CN103199505A - Output short-circuit protection circuit for high tension battery - Google Patents
Output short-circuit protection circuit for high tension battery Download PDFInfo
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- CN103199505A CN103199505A CN2013101582062A CN201310158206A CN103199505A CN 103199505 A CN103199505 A CN 103199505A CN 2013101582062 A CN2013101582062 A CN 2013101582062A CN 201310158206 A CN201310158206 A CN 201310158206A CN 103199505 A CN103199505 A CN 103199505A
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Abstract
The invention relates to an output short-circuit protection circuit for a high tension battery. The output short-circuit protection circuit structurally comprises a detection control circuit, a switch circuit, a choke circuit, a load capacity match circuit and a switch buffer circuit. According to the output short-circuit protection circuit, the voltage of the load capacity match circuit or the choke circuit is detected by the detection control circuit, after the output short circuit is confirmed, the switch circuit is controlled to be switched off rapidly; after the switch buffer circuit is arranged, the switch circuit realizes the zero-voltage switching on and off, so that the energy impact and the voltage impact to the switch circuit can be reduced; and therefore, the switch circuit can be safely switched on and off. The short-circuit current is limited by the choke circuit, so that the energy impact to the battery and the switch circuit can be reduced. After the short-circuit fault is eliminated, the switch is controlled to be switched on by detecting the voltage condition of the detection control circuit, so that the battery can be reset to normally supply power.
Description
Technical field
The present invention relates to a kind of power supply protection circuit, specifically a kind of high-tension battery group output short circuit protection circuit.
Background technology
Along with development of science and technology, the application of battery pack more and more widely, so the requirement of its security performance is also correspondingly improved the Vehicular dynamic battery group that especially capacity is big and voltage is high.The battery pack output short-circuit namely causes the output positive and negative electrode of battery pack to interconnect under the very little situation of resistance for a certain reason.This short circuit meeting produces excessive electric current and too much heat, causes the life-span of battery pack to be badly damaged.Because short circuit produces too much heat, causes it to produce the high temperature that is enough to melt common metal before opening circuit, easily cause electrical equipment to burn out generation with fire incident, make people's security of the lives and property be subjected to very big threat.Battery pack generation output short-circuit also can produce huge adverse effect to the security performance of battery pack.
At present, the common method of battery pack output short circuit protection is: the rapid increase with loop current is foundation and the condition that short circuit is judged, after testing circuit detects the short circuit generation, disconnects output loop by control circuit control switch element.Because switching circuit, testing circuit and control circuit have certain delay time; in this section delay time; loop current also can increase rapidly; switching circuit must bear very big short circuit current; and the energy that these short circuit currents produce; be easy to cause the damage of switching circuit, cause battery pack to lose protection then.Energy computing formula (Q=U according to the short circuit generation
2T/R) as can be known, square being directly proportional of this energy and battery pack output voltage, and these energy all will converge on the switching circuit, and the energy that switching circuit can bear is limited, and when the output voltage of battery pack had only tens of volt, switching circuit commonly used can bear reluctantly, but, when the output voltage of battery pack reaches up to a hundred even during a few hectovolt, the energy that short circuit produces can jumbo increase, and switching circuit commonly used just is difficult to bear.So the selection of switching circuit components and parts is very stubborn problems.
If 1 adopts mechanical switch, can be because mechanical switch disconnects action very slow (time is Millisecond), the big electric current that produces can burn out the contact, cause after the short circuit can not cutoff circuit serious consequence.
If 2 adopt electronic switch, though it is fast to disconnect action, energy and voltage that electronic switch bears are limited, are easy to cause power disruption or over-voltage breakdown, thereby can not cutoff circuit.
If 3 adopt the fusible safe silk, can finish short-circuit protection, but the fusible safe silk is disposable use, after short trouble solved, circuit can not recover automatically, needs could devote oneself to work again behind the new fuse of dismounting and change.
The short circuit current that the loop produces during short circuit is considerably beyond the specified ability to bear of battery pack and switch element; so in existing protective circuit technology; namely enable by switching circuit battery pack to be protected the injury that to avoid short circuit current that battery pack and switching circuit are caused.And short circuit injury also can accumulate, thereby causes degradation failure and the reduction in battery pack life-span of switching circuit.
