Power failure protection device, control system and new energy system

Abstract

The utility model relates to the technical field of power electronics, and discloses a power failure protection device, a control system and a new energy system, which are used for preventing a main control unit from being powered on repeatedly. The power failure protection device comprises an energy storage unit, a threshold value control unit and a voltage conversion unit, the energy storage unit is used for storing electric energy and providing the electric energy for the threshold value control unit, and the output end of the energy storage unit is connected with the input end of the threshold value control unit; the threshold value control unit is used for providing electric energy for the voltage conversion unit according to a first voltage threshold value and a second voltage threshold value, the first voltage threshold value is used for controlling the threshold value control unit to be switched on, the second voltage threshold value is used for controlling the threshold value control unit to be switched off, and the output end of the threshold value control unit is connected with the first input end of the voltage conversion unit; and the voltage conversion unit is used for converting the output voltage of the threshold value control unit into target voltage required by the main control unit so as to supply power to the main control unit, and the output end of the voltage conversion unit is connected with the first input end of the main control unit.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a power-off protection device, a control system, and a new energy system. Background Art

[0002] A stable and properly powered system power supply is the key to a system's robust operation. When the system power supply fails or is damaged, the main control unit within the system will be abnormally powered off, so power-off protection is required.

[0003] In the related art, although the energy storage unit can provide electric energy after power failure, as the discharge voltage of the energy storage unit continues to decrease, the main control unit will be repeatedly powered on. Utility Model Content

[0004] The present application provides a power-off protection device, a control system, and a new energy system, which are used to control the input voltage provided by the energy storage unit to the voltage conversion unit through the first voltage threshold and the second voltage threshold of the threshold control unit, so that the voltage conversion unit provides a stable target voltage to the main control unit, solving the problem that the input voltage received by the main control unit will oscillate in the event of a power outage, and achieving the effect of avoiding repeated power-on of the main control unit.

[0005] The first aspect of the present application provides a power-off protection device, comprising: an energy storage unit, a threshold control unit and a voltage conversion unit; the energy storage unit is used to store electrical energy and provide electrical energy to the threshold control unit, and the output end of the energy storage unit is connected to the input end of the threshold control unit; the threshold control unit is used to provide electrical energy to the voltage conversion unit according to a first voltage threshold and a second voltage threshold, the first voltage threshold is used to control the conduction of the threshold control unit, and the second voltage threshold is used to control the shutdown of the threshold control unit, and the output end of the threshold control unit is connected to the first input end of the voltage conversion unit; the voltage conversion unit is used to convert the output voltage of the threshold control unit into a target voltage required by a main control unit to power the main control unit, and the output end of the voltage conversion unit is connected to the first input end of the main control unit.

[0006] In a feasible embodiment, the threshold control unit includes a first switching tube, a first protection transistor, a second protection transistor, a first threshold control branch and a second threshold control branch; the first end of the first switching tube is connected to the emitter of the first protection transistor and the output end of the energy storage unit; the second end of the first switching tube is connected to the first input end of the voltage conversion unit; the base of the first protection transistor is connected to the first end of the first threshold control branch, the collector of the first protection transistor is connected to the first end of the second threshold control branch, the second end of the first threshold control branch is connected to the collector of the second protection transistor and the third end of the first switching tube, and the second end of the second threshold control branch is connected to the base of the second protection transistor; the third end of the first threshold control branch is grounded, and the emitter of the second protection transistor is grounded.

[0007] In a feasible embodiment, the first threshold control branch includes a first threshold control sub-branch and a second threshold control sub-branch, the first end of the first threshold control sub-branch serves as the first end of the first threshold control branch, the second end of the first threshold control sub-branch and the first end of the second threshold control sub-branch are connected to serve as the second end of the first threshold control branch, and the second end of the second threshold control sub-branch serves as the third end of the first threshold control branch; wherein, the sum of the voltage drops of the first threshold control branch and the first protection transistor is the first voltage threshold, the sum of the voltage drops of the second threshold control branch, the first protection transistor and the second protection transistor is the second voltage threshold, the first voltage threshold is greater than the second voltage threshold, and the voltage drop of the second threshold control sub-branch is greater than the voltage drop of the second protection transistor.

[0008] In a feasible embodiment, the first threshold control sub-branch includes N second switching tubes connected in series, and one end of the series connection serves as the first end of the first threshold control sub-branch, and the other end of the series connection serves as the second end of the first threshold control sub-branch; wherein the second switching tube is a switching tube with a unidirectional conduction characteristic, and N is an integer greater than or equal to 1; the second threshold control sub-branch includes a third switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control sub-branch, and the other end of the series connection serves as the second end of the second threshold control sub-branch; wherein the third switching tube is a switching tube with a unidirectional conduction characteristic, and a is an integer greater than or equal to 1.

[0009] In a feasible embodiment, the second threshold control branch includes M fourth switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control branch, and the other end of the series connection serves as the second end of the second threshold control branch; wherein the fourth switching tube is a switching tube with a unidirectional conduction characteristic, and M is an integer greater than or equal to 1.

[0010] In a feasible embodiment, the N second switching tubes include one or more of a triode, a diode, an insulated gate bipolar transistor, and a thyristor; wherein, when the N second switching tubes are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the first threshold control sub-branch, the emitter of the i-th triode is connected to the collector of the i+1-th triode, and the emitter of the N-th triode serves as the second end of the first threshold control sub-branch; when the N second switching tubes are all diodes, the anode of the first diode serves as the first end of the first threshold control sub-branch, the cathode of the i-th diode is connected to the anode of the i+1-th diode, and the cathode of the N-th diode serves as the second end of the first threshold control sub-branch; When both switching tubes are insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the first threshold control sub-branch, the emitter of the i-th insulated gate bipolar transistor is connected to the collector of the i+1-th insulated gate bipolar transistor, and the emitter of the N-th insulated gate bipolar transistor serves as the second end of the first threshold control sub-branch; when the N second switching tubes are all thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the first threshold control sub-branch, the cathode of the i-th thyristor is connected to the anode of the i+1-th thyristor, and the cathode of the N-th thyristor serves as the second end of the first threshold control sub-branch; wherein, 1≤i<N.

[0011] In a feasible embodiment, the a third switching tubes include one or more of a triode, a diode, an insulated gate bipolar transistor and a thyristor; wherein, in the case that the a third switching tubes are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control sub-branch, the emitter of the jth triode is connected to the collector of the j+1th triode, and the emitter of the ath triode serves as the second end of the second threshold control sub-branch; in the case that the a third switching tubes are all diodes, the anode of the first diode serves as the first end of the second threshold control sub-branch, the cathode of the jth diode is connected to the anode of the j+1th diode, and the cathode of the ath diode serves as the second end of the second threshold control sub-branch; in the case that the a third switching tubes are all diodes, the anode of the first diode serves as the first end of the second threshold control sub-branch, the cathode of the jth diode is connected to the anode of the j+1th diode, and the cathode of the ath diode serves as the second end of the second threshold control sub-branch; When all three switching tubes are insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control sub-branch, the emitter of the j-th insulated gate bipolar transistor is connected to the collector of the j+1-th insulated gate bipolar transistor, and the emitter of the a-th insulated gate bipolar transistor serves as the second end of the second threshold control sub-branch; when all a third switching tubes are thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control sub-branch, the cathode of the j-th thyristor is connected to the anode of the j+1-th thyristor, and the cathode of the a-th thyristor serves as the second end of the second threshold control sub-branch; wherein, 1≤j<a.

[0012] In a feasible embodiment, the M fourth switching tubes include one or more of a triode, a diode, an insulated gate bipolar transistor, and a thyristor; wherein, when the M fourth switching tubes are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control branch, the emitter of the kth triode is connected to the collector of the k+1th triode, and the emitter of the Mth triode serves as the second end of the second threshold control branch; when the M fourth switching tubes are all diodes, the anode of the first diode serves as the first end of the second threshold control branch, the cathode of the kth diode is connected to the anode of the k+1th diode, and the cathode of the Mth diode serves as the second end of the second threshold control branch; When all four switching tubes are insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control branch, the emitter of the kth insulated gate bipolar transistor is connected to the collector of the k+1th insulated gate bipolar transistor, and the emitter of the Mth insulated gate bipolar transistor serves as the second end of the second threshold control branch; when all M fourth switching tubes are thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control branch, the cathode of the kth thyristor is connected to the anode of the k+1th thyristor, and the cathode of the Mth thyristor serves as the second end of the second threshold control branch; wherein, 1≤k<M.

[0013] In a feasible embodiment, the threshold control unit also includes a first resistor and / or a second resistor, wherein the first end of the first resistor is connected to the base of the first protection transistor, and the second end of the first resistor is connected to the first end of the first threshold control branch; the first end of the second resistor is connected to the second end of the second threshold control branch, and the second end of the second resistor is connected to the base of the second protection transistor.

[0014] In a feasible embodiment, the threshold control unit also includes a third resistor and / or a fourth resistor, wherein the third resistor is connected in parallel between the first end of the first switching tube and the third end of the first switching tube; the fourth resistor is connected in series between the third end of the first switching tube and the collector of the second protection transistor.

