CN217307324U - Power battery charging circuit - Google Patents
Power battery charging circuit Download PDFInfo
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- CN217307324U CN217307324U CN202220911997.6U CN202220911997U CN217307324U CN 217307324 U CN217307324 U CN 217307324U CN 202220911997 U CN202220911997 U CN 202220911997U CN 217307324 U CN217307324 U CN 217307324U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
Abstract
The utility model discloses a power battery charging circuit, which comprises an AC/DC conversion module, a DC voltage reduction circuit, a controller and a charging/discharging switch, wherein the AC/DC conversion module is used for converting AC into DC; the direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and used for reducing the direct current into low-voltage direct current; the controller is connected with the direct current voltage reduction circuit to carry out voltage reduction control on the direct current voltage reduction circuit; and the charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack. Therefore, the lithium battery pack of the battery car can be charged by directly connecting the plug or the connecting wire with the commercial power alternating current, and the use of a power supply charger is reduced. Therefore, the situation that the lithium battery pack cannot be charged due to mismatching of the chargers and even burnt out is reduced.
Description
Technical Field
The utility model relates to a lithium battery protection technical field especially relates to a power battery charging circuit.
Background
The battery car is taken as a clean and pollution-free green travel tool, and is accepted and used by the consumers. The lithium ion battery pack has the advantages of light weight, long cycle life, good low-temperature discharge performance, strong cruising ability, short charging time, no influence on cycle life due to large-current discharge and the like, and is rapidly replacing the lead-acid battery pack to be used by the electric vehicle.
The existing power lithium battery pack is generally a split type in which a lithium battery pack is separated from a charger. The charging of the lithium battery pack generally adopts a matched charger to charge the lithium battery pack. Different types of lithium battery packs need to be charged by selecting a matched charger. When a non-matching charger is used to charge the lithium battery pack, the lithium battery pack may not be charged due to the non-matching of the charging voltages, or even burn out of the lithium battery pack.
In addition, the lithium battery is made of materials which determine that the lithium battery cannot be overcharged, overdischarged, overcurrent, short-circuited and charged and discharged at ultrahigh temperature, and once the lithium battery is short-circuited, the lithium battery is ignited if light and explodes if heavy. Lithium cell car among the prior art has therefore contained a plurality of lithium cell groups because the power demand is high, wherein when carrying out lithium cell group charging operation, charging current is great relatively usually, just so appears voltage and current too high easily, surpasss maximum working value to appear phenomena such as short circuit, excessive pressure overflow, and damage the components and parts of circuit, even catch fire or explosion. Therefore, effective measures need to be taken to quickly turn off when the lithium battery pack is abnormally charged by the commercial power alternating current.
SUMMERY OF THE UTILITY MODEL
The present invention aims at solving at least one of the technical problems in the related art to a certain extent. Therefore, an object of the present invention is to provide a power battery charging circuit.
In order to achieve the above object, according to the utility model discloses a power battery charging circuit, include:
the alternating current-direct current conversion module is used for converting alternating current into direct current;
the direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and is used for reducing the direct current into low-voltage direct current;
the controller is connected with the direct current voltage reduction circuit to perform voltage reduction control on the direct current voltage reduction circuit;
and the charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack.
Further, according to the utility model discloses an embodiment, direct current step-down circuit includes:
a drain of the MOS transistor Q1 is connected to the direct-current positive output end of the alternating-current/direct-current conversion module, and a gate of the MOS transistor Q1 is connected to the first control end of the controller;
a drain of the MOS transistor Q2 is connected with a source of the MOS transistor Q1, a source of the MOS transistor Q2 is connected with a direct current negative output end of the alternating current-direct current conversion module, and a gate of the MOS transistor Q2 is connected with a second control end of the controller;
an inductor L1, wherein one end of the inductor L1 is connected with the source electrode of the MOS transistor Q1, and the other end of the inductor L1 outputs the low-voltage direct current;
one end of the capacitor C2, one end of the capacitor C2 is connected to the other end of the inductor L1, and the other end of the capacitor C2 is connected to a direct current negative output end of the alternating current-direct current conversion module.
