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

Abstract

The invention relates to a current-limiting control circuit based on a constant current source and energy storage equipment, and the circuit comprises an input source judgment module which is used for generating a first judgment signal based on the input voltage of a dual-path power supply circuit, generating a second judgment signal based on the input current when the sampling end of a target power supply circuit is powered by the constant current source, whether the two power supply circuits are connected with the same input source is judged; the constant current driving module is respectively connected with the constant current source and the input source judgment module, and is used for controlling the constant current source to supply power to the sampling end of the target power supply circuit within the target time when whether the double-path power supply circuit is connected with the same input source cannot be determined based on the first judgment signal; the current limiting mode control module is used for adopting a first current limiting mode under the condition that the double-path power supply circuit is connected with different input sources; under the condition that the two power supply circuits are connected with the same input source, a second current limiting mode is adopted, and the electrical parameter value corresponding to the first current limiting mode is larger than the electrical parameter value corresponding to the second current limiting mode. The circuit can protect the safety of the circuit.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a current limiting control circuit and energy storage device based on a constant current source. Background Art

[0002] As a new energy product, energy storage power supplies require PV charging capabilities. For energy storage power supplies with large battery packs, dual PV power supply circuits are typically designed to achieve high-power PV charging. If a single PV input voltage range is 12-60Vdc and the maximum input current limit is 20A, the maximum charging power of a single PV circuit is 1200W, and the maximum power of two PV circuits charging simultaneously is 2400W.

[0003] When the energy storage power supply has dual PV power supply circuits, if the same input source is used to charge the dual PV circuits, the sampling resistors of the PV1 circuit and the PV2 circuit will inevitably be connected in parallel, making the current sampling value half of the actual current. As a result, the actual input and output current of the PV circuit exceeds the rated current of the fuse, damaging the PV power supply circuit. Summary of the Invention

[0004] Based on this, it is necessary to provide a current limiting control circuit and energy storage device based on a constant current source that can protect circuit safety.

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

[0006] 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 a sampling terminal of a target power supply circuit when the sampling terminal is powered by a constant current source, and to 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; wherein the target power supply circuit is one of the dual power supply circuits connected to the constant current source;

[0007] 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;

[0008] The current limiting mode control module is used for the current limiting mode control module to adopt a first current limiting mode when the dual power supply circuit is connected to different input sources; and adopt a second current limiting mode when the dual power supply circuit is connected to a unified 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.

[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 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;

[0020] 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.

[0021] In one embodiment, the constant current driving module includes:

[0022] 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;

[0023] 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;

[0024] 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.

[0025] In one embodiment, the constant current driving module further includes:

[0026] 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;

[0027] 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.

[0028] In one embodiment, the current sampling time control unit includes:

[0029] 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;

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

[0031] 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;

[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 embodiment, the current limiting mode control module includes:

[0034] 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;

[0035] an interlocking unit, wherein an input end of the interlocking unit is connected to an output end of the first judgment unit;

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

[0037] 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.

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

[0039] The above-mentioned current limiting control circuit and energy storage device based on the constant current source, the input source judgment module, is used to generate a first judgment signal based on the input voltage of the dual-way power supply circuit and a second judgment signal based on the input current when the sampling end of the target power supply circuit is powered by the constant current source, and judge whether the dual-way 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 constant current drive module connected to the constant current source in the dual-way power supply circuit, and the constant current drive module is respectively connected to the constant current source and the input source judgment module, and is used to determine whether the dual-way power supply circuit is connected to the same input source based on the first judgment signal. In the case of one input source, the constant current source is controlled to supply power to the sampling end of the target power supply circuit within the target time; the current limiting mode control module is used for the current limiting mode control module to adopt the first current limiting mode when the dual power supply circuit is connected to different input sources; when the dual power supply circuit is connected to the same input source, the second current limiting mode is adopted, 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. In this way, the current limiting mode is adjusted in time based on the input source of the dual power supply circuit, so that under any working condition, the maximum input current of the dual power supply circuit is less than the electrical parameter value under the corresponding current limiting mode, thereby ensuring circuit safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 is a schematic diagram of a dual power supply circuit in one embodiment;

[0042] Figure 2 1 is a block diagram of a current limiting control circuit based on a constant current source in one embodiment;

[0043] Figure 3 4 is a circuit diagram of a current limiting control circuit based on a constant current source in one embodiment.

