Reverse connection prevention pre-charging circuit, energy storage converter, control method and energy storage system

Abstract

The invention discloses an anti-reverse-connection pre-charging circuit, an energy storage converter, a control method and an energy storage system, and the anti-reverse-connection pre-charging circuit comprises a battery connection end which comprises a first positive electrode connection end and a first negative electrode connection end; the inverter connecting end comprises a second positive electrode connecting end and a second negative electrode connecting end; the switch module is arranged between the first positive electrode connecting end and the second positive electrode connecting end; the pre-charging branch comprises an impedance element and a one-way conduction module which are connected in series, the pre-charging branch is connected with the switch module in parallel, and the current conduction direction of the one-way conduction module is from the second positive electrode connecting end to the first positive electrode connecting end; and one end of the pre-charging capacitor is connected to a connecting point of the first positive electrode connecting end and the pre-charging branch, and the other end of the pre-charging capacitor is connected to the first negative electrode connecting end. According to the embodiment of the invention, reverse connection prevention and pre-charging can be realized on hardware, and reverse connection fault detection and pre-charging voltage judgment on software can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and particularly to an anti-reverse connection pre-charge circuit, an energy storage converter, a control method, and an energy storage system. Background Art

[0002] In recent years, the rise of clean energy has brought about various technological innovations. For an energy storage system based on clean energy, in addition to being able to reduce the power consumption burden on the power grid to a certain extent, when the electric energy of the energy storage system is sufficient, it can also be connected to the power grid to transmit power to the power grid. An energy storage converter is provided between the energy storage unit such as a battery of the energy storage system and the inverter, which has functions such as converting voltage and managing the flow of electric energy.

[0003] The positive and negative electrodes of the energy storage converter need to be correctly connected to the positive and negative electrodes of the DC bus of the inverter. At the same time, it is necessary to avoid the large current output by the battery at the moment of connecting the battery to the energy storage converter from impacting the capacitor of the energy storage converter. In related technologies, a pre-charge branch is usually composed of a relay and a resistor. Before the energy storage converter starts, the pre-charge branch is turned on first. When the positive and negative connections are incorrect, the capacitor of the energy storage converter cannot be pre-charged, so that the energy storage converter cannot start. When the positive and negative connections are correct, due to the existence of the resistor, the charging current of the battery for the capacitor of the energy storage converter is reduced, so as to start safely. Although the above solution can avoid reverse connection start, the software cannot identify the reverse connection fault, and the user needs to check the reason for the inability to start. Summary of the Invention

[0004] Embodiments of the present application provide an anti-reverse connection pre-charge circuit, an energy storage converter, a control method, and an energy storage system, which can achieve anti-reverse connection and pre-charge on the hardware, and detect reverse connection faults and judge pre-charge voltages on the software.

[0005] In a first aspect, an embodiment of the present application provides a DC bus anti-reverse connection pre-charge circuit, including:

[0006] A battery connection end, including a first positive connection end and a first negative connection end;

[0007] An inverter connection end, including a second positive connection end and a second negative connection end;

[0008] A switch module, disposed between the first positive connection end and the second positive connection end;

[0009] A pre-charge branch, including an impedance element and a unidirectional conduction module connected in series, the pre-charge circuit is connected in parallel with the switch module, and the current conduction direction of the unidirectional conduction module is from the second positive connection end to the first positive connection end;

[0010] A pre-charge capacitor, one end of the pre-charge capacitor is connected to the connection point between the first positive electrode connection terminal and the pre-charge branch, and the other end of the pre-charge capacitor is connected to the first negative electrode connection terminal.

[0011] In some embodiments, it further includes a first voltage acquisition module and a second voltage acquisition module. The first voltage acquisition module is used to acquire the voltage at the connection point between the first positive electrode connection terminal and the pre-charge branch, and the second voltage acquisition module is used to acquire the voltage at the connection point between the second positive electrode connection terminal and the pre-charge branch.

[0012] In some embodiments, the impedance element is composed of at least two resistors connected in series, and the unidirectional conduction module is composed of at least two diodes connected in series in the same direction.

[0013] In a second aspect, an embodiment of the present application provides an energy storage converter, including a first auxiliary power supply, a second auxiliary power supply, a controller, and the reverse connection prevention pre-charge circuit described in the first aspect;

[0014] The input end of the first auxiliary power supply is connected to the battery connection terminal, the output end of the first auxiliary power supply is connected to the power supply pin of the controller, the input end of the second auxiliary power supply is connected to the inverter connection terminal, and the output end of the second auxiliary power supply is connected to the power supply pin of the controller;

[0015] The controller is used to obtain the second voltage value at the connection point between the second positive electrode connection terminal and the pre-charge branch when detecting the power supply input of the first auxiliary power supply or the second auxiliary power supply, and is further used to determine that the DC bus of the inverter is reversely connected to the energy storage converter when the second voltage value is a negative voltage, and to disconnect the switch module to pre-charge the pre-charge capacitor through the pre-charge branch when the second voltage value is a positive voltage.

