Current limiting control circuit based on constant current source and energy storage device

Abstract

The application relates to a constant-current-source-based current-limiting control circuit and an energy storage device, which comprises an input source judgment module, a constant-current driving module and a current-limiting mode control module. The input source judgment module is used for generating a first judgment signal based on the input voltage of a dual-circuit power supply circuit and generating a second judgment signal based on the input current when the sampling end of a target power supply circuit is powered by a constant-current source, so as to judge whether the dual-circuit power supply circuit is connected to the same input source. The constant-current driving module is connected with the constant-current source and the input source judgment module, and is used for controlling the constant-current source to power the sampling end of the target power supply circuit within a target time when it is impossible to determine whether the dual-circuit power supply circuit is connected to the same input source based on the first judgment signal. The current-limiting mode control module is used for adopting a first current-limiting mode when the dual-circuit power supply circuit is connected to different input sources and adopting a second current-limiting mode when the dual-circuit power supply circuit is connected to the same input source. The electric parameter value corresponding to the first current-limiting mode is greater than the electric parameter value corresponding to the second current-limiting mode. The circuit can protect the circuit safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a constant current source-based current limiting control circuit and energy storage equipment. BACKGROUND

[0002] As one of new energy products, the PV charging function is essential for energy storage power supply. In order to realize PV high-power charging, a double-channel PV power supply circuit is generally designed for an energy storage power supply with a large battery capacity. If the single-channel PV input voltage range is 12-60Vdc and the maximum input current limit is 20A, the single-channel PV maximum charging power is 1200W, and the maximum power of two-channel PV simultaneous charging is 2400W.

[0003] When the energy storage power supply has a double-channel PV power supply circuit, if the same input source is used to charge the double-channel PV circuit, the sampling resistors of the PV1 circuit and the PV2 circuit will be connected in parallel, so that the current sampling value is half of the actual current, resulting in that the actual input and output current of the PV circuit exceeds the rated current of the fuse, and the PV power supply circuit is damaged. SUMMARY

[0004] Therefore, it is necessary to provide a constant current source-based current limiting control circuit and energy storage equipment which can protect the circuit safety.

[0005] In a first aspect, the present application provides a constant current source-based current limiting control circuit, comprising:

[0006] An input source judgment module is configured to generate a first judgment signal based on the input voltage of a double-channel power supply circuit and a second judgment signal based on the input current when the sampling end of a target power supply circuit is supplied by a constant current source, and to judge whether the double-channel power supply circuit is connected to the same input source based on the first judgment signal and the second judgment signal; wherein the target power supply circuit is a power supply circuit connected to the constant current source in the double-channel power supply circuit;

[0007] A constant current drive module is connected to the constant current source and the input source judgment module, and is configured to supply the sampling end of the target power supply circuit with the constant current source for a target time when it is unable to determine whether the double-channel power supply circuit is connected to the same input source based on the first judgment signal;

[0008] A current limiting mode control module is configured to adopt a first current limiting mode when the double-channel power supply circuit is connected to different input sources, and to adopt a second current limiting mode when the double-channel power supply circuit is connected to the same input source, and the electric parameter value corresponding to the first current limiting mode is greater than the electric parameter value corresponding to the second current limiting mode.

[0009] In one embodiment, the input source judgment module is used to determine that the dual power supply circuits are connected to different input sources when the absolute value of the difference in the input voltages of the dual power supply circuits is greater than or equal to a voltage threshold; and to determine that the dual power supply circuits are connected to the same input source when the absolute value of the difference in the input voltages of the dual power supply circuits is less than the voltage threshold, and the input current of the sampling end of the target power supply circuit when it is powered by the constant current source is less than a first current threshold and greater than a second current threshold, and to determine that the dual power supply circuits are connected to different input sources when the input current of the sampling end of the target power supply circuit when it is powered by the constant current source is greater than the first current threshold and greater than the second current threshold.

[0010] In one embodiment, the input source determination module includes:

[0011] a voltage comparison unit, wherein two input terminals of the voltage comparison unit respectively receive input voltages of the dual power supply circuit, and are used to compare the input voltages of the dual power supply circuit to obtain a first judgment signal;

[0012] A current comparison unit, wherein the three input terminals of the current comparison unit respectively receive the input current, the first current threshold and the second current threshold of the target power supply circuit, and are used to obtain a second judgment signal based on the input current, the first current threshold and the second current threshold.

[0013] In one embodiment, the voltage comparison unit includes:

[0014] An operational amplifier unit, wherein two input terminals of the operational amplifier unit respectively receive input voltages of the dual power supply circuit;

[0015] an absolute value output unit, wherein an input terminal of the absolute value output unit is connected to an output terminal of the operational amplifier unit, and is used to obtain an absolute value of a difference between the input voltages of the dual power supply circuit obtained by the operational amplifier unit;

[0016] A comparison unit, one input end of the comparison unit is connected to the output end of the absolute value output unit, and the other input end of the comparison unit receives a voltage threshold. The comparison unit is used to obtain a first judgment signal based on the absolute value of the difference between the input voltages of the dual power supply circuit and the voltage threshold.

[0017] In one embodiment, the current comparison unit includes:

[0018] a first comparing subunit, wherein one input terminal of the first comparing subunit receives a first current threshold, and another input terminal of the first comparing subunit receives an input current of a target power supply circuit;

[0019] a second comparison subunit, an input terminal of the second comparison subunit receiving a second current threshold, and another input terminal of the second comparison subunit receiving an input current of the target power supply circuit;

[0020] a logic unit, an input terminal of the logic unit being connected with an output terminal of the first comparison subunit, and another input terminal of the logic unit being connected with an output terminal of the second comparison subunit, for generating a second judgment signal based on a comparison result of the first comparison subunit and a comparison result of the second comparison subunit.

[0021] In one of the embodiments, the constant current driving module comprises:

[0022] a control signal generating unit, an input terminal of the control signal generating unit being connected with a first output terminal of the input source judgment module;

[0023] a constant current switch unit, the constant current switch unit being connected in series with the constant current source and being connected in parallel between an input ground of the target power supply circuit and an input ground of the battery pack;

[0024] the control signal generating unit is configured to output a first control signal in a case where the first judgment signal cannot determine whether the dual power supply circuit is connected with the same input source, and the constant current switch unit is configured to control the constant current source to supply power to the sampling terminal of the target power supply circuit for a target time based on the first control signal; and output a second control signal in a case where the first judgment signal determines that the dual power supply circuit is connected with different input sources, and the constant current switch unit is configured to control the constant current source to be disconnected from the sampling terminal of the target power supply circuit based on the second control signal.

[0025] In one of the embodiments, the constant current driving module further comprises:

[0026] a current sampling time control unit, an input terminal of the current sampling time control unit being connected with the first output terminal of the input source judgment module, and an output terminal of the current sampling time control unit being connected with a control terminal of the control signal generating unit;

[0027] the current sampling time control unit is configured to control the control signal generating unit to output the second control signal after a delay of a target time in a case where the constant current switch unit controls the constant current source to supply power to the sampling terminal of the target power supply circuit, so that the constant current switch unit disconnects the connection between the constant current source and the sampling terminal of the target power supply circuit based on the second control signal, wherein the target time is less than a time length from when an input voltage exists in the target power supply circuit to when the target power supply circuit starts to work.

