A non-dissipative balancing management system for space lithium-ion batteries

Abstract

The invention relates to a non-dissipative balancing management system for a space lithium-ion battery, belonging to the technical field of lithium-ion battery management; the system comprises two non-dissipative balancing management modules and a lithium-ion battery pack; the two non-dissipative balancing management modules are respectively connected to the lithium-ion battery pack; the two non-dissipative balancing management modules use a dual-machine cold standby mode to achieve balancing control of the lithium-ion battery pack; the non-dissipative balancing management module comprises a central control module, a first balancing module and a second balancing module; the first balancing module comprises a low 3-way group voltage conditioning circuit, a 1-11-way balancing control circuit and a frequency tracking point circuit; the second balancing module comprises a high 3-way group voltage conditioning circuit and a 12-22-way balancing control circuit; the lithium-ion battery pack comprises 22 battery cells connected in series; the two battery cells are respectively connected in parallel to the 1-22-way balancing control circuit; the invention solves the problem of measuring the battery cell voltage under a high common mode voltage, and can also achieve energy transfer between lithium-ion battery cells.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium ion batteries and relates to a non-dissipative balancing management system for space lithium ion batteries. Background Art

[0002] Lithium-ion batteries have replaced nickel-hydrogen batteries and are widely used in satellites. They can greatly reduce the mass of the power system, reduce the cost of satellite launches, and improve the payload ratio. Compared with traditional space energy storage batteries such as nickel-hydrogen and nickel-cadmium, lithium-ion batteries have high coulombic efficiency. The voltage difference between cells will gradually increase as the charge and discharge cycles of the battery pack increase. If not controlled, it will lead to overcharge and over-discharge of individual cells, thus affecting the safety of the entire group and even the satellite power system. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and propose a non-dissipative balancing management system for spatial lithium-ion batteries, which solves the problem of measuring the voltage of battery cells under high common mode voltage and can also realize energy transfer between lithium-ion battery cells.

[0004] The solution of the present invention is:

[0005] A non-dissipative balancing management system for a space lithium-ion battery comprises two non-dissipative balancing management modules and a lithium-ion battery pack; the two non-dissipative balancing management modules are respectively connected to the lithium-ion battery pack; the two non-dissipative balancing management modules use a dual-machine cold standby mode to achieve balancing control of the lithium-ion battery pack; the non-dissipative balancing management module comprises a central control module, a first balancing module and a second balancing module; the first balancing module comprises a low 3-way group voltage conditioning circuit, a 1-11-way balancing control circuit, and a frequency tracking point circuit; the second balancing module comprises a high 3-way group voltage conditioning circuit and a 12-22-way balancing control circuit; the lithium-ion battery pack comprises 22 battery cells connected in series; the 1-11 battery cells are connected in parallel with the 1-11-way balancing control circuit, and the other 12-22 battery cells are connected in parallel with the 12-22-way balancing control circuit;

[0006] Central control module: receives 1553B instructions from an external host computer; parses 1553B instructions, selects the equalization mode, and generates 1-22 excitation signals; sends 1-11 excitation signals to 1-11 equalization control circuits; sends 12-22 excitation signals to 12-22 equalization control circuits; sends 1-22 excitation signals to the frequency tracking point circuit;

[0007] Frequency tracking point circuit: receives 1-22 excitation signals from the central control module, adjusts 1-22 excitation signals, generates frequency control signals, and controls the connection lines between 1-11 equalization control circuits and 12-22 equalization control circuits to transmit current within the working frequency range through the frequency control signals;

[0008] 1-11 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 1-11 channel excitation signals from the central control module, controls the on-off of each bidirectional DC / AC converter according to the 1-11 channel excitation signals, and realizes the connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring;

[0009] 12-22 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 12-22 channel excitation signals from the central control module, controls the on-off of each bidirectional DC / AC converter according to the 12-22 channel excitation signals, and realizes the connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring;

[0010] The 22 battery cells connected in series in the lithium-ion battery pack are divided into 6 groups according to pre-settings; the low 3-way group voltage conditioning circuit is connected to 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer; the high 3-way group voltage conditioning circuit is connected to the other 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer.

