CN115117970A - Active equalization circuit, device and vehicle battery - Google Patents
Active equalization circuit, device and vehicle battery Download PDFInfo
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- CN115117970A CN115117970A CN202210818177.7A CN202210818177A CN115117970A CN 115117970 A CN115117970 A CN 115117970A CN 202210818177 A CN202210818177 A CN 202210818177A CN 115117970 A CN115117970 A CN 115117970A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
- H02J7/0014—Circuits for equalisation of charge between batteries
- H02J7/0016—Circuits for equalisation of charge between batteries using shunting, discharge or bypass circuits
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/44—Methods for charging or discharging
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
- H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Abstract
The embodiment of the invention relates to an active equalization circuit, equipment and a vehicle battery, wherein the circuit comprises: one or more unidirectional active equalization subcircuits, wherein any two unidirectional active equalization subcircuits are connected in parallel; wherein the unidirectional active equalization subcircuit comprises: the system comprises a battery pack module, a balancing module and an energy control module; the battery pack module is connected with the output end of the balancing module; the first end of the energy control module is connected with the first input end of the balancing module, and the second end of the energy control module is connected with the second input end of the balancing module; the unidirectional active equalization subcircuit is configured to: controlling the balancing module to obtain the energy output by the energy control module, and controlling the battery pack module to realize charge/discharge balancing by using the energy; therefore, the technical effect of improving the active equalization speed can be achieved.
Description
Technical Field
The embodiment of the invention relates to the technical field of active equalization of batteries, in particular to an active equalization circuit, active equalization equipment and a vehicle battery.
Background
Currently applied vehicle-mounted power batteries are generally formed by connecting a plurality of battery cells in series, so that the performance and the service life of the battery have a direct relationship with the states of the battery cells in the series. The electric cores in the electric automobile vehicle-mounted power battery pack generally have inconsistency due to differences in the production process, the more serious the problem of the inconsistency of the electric cores is, and the shorter the service life of the battery is. For this reason, a technology of maintaining the consistency of each cell in the Battery, namely, a Battery Management System (BMS), has been developed. The intervention of the BMS can greatly extend the life span of the battery.
Currently, a single-winding bidirectional flyback DC-DC converter is generally adopted in a mainstream BMS active equalization topology, that is, only one set of winding coil is used for the primary side and the secondary side of a high-frequency transformer. A switch array is formed by a large number of power switch tubes so as to achieve the independent control of each battery cell and realize the charging and discharging of the battery cells; however, only one battery cell can be charged and discharged each time, the charging scheme of cyclic queuing slows down the overall equalization speed of the battery under the control of the BMS, and has phase change delay caused by battery cell switching, and a large number of switch driving circuits are needed, so that the situation that the battery cell state changes rapidly cannot be coped with, and the problem of slow active equalization speed exists.
Disclosure of Invention
In view of this, in order to solve the technical problem of slow active equalization speed, embodiments of the present invention provide an active equalization circuit, an active equalization device, and a vehicle battery.
In a first aspect, an embodiment of the present invention provides an active equalization circuit, including: one or more unidirectional active equalization subcircuits, wherein any two unidirectional active equalization subcircuits are connected in parallel;
wherein the unidirectional active equalization subcircuit comprises: the system comprises a battery pack module, a balancing module and an energy control module;
the battery pack module is connected with the output end of the balancing module;
the first end of the energy control module is connected with the first input end of the balancing module, and the second end of the energy control module is connected with the second input end of the balancing module;
the unidirectional active equalization subcircuit is configured to: and controlling the balancing module to acquire the energy output by the energy control module, and controlling the battery pack module to realize charge/discharge balancing by using the energy.
In one possible embodiment, the equalization module comprises: the high-frequency transformer and the multiple groups of equalization submodules;
the high-frequency transformer comprises a plurality of secondary winding coils and a primary winding coil, and the battery pack module comprises one or more battery cells which are mutually connected in series;
the first end of the balancing sub-module is connected with the positive electrode of a battery cell in the battery pack module, the second end of the balancing sub-module is connected with the negative electrode of the battery cell, the third end of the balancing sub-module is connected with the first end of a secondary winding coil of the high-frequency transformer, and the fourth end of the balancing sub-module is connected with the second end of the secondary winding coil;
the first end of a primary winding coil of the high-frequency transformer is connected with the first end of the energy control module, and the second end of the primary winding coil of the high-frequency transformer is connected with the second end of the energy control module;
the equalization module is configured to: and controlling the high-frequency transformer to obtain the energy output by the energy control module, and outputting the energy to the multiple groups of balancing sub-modules through the multiple secondary winding coils.
In one possible embodiment, the equalization submodule includes: the device comprises a voltage sampling unit, a first current sampling unit and an equalizing unit;
one end of the voltage sampling unit is connected with the positive electrode of a battery cell in the battery pack module and one end of the first current sampling unit, and the other end of the voltage sampling unit is connected with the negative electrode of the battery cell and the negative electrode connecting end of the balancing unit;
the other end of the first current sampling unit is connected with the positive connecting end of the equalizing unit;
and the first end of the equalizing unit is connected with the first end of one secondary winding coil of the high-frequency transformer, and the second end of the equalizing unit is connected with the second end of the secondary winding coil.