[0016] In some embodiments, it further includes a first voltage acquisition module and a second voltage acquisition module. The first voltage acquisition module is used to acquire the voltage at the connection point between the first positive electrode connection terminal and the pre-charge branch, the second voltage acquisition module is used to acquire the voltage at the connection point between the second positive electrode connection terminal and the pre-charge branch, and both the first voltage acquisition module and the second voltage acquisition module are communicatively connected to the controller.

[0017] In a second aspect, an embodiment of the present application provides a control method for an energy storage converter, which is applied to the energy storage converter described in the second aspect. The method includes:

[0018] When detecting the power supply input of the first auxiliary power supply or the second auxiliary power supply, obtain the second voltage value at the connection point between the second positive electrode connection terminal and the pre-charge branch;

[0019] When the second voltage value is a negative voltage, it is determined that the DC bus of the inverter is reversely connected to the energy storage converter;

[0020] When the second voltage value is a positive voltage, the switch module is disconnected to pre-charge the pre-charge capacitor through the pre-charge branch.

[0021] In some embodiments, after disconnecting the switch module to pre-charge the pre-charge capacitor through the pre-charge branch, the method further includes:

[0022] Obtain a first voltage value at the connection point between the first positive connection terminal and the pre-charge branch;

[0023] When the absolute value of the difference between the first voltage value and the second voltage value is less than a preset voltage value, the switch module is closed to bypass the pre-charge branch.

[0024] In a fourth aspect, an embodiment of the present application provides a controller, including at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the control method as described in the third aspect.

[0025] In a fifth aspect, an embodiment of the present application provides an energy storage system, including a battery, an inverter, and the energy storage converter according to the second aspect, where the battery is connected to the battery connection terminal, and the inverter is connected to the inverter connection terminal.

[0026] In some embodiments, a power supply switch is provided between the battery and the battery connection terminal.

[0027] The anti-reverse connection pre-charge circuit, energy storage converter, control method and energy storage system of the embodiments of the present application have at least the following beneficial effects: In terms of hardware implementation, the anti-reverse connection pre-charge circuit of the embodiments of the present application is provided with a unidirectional conduction module from one end of the inverter to one end of the battery. If the inverter is reversely connected to the anti-reverse connection pre-charge circuit, the negative pole of the inverter is at a low potential and cannot pass through the unidirectional conduction module, thus realizing physical anti-reverse connection. If the inverter is correctly connected to the anti-reverse connection pre-charge circuit, the pre-charge branch is used to connect with the pre-charge capacitor to realize pre-charge before startup; In terms of software implementation, two auxiliary power supplies are used to connect to the controller to supply power to the controller. The first auxiliary power supply is powered by the battery, and the second auxiliary power supply is powered by the DC bus of the inverter. When the inverter is reversely connected to the energy storage converter, the power supply of the second auxiliary power supply fails. At this time, if the first auxiliary power supply is normally powered, the controller can be powered on and work, and judge whether the inverter is reversely connected according to the positive and negative of the collected second voltage value, so as to be able to remind of the reverse connection fault at the software level. The embodiments of the present application realize anti-reverse connection and pre-charge startup, and can also prompt the reverse connection fault when the inverter is reversely connected, solving the problem in the prior art that it is necessary for humans to judge what kind of fault after the energy storage converter fails to start.

[0028] Other features and advantages of the present application will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present application. The objectives and other advantages of the present application can be achieved and obtained by the structures specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the anti-reverse connection pre-charge circuit provided by the embodiments of the present application;

[0030] Figure 2 is a schematic circuit diagram of the anti-reverse connection pre-charge circuit provided by the embodiments of the present application;

[0031] Figure 3 is a schematic structural diagram of the energy storage converter provided by the embodiments of the present application;

[0032] Figure 4 is the control method of the energy storage converter provided by the embodiments of the present application;

[0033] Figure 5 is a flowchart of the control method provided by another embodiment of the present application;

[0034] Figure 6 is a schematic structural diagram of the energy storage system provided by an example of the present application;

[0035] Figure 7 is a schematic structural diagram of the energy storage system provided by another example of the present application;

[0036] Figure 8It is a schematic structural diagram of an energy storage system provided by another example of the present application;

[0037] Figure 9 It is a schematic structural diagram of an energy storage system provided by another example of the present application;

[0038] Figure 10 It is an overall flowchart of a control method provided by an example of the present application;

[0039] Figure 11 It is a schematic diagram of a controller provided by an embodiment of the present application. Detailed implementation manners

[0040] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences unless it is stated that a certain sequence must be followed.