Further, according to the utility model discloses an embodiment, power battery charging circuit still includes: and the voltage detection circuit is respectively connected with the controller and the lithium battery pack so as to detect the charging voltage of the lithium battery pack.
Further, according to the utility model discloses an embodiment, voltage detection circuit includes:
a resistor R1, wherein one end of the resistor R1 is connected with the positive end of the lithium battery pack;
and one end of the resistor R2 is connected with the other end of the resistor R1, and the other end of the resistor R2 is connected with the negative end of the lithium battery pack.
Further, according to the utility model discloses an embodiment, charge and discharge switch includes:
a source electrode of the MOS transistor Q4 is connected with a negative end of the lithium battery pack, and a grid electrode of the MOS transistor Q4 is connected with a discharge control end of the controller;
the drain of the MOS tube Q3 is connected with the drain of the MOS tube Q4, and the source of the MOS tube Q3 is connected with the direct current negative output end of the alternating current-direct current conversion module.
Further, according to an embodiment of the present invention, the power battery charging circuit further includes a charging overcurrent protection circuit, and the charging overcurrent protection circuit is used for overcurrent protection of the charging circuit;
the charging overcurrent protection circuit includes:
the MOS tube Q4 is connected with the negative end of the lithium battery pack through the overcurrent detection resistor RS 1; one end of the over-current detection resistor RS1 is connected with the source electrode of the MOS transistor Q4, and the other end of the over-current detection resistor RS1 is connected with the negative end of the lithium battery pack;
an operational amplifier U4, wherein a non-inverting input terminal of the operational amplifier U4 is connected with the one end of the over-current detection resistor RS 1;
one end of the resistor R8 is connected with a power supply P +, and the other end of the resistor R8 is connected with the inverting input end of the operational amplifier U4;
a resistor R9, one end of the resistor R9 being connected to the other end of the resistor R8, the other end of the resistor R9 being connected to a reference ground;
a voltage regulator D6, wherein the cathode of the voltage regulator D6 is connected with the negative input end of the operational amplifier U4, and the voltage regulator D6 is connected with the reference ground;
a transistor Q8, a base of the transistor Q8 is connected to the output terminal of the operational amplifier U4, an emitter of the transistor Q8 is connected to the source of the MOS transistor Q3, a collector of the transistor Q8 is connected to a pull-up power source through a resistor R15, and a collector of the transistor Q8 is further connected to the gate of the MOS transistor Q3, so as to output a low-level signal to turn off the MOS transistor Q3 when a short circuit of the charging circuit is detected.
Further, according to an embodiment of the present invention, the power battery charging circuit further includes a discharging overcurrent protection circuit, and the discharging overcurrent protection circuit is used for overcurrent protection of the discharging loop;
the discharge overcurrent protection circuit includes:
an operational amplifier U3, wherein a non-inverting input terminal of the operational amplifier U3 is connected with the other terminal of the over-current detection resistor RS 1;
one end of the resistor R3 is connected with a power supply P +, and the other end of the resistor R3 is connected with the inverting input end of the operational amplifier U3;
a resistor R4, one end of the resistor R4 being connected to the other end of the resistor R3, the other end of the resistor R4 being connected to a reference ground;
a voltage regulator D1, wherein the cathode of the voltage regulator D1 is connected with the negative input end of the operational amplifier U3, and the voltage regulator D1 is connected with the reference ground;
a transistor Q5, a base of the transistor Q5 is connected to the output terminal of the operational amplifier U3, an emitter of the transistor Q5 is connected to the ground reference, a collector of the transistor Q5 is connected to a pull-up power source through a resistor R11, and a collector of the transistor Q5 is further connected to a gate of the MOS transistor Q4, so as to output a low level signal to turn off the MOS transistor Q4 when a short circuit occurs in a discharge loop.
