A DC delayed power-off control system and method

Abstract

The present invention relates to a DC delayed power-off control system and method, belonging to the technical field of delayed power-off, and solves the problem in the prior art that the requirements of harsh environments or high reliability of energy storage circuits cannot be met. The system includes: a buck module, connected between the input power supply and the distributed energy storage module, and used for reducing the input power supply voltage to the voltage value required for charging the distributed energy storage module; the distributed energy storage module includes a plurality of energy storage devices with different capacities, and the energy storage devices with different capacities are all connected to the input end of the boost module; the output end of the boost module is connected to the input end of the selection output module and is used for boosting the distributed energy storage module; the selection output module is also directly connected to the input power supply and is used for selecting the input power supply or the distributed energy storage module to supply power to the load according to the power supply / off situation of the system. DC delayed power-off is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of delayed power-off, and particularly to a DC delayed power-off control system and method. Background Art

[0002] In the field of monitoring and detection, it is necessary to record the currently running data in real time. Most systems need to packetize and store the data regularly or quantitatively when storing data. For example, when storing video images, the images need to be packed into the MP4 format at different times.

[0003] For vehicle-mounted storage products, such as night vision storage devices, the system is powered by the vehicle battery and is powered on when the vehicle starts. When the entire system encounters abnormal power-off, the system cannot timely packetize the current data. In actual use, if the data at the last moment is not specially processed, it cannot be directly read after being powered on again. The common processing methods are as follows: 1. In the application scenario where the storage medium does not need to be taken out, the data is packetized again after being powered on again; 2. Add a small-capacity lithium battery to supply power to the system for a period of time after sudden power-off to ensure normal shutdown of the system. The first scenario is not applicable to the occasion where the hard disk needs to be taken out. In the second scenario, the lithium battery has limitations in service life and is greatly affected by temperature, and is not applicable to some harsh environments; at the same time, in some special occasions, the too long charging time affects the system's performance in some abnormal situations.

[0004] Therefore, there is a lack of a DC delayed power-off control system and method in the prior art that can meet the requirements in harsh environments or has high reliability requirements for energy storage circuits. Summary of the Invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a DC delayed power-off control system and method to solve the problem that the prior art cannot meet the requirements of harsh environments or high reliability and fast response of energy storage circuits.

[0006] On the one hand, the embodiments of the present invention provide a DC delayed power-off control system, including:

[0007] A buck module, connected between the input power supply and the distributed energy storage module, for reducing the input power supply voltage to the voltage value required for charging the distributed energy storage module;

[0008] A distributed energy storage module, including a plurality of energy storage devices with different capacities, and the energy storage devices with different capacities are all connected to the input end of the boost module;

[0009] The output end of the boost module is connected to the input end of the selection output module, for boosting the distributed energy storage module;

[0010] The selection output module is also directly connected to the input power supply and is used to select the input power supply or the distributed energy storage module to supply power to the load according to the system power supply / off status.

[0011] Further, the distributed energy storage module includes a first supercapacitor, a second supercapacitor, a third supercapacitor, and a fourth supercapacitor, and the capacities of the first to fourth supercapacitors are all different.

[0012] Further, the first to fourth supercapacitors are respectively connected to the buck module through the first to fourth diodes:

[0013] The output end of the buck module is connected to the positive electrode of the first diode, the negative electrode of the first diode is connected to the positive electrode of the first supercapacitor, and the negative electrode of the first supercapacitor is grounded;

[0014] The output end of the buck module is connected to the positive electrode of the second diode, the negative electrode of the second diode is connected to the positive electrode of the second supercapacitor, and the negative electrode of the second supercapacitor is grounded;

[0015] The output end of the buck module is connected to the positive electrode of the third diode, the negative electrode of the third diode is connected to the positive electrode of the third supercapacitor, and the negative electrode of the third supercapacitor is grounded;

[0016] The output end of the buck module is connected to the positive electrode of the fourth diode, the negative electrode of the fourth diode is connected to the positive electrode of the fourth supercapacitor, and the negative electrode of the fourth supercapacitor is grounded.

