CN104158155B - Balancing protection circuit for lithium battery - Google Patents

Abstract

The invention relates to a balancing protection circuit for a lithium battery. The circuit comprises a sampling circuit, a balancing circuit, an under-voltage protection circuit, comparison circuits, a driving circuit, first reference voltage, second reference voltage, supply voltage and a state output circuit, wherein each comparison circuit is used for comparing the first reference voltage and the second reference voltage with the corresponding sampling battery voltage of the lithium battery respectively, and outputting a first level signal; the state output circuit is used for outputting a second level signal according to the first level signals output by all the comparison circuits; the driving circuit is used for determining whether to output a driving signal to a corresponding balancing circuit or not according to the second level signal and the corresponding first level signal; the balancing circuit is used for controlling the connection of the positive pole and the negative pole of the corresponding lithium battery according to the corresponding driving signal so as to discharge the corresponding lithium battery. The balancing protection circuit has the advantage of low manufacture cost.

Description

The balanced protection circuit of lithium battery

Technical field

The present invention relates to the protection circuit technology of lithium battery, and in particular to the protection circuit technology of multi-series lithium battery.

Background technology

Currently on the market the protection circuit of multi-string lithium ion battery has following situation：

1. hardware Acquisition Circuit and MCU are controlled；

2. the IC that goes here and there single is gathered and controlled more；

3. many single-unit cascade IC collections and control；

The software and hardware combining of scheme 1, increased the complexity of circuit, with high costs；Scheme 2 is confined to the function of IC, section Number is restricted (although its maximum can detect the series connection of n batteries, might not can use from 2-n sections), or Can only be charged end balance (just starting balancing circuitry under the fast full condition of single battery)；Scheme 3 is equally high cost, or Person only has end equilibrium function.

Because the consensus of cell in lithium ion battery bag cause cell to overcharge and after to one's heart's content condition, on market Protection circuit can process just for the smaller problem of monomer battery voltage pressure reduction, long-term accumulation, cell electricity Pressure pressure reduction will gradually increase, and after the completion of whole charge and discharge process, battery is again without reaching the balance of voltage so that go here and there more The balancing circuitry of lithium ion battery bag circuit protection plate gradually fails, while the output of battery strings is reduced, battery bag makes Use reduced lifetime.

The content of the invention

It is an object of the invention to propose a kind of balanced protection circuit of lithium battery, it can solve the problems, such as high cost.

In order to achieve the above object, the technical solution adopted in the present invention is as follows：

A kind of balanced protection circuit of lithium battery, the quantity of the lithium battery is at least two, and all lithium batteries are connected Connection, the balanced protection circuit includes：It is identical with the quantity of the lithium battery and connect one to one with the lithium battery Sample circuit, balancing circuitry, under-voltage protecting circuit, comparison circuit and drive circuit, one first reference voltage, one second benchmark Voltage, a supply voltage and a State- output circuit；

The sample circuit, for obtaining the sampling battery voltage of corresponding lithium battery；

The under-voltage protecting circuit, for judging the sampling battery voltage of corresponding lithium battery whether more than first base Quasi- voltage, if so, then disconnects with corresponding balancing circuitry, if it is not, then controlling the lithium battery in corresponding balancing circuitry Positive pole is disconnected with negative pole；

The comparison circuit, for by the first reference voltage and the second reference voltage respectively with the sampling of corresponding lithium battery Cell voltage is compared, and exports one first level signal；

The State- output circuit, for the first level signal exported according to all comparison circuits, output one second is electric Ordinary mail number；

The drive circuit, for according to second electrical level signal and corresponding first level signal, judging whether to correspondence Balancing circuitry output drive signal；

The balancing circuitry, for according to corresponding drive signal, the positive pole for controlling corresponding lithium battery to be connected with negative pole, So as to carry out discharge process to corresponding lithium battery；

The supply voltage, for providing work for sample circuit, under-voltage protecting circuit, comparison circuit and State- output circuit Make voltage.

The balanced protection circuit of another kind of lithium battery of the present invention, the quantity of the lithium battery is at least two, and all Lithium battery is connected in series, and the balanced protection circuit includes：It is identical with the quantity of the lithium battery and with the lithium battery one Sample circuit, balancing circuitry and under-voltage protecting circuit, at least one primary control comparison circuit, a final stage control that one correspondence connects Comparison circuit processed, a reference voltage output circuit and a supply voltage；

It is more electric that at least one primary control comparison circuit is designated as respectively the 1st grade of control comparison circuit, the 2nd grade of control ratio Road ..., N levels control comparison circuit, N >=1 and for natural number；The primary control comparison circuit includes primary more electric Road, primary first state output circuit, primary second State- output circuit, primary control circuit and first stage drive circuit；Wherein, 1st grade of control comparison circuit provides running voltage by the supply voltage；

Final stage control comparison circuit includes final stage comparison circuit, final stage State- output circuit and final driving circuit；

The quantity of primary comparison circuit, first stage drive circuit, final stage comparison circuit and final driving circuit is and lithium battery Quantity it is identical and connect one to one with lithium battery respectively；

The reference voltage output circuit, for exporting (N+2) individual reference voltage, (N+2) individual reference voltage difference Be designated as the 1st reference voltage, the 2nd reference voltage ..., N+2 reference voltages；1st reference voltage<2nd reference voltage<……< N+2 reference voltages；

The sample circuit, for obtaining the sampling battery voltage of corresponding lithium battery；

The under-voltage protecting circuit, for judging the sampling battery voltage of corresponding lithium battery whether more than the 1st base Quasi- voltage, if so, then disconnects with corresponding balancing circuitry, if it is not, then controlling the lithium battery in corresponding balancing circuitry Positive pole is disconnected with negative pole；

At least one primary control comparison circuit is used for successively the sampling battery voltage according to corresponding lithium battery, sentences It is disconnected whether to control corresponding balancing circuitry discharge process is carried out to corresponding lithium battery, it is specific as follows：

The 1st grade of control comparison circuit, for by its primary comparison circuit that the 1st reference voltage and the 2nd benchmark is electric Pressure is compared respectively with the sampling battery voltage of corresponding lithium battery, and exports one the 11st primary level signal；By at the beginning of it Level first state output circuit is according to the primary level signal of all 11 primary level signal output one the 12nd；By its primary Two-state output circuit is according to the primary level signal of all 11 primary level signal output one the 13rd；By its primary control electricity Road judges whether to corresponding just stage drive circuit output the 11st according to the 12nd primary level signal and the 13rd primary level signal Primary drive signal, and judge whether to provide running voltage to the 2nd grade of control comparison circuit；By its first stage drive circuit root According to the 11st primary drive signal and the 11st primary level signal, judge whether to be driven to corresponding balancing circuitry output the 12nd is primary Signal；

The 2nd grade of control comparison circuit, for by its primary comparison circuit that the 2nd reference voltage and the 3rd benchmark is electric Pressure is compared respectively with the sampling battery voltage of corresponding lithium battery, and exports one the 21st primary level signal；By at the beginning of it Level first state output circuit is according to the primary level signal of all 21 primary level signal output one the 22nd；By its primary Two-state output circuit is according to the primary level signal of all 21 primary level signal output one the 23rd；By its primary control electricity Road judges whether to corresponding just stage drive circuit output the 21st according to the 22nd primary level signal and the 23rd primary level signal Primary drive signal, and judge whether to provide running voltage to 3rd level control comparison circuit；By its first stage drive circuit root According to the 21st primary drive signal and the 21st primary level signal, judge whether to be driven to corresponding balancing circuitry output the 22nd is primary Signal；

……；

The N levels control comparison circuit, for passing through its primary comparison circuit by N reference voltages and N+1 benchmark Voltage is compared respectively with the sampling battery voltage of corresponding lithium battery, and exports N1 primary level signals；By it Primary first state output circuit exports N2 primary level signals according to all N1 primary level signals；It is primary by it Second State- output circuit exports N3 primary level signals according to all N1 primary level signals；By its primary control Circuit judges whether to corresponding just stage drive circuit output the according to N2 primary level signals and N3 primary level signals N1 primary drive signals, and judge whether to provide running voltage to final stage control comparison circuit；By its first stage drive circuit According to N1 primary drive signals and N1 primary level signals, judge whether to be driven to corresponding balancing circuitry output N2 is primary Dynamic signal；

The final stage controls comparison circuit, for passing through its final stage comparison circuit by N+1 reference voltages and N+2 benchmark Voltage is compared respectively with the sampling battery voltage of corresponding lithium battery, and exports one first final stage level signal；By it Final stage State- output circuit exports one second final stage level signal according to all first final stage level signals；Driven by its final stage Circuit judges whether to be exported to corresponding balancing circuitry according to the second final stage level signal and corresponding first final stage level signal Final stage drive signal；

The balancing circuitry, for according at the beginning of the corresponding 12nd primary drive signal or the 22nd primary drive signal or N2 Level drive signal or final stage drive signal, the positive pole for controlling corresponding lithium battery is connected with negative pole, so as to corresponding lithium battery Carry out discharge process；

The supply voltage, for being that sample circuit and under-voltage protecting circuit provide running voltage.

