An intelligent charging system for hydrogen fuel cell stacks

Abstract

The present invention provides an intelligent charging system for a hydrogen fuel cell stack, including a lithium battery pack, and the intelligent charging system includes: a boost charging circuit, receiving the output voltage of the hydrogen fuel cell stack, and boosting the voltage to a charging voltage supplied to the lithium battery pack; a constant voltage control circuit, receiving the output voltage and comparing the output voltage with a first voltage threshold, when the first voltage threshold is greater than the output voltage, controlling the boost charging circuit to boost the output voltage to a constant value; a constant current control circuit, receiving the output voltage and comparing the output voltage with a second voltage threshold, when the second voltage threshold is greater than the output voltage, controlling the boost charging circuit to increase the output current to a constant value; a current sampling circuit, collecting the discharge current of the hydrogen fuel cell stack, the charge and discharge current of the lithium battery pack, and the load current. After adopting the above technical solution, the hydrogen fuel cell cooperates with the lithium battery pack to effectively output electrical energy under different use conditions of the power-assisted vehicle.

Description

Technical Field

[0001] The present invention relates to the field of energy management, and in particular to an intelligent charging system for use. Background Art

[0002] A hydrogen fuel cell is a device that uses hydrogen as fuel to generate electricity through a chemical reaction with oxygen. Its only byproduct is water. Therefore, hydrogen fuel cells have developed rapidly in the field of transportation equipment. Hydrogen fuel cells are used as a source of electricity for motor vehicles and non-motor vehicles. As a result, bicycles powered by hydrogen fuel cells have become an ideal green means of transportation.

[0003] In the form of a hydrogen-powered bicycle, a lithium battery pack is also provided to cooperate with the hydrogen fuel cell to provide power to the bicycle. However, under the existing technology, after the lithium battery pack is provided, the lithium battery pack is still used as the main power source to provide power to the bicycle, so the role of the hydrogen fuel cell cannot be fully reflected. The intelligent charging system is also an important component unit in the hydrogen fuel cell system. For the hydrogen fuel cell stack, how to optimize its performance is a key issue.

[0004] Therefore, there is a need for an intelligent charging system for a hydrogen fuel cell stack that can mainly utilize hydrogen energy to provide the main energy for a power-assisted vehicle. Summary of the invention

[0005] In order to overcome the above technical defects, the purpose of the present invention is to provide an intelligent charging system for a hydrogen fuel cell stack, so that the hydrogen fuel cell and the lithium battery pack can cooperate to effectively output electrical energy under different usage conditions of the power-assisted bicycle.

[0006] The present invention discloses an intelligent charging system for a hydrogen fuel cell stack, including a lithium battery pack. The intelligent charging system includes:

[0007] A boost charging circuit is electrically connected to the lithium battery pack and the hydrogen fuel cell stack, receives the output voltage of the hydrogen fuel cell stack, and boosts the output voltage to a charging voltage supplied to the lithium battery pack, so that the charging voltage of the lithium battery pack is constant;

[0008] A constant voltage control circuit is connected to the boost charging circuit, receives the output voltage and compares the output voltage with a first voltage threshold, and controls the boost charging circuit to boost the output voltage to a constant value when the first voltage threshold is greater than the output voltage;

[0009] A constant current control circuit is connected to the boost charging circuit, receives the output voltage and compares the output voltage with a second voltage threshold, and controls the boost charging circuit to increase the output current to a constant value when the second voltage threshold is greater than the output voltage;

[0010] A current sampling circuit is electrically connected to the lithium battery pack and the hydrogen fuel cell stack to collect the discharge current of the hydrogen fuel cell stack, the charge and discharge current of the lithium battery pack, and the load current;

[0011] A hydrogen detection circuit is arranged at the outlet pipe of the hydrogen tank connected to the hydrogen fuel cell stack, detects the flow of hydrogen and sends a control instruction to the boost charging circuit. When the flow is greater than a flow threshold interval or less than a flow threshold interval, the boost charging circuit is closed to the charging circuit of the lithium battery pack.

