A bidirectional active balancing battery management system based on multi-cell sorting

Abstract

The present invention belongs to the field of battery energy storage technology, and specifically relates to a bidirectional active balancing battery management system and control method based on multi-unit sorting. The present invention utilizes a bidirectional active balancing method of multi-unit sorting, takes a battery string as a power source and load for balancing electric power, and simultaneously performs effective active current balancing and regulation on multiple non-connected battery cells in the battery string, which can effectively realize high-precision real-time monitoring of battery operation, precise and scientific charge and discharge current control, and active and effective balancing and regulation of the voltage and power consistency of each battery cell in the battery string. The battery can realize battery string balancing control in each charging and discharging process, achieve effective consistency control of the battery string voltage and power, and realize safe, healthy, and efficient operation of the battery energy storage system, which has great positive significance for the application of energy storage systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery energy storage, and in particular relates to a bidirectional active balancing battery management system based on multi-unit sorting. Background Art

[0002] Energy storage system is an important component of new energy power, smart grid and energy Internet, especially electrochemical energy storage. As we all know, electrochemical energy storage system is a battery string composed of multiple unit battery cells connected to enter the inverter equipment for charging and discharging, and completes power regulation under control. Real-time monitoring of battery operation, charge and discharge current control, and balanced control of voltage and power consistency of each battery cell in the battery string are the key to the safe, healthy and efficient operation of the energy storage system. For this reason, it is necessary to design an effective battery management system BMS to complete the above tasks. High-precision real-time monitoring of battery operation, precise and scientific charge and discharge current control, and active and effective balanced adjustment of voltage and power consistency of each battery cell in the battery string are the key technologies and implementation difficulties of the battery management system. Summary of the invention

[0003] In order to realize effective battery monitoring and management, the present invention proposes a bidirectional active balancing battery management system based on multi-unit sorting, which mainly includes: a bidirectional charging and discharging DC / DC module, a DC transformer, a high-voltage positive DC bus, a high-voltage negative DC bus, a battery string negative terminal, a battery string positive terminal, a low-voltage positive DC bus, a low-voltage negative DC bus, a system control module, an electric control switch drive circuit, a battery parameter acquisition module, a system bus, a system power module, a communication interface circuit, a signal parameter acquisition harness, an electric control Switch drive control line, upper control machine, bidirectional energy storage commutation device, external communication link, first battery cell, second battery cell, mth battery cell, nth battery cell, first battery cell negative electrode, first battery cell positive electrode, second battery cell negative electrode, second battery cell positive electrode, mth battery cell negative electrode, mth battery cell positive electrode, nth battery cell negative electrode, nth battery cell positive electrode, first electric control selection switch, second electric control selection switch, mth electric control selection switch, nth electric control selection switch, first electric control selection switch the positive connection terminal of the electric control switch, the negative connection terminal of the first electric control switch, the battery connection terminal of the first electric control switch, the positive connection terminal of the second electric control switch, the negative connection terminal of the second electric control switch, the battery connection terminal of the second electric control switch, the positive connection terminal of the mth electric control switch, the negative connection terminal of the mth electric control switch, the battery connection terminal of the mth electric control switch, the positive connection terminal of the nth electric control switch, the negative connection terminal of the nth electric control switch, the battery connection terminal of the nth electric control switch, the negative voltage of the first battery cell and Temperature parameter acquisition sensor, first battery cell positive electrode voltage and temperature parameter acquisition sensor, second battery cell negative electrode voltage and temperature parameter acquisition sensor, second battery cell positive electrode voltage and temperature parameter acquisition sensor, mth battery cell negative electrode voltage and temperature parameter acquisition sensor, first battery cell positive electrode voltage and temperature parameter acquisition sensor, nth battery cell negative electrode voltage and temperature parameter acquisition sensor, nth battery cell positive electrode voltage and temperature parameter acquisition sensor, battery string current parameter acquisition sensor, wherein:

