltage divider circuit during normal operation, and the voltage of the high-voltage backup power supply through the first voltage divider circuit is compared through the first comparator. Only when the high-voltage backup power supply is in a normal power-on state, the first comparator outputs a high-level signal. At this time, the low-voltage power supply drives the first controlled switch to turn on, thereby triggering the control circuit of the high-voltage backup power supply to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit. When the high-voltage backup power supply is not powered on, the first comparator outputs a low-level signal. The control switch is in the off state, and the control circuit of the high-voltage backup power supply is also in the off state. The high-voltage backup power supply does not supply power to the power load, thereby realizing the safe startup of the high-voltage backup power supply through simple circuit components, without the need to set up additional control chips and other power supplies, low cost, and avoiding the delay in the startup of the high-voltage backup power supply due to the control delay of the control chip itself, affecting the power supply stability, improving the startup response speed of the high-voltage backup power supply, avoiding the problem of abnormal power-on and operation of the power load due to reverse charging without high voltage power, resulting in damage to the power load, further improving the safety of the power supply of the high-voltage backup power supply, improving the power supply stability and safety of the entire power supply system, ensuring that the basic safety functions of the power load of the entire vehicle can be normally realized during driving, and improving the safety of vehicle driving.

[0087] In actual applications, the high-voltage backup power supply in the above-mentioned power supply system 600 is the vehicle's power battery, and the low-voltage power supply in the power supply system 600 is the vehicle's battery. For example, the low-voltage power supply is a small 12V battery on the vehicle.

[0088] The embodiments of the present invention improve the power supply stability and safety of the vehicle's electrical loads by utilizing the vehicle's power battery as a backup power source for the vehicle's storage battery. When the storage battery fails abnormally, the basic safety functions of the vehicle can be guaranteed, thereby improving the vehicle's driving safety.

[0089] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A high voltage backup power supply startup circuit, characterized in that: include: a first voltage dividing circuit, a second voltage dividing circuit, a first comparator and a first controlled switch, wherein: The high-voltage backup power supply is connected to the positive input terminal of the first comparator through the first voltage divider circuit; The low-voltage power supply is connected to the inverting input terminal of the first comparator through the second voltage divider circuit, and the high-voltage backup power supply is a backup power supply for the low-voltage power supply; The output end of the first comparator is connected to the control end of the first controlled switch and the low-voltage power supply respectively; The output end of the first controlled switch is connected to the control circuit of the high-voltage backup power supply. When the first controlled switch is turned on, the control circuit of the high-voltage backup power supply is triggered to turn on, so that the high-voltage backup power supply supplies power to the power load through the control circuit.

2. The high-voltage backup power supply startup circuit according to claim 1, characterized in that: Also includes: A low-voltage power supply verification circuit, comprising: a third voltage divider circuit, a fourth voltage divider circuit and a second comparator, wherein: The high-voltage backup power supply is connected to the inverting input terminal of the second comparator through the third voltage divider circuit; The low-voltage power supply is connected to the positive input terminal of the second comparator through the fourth voltage divider circuit. The low-voltage power supply is connected to the input end of the second voltage divider circuit via the output end of the second comparator.

3. The high-voltage backup power supply startup circuit according to claim 2, characterized in that: The low-voltage power supply verification circuit further includes: a fifth voltage divider circuit and a first voltage stabilizing circuit, wherein: The high-voltage backup power supply is connected to the input end of the third voltage divider circuit through the fifth voltage divider circuit; The first voltage stabilizing circuit is provided at the output end of the fifth voltage dividing circuit to stabilize the voltage output by the fifth voltage dividing circuit.

4. The high-voltage backup power supply startup circuit according to claim 1, characterized in that: The control circuit includes: a second controlled switch, a sixth voltage divider circuit and a second voltage stabilizing circuit, wherein: The high-voltage backup power supply is connected to the input end of the first voltage-dividing circuit and the first end of the second controlled switch respectively through the sixth voltage-dividing circuit; The control end of the second controlled switch is connected to the output end of the first controlled switch, and the second end is connected to the power load; The second voltage stabilizing circuit is provided at the output end of the sixth voltage dividing circuit to stabilize the voltage output by the sixth voltage dividing circuit.

5. The high-voltage backup power supply startup circuit according to claim 4, characterized in that: The first controlled switch is an NMOS transistor, and the second controlled switch is a triode.

6. A power supply system, characterized in that: include: A low-voltage power supply, a high-voltage backup power supply, a control circuit for a high-voltage backup power supply, and a high-voltage backup power supply startup circuit as claimed in any one of claims 1 to 5, wherein: The high-voltage backup power supply is connected to the power supply end of the power load through the control circuit; The high-voltage backup power supply startup circuit is connected to the control circuit and is used to trigger the control circuit to be turned on or off; The power supply end of the electrical load is also connected to the low-voltage power supply.

7. The power supply system according to claim 6, characterized in that: Also includes: Backup power drive circuit and isolation transformer, where The input end of the backup power drive circuit is connected to the high-voltage backup power start-up circuit, and the output end is connected to the input end of the isolation transformer; The power supply end of the isolation transformer is connected to the high-voltage backup power supply, and the output end is connected to the power load.

8. The power supply system according to claim 7, characterized in that: The isolation transformer includes a first secondary coil and a second secondary coil. The first secondary coil is connected to the power supply end of the power load, and the second secondary coil is connected to the input end of the backup power drive circuit.

9. A vehicle, characterized in that: The vehicle comprises: an electrical load and a power supply system according to any one of claims 6 to 8.

10. The vehicle according to claim 9, characterized in that The high-voltage backup power source in the power supply system is the vehicle's power battery, and the low-voltage power source in the power supply system is the vehicle's storage battery.

Images