[0012] Preferably, the boost charging circuit includes a converter module, resistors R101 to R120, capacitors C101 to C119, field effect transistors M101 and M102, and diodes D101 and D102;

[0013] The pin of the converter module is grounded through capacitors C102 and C103, connected to the 3.3V voltage terminal, connected to the cathode of diode D101 and then grounded through the anode of D101;

[0014] The drain of the field effect transistor M101 is connected to the positive electrode of the lithium battery pack, and the source is connected to the drain of the field effect transistor M102;

[0015] The source of the field effect transistor M102 is grounded;

[0016] The converter module, field effect transistors M101, M102 and diodes D101, D102 form a synchronous rectification Boost DC TODC converter.

[0017] Preferably, the constant voltage control circuit comprises a comparator;

[0018] The comparator compares a first voltage threshold preset at the first input terminal and an output voltage received at the second input terminal, and when the first voltage threshold is greater than the output voltage, reduces the voltage at the output terminal, so that the boost charging circuit enters an input constant voltage mode.

[0019] Preferably, the current sampling circuit includes a hydrogen fuel cell stack current sampling circuit, a lithium battery pack current sampling circuit, a load current sampling circuit and a reference voltage source circuit;

[0020] The hydrogen fuel cell stack current sampling circuit, the lithium battery group current sampling circuit, the load current sampling circuit and the reference voltage source circuit are respectively connected to an external central control circuit to receive the hydrogen fuel cell stack current signal, the lithium battery group current signal and the load current of the central control circuit.

[0021] Preferably, the hydrogen fuel cell stack current sampling circuit includes a first integrated circuit and resistors R201 to R203;

[0022] The first integrated circuit is grounded via a resistor R201, connected to a voltage terminal VB- and a voltage terminal Vref via resistors R202 and R203 respectively, and an output terminal is connected to a voltage terminal Uip.

[0023] Preferably, the lithium battery pack current sampling circuit includes a second integrated circuit and resistors R205 to R207;

[0024] The second integrated circuit is grounded via a resistor R205, and is connected to the negative electrode BAT- and the Vref voltage terminal of the lithium battery pack via resistors R206 and R207, and the output terminal is connected to the voltage terminal Uob.

[0025] Preferably, the load current sampling circuit includes a third integrated circuit and resistors R209 to R211;

[0026] The second integrated circuit is grounded via a resistor R209, connected to a load terminal LOAD- and a Vref voltage terminal via resistors R210 and R211 respectively, and an output terminal is connected to a voltage terminal Uol.

[0027] Preferably, the reference voltage source circuit comprises a fourth integrated circuit;

[0028] The fourth integrated circuit is connected to the 3.3V voltage terminal and the ground.

[0029] Preferably, the constant current control circuit includes a comparator group and resistors R223 to R232;

[0030] The comparator group compares the second voltage threshold preset at the first input terminal and the output voltage received at the second input terminal, and when the second voltage threshold is greater than the output voltage, reduces the voltage at the output terminal, so that the boost charging circuit enters an input constant current mode.

[0031] Compared with the prior art, the above technical solution has the following beneficial effects:

[0032] 1. When the power-assisted bicycle is first used, in order to protect the hydrogen fuel cell stack, it is first powered by the lithium battery pack, so that the user can also feel the power assistance during the initial use;

[0033] 2. It can effectively detect the remaining amount of hydrogen and protect the hydrogen fuel cell stack and the entire intelligent charging system;

[0034] 3. Intelligently manage the charging and discharging of hydrogen fuel cells and lithium battery packs to improve the service life and efficiency of hydrogen fuel cell stacks. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the system structure of an intelligent charging system for a hydrogen fuel cell stack in accordance with a preferred embodiment of the present invention;

[0036] Figure 2A circuit diagram of a boost charging circuit of an intelligent charging system for a hydrogen fuel cell stack in accordance with a preferred embodiment of the present invention;