Preferably, the sample circuit includes the first to the 5th resistance and difference amplifier, difference amplifier it is anti-phase defeated Enter negative pole connection of the end by 3rd resistor and corresponding lithium battery, the normal phase input end of difference amplifier by the 4th resistance with The positive pole connection of corresponding lithium battery, the normal phase input end of difference amplifier also passes through the 5th resistance eutral grounding, difference amplifier Inverting input is also grounded by first resistor, and the inverting input of difference amplifier is also by second resistance and difference amplifier Outfan connection, the outfan of difference amplifier exports the sampling battery voltage of corresponding lithium battery.

Preferably, the under-voltage protecting circuit includes the 6th to the 9th resistance, operational amplifier and the first audion, computing The inverting input of amplifier is connected by the 6th resistance with the sampling battery voltage of corresponding lithium battery, and operational amplifier is just Phase input is connected by the 7th resistance with the 1st reference voltage, and the outfan of operational amplifier passes through the 8th resistance and the one or three The base stage connection of pole pipe, the outfan of operational amplifier also by the 9th resistance eutral grounding, the grounded emitter of the first audion, the The colelctor electrode of one audion is connected with the control end of balancing circuitry.

Preferably, the balancing circuitry includes photoelectrical coupler, the tenth to the 12nd resistance and the first metal-oxide-semiconductor, a MOS The drain electrode of pipe passes through the positive pole connection of the 11st resistance and corresponding lithium battery, the source electrode of the first metal-oxide-semiconductor and corresponding lithium battery Negative pole connection, the transistor emitter outfan of photoelectrical coupler is connected with the grid of the first metal-oxide-semiconductor, the three of photoelectrical coupler Pole pipe emitter stage outfan is also connected by the 12nd resistance with the negative pole of corresponding lithium battery, the audion collection of photoelectrical coupler The positive pole connection that electrode input passes through the 11st resistance and corresponding lithium battery, the diode input of photoelectrical coupler with The outfan connection of the outfan of corresponding under-voltage protecting circuit and corresponding drive circuit.

Preferably, the primary comparison circuit includes the 13rd to the 16th resistance, first voltage comparator, second voltage Comparator, the first diode and the second diode, the normal phase input end of first voltage comparator is by the 14th resistance and N bases Quasi- voltage connection, the inverting input of first voltage comparator is connected by the 13rd resistance with the sampling battery voltage, the The inverting input of two voltage comparators is connected by the 16th resistance with N+1 reference voltages, and second voltage comparator is just Phase input is connected by the 15th resistance with the sampling battery voltage, the outfan of first voltage comparator and the one or two pole The anode connection of pipe, the negative electrode of the first diode and corresponding input, the corresponding primary of primary first state output circuit The corresponding input connection of the first input end of drive circuit and primary second State- output circuit；Second voltage comparator Outfan be connected with the anode of the second diode, the negative electrode of the second diode is connected with the negative electrode of the first diode.

It is further preferred that the primary first state output circuit includes the quantity identical first state with lithium battery Output electronic circuit, each first state output electronic circuit includes the 17th resistance, the 18th resistance and the second audion, the two or three The base stage of pole pipe is connected by the 18th resistance with the outfan of corresponding primary comparison circuit, and the base stage of the second audion is also led to Cross the 17th resistance to be connected with the supply voltage, the grounded collector of the second audion, the emitter stage of the second audion with it is first The first input end connection of level control circuit, the emitter stage of the second audion of one of first state output electronic circuit also leads to Cross 1 the 19th resistance to be connected with the supply voltage；

The primary second State- output circuit includes the diode of quantity identical the 3rd and the 23rd with lithium battery Resistance, the 3rd audion and the 20th to the 22nd resistance, per one the 3rd diode with corresponding 1 the 23rd resistance Series connection forms a series arm, and one end of each series arm connects with the outfan of corresponding primary comparison circuit, per a string The other end of connection branch road is connected with the base stage of the 3rd audion, and the base stage of the 3rd audion passes through the 22nd resistance eutral grounding, the The emitter stage of three audions is by the 21st resistance eutral grounding, and the emitter stage of the 3rd audion is defeated with the second of primary control circuit Enter end connection, the colelctor electrode of the 3rd audion is connected by the 20th resistance with the supply voltage；

The primary control circuit include reduction voltage circuit, the 24th to the 37th resistance, the 3rd to the 4th metal-oxide-semiconductor, 4th to the 6th audion, the 4th diode, the 5th diode, first to fourth electric capacity, tertiary voltage comparator and the 4th are electric Pressure comparator；The reduction voltage circuit is used to for the supply voltage to be converted to a comparison voltage；Tertiary voltage comparator it is anti-phase Input is connected by the 24th resistance with the voltage that compares, the normal phase input end of tertiary voltage comparator and the 25th One end connection of resistance, the other end of the 25th resistance is used as the second input of the primary control circuit of this grade, and the 4th is electric The inverting input of pressure comparator is connected with one end of the 26th resistance, and the other end of the 26th resistance is used as the first of this grade The first input end of level control circuit, the normal phase input end of the 4th voltage comparator is connected by the 27th resistance with voltage is compared Connect, the outfan of tertiary voltage comparator is connected by the 28th resistance with the base stage of the 4th audion, the 4th audion Base stage passes through the first electric capacity by the 30th resistance eutral grounding, the grounded emitter of the 4th audion, the emitter stage of the 4th audion Connect with the second input of corresponding just stage drive circuit, the colelctor electrode of the 4th audion is connected with the grid of the second metal-oxide-semiconductor, The colelctor electrode of the 4th audion is connected by the 31st resistance with the drain electrode of the second metal-oxide-semiconductor, the source electrode of the second metal-oxide-semiconductor with it is corresponding First stage drive circuit the second input, the base stage of the 4th audion and the base stage of the 5th audion are electric by the 29th Resistance is connected with the outfan of the 4th voltage comparator, and the base stage of the 5th audion passes through the 37th resistance and the 4th metal-oxide-semiconductor Source electrode connects, and the grounded collector of the 5th audion and is connected with the source electrode of the 3rd metal-oxide-semiconductor by the second electric capacity, the 3rd metal-oxide-semiconductor Source electrode be used to provide running voltage for the primary control comparison circuit of next stage, the emitter stage of the 5th audion is by the 30th Two resistance are connected with the drain electrode of the 3rd metal-oxide-semiconductor, and the emitter stage of the 5th audion is connected with the grid of the 3rd metal-oxide-semiconductor, the second metal-oxide-semiconductor Drain electrode and the drain electrode of the 3rd metal-oxide-semiconductor be connected with the source electrode of the 4th metal-oxide-semiconductor, drain electrode and the supply voltage of the 4th metal-oxide-semiconductor Connection, the first input end of the primary control circuit of this grade passes sequentially through the 4th diode and the 34th resistance and the six or three pole The base stage connection of pipe, the first input end of the primary control circuit of this grade pass sequentially through the 5th diode and the 35th resistance with The base stage connection of the 6th audion, the base stage of the 6th audion is by the 36th resistance eutral grounding, the emitter stage of the 6th audion It is grounded and is connected with the source electrode of the 4th metal-oxide-semiconductor by the 3rd electric capacity, the colelctor electrode of the 6th audion and the grid of the 4th metal-oxide-semiconductor connects Connect, the colelctor electrode of the 6th audion is connected by the 33rd resistance with the supply voltage；

The just stage drive circuit, including the 38th to the 42nd resistance, the 6th diode and the 7th audion, the The colelctor electrode of seven audions is connected with one end of the 38th resistance, and the other end of the 38th resistance is used as first stage drive circuit The second input, the base stage of the 7th audion is connected by the 39th resistance with the negative electrode of the 6th diode, the six or two pole The anode of pipe as first stage drive circuit first input end, the base stage of the 7th audion by the 41st resistance eutral grounding, the The anode of six diodes by the 40th resistance eutral grounding, the emitter stage of the 7th audion by the 42nd resistance eutral grounding, the 7th The emitter stage of audion connects with the control end of corresponding balancing circuitry.