[0004] The battery string is arranged in the order of the first battery cell, the second battery cell, the mth battery cell, and the nth battery cell. Starting from the first battery cell, the positive electrode of each battery is connected to the negative electrode of the next battery in turn to form a series-connected battery string, and the negative electrode of the first battery cell of the battery string is connected to the negative terminal of the battery string, while the positive electrode of the last nth battery cell of the battery string is connected to the positive terminal of the battery string. Then, the negative terminal of the battery string and the positive terminal of the battery string are connected to the negative electrode and positive electrode of the DC input side of the bidirectional energy storage converter through the high-voltage negative self-flow bus and the high-voltage positive DC bus, respectively, to form a charging and discharging power path of the battery string energy storage system;

[0005] The battery string is arranged in the order of the first battery cell, the second battery cell, the mth battery cell, and the nth battery cell. Starting from the first battery cell, the positive electrode of each battery is connected to the negative electrode of the next battery to form a series-connected battery string. The negative electrode of the first battery cell of the battery string is connected to the negative terminal of the battery string, and the positive electrode of the last nth battery cell of the battery string is connected to the positive terminal of the battery string. Then, the negative terminal of the battery string and the positive terminal of the battery string are connected to the DC transformer and the bidirectional charging and discharging DC / DC module in sequence through the high-voltage negative DC bus and the high-voltage positive DC bus, respectively, to form a bidirectional power supply and absorption path for equal current charging and discharging of the battery string.

[0006] The negative electrode of the first battery cell is connected to the low-voltage negative DC bus, and the positive electrode of the first battery cell is connected to the first electrically controlled switching switch battery connection end of the first electrically controlled switching switch, and the battery connection end of the first electrically controlled switching switch is connected to the low-voltage positive DC bus through the positive connection end of the first electrically controlled switching switch, and at the same time, the low-voltage positive DC bus and the low-voltage negative DC bus are respectively connected to the positive electrode and the negative electrode of the bidirectional charging and discharging DC / DC module, forming a charging and discharging power path for the first battery cell to perform current sharing;

[0007] The negative electrode of the second battery cell is connected to the first electrically controlled switching switch battery connection end of the first electrically controlled switching switch through the positive electrode of the first battery cell, and the battery connection end of the first electrically controlled switching switch is connected to the low-voltage negative DC bus through the negative electrode connection end of the first electrically controlled switching switch, and the positive electrode of the second battery cell is connected to the second electrically controlled switching switch battery connection end of the second electrically controlled switching switch, and the battery connection end of the second electrically controlled switching switch is connected to the low-voltage positive DC bus through the positive electrode connection end of the second electrically controlled switching switch, and at the same time, the low-voltage positive DC bus and the low-voltage negative DC bus are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module, forming a charging and discharging power path for the second battery cell to perform current sharing;

[0008] Assuming that the n-1th battery is the mth battery, the negative electrode of the nth battery cell is connected to the mth electrically controlled switching switch battery connection end of the mth electrically controlled switching switch through the positive electrode of the mth battery cell, and the battery connection end of the mth electrically controlled switching switch is connected to the low-voltage negative DC bus through the negative electrode connection end of the mth electrically controlled switching switch, and the positive electrode of the nth battery cell is connected to the nth electrically controlled switching switch battery connection end of the nth electrically controlled switching switch, and the battery connection end of the nth electrically controlled switching switch is connected to the low-voltage positive DC bus through the positive electrode connection end of the nth electrically controlled switching switch, and at the same time, the low-voltage positive DC bus and the low-voltage negative DC bus are respectively connected to the positive electrode and the negative electrode of the bidirectional charging and discharging DC / DC module, forming a charging and discharging power path for the nth battery cell to perform current sharing;

[0009] The system control module is connected to the bidirectional charging and discharging DC / DC module, the electric control switch driving circuit, and the battery parameter acquisition module through the system bus to form a system monitoring and control link;

[0010] The electric control switch driving circuit is connected to the first electric control gating switch, the second electric control gating switch, the mth electric control gating switch and the nth electric control gating switch respectively through the electric control switch driving control line, so as to form a controlled gating control driving link for connecting the battery to the low voltage positive DC bus and the low voltage negative DC bus;