[0015] In a feasible embodiment, the threshold control unit includes a third protection transistor, a fourth protection transistor, a third threshold control branch and a fourth threshold control branch; the emitter of the third protection transistor is connected to the output end of the energy storage unit; the collector of the third protection transistor is connected to the first end of the third threshold control branch and the first input end of the voltage conversion unit; the base of the third protection transistor is connected to the first end of the fourth threshold control branch and the collector of the fourth protection transistor; the second end of the third threshold control branch is connected to the base of the fourth protection transistor; the second end of the fourth threshold control branch is connected to the emitter of the fourth protection transistor and is grounded.

[0016] In a feasible embodiment, the third threshold control branch includes a first voltage regulator diode, the cathode of the first voltage regulator diode serves as the first end of the third threshold control branch, and the anode of the first voltage regulator diode serves as the second end of the third threshold control branch.

[0017] In a feasible embodiment, the fourth threshold control branch includes a second voltage regulator diode, the cathode of the second voltage regulator diode serves as the first end of the fourth threshold control branch, and the anode of the second voltage regulator diode serves as the second end of the fourth threshold control branch.

[0018] In a feasible embodiment, the threshold control unit also includes a fifth resistor and / or a sixth resistor, wherein the first end of the fifth resistor is connected to the collector of the fourth protection transistor and the first input end of the voltage conversion unit, and the second end of the fifth resistor is connected to the first end of the third threshold control branch; the first end of the sixth resistor is connected to the base of the fourth protection transistor, and the second end of the sixth resistor is connected to the first end of the fourth threshold control branch.

[0019] In a feasible embodiment, the voltage drop of the third threshold control branch is the second voltage threshold, the voltage drop of the fourth threshold control branch is the first voltage threshold, and the second voltage threshold is smaller than the first voltage threshold.

[0020] The second aspect of the present application provides a control system, comprising: a power-off protection device, a main control unit and a system power supply according to any one of the embodiments of the first aspect above; the first output end of the system power supply is connected to the input end of the power-off protection device, and the output end of the power-off protection device is connected to the first input end of the main control unit; the second output end of the system power supply is connected to the second input end of the main control unit.

[0021] In a feasible embodiment, the control system also includes: a monitoring unit; the monitoring unit is used to monitor the system power supply and send a system power failure notification to the voltage conversion unit in the power failure protection device and the main control unit when the system power supply is cut off; the input end of the monitoring unit is connected to the third output end of the system power supply; the first output end of the monitoring unit is connected to the second input end of the voltage conversion unit, and the second output end of the monitoring unit is connected to the third input end of the main control unit.

[0022] A third aspect of the present application provides a new energy system, including: a power-off protection device or control system according to any one of the above embodiments.

[0023] In the technical solution provided by the present application, the power-off protection device includes an energy storage unit, a threshold control unit and a voltage conversion unit; the energy storage unit is used to store electrical energy and provide electrical energy to the threshold control unit, and the output end of the energy storage unit is connected to the input end of the threshold control unit; the threshold control unit is used to provide electrical energy to the voltage conversion unit according to a first voltage threshold and a second voltage threshold, the first voltage threshold is used to control the conduction of the threshold control unit, and the second voltage threshold is used to control the shutdown of the threshold control unit, and the output end of the threshold control unit is connected to the first input end of the voltage conversion unit; the voltage conversion unit is used to convert the output voltage of the threshold control unit into the target voltage required by the main control unit to power the main control unit, and the output end of the voltage conversion unit is connected to the first input end of the main control unit. In the present application, the input voltage provided by the energy storage unit to the voltage conversion unit is controlled by the first voltage threshold and the second voltage threshold of the threshold control unit, so that the voltage conversion unit provides a stable target voltage to the main control unit, and the input voltage received by the main control unit will not produce oscillation, thereby avoiding repeated power-on of the main control unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of a power-off protection device in the related art;

[0025] Figure 2 for Figure 1 A schematic diagram showing a comparison between the output voltage of the energy storage unit and the output voltage of the voltage conversion unit in the power-off protection device shown;

[0026] Figure 3 This is a structural diagram of a power-off protection device in one embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of the specific structure of the threshold control unit in the first embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the specific structure of the threshold control unit in the second embodiment of the present application;

[0029] Figure 6This is a schematic diagram of the specific structure of the threshold control unit in the third embodiment of the present application;

[0030] Figure 7 Schematic diagram of the specific structure of the threshold control unit in the fourth embodiment of the present application;

[0031] Figure 8 This is a schematic diagram of the specific structure of the threshold control unit in the fifth embodiment of the present application;

[0032] Figure 9 Schematic diagram of the specific structure of the threshold control unit in the sixth embodiment of the present application;

[0033] Figure 10 Schematic diagram of the specific structure of the threshold control unit in the seventh embodiment of the present application;

[0034] Figure 11 Schematic diagram of the specific structure of the threshold control unit in the eighth embodiment of the present application;

[0035] Figure 12 Schematic diagram of the specific structure of the threshold control unit in the ninth embodiment of the present application;

[0036] Figure 13 This is a schematic diagram of the specific structure of the threshold control unit in the tenth embodiment of the present application;

[0037] Figure 14 This is a schematic diagram of the specific structure of the threshold control unit in the eleventh embodiment of the present application;

[0038] Figure 15 This is a schematic diagram of the specific structure of the threshold control unit in the twelfth embodiment of the present application;

[0039] Figure 16 This is a schematic diagram of the structure of a control system in one embodiment of the present application;

[0040] Figure 17 This is a structural diagram of a control system in another embodiment of the present application. DETAILED DESCRIPTION

[0041] The present application provides a power-off protection device, a control system, and a new energy system, which are used to control the input voltage provided by the energy storage unit to the voltage conversion unit through the first voltage threshold and the second voltage threshold of the threshold control unit, so that the voltage conversion unit provides a stable target voltage to the main control unit, solving the problem that the input voltage received by the main control unit will oscillate in the event of a power outage, and achieving the effect of avoiding repeated power-on of the main control unit.

[0042] The terms "first," "second," "third," "fourth," etc. (if any) in the specification and claims of the present application and in the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or apparatus.

[0043] In related technologies, the following are usually used: Figure 1 In the power-off protection device shown, the energy storage unit is used to store electric energy to provide the main control unit with the electric energy required for operation when the system power fails, and the voltage conversion unit is used to convert the voltage.

[0044] like Figure 1 As shown in the figure, when the system power supply is normal, the system power supply directly supplies power to the main control unit. When the system power supply is off, the energy storage unit starts to supply power to the voltage conversion unit, and then the voltage conversion unit provides the converted electric energy with a stable voltage to the main control unit. However, as the energy in the energy storage unit continues to be consumed by the main control unit, the output voltage of the energy storage unit continues to decrease. Figure 2 As shown, when the output voltage of the energy storage unit drops to a certain threshold, the energy storage unit cannot provide a sufficient voltage to the voltage conversion unit, causing the output voltage of the voltage conversion unit to become unstable and begin to oscillate. This oscillating voltage acts on the subsequent main control unit, causing the electrical components on the main control unit to repeatedly start and stop, that is, the main control unit is repeatedly powered on and off.

[0045] In order to solve the above problems, Figure 3 As shown, an embodiment of the present application provides a power-off protection device 100 , which specifically includes: an energy storage unit 110 , a threshold control unit 120 and a voltage conversion unit 130 .

[0046] The energy storage unit 110 is used to store electrical energy and provide electrical energy to the threshold control unit 120. The output end of the energy storage unit 110 is connected to the input end of the threshold control unit 120; the threshold control unit 120 is used to provide electrical energy to the voltage conversion unit 130 according to a first voltage threshold and a second voltage threshold. The first voltage threshold is used to control the conduction of the threshold control unit 120, and the second voltage threshold is used to control the shutdown of the threshold control unit 120. The output end of the threshold control unit 120 is connected to the first input end of the voltage conversion unit 130; the voltage conversion unit 130 is used to convert the output voltage of the threshold control unit 120 into the target voltage required by the main control unit 200 to power the main control unit 200. The output end of the voltage conversion unit 130 is connected to the first input end of the main control unit 200.

[0047] For example, the energy storage unit 110 can be composed of multiple capacitors connected in series, or multiple battery packs connected in series or in parallel, or other components with energy storage functions, which are not limited here. For ease of description, the following embodiments are described using multiple capacitors connected in series as an example.

[0048] The threshold control unit 120 may provide a first voltage threshold and a second voltage threshold, and may be turned on or off based on the first and second voltage thresholds. For example, when the output voltage of the energy storage unit 110 is greater than the first voltage threshold, the threshold control unit 120 is turned on to supply power to the voltage conversion unit 130. Furthermore, when the voltage of the energy storage unit 110 is less than the second voltage threshold, the threshold control unit 120 is turned off to stop supplying power to the voltage conversion unit 130. The first voltage threshold is greater than the second voltage threshold so that the threshold control unit 120 can remain on for a period of time, thereby preventing the threshold control unit 120 from being turned on and then immediately turned off.