[0037] Figure 3 A circuit diagram of a constant voltage control circuit for an intelligent charging system for a hydrogen fuel cell stack in accordance with a preferred embodiment of the present invention;

[0038] Figure 4 A circuit diagram of a hydrogen fuel cell stack current sampling circuit that complies with a current sampling circuit in a preferred embodiment of the present invention;

[0039] Figure 5 A circuit diagram of a lithium battery pack current sampling circuit in accordance with a preferred embodiment of the present invention;

[0040] Figure 6 A circuit diagram of a load current sampling circuit of a current sampling circuit in accordance with a preferred embodiment of the present invention;

[0041] Figure 7 A circuit diagram of a reference voltage source circuit of a current sampling circuit in accordance with a preferred embodiment of the present invention;

[0042] Figure 8 The figure is a circuit diagram of a constant current control circuit of a current sampling circuit in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0043] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0044] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0045] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0046] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0047] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0049] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0050] See also Figure 1 , is a structural diagram of an intelligent charging system for a hydrogen fuel cell stack in accordance with a preferred embodiment of the present invention. To assist the power supply of the hydrogen fuel cell, the intelligent charging system includes a lithium battery pack. When the lithium battery pack supplies power to the outside, it serves as an auxiliary to the hydrogen fuel cell. When the lithium battery pack receives power from the hydrogen fuel cell, it charges itself. For application scenarios in different usage situations, the intelligent charging system includes:

[0051] -Boost charging circuit

[0052] After the hydrogen is released from the hydrogen fuel cell stack, the hydrogen fuel cell can output voltage to the outside, thereby supplying electrical energy to the electrical devices connected to the hydrogen fuel cell. According to the electrochemical characteristics of the hydrogen fuel cell stack, the output voltage of the hydrogen fuel cell stack is generally 24V, while the general charging voltage of the lithium battery pack is 36V, that is, the output voltage of the hydrogen fuel cell stack cannot directly charge the lithium battery pack. Therefore, the intelligent charging system includes a boost charging circuit, which is electrically connected to the lithium battery pack and the hydrogen fuel cell stack, receives the output voltage of the hydrogen fuel cell stack, and boosts the output voltage to a charging voltage that can be charged by the lithium battery pack, and can keep the charging voltage required by the lithium battery pack constant, so that the lithium battery pack is safe and stable when charging.

[0053] -Constant voltage control circuit

[0054] Taking into account that the output voltage of the hydrogen fuel cell may change dynamically during the hydrogen release process and float near the charging voltage required by the lithium battery pack, a constant voltage control circuit is required, which is connected to the boost charging circuit to receive the output voltage of the hydrogen fuel cell stack and compare the output voltage with a preset first voltage threshold. When the output voltage is lower than the first voltage threshold, it indicates that the output voltage of the hydrogen fuel cell does not reach the charging voltage required by the lithium battery pack, and a control instruction will be sent to the boost charging circuit to activate the boost charging circuit to boost the output voltage of the hydrogen fuel cell to a preset constant value; and when the output voltage is higher than the first voltage threshold, it indicates that the output voltage of the hydrogen fuel cell has reached or even exceeded the charging voltage required by the lithium battery pack, and the lithium battery pack can directly accept the output voltage to be charged.

[0055] -Constant current control circuit

[0056] In addition to the output voltage, the intelligent charging system will also control the output current of the hydrogen fuel cell. Specifically, the intelligent charging system also includes a constant current control circuit, which is connected to the boost charging circuit, receives the output voltage of the hydrogen fuel cell stack (rather than the output current, and the circuit design can be simplified by using the output voltage together), and compares the output voltage with a preset second voltage threshold. When the output voltage is lower than the second voltage threshold, it means that the output voltage of the hydrogen fuel cell does not reach the charging voltage required by the lithium battery pack. If the lithium battery pack is charged with the output voltage, the charging power of the lithium battery pack will be low and the charging speed will be extremely slow. In this regard, a control instruction will be sent to the boost charging circuit to activate the boost charging circuit to boost the output current of the hydrogen fuel cell to a preset constant value, so that when the output voltage cannot be increased or the output voltage is stable, the charging power is increased by increasing the output current value; and when the output voltage is higher than the second voltage threshold, it means that the output voltage of the hydrogen fuel cell has reached or even exceeded the charging voltage required by the lithium battery pack, and the lithium battery pack can directly accept the output voltage or output current to be charged.