[0044] Description of reference numerals:

[0045] 100 input source judgment module, 200 current limiting mode control module, 500 constant current drive 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 generation unit, 520 constant current switch unit, 530 current sampling time control unit, 210 first judgment unit, 220 interlock unit, 230 selection unit. DETAILED DESCRIPTION

[0046] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided 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 those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0048] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0049] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0050] It is understood that “at least one” refers to one or more, “a plurality” refers to two or more, and “at least a portion of an element” refers to a portion or all of an 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 power supply circuits are charged from the same input source, the input terminals of the first power supply circuit PV1 and the second power supply circuit PV2 are connected in parallel. This also applies to the current sampling resistors R1 and R2, resulting in a 2.5mΩ resistance for each. If the input voltage is 60V and the input current is 20A, the sampled values ​​of the current sampling resistors R1 and R2 are both 1V (20A * 2.5mΩ * 20). The sampled single-channel charging power is only 600W, while the actual charging power is 1200W. If the first and second power supply circuits PV1 and PV2 detect that the sampled current value is far below the 2V parameter corresponding to the first current limiting mode, they continue to release the input current until the sampled current value reaches 2V, causing the input current to reach 40A. At this point, the sampled single-channel charging power is 1200W, while the actual charging power is 2400W. If the battery pack voltage is 45V, 53.33A (2400W / 45V) will enter the battery pack. At this time, both the input current and the output current (the current entering the battery pack) far exceed the rated current of fuses F1, F2, F3, and F4, causing the fuses to melt and damaging the first power supply circuit PV1 and the second power supply circuit PV2.

[0055] In summary, when the energy storage power supply has dual power supply circuits, if the same input source is used to charge the dual power supply circuits, the sampling resistors of the first power supply circuit PV1 and the second power supply circuit PV2 will inevitably be connected in parallel, making the current sampling value half of the actual current. As a result, the actual input and output currents of the dual power supply circuits exceed the rated current of the fuses, thereby damaging the dual power supply circuits.

[0056] In order to solve the above technical problems, the present application provides a current limiting control circuit based on a constant current source, combined with Figure 2 As shown, the current limiting control circuit based on the constant current source includes an input source judgment module 100 , a current limiting mode control module 200 and a constant current driving module 500 .

[0057] The dual-path power supply circuit may be a dual-path photovoltaic charging circuit. In other embodiments, it may be other power supply circuits, which are not specifically limited here. The input source may include a DC source, a PV solar panel, etc., which are not specifically limited here.

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

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

[0060] Among them, 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 circuits are connected to the same input source based on the first judgment signal and the second judgment signal, wherein the target power supply circuit is one of the dual power supply circuits connected to the constant current source.

[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, whether the dual power supply circuits are connected to the same input source is determined by judging whether the input voltages of the dual power supply circuits are the same or whether the difference between the input voltages is within an allowable error range. If the difference between the input voltages is not within the allowable error range, it indicates that the dual power supply circuits are connected to different input sources. Otherwise, the judgment is continued based on the input current.

[0062] When at least one of the dual power supply circuits has an input source, the voltage of the dual power supply circuit is sampled to obtain the input voltage. For ease of understanding, the dual power supply circuit includes a first power supply circuit PV1 and a second power supply circuit PV2. When the first power supply circuit PV1 and / or the second power supply circuit PV2 have an input source, the 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 input sources, the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 are different. Therefore, a first judgment 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. Whether the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 are the same can be determined by comparing the absolute value of the difference between the input voltages of the dual power supply circuits with a voltage threshold. For example, when the absolute value of the difference between the input voltages of the dual power supply circuits is greater than or equal to the voltage threshold, 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 in input voltage of the dual power supply circuit is less than the voltage threshold, it is impossible to determine 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. Therefore, taking the error into account, it is also necessary to generate a second judgment signal through the input current of the target power supply circuit. The input current of the target power supply circuit may include the input current of the first power supply circuit PV1 or the second power supply circuit PV2. The second judgment signal is generated based on the input current of any one of the circuits, and for the convenience of description, it is referred to as the target power supply circuit. The input source judgment module 100 determines whether the dual power supply circuits are 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 the threshold.

[0063] The input source determination module 100 is further configured to generate a second determination signal based on an input current when the sampling terminal of the target power supply circuit is powered by a constant current source.

[0064] Finally, the input source determination module 100 determines whether the dual power supply circuits are connected to the same input source by combining the first determination signal obtained based on the input voltage and the second determination signal obtained based on the input current.