[0011] The battery parameter acquisition module is respectively connected to the first battery cell negative electrode voltage and temperature parameter acquisition sensor, the first battery cell positive electrode voltage and temperature parameter acquisition sensor, the second battery cell negative electrode voltage and temperature parameter acquisition sensor, the second battery cell positive electrode voltage and temperature parameter acquisition sensor, the mth battery cell negative electrode voltage and temperature parameter acquisition sensor, the mth battery cell positive electrode voltage and temperature parameter acquisition sensor, the nth battery cell negative electrode voltage and temperature parameter acquisition sensor, the nth battery cell positive electrode voltage and temperature parameter acquisition sensor and the battery string current parameter acquisition sensor through the signal parameter acquisition harness, forming an information link for battery voltage and temperature parameter acquisition;

[0012] The system power module is respectively connected to the bidirectional charging and discharging DC / DC module and the system control module to form a power supply path of the battery management system;

[0013] The system control module is connected to the communication interface circuit, and the communication interface circuit is respectively connected to the upper control machine and the bidirectional energy storage commutation device through an external communication link, so as to form a communication link for the battery management system to accept the control of the upper control machine and exchange information with the upper control machine and the bidirectional energy storage commutation device;

[0014] It is also characterized in that a main control method of a bidirectional active balancing battery management system based on multi-cell sorting is:

[0015] 1) The battery management system is powered on by the system power module, self-checks abnormal alarms and enters the fault handling mode;

[0016] 2) If the self-check is normal, the system is running, and:

[0017] 3) The system control module exchanges information with the host control machine and the bidirectional energy storage commutation device through the communication interface circuit, and accepts the parameter settings of the host control machine and executes the instructions issued by the host control machine;

[0018] 4) The system control module analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately alarms and enters the fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is being charged, the battery cell with a voltage value and power value greater than the average voltage value and power value of the battery string is connected to the low-voltage positive DC bus and the low-voltage negative DC bus connected to the bidirectional charge and discharge DC / DC module through the electronic control switch drive control line, and the bidirectional charge and discharge DC / DC module is controlled by the system control module to discharge, so that the battery cell with a voltage value and power value greater than the average voltage value and power value of the battery string is discharged to a value less than or equal to the average voltage value and power value of the battery string or the value set by the upper control machine;

[0019] 5) The system control module analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately alarms and enters the fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is discharged, the battery cell with a voltage value and power value less than the average voltage value and power value of the battery string is connected to the low-voltage positive DC bus and the low-voltage negative DC bus connected to the bidirectional charge and discharge DC / DC module through the electronic control switch drive control line, and the bidirectional charge and discharge DC / DC module is controlled by the system control module to charge the battery cell with a voltage value and power value less than the average voltage value and power value of the battery string to a value greater than or equal to the average voltage value and power value of the battery string or the value set by the upper control machine;

[0020] 6) The system control module analyzes and calculates the battery state of charge and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and according to the set control strategy, the system control module repeats the operation process from 2) to 6) at the set time rhythm.

[0021] The present invention proposes a bidirectional active balancing battery management system based on multi-cell sorting. The bidirectional active balancing method of multi-cell sorting is used to select the battery string and the external power supply as the power source and "load" for balancing the power. At the same time, multiple non-connected battery cells in the battery string are effectively and actively regulated for current balancing. It can effectively realize high-precision real-time monitoring of battery operation, precise and scientific charge and discharge current control, and active and effective balancing of the voltage and power consistency of each battery cell in the battery string. It can realize battery balancing control of the battery string in each charging and discharging process, achieve fast and efficient consistency control of the voltage and power of the battery string, realize safe, healthy and efficient operation of the battery energy storage system, and has great positive significance for the application of energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a block diagram of the composition principle of a bidirectional active balancing battery management system based on multi-cell sorting. DETAILED DESCRIPTION

[0023] As an implementation example, Figure 1 A bidirectional active balancing battery management system based on multi-cell sorting is described, but the technology and solution of the present invention are not limited to the content given in this embodiment example.

