Photovoltaic charging activation circuit and photovoltaic charging system

Abstract

The present application relates to a photovoltaic charging activation circuit and a photovoltaic charging system. The circuit comprises an activation control module (2) and a signal output module (4); the activation control module (2) and the signal output module (4) are successively connected in series between a photovoltaic power supply (300) and a battery management system (500), and the signal output module (4) is further connected to a power supply (700); the activation control module (2) is used for outputting a driving signal to the signal output module (4) when the output voltage of the photovoltaic power supply (300) at the current moment is greater than a target voltage threshold value and greater than the output voltage thereof at a previous moment, such that the signal output module (4) outputs an activation signal to the battery management system (500) on the basis of the power supply voltage of the power supply (700), the target voltage threshold value being used for representing the lowest voltage for activating the battery management system (500). The present circuit can avoid frequent output of activation signals when output voltages of photovoltaic power supplies jitter.

Description

Photovoltaic charging activation circuit and photovoltaic charging system

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 2024113485907, filed on September 26, 2024, and entitled “Photovoltaic charging activation circuit and photovoltaic charging system”, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of energy storage, in particular to a photovoltaic charging activation circuit and a photovoltaic charging system. BACKGROUND

[0004] With the rapid development of lithium battery technology and power electronics technology, integrated photovoltaic and energy storage devices have become a market hotspot. Among them, solar charging is one of the important functions of such products, and the output voltage-based activation charging of photovoltaic power supply is particularly critical.

[0005] The existing solutions for output voltage-based activation charging of photovoltaic power supply are relatively limited and usually have complex circuits or obvious limitations. For example, when the output voltage of the photovoltaic power supply is unstable or dithering, the activation signal is frequently sent to the battery management system. This unstable activation mechanism not only increases the energy consumption of the system and reduces the efficiency of the entire energy storage system, but also affects the service life of the battery management system due to frequent start-stop. SUMMARY

[0006] Therefore, it is necessary to provide a photovoltaic charging activation circuit and a photovoltaic charging system.

[0007] In a first aspect, the present application provides a photovoltaic charging activation circuit, comprising: an activation control module and a signal output module;

[0008] The activation control module and the signal output module are connected in series between the photovoltaic power supply and the battery management system in sequence, and the signal output module is further connected with a power supply;

[0009] The activation control module is configured to output a driving signal to the signal output module in a case that the output voltage of the photovoltaic power supply at a current time is greater than a target voltage threshold and greater than the output voltage at a previous time, so that the signal output module outputs an activation signal to the battery management system based on the power supply voltage of the power supply.

[0010] The target voltage threshold is used to represent the minimum voltage for activating the battery management system.

[0011] In one of the embodiments, the activation control module is further configured to stop outputting the driving signal in a case that the output voltage at the current time is less than the target voltage threshold and / or less than or equal to the output voltage at the previous time.

[0012] In one of the embodiments, the driving signal comprises a first sub-driving signal and a second sub-driving signal, and the activation control module comprises a voltage detection unit and a step detection unit;

[0013] The first input terminal of the voltage detection unit is connected to the photovoltaic power supply, and the first output terminal of the voltage detection unit is connected to the first input terminal of the signal output module;

[0014] The step detection unit is connected in series between the second output terminal of the voltage detection unit and the second input terminal of the signal output module;

[0015] The voltage detection unit is configured to output an intermediate voltage signal to the step detection unit and output the first sub-driving signal to the signal output module when the output voltage of the photovoltaic power supply at the current time is greater than the target voltage threshold, and the intermediate voltage signal is positively correlated with the output voltage;

[0016] The step detection unit is configured to output the second sub-driving signal to the signal output module when the intermediate voltage signal at the current time is greater than the intermediate voltage signal at the previous time, so that the signal output module outputs the activation signal when receiving the first sub-driving signal and the second sub-driving signal.

[0017] In one of the embodiments, the voltage detection unit is further configured to stop outputting the intermediate voltage signal and the first sub-driving signal when the output voltage at the current time is less than the target voltage threshold; and / or,

[0018] The step detection unit is further configured to stop outputting the second sub-driving signal when the intermediate voltage signal at the current time is less than or equal to the intermediate voltage signal at the previous time.

[0019] In one of the embodiments, the output terminal of the step detection unit is further connected to the second input terminal of the voltage detection unit;

[0020] The voltage detection unit is further configured to continuously output the first sub-driving signal when receiving the second sub-driving signal.

[0021] In one of the embodiments, the step detection unit comprises a switching circuit, a first charge-discharge circuit and a second charge-discharge circuit;

[0022] The input end of the switch circuit is connected with the second output end of the voltage detection unit, the first output end of the switch circuit is connected with the input end of the first charge-discharge circuit, the second output end of the switch circuit is connected with the input end of the second charge-discharge circuit, and the discharge controlled end of the first charge-discharge circuit is connected with the second output end of the voltage detection unit; the output end of the second charge-discharge circuit is connected with the second input end of the signal output module, or the output end of the second charge-discharge circuit is respectively connected with the second input end of the signal output module and the second input end of the voltage detection unit;

[0023] The switch circuit is turned on when the voltage difference between the input end and the first output end of the switch circuit meets the turn-on condition, and charges the first charge-discharge circuit and the second charge-discharge circuit, so that the second charge-discharge circuit outputs the second sub-driving signal.

[0024] The switch circuit is turned off when the voltage difference does not meet the turn-on condition, so that the first charge-discharge circuit and the second charge-discharge circuit are discharged.

[0025] In one of the embodiments, the switch circuit comprises: a switch tube Q1; the emitter of the switch tube Q1 is connected with the second output end of the voltage detection unit, the collector of the switch tube is connected with the second input end of the signal output module, and the base of the switch tube Q1 is connected with the input end of the first charge-discharge circuit; and / or,

[0026] The first charge-discharge circuit comprises: a resistor R2, a capacitor C1, a diode D1 and a resistor R1; the resistor R2, the anode of the diode D1, the cathode of the diode D1 and the resistor R1 are connected in series between the first output end of the switch circuit and the ground end, and the capacitor C1 is connected in parallel with the resistor R1; and / or,

[0027] The second charge-discharge circuit comprises: a capacitor C2 and a resistor R3; the capacitor C2 and the resistor R3 are connected in parallel between the second output end of the switch circuit and the ground end.

[0028] In one of the embodiments, the voltage detection unit comprises: a voltage stabilizing diode ZD1, a switch tube Q4 and a switch tube Q5;

[0029] The cathode of the voltage stabilizing diode ZD1 is used to connect with the photovoltaic power supply, the anode of the voltage stabilizing diode ZD1 is respectively connected with the collector of the switch tube Q4 and the base of the switch tube Q5, the emitter of the switch tube Q4 is connected with the output end of the step detection unit, the base of the switch tube Q4 is connected with the collector of the switch tube Q5, and the emitter of the switch tube Q5 is grounded.

