Energy storage battery and control method thereof

Abstract

The application discloses a kind of energy storage batteries and its control method, including several parallelly formed battery groups, and each battery group includes several batteries connected in series;Wherein the battery includes charge-discharge circuit;The charge-discharge circuit includes battery, first switch and second switch;The first switch and second switch are used to control the disconnection or closure of connecting line between two batteries.The application is connected in series by several batteries to form battery group, and simultaneously several battery groups are connected in parallel to form energy storage battery.In the operation process of energy storage battery, the disconnection and closure of first switch and second switch of each battery are independently controlled by each battery, so as to control the connection or closure of connecting line of each battery and the remaining battery, so that each battery in energy storage battery can be freely expanded.When a certain battery fails, only the battery group needs to be controlled, and the faulty battery is powered down and repaired, which improves the overall operation efficiency of energy storage battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution, in particular to a storage battery and a control method thereof. BACKGROUND

[0002] At present, electrochemical energy storage has developed rapidly in recent years, and market demand is also increasing. Short power outages caused by energy storage system failures can have a serious impact on user experience and economic benefits. Therefore, when designing an energy storage system, the fault tolerance and scalability of the energy storage system should be fully considered. The market energy storage system is generally composed of an inverter and a storage battery, wherein the storage battery is composed of a battery management system and multiple batteries.

[0003] A storage battery currently available is a single whole battery, which does not have scalability, and when capacity expansion or voltage platform is required, the entire storage battery must be replaced. In addition, the single whole storage battery has low fault tolerance, and when a component or battery in the storage battery fails, the entire system needs to stop working and the entire storage battery needs to be repaired or even scrapped, which is low in system operation efficiency and high in maintenance cost. SUMMARY

[0004] The present application provides a storage battery and a control method thereof to solve the technical problems of low fault tolerance and high maintenance cost of the existing storage battery in the energy storage system.

[0005] In order to solve the above technical problems, the present application provides a storage battery, which comprises a plurality of battery groups connected in parallel, and each battery group comprises a plurality of batteries connected in series.

[0006] The battery comprises a charge-discharge circuit, and the charge-discharge circuit comprises a storage battery, a first switch and a second switch. The first switch and the second switch are used to control the opening or closing of the connecting line between two batteries.

[0007] The present application comprises a plurality of batteries connected in series to form a battery group, and a plurality of battery groups connected in parallel to form a storage battery. During the operation of the storage battery, the opening and closing of the first switch and the second switch of each battery are independently controlled, thereby controlling the connection or closing of the connecting line between each battery and the remaining batteries, so that each battery in the storage battery can be freely expanded, and the operation of the batteries in other battery groups in the storage battery will not be affected when the batteries are disassembled or added. When a battery fails, only the battery group needs to be controlled, and the faulty battery needs to be powered off and repaired, without the need to stop the operation of the entire storage battery, thereby improving the overall operation efficiency of the storage battery and improving the fault tolerance.

[0008] Further, the battery includes a positive terminal and a negative terminal, in the charge-discharge circuit, the positive electrode of the storage battery is connected with the positive terminal, and the negative electrode of the storage battery is connected with the negative terminal; the first switch is arranged between the positive electrode of the storage battery and the positive terminal; and the second switch is arranged between the negative electrode of the storage battery and the negative terminal.

[0009] Further, the battery further includes a limit charge-discharge branch, which is arranged in parallel with the first switch.

[0010] Further, the limit charge-discharge branch includes a limit charge branch and a limit discharge branch; the limit charge branch and the limit discharge branch are arranged in parallel;

[0011] The limit charge branch includes a first diode and a fourth switch, the first diode and the fourth switch are arranged in series between the positive electrode of the storage battery and the positive terminal, and the anode of the first diode is connected with the positive electrode of the storage battery.

[0012] The limit discharge branch includes a second diode and a fifth switch, the second diode and the fifth switch are arranged in series between the positive electrode of the storage battery and the positive terminal, and the cathode of the second diode is connected with the positive electrode of the storage battery.

[0013] Further, the battery further includes a pre-charge branch, which is arranged in parallel with the first switch.

[0014] Further, the pre-charge branch includes a pre-charge resistor and a third switch, the pre-charge resistor and the third switch are arranged in series between the positive electrode of the storage battery and the positive terminal.

[0015] Further, the energy storage battery adopts a CAN bus architecture to connect each battery pack; one battery in the battery pack is set as a master control battery, and the remaining batteries are set as slave control batteries.

[0016] In a second aspect, the present application provides a method for balancing charge and discharge of an energy storage battery, which is applied to the energy storage battery and includes the following steps.

[0017] The energy storage battery is started and enters a discharge mode; when it is detected that the energy storage battery is completely discharged, the energy storage battery enters a charge mode according to an inductive switching operation; when it is detected that the energy storage battery is completely charged, the energy storage battery enters the discharge mode according to the inductive switching operation.

[0018] After the battery enters the discharge mode, each battery pack is balanced and discharged according to a first voltage, and all the batteries are completely discharged according to the SOC value; the first voltage is the maximum voltage of each non-faulty battery pack in the energy storage battery.

[0019] When entering the charging mode, each battery pack is balanced charged according to a second voltage, and full charging is performed according to the SOC values of all the batteries; the second voltage is the minimum voltage of each non-faulty battery pack in the energy storage battery.

[0020] Further, the balancing discharging voltage operation of each battery pack according to the first voltage comprises:

[0021] determining the current first voltage of the energy storage battery, the first voltage being the maximum voltage of each non-faulty battery pack in the energy storage battery;

[0022] screening the unpowered battery packs according to the first voltage and a preset first voltage difference, to determine all second battery packs meeting the powering-on condition;

[0023] limiting the total charging and discharging current of the energy storage battery according to the number of currently online battery packs, and powering on the second battery packs;

[0024] after the second battery packs complete the powering-on operation, the total charging and discharging current limitation of the energy storage battery is released, and the balancing discharging voltage operation is completed.

[0025] Further, the balancing charging voltage operation of each battery pack according to the second voltage comprises:

[0026] determining the current second voltage of the energy storage battery, the second voltage being the minimum voltage of each non-faulty battery pack in the energy storage battery;

[0027] screening the unpowered battery packs according to the second voltage and a preset second voltage difference, to determine all third battery packs meeting the powering-on condition;

[0028] limiting the total charging and discharging current of the energy storage battery according to the number of currently online battery packs, and powering on the second battery packs;

[0029] after the second battery packs complete the powering-on operation, the total charging and discharging current limitation of the energy storage battery is released, and the balancing charging voltage operation is completed.

[0030] In a third aspect, the present application provides a method for removing faults of an energy storage battery, applied to the energy storage battery, comprising:

[0031] starting the energy storage battery and entering a discharging mode; when detecting that the energy storage battery is fully discharged, entering a charging mode according to a non-inductive switching operation; when detecting that the energy storage battery is fully charged, entering the discharging mode according to the non-inductive switching operation;

[0032] After entering the discharging mode or the charging mode, when a fault battery pack is detected, a current limiting instruction is sent to the battery packs other than the fault battery pack according to the number of the powered-on battery packs and a first current threshold value, so as to limit the total charging and discharging current; a power-off instruction is sent to the fault battery pack, and after the fault battery pack is powered off, a current limiting release instruction is sent to each powered-on battery pack; wherein the fault battery pack is a powered-on battery pack in which a battery has a serious fault.