Preferably, the final stage comparison circuit include the 43rd to the 46th resistance, the 5th voltage comparator, the 6th Voltage comparator, the 7th diode and the 8th diode, the normal phase input end of the 5th voltage comparator passes through the 44th resistance It is connected with N+1 reference voltages, the inverting input of the 5th voltage comparator is by the 43rd resistance and the sampling battery Voltage connects, and the inverting input of the 6th voltage comparator is connected by the 46th resistance with N+2 reference voltages, and the 6th is electric Pressure comparator normal phase input end be connected with the sampling battery voltage by the 45th resistance, the 5th voltage comparator it is defeated Go out end to be connected with the anode of the 7th diode, the negative electrode of the 7th diode and the corresponding input of final stage State- output circuit with And the first input end connection of corresponding final driving circuit；The outfan of the 6th voltage comparator and the anode of the 8th diode Connection, the negative electrode of the 8th diode is connected with the negative electrode of the 7th diode.

It is further preferred that the final stage State- output circuit include the diode of quantity identical the 9th with lithium battery and 43rd resistance, the 8th audion and the 44th to the 45th resistance, per one the 9th diode with corresponding 1 43 resistant series form a series arm, and one end of each series arm connects with the outfan of corresponding final stage comparison circuit Connect, the other end of each series arm is connected with the base stage of the 8th audion, the base stage of the 8th audion is electric by the 45th Resistance ground connection, the grounded emitter of the 8th audion and is connected by the 4th electric capacity with the source electrode of the 5th metal-oxide-semiconductor, the 5th metal-oxide-semiconductor Source electrode is connected with the second input of final driving circuit, and the colelctor electrode of the 8th audion is by the 44th resistance and the electricity Source voltage connects and is connected with the drain electrode of the 5th metal-oxide-semiconductor, and the colelctor electrode of the 8th audion and the grid of the 5th metal-oxide-semiconductor connect Connect；

The final driving circuit, including the 48th to the 50th resistance, the tenth diode and the 9th audion, the 9th The colelctor electrode of audion is connected with one end of the 48th resistance, and the other end of the 48th resistance is used as final driving circuit Second input, the base stage of the 9th audion is connected by the 47th resistance with the negative electrode of the tenth diode, the tenth diode Anode as final driving circuit first input end, the base stage of the 9th audion by the 49th resistance eutral grounding, the 9th The anode of diode by the 46th resistance eutral grounding, the emitter stage of the 9th audion by the 50th resistance eutral grounding, the 9th 3 The emitter stage of pole pipe connects with the control end of corresponding balancing circuitry.

The present invention has the advantages that：

Charging, discharging, standing in the case of three kinds, the balance of real-time controlling lithium battery, it is ensured that lithium battery voltage Concordance, so that the life of lithium battery string, volume output lifting, improve the stability and reliability of lithium battery string. And the present invention is without using MCU and IC, low cost.

Description of the drawings

Fig. 1 is the functional-block diagram of the balanced protection circuit of the lithium battery of the embodiment of the present invention one；

Fig. 2 is the functional-block diagram of the balanced protection circuit of the lithium battery of the embodiment of the present invention two；

Fig. 3 is the attachment structure schematic diagram that the 1st grade of control comparison circuit and final stage control comparison circuit in Fig. 2；

Fig. 4 is the circuit diagram of the sample circuit of Fig. 2；

Fig. 5 is the circuit diagram of the under-voltage protecting circuit of Fig. 2；

Fig. 6 is the circuit diagram of the balancing circuitry of Fig. 2；

Fig. 7 is the circuit diagram of the primary comparison circuit of Fig. 3；

Fig. 8 is the circuit diagram of the primary first state output circuit of Fig. 3；

Fig. 9 is the circuit diagram of primary the second State- output circuit of Fig. 3；

Figure 10 is the circuit diagram of the primary control circuit of Fig. 3；

Figure 11 is the circuit diagram of the first stage drive circuit of Fig. 3；

Figure 12 is the circuit diagram of the final stage comparison circuit of Fig. 3；

Figure 13 is the circuit diagram of the final stage State- output circuit of Fig. 3；

Figure 14 is the circuit diagram of the final driving circuit of Fig. 3.

Specific embodiment

Below, with reference to accompanying drawing and specific embodiment, the present invention is described further.

Embodiment one

As shown in figure 1, a kind of balanced protection circuit of lithium battery, the quantity of the lithium battery is at least two, and owns Lithium battery is connected in series.The balanced protection circuit includes：It is identical with the quantity of the lithium battery and with the lithium battery one The sample circuit of one correspondence connection, balancing circuitry, under-voltage protecting circuit, comparison circuit and drive circuit, one first reference voltage, One second reference voltage, a supply voltage and a State- output circuit.

The sample circuit (referring to Fig. 4), for obtaining the sampling battery voltage of corresponding lithium battery, the sampling electricity Cell voltage can be the half of the virtual voltage of lithium battery.Because the normal voltage range of lithium battery is 3-4.2V, therefore, first Reference voltage is 1.5V, and the second reference voltage is 2.1V.First reference voltage and the second reference voltage can be passed through by supply voltage Voltage conversion circuit transformation.

Whether the under-voltage protecting circuit (referring to Fig. 5), the sampling battery voltage for judging corresponding lithium battery is big In first reference voltage, if so, then disconnect with corresponding balancing circuitry, so that balancing circuitry is by under-voltage protection electricity The control on road, if it is not, then control the positive pole of the lithium battery in corresponding balancing circuitry and negative pole is disconnected, so that balancing circuitry Discharge process is stopped to lithium battery.

The comparison circuit (referring to Fig. 7 or Figure 12), for by the first reference voltage and the second reference voltage respectively with The sampling battery voltage of corresponding lithium battery is compared, and exports one first level signal.For example, if sampling battery voltage exists Between first reference voltage and the second reference voltage, then the first level signal is low level signal, is otherwise high level signal.

The State- output circuit (referring to Figure 13), for the first level signal exported according to all comparison circuits, Export a second electrical level signal.For example, if all of first level signal is low level signal, second electrical level signal is also Low level signal, if wherein there is one first level signal to be high level signal, second electrical level signal is high level signal.

The drive circuit (referring to Figure 14), for according to second electrical level signal and corresponding first level signal, sentencing Whether break to corresponding balancing circuitry output drive signal.For example, second electrical level signal is low level signal, then illustrate corresponding First level signal is also low level signal, drive circuit not output drive signal, if second electrical level signal is high level signal, And corresponding first level signal is high level signal, then the balance of drive circuit output drive signal to corresponding connection Circuit.

The balancing circuitry (referring to Fig. 6), for according to corresponding drive signal, controlling the positive pole of corresponding lithium battery It is connected with negative pole, so as to discharge process is carried out to corresponding lithium battery, until under-voltage protecting circuit determines corresponding lithium battery Sampling battery voltage be less than or equal to first reference voltage.

The supply voltage, for providing work for sample circuit, under-voltage protecting circuit, comparison circuit and State- output circuit Make voltage.Supply voltage can be provided by DC source, also can be by civil power Jing direct current transformation circuit conversions or electric by power supply Pond provides.

Embodiment two

With reference to shown in Fig. 2 to Figure 14, the balanced protection circuit of another kind of lithium battery, the present embodiment is with two lithium batteries and two Illustrate as a example by level control comparison circuit.Two lithium batteries are connected in series.The balanced protection circuit includes：Two sampling electricity Road, two balancing circuitrys, two under-voltage protecting circuits, a primary control comparison circuit, final stage control comparison circuit, a benchmark Voltage follower circuit and a supply voltage VCC.

Due to the primary control comparison circuit only one of which of the present embodiment, so being the 1st grade of control comparison circuit.1st grade Control comparison circuit includes primary comparison circuit, primary first state output circuit, primary second State- output circuit, primary control Circuit processed and first stage drive circuit.1st grade of control comparison circuit provides running voltage by the supply voltage.