[0030] In one of the embodiments, the signal output module comprises: a switch tube Q6, a resistor R9, a switch tube Q3, a resistor R5, a capacitor C4, a switch tube Q2, a resistor R4 and a capacitor C3;

[0031] The emitter of the switch tube Q6 is used for connecting a power supply, the base of the switch tube Q6 is connected with the first output end of the voltage detection unit, and the collector of the switch tube Q6 is connected with the emitter of the switch tube Q3;

[0032] The resistor R9 is connected between the emitter and the base of the switch tube Q6;

[0033] The collector of the switch tube Q3 is used for connecting a battery management system, the resistor R5 and the capacitor C4 are connected in series between the base of the switch tube Q3 and the ground;

[0034] The resistor R4 and the capacitor C3 are connected in series between the output end of the step detection unit and the ground;

[0035] The collector of the switch tube Q2 is connected between the resistor R5 and the capacitor C4, the emitter of the switch tube Q2 is grounded, and the base of the switch tube Q2 is connected between the resistor R4 and the capacitor C3.

[0036] In a second aspect, the present application further provides a photovoltaic charging system, which comprises:

[0037] a photovoltaic power supply;

[0038] a battery management system;

[0039] and the photovoltaic charging activation circuit in the above embodiments, wherein the photovoltaic charging activation circuit is connected with the photovoltaic power supply and the battery management system respectively.

[0040] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features and advantages of the present application will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on the disclosed drawings.

[0042] Fig. 1 is a structural schematic diagram of a photovoltaic charging activation circuit according to one or more embodiments;

[0043] Fig. 2 is a structural schematic diagram of a photovoltaic charging activation circuit according to one or more embodiments;

[0044] Fig. 3 is a structural schematic diagram of a photovoltaic charging activation circuit according to one or more embodiments;

[0045] Fig. 4 is a schematic diagram of a structure of a photovoltaic charging activation circuit according to one or more embodiments;

[0046] Fig. 5 is a schematic diagram of a structure of a photovoltaic charging activation circuit according to one or more embodiments;

[0047] Fig. 6 is a schematic diagram of a structure of a photovoltaic charging activation circuit according to one or more embodiments;

[0048] Fig. 7 is a schematic diagram of a structure of a photovoltaic charging activation circuit according to one or more embodiments;

[0049] Fig. 8 is a schematic diagram of a structure of a photovoltaic charging activation circuit according to one or more embodiments. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description herein is for describing the specific embodiments only and is not intended to be limiting of the present application.

[0052] It can be understood that the terms "first", "second", and the like used herein are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. For example, without departing from the scope of the present application, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0053] It can be understood that "connection" in the following embodiments means that the circuits, modules, units, etc. connected to each other have transmission of electrical signals or data.

[0054] It can be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of an element" means part or all of the element.

[0055] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", or the like, when used in this specification, specify the presence of stated features, integers, steps, operations, components, parts, or the like, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or the like.

[0056] In one example embodiment, as shown in FIG. 1, the application provides a photovoltaic charging activation circuit, which includes an activation control module 2 and a signal output module 4. The activation control module 2 and the signal output module 4 are connected in series between a photovoltaic power supply 300 and a battery management system 500, and the signal output module 4 is further connected with a power supply 700; the activation control module 2 is configured to output a driving signal to the signal output module 4 when the output voltage of the photovoltaic power supply 300 at the current time is greater than a target voltage threshold and greater than the output voltage at the last time, so that the signal output module 4 outputs an activation signal to the battery management system 500 based on the power supply voltage of the power supply 700; wherein the target voltage threshold is used to represent the minimum voltage for activating the battery management system 500.

[0057] For example, the output characteristic of a photovoltaic power supply is that its output voltage changes with the change of light intensity. When the light condition changes, such as cloud cover or shadow, the output voltage of the photovoltaic power supply (such as a solar panel) will be unstable or fluctuate. In a photovoltaic charging system that activates charging based on the output voltage of the photovoltaic power supply, when the output voltage of the photovoltaic power supply exceeds the minimum voltage requirement for activating the battery management system, the photovoltaic charging system will consider that there is enough energy to supply power, and will send an activation signal to the battery management system (BMS) to start the charging process. However, if the output voltage of the photovoltaic power supply fluctuates frequently due to environmental factors, the output voltage may repeatedly cross the minimum voltage for activating the battery management system, i.e. every time the output voltage of the photovoltaic power supply is higher than the minimum voltage for activating the battery management system, the photovoltaic charging system will try to activate charging; and when the output voltage of the photovoltaic power supply is lower than the minimum voltage for activating the battery management system, the photovoltaic charging system will stop charging. Such frequent start and stop not only increases energy consumption, but also reduces charging efficiency and the service life of the energy storage device.

[0058] For the above reasons, as shown in FIG. 1, the activation control module 2 is configured to sample and record the output voltage of the photovoltaic power supply 300 in real time, and output a driving signal to the signal output module 4 only when the output voltage of the photovoltaic power supply 300 at the current time is greater than the minimum voltage for activating the battery management system 500 and greater than the output voltage at the previous time, so that the signal output module 4 outputs an activation signal to the battery management system 500 based on the supply voltage of the power supply 700. When the output voltage of the photovoltaic power supply 300 at the current time is less than or equal to the minimum voltage for activating the battery management system 500, it means that the output voltage at this time does not meet the minimum voltage requirement for activating the battery management system 500, and the activation control module 2 will not output a driving signal to activate the battery management system 500. When the output voltage of the photovoltaic power supply 300 at the current time is greater than the minimum voltage for activating the battery management system 500 but less than the output voltage at the previous time, it means that the output voltage of the photovoltaic power supply 300 at this time may have a downward trend in a continuous time period, and the energy provided by the photovoltaic power supply 300 may not be stable, so the activation control module 2 will not output a driving signal at this time. When the output voltage of the photovoltaic power supply 300 at the current time is greater than the minimum voltage for activating the battery management system 500 and greater than the output voltage at the previous time, it means that the output voltage of the photovoltaic power supply 300 at this time meets the minimum voltage requirement for activating the battery management system 500 and has a continuous upward trend in a continuous time period, and the energy provided by the photovoltaic power supply 300 is sufficient and stable, so the activation control module 2 will output a driving signal to the signal output module 4 to activate the battery management system 500. It should be noted that for the first time the output voltage of the photovoltaic power supply 300 is connected, since the output voltage at the previous time is zero, the activation control module 2 will output a driving signal to the signal output module 4 to activate the battery management system 500 as long as the output voltage at the current time is greater than the minimum voltage for activating the battery management system 500.