[0033] In a fourth aspect, the present application provides a method for inductance-free switching of charging and discharging of an energy storage battery, applied to the energy storage battery, comprising:

[0034] starting the energy storage battery and entering a discharging mode; when it is detected that the energy storage battery is completely discharged, entering a charging mode according to an inductance-free switching operation; when it is detected that the energy storage battery is completely charged, entering the discharging mode according to the inductance-free switching operation;

[0035] the inductance-free switching operation comprises: when it is detected that there is a first battery pack in a powered-on state but not meeting a power-on condition, sending a control instruction to a first battery; the first battery is a first battery in the first battery pack; the first battery adjusts a charging and discharging circuit according to the control instruction and a switching operation, wherein the switching operation comprises discharging-to-charging and charging-to-discharging.

[0036] Further, the first battery adjusts the charging and discharging circuit according to the control instruction and the switching operation, comprising:

[0037] when the switching operation is discharging-to-charging, closing a fifth switch of the first battery to access a discharging limiting branch provided with a second diode and opening a first switch;

[0038] when the switching operation is charging-to-discharging, closing a fourth switch of the first battery to access a charging limiting branch provided with a first diode and opening the first switch.

[0039] Further, the inductance-free switching operation further comprises a second power-on operation, and the second power-on operation comprises:

[0040] closing a second switch of a third battery in each battery pack meeting the power-on condition and the fifth switch of the first battery;

[0041] closing the second switch of the third battery in each battery pack not meeting the power-on condition and the first switch of the first battery;

[0042] wherein the third battery is a last battery in the battery pack and the first battery is a first battery in the battery pack.

[0043] In a fifth aspect, the present application provides a method for controlling an energy storage battery, applied to the energy storage battery, comprising:

[0044] receiving a power-on instruction, so that the master battery performs a first power-on operation on all batteries according to the power-on instruction, and enters a discharging mode after the power-on is successful; when it is detected that the energy storage battery is completely discharged, entering a charging mode according to a non-inductive switching operation; when it is detected that the energy storage battery is completely charged, entering the discharging mode according to the non-inductive switching operation;

[0045] Further, when the battery enters the discharging mode, performing a balanced discharging voltage operation on each battery pack according to a first voltage; and performing a complete discharging operation according to the SOC values of all batteries; the first voltage is the maximum voltage of each non-faulty battery pack in the energy storage battery;

[0046] When entering the charging mode, performing a balanced charging voltage operation on each battery pack according to a second voltage; and performing a complete charging operation according to the SOC values of all batteries; the second voltage is the minimum voltage of each non-faulty battery pack in the energy storage battery.

[0047] Further, the balanced discharging voltage operation on each battery pack according to the first voltage comprises:

[0048] determining the current first voltage of the energy storage battery, the first voltage being the maximum voltage of each non-faulty battery pack in the energy storage battery;

[0049] screening the battery packs that have not been powered on according to the first voltage and a preset first voltage difference, to determine all second battery packs that meet the power-on condition;

[0050] limiting the total charging and discharging current of the energy storage battery according to the number of currently online battery packs, and performing a power-on operation on the second battery packs;

[0051] after the second battery packs complete the power-on operation, the total charging and discharging current limitation of the energy storage battery is removed, and the balanced discharging voltage operation is completed.

[0052] Further, the balanced charging voltage operation on each battery pack according to the second voltage comprises:

[0053] determining the current second voltage of the energy storage battery, the second voltage being the minimum voltage of each non-faulty battery pack in the energy storage battery;

[0054] screening the battery packs that have not been powered on according to the second voltage and a preset second voltage difference, to determine all third battery packs that meet the power-on condition;

[0055] According to the current online battery pack quantity limit the total charge and discharge current of the energy storage battery, and power on the second battery pack;

[0056] After the second battery pack completes the power-on operation, the total charge and discharge current limit of the energy storage battery is released, and the balanced charging voltage operation is completed.

[0057] Further, after entering the discharge mode or the charging mode, when a fault battery pack is detected, a current limiting instruction is sent to the battery packs other than the fault battery pack according to the number of powered-on battery packs and a first current threshold, to limit the total charge and discharge current; and a power-off instruction is sent to the fault battery pack, until the fault battery pack is powered off, and a current limiting release instruction is sent to each powered-on battery pack; wherein the fault battery pack is a powered-on battery pack in which a battery has a serious fault.

[0058] Further, the non-inductive switching operation includes:

[0059] When a first battery pack in a powered-on state but not meeting the power-on condition is detected, a control instruction is sent to the first battery; the first battery is the first battery in the first battery pack;

[0060] The first battery adjusts the charge and discharge circuit according to the control instruction and the switching operation, wherein the switching operation includes discharge-to-charge and charge-to-discharge.

[0061] Further, the first battery adjusts the charge and discharge circuit according to the control instruction and the switching operation, including:

[0062] When the switching operation is discharge-to-charge, the fifth switch of the first battery is closed to access a limited discharge branch provided with a second diode, and the first switch is opened;

[0063] When the switching operation is charge-to-discharge, the fourth switch of the first battery is closed to access a limited charging branch provided with a first diode, and the first switch is opened. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 A structural schematic diagram of an energy storage battery provided for an embodiment of the present application;

[0065] Figure 2 An electrical diagram of a battery of an energy storage battery provided for an embodiment of the present application.

[0066] In the drawings of the specification, the reference signs are as follows:

[0067] 1, charge and discharge circuit; 2, pre-charge branch; 3, limit charge and discharge branch; 4, storage battery; 5, first switch; 6, second switch; 7, positive terminal; 8, negative terminal; 9, third switch; 10, fourth switch; 11, fifth switch; 12, first diode; 13, second diode; 14, pre-charge resistor. DETAILED DESCRIPTION

[0068] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0069] Embodiment one

[0070] Please refer to Figure 1 , Figure 1 A structural schematic diagram of the energy storage battery provided in the embodiment of the present application comprises a plurality of battery groups connected in parallel, and each of the battery groups comprises a plurality of batteries connected in series.

[0071] The battery comprises a charge and discharge circuit; the charge and discharge circuit comprises a storage battery, a first switch and a second switch; and the first switch and the second switch are used to control the opening or closing of the connecting line between two batteries.

[0072] In the embodiment, the energy storage battery adopts a CAN bus architecture to connect each battery group; one battery in the battery group is set as a master battery, and the remaining batteries are set as slave batteries.

[0073] In the embodiment, the energy storage battery is connected in parallel by m battery groups, and the battery group comprises n batteries. In each battery group, an optional battery is set as a master battery, and the remaining batteries are set as slave batteries. Configuration information sent by an external device is used to mark the number of batteries of the current energy storage battery, i.e. m battery groups each comprising n batteries are connected in parallel; each battery is marked by a DIP switch on the battery, and the number of each battery is marked from 1 to n*m-1.

[0074] In the embodiment, the external device comprises an inverter and an external control device.

[0075] In the embodiment, the slave battery sends second battery information to the master battery according to the network, the master battery collects the second battery information of all the slave batteries, processes the second battery information and the first battery information of itself, and sends the battery information of the entire energy storage battery to the external device.

[0076] In the embodiment, the energy storage device sends the received battery information of the energy storage battery to the external control device through the inverter, and obtains the power-on and power-off instructions of the external control device through the inverter and sends them to the master battery.

[0077] In the embodiment, a plurality of batteries are connected in series to form a battery pack, and a plurality of battery packs are connected in parallel to form an energy storage battery. During the operation of the energy storage battery, the opening and closing of the first switch and the second switch of each battery are independently controlled, thereby controlling the connection or closing of the connection line of each battery with the remaining batteries, so that each battery in the energy storage battery can be freely expanded, and when a battery is disassembled or added, the operation of the batteries in other battery packs in the energy storage battery will not be affected. When a battery fails, only the battery pack needs to be controlled, and the faulty battery needs to be powered off and repaired, without the need to stop the operation of the entire energy storage battery, thereby improving the overall operation efficiency of the energy storage battery and improving the fault tolerance.