[0011] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, the balancing mode includes a continuous balancing mode and a gap balancing mode; when in the continuous balancing mode, the current of the high-voltage battery cells in the lithium-ion battery pack is continuously flowed into the low-voltage battery cells to achieve balancing; when in the gap balancing mode, the current of the high-voltage battery cells in the lithium-ion battery pack is gap-flown into the low-voltage battery cells to achieve balancing.

[0012] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, the 1-11 balancing control circuits are connected to the 12-22 balancing control circuits through the sharebus line; the current of the high-voltage battery cell flows into the low-voltage battery cell via the 1-11 balancing control circuits, the sharebus line, and the 12-22 balancing control circuits in sequence; or the current of the high-voltage battery cell flows into the low-voltage battery cell via the 12-22 balancing control circuits, the sharebus line, and the 1-11 balancing control circuits in sequence.

[0013] In the above-mentioned non-dissipative balancing management system for space lithium-ion batteries, the frequency tracking point circuit controls the operating frequency range of the sharebus line to be 25-50kHz.

[0014] In the above-mentioned spatial lithium-ion battery non-dissipative balancing management system, the low 3-way group voltage conditioning circuit and the high 3-way group voltage conditioning circuit realize the detection of voltage changes in the lithium-ion battery group balancing management process in units of groups, which serves as auxiliary monitoring of the voltage feedback of the 1-11-way balancing control circuit and the 12-22-way balancing control circuit.

[0015] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, the bidirectional DC / AC converters correspond to the battery cells one by one, and each bidirectional DC / AC converter is connected in parallel with the corresponding battery cell.

[0016] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, the bidirectional DC / AC converter includes a voltage-stabilizing capacitor C1, a resonant capacitor C2, a MOSFET switch Q, a transformer TF, a fuse and a resistor R; wherein the voltage-stabilizing capacitor C1 is connected in parallel with the corresponding battery cell, and one end of the voltage-stabilizing capacitor C1 is connected to one end of the primary side of the transformer TF, and the other end of the voltage-stabilizing capacitor C1 is respectively connected to the drain of the MOSFET switch Q and one end of the resonant capacitor C2; the other end of the resonant capacitor C2 is respectively connected to the source of the MOSFET switch Q and the other end of the primary side of the transformer TF; the gate of the MOSFET switch Q inputs an excitation signal; one end of the secondary side of the transformer TF is respectively connected to one end of the fuse and the central control module; the other end of the fuse is connected to one end of the resistor R; the other end of the resistor R is connected to the sharebus line; the voltage-stabilizing capacitors C1 of 22 bidirectional DC / AC converters are connected in series; the other end of the secondary side of the transformer TF of the 22 bidirectional DC / AC converters is connected to the same ground.

[0017] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, the natural frequency of the bidirectional DC / AC converter depends on the primary inductance of the transformer TF, the gate capacitance of the MOSFET switch Q and the resonant capacitor C2; the on and off of the MOSFET switch Q is controlled by the excitation signal sent by the central control module, so that the bidirectional DC / AC converter can operate in the resonant mode.

[0018] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, after the balancing management of the lithium-ion battery pack is completed, the voltages of all battery cells in the lithium-ion battery pack are completely equal, and the secondary voltages of the transformer TF are also completely equal. At this time, the current flowing through the resistor R is 0.