[0059] The sampling frequency of the activation control module 2 for the output voltage of the photovoltaic power supply 300 can be set according to the actual activation accuracy requirement, which is not limited herein. For example, if it is desired to reduce the activation frequency as much as possible, the sampling frequency can be reduced (i.e. the sampling time interval between the current time and the previous time is increased) so that the charging process is activated only when the energy provided by the photovoltaic power supply 300 remains stable and has a continuous growth trend for a longer continuous time period.

[0060] The photovoltaic charging activation circuit sets the activation control module to sample the output voltage of the photovoltaic power supply in real time, and outputs the driving signal to the signal output module only when the voltage is not only higher than the minimum voltage for activating the battery management system, but also higher than the voltage at the previous time, that is, when the photovoltaic power supply truly provides stable and continuously increasing energy, the charging process is activated, thereby reducing the number of invalid start-ups, realizing reliable activation, reducing the energy consumption of the system, improving the charging efficiency, prolonging the service life of the energy storage device, and the like.

[0061] In one of the example embodiments, the power supply 700 can be a power supply provided by a battery module in the energy storage device. For example, the power supply 700 can be another power supply outside the battery module.

[0062] In one of the example embodiments, the activation control module 2 is further configured to stop outputting the driving signal when the output voltage at the current time is less than the target voltage threshold, and / or, less than or equal to the output voltage at the previous time.

[0063] For example, as described above, when the output voltage of the photovoltaic power supply 300 at the current time is less than or equal to the minimum voltage for activating the battery management system 500, it indicates that the output voltage at this time does not meet the minimum voltage requirement for activating the battery management system 500, and the activation control module 2 does not output the driving signal to activate the battery management system 500 by the signal output module 4; when the output voltage of the photovoltaic power supply 300 at the current time is greater than the minimum voltage for activating the battery management system 500 but less than the output voltage at the previous time, it indicates that the output voltage at this time can have a downward trend in a continuous time period, and the energy provided by the photovoltaic power supply 300 can not be stable, and the activation control module 2 also does not output the driving signal. Based on this, during the activation process of the battery management system 500, when the output voltage at the current time is less than the target voltage threshold, and / or, less than or equal to the output voltage at the previous time, the driving signal needs to be stopped at this time to stop the battery management system 500 from working.

[0064] In this embodiment, the activation control module can also stop outputting the driving signal when the output voltage at the current time is less than the target voltage threshold, and / or, less than or equal to the output voltage at the previous time, to ensure that the charging is performed only when the energy provided by the photovoltaic power supply is stable and continuously increasing during the entire charging process, thereby improving the charging efficiency, and ensuring that the battery management system 500 can be powered off during the power supply process of the photovoltaic power supply.

[0065] In one of the example embodiments, as shown in FIG. 2, the driving signal includes a first sub-driving signal and a second sub-driving signal, and the activation control module 2 includes a voltage detection unit 22 and a step detection unit 24. The first input end of the voltage detection unit 22 is connected to the photovoltaic power supply 300, the first output end of the voltage detection unit 22 is connected to the first input end of the signal output module 4, and the step detection unit 24 is connected in series between the second output end of the voltage detection unit 22 and the second input end of the signal output module 4. The voltage detection unit 22 is configured to output an intermediate voltage signal to the step detection unit 24 and output the first sub-driving signal to the signal output module 4 when the output voltage of the photovoltaic power supply 300 at the current time is greater than the target voltage threshold, and the intermediate voltage signal is positively correlated with the output voltage. The step detection unit 24 is configured to output the second sub-driving signal to the signal output module 4 when the intermediate voltage signal at the current time is greater than the intermediate voltage signal at the previous time, so that the signal output module 4 outputs the activation signal when receiving the first sub-driving signal and the second sub-driving signal.

[0066] In the above example embodiments, the voltage detection unit 22 is configured to detect whether the output voltage of the photovoltaic power supply 300 is greater than the target voltage threshold, i.e., to determine whether the output voltage of the photovoltaic power supply 300 is greater than the minimum voltage for activating the battery management system 500. The step detection unit 24 can receive and store the voltage output by the voltage detection unit 22, and is configured to detect whether the voltage output by the voltage detection unit 22 at the current time is greater than the voltage output by the voltage detection unit 22 at the previous time.

[0067] Exemplarily, the output voltage of the photovoltaic power supply 300 is input to the voltage detection unit 22, and the voltage detection unit 22 compares the output voltage of the photovoltaic power supply 300 received at the current time with the minimum voltage for activating the battery management system 500. When the output voltage of the photovoltaic power supply 300 at the current time is greater than the minimum voltage for activating the battery management system 500, it indicates that the output voltage of the photovoltaic power supply 300 at the current time meets the minimum voltage requirement for activating the battery management system 500. Based on the comparison result, the voltage detection unit 22 outputs a first sub-driving signal to the signal output module 4, and at the same time, the voltage detection unit 22 also converts the output voltage of the photovoltaic power supply 300 at the current time into an intermediate voltage signal and outputs the intermediate voltage signal to the step detection unit 24. After receiving the intermediate voltage signal, the step detection unit 24 compares the intermediate voltage signal at the current time with the intermediate voltage signal at the previous time stored in the step detection unit 24. When the intermediate voltage signal at the current time is greater than the intermediate voltage signal at the previous time, it indicates that the output voltage of the photovoltaic power supply 300 has a continuous rising trend in a continuous time period, and the energy provided by the photovoltaic power supply 300 is sufficient and stable. The step detection unit 24 outputs a second sub-driving signal to the signal output module. When the signal output module 4 receives the first sub-driving signal and the second sub-driving signal at the same time, the signal output module 4 outputs an activation signal to the battery management system 500 based on the supply voltage of the power supply 700 to complete the activation operation.

[0068] In the embodiment, the voltage detection unit and the step detection unit are introduced to jointly determine the state of the output voltage of the photovoltaic power supply, so that the battery management system is activated only when the voltage is not only higher than the preset threshold but also has a continuous rising trend, which helps to avoid false activation caused by voltage fluctuation, thereby improving the stability and reliability of system operation, prolonging the service life of the battery management system, and ensuring the effective utilization of photovoltaic system energy.

[0069] In one of the exemplary embodiments, the voltage detection unit 22 is further configured to stop outputting the intermediate voltage signal and the first sub-driving signal when the output voltage at the current time is less than the target voltage threshold; and / or the step detection unit is further configured to stop outputting the second sub-driving signal when the intermediate voltage signal at the current time is less than or equal to the intermediate voltage signal at the previous time.