In one possible embodiment, the equalization unit includes: a first switch tube and a first capacitor;
one end of the first capacitor is connected with the first end of the first switching tube and the other end of the first current sampling unit, and the other end of the first capacitor is connected with the other end of the voltage sampling unit and the synonym end of a secondary winding coil of the high-frequency transformer;
and the second end of the first switching tube is connected with the homonymous end of the secondary winding coil.
In one possible embodiment, the energy control module comprises: the unidirectional flyback unit and the second current sampling unit;
the first end of the unidirectional flyback unit is connected with the first input end of the balancing module, the second end of the unidirectional flyback unit is connected with one end of the second current sampling unit, the third end of the unidirectional flyback unit is connected with the anode of an external power supply, and the fourth end of the unidirectional flyback unit is connected with the cathode of the external power supply;
and the other end of the second current sampling unit is connected with a second input end of the equalizing module.
In one possible embodiment, the unidirectional flyback unit includes: a second switch tube and a second capacitor;
the first end of the second switch tube is connected with the first input end of the equalizing module, and the second end of the second switch tube is connected with one end of the second capacitor and the anode of the external power supply;
the other end of the second capacitor is connected with the other end of the second current sampling unit and the negative electrode of the external power supply.
In one possible embodiment, the first switch tube and the second switch tube are both insulated gate bipolar transistors.
In one possible embodiment, the circuit further comprises: an external power supply;
the positive pole of the external power supply is connected with the positive pole connecting end of the unidirectional active balancing sub-circuit, and the negative pole of the external power supply is connected with the negative pole connecting end of the unidirectional active balancing sub-circuit.
In a second aspect, an embodiment of the present invention provides an active equalization apparatus, where the active equalization apparatus includes: an active equalization circuit as claimed in any one of the first aspect.
In a third aspect, an embodiment of the present invention provides a vehicle battery, including: the active equalization apparatus as described in the second aspect.
According to the active equalization scheme provided by the embodiment of the invention, one or more unidirectional active equalization sub-circuits are arranged, and any two unidirectional active equalization sub-circuits are connected in parallel; wherein the unidirectional active equalization subcircuit comprises: the system comprises a battery pack module, a balancing module and an energy control module; the battery pack module is connected with the output end of the balancing module; the first end of the energy control module is connected with the first input end of the balancing module, and the second end of the energy control module is connected with the second input end of the balancing module; the unidirectional active equalization subcircuit is configured to: and controlling the balancing module to acquire the energy output by the energy control module, and controlling the battery pack module to realize charge/discharge balancing by using the energy. By the scheme, the technical effect of improving the active equalization speed can be achieved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
Fig. 1 is a schematic structural diagram of an active equalization circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another active equalization circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another active equalization circuit according to an embodiment of the present invention;
fig. 4 is a timing diagram illustrating charging of an active equalization circuit according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "comprising" and "having" in the embodiments of the present invention are used to mean open-ended inclusion, and mean that there may be additional elements/components/etc. in addition to the listed elements/components/etc.; the terms "first" and "second", etc. are used merely as labels, and are not limiting on the number of their objects. Further, the different elements and regions in the drawings are only schematically shown, and thus the present invention is not limited to the dimensions or distances shown in the drawings.
For the convenience of understanding of the embodiments of the present invention, the following description will be further explained with reference to specific embodiments, which are not to be construed as limiting the embodiments of the present invention.
Flyback (Flyback) transformers are also known as single-ended Flyback or "Buck-Boost" converters. The power source is connected with the primary winding and the output end of the primary winding. The flyback converter is very popular with development engineers due to the simple circuit structure and low cost. The flyback transformer is suitable for a low-power supply and various power adapters. However, the design difficulty of the flyback converter is the design of the transformer, because the input voltage range is wide, especially at low input voltage and full load, the transformer will work in continuous current mode, and at high input voltage and light load, the transformer will work in discontinuous current mode.
The consistency of the battery cores refers to the consistency of physical properties, and generally, the consistency can be basically ensured only by using batteries of the same brand and batch and not using new and old batteries in a mixed manner. Lithium battery uniformity refers to the uniformity of the initial performance metrics for grouped individual cells, including: capacity, impedance, electrical characteristics of the electrodes, electrical connections, temperature characteristics, decay rate, and the like. The inconsistency of the above factors directly affects the difference of the output electrical parameters in operation, and the inconsistency of the battery parameters is a key factor affecting the service life of the battery pack.
Fig. 1 is a schematic structural diagram of an active equalization circuit according to an embodiment of the present invention. According to the diagram provided in fig. 1, the active equalization circuit specifically comprises:
one or more unidirectional active equalization subcircuits 11, any two unidirectional active equalization subcircuits 11 are connected in parallel.
Wherein, one-way active equalization subcircuit includes: a battery pack module 12, an equalization module 13, and an energy control module 14.
An internal circuit structure of an active equalization circuit according to an embodiment of the present invention includes:
the battery module 12 is connected to the output of the equalization module 13.
A first end of the energy control module 14 is connected to a first input end of the equalization module 13, and a second end is connected to a second input end of the equalization module 13.