Further, according to an embodiment of the present invention, the power battery charging circuit further includes an over-temperature protection circuit, and the over-temperature protection circuit is used for performing over-temperature protection on the charging and discharging circuit;
the over-temperature protection circuit includes:
the resistor R7, one end of the said resistor R7 is connected with power supply VT;
a thermistor RT1, one end of the thermistor RT1 is connected with the other end of the resistor R7, and the other end of the thermistor RT1 is connected with a reference ground;
an operational amplifier U2, wherein a non-inverting input terminal of the operational amplifier U2 is connected with the other terminal of the resistor R7;
one end of the resistor R5 is connected with a power supply P +, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2;
a resistor R6, one end of the resistor R6 being connected to the other end of the resistor R5, the other end of the resistor R6 being connected to a reference ground;
a voltage regulator D4, wherein the cathode of the voltage regulator D4 is connected with the negative input end of the operational amplifier U2, and the voltage regulator D4 is connected with the reference ground;
a transistor Q6, a base of the transistor Q6 is connected to the output terminal of the operational amplifier U2, an emitter of the transistor Q6 is connected to a ground reference, a collector of the transistor Q6 is connected to a pull-up power source through a resistor R12, and a collector of the transistor Q6 is further connected to a gate of the MOS transistor Q4 and/or a gate of the MOS transistor Q3, so as to output a low level signal to turn off the MOS transistor Q4 and/or the MOS transistor Q3 when an over-temperature is detected.
Further, according to the utility model discloses an embodiment, the excess temperature protection circuit still includes:
a diode D2, wherein the collector of the triode Q6 is connected with the gate of the MOS transistor Q3 through the diode D2; the cathode of the diode D3 is connected with the collector of the triode Q6, and the anode of the diode D2 is connected with the gate of the MOS transistor Q3;
a diode D3, wherein the collector of the triode Q6 is connected with the gate of the MOS transistor Q4 through the diode D3; the cathode of the diode D3 is connected to the collector of the transistor Q6, and the anode of the diode D3 is connected to the gate of the MOS transistor Q4.
The embodiment of the utility model provides a power battery charging circuit is used for converting alternating current into direct current through the alternating current-direct current conversion module; the direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and used for reducing the direct current into low-voltage direct current; the controller is connected with the direct current voltage reduction circuit to perform voltage reduction control on the direct current voltage reduction circuit; and the charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack. Therefore, the lithium battery pack of the battery car can be charged by directly connecting the plug or the connecting wire with the commercial power alternating current, and the use of a power supply charger is reduced. Therefore, the situation that the lithium battery pack cannot be charged due to mismatching of the chargers and even burnt out is reduced.
Drawings
Fig. 1 is a block diagram of a charging circuit of a power battery according to an embodiment of the present invention;
fig. 2 is a charging circuit diagram of the power battery provided by the embodiment of the present invention.
Reference numerals are as follows:
the purpose of the present invention is to provide a portable electronic device, which can be easily and conveniently operated.
Detailed Description
In order to make the technical field person understand the scheme of the present invention better, the technical scheme in the embodiment of the present invention will be clearly and completely described below with reference to the attached drawings in the embodiment of the present invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
Referring to fig. 1 and 2, the utility model provides a power battery charging circuit, include: the alternating current-direct current conversion module is used for converting alternating current into direct current; as shown in fig. 1 and 2, the ac-dc conversion module converts the commercial power into high-voltage dc power. Therefore, the lithium battery can be conveniently charged and is connected to 220V mains supply alternating current through the connector.
The direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and is used for reducing the direct current into low-voltage direct current; because the rectification output power supply voltage of the alternating-current-direct-current conversion module is high-voltage direct current, the high-voltage direct current generally cannot directly charge the lithium battery pack, and the direct-current voltage reduction circuit can convert the high-voltage direct current into adaptive voltage direct current so as to charge the lithium battery pack.
The controller is connected with the direct current voltage reduction circuit to perform voltage reduction control on the direct current voltage reduction circuit; the controller outputs a PWM pulse width signal to the direct current voltage reduction circuit to realize modulation control on the direct current voltage reduction circuit, and the high-voltage direct current can be reduced to a set value by modulating the duty ratio of the PWM pulse width signal, so that the lithium battery pack is charged.
The charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack. The charge and discharge switch is arranged on the lithium battery pack slave charge and discharge loop. And the charge and discharge switch is switched on or off under the control of the controller. Thereby controlling the charging of the lithium battery pack. Therefore, the lithium battery protection circuit is directly connected with the mains supply alternating current through the plug or the connecting wire, so that the lithium battery pack of the battery car can be charged, and the use of a power supply charger is reduced. Therefore, the situation that the lithium battery pack cannot be charged due to mismatching of the charger and even burnt out is reduced.
The embodiment of the utility model provides a power battery charging circuit is used for converting alternating current into direct current through the alternating current-direct current conversion module; the direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and used for reducing the direct current into low-voltage direct current; the controller is connected with the direct current voltage reduction circuit to carry out voltage reduction control on the direct current voltage reduction circuit; and the charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack. Therefore, the lithium battery pack of the battery car can be charged by directly connecting the plug or the connecting wire with the commercial power alternating current, and the use of a power supply charger is reduced. Therefore, the situation that the lithium battery pack cannot be charged due to mismatching of the charger and even burnt out is reduced.
The direct current step-down circuit includes: the controller comprises a MOS tube Q1, a MOS tube Q2, an inductor L1 and a capacitor C2, wherein the drain electrode of the MOS tube Q1 is connected with the direct current positive output end of the alternating current-direct current conversion module, and the grid electrode of the MOS tube Q1 is connected with the first control end of the controller; the drain of the MOS transistor Q2 is connected to the source of the MOS transistor Q1, the source of the MOS transistor Q2 is connected to the dc negative output terminal of the ac-dc conversion module, and the gate of the MOS transistor Q2 is connected to the second control terminal of the controller; one end of the inductor L1 is connected with the source electrode of the MOS transistor Q1, and the other end of the inductor L1 outputs the low-voltage direct current; one end of the capacitor C2 is connected to the other end of the inductor L1, and the other end of the capacitor C2 is connected to the dc negative output terminal of the ac-dc conversion module.
As shown in fig. 2, a voltage reduction circuit is formed among the MOS transistor Q1, the MOS transistor Q2, the inductor L1 and the capacitor C2, so as to reduce the voltage of the input high-voltage direct-current power supply and output the high-voltage direct-current power supply. The working process is as follows: the controller outputs a PWM control signal to the grid of the MOS tube Q1, the frequency and the duty ratio of the PWM control signal are determined by the height of input voltage, when the PWM control signal is at a high level, the MOS tube Q8 is conducted, when the PWM control signal is at a low level, the MOS tube Q1 is closed, and by controlling the size of the duty ratio of the PWM control signal, the power supply circuit reduces the voltage of the input voltage to obtain preset voltage. The specific process is as follows: when the PWM control signal is at a high level, the MOS transistor Q1 is switched on, the MOS transistor Q2 is controlled to be switched off, and the switch circuit charges and stores energy for the inductor L1; when the PWM control signal is at low level, the MOS transistor Q1 is turned off, and at the same time, the MOS transistor Q2 is controlled to be turned on, the stored energy in the inductor L1 charges the capacitor C2, and the cross conduction and the cross cut-off of the MOS transistor Q1 and the MOS transistor Q2 are repeatedly controlled in the step-down control. Thus, the step-down output of the input power supply is realized.
The power battery charging circuit further comprises: and the voltage detection circuit is respectively connected with the controller and the lithium battery pack so as to detect the charging voltage of the lithium battery pack.
The voltage detection circuit includes: the resistor R1 and the resistor R2, one end of the resistor R1 is connected with the positive end of the lithium battery pack; one end of the resistor R2 is connected with the other end of the resistor R1, and the other end of the resistor R2 is connected with the negative end of the lithium battery pack.