[0041] In the description of the present application, the meaning of several is one or more, the meaning of multiple is more than two, understand greater than, less than, exceeding, etc. as not including the present number, and understand above, below, within, etc. as including the present number. If the first and second are described only for the purpose of distinguishing technical features, they cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0042] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0043] In the context of "carbon peak" and "carbon neutrality", as new clean energy sources, wind and photovoltaic energy will become the absolute main energy sources in the future. However, due to the characteristics of discontinuous, unstable and uncontrollable power generation of renewable energy sources such as wind energy and solar energy, large-scale integration into the power grid will bring serious impacts to the safe and stable operation of the power grid. Therefore, energy storage technology, as one of the important supporting technologies, is an important means to reduce the impact on the power grid caused by large-scale access of new energy.

[0044] The rise of clean energy has brought about various technological innovations. For the energy storage system based on clean energy, in addition to being able to relieve the power consumption burden of the power grid to a certain extent, when the electric energy in the energy storage system is sufficient, it can also be connected to the power grid to transmit power to the power grid. A energy storage converter is arranged between energy storage units such as the battery of the energy storage system and the inverter, which has functions such as converting voltage and managing the flow of electric energy.

[0045] The positive and negative poles of the energy storage converter need to be correctly connected to the positive and negative poles of the DC bus of the inverter. At the same time, it is necessary to avoid the large current output by the battery at the moment of connecting the battery to the energy storage converter from impacting the capacitor of the energy storage converter. In related technologies, a pre-charge branch is usually composed of a relay and a resistor. Before the energy storage converter starts, the pre-charge branch is connected first. When the positive and negative pole wiring is incorrect, the capacitor of the energy storage converter cannot be pre-charged, resulting in the inability of the energy storage converter to start. When the positive and negative pole wiring is correct, due to the existence of the resistor, the charging current of the battery to the capacitor of the energy storage converter is reduced, so as to start safely. Although the above scheme can avoid reverse connection start, the software cannot identify the reverse connection fault, and the user needs to check the reason for the inability to start.

[0046] Based on this, the embodiments of the present application provide an anti-reverse connection pre-charge circuit, an energy storage converter, a control method and an energy storage system. In terms of hardware implementation, the anti-reverse connection pre-charge circuit of the embodiments of the present application sets a unidirectional conduction module from one end of the inverter to one end of the battery. If the inverter is reversely connected to the anti-reverse connection pre-charge circuit, the negative pole of the inverter is at a low potential and cannot pass through the unidirectional conduction module, thus realizing physical anti-reverse connection. If the inverter is correctly connected to the anti-reverse connection pre-charge circuit, the pre-charge branch is used to connect with the pre-charge capacitor to realize pre-charge before starting; in terms of software implementation, two auxiliary power supplies are used to connect to the controller to supply power to the controller. The first auxiliary power supply is powered by the battery, and the second auxiliary power supply is powered by the DC bus of the inverter. When the inverter is reversely connected to the energy storage converter, the power supply of the second auxiliary power supply fails. At this time, if the first auxiliary power supply is normally powered, the controller can be powered on and work, and judge whether the inverter is reversely connected according to the positive and negative of the collected second voltage value, so as to be able to remind the reverse connection fault at the software level. The embodiments of the present application realize anti-reverse connection and pre-charge start, and can also prompt the reverse connection fault when the inverter is reversely connected, solving the problem that it is necessary for humans to judge what kind of fault occurs after the energy storage converter cannot start in the prior art.

[0047] The anti-reverse connection pre-charge circuit, the energy storage converter, the control method and the energy storage system will be described below with reference to the drawings:

[0048] Refer to Figure 1 shown, Figure 1 is a schematic structural diagram of the anti-reverse connection pre-charge circuit provided by the embodiments of the present application.

[0049] In some embodiments, the reverse connection prevention pre-charge circuit includes: a battery connection terminal, including a first positive connection terminal 110 and a first negative connection terminal 120;

[0050] an inverter connection terminal, including a second positive connection terminal 210 and a second negative connection terminal 220;

[0051] a switch module 300, disposed between the first positive connection terminal 110 and the second positive connection terminal 210;

[0052] It should be noted that the switch module 300 can be switched by a relay, a contactor, or other controlled switch devices, and no specific limitation is made in this embodiment.

[0053] a pre-charge branch, including an impedance element 410 and a one-way conduction module 420 connected in series, the pre-charge circuit is connected in parallel with the switch module 300, and the current conduction direction of the one-way conduction module 420 is from the second positive connection terminal 210 to the first positive connection terminal 110;

[0054] a pre-charge capacitor 500, one end of the pre-charge capacitor 500 is connected to the connection point of the first positive connection terminal 110 and the pre-charge branch, and the other end of the pre-charge capacitor 500 is connected to the first negative connection terminal 120.