[0078] Please refer to Figure 2 , Figure 2 The electrical diagram of a battery of the energy storage battery provided in the embodiment.

[0079] In the embodiment, the battery includes a positive terminal and a negative terminal, and in the charging and discharging circuit, the positive electrode of the battery is connected to the positive terminal, and the negative electrode of the battery is connected to the negative terminal; the first switch is arranged between the positive electrode of the battery and the positive terminal; and the second switch is arranged between the negative electrode of the battery and the negative terminal.

[0080] In the embodiment, since each battery has an independent charging and discharging circuit and a battery management system, all the batteries can be master batteries or slave batteries, so that when a battery fails, only the battery pack needs to be powered off and repaired, without the need to stop the operation of the entire energy storage battery, thereby improving the operation efficiency of the entire energy storage battery and improving the fault tolerance.

[0081] In the embodiment, by arranging an independent battery management system in each battery, all the batteries can be master batteries or slave batteries; when a single battery fails, the entire energy storage battery does not need to be stopped, thereby improving the operation efficiency of the entire energy storage battery; at the same time, the entire energy storage battery does not need to be repaired, only the current battery needs to be repaired, thereby reducing the repair cost.

[0082] In the embodiment, the battery further includes a limit charging and discharging branch, which is arranged in parallel with the first switch.

[0083] In the embodiment, the limit charging and discharging branch includes a limit charging branch and a limit discharging branch; the limit charging branch and the limit discharging branch are arranged in parallel.

[0084] The limited charging branch includes a first diode and a fourth switch, the first diode and the fourth switch are connected in series between the positive electrode of the storage battery and the positive electrode terminal, and the positive electrode of the first diode is connected with the positive electrode of the storage battery.

[0085] The limited discharging branch includes a second diode and a fifth switch, the second diode and the fifth switch are connected in series between the positive electrode of the storage battery and the positive electrode terminal, and the negative electrode of the second diode is connected with the positive electrode of the storage battery.

[0086] In the embodiment, by arranging the first diode in the limited charging branch, in the charging-to-discharging process, the fourth switch is connected to the limited charging branch to control the current flow in the battery, so as to avoid the current backflow caused by the excessive voltage difference in the charging-to-discharging process of the battery, thereby realizing the inductive switching of the battery in the charging-to-discharging process. By arranging the second diode in the limited discharging branch, in the discharging-to-charging process, the fifth switch is connected to the limited discharging branch to control the current flow in the battery, so as to avoid the current backflow caused by the excessive voltage difference in the discharging-to-charging process of the battery, thereby realizing the inductive switching of the battery in the discharging-to-charging process.

[0087] In the embodiment, the battery further includes a pre-charging branch, and the pre-charging branch is arranged in parallel with the first switch.

[0088] In the embodiment, the pre-charging branch includes a pre-charging resistor and a third switch, and the pre-charging resistor and the third switch are connected in series between the positive electrode of the storage battery and the positive electrode terminal.

[0089] In the embodiment, by arranging the pre-charging branch, the current in the battery can be automatically controlled through the pre-charging branch. When the external input current is too large, the pre-charging branch can be opened through the fifth switch to charge the battery, thereby avoiding the damage of the battery caused by the excessive external input current. Thus, the effect of adjusting the current in the battery is realized.

[0090] In the embodiment, the first switch, the second switch, the third switch, the fourth switch and the fifth switch in the battery are all arranged as relays, and the connection or closure of the circuit is automatically adjusted according to the current in the battery through the relays, thereby realizing the effect of automatically adjusting the current in the battery.

[0091] As a specific example of the embodiment of the application, the voltage platform of the battery is 50V, and each battery has an independent charging and discharging circuit and a battery management system. The charging and discharging circuit includes Rly1, Rly2 and Rly3, wherein Rly1 and Rly2 are respectively a first switch and a second switch, and Rly3 is a third switch, and the circuit in which Rly3 is located is a pre-charging circuit. The first switch, the second switch and the third switch are all set as relays.

[0092] In the embodiment, the energy storage battery adopts a CAN bus architecture to connect each battery pack, and the battery information of the master battery in each battery pack is calibrated through the configuration information sent by the external device, and the battery information of the slave battery is calibrated through the DIP switch on each battery.

[0093] In the embodiment, the entire energy storage battery adopts a CAN communication network architecture, and the battery connected with the inverter CAN in the external device is adaptively set as a master battery, and the remaining batteries are set as slave batteries.

[0094] In the embodiment, the external device and each battery in the energy storage battery are connected through a CAN bus architecture, the battery connected with the external device CAN is adaptively set as a master battery, and the remaining batteries are set as slave batteries. The slave batteries set different CANIDs according to their own numbers, and send the second battery information to the master battery through the intermediate CAN network, the master battery collects the second battery information of all slave batteries and the first battery information of itself, and sends the processed information to the external device.

[0095] In the embodiment, the external device includes a computer, an inverter and other devices capable of sending instructions.

[0096] The embodiment of the application also provides a method for balancing charging and discharging of an energy storage battery.

[0097] The energy storage battery is started and enters a discharging mode; when it is detected that the energy storage battery is completely discharged, the energy storage battery enters a charging mode according to a non-inductive switching operation; when it is detected that the energy storage battery is completely charged, the energy storage battery enters the discharging mode according to the non-inductive switching operation;

[0098] When the battery enters the discharging mode, the battery performs a balancing discharging voltage operation on each battery pack according to a first voltage, and performs a complete discharging operation according to the SOC values of all batteries; the first voltage is the maximum voltage of each non-faulty battery pack in the energy storage battery;

[0099] When the battery enters the charging mode, the battery performs a balancing charging voltage operation on each battery pack according to a second voltage, and performs a complete charging operation according to the SOC values of all batteries; the second voltage is the minimum voltage of each non-faulty battery pack in the energy storage battery.

[0100] In the embodiment, the energy storage battery further comprises a pretreatment operation before receiving the power-on instruction, and the pretreatment operation comprises: the energy storage battery performs an initialization self-check, and after the self-check passes, the battery packs in the energy storage battery are subjected to series pretreatment and discharge pre-power-on operation.

[0101] In the embodiment, the series pretreatment of the battery packs in the energy storage battery comprises: the master control battery sends an instruction, closes the second relay of the first battery (i.e., the 1st, n+1st, 2n+1st,..., n*m-n+1st battery) of each series battery pack, closes the first switch of the last battery (i.e., the n-th, 2n-th, m*n-th battery) of each series battery pack, and closes the first switch and the second switch of the remaining batteries.

[0102] In the embodiment, the discharge pre-power-on operation comprises: selecting, in units of battery packs, the battery packs without battery faults, calculating the total voltage of the battery packs, obtaining the highest voltage among all the battery packs as a first power-on voltage, and selecting, according to the first power-on voltage, all the battery packs satisfying the power-on condition, setting the pre-power-on instruction of the battery packs satisfying the power-on condition to 1, and setting the pre-power-on instruction of the battery packs not satisfying the power-on condition to 2.

[0103] As a specific example of the embodiment, selecting, according to the first power-on voltage, all the battery packs satisfying the power-on condition comprises: determining, as the battery packs satisfying the power-on condition, the battery packs whose voltage difference from the first power-on voltage is within a default threshold.

[0104] In the embodiment, by controlling the master control battery to power on each battery pack, the voltage of each battery is balanced, the high-voltage battery is selected to be incorporated into the energy storage system during discharging, and the low-voltage battery is selected to be incorporated into the energy storage system during charging, so as to fully release the battery capacity and balance the battery voltage, thereby improving the charging and discharging efficiency of the battery; at the same time, by using the non-inductive switching operation, the charging and discharging of the inverter is avoided to be uncontrollable, the switching of the battery voltage is completed while the voltage end is stable.

