Series battery discharge and recharge compound automatic equalization circuit and equalization methods
Technical field
The present invention relates to the technical field of series battery, particularly, relate to the compound automatic equalization circuit of discharging and recharging of a kind of series battery and equalization methods.
Background technology
The electric power storage such as storage battery, super capacitor energy storage device is widely used in each field.Especially, in electric automobile, electrokinetic cell is regarded as one of its critical component as lithium ion battery, super capacitor system etc. in recent years.To these batteries, the capacitance group with series system work, how guaranteeing each battery unit, capacitor cell automatic equalization rapidly and efficiently, is to guarantee its safety and reliability, extend its useful life, reduce its use cost and give full play to a key technology of its usefulness.
At present, to the automatic equalization of series-connected cell, capacitance group, the general automatic balancing method that adopts battery unit parallel resistance high to voltage or that electric weight is high to be discharged.Said method can synchronously carry out equilibrium to each battery unit, but this is a kind of energy consumption formula balanced way, has the problems such as balanced efficiency is low, time for balance is long.For example, to the battery pack of 100Ah, when the battery charge amount SOC of battery unit difference 10%, due to the equalization discharge mode, can only take voltage or the low battery unit of electric weight and carry out equilibrium as target, mean that this kind of equilibrium will waste the electric weight of battery pack nearly 10%.As the euqalizing current 500mA with common calculates, roughly need 20h, this obviously can not meet the time requirement of online equilibrium.In addition, the equalization methods that also has the energy based on inductance, electric capacity to shift, it is a kind of non-energy consumption formula equalization methods, but exist, equalizing circuit is complicated, cost is high, manufacture difficulty is large, reliability waits the problems such as raising, and in this equalization methods, the multistage transmission of energy also will limit the raising of balanced efficiency.
Through the literature search to prior art, find, the Chinese invention patent that publication number is CN102208821A, the day for announcing is 2011.10.05, denomination of invention is the " equalizing system of power brick, the method of equalizing circuit and the equilibrium of control power brick ", it discloses following technical scheme: described battery comprises a plurality of modules, and described module further comprises the subset of a plurality of battery units, described equalizing system at least comprises one-level equalization stages and the secondary equalization stages be coupled with the one-level equalization stages, wherein, the one-level equalization stages is for balance module, the secondary equalization stages is for the battery unit in balance module, be primarily characterized in that, balance module adopts coaxial transformer to utilize power brick electric voltage equalization battery module, further adopt coaxial transformer.Yet above-mentioned equalizing system has the following disadvantages: (1) is high to the required precision of coaxial transformer, causes it to manufacture difficulty; (2) can only utilize power brick energy or battery module energy to carry out charge balancing to battery unit, due to the restriction that is subject to balance module power or volume, time for balance is long.
Summary of the invention
The present invention is directed to the above-mentioned defect that prior art exists; the compound automatic equalization circuit of discharging and recharging of a kind of series battery and equalization methods are provided; it can overcome that time for balance that prior art exists is long, balanced efficiency is low, equalizing system too complexity and the high defect of cost; on-line automatic, the equilibrium rapidly and efficiently of realization to battery, capacitance group, and its reliability is high, cost is low, volume is little, lightweight, complete function, be easy to scale, industrialized manufacture and application.
