A charging control circuit for a charging pile

Abstract

The present invention discloses a charging control circuit for a charging pile, which relates to the field of charging. The charging control circuit for the charging pile includes: a voltage conversion module, which is used to convert mains alternating current into direct current as the supply voltage and supply it to a constant current supply module and a constant voltage supply module; a constant current supply module, which is used to provide a constant current for a battery charging module to charge the battery in the constant current charging mode; Compared with the prior art, the beneficial effects of the present invention are as follows: The battery charging module provided by the present invention charges the super capacitor while charging the battery in the constant voltage charging stage. When the battery is about to be fully charged, the power supply circuit of the mains is disconnected. Under the condition of reducing resistance, the super capacitor charges the battery to full power until the battery is completely full. At the same time, it also serves as a power supply in the trickle charging mode after the battery is full. While ensuring the charging of the battery, the power consumption time of the mains is reduced and the charge is less.

Description

Technical Field

[0001] The present invention relates to the field of charging, and specifically to a charging control circuit for a charging pile. Background Art

[0002] When charging an electric vehicle, it is usually not simply using a constant voltage or constant current charging method, but rather combining multiple methods such as constant current charging, constant voltage charging, and trickle charging according to different charging stages. Constant current charging is used in the initial stage, constant voltage charging is used in the middle stage until the battery is fully charged, and trickle charging is used after being fully charged.

[0003] During constant voltage charging, as the battery voltage rises, the charging speed will slow down, resulting in a longer time for the battery to be fully charged. Since the charging pile charges based on the charging time, it leads to more charges, which needs to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a charging control circuit for a charging pile to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A charging control circuit for a charging pile, comprising:

[0007] A voltage conversion module for converting mains alternating current into direct current as the supply voltage to supply the constant current supply module and the constant voltage supply module;

[0008] A constant current supply module for providing a constant current to the battery charging module for charging the battery in the constant current charging mode;

[0009] A constant voltage supply module for providing a constant voltage to the battery charging module for charging the battery in the constant voltage charging mode;

[0010] A battery charging module for charging the battery; in the constant voltage charging mode, detecting the current flowing through the battery, maintaining the impedance of the battery charging circuit when the current flowing through the battery exceeds the set threshold, reducing the impedance of the battery charging circuit when the current flowing through the battery is less than the set threshold, and disconnecting the mains alternating current, and continuing to supply power to the battery by the super capacitor;

[0011] A charging mode control module for controlling the operation of the constant voltage supply module or the constant current supply module based on the battery voltage magnitude;

[0012] The output terminal of the voltage conversion module is connected to the first input terminal of the constant-current power supply module and the first input terminal of the constant-voltage power supply module. The output terminal of the constant-current power supply module is connected to the first input terminal of the battery charging module (common point E). The output terminal of the constant-voltage power supply module is connected to the second input terminal of the battery charging module (common point D). The output terminal of the battery charging module is connected to the input terminal of the charging mode control module (common point C). The output terminal of the charging mode control module is connected to the second input terminal of the constant-voltage power supply module and the second input terminal of the constant-current power supply module (the relay controls the corresponding switch).

[0013] As a further solution of the present invention: The constant-current power supply module includes a second chip, the model of the second chip is MIC5158. The 5th pin of the second chip is grounded through a fifth capacitor. The 6th pin of the second chip is connected to the 7th pin of the second chip through a fourth capacitor. The 8th pin of the second chip is connected to the 9th pin of the second chip through a third capacitor. The 10th pin of the second chip is connected to the supply voltage and one end of a second switch. The other end of the second switch is connected to one end of a first potentiometer. The other end of the first potentiometer is connected to one end of a second resistor. The other end of the second resistor is connected to the D pole of a first MOS transistor and the 12th pin of the second chip. The G pole of the first MOS transistor is connected to the 11th pin of the second chip. The S pole of the first MOS transistor is connected to the 13th pin of the second chip, one end of a third resistor, and the base of a third triode. The emitter of the third triode is connected to the common point E. The collector of the third triode is connected to the supply voltage through an eleventh resistor. The other end of the third resistor is connected to one end of a fourth resistor and the 1st pin of the second chip. The other end of the fourth resistor is grounded.