[0105] In the embodiment, after the pretreatment operation is completed, the energy storage battery receives the power-on instruction and transmits the power-on instruction to the master control battery of each battery pack to perform a first power-on operation. The first power-on operation comprises: according to the external instruction, closing the second switch of the last battery of all the battery packs with the pre-power-on instruction of 1, and closing the third switch of the first battery of all the battery packs with the pre-power-on instruction of 1, so as to enter the pre-charging mode, and closing the first switch after the pre-charging is successful.

[0106] In the embodiment, when all the battery packs with the pre-power-on instruction of 1 are successfully powered on and enter the discharging mode, otherwise, the pretreatment operation is returned.

[0107] In the embodiment, the judging whether each battery pack in the energy storage battery meets the power-on condition comprises: obtaining an upper power-on voltage of the energy storage battery according to a charge-discharge mode of the energy storage battery, judging a difference between a total voltage of each battery pack in the energy storage battery and the upper power-on voltage, if the difference is within a preset threshold range, the battery pack meets the power-on condition, and if the difference is not within the preset threshold range, the battery pack does not meet the power-on condition.

[0108] In the embodiment, the obtaining the upper power-on voltage of the energy storage battery according to the charge-discharge mode of the energy storage battery specifically comprises: if the charge-discharge mode is a discharge mode, the upper power-on voltage is a maximum voltage of each non-faulty battery pack in the energy storage battery; and if the charge-discharge mode is a charge mode, the upper power-on voltage is a minimum voltage of each non-faulty battery pack in the energy storage battery.

[0109] In the embodiment, one pre-power-on instruction value is set for each battery pack, and whether the battery pack meets the power-on condition is judged according to the pre-power-on instruction value.

[0110] As a specific example of the embodiment, if the pre-power-on instruction value is 1, the power-on condition is met, and if the pre-power-on instruction value is 2, the power-on condition is not met. Whether each battery pack in the energy storage battery meets the power-on condition is determined by a pre-power-on instruction in the battery pack.

[0111] In the embodiment, the balancing discharge voltage operation on each battery pack according to the first voltage comprises:

[0112] The first voltage of the energy storage battery is determined, and the first voltage is a maximum voltage of each non-faulty battery pack in the energy storage battery.

[0113] The second battery pack meeting the power-on condition is determined by screening the battery pack not powered on according to the first voltage and a preset first voltage difference.

[0114] The total charge-discharge current of the energy storage battery is limited according to the number of the current online battery pack, and the second battery pack is powered on.

[0115] After the second battery pack completes the power-on operation, the total charge-discharge current limitation of the energy storage battery is released, and the balancing discharge voltage operation is completed.

[0116] In the embodiment, the battery with the highest voltage among all the current battery packs is recorded as the first voltage, and the voltage of all the current battery packs that do not meet the power-on condition is determined. If the voltage of a battery pack that does not meet the power-on condition is within a first threshold range of the first voltage, and the battery pack has no fault, the pre-power-on instruction of the battery pack is set to 1. The energy storage battery is subjected to a current limiting operation according to the number of the current online battery packs, so as to control the battery packs to perform the power-on operation, and the current limiting operation is released after the power-on operation is completed.

[0117] In the embodiment, the current limiting operation on the energy storage battery according to the number of the current online battery packs comprises: limiting the total charge-discharge current in the energy storage battery, and the online battery pack is a battery pack in which all the batteries in the battery pack have no fault and all the batteries in the battery pack are successfully powered on.

[0118] In the embodiment, the current limiting operation comprises: sending a current limiting instruction to the master battery of each battery pack according to the number of the battery packs that are powered on and a first current threshold, so as to limit the total charge-discharge current.

[0119] As a specific example of the embodiment, when the current limiting operation is performed, the total charge-discharge current of the energy storage battery is limited to (10A*number of online battery packs) A, wherein the online battery pack is a battery pack that has been powered on.

[0120] As a specific example of the embodiment, the first threshold range is set to be greater than or equal to 2V and less than or equal to 4V. When the balancing discharge voltage operation is performed on each battery pack according to the first voltage, the voltage of the battery pack with the highest current voltage is recorded as the first voltage, and the voltage of a second battery pack that does not meet the power-on condition, i.e., the pre-power-on instruction is 2, is determined. If the difference between the second voltage and the first voltage is greater than or equal to 2V or less than or equal to 4V, and the second battery pack has no fault, the pre-power-on instruction of the second battery pack is set to 1, the total charge-discharge current in the energy storage battery is limited to (10*number of online battery packs) A, and the power-on instruction is sent to the second battery pack. After the second battery pack is powered on, the total charge-discharge current limitation is released.

[0121] In the embodiment, the balancing charge voltage operation on each battery pack according to the second voltage comprises:

[0122] The second voltage of the energy storage battery is determined, and the second voltage is the minimum voltage of each fault-free battery pack in the energy storage battery.

[0123] The second voltage and a preset second voltage difference are used to screen the battery packs that are not powered on, and all the third battery packs that meet the power-on condition are determined.

[0124] limit the total charge-discharge current of the energy storage battery according to the number of the current online battery groups, and perform the power-up operation on the second battery group;

[0125] After the power-up operation of the second battery group is completed, the total charge-discharge current limit of the energy storage battery is removed, and the balanced charging voltage operation is completed.

[0126] In this embodiment, the voltage of the battery group with the lowest voltage among all the current fault-free battery groups is recorded as the second voltage, and the voltage of all the current battery groups that do not meet the power-up condition is determined. If the difference between the voltage of the battery group that does not meet the power-up condition and the second voltage is within the second threshold range, and the battery group is fault-free, the pre-power-up instruction of the battery group is set to 1. The energy storage battery is subjected to current limiting operation according to the number of the current online battery groups, so that the third battery group is subjected to power-up operation, and the current limiting operation is removed after the power-up is completed.

[0127] In this embodiment, the current limiting operation on the energy storage battery according to the number of the current online battery groups includes limiting the total charge-discharge current inside the energy storage battery, and the online battery group is a battery group in which all the batteries are currently fault-free and successfully powered up.

[0128] In this embodiment, the current limiting operation includes sending a current limiting instruction to the master battery of each battery group according to the number of the powered-up battery groups and the first current threshold, so as to limit the total charge-discharge current.

[0129] As a specific example of an embodiment of the present application, when the current limiting operation is performed, the total charge-discharge current of the energy storage battery is limited to (10A*number of online battery groups) A, wherein the online battery group is a powered-up battery group.

[0130] As a specific example of an embodiment of the present application, the second threshold range is set to be greater than or equal to 2V and less than or equal to 4V. When the balanced charging voltage operation is performed on each battery group according to the second voltage, the voltage of the battery group with the lowest voltage is recorded as the second voltage, and the voltage of all the current battery groups that do not meet the power-up condition, i.e., the third battery group with the pre-power-up instruction of 2, is determined. If the difference between the voltage of the third battery group and the second voltage is greater than or equal to 2V or less than or equal to 4V, and the third battery group is fault-free, the pre-power-up instruction of the third battery group is set to 1, the total charge-discharge current inside the energy storage battery is limited to (10*number of online battery groups) A, and the power-up instruction is sent to the s-th battery group. After the third battery group is powered up, the total charge-discharge current limit is removed.

[0131] In the embodiment, since there is a battery pack with too large voltage difference not incorporated into the system, the energy storage battery can incorporate the battery pack into the system when the voltage difference meets the preset threshold value during the charging and discharging process, balance the battery voltage, and increase the system capacity. When there is a battery with too large voltage difference in the battery pack, the master control battery can adjust the internal circuit of the high-voltage battery until the voltages of the batteries in the battery string are uniform.