[0017] Further, the first to fourth supercapacitors are respectively connected to the boost module through the fifth to eighth diodes, and when the system is powered off, one or more of the first to fourth supercapacitors with the highest voltage are selected to supply power to the load;

[0018] The positive electrode of the first supercapacitor is connected to the positive electrode of the fifth diode, and the negative electrode of the fifth diode is connected to the input end of the boost module;

[0019] The positive electrode of the second supercapacitor is connected to the positive electrode of the sixth diode, and the negative electrode of the sixth diode is connected to the input end of the boost module;

[0020] The positive electrode of the third supercapacitor is connected to the positive electrode of the seventh diode, and the negative electrode of the seventh diode is connected to the input end of the boost module;

[0021] The positive electrode of the fourth supercapacitor is connected to the positive electrode of the eighth diode, and the negative electrode of the eighth diode is connected to the input end of the boost module.

[0022] Further, the selection and output module includes: a first selection and output unit and a second selection and output unit; the input power supply is directly connected to the first selection and output unit; the output end of the boost module is connected to the second selection and output unit; the selection and output module is used to select the line with the higher output voltage between the first selection and output unit and the second selection and output unit to supply power to the load.

[0023] Further, it also includes:

[0024] A filter circuit, which is connected in series between the selection and output module and the delayed power-off output end, and is used for filtering and smoothing during power supply switching.

[0025] Further, the power supply switching includes: the switching between the input power supply and the output end of the boost module, and the switching between different capacitors of the distributed energy storage module for power supply.

[0026] Further, the DC delayed power-off control system further includes: a main controller, which is used to record the power-on time of the input power supply and monitor the power-off of the input power supply, and perform power-off abnormal processing according to the power-on time when the input power supply is abnormal;

[0027] The power input end of the main controller is connected to the delayed power-off output end, and the voltage output by the delayed power-off output end supplies power to the main controller.

[0028] Further, the power-off abnormal processing includes:

[0029] When the power-on time is less than the time threshold, the main controller is powered by the distributed energy storage module and only records the abnormal situation;

[0030] When the power-on time is greater than the power-on threshold, the main controller is powered by the distributed energy storage module and performs normal shutdown processing.

[0031] On the other hand, an embodiment of the present invention provides a DC delayed power-off control method, including:

[0032] When the input power supply supplies power normally, the input power supply is divided into two paths, one path is output as the first output voltage, and the other path is stepped down through a buck module to output the second voltage; when the input power supply is normal, the first output voltage supplies power to the load;

[0033] The second voltage is used to charge different-capacity energy storage devices in the energy storage device separately;

[0034] The output voltages of the different-capacity energy storage devices are all connected to the boost module for boost processing and output as the third output voltage used during power-off;

[0035] When the system is powered off, one or more energy storage devices with higher voltage among the energy storage devices with different capacities are selected to supply power to the load.

[0036] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0037] 1. This invention solves the problem of supercapacitor charging delay at the startup moment by using supercapacitors of different capacities as new energy storage containers, combining their usage scenarios and voltages, charging capacitors of different capacities through different channels, and performing voltage boost control on the charged capacitors.

[0038] 2. The present invention adopts an ultra-low voltage boost chip, which can achieve voltage boost at no less than 2.7V, and can maximize the use of the capacitance of the farad capacitor to realize the energy storage circuit in a relatively fast way. At the same time, due to the control of the boost chip, the output voltage is very stable and reliable;

[0039] 3. In the present invention, a high-current Schottky diode MBRD10200CT-13 is passed through during the charging process, so that a smaller-capacity capacitor can reach the startup threshold of the boost chip in a short time, while the configuration of the large-capacity capacitor meets the overall power requirement of the system.