[0014] As a further solution of the present invention: The constant-voltage power supply module includes a first switch, a first capacitor, a second capacitor, a voltage regulator, a fourth triode, and a fifth resistor. One end of the first switch is connected to the supply voltage. The other end of the first switch is connected to one end of the first capacitor and the input terminal of the voltage regulator. The other end of the first capacitor is grounded. The ground terminal of the voltage regulator is grounded. The output terminal of the voltage regulator is connected to one end of the second capacitor and the base of the fourth triode. The other end of the second capacitor is grounded. The emitter of the fourth triode is connected to the common point D. The collector of the fourth triode is connected to the supply voltage through the fifth resistor.

[0015] As a further solution of the present invention: The battery charging module includes:

[0016] A battery charging unit for charging the battery;

[0017] A signal conversion unit for detecting the current flowing through the battery in the constant-voltage charging mode and converting it into a voltage signal for output to the loop impedance control unit;

[0018] A circuit impedance control unit is used to maintain the impedance of the battery power supply circuit when the voltage signal reaches the set threshold; when the voltage signal is less than the set threshold, reduce the impedance of the battery power supply circuit, disconnect the mains AC power, and continue to supply power to the battery by the supercapacitor;

[0019] The first input terminal of the battery charging unit is connected to the output terminal (common point E) of the constant current power supply module, the second input terminal of the battery charging unit is connected to the output terminal (common point D) of the constant voltage power supply module, the first output terminal of the battery charging unit is connected to the input terminal (common points A and B) of the signal conversion unit, the output terminal of the signal conversion unit is connected to the input terminal of the circuit impedance control unit, the output terminal of the circuit impedance control unit is connected to the third input terminal of the battery charging unit, and the second output terminal of the battery charging unit is connected to the input terminal (common point C) of the charging mode control module.

[0020] As a further solution of the present invention: the battery charging unit includes a first resistor, a first diode, a second diode, a battery, and a second MOS transistor. One end of the first resistor is connected to common point D, one end of the supercapacitor, the D pole of the second MOS transistor, and common point A. The other end of the first resistor is connected to the positive pole of the first diode, the S pole of the second MOS transistor, and common point B. The negative pole of the first diode is connected to the negative pole of the second diode, the positive pole of the battery, and common point C. The positive pole of the second diode is connected to common point E. The negative pole of the battery is grounded. The G pole of the second MOS transistor is connected to the output terminal of the circuit impedance control unit.

[0021] As a further solution of the present invention: the signal conversion unit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a sixth capacitor, and a third amplifier. One end of the sixth resistor is connected to common point A. The other end of the sixth resistor is connected to one end of the seventh resistor and the non-inverting input terminal of the third amplifier. The other end of the seventh resistor is grounded. The inverting input terminal of the third amplifier is connected to one end of the eighth resistor and one end of the ninth resistor. The other end of the eighth resistor is connected to common point B. The other end of the ninth resistor is connected to the output terminal of the third amplifier and one end of the tenth resistor. The other end of the tenth resistor is connected to one end of the sixth capacitor and the input terminal of the circuit impedance control unit. The other end of the sixth capacitor is grounded. The resistance ratio of the seventh resistor to the sixth resistor is equal to the resistance ratio of the ninth resistor to the eighth resistor.

[0022] As a further solution of the present invention: The loop impedance control unit includes a fourth amplifier, a fifth inverter, a first thyristor, a third relay, and a fifth diode. The non-inverting input terminal of the fourth amplifier is connected to the output terminal of the signal conversion unit, the inverting input terminal of the fourth amplifier is connected to the first reference voltage, the output terminal of the fourth amplifier is connected to the input terminal of the fifth inverter, the output terminal of the fifth inverter is connected to the control electrode of the first thyristor, the positive electrode of the first thyristor is connected to the 5V voltage, the negative electrode of the first thyristor is connected to the third input terminal of the battery charging unit, one end of the third relay, and the negative electrode of the fifth diode. The other end of the third relay is grounded, and the positive electrode of the fifth diode is grounded.