[0049] The voltage conversion unit 130 may include a buck-boost circuit that converts the energy stored in the energy storage unit 110 into the operating voltage required by the main control unit 200. The buck-boost circuit may also be replaced by a boost circuit or a buck circuit, depending on the actual situation.

[0050] The main control unit 200 may include a core processor of the working circuit and other electrical components. The core processor may be a central processing unit (CPU), a field programmable gate array (FPGA), a digital signal processing (DSP) chip or other processors, and the specific details are not limited here.

[0051] Under normal circumstances, the system power supply supplies power to the main control unit 200. After the system power supply is lost, the energy storage unit 110 supplies power to the threshold control unit 120. When the output voltage of the energy storage unit 110 is greater than the first voltage threshold, the threshold control unit 120 is turned on and begins to supply power to the voltage conversion unit 130. The voltage conversion unit 130 performs voltage conversion and inputs the converted voltage to the input terminal of the main control unit 200, supplying power to the main control unit 200 so that it can continue to operate.

[0052] After a period of time, the output voltage of the energy storage unit 110 gradually decreases. When it decreases to the second voltage threshold, the threshold control unit 120 is disconnected, and the threshold control unit 120 stops supplying power to the voltage conversion unit 130. Since the threshold control unit 120 cuts off the connection between the energy storage unit 110 and the voltage conversion unit 130, the voltage conversion unit 130 is without power, and the voltage conversion unit 130 will not generate an oscillating output voltage due to the excessively low output voltage of the threshold control unit 120, causing the main control unit 200 to be repeatedly powered on. Therefore, the power-off protection device 100 of the embodiment of the present application can prevent the main control unit 200 from being repeatedly powered on, and setting the first voltage threshold and the second voltage threshold. Compared with setting only the second voltage threshold, it can prevent the voltage of the energy storage unit 110 from being higher than the second voltage threshold again due to the presence of a virtual voltage after long-term use of the energy storage unit 110, causing the threshold control unit 120 to be turned on again, thereby causing the output voltage of the voltage conversion unit 130 to oscillate and the main control unit 200 to be repeatedly powered on.

[0053] In the above embodiment, the input voltage provided by the energy storage unit to the voltage conversion unit is controlled by the first voltage threshold and the second voltage threshold of the threshold control unit, so that the voltage conversion unit provides a stable target voltage to the main control unit, thereby solving the problem that the input voltage received by the main control unit will oscillate when the system power is cut off, and avoiding repeated power-on of the main control unit.

[0054] In one embodiment, if Figure 4As shown, the threshold control unit 120 includes a first switch tube Q1, a first protection transistor Q2, a second protection transistor Q3, a first threshold control branch 121, and a second threshold control branch 122. The first terminal of the first switch tube Q1 is connected to the emitter of the first protection transistor Q2 and the output terminal of the energy storage unit 110; the second terminal of the first switch tube Q1 is connected to the first input terminal of the voltage conversion unit 130; the base of the first protection transistor Q2 is connected to the first terminal of the first threshold control branch 121, the collector of the first protection transistor Q2 is connected to the first terminal of the second threshold control branch 122, the second terminal of the first threshold control branch 121 is connected to the collector of the second protection transistor Q3 and the third terminal of the first switch tube Q1, and the second terminal of the second threshold control branch 122 is connected to the base of the second protection transistor Q3; the third terminal of the first threshold control branch 121 is grounded, and the emitter of the second protection transistor Q3 is grounded.

[0055] For example, the first switch Q1 is primarily used to control the on / off state of the threshold control unit 120. The first switch Q1 may be a MOS transistor, a thyristor, an IGBT, or the like, without limitation herein. For ease of illustration, the following embodiments utilize a first MOS transistor as an example. The first protection transistor Q2 may be a PNP transistor, and the second protection transistor Q3 may be an NPN transistor.

[0056] The first threshold control branch 121 is used to provide a certain voltage drop. By changing the voltage drop of the first threshold control branch 121, the first voltage threshold of the threshold control unit 120 can be adjusted. The second threshold control branch 122 is used to provide a certain voltage drop. By changing the voltage drop of the second threshold control branch 122, the second voltage threshold of the threshold control unit 120 can be adjusted. The first threshold control branch 121 and the second threshold control branch 122 can both be composed of multiple switching transistors with a conduction voltage drop.

[0057] The magnitude of the first voltage threshold is determined by the voltage drop of the first threshold control branch 121 and the voltage drop of the protection transistor in the loop, and the magnitude of the second voltage threshold is determined by the voltage drop of the second threshold control branch 122 and the voltage drop of the protection transistor in the loop. For example, the voltage drop of the first threshold control branch 121 is V Q1′ , the voltage drop of the first protection transistor Q2 is V Q2 , the first voltage threshold is V th1 , V th1 =V Q1′ +V Q2 The voltage drop of the second threshold control branch 122 is V Q2′ , the voltage drop of the first protection transistor Q2 is V Q2 , the voltage drop of the second protection transistor Q3 is V Q3, the second voltage threshold is V th2 , V th2 =V Q2′ +V Q2 +V Q3 Therefore, by changing the voltage drop of the first threshold control branch 121 , the first voltage threshold of the threshold control unit 120 can be adjusted, and by changing the voltage drop of the second threshold control branch 122 , the second voltage threshold of the threshold control unit 120 can be adjusted.

[0058] The first voltage threshold is used to control the conduction of the first switch tube Q1, so that the energy storage unit 110 supplies power to the main control unit 200 after passing through the threshold control unit 120 and the voltage conversion unit 130; the second voltage threshold is used to control the shutdown of the first switch tube Q1, so that the energy storage unit 110 stops supplying power to the voltage conversion unit 130, thereby interrupting the output voltage provided by the voltage conversion unit 130 to the main control unit 200.

[0059] It should be noted that, in the embodiment of the present application, the first voltage threshold V th1 The purpose is to wait for the energy storage unit 110 to be charged to a suitable amount of electricity before turning on the first switch tube Q1 to supply power to the voltage conversion unit 130. th2 The purpose is that when the energy storage unit 110 releases electricity, its output voltage continues to decrease, and when it drops to the second voltage threshold V th2 When the power is on, the first switch Q1 is turned off in time to stop supplying power to the voltage conversion unit 130, thereby preventing the output voltage of the voltage conversion unit 130 from oscillating, causing the main control unit 200 to be powered on repeatedly and causing unpredictable problems.

[0060] When the voltage of the energy storage unit 110 reaches the first voltage threshold V th1 When the threshold control unit 120 is turned on, it starts to supply power to the voltage conversion unit 130. The first voltage threshold V th1 That is, the minimum starting voltage threshold of the energy storage unit 110 .

[0061] When the voltage of the energy storage unit 110 drops to the second voltage threshold V th2 When the threshold control unit 120 is turned from on to off, the power supply to the voltage conversion unit 130 is stopped, and the second voltage threshold V th2 That is, the maximum stop voltage threshold of the energy storage unit 110 .

[0062] The first voltage threshold V th1 and the second voltage threshold V th2 The following conditions must also be met during setup:

[0063] (1)V th1 >V th2 ;

[0064] (2) The gate-source voltage V of the first switch Q1 SG The value should be greater than the minimum conduction threshold voltage V of the first switch tube Q1 SGth .

[0065] For example, when the first switching transistor Q1 is a first MOS transistor, the first end (source S) of the first MOS transistor is connected to the emitter e of the first protection transistor Q2 and the output end of the energy storage unit 110; the second end (drain D) of the first MOS transistor Q1 is connected to the first input end of the voltage conversion unit 130; the base b of the first protection transistor Q2 is connected to the first end of the first threshold control branch 121, the collector c of the first protection transistor Q2 is connected to the first end of the second threshold control branch 122, the second end of the first threshold control branch 121 is connected to the collector c of the second protection transistor Q3 and the third end (gate G) of the first MOS transistor, and the second end of the second threshold control branch 122 is connected to the base b of the second protection transistor Q3; the third end of the first threshold control branch 121 is grounded, and the emitter e of the second protection transistor Q3 is grounded.

[0066] like Figure 4 As shown, the output end of the energy storage unit 110 is connected to the first input end of the voltage conversion unit 130 after passing through the first MOS transistor in the threshold control unit 120. If the energy storage unit 110 wants to supply power to the voltage conversion unit 130, the first MOS transistor needs to be turned on. When the output voltage VS of the energy storage unit 110 is less than the first voltage threshold V th1 When VS <V th1 , the first MOS tube is in the off state, and the voltage conversion unit 130 does not work. When the output voltage VS of the energy storage unit 110 is greater than or equal to the first voltage threshold V th1 When VS≥V th1 , the first MOS transistor is turned on, and the voltage conversion unit 130 starts to work. During the process of the first MOS transistor being turned on, when the output voltage VS of the energy storage unit 110 is less than the second voltage threshold V th2 When VS≤V th2 , the first MOS tube is turned off, and the voltage conversion unit 130 also stops working. Among them, the first voltage threshold V th1 The second voltage threshold V is determined by the circuit composed of the first protection transistor Q2 and the first threshold control branch 121. th2 The threshold is determined by a circuit consisting of the first protection transistor Q2 , the second protection transistor Q3 and the second threshold control branch 122 .