[0028] In one of the embodiments, the current sampling time control unit comprises:

[0029] a first capacitor, a first end of the first capacitor is connected with a first output end of the input source judging module, and a second end of the first capacitor is grounded;

[0030] a diode, a cathode of the diode is connected with the first end of the first capacitor, and an anode of the diode is connected with a control end of the control signal generating unit;

[0031] a second capacitor, a first end of the second capacitor is connected with the control end of the control signal generating unit, and a second end of the second capacitor is grounded;

[0032] the charging time of the second capacitor is greater than the charging time of the first capacitor, and the charging time of the second capacitor is the target time.

[0033] In one of the embodiments, the current-limiting mode control module comprises:

[0034] a first judging unit, a first input end of the first judging unit is connected with a first output end of the input source judging module, and a second input end of the first judging unit is connected with a second output end of the input source judging module;

[0035] an interlocking unit, an input end of the interlocking unit is connected with an output end of the first judging unit;

[0036] a selection unit, an input end of the selection unit is connected with an output end of the interlocking unit;

[0037] the first judging unit is configured to output a fourth judging signal in the case that the first judging signal cannot determine whether the dual-path power supply circuit is connected with the same input source and the second judging signal indicates that the dual-path power supply circuit is connected with the same input source, and the interlocking unit is configured to output a second current-limiting mode selection signal to the selection unit based on the fourth judging signal, so that the selection unit selects a second current-limiting mode.

[0038] In a second aspect, the application further provides an energy storage device comprising the current-limiting control circuit based on the constant current source.

[0039] The constant current source-based current limiting control circuit and the energy storage device, an input source judgment module, is configured to generate a first judgment signal based on an input voltage of the dual-path power supply circuit and a second judgment signal based on an input current when a sampling terminal of a target power supply circuit is supplied with power by the constant current source, and judge whether the dual-path power supply circuit is connected to the same input source based on the first judgment signal and the second judgment signal; wherein the target power supply circuit is a power supply circuit connected to the constant current source in the dual-path power supply circuit, and a constant current driving module of the target power supply circuit is connected to the constant current source and the input source judgment module, respectively, and is configured to supply the sampling terminal of the target power supply circuit with power by the constant current source for a target time in a case where the first judgment signal cannot determine whether the dual-path power supply circuit is connected to the same input source; a current limiting mode control module, which is further configured to adopt a first current limiting mode in a case where the dual-path power supply circuit is connected to different input sources, and adopt a second current limiting mode in a case where the dual-path power supply circuit is connected to the same input source, and an electric parameter value corresponding to the first current limiting mode is greater than an electric parameter value corresponding to the second current limiting mode, so that the input source of the dual-path power supply circuit is used to adjust the current limiting mode in time, and the maximum input current of the dual-path power supply circuit is less than the electric parameter value corresponding to the current limiting mode in any working condition, thereby ensuring the safety of the circuit. BRIEF DESCRIPTION OF DRAWINGS

[0040] 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. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0041] Figure 1 A schematic diagram of a dual-path power supply circuit in an embodiment;

[0042] Figure 2 A module diagram of a constant current source-based current limiting control circuit in an embodiment;

[0043] Figure 3 A circuit diagram of a constant current source-based current limiting control circuit in an embodiment.

[0044] Explanation of reference signs:

[0045] 100 input source judging module, 200 current limiting mode control module, 500 constant current driving module, 110 voltage comparison unit, 120 current comparison unit, 111 operational amplifier unit, 112 absolute value output unit, 113 comparison unit, 121 first comparison subunit, 122 second comparison subunit, 123 logic unit, 510 control signal generating unit, 520 constant current switch unit, 530 current sampling time control unit, 210 first judging unit, 220 interlocking unit, 230 selection unit. DETAILED DESCRIPTION

[0046] For the purpose of clarity, the present application will be described in greater detail below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0047] 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 of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0048] It can be understood that the terms "first", "second", and the like used herein can be 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.

[0049] 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.

[0050] It can be understood that "at least one" means one or more, and "a plurality of" means two or more. "At least part of an element" means part or all of the element.

[0051] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0052] Figure 1 FIG. 1 is a schematic diagram of a dual-path power supply circuit in one embodiment, Figure 1 As shown, in this embodiment, the output terminals of the dual power supply circuit are connected in parallel, both connected to the positive terminal BAT+ and the negative terminal GND_BAT of the battery pack. Assume that the battery pack voltage range is 45-57V; the resistance values ​​of the current sampling resistors R1 and R2 in the dual power supply circuit are 5mΩ. After sampling, the current is amplified by 20 times through the operational amplifier. That is, when the current flows through 20A, the sampled current value after the operational amplifier is amplified is 2V (20A * 5mΩ * 20); the rated current of fuses F1, F2, F3, and F4 is 30A; and the conversion efficiency of the dual power supply circuit is 95%.

[0053] When a dual-power supply circuit uses two input sources (DC source, PV solar panel, etc.) to charge the first and second power supply circuits, PV1 and PV2, respectively, if both input voltages are 60V and currents are 20A, the charging power for both PV1 and PV2 is 1200W. With a 95% conversion efficiency, the power entering the battery pack is 1140W. If the battery pack voltage is 45V, the current entering the battery pack is 25.33A (1140W / 45V). The rated currents of fuses F1, F2, F3, and F4 are all greater than the actual application current, meeting design requirements. The sampling values ​​of current sampling resistors R1 and R2 are both 2V.

[0054] When the dual-channel power supply circuit is charged by the same input source, the input terminals of the first power supply circuit PV1 and the second power supply circuit PV2 are in parallel, and the current sampling resistors R1 and R2 are also in parallel, so that the current sampling resistor value of the first power supply circuit PV1 and the second power supply circuit PV2 becomes 2.5 mΩ. If the input voltage is 60 V and the input current is 20 A, the sampling values of the current sampling resistors R1 and R2 are both 1 V (20 A*2.5 mΩ*20), and the sampled single-channel charging power is only 600 W, while the actual charging power is 1200 W. When the first power supply circuit PV1 and the second power supply circuit PV2 identify that the current sampling value is far from the parameter value 2 V corresponding to the first current limiting mode, the input current will continue to be released to 2 V, so that the input current reaches 40 A, and the sampled single-channel charging power is 1200 W, while the actual charging power is 2400 W. If the battery pack voltage is 45 V, the current entering the battery pack is 53.33 A (2400 W / 45 V). At this time, both the input current and the output current (the current entering the battery pack) far exceed the rated current of the fuses F1, F2, F3 and F4, thereby causing the fuses to be blown and the first power supply circuit PV1 and the second power supply circuit PV2 to be damaged.