[0023] As a further solution of the present invention: The charging mode control module includes a sixth amplifier, a seventh amplifier, a first relay, a second relay, a third diode, and a fourth diode. The non-inverting input terminal of the sixth amplifier is connected to the common point C and the inverting input terminal of the seventh amplifier. The inverting input terminal of the sixth amplifier is connected to the second reference voltage and the non-inverting input terminal of the seventh amplifier. The output terminal of the sixth amplifier is connected to one end of the first relay and the negative electrode of the third diode. The other end of the first relay is grounded, and the positive electrode of the third diode is grounded. The output terminal of the seventh amplifier is connected to one end of the second relay and the negative electrode of the fourth diode. The other end of the second relay is grounded, and the positive electrode of the fourth diode is grounded.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The battery charging module provided by the present invention, during the constant voltage charging stage, charges the super capacitor while charging the battery. When the battery is about to be fully charged, the power supply circuit of the mains is disconnected. Under the condition of reducing the resistance, the super capacitor charges the battery to full charge until the battery is completely full. At the same time, it also serves as the power supply in the trickle charging mode after the battery is fully charged. While ensuring the battery charging, it reduces the power consumption time of the mains and the cost is less. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the charging control circuit of a charging pile.

[0026] Figure 2 It is a circuit diagram of the constant current power supply module.

[0027] Figure 3 It is a circuit diagram of the constant voltage power supply module.

[0028] Figure 4 It is a circuit diagram of the battery charging module.

[0029] Figure 5 It is a circuit diagram of the charging mode control module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figure 1 , a charging control circuit for a charging pile, comprising:

[0032] A voltage conversion module 1 for converting mains alternating current into direct current as the supply voltage VCC to supply a constant current power supply module 2 and a constant voltage power supply module 3;

[0033] A constant current power supply module 2 for providing a constant current to a battery charging module 4 in a constant current charging mode to charge a battery E1;

[0034] A constant voltage power supply module 3 for providing a constant voltage to a battery charging module 4 in a constant voltage charging mode to charge a battery E1;

[0035] A battery charging module 4 for charging the battery E1; in a constant voltage charging mode, detecting the current flowing through the battery E1, maintaining the impedance of the charging circuit of the battery E1 when the current flowing through the battery E1 exceeds the set threshold; reducing the impedance of the charging circuit of the battery E1 when the current flowing through the battery E1 is less than the set threshold, and disconnecting the mains alternating current, and continuing to supply power to the battery E1 by a super capacitor C7;

[0036] A charging mode control module 5 for controlling the operation of the constant voltage power supply module 3 or the constant current power supply module 2 based on the voltage magnitude of the battery E1;

[0037] The output end of the voltage conversion module 1 is connected to the first input end of the constant current power supply module 2 and the first input end of the constant voltage power supply module 3. The output end of the constant current power supply module 2 is connected to the first input end of the battery charging module 4 (common point E). The output end of the constant voltage power supply module 3 is connected to the second input end of the battery charging module 4 (common point D). The output end of the battery charging module 4 is connected to the input end of the charging mode control module 5 (common point C). The output end of the charging mode control module 5 is connected to the second input end of the constant voltage power supply module 3 and the second input end of the constant current power supply module 2 (relay controls the corresponding switch).

[0038] In a specific embodiment: The voltage conversion module 1 is a common technology for converting mains alternating current into direct current. It can be converted into stable direct current through an AC-DC conversion chip, or can also be converted into stable direct current through a transformer, a rectifier, and a filter.