[0070] Exemplarily, when the output voltage at the current time detected by the voltage detection unit 22 is less than the target voltage threshold, it indicates that the output voltage of the photovoltaic power supply 300 does not meet the minimum voltage requirement for activating the battery management system 500, and the intermediate voltage signal and the first sub-driving signal are immediately stopped. Secondly, even if the output voltage at the current time is greater than the target voltage threshold, and the intermediate voltage signal at the current time detected by the step detection unit 24 is less than or equal to the intermediate voltage signal at the previous time, it indicates that even if the output voltage of the photovoltaic power supply 300 at the current time meets the minimum requirement for activating the battery management system 500, the output voltage of the photovoltaic power supply 300 can have a downward trend in a continuous time period, and the energy provided by the photovoltaic power supply 300 can not be stable, at which time the step detection unit stops outputting the second sub-driving signal.

[0071] In the embodiment, by setting the mechanism of stopping outputting the driving signal when the output voltage of the photovoltaic power supply is lower than the target threshold and / or the output voltage of the photovoltaic power supply has no upward trend, the battery management system is effectively prevented from being activated due to unstable or insufficient voltage, thereby ensuring the safety and efficiency of the system operation, reducing unnecessary energy consumption, and enhancing the reliability and stability of the entire photovoltaic system.

[0072] In one of the exemplary embodiments, as shown in FIG. 3, the output end of the step detection unit 24 is also connected with the second input end of the voltage detection unit 22; and the voltage detection unit 22 is further configured to continuously output the first sub-driving signal in the case of receiving the second sub-driving signal.

[0073] Exemplarily, once the step detection unit 24 confirms that the output voltage of the photovoltaic power supply 300 has a sustained upward trend, the second sub-driving signal is outputted, and the voltage detection unit 22 receives the second sub-driving signal through the second input end and continuously outputs the first sub-driving signal, so as to ensure the stable output of the first sub-driving signal after detecting the appropriate and stable activation condition. Based on this, the second sub-driving signal acts on the signal output module 4 together, so as to ensure that the signal output module 4 can uninterruptedly maintain the generation of the activation signal, thereby ensuring that the battery management system 500 is stably activated, and avoiding the problems of unstable system operation or reactivation due to signal interruption.

[0074] In an exemplary embodiment, as shown in FIG. 4, the step detection unit 24 includes a switching circuit 242, a first charge-discharge circuit 244, and a second charge-discharge circuit 246. An input end of the switching circuit 242 is connected with the second output end of the voltage detection unit 22, a first output end of the switching circuit 242 is connected with an input end of the first charge-discharge circuit 244, a second output end of the switching circuit 242 is connected with an input end of the second charge-discharge circuit 246, a discharge controlled end of the first charge-discharge circuit 244 is connected with the second output end of the voltage detection unit 22, and an output end of the second charge-discharge circuit 246 is connected with the second input end of the signal output module 4, or the output end of the second charge-discharge circuit 246 is respectively connected with the second input end of the signal output module 4 and the second input end of the voltage detection unit 22. The switching circuit 242 is turned on when a voltage difference between the input end and the first output end of the switching circuit 242 satisfies a turn-on condition, and charges the first charge-discharge circuit 244 and the second charge-discharge circuit 246 to make the second charge-discharge circuit 246 output the second sub-driving signal; the switching circuit 242 is turned off when the voltage difference does not satisfy the turn-on condition, so as to discharge the first charge-discharge circuit 244 and the second charge-discharge circuit 246.

[0075] The turn-on condition can be that the voltage difference between the input end and the first output end of the switching circuit 242 is greater than a preset voltage threshold, and the specific preset voltage threshold can be set according to the actual circuit design, which is not limited here.

[0076] Exemplarily, when the output voltage of the photovoltaic power supply 300 is first connected, if the output voltage of the photovoltaic power supply 300 is greater than the target voltage threshold, the voltage detection unit 22 outputs the intermediate voltage signal to the input end of the switch circuit 242. At this time, the voltage provided by the intermediate voltage signal is relatively large, and the voltage provided to the output end of the switch circuit 242 is also relatively large. At the same time, the first charge-discharge circuit 244 has not been charged before, so the voltage provided by the first charge-discharge circuit 244 to the first output end of the switch circuit 242 is relatively small (almost zero). Therefore, when the output voltage of the photovoltaic power supply 300 is first connected, as long as the output voltage of the photovoltaic power supply 300 is greater than the target voltage threshold, the voltage difference between the input end and the first output end of the switch circuit 242 satisfies the conduction condition, so that the switch circuit 242 is turned on, and the intermediate voltage signal charges the first charge-discharge circuit 244 and the second charge-discharge circuit 246 through the switch circuit 242. When the second charge-discharge circuit 246 reaches a certain charging time and the voltage reaches a certain value, it starts to output the second sub-driving signal to the signal output module 4. In the case where the output end of the second charge-discharge circuit 246 is connected to the second input end of the signal output module 4 and the second input end of the voltage detection unit 22, respectively, the second sub-driving signal output by the second charge-discharge circuit 246 can also be output to the voltage detection unit 22, so that the voltage detection unit 22 continuously outputs the first sub-driving signal. When the first charge-discharge circuit 244 is fully charged, the voltage provided by the first charge-discharge circuit 244 to the first output end of the switch circuit 242 is equal to the voltage of the input end of the switch circuit 242 (i.e. the voltage of the input end of the switch circuit 242 and the voltage of the first output end of the switch circuit 242 are both the voltage provided by the intermediate voltage signal), so the switch circuit 242 is turned off because the voltage difference between the input end and the first output end of the switch circuit 242 cannot satisfy the conduction condition, and the second charge-discharge circuit 246 starts to discharge, and the voltage gradually decreases until the second sub-driving signal is stopped. Since the discharge control end of the first charge-discharge circuit 244 is connected to the second output end of the voltage detection unit 22, the voltage of the discharge end of the first charge-discharge circuit 244 is equal to the voltage provided by the intermediate voltage signal at this time, so the first charge-discharge circuit 244 cannot discharge at this time, and still maintains the voltage provided by the intermediate voltage signal, keeping the switch circuit 242 in the off state, to avoid the premature discharge of the first charge-discharge circuit 244, which causes the switch tube to be frequently turned on, and the second charge-discharge circuit 246 to frequently output the second sub-driving signal to the signal output module 4.

[0077] When the output voltage of the photovoltaic power supply 300 at the next time (compared to the output voltage of the photovoltaic power supply 300 at the first time of being connected) is greater than the target voltage threshold and greater than the output voltage of the photovoltaic power supply 300 at the first time of being connected, the voltage detection unit 22 outputs the intermediate voltage signal to the input end of the switch circuit 242. As described above, since the voltage at the input end of the switch circuit 242 and the voltage at the first output end of the switch circuit 242 are both equal to the voltage provided by the intermediate voltage signal when the first charge-discharge circuit 244 is fully charged, in order to make the voltage difference between the input end and the first output end of the switch circuit 242 again satisfy the conduction condition, the intermediate voltage signal output at this time (the next time) must at least satisfy the intermediate voltage signal output at the first time of being connected. Since the output voltage of the photovoltaic power supply 300 at the next time is greater than the output voltage of the photovoltaic power supply 300 at the first time of being connected, i.e., the intermediate voltage signal output at the next time is also greater than the intermediate voltage signal output at the first time of being connected, the switch circuit 242 is again turned on, and the intermediate voltage signal charges the first charge-discharge circuit 244 and the second charge-discharge circuit 246 through the switch circuit 242. When the second charge-discharge circuit 246 has been charged for a certain time and the voltage reaches a certain value, the second sub-driving signal is output.