[0065] Among them, the constant current driving module 500 is respectively connected to the constant current source and the input source judgment module 100, and is used to control the constant current source to power the sampling end of the target power supply circuit within the 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.

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

[0067] The constant current driving module 500 is used to fix the input current of the target power supply circuit when it is impossible to determine whether the input sources of the dual power supply circuits are the same input source based on the first judgment signal, that is, to supply power to the target power supply circuit with 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 of the sampling resistor of one power supply circuit is half of the original resistance value. If the first power supply circuit PV1 or the second power supply circuit PV2 is connected to different input sources, the resistance of the sampling resistor of one power supply circuit is the original resistance value. Therefore, the input current of the target power supply circuit is subsequently sampled, and the current sampling value obtained can finally be used to determine whether the input source of the first power supply circuit PV1 or the second power supply circuit PV2 is the same input source based on the current sampling value.

[0068] In addition, in order to avoid affecting the normal operation of the dual power supply circuit, after the dual power supply circuit adopts the second current limiting mode, the constant current source is disconnected from the target power supply circuit to enable the target power supply circuit to operate normally.

[0069] If 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 dual power supply circuit to operate in the first current limiting mode. If 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 dual power supply circuit to operate in the second current limiting mode, 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. In conjunction with the dual power supply circuit described above, the electrical parameter value corresponding to the second current limiting mode is half the electrical parameter value corresponding to the first current limiting mode. For example, if the electrical parameter value corresponding to the first current limiting mode is 2V, the electrical parameter value corresponding to the second current limiting mode is 1V. The above values ​​can be adjusted according to circuit design requirements and different application scenarios.

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

[0071] In some optional embodiments, the input source judgment module 100 is used to determine that the dual power supply circuits are connected to different input sources when the absolute value of the difference between 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 between 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 response target circuit when powered by the constant current source is less than a first current threshold and greater than a second current threshold, and the input current of the sampling end of the response target circuit when powered by the constant current source is greater than the first current threshold and greater than the second current threshold, then determine that the dual power supply circuits are connected to different input sources.

[0072] In some of these optional embodiments, combined with Figure 3 As shown, Figure 3 The circuit diagram of a dual-input control circuit in one embodiment is shown. The input source determination module 100 includes a voltage comparison unit 110 and a current comparison unit 120. The two input terminals of the voltage comparison unit 110 receive the input voltages of the dual power supply circuits, respectively. The output terminal of the voltage comparison unit 110 is connected to the first input terminal of the current limiting mode control module 200, and is used to compare the input voltages of the dual power supply circuits to obtain a first determination signal. The current comparison unit 120 receives a sampled current of the target power supply circuit at one input terminal and a current threshold at the other input terminal, and is used to compare the input current of the target power supply circuit with the current threshold to obtain a second determination signal.

[0073] The voltage comparison unit 110 is used to compare the input voltages of the dual power supply circuit to determine the relationship between the absolute value of the difference between the input voltages of the dual power supply circuit and the voltage threshold. If 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, it indicates that the dual power supply circuits are connected to different input sources. If the absolute value of the difference between the input voltages of the dual power supply circuit is less than the voltage threshold, it cannot be determined whether the dual power supply circuits are connected to the same input source. Therefore, the current comparison unit 120 is required to compare the input currents. The current comparison unit 120 mainly compares the input current of the target power supply circuit with the current threshold. If the input current of the target power supply circuit is less than the current threshold, it indicates that the dual power supply circuits are connected to different input sources. Otherwise, it indicates that the dual power supply circuits are connected to the same input source.

[0074] Among them combined Figure 3The voltage comparison unit 110 includes an operational amplifier unit 111, an absolute value output unit 112, and a comparison unit 113. The operational amplifier unit 111 has two input terminals that receive the input voltages of the dual-power supply circuit, respectively. The absolute value output unit 112 has an input terminal connected to the output terminal of the operational amplifier unit 111 and is configured to obtain the absolute value of the input voltage difference of the dual-power supply circuit obtained by the operational amplifier unit 111. The comparison unit 113 has one input terminal connected to the output terminal of the absolute value output unit 112 and one input terminal that receives a voltage threshold. The comparison unit 113 is configured to obtain a first determination signal based on the absolute value of the input voltage difference of the dual-power supply circuit and the voltage threshold.