Final stage control comparison circuit includes final stage comparison circuit, final stage State- output circuit and final driving circuit.

The quantity of primary comparison circuit, first stage drive circuit, final stage comparison circuit and final driving circuit is and lithium battery Quantity it is identical and connect one to one with lithium battery respectively.

The reference voltage output circuit, for exporting 3 reference voltages, 3 reference voltages are designated as respectively the 1st benchmark electricity Pressure, the 2nd reference voltage, the 3rd reference voltage.1st reference voltage<2nd reference voltage<3rd reference voltage.Due to lithium battery just Often voltage range is 3-4.2V, therefore, the 1st reference voltage is 1.5V, and the 2nd reference voltage is 1.8V, and the 3rd reference voltage is 2.1V.1st reference voltage, the 2nd reference voltage and the 3rd reference voltage can be become by supply voltage VCC by voltage conversion circuit Pressure.

As shown in figure 4, the sample circuit, for obtaining the sampling battery voltage of corresponding lithium battery.Due to sampling electricity The quantity on road is 2, and the 1st sample circuit and the 2nd sample circuit are designated as respectively.1st sample circuit by resistance R1, resistance R12 extremely R14, difference amplifier U1 are constituted.2nd sample circuit is made up of resistance R3 to R7, difference amplifier U11.Specific annexation Illustrated with the 2nd sample circuit, the inverting input of difference amplifier U11 passes through the negative pole of resistance R3 and corresponding lithium battery B1 connects, and the normal phase input end of difference amplifier U11 is connected by resistance R4 with the positive pole B2 of corresponding lithium battery, differential amplification The normal phase input end of device U11 is also grounded by resistance R6, and the inverting input of difference amplifier U11 is also grounded by resistance R7, The inverting input of difference amplifier U11 is also connected by resistance R5 with the outfan of difference amplifier U11, difference amplifier The outfan of U11 exports the sampling battery voltage BATV2 of corresponding lithium battery.Difference amplifier U11 and difference amplifier U1 are equal There is supply voltage VCC to power.The attachment structure of the 1st sample circuit is similar with the attachment structure of the 2nd sample circuit, differs only in The inverting input of the difference amplifier U1 of the 1st sample circuit is directly grounded by resistance R12, therefore, it can omit one instead One earth resistance of phase input, this is that, because terminal B1 connects the positive pole of corresponding lithium battery, and the negative pole of the lithium battery is straight Ground connection.Sampling battery voltage is the half of the virtual voltage of lithium battery.

As shown in figure 5, the under-voltage protecting circuit, for judging whether the sampling battery voltage of corresponding lithium battery is more than 1st reference voltage, if so, then disconnects with corresponding balancing circuitry, if it is not, then controlling in corresponding balancing circuitry The positive pole of lithium battery is disconnected with negative pole.Because the quantity of under-voltage protecting circuit is 2, the 1st under-voltage protection electricity is designated as respectively Road and the 2nd under-voltage protecting circuit.1st under-voltage protecting circuit is by resistance R109 to R112, audion Q13 and operational amplifier U29 Composition.2nd under-voltage protecting circuit is made up of resistance R113 to R116, audion Q15 and operational amplifier U30.With the 1st under-voltage guarantor The explanation of structure is attached as a example by protection circuit, the inverting input of operational amplifier U29 is by resistance R109 and corresponding lithium The sampling battery voltage BATV1 connections of battery, the normal phase input end of operational amplifier U29 is by resistance R110 and the 1st benchmark electricity Pressure connection, the outfan of operational amplifier U29 is connected by resistance R111 with the base stage of audion Q13, operational amplifier U29's Outfan is also grounded by resistance R112, the grounded emitter of audion Q13, the colelctor electrode of audion Q13 and corresponding balance The control end DISC_01 connection of circuit.

With reference to shown in Fig. 7 to Figure 11, the 1st grade of control comparison circuit, for passing through its primary comparison circuit by the 1st base Quasi- voltage and the 2nd reference voltage are compared respectively with the sampling battery voltage of corresponding lithium battery, and it is primary to export one the 11st Level signal；By its primary first state output circuit according to the primary level of all 11 primary level signal output one the 12nd Signal；One the 13rd primary electrical ordinary mail is exported according to all 11 primary level signals by its primary second State- output circuit Number；By its primary control circuit according to the 12nd primary level signal and the 13rd primary level signal judge whether to it is corresponding just The primary drive signal of stage drive circuit output the 11st, and judge whether to provide running voltage to final stage control comparison circuit；It is logical Its first stage drive circuit is crossed according to the 11st primary drive signal and the 11st primary level signal, is judged whether to corresponding balance electricity The primary drive signal of road output the 12nd.

As shown in fig. 7, the quantity of primary comparison circuit is 2, the 1st primary comparison circuit is designated as respectively and the 2nd primary compares Circuit.1st primary comparison circuit is by resistance R166 to R167, voltage comparator U43-A, voltage comparator U43-B, diode D2 With diode D3 compositions.2nd primary comparison circuit is by resistance R2, resistance R161 to R163, voltage comparator U42-A, voltage ratio Compared with device U42-B, diode D4 and diode D5 composition.Relation explanation, voltage ratio are attached by taking the 1st primary comparison circuit as an example Normal phase input end compared with device U43-B is connected by resistance R164 with the 1st reference voltage, the anti-phase input of voltage comparator U43-B End is connected by resistance R166 with sampling battery voltage BATV1, and the inverting input of voltage comparator U43-A passes through resistance R167 It is connected with the 2nd reference voltage, the normal phase input end of voltage comparator U43-A is by resistance R165 and the sampling battery voltage BATV1 connects, and the outfan of voltage comparator U43-B be connected with the anode of diode D2, the negative electrode and primary of diode D2 the The corresponding input (DRIVE1) of one State- output circuit, corresponding just stage drive circuit first input end (DRIVE1) with And corresponding input (DRIVE1) connection of primary second State- output circuit；The outfan of voltage comparator U43-1 and two The anode connection of pole pipe D3, the negative electrode of diode D3 is connected with the negative electrode of diode D2.

As shown in figure 8, the primary first state output circuit includes that 2 first states export electronic circuit, it is designated as respectively 1st electronic circuit and the 2nd electronic circuit.1st electronic circuit is made up of resistance R671, resistance R672 and audion Q113, the 2nd electronic circuit by Resistance R674, resistance R675 and audion Q114 are constituted.Structure explanation, audion Q113 are attached by taking the 1st electronic circuit as an example Base stage outfan (DRIVE1) connection that passes through resistance R672 and corresponding primary comparison circuit, the base stage of audion Q113 is also Be connected with the supply voltage VCC by resistance R671, the grounded collector of audion Q113, the emitter stage of audion Q113 with First input end (STATE00) connection of primary control circuit.1st electronic circuit and the 2nd electronic circuit differ only in the 1st son electricity The emitter stage of the audion Q113 on road is also connected by a resistance R673 with the supply voltage VCC.

As shown in figure 9, the primary second State- output circuit include diode D162, diode D163, resistance R376, Resistance R377, audion Q29, resistance R390, resistance R389 and resistance R713.Diode D162 connects to form one with resistance R376 First series arm, one end of the first series arm connects with the outfan (DRIVE1) of corresponding primary comparison circuit, and first The other end of series arm is connected with the base stage of audion Q29, and diode D163 connects to form one second series connection with resistance R377 Branch road, one end of the second series arm connects with the outfan (DRIVE2) of corresponding primary comparison circuit, the second series arm The other end be connected with the base stage of audion Q29, the base stage of audion Q29 is grounded by resistance R390, and audion Q29's sends out Emitter-base bandgap grading is grounded by resistance R713, and the emitter stage of audion Q29 is with second input (STATE01) of primary control circuit even Connect, the colelctor electrode of audion Q29 is connected by resistance R389 with the supply voltage VCC.