[0132] The embodiment of the present application also provides a method for removing a fault battery pack, applied to the energy storage battery, and comprising the following steps:

[0133] The energy storage battery is started and enters a discharging mode; when it is detected that the energy storage battery is completely discharged, the energy storage battery enters a charging mode according to a non-inductive switching operation; when it is detected that the energy storage battery is completely charged, the energy storage battery enters the discharging mode according to the non-inductive switching operation;

[0134] After entering the discharging mode or the charging mode, when a fault battery pack is detected, a current limiting operation is performed on the battery packs except the fault battery pack according to the number of the battery packs powered on and a first current threshold value, so as to limit the total charging and discharging current; a power-off instruction is sent to the fault battery pack until the fault battery pack is powered off, and a current limiting release instruction is sent to each battery pack powered on; wherein the fault battery pack is a battery pack powered on and having a battery with a serious fault.

[0135] In the embodiment, the current limiting operation comprises: sending a current limiting instruction to the master control battery of each battery pack according to the number of the battery packs powered on and the first current threshold value, so as to limit the total charging and discharging current.

[0136] As a specific example of the embodiment, when the current limiting operation is performed, the total charging and discharging current of the energy storage battery is limited to (10A*the number of the battery packs powered on) A, wherein the battery packs powered on are the battery packs powered on.

[0137] In the embodiment, after entering the discharging mode, there is a voltage difference in the energy storage battery due to the harness and the difference between the battery cells. In a single energy storage battery, if there is a voltage difference at the end of the discharging of the single energy storage battery, the entire energy storage battery cannot continue to discharge when the voltage of the lowest single battery reaches the lower limit value, at this time, the other single batteries still have a certain amount of electricity not discharged, thereby leading to the low capacity of the entire energy storage battery. In the energy storage battery composed of multiple batteries, when the voltage of a battery reaches the lower limit value at the end of the discharging, the master control battery can perform a power-off operation, and the remaining batteries can continue to discharge until the voltage of the last battery reaches the lower limit value.

[0138] In the embodiment, whether the energy storage battery is completely discharged is determined by:

[0139] When entering the discharging mode, if there is a battery whose SOC value reaches a second threshold, the battery group where the battery is located is subjected to a current limiting operation, and the battery reaching the second threshold is subjected to a power-off operation, and after the power-off is completed, the current limiting operation is released.

[0140] In this embodiment, when the SOC value of the last battery reaches the second threshold, the connection of the last battery is maintained, and the discharging current of the master battery is limited to 0.

[0141] As a specific example of an embodiment of the present application, when the SOC value of a battery reaches 0% during discharging, the master battery requests the external device to limit the discharging current of the current battery group to 10A, and then sends a power-off instruction to the battery whose SOC value is 0%. When it is confirmed that the battery whose SOC value is 0% is powered off and disconnected, the discharging current of the current battery group is restored. If the last battery of the current battery group will be 0%, the connection of the current battery is maintained, and the master battery limits the discharging current of the current battery group to 0A.

[0142] In this embodiment, the power-off operation of the battery group includes that the master battery sends a power-off instruction to the first battery and the last battery of the battery group, controls the first battery to disconnect the first switch, and controls the last battery to disconnect the second switch.

[0143] In this embodiment, when the external device sends a power-off instruction to the master battery, the master battery disconnects the connection of all batteries.

[0144] In this embodiment, the judgment of whether the energy storage battery is fully charged includes:

[0145] When entering the charging mode, if there is a battery whose SOC value reaches a third threshold, the battery group where the battery is located is subjected to a current limiting operation, and the battery reaching the third threshold is subjected to a power-off operation, and after the power-off is completed, the current limiting operation is released.

[0146] In this embodiment, when the SOC value of the last battery reaches the third threshold, the connection of the last battery is maintained, and the charging current of the master battery is limited to 0.

[0147] As a specific example of an embodiment of the present application, when the SOC value of a battery reaches 100% during discharging, the master battery requests the external device to limit the charging current of the current battery group to 10A, and then sends a power-off instruction to the battery whose SOC value is 100%. When it is confirmed that the battery whose SOC value is 100% is powered off and disconnected, the charging current of the current battery group is restored. If the last battery of the current battery group will be 100%, the connection of the current battery is maintained, and the master battery limits the charging current of the current battery group to 0A.

[0148] In the embodiment, when the external device sends a power-off instruction to the master battery, the master battery disconnects all the batteries.

[0149] In the embodiment, by connecting a plurality of batteries in series and parallel, by removing the fault battery group, when a battery fails seriously and cannot support charging and discharging, the whole energy storage battery is current-limited, and the battery group where the fault battery is located is disconnected, and the remaining battery groups can continue to work normally, thereby increasing the redundancy of the system.

[0150] The embodiment of the application further provides a non-inductive switching charging and discharging method for an energy storage battery, which is applied to the energy storage battery and comprises the following steps:

[0151] The energy storage battery is started and enters a discharging mode; when it is detected that the energy storage battery is completely discharged, the non-inductive switching operation is used to enter a charging mode; when it is detected that the energy storage battery is completely charged, the non-inductive switching operation is used to enter the discharging mode.

[0152] The non-inductive switching operation comprises the following steps: when it is detected that there is a first battery group in a power-on state but not satisfying a power-on condition, a control instruction is sent to a first battery; the first battery is the first battery in the first battery group; and the first battery adjusts a charging and discharging circuit according to the control instruction and a switching operation, wherein the switching operation comprises discharging-to-charging and charging-to-discharging.

[0153] In the embodiment, the first battery group in the power-on state but not satisfying the power-on condition specifically refers to a battery group in the power-on state but having a pre-power-on instruction of 2.

[0154] In the embodiment, when it is detected that the energy storage battery is completely discharged, the charging and discharging circuit is adjusted according to the control instruction and the switching operation, so as to enter the charging mode; the detection that the energy storage battery is completely discharged comprises the following step: when it is detected that the internal current of the energy storage battery is negative, the energy storage battery is completely discharged.

[0155] In the embodiment, before the non-inductive switching operation is used to enter the charging mode, the following step is further included: a charging pre-power-on operation is performed on all the battery groups. The charging pre-power-on operation comprises the following steps: all the battery groups are screened in units of battery groups without battery faults, the total voltage of the battery group is calculated, the lowest voltage of all the battery groups is obtained as a second power-on voltage, all the battery groups satisfying the power-on condition are screened according to the second power-on voltage, the pre-power-on instruction of the battery group satisfying the power-on condition is set to 1, and the pre-power-on instruction of the battery group not satisfying the power-on condition is set to 2.

[0156] As a specific example of the embodiment of the present application, the step of screening all battery packs meeting the power-up condition according to the second power-up voltage includes determining the battery packs whose voltage difference from the second power-up voltage is within a default threshold as the battery packs meeting the power-up condition.

[0157] In the embodiment, when it is detected that the energy storage battery is fully charged, the charging and discharging circuit is adjusted according to the control instruction and the switching operation, so as to enter the discharging mode; the detection that the energy storage battery is fully charged includes that when it is detected that the internal current of the energy storage battery is positive, the energy storage battery is fully charged.

[0158] In the embodiment, before entering the discharging mode according to the non-inductive switching operation, the step further includes a discharging pre-power-up operation on all battery packs. The discharging pre-power-up operation includes: screening the battery packs without battery failure in a battery pack unit, calculating the total voltage of the battery packs, obtaining the highest voltage in all battery packs as a first power-up voltage, and screening all battery packs meeting the power-up condition according to the first power-up voltage; the pre-power-up instruction of the battery pack meeting the power-up condition is set to 1, and the pre-power-up instruction of the battery pack not meeting the power-up condition is set to 2.