The unidirectional active equalization subcircuit 11 is configured to: the control equalization module 13 obtains the energy output by the energy control module 14, and controls the battery pack module 12 to realize charge/discharge equalization by using the energy.
Further, one or more active equalization subcircuits 11 are connected in parallel, so that independent charge/discharge equalization can be performed on the battery module 12 of each active equalization subcircuit 11, the energy control module 13 obtains electric energy from an external circuit and transmits the obtained electric energy to the equalization module 13, the electric energy obtained by different active equalization subcircuits 11 through the energy control module 14 is different, the equalization module 13 analyzes and judges whether the battery module 12 connected with the equalization module needs to be charged/discharged, and under the condition that the battery module 12 needs to be charged/discharged, the obtained electric energy is distributed to the battery module 12, so that charge/discharge equalization processing on the battery module 12 is completed, and active equalization processing on the battery module is realized.
In a possible implementation manner, whether each unidirectional active balancing sub-circuit needs to be charged/discharged is judged through an external circuit, electric energy is provided for the unidirectional active balancing sub-circuit needing to be charged/discharged, corresponding electric energy is received through the energy control module 14 and then is output to the balancing module 13 connected with the energy control module, the balancing module 13 analyzes the charging/discharging condition of the battery pack, the electric energy is transmitted to the battery needing to be charged/discharged through the balancing module 13, independent charging and discharging balancing processing is performed on the battery in the battery pack module 12, the condition that a plurality of batteries in the battery pack module are queued for charging/discharging is further improved, and the technical effect of improving the active balancing speed is achieved.
According to the active equalization circuit provided by the embodiment of the invention, one or more active equalization sub-circuits are arranged, and any two unidirectional active equalization sub-circuits 11 are connected in parallel; each active equalization sub-circuit is provided with a battery pack module, an equalization module and an energy control module, and the battery pack module is connected with the output end of the equalization module; the first end of the energy control module is connected with the first input end of the balancing module, and the second end of the energy control module is connected with the second input end of the balancing module; the balancing module is controlled by the one-way active balancing sub-circuit to obtain the energy output by the energy control module, and the battery pack module is controlled by the energy to realize charge/discharge balancing; and then the independent charging/discharging active equalization processing of the batteries in the battery pack module is completed, and the technical effect of improving the active equalization speed is realized.
In an alternative aspect of the embodiments of the present invention, the equalization module includes: the high-frequency transformer and the multiple groups of equalization submodules; the high-frequency transformer comprises a plurality of secondary winding coils and a primary winding coil, and the battery pack module comprises one or more battery cells which are mutually connected in series; the first end of the balancing submodule is connected with the positive electrode of a battery core in the battery pack module, the second end of the balancing submodule is connected with the negative electrode of the battery core, the third end of the balancing submodule is connected with the first end of a secondary winding coil of the high-frequency transformer, and the fourth end of the balancing submodule is connected with the second end of the secondary winding coil; the first end of a primary winding coil of the high-frequency transformer is connected with the first end of the energy control module, and the second end of the primary winding coil of the high-frequency transformer is connected with the second end of the energy control module; the equalization module is configured to: and controlling the high-frequency transformer to obtain the energy output by the energy control module, and outputting the energy to the multiple groups of balancing sub-modules through the multiple secondary winding coils.
In an alternative aspect of the embodiments of the present invention, the equalization submodule includes: the device comprises a voltage sampling unit, a first current sampling unit and an equalizing unit; one end of the voltage sampling unit is connected with the positive electrode of the battery core in the battery pack module and one end of the first current sampling unit, and the other end of the voltage sampling unit is connected with the negative electrode of the battery core and the negative electrode connecting end of the balancing unit; the other end of the first current sampling unit is connected with the positive connecting end of the equalizing unit; the first end of the equalizing unit is connected with the first end of a secondary winding coil of the high-frequency transformer, and the second end of the equalizing unit is connected with the second end of the secondary winding coil.
In an alternative of the embodiment of the present invention, the equalizing unit includes: a first switch tube and a first capacitor; one end of the first capacitor is connected with the first end of the first switch tube and the other end of the first current sampling unit, and the other end of the first capacitor is connected with the other end of the voltage sampling unit and the synonym end of a secondary winding coil of the high-frequency transformer; and the second end of the first switching tube is connected with the homonymous end of the secondary winding coil.
In an alternative of the embodiments of the invention, the energy control module comprises: the unidirectional flyback unit and the second current sampling unit; the first end of the unidirectional flyback unit is connected with the first input end of the balancing module, the second end of the unidirectional flyback unit is connected with one end of the second current sampling unit, the third end of the unidirectional flyback unit is connected with the anode of the external power supply, and the fourth end of the unidirectional flyback unit is connected with the cathode of the external power supply; the other end of the second current sampling unit is connected with the second input end of the balancing module.
In an alternative aspect of the embodiments of the present invention, the unidirectional flyback unit includes: a second switch tube and a second capacitor; the first end of the second switch tube is connected with the first input end of the balancing module, and the second end of the second switch tube is connected with one end of the second capacitor and the anode of the external power supply; the other end of the second capacitor is connected with the other end of the second current sampling unit and the negative electrode of the external power supply.
In an alternative of the embodiment of the present invention, the first switch tube and the second switch tube are both insulated gate bipolar transistors.