[0040] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0042] Figure 1 This is a schematic diagram of the division of the delayed power-off module shown in an embodiment of the present application;

[0043] Figure 2 This is a schematic diagram of the application connection of a DC delayed power-off control system according to an embodiment of the present application;

[0044] Figure 3 This is a connection diagram of a delayed power-off module shown in one embodiment of the present application;

[0045] Figure 4 This is a circuit diagram of a step-down module shown in one embodiment of the present application;

[0046] Figure 5Circuit diagram of the DC delay power-off module shown in an embodiment of the present application;

[0047] Figure 6 Flowchart of the DC delay power-off control method shown in another embodiment of the present application.

[0048] Reference numerals:

[0049] 10 - Step-down module; 20 - Distributed energy storage module; 30 - Boost module; 40 - Selective output module. Detailed implementation manners

[0050] The following will specifically describe the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings form a part of the present application and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0051] As Figure 1 shown, a specific embodiment of the present invention discloses a DC delay power-off control system, including: a delay power-off module and a main controller; specifically, the delay power-off module includes: a step-down module 10, a distributed energy storage module 20, a boost module 30, a selective output module 40, and a filter circuit;

[0052] As Figures 2 - 3 shown, this embodiment is described by taking an in-vehicle product as an example. After the on-vehicle chassis generator is powered on, the main supply voltage is 18 - 36V. The voltage is converted into a 12V input power supply through a voltage regulator module. One path of the 12V input power supply is supplied to the main controller through the delay power-off module, and the other path of 12V is supplied to the subsequent display, camera, and ultrasonic radar through a relay.

[0053] Specifically, the step-down module 10 is connected between the input power supply and the distributed energy storage module 20 and is used to supply power to the distributed energy storage module 20;

[0054] More specifically, as Figure 4 shown, the step-down module 10 is used to convert the input 12V into a 5V output, and the 5V output is used to charge the distributed energy storage module 20.

[0055] Specifically, the distributed energy storage module 20 includes a plurality of energy storage devices with different capacities, and the energy storage devices with different capacities are all connected to the input end of the boost module 30.

[0056] Generally speaking, for a 10F supercapacitor, if only capacitors of the same capacity are used, it takes about 80S to fully charge it without limiting the current. In some special occasions, the long charging time affects the performance of the system under certain abnormal conditions. Specifically, in this embodiment, four supercapacitors with different capacities are selected. For example, the capacities of the four supercapacitors with different capacities are 1F, 2F, 5F and 10F respectively. At the moment the system is powered on, the four capacitors with different capacities start charging at the same time. Since the 1F capacitor has a smaller capacity, it will first reach the startup threshold of 2.7V of the boost chip in the boost circuit. At this time, the charging time of the 1F capacitor when it is fully charged is 1 / 10 of the time of the 10F capacitor when it is fully charged. If the system loses power at this time, the 1F supercapacitor will be enabled first to discharge. Since the system can determine the time of power failure through the timer at this time, different power failure exception handling strategies can be used to handle it.

[0057] This embodiment uses supercapacitors of different capacities as new energy storage containers, combines their usage scenarios and voltages, and solves the startup time problem of supercapacitors through boost control of capacitors of different capacities, that is, solves the instantaneous charging delay problem; the withstand voltage of supercapacitors is generally low, and capacitors with a withstand voltage of 5.5V are selected in the circuit. Since the internal resistance of the farad capacitor is large, there is no need to limit the charging current; by selecting supercapacitors of different capacities as new energy storage devices, this embodiment solves the high reliability requirement for energy storage circuits in harsh environments and the disadvantage of long charging time of high-capacity supercapacitors at startup, while the circuit has a certain degree of versatility.