[0055] It should be noted that in this embodiment, the battery, the pre-charge capacitor 500, the pre-charge branch, and the inverter are connected in sequence, the battery and the inverter are respectively disposed on both sides of the pre-charge capacitor 500, and a one-way conduction module 420 is provided in the reverse connection prevention pre-charge circuit from one end of the inverter to one end of the battery. If the inverter is reversely connected to the reverse connection prevention pre-charge circuit, the negative electrode of the inverter is at a low potential and cannot pass through the one-way conduction module 420, thereby realizing physical reverse connection prevention. If the inverter is correctly connected to the reverse connection prevention pre-charge circuit, the pre-charge branch is used to connect with the pre-charge capacitor 500 to realize pre-charge before startup, preventing the impact problem caused by large current.

[0056] It can be understood that due to too much charge stored inside the capacitor, the current increases sharply instantaneously, thereby causing an impact of instant high voltage and high current on the electronic components, and even causing component damage. Through the pre-charge branch, the charge stored inside the capacitor can be gradually released, thereby avoiding the instantaneous increase of current and protecting the circuit components.

[0057] In some embodiments, a first voltage acquisition module and a second voltage acquisition module are further included. The first voltage acquisition module is used to acquire the voltage at the connection point of the first positive connection terminal 110 and the pre-charge branch, that is, the voltage at point B, and the second voltage acquisition module is used to acquire the voltage at the connection point of the second positive connection terminal 210 and the pre-charge branch, that is, the voltage at point A, so as to realize the sampling of the voltages at points A and B.

[0058] It should be noted that by setting the first voltage acquisition module and the second voltage acquisition module, the voltage across the pre-charge circuit can be monitored in real time, realizing the monitoring of the voltage change inside the pre-charge capacitor 500, so as to control the working state of the pre-charge circuit.

[0059] It can be understood that the first voltage acquisition module and the second voltage acquisition module in this embodiment can be voltage sensors, comparator circuits, etc., or can be single-chip microcontrollers or digital circuits, and this embodiment does not make specific limitations.

[0060] In some embodiments, the impedance element 410 is composed of at least two resistors connected in series, and the unidirectional conduction module 420 is composed of at least two diodes connected in series in the same direction. By setting multiple resistors in series, the current impact can be dispersed, reducing the damage degree to the pre-charge capacitor 500, and by setting multiple diodes in series, the reverse connection of the inverter can be prevented.

[0061] It should be noted that if there is only one resistor and one diode in the pre-charge branch, the voltage inside the pre-charge capacitor 500 is likely to be unevenly distributed, resulting in some resistors being subjected to too high voltage, thus affecting the stability of the entire circuit. The setting of multiple resistors and diodes can achieve the voltage equalization effect, making the voltage inside the capacitor evenly distributed, thereby improving the stability and reliability of the anti-reverse connection pre-charge circuit.

[0062] It can be understood that the current conduction direction of the unidirectional conduction module 420 is from the second positive connection end 210 to the first positive connection end 110, that is, the positive direction of the diode is from point A to point B.

[0063] Refer to Figure 2 as shown in Figure 2 is the circuit schematic diagram of the anti-reverse connection pre-charge circuit provided by the embodiment of the present application.

[0064] In some embodiments, the battery and the inverter are respectively arranged on both sides of the pre-charge capacitor 500, and the anti-reverse connection pre-charge circuit is provided with a unidirectional conduction module 420 from one end of the inverter to one end of the battery. If the inverter is reversely connected to the anti-reverse connection pre-charge circuit, the negative electrode of the inverter is at a low potential and cannot pass through the unidirectional conduction module 420, thus realizing physical anti-reverse connection. If the inverter is correctly connected to the anti-reverse connection pre-charge circuit, the pre-charge before startup is realized by connecting the pre-charge branch to the pre-charge capacitor 500, preventing the impact problem caused by large current.

[0065] Refer to Figure 3 as shown in Figure 3 is the structural schematic diagram of the energy storage converter provided by the embodiment of the present application.

[0066] In some embodiments, the energy storage converter includes a first auxiliary power supply 610, a second auxiliary power supply 620, a controller 1000 andFigure 1 The reverse connection prevention precharge circuit shown

[0067] The input terminal of the first auxiliary power supply 610 is connected to the battery connection terminal, and the output terminal of the first auxiliary power supply 610 is connected to the power supply pin of the controller 1000 to draw power from the battery. The input terminal of the second auxiliary power supply 620 is connected to the inverter connection terminal, and the output terminal of the second auxiliary power supply 620 is connected to the power supply pin of the controller 1000 to draw power from the inverter. Thus, the controller 1000 can be powered by using two auxiliary power supplies connected to the controller 1000

[0068] It should be noted that by setting the first auxiliary power supply 610 and the second auxiliary power supply 620, the stability of the energy storage converter can be improved, and stable voltage and current can be provided for the controller 1000. When one of the auxiliary power supplies fluctuates, the normal operation of the energy storage converter can be maintained by the other auxiliary power supply, further enhancing the safety and reliability of the energy storage converter.