[0039] In this embodiment: Please refer to Figure 2, the constant current power supply module 2 includes a second chip U2, the model of the second chip U2 is MIC5158, the 5th pin of the second chip U2 is grounded through a fifth capacitor C5, the 6th pin of the second chip U2 is connected to the 7th pin of the second chip U2 through a fourth capacitor C4, the 8th pin of the second chip U2 is connected to the 9th pin of the second chip U2 through a third capacitor C3, the 10th pin of the second chip U2 is connected to the power supply voltage VCC and one end of a second switch S2, the other end of the second switch S2 is connected to one end of a first potentiometer RP1, the other end of the first potentiometer RP1 is connected to one end of a second resistor R2, the other end of the second resistor R2 is connected to the D pole of a first MOS transistor V1 and the 12th pin of the second chip U2, the G pole of the first MOS transistor V1 is connected to the 11th pin of the second chip U2, the S pole of the first MOS transistor V1 is connected to the 13th pin of the second chip U2, one end of a third resistor R3 and the base of a third triode V3, the emitter of the third triode V3 is connected to the common point E, the collector of the third triode V3 is connected to the power supply voltage VCC through an eleventh resistor R11, the other end of the third resistor R3 is connected to one end of a fourth resistor R4 and the 1st pin of the second chip U2, and the other end of the fourth resistor R4 is grounded.

[0040] The magnitude of the constant current output by MIC5158 (at the 13th pin) is related to the internal reference voltage of 35 mV and the resistance values of the first potentiometer RP1 and the second resistor R2. By adjusting the resistance value of the first potentiometer RP1, the magnitude of the output constant current can be changed. Here, MIC5158 is selected as the constant current source because it can provide a stable current output and is applicable to a variety of application scenarios. MIC5158 can provide a stable current output under different voltage conditions, meeting the requirements of the constant current source.

[0041] In another embodiment: Chips such as LM317 and LM337 can also be selected to construct the constant current power supply.

[0042] In this embodiment: Please refer to Figure 3 , the constant voltage power supply module 3 includes a first switch S1, a first capacitor C1, a second capacitor C2, a voltage regulator U1, a fourth triode V4, and a fifth resistor R5. One end of the first switch S1 is connected to the power supply voltage VCC, the other end of the first switch S1 is connected to one end of the first capacitor C1 and the input end of the voltage regulator U1, the other end of the first capacitor C1 is grounded, the grounding end of the voltage regulator U1 is grounded, the output end of the voltage regulator U1 is connected to one end of the second capacitor C2 and the base of the fourth triode V4, the other end of the second capacitor C2 is grounded, the emitter of the fourth triode V4 is connected to the common point D, and the collector of the fourth triode V4 is connected to the power supply voltage VCC through the fifth resistor R5.

[0043] The voltage regulator U1 is used for constant voltage power supply, and the first capacitor C1 and the second capacitor C2 are used for filtering to reduce interference.

[0044] In another embodiment, a voltage stabilizing diode or a voltage stabilizing circuit can also be selected to construct a voltage stabilizing output.

[0045] In this embodiment, please refer to Figure 4 , the battery charging module 4 includes:

[0046] A battery charging unit for charging the battery E1;

[0047] A signal conversion unit for detecting the current flowing through the battery E1 in the constant voltage charging mode and converting it into a voltage signal for output to the loop impedance control unit;

[0048] A loop impedance control unit for maintaining the impedance of the power supply loop of the battery E1 when the voltage signal reaches the set threshold; when the voltage signal is less than the set threshold, reducing the impedance of the power supply loop of the battery E1 and disconnecting the mains alternating current, and the super capacitor C7 continues to supply power to the battery E1;

[0049] The first input end of the battery charging unit is connected to the output end (common point E) of the constant current power supply module 2, the second input end of the battery charging unit is connected to the output end (common point D) of the constant voltage power supply module 3, the first output end of the battery charging unit is connected to the input end of the signal conversion unit (common points A and B), the output end of the signal conversion unit is connected to the input end of the loop impedance control unit, the output end of the loop impedance control unit is connected to the third input end of the battery charging unit, and the second output end of the battery charging unit is connected to the input end of the charging mode control module 5 (common point C).