[0058] Specifically, if Figure 5 As shown, the distributed energy storage module includes a first supercapacitor C14, a second supercapacitor C15, a third supercapacitor C26 and a fourth supercapacitor C28, and the capacities of the first to fourth supercapacitors are different; optionally, the capacity of the first supercapacitor C14 is 1F, the capacity of the second supercapacitor C15 is 2F, the capacity of the third supercapacitor C26 is 5F and the capacity of the fourth supercapacitor C28 is 10F;

[0059] The first to fourth supercapacitors are connected to the step-down module 10 via first to fourth diodes, respectively. Optionally, a Schottky diode MBRD10200CT-13 is passed through during the charging process. When the Schottky diode is selected, the conduction current should be as large as possible. More specifically:

[0060] The output end of the step-down module 10 is connected to the anode of the first diode D2, the cathode of the first diode D2 is connected to the anode of the first supercapacitor C14, and the cathode of the first supercapacitor C14 is grounded;

[0061] The output terminal of the step-down module is connected to the positive electrode of the second diode D4. The negative electrode of the second diode D4 is connected to the positive electrode of the second super capacitor C15, and the negative electrode of the second super capacitor C15 is grounded.

[0062] The output terminal of the step-down module is connected to the positive electrode of the third diode D6. The negative electrode of the third diode D6 is connected to the positive electrode of the third super capacitor C26, and the negative electrode of the third super capacitor C26 is grounded.

[0063] The output terminal of the step-down module is connected to the positive electrode of the fourth diode D8. The negative electrode of the fourth diode D8 is connected to the positive electrode of the fourth super capacitor C28, and the negative electrode of the fourth super capacitor C28 is grounded.

[0064] The first to fourth super capacitors are respectively connected to the boost module through the fifth to eighth diodes. When the system is powered off, one or more of the first to fourth super capacitors with the highest voltage are selected to supply power to the system. Specifically, the fifth to eighth diodes divide the super capacitors into four independent power supply paths, and output one or more of the paths with the highest voltage among the four output capacitors. When the voltage of the super capacitor with the highest voltage drops to the second highest due to use, the switching circuit supplies power. When the system is powered on for a long enough time and the four super capacitors are fully charged, after the system is powered off, the four super capacitors jointly supply power to the subsequent circuit. More specifically:

[0065] The positive electrode of the first super capacitor C14 is connected to the positive electrode of the fifth diode D3. The negative electrode of the fifth diode D3 is connected to the input terminal of the boost module 30.

[0066] The positive electrode of the second super capacitor C15 is connected to the positive electrode of the sixth diode D5. The negative electrode of the sixth diode D5 is connected to the input terminal of the boost module 3°.

[0067] The positive electrode of the third super capacitor C26 is connected to the positive electrode of the seventh diode D7. The negative electrode of the seventh diode D7 is connected to the input terminal of the boost module 30.

[0068] The positive electrode of the fourth super capacitor C28 is connected to the positive electrode of the eighth diode D9. The negative electrode of the eighth diode D9 is connected to the input terminal of the boost module 30.

[0069] Specifically, the output terminal of the boost module 30 is connected to the selection output module 40, which is used to boost the distributed energy storage module 20. Since the voltage of the super capacitor is too low to meet most usage scenarios, the boost module 30 is used for boosting at the back end. The boosted voltage is adjustable, ranging from 5 - 10V, and the output voltage can be adjusted by configuring resistors. Optionally, the boost chip TI can be TPS61088, and the output voltage is adjusted to 10V.

[0070] The selection output module 40 is configured to select an output power supply line to supply power to a load according to the system power supply / off status. Specifically, the selection output module includes: a first selection output unit and a second selection output unit; the input power supply is connected to the first selection output unit; the output end of the boost module is connected to the second selection output unit; the selection output module is configured to select the line with a higher output voltage between the first selection output unit and the second selection output unit to supply power to the load. Specifically, during normal use, the voltage at the output end of the boost module is 10V, and the voltage of the input power supply is 12V. Therefore, the selection output module 40 does not use the second selection output unit (i.e., the super capacitor in the distributed energy storage module 20) to supply power, but selects to supply power through the first selection output unit (i.e., supply power with 12V of the front-end input power supply).