[0024] like Figure 1As shown, the present invention proposes a bidirectional active balancing battery management system based on multi-cell sorting, which mainly includes: a bidirectional charging and discharging DC / DC module (1), a DC transformer (2), a high-voltage positive DC bus (3), a high-voltage negative DC bus (4), a battery string negative terminal (5), a battery string positive terminal (6), a low-voltage positive DC bus (7), a low-voltage negative DC bus (8), a system control module (9), an electric control switch drive circuit (10), a battery parameter acquisition module (11), a system bus (12), a system power module (13), a communication interface circuit (14), a signal parameter acquisition harness (15), an electric control switch drive control line (16), and an upper control module (17). a first battery cell (S1), a second battery cell (S2), an mth battery cell (Sm), an nth battery cell (Sn), a first battery cell negative electrode (S11), a first battery cell positive electrode (S12), a second battery cell negative electrode (S21), a second battery cell positive electrode (S22), an mth battery cell negative electrode (Sm1), an mth battery cell positive electrode (Sm2), an nth battery cell negative electrode (Sn1), an nth battery cell positive electrode (Sn2), a first electrically controlled gate switch (K1), a second electrically controlled gate switch (K2), and an mth electrically controlled gate switch (Km) , the nth electrically controlled switching switch (Kn), the positive connection terminal (a1) of the first electrically controlled switching switch, the negative connection terminal (b1) of the first electrically controlled switching switch, the battery connection terminal (c1) of the first electrically controlled switching switch, the positive connection terminal (a2) of the second electrically controlled switching switch, the negative connection terminal (b2) of the second electrically controlled switching switch, the battery connection terminal (c2) of the second electrically controlled switching switch, the positive connection terminal (am) of the mth electrically controlled switching switch, the negative connection terminal (bm) of the mth electrically controlled switching switch, the battery connection terminal (cm) of the mth electrically controlled switching switch, the positive connection terminal (an) of the nth electrically controlled switching switch, the negative connection terminal (bn) of the nth electrically controlled switching switch, the battery connection terminal (cn) of the 1st electrically controlled switching switch A battery cell negative electrode voltage and temperature parameter acquisition sensor (T11), a first battery cell positive electrode voltage and temperature parameter acquisition sensor (T12), a second battery cell negative electrode voltage and temperature parameter acquisition sensor (T21), a second battery cell positive electrode voltage and temperature parameter acquisition sensor (T22), an mth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tm1), a first battery cell positive electrode voltage and temperature parameter acquisition sensor (Tm2), an nth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tn1), an nth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tn2), and a battery string current parameter acquisition sensor (Ti), wherein:

[0025] The battery string is arranged in the order of the first battery cell (S1), the second battery cell (S2), the mth battery cell (Sm), and the nth battery cell (Sn). Starting from the first battery cell (S1), the positive electrode of each battery is connected to the negative electrode of the next battery to form a series-connected battery string. The negative electrode (S11) of the first battery cell in the battery string is connected to the negative terminal (5) of the battery string. At the same time, the positive electrode (Sn2) of the last battery cell in the battery string is connected to the positive terminal (6) of the battery string. The negative terminal (5) of the battery string and the positive terminal (6) of the battery string are respectively connected to the negative electrode and the positive electrode of the DC input side of the bidirectional energy storage commutation device (18) through the high-voltage negative DC bus (4) and the high-voltage positive DC bus (3), forming a charging and discharging power path of the battery string energy storage system.

[0026] The battery string is arranged in the order of the first battery cell (S1), the second battery cell (S2), the mth battery cell (Sm), and the nth battery cell (Sn). Starting from the first battery cell (S1), the positive electrode of each battery is connected to the negative electrode of the next battery to form a series-connected battery string. The negative electrode (S11) of the first battery cell in the battery string is connected to the negative terminal (5) of the battery string, and the positive electrode (Sn2) of the last battery cell in the battery string is connected to the positive terminal (6) of the battery string. The negative terminal (5) of the battery string and the positive terminal (6) of the battery string are then connected to a direct current transformer (2) and a bidirectional charging and discharging DC / DC module (1) in sequence through a high-voltage negative DC bus (4) and a high-voltage positive DC bus (3), respectively, to form a bidirectional power supply and absorption path for equalizing charging and discharging of the battery string.