As shown in fig. 2, the resistor R1 and the resistor R2 constitute a series circuit. Can carry out the step-down output power supply after dividing the voltage, export extremely the controller, the voltage value of the output power supply of step-down module can be obtained through reading the voltage at resistance R2 both ends to the controller, through feedback voltage value, adjustable PWM pulse width duty cycle guarantees that output voltage is stable voltage value. The voltage sampling circuit is low in cost.
The charge and discharge switch includes: the MOS tube Q4 and the MOS tube Q3, the source electrode of the MOS tube Q4 is connected with the negative end of the lithium battery pack, and the grid electrode of the MOS tube Q4 is connected with the discharge control end of the controller; the MOS transistor Q4 can be switched on or off under the control of the controller. So as to protect and control the discharge of the lithium battery pack.
The drain electrode of the MOS transistor Q3 is connected with the drain electrode of the MOS transistor Q4, and the source electrode of the MOS transistor Q3 is connected with the direct current negative output end of the alternating current-direct current conversion module. The MOS transistor Q3 can be switched on or off under the control of the controller. So as to carry out protection control on the charging of the lithium battery pack.
The power battery charging circuit also comprises a charging overcurrent protection circuit, and the charging overcurrent protection circuit is used for overcurrent protection of the charging circuit; as shown in fig. 2, the charging overcurrent protection circuit includes: the over-current detection circuit comprises an over-current detection resistor RS1, an operational amplifier U4, a resistor R8, a resistor R9, a voltage stabilizer D6 and a triode Q8, wherein the MOS tube Q4 is connected with the negative end of the lithium battery pack through the over-current detection resistor RS 1; one end of the over-current detection resistor RS1 is connected with the source electrode of the MOS transistor Q4, and the other end of the over-current detection resistor RS1 is connected with the negative end of the lithium battery pack; a positive phase input end of the operational amplifier U4 is connected with the one end of the over-current detection resistor RS 1; one end of the resistor R8 is connected with a power supply P +, and the other end of the resistor R8 is connected with the inverting input end of the operational amplifier U4; one end of the resistor R9 is connected with the other end of the resistor R8, and the other end of the resistor R9 is connected with the reference ground; the cathode of the voltage stabilizer D6 is connected with the negative input end of the operational amplifier U4, and the voltage stabilizer D6 is connected with the reference ground; the base electrode of the triode Q8 is connected with the output end of the operational amplifier U4, the emitter electrode of the triode Q8 is connected with the source electrode of the MOS tube Q3, the collector electrode of the triode Q8 is connected with a pull-up power source through a resistor R15, and the collector electrode of the triode Q8 is further connected with the gate electrode of the MOS tube Q3, so that when a short circuit of a charging loop is detected, a low-level signal is output, and the MOS tube Q3 is cut off.
The overcurrent detection resistor RS1, the operational amplifier U4, the resistor R8, the resistor R9, the voltage stabilizer D6 and the triode Q8 form a charging overcurrent protection circuit, and when a charging loop generates overcurrent, the voltage at two ends of the overcurrent detection resistor RS1 is increased. The voltage of the over-current detection resistor RS1 can be detected through the CI signal end and is output to the non-inverting input end of the operational amplifier U4, and the inverting input end of the operational amplifier U4 generates a reference voltage through the resistor R9 and the voltage regulator D5. When the voltage value of the non-inverting input terminal of the operational amplifier U4 is greater than the voltage value of the inverting input terminal, the operational amplifier U4 outputs a high level signal to the base of the transistor Q8. Causing transistor Q8 to conduct. The collector of the transistor Q8 outputs a low CO. This level turns off the charge switch CO. Thereby achieving the closing of the charging loop.