[0050] In this embodiment, please refer to Figure 4 , the battery charging unit includes a first resistor R1, a first diode D1, a second diode D2, a battery E1, and a second MOS transistor V2. One end of the first resistor R1 is connected to the common point D, one end of the super capacitor C7, the D pole of the second MOS transistor V2, and the common point A. The other end of the first resistor R1 is connected to the positive electrode of the first diode D1, the S pole of the second MOS transistor V2, and the common point B. The negative electrode of the first diode D1 is connected to the negative electrode of the second diode D2, the positive electrode of the battery E1, and the common point C. The positive electrode of the second diode D2 is connected to the common point E. The negative electrode of the battery E1 is grounded, and the G pole of the second MOS transistor V2 is connected to the output end of the loop impedance control unit.

[0051] During constant current power supply, the current charges the battery E1 through the second diode D2. During constant voltage power supply, the current is input from the common point D and charges the battery E1 through the first resistor R1 and the first diode D1.

[0052] In another embodiment: Here, the first diode D1 and the second diode D2 are selected to isolate the power supply and prevent the battery E1 from supplying power in the reverse direction. Two separate diodes can be used, or a device with two or more diodes packaged together can be selected.

[0053] In this embodiment: Please refer to Figure 4 , the signal conversion unit includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a sixth capacitor C6, and a third amplifier U3. One end of the sixth resistor R6 is connected to the common point A, and the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the non-inverting input terminal of the third amplifier U3. The other end of the seventh resistor R7 is grounded. The inverting input terminal of the third amplifier U3 is connected to one end of the eighth resistor R8 and one end of the ninth resistor R9. The other end of the eighth resistor R8 is connected to the common point B. The other end of the ninth resistor R9 is connected to the output terminal of the third amplifier U3 and one end of the tenth resistor R10. The other end of the tenth resistor R10 is connected to one end of the sixth capacitor C6 and the input terminal of the loop impedance control unit. The other end of the sixth capacitor C6 is grounded. The resistance ratio of the seventh resistor R7 to the sixth resistor R6 is equal to the resistance ratio of the ninth resistor R9 to the eighth resistor R8.

[0054] A differential amplifier circuit is used to sample and amplify the voltage between the common points A and B. That is, the voltage at the output terminal of the third amplifier U3 reflects the current flowing through the first resistor R1 (i.e., the charging current of the battery E1 during constant voltage charging), and is output after passing through the tenth resistor R10 and the sixth capacitor C6.

[0055] In another embodiment: Here, the resistance ratio of the seventh resistor R7 to the sixth resistor R6 is equal to the resistance ratio of the ninth resistor R9 to the eighth resistor R8. The resistance values of the sixth resistor R6 and the eighth resistor R8 can be further made equal, and the resistance values of the seventh resistor R7 and the ninth resistor R9 can be made equal, which is more convenient when purchasing and selecting resistors.

[0056] In this embodiment: Please refer to Figure 4 , the loop impedance control unit includes a fourth amplifier U4, a fifth inverter U5, a first thyristor Z1, a third relay J3, and a fifth diode D5. The non-inverting input terminal of the fourth amplifier U4 is connected to the output terminal of the signal conversion unit. The inverting input terminal of the fourth amplifier U4 is connected to the first reference voltage VREF1. The output terminal of the fourth amplifier U4 is connected to the input terminal of the fifth inverter U5. The output terminal of the fifth inverter U5 is connected to the control electrode of the first thyristor Z1. The positive electrode of the first thyristor Z1 is connected to the 5V voltage. The negative electrode of the first thyristor Z1 is connected to the third input terminal of the battery charging unit, one end of the third relay J3, and the negative electrode of the fifth diode D5. The other end of the third relay J3 is grounded. The positive electrode of the fifth diode D5 is grounded.