[0069] The controller 1000 is configured to obtain the second voltage value of the connection point between the second positive connection terminal 210 and the precharge branch when detecting the power supply input of the first auxiliary power supply 610 or the second auxiliary power supply 620. The controller 1000 is also configured to determine that the DC bus of the inverter is reversely connected to the energy storage converter when the second voltage value is a negative voltage, and to disconnect the switch module 300 to precharge the precharge capacitor 500 through the precharge branch when the second voltage value is a positive voltage, realizing the judgment of reverse connection prevention, and being able to start precharging under normal conditions, thereby reducing the instantaneous increase in current and protecting the load and equipment.

[0070] In some embodiments, when the second voltage value is a negative voltage and it is determined that the DC bus of the inverter is reversely connected to the energy storage converter, the unidirectional conduction module 420 in the precharge branch will block the reverse connection loop to protect the hardware device.

[0071] It is worth noting that the precharge branch is connected in parallel with the main circuit of the reverse connection prevention precharge circuit. When the second voltage value is a positive voltage, the switch module 300 is disconnected to precharge the precharge capacitor 500 through the precharge branch, avoiding the situation of instantaneous sharp increase in current and damaging components. And the controller 1000 is also configured to obtain the first voltage value of the connection point between the first positive connection terminal 110 and the precharge branch, facilitating subsequent judgment of whether the first voltage value and the second voltage value meet the condition for stopping precharging; when the absolute value of the difference between the first voltage value and the second voltage value is less than the preset voltage value, it indicates that the precharging is completed, and the switch module 300 is closed to bypass the precharge branch, completing the precharge soft start process and avoiding overcharging and damage.

[0072] It can be understood that, taking the switch module 300 controlling the switch through a relay as an example, when the second voltage value is a positive voltage, the relay is controlled to disconnect. At this time, the main circuit of the reverse connection prevention pre-charge circuit is disconnected, and the inverter pre-charges the pre-charge capacitor 500 through the impedance element 410 and the unidirectional conduction module 420 connected in series in the pre-charge branch; when the absolute value of the difference between the first voltage value and the second voltage value is less than the preset voltage value, the relay is closed, and the inverter directly charges the pre-charge capacitor 500 through the main circuit without passing through the pre-charge branch.

[0073] In some embodiments, it further includes a first voltage acquisition module and a second voltage acquisition module. The first voltage acquisition module is used to acquire the voltage at the connection point of the first positive connection end 110 and the pre-charge branch, that is, the voltage at point B. The second voltage acquisition module is used to acquire the voltage at the connection point of the second positive connection end 210 and the pre-charge branch, that is, the voltage at point A. Both the first voltage acquisition module and the second voltage acquisition module are communicatively connected to the controller 1000, so as to be able to monitor the voltage across the pre-charge branch and the voltage of the pre-charge capacitor 500 in real time, discover problems in time and feedback them to the controller 1000 for processing, improve the reliability and stability of the energy storage converter, and realize the real-time monitoring and control of the working state of the energy storage converter.

[0074] Those skilled in the art can understand that Figures 1 to 3 the schematic diagram shown in

[0075] does not constitute a limitation to the embodiments of the present application. It may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements. The control method of the energy storage converter in this embodiment will be specifically described below. Figure 4 As shown in Figure 4 is the control method of the energy storage converter provided by the embodiments of the present application, which is applied to but not limited to Figure 3 the energy storage converter in

[0076] Step S101, when the power supply input of the first auxiliary power supply 610 or the second auxiliary power supply 620 is detected, obtain the second voltage value at the connection point of the second positive connection end 210 and the pre-charge branch;

[0077] Step S102, when the second voltage value is a negative voltage, determine that the DC bus of the inverter is reversely connected to the energy storage converter;

[0078] Step S103, when the second voltage value is a positive voltage, disconnect the switch module 300 to pre-charge the pre-charge capacitor 500 through the pre-charge branch.

[0079] In steps S101 to S103 of some embodiments, when the power supply input of the first auxiliary power supply 610 or the second auxiliary power supply 620 is detected, the second voltage value of the connection point between the second positive connection terminal 210 and the pre-charge branch is obtained, that is, the voltage value at point A. When the second voltage value is a negative voltage, it indicates that the positive and negative poles of the inverter are connected reversely, resulting in the inverter being reversely connected to the anti-reverse pre-charge circuit, and it is determined that the DC bus of the inverter is reversely connected to the energy storage converter. When the second voltage value is a positive voltage, it indicates that the connection of the inverter is normal, and then the switch module 300 can be disconnected to pre-charge the pre-charge capacitor 500 through the impedance element 410 and the unidirectional conduction module 420 in the pre-charge branch, thereby restricting the rising rate and the flowing direction of the current and realizing the slow pre-charge of the pre-charge capacitor 500.

[0080] It should be noted that in this embodiment, an anti-reverse threshold can also be set to determine whether the DC bus of the inverter is reversely connected to the energy storage converter. When the second voltage value is lower than the anti-reverse threshold, it is regarded that the DC bus of the inverter is reversely connected to the energy storage converter; when the second voltage value is higher than the anti-reverse threshold, it is regarded that the connection of the inverter is normal, and the switch module 300 can be disconnected to pre-charge the pre-charge capacitor 500 through the pre-charge branch.