The present invention is achieved by the following technical solutions:
A kind of series battery discharge and recharge compound automatic equalization circuit, comprising: according to n the compound balance module of battery unit that in series battery, battery unit quantity arranges, the battery modules balance module formed by main control module and high pressure DCDC module, wherein, n >=1, the compound balance module of described the battery unit corresponding battery modules formed by the battery unit of k series connection, wherein k>1, the compound balance module of described battery unit is comprised of switch matrix, Local Control Module, low-voltage DC/DC module, a k discharge equalizing circuit and mode control switch, and each assembly of inside of the compound balance module of each battery unit and with external module between all there is identical annexation, each output of the switch matrix of the compound balance module of described battery unit independently of each other respectively the pole circuitry phase of each battery unit in the battery modules corresponding with it connect, and the input of described switch matrix is connected with the output circuitry phase of described low-voltage DC/DC module, described discharge equalizing circuit is connected between two adjacent output circuits of described switch matrix with the battery unit parallel connection with corresponding, the positive input terminal of described low-voltage DC/DC module is connected with the anode circuitry phase of its corresponding battery modules, negative input end is connected with the negative terminal circuitry phase of its corresponding battery modules, the positive-negative input end that described mode control switch is arranged on described low-voltage DC/DC module is with in the connecting circuit of the positive and negative terminal of its corresponding battery modules, and the positive-negative input end of described low-voltage DC/DC module is connected with the positive-negative output end circuitry phase of described high pressure DCDC module by the equalizing circuit bus, the positive-negative input end of described high pressure DCDC module is connected with the anode of series battery, negative terminal circuitry phase, in the compound balance module of described battery unit, described low-voltage DC/DC module, switch matrix, a k discharge equalizing circuit, mode control switch all with described Local Control Module circuitry phase be connected and be subject to the control of described Local Control Module, described high pressure DCDC module and described main control module circuitry phase are connected and are subject to the control of described main control module, between the Local Control Module of described main control module and the compound balance module of described battery unit, circuitry phase is connected.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit, wherein, in the compound balance module of described battery unit, described switch matrix for any one of the corresponding battery modules by it, need carry out charge balancing battery unit positive and negative pole respectively gating be connected to the positive and negative output of described low-voltage DC/DC module, wherein, the gate-controlled switch in described switch matrix adopts electronic switch or the relay of MOSFET; Described discharge equalizing circuit comprises discharge resistance and gate-controlled switch, described gate-controlled switch adopts electronic switch or the relay of MOSFET, the quantity of described discharge equalizing circuit is no less than the quantity of battery unit in the respective battery module, and the battery unit parallel connection corresponding with it.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit, wherein, described high pressure DCDC module is the isolated buck-type DC-DC converter, also is provided with for the Limited Current direction at its positive and negative input and output, prevents that electric current is excessive, prevents overtension, prevents device or the circuit of short circuit.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit, wherein, in the compound balance module of described battery unit, described low-voltage DC/DC module is the isolated buck-type DC-DC converter, also is provided with for the Limited Current direction at its positive and negative input and output, prevents that electric current is excessive, prevents overtension, prevents device or the circuit of short circuit.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit, wherein, between described main control module and all Local Control Module, adopt the mode of bus communication to carry out circuit and be connected.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit; wherein; described main control module is to described battery modules balance module diagnosis protection; current sample, total voltage sampling, parameter Estimation, high-voltage safety control, heat management, failure diagnosis and the system that also can have the host controller of batteries management system battery system used are controlled the functions such as power management, CAN communication, and described high pressure DCDC module is carried out to diagnosis control.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit; wherein; described Local Control Module also has in batteries management system that the battery cell voltage sampling used of lower level controller, battery temperature sampling, battery thermal management are controlled, battery parameter is estimated, the function of Battery Diagnostic protection, CAN communication, and the switch matrix diagnosis and interlocking is controlled, to the diagnosis control function of low-voltage DC/DC module and mode control switch.
Above-mentioned series battery discharge and recharge compound automatic equalization circuit, wherein, switch matrix, Local Control Module, low-voltage DC/DC module, discharge equalizing circuit and the mode control switch in the compound balance module of described battery unit becomes one or independent the setting; Main control module in described battery modules balance module and high pressure DCDC module integration are integrated or independent the setting; Described Local Control Module and main control module become one or independent the setting, or partly or entirely are integrated in the corresponding controllers in battery management system.