[0019] In the above-mentioned non-dissipative balancing management system for spatial lithium-ion batteries, in the process of balancing management of lithium-ion battery packs, the energy consumption factor on the energy transfer path is only the resistance R; there is no energy loss in the process of cyclic exchange of alternating energy between the battery cells, the transformer TF inductor and the MOSFET switch Q at the resonant frequency, thus realizing non-dissipative balancing management.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] (1) The non-dissipative balancing management method of the present invention can solve the problem of measuring the voltage of a battery cell under a high common mode voltage, and can also realize the energy transfer between lithium-ion battery cells, so it is called a non-dissipative balancing management method;

[0022] (2) The bidirectional DC / AC converter of the present invention removes the high common-mode voltage of the series-connected lithium-ion cells through transformer isolation, thereby avoiding the impact of inconsistent voltage references between cells on measurement and control, and realizing energy transfer between different battery cells;

[0023] (3) In the present invention, when the voltages of all battery cells are equal, the current flowing through the DC / AC converter and the battery cells is 0; when the voltages between cells are unbalanced, the current flows from the high-voltage cells through the corresponding converters and the common bus to the low-voltage cells. The voltage of the high-voltage cells decreases during the discharge process, while the voltage of the low-voltage cells increases during the charging process. The voltage difference between the cells gradually decreases, and finally the cell voltage is balanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the non-dissipative balanced management system of the present invention;

[0025] Figure 2 Schematic diagram of the bidirectional DC / AC converter circuit of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the embodiments.

[0027] The present invention provides a non-dissipative balancing management system for space lithium-ion batteries. The non-dissipative balancing management method for space lithium-ion batteries based on DC / AC conversion can realize high-precision measurement by using a DC / AC converter, and realize energy transfer between cells at the same time, thereby achieving the purpose of voltage balancing between cells.

[0028] Non-dissipative balance management system for space lithium-ion batteries, such as Figure 1As shown, it specifically includes 2 non-dissipative balancing management modules and a lithium-ion battery pack; the 2 non-dissipative balancing management modules are respectively connected to the lithium-ion battery pack; the 2 non-dissipative balancing management modules use a dual-machine cold standby method to achieve balancing control of the lithium-ion battery pack; the non-dissipative balancing management module includes a central control module, a first balancing module and a second balancing module; the first balancing module includes a low 3-way group voltage conditioning circuit, a 1-11-way balancing control circuit, and a frequency tracking point circuit; the second balancing module includes a high 3-way group voltage conditioning circuit, and a 12-22-way balancing control circuit; the lithium-ion battery pack includes 22 battery cells connected in series; among them, 1-11 battery cells are connected in parallel with 1-11-way balancing control circuits, and in addition, 12-22 battery cells are connected in parallel with 12-22-way balancing control circuits.

[0029] The non-dissipative balancing management system for battery packs uses a dual-machine cold standby method to complete collection and balancing control, and the main and backup are completely independent. The non-dissipative balancing management device for lithium-ion battery packs based on a bidirectional DC / AC converter is shown below, which can realize the voltage collection function, temperature collection function, balancing control function, internal power conversion function and 1553B bus communication function of the lithium-ion battery pack. According to the modular design concept, the circuit of the non-dissipative balancing management device for the battery pack is uniformly designed, divided into the main and backup circuits, and the cold backup and main backup circuits are designed in the same way. Only a single copy is on duty at the same time, and the main and backup circuits can be powered on at the same time.

[0030] According to the functional division, the main (backup) part is composed of three modules: the central control module, the first balancing module and the second balancing module. The communication interfaces between the modules are allocated in a coordinated manner according to the internal electrical connector resources of the whole machine. Take the main part as an example for introduction.

[0031] Central control module: Receive 1553B instructions from external host computer; parse 1553B instructions, select balancing mode, and generate 1-22 excitation signals. The balancing mode includes continuous balancing mode and gap balancing mode; when in continuous balancing mode, the current of high-voltage battery cells in the lithium-ion battery pack flows continuously into low-voltage battery cells to achieve balancing; when in gap balancing mode, the current gap of high-voltage battery cells in the lithium-ion battery pack flows into low-voltage battery cells to achieve balancing. Send 1-11 excitation signals to 1-11 balancing control circuits; send 12-22 excitation signals to 12-22 balancing control circuits; send 1-22 excitation signals to the frequency tracking point circuit.