The power battery charging circuit also comprises a discharge overcurrent protection circuit, and the discharge overcurrent protection circuit is used for overcurrent protection of a discharge loop; as shown in fig. 2, the discharge overcurrent protection circuit includes: an operational amplifier U3, a resistor R3, a resistor R4, a voltage stabilizer D1 and a triode Q5, wherein a positive phase input end of the operational amplifier U3 is connected with the other end of the over-current detection resistor RS 1; one end of the resistor R3 is connected with a power supply P +, and the other end of the resistor R3 is connected with the inverting input end of the operational amplifier U3; one end of the resistor R4 is connected with the other end of the resistor R3, and the other end of the resistor R4 is connected with the reference ground; the cathode of the voltage stabilizer D1 is connected with the negative input end of the operational amplifier U3, and the voltage stabilizer D1 is connected with the reference ground; the base electrode of the triode Q5 is connected with the output end of the operational amplifier U3, the emitter electrode of the triode Q5 is connected with the reference ground, the collector electrode of the triode Q5 is connected with a pull-up power source through a resistor R11, and the collector electrode of the triode Q5 is further connected with the grid electrode of the MOS tube Q4, so that when a discharge loop is short-circuited, a low-level signal is output, and the MOS tube Q4 is cut off. The circuit structure of the discharging loop is basically the same as that of the charging loop, and the working process is also basically the same, which is not repeated.
The power battery charging circuit further comprises an over-temperature protection circuit, and the over-temperature protection circuit is used for performing over-temperature protection on the charging and discharging loop; as shown in fig. 2, the over-temperature protection circuit includes: the circuit comprises a resistor R7, a thermistor RT1, an operational amplifier U2, a resistor R5, a resistor R6, a voltage stabilizer D4 and a triode Q6, wherein one end of the resistor R7 is connected with a power supply VT; one end of the thermistor RT1 is connected with the other end of the resistor R7, and the other end of the thermistor RT1 is connected with a reference ground; by the resistor R15 and the thermistor RT1 forming a series circuit, the voltage value of the thermistor RT1 can be changed correspondingly according to the change of the temperature. So that the divided voltage by the thermistor RT1 is also different. When the voltage of the charge-discharge loop reaches a set height value, the parameter at one end of the thermistor RT1 generates higher voltage, and whether the temperature is over-temperature can be judged by detecting whether the voltage reaches a set value.
The non-inverting input end of the operational amplifier U2 is connected with the other end of the resistor R7; one end of the resistor R5 is connected with a power supply P +, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2; one end of the resistor R6 is connected with the other end of the resistor R5, and the other end of the resistor R6 is connected with the reference ground; the cathode of the voltage stabilizer D4 is connected with the negative input end of the operational amplifier U2, and the voltage stabilizer D4 is connected with the reference ground; the base electrode of the triode Q6 is connected with the output end of the operational amplifier U2, the emitter electrode of the triode Q6 is connected with the reference ground, the collector electrode of the triode Q6 is connected with a pull-up power supply through a resistor R12, and the collector electrode of the triode Q6 is further connected with the grid electrode of the MOS tube Q4 and/or the grid electrode of the MOS tube Q3, so that when the over-temperature is detected, a low-level signal is output, and the MOS tube Q4 or the MOS tube Q3 is controlled to be cut off. The circuit structure of the over-temperature protection is basically the same as that of the charging loop, except that the input of the operational amplifier U2 is changed into the voltage of the thermistor RT1 due to the voltage of the over-current detection resistor RS 1.
The working process is basically the same, and repeated description is omitted again.
The over-temperature protection circuit further includes: a diode D2 and a diode D3, wherein the collector of the triode Q6 is connected with the gate of the MOS transistor Q3 through the diode D2; the cathode of the diode D3 is connected with the collector of the triode Q6, and the anode of the diode D2 is connected with the gate of the MOS transistor Q3; the collector of the triode Q6 is connected with the gate of the MOS transistor Q4 through the diode D3; the cathode of the diode D3 is connected to the collector of the transistor Q6, and the anode of the diode D3 is connected to the gate of the MOS transistor Q4. As shown in fig. 2, the diode D2 and the diode D3 have unidirectional conductivity. The over-temperature protection signal generated by the temperature protection circuit can be transmitted to the MOS transistor Q4 and the MOS transistor Q3, so that the cut-off control of charging and discharging can be realized. And at the same time, mutual interference between the charge cut-off signal and the discharge cut-off signal can be avoided.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing detailed description, or equivalent replacements may be made for some of the technical features of the embodiments. All utilize the equivalent structure that the content of the utility model discloses a specification and attached drawing was done, direct or indirect application is in other relevant technical field, all is in the same way the utility model discloses within the patent protection scope.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the principles and spirit of the present invention.