[0159] As a specific example of the embodiment of the present application, the step of screening all battery packs meeting the power-up condition according to the first power-up voltage includes determining the battery packs whose voltage difference from the first power-up voltage is within a default threshold as the battery packs meeting the power-up condition.

[0160] In the embodiment, the switching operation includes discharging to charging and charging to discharging, and after the first battery enters the non-inductive switching operation, the relay is closed according to the type of the switching operation.

[0161] In the embodiment, the step of adjusting the charging and discharging circuit of the first battery according to the control instruction and the switching operation includes:

[0162] When the switching operation is discharging to charging, the first battery is connected to the charging circuit provided with the second diode, and the first switch is disconnected.

[0163] When the switching operation is charging to discharging, the first battery is connected to the discharging circuit provided with the first diode, and the first switch is disconnected.

[0164] In the embodiment, when the charging pre-power-up operation processing is completed, it is detected that there is a first battery pack in the power-up state but the pre-power-up instruction is 2, and then the non-inductive switching operation is entered. If the switching operation is discharging to charging at this time, the master battery of the first battery pack controls the first battery in the first battery pack to close the second switch and connect to the charging circuit, and disconnects the first switch.

[0165] The second power-on operation further comprises:

[0166] closing the second switch of the third battery and the fifth switch of the first battery in all the battery packs meeting the power-on condition;

[0167] closing the second switch of the third battery and the first switch of the first battery in all the battery packs not meeting the power-on condition;

[0168] The third battery is the last battery in the battery pack, and the first battery is the first battery in the battery pack.

[0169] In the embodiment, after the non-inductive switching operation of the first battery is completed, the second power-on operation is performed on all the battery packs, and the charging mode is entered after the power-on is successful.

[0170] In the embodiment, after the charging mode is entered, there is a pressure difference in the energy storage battery due to harness, cell difference and other problems. In the battery system composed of multiple batteries in the energy storage battery, at the end of charging, when the voltage of a battery reaches the upper limit value, the master control battery can perform a power-on operation on it, and the remaining batteries can continue to charge until the voltage of the last battery reaches the upper limit value.

[0171] In the embodiment, the full charging operation of the energy storage battery comprises:

[0172] When the charging mode is entered, if the SOC value of a battery reaches a third threshold value, a current limiting operation is performed on the battery pack in which the battery is located, and a power-off operation is performed on the battery reaching the third threshold value. After the power-off is completed, the current limiting operation is released.

[0173] In the embodiment, when the SOC value of the last battery reaches the third threshold value, the connection of the last battery is retained, and the charging current of the master control battery is limited to 0.

[0174] As a specific example of the embodiment, when the SOC value of a battery reaches 100% during discharging, the master control battery requests an external device to limit the charging current of the current battery pack to 10A, and sends a power-off instruction to the battery with the SOC value of 100%. When it is confirmed that the battery with the SOC value of 100% is disconnected after power-off, the charging current of the current battery pack is restored. If the last battery of the current battery pack will be 100%, the connection of the current battery is retained, and the master control battery limits the charging current of the current battery pack to 0A.

[0175] In the embodiment, when the charging and discharging conversion is performed, the end voltage is kept stable according to switching the charging circuit and the discharging circuit in the battery, and the switching of the high and low voltage batteries is completed, so that the end voltage connected with the external device is not suddenly lost, and the normal operation of the battery is not affected.

[0176] In the embodiment, before the discharging mode is entered according to the non-inductive switching operation, the pre-power-on operation of discharging is performed on all the battery groups.

[0177] The embodiment of the application further provides a control method of the energy storage battery, which is applied to the energy storage battery and comprises the following steps:

[0178] The power-on instruction is received, so that the master battery performs the first power-on operation on all the batteries according to the power-on instruction, and enters the discharging mode after the power-on is successful; when it is detected that the energy storage battery is completely discharged, the charging mode is entered according to the non-inductive switching operation; when it is detected that the energy storage battery is completely charged, the discharging mode is entered according to the non-inductive switching operation;

[0179] In the embodiment, when the discharging mode is entered, the balanced discharging voltage operation is performed on each battery group according to a first voltage, and the complete discharging operation is performed according to the SOC values of all the batteries; the first voltage is the maximum voltage of each non-faulty battery group in the energy storage battery.

[0180] When the charging mode is entered, the balanced charging voltage operation is performed on each battery group according to a second voltage, and the complete charging operation is performed according to the SOC values of all the batteries; the second voltage is the minimum voltage of each non-faulty battery group in the energy storage battery.

[0181] In the embodiment, the energy storage battery adopts the CAN bus architecture to connect each battery group; one battery in the battery group is set as the master battery, and the remaining batteries are set as the slave batteries. The energy storage battery is composed of m battery groups in parallel, and each battery group comprises n batteries. In each battery group, the battery of an optional battery is set as the master battery, and the remaining batteries are set as the slave batteries. The configuration information sent by the external device is used to mark the number of batteries in the current energy storage battery, that is, m battery groups each composed of n batteries are connected in parallel; the DIP switch on the battery is used to mark each battery, and the numbers of the batteries are marked from 1 to n*m-1.

[0182] In the embodiment, the external device and each battery in the energy storage battery are connected through the CAN bus architecture, the battery connected with the external device CAN is adaptively set as a master battery, and the remaining batteries are set as slave batteries. The slave batteries set different CANIDs according to their own numbers, and send second battery information to the master battery through the intermediate CAN network. The master battery collects second battery information of all slave batteries and first battery information of itself, and sends the processed information to the external device.

[0183] In the embodiment, after the energy storage battery is started by receiving an instruction, a pretreatment operation is performed on the energy storage battery. The pretreatment operation includes that the energy storage battery performs an initialization self-check, and after the self-check passes, a series pretreatment and a discharge pre-power-on operation are performed on the battery pack in the energy storage battery.

[0184] In the embodiment, after the battery pack completes the series pretreatment and the discharge pre-power-on operation, the battery pack enters a discharge mode, and a balanced discharge voltage operation is performed on each battery pack according to a first voltage.

[0185] In the embodiment, the balanced discharge voltage operation performed on each battery pack according to the first voltage includes:

[0186] The first voltage is determined as a maximum voltage of each fault-free battery pack in the energy storage battery.

[0187] The second battery pack that meets the power-on condition is determined by screening the battery pack that is not powered on according to the first voltage and a preset first voltage difference.

[0188] The total charge-discharge current of the energy storage battery is limited according to the number of currently online battery packs, and the second battery pack is powered on.

[0189] After the second battery pack completes the power-on operation, the total charge-discharge current limitation of the energy storage battery is released, and the balanced discharge voltage operation is completed.

[0190] In the embodiment, the balanced charge voltage operation performed on each battery pack according to a second voltage includes:

[0191] The second voltage is determined as a minimum voltage of each fault-free battery pack in the energy storage battery.

[0192] The third battery pack that meets the power-on condition is determined by screening the battery pack that is not powered on according to the second voltage and a preset second voltage difference.

[0193] The total charge-discharge current of the energy storage battery is limited according to the number of currently online battery packs, and the second battery pack is powered on.

[0194] After the second battery group completes the power-on operation, the total charge-discharge current limit of the energy storage battery is removed, and the balancing charge voltage operation is completed.

[0195] In the embodiment, after entering the discharging mode or the charging mode, when a fault battery group is detected, a current limiting instruction is sent to the battery groups other than the fault battery group according to the number of the power-on battery groups and the first current threshold, so as to limit the total charge-discharge current; a power-off instruction is sent to the fault battery group, and after the fault battery group is powered off, a current limiting release instruction is sent to each power-on battery group; the fault battery group is a power-on battery group in which a serious fault occurs in a battery.