[0057] When the charging current of battery E1 is greater than the threshold, the voltage output to the non-inverting terminal of the fourth amplifier U4 is greater than the first reference voltage VREF1. The fourth amplifier U4 outputs a high level, which, after passing through the fifth inverter U5, outputs a low level and does not trigger the conduction of the first thyristor Z1. When the charging current of battery E1 is less than the threshold, the voltage output to the non-inverting terminal of the fourth amplifier U4 is less than the first reference voltage VREF1. The fourth amplifier U4 outputs a low level, which, after passing through the fifth inverter U5, outputs a high level and triggers the conduction of the first thyristor Z1, thereby triggering the conduction of the second MOS transistor V2 to reduce the charging circuit impedance of battery E1 after constant voltage charging. At the same time, the third relay J3 is energized to control the disconnection of the third switch S3, disconnecting the mains AC power supply and the voltage conversion module 1. At this time, the supercapacitor C7 charges battery E1 through the parallel structure of the first resistor R1 and the second MOS transistor V2 and the first diode D1. Based on the large capacity and stable voltage of the supercapacitor C7, continuous constant voltage charging is ensured to ensure that battery E1 can be fully charged and reach the best stable state. After battery E1 is fully charged, based on the very small difference between the voltage of battery E1 and the voltage of supercapacitor C7, it switches to the trickle charging mode to maintain the voltage of battery E1. By disconnecting the mains AC power supply and the voltage conversion module 1 in advance, the mains power supply time is reduced, and the cost of charging using the charging pile is reduced. At the same time, when the supercapacitor C7 is enabled to charge, the charging circuit impedance of battery E1 is reduced, ensuring the charging speed of battery E1.

[0058] In another embodiment: Here, a 5V voltage is used to supply power to the second MOS transistor V2 through the first thyristor Z1. Based on the fact that the full conduction voltage of the NMOS transistor is a voltage difference of 5 - 10V between the gate and the source, the 5V voltage can be adjusted based on different field effect transistor models. The 5V voltage can be obtained by voltage processing from the supercapacitor C7.

[0059] In this embodiment: Please refer to Figure 5 , the charging mode control module 5 includes a sixth amplifier U6, a seventh amplifier U7, a first relay J1, a second relay J2, a third diode D3, and a fourth diode D4. The non-inverting terminal of the sixth amplifier U6 is connected to the common point C and the inverting terminal of the seventh amplifier U7. The inverting terminal of the sixth amplifier U6 is connected to the second reference voltage VREF2 and the non-inverting terminal of the seventh amplifier U7. The output terminal of the sixth amplifier U6 is connected to one end of the first relay J1 and the negative electrode of the third diode D3. The other end of the first relay J1 is grounded, and the positive electrode of the third diode D3 is grounded. The output terminal of the seventh amplifier U7 is connected to one end of the second relay J2 and the negative electrode of the fourth diode D4. The other end of the second relay J2 is grounded, and the positive electrode of the fourth diode D4 is grounded.

[0060] The common point C is the magnitude of the voltage on the battery E1. When the voltage of the battery E1 is insufficient for charging, the voltage of the common point C is less than the second reference voltage VREF2 at this time, the first relay J1 does not work, and the second relay J2 works to control the second switch S2 to close. At this time, the first switch S1 pops open, and constant current charging is performed. As the battery E1 is charged, the voltage of the common point C is higher than the second reference voltage VREF2. At this time, the first relay J1 is energized to work (the second relay J2 does not work), controlling the first switch S1 to close. At this time, the second switch S2 pops open, and constant voltage charging is performed. When the battery E1 is charged to near full charge, the current flowing through the first resistor R1 is small, making the non-inverting input voltage of the fourth amplifier U4 less than the first reference voltage VREF1. The fourth amplifier U4 triggers the first thyristor Z1 to conduct through the fifth inverter U5. At this time, the mains AC power is disconnected, and the super capacitor C7 is used for charging. When the battery E1 is fully charged, it becomes trickle charging.

[0061] In another embodiment: A relay is used here to control the power supply switch, and a switching transistor can also be selected as the power supply switch. By designing the relevant circuit, the on and off control of the switching transistor can be completed.