Claims (9)
1. A power battery charging circuit, comprising:
the alternating current-direct current conversion module is used for converting alternating current into direct current;
the direct current voltage reduction circuit is connected with the alternating current-direct current conversion module and is used for reducing the direct current into low-voltage direct current;
the controller is connected with the direct current voltage reduction circuit to perform voltage reduction control on the direct current voltage reduction circuit;
and the charge and discharge switch is connected with the controller so as to control the output of the low-voltage direct current under the action of the controller, and charge the lithium battery pack or control the discharge of the lithium battery pack.
2. The power battery charging circuit of claim 1, wherein the dc voltage reduction circuit comprises:
a drain of the MOS transistor Q1 is connected to the direct-current positive output end of the alternating-current/direct-current conversion module, and a gate of the MOS transistor Q1 is connected to the first control end of the controller;
a drain of the MOS transistor Q2 is connected with a source of the MOS transistor Q1, a source of the MOS transistor Q2 is connected with a direct current negative output end of the alternating current-direct current conversion module, and a gate of the MOS transistor Q2 is connected with a second control end of the controller;
an inductor L1, one end of the inductor L1 is connected with the source electrode of the MOS transistor Q1, and the other end of the inductor L1 outputs the low-voltage direct current;
one end of the capacitor C2 is connected to the other end of the inductor L1, and the other end of the capacitor C2 is connected to a direct-current negative output end of the alternating-current-direct-current conversion module.
3. The power battery charging circuit of claim 1, further comprising: and the voltage detection circuit is respectively connected with the controller and the lithium battery pack so as to detect the charging voltage of the lithium battery pack.
4. The power battery charging circuit of claim 3, wherein the voltage detection circuit comprises:
a resistor R1, wherein one end of the resistor R1 is connected with the positive end of the lithium battery pack;
and one end of the resistor R2 is connected with the other end of the resistor R1, and the other end of the resistor R2 is connected with the negative end of the lithium battery pack.
5. The power battery charging circuit of claim 1, wherein the charge and discharge switch comprises:
a source electrode of the MOS transistor Q4 is connected with a negative end of the lithium battery pack, and a grid electrode of the MOS transistor Q4 is connected with a discharge control end of the controller;
the drain of the MOS tube Q3 is connected with the drain of the MOS tube Q4, and the source of the MOS tube Q3 is connected with the direct current negative output end of the alternating current-direct current conversion module.
6. The power battery charging circuit according to claim 5, further comprising a charging overcurrent protection circuit, wherein the charging overcurrent protection circuit is used for overcurrent protection of the charging circuit;
the charging overcurrent protection circuit includes:
the MOS tube Q4 is connected with the negative end of the lithium battery pack through the overcurrent detection resistor RS 1; one end of the over-current detection resistor RS1 is connected with the source electrode of the MOS transistor Q4, and the other end of the over-current detection resistor RS1 is connected with the negative end of the lithium battery pack;
an operational amplifier U4, wherein a non-inverting input terminal of the operational amplifier U4 is connected with the one end of the over-current detection resistor RS 1;
one end of the resistor R8 is connected with a power supply P +, and the other end of the resistor R8 is connected with the inverting input end of the operational amplifier U4;
a resistor R9, one end of the resistor R9 being connected to the other end of the resistor R8, the other end of the resistor R9 being connected to a reference ground;
a voltage regulator D6, wherein the cathode of the voltage regulator D6 is connected with the negative input end of the operational amplifier U4, and the voltage regulator D6 is connected with the reference ground;
a transistor Q8, a base of the transistor Q8 is connected to the output terminal of the operational amplifier U4, an emitter of the transistor Q8 is connected to the source of the MOS transistor Q3, a collector of the transistor Q8 is connected to a pull-up power source through a resistor R15, and a collector of the transistor Q8 is further connected to the gate of the MOS transistor Q3, so as to output a low-level signal to turn off the MOS transistor Q3 when a short circuit of the charging circuit is detected.