As shown in Figure 10, the attachment structure of the primary control circuit is：Supply voltage VCC is converted to into a ratio including one Reduction voltage circuit to voltage, the contrast potential is the 1/3 of supply voltage VCC, and the reduction voltage circuit includes resistance R711 and electricity Resistance R712, supply voltage VCC pass sequentially through resistance R711 and resistance R712 ground connection, the connecting node of resistance R711 and resistance R712 For exporting the comparison voltage.The inverting input of voltage comparator U100 is connected by resistance R445 with the contrast potential Connect, the normal phase input end of voltage comparator U100 is connected with one end of resistance R446, and the other end of resistance R446 is used as this grade Second input (STATE01) of primary control circuit, the inverting input of voltage comparator U115 and one end of resistance R437 Connection, the other end of resistance R437 as the primary control circuit of this grade first input end (STATE00), voltage comparator The normal phase input end of U115 is connected by resistance R618 with voltage is compared, and the outfan of voltage comparator U100 passes through resistance R449 It is connected with the base stage of audion Q37, the base stage of audion Q37 is grounded by resistance R448, the grounded emitter of audion Q37, The emitter stage of audion Q37 is connected by electric capacity C11 with second input (CHANNEL0) of corresponding just stage drive circuit, and three The colelctor electrode of pole pipe Q37 is connected with the grid of metal-oxide-semiconductor Q35, and the colelctor electrode of audion Q37 is by resistance R444 and metal-oxide-semiconductor Q35's Drain electrode connection, second input (CHANNEL0) of the source electrode of metal-oxide-semiconductor Q35 and corresponding just stage drive circuit, audion Q37's The base stage of base stage and audion Q98 is connected by resistance R436 with the outfan of voltage comparator U115, the base of audion Q98 Pole is connected by resistance R716 with the source electrode of metal-oxide-semiconductor Q33, the grounded collector of audion Q98 and by electric capacity C12 and metal-oxide-semiconductor The source electrode connection of Q27, the source electrode of metal-oxide-semiconductor Q27 is used to provide running voltage (POWER00), three poles for final stage control comparison circuit The emitter stage of pipe Q98 is connected by resistance R714 with the drain electrode of metal-oxide-semiconductor Q27, the emitter stage of audion Q98 and the grid of metal-oxide-semiconductor Q27 Pole connects, and the drain electrode of metal-oxide-semiconductor Q35 and the drain electrode of metal-oxide-semiconductor Q27 are connected with the source electrode of metal-oxide-semiconductor Q33, the drain electrode of metal-oxide-semiconductor Q33 and The supply voltage VCC connections, the first input end of the primary control circuit of this grade leads to successively diode D197 and resistance R577 It is connected with the base stage of audion Q80, the first input end of the primary control circuit of this grade passes sequentially through diode D198 and resistance R578 is connected with the base stage of audion Q80, and the base stage of audion Q80 is grounded by resistance R435, and the emitter stage of audion Q80 connects Ground and be connected with the source electrode of metal-oxide-semiconductor Q33 by electric capacity C17, the colelctor electrode of audion Q80 is connected with the grid of metal-oxide-semiconductor Q33, three The colelctor electrode of pole pipe Q80 is connected by resistance R434 with the supply voltage VCC.

As shown in figure 11, the just stage drive circuit is 2, and the 1st just stage drive circuit and the 2nd primary driving is designated as respectively Circuit.1st first stage drive circuit is by resistance R442, resistance R443, resistance R698, resistance R715, resistance R447, diode D214 With audion Q36 compositions.2nd first stage drive circuit is by resistance R456, resistance R457, resistance R699, resistance R717, resistance R458, diode D215 and audion Q40 are constituted.Structure explanation, audion are attached by taking the 1st just stage drive circuit as an example The colelctor electrode of Q36 is connected with one end of resistance R442, and the other end of resistance R442 is input into as the second of the 1st first stage drive circuit End (CHANNEL0), the base stage of audion Q36 is connected by resistance 698 with the negative electrode of diode D214, the sun of D diodes 214 Used as the first input end (DRIVE1) of the 1st first stage drive circuit, the base stage of audion Q36 is grounded by resistance R443 for pole, and two The anode of pole pipe D214 is grounded by resistance R715, and the emitter stage of audion Q35 is grounded by resistance R447, audion Q36's Emitter stage connects with the control end (DISC_01) of corresponding balancing circuitry.

With reference to shown in Figure 12 to Figure 14, the final stage controls comparison circuit, for passing through its final stage comparison circuit by the 3rd base Quasi- voltage and the 2nd reference voltage are compared respectively with the sampling battery voltage of corresponding lithium battery, and export one first final stage Level signal；One second final stage level letter is exported according to all first final stage level signals by its final stage State- output circuit Number；Judged whether to right according to the second final stage level signal and corresponding first final stage level signal by its final driving circuit The balancing circuitry output final stage drive signal answered.

As shown in figure 12, the final stage comparison circuit is 2, the 1st final stage comparison circuit is designated as respectively and the 2nd final stage compares Circuit.1st final stage comparison circuit is by resistance R324 to R327, voltage comparator U85-A, voltage comparator U85-B, diode D80 and diode D81 is constituted, and the 2nd final stage comparison circuit is by resistance R328 to R331, voltage comparator U86-A, voltage comparator U86-B, diode D82 and diode D83 are constituted.Be attached by taking the 1st final stage comparison circuit as an example structure explanation, voltage ratio compared with The normal phase input end of device U85-B is connected by resistance R324 with the 2nd reference voltage, the inverting input of voltage comparator U85-B Be connected with the sampling battery voltage by resistance R326, the inverting input of voltage comparator U85-A by resistance R327 with 3rd reference voltage connects, and the normal phase input end of voltage comparator U85-A is connected by resistance R325 with the sampling battery voltage Connect, the outfan of voltage comparator U85-B is connected with the anode of diode D80, negative electrode and the final stage State- output of diode D80 The corresponding input (DRIVE31) of circuit and first input end (DRIVE31) connection of corresponding final driving circuit；Electricity The outfan of pressure comparator U85-A is connected with the anode of diode D81, and the negative electrode of diode D81 connects with the negative electrode of diode D80 Connect.

As shown in figure 13, the final stage State- output circuit includes diode D148, resistance R421, diode D149, electricity Resistance R422, resistance R590, resistance R589, metal-oxide-semiconductor 85, electric capacity C19 and audion Q86.Diode D148 connects with resistance R421 One the 3rd series arm is formed, one end of the 3rd series arm connects with the outfan (DRIVE31) of corresponding final stage comparison circuit Connect, the other end of the 3rd series arm is connected with the base stage of audion Q86, diode D149 connects to form one with resistance R422 Four series arms, one end of the 4th series arm connects with the outfan (DRIVE32) of corresponding final stage comparison circuit, the 4th string The other end of connection branch road is connected with the base stage of audion Q86, and the base stage of audion Q86 is grounded by resistance R590, audion Q86 Grounded emitter and be connected with the source electrode of metal-oxide-semiconductor Q85 by electric capacity C19, the source electrode of metal-oxide-semiconductor Q85 and final driving circuit Second input (CHANNEL03) connects, and the colelctor electrode of audion Q86 is connected by resistance R589 with the supply voltage VCC And be connected with the drain electrode of metal-oxide-semiconductor Q85, the colelctor electrode of audion Q86 is connected with the grid of metal-oxide-semiconductor Q85.

As shown in figure 14, the final driving circuit is 2, the 1st final driving circuit is designated as respectively and the 2nd final stage drives Circuit.1st final driving circuit is by resistance R574, resistance R575, resistance R576, resistance R616, resistance R889, diode D161 With audion Q34 compositions, the 2nd final driving circuit is by resistance R580, resistance R582, resistance R581, resistance R617, resistance R890, diode D185 and audion Q82 are constituted.Structure explanation, audion are attached by taking the 1st final driving circuit as an example The colelctor electrode of Q34 is connected with one end of resistance R574, and the other end of resistance R574 is input into as the second of the 1st final driving circuit End (CHANNEL03), the base stage of audion Q34 is connected by resistance R616 with the negative electrode of diode D161, diode D161's Used as the first input end (DRIVE31) of the 1st final driving circuit, the base stage of audion Q34 is grounded anode by resistance R575, The anode of diode D161 is grounded by resistance R889, and the emitter stage of audion Q34 is grounded by resistance R576, audion Q34 The control end (DISC_01) of emitter stage and corresponding balancing circuitry connect.