A kind of equalization methods that discharges and recharges compound automatic equalization circuit that adopts above-mentioned series battery of the present invention, comprise the steps:
Described main control module is responsible for judging that equilibrium enables condition, balanced mode, work out balance policy, and to take the mean value of balance parameters P be equalization target T, wherein, the integrated value of the voltage that described balance parameters P is battery unit in series battery or SOC or voltage and SOC;
According to described equalization target T, determine in each Local Control Module battery modules corresponding at it and need the battery unit of equalization discharge and the battery unit of the preferential charge balancing of needs; When the balance parameters P of battery unit and the difference of equalization target T are less than set point or the described balanced condition that enables and do not meet, forbid or exit balancing procedure;
Calculate respectively battery modules balance parameters Pm, the mean value of its balance parameters P that is the battery unit in the battery modules that the compound balance module of each battery unit is corresponding;
When the difference between described battery modules balance parameters Pm is greater than set point, employing discharges and recharges the pattern 1 of composite balancing, , under the control of described main control module and Local Control Module, described mode control switch is disconnected, by battery pack power, through described high pressure DCDC module and low-voltage DC/DC module and switch matrix, the battery unit to the preferential charge balancing of all needs carries out synchronously, automatic series battery energy transfer type charge balancing, simultaneously, utilize described discharge equalizing circuit to carry out synchronously all battery units of equalization discharge that need, automatic equalization discharge,
When the difference between battery modules balance parameters Pm is less than set point, employing discharges and recharges the pattern 2 of composite balancing, , under the control of described main control module and Local Control Module, make described high pressure DCDC module in stopped status, make to need the mode control switch conducting corresponding to battery unit place battery modules of charge balancing, through each self-corresponding low-voltage DC/DC module and switch matrix, the battery unit to the preferential charge balancing of needs separately carries out synchronously the energy of battery modules, automatic battery modules energy transfer type charge balancing, simultaneously, utilize described discharge equalizing circuit to carry out synchronously all battery units of equalization discharge that need, automatic equalization discharge,
In the discharge equalizing circuit fault in particular cases, adopt mode 3, that is, in pattern 1, forbid equalization discharge, and the series battery energy is carried out to charge balancing through described high pressure DCDC module, low-voltage DC/DC module and switch matrix to the battery unit of the preferential charge balancing of needs;
At described high pressure DCDC module failure in particular cases, employing pattern 4, that is, in pattern 2, forbid equalization discharge, and the battery modules energy is carried out to charge balancing through described mode control switch, low-voltage DC/DC and switch matrix to the battery unit of the preferential charge balancing of needs;
In described high pressure DCDC module failure, low-voltage DC/DC module fault, switch matrix fault in particular cases, employing pattern 5, only utilize discharge equalizing circuit to carry out equalization discharge to battery unit.
Above-mentioned series battery discharge and recharge the equilibrium that compound automatic balancing method also can be used for the serial connected super capacitance group.
Compared with prior art, the present invention has following useful technique effect:
1) speed is fast, efficiency is high;
Equalizing circuit of the present invention and equalization methods, adopted the compound active equalization scheme that conductive discharge is balanced and energy transfer charge balancing combines, the time for balance length of existing passive type conductive discharge equalization scheme, balanced inefficient shortcoming have been overcome dexterously, simultaneously the too low shortcoming of balanced efficiency of existing active equalization scheme, meet better the actual demand of using.
Particularly, for passive type conductive discharge equalization scheme, its balance policy be by the energy of the voltage in series battery or the high battery unit of electric weight by conductive discharge until with the consistent equilibrium realized series battery of the battery unit that wherein voltage or electric weight are minimum, its balanced efficiency is zero.Can produce a large amount of heats because the equalizing resistance electric discharge consumes electric energy, for fear of excess Temperature, euqalizing current can not be excessive.In prior art, the euqalizing current of this class equalizing system is generally 100mA~500mA, so time for balance is long.And equalizing circuit of the present invention, the equalization discharge electric current can reach 500mA, and energy transfer type charge balancing electric current can reach 5~10A, and balanced efficiency can reach more than 80%.The series battery of 100Ah, battery unit electric weight difference 10% of take is example, utilize equalizing circuit of the present invention and equalization methods, can utilize the series battery energy to transfer to the synchronous energy transfer type charge balancing that a plurality of battery units carry out large electric current, also can utilize the battery modules energy a plurality of battery units to be carried out to the synchronous energy transfer type charge balancing of large electric current, can also carry out synchronous equalization discharge to all cells, thereby make time for balance greatly shorten.With respect to the equalization methods that utilizes the passive type conductive discharge, time for balance has shortened 67%, and balanced rear series battery electric weight is high by 8.1%.And, for the existing energy transfer type equalization scheme based on inductance, electric capacity, because the battery unit of connecting in high-tension series battery often surpasses 100, cause in this scheme long, the balanced efficiency of energy transfer path too low.For example, when the energy demand of battery unit is shifted through 10 grades, its energy transfer efficiency often just only has about 0.9
10, be 34.9%.If consider electric discharge and the charge efficiency of battery unit, actual efficiency will be lower.