[0032] The central control module of the battery non-dissipative balancing management device integrates a power module. The core uses FPGA and 1553B to communicate, realize the information interaction between the host computer CMU, and output the internal circuit instructions of the battery non-dissipative balancing management device to execute the corresponding functions.

[0033] The central control module serves as the external interface of the battery non-dissipative balancing management device. It is connected to the service module business unit and the host computer CMU, receives a +100V bus power supply and matrix instructions from the service module business unit, and transmits the +12V and +5V telemetry signals generated by the internal DC / DC conversion circuit to the service module business unit; it is connected to the host computer CMU 1553B bus interface and realizes information exchange with the host computer 1553B through the internal 1553B bus interface circuit.

[0034] The central control module is the control module inside the non-dissipative balancing management device for batteries. It is connected to the first balancing module and 2 internally, and collects analog inputs such as single cell voltage and group voltage from the first balancing module and the second balancing module. At the same time, the internal temperature acquisition circuit collects and transforms the internal temperature from the central control module and the balancing module, and uses them as the input of the analog acquisition circuit. The A / D conversion circuit inside the central control module converts them into digital quantities and transmits them to the core FPGA of the central control module. The FPGA processes the instructions and telemetry of the host computer 1553B at the same time, outputs frequency point tracking signals and 1-22 pulse instructions internally, and outputs various telemetry information to the host computer CMU externally. At the same time, the +12V and +5V generated by the DC / DC conversion circuit inside the central control module power the circuits inside the module such as FPGA, as well as the internal circuits of the first balancing module and 2.

[0035] The 1-11 balancing control circuit is connected to the 12-22 balancing control circuit via the sharebus line; the current of the high-voltage battery cell flows into the low-voltage battery cell via the 1-11 balancing control circuit, the sharebus line, and the 12-22 balancing control circuit in sequence; or the current of the high-voltage battery cell flows into the low-voltage battery cell via the 12-22 balancing control circuit, the sharebus line, and the 1-11 balancing control circuit in sequence.

[0036] Frequency tracking point circuit: Receives 1-22 excitation signals from the central control module, adjusts 1-22 excitation signals, generates frequency control signals, and controls the connection lines between 1-11 equalization control circuits and 12-22 equalization control circuits to transmit current within the operating frequency range through the frequency control signals. The frequency tracking point circuit controls the operating frequency range of the sharebus line to be 25-50kHz.

[0037] The main function of the balancing module is to receive 22 balancing excitation pulses from the central control module for balancing control of single cells. At the same time, it realizes the collection of single cell voltage, combined battery voltage and whole battery voltage, and sends the telemetry data to the central control module through the 1553B bus and uploads it to the host computer for processing. The balancing module is divided into 1-11 balancing control circuits and 12-22 balancing control circuits.

[0038] 1-11 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 1-11 channel excitation signals from the central control module, controls the on and off of each bidirectional DC / AC converter according to the 1-11 channel excitation signals, and realizes connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring.

[0039] 12-22 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 12-22 channel excitation signals from the central control module, controls the on and off of each bidirectional DC / AC converter according to the 12-22 channel excitation signals, and realizes connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring.

[0040] The balancing control circuit is the core power conversion part of the balancing module. The first balancing module is externally connected to the 1-11 cells of the battery pack. Built-in fuses are installed on the positive and return lines of the battery cells. The collected cell voltages are input to the 1-11 balancing control circuits for conversion. The control signal of the balancing control circuit comes from the sharebus signal on the one hand and from the balancing command circuit on the other hand to realize the non-dissipative balancing function, and is connected to the central control module through the analog output circuit.

[0041] The balancing control circuit is the core power conversion part of the balancing module. The second balancing module is externally connected to the 12-22 cells of the battery pack. Built-in fuses are installed on the positive and return lines of the battery cells. The collected cell voltages are input to the 12-22 balancing control circuits for conversion. The control signal of the balancing control circuit comes from the sharebus signal on the one hand and from the balancing command circuit on the other hand to realize the non-dissipative balancing function, and is connected to the central control module through the analog output circuit.