In an alternative aspect of the embodiments of the present invention, the circuit further includes: an external power supply; the positive pole of the external power supply is connected with the positive pole connecting end of the unidirectional active balancing sub-circuit, and the negative pole of the external power supply is connected with the negative pole connecting end of the unidirectional active balancing sub-circuit.
Hereinafter, with the battery module, the balancing module includes: high frequency transformer and multiunit balanced submodule piece, balanced submodule piece includes: voltage sampling unit, first current sampling unit and balanced unit, the energy control module includes: one-way flyback unit and second current sampling unit, the circuit still includes: an external power supply is described as an example. The resistor in the embodiment of the present invention represents a resistor device, and may be represented by a resistor but is not limited to a representation of a resistor device. Referring to fig. 2, a schematic structural diagram of another active equalization circuit provided in the embodiment of the present invention is shown. The active equalization circuit is explained on the basis of the first active equalization circuit. As shown in fig. 2, the method specifically includes:
a battery pack module 12, an equalization module 13, and an energy control module 14.
Further, the active equalization circuit further comprises an external power source VCC for providing a stable voltage source for the active equalization circuit.
Further, the battery pack module in the active equalization circuit comprises one or more cells (hereinafter, collectively referred to as B1, B2.., Bn) connected in series, and is used for performing independent charging/discharging processing on each cell (hereinafter, collectively referred to as B1, B2.., Bn) in the battery pack module.
Wherein, the equalizing module 13 specifically includes:
a high frequency transformer T and a plurality of sets of equalization submodules 21.
The high-frequency transformer T includes a plurality of secondary winding coils and a primary winding coil, and the battery module 12 includes one or more cells (hereinafter, collectively referred to as B1, B2.., Bn) connected in series; a first end of the balancing sub-module 21 is connected to a positive electrode of a cell (hereinafter, collectively referred to as B1, B2., Bn) in the battery module 12, a second end is connected to a negative electrode of the cell (hereinafter, collectively referred to as B1, B2., Bn), a third end is connected to a first end of a secondary winding coil of the high-frequency transformer T, and a fourth end is connected to a second end of the secondary winding coil; a first end of a primary winding coil of the high-frequency transformer T is connected with a first end of the energy control module 14, and a second end of the primary winding coil of the high-frequency transformer T is connected with a second end of the energy control module 14; the equalization module 13 is configured to: and controlling the high-frequency transformer T to obtain the energy output by the energy control module 14, and outputting the energy to the multi-group equalization submodule 21 through a plurality of secondary winding coils.
Further, each set of equalization sub-modules 21 is identical in structure. One end of the first group of equalization submodule 21 is connected to the positive electrode of the first battery cell (hereinafter, collectively referred to as B1), and the other end of the first group of equalization submodule is connected to the negative electrode of the first battery cell (hereinafter, collectively referred to as B1); one end of the second group of equalization submodule 21 is connected with the anode of the second battery cell (hereinafter, collectively referred to as B2), and the other end is connected with the cathode of the second battery cell (hereinafter, collectively referred to as B2); in the same connection relationship, by analogy, one end of the (n-1) th group of balancing sub-modules 21 is connected to the positive electrode of the (n-1) th cell (hereinafter collectively referred to as Bn-1), and the other end is connected to the negative electrode of the (n-1) th cell (hereinafter collectively referred to as Bn-1); one end of the nth group of equalization sub-modules 21 is connected to the positive electrode of the nth cell (hereinafter, collectively referred to as Bn), and the other end is connected to the negative electrode of the nth cell (hereinafter, collectively referred to as Bn).
Further, the obtained electric energy is transmitted to the homonymous terminal and the synonym terminal of the primary winding coil of the high-frequency transformer T through the energy control module 14, and different electric energy corresponding to the plurality of corresponding secondary winding coils is obtained through overvoltage conversion through the secondary multi-winding structure of the high-frequency transformer T. A plurality of secondary winding coils of the high-frequency transformer are connected with a plurality of groups of balancing sub-modules 21, and obtained different electric energy is transmitted to each group of balancing sub-modules 21. Each group of balancing submodule 21 is connected to one cell in the battery module, and each group of balancing submodule 21 analyzes the electric quantity missing condition of the correspondingly connected cell to determine whether the cell needs to be charged/discharged. For the battery core needing to be charged, the corresponding electric energy is input through the equalization submodule 21 connected with the battery core, so that the independent charging processing of the battery core is completed, and under the same condition, the battery core needing to be charged in the whole battery pack module is simultaneously charged by the multiple groups of equalization submodules 21, so that the effects of independent charging and quick charging are achieved.
According to the diagram provided in fig. 2, in a possible exemplary scenario, the external power source VCC provides the energy control module 14 with electric energy, the high-frequency transformer T of the connected primary winding coil is subjected to voltage conversion, different electric energy of the secondary winding coils is correspondingly obtained, and the electric energy is transmitted to each group of balancing sub-modules 21 through the balancing sub-modules 21 connected to the secondary winding coils; the equalizing submodule 21 determines whether the electric quantity of the battery cell B1 connected to the battery pack module 12 needs to be charged, when it is detected that the battery cell B1 needs to be charged and equalized, the electric energy in the equalizing submodule 21 is provided for the battery cell B1, and then the battery cell B1 is subjected to charge equalization processing, after charging is completed, the equalizing submodule 21 is stopped to continue to charge the battery cell B1, independent active equalization processing on the battery cell is completed, consistency of the battery cells in the battery pack module is ensured, and a technical effect of improving the speed of active equalization is achieved.