[0078] When the output voltage of the photovoltaic power supply 300 at the next time (compared to the output voltage of the photovoltaic power supply 300 at the first time of being connected) is greater than the target voltage threshold and less than the output voltage of the photovoltaic power supply 300 at the first time of being connected, the intermediate voltage signal output at the next time is also less than the intermediate voltage signal output at the first time of being connected, and the voltage difference between the input end and the first output end of the switch circuit 242 does not satisfy the conduction condition, the switch circuit 242 is turned off, and the second charge-discharge circuit 246 starts to discharge until the second sub-driving signal is stopped. At the same time, since the intermediate voltage signal output at the next time is less than the intermediate voltage signal output at the first time of being connected, i.e., the voltage at the controlled end of the first charge-discharge circuit 244 discharged at the next time is less than the voltage when the first charge-discharge circuit 244 is fully charged, the first charge-discharge circuit 244 starts to discharge at this time until the voltage of the first charge-discharge circuit 244 drops to be equal to the voltage at the controlled end of the first charge-discharge circuit 244 discharged, so that when the output voltage of the photovoltaic power supply 300 at the next time is greater than the output voltage of the photovoltaic power supply 300 at the next time, the switch circuit 242 can be turned on again to charge the second charge-discharge circuit 246 to output the second sub-driving signal.

[0079] In the embodiment, through the design of the switch circuit and the two charge-discharge circuits (the first charge-discharge circuit and the second charge-discharge circuit), the variation trend of the output voltage of the photovoltaic power supply can be more accurately judged, and it is determined whether to activate the battery management system. Not only can the battery management system be activated in the case that the output voltage of the photovoltaic power supply continuously rises, thereby avoiding the problem of false activation caused by transient voltage fluctuation, but also through the controlled discharge mechanism of the first charge-discharge circuit, the frequent turn-on and turn-off of the switch circuit is effectively prevented, the second sub-driving signal of the second charge-discharge circuit is prevented from being frequently output, and the circuit is protected from unnecessary stress damage, thereby prolonging the service life of the equipment.

[0080] In one of the example embodiments, as shown in FIG. 5, the switch circuit 242 includes a switch tube Q1; the emitter of the switch tube Q1 is connected with the second output end of the voltage detection unit 22, the collector of the switch tube is connected with the second input end of the signal output module 4, and the base of the switch tube Q1 is connected with the input end of the first charge-discharge circuit 244; and / or, the first charge-discharge circuit 244 includes a resistor R2, a capacitor C1, a diode D1 and a resistor R1; the resistor R2, the anode of the diode D1, the cathode of the diode D1 and the resistor R1 are connected in series between the first output end of the switch circuit 242 and the ground end, the cathode of the diode D1 is also connected with the second output end of the voltage detection unit 22, and the capacitor C1 is connected with the resistor R1 in parallel; and / or, the second charge-discharge circuit 246 includes a capacitor C2 and a resistor R3; the capacitor C2 and the resistor R3 are connected in parallel between the second output end of the switch circuit 242 and the ground end.

[0081] The switch tube Q1 can be a PNP triode.

[0082] Exemplarily, when the output voltage of the photovoltaic power supply 300 is first connected, if the output voltage of the photovoltaic power supply 300 is greater than the target voltage threshold, the voltage detection unit 22 outputs the intermediate voltage signal to the emitter of the switching tube Q1. At this time, the voltage provided by the intermediate voltage signal is relatively large, and the voltage provided to the emitter of the switching tube Q1 is also relatively large. At the same time, since the capacitor C1 has not been charged before, the voltage provided by the capacitor C1 to the base of the switching tube Q1 is relatively small (almost zero). Therefore, when the output voltage of the photovoltaic power supply 300 is first connected, as long as the output voltage of the photovoltaic power supply 300 is greater than the target voltage threshold, the voltage difference between the emitter and the base of the switching tube Q1 satisfies the conduction condition, so that the switching tube Q1 is turned on, and the intermediate voltage signal charges the capacitor C1 and the capacitor C2 through the switching tube Q1. When the capacitor C2 reaches a certain charging time and the voltage reaches a certain value, the second sub-driving signal starts to be output to the signal output module 4. In the case where the capacitor C2 is connected to the second input end of the signal output module 4 and the second input end of the voltage detection unit 22, respectively, the second sub-driving signal output by the capacitor C2 can also be output to the voltage detection unit 22, so that the voltage detection unit 22 continuously outputs the first sub-driving signal. When the capacitor C1 is fully charged, since the voltage provided by the capacitor C1 to the base of the switching tube Q1 is equal to the voltage of the emitter of the switching tube Q1 (i.e., the voltage of the emitter of the switching tube Q1 and the voltage of the base of the switching tube Q1 are both the voltage provided by the intermediate voltage signal), the switching tube Q1 is turned off because the voltage difference between the emitter and the base of the switching tube Q1 cannot satisfy the conduction condition. The capacitor C2 starts to discharge through the resistor R3, and the voltage gradually decreases until the second sub-driving signal is stopped. Since the cathode of the diode D1 is also connected to the second output end of the voltage detection unit 22, the voltage of the cathode of the diode D1 is equal to the voltage provided by the intermediate voltage signal at this time. Therefore, at this time, the capacitor C1 cannot be discharged and still maintains the voltage provided by the intermediate voltage signal, keeping the switching tube Q1 in the off state to avoid the premature discharge of the capacitor C1 causing the switching tube Q1 to be frequently turned on, and the capacitor C2 to frequently output the second sub-driving signal to the signal output module 4.

[0083] When the output voltage of the photovoltaic power supply 300 at the next time (compared to the next time of the output voltage of the photovoltaic power supply 300 when it is first connected) is greater than the target voltage threshold and greater than the output voltage of the photovoltaic power supply 300 when it is first connected, the voltage detection unit 22 outputs the intermediate voltage signal to the emitter of the switching tube Q1. As described above, since the voltage at the emitter of the switching tube Q1 and the voltage at the base of the switching tube Q1 are both equal to the voltage provided by the intermediate voltage signal when the charging of the capacitor C1 is completed, in order to make the voltage difference between the emitter and the base of the switching tube Q1 again meet the conduction condition, the intermediate voltage signal output at this time (the next time) must at least meet the intermediate voltage signal output when the output voltage of the photovoltaic power supply 300 is first connected. Since the output voltage of the photovoltaic power supply 300 at the next time is greater than the output voltage of the photovoltaic power supply 300 when it is first connected, that is, the intermediate voltage signal output at the next time is also greater than the intermediate voltage signal output when it is first connected, the switching tube Q1 is again turned on, and the intermediate voltage signal charges the capacitors C1 and C2 through the switching tube Q1. When the capacitor C2 is charged for a certain time and the voltage reaches a certain value, the second sub-driving signal is output.