[0055] In summary, when the energy storage power supply has a dual-channel power supply circuit, if the same input source is used to charge the dual-channel power supply circuit, the sampling resistors of the first power supply circuit PV1 and the second power supply circuit PV2 will be connected in parallel, so that the current sampling value is half of the actual current, resulting in that the actual input and output currents of the dual-channel power supply circuit exceed the rated current of the fuses, and the dual-channel power supply circuit is damaged.

[0056] To solve the above technical problems, the application provides a constant current source-based current limiting control circuit, which combines Figure 2 As shown in the figure, the constant current source-based current limiting control circuit includes an input source judgment module 100, a current limiting mode control module 200 and a constant current driving module 500.

[0057] The dual-channel power supply circuit can be a dual-channel photovoltaic charging circuit, and in other embodiments, it can also be other power supply circuits, which are not limited here. The input source can include a DC source, a PV solar panel, etc., which are not limited here.

[0058] The constant current driving module 500 is connected with the constant current source and the input source judgment module 100, and the current limiting mode control module 200 is connected with the input source judgment module 100.

[0059] The input source judgment module 100 can judge whether the dual power supply circuit is connected to the same input source based on the input voltage or input current of the dual power supply circuit. In other embodiments, the input source judgment module 100 can also combine the input voltage and input current to judge whether the dual power supply circuit is connected to the same input source, which is not specifically limited here.

[0060] The input source judgment module 100 mainly generates a first judgment signal based on the input voltage of the dual power supply circuit, generates a second judgment signal based on the input current of the target power supply circuit, and judges whether the dual power supply circuit is connected to the same input source based on the first judgment signal and the second judgment signal, wherein the target power supply circuit is a power supply circuit connected to the constant current source in the dual power supply circuit.

[0061] The first judgment signal is generated by the input source judgment module 100 based on the input voltage of the dual power supply circuit, for example, by judging whether the input voltage of the dual power supply circuit is the same or the difference of the input voltage is within the allowed error range to determine whether the dual power supply circuit is connected to the same input source. If the input voltage difference is not within the allowed error range, it means that the dual power supply circuit is connected to different input sources, otherwise continue to judge by input current.

[0062] The input voltage is obtained by sampling the voltage of the dual power supply circuit when there is an input source in at least one of the dual power supply circuit. For the convenience of understanding, the dual power supply circuit includes a first power supply circuit PV1 and a second power supply circuit PV2. When there is an input source in the first power supply circuit PV1 and / or the second power supply circuit PV2, the input voltage of the first power supply circuit PV1 and the second power supply circuit PV2 can be sampled to obtain the input voltage. If the input sources of the first power supply circuit PV1 and the second power supply circuit PV2 are different, the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 are different, and thus the first determination signal can be obtained based on the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 to detect whether the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source. The comparison result of the absolute value of the difference between the input voltages of the dual power supply circuit and the voltage threshold value can be used to determine whether the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 are the same. For example, when the absolute value of the difference between the input voltages of the dual power supply circuit is greater than or equal to the voltage threshold value, it is determined that the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source. When the absolute value of the difference between the input voltages of the dual power supply circuit is less than the voltage threshold value, it cannot be determined whether the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source. This is because there is an error in the detection of the input voltage, and therefore, in consideration of the error, the second determination signal needs to be generated based on the input current of the target power supply circuit. The input current of the target power supply circuit can include the input current of the first power supply circuit PV1 or the second power supply circuit PV2. The second determination signal is generated based on the input current of the target power supply circuit, which is referred to as the target power supply circuit for the convenience of description. The input source judgment module 100 judges whether the dual power supply circuit is connected to the same input source by collecting the input current of the target power supply circuit, for example, by comparing the input current of the target power supply circuit with a threshold value.

[0063] The input source judgment module 100 is further configured to generate the second determination signal based on the input current of the target power supply circuit when the sampling end of the target power supply circuit is supplied with a constant current source.

[0064] Finally, the input source judgment module 100 comprehensively determines whether the dual power supply circuit is connected to the same input source based on the first determination signal obtained based on the input voltage and the second determination signal obtained based on the input current.

[0065] The constant current driving module 500 is connected to the constant current source and the input source judgment module 100, respectively, and is configured to control the constant current source to supply power to the sampling end of the target power supply circuit within a target time when the first determination signal cannot determine whether the dual power supply circuit is connected to the same input source.

[0066] The constant current source driving module is configured to control the constant current source to supply power to the sampling end of the target power supply circuit within a target time, so as to determine the input source of the input source through the input current of the target power supply circuit.

[0067] The constant current driving module 500 is configured to, in a case where the input source of the dual power supply circuit cannot be determined to be the same input source based on the first determination signal, fix the input current of the target power supply circuit, that is, supply power to the target power supply circuit by the constant current source, so that the current of the target power supply circuit is the current of the constant current source. In this way, if the first power supply circuit PV1 or the second power supply circuit PV2 is connected to the same input source, the resistance value of the sampling resistor of one of the power supply circuits is half of the original resistance value, and if the first power supply circuit PV1 or the second power supply circuit PV2 is connected to different input sources, the resistance value of the sampling resistor of one of the power supply circuits is the original resistance value. Therefore, when the input current of the target power supply circuit is subsequently sampled, the current sampling value obtained, and finally, whether the input source of the first power supply circuit PV1 or the second power supply circuit PV2 is the same input source can be determined based on the current sampling value.

[0068] In addition, in order to avoid affecting the normal work of the dual power supply circuit, after the working mode of the dual power supply circuit adopts the second current limiting mode, the connection between the constant current source and the target power supply circuit is disconnected, so that the target power supply circuit works normally.

[0069] In a case where the input source determination module 100 determines that the dual power supply circuit is connected to different input sources, the current limiting mode control module 200 controls the working mode of the dual power supply circuit to adopt the first current limiting mode; in a case where the input source determination module 100 determines that the dual power supply circuit is connected to the same input source, the current limiting mode control module 200 controls the working mode of the dual power supply circuit to adopt the second current limiting mode, and the electric parameter value corresponding to the first current limiting mode is greater than the electric parameter value corresponding to the second current limiting mode, in combination with the dual power supply circuit described above, wherein the electric parameter value corresponding to the second current limiting mode is half of the electric parameter value corresponding to the first current limiting mode, for example, the electric parameter value corresponding to the first current limiting mode is 2V, and the electric parameter value corresponding to the second current limiting mode is 1V. The above values can be adjusted according to the design requirements of the circuit and different application scenarios.

[0070] In the above embodiment, the current limiting mode is adjusted in time based on the input source of the dual power supply circuit, so that the maximum input current of the dual power supply circuit under any working condition is less than the electric parameter value under the corresponding current limiting mode, thereby ensuring the safety of the circuit.