[0067] In the embodiment of the present application, by changing the first voltage threshold corresponding to the threshold control unit 120, the starting condition of the power-off protection device 100 can be controlled, that is, when the energy stored in the energy storage unit 110 does not reach the first voltage threshold V designed by the user, th1 When the power-off protection function is not started; and by changing the second voltage threshold corresponding to the threshold control unit 120, the stop condition of the power-off protection device 100 can be controlled, that is, when the energy stored in the energy storage unit 110 is reduced to the second voltage threshold V designed by the user th2 The power-off protection function is stopped when the power of the energy storage unit 110 is insufficient. The power of the energy storage unit 110 is controlled by the threshold control unit 120. When the voltage of the energy storage unit 110 reaches the first voltage threshold, the threshold control unit 120 is turned on and supplies power to the voltage conversion unit 130, thereby avoiding the activation of the power-off protection function when the power of the energy storage unit 110 is insufficient. When the output voltage of the energy storage unit 110 drops to the second voltage threshold, the threshold control unit 120 is turned off and stops supplying power to the voltage conversion unit 130.

[0068] In one embodiment, if Figure 5 As shown, the first threshold control branch 121 includes a first threshold control sub-branch 1211 and a second threshold control sub-branch 1212, the first end of the first threshold control sub-branch 1211 serves as the first end of the first threshold control branch 121, the second end of the first threshold control sub-branch 1211 and the first end of the second threshold control sub-branch 1212 are connected to serve as the second end of the first threshold control branch 121, and the second end of the second threshold control sub-branch 1212 serves as the third end of the first threshold control branch 121; wherein, the sum of the voltage drops of the first threshold control branch 121 and the first protection transistor Q2 is the first voltage threshold, the sum of the voltage drops of the second threshold control branch 122, the first protection transistor Q2 and the second protection transistor Q3 is the second voltage threshold, the first voltage threshold is greater than the second voltage threshold, and the voltage drop of the second threshold control sub-branch 1212 is greater than the voltage drop of the second protection transistor Q3.

[0069] Specifically, when the output voltage of the energy storage unit 110 is greater than the first voltage threshold, the first protection transistor Q2, the first threshold control sub-branch 1211, and the second threshold control sub-branch 1212 are turned on. Based on the voltage drop across the second threshold control sub-branch 1212, the first switch Q1 is turned on, and the energy storage unit 110 supplies power to the voltage conversion unit 130 via the first switch Q1. Because the first voltage threshold is greater than the second voltage threshold and the first protection transistor Q2 is in the on state, the second threshold control branch 122 and the second protection transistor Q3 are turned on. Because the voltage drop across the second threshold control sub-branch 1212 is greater than the voltage drop across the second protection transistor Q3, the second threshold control sub-branch 1212 is clamped by the second protection transistor Q3, and the voltage threshold of the threshold control unit 120 switches from the first voltage threshold to the second voltage threshold. When the output voltage of the energy storage unit 110 is lower than the second voltage threshold, the first protection transistor Q2, the second threshold control branch 122 and the second protection transistor Q3 are disconnected, thereby disconnecting the first switch tube Q1, and the energy storage unit 110 stops supplying power to the voltage conversion unit 130.

[0070] In an embodiment of the present application, the main control unit can be prevented from being repeatedly powered on by the first switch tube Q1, the first threshold control sub-branch 1211, the second threshold control sub-branch 1212, the first protection transistor Q2, the second threshold control branch 122 and the second protection transistor Q3, and by the first voltage threshold being greater than the second voltage threshold and the voltage drop of the second threshold control sub-branch 1212 being greater than the voltage drop of the second protection transistor Q3.

[0071] In one embodiment, the first threshold control sub-branch 1211 includes N second switching tubes connected in series, and one end of the series connection serves as the first end of the first threshold control sub-branch 1211, and the other end of the series connection serves as the second end of the first threshold control sub-branch 1211; wherein, the second switching tube is a switching tube with a unidirectional conduction characteristic, and N is an integer greater than or equal to 1; the second threshold control sub-branch 1212 includes a third switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control sub-branch 1212, and the other end of the series connection serves as the second end of the second threshold control sub-branch 1212; wherein, the third switching tube is a switching tube with a unidirectional conduction characteristic, and a is an integer greater than or equal to 1.

[0072] Exemplarily, the second switch tube and the third switch tube can be switching devices such as triodes, diodes, thyristors (thyristors SCRs), insulated gate bipolar transistors (IGBTs), etc., and can be used as the second switch tube and the third switch tube as long as they have unidirectional conduction characteristics.

[0073] In the embodiment of the present application, by adjusting the number of the second switch tube in the first threshold control sub-branch 1211 and the third switch tube in the second threshold control sub-branch 1212, the first voltage threshold V can be configured with high precision. th1 Each time a second switch is added to the first threshold control sub-branch 1211, the voltage at which the first MOS transistor is turned on increases by one on-state voltage drop of the second switch. Each time a third switch is added to the second threshold control sub-branch 1212, the voltage at which the first MOS transistor is turned on increases by one on-state voltage drop of the third switch. By adjusting the number of third switches in the second threshold control sub-branch 1212, the voltage at which the second threshold control sub-branch 1212 is clamped by the second protection transistor Q3 can be adjusted.

[0074] The above embodiment describes the number of second switches in the first threshold control sub-branch 1211 and the number of third switches in the second threshold control sub-branch 1212 . The types of the second switches and the third switches are described below.

[0075] In one embodiment, when all N second switching tubes are triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the first threshold control sub-branch 1211, the emitter of the i-th triode is connected to the collector of the i+1-th triode, and the emitter of the N-th triode serves as the second end of the first threshold control sub-branch 1211, where 1≤i<N.

[0076] When the a third switching tubes are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control sub-branch 1212, the emitter of the jth triode is connected to the collector of the j+1th triode, and the emitter of the ath triode serves as the second end of the second threshold control sub-branch 1212, where 1≤j<a.

[0077] For example, Figure 6As shown, the first threshold control sub-branch 1211 includes transistors Q1'1, Q1'2, ..., Q1'N connected in series, and the second threshold control sub-branch 1212 includes transistors Q1'(N+1), ..., Q1'(N+a) connected in series. The collector of the first transistor Q1'1 serves as the first end of the first threshold control sub-branch 1211 and is connected to the base of the first protection transistor Q2. The emitter of the Nth transistor Q1'N serves as the second end of the first threshold control sub-branch 1211 and is connected to the collector of the second protection transistor Q3, the third end of the first switch Q1, and the first end of the second threshold control sub-branch 1212. The collector of the N+1th transistor Q1'(N+1) serves as the first end of the second threshold control sub-branch 1212, and the emitter of the N+ath transistor Q1'(N+a) serves as the third end of the second threshold control sub-branch 1212 and is grounded.

[0078] Because the base b and collector c of the transistor are short-circuited, the transistor exhibits a unidirectional conduction characteristic. It can be understood that by short-circuiting the base and collector of each transistor, a stable 0.7V voltage drop is achieved for each transistor.

[0079] In the embodiment of the present application, a first threshold control sub-branch 1211 and a second threshold control sub-branch 1212 are formed by connecting a plurality of transistors in series, and a first voltage threshold V is obtained by combining the voltage drop of the first protection transistor Q2. th1 , can control the minimum starting voltage threshold of the power-off protection device 100. The solution using a transistor can improve the overall stability of the system, the solution is simple, and the stability is higher.

[0080] In one embodiment, Figure 6 As shown, when the output voltage VS of the energy storage unit 110 satisfies VS≥V th1 When all transistors in the first threshold control branch 121 are turned on, the gate-source voltage V SG =VS-0.7V*a. The gate-source voltage of the first MOS tube is V SG Greater than its own minimum turn-on threshold voltage V SGth (For example, the minimum on-threshold voltage V GSth 1V), the first MOS tube is turned on. After the first MOS tube is turned on, it is necessary to maintain its on state, and the maintenance condition is V SG ≥V SGth , wherein the third terminal (gate) of the first MOS tube is connected to the collector c (also the base b) of the N+a th transistor Q1 '(N+a).

[0081] In this embodiment, the gate-source voltage V of the first MOS transistor can be changed by changing the lead-out position of the second end of the first threshold control branch 121. SGsize.

[0082] In one embodiment, when all N second switching transistors are diodes, the anode of the first diode serves as the first end of the first threshold control sub-branch 1211, the cathode of the i-th diode is connected to the anode of the (i+1)-th diode, and the cathode of the N-th diode serves as the second end of the first threshold control sub-branch 1211, where 1≤i<N.

[0083] When a third switching tubes are all diodes, the anode of the first diode serves as the first end of the second threshold control sub-branch 1212, the cathode of the jth diode is connected to the anode of the j+1th diode, and the cathode of the ath diode serves as the second end of the second threshold control sub-branch 1212, where 1≤j<a.