[0062] The working principle of the present invention is as follows: The voltage conversion module 1 is used to convert the mains AC power into DC power as the power supply voltage VCC to supply the constant current power supply module 2 and the constant voltage power supply module 3; the constant current power supply module 2 is used to provide a constant current for the battery charging module 4 in the constant current charging mode to charge the battery E1; the constant voltage power supply module 3 is used to provide a constant voltage for the battery charging module 4 in the constant voltage charging mode to charge the battery E1; the battery charging module 4 is used to charge the battery E1; in the constant voltage charging mode, the current flowing through the battery E1 is detected. When the current flowing through the battery E1 exceeds the set threshold, the impedance of the battery E1 charging circuit is maintained; when the current flowing through the battery E1 is less than the set threshold, the impedance of the battery E1 charging circuit is reduced, and the mains AC power is disconnected, and the super capacitor C7 continues to supply power to the battery E1; the charging mode control module 5 is used to control the operation of the constant voltage power supply module 3 or the constant current power supply module 2 based on the magnitude of the voltage of the battery E1.

[0063] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive.

[0064] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A charging control circuit for a charging pile, characterized in that, The charging control circuit of this charging pile includes: A voltage conversion module for converting mains alternating current into direct current as the supply voltage to supply the constant current supply module and the constant voltage supply module; A constant current supply module for providing a constant current to the battery charging module to charge the battery in the constant current charging mode; A constant voltage supply module for providing a constant voltage to the battery charging module to charge the battery in the constant voltage charging mode; A battery charging module for charging the battery; in the constant voltage charging mode, it detects the current flowing through the battery, and when the current flowing through the battery exceeds the set threshold, it maintains the impedance of the battery charging circuit; when the current flowing through the battery is less than the set threshold, it reduces the impedance of the battery charging circuit and disconnects the mains alternating current, and the super capacitor continues to supply power to the battery; A charging mode control module for controlling the operation of the constant voltage supply module or the constant current supply module based on the battery voltage; The output terminal of the voltage conversion module is connected to the first input terminal of the constant current supply module and the first input terminal of the constant voltage supply module. The output terminal of the constant current supply module is connected to the first input terminal of the battery charging module. The output terminal of the constant voltage supply module is connected to the second input terminal of the battery charging module. The output terminal of the battery charging module is connected to the input terminal of the charging mode control module. The output terminal of the charging mode control module is connected to the second input terminal of the constant voltage supply module and the second input terminal of the constant current supply module; The battery charging module includes: A battery charging unit for charging the battery; A signal conversion unit for detecting the current flowing through the battery in the constant voltage charging mode and converting it into a voltage signal for output to the loop impedance control unit; A loop impedance control unit for maintaining the impedance of the battery power supply circuit when the voltage signal reaches the set threshold; when the voltage signal is less than the set threshold, it reduces the impedance of the battery power supply circuit and disconnects the mains alternating current, and the super capacitor continues to supply power to the battery; The first input terminal of the battery charging unit is connected to the output terminal of the constant current supply module. The second input terminal of the battery charging unit is connected to the output terminal of the constant voltage supply module. The first output terminal of the battery charging unit is connected to the input terminal of the signal conversion unit. The output terminal of the signal conversion unit is connected to the input terminal of the loop impedance control unit. The output terminal of the loop impedance control unit is connected to the third input terminal of the battery charging unit. The second output terminal of the battery charging unit is connected to the input terminal of the charging mode control module; The loop impedance control unit includes a fourth amplifier, a fifth inverter, a first thyristor, a third relay, and a fifth diode. The non-inverting input terminal of the fourth amplifier is connected to the output terminal of the signal conversion unit. The inverting input terminal of the fourth amplifier is connected to the first reference voltage. The output terminal of the fourth amplifier is connected to the input terminal of the fifth inverter. The output terminal of the fifth inverter is connected to the control electrode of the first thyristor. The positive electrode of the first thyristor is connected to the 5V voltage. The negative electrode of the first thyristor is connected to the third input terminal of the battery charging unit, one end of the third relay, and the negative electrode of the fifth diode. The other end of the third relay is grounded. The positive electrode of the fifth diode is grounded.