[0071] A filter circuit, which is connected in series between the selection output module and the output end, is configured to perform filtering and smoothing during power supply switching. The power supply switching includes: switching between the input power supply and the output end of the boost module, and switching between different capacitors for power supply in the distributed energy storage module. Since there is a boost chip for voltage stabilization in the subsequent circuit of the super capacitor in the distributed energy storage module, this reduces the ripple during system output. However, the front stage of the voltage stabilization chip selects the output through 4 super capacitors, and inevitably there will be a small oscillation in the subsequent circuit. Specifically, filtering and smoothing are performed through the subsequent capacitors C29 to C36 to reduce the ripple and oscillation of the system. Optionally, C29 to C33 are 5 capacitors of 47uF, and C34 to C36 are 3 capacitors of 1uF.

[0072] Specifically, the main controller is configured to record the power-on time of the input power supply, and perform power-off abnormal processing according to the power-on time when the input power supply is abnormal; the system starts counting seconds as soon as it is powered on. At this time, if the system has an abnormal power-off, the main controller first detects the voltage disappearance through the source end and triggers the abnormal working process. Then, the system enters different abnormal working processes according to the power-on counting seconds. If the power-on time is too short, only record the abnormal situation (for example, for a night vision storage device, video storage will not be performed first); if the power-on time meets the power required for system shutdown, the system performs a shutdown process at this time.

[0073] More specifically, the power-off abnormal processing includes: when the power-on time is less than the time threshold, the main controller is powered by the distributed energy storage module and only records the abnormal situation; when the power-on time is greater than the power-on threshold, the main controller is powered by the distributed energy storage module and performs a normal shutdown process. Optionally, the time threshold is 20S.

[0074] The power input end of the main controller is connected to the output end of the delay power-off module, and the power supply circuit selected by the selection output module in the delay power-off module supplies power to the main controller.

[0075] In this embodiment, the delay power-off module can continuously output for more than 10 seconds at a power consumption of 12W. The system's instantaneous power-off response can be shortened to within 10 seconds. Without using a lithium battery, through a boost circuit and a normal power supply selection, normal power supply using the input power supply is achieved before power-off, and power consumption is promptly switched to a super capacitor after power-off. By selecting a super-low voltage boost chip, boosting can be achieved at no less than 2.7V, and the capacitance of the farad capacitor can be utilized to the greatest extent, realizing an energy storage circuit by a relatively fast means. At the same time, due to the control of the boost chip, the output voltage is very stable and reliable.

[0076] As Figure 6 shown, a specific embodiment of the present invention discloses a DC delay power-off control method, which is characterized by including:

[0077] S10. When the input power supply is normally supplying power, the input power supply is divided into two paths. One path is output as the first output voltage, and the other path is stepped down through a buck module to output a second voltage; when the input power supply is normal, the first output voltage supplies power to the load.

[0078] S20. The second voltage separately charges energy storage devices with different capacities in the energy storage device.

[0079] S30. The output voltages of the energy storage devices with different capacities are all connected to a boost module for boost processing and output as the third output voltage used when power-off occurs.

[0080] S40. When the system is powered off, one or more energy storage devices with a higher voltage among the energy storage devices with different capacities are selected to supply power to the load.

[0081] Those skilled in the art can understand that all or part of the processes of implementing the above embodiment methods can be completed by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a magnetic disk, an optical disc, a read-only memory, or a random access memory, etc.