[0057] -Current sampling circuit

[0058] The intelligent charging system also includes a current sampling circuit. It is connected to the lithium battery pack and the hydrogen fuel cell stack respectively, and detects the discharge current of the hydrogen fuel cell stack, the charge and discharge current of the lithium battery pack, and the power load connected to the hydrogen fuel cell stack to obtain the load current. By detecting the discharge current, the charge and discharge current of the lithium battery pack, and the load current, the working state of the hydrogen fuel cell stack, the working state of the lithium battery pack, and the power supply state of the load can be obtained in real time.

[0059] -Hydrogen detection circuit

[0060] The hydrogen detection circuit is arranged at the outlet pipe of the hydrogen tank connected to the hydrogen fuel cell stack to detect the flow rate of hydrogen. When it detects that the flow rate is greater than the flow threshold interval or less than the flow threshold interval, it indicates that the hydrogen gas release rate is too large, the workload of the boost charging circuit is too large, or the hydrogen itself is insufficient and is no longer suitable for controlling the hydrogen fuel cell stack to supply power to the lithium battery pack. Therefore, the hydrogen detection circuit will send a control instruction to the boost charging circuit to shut down the charging circuit of the boost charging circuit to the lithium battery pack, thereby protecting the boost charging circuit and the hydrogen fuel cell stack respectively.

[0061] Through the above configuration, when the hydrogen fuel cell stack supplies power to the load, the status of the hydrogen fuel cell stack can be monitored in real time through the current sampling circuit to see if there is any fault. When the hydrogen fuel cell stack charges the lithium battery (and / or supplies electrical energy to the load at the same time), the output voltage is boosted, so that the hydrogen fuel cell can charge the lithium battery pack safely and stably without considering the charging time and charging loss of the lithium battery pack.

[0062] See also Figure 2, shows a circuit diagram of a boost charging circuit of an intelligent charging system in a preferred embodiment. In this embodiment, the boost charging circuit includes a converter module, resistors R101 to R120, capacitors C101 to C119, field effect transistors M101, M102, and diodes D101, D102. Pin 1 of the converter module is grounded via resistor R101, pin 2 is grounded via capacitor C101, pin 3 (VCOMP pin) is grounded via an RC circuit composed of capacitors C102, C103 and resistor R108, pin 4 is grounded via resistor R102 and connected to the VO+ voltage terminal via resistor R107, pins 5 and 6 are connected in parallel via capacitor C105 and are connected to ISNS- and ISNS+, respectively, pin 7 is connected to the VB+ voltage terminal, pin 8 is connected to LG via resistor R106, and pins 9 and 10 are connected via R110 and C108. The formed RC circuit is connected to both ends of capacitor C107 and then grounded, and is connected to the anode of diode D101, pin 11 is connected to the cathode of diode D101 and connected to one end of capacitor C109, pin 12 is connected to the other end of capacitor C109, pin 13 is connected to resistor R105, pin 14 is connected to resistor R111 and connected to a 3.3V voltage terminal to output a BOOST state, pin 15 is connected to one end of resistor R109, pin 17 is connected to the other end of resistor R109, and is connected in parallel with pin 16 and then grounded. On one side of the lithium battery pack, after capacitors C110, C112, and C111 are connected in parallel, the positive end of capacitor C110 is connected to the VB+ voltage terminal, and the negative end is connected to the parallel resistor R119 and the resistor RF120, and then connected to the VB- voltage terminal. The positive ends of capacitors C112 and C111 are connected to the VB+ voltage terminal, and the negative ends are grounded. Resistors R114 to R116 are connected in parallel to one end of resistor R117, and the other end of resistor R117 is connected to ISNS+, and resistor R After being connected in parallel, resistors R114 to R116 are connected to one end of resistor R118, and the other end of resistor R118 is connected to ISNS-. After being connected in parallel, resistors R114 to R116 are also connected to inductor L1, and the other end of inductor L1 is connected to field effect transistors M102 and M101. After being connected in parallel, inductors C114 to C119 are connected in parallel with resistors R112 and R113 to both ends of the lithium battery pack, and resistors R112 and R113 are connected to LOAD- and BAT- ground terminals, respectively. The converter module, field effect transistors M101, M102, and diodes D101, D102 form a synchronous rectification Boost DC TO DC converter.