As shown in fig. 6, the balancing circuitry, for according to the corresponding 12nd primary drive signal or final stage drive signal, The positive pole for controlling corresponding lithium battery is connected with negative pole by power discharge resistance, so as to carry out at electric discharge to corresponding lithium battery Reason.The balancing circuitry is 2, and the 1st balancing circuitry and the 2nd balancing circuitry are designated as respectively.1st balancing circuitry is by photoelectrical coupler U9, resistance R82 (i.e. power discharge resistance), resistance R48, resistance R46 and metal-oxide-semiconductor Q6 composition, the 2nd balancing circuitry is by photoelectric coupling Device U8, resistance R81 (i.e. another power discharge resistance), resistance R45, resistance R43 and metal-oxide-semiconductor Q5 composition.It is with the 1st balancing circuitry Example is attached structure explanation, and the drain electrode of metal-oxide-semiconductor Q6 is connected by resistance R82 with the positive pole B1 of corresponding lithium battery, metal-oxide-semiconductor Q6 The negative pole B- of source electrode and corresponding lithium battery connect, the transistor emitter outfan of photoelectrical coupler U9 is with metal-oxide-semiconductor Q6's Grid connects, and the transistor emitter outfan of photoelectrical coupler U9 also passes through the negative pole B- of resistance R46 and corresponding lithium battery Connection, the transistor collector input of photoelectrical coupler U9 is connected by resistance R48 with the positive pole B1 of corresponding lithium battery, light The diode input of electric coupler U9 is electric with the outfan (DISC_01) of corresponding under-voltage protecting circuit and corresponding driving Outfan (DISC_01) connection on road.

The supply voltage VCC, for being that sample circuit and under-voltage protecting circuit provide running voltage.

The operation principle of the present embodiment is as follows：

It is 1.5V to arrange the 1st reference voltage, and the 2nd reference voltage is 1.8V, and the 3rd reference voltage is 2.1V.User can also As needed, add the quantity of reference voltage and be configured, such as 1.5V, 1.65V, 1.8V, 1.95V, 2.1V, reference voltage is got over Many, precision is higher.

Lithium battery string is connected by pricking with needle with sample circuit, exports BATV (i.e. sampling battery voltage) for single lithium battery Voltage half.

In under-voltage protecting circuit, BATV is compared with 1.5V, if BATV>1.5V, audion Q13 end, under-voltage guarantor Protection circuit disconnects with balancing circuitry, does not process, if BATV≤1.5V, the control end of balancing circuitry is grounded, and makes monomer Lithium battery voltage is not processed when being less than 3.0V, so as to protect the lithium battery will not over-discharge.

In BATV>During 1.5V, single lithium battery voltage is processed according to the method for Approach by inchmeal, described in detail below：

First, the condition that balancing circuitry starts is determined, the condition of triggering is exactly that monomer lithium electricity battery pressure reduction is higher by higher limit, Higher limit is chosen and is determined according to reference voltage value, and such as the 1st reference voltage selects 1.5V, the 2nd reference voltage to select 1.8V, illustrates that cell voltage is not processed between 3.0-3.6V, but outside this voltage range, i.e. single lithium battery voltage difference Lithium battery higher than 0.6V will carry out discharge process.The present embodiment have 1 primary control comparison circuit and 1 final stage control ratio compared with Circuit, is that two grades of comparisons are processed from overall, and the order of startup is the conditional decision according to power supply. it is specific as follows：

A. due to power supply order, the 1st grade of control comparison circuit is started first, and (principle of primary comparison circuit is lithium battery It is pressed between 1.5-1.8V, DRIVEn low level outputs, otherwise high level output, n=1,2), single lithium battery can be analyzed Sampling battery voltage BATVn whether between 1.5-1.8V (3.0-3.6V), if so, primary comparison circuit output DRIVEn is low Level, otherwise DRIVEn export high level, there is 3 kinds of situations here：Situation 1：DRIVEn is all high level, and (sampling battery voltage is complete Portion is higher than 1.8V)；Situation 2：DRIVEn is all low level (sampling battery voltage is between 1.5-1.8V)；Situation 3：DRIVEn is complete Have for low and high level (sampling battery voltage have between 1.5-1.8V, also have higher than 1.8V's).

B. primary first state output circuit, it is whether the sampling battery voltage for gathering single lithium battery has in 1.5- Between 1.8V, if single lithium battery at least 1 (DRIVEn at least 1 is output as low level) in the range of this, STATE00 can just draw ground, export low level；Primary second State- output circuit, sampling battery voltage at least 1 is higher than 1.8V (DRIVEn at least 1 is output as high level), STATE01 can just export high level, be exported by primary first state Circuit and primary second State- output circuit can obtain 3 kinds of combinations, combine 1 (STATE00：STATE01=00, monomer lithium electricity The sampling battery voltage in pond is between 1.5-1.8V)；2 (STATE00 of combination：STATE01=01, the sampling electricity of single lithium battery Existing also the having higher than 1.8V's between 1.5-1.8V of cell voltage)；3 (STATE00 of combination：STATE01=11, monomer lithium electricity The sampling battery voltage in pond is entirely on 1.8V)；

C. it is input in primary control circuit in 3 kinds of possible composite signals, if the situation of combination 1, whole electricity Road will not do Balance Treatment (close metal-oxide-semiconductor Q33, metal-oxide-semiconductor Q35, CHANNEL0 without output), while also to final stage control ratio compared with Circuit is powered (close metal-oxide-semiconductor Q27, POWER00 is without output) so as to failed.If the situation of combination 2：Close final stage control Comparison circuit is powered (close metal-oxide-semiconductor Q27, POWER00 is without output), the primary drive circuitry of opening (metal-oxide-semiconductor Q33 is opened, Metal-oxide-semiconductor Q35, CHANNEL0 output drive signal).If the situation of combination 3：Opening final stage control comparison circuit is powered and (is beaten Open metal-oxide-semiconductor Q27, POWER00 outputs), close primary drive circuitry and (close metal-oxide-semiconductor Q33, metal-oxide-semiconductor Q35, CHANNEL0 is defeated Go out).

Final stage control comparison circuit is similar with the principle of the 1st grade of control comparison circuit, and simply a reference source voltage range differs Sample, final stage is the higher limit of reference voltage, equivalent to eliminating primary first state output circuit and primary control circuit, due to Battery voltage limit value is 4.2V, and it directly may determine that the monomer lithium electricity whether having beyond 4.2V in final stage comparison circuit The cell voltage in pond, so as to open balancing circuitry, final stage State- output circuit provides final driving circuit supply voltage, and end Stage drive circuit can just drive corresponding balancing circuitry to discharge corresponding single lithium battery with reference to final stage comparison circuit.

Balancing circuitry prevents lithium battery string (high voltage) and control circuit (low-voltage) using photoelectric coupler isolation control Between the control that causes of pressure reduction problem and safety problem.

Knowable to above-mentioned two embodiment, embodiment one only has one-level control comparison circuit and 2 reference voltages, precision compared with It is low, and embodiment two has Two-stage control comparison circuit and 3 reference voltages, precision is high compared with embodiment one.Therefore, if control ratio More compared with the series of circuit, reference voltage is more, and precision is higher.

Low manufacture cost of the present invention, using simple, can be optionally combined, the voltage difference mark of artificial setting single lithium battery Standard, is charging, is discharging, is standing in the case of 3 kinds, and the balance matching of real-time ensuring lithium battery improves the use longevity of multi-series lithium battery Life, increased the stability and reliability of multi-series lithium battery.

For a person skilled in the art, technical scheme that can be as described above and design, make other each Plant corresponding change and deform, and all these changes and deforms the protection model that should all belong to the claims in the present invention Within enclosing.

Claims (9)

1. the balanced protection circuit of lithium battery, the quantity of the lithium battery is at least two, and all lithium batteries are connected in series, its It is characterised by, the balanced protection circuit includes：It is identical with the quantity of the lithium battery and with the lithium battery correspond The sample circuit of connection, balancing circuitry, under-voltage protecting circuit, comparison circuit and drive circuit, one first reference voltage, one second Reference voltage, a supply voltage and a State- output circuit；

The sample circuit, for obtaining the sampling battery voltage of corresponding lithium battery；

The under-voltage protecting circuit, for judging the sampling battery voltage of corresponding lithium battery whether more than first benchmark electricity Pressure, if so, then disconnects with corresponding balancing circuitry, if it is not, then controlling the positive pole of the lithium battery in corresponding balancing circuitry Disconnect with negative pole；

The comparison circuit, for by the first reference voltage and the second reference voltage respectively with the sampling battery of corresponding lithium battery Voltage is compared, and exports one first level signal；

The State- output circuit, for the first level signal exported according to all comparison circuits, output one second electrical level letter Number；

The drive circuit, for according to second electrical level signal and corresponding first level signal, judging whether to be put down to corresponding Weighing apparatus circuit output drive signal；

The balancing circuitry, for according to corresponding drive signal, the positive pole for controlling corresponding lithium battery to be connected with negative pole, so that Discharge process is carried out to corresponding lithium battery；

The supply voltage, for providing work electricity for sample circuit, under-voltage protecting circuit, comparison circuit and State- output circuit Pressure.