7. The power battery charging circuit of claim 6, further comprising a discharge over-current protection circuit for over-current protection of a discharge loop;
the discharge overcurrent protection circuit includes:
an operational amplifier U3, wherein a non-inverting input terminal of the operational amplifier U3 is connected with the other terminal of the over-current detection resistor RS 1;
one end of the resistor R3 is connected with a power supply P +, and the other end of the resistor R3 is connected with the inverting input end of the operational amplifier U3;
a resistor R4, one end of the resistor R4 being connected to the other end of the resistor R3, the other end of the resistor R4 being connected to a reference ground;
a voltage regulator D1, wherein the cathode of the voltage regulator D1 is connected with the negative input end of the operational amplifier U3, and the voltage regulator D1 is connected with the reference ground;
a transistor Q5, a base of the transistor Q5 is connected to the output terminal of the operational amplifier U3, an emitter of the transistor Q5 is connected to the ground reference, a collector of the transistor Q5 is connected to a pull-up power source through a resistor R11, and a collector of the transistor Q5 is further connected to a gate of the MOS transistor Q4, so as to output a low level signal to turn off the MOS transistor Q4 when a short circuit occurs in a discharge loop.
8. The power battery charging circuit according to claim 5, further comprising an over-temperature protection circuit, wherein the over-temperature protection circuit is used for over-temperature protection of the charging and discharging circuit;
the over-temperature protection circuit includes:
a resistor R7, wherein one end of the resistor R7 is connected with a power supply VT;
a thermistor RT1, one end of the thermistor RT1 is connected with the other end of the resistor R7, and the other end of the thermistor RT1 is connected with a reference ground;
an operational amplifier U2, wherein a non-inverting input terminal of the operational amplifier U2 is connected with the other terminal of the resistor R7;
one end of the resistor R5 is connected with a power supply P +, and the other end of the resistor R5 is connected with the inverting input end of the operational amplifier U2;
a resistor R6, one end of the resistor R6 being connected to the other end of the resistor R5, the other end of the resistor R6 being connected to a reference ground;
a voltage regulator D4, wherein the cathode of the voltage regulator D4 is connected with the negative input end of the operational amplifier U2, and the voltage regulator D4 is connected with the reference ground;
a triode Q6, wherein the base of the triode Q6 is connected with the output end of the operational amplifier U2, the emitter of the triode Q6 is connected with the reference ground, the collector of the triode Q6 is connected with a pull-up power source through a resistor R12, and the collector of the triode Q6 is also connected with the gate of the MOS tube Q4 and/or the gate of the MOS tube Q3, so that when the over-temperature is detected, a low-level signal is output, and the MOS tube Q4/or the MOS tube Q3 is cut off and controlled.
9. The power battery charging circuit of claim 8, wherein the over-temperature protection circuit further comprises:
a diode D2, wherein the collector of the triode Q6 is connected with the gate of the MOS transistor Q3 through the diode D2; the cathode of the diode D3 is connected with the collector of the triode Q6, and the anode of the diode D2 is connected with the gate of the MOS transistor Q3;
a diode D3, wherein the collector of the triode Q6 is connected with the gate of the MOS transistor Q4 through the diode D3; the cathode of the diode D3 is connected to the collector of the transistor Q6, and the anode of the diode D3 is connected to the gate of the MOS transistor Q4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220911997.6U CN217307324U (en) | 2022-04-19 | 2022-04-19 | Power battery charging circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220911997.6U CN217307324U (en) | 2022-04-19 | 2022-04-19 | Power battery charging circuit |
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| Publication Number | Publication Date |
|---|---|
| CN217307324U true CN217307324U (en) | 2022-08-26 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220911997.6U Active CN217307324U (en) | 2022-04-19 | 2022-04-19 | Power battery charging circuit |
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| Country | Link |
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| CN (1) | CN217307324U (en) |
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