[0071] In some optional embodiments, the input source judgment module 100 is configured to determine that the dual-path power supply circuit is connected to different input sources when the absolute value of the difference between the input voltages of the dual-path power supply circuit is greater than or equal to a voltage threshold; and determine that the dual-path power supply circuit is connected to the same input source when the absolute value of the difference between the input voltages of the dual-path power supply circuit is less than the voltage threshold, and the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is less than a first current threshold and greater than a second current threshold; and determine that the dual-path power supply circuit is connected to different input sources when the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is greater than the first current threshold and greater than the second current threshold.

[0072] In some optional embodiments, the input source judgment module 100 is configured to determine that the dual-path power supply circuit is connected to different input sources when the absolute value of the difference between the input voltages of the dual-path power supply circuit is greater than or equal to a voltage threshold; and determine that the dual-path power supply circuit is connected to the same input source when the absolute value of the difference between the input voltages of the dual-path power supply circuit is less than the voltage threshold, and the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is less than a first current threshold and greater than a second current threshold; and determine that the dual-path power supply circuit is connected to different input sources when the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is greater than the first current threshold and greater than the second current threshold. Figure 3 As shown in the accompanying drawings, Figure 3 As shown in the accompanying drawings,

[0073] The voltage comparison unit 110 is configured to compare the input voltages of the dual-path power supply circuit to determine the relationship between the absolute value of the difference between the input voltages of the dual-path power supply circuit and the voltage threshold. When the absolute value of the difference between the input voltages of the dual-path power supply circuit is greater than or equal to the voltage threshold, it indicates that the dual-path power supply circuit is connected to different input sources. When the absolute value of the difference between the input voltages of the dual-path power supply circuit is less than the voltage threshold, it cannot be determined whether the dual-path power supply circuit is connected to the same input source, so the current comparison unit 120 is further configured to compare the input current of the target circuit with the current threshold. When the input current of the target circuit is less than the current threshold, it indicates that the dual-path power supply circuit is connected to different input sources. Otherwise, it indicates that the dual-path power supply circuit is connected to the same input source.

[0074] In some optional embodiments, the input source judgment module 100 is configured to determine that the dual-path power supply circuit is connected to different input sources when the absolute value of the difference between the input voltages of the dual-path power supply circuit is greater than or equal to a voltage threshold; and determine that the dual-path power supply circuit is connected to the same input source when the absolute value of the difference between the input voltages of the dual-path power supply circuit is less than the voltage threshold, and the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is less than a first current threshold and greater than a second current threshold; and determine that the dual-path power supply circuit is connected to different input sources when the input current of the target circuit when the sampling end of the target circuit is supplied by the constant current source is greater than the first current threshold and greater than the second current threshold. Figure 3The voltage comparison unit 110 comprises an operational amplifier unit 111, an absolute value output unit 112 and a comparison unit 113. Two input terminals of the operational amplifier unit 111 receive input voltages of the dual power supply circuit respectively; an input terminal of the absolute value output unit 112 is connected with an output terminal of the operational amplifier unit 111, for obtaining an absolute value of the voltage difference of the dual power supply circuit obtained by the operational amplifier unit 111; one input terminal of the comparison unit 113 is connected with an output terminal of the absolute value output unit 112, and the other input terminal receives a voltage threshold value, and the comparison unit 113 is used for obtaining a first judgment signal based on the absolute value of the voltage difference of the dual power supply circuit and the voltage threshold value.

[0075] As shown in Figure 3 The operational amplifier unit 111 comprises an operational amplifier U3A and its peripheral circuit, the comparison unit 113 comprises a comparator U2A and its peripheral circuit, and the absolute value output unit 112 comprises an operational amplifier U1A, an operational amplifier U1B and their peripheral circuit.

[0076] In the operational amplifier unit 111, a non-inverting input terminal of the operational amplifier U3A is connected with a second terminal of a resistor R9, a first terminal of the resistor R9 receives an input voltage of the first power supply circuit PV1, an inverting input terminal of the operational amplifier U3A is connected with a second terminal of a resistor R11, a first terminal of the resistor R11 receives an input voltage of the second power supply circuit PV2, the second terminal of the resistor R9 is also connected with a second terminal of a resistor R7, the second terminal of the resistor R7 is connected with a ground GND of the dual input control circuit, the second terminal of the resistor R11 is also connected with a first terminal of a resistor R16, and a second terminal of the resistor R16 is connected with an output terminal of the operational amplifier U3A.

[0077] In the absolute value output unit 112, a first terminal of a resistor R10 is connected with an output terminal of the operational amplifier unit 111 and a first terminal of a resistor R4, a second terminal of the resistor R10 is connected with a non-inverting input terminal of the operational amplifier U1A, an inverting input terminal of the operational amplifier U1A is connected with a first terminal of a resistor R18, a second terminal of the resistor R18 is connected with an output terminal of the operational amplifier U1A and a first terminal of a resistor R5, a second terminal of the resistor R5 is connected with a non-inverting input terminal of the operational amplifier U1B, a second terminal of the resistor R4, a first terminal of a resistor R3 and an inverting input terminal of the operational amplifier U1B are connected, a second terminal of the resistor R3 is connected with an output terminal of the operational amplifier U1B, as an output terminal of the absolute value output unit 112.

[0078] In the comparison unit 113, a non-inverting input terminal of the comparator U2 inputs a voltage threshold value, an inverting input terminal of the comparator U2 is connected with an output terminal of the absolute value output unit 112, and an output terminal of the comparator U2 outputs a first judgment signal.

[0079] The difference between the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 is input to the operational amplifier U3A, and the output of the operational amplifier U3A is positive or negative. The absolute value output circuit outputs the absolute value of the output of the operational amplifier U3A. The output of the absolute value output circuit is input to the inverting input terminal of the comparator U2.

[0080] In some optional embodiments, the voltage threshold is the difference between the input voltages of the dual power supply circuit, and the target value is determined based on the line loss and the sampling deviation.

[0081] In some optional embodiments, the voltage threshold is the difference between the input voltages of the dual power supply circuit, and the target value is determined based on the line loss and the sampling deviation.

[0082] In some optional embodiments, the voltage threshold is the difference between the input voltages of the dual power supply circuit, and the target value is determined based on the line loss and the sampling deviation.

[0083] In some optional embodiments, the voltage threshold is the difference between the input voltages of the dual power supply circuit, and the target value is determined based on the line loss and the sampling deviation.

[0084] In a case where the input source judgment module 100 cannot determine whether the first power supply circuit PV1 or the second power supply circuit PV2 is connected to the same input source based on the input voltage of the dual-path power supply circuit, the constant current source is controlled to supply power to the sampling end of the target power supply circuit within a target time, and then the input current of the target power supply circuit when the constant current source supplies power is collected. In a case where the input sources of the first power supply circuit PV1 and the second power supply circuit PV2 are the same input source, the sampling resistors of the first power supply circuit PV1 and the second power supply circuit PV2 are connected in parallel. Therefore, in a case where the constant current source determines the input, the current sampling values are different when the resistance values of the sampling resistors are different. Therefore, whether the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source can be determined based on the different current sampling values. In a case where the first power supply circuit PV1 and the second power supply circuit PV2 are connected to different input sources, a first current sampling value can be determined, and in a case where the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source, a second current sampling value can be determined. Based on the first current sampling value and the second current sampling value, a first current threshold value and a second current threshold value corresponding to the first current sampling value and the second current sampling value can be determined. Therefore, in a case where the input current of the target circuit when the sampling end of the target circuit is supplied with power by the constant current source is less than the first current threshold value and greater than the second current threshold value, it is determined that the dual-path power supply circuit is connected to the same input source. In a case where the input current of the target circuit when the sampling end of the target circuit is supplied with power by the constant current source is greater than the first current threshold value and greater than the second current threshold value, it is determined that the dual-path power supply circuit is connected to different input sources.