[0084] For example, Figure 7 As shown, the first threshold control sub-branch 1211 includes diodes Q1'1, Q1'2, ..., Q1'N connected in series, and the second threshold control sub-branch 1212 includes diodes Q1'(N+1), ..., Q1'(N+a) connected in series. The anode of the first diode Q1'1 serves as the first end of the first threshold control sub-branch 1211 and is connected to the base of the first protection transistor Q2. The cathode of the Nth diode Q1'N serves as the second end of the first threshold control sub-branch 1211 and is connected to the collector of the second protection transistor Q3, the third end of the first switch Q1, and the first end of the second threshold control sub-branch 1212. The anode of the N+1th diode Q1'(N+1) serves as the first end of the second threshold control sub-branch 1212, and the cathode of the N+ath diode Q1'(N+a) serves as the third end of the second threshold control sub-branch 1212 and is grounded.

[0085] It should be noted that when the second switching tube and the third switching tube are diodes, the voltage drop of the diode can be selected according to actual conditions. For example, a diode with a voltage drop of 0.5V can be selected, or a diode with a voltage drop of 0.25V can be selected. The specific details are not limited here.

[0086] In the embodiment of the present application, a first threshold control branch 121 is formed by connecting a plurality of diodes in series, and a first voltage threshold V is obtained by combining the voltage reduction of the first protection transistor Q2. th1 , which can control the minimum starting voltage threshold of the power-off protection device 100. The solution using diodes can use diodes with different voltage drop specifications, which is lower in cost and more flexible than using transistors.

[0087] In one embodiment, when all N second switching transistors are insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the first threshold control sub-branch 1211. The emitter of the i-th insulated gate bipolar transistor is connected to the collector of the (i+1)-th insulated gate bipolar transistor, and the emitter of the N-th insulated gate bipolar transistor serves as the second end of the first threshold control sub-branch 1211, where 1≤i<N.

[0088] In the case where a third switching tubes are all insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control sub-branch 1212, the emitter of the j-th insulated gate bipolar transistor is connected to the collector of the j+1-th insulated gate bipolar transistor, and the emitter of the a-th insulated gate bipolar transistor serves as the second end of the second threshold control sub-branch 1212, where 1≤j<a.

[0089] For example, Figure 8 As shown, the first threshold control sub-branch 1211 includes insulated gate bipolar transistors Q1'1, Q1'2, ..., Q1'N connected in series, and the second threshold control sub-branch 1212 includes insulated gate bipolar transistors Q1'(N+1), ..., Q1'(N+a) connected in series. The collector of the first insulated gate bipolar transistor Q1'1 serves as the first end of the first threshold control sub-branch 1211 and is connected to the base of the first protection transistor Q2. The emitter of the Nth insulated gate bipolar transistor Q1'N serves as the second end of the first threshold control sub-branch 1211 and is connected to the collector of the second protection transistor Q3, the third end of the first switch Q1, and the first end of the second threshold control sub-branch 1212. The collector of the N+1th insulated gate bipolar transistor Q1′(N+1) serves as the first end of the second threshold control sub-branch 1212, and the emitter of the N+ath insulated gate bipolar transistor Q1′(N+a) serves as the third end of the second threshold control sub-branch 1212 and is grounded.

[0090] In one embodiment, when all N second switching tubes are thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the first threshold control sub-branch, the cathode of the i-th thyristor is connected to the anode of the (i+1)-th thyristor, and the cathode of the N-th thyristor serves as the second end of the first threshold control sub-branch; wherein 1≤i<N.

[0091] In the case where all a third switching tubes are thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control sub-branch, the cathode of the jth thyristor is connected to the anode of the j+1th thyristor, and the cathode of the ath thyristor serves as the second end of the second threshold control sub-branch; wherein 1≤j<a.

[0092] For example, Figure 9 As shown, the first threshold control sub-branch 1211 includes thyristors Q1'1, Q1'2, ..., Q1'N connected in series, and the second threshold control sub-branch 1212 includes thyristors Q1'(N+1), ..., Q1'(N+a) connected in series. The anode A of the first thyristor Q1'1 serves as the first terminal of the first threshold control sub-branch 1211 and is connected to the base of the first protection transistor Q2. The cathode K of the Nth thyristor Q1'N serves as the second terminal of the first threshold control sub-branch 1211 and is connected to the collector of the second protection transistor Q3, the third terminal of the first switch Q1, and the first terminal of the second threshold control sub-branch 1212. The anode of the N+1th thyristor Q1'(N+1) serves as the first terminal of the second threshold control sub-branch 1212 and the cathode K of the N+ath thyristor Q1'(N+a) serves as the third terminal of the second threshold control sub-branch 1212 and is grounded.

[0093] It should be noted that different types of second switch tubes can be used in the same first threshold control sub-branch 1211, and different types of third switch tubes can be used in the same second threshold control sub-branch 1212, that is, each second switch tube or third switch tube can be selected from any one of a triode, a diode, an insulated gate bipolar transistor or a thyristor. The specific connection method is as described in the above embodiment and will not be repeated here.

[0094] The above embodiment describes the types of the second switch tube and the third switch tube in the first threshold control branch 121 . The following describes the number and type of the fourth switch tube in the second threshold control branch 122 .

[0095] In one embodiment, the second threshold control branch 122 includes M fourth switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control branch 122, and the other end of the series connection serves as the second end of the second threshold control branch 122; wherein the fourth switching tube is a switching tube with a unidirectional conduction characteristic, and M is an integer greater than or equal to 1.

[0096] Exemplarily, the fourth switch tube can be a switching device such as a triode, a diode, a thyristor (SCR), an insulated gate bipolar transistor (IGBT), etc., and any device with a unidirectional conduction characteristic can be used as the fourth switch tube.

[0097] In the embodiment of the present application, by adjusting the number of the fourth switch tubes in the second threshold control branch 122, a high-precision configuration of the second voltage threshold V th2 Every time a fourth switch tube is added to the second threshold control branch 122, the voltage at which the first switch tube Q1 is turned off increases by a conduction voltage drop of the fourth switch tube.

[0098] The above embodiment describes the number of fourth switch tubes in the second threshold control branch 122 . The following describes the type of the fourth switch tubes.

[0099] In one embodiment, when all M fourth switching transistors are triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control branch 122, the emitter of the kth triode is connected to the collector of the k+1th triode, and the emitter of the Mth triode serves as the second end of the second threshold control branch 122, where 1≤k<M.

[0100] For example, Figure 6 As shown, the second threshold control branch 122 includes transistors Q2'1, Q2'2, ..., Q2'M connected in series. The collector of the first transistor Q2'1 serves as the first end of the second threshold control branch 122 and is connected to the collector of the first protection transistor Q2. The emitter of the Mth transistor Q2'M serves as the second end of the second threshold control branch 122 and is connected to the base of the second protection transistor Q3.

[0101] In one embodiment, when all M fourth switching tubes are diodes, the anode of the first diode serves as the first end of the second threshold control branch 122, the cathode of the kth diode is connected to the anode of the k+1th diode, and the cathode of the Mth diode serves as the second end of the second threshold control branch 122, where 1≤k<M.

[0102] For example, Figure 7 As shown, the second threshold control branch 122 includes diodes Q2'1, Q2'2, ..., Q2'M connected in series, wherein the anode of the first diode Q2'1 serves as the first end of the second threshold control branch 122 and is connected to the collector of the first protection transistor Q2. The cathode of the Mth diode Q2'M serves as the second end of the second threshold control branch 122 and is connected to the base of the second protection transistor Q3.

[0103] In one embodiment, when all M fourth switching tubes are insulated gate bipolar transistors, the gate and collector of each insulated gate bipolar transistor are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control branch 122, the emitter of the kth insulated gate bipolar transistor is connected to the collector of the k+1th insulated gate bipolar transistor, and the emitter of the Mth insulated gate bipolar transistor serves as the second end of the second threshold control branch 122, wherein 1≤k<M.

[0104] For example, Figure 8 As shown, the second threshold control branch 122 includes insulated gate bipolar transistors Q2'1, Q2'2, ..., Q2'M connected in series. The collector of the first insulated gate bipolar transistor Q2'1 serves as the first end of the second threshold control branch 122 and is connected to the collector of the first protection transistor Q2. The emitter of the Mth insulated gate bipolar transistor Q2'M serves as the second end of the second threshold control branch 122 and is connected to the base of the second protection transistor Q3.

[0105] In one embodiment, when all M fourth switching tubes are thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control branch 122, the cathode of the kth thyristor is connected to the anode of the k+1th thyristor, and the cathode of the Mth thyristor serves as the second end of the second threshold control branch 122; wherein 1≤k<M.

[0106] For example, Figure 9 As shown, the second threshold control branch 122 includes thyristors Q2'1, Q2'2, ..., Q2'M connected in series, wherein the anode of the first thyristor Q2'1 serves as the first end of the second threshold control branch 122 and is connected to the collector of the first protection transistor Q2. The cathode of the Mth thyristor Q2'M serves as the second end of the second threshold control branch 122 and is connected to the base of the second protection transistor Q3.

[0107] It should be noted that in the same second threshold control branch 122, different types of fourth switch tubes can be sampled, that is, each fourth switch tube can select any one of a triode, a diode, an insulated gate bipolar transistor or a thyristor. The specific connection method is as described in the above embodiment and will not be repeated here.

