A kind of non-dissipative equalizing circuit for electric automobile power batteryTechnical field
The present invention relates to electric automobile or large power energy storage power station battery management system technical field, specifically onePlant the non-dissipative equalizing circuit for electric automobile power battery.
Background technology
Electric automobile or large power energy storage system are composed in series by a large amount of battery modules, due to lithium ion battery listThere is inconsistency in body performance, in battery set charge/discharge, it may appear that the inconsistency of monomer voltage.During battery pack charge or discharge, as long as there is a battery cell to reach the charging/discharging voltage limit of battery,Whole battery pack will stop discharge and recharge, and otherwise the monomer will be overcharged or crossed and put, and have a strong impact on the battery longevityLife, this phenomenon seriously constrains the charging and discharging capabilities of battery.
Current balanced way is divided to two kinds.One kind is to damage equilibrium, also known as passive balanced, generally using withThe method of battery cell parallel resistance, bypasses unnecessary electric energy.Balanced way is damaged to convert electrical energy intoHeat, while inefficiency, the heat changed into brings larger burden to the heat management of battery pack again.Another is non-dissipative equalizing, also known as active equalization, and generally carrying out energy using method inductively or capacitively turnsMove.Also useful transformer carries out bottom or top way in a balanced way, after the high monomer energy of voltage is released,Charged to whole battery module, efficiency and portfolio effect be not universal high, and controlling switch structure design is multipleMiscellaneous, system reliability is not high.
The content of the invention
The present invention proposes a kind of non-dissipative equalizing circuit for electric automobile power battery, solves prior artIn balanced way efficiency it is low, the problem of portfolio effect is poor, system reliability is not high.
The technical proposal of the invention is realized in this way：
A kind of non-dissipative equalizing circuit for electric automobile power battery, including：
Series battery, includes the battery cell of some series connection；
Voltage detecting circuit, the information of voltage for gathering each battery cell in real time；
Microprocessor, receiving voltage detection circuit collect information of voltage, judge whether to equilibrium, andSend balanced control signal；
Switch driving circuit, receives the balanced control signal that microprocessor is sent, changes into switch controlling signalAnd send；
Equalizer switch circuit, receives switch controlling signal and action that switch driving circuit is sent；
Two-winding transformer；It is connected by equalizer switch circuit with series battery.
Further, the two-winding transformer is inverse-excitation type two-winding transformer, including the first winding and theTwo windings.
Further, the equalizer switch circuit includes：
The negative switch S being connected with the negative pole of n-th of battery celln1,
The positive switch S being connected with the positive pole of n-th of battery celln2,
Each negative switch Sn1It is connected with one end of the first winding, each positive switch Sn2It is another with the first windingEnd is connected,
Each negative switch Sn1It is connected with one end of the second winding, each positive switch Sn2It is another with the second windingEnd is connected.
Further, first winding and the second winding are in series with sense of current control diode respectively.
Further, first winding and the second winding are in series with controlling switch respectively.
Further, the negative switch Sn1With positive switch Sn2For N-channel MOS FET.
Further, the N-channel MOS FET is equipped with FET protection circuit.
Beneficial effects of the present invention are：
Structure design of the present invention is simple, easy to use；Equalizer switch circuit is connected to series battery and double wrapGroup transformer, implements switch motion, controls the energy of battery cell by two-winding transformer unbalancedBattery cell between flow.Switch driving circuit is responsible for controlling what is switched in equalizer switch circuit to lead on and offOpen.The present invention improves in the past big based on dissipation type equalizing system caloric value, the unconspicuous shortcoming of portfolio effect,The energy content of battery is set directly to flow to the low battery cell of voltage by the high battery cell of voltage, it is low with high efficiencyCost, the simple advantage of transformer control structure.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to implementingThe accompanying drawing used required in example or description of the prior art is briefly described, it should be apparent that, describe belowIn accompanying drawing be only some embodiments of the present invention, for those of ordinary skill in the art, do not payingOn the premise of going out creative work, other accompanying drawings can also be obtained according to these accompanying drawings.