[0085] In combination Figure 3 As shown in FIG. 1, in some optional embodiments, the current comparison unit 120 includes a first comparison subunit 121, a second comparison subunit 122, and a logic unit 123. An input end of the first comparison subunit 121 receives the first current threshold value, and another input end of the first comparison subunit 121 receives the input current of the target power supply circuit. An input end of the second comparison subunit 122 receives the second current threshold value, and another input end of the second comparison subunit 122 receives the input current of the target power supply circuit. An input end of the logic unit 123 is connected to an output end of the first comparison subunit 121, and another input end of the logic unit 123 is connected to an output end of the second comparison subunit 122, for generating a second judgment signal based on a comparison result of the first comparison subunit 121 and a comparison result of the second comparison subunit 122.

[0086] The current comparison unit 120 mainly compares the input current of the target power supply circuit supplied with power by the constant current source with the first current threshold value and the second current threshold value, to determine whether the dual-path power supply circuit is connected to the same input source.

[0087] The current comparison unit 120 includes a first comparison subunit 121, a second comparison subunit 122, and a logic unit 123, in combinationFigure 3 The first comparison subunit 121 comprises a comparator U6A and its peripheral circuit, the second comparison subunit 122 comprises a comparator U6B and its peripheral circuit, and the logic unit 123 comprises an AND gate U7 and its peripheral circuit. The non-inverting input terminal of the comparator U6A in the first comparison subunit 121 receives the first current threshold value, the inverting input terminal receives the input current of the target power supply circuit powered by the constant current source, and the output terminal is connected to the second terminal of a resistor R17, and the first terminal of the resistor R17 is connected to the power supply VCC. In the second comparison subunit 122, the non-inverting input terminal of the comparator U6B receives the input current of the target power supply circuit powered by the constant current source, the inverting input terminal receives the second current threshold value, and the output terminal is connected to the second terminal of a resistor R36, and the first terminal of the resistor R36 is connected to the power supply VCC. In the logic unit 123, the first terminal of the AND gate U7 is connected to the output terminal of the comparator U6A, the second terminal of the AND gate U7 is connected to the output terminal of the comparator U6B, and the output terminal of the AND gate U7 serves as the output terminal of the current comparison unit 120.

[0088] In one of the optional embodiments, the first current threshold value is smaller than the first current sampling value and larger than the second current sampling value, and the second current threshold value is smaller than the first current sampling value and smaller than the second current sampling value; the first current sampling value is the current sampling value when the dual-path power supply circuit accesses different input sources, and the second current sampling value is the current sampling value when the dual-path power supply circuit accesses the same input source.

[0089] In order to facilitate understanding, the size of the constant current source can be determined based on the maximum power consumption of the sampling resistor. The size of the constant current source is determined under the condition of ensuring that the maximum power consumption of the sampling resistor is less than the maximum power consumption of the sampling resistor. For example, the output current of the constant current source can be defined as 0.5A. In other embodiments, the size of the output current of the constant current source is also related to the amplification factor. Based on the size of the constant current source and the amplification factor and the resistance value of the sampling resistor, the current sampling value is appropriate to avoid errors caused by too small current sampling value. The current sampling value of the first power supply circuit PV1 is amplified, i.e. when the dual-path power supply circuit accesses different input sources, the current sampling value of the first power supply circuit PV1 is the first current sampling value, which can be 1V (5mΩ*0.5A*400), wherein 400 is the amplification factor, which can be other values in other embodiments. When the dual-path power supply circuit accesses the same input source, the current sampling value of the first power supply circuit PV1 is the second current sampling value, which can be 0.5V (2.5mΩ*0.5A*400).

[0090] The first current threshold is less than the first current sampling value and greater than the second current sampling value, and the second current threshold is less than the first current sampling value and less than the second current sampling value. Taking the first current sampling value as 1V and the second current sampling value as 0.5V as an example for description, the first current threshold can be 0.9V, and the second current threshold can be 0.4V. In other embodiments, the first current threshold and the second current threshold can also be other values, as long as the input current of the target power supply circuit powered by the constant current source is ensured, and different second judgment signals are output by the current comparison unit 120 in the case that the dual-path power supply circuit accesses the same input source or different input sources.

[0091] In the above embodiment, the input voltage and the input current are used to determine the input source of the dual-path power supply circuit.

[0092] In some optional embodiments, the constant current driving module 500 includes a control signal generation unit 510 and a constant current switch unit 520. The input end of the control signal generation unit 510 is connected to the first output end of the input source determination module 100, and the constant current switch unit 520 is connected in parallel between the input ground of the target power supply circuit and the input ground of the battery pack after being connected in series with the constant current source. The control signal generation unit 510 is configured to output a first control signal when the first judgment signal cannot determine whether the dual-path power supply circuit is connected to the same input source, and the constant current switch unit 520 is configured to control the constant current source to supply power to the sampling end of the target power supply circuit for a target time based on the first control signal. The control signal generation unit 510 is configured to output a second control signal when the first judgment signal determines that the dual-path power supply circuit is connected to different input sources, and the constant current switch unit 520 is configured to control the constant current source to be disconnected from the sampling end of the target power supply circuit based on the second control signal.

[0093] In combination with Figure 3 As shown in FIG. 16, the control signal generation unit 510 includes a transistor Q16, the emitter of the transistor Q16 is connected to the first output end of the input source determination module 100 and the first end of a resistor R33, the second end of the resistor R33 is connected to the base of the transistor Q16, and the collector of the transistor Q16 is connected to the control end of the constant current switch unit 520. The constant current switch unit 520 includes a switch tube Q17, the gate of the switch tube Q17 is connected to the second end of a resistor R34 and the first end of a resistor R35, the first end of the resistor R34 is the control end of the constant current switch unit 520, the second end of the resistor R35 is connected to the input ground of the battery pack and the source of the switch tube Q17, the drain of the switch tube Q17 is connected to the second end of the constant current source, and the first end of the constant current source is connected to the input ground of the target power supply circuit.

[0094] In the case where the first judgment signal indicates that the input source of the dual supply circuit is connected to different input sources, the control signal generation unit 510 outputs a second control signal, and the constant current switch unit 520 controls the constant current source to be disconnected from the sampling end of the target supply circuit based on the second control signal under the second control signal.