2) high safety, high reliability and high fault tolerance;
Equalizing circuit of the present invention, adopt the DCDC module of isolated form, and equalizing circuit, battery unit, battery system carried out to real-time diagnosis.When switch matrix is used for the gating battery unit, also for cutting off being connected of battery unit and equalizing circuit, thereby guaranteed high security and the high reliability of equalizing circuit, avoided existing energy transfer type equalization methods problem, the problem includes: the safety and reliability problem.Equalization methods provided by the invention, have 5 kinds of balanced mode, can, in equalizing circuit partial fault situation, still series battery be carried out to automatic equalization control, thereby make it have high fault tolerance.
3) the high accuracy of equalization;
Equalizing circuit of the present invention and equalization methods capable of dynamic are determined equalization target, are controlled euqalizing current in real time, can utilize the energy of series battery to carry out equilibrium between battery modules, utilize the energy of battery modules to carry out the equilibrium of battery unit, and be aided with controlled electric discharge sync equalizing, thereby significantly improve the accuracy of equalization, the useful life of significant prolongation series battery, reduce its use cost.After adopting equalizing circuit of the present invention and equalization methods, the voltage difference of each battery unit can reach 1mV.
4) high, the modular construction of complete function, integrated level, low cost, easily industrialization realizes;
Equalizing circuit of the present invention, adopt modular construction, wherein energy transfer type equalizing circuit has adopted multiplexing high pressure DCDC module, low-voltage DC/DC module and switch matrix to battery unit, but and the repertoire of integrated battery group management system BMS, can simplify wire harness by bus communication, significantly reduce cost, be easy to and other system integration application, had a wide range of applications field.
The accompanying drawing explanation
Fig. 1 is the structural representation that discharges and recharges compound automatic equalization circuit of series battery of the present invention.
Embodiment
Technique effect below with reference to accompanying drawing to design of the present invention, concrete structure and generation is described further, to understand fully purpose of the present invention, feature and effect.
As shown in Figure 1, the compound automatic equalization circuit that discharges and recharges of series battery of the present invention comprises: according to the compound balance module of n (n >=1) individual battery unit that in series battery, battery unit quantity arranges, the compound balance module 1 of battery unit ..., the compound balance module n of battery unit; The battery modules balance module 2 formed by main control module 21 and high pressure DCDC module 22.Wherein, the compound balance module 1~n of battery unit is comprised of the switch matrix 11~n1 with same structure, Local Control Module 12~n2, low-voltage DC/DC module 13~n3, discharge equalizing circuit (141~14k)~(n41~n4j) and mode control switch 15~n5 respectively accordingly.The battery modules BM-1 that wherein, the compound balance module 1~n difference of battery unit correspondence is comprised of battery unit ..., battery modules BM-n.