2. the balanced protection circuit of lithium battery, the quantity of the lithium battery is at least two, and all lithium batteries are connected in series, its It is characterised by, the balanced protection circuit includes：It is identical with the quantity of the lithium battery and with the lithium battery correspond The sample circuit of connection, balancing circuitry and under-voltage protecting circuit, at least one primary control comparison circuit, a final stage control ratio compared with Circuit, a reference voltage output circuit and a supply voltage；

At least one primary control comparison circuit be designated as respectively the 1st grade of control comparison circuit, the 2nd grade of control comparison circuit ..., N levels control comparison circuit, N >=1 and for natural number；The primary control comparison circuit include primary comparison circuit, primary the One State- output circuit, primary second State- output circuit, primary control circuit and first stage drive circuit；Wherein, the 1st grade of control Comparison circuit provides running voltage by the supply voltage；

Final stage control comparison circuit includes final stage comparison circuit, final stage State- output circuit and final driving circuit；

The quantity of primary comparison circuit, first stage drive circuit, final stage comparison circuit and final driving circuit with the number of lithium battery Amount is identical and connects one to one with lithium battery respectively；

The reference voltage output circuit, for exporting (N+2) individual reference voltage, (N+2) individual reference voltage is designated as respectively 1st reference voltage, the 2nd reference voltage ..., N+2 reference voltages；1st reference voltage<2nd reference voltage<……<N+2 Reference voltage；

The sample circuit, for obtaining the sampling battery voltage of corresponding lithium battery；

The under-voltage protecting circuit, for judging the sampling battery voltage of corresponding lithium battery whether more than the 1st benchmark electricity Pressure, if so, then disconnects with corresponding balancing circuitry, if it is not, then controlling the positive pole of the lithium battery in corresponding balancing circuitry Disconnect with negative pole；

At least one primary control comparison circuit is used for successively the sampling battery voltage according to corresponding lithium battery, and judgement is The corresponding balancing circuitry of no control carries out discharge process to corresponding lithium battery, specific as follows：

The 1st grade of control comparison circuit, for being divided the 1st reference voltage and the 2nd reference voltage by its primary comparison circuit Do not compare with the sampling battery voltage of corresponding lithium battery, and export one the 11st primary level signal；By its primary One State- output circuit is according to the primary level signal of all 11 primary level signal output one the 12nd；By its primary second shape State output circuit is according to the primary level signal of all 11 primary level signal output one the 13rd；By its primary control circuit root Judge whether according to the 12nd primary level signal and the 13rd primary level signal primary to the output the 11st of corresponding just stage drive circuit Drive signal, and judge whether to provide running voltage to the 2nd grade of control comparison circuit；By its first stage drive circuit according to 11 primary drive signals and the 11st primary level signal, judge whether to drive letter to corresponding balancing circuitry output the 12nd is primary Number；

The 2nd grade of control comparison circuit, for being divided the 2nd reference voltage and the 3rd reference voltage by its primary comparison circuit Do not compare with the sampling battery voltage of corresponding lithium battery, and export one the 21st primary level signal；By its primary One State- output circuit is according to the primary level signal of all 21 primary level signal output one the 22nd；By its primary second shape State output circuit is according to the primary level signal of all 21 primary level signal output one the 23rd；By its primary control circuit root Judge whether according to the 22nd primary level signal and the 23rd primary level signal primary to the output the 21st of corresponding just stage drive circuit Drive signal, and judge whether to provide running voltage to 3rd level control comparison circuit；By its first stage drive circuit according to 21 primary drive signals and the 21st primary level signal, judge whether to drive letter to corresponding balancing circuitry output the 22nd is primary Number；

……；

The N levels control comparison circuit, for passing through its primary comparison circuit by N reference voltages and N+1 reference voltages Compare with the sampling battery voltage of corresponding lithium battery respectively, and export N1 primary level signals；It is primary by it First state output circuit exports N2 primary level signals according to all N1 primary level signals；By its primary second State- output circuit exports N3 primary level signals according to all N1 primary level signals；By its primary control circuit According at the beginning of N2 primary level signals and N3 primary level signals judge whether to corresponding just stage drive circuit output N1 Level drive signal, and judge whether to provide running voltage to final stage control comparison circuit；By its first stage drive circuit according to N1 primary drive signals and N1 primary level signals, judge whether to drive letter to corresponding balancing circuitry output N2 is primary Number；

The final stage controls comparison circuit, for passing through its final stage comparison circuit by N+1 reference voltages and N+2 reference voltages Compare with the sampling battery voltage of corresponding lithium battery respectively, and export one first final stage level signal；By its final stage State- output circuit exports one second final stage level signal according to all first final stage level signals；By its final driving circuit Judged whether to export final stage to corresponding balancing circuitry according to the second final stage level signal and corresponding first final stage level signal Drive signal；

The balancing circuitry, for according to the corresponding 12nd primary drive signal or the 22nd primary drive signal or the primary drives of N2 Dynamic signal or final stage drive signal, the positive pole for controlling corresponding lithium battery is connected with negative pole, so as to carry out to corresponding lithium battery Discharge process；

The supply voltage, for being that sample circuit and under-voltage protecting circuit provide running voltage.

3. balanced protection circuit as claimed in claim 2, it is characterised in that the sample circuit includes the first to the 5th resistance And difference amplifier, the negative pole connection that the inverting input of difference amplifier passes through 3rd resistor and corresponding lithium battery, difference The normal phase input end of amplifier is connected by the 4th resistance with the positive pole of corresponding lithium battery, the normal phase input end of difference amplifier Also by the 5th resistance eutral grounding, the inverting input of difference amplifier is also grounded by first resistor, difference amplifier it is anti-phase Input is also connected by second resistance with the outfan of difference amplifier, and the outfan of difference amplifier exports corresponding lithium electricity The sampling battery voltage in pond.

4. balanced protection circuit as claimed in claim 2, it is characterised in that the under-voltage protecting circuit includes the 6th to the 9th Resistance, operational amplifier and the first audion, the inverting input of operational amplifier is by the 6th resistance and corresponding lithium battery Sampling battery voltage connection, the normal phase input end of operational amplifier is connected by the 7th resistance with the 1st reference voltage, and computing is put The outfan of big device is connected by the 8th resistance with the base stage of the first audion, and the outfan of operational amplifier is also electric by the 9th Resistance ground connection, the grounded emitter of the first audion, the colelctor electrode of the first audion is connected with the control end of balancing circuitry.

5. balanced protection circuit as claimed in claim 2, it is characterised in that the balancing circuitry include photoelectrical coupler, the Ten to the 12nd resistance and the first metal-oxide-semiconductor, the drain electrode of the first metal-oxide-semiconductor is connected by the 11st resistance with the positive pole of corresponding lithium battery Connect, the negative pole of the source electrode of the first metal-oxide-semiconductor and corresponding lithium battery connects, the transistor emitter outfan of photoelectrical coupler and the The grid connection of one metal-oxide-semiconductor, the transistor emitter outfan of photoelectrical coupler is also by the 12nd resistance and corresponding lithium electricity The negative pole connection in pond, the transistor collector input of photoelectrical coupler passes through the positive pole of the 11st resistance and corresponding lithium battery Connection, the diode input of photoelectrical coupler with the outfan of corresponding under-voltage protecting circuit and corresponding drive circuit Outfan connects.