[0095] In the case where the first judgment signal indicates that it is unable to determine whether the dual supply circuit is connected to the same input source, the control signal generation unit 510 outputs a first control signal, and the constant current switch unit 520 controls the constant current source to supply power to the sampling end of the target supply circuit for a target time under the first control signal.

[0096] In the case where it is determined based on the input voltage of the dual supply circuit that the dual supply circuit is connected to different input sources, current sampling is not required, and thus the constant current source does not need to supply power to the sampling end of the target supply circuit for a target time. In the case where it is unable to determine based on the input voltage of the dual supply circuit whether the dual supply circuit is connected to the same input source, the judgment of the input current needs to be continued, and thus the constant current source supplies power to the sampling end of the target supply circuit for a target time, so that the input current of the target supply circuit can be sampled to determine whether the input source of the dual supply circuit is the same input source.

[0097] In some optional embodiments, the constant current driving module 500 further includes a current sampling time control unit 530, an input end of the current sampling time control unit 530 is connected to the first output end of the input source judgment module 100, and an output end of the current sampling time control unit 530 is connected to a control end of the control signal generation unit 510.

[0098] The current sampling time control unit 530 is configured to, in the case where the constant current source supplies power to the sampling end of the target supply circuit, control the control signal generation unit 510 to output a second control signal after a target time, so that the constant current switch unit 520 disconnects the connection between the constant current source and the sampling end of the target supply circuit based on the second control signal, where the target time is less than a time length from the presence of the input voltage of the target supply circuit to the start of work.

[0099] Wherein the access of the constant current source will affect the normal work of the power supply circuit, so in this application, the time when the constant current source supplies power to the target power supply circuit, i.e. the current sampling time, needs to be controlled, so after a delay of the target time, the constant current source is disconnected from the sampling end of the target power supply circuit. The delay and disconnection are controlled by the current sampling time control unit 530. Further, the current limiting control circuit based on the constant current source in this embodiment judges whether the input source is the same when the input source is connected, and selects the current limiting mode according to whether it is the same input source, and only after the current limiting mode is selected, the power supply circuit is controlled to work normally.

[0100] In some optional embodiments, the current sampling time control unit 530 includes a first capacitor C8, a diode D2, and a second capacitor C9, wherein the first end of the first capacitor C8 is connected to the first output end of the input source judgment module 100, and the second end of the first capacitor C8 is grounded; the cathode of the diode D2 is connected to the first end of the first capacitor C8, and the anode of the diode D2 is connected to the control end of the control signal generation unit 510; the first end of the second capacitor C9 is connected to the control end of the control signal generation unit 510, and the second end of the second capacitor C9 is grounded; the charging time of the second capacitor C9 is greater than the charging time of the first capacitor C8, and the charging time of the second capacitor C9 is the target time.

[0101] In combination Figure 3 Wherein the VCC voltage charges the first capacitor C8 through the resistor R6, and charges the second capacitor C9 through the resistor R6 and the resistor R33, the charging time of the first capacitor C8 is faster than that of the second capacitor C9, and finally the voltages of the first capacitor C8 and the second capacitor C9 are equal, the diode D2 is in the off state, when the second capacitor C9 is fully charged, the b electrode voltage of the triode Q16 is equal to the e electrode voltage, the triode Q16 is off, and the MOS tube Q17 also follows off, so the time when the constant current source supplies power to the sampling resistor R1 of the target power supply circuit is the time when the second capacitor C9 is fully charged. In addition, if the current limiting mode needs to be switched, the switching time of the current limiting mode switching is less than the time when the second capacitor C9 is fully charged, that is, before the second capacitor C9 is fully charged, the current limiting mode switching has been completed.

[0102] In one of the optional embodiments, the current limiting mode control module 200 includes a first judgment unit 210, an interlocking unit 220, and a selection unit 230, wherein the first input end and the second input end of the first judgment unit 210 are respectively connected to the two output ends of the input source judgment module 100, and the second input end is also connected to the output end of the lock module 400; the input end of the interlocking unit 220 is connected to the output end of the first judgment unit 210; the input end of the selection unit 230 is connected to the output end of the interlocking unit 220.

[0103] The first judgment unit 210 is used to generate a third judgment signal based on the first judgment signal and the second judgment signal to determine whether the dual power supply circuit is connected to the same input source, and the interlock unit 220 is used to output a second current limiting mode selection signal to the selection unit 230 based on the third judgment signal, so that the selection unit 230 adopts the second current limiting mode; and when the output of the first judgment unit 210 is converted into a fourth judgment signal under the locking signal of the locking module 400, the interlock unit 220 outputs the second current limiting mode selection signal to the selection unit 230; the first judgment unit 210 is also used to generate a fourth judgment signal based on the first judgment signal and the second judgment signal to determine whether the dual power supply circuit is connected to different input sources, and the interlock unit 220 is also used to output the first current limiting mode selection signal to the selection unit 230 based on the fourth judgment signal, so that the selection unit 230 adopts the first current limiting reference.

[0104] The first judgment unit 210 includes an AND gate U4, a first input terminal of which is connected to the output terminal of the voltage comparison unit 110, a second input terminal of which is connected to the output terminal of the current comparison unit 120 and the first terminal of the capacitor C6, the second terminal of the capacitor C6 being grounded, and the output terminal of the AND gate U4 being connected to the first terminal of the interlock unit 220. The interlock unit 220 includes a transistor Q11 and a transistor Q13, wherein the emitter of the transistor Q11 is connected to the power supply VCC and the first terminal of the resistor R20, the second terminal of the resistor R20, the base of the transistor Q11, and the first terminal of the resistor R23 are connected, the collector of the transistor Q11 is connected to the first terminal of the resistor R27, the base of the transistor Q13 is connected to the second terminal of the resistor R27, the emitter is grounded GND, and the collector is connected to the second terminal of the resistor R23. The second terminal of the resistor R23 is also connected to the input terminal of the selection unit 230, which is used to select the current limiting mode, which can be implemented by the relay RLY1.

[0105] In order to facilitate the understanding of the working principle of the dual-input control circuit in this application, combined with Figure 3 As shown, the following explanations are given:

[0106] When both power supply circuits have input source input, the application samples the input voltage of the first power supply circuit PV1 and the second power supply circuit PV2, and the sampling values enter the 1-pin in-phase input end and the 3-pin reverse-phase input end of the operational amplifier U3 respectively, and the output value of the operational amplifier U3 enters the 2-pin reverse-phase input end of the comparator U2A after entering the absolute value output circuit, and when the absolute value of the difference between the actual input voltage of the first power supply circuit PV1 and the second power supply circuit PV2 is greater than 2V (i.e. the target value in the above), it is indicated that the dual power supply circuit is connected to different input sources, i.e. the value Vsamp output by the absolute value output circuit is greater than the value of the voltage threshold Vref, the comparator U2A outputs low level, at this time the triode Q16 is cut off, the MOS tube Q17 is cut off, and the constant current source does not form a loop with the sampling resistor R1 of the first power supply circuit PV1. At the same time, the 1-pin input end of the AND gate U4 is low level, then no matter the 2-pin input is high or low level, the AND gate U4 outputs low level, the triode Q13 is cut off due to the low level of the base, the triode Q11 is cut off due to the same potential of the b electrode and the e electrode, the relay RLY1 does not work, and the first power supply circuit PV1 and the second power supply circuit PV2 work in the first current limiting mode.