[0108] It can be understood that, for the threshold control unit 120, when the second protection transistor Q3 is turned on, the voltage at the third terminal of the first switch tube Q1 is lowered, thereby clamping the a third switch tubes in the first threshold control sub-branch 1212 (equivalent to short circuit).

[0109] Assume that Figure 10As shown, the first threshold control branch 121 includes 4 transistors, the voltage drop of each transistor is 0.7V, and in the first threshold control branch 121, N is 2, a is 2, then the first voltage threshold V th1 =0.7V*(1+2+2)=3.5V. In the second threshold control branch 122, M is 1, and the second voltage threshold V th2 =0.7V*(1+2)=2.1V.

[0110] The above embodiment describes the number and type of the fourth switch tubes of the second threshold control branch 122 . The following describes the resistors included in the threshold control unit 120 .

[0111] In one embodiment, the threshold control unit 120 further includes a first resistor R1 , a first end of the first resistor R1 is connected to the base of the first protection transistor Q2 , and a second end of the first resistor R1 is connected to the first end of the first threshold control branch 121 .

[0112] For example, Figure 11 As shown, the first end of the first resistor R1 is connected to the base b of the first protection transistor Q2, the second end of the first resistor R1 is connected to the first end of the first threshold control branch 121, the second end of the first threshold control branch 121 is connected to the collector c of the second protection transistor Q3 and the third end of the first switch tube Q1, and the third end of the first threshold control branch 121 is grounded.

[0113] In order to turn on the first switch tube Q1, the third terminal of the first switch tube Q1 needs to be energized, so the first protection transistor Q2 needs to be turned on. The condition for the first protection transistor Q2 to be turned on is: the potential difference between the base and the emitter is greater than the voltage drop of the first protection transistor Q2. The voltage drop of the transistor is generally set to 0.7V. Therefore, the conduction condition of Q2 is V eb ≥0.7V, therefore, the voltage between the base and emitter of the first protection transistor Q2 must be greater than or equal to 0.7V before it will be turned on.

[0114] like Figure 11 As shown, the voltage drop of the first threshold control branch 121 is VF1=0.7V*(N+a), which is equivalent to increasing the base voltage of the first protection transistor Q2. At this time, the conduction condition of the first protection transistor Q2 is V eb ≥0.7V*(N+a+1). When the first protection transistor Q2 and the first threshold control branch 121 are turned on at the same time, the gate voltage of the first MOS tube is the sum of the voltage drops of a third switching tubes, so that the gate voltage of the first MOS tube is higher than the source voltage, thereby realizing the conduction of the first MOS tube.

[0115] It is understandable that the first resistor R1 can be a K-class resistor, in order to reduce the power consumption of the first threshold control branch 121 so that more energy provided by the energy storage unit 110 is transferred to the voltage conversion unit 130 .

[0116] In this embodiment of the present application, the added first resistor R1 can reduce the power consumption of the first threshold control branch 121. When the system power is cut off, the energy in the energy storage unit 110 can be provided to the main control unit 200 as much as possible instead of being consumed in other circuit components.

[0117] In one embodiment, the threshold control unit 120 further includes a second resistor R2 , a first end of the second resistor R2 is connected to the second end of the second threshold control branch 122 , and a second end of the second resistor R2 is connected to the base of the second protection transistor Q3 .

[0118] The collector of the first protection transistor Q2 is connected to the first end of the second threshold control branch 122 , the second end of the second threshold control branch 122 is connected to the first end of the second resistor R2 , and the second end of the second resistor R2 is connected to the base of the second protection transistor Q3 .

[0119] For example, Figure 11 As shown, the voltage drop of the second threshold control branch 122 is VF2=0.7V*M, which is equivalent to increasing the base voltage of the second protection transistor Q3. At this time, the conduction condition of the second protection transistor Q3 is: the potential difference between the base and the emitter is greater than the voltage drop of the second protection transistor Q3. The voltage drop of the transistor is generally set to 0.7V. Therefore, the conduction condition of the second protection transistor Q3 is V eb ≥0.7V*(M+2). After the second protection transistor Q3 is turned on, the gate voltage of the first MOS transistor is pulled down to the voltage drop of the second protection transistor Q3, 0.7V, and the first MOS transistor remains turned on. When the output voltage of the energy storage unit 110 decreases (that is, the source voltage of the first MOS transistor continues to decrease), it drops to less than or equal to V th2 When , the second protection transistor Q3 and the first protection transistor Q2 are turned off, and the first switch tube Q1 is further turned off, and the threshold control unit 120 stops working.

[0120] It should be noted that, after the first protection transistor Q2 and the first threshold control branch 121 are turned on, the second threshold control branch 122 and the second protection transistor Q3 will be turned on. Figure 11As shown, the conduction time of Q3, Q2'1, Q2'2, ..., Q2'M occurs after Q2, Q1'1, Q1'2, ..., Q1'N, ..., Q1'(N+a) are turned on (if this link is not turned on, Q3 cannot be turned on, and then Q2'1, Q2'2, ..., Q2'M cannot be turned on). When the second protection transistor Q3 is turned on, the voltage between Q1'(N+1), ..., Q1'(N+a) is clamped by the second protection transistor Q3 (similar to being short-circuited), that is, Q1'(N+1), ..., Q1'(N+a) are all ineffective.

[0121] It is understandable that the second resistor R2 can be a K-class resistor, in order to reduce the power consumption of the second threshold control branch 122 so that more energy provided by the energy storage unit 110 is transferred to the voltage conversion unit 130 .

[0122] In this embodiment of the present application, the added second resistor R2 can reduce the power consumption of the second threshold control branch 122. When the system power is cut off, the energy in the energy storage unit 110 can be provided to the main control unit 200 as much as possible instead of being consumed in other circuit components.

[0123] It should be noted that, in practical applications, one or both of the first resistor R1 and the second resistor R2 may be selected and set, and there is no limitation here.

[0124] In one embodiment, the threshold control unit 120 further includes a third resistor R3 , which is connected in parallel between the first terminal of the first switch tube Q1 and the third terminal of the first switch tube Q1 .

[0125] For example, Figure 11 As shown, assuming that the threshold control unit 120 does not include the fourth resistor R4, the first end of the third resistor R3 is connected to the emitter of the first protection transistor Q2, the source of the first switch tube Q1 and the output end of the energy storage unit 110, and the second end of the third resistor R3 is connected to the gate of the first switch tube Q1 and the collector of the second protection transistor Q3.

[0126] It is understandable that the third resistor R3 can be a K-class resistor, in order to reduce the power consumption of the threshold control unit 120 and allow more energy provided by the energy storage unit 110 to be transferred to the voltage conversion unit 130 .

[0127] In one embodiment, the threshold control unit 120 further includes a fourth resistor R4 , which is connected in series between the third terminal of the first switch tube Q1 and the collector of the second protection transistor Q3 .

[0128] It is understandable that the fourth resistor R4 can be a K-class resistor, in order to reduce the power consumption of the threshold control unit 120 and allow more energy provided by the energy storage unit 110 to be transferred to the voltage conversion unit 130 .

[0129] It should be noted that, in practical applications, one or both of the third resistor R3 and the fourth resistor R4 may be selected and set, and there is no limitation here.

[0130] In the above embodiment, the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 can be set to a value that allows each switch to enter a saturated conduction range, that is, Ic<β*I b The values ​​of the first resistor R1, the second resistor R2, the third resistor R3 and the fourth resistor R4 may be the same or different.

[0131] This application also discloses an embodiment. Figure 12 As shown, the threshold control unit 120 includes a third protection transistor Q4, a fourth protection transistor Q5, a third threshold control branch 123, and a fourth threshold control branch 124. The emitter of the third protection transistor Q4 is connected to the output end of the energy storage unit 110; the collector of the third protection transistor Q4 is connected to the first end of the third threshold control branch 123 and the first input end of the voltage conversion unit 130; the base of the third protection transistor Q4 is connected to the first end of the fourth threshold control branch 124 and the collector of the fourth protection transistor Q5; the second end of the third threshold control branch 123 is connected to the base of the fourth protection transistor Q5; and the second end of the fourth threshold control branch 124 is connected to the emitter of the fourth protection transistor Q5 and is grounded.

[0132] The third protection transistor Q4 may be a PNP transistor, and the fourth protection transistor Q5 may be an NPN transistor.

[0133] In this embodiment, a simpler structure of the threshold control unit 120 is provided, which reduces hardware costs.

[0134] In one embodiment, if Figure 13 As shown, the third threshold control branch 123 includes a first zener diode D1 , the cathode of the first zener diode D1 serves as the first end of the third threshold control branch 123 , and the anode of the first zener diode D1 serves as the second end of the third threshold control branch 123 .

[0135] The conduction condition of the fourth protection transistor Q5 is: the output voltage of the energy storage unit 110 is greater than the second voltage threshold V th2 .in, is the voltage drop of the fourth protection transistor Q5, which is 0.7V; V z1is the reverse conduction voltage drop of the first voltage stabilizing diode D1.