[0042] The 22 battery cells connected in series in the lithium-ion battery pack are divided into 6 groups according to pre-settings; the low 3-way group voltage conditioning circuit is connected to 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer; the high 3-way group voltage conditioning circuit is connected to the other 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer.

[0043] The low 3-way group voltage conditioning circuit and the high 3-way group voltage conditioning circuit detect the voltage change in the process of lithium-ion battery group balancing management in units of groups, and serve as auxiliary monitoring of the voltage feedback of the 1-11-way balancing control circuit and the 12-22-way balancing control circuit.

[0044] The bidirectional DC / AC converters correspond to the battery cells one by one, and each bidirectional DC / AC converter is connected in parallel with the corresponding battery cell. Figure 2 As shown, the bidirectional DC / AC converter includes a voltage-stabilizing capacitor C1, a resonant capacitor C2, a MOSFET switch Q, a transformer TF, a fuse and a resistor R; wherein the voltage-stabilizing capacitor C1 is connected in parallel with the corresponding battery cell, and one end of the voltage-stabilizing capacitor C1 is connected to one end of the primary side of the transformer TF, and the other end of the voltage-stabilizing capacitor C1 is respectively connected to the drain of the MOSFET switch Q and one end of the resonant capacitor C2; the other end of the resonant capacitor C2 is respectively connected to the source of the MOSFET switch Q and the other end of the primary side of the transformer TF; the gate of the MOSFET switch Q inputs an excitation signal; one end of the secondary side of the transformer TF is respectively connected to one end of the fuse and the central control module; the other end of the fuse is connected to one end of the resistor R; the other end of the resistor R is connected to the sharebus line; the voltage-stabilizing capacitors C1 of 22 bidirectional DC / AC converters are connected in series; the other ends of the secondary sides of the transformers TF of the 22 bidirectional DC / AC converters are connected to the same ground.

[0045] The natural frequency of the bidirectional DC / AC converter depends on the primary inductance of the transformer TF, the gate capacitance of the MOSFET switch Q and the resonant capacitor C2; the on-off of the MOSFET switch Q is controlled by the excitation signal sent by the central control module, so that the bidirectional DC / AC converter can work in the resonant mode.

[0046] After the lithium-ion battery pack is balanced, the voltages of all the battery cells in the lithium-ion battery pack are completely equal, and the secondary voltages of the transformer TF are also completely equal. At this time, the current flowing through the resistor R is 0.

[0047] In the process of balancing management of lithium-ion battery packs, the energy consumption factor on the energy transfer path is only the resistance R; there is no energy loss in the process of cyclic exchange of alternating energy between the battery cells, transformer TF inductance and MOSFET switch Q at the resonant frequency, realizing non-dissipative balancing management.

[0048] A temperature measurement point is designed in each of the central control module, the first balancing module and the balancing 2 of the battery pack interface management unit. The central control module is designed on the power module to monitor the temperature of the power module; the first balancing module and the second balancing module are designed on the planar transformer to monitor the temperature of the transformer.

[0049] In the present invention, the balancing control circuit is a lithium-ion battery pack balancing system based on a bidirectional DC / AC converter. The balancing module is composed of a voltage-stabilizing capacitor C1, a resonant capacitor C2, a MOSFET switch Q, a transformer TF, a fuse, a resistor R and a drive circuit (excitation signal). The secondary sides of all transformers are connected together through current-limiting resistors to form a common bus (Sharebus); the MOSFET switch control signal is provided by a pulse instruction sent by a central control module.

[0050] Each balancing unit in the balancing control circuit adopts a bidirectional DC / AC converter lossless balancing circuit. The natural frequency of the bidirectional DC / AC converter depends on the primary inductance of the transformer, the gate capacitance of the MOS tube and the parallel resonant capacitance. The pulse command sent by the central control module controls the on and off of the MOS tube switch, so that the bidirectional DC / AC converter works in the resonant mode (the frequency of the balancing pulse is equal to the resonant frequency).