[0082] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A DC delayed power-off control system, characterized in that: include: The step-down module is connected between the input power supply and the distributed energy storage module, and is used to reduce the input power supply voltage to the voltage required for charging the distributed energy storage module; A distributed energy storage module, comprising a plurality of energy storage devices of different capacities, wherein the energy storage devices of different capacities are all connected to the input end of the boost module; The output end of the boost module is connected to the input end of the selection output module, and is used to boost the distributed energy storage module; The output selection module is also directly connected to the input power supply and is used to select the input power supply or the distributed energy storage module to supply power to the load according to the power on / off status of the system; The distributed energy storage module includes a first supercapacitor, a second supercapacitor, a third supercapacitor and a fourth supercapacitor, and the capacities of the first to fourth supercapacitors are different; The first to fourth supercapacitors are connected to the step-down module via first to fourth diodes respectively. The output end of the step-down module is connected to the anode of the first diode, the cathode of the first diode is connected to the anode of the first super capacitor, and the cathode of the first super capacitor is grounded; The output end of the step-down module is connected to the anode of the second diode, the cathode of the second diode is connected to the anode of the second super capacitor, and the cathode of the second super capacitor is grounded; The output end of the step-down module is connected to the anode of the third diode, the cathode of the third diode is connected to the anode of the third super capacitor, and the cathode of the third super capacitor is grounded; The output end of the step-down module is connected to the anode of the fourth diode, the cathode of the fourth diode is connected to the anode of the fourth super capacitor, and the cathode of the fourth super capacitor is grounded; The first to fourth supercapacitors are connected to the boost module via fifth to eighth diodes, respectively, and when the system is powered off, one or more of the first to fourth supercapacitors with the highest voltage are selected to supply power to the load; The positive electrode of the first supercapacitor is connected to the positive electrode of the fifth diode, and the negative electrode of the fifth diode is connected to the input end of the boost module; The positive electrode of the second supercapacitor is connected to the positive electrode of the sixth diode, and the negative electrode of the sixth diode is connected to the input end of the boost module; The positive electrode of the third supercapacitor is connected to the positive electrode of the seventh diode, and the negative electrode of the seventh diode is connected to the input end of the boost module; The anode of the fourth supercapacitor is connected to the anode of the eighth diode, and the cathode of the eighth diode is connected to the input end of the boost module.

2. The DC delayed power-off control system according to claim 1, characterized in that: The selection output module includes: a first selection output unit and a second selection output unit; the input power supply is directly connected to the first selection output unit; the output end of the boost module is connected to the second selection output unit; the selection output module is used to select the circuit with the higher output voltage among the first selection output unit and the second selection output unit to power the load.

3. The DC delayed power-off control system according to claim 1, characterized in that: Also includes: A filter circuit is connected in series between the selection output module and the delayed power-off output terminal, and is used for performing filtering and smoothing processing when power supply is switched.

4. The DC delayed power-off control system according to claim 3, characterized in that: The power supply switching includes: switching between the input power supply and the power supply of the boost module output end, and switching between the power supplies of different capacitors of the distributed energy storage module.

5. The DC delayed power-off control system according to claim 1 or 3, characterized in that: The DC delayed power-off control system further includes: a main controller for recording the power-on time of the input power supply, and performing power-off monitoring of the input power supply, and performing power-off abnormality processing according to the power-on time when the input power supply is abnormal; The power input terminal of the main controller is connected to the delayed power-off output terminal, and the output voltage of the delayed power-off output terminal is used to supply power to the main controller.

6. The DC delayed power-off control system according to claim 5, characterized in that: The power failure exception handling includes: When the power-on time is less than the time threshold, the main controller is powered by the distributed energy storage module and only records the abnormal condition; When the power-on time is greater than the power-on threshold, the main controller is powered by the distributed energy storage module and performs a normal shutdown process.

7. A control method for a DC delayed power-off control system according to claim 1, characterized in that: include: When the input power supply is normal, the input power is divided into two paths, one path is output as a first output voltage, and the other path is stepped down by the step-down module to output a second voltage; when the input power supply is normal, the first output voltage is used to supply power to the load; The second voltage is used to charge energy storage devices of different capacities in the energy storage device separately; The output voltages of the energy storage devices of different capacities are all connected to the boost module for boosting and output as the third output voltage used in case of power failure; When the system is powered off, one or more energy storage devices with higher voltage among the energy storage devices with different capacities are selected to supply power to the load.

Images