[0075] like Figure 3 In the embodiment, the operational amplifier unit 111 includes an operational amplifier U3A and its peripheral circuits, the comparison unit 113 includes a comparator U2A and its peripheral circuits, and the absolute value output unit 112 includes an operational amplifier U1A and an operational amplifier U1B and their peripheral circuits.

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

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

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

[0079] The difference between the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 will output positive or negative values ​​after passing through the operational amplifier U3A. After passing through the absolute value output circuit, the value entering the inverting input terminal of pin 3 of the comparator U2 is all positive.

[0080] In some optional embodiments, the voltage threshold is obtained by the absolute value output unit 112 when the difference between the input voltages of the dual power supply circuit is a target value, wherein the value range of the target value is determined based on line loss and sampling deviation.

[0081] The value of the voltage threshold Vref in this embodiment is defined as the value Vsamp output by the operational amplifier U3A and the absolute value output circuit when the difference between the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 is the target value. The target value range is determined based on line loss and sampling deviation, which can be 1V-3V. The line loss is due to the fact that the input of the input source needs to be connected to the corresponding first power supply circuit PV1 and the second power supply circuit PV2 through a line. Therefore, there may be line loss in the input voltage, and the line loss of the first power supply circuit PV1 and the second power supply circuit PV2 may be different. In addition, the input voltage is obtained through sampling, which may have a sampling deviation. Therefore, as long as the difference between the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 is greater than or equal to the target value, it is considered that the first power supply circuit PV1 and the second power supply circuit PV2 are connected to different input sources.

[0082] In addition, the voltage threshold is taken from the input voltage of the first power supply circuit PV1 or the second power supply circuit PV2 to ensure that the control part of the second power supply circuit PV2 enable pin PV2_EN only controls the operation when the first power supply circuit PV1 or the second power supply circuit PV2 is connected to the input source.

[0083] In other embodiments, the target power supply circuit may also be a power supply circuit whose sampling end is powered by a constant current source. That is, when it is impossible to determine whether the dual power supply circuits are connected to the same input source based on the first judgment signal, the constant current source is first supplied to the target power supply circuit, thereby fixing the current of the sampling resistor of the target power supply circuit. The connection status of the input source of the dual power supply circuit is determined by detecting the input current corresponding to the sampling resistor. After determining the connection status of the input source of the dual power supply circuit, the target power supply circuit is controlled to operate normally, that is, the connection between the constant current source and the sampling end of the target power supply circuit is disconnected. Therefore, the target power supply circuit is powered by the constant current source only during the period of time determined by the input source.

[0084] In which case, if 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 power supply circuit, the constant current source is controlled to power the sampling end of the target power supply circuit within the target time, and then the input current of the target power supply circuit when the constant current source is powering is collected. In which case, if the input source of the first power supply circuit PV1 and the second power supply circuit PV2 is 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, when the constant current source determines that the input is constant, the resistance of the sampling resistor is different, and the corresponding current sampling values ​​are different. Therefore, it is possible to determine whether the first power supply circuit PV1 and the second power supply circuit PV2 are connected to the same input source based on different current sampling values. When 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. When 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, the corresponding first current threshold and second current threshold can be determined. Thus, when the input current of the sampling end of the target circuit is 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; when the input current of the sampling end of the target circuit is 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.

[0085] Combine Figure 3 As shown, 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, wherein one input end of the first comparison subunit 121 receives a first current threshold, and another input end of the first comparison subunit 121 receives an input current of the target power supply circuit; one input end of the second comparison subunit 122 receives a second current threshold, and another input end of the second comparison subunit 122 receives an input current of the target power supply circuit; one 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 the comparison result of the first comparison subunit 121 and the 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 powered by the constant current source with the first current threshold and the second current threshold to determine whether the dual power supply circuits are 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. Figure 3 The first comparison subunit 121 includes a comparator U6A and its peripheral circuits, the second comparison subunit 122 includes a comparator U6B and its peripheral circuits, and the logic unit 123 includes an AND gate U7 and its peripheral circuits. In the first comparison subunit 121, the comparator U6A has a non-inverting input terminal that receives a first current threshold, an inverting input terminal that receives an input current from a target power supply circuit powered by a constant current source, and an output terminal that is connected to the second terminal of a resistor R17, the first terminal of which is connected to a power supply VCC. In the second comparison subunit 122, the comparator U6B has a non-inverting input terminal that receives an input current from a target power supply circuit powered by a constant current source, an inverting input terminal that receives a second current threshold, and an output terminal that is connected to the second terminal of a resistor R36, the first terminal of which is connected to a power supply VCC. In the logic unit 123, the first terminal of an AND gate U7 is connected to the output terminal of the comparator U6A, and the second terminal of the AND gate U7 is connected to the output terminal of the comparator U6B. 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 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; the first current sampling value is the current sampling value when the dual power supply circuit is connected to different input sources, and the second current sampling value is the current sampling value when the dual power supply circuit is connected to the same input source.