The short circuit of existing protective circuit judges it is to surpass a certain numerical value as criterion according to current in loop, and in general, this value is much larger than the load current value of battery pack output.After short-circuit condition was detected, the control switch circuit disconnected output loop.Owing to detect the time-delay of control circuit, add the time-delay of switching circuit, in this process, loop current can further increase rapidly, rated value considerably beyond battery pack and switching circuit, so must bear very powerful short circuit current and energy when switching circuit cuts out, make switching circuit be easy to emergent power or withstand voltage damage thus.In order to reduce the stress of switching circuit, need to reduce the judgment value of short circuit current, accelerate to detect the speed of control circuit and switching circuit.Take this measure can not guarantee that still switch element is not damaged, but also can bring new problem.
The moment that adds capacitive load can be triggered short-circuit protection, because capacitive load powered on moment loop current is very big, is similar to short circuit current, so during battery pack band capacitive load, trigger short-circuit protection easily, battery electric quantity is normally exported.Add capacitive load and real short circuit, in available circuit, can't accurately distinguish.
Summary of the invention
Purpose of the present invention just provides a kind of high-tension battery group output short circuit protection circuit, and existing high-tension battery group output short circuit protection circuit switching circuit shutoff stress is big, short circuit current big and connect the problem that capacitive load easily causes the mistake protection to solve.
The present invention is achieved in that a kind of high-tension battery group output short circuit protection circuit, includes:
Detect control circuit, be connected in parallel between the positive pole and negative pole of high-tension battery group, join with switching circuit, choke circuit and load capacity match circuit respectively, for detection of the voltage of switching circuit, choke circuit and load capacity match circuit, and control the keying of described switching circuit according to testing result;
Switching circuit, be connected in series on the line between the cathode output end of the negative pole end of high-tension battery group and above-mentioned protective circuit, or be connected in series on the line between the cathode output end of the positive terminal of high-tension battery group and above-mentioned protective circuit, join with described detection control circuit, choke circuit and switch buffer circuit respectively, be used for the power supply output of high-tension battery group is opened and closed operation;
The switch buffer circuit is connected in the both sides of described switching circuit in parallel, is used for reducing when described switching circuit cuts out loss and the voltage peak of described switching circuit, makes described switching circuit be in the safety operation area;
Choke circuit joins with described detection control circuit, described switching circuit and load capacity match circuit respectively, for detection of the output short-circuit situation of high-tension battery group, and stops the fast rise of loop current when output short-circuit takes place;
The load capacity match circuit is arranged between the cathode output end and cathode output end of above-mentioned protective circuit, is used for the matched load capacity, reduces the voltage variety of described choke circuit in the moment of connecting load, and filtering is carried out in output to power supply.
Described switching circuit is metal-oxide-semiconductor Q1, negative pole end and the described detection control circuit of the source electrode tap high-tension battery group of described metal-oxide-semiconductor Q1, and the drain electrode of described metal-oxide-semiconductor Q1 and described choke circuit join, and the grid of described metal-oxide-semiconductor Q1 and described detection control circuit join.
Described switch buffer circuit is to be parallel to the source electrode of described metal-oxide-semiconductor Q1 and the shunt capacitance C1 between the drain electrode.
Described choke circuit comprises choke induction L1 and sustained diode 1; Source electrode and the described detection control circuit of the described metal-oxide-semiconductor Q1 of an end tap of described choke induction L1, the other end of described choke induction L1 and the cathode output end of above-mentioned protective circuit join; The anode of described sustained diode 1 joins with an end and the described detection control circuit of choke induction L1 respectively, and the negative electrode of described sustained diode 1 is connected on the cathode output end or cathode output end of above-mentioned protective circuit.
Described load capacity match circuit is to be connected capacitor C 2 between the cathode output end of above-mentioned protective circuit and the cathode output end, and the inductance value of the capacitance of described capacitor C 2 and described choke induction L1 is complementary.
Protective circuit of the present invention is to detect the voltage of load capacity match circuit or choke circuit as the short circuit basis for estimation; be different from traditional detection loop current as the working method of short circuit basis for estimation; after determining that output short-circuit takes place, the control switch circuit turn-offs rapidly.This detection speed to voltage can be avoided detecting the excessive situation of the long short circuit current that causes of time-delay and take place faster than current detecting speed.And, in protective circuit, be provided with choke circuit, therefore, short circuit current can not rise rapidly.Behind definite battery pack generation output short-circuit, detection control circuit control switch circuit rapidly turn-offs; And realize that by the switch buffer circuit that is connected in parallel on the switching circuit two ends zero-pressure of switching circuit turn-offs, and reduced energy impact and voltge surge that switching circuit bears thus, make switching circuit can realize safe shutdown.Key of the present invention just is this.