[0081] It can be understood that the existing anti-reverse technologies are usually one of the two types: software anti-reverse solutions and hardware anti-reverse solutions. Whether there is an anti-reverse situation is judged according to whether the controller 1000 has power supply. However, there may be some anti-reverse blind areas. For example, after hardware anti-reverse, the software cannot directly identify that an anti-reverse fault has occurred. In addition, the pre-charge function and the anti-reverse function are not combined in the existing technology. And this embodiment can organically combine the software and hardware anti-reverse functions, improving the safety of equipment installation and operation. And directly reuse the circuits of the pre-charge function and the anti-reverse function, unifying the two functions in software logic, so as to be able to pre-charge the capacitor during the process of judging reverse connection.

[0082] It is worth noting that after determining that the DC bus of the inverter is reversely connected to the energy storage converter, this embodiment can remind of the reverse connection fault at the software level. Among them, the reminder of the reverse connection of the inverter can be realized by means such as light reminder and voice reminder, solving the problem in the existing technology that it is necessary to manually judge what kind of fault occurs after the energy storage converter cannot start.

[0083] Refer to Figure 5 , Figure 5 is the flowchart of the control method provided by another embodiment of the present application. It includes but is not limited to the following steps S201 to S202.

[0084] It should be noted that steps S201 to S202 occur after the switch module 300 is disconnected to pre-charge the pre-charge capacitor 500 through the pre-charge branch.

[0085] Step S201: Obtain the first voltage value at the connection point between the first positive electrode connection terminal 110 and the pre-charge branch.

[0086] Step S202: When the absolute value of the difference between the first voltage value and the second voltage value is less than the preset voltage value, close the switch module 300 to bypass the pre-charge branch.

[0087] In steps S201 to S202 of some embodiments, after pre-charging the pre-charge capacitor 500, obtain the first voltage value at the connection point between the first positive electrode connection terminal 110 and the pre-charge branch, that is, the voltage value at point B, and calculate the absolute value of the difference between the first voltage and the second voltage value, that is, calculate the absolute value of the difference between the voltage value at point B and the voltage value at point A. When this absolute value is less than the preset voltage value, it indicates that the capacitor has been charged to the target voltage or is fully charged. Then close the switch module 300 to bypass the pre-charge branch, completing the pre-charging process of the pre-charge capacitor 500, avoiding overcharging the pre-charge capacitor 500, and extending the life of the capacitor.

[0088] It should be noted that in this embodiment, the preset voltage value can be set according to the user's needs. For example, 20 volts, 30 volts, 35 volts, etc. There is no specific limitation in this embodiment.

[0089] In some embodiments, this embodiment also provides an energy storage system. The energy storage system includes a battery, an inverter, and an energy storage converter as Figure 3 shown. The battery is connected to the battery connection terminal to supply power to the controller 1000 through the battery, and the inverter is connected to the inverter connection terminal to supply power to the pre-charge capacitor 500 through the inverter.

[0090] Since the energy storage system includes an energy storage converter as Figure 3 shown, therefore, for the specific implementation manners and technical effects of the energy storage system in the embodiments of this application, reference can be made to the specific implementation manners and technical effects of the energy storage converter in any of the above embodiments.

[0091] It can be understood that in this embodiment, the energy storage system can be applied to fields such as electric vehicle charging piles, on-vehicle chargers, industrial and commercial energy storage, etc. There is no specific limitation in this embodiment.

[0092] In some embodiments, a power supply switch is provided between the battery and the battery connection terminal. Among them, the power supply switch can be arranged on the positive connection line, negative connection line between the battery and the battery connection terminal, or simultaneously arranged on the positive connection line and the negative connection line, so as to protect the system and equipment from possible failures or accidents during the battery power supply process.

[0093] In order to more clearly and comprehensively explain the above anti-reverse connection pre-charge circuit, energy storage converter, control method, and energy storage system, specific examples will be used for illustration below.

[0094] Example 1:

[0095] Example 1 is a specific description of four situations of the energy storage system. Among them, the energy storage system includes a battery, an inverter, and an energy storage converter as shown in Figure 3 The battery is connected to the battery connection terminal to supply power to the controller 1000 through the battery, and the inverter is connected to the inverter connection terminal to supply power to the pre-charge capacitor 500 through the inverter.

[0096] It should be noted that a power supply switch is provided between the battery and the battery connection terminal.

[0097] Refer to Figure 6 , Figure 6 which is a schematic structural diagram of the energy storage system provided by an example of this application.

[0098] In some embodiments, Figure 6 a power supply switch is provided on the positive connection line between the battery of

[0099] Refer to Figure 7 , Figure 7 which is a schematic structural diagram of the energy storage system provided by another example of this application.