[0084] When the output voltage of the photovoltaic power supply 300 at the next time (compared to the next time of the output voltage of the photovoltaic power supply 300 when it is first connected) is greater than the target voltage threshold and less than the output voltage of the photovoltaic power supply 300 when it is first connected, then the intermediate voltage signal output at the next time is also less than the intermediate voltage signal output when it is first connected, and the voltage difference between the emitter and the base of the switching tube Q1 does not meet the conduction condition, the switching tube Q1 is cut off, and the capacitor C2 starts to discharge through the resistor R3 until the second sub-driving signal is stopped. At the same time, since the intermediate voltage signal output at the next time is less than the intermediate voltage signal output when it is first connected, that is, the voltage at the cathode of the diode D1 at the next time is less than the voltage at which the capacitor C1 is fully charged when the photovoltaic power supply 300 is first connected, at this time the capacitor C1 starts to discharge through the resistor R1 until the voltage of the capacitor C1 drops to equal the voltage at the cathode of the diode D1, so that the switching tube Q1 can be turned on again to charge the capacitor C2 to output the second sub-driving signal when the output voltage of the photovoltaic power supply 300 at the next time is greater than the output voltage of the photovoltaic power supply 300 at the next time.

[0085] In this embodiment, by controlling the charging process of the capacitors C1 and C2 through the switching tube Q1, the second sub-driving signal can be stably output when the photovoltaic power supply voltage is stably increasing, so that the battery management system can be continuously activated. At the same time, by limiting the discharge condition of the capacitor C1, the frequent conduction and cut-off of the switching tube Q1 is avoided, the risk of misoperation caused by voltage fluctuation is reduced, the stability and reliability of the system are enhanced, the efficient operation of the photovoltaic system when the battery management system is activated is ensured, and the additional energy consumption and potential hardware damage risk caused by frequent activation are reduced.

[0086] In one of the example embodiments, as shown in FIG. 6, the voltage detection unit 22 includes a Zener diode ZD1, a switch Q4 and a switch Q5. The cathode of the Zener diode ZD1 is connected to the photovoltaic power supply 300, the anode of the Zener diode ZD1 is connected to the collector of the switch Q4 and the base of the switch Q5, the emitter of the switch Q4 is connected to the output of the step detection unit 24, the base of the switch Q4 is connected to the collector of the switch Q5, and the emitter of the switch Q5 is grounded.

[0087] In this embodiment, the switch Q4 can be a PNP triode, and the switch Q5 can be an NPN triode. In order to meet the requirements of circuit design, the voltage detection unit 22 further includes a resistor R7 and a resistor R6, and the specific connection relationship can be referred to FIG. 6, which will not be described here. The Zener diode ZD1 and the resistor R7 are used to set a target voltage threshold, below which the battery management system 500 cannot be activated. The resistor R6 is a current limiting resistor, which limits the current of the output voltage of the photovoltaic power supply 300 flowing through the base of the switch Q4 and the switch Q5.

[0088] For example, when the output voltage of the photovoltaic power supply 300 (i.e. the PV_IN voltage) is greater than the reverse breakdown voltage of the Zener diode ZD1, the Zener diode ZD1 is turned on, the current flows through the resistor R7 and the base of the switch Q5, the switch Q5 is turned on, and the first sub-driving signal (i.e. the WAKE_UP0 signal) is output. In the case where the switch Q4 is connected to the output of the step detection unit 24 through the resistor R6, since the switch Q5 and the switch Q4 are in a thyristor structure, under the action of the second sub-driving signal (i.e. the PV_IN0 signal) output by the step detection unit 24, the switch Q4 is turned on, the base of the switch Q5 is raised by the PV_IN0 voltage, and the switch Q5 is reliably turned on, i.e. the first sub-driving signal (the WAKE_UP0 signal is low and effective) is continuously output.

[0089] In this embodiment, when the output voltage of the photovoltaic power supply exceeds the target voltage threshold, the Zener diode ZD1 is turned on, triggering the switch Q5 to output the first sub-driving signal (the WAKE_UP0 signal), and under the action of the second sub-driving signal (the PV_IN0 signal) output by the step detection unit, the switch Q4 is turned on, further consolidating the output of the first sub-driving signal, so as to ensure that the battery management system is activated only when the photovoltaic power supply provides sufficient and stable voltage, reducing unnecessary activation attempts.

[0090] In one of the example embodiments, as shown in FIG. 7, the signal output module 4 comprises a switch tube Q6, a resistor R9, a switch tube Q3, a resistor R5, a capacitor C4, a switch tube Q2, a resistor R4 and a capacitor C3. The emitter of the switch tube Q6 is connected to a power supply 700, the base of the switch tube Q6 is connected to the first output terminal of the voltage detection unit 22, and the collector of the switch tube Q6 is connected to the emitter of the switch tube Q3; the resistor R9 is connected between the emitter and the base of the switch tube Q6; the collector of the switch tube Q3 is connected to the battery management system 500, the resistor R5 and the capacitor C4 are connected in series between the base of the switch tube Q3 and the ground; the resistor R4 and the capacitor C3 are connected in series between the output terminal of the step detection unit 24 and the ground; the collector of the switch tube Q2 is connected between the resistor R5 and the capacitor C4, the emitter of the switch tube Q2 is grounded, and the base of the switch tube Q2 is connected between the resistor R4 and the capacitor C3.

[0091] In the example embodiments, the switch tube Q6 and the switch tube Q3 can be PNP triodes, and the switch tube Q2 can be an NPN triode. In order to meet the requirements of circuit design, the voltage detection unit 22 further comprises a resistor R8 and a resistor R10, and the specific connection relationship can be referred to FIG. 7, which will not be described herein.

[0092] In the example embodiments, when the output voltage of the photovoltaic power supply 300 at the current time is greater than the target voltage threshold and greater than the output voltage at the last time, the voltage detection unit 22 outputs the valid first sub-driving signal to the signal output module 4, and the step detection unit 24 outputs the second sub-driving signal to the signal output module 4 and the voltage detection unit 22, and the voltage detection unit 22 continuously outputs the valid first sub-driving signal upon receiving the second sub-driving signal. Upon receiving the first sub-driving signal output by the voltage detection unit 22, the signal output module 4 turns on the switch tube Q6 and the switch tube Q3; upon receiving the second sub-driving signal, the signal output module 4 turns on the switch tube Q2, and the second sub-driving signal flows through the resistor R4, the capacitor C3 and the base of the switch tube Q2. The current of the power supply 700 flows through the current-limiting resistor R10, the emitter and the collector of the switch tube Q6, the emitter and the base of the switch tube Q3, the resistor R5, the collector and the emitter of the switch tube Q2 to the ground, and the valid output activation signal (i.e., the WAKE_UP is high) is output to the battery management system 500.