[0136] In one embodiment, if Figure 13 As shown, the fourth threshold control branch 124 includes a second voltage regulator diode D2 , the cathode of the second voltage regulator diode D2 serves as the first end of the fourth threshold control branch 124 , and the anode of the second voltage regulator diode D2 serves as the second end of the fourth threshold control branch 124 .

[0137] The conduction condition of the third protection transistor Q4 is: the output voltage of the energy storage unit 110 is greater than the first voltage threshold V th1 Among them, the first voltage threshold is is the voltage drop of the third protection transistor Q4, which is 0.7V; V z2 is the reverse conduction voltage drop of the second voltage stabilizing diode D2.

[0138] In one embodiment, if Figure 13 As shown, the threshold control unit 120 also includes a fifth resistor R5, a first end of the fifth resistor R5 is connected to the collector of the fourth protection transistor Q5 and the first input end of the voltage conversion unit 130, and a second end of the fifth resistor R5 is connected to the first end of the third threshold control branch 123.

[0139] It is understandable that the fifth resistor R5 can be a K-class resistor, in order to reduce the power consumption of the threshold control unit 120 and allow more energy provided by the energy storage unit 110 to be transferred to the voltage conversion unit 130 .

[0140] In one embodiment, if Figure 14 As shown, the threshold control unit 120 further includes a sixth resistor R6 , which is connected in series between the base of the third protection transistor Q4 and the first end of the fourth threshold control branch 124 .

[0141] It is understandable that the sixth resistor R6 can be a K-class resistor, in order to reduce the power consumption of the threshold control unit 120 and allow more energy provided by the energy storage unit 110 to be transferred to the voltage conversion unit 130 .

[0142] It should be noted that, in practical applications, one or both of the fifth resistor R5 and the sixth resistor R6 may be selected, and there is no limitation here.

[0143] In one embodiment, the voltage drop across the third threshold control branch 123 is a second voltage threshold, the voltage drop across the fourth threshold control branch 124 is a first voltage threshold, and the second voltage threshold is less than the first voltage threshold. For example, when the third threshold control branch 123 includes only the first Zener diode D1 and the fourth threshold control branch 124 includes only the second Zener diode D2, the regulated voltage of the first Zener diode D1 is less than the regulated voltage of the second Zener diode D2.

[0144] It should be noted that when the output voltage of the energy storage unit 110 is greater than the first voltage threshold V th1 When the third protection transistor Q4 is turned on, the voltage conversion unit 130 starts to work. th1 >V th2 , the fourth protection transistor Q5 must also be turned on. After the fourth protection transistor Q5 is turned on, the second voltage regulator diode D2 is short-circuited. At this moment, the output voltage of the energy storage unit 110 is still greater than V th2 , the third protection transistor Q4 remains on, that is, the threshold control unit 120 remains on. When the output voltage of the energy storage unit 110 is less than V th2 When the value of , the third protection transistor Q4 is turned off, the threshold control unit 120 is disconnected, and the voltage conversion unit 130 stops working.

[0145] In order to meet V th1 >V th2 Under the condition restriction, when the voltage drop of the third protection transistor Q4 and the fourth protection transistor Q5 is the same, the reverse conduction voltage drop of the first voltage zener diode D1 should be smaller than the reverse conduction voltage drop of the second voltage zener diode D2, that is, V z1 <V z2 .

[0146] For example, for the first Zener diode D1: when the cathode voltage of the first Zener diode D1 is less than the reverse breakdown voltage V z1 When the cathode voltage of the first Zener diode D1 is greater than the reverse breakdown voltage V z1 When , the first voltage zener diode D1 is in a reverse conduction state, and current flows through the first voltage zener diode D1 in this stage. The working principle of the second voltage zener diode D2 is the same and will not be described in detail.

[0147] It is understandable that the first voltage threshold V can also be adjusted by changing the number of the first voltage stabilizing diodes D1 in the third threshold control branch 123. th1 By changing the number of the second voltage stabilizing diodes D2 in the fourth threshold control branch 124, the second voltage threshold V th2 ,like Figure 15 As shown, the third threshold control branch 123 includes two first voltage-stabilizing diodes D1, and the fourth threshold control branch 124 includes two second voltage-stabilizing diodes D2. The specific number is adjusted and set with reference to the relevant content of the first threshold control branch 121 or the second threshold control branch 122 in the above embodiment, and will not be repeated here.

[0148] The present application also provides a control system 1000, such as Figure 16 As shown, the control system 1000 includes the power-off protection device 100, the main control unit 200 and the system power supply 300 in any of the above embodiments; the first output end of the system power supply 300 is connected to the input end of the power-off protection device 100, and the output end of the power-off protection device 100 is connected to the first input end of the main control unit 200; the second output end of the system power supply 300 is connected to the second input end of the main control unit 200.

[0149] The input end of the power-off protection device 100 is the input end of the energy storage unit 110 , and the output end of the power-off protection device 100 is the output end of the voltage conversion unit 130 .

[0150] It is understandable that, in the above embodiment, the various output terminals of the system power supply 300 may be the same output terminal, and the various input terminals of the main control unit 200 may also be the same input terminal.

[0151] For example, when the system power supply 300 is an output terminal and the main control unit 200 is an input terminal, when the system power supply is not powered off: 1. The main control unit 200 can select the one with the higher output potential, either the system power supply 300 or the power-off protection device 100, to supply power to it. 2. A diode can be added between the voltage conversion unit 130 and the input terminal of the main control unit 200, with the anode of the diode connected to the voltage conversion unit 130 and the cathode connected to the main control unit 200. This is used to adjust the output value of the voltage conversion unit 130 so that the voltage output value of the voltage conversion unit 130 is lower than the voltage output value of the system power supply 300, so that the main control unit 200 is powered by the system power supply 300; and it is used to prevent the output current of the system power supply 300 from flowing back into the voltage conversion unit 130, thereby damaging the voltage conversion unit 130.

[0152] In one embodiment, if Figure 17 As shown, the control system 1000 further includes: a monitoring unit 400;

[0153] The monitoring unit 400 is used to monitor the system power supply 300 and send a power failure notification of the system power supply 300 to the voltage conversion unit 130 in the power failure protection device 100 and the main control unit 200 when the system power supply 300 is powered off;

[0154] The input terminal of the monitoring unit 400 is connected to the third output terminal of the system power supply 300;

[0155] The first output terminal of the monitoring unit 400 is connected to the second input terminal of the voltage conversion unit 130 , and the second output terminal of the monitoring unit 400 is connected to the third input terminal of the main control unit 200 .

[0156] In this embodiment, the monitoring unit 400 activates the power-off protection device 100 to supply power to the main control unit 200 when the system power supply 300 loses power.

[0157] It should be noted that the control system 1000 described in the embodiments of the present application can be applied to various circuits requiring power-off protection. For example, the control system 1000 can be used as an embedded system in various circuits. In different circuits, the embedded system requires different voltages for power-off protection. The flexibly configurable threshold voltage of the control system 1000 can better adapt to different embedded applications.

[0158] The present application also provides a new energy system, including the power failure protection device 100 or the control system 1000 described in any of the above embodiments. The new energy system can be a photovoltaic power generation system, a wind power generation system, an energy storage system, or a vehicle charging system, which is not specifically limited here.

[0159] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art who is familiar with the technical field can still modify the technical solutions described in the above embodiments within the technical scope disclosed in the present application, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A power-off protection device, characterized in that: include: Energy storage unit, threshold control unit and voltage conversion unit; The energy storage unit is used to store electrical energy and provide electrical energy to the threshold control unit, and the output end of the energy storage unit is connected to the input end of the threshold control unit; The threshold control unit is configured to provide electrical energy to the voltage conversion unit according to a first voltage threshold and a second voltage threshold, wherein the first voltage threshold is used to control the on-state of the threshold control unit, and the second voltage threshold is used to control the off-state of the threshold control unit, and the output terminal of the threshold control unit is connected to the first input terminal of the voltage conversion unit; The voltage conversion unit is used to convert the output voltage of the threshold control unit into a target voltage required by the main control unit to power the main control unit, and the output end of the voltage conversion unit is connected to the first input end of the main control unit.

2. The power-off protection device according to claim 1, characterized in that: The threshold control unit includes a first switch tube, a first protection transistor, a second protection transistor, a first threshold control branch and a second threshold control branch; The first end of the first switching tube is connected to the emitter of the first protection transistor and the output end of the energy storage unit; The second end of the first switch tube is connected to the first input end of the voltage conversion unit; The base of the first protection transistor is connected to the first end of the first threshold control branch, the collector of the first protection transistor is connected to the first end of the second threshold control branch, the second end of the first threshold control branch is connected to the collector of the second protection transistor and the third end of the first switch transistor, and the second end of the second threshold control branch is connected to the base of the second protection transistor; The third end of the first threshold control branch is grounded, and the emitter of the second protection transistor is grounded.