[0027] The negative electrode (S11) of the first battery cell is connected to the low-voltage negative DC bus (8), and the positive electrode (S12) of the first battery cell is connected to the first electrically controlled switching switch battery connection terminal (c1) of the first electrically controlled switching switch (K1), and the first electrically controlled switching switch battery connection terminal (c1) is connected to the low-voltage positive DC bus (7) through the first electrically controlled switching switch positive connection terminal (a1), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the first battery cell (S1) to perform current sharing;

[0028] The negative electrode (S21) of the second battery cell is connected to the first electrically controlled switching switch battery connection terminal (c1) of the first electrically controlled switching switch (K1) through the positive electrode (S12) of the first battery cell, and the first electrically controlled switching switch battery connection terminal (c1) is connected to the low-voltage negative DC bus (8) through the first electrically controlled switching switch negative electrode connection terminal (b1), and the positive electrode (S22) of the second battery cell is connected to the second electrically controlled switching switch battery connection terminal (c2) of the second electrically controlled switching switch (K2), and the second electrically controlled switching switch battery connection terminal (c2) is connected to the low-voltage positive DC bus (7) through the second electrically controlled switching switch positive electrode connection terminal (a2), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the second battery cell (S2) to perform current sharing;

[0029] Assuming that the n-1th storage battery is the mth storage battery, the negative electrode (Sn1) of the nth storage battery monomer is connected to the mth electric control switching switch battery connection terminal (cm) of the mth electric control switching switch (Km) through the positive electrode (Sm2) of the mth storage battery monomer, and the mth electric control switching switch battery connection terminal (cm) is connected to the low-voltage negative electrode DC bus (8) through the negative electrode connection terminal (bm) of the mth electric control switching switch, and the positive electrode (Sn2) of the nth storage battery monomer is connected to the nth electric control switching switch battery connection terminal (cm). The nth electrically controlled gate switch battery connection terminal (cn) of the switch (Kn) is connected to the low-voltage positive DC bus (7) through the nth electrically controlled gate switch positive connection terminal (an), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the nth battery cell (Sn) to perform current sharing;

[0030] The system control module (9) is respectively connected to the bidirectional charging and discharging DC / DC module (1), the electric control switch driving circuit (10), and the battery parameter acquisition module (11) through the system bus (12), thereby forming a system monitoring and control link;

[0031] The electric control switch driving circuit (10) is respectively connected to the first electric control selection switch (K1), the second electric control selection switch (K2), the mth electric control selection switch (Km), and the nth electric control selection switch (Kn) through the electric control switch driving control line (16), so as to form a controlled selection control driving link for connecting the storage battery to the low voltage positive DC bus (7) and the low voltage negative DC bus (8);

[0032] The battery parameter acquisition module (11) is respectively connected to the first battery cell negative electrode voltage and temperature parameter acquisition sensor (T11), the first battery cell positive electrode voltage and temperature parameter acquisition sensor (T12), the second battery cell negative electrode voltage and temperature parameter acquisition sensor (T21), the second battery cell positive electrode voltage and temperature parameter acquisition sensor (T22), the nth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tn1), the mth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tm1), the mth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tm2), the nth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tn2) and the battery string current parameter acquisition sensor (Ti) through the signal parameter acquisition harness (15), forming an information link for battery voltage and temperature parameter acquisition;

[0033] The system power supply module (13) is respectively connected to the bidirectional charging and discharging DC / DC module (1) and the system control module (9), forming a power supply path of the battery management system;

[0034] The system control module (9) is connected to the communication interface circuit (14), and the communication interface circuit (14) is respectively connected to the upper control machine (17) and the bidirectional energy storage commutation device (18) through the external communication link (19), so as to form a communication link for the battery management system to accept the control of the upper control machine and exchange information with the upper control machine (17) and the bidirectional energy storage commutation device (18);

[0035] It is also characterized in that a main control method of a bidirectional active balancing battery management system based on multi-cell sorting is:

[0036] 1) The battery management system is powered on and started by the system power module (13), self-checks for abnormalities, alarms, and enters a fault handling mode;

[0037] 2) If the self-check is normal, the system is running, and:

[0038] The system control module (9) exchanges information with the upper control machine (17) and the bidirectional energy storage commutation device (18) through the communication interface circuit (14), and accepts parameter settings of the upper control machine (17) and executes instructions issued by the upper control machine (17);

[0039] 4) The system control module (9) analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately issues an alarm to enter a fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is being charged, the battery cell having a voltage value and a power value greater than the average voltage value and power value of the battery string is controlled by the electric control switch drive control line (16) to be connected to the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) connected to the bidirectional charging and discharging DC / DC module (1), and the system control module (9) controls the bidirectional charging and discharging DC / DC module (1) to discharge the battery cell having a voltage value and a power value greater than the average voltage value and power value of the battery string to be less than or equal to the average voltage value and power value of the battery string or the value set by the upper control machine (17);

[0040] 5) The system control module (9) analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately issues an alarm to enter a fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is being discharged, the battery cell having a voltage value and a power value less than the average voltage value and power value of the battery string is connected to the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) connected to the bidirectional charging and discharging DC / DC module (1) through the electric control switch driving control line (16), and the bidirectional charging and discharging DC / DC module (1) is controlled by the system control module (9) to charge the battery cell having a voltage value and a power value less than the average voltage value and power value of the battery string to a value greater than or equal to the average voltage value and power value of the battery string or a value set by the upper control machine (17);

[0041] The system control module (9) analyzes and calculates the state of charge of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and according to the set control strategy, the system control module (9) repeatedly executes the operation process from 2) to 6) according to the set time beat.

[0042] The present invention proposes a bidirectional active balancing battery management system based on multi-cell sorting. The bidirectional active balancing method of multi-cell sorting is used to take the battery string and the external power supply as the power source and "load" for balancing the power. At the same time, multiple non-connected battery cells in the battery string are effectively and actively regulated for current balancing. This can effectively realize high-precision real-time monitoring of battery operation, precise and scientific charge and discharge current control, and active and effective balancing of the voltage and power consistency of each battery cell in the battery string. The battery can realize battery string balancing control in each charging and discharging process, achieve effective consistency control of the battery string voltage and power, realize safe, healthy and efficient operation of the battery energy storage system, and has great positive significance for the application of energy storage systems.