[0051] If the voltages of all cells in the series battery pack are completely equal, then the secondary voltage of the transformer is also completely equal. At this time, the current flowing through the current limiting resistor is 0. Otherwise, the current will flow from the high-voltage battery cell through the transformer, the current limiting resistor and the common bus to the low-voltage battery cell.

[0052] During the operation of the above balancing control circuit, the energy consumption factors on the energy transfer path only include the current limiting resistor and the parasitic resistor. The energy consumption of both is very small and can be ignored. There is no energy loss in the process of cyclic exchange of alternating energy between the battery cell, the transformer inductor and the MOS tube parallel capacitor at the resonant frequency, thus realizing non-dissipative balancing management.

[0053] The spatial lithium-ion battery non-dissipative balancing management method system provided by the present invention can realize the measurement and non-dissipative balancing functions of lithium-ion monomers. Each battery cell is configured with a bidirectional DC / AC converter, the DC end is connected to the battery cell end, and the AC end is connected to the common bus through a current-limiting resistor. The bidirectional DC / AC converter removes the high common-mode voltage of the series-connected lithium-ion monomer batteries through transformer isolation, thereby avoiding the influence of the inconsistent voltage reference between the monomers on the measurement and control, and on the other hand, realizes the transfer of energy between different battery cells. When the voltages of all battery cells are equal, the current flowing through the DC / AC converter and the battery cells is 0; when the voltages between the monomers are unbalanced, the current flows from the high-voltage monomer through the corresponding converter and the common bus to the low-voltage monomer. The voltage of the high-voltage monomer decreases with the discharge process, and the voltage of the low-voltage monomer increases with the charging process. The voltage difference between each section of the monomer gradually decreases, and finally the voltage of the monomer is balanced.

[0054] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A non-dissipative balance management system for space lithium-ion batteries, characterized in that: It includes two non-dissipative balancing management modules and a lithium-ion battery pack; the two non-dissipative balancing management modules are respectively connected to the lithium-ion battery pack; the two non-dissipative balancing management modules use a dual-machine cold standby method to achieve balancing control of the lithium-ion battery pack; the non-dissipative balancing management module includes a central control module, a first balancing module and a second balancing module; the first balancing module includes a low 3-way group voltage conditioning circuit, a 1-11-way balancing control circuit, and a frequency tracking point circuit; the second balancing module includes a high 3-way group voltage conditioning circuit and a 12-22-way balancing control circuit; the lithium-ion battery pack includes 22 battery cells connected in series; the 1-11 battery cells are connected in parallel with the 1-11-way balancing control circuit, and the other 12-22 battery cells are connected in parallel with the 12-22-way balancing control circuit; Central control module: receives 1553B commands from external host computer; Parse the 1553B instruction, select the equalization mode, and generate 1-22 excitation signals; send 1-11 excitation signals to 1-11 equalization control circuits; Send the 12-22 channel excitation signal to the 12-22 channel equalization control circuit; send the 1-22 channel excitation signal to the frequency tracking point circuit; Frequency tracking point circuit: receives 1-22 excitation signals from the central control module, adjusts 1-22 excitation signals, generates frequency control signals, and controls the connection lines between 1-11 equalization control circuits and 12-22 equalization control circuits to transmit current within the working frequency range through the frequency control signals; 1-11 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 1-11 channel excitation signals from the central control module, controls the on-off of each bidirectional DC / AC converter according to the 1-11 channel excitation signals, and realizes the connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring; 12-22 channel balancing control circuit: includes 11 bidirectional DC / AC converters; receives 12-22 channel excitation signals from the central control module, controls the on-off of each bidirectional DC / AC converter according to the 12-22 channel excitation signals, and realizes the connection with the battery cells that need balancing control; and sends the voltage of the connected battery cells to the host computer in real time through the central control module to realize voltage monitoring; The 22 battery cells connected in series in the lithium-ion battery pack are divided into 6 groups according to the preset settings; the low 3-way group voltage conditioning circuit is connected to 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer; the high 3-way group voltage conditioning circuit is connected to the other 3 groups of battery cells, the voltages of the 3 groups of battery cells are collected, and sent to the host computer; The bidirectional DC / AC converters correspond to the battery cells one by one, and each bidirectional DC / AC converter is connected in parallel with the corresponding battery cell; The bidirectional DC / AC converter includes a voltage-stabilizing capacitor C1, a resonant capacitor C2, a MOSFET switch Q, a transformer TF, a fuse and a resistor R; wherein the voltage-stabilizing capacitor C1 is connected in parallel with the corresponding battery cell, and one end of the voltage-stabilizing capacitor C1 is connected to one end of the primary side of the transformer TF, and the other end of the voltage-stabilizing capacitor C1 is respectively connected to the drain of the MOSFET switch Q and one end of the resonant capacitor C2; the other end of the resonant capacitor C2 is respectively connected to the source of the MOSFET switch Q and the other end of the primary side of the transformer TF; the gate of the MOSFET switch Q inputs an excitation signal; one end of the secondary side of the transformer TF is respectively connected to one end of the fuse and the central control module; the other end of the fuse is connected to one end of the resistor R; the other end of the resistor R is connected to the sharebus line; the voltage-stabilizing capacitors C1 of 22 bidirectional DC / AC converters are connected in series; the other end of the secondary side of the transformer TF of the 22 bidirectional DC / AC converters is connected to the same ground; The natural frequency of the bidirectional DC / AC converter depends on the primary inductance of the transformer TF, the gate capacitance of the MOSFET switch Q and the resonant capacitor C2; the on and off of the MOSFET switch Q is controlled by the excitation signal sent by the central control module, so that the bidirectional DC / AC converter works in the resonant mode.