As shown in fig. 2, the equalization submodule 21 in the active equalization circuit specifically includes:
a voltage sampling unit 22, a first current sampling unit 23 and an equalizing unit 24.
One end of the voltage sampling unit 22 is connected to the positive electrode of the battery cell (hereinafter, collectively referred to as B1, B2.., Bn) in the battery module 12 and one end of the first current sampling unit 23, and the other end is connected to the negative electrode of the battery cell (hereinafter, collectively referred to as B1, B2.., Bn) and the negative electrode connection end of the equalizing unit 24; the other end of the first current sampling unit 23 is connected with the positive connecting end of the equalizing unit 24; the equalizing unit 24 has a first end connected to a first end of a secondary winding coil of the high-frequency transformer T, and a second end connected to a second end of the secondary winding coil.
Further, the voltage sampling unit 22 is configured to collect voltage values at two ends of a battery cell (hereinafter, collectively referred to as B1, B2., Bn) in the battery module 12, and the first current sampling unit 23 is configured to collect a current condition in a circuit where the first current sampling unit 23 is located, so as to monitor whether a current of the circuit is too large; the equalizing unit 24 transmits the electric energy obtained from the secondary winding coil of the high-frequency transformer T to the correspondingly connected battery cell, and performs charge equalization on the battery cell.
According to the diagram provided in fig. 2, in a possible exemplary scenario, the primary winding coil of the high-frequency transformer obtains corresponding electric energy, and the voltage is converted by the high-frequency transformer to obtain electric energy of the plurality of secondary winding coils; each secondary winding coil transmits the obtained electric energy to the connected equalizing unit 24, the voltage sampling unit 22 analyzes the electric quantity of the current battery cell, judges whether the current battery cell is lower than a preset threshold voltage, and determines whether the current battery cell needs to be charged. And when the electric quantity of the current battery cell is judged to be lower than the threshold voltage, determining that the battery cell needs to be charged. Then, the first current sampling unit 23 monitors the current in the current line in real time, so that the current in the current line is not too large, and the charging and discharging speed of the battery cell is effectively monitored. The cell is subjected to charge equalization processing by the equalization unit 24, and charge equalization of the cell is completed; the plurality of equalization submodules 21 correspondingly process charge/discharge equalization of a plurality of sections of battery cells, so that independent charge/discharge equalization processing of the battery cells of the battery pack module 12 is realized, and the technical effect of improving the active equalization speed is realized.
As shown in fig. 2, the energy control module 14 in the active equalization circuit specifically includes:
a unidirectional flyback unit 25 and a second current sampling unit 26.
A first end of the unidirectional flyback unit 25 is connected with a first input end of the equalization module 13, a second end is connected with one end of the second current sampling unit 26, a third end is connected with an anode of an external power supply VCC, and a fourth end is connected with a cathode of the external power supply VCC; the other end of the second current sampling unit 26 is connected to a second input end of the equalizing module 13.
Further, the unidirectional flyback unit 25 is configured to transmit the electric energy obtained from the external circuit to the high-frequency transformer T, so as to perform a switching function when charging/discharging the battery cell; the second current sampling unit 26 is configured to monitor whether the charging current is too large in an active equalization process of battery charging and discharging, so as to protect the battery core.
According to the diagram provided in fig. 2, in a possible example scenario, the external power VCC provides corresponding electric energy to the unidirectional flyback unit 25, and under the condition that the equalization module 13 determines that the battery cell B1 needs to be charged, the unidirectional flyback unit 25 provides corresponding electric energy to the high-frequency transformer T, which helps the equalization module 13 to perform charge equalization on the battery cell B1, and meanwhile, the second current sampling unit 26 monitors the current magnitude in the charging process in real time, and when the charging current is too large, feeds back the charging current to the main controller controlling the active equalization circuit, and sends a charging stop signal to the corresponding battery pack module 12 through the main controller, so that the unidirectional flyback unit 25 stops outputting electric energy continuously, and further stops charging the battery cell B1, thereby achieving the purpose of stopping charging. Similarly, when the electric quantity charged by the battery cell B1 is the same as the preset threshold voltage Vth corresponding to the current battery cell, the completion of charging is judged, and then the electric quantity is fed back to the master controller controlling the active equalization circuit, the master controller receives a signal indicating that the charging of the current battery cell B1 is completed, sends a charging stop instruction to the corresponding slave controller, the slave controller controls the unidirectional flyback unit 25 to stop transmitting electric energy to the high-frequency transformer T, so that the charging stop operation is realized, the charging of the battery cell B1 is completed, and further, the technical effect of improving the active equalization speed is realized.
In an alternative, the master controller may be an MCU that controls charging/discharging of a plurality of battery modules, and the slave controller may be understood as a control unit corresponding to each battery module.
As shown in fig. 2, the active equalization circuit specifically includes:
an external power supply VCC.