[0063] See also Figure 3, shows a circuit diagram of a constant voltage control circuit of an intelligent charging system. In this embodiment, the constant voltage control circuit includes a comparator, a first voltage threshold is preset in the comparator, a first output terminal is connected to the Vref voltage terminal via a resistor R219, a second output terminal is connected to the VB+ voltage terminal via a resistor R220, and the output terminal is connected to pin 3 of U101 of the boost charging circuit. After the comparator compares the first voltage threshold with the output voltage received by the second input terminal, when the comparison result is that the first voltage threshold is greater than the output voltage, the comparator reduces the voltage at the output terminal, thereby causing the boost charging circuit to enter a constant voltage mode, and controlling the boost charging circuit to work in the hydrogen fuel cell stack to charge the lithium battery in a constant voltage mode.

[0064] In one embodiment, the current sampling circuit includes a hydrogen fuel cell stack current sampling circuit, a lithium battery pack current sampling circuit, a load current sampling circuit and a reference voltage source circuit to respectively detect the output current of the hydrogen fuel cell stack, the output and input current of the lithium battery pack, the input current of the power load, and the output current of the reference voltage source. The hydrogen fuel cell stack current sampling circuit, the lithium battery pack current sampling circuit, the load current sampling circuit and the reference voltage source circuit are respectively connected to an external central control circuit to receive the hydrogen fuel cell stack current signal, the lithium battery pack current signal and the load current from the central control circuit. Figure 4 Specifically, the hydrogen fuel cell stack current sampling circuit includes a first integrated circuit and resistors R201 to R203; the first end of the first integrated circuit is grounded via resistor R201, the second end is connected to the voltage terminal VB- and the Vref voltage terminal via resistors R202 and R203 respectively, and the output end is connected to the voltage terminal Uip to detect the output current of the hydrogen fuel cell stack. Figure 5 The lithium battery pack current sampling circuit includes a second integrated circuit and resistors R205 to R207; the first end of the second integrated circuit is grounded via resistor R205, the second end is connected to the negative electrode BAT- and the Vref voltage terminal of the lithium battery pack via resistors R206 and R207, the third end is connected to the 3.3V voltage terminal, the fourth end is grounded, and the output end is connected to the voltage terminal Uob to detect the output and input current of the lithium battery pack. Figure 6 The load current sampling circuit includes a third integrated circuit and resistors R209 to R211; the first end of the third integrated circuit is grounded via resistor R209, the second end is connected to the load end LOAD- and the Vref voltage end via resistors R210 and R211, and the output end is connected to the voltage end Uol to detect the load current. Figure 7 , the reference voltage source circuit includes a fourth integrated circuit; the first end of the fourth integrated circuit is connected to the 3.3V voltage terminal, the second end is grounded, and the output end is connected to the Vref voltage terminal to detect the output current of the reference voltage source.