Because the short circuit current of protective circuit of the present invention is less, can impact and damage switching circuit and battery pack.Can not produce build-up effect even take place after the repeatedly short circuit yet.After short trouble is eliminated, come control switch to open by the voltage condition that detects the control circuit sense switch, make battery pack recover normal power supply.
Between the cathode output end of protective circuit of the present invention and cathode output end, the load capacity match circuit is set, can makes the load of circuit region branch capacitive and true short circuit, avoid the circuit misoperation.
Protective circuit of the present invention is simple in structure, and protection speed is fast, and the withstand voltage and power of switching circuit is not had harsh requirement; reduced production cost; to not damage of switch element, the life-span of switching circuit was protected when short circuit was turn-offed, and the security performance of battery pack is significantly improved.
Description of drawings
Fig. 1 is schematic block circuit diagram of the present invention.
Fig. 2, Fig. 3 are the electrical schematic diagrams of two kinds of physical circuits of the present invention.
Among the figure: 1, detect control circuit, 2, switching circuit.3, choke circuit.4, switch buffer circuit, 5, the load capacity match circuit, 6, the N-channel MOS pipe, 7, shunt capacitance, 8, choke induction, 9, fly-wheel diode, 10, output capacitance.
Embodiment
As shown in Figure 1, the present invention includes parts such as detecting control circuit 1, switching circuit 2, choke circuit 3, switch buffer circuit 4 and load capacity match circuit 5.Its left end joins with positive terminal B+ and the negative pole end B – of high-tension battery group BT respectively; Its right-hand member is cathode output end P+ and the cathode output end P – of protective circuit of the present invention, also is the positive and negative electrode output that the high-tension battery group BT after the protective circuit of the present invention is set.
Detecting control circuit 1 is connected between the positive terminal B+ and negative pole end B – of high-tension battery group BT, and join with switching circuit 2, choke circuit 3 and load capacity match circuit 5 respectively, voltage for detection of switching circuit 2, choke circuit 3 and load capacity match circuit 5, and according to testing result to switching circuit 2 output control signals, the keying of control switch circuit 2.
Load capacity match circuit 5 is arranged between the cathode output end P+ and cathode output end P – of protective circuit of the present invention, is used for the matched load capacity, reduces the voltage variety of choke circuit 3 in the moment of connecting load, and filtering is carried out in output to power supply.
Embodiment 1:
As shown in Figure 2, the detection control circuit 1 in the present embodiment can adopt the existing conventional circuit; Switching circuit 2 is the metal-oxide-semiconductor Q1 of serial connection, the negative pole end B – of the source electrode tap high-tension battery group BT of metal-oxide-semiconductor Q1 and detection control circuit 1, and the drain electrode of metal-oxide-semiconductor Q1 and choke circuit 3 join, and the grid of metal-oxide-semiconductor Q1 joins with detection control circuit 1.Switching circuit 2 can be single metal-oxide-semiconductor or several metal-oxide-semiconductors in parallel, can be N-channel MOS pipe or P channel MOS tube, also can select the IGBT pipe for use.Switching circuit 2 also can be arranged between the cathode output end P+ of the positive terminal B+ of high-tension battery group BT and protective circuit of the present invention, the positive pole output of control battery pack.
Load capacity match circuit 5 is capacitor C 2 between the cathode output end P+ that is connected protective circuit of the present invention and the cathode output end P –; the inductance value of the capacitance of capacitor C 2 and choke induction L1 is complementary; be used in the moment of connecting load; reduce the voltage variety of choke circuit 3, and filtering is carried out in output to power supply.
In order to reduce the stress of switching circuit, can take to reduce the short circuit time of judging and the measure that reduces short circuit current.The present invention detects by the voltage that detects 1 pair of load capacity match circuit 5 of control circuit or choke induction L1, this detection speed to voltage is faster than current detecting speed commonly used, can avoid causing damage to each device in battery pack and the circuit because of unnecessary time delays.The growth rate of choke induction L1 limit circuit electric current can just reduce short circuit current.
Reduce voltage near 0 volt or choke induction L1 rapidly and become big when surpassing certain threshold value rapidly if detect voltage that control circuit 1 detects load capacity match circuit 5, namely determine to take place output short-circuit, control switch circuit 2 turn-offs rapidly.At this moment, switch buffer circuit 4 slowly rises the both end voltage of switching circuit 2, to reduce the energy impact that switching circuit 2 is born, makes switching circuit 2 energy safe shutdowns.