Each assembly of inside of the compound balance module of each battery unit and with external module between all there is identical annexation.As for the compound balance module 1 of battery unit, in its corresponding battery modules BM_1, have k series connection battery unit Cell_11, Cell_12 ..., Cell_1k, wherein, k>1; Output B11, the B12 of switch matrix 11 ..., B1k, B1k+1 independently of each other respectively with battery modules BM_1 in each battery unit Cell_11, Cell_12 ..., Cell_1k the pole circuitry phase connect, and the input of switch matrix 11 is connected with the output circuitry phase of low-voltage DC/DC module 13.K the discharge equalizing circuit 14 with same structure is connected between two outputs that switch matrix 11 is adjacent, as B11 and B12 ..., between B1k and B1k+1, with corresponding and battery unit Cell_11, Cell_12 respectively ..., the Cell_1k parallel connection.The positive input terminal LVlin+ of low-voltage DC/DC module 13 is connected with the anode BM 1+ circuitry phase of its corresponding battery modules, negative input end LV1in-is connected with the negative terminal BM 1-circuitry phase of its corresponding battery modules by mode control switch 15, and the positive-negative input end of low-voltage DC/DC module 13 is connected with the positive-negative output end circuitry phase of high pressure DCDC module 22 with BB-by equalizing circuit bus B B+ respectively.Positive-negative input end HVin+, the HVin-of high pressure DCDC module 22 is connected with anode BP+, the negative terminal BP-circuitry phase of series battery respectively.Low-voltage DC/DC module 13 in the compound balance module 1 of battery unit, switch matrix 11, a k discharge equalizing circuit 14, mode control switch 15 are connected with Local Control Module 12 circuitry phases, and are subject to the control of Local Control Module 12.High pressure DCDC module 22 and main control module 21 circuitry phases are connected and are subject to the control of main control module 21; Local Control Module 12 in main control module 21 and the compound balance module 1~n of battery unit ..., circuitry phase connects between n2.
Switch matrix 11 ..., n1 be respectively used to the battery modules BM_1 that it is corresponding ..., any one in BM_n need carry out charge balancing battery unit positive and negative pole respectively gating connect and receive the positive and negative output of the low-voltage DC/DC module in the compound balance module of battery unit at each switch matrix place, wherein, the gate-controlled switch in switch matrix adopts electronic switch or the relay as MOSFET.
Discharge equalizing circuit in the compound balance module 1~n of battery unit (141,142 ..., 14k) ..., (n41, n42 ..., n4j) include discharge resistance and gate-controlled switch, and the quantity of discharge equalizing circuit is no less than the quantity of battery unit in corresponding battery modules, and the battery unit corresponding with it (Cell_11, Cell_12 ..., Cell_1k) ..., (Cell_n1, Cell_n2 ..., Cell_nj) parallel connection.Wherein, gate-controlled switch adopts electronic switch or the relay as MOSFET.
High pressure DCDC module 22 is the isolated buck-type DC-DC converter, also can be provided with for the Limited Current direction at its positive and negative input and output, prevents that electric current is excessive, prevents overtension, prevent device or the circuit of short circuit etc.
Low-voltage DC/DC module 13 ..., n3 is the isolated buck-type DC-DC converter, also can be provided with for the Limited Current direction at its positive and negative input and output, prevent that electric current is excessive, prevent overtension, prevent device or the circuit of short circuit etc.
Main control module 21 and Local Control Module 12 ..., adopt between n2 the mode of bus communication to carry out the circuit connection.
Main control module 21 also can be diagnosed protection to battery modules balance module 2; and current sample, total voltage sampling, parameter Estimation, high-voltage safety control, heat management, failure diagnosis and system that the host controller BMU of batteries management system BMS is carried out as battery system control power management, CAN communication etc., and high pressure DCDC module 22 is carried out to diagnosis control.
Local Control Module 12 ..., n2 also has respectively in the BMS such as battery cell voltage sampling, battery temperature sampling, battery thermal management control, battery parameter estimation, Battery Diagnostic protection, CAN communication the function used of lower level controller LECU, and the switch matrix diagnosis and interlocking is controlled, to low-voltage DC/DC module (13 ..., n3) and mode control switch (15 ..., n5) the functions such as diagnosis control.
In the compound balance module 1~n of battery unit, the switch matrix in each module, Local Control Module, low-voltage DC/DC module, discharge equalizing circuit and mode control switch can become one, and also can independently arrange.
Main control module 21 in battery modules balance module 2 and high pressure DCDC module 22 can become one, and also can independently arrange.
Local Control Module 12 ..., n2 and main control module 21 can be integrated, also can independently arrange, can also partly or entirely be integrated in the corresponding controllers in battery management system.