6. balanced protection circuit as claimed in claim 2, it is characterised in that the primary comparison circuit includes the 13rd to the 16 resistance, first voltage comparator, second voltage comparator, the first diode and the second diode, first voltage comparator Normal phase input end be connected with N reference voltages by the 14th resistance, the inverting input of first voltage comparator is by the 13 resistance are connected with the sampling battery voltage, and the inverting input of second voltage comparator is by the 16th resistance and N+ 1 reference voltage connects, and the normal phase input end of second voltage comparator is connected by the 15th resistance with the sampling battery voltage, The outfan of first voltage comparator is connected with the anode of the first diode, and the negative electrode of the first diode is defeated with primary first state Go out corresponding input, the corresponding just first input end of stage drive circuit and the primary second State- output circuit of circuit Corresponding input connection；The outfan of second voltage comparator is connected with the anode of the second diode, the moon of the second diode Pole is connected with the negative electrode of the first diode.

7. balanced protection circuit as claimed in claim 6, it is characterised in that the primary first state output circuit include with The quantity identical first state output electronic circuit of lithium battery, each first state output electronic circuit include the 17th resistance, the 18 resistance and the second audion, the base stage of the second audion passes through the output of the 18th resistance and corresponding primary comparison circuit End connection, the base stage of the second audion is also connected by the 17th resistance with the supply voltage, the colelctor electrode of the second audion Ground connection, the emitter stage of the second audion is connected with the first input end of primary control circuit, one of first state output The emitter stage of the second audion of circuit is also connected by 1 the 19th resistance with the supply voltage；

The primary second State- output circuit include the diode of quantity identical the 3rd and the 23rd resistance with lithium battery, 3rd audion and the 20th to the 22nd resistance, per one the 3rd diode with corresponding 1 the 23rd resistant series shape Into a series arm, one end of each series arm connects with the outfan of corresponding primary comparison circuit, each series arm The other end be connected with the base stage of the 3rd audion, the base stage of the 3rd audion is by the 22nd resistance eutral grounding, the three or three pole The emitter stage of pipe is connected by the 21st resistance eutral grounding, the emitter stage of the 3rd audion with the second input of primary control circuit Connect, the colelctor electrode of the 3rd audion is connected by the 20th resistance with the supply voltage；

The primary control circuit include reduction voltage circuit, the 24th to the 37th resistance, the 3rd to the 4th metal-oxide-semiconductor, the 4th To the 6th audion, the 4th diode, the 5th diode, first to fourth electric capacity, tertiary voltage comparator and the 4th voltage ratio Compared with device；The reduction voltage circuit is used to for the supply voltage to be converted to a comparison voltage；The anti-phase input of tertiary voltage comparator End is connected by the 24th resistance with the voltage that compares, the normal phase input end of tertiary voltage comparator and the 25th resistance One end connection, the other end of the 25th resistance as the primary control circuit of this grade the second input, the 4th voltage ratio It is connected with one end of the 26th resistance compared with the inverting input of device, the other end of the 26th resistance is controlled as the primary of this grade The first input end of circuit processed, the normal phase input end of the 4th voltage comparator by the 27th resistance with compare voltage and be connected, The outfan of tertiary voltage comparator is connected by the 28th resistance with the base stage of the 4th audion, the base stage of the 4th audion By the 30th resistance eutral grounding, the grounded emitter of the 4th audion, the emitter stage of the 4th audion by the first electric capacity with it is right The second input connection of the first stage drive circuit answered, the colelctor electrode of the 4th audion is connected with the grid of the second metal-oxide-semiconductor, and the 4th The colelctor electrode of audion is connected by the 31st resistance with the drain electrode of the second metal-oxide-semiconductor, and the source electrode of the second metal-oxide-semiconductor is first with corresponding Second input of stage drive circuit, the base stage of the 4th audion and the base stage of the 5th audion by the 29th resistance with The outfan connection of the 4th voltage comparator, the base stage of the 5th audion is by the 37th resistance and the source electrode of the 4th metal-oxide-semiconductor Connection, the grounded collector of the 5th audion and is connected, the source of the 3rd metal-oxide-semiconductor by the second electric capacity with the source electrode of the 3rd metal-oxide-semiconductor Pole is used to provide running voltage for the primary control comparison circuit of next stage, and the emitter stage of the 5th audion is electric by the 32nd Resistance is connected with the drain electrode of the 3rd metal-oxide-semiconductor, and the emitter stage of the 5th audion is connected with the grid of the 3rd metal-oxide-semiconductor, the leakage of the second metal-oxide-semiconductor The drain electrode of pole and the 3rd metal-oxide-semiconductor is connected with the source electrode of the 4th metal-oxide-semiconductor, and the drain electrode of the 4th metal-oxide-semiconductor is connected with the supply voltage, The first input end of this grade of primary control circuit passes sequentially through the 4th diode and the 34th resistance and the 6th audion Base stage connects, and the first input end of the primary control circuit of this grade passes sequentially through the 5th diode and the 35th resistance and the 6th The base stage connection of audion, the base stage of the 6th audion is by the 36th resistance eutral grounding, the grounded emitter of the 6th audion And be connected with the source electrode of the 4th metal-oxide-semiconductor by the 3rd electric capacity, the colelctor electrode of the 6th audion is connected with the grid of the 4th metal-oxide-semiconductor, The colelctor electrode of the 6th audion is connected by the 33rd resistance with the supply voltage；

The just stage drive circuit, including the 38th to the 42nd resistance, the 6th diode and the 7th audion, the seven or three The colelctor electrode of pole pipe is connected with one end of the 38th resistance, and the other end of the 38th resistance is used as the of first stage drive circuit Two inputs, the base stage of the 7th audion is connected by the 39th resistance with the negative electrode of the 6th diode, the 6th diode Anode as first stage drive circuit first input end, the base stage of the 7th audion by the 41st resistance eutral grounding, the six or two , by the 40th resistance eutral grounding, the emitter stage of the 7th audion is by the 42nd resistance eutral grounding, the seven or three pole for the anode of pole pipe The emitter stage of pipe connects with the control end of corresponding balancing circuitry.

8. balanced protection circuit as claimed in claim 2, it is characterised in that the final stage comparison circuit include the 43rd to 46th resistance, the 5th voltage comparator, the 6th voltage comparator, the 7th diode and the 8th diode, the 5th voltage ratio It is connected with N+1 reference voltages by the 44th resistance compared with the normal phase input end of device, the anti-phase input of the 5th voltage comparator End is connected by the 43rd resistance with the sampling battery voltage, and the inverting input of the 6th voltage comparator passes through the 40th Six resistance are connected with N+2 reference voltages, and the normal phase input end of the 6th voltage comparator is adopted by the 45th resistance with described Sample cell voltage connects, and the outfan of the 5th voltage comparator is connected with the anode of the 7th diode, the negative electrode of the 7th diode Corresponding input and the first input end connection of corresponding final driving circuit with final stage State- output circuit；6th is electric The outfan of pressure comparator is connected with the anode of the 8th diode, and the negative electrode of the 8th diode and the negative electrode of the 7th diode connect Connect.

9. balanced protection circuit as claimed in claim 8, it is characterised in that the final stage State- output circuit includes and lithium electricity The diode of quantity identical the 9th in pond and the 43rd resistance, the 8th audion and the 44th to the 45th resistance, Per one the 9th diode with corresponding 1 the 43rd resistant series formed a series arm, one end of each series arm with it is right The outfan connection of the final stage comparison circuit answered, the other end of each series arm is connected with the base stage of the 8th audion, and the 8th The base stage of audion is by the 45th resistance eutral grounding, the grounded emitter of the 8th audion and by the 4th electric capacity and the 5th The source electrode connection of metal-oxide-semiconductor, the source electrode of the 5th metal-oxide-semiconductor is connected with the second input of final driving circuit, the collection of the 8th audion Electrode is connected with the supply voltage by the 44th resistance and is connected with the drain electrode of the 5th metal-oxide-semiconductor, the 8th audion Colelctor electrode be connected with the grid of the 5th metal-oxide-semiconductor；

The final driving circuit, including the 48th to the 50th resistance, the tenth diode and the 9th audion, the 9th 3 pole The colelctor electrode of pipe is connected with one end of the 48th resistance, and the other end of the 48th resistance is used as the second of final driving circuit Input, the base stage of the 9th audion is connected by the 47th resistance with the negative electrode of the tenth diode, the sun of the tenth diode Used as the first input end of final driving circuit, the base stage of the 9th audion is by the 49th resistance eutral grounding, the 9th 2 pole for pole , by the 46th resistance eutral grounding, the emitter stage of the 9th audion is by the 50th resistance eutral grounding, the 9th audion for the anode of pipe The control end of emitter stage and corresponding balancing circuitry connect.