[0089] For ease of 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 while ensuring that the power consumption 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 output current of the constant current source is also related to the amplification factor. The size of the constant current source, the amplification factor, and the resistance of the sampling resistor are used to ensure that the current sampling value is appropriate and avoid errors caused by current sampling values ​​that are too small. The current sampling value of the first power supply circuit PV1 is amplified. That is, when the dual power supply circuits are connected to different input sources, the current sampling value of the first power supply circuit PV1 is a first current sampling value. This first current sampling value can be 1V (5mΩ*0.5A*400), where 400 is the amplification factor. In other embodiments, it can be other values. When the dual power supply circuits are connected to the same input source, the current sampling value of the first power supply circuit PV1 is a second current sampling value. This second current sampling value 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. For example, the first current sampling value is 1V and the second current sampling value is 0.5V. 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. It is only necessary to ensure the input current of the target power supply circuit powered by the constant current source. When the dual power supply circuits are connected to the same input source or different input sources, the current comparison unit 120 outputs different second judgment signals.

[0091] In the above embodiment, the input source of the dual power supply circuit is determined by the input voltage and the input current.

[0092] In some optional embodiments, the constant current driver module 500 includes: a control signal generating unit 510 and a constant current switch unit 520. The input end of the control signal generating unit 510 is connected to the first output end of the input source judgment module 100; the constant current switch unit 520 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 510 is configured to output a first control signal if the first judgment signal cannot determine whether the dual power supply circuits are 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 within a target time based on the first control signal; and to output a second control signal if the first judgment signal determines that the dual power supply circuits are connected to different input sources, and the constant current switch unit 520 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.

[0093] Among them, combined Figure 3 As shown, the control signal generating unit 510 includes a transistor Q16. The emitter of the transistor Q16 is connected to the first output terminal of the input source determination module 100 and the first end of the resistor R33. The second end of the resistor R33 is connected to the base of the transistor Q16. The collector of the transistor Q16 is connected to the control terminal of the constant current switch unit 520. The constant current switch unit 520 includes a switch Q17. The gate of the switch Q17 is connected to the second end of the resistor R34 and the first end of the resistor R35. The first end of the resistor R34 serves as the control terminal of the constant current switch unit 520. The second end of the resistor R35 and the source of the switch Q17 are connected to the input ground of the battery pack. The drain of the switch Q17 is connected to the second end of the constant current source. The first end of the constant current source is connected to the input ground of the target power supply circuit.

[0094] In which, when the first judgment signal indicates that the input sources of the dual power supply circuit are connected to different input sources, the control signal generating unit 510 outputs a second control signal, and the constant current switch unit 520 controls the constant current source to disconnect from the sampling end of the target power supply circuit based on the second control signal under the second control signal.

[0095] When the first judgment signal indicates that it is impossible to determine whether the dual power supply circuits are 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 power supply circuit within the target time under the first control signal.

[0096] Specifically, when it is determined based on the input voltages of the dual power supply circuits that the dual power supply circuits are connected to different input sources, current sampling is not required, and therefore, there is no need to control the constant current source to supply power to the sampling terminal of the target power supply circuit within a target time. When it is not possible to determine based on the input voltages of the dual power supply circuits whether the dual power supply circuits are connected to the same input source, it is necessary to continue determining the input current. Therefore, the constant current source is controlled to supply power to the sampling terminal of the target power supply circuit within a target time, thereby sampling the input current of the target power supply circuit to determine whether the input sources of the dual power supply circuits are the same input source.

[0097] In some optional embodiments, the constant current driving module 500 further includes: a current sampling time control unit 530, wherein the 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 the output end of the current sampling time control unit 530 is connected to the control end of the control signal generating unit 510.

[0098] The current sampling time control unit 530 is used to control the signal generating unit 510 to output a second control signal after a target time delay when the constant current source supplies power to the sampling end of the target power supply circuit, so that the constant current switch unit 520 disconnects the connection between the constant current source and the sampling end of the target power supply circuit based on the second control signal, wherein the target time is less than the time from the presence of input voltage to the start of operation of the target power supply circuit.