3. The power-off protection device according to claim 2, characterized in that: The first threshold control branch includes a first threshold control sub-branch and a second threshold control sub-branch, wherein the first end of the first threshold control sub-branch serves as the first end of the first threshold control branch, the second end of the first threshold control sub-branch is connected to the first end of the second threshold control sub-branch to serve as the second end of the first threshold control branch, and the second end of the second threshold control sub-branch serves as the third end of the first threshold control branch; wherein, The sum of the voltage drops of the first threshold control branch and the first protection transistor is the first voltage threshold, the sum of the voltage drops of the second threshold control branch, the first protection transistor and the second protection transistor is the second voltage threshold, the first voltage threshold is greater than the second voltage threshold, and the voltage drop of the second threshold control sub-branch is greater than the voltage drop of the second protection transistor.

4. The power-off protection device according to claim 3, characterized in that: The first threshold control sub-branch includes N second switching transistors connected in series, with one end of the series connection serving as the first end of the first threshold control sub-branch and the other end of the series connection serving as the second end of the first threshold control sub-branch; wherein the second switching transistor is a switching transistor having a unidirectional conduction characteristic, and N is an integer greater than or equal to 1; The second threshold control sub-branch includes a third switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control sub-branch, and the other end of the series connection serves as the second end of the second threshold control sub-branch; wherein the third switching tube is a switching tube with a unidirectional conduction characteristic, and a is an integer greater than or equal to 1.

5. The power-off protection device according to claim 3, characterized in that: The second threshold control branch includes M fourth switching tubes connected in series, and one end of the series connection serves as the first end of the second threshold control branch, and the other end of the series connection serves as the second end of the second threshold control branch; wherein the fourth switching tube is a switching tube with a unidirectional conduction characteristic, and M is an integer greater than or equal to 1.

6. The power-off protection device according to claim 4, characterized in that: The N second switching tubes include one or more of a triode, a diode, an insulated gate bipolar transistor and a thyristor; In the case where the N second switching transistors are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the first threshold control sub-branch, the emitter of the i-th triode is connected to the collector of the (i+1)-th triode, and the emitter of the N-th triode serves as the second end of the first threshold control sub-branch; In the case where the N second switching tubes are all diodes, the anode of the first diode serves as the first end of the first threshold control sub-branch, the cathode of the i-th diode is connected to the anode of the (i+1)-th diode, and the cathode of the N-th diode serves as the second end of the first threshold control sub-branch; In the case where the N second switching transistors are all the insulated gate bipolar transistors, the gate and collector of each of the insulated gate bipolar transistors are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the first threshold control sub-branch, the emitter of the i-th insulated gate bipolar transistor is connected to the collector of the (i+1)-th insulated gate bipolar transistor, and the emitter of the N-th insulated gate bipolar transistor serves as the second end of the first threshold control sub-branch; When the N second switching tubes are all thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the first threshold control sub-branch, the cathode of the i-th thyristor is connected to the anode of the i+1-th thyristor, and the cathode of the N-th thyristor serves as the second end of the first threshold control sub-branch; wherein 1≤i<N.

7. The power-off protection device according to claim 4, characterized in that: The a third switching tube includes one or more of a triode, a diode, an insulated gate bipolar transistor and a thyristor; In the case where the a third switching transistors are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control sub-branch, the emitter of the j-th triode is connected to the collector of the j+1-th triode, and the emitter of the a-th triode serves as the second end of the second threshold control sub-branch; In the case where the a third switching tubes are all diodes, the anode of the first diode serves as the first end of the second threshold control sub-branch, the cathode of the jth diode is connected to the anode of the j+1th diode, and the cathode of the ath diode serves as the second end of the second threshold control sub-branch; In the case where the a third switching transistors are all the insulated gate bipolar transistors, the gate and collector of each of the insulated gate bipolar transistors are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control sub-branch, the emitter of the j-th insulated gate bipolar transistor is connected to the collector of the j+1-th insulated gate bipolar transistor, and the emitter of the a-th insulated gate bipolar transistor serves as the second end of the second threshold control sub-branch; In the case where the a third switching tubes are all thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control sub-branch, the cathode of the jth thyristor is connected to the anode of the j+1th thyristor, and the cathode of the ath thyristor serves as the second end of the second threshold control sub-branch; wherein 1≤j<a.

8. The power-off protection device according to claim 5, characterized in that: The M fourth switching transistors include one or more of a triode, a diode, an insulated gate bipolar transistor and a thyristor; In the case where the M fourth switching transistors are all triodes, the base and collector of each triode are connected, and the collector of the first triode serves as the first end of the second threshold control branch, the emitter of the kth triode is connected to the collector of the k+1th triode, and the emitter of the Mth triode serves as the second end of the second threshold control branch; In the case where the M fourth switching transistors are all diodes, the anode of the first diode serves as the first end of the second threshold control branch, the cathode of the kth diode is connected to the anode of the k+1th diode, and the cathode of the Mth diode serves as the second end of the second threshold control branch; In the case where the M fourth switching transistors are all the insulated gate bipolar transistors, the gate and collector of each of the insulated gate bipolar transistors are connected, and the collector of the first insulated gate bipolar transistor serves as the first end of the second threshold control branch, the emitter of the kth insulated gate bipolar transistor is connected to the collector of the k+1th insulated gate bipolar transistor, and the emitter of the Mth insulated gate bipolar transistor serves as the second end of the second threshold control branch; When the M fourth switching tubes are all thyristors, the control electrode and anode of each thyristor are connected, and the anode of the first thyristor serves as the first end of the second threshold control branch, the cathode of the kth thyristor is connected to the anode of the k+1th thyristor, and the cathode of the Mth thyristor serves as the second end of the second threshold control branch; wherein 1≤k<M.

9. The power-off protection device according to any one of claims 2 to 8, characterized in that: The threshold control unit further includes a first resistor and / or a second resistor, wherein: A first end of the first resistor is connected to the base of the first protection transistor, and a second end of the first resistor is connected to the first end of the first threshold control branch; The first end of the second resistor is connected to the second end of the second threshold control branch, and the second end of the second resistor is connected to the base of the second protection transistor.

10. The power-off protection device according to any one of claims 2 to 8, characterized in that: The threshold control unit further includes a third resistor and / or a fourth resistor, wherein: The third resistor is connected in parallel between the first end of the first switch tube and the third end of the first switch tube; The fourth resistor is connected in series between the third terminal of the first switch tube and the collector of the second protection transistor.

11. The power-off protection device according to claim 1, characterized in that: The threshold control unit includes a third protection transistor, a fourth protection transistor, a third threshold control branch and a fourth threshold control branch; The emitter of the third protection transistor is connected to the output end of the energy storage unit; The collector of the third protection transistor is connected to the first end of the third threshold control branch and the first input end of the voltage conversion unit; The base of the third protection transistor is connected to the first end of the fourth threshold control branch and the collector of the fourth protection transistor; The second end of the third threshold control branch is connected to the base of the fourth protection transistor; The second end of the fourth threshold control branch is connected to the emitter of the fourth protection transistor and is grounded.

12. The power-off protection device according to claim 11, characterized in that: The third threshold control branch includes a first voltage regulator diode, the cathode of the first voltage regulator diode serves as the first end of the third threshold control branch, and the anode of the first voltage regulator diode serves as the second end of the third threshold control branch.

13. The power-off protection device according to claim 11, characterized in that: The fourth threshold control branch includes a second voltage regulator diode, the cathode of the second voltage regulator diode serves as the first end of the fourth threshold control branch, and the anode of the second voltage regulator diode serves as the second end of the fourth threshold control branch.

14. The power-off protection device according to claim 11, characterized in that: The threshold control unit further includes a fifth resistor and / or a sixth resistor, wherein: A first end of the fifth resistor is connected to the collector of the fourth protection transistor and the first input end of the voltage conversion unit, and a second end of the fifth resistor is connected to the first end of the third threshold control branch; A first end of the sixth resistor is connected to the base of the fourth protection transistor, and a second end of the sixth resistor is connected to the first end of the fourth threshold control branch.

15. The power-off protection device according to any one of claims 11 to 14, characterized in that: The voltage drop of the third threshold control branch is the second voltage threshold, the voltage drop of the fourth threshold control branch is the first voltage threshold, and the second voltage threshold is smaller than the first voltage threshold.

16. A control system, characterized in that: The power-off protection device, main control unit and system power supply according to any one of claims 1 to 15 are included; The first output terminal of the system power supply is connected to the input terminal of the power-off protection device, and the output terminal of the power-off protection device is connected to the first input terminal of the main control unit; The second output terminal of the system power supply is connected to the second input terminal of the main control unit.

17. The control system according to claim 16, characterized in that: The control system further comprises: a monitoring unit; The monitoring unit is configured to monitor the system power supply and send a power failure notification of the system power supply to the voltage conversion unit in the power failure protection device and the main control unit when the system power supply is powered off; The input terminal of the monitoring unit is connected to the third output terminal of the system power supply; The first output terminal of the monitoring unit is connected to the second input terminal of the voltage conversion unit, and the second output terminal of the monitoring unit is connected to the third input terminal of the main control unit.

18. A new energy system, characterized in that: The invention comprises the power-off protection device according to any one of claims 1 to 15 or the control system according to claim 16 or 17.

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