Fig. 1 is the theory diagram of one embodiment of the invention；
Fig. 2 is the connection circuit diagram of equalizer switch circuit, two-winding transformer and series battery；
Fig. 3 is the control oscillogram of discharge process in one embodiment；
Fig. 4 is the theoretical current oscillogram of the first winding L1 in discharge process in one embodiment；
Fig. 5 is the control oscillogram of charging process in one embodiment；
Fig. 6 is the theoretical current oscillogram of the second winding L2 in charging process in one embodiment.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clearChu, it is fully described by, it is clear that described embodiment is only a part of embodiment of the invention, rather thanWhole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not making creationProperty work under the premise of the every other embodiment that is obtained, belong to the scope of protection of the invention.
As shown in figure 1, the non-dissipative equalizing circuit for electric automobile power battery in the present embodiment, including：
Series battery, includes the battery cell C1-C6 of 6 series connection；
Voltage detecting circuit, the information of voltage for gathering each battery cell in real time；
Microprocessor, receiving voltage detection circuit collect information of voltage, judge whether to equilibrium, andSend balanced control signal；
Switch driving circuit, receives the balanced control signal that microprocessor is sent, changes into switch controlling signalAnd send；
Equalizer switch circuit, receives switch controlling signal and action that switch driving circuit is sent；
Two-winding transformer；It is connected by equalizer switch circuit with series battery.
As shown in Fig. 2 in the present embodiment, the two-winding transformer is inverse-excitation type two-winding transformer, bagInclude the first winding L1 and the second winding L2.
Wherein, the equalizer switch circuit includes：
The negative switch S being connected with the negative pole of n-th of battery celln1,
The positive switch S being connected with the positive pole of n-th of battery celln2,
Each negative switch Sn1It is connected with one end of the first winding, each positive switch Sn2It is another with the first windingEnd is connected,
Each negative switch Sn1It is connected with one end of the second winding, each positive switch Sn2It is another with the second windingEnd is connected.
In the present embodiment, first windings in series have the sense of current control diode D1 and controlling switch K1,K2。
Second windings in series has the sense of current to control diode D2 and controlling switch K3, K4.
Here, the negative switch Sn1With positive switch Sn2For N-channel MOS FET, and arrangeThere is FET protection circuit.
Illustrate the course of work of the present embodiment by taking a balancing procedure as an example below, voltage detecting circuit is adopted in real timeCollect the information of voltage of each battery cell, when detect C5 voltages highest, C2 voltages it is minimum when, microprocessorInformation of voltage that receiving voltage detection circuit is collected, judge to need to carry out balanced, and send Balance route letterNumber；Switch driving circuit receives the balanced control signal that microprocessor is sent, and changes into switch controlling signal simultaneouslySend；Equalizer switch circuit receives switch controlling signal and the action that switch driving circuit is sent：
S first51, S52, K1, K2 adhesive, C5 discharged by the first winding L1, S51, S52, K1,K2 control waveform is as shown in figure 3, the first winding L1 theoretical current waveform is as shown in Figure 4；
Then, S51, S52, K1, K2 disconnection, S21, S22, K3, K4 adhesive, according to flyback transformerPrinciple, the second winding L2 charges to battery cell C2, S21, S22, K3, K4 control waveform such as Fig. 5Shown, the second winding L2 theoretical current waveform is as shown in Figure 6.
By said process, by the energy transmission in C5 to C2, a balancing procedure is completed.This kind repeatedlyBalancing procedure, just can ensure balancing energy between the battery cell in series battery.
Microprocessor is when judging whether to equilibrium, and Rule of judgment depends on battery behavior and system equalization energyPower, actual is the limit value for considering the unbalanced condition of the battery of battery and system factor, in advance with programMode writes microprocessor.When needing to carry out balanced, start equalization step, when not needing balanced, electricityPressure detection circuit continues to gather the information of voltage of each battery cell in real time., can in equilibrium condition deterministic processTo include certain delay process.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in this hairWithin bright spirit and principle, any modification, equivalent substitution and improvements made etc. should be included in this hairWithin bright protection domain.