[0099] Since the access of the constant current source will affect the normal operation of the power supply circuit, it is necessary to control the time when the constant current source supplies power to the target power supply circuit, that is, the time of current sampling. Therefore, when the constant current source supplies power to the target power supply circuit, the target time is delayed, and then the constant current source is controlled to disconnect from the sampling end of the target power supply circuit. The delay and disconnection actions are controlled by the current sampling time control unit 530. It is further explained that 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 performs current limiting mode selection based on whether it is the same input source, and controls the power supply circuit to work normally only after the current limiting mode is selected.

[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] Combine Figure 3 , where the VCC voltage charges the first capacitor C8 through resistor R6 and charges the second capacitor C9 through resistor R6 and resistor R33. The first capacitor C8 charges faster than the second capacitor C9, and eventually the voltages of the first capacitor C8 and the second capacitor C9 are equal. Diode D2 is in the off state. When the second capacitor C9 is fully charged, the voltage at the b-pole of transistor Q16 is equal to the voltage at the e-pole, transistor Q16 is turned off, and MOS transistor Q17 is also turned off. Therefore, the time the constant current source supplies power to the sampling resistor R1 of the target power supply circuit is the time it takes for the second capacitor C9 to be fully charged. In addition, if a current limiting mode switch is required, the switching time of the current limiting mode switch is less than the time it takes for the second capacitor C9 to be fully charged. That is, the current limiting mode switch is completed before the second capacitor C9 is fully charged.

[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 locking module 400; the input end of the interlocking unit 220 is connected to the output end of the first judgment unit 210; and 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 the dual power supply circuits have input sources, the present application samples the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2. The sampled values ​​enter the non-inverting input terminal of pin 1 and the inverting input terminal of pin 3 of the operational amplifier U3, respectively. The output value of the operational amplifier U3 enters the absolute value output circuit and then enters the inverting input terminal of pin 2 of the comparator U2A. When the absolute value of the difference between the actual input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 is greater than 2V (i.e., the target value mentioned above), it indicates that the dual power supply circuits are 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, and the comparator U2A outputs a low level. At this time, the transistor Q16 is turned off, the MOS tube Q17 is turned 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 input terminal of pin 1 of the AND gate U4 is at a low level. No matter whether the input terminal of pin 2 is at a high level or a low level, the AND gate U4 outputs a low level. The transistor Q13 is cut off because the base is at a low level, and the transistor Q11 is cut off because the b pole and the e pole are at the same potential. The relay RLY1 does not work, and the first power supply circuit PV1 and the second power supply circuit PV2 operate in the first current limiting mode.

[0107] This working condition may 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 sources, the present application samples the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2. The sampled values ​​enter the non-inverting input terminal 1 and the inverting input terminal 3 of the operational amplifier U3, respectively. The output value of the operational amplifier U3 enters the absolute value output circuit and then the inverting input terminal 2 of the comparator U2A. When the input voltages of the first power supply circuit PV1 and the second power supply circuit PV2 are actually less than 2V (i.e., the target value mentioned above), that is, the value Vsamp output by the absolute value output circuit is less than the voltage threshold Vref, the comparator U2A outputs a high level. At this time, the e-pole voltage of the transistor Q16 is greater than the b-pole voltage, the transistor Q16 is turned on, and the VCC voltage is divided by resistor R6, transistor Q16 resistor R34, and resistor R35, controlling the MOS transistor Q17 to turn on. The constant current source then supplies power to the sampling terminal of the first power supply circuit PV1 within the target time. At this time, the current sampling of the first power supply circuit PV1 samples the sampling resistor R1 of the first power supply circuit PV1:

[0109] When the current sampling value of the first power supply circuit PV1 is 0.5V (see the second current sampling value above for details), it means that the dual power supply circuits are connected to the same source, and the comparators U6A and U6B both output high levels, that is, pins 1 and 2 of the AND gate U7 both input high levels, then pin 4 of the AND gate U7 outputs a high level, and pins 1 and 2 of the AND gate U4 input high levels, then pin 4 of the AND gate U4 outputs a high level, the transistor Q13 is turned on because the base is at a high level, the coil of the relay RLY1 has a current loop, the relay RLY1 works, and 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, transistor Q11 turns on because the voltage at its e-pole is greater than the voltage at its b-pole. At this point, transistor Q11 interlocks with transistor Q13, maintaining the base of transistor Q13 at a high level. This causes transistor Q13 to remain on, allowing relay RLY1 to continue operating and the dual power supply circuit to operate in the second current-limiting mode. Without the interlock circuit, when the first power supply circuit PV1 is operational, the current sampled value of the first power supply circuit PV1 will be greater than the first threshold value Iref1. This will cause pin 1 of AND gate U7 to be low, and AND gate U7 will output a low level. AND gate U7 will also output a low level, turning transistor Q13 off and relay RLY1 off. This will cause the current-limiting modes of the first and second power supply circuits PV1 and PV2 to operate in the first current-limiting mode, damaging 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 eventually 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 voltage at the b-pole of the transistor Q16 is equal to the voltage at the e-pole, and the transistor Q16 is turned off. The MOS transistor Q17 is also turned off. Therefore, the time the constant current source supplies power to the first power supply circuit PV1 for current sampling is the time it takes for the second capacitor C9 to be fully charged. This time is the target time, which must be less than the time from the input voltage to the start of operation of the power supply circuit to avoid affecting current sampling during normal operation of the circuit.

[0112] In this way, the maximum input current of the first power supply circuit PV1 and the second power supply circuit PV2 is halved and limited to 20A due to the current limiting mode, maintaining the maximum operation of the single power supply circuit at 1200W. The input current and output current of the dual power supply circuit will not exceed the rated current of fuses F1, F2, F3, and F4, making the dual power supply circuit stable and reliable.

[0113] When the current sampling value of the first power supply circuit PV1 is 1V (that is, the first current sampling value mentioned above), it means that the dual power supply circuits are connected to different input sources, the comparator U6A outputs a low level, and the comparator U6B outputs a high level, that is, pin 1 of the AND gate U7 is a low level and pin 2 is a high level, then pin 4 of the AND gate U7 outputs a low level, pin 1 of the AND gate U4 is a high level and pin 2 is a low level, then pin 4 of the AND gate U4 outputs a low level, the transistor Q13 is cut off because the base is at a low level, the transistor Q11 is cut off because the b pole and the e pole are at the same potential, the relay RLY1 does not work, and the first power supply circuit PV1 and the second power supply circuit PV2 operate 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 charges faster than the second capacitor C9, and eventually 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 voltage at the b-pole of the transistor Q16 is equal to the voltage at the e-pole, and the transistor Q16 is turned off. The MOS transistor Q17 is also turned off. Therefore, the time when the constant current source supplies power to the first power supply circuit PV1 for current sampling is the time when the second capacitor C9 is fully charged.

[0115] In this way, the present application samples the input voltage of the dual power supply circuit and compares it. If it is greater than the voltage threshold Vref, the first current limiting mode is adopted; if it is less than the voltage threshold Vref, the first power supply circuit PV1 is powered by a constant current source, and the current sampling value of the first power supply circuit PV1 is used to determine whether it is the same input source. If the sampling value is 0.5V, it means that it is the same source, and the second current limiting reference will be adopted; if the sampling value is 1V, it means 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, by adding the current limiting control circuit based on the constant current source of the present application, can complete the detection of whether the input source is the same and the adjustment of the current limiting mode during the period from the dual power supply circuit being connected to the input source to the dual power supply circuit starting to work, so that the maximum input current of the dual power supply circuit is limited to 20A in any working condition, thereby ensuring the reliability of the PV circuit components and avoiding damage to the dual power supply circuit.

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

[0118] In the description of this specification, reference to the terms "some embodiments" or "other embodiments" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0119] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0120] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by 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; The current limiting mode control module is used for the current limiting mode control module to adopt a first current limiting mode when the dual power supply circuit is connected to different input sources; and adopt a second current limiting mode when the dual power supply circuit is 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.

2. The circuit according to claim 1, wherein: The input source judgment module is configured to determine that the dual power supply circuits are connected to different input sources when the absolute value of the difference between 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 between 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.

3. 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.

4. The circuit according to claim 3, 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.

5. The circuit according to claim 3, 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.

6. The circuit according to any one of claims 1 to 5, 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.

7. The circuit according to claim 6, 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.

8. The circuit according to claim 7, 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, a cathode of the diode being connected to the first end of the first capacitor, and an anode of the diode being 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.

9. The circuit according to claim 1 or 2, characterized in that 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.

10. 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 9.

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