The positive pole of external power source VCC connects the positive pole link of one-way active equalizer sub-circuit 11, and the negative pole connects the negative pole link of one-way active equalizer sub-circuit 11.
Further, the structure of each set of active equalization subcircuits 11 is the same. The positive connecting end of the first active equalization sub-circuit 11 is connected with the positive electrode of an external power supply VCC, and the negative connecting end is connected with the negative electrode of the external power supply VCC; the positive connecting end of the second active equalization sub-circuit 11 is connected with the positive electrode of an external power supply VCC, and the negative connecting end is connected with the negative electrode of the external power supply VCC; in the same connection relation, in this way, the positive connecting end of the (n-1) th active equalization sub-circuit 11 is connected with the positive electrode of the external power supply VCC, and the negative connecting end is connected with the negative electrode of the external power supply VCC; the positive connecting end of the nth active equalization sub-circuit 11 is connected with the positive electrode of the external power supply VCC, and the negative connecting end is connected with the negative electrode of the external power supply VCC.
Further, the plurality of active equalization subcircuits 11 are respectively connected with the positive electrode and the negative electrode of the external power supply VCC, so that electric energy required for charging is provided for the plurality of active equalization subcircuits.
According to the diagram provided in fig. 1, in a possible exemplary scenario, one active equalization subcircuit 11 corresponds to one group of battery modules, and a plurality of active equalization subcircuits 11 correspond to a plurality of groups of battery modules, when it is determined that the battery modules in the active equalization subcircuits 11 need to be charged, the charging time of each active equalization subcircuit 11 needs to be different, energy is provided by an external power source VCC, the active equalization subcircuits 11 that need to be charged are simultaneously charged, the charging speed of the plurality of active equalization subcircuits 11 is increased, independent charging equalization processing on the plurality of active equalization subcircuits 11 is completed, and the technical effect of increasing the active equalization speed is achieved.
The battery pack module comprises one or more battery cells connected in series, a voltage sampling unit, a first current sampling unit and an equalizing unit, wherein the equalizing unit comprises: first switch tube and first electric capacity, high frequency transformer, one-way flyback unit includes: the first switch tube and the second switch tube are both insulated gate bipolar transistors, and the second current sampling unit is described as an example. The resistor, the capacitor and the transistor in the embodiment of the present invention respectively represent a resistor, a capacitor and a transistor device, and may be respectively represented by, but not limited to, a resistor, a capacitor and a transistor. Referring to fig. 3, a schematic structural diagram of another active equalization circuit provided in the embodiment of the present invention is shown. The active equalization circuit is explained on the basis of the second active equalization circuit. The active equalization circuit specifically further comprises:
the battery pack comprises a battery pack module 12, a voltage sampling unit 22, a first current sampling unit 23, an equalizing unit 24, a high-frequency transformer T, a unidirectional flyback unit 25 and a second current sampling unit 26.
As shown in fig. 3, the equalizing unit 24 in the active equalizing circuit specifically includes:
a first switch tube K1 and a first capacitor C1.
One end of the first capacitor C1 is connected to the first end of the first switch tube K1 and the other end of the first current sampling unit 23, and the other end is connected to the other end of the voltage sampling unit 22 and the synonym end of a secondary winding coil of the high-frequency transformer T; the second end of the first switch tube K1 is connected with the end with the same name of the secondary winding coil.
In an alternative, the battery management system (hereinafter, referred to as BMS) includes a master controller and a plurality of slave controllers. Each BMS slave controller comprises 1 one-way active balancing sub-circuit 11 which correspondingly controls the charge/discharge balance of a plurality of battery cells in 1 group of battery pack modules.
Further, when it is determined that the battery cell B1 in the battery pack module 12 is compared with a preset threshold voltage and a power shortage phenomenon exists, it is determined that the battery cell B1 needs to be charged and equalized, after the electric energy is transmitted to the unidirectional flyback unit 25 through the external power source VCC, the electric energy is transmitted from the primary winding coil to the plurality of secondary winding coils under the conversion of the high-frequency transformer T, the lower the voltage of the battery cell B1 is relative to the threshold voltage Vth, the larger the duty ratio of Pulse Width Modulation (PWM) of the first switching tube K1 is, and the circuit where the first switching tube K1 is located can be charged quickly; the closer the voltage of the battery cell B1 is to the threshold voltage Vth, the less electric energy is required to be charged, the smaller the PWM duty ratio of the first switching tube K1 is, and the slow charging is performed on the circuit where the first switching tube K1 is located. The first capacitor C1 provides a stable voltage source for the cell B1 through filtering. When charging is finished, a charging completion signal is fed back to the MCU1 in the BMS slave controller, and the charging completion signal is fed back to the MCU2 in the master controller by the MCU1 in the BMS slave controller, so that the external power supply VCC is controlled to stop charging the one-way active equalization sub-circuit.
As shown in fig. 3, the unidirectional flyback unit 25 in the active equalization circuit specifically includes:
a second switch tube K2 and a second capacitor C2.
A first end of the second switch tube K2 is connected to a first input end of the equalizing module 13, and a second end is connected to one end of the second capacitor C2 and the anode of the external power VCC; the other end of the second capacitor C2 is connected to the other end of the second current sampling unit 26 and the negative terminal of the external power source VCC.