[0107] This working condition can also include that only the first power supply circuit PV1 is connected to the input source or only the second power supply circuit PV2 is connected to the input source.

[0108] When both power supply circuits have input source input, the application samples the input voltage of the first power supply circuit PV1 and the second power supply circuit PV2, and the sampling values enter the 1-pin in-phase input end and the 3-pin reverse-phase input end of the operational amplifier U3 respectively, and the output value of the operational amplifier U3 enters the 2-pin reverse-phase input end of the comparator U2A after entering the absolute value output circuit, and when the absolute value of the difference between the actual input voltage of the first power supply circuit PV1 and the second power supply circuit PV2 is greater than 2V (i.e. the target value in the above), it is indicated that the dual power supply circuit is connected to different input sources, i.e. the value Vsamp output by the absolute value output circuit is greater than the value of the voltage threshold Vref, the comparator U2A outputs low level, at this time the triode Q16 is cut off, the MOS tube Q17 is cut off, and the constant current source does not form a loop with the sampling resistor R1 of the first power supply circuit PV1. At the same time, the 1-pin input end of the AND gate U4 is low level, then no matter the 2-pin input is high or low level, the AND gate U4 outputs low level, the triode Q13 is cut off due to the low level of the base, the triode Q11 is cut off due to the same potential of the b electrode and the e electrode, the relay RLY1 does not work, and the first power supply circuit PV1 and the second power supply circuit PV2 work in the first current limiting mode.

[0109] When the current sampling value of the first power supply circuit PV1 is 0.5V (see the second current sampling value above), it indicates that the dual power supply circuit is connected to the same source. The comparators U6A and U6B both output high level, the 1st and 2nd pins of the AND gate U7 input high level, the 4th pin of the AND gate U7 outputs high level, the 1st and 2nd pins of the AND gate U4 input high level, the 4th pin of the AND gate U4 outputs high level, and the transistor Q13 is turned on due to the high level at the base, so that the relay RLY1 has a current loop and works. The current limiting mode of the first power supply circuit PV1 and the second power supply circuit PV2 adopts the second current limiting mode.

[0110] At the same time, the transistor Q11 is turned on due to the fact that the e terminal voltage is greater than the b terminal voltage. At this time, the transistors Q11 and Q13 form a mutual lock, keep the base of the transistor Q13 at high level, and make the transistor Q13 continuously conduct, so that the relay RLY1 continuously works. The dual power supply circuit works in the second current limiting mode. If there is no mutual lock circuit, when the first power supply circuit PV1 works, the current sampling value of the first power supply circuit PV1 will be greater than the first threshold Iref1, the 1st pin of the AND gate U7 is low, the AND gate U7 outputs low, and the AND gate U7 also follows to output low. The transistor Q13 is cut off, the relay RLY1 does not work, and the dual power supply circuit works in the first current limiting mode, which damages the dual power supply circuit.

[0111] At the same time, the VCC voltage charges the first capacitor C8 through the resistor R6 and charges the second capacitor C9 through the resistor R6 and the resistor R33. The first capacitor C8 charges faster than the second capacitor C9, and the voltages of the first capacitor C8 and the second capacitor C9 are equal eventually. The diode D2 is in the cut-off state. When the second capacitor C9 is fully charged, the b terminal voltage of the transistor Q16 is equal to the e terminal voltage, the transistor Q16 is cut off, and the MOS transistor Q17 is also cut off. Therefore, the time for the constant current source to supply power to the first power supply circuit PV1 for current sampling is the time for the second capacitor C9 to be fully charged, which is the target time. The target time needs to be less than the time from when the power supply circuit has input voltage to when the power supply circuit starts to work, so as to avoid affecting the current sampling when the circuit works normally.

[0112] In this way, the maximum input current of the first power supply circuit PV1 and the second power supply circuit PV2 is limited to 20A due to the current limiting mode, and the maximum 1200W of the single power supply circuit is maintained, so that the input current and the output current of the dual power supply circuit do not exceed the rated current of the fuses F1, F2, F3 and F4, and the dual power supply circuit works stably and reliably.

[0113] When the current sampling value of the first power supply circuit PV1 is 1V (i.e. the first current sampling value in the above), it indicates that the dual power supply circuit is connected to different input sources, the comparator U6A outputs a low level, the comparator U6B outputs a high level, the pin 1 of the AND gate U7 is a low level, the pin 2 is a high level, the pin 4 of the AND gate U7 outputs a low level, the pin 1 of the AND gate U4 is a high level, the pin 2 is a low level, the pin 4 of the AND gate U4 outputs a low level, the transistor Q13 is cut off due to the low level of the base, the transistor Q11 is cut off due to the same potential of the b electrode and the e electrode, the relay RLY1 does not work, and the first power supply circuit PV1 and the second power supply circuit PV2 work in the first current limiting mode.

[0114] Similarly, the VCC voltage charges the first capacitor C8 through the resistor R6 and charges the second capacitor C9 through the resistor R6 and the resistor R33. The first capacitor C8 is charged faster than the second capacitor C9, and the voltages of the first capacitor C8 and the second capacitor C9 are equal eventually. The diode D2 is in the cut-off state. When the second capacitor C9 is fully charged, the b electrode voltage of the transistor Q16 is equal to the e electrode voltage, the transistor Q16 is cut off, and the MOS tube Q17 is also cut off. Therefore, the time for the constant current source to supply power to the first power supply circuit PV1 for current sampling is the time for the second capacitor C9 to be fully charged.

[0115] In this way, the dual power supply circuit inputs the voltage sampling and comparison. If the voltage is greater than the voltage threshold Vref, the first current limiting mode is adopted. If the voltage is less than the voltage threshold Vref, the constant current source supplies power to the first power supply circuit PV1 to determine whether it is the same input source through the current sampling value of the first power supply circuit PV1. If the sampling value is 0.5V, it indicates that it is the same source, and the second current limiting reference is adopted. If the sampling value is 1V, it indicates that it is not the same source, and the first current limiting reference is adopted.

[0116] In summary, the energy storage power supply of the dual power supply circuit can detect whether it is the same input source and adjust the current limiting mode during the period from when the input source is connected to the dual power supply circuit to when the dual power supply circuit starts working by adding the current limiting control circuit based on the constant current source of the present application. The maximum input current of the dual power supply circuit is limited to 20A in any working condition, which guarantees the reliability of the PV circuit device and avoids damage to the dual power supply circuit.

[0117] In other embodiments, the present application also provides an energy storage device comprising the dual charging current limiting control circuit in any one of the above embodiments.