[0196] In the embodiment, the non-inductive switching operation includes:

[0197] When a first battery group in a power-on state but not satisfying the power-on condition is detected, a control instruction is sent to the first battery group; the first battery is the first battery in the first battery group.

[0198] The first battery adjusts the charge-discharge loop according to the control instruction and the switching operation, wherein the switching operation includes discharging to charging and charging to discharging.

[0199] In the embodiment, the first battery adjusts the charge-discharge loop according to the control instruction and the switching operation, including:

[0200] When the switching operation is discharging to charging, the fifth switch of the first battery is closed to access the limited discharge branch provided with the second diode, and the first switch is disconnected.

[0201] When the switching operation is charging to discharging, the fourth switch of the first battery is closed to access the limited charging branch provided with the first diode, and the first switch is disconnected.

[0202] In the embodiment, after entering the discharging mode, there is inevitably a pressure difference in the energy storage battery due to the harness, cell difference and other problems. In a single energy storage battery, if there is a pressure difference at the end of discharging of the single energy storage battery, when the voltage of the lowest single battery reaches the lower limit value, the entire energy storage battery cannot continue to discharge, and other single batteries still have a certain amount of electricity not discharged, thereby causing the capacity of the entire energy storage battery to be low. In the energy storage battery composed of multiple batteries, at the end of discharging, when the voltage of a battery reaches the lower limit value, the master control battery can be powered off, and the remaining batteries can continue to discharge until the voltage of the last battery reaches the lower limit value.

[0203] In the embodiment, the determination of whether the energy storage battery is completely discharged includes:

[0204] When entering the discharging mode, if there is a battery whose SOC value reaches the second threshold, the battery group where the battery is located is subjected to current limiting operation, and the battery reaching the second threshold is subjected to power-off operation, and after the power-off is completed, the current limiting operation is released.

[0205] In this embodiment, when the SOC value of the last battery reaches the second threshold, the connection of the last battery is maintained, and the discharging current of the master battery is limited to 0.

[0206] As a specific example of an embodiment of the present application, when there is a battery whose SOC value reaches 0% during discharging, the master battery requests the external device to limit the discharging current of the current battery group to 10A, and then sends a power-off instruction to the battery whose SOC value is 0%. When it is confirmed that the battery whose SOC value is 0% is powered off and disconnected, the discharging current of the current battery group is restored. If the last battery of the current battery group will be 0%, the connection of the current battery is maintained, and the master battery limits the discharging current of the current battery group to 0A.

[0207] In this embodiment, the power-off operation of the battery group includes that the master battery sends a power-off instruction to the first battery and the last battery of the battery group, controls the first battery to disconnect the first switch, and controls the last battery to disconnect the second switch.

[0208] In this embodiment, when the external device sends a power-off instruction to the master battery, the master battery disconnects the connection of all batteries.

[0209] In this embodiment, the judgment of whether the energy storage battery is fully charged includes:

[0210] When entering the charging mode, if there is a battery whose SOC value reaches the third threshold, the battery group where the battery is located is subjected to current limiting operation, and the battery reaching the third threshold is subjected to power-off operation, and after the power-off is completed, the current limiting operation is released.

[0211] In this embodiment, when the SOC value of the last battery reaches the third threshold, the connection of the last battery is maintained, and the charging current of the master battery is limited to 0.

[0212] As a specific example of an embodiment of the present application, when there is a battery whose SOC value reaches 100% during discharging, the master battery requests the external device to limit the charging current of the current battery group to 10A, and then sends a power-off instruction to the battery whose SOC value is 100%. When it is confirmed that the battery whose SOC value is 100% is powered off and disconnected, the charging current of the current battery group is restored. If the last battery of the current battery group will be 100%, the connection of the current battery is maintained, and the master battery limits the charging current of the current battery group to 0A.

[0213] In the embodiment, when the external device sends a power-off instruction to the master battery, the master battery disconnects all the batteries.

[0214] In the embodiment, after entering the discharging mode or the charging mode, when a fault battery pack is detected, a current limiting instruction is sent to the master battery of each battery pack according to the number of the powered-on battery packs and the first current threshold, so as to limit the total charging and discharging current; a power-off instruction is sent to the fault battery pack until the fault battery pack is powered off, and a current limiting release instruction is sent to the master battery of each battery pack; wherein the fault battery pack is a powered-on battery pack in which a serious fault occurs.

[0215] In the embodiment, a plurality of batteries are connected in series to form a battery pack, and a plurality of battery packs are connected in parallel to form the energy storage battery. During operation, each master battery collects information of all the batteries in the battery pack and sends the information to the external device, so that when the modular battery is disassembled or added, the information collection and operation of other battery packs in the energy storage battery are not affected, and when a fault occurs in a battery, the battery pack in which the battery is located can be powered off and repaired, without the need to stop the operation of the entire energy storage battery, thereby improving the operation efficiency of the entire energy storage battery and improving the fault tolerance. At the same time, the overall total capacity of the energy storage battery can be improved by series connection and parallel connection, and the expandability of the energy storage battery is improved.

[0216] The above-described specific embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above-described specific embodiments are merely examples of the present application and are not intended to limit the protection scope of the present application. It should be particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An energy storage cell, characterized by, The energy storage battery comprises a plurality of battery groups connected in parallel, and each battery group comprises a plurality of batteries connected in series. The battery comprises a charging and discharging circuit, a positive terminal and a negative terminal. The charging and discharging circuit comprises a storage battery, a first switch and a second switch. The positive terminal of the storage battery is connected to the positive terminal, and the negative terminal of the storage battery is connected to the negative terminal. The first switch is arranged between the positive terminal of the storage battery and the positive terminal. The second switch is arranged between the negative terminal of the storage battery and the negative terminal. The first switch and the second switch are used to control the opening or closing of the connecting line between the two batteries. The battery further comprises a limiting charging and discharging branch, which is arranged in parallel with the first switch. The limiting charging and discharging branch comprises a limiting charging branch and a limiting discharging branch. The limiting charging branch and the limiting discharging branch are arranged in parallel. The limiting charging branch comprises a first diode and a fourth switch arranged in series, and the positive terminal of the first diode is connected to the positive terminal of the storage battery. The limiting discharging branch comprises a second diode and a fifth switch arranged in series, and the negative terminal of the second diode is connected to the positive terminal of the storage battery. The energy storage battery can be used for inductive switching operation. When the switching operation is discharging to charging, the fifth switch of the battery is closed to access the limiting discharging branch provided with the second diode, and the first switch is opened. When the switching operation is charging to discharging, the fourth switch of the battery is closed to access the limiting charging branch provided with the first diode, and the first switch is opened.

2. The energy storage cell of claim 1, wherein, The battery further comprises a pre-charging branch, which is arranged in parallel with the first switch.

3. The energy storage cell of claim 2, wherein, The pre-charging branch comprises a pre-charging resistor and a third switch, which are arranged in series between the positive terminal of the storage battery and the positive terminal.

4. The energy storage cell of claim 1, wherein, The energy storage battery adopts a CAN bus architecture to connect each battery group. One battery in the battery group is set as a master battery, and the remaining batteries are set as slave batteries.

5. A method for non-inductive switching charge and discharge of an energy storage battery, characterized in that, The energy storage battery is applied to any one of claims 1-4, comprising: The energy storage battery is started and enters a discharging mode. When it is detected that the energy storage battery is completely discharged, the energy storage battery enters a charging mode according to inductive switching operation. When it is detected that the energy storage battery is completely charged, the energy storage battery enters a discharging mode according to the inductive switching operation. The inductive switching operation comprises: when it is detected that there is a first battery group in a powered-on state but not meeting the powered-on condition, a control instruction is sent to the first battery. The first battery is the first battery in the first battery group. The first battery adjusts the charging and discharging circuit according to the control instruction and the switching operation, comprising: when the switching operation is discharging to charging, the fifth switch of the first battery is closed to access the limiting discharging branch provided with the second diode, and the first switch is opened. When the switching operation is charging to discharging, the fourth switch of the first battery is closed to access the limiting charging branch provided with the first diode, and the first switch is opened.