[0100] In some embodiments, Figure 7 the battery and the inverter in

[0101] Refer to Figure 8 , Figure 8 which is a schematic structural diagram of the energy storage system provided by another example of this application.

[0102] In some embodiments, Figure 8A power supply switch is provided on the positive connection line between the battery and the battery connection terminal, and the inverter is reversely connected to the energy storage converter. When the power supply switch is turned off, the battery stops supplying power, resulting in the first auxiliary power supply 610 being unable to supply power to the controller 1000. Since the inverter is reversely connected to the energy storage converter, it cannot pass through the unidirectional conduction module 420 in the anti-reverse connection pre-charge circuit, and similarly cannot supply power to the second auxiliary power supply 620. At this time, neither the first auxiliary power supply 610 nor the second auxiliary power supply 620 can supply power to the controller 1000, and the controller 1000 remains in a power-off state.

[0103] Reference Figure 9 , Figure 9 is a schematic structural diagram of an energy storage system provided by another example of the present application.

[0104] In some embodiments, Figure 9 the battery in is directly connected to the energy storage converter, and the inverter is reversely connected to the energy storage converter. The direct connection between the battery and the energy storage converter enables the first auxiliary power supply 610 to draw power from the power source and use the power drawn from the power source to supply power to the controller 1000. Since the inverter is reversely connected to the energy storage converter, it cannot pass through the unidirectional conduction module 420 in the anti-reverse connection pre-charge circuit. Therefore, at this time, only the battery and the first auxiliary power supply 610 can provide electrical energy to the controller 1000.

[0105] Example 2:

[0106] Example 2 provides a specific description of the control method for the energy storage converter, which specifically includes the following steps.

[0107] Reference Figure 10 , Figure 10 is an overall flowchart for judging the reverse connection of the DC bus from both hardware and software-hardware combination provided by an example of the present application, including:

[0108] Pure hardware judgment:

[0109] When the controller 1000 has no power supply, judge whether there is a reverse connection of the bus;

[0110] When it is determined that there is a reverse connection of the bus, the unidirectional conduction module 420 reversely connects the circuit to protect the hardware, and the energy storage system does not start;

[0111] When it is determined that there is no reverse connection of the bus, it is determined that the controller 1000 has no power and the system cannot start;

[0112] Complete the anti-reverse connection and pre-charge start. When there is a reverse connection, the interface current is close to 0, and the energy storage system cannot start; when it is correct, the energy storage system starts normally.

[0113] Judgment in the software-hardware combination method:

[0114] Step S1: Determine whether the controller 1000 is powered on;

[0115] Step S2: When the controller 1000 is powered on, determine whether the second voltage value sampled at point A is a negative voltage;

[0116] Step S3: When the second voltage value is a negative voltage, determine that the DC bus of the inverter is reversely connected to the energy storage converter, reverse the connection loop of the unidirectional conduction module 420, protect the hardware, and the energy storage system does not start;

[0117] Step S4: When the second voltage value is a positive voltage, disconnect the switch module 300 to pre-charge the pre-charge capacitor 500 through the pre-charge branch, and the energy storage system can start;

[0118] Step S5: When the absolute value of the difference between the first voltage value sampled at point B and the second voltage value sampled at point A is less than the preset voltage value, close the switch module 300 to bypass the pre-charge branch;

[0119] The anti-reverse connection and pre-charge start are completed. When reverse connection occurs, the interface current is close to 0, and the energy storage system cannot start; when it is correctly connected, the energy storage system starts normally.

[0120] In some embodiments, the existing anti-reverse connection technologies are usually only one of the two types: software anti-reverse connection schemes and hardware anti-reverse connection schemes. According to whether the controller is powered on, there are some anti-reverse blind zone situations. For example, after hardware anti-reverse, the software cannot directly identify that a reverse connection fault has occurred. And the pre-charge function and the anti-reverse connection function are not combined. It is easy to cause logical conflicts between the two functions. This embodiment organically combines software and hardware anti-reverse, eliminates the problem of anti-reverse blind zones, and improves the safety of equipment installation and operation. And directly multiplexes the sampling circuits of the pre-charge function and the anti-reverse connection function, and unifies the two functions in software logic.

[0121] As Figure 11 shown, Figure 11 is a schematic diagram of the controller 1000 provided by an embodiment of the present application.

[0122] The controller 1000 of the embodiment of the present application includes one or more processors 1001 and a memory 1002. Figure 11 Taking one processor 1001 and one memory 1002 as an example.

[0123] The processor 1001 and the memory 1002 can be connected through a bus or other means. Figure 11 Taking connection through a bus as an example.