The equalization methods that discharges and recharges compound automatic equalization circuit of series battery of the present invention is as follows: main control module 21 is responsible for the judgement equilibrium and is enabled condition, balanced mode, work out balance policy, and to take the mean value of balance parameters P be equalization target T, wherein, balance parameters P be battery unit in series battery (Cell_11, Cell_12 ..., Cell_1k) ..., (Cell_n1, Cell_n2 ..., Cell_nj) voltage or the integrated value of SOC or voltage and SOC, according to this equalization target T, each Local Control Module 12 ..., n2 respectively at it corresponding battery modules BM-1 ..., determine and need the battery unit of equalization discharge and the battery unit of the preferential charge balancing of needs in battery modules BM-n, when battery unit (Cell_11, Cell_12 ..., Cell_1k) ..., (Cell_n1, Cell_n2 ..., Cell_nj) balance parameters P and the difference of equalization target T when being less than set point or the balanced condition that enables and not meeting, forbid or exit balancing procedure, calculate respectively battery modules BM-1 that the compound balance module 1~n of each battery unit is corresponding ..., the battery unit in battery modules BM-n (Cell_11, Cell_12 ..., Cell_1k) ..., (Cell_n1, Cell_n2 ..., Cell_nj) the mean value of balance parameters P, it is called " battery modules balance parameters Pm ", when the difference between each battery modules balance parameters Pm is greater than set point, employing discharges and recharges the pattern 1 of composite balancing, , at main control module 21 and Local Control Module 12, under the control of n2, make mode control switch 15, n5 all disconnects, by battery pack power through high pressure DCDC module 22, low-voltage DC/DC module 13, n3 and switch matrix 11, n1 carries out synchronously the battery unit of the preferential charge balancing of all needs, automatic series battery energy transfer type charge balancing, simultaneously, utilize discharge equalizing circuit (141, 142, 14k), (n41, n42, n4j) all battery units of equalization discharge that need are carried out synchronously, automatic equalization discharge, when the difference between each battery modules balance parameters Pm is less than set point, employing discharges and recharges the pattern 2 of composite balancing, , at main control module 21 and Local Control Module 12, under the control of n2, make high pressure DCDC module 22 in stopped status, make to need the mode control switch 15 corresponding to battery unit place battery modules of charge balancing, the n5 conducting, by the energy of battery modules through each self-corresponding low-voltage DC/DC module 13, n3 and switch matrix 11, n1 carries out synchronously the battery unit of the preferential charge balancing of needs separately, automatic battery modules energy transfer type charge balancing, simultaneously, utilize discharge equalizing circuit (141, 142, 14k), (n41, n42, n4j) all battery units of equalization discharge that need are carried out synchronously, automatic equalization discharge, as discharge equalizing circuit (141, 142, 14k), (n41, n42, n4j) fault etc. in particular cases, also can be by forbidding that equalization discharge adopts the series battery energy through high pressure DCDC module 22 in pattern 1, low-voltage DC/DC module 13, n3 and switch matrix 11, n1 carries out the mode 3 of charge balancing to the battery unit of the preferential charge balancing of needs, and in particular cases also can be by forbidding that equalization discharge adopts the battery modules energy through mode control switch 15 in pattern 2 in high pressure DCDC module 22 faults etc., n5, low-voltage DC/DC module 13, n3 and switch matrix 11, n1 carries out the pattern 4 of charge balancing to the battery unit of the preferential charge balancing of needs, high pressure DCDC module 22 faults, low-voltage DC/DC module 13 ..., n3 fault, switch matrix 11 ..., n1 fault etc. in particular cases, also can only utilize discharge equalizing circuit (141,142 ..., 14k) ..., (n41, n42 ..., n4j) battery unit is carried out to the pattern 5 of equalization discharge.
Simultaneously, above-mentioned series battery discharges and recharges the equilibrium that compound automatic balancing method also can be used for the serial connected super capacitance group.
More than describe preferred embodiment of the present invention in detail.The ordinary skill that should be appreciated that this area just can design according to the present invention be made many modifications and variations without creative work.Therefore, all technical staff in the art, all should be in the determined protection range by claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.