Have no progeny in switching circuit 2 passes, sustained diode 1 is choke induction L1 afterflow, and the energy of choke induction L1 can not impact to switching circuit 2.After short trouble is eliminated, whether revert to 0 by the voltage that detects control circuit 1 sense switch circuit 2, if revert to 0, then control switch circuit 2 is opened, and makes high-tension battery group BT recover normal power supply.
When high-tension battery group BT connects capacitive load, come to the capacitive load charging by the output capacitance C2 of load capacity match circuit 5, the voltage of choke circuit 3 can not exceed set point, does not do short circuit and handles.
Embodiment 2:
The basic structure of present embodiment is identical with embodiment's 1; just the negative electrode of the sustained diode 1 in the choke circuit 3 is connected on the cathode output end P – of protective circuit of the present invention; namely form the form that is connected in parallel with choke induction L1; for choke induction L1 provides a kind of minimum, the most direct earial drainage loop, in order to the energy among the quick release choke induction L1.
The operation principle of present embodiment is identical with embodiment's 1, and has identical short-circuit protection effect.
Claims (5)
1. a high-tension battery group output short circuit protection circuit is characterized in that, includes:
Detect control circuit, be connected in parallel between the positive pole and negative pole of high-tension battery group, join with switching circuit, choke circuit and load capacity match circuit respectively, for detection of the voltage of switching circuit, choke circuit and load capacity match circuit, and control the keying of described switching circuit according to testing result;
Switching circuit, be connected in series on the line between the cathode output end of the negative pole end of high-tension battery group and above-mentioned protective circuit, or be connected in series on the line between the cathode output end of the positive terminal of high-tension battery group and above-mentioned protective circuit, join with described detection control circuit, choke circuit and switch buffer circuit respectively, be used for the power supply output of high-tension battery group is opened and closed operation;
The switch buffer circuit is connected in the both sides of described switching circuit in parallel, is used for reducing when described switching circuit cuts out loss and the voltage peak of described switching circuit, makes described switching circuit be in the safety operation area;
Choke circuit joins with described detection control circuit, described switching circuit and load capacity match circuit respectively, for detection of the output short-circuit situation of high-tension battery group, and stops the fast rise of loop current when output short-circuit takes place;
The load capacity match circuit is arranged between the cathode output end and cathode output end of above-mentioned protective circuit, is used for the matched load capacity, reduces the voltage variety of described choke circuit in the moment of connecting load, and filtering is carried out in output to power supply.
2. high-tension battery group output short circuit protection circuit according to claim 1; it is characterized in that; described switching circuit is metal-oxide-semiconductor Q1; negative pole end and the described detection control circuit of the source electrode tap high-tension battery group of described metal-oxide-semiconductor Q1; the drain electrode of described metal-oxide-semiconductor Q1 and described choke circuit join, and the grid of described metal-oxide-semiconductor Q1 and described detection control circuit join.
3. high-tension battery group output short circuit protection circuit according to claim 2 is characterized in that, described switch buffer circuit is to be parallel to the source electrode of described metal-oxide-semiconductor Q1 and the shunt capacitance C1 between the drain electrode.
4. high-tension battery group output short circuit protection circuit according to claim 3 is characterized in that, described choke circuit comprises choke induction L1 and sustained diode 1; Source electrode and the described detection control circuit of the described metal-oxide-semiconductor Q1 of an end tap of described choke induction L1, the other end of described choke induction L1 and the cathode output end of above-mentioned protective circuit join; The anode of described sustained diode 1 joins with an end and the described detection control circuit of choke induction L1 respectively, and the negative electrode of described sustained diode 1 is connected on the cathode output end or cathode output end of above-mentioned protective circuit.