[0118] In the description of the specification, the description of the terms "some embodiments", "other embodiments", etc. means that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The illustrative descriptions in this specification are not necessarily to be construed as indicating that all embodiments or examples of the application include the described feature, structure, material or characteristic.

[0119] The technical features of the above-described embodiments can be combined in any manner, and for brevity, not all possible combinations of the technical features in the above-described embodiments are described, but it should be considered that any combination of the technical features is within the scope of the present application as long as the combination does not result in a contradiction.

[0120] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A current limiting control circuit based on a constant current source, characterized in that: include: an input source determination module, configured to generate a first determination signal based on the input voltage of the dual power supply circuit and a second determination signal based on the input current of the sampling terminal of the target power supply circuit when the sampling terminal is powered by the constant current source, and determine whether the dual power supply circuits are connected to the same input source based on the first determination signal and the second determination signal; The target power supply circuit is a power supply circuit in a dual-way power supply circuit connected to the constant current source; a constant current driving module, the constant current driving module being connected to the constant current source and the input source judgment module respectively, and being configured to control the constant current source to supply power to the sampling end of the target power supply circuit within a target time when it cannot be determined whether the dual power supply circuits are connected to the same input source based on the first judgment signal; a current limiting mode control module, wherein the current limiting mode control module is further configured to adopt a first current limiting mode when the dual power supply circuits are connected to different input sources; and adopt a second current limiting mode when the dual power supply circuits are connected to the same input source, and the electrical parameter value corresponding to the first current limiting mode is greater than the electrical parameter value corresponding to the second current limiting mode; The input source judgment module is configured to determine that the dual power supply circuit is connected to different input sources when the absolute value of the difference between the input voltages of the dual power supply circuit is greater than or equal to a voltage threshold; And when the absolute value of the difference between the input voltages of the dual power supply circuit is less than the voltage threshold, and the input current in response to the sampling end of the target power supply circuit being powered by the constant current source is less than the first current threshold and greater than the second current threshold, it is determined that the dual power supply circuits are connected to the same input source, and when the input current in response to the sampling end of the target power supply circuit being powered by the constant current source is greater than the first current threshold and greater than the second current threshold, it is determined that the dual power supply circuits are connected to different input sources.

2. The circuit according to claim 1, wherein: The input source judgment module includes: a voltage comparison unit, wherein two input terminals of the voltage comparison unit respectively receive input voltages of the dual power supply circuit, and are used to compare the input voltages of the dual power supply circuit to obtain a first judgment signal; A current comparison unit, wherein the three input terminals of the current comparison unit respectively receive the input current, the first current threshold and the second current threshold of the target power supply circuit, and are used to obtain a second judgment signal based on the input current, the first current threshold and the second current threshold.

3. The circuit according to claim 2, characterized in that The voltage comparison unit includes: An operational amplifier unit, wherein two input terminals of the operational amplifier unit respectively receive input voltages of the dual power supply circuit; an absolute value output unit, wherein an input terminal of the absolute value output unit is connected to an output terminal of the operational amplifier unit, and is used to obtain an absolute value of a difference between the input voltages of the dual power supply circuit obtained by the operational amplifier unit; A comparison unit, one input end of the comparison unit is connected to the output end of the absolute value output unit, and the other input end of the comparison unit receives a voltage threshold. The comparison unit is used to obtain a first judgment signal based on the absolute value of the difference between the input voltages of the dual power supply circuit and the voltage threshold.

4. The circuit according to claim 2, characterized in that The current comparison unit includes: a first comparing subunit, wherein one input terminal of the first comparing subunit receives a first current threshold, and another input terminal of the first comparing subunit receives an input current of a target power supply circuit; a second comparing subunit, wherein one input terminal of the second comparing subunit receives a second current threshold, and another input terminal of the second comparing subunit receives an input current of a target power supply circuit; A logic unit, one input end of the logic unit is connected to the output end of the first comparison subunit, and the other input end of the logic unit is connected to the output end of the second comparison subunit, for generating a second judgment signal based on the comparison result of the first comparison subunit and the comparison result of the second comparison subunit.

5. The circuit according to any one of claims 1 to 4, characterized in that The constant current drive module includes: a control signal generating unit, wherein an input end of the control signal generating unit is connected to the first output end of the input source determining module; a constant current switch unit, wherein the constant current switch unit is connected in series with the constant current source and then connected in parallel between the input ground of the target power supply circuit and the input ground of the battery pack; The control signal generating unit is configured to output a first control signal when the first judgment signal cannot determine whether the dual power supply circuit is connected to the same input source, and the constant current switch unit is configured to control the constant current source to supply power to the sampling end of the target power supply circuit within a target time based on the first control signal; and output a second control signal when the first judgment signal determines that the dual power supply circuit is connected to different input sources, and the constant current switch unit is configured to control the constant current source to disconnect from the sampling end of the target power supply circuit based on the second control signal.

6. The circuit according to claim 5, characterized in that The constant current drive module also includes: a current sampling time control unit, wherein an input end of the current sampling time control unit is connected to the first output end of the input source judgment module, and an output end of the current sampling time control unit is connected to the control end of the control signal generating unit; The current sampling time control unit is configured to control the control signal generating unit to output a second control signal after a delay of a target time when the constant current source of the constant current switch unit supplies power to the sampling end of the target power supply circuit, so that the constant current switch unit disconnects the constant current source from the sampling end of the target power supply circuit based on the second control signal, wherein the target time is less than the duration from the presence of input voltage to the start of operation of the target power supply circuit.

7. The circuit according to claim 6, characterized in that The current sampling time control unit includes: a first capacitor, wherein a first end of the first capacitor is connected to the first output end of the input source determination module, and a second end of the first capacitor is grounded; a diode, wherein a cathode of the diode is connected to the first end of the first capacitor, and an anode of the diode is connected to the control end of the control signal generating unit; a second capacitor, wherein a first end of the second capacitor is connected to the control end of the control signal generating unit, and a second end of the second capacitor is grounded; The charging time of the second capacitor is greater than the charging time of the first capacitor, and the charging time of the second capacitor is the target time.

8. The circuit according to claim 1, wherein: The current limiting mode control module includes: a first judgment unit, wherein a first input terminal of the first judgment unit is connected to a first output terminal of the input source judgment module, and a second input terminal of the first judgment unit is connected to a second output terminal of the input source judgment module; an interlocking unit, wherein an input end of the interlocking unit is connected to an output end of the first judgment unit; a selection unit, wherein an input end of the selection unit is connected to an output end of the interlocking unit; The first judgment unit is configured to output a fourth judgment signal when the first judgment signal cannot determine whether the dual power supply circuits are connected to the same input source, and the second judgment signal indicates that the dual power supply circuits are connected to the same input source. The interlock unit is configured to output a second current limiting mode selection signal to the selection unit based on the fourth judgment signal, so that the selection unit selects the second current limiting mode.

9. An energy storage device, characterized in that: The invention comprises a current limiting control circuit based on a constant current source according to any one of claims 1 to 8.

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