Claims

1. A bidirectional active balancing battery management system based on multi-cell sorting, mainly comprising: Bidirectional charging and discharging DC / DC module (1), DC transformer (2), high-voltage positive DC bus (3), high-voltage negative DC bus (4), negative terminal of battery string (5), positive terminal of battery string (6), low-voltage positive DC bus (7), low-voltage negative DC bus (8), system control module (9), electric control switch drive circuit (10), battery parameter acquisition module (11), system bus (12), system power module (13), communication interface circuit (14), signal parameter acquisition harness (15), electric control switch drive control line (16), upper control machine (17), bidirectional energy storage commutation device (18), external communication link (19 ), the first battery cell (S1), the second battery cell (S2), the mth battery cell (Sm), the nth battery cell (Sn), the first battery cell negative electrode (S11), the first battery cell positive electrode (S12), the second battery cell negative electrode (S21), the second battery cell positive electrode (S22), the mth battery cell negative electrode (Sm1), the mth battery cell positive electrode (Sm2), the nth battery cell negative electrode (Sn1), the nth battery cell positive electrode (Sn2), the first electric control selection switch (K1), the second electric control selection switch (K2), the mth electric control selection switch (Km), the nth electric control selection switch (Kn), the first electric control selection switch a positive connection terminal (a1) of the first electric control selector switch, a negative connection terminal (b1) of the first electric control selector switch, a battery connection terminal (c1) of the first electric control selector switch, a positive connection terminal (a2) of the second electric control selector switch, a negative connection terminal (b2) of the second electric control selector switch, a battery connection terminal (c2) of the second electric control selector switch, a positive connection terminal (am) of the mth electric control selector switch, a negative connection terminal (bm) of the mth electric control selector switch, a battery connection terminal (cm) of the mth electric control selector switch, a positive connection terminal (an) of the nth electric control selector switch, a negative connection terminal (bn) of the nth electric control selector switch, a battery connection terminal (cn) of the nth electric control selector switch, and a negative voltage of the first battery cell. and temperature parameter acquisition sensor (T11), the first battery cell positive electrode voltage and temperature parameter acquisition sensor (T12), the second battery cell negative electrode voltage and temperature parameter acquisition sensor (T21), the second battery cell positive electrode voltage and temperature parameter acquisition sensor (T22), the mth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tm1), the first battery cell positive electrode voltage and temperature parameter acquisition sensor (Tm2), the nth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tn1), the nth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tn2), and the battery string current parameter acquisition sensor (Ti), wherein: The battery string is arranged in the order of the first battery cell (S1), the second battery cell (S2), the mth battery cell (Sm), and the nth battery cell (Sn). Starting from the first battery cell (S1), the positive electrode of each battery is connected to the negative electrode of the next battery to form a series-connected battery string. The negative electrode (S11) of the first battery cell in the battery string is connected to the negative terminal (5) of the battery string. At the same time, the positive electrode (Sn2) of the last battery cell in the battery string is connected to the positive terminal (6) of the battery string. The negative terminal (5) of the battery string and the positive terminal (6) of the battery string are respectively connected to the negative electrode and the positive electrode of the DC input side of the bidirectional energy storage commutation device (18) through the high-voltage negative DC bus (4) and the high-voltage positive DC bus (3), forming a charging and discharging power path of the battery string energy storage system. The battery string is arranged in the order of the first battery cell (S1), the second battery cell (S2), the mth battery cell (Sm), and the nth battery cell (Sn). Starting from the first battery cell (S1), the positive electrode of each battery is connected to the negative electrode of the next battery to form a series-connected battery string. The negative electrode (S11) of the first battery cell in the battery string is connected to the negative terminal (5) of the battery string, and the positive electrode (Sn2) of the last battery cell in the battery string is connected to the positive terminal (6) of the battery string. The negative terminal (5) of the battery string and the positive terminal (6) of the battery string are then connected to a direct current transformer (2) and a bidirectional charging and discharging DC / DC module (1) in sequence through a high-voltage negative DC bus (4) and a high-voltage positive DC bus (3), respectively, to form a bidirectional power supply and absorption path for equalizing charging and discharging of the battery string. The negative electrode (S11) of the first battery cell is connected to the low-voltage negative DC bus (8), and the positive electrode (S12) of the first battery cell is connected to the first electrically controlled switching switch battery connection terminal (c1) of the first electrically controlled switching switch (K1), and the first electrically controlled switching switch battery connection terminal (c1) is connected to the low-voltage positive DC bus (7) through the first electrically controlled switching switch positive connection terminal (a1), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the first battery cell (S1) to perform current sharing; The negative electrode (S21) of the second battery cell is connected to the first electrically controlled switching switch battery connection terminal (c1) of the first electrically controlled switching switch (K1) through the positive electrode (S12) of the first battery cell, and the first electrically controlled switching switch battery connection terminal (c1) is connected to the low-voltage negative DC bus (8) through the first electrically controlled switching switch negative electrode connection terminal (b1), and the positive electrode (S22) of the second battery cell is connected to the second electrically controlled switching switch battery connection terminal (c2) of the second electrically controlled switching switch (K2), and the second electrically controlled switching switch battery connection terminal (c2) is connected to the low-voltage positive DC bus (7) through the second electrically controlled switching switch positive electrode connection terminal (a2), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the second battery cell (S2) to perform current sharing; Assuming that the n-1th storage battery is the mth storage battery, the negative electrode (Sn1) of the nth storage battery monomer is connected to the mth electric control switching switch battery connection terminal (cm) of the mth electric control switching switch (Km) through the positive electrode (Sm2) of the mth storage battery monomer, and the mth electric control switching switch battery connection terminal (cm) is connected to the low-voltage negative electrode DC bus (8) through the negative electrode connection terminal (bm) of the mth electric control switching switch, and the positive electrode (Sn2) of the nth storage battery monomer is connected to the nth electric control switching switch battery connection terminal (cm). The nth electrically controlled gate switch battery connection terminal (cn) of the switch (Kn) is connected to the low-voltage positive DC bus (7) through the nth electrically controlled gate switch positive connection terminal (an), and the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) are respectively connected to the positive electrode and negative electrode of the bidirectional charging and discharging DC / DC module (1), forming a charging and discharging power path for the nth battery cell (Sn) to perform current sharing; The system control module (9) is respectively connected to the bidirectional charging and discharging DC / DC module (1), the electric control switch driving circuit (10), and the battery parameter acquisition module (11) through the system bus (12), thereby forming a system monitoring and control link; The electric control switch driving circuit (10) is respectively connected to the first electric control selection switch (K1), the second electric control selection switch (K2), the mth electric control selection switch (Km), and the nth electric control selection switch (Kn) through the electric control switch driving control line (16), so as to form a controlled selection control driving link for connecting the storage battery to the low voltage positive DC bus (7) and the low voltage negative DC bus (8); The battery parameter acquisition module (11) is respectively connected to the first battery cell negative electrode voltage and temperature parameter acquisition sensor (T11), the first battery cell positive electrode voltage and temperature parameter acquisition sensor (T12), the second battery cell negative electrode voltage and temperature parameter acquisition sensor (T21), the second battery cell positive electrode voltage and temperature parameter acquisition sensor (T22), the nth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tn1), the mth battery cell negative electrode voltage and temperature parameter acquisition sensor (Tm1), the mth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tm2), the nth battery cell positive electrode voltage and temperature parameter acquisition sensor (Tn2) and the battery string current parameter acquisition sensor (Ti) through the signal parameter acquisition harness (15), forming an information link for battery voltage and temperature parameter acquisition; The system power supply module (13) is respectively connected to the bidirectional charging and discharging DC / DC module (1) and the system control module (9), forming a power supply path of the battery management system; The system control module (9) is connected to the communication interface circuit (14), and the communication interface circuit (14) is respectively connected to the upper control machine (17) and the bidirectional energy storage commutation device (18) through the external communication link (19), so as to form a communication link for the battery management system to accept the control of the upper control machine and exchange information with the upper control machine (17) and the bidirectional energy storage commutation device (18); It is also characterized in that a main control method of a bidirectional active balancing battery management system based on multi-cell sorting is: 1) The battery management system is powered on and started by the system power module (13), self-checks for abnormalities, alarms, and enters a fault handling mode; 2) If the self-check is normal, the system is running, and: 3) The system control module (9) exchanges information with the upper control machine (17) and the bidirectional energy storage commutation device (18) through the communication interface circuit (14), and accepts parameter settings of the upper control machine (17) and executes instructions issued by the upper control machine (17); 4) The system control module (9) analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately issues an alarm to enter a fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is being charged, the battery cell having a voltage value and a power value greater than the average voltage value and power value of the battery string is controlled by the electric control switch drive control line (16) to be connected to the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) connected to the bidirectional charging and discharging DC / DC module (1), and the system control module (9) controls the bidirectional charging and discharging DC / DC module (1) to discharge the battery cell having a voltage value and a power value greater than the average voltage value and power value of the battery string to be less than or equal to the average voltage value and power value of the battery string or the value set by the upper control machine (17); 5) The system control module (9) analyzes and calculates the charge state of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and immediately issues an alarm to enter a fault handling mode when it is determined that the battery is abnormal; otherwise, when the deviation is greater than or equal to the set allowable deviation value and the battery string is being discharged, the battery cell having a voltage value and a power value less than the average voltage value and power value of the battery string is connected to the low-voltage positive DC bus (7) and the low-voltage negative DC bus (8) connected to the bidirectional charging and discharging DC / DC module (1) through the electric control switch driving control line (16), and the bidirectional charging and discharging DC / DC module (1) is controlled by the system control module (9) to charge the battery cell having a voltage value and a power value less than the average voltage value and power value of the battery string to a value greater than or equal to the average voltage value and power value of the battery string or a value set by the upper control machine (17); 6) The system control module (9) analyzes and calculates the state of charge of the battery and the consistency of the voltage and power of each battery cell according to the real-time monitored battery cell voltage, temperature parameters and battery string current parameters, and according to the set control strategy, the system control module (9) repeatedly executes the operation process from 2) to 6) according to the set time beat.

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