5. high-tension battery group output short circuit protection circuit according to claim 4; it is characterized in that; described load capacity match circuit is to be connected capacitor C 2 between the cathode output end of above-mentioned protective circuit and the cathode output end, and the inductance value of the capacitance of described capacitor C 2 and described choke induction L1 is complementary.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310158206.2A CN103199505B (en) | 2013-05-02 | 2013-05-02 | Output short-circuit protection circuit for high tension battery |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310158206.2A CN103199505B (en) | 2013-05-02 | 2013-05-02 | Output short-circuit protection circuit for high tension battery |
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| CN103199505A true CN103199505A (en) | 2013-07-10 |
| CN103199505B CN103199505B (en) | 2016-02-03 |
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| CN201310158206.2A Active CN103199505B (en) | 2013-05-02 | 2013-05-02 | Output short-circuit protection circuit for high tension battery |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103701101A (en) * | 2013-12-14 | 2014-04-02 | 苏州市博得立电源科技有限公司 | Circuit structure for improving short-circuit protection performance of large-sized battery pack by using capacitor |
| CN107703365A (en) * | 2016-08-08 | 2018-02-16 | 联合汽车电子有限公司 | Power inductance dynamic equivalent inductance value test system and its method of testing |
| CN109606113A (en) * | 2017-10-02 | 2019-04-12 | 罗伯特·博世有限公司 | Method for being provided protection against in the energy accumulator of vehicle |
| WO2020135356A1 (en) * | 2018-12-24 | 2020-07-02 | 宁德时代新能源科技股份有限公司 | Protection circuit and battery management system |
| CN112462163A (en) * | 2020-10-30 | 2021-03-09 | 广州汽车集团股份有限公司 | High-voltage interlocking loop fault detection method and device |
| CN112798909A (en) * | 2020-12-24 | 2021-05-14 | 深圳供电局有限公司 | Short circuit detection device and detection method |
| CN113629820A (en) * | 2021-09-02 | 2021-11-09 | 阳光储能技术有限公司 | Battery module, energy storage system and control method thereof |
| CN113765084A (en) * | 2021-09-10 | 2021-12-07 | 华为技术有限公司 | Power supply equipment, power supply system and server cabinet |
Families Citing this family (1)
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| TWI813055B (en) * | 2021-11-08 | 2023-08-21 | 啓碁科技股份有限公司 | Short circuit protection circuit, electronic device and operation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101632215A (en) * | 2007-02-16 | 2010-01-20 | 奥地利西门子公司 | Electronic security for a power supply |
| CN201708697U (en) * | 2010-05-31 | 2011-01-12 | 比亚迪股份有限公司 | Direct-current power source switching device |
| CN102381030A (en) * | 2010-08-25 | 2012-03-21 | 佳能株式会社 | Power supply device and recording apparatus including the device |
| JP2013078203A (en) * | 2011-09-30 | 2013-04-25 | Nec Computertechno Ltd | Power source failure detection circuit and power source failure detection method |
| CN203193261U (en) * | 2013-05-02 | 2013-09-11 | 石家庄迅能电子科技有限公司 | Protection circuit for output short circuit of high-voltage battery pack |
-
2013
- 2013-05-02 CN CN201310158206.2A patent/CN103199505B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101632215A (en) * | 2007-02-16 | 2010-01-20 | 奥地利西门子公司 | Electronic security for a power supply |
| CN201708697U (en) * | 2010-05-31 | 2011-01-12 | 比亚迪股份有限公司 | Direct-current power source switching device |
| CN102381030A (en) * | 2010-08-25 | 2012-03-21 | 佳能株式会社 | Power supply device and recording apparatus including the device |
| JP2013078203A (en) * | 2011-09-30 | 2013-04-25 | Nec Computertechno Ltd | Power source failure detection circuit and power source failure detection method |
| CN203193261U (en) * | 2013-05-02 | 2013-09-11 | 石家庄迅能电子科技有限公司 | Protection circuit for output short circuit of high-voltage battery pack |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103701101A (en) * | 2013-12-14 | 2014-04-02 | 苏州市博得立电源科技有限公司 | Circuit structure for improving short-circuit protection performance of large-sized battery pack by using capacitor |
| CN107703365A (en) * | 2016-08-08 | 2018-02-16 | 联合汽车电子有限公司 | Power inductance dynamic equivalent inductance value test system and its method of testing |
| CN109606113A (en) * | 2017-10-02 | 2019-04-12 | 罗伯特·博世有限公司 | Method for being provided protection against in the energy accumulator of vehicle |
| WO2020135356A1 (en) * | 2018-12-24 | 2020-07-02 | 宁德时代新能源科技股份有限公司 | Protection circuit and battery management system |
| US11962174B2 (en) | 2018-12-24 | 2024-04-16 | Contemporary Amperex Technology Co., Limited | Protection circuit and battery management system |
| CN112462163A (en) * | 2020-10-30 | 2021-03-09 | 广州汽车集团股份有限公司 | High-voltage interlocking loop fault detection method and device |
| CN112798909A (en) * | 2020-12-24 | 2021-05-14 | 深圳供电局有限公司 | Short circuit detection device and detection method |
| CN113629820A (en) * | 2021-09-02 | 2021-11-09 | 阳光储能技术有限公司 | Battery module, energy storage system and control method thereof |
| CN113765084A (en) * | 2021-09-10 | 2021-12-07 | 华为技术有限公司 | Power supply equipment, power supply system and server cabinet |
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| CN103199505B (en) | 2016-02-03 |
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