2. The charging control circuit of the charging pile according to claim 1, wherein The constant current power supply module includes a second chip, the model of the second chip is MIC5158. The 5th pin of the second chip is grounded through a fifth capacitor. The 6th pin of the second chip is connected to the 7th pin of the second chip through a fourth capacitor. The 8th pin of the second chip is connected to the 9th pin of the second chip through a third capacitor. The 10th pin of the second chip is connected to the power supply voltage and one end of a second switch. The other end of the second switch is connected to one end of a first potentiometer. The other end of the first potentiometer is connected to one end of a second resistor. The other end of the second resistor is connected to the D pole of a first MOS transistor and the 12th pin of the second chip. The G pole of the first MOS transistor is connected to the 11th pin of the second chip. The S pole of the first MOS transistor is connected to the 13th pin of the second chip, one end of a third resistor, and the base of a third triode. The emitter of the third triode is connected to the common point E. The collector of the third triode is connected to the power supply voltage through an eleventh resistor. The other end of the third resistor is connected to one end of a fourth resistor and the 1st pin of the second chip. The other end of the fourth resistor is grounded.

3. The charging control circuit of the charging pile according to claim 1, wherein The constant voltage power supply module includes a first switch, a first capacitor, a second capacitor, a voltage regulator, a fourth triode, and a fifth resistor. One end of the first switch is connected to the power supply voltage. The other end of the first switch is connected to one end of the first capacitor and the input end of the voltage regulator. The other end of the first capacitor is grounded. The grounding end of the voltage regulator is grounded. The output end of the voltage regulator is connected to one end of the second capacitor and the base of the fourth triode. The other end of the second capacitor is grounded. The emitter of the fourth triode is connected to the common point D. The collector of the fourth triode is connected to the power supply voltage through the fifth resistor.

4. The charging control circuit of the charging pile according to claim 1, wherein The battery charging unit includes a first resistor, a first diode, a second diode, a battery, and a second MOS transistor. One end of the first resistor is connected to the common point D, one end of a super capacitor, the D pole of the second MOS transistor, and the common point A. The other end of the first resistor is connected to the positive electrode of the first diode, the S pole of the second MOS transistor, and the common point B. The negative electrode of the first diode is connected to the negative electrode of the second diode, the positive electrode of the battery, and the common point C. The positive electrode of the second diode is connected to the common point E. The negative electrode of the battery is grounded. The G pole of the second MOS transistor is connected to the output end of the loop impedance control unit.

5. The charging control circuit of the charging pile according to claim 1, characterized in that, The signal conversion unit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a sixth capacitor, and a third amplifier. One end of the sixth resistor is connected to the common point A. The other end of the sixth resistor is connected to one end of the seventh resistor and the non-inverting input end of the third amplifier. The other end of the seventh resistor is grounded. The inverting input end of the third amplifier is connected to one end of the eighth resistor and one end of the ninth resistor. The other end of the eighth resistor is connected to the common point B. The other end of the ninth resistor is connected to the output end of the third amplifier and one end of the tenth resistor. The other end of the tenth resistor is connected to one end of the sixth capacitor and the input end of the loop impedance control unit. The other end of the sixth capacitor is grounded. The resistance ratio of the seventh resistor to the sixth resistor is equal to the resistance ratio of the ninth resistor to the eighth resistor.

6. The charging control circuit of the charging pile according to claim 1, characterized in that The charging mode control module includes a sixth amplifier, a seventh amplifier, a first relay, a second relay, a third diode, and a fourth diode. The non-inverting input terminal of the sixth amplifier is connected to the common point C and the inverting input terminal of the seventh amplifier. The inverting input terminal of the sixth amplifier is connected to the second reference voltage and the non-inverting input terminal of the seventh amplifier. The output terminal of the sixth amplifier is connected to one end of the first relay and the cathode of the third diode. The other end of the first relay is grounded, and the anode of the third diode is grounded. The output terminal of the seventh amplifier is connected to one end of the second relay and the cathode of the fourth diode. The other end of the second relay is grounded, and the anode of the fourth diode is grounded.

Images