Further, when it is determined that the battery cell B1 in the battery pack module 12 is compared with the preset threshold voltage and a power shortage phenomenon exists, it is determined that the battery cell B1 needs to be charged and equalized, after the electric energy is transmitted to the unidirectional flyback unit 25 through the external power source VCC, the PWM duty ratio of the second switching tube K2 is determined through the second switching tube K2, and when the battery cell is more serious in power shortage, the larger the PWM duty ratio is, the second switching tube K2 is turned on, and a stable voltage source is obtained under the action of the second capacitor C2. And under the conversion of the high-frequency transformer T, the electric energy is transmitted to a plurality of secondary winding coils from the primary winding coil to perform charge equalization on the battery cell B1. When charging is finished, a charging completion signal is fed back to the MCU1 in the BMS slave controller, and the charging completion signal is fed back to the MCU2 in the master controller by the MCU1 in the BMS slave controller, so that the external power supply VCC is controlled to stop charging the one-way active equalization sub-circuit.
In the structure shown in fig. 3, the first switch tube and the second switch tube in the active equalization circuit are both insulated gate bipolar transistors.
The first end of the first switch tube and the first end of the second switch tube are drain electrodes of the insulated gate bipolar transistor, the second end of the first switch tube and the second end of the second switch tube are both source electrodes of the insulated gate bipolar transistor, and the third end of the first switch tube and the third end of the second switch tube are both grid electrodes of the insulated gate bipolar transistor.
Further, first, the BMS slave controller samples the voltage of each cell in the battery module 12, and after the acquired cell (hereinafter, collectively referred to as B1, B2., Bn) voltage is analyzed by the BMS slave controller, the voltage data of the cell (hereinafter, collectively referred to as B1, B2., Bn) in the battery module 12 is transmitted to the MCU2 in the BMS master controller as voltage information data. The conditions of all the cells (hereinafter, collectively referred to as B1, B2,.., Bn) are summarized and analyzed by the MCU2 in the master controller, and then the equalization threshold voltage Vth of each cell is issued to the MCU1 in different slave controllers. Then, after comparing the cell voltage Vth with the equalization threshold voltage Vth transmitted from the MCU2 in the master controller, the MCU1 in the slave controller of the BMS performs a state analysis on the state of the battery cells (hereinafter, collectively referred to as B1, B2., Bn) in the battery module 12, and determines the state of each battery cell (hereinafter, collectively referred to as B1, B2., Bn) in the battery module 12, as the cell voltage is lower than the equalization threshold voltage Vth and the power shortage is more severe. And then determines which cell is charged by the BMS slave controller, and then the equalization circuit starts to operate. The primary side of the high-frequency transformer T supplies electric energy to a plurality of secondary sides, and the second switching tube K2 has different control modes according to different states of a power-shortage battery cell (hereinafter, collectively referred to as B1, B2, Bn) judged by a controller. The PWM duty ratio of the power switch tube of the path with relatively low cell voltage is large, and quick charging is carried out; and the PWM duty ratio of the power switch tube of the path with relatively higher voltage is smaller, and slow charging is carried out. The total charging time is based on the charging time of the battery cell with the largest power shortage in the battery pack module. When the charging of the battery cell (hereinafter, collectively referred to as B1, B2., Bn) in the battery pack module 12 is completed, a charging completion signal is fed back to the MCU1 in the BMS slave controller, and the charging completion signal is fed back to the MCU2 in the BMS slave controller from the MCU1 in the BMS slave controller, so as to control the external power VCC to stop charging the unidirectional active equalization sub-circuit. Thereby realizing the technical effect of improving the active equalization speed.
The structure shown in fig. 4 provides a timing diagram for charging in an active equalization circuit. In one possible example scenario, assume that a total of six battery cells within a group of battery modules 12 are in a power-out state, where the power-out level is compared: bx > Bx +3> Bx +1> Bx +2> Bx +5> Bx +4, and the more severe the power shortage, the longer the charging time. The active equalization circuit provided by the embodiment of the invention can charge all the electric cells in the battery pack module 12 at the same time. After charging for a period of time, when the voltages at the two ends of the power-lack cell reach the preset threshold voltage Vth, the corresponding first switch tube K1 is turned off, and the charging of the cell is stopped. The total time for cell equalization charging in the battery pack module 12 depends on the cell with the lowest cell voltage in the battery pack module 12 (Bx in the present example is the most power-deficient), so the total charging time is about 1 unit time. And then can charge the equalization in real time to each electricity core in the battery pack module 12, compare the previous equalization processing mode that each electricity core queues up waiting to charge, the invention can charge the electricity core of lack of power for the initiative equalization rapidly, therefore, realize the technological effect to improve the speed of initiative equalization.
According to the active equalization circuit provided by the embodiment of the invention, through the arrangement of the one-way active equalization subcircuit, electric energy provided by an external power supply is transmitted to the high-frequency transformer through the second switching tube and the second capacitor, the electric energy is transmitted from the primary side to the plurality of secondary sides through the high-frequency transformer, under the condition that the electricity shortage of the electric core is different, the corresponding electric core is controlled to be charged at different speeds through different PWM (pulse width modulation) of the first switching tube, the magnitude of the charging current in the circuit is monitored in real time through the first current sampling unit and the second current sampling unit, the charging current is ensured not to be too large, the circuit safety is not influenced, the charging equalization treatment on the electricity shortage electric core is further completed, and the technical effect of improving the active equalization speed is realized.