[0093] Upon stopping outputting the second sub-driving signal by the step detection unit 24, the switch tube Q2 is turned off, and the current of the power supply 700 flows through the current-limiting resistor R10, the emitter and the collector of the switch tube Q6, the emitter and the base of the switch tube Q3, the resistor R5 to charge the capacitor C4. Upon the capacitor C4 being fully charged, the switch tube Q3 is turned off, and the activation signal (i.e., the WAKE_UP is low) is stopped to be output to the battery management system 500.

[0094] Wherein, in the case of voltage detection unit 22 stops outputting the first sub driving signal (such as the output voltage of photovoltaic power supply 300 at the current moment is less than the target voltage threshold), the base voltage of switch tube Q6 in signal output module 4 is pulled up to the voltage of power supply 700 by resistor R9, switch tube Q6 is cut off, at the same time, switch tube Q3 is also cut off, at this time, the active signal (i.e. WAKE_UP is low) to battery management system 500 is also stopped outputting.

[0095] In this embodiment, through different working states of switch tube Q6, switch tube Q3 and switch tube Q2, combined with the filter and delay circuit composed of resistors and capacitors, when the system detects the appropriate voltage condition, the effective active signal path is formed, thereby avoiding the false activation caused by voltage fluctuation, and enhancing the stability and reliability of the system.

[0096] In one specific embodiment, in order to describe the scheme of the present application in more detail, the following is described in combination with FIG. 8. The detailed circuit structure diagram is shown in FIG. 8, which will not be described here again, and the implementation principle is as follows:

[0097] When the output voltage PV_IN of photovoltaic power supply 300 is greater than the target voltage threshold (i.e. the reverse breakdown voltage of voltage stabilizing diode ZD1), voltage stabilizing diode ZD1 is broken down, PV_IN voltage charges capacitor C1 through voltage stabilizing diode ZD1, the base of PNP transistor Q1 and resistor R2, and the conduction time of PNP transistor Q1 is set by setting the charging time constant of resistor R2 and capacitor C1. In the case of conduction of PNP transistor Q1, PV_IN voltage charges capacitor C2 through voltage stabilizing diode ZD1, the emitter and collector of PNP transistor Q1, and the voltage value between capacitor C2 is equal to the PV_IN voltage value minus the reverse breakdown voltage value of voltage stabilizing diode ZD1. When energy storage capacitor C2 is powered and the voltage reaches the set value, current flows through resistor R4 and the base of NPN transistor Q2, and NPN transistor Q2 is turned on. After the output voltage PV_IN of photovoltaic power supply 300 breaks down voltage stabilizing diode ZD1, current also flows through resistor R7 and the base of NPN transistor Q5, and NPN transistor Q5 is turned on; NPN transistor Q5 and PNP transistor Q4 are thyristor structures, and then PNP transistor Q4 is turned on, under the action of PV_IN0 voltage of capacitor C2, the base voltage of NPN transistor Q5 is filled high, and the reliable conduction of NPN transistor Q5 is ensured, that is, the effective WAKE_UP0 signal (i.e. the WAKE_UP0 signal is low) is outputted.

[0098] When the signal output module 4 receives the valid WAKE_UP0 signal, the PNP transistor Q6 is turned on, and the current provided by the supply voltage BAT of the power supply 700 flows through the current-limiting resistor R10, the emitter and collector of the PNP transistor Q6, the emitter and base of the PNP transistor Q3, the resistor R5, and the collector and emitter of the NPN transistor Q2 to the ground, thereby outputting a valid activation signal WAKE_UP (i.e., the WAKE_UP signal is at a high level).

[0099] When the input PV_IN voltage is stable (the capacitor C1 is fully charged) or the PV_IN voltage decreases, the PNP transistor Q1 is turned off, the resistor R3 starts to discharge the electric quantity on the capacitor C2, the voltage of the capacitor C2 is discharged to below the minimum conduction voltage of the NPN transistor Q2, and the NPN transistor Q2 is turned off. The current provided by the supply voltage BAT of the power supply 700 flows through the current-limiting resistor R10, the emitter and collector of the PNP transistor Q6, the emitter and base of the PNP transistor Q3, the resistor R5, and charges the capacitor C4. After the capacitor C4 is fully charged, the PNP transistor Q3 is turned off, and the signal output module 4 outputs an invalid activation signal WAKE_UP (i.e., the WAKE_UP signal is at a low level).

[0100] When the output voltage PV_IN of the photovoltaic power supply 300 is less than the target voltage threshold, the WAKE_UP0 signal is a high-level signal, i.e., an invalid WAKE_UP0 signal. At this time, the base voltage of the PNP transistor Q6 is pulled up to the supply voltage BAT of the power supply 700 by the resistor R9, the PNP transistor Q6 is turned off, the PNP transistor Q3 is also turned off, and the signal output module 4 outputs an invalid activation signal WAKE_UP (i.e., the WAKE_UP signal is at a low level).

[0101] The following discharge circuit is formed by the diode D1 and the resistor R1. When the PV_IN voltage decreases, the voltage of the capacitor C1 is discharged through the diode D1 and the resistor R1, so that when the PV_IN voltage rises next time, the PV_IN voltage is charged to the capacitor C1 through the zener diode ZD1, the emitter and base of the PNP transistor Q1, and the resistor R2 (at this time, the PV_IN voltage value minus the reverse breakdown voltage value of the zener diode ZD1 is greater than the voltage value of the capacitor C1), the PNP transistor Q1 is turned on, and the PV_IN voltage is charged to the capacitor C2 through the zener diode ZD1 and the PNP transistor Q1. That is, through the following discharge circuit, the capacitor C2 is powered every time the PV_IN voltage rises, thereby turning on the NPN transistor Q2.

[0102] In the embodiment, the input PV_IN voltage is rising, the effective activation pulse signal is outputted reliably, the battery management system is activated, and the activation signal is outputted frequently when the PV_IN voltage is dithering. After the input PV_IN voltage is stable, the activation signal disappears, and the battery management system can be shut down normally.

[0103] In one of the example embodiments, the application also provides a photovoltaic charging system, which comprises a photovoltaic power supply, a battery management system, and a photovoltaic charging activation circuit as in the above embodiment, wherein the photovoltaic charging activation circuit is connected with the photovoltaic power supply and the battery management system respectively.