2. A non-dissipative balancing management system for space lithium-ion batteries according to claim 1, characterized in that: The balancing mode includes a continuous balancing mode and a gap balancing mode; when in the continuous balancing mode, the current of the high-voltage battery cells in the lithium-ion battery pack is continuously flowed into the low-voltage battery cells to achieve balancing; when in the gap balancing mode, the current of the high-voltage battery cells in the lithium-ion battery pack is gap-flowed into the low-voltage battery cells to achieve balancing.

3. A non-dissipative balancing management system for space lithium-ion batteries according to claim 2, characterized in that: The 1-11 balancing control circuit is connected to the 12-22 balancing control circuit via the sharebus line; the current of the high-voltage battery cell flows into the low-voltage battery cell via the 1-11 balancing control circuit, the sharebus line, and the 12-22 balancing control circuit in sequence; or the current of the high-voltage battery cell flows into the low-voltage battery cell via the 12-22 balancing control circuit, the sharebus line, and the 1-11 balancing control circuit in sequence.

4. A non-dissipative balancing management system for space lithium-ion batteries according to claim 3, characterized in that: The frequency tracking point circuit controls the operating frequency range of the sharebus line to be 25-50kHz.

5. The non-dissipative balancing management system for space lithium-ion batteries according to claim 1, characterized in that: The low 3-way group voltage conditioning circuit and the high 3-way group voltage conditioning circuit detect the voltage change in the process of lithium-ion battery group balancing management in units of groups, and serve as auxiliary monitoring of the voltage feedback of the 1-11-way balancing control circuit and the 12-22-way balancing control circuit.

6. A non-dissipative balancing management system for space lithium-ion batteries according to claim 1, characterized in that: After the lithium-ion battery pack is balanced, the voltages of all the battery cells in the lithium-ion battery pack are completely equal, and the secondary voltages of the transformer TF are also completely equal. At this time, the current flowing through the resistor R is 0.

7. A non-dissipative balancing management system for space lithium-ion batteries according to claim 6, characterized in that: In the process of balancing management of lithium-ion battery packs, the energy consumption factor on the energy transfer path is only the resistance R; there is no energy loss in the process of cyclic exchange of alternating energy between the battery cells, transformer TF inductance and MOSFET switch Q at the resonant frequency, realizing non-dissipative balancing management.

Images