[0124] The memory 1002, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory 1002 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 1002 may optionally include a memory 1002 that is remotely disposed relative to the processor 1001, and these remote memories can be connected to the controller 1000 through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0125] Those skilled in the art can understand that Figure 11 the device structure shown in does not constitute a limitation on the controller 1000, and may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0126] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory may optionally include a memory that is remotely disposed relative to the processor, and these remote memories can be connected to the processor through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0127] The non-transitory software programs and instructions required to implement the battery control method of the above embodiments are stored in the memory, and when executed by the processor, perform the above embodiments.

[0128] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place, or may be distributed to multiple network nodes. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0129] In addition, an embodiment of the present application also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are executed by a processor or a controller 1000.

[0130] Those of ordinary skill in the art will understand that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, and their appropriate combinations. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that a communication medium typically contains computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0131] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (one) of the following" or its similar expression refers to any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0132] In several embodiments provided in the present application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces, indirect couplings or communication connections of apparatuses or units, and can be in electrical, mechanical, or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0133] It should also be understood that the various embodiments provided in the embodiments of the present application can be combined arbitrarily to achieve different technical effects.

[0134] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the above embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present application.

Claims

1. An anti-reverse connection pre-charge circuit, characterized in that, it includes: A battery connection terminal, including a first positive connection terminal and a first negative connection terminal; An inverter connection terminal, including a second positive connection terminal and a second negative connection terminal; A switch module, arranged between the first positive connection terminal and the second positive connection terminal; A pre-charge branch, including an impedance element and a unidirectional conduction module connected in series, the pre-charge circuit is connected in parallel with the switch module, and the current conduction direction of the unidirectional conduction module is from the second positive connection terminal to the first positive connection terminal; A pre-charge capacitor, one end of the pre-charge capacitor is connected to the connection point of the first positive connection terminal and the pre-charge branch, and the other end of the pre-charge capacitor is connected to the first negative connection terminal.

2. The anti-reverse connection pre-charge circuit according to claim 1, characterized in that, it further includes a first voltage acquisition module and a second voltage acquisition module, the first voltage acquisition module is used to acquire the voltage of the connection point of the first positive connection terminal and the pre-charge branch, and the second voltage acquisition module is used to acquire the voltage of the connection point of the second positive connection terminal and the pre-charge branch.

3. The anti-reverse connection pre-charge circuit according to claim 1, characterized in that, the impedance element is composed of at least two resistors connected in series, and the unidirectional conduction module is composed of at least two diodes connected in series in the same direction.

4. An energy storage converter, characterized in that, it includes a first auxiliary power supply, a second auxiliary power supply, a controller and the anti-reverse connection pre-charge circuit according to any one of claims 1 to 3; The input end of the first auxiliary power supply is connected to the battery connection terminal, the output end of the first auxiliary power supply is connected to the power supply pin of the controller, the input end of the second auxiliary power supply is connected to the inverter connection terminal, and the output end of the second auxiliary power supply is connected to the power supply pin of the controller; The controller is used to obtain the second voltage value of the connection point of the second positive connection terminal and the pre-charge branch when detecting the power supply input of the first auxiliary power supply or the second auxiliary power supply, and is also used to determine that the DC bus of the inverter is reversely connected to the energy storage converter when the second voltage value is a negative voltage, and to disconnect the switch module to pre-charge the pre-charge capacitor through the pre-charge branch when the second voltage value is a positive voltage.

5. The energy storage converter according to claim 4, characterized in that, it further includes a first voltage acquisition module and a second voltage acquisition module, the first voltage acquisition module is used to acquire the voltage of the connection point of the first positive connection terminal and the pre-charge branch, the second voltage acquisition module is used to acquire the voltage of the connection point of the second positive connection terminal and the pre-charge branch, and the first voltage acquisition module and the second voltage acquisition module are both communicatively connected to the controller.

6. A control method for an energy storage converter, characterized in that, applied to the energy storage converter according to claim 4 or 5, the method includes: When detecting the power supply input of the first auxiliary power supply or the second auxiliary power supply, obtain the second voltage value of the connection point of the second positive connection terminal and the pre-charge branch; When the second voltage value is a negative voltage, it is determined that the DC bus of the inverter is reversely connected to the energy storage converter; When the second voltage value is a positive voltage, the switch module is disconnected to pre-charge the pre-charge capacitor through the pre-charge branch.

7. The method according to claim 6, wherein, after disconnecting the switch module to pre-charge the pre-charge capacitor through the pre-charge branch, the method further includes: acquiring a first voltage value of a connection point between the first positive connection end and the pre-charge branch; when an absolute value of a difference between the first voltage value and the second voltage value is less than a preset voltage value, closing the switch module to bypass the pre-charge branch.

8. A controller, wherein, comprises at least one processor and a memory for communicatively connecting with the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the control method according to claim 6 or 7.

9. An energy storage system, wherein, comprises a battery, an inverter and an energy storage converter according to claim 4 or 5, the battery is connected to the battery connection end, and the inverter is connected to the inverter connection end.

10. The energy storage system according to claim 9, wherein, a power supply switch is arranged between the battery and the battery connection end.

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