Based on the active equalization circuit provided in the above embodiment, the present invention further provides an active equalization device, which includes the active equalization circuit provided in the above embodiment.
Based on the active equalization device, the invention further provides a vehicle battery, and the vehicle battery comprises the active equalization device provided in the embodiment.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. An active equalization circuit, comprising: one or more unidirectional active equalization subcircuits, wherein any two unidirectional active equalization subcircuits are connected in parallel;
wherein the unidirectional active equalization subcircuit comprises: the system comprises a battery pack module, a balancing module and an energy control module;
the battery pack module is connected with the output end of the balancing module;
the first end of the energy control module is connected with the first input end of the balancing module, and the second end of the energy control module is connected with the second input end of the balancing module;
the unidirectional active equalization subcircuit is configured to: and controlling the balancing module to acquire the energy output by the energy control module, and controlling the battery pack module to realize charge/discharge balancing by using the energy.
2. The circuit of claim 1, wherein the equalization module comprises: the high-frequency transformer and the multiple groups of equalization submodules;
the high-frequency transformer comprises a plurality of secondary winding coils and a primary winding coil, and the battery pack module comprises one or more battery cells which are mutually connected in series;
the first end of the balancing sub-module is connected with the positive electrode of a battery cell in the battery pack module, the second end of the balancing sub-module is connected with the negative electrode of the battery cell, the third end of the balancing sub-module is connected with the first end of a secondary winding coil of the high-frequency transformer, and the fourth end of the balancing sub-module is connected with the second end of the secondary winding coil;
the first end of a primary winding coil of the high-frequency transformer is connected with the first end of the energy control module, and the second end of the primary winding coil of the high-frequency transformer is connected with the second end of the energy control module;
the equalization module is configured to: and controlling the high-frequency transformer to obtain the energy output by the energy control module, and outputting the energy to the plurality of groups of balancing sub-modules through a plurality of secondary winding coils.
3. The circuit of claim 2, wherein the equalization submodule comprises: the device comprises a voltage sampling unit, a first current sampling unit and an equalizing unit;
one end of the voltage sampling unit is connected with the positive electrode of a battery cell in the battery pack module and one end of the first current sampling unit, and the other end of the voltage sampling unit is connected with the negative electrode of the battery cell and the negative electrode connecting end of the balancing unit;
the other end of the first current sampling unit is connected with the positive electrode connecting end of the balancing unit;
and the first end of the equalizing unit is connected with the first end of one secondary winding coil of the high-frequency transformer, and the second end of the equalizing unit is connected with the second end of the secondary winding coil.
4. The circuit of claim 3, wherein the equalization unit comprises: a first switch tube and a first capacitor;
one end of the first capacitor is connected with the first end of the first switching tube and the other end of the first current sampling unit, and the other end of the first capacitor is connected with the other end of the voltage sampling unit and the synonym end of a secondary winding coil of the high-frequency transformer;
and the second end of the first switching tube is connected with the homonymous end of the secondary winding coil.
5. The circuit of claim 1, wherein the energy control module comprises: the unidirectional flyback unit and the second current sampling unit;
the first end of the unidirectional flyback unit is connected with the first input end of the balancing module, the second end of the unidirectional flyback unit is connected with one end of the second current sampling unit, the third end of the unidirectional flyback unit is connected with the anode of an external power supply, and the fourth end of the unidirectional flyback unit is connected with the cathode of the external power supply;
and the other end of the second current sampling unit is connected with the second input end of the balancing module.
6. The circuit of claim 5, wherein the unidirectional flyback unit comprises: a second switch tube and a second capacitor;
the first end of the second switch tube is connected with the first input end of the equalizing module, and the second end of the second switch tube is connected with one end of the second capacitor and the anode of the external power supply;
the other end of the second capacitor is connected with the other end of the second current sampling unit and the negative electrode of the external power supply.
7. The circuit of claim 4 or 6, wherein the first switch tube and the second switch tube are both insulated gate bipolar transistors.
8. The circuit of claim 1, further comprising: an external power supply;
the positive pole of the external power supply is connected with the positive pole connecting end of the unidirectional active balancing sub-circuit, and the negative pole of the external power supply is connected with the negative pole connecting end of the unidirectional active balancing sub-circuit.
9. An active equalization device, characterized in that the active equalization device comprises: an active equalization circuit as claimed in any one of claims 1 to 8.
10. A vehicle battery, characterized by comprising: the active equalization apparatus of claim 9.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116316942A (en) * | 2022-12-02 | 2023-06-23 | 中兴通讯股份有限公司 | Energy storage system, charge-discharge balancing method, terminal equipment and computer storage medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116316942A (en) * | 2022-12-02 | 2023-06-23 | 中兴通讯股份有限公司 | Energy storage system, charge-discharge balancing method, terminal equipment and computer storage medium |
| CN116316942B (en) * | 2022-12-02 | 2023-12-19 | 中兴通讯股份有限公司 | Energy storage system, charge-discharge balancing method, terminal equipment and computer storage medium |
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