6. The energy storage battery non-inductive switching charge and discharge method according to claim 5, characterized in that, The second power-on operation further comprises: closing the second switch of the third battery and the fifth switch of the first battery in all battery packs meeting the power-on condition; opening the second switch of the third battery and the first switch of the first battery in all battery packs not meeting the power-on condition; The third battery is the last battery in the battery pack, and the first battery is the first battery in the battery pack.

7. A method for balancing charge and discharge of energy storage cells, characterized by, The application is applied to the energy storage battery as claimed in any one of claims 1-4, comprising: starting the energy storage battery and entering the discharging mode; when detecting that the energy storage battery is completely discharged, entering the charging mode according to the non-inductive switching operation; when detecting that the energy storage battery is completely charged, entering the discharging mode according to the non-inductive switching operation; when entering the discharging mode, performing the balanced discharging voltage operation on each battery pack according to the first voltage, and performing the complete discharging operation according to the SOC value of all batteries; the first voltage is the maximum voltage of each non-faulty battery pack in the energy storage battery; when entering the charging mode, performing the balanced charging voltage operation on each battery pack according to the second voltage, and performing the complete charging operation according to the SOC value of all batteries; the second voltage is the minimum voltage of each non-faulty battery pack in the energy storage battery.

8. The energy storage cell balancing charge and discharge method of claim 7, wherein, The balanced discharging voltage operation on each battery pack according to the first voltage comprises: determining the current first voltage of the energy storage battery, the first voltage being the maximum voltage of each non-faulty battery pack in the energy storage battery; screening the second battery pack meeting the power-on condition according to the first voltage and a preset first voltage difference; limiting the total charging and discharging current of the energy storage battery according to the number of currently online battery packs, and performing the power-on operation on the second battery pack; after the second battery pack completes the power-on operation, removing the limitation of the total charging and discharging current of the energy storage battery, and completing the balanced discharging voltage operation.

9. The energy storage cell balancing charge and discharge method of claim 7, wherein, The balanced charging voltage operation on each battery pack according to the second voltage comprises: determining the current second voltage of the energy storage battery, the second voltage being the minimum voltage of each non-faulty battery pack in the energy storage battery; screening the third battery pack meeting the power-on condition according to the second voltage and a preset second voltage difference; limiting the total charging and discharging current of the energy storage battery according to the number of currently online battery packs, and performing the power-on operation on the third battery pack; after the third battery pack completes the power-on operation, removing the limitation of the total charging and discharging current of the energy storage battery, and completing the balanced charging voltage operation.

10. A method for rejecting a failure of an energy storage battery, characterized by, The application is applied to the energy storage battery as claimed in any one of claims 1-4, comprising: starting the energy storage battery and entering the discharging mode; when detecting that the energy storage battery is completely discharged, entering the charging mode according to the non-inductive switching operation; when detecting that the energy storage battery is completely charged, entering the discharging mode according to the non-inductive switching operation; When a fault battery pack is detected after entering the discharging mode or the charging mode, the battery packs other than the fault battery pack are subjected to current limiting operation according to the number of the battery packs that are powered on and a first current threshold, so as to limit the total charging and discharging current; and a power-off instruction is sent to the fault battery pack until the fault battery pack is powered off, and a current limiting release instruction is sent to each battery pack that is powered on; wherein the fault battery pack is a powered-on battery pack in which a serious fault occurs in a battery.

11. An energy storage battery control method, comprising: The energy storage battery is applied to the energy storage battery of any one of claims 1-4, and comprises: receiving a power-on instruction, so that the master battery performs first power-on operation on all the batteries according to the power-on instruction, and enters a discharging mode after the power-on operation is successful; when it is detected that the energy storage battery is completely discharged, entering a charging mode according to a non-inductive switching operation; when it is detected that the energy storage battery is completely charged, entering the discharging mode according to the non-inductive switching operation; the non-inductive switching operation comprises: when it is detected that there is a first battery pack in a powered-on state but not meeting a power-on condition, sending a control instruction to a first battery in the first battery pack; the first battery is a first battery in the first battery pack; and the first battery adjusts the charging and discharging loop according to the control instruction and a switching operation, wherein the switching operation comprises discharging-to-charging and charging-to-discharging.

12. The energy storage battery control method of claim 11, wherein, After the battery enters the discharging mode, each battery pack is subjected to balanced discharging voltage operation according to a first voltage; and complete discharging operation is performed according to the SOC values of all the batteries; the first voltage is the maximum voltage of each non-fault battery pack in the energy storage battery; After entering the charging mode, each battery pack is subjected to balanced charging voltage operation according to a second voltage; and complete charging operation is performed according to the SOC values of all the batteries; the second voltage is the minimum voltage of each non-fault battery pack in the energy storage battery.

13. The energy storage battery control method of claim 12, wherein, The balanced discharging voltage operation of each battery pack according to the first voltage comprises: determining a current first voltage of the energy storage battery, the first voltage being the maximum voltage of each non-fault battery pack in the energy storage battery; screening unpowered battery packs according to the first voltage and a preset first voltage difference, to determine all second battery packs meeting a power-on condition; limiting the total charging and discharging current of the energy storage battery according to the number of the current online battery packs, and performing power-on operation on the second battery packs; after the second battery packs complete the power-on operation, releasing the limitation of the total charging and discharging current of the energy storage battery, and completing the balanced discharging voltage operation.

14. The energy storage battery control method of claim 12, wherein, The balanced charging voltage operation of each battery pack according to the second voltage comprises: determining a current second voltage of the energy storage battery, the second voltage being the minimum voltage of each non-fault battery pack in the energy storage battery; screening unpowered battery packs according to the second voltage and a preset second voltage difference, to determine all third battery packs meeting a power-on condition; limiting the total charging and discharging current of the energy storage battery according to the number of the current online battery packs, and performing power-on operation on the third battery packs; after the third battery packs complete the power-on operation, releasing the limitation of the total charging and discharging current of the energy storage battery, and completing the balanced charging voltage operation.

15. The energy storage battery control method of claim 11, wherein, After entering the discharging mode or the charging mode, when a fault battery pack is detected, a current limiting instruction is sent to the battery packs other than the fault battery pack according to the number of the battery packs powered on and a first current threshold value, so as to limit the total charging and discharging current; a power-off instruction is sent to the fault battery pack, and after the fault battery pack is powered off, a current limiting release instruction is sent to each battery pack powered on; wherein the fault battery pack is a battery pack powered on and having a serious fault.

16. The energy storage battery control method of claim 11, wherein, The non-inductive switching operation comprises: When a first battery pack in a powered-on state but not meeting the power-on condition is detected, a control instruction is sent to the first battery; The first battery adjusts the charging and discharging circuit according to the control instruction and the switching operation, wherein the switching operation comprises discharging to charging and charging to discharging.

17. The energy storage battery control method of claim 16, wherein, The first battery adjusts the charging and discharging circuit according to the control instruction and the switching operation, comprising: When the switching operation is discharging to charging, the fifth switch of the first battery is closed to access a discharging limiting branch provided with a second diode, and the first switch is disconnected; When the switching operation is charging to discharging, the fourth switch of the first battery is closed to access a charging limiting branch provided with a first diode, and the first switch is disconnected.

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