[0104] In the embodiment, an integrated photovoltaic charging system is provided, the photovoltaic charging activation circuit is introduced, the battery management system is activated when the photovoltaic power supply meets the specific voltage condition, the misoperation caused by the unstable voltage is avoided effectively, and the reliability and energy efficiency of the system are improved.

[0105] The technical features of the above embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0106] The above embodiments only express several implementation manners of the application, the description is more specific and detailed, but it should not be understood as the limitation of the patent application scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which all belong to the protection scope of the application. Therefore, the patent protection scope of the application should be subject to the appended claims.

Claims

1. A photovoltaic charge activation circuit, characterized by, include: Activate the control module and signal output module; The activation control module and the signal output module are connected in series between the photovoltaic power supply and the battery management system. The signal output module is also connected to the power supply. The activation control module is used to output a drive signal to the signal output module when the output voltage of the photovoltaic power supply at the current moment is greater than the target voltage threshold and greater than the output voltage at the previous moment, so that the signal output module outputs an activation signal to the battery management system based on the power supply voltage of the power supply. The target voltage threshold is used to characterize the minimum voltage required to activate the battery management system.

2. The photovoltaic charge activation circuit of claim 1, wherein, The activation control module is also used to stop outputting the drive signal when the output voltage at the current moment is less than the target voltage threshold and / or less than or equal to the output voltage at the previous moment.

3. The photovoltaic charge activation circuit of claim 1, wherein, The driving signal includes a first sub-driving signal and a second sub-driving signal, and the activation control module includes a voltage detection unit and a step detection unit. The first input terminal of the voltage detection unit is used to connect to the photovoltaic power source, and the first output terminal of the voltage detection unit is connected to the first input terminal of the signal output module. The step detection unit is connected in series between the second output terminal of the voltage detection unit and the second input terminal of the signal output module; The voltage detection unit is used to output an intermediate voltage signal to the step detection unit and output the first sub-drive signal to the signal output module when the output voltage of the photovoltaic power source at the current moment is greater than the target voltage threshold; the intermediate voltage signal is positively correlated with the output voltage. The step detection unit is used to output the second sub-drive signal to the signal output module when the intermediate voltage signal at the current moment is greater than the intermediate voltage signal at the previous moment, so that the signal output module outputs the activation signal when it receives the first sub-drive signal and the second sub-drive signal.

4. The photovoltaic charge activation circuit of claim 3, wherein, The voltage detection unit is also used to stop outputting the intermediate voltage signal and the first sub-drive signal when the output voltage at the current moment is less than the target voltage threshold. And / or, The step detection unit is further configured to stop outputting the second sub-drive signal when the intermediate voltage signal at the current moment is less than or equal to the intermediate voltage signal at the previous moment.

5. The photovoltaic charge activation circuit of claim 3, wherein, The output terminal of the step detection unit is also connected to the second input terminal of the voltage detection unit; The voltage detection unit is also used to continuously output the first sub-drive signal when the second sub-drive signal is received.

6. The photovoltaic charge activation circuit of any of claims 3-5, wherein, The step detection unit includes: a switching circuit, a first charging / discharging circuit, and a second charging / discharging circuit. The input end of the switch circuit is connected with the second output end of the voltage detection unit, the first output end of the switch circuit is connected with the input end of the first charge-discharge circuit, the second output end of the switch circuit is connected with the input end of the second charge-discharge circuit, and the bleed controlled end of the first charge-discharge circuit is connected with the second output end of the voltage detection unit; the output end of the second charge-discharge circuit is connected with the second input end of the signal output module, or the output end of the second charge-discharge circuit is respectively connected with the second input end of the signal output module and the second input end of the voltage detection unit; The switch circuit is turned on when the voltage difference between the input end and the first output end of the switch circuit meets the turn-on condition, and the first charge-discharge circuit and the second charge-discharge circuit are charged, so that the second charge-discharge circuit outputs the second sub-driving signal; The switch circuit is turned off when the voltage difference does not meet the turn-on condition, so that the first charge-discharge circuit and the second charge-discharge circuit are discharged.

7. The photovoltaic charge activation circuit of claim 6, wherein, The switch circuit comprises a switch tube Q1; the emitter of the switch tube Q1 is connected with the second output end of the voltage detection unit, the collector of the switch tube is connected with the second input end of the signal output module, and the base of the switch tube Q1 is connected with the input end of the first charge-discharge circuit; and / or, The first charge-discharge circuit comprises a resistor R2, a capacitor C1, a diode D1 and a resistor R1; the resistor R2, the anode of the diode D1, the cathode of the diode D1 and the resistor R1 are connected in series between the first output end of the switch circuit and the ground end, and the capacitor C1 is connected in parallel with the resistor R1; and / or, The second charge-discharge circuit comprises a capacitor C2 and a resistor R3; the capacitor C2 and the resistor R3 are connected in parallel between the second output end of the switch circuit and the ground end.

8. The photovoltaic charge activation circuit of claim 3, wherein, The voltage detection unit comprises a voltage stabilizing diode ZD1, a switch tube Q4 and a switch tube Q5; The cathode of the voltage stabilizing diode ZD1 is used for connecting the photovoltaic power supply, the anode of the voltage stabilizing diode ZD1 is respectively connected with the collector of the switch tube Q4 and the base of the switch tube Q5, the emitter of the switch tube Q4 is connected with the output end of the step detection unit, the base of the switch tube Q4 is connected with the collector of the switch tube Q5, and the emitter of the switch tube Q5 is grounded.

9. The photovoltaic charge activation circuit of claim 3, wherein, The signal output module comprises a switch tube Q6, a resistor R9, a switch tube Q3, a resistor R5, a capacitor C4, a switch tube Q2, a resistor R4 and a capacitor C3; The emitter of the switch tube Q6 is used for connecting the power supply, the base of the switch tube Q6 is connected with the first output end of the voltage detection unit, and the collector of the switch tube Q6 is connected with the emitter of the switch tube Q3; The resistor R9 is connected between the emitter and the base of the switch tube Q6; The collector of the switch tube Q3 is used for connecting the battery management system, and the resistor R5 and the capacitor C4 are connected in series between the base of the switch tube Q3 and the ground end; The resistor R4 and the capacitor C3 are connected in series between the output end of the step detection unit and the ground; The collector of the switch tube Q2 is connected between the resistor R5 and the capacitor C4, the emitter of the switch tube Q2 is grounded, and the base of the switch tube Q2 is connected between the resistor R4 and the capacitor C3.

10. A photovoltaic charging system, characterized by, The photovoltaic charging system comprises: a photovoltaic power supply; a battery management system; and the photovoltaic charging activation circuit according to any one of claims 1-9, wherein the photovoltaic charging activation circuit is connected with the photovoltaic power supply and the battery management system respectively.

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