[0065] See also Figure 8, shows a circuit diagram of a constant current control circuit in a preferred embodiment. In this embodiment, the constant current control circuit includes a comparator group and resistors R223 to R232. The constant current control circuit receives a PWM current input signal and inputs it to one end of the resistor R232. The other end of the resistor R232 is grounded, and the PWM current input signal is input to the first comparator in the comparator group. The second input end of the first comparator is connected to the output end. After forming a feedback circuit, it is connected to the first input end of the second comparator through resistor R228. The Vref voltage end is connected to the first input end of the third comparator through resistor R230. The second input end is connected to the output end. After forming a feedback circuit, it is connected to the second input end of the second comparator after being connected in parallel with the resistor R226 through resistor R227. The other end of the resistor R226 is connected to the 3.3V voltage end. The output end of the second comparator is connected to the first input end of the fourth comparator through resistor R223. The second input end of the fourth comparator is connected to the Uip voltage end through resistor R224. The output end of the fourth comparator is connected to the VCOMP pin of U101 of the boost charging circuit. Each comparator in the comparator group compares the preset second voltage threshold and the received output voltage. When the comparison result is that the second voltage threshold is greater than the output voltage, the voltage at the output end will be reduced, so that the boost charging circuit enters the input constant current mode, and controls the boost charging circuit to operate in the hydrogen fuel cell stack in the constant current mode to charge the lithium battery.

[0066] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An intelligent charging system for a hydrogen fuel cell stack, comprising a lithium battery pack, characterized in that: The intelligent charging system comprises: a boost charging circuit, electrically connected to the lithium battery pack and the hydrogen fuel cell stack, receiving an output voltage of the hydrogen fuel cell stack, and boosting the output voltage to a charging voltage supplied to the lithium battery pack, so that the charging voltage of the lithium battery pack is constant; a constant voltage control circuit, connected to the boost charging circuit, receiving the output voltage and comparing the output voltage with a first voltage threshold, and controlling the boost charging circuit to boost the output voltage to a constant value when the first voltage threshold is greater than the output voltage; a constant current control circuit, connected to the boost charging circuit, receiving the output voltage and comparing the output voltage with a second voltage threshold, and controlling the boost charging circuit to increase the output current to a constant value when the second voltage threshold is greater than the output voltage; A current sampling circuit is electrically connected to the lithium battery pack and the hydrogen fuel cell stack to collect the discharge current of the hydrogen fuel cell stack, the charge and discharge current of the lithium battery pack and the load current; A hydrogen detection circuit is arranged at the outlet pipe of the hydrogen tank connected to the hydrogen fuel cell stack, detects the flow of hydrogen and sends a control instruction to the boost charging circuit. When the flow is greater than a flow threshold interval or less than a flow threshold interval, the boost charging circuit is closed to the charging circuit of the lithium battery pack.

2. The intelligent charging system according to claim 1, characterized in that: The boost charging circuit includes a converter module, resistors R101 to R120, capacitors C101 to C119, field effect transistors M101 and M102, and diodes D101 and D102; The pin of the converter module is grounded through capacitors C102 and C103, connected to the 3.3V voltage terminal, connected to the cathode of diode D101 and then grounded through the anode of D101; The drain of the field effect transistor M101 is connected to the positive electrode of the lithium battery pack, and the source is connected to the drain of the field effect transistor M102; The source of the field effect transistor M102 is grounded; The converter module, field effect transistors M101, M102 and diodes D101, D102 form a synchronous rectification Boost DC TODC converter.

3. The intelligent charging system according to claim 2, characterized in that: The constant voltage control circuit comprises a comparator; The comparator compares a first voltage threshold preset at the first input terminal and an output voltage received at the second input terminal, and when the first voltage threshold is greater than the output voltage, reduces the voltage at the output terminal, so that the boost charging circuit enters an input constant voltage mode.

4. The intelligent charging system according to claim 1, characterized in that: The current sampling circuit includes a hydrogen fuel cell stack current sampling circuit, a lithium battery pack current sampling circuit, a load current sampling circuit and a reference voltage source circuit; The hydrogen fuel cell stack current sampling circuit, lithium battery group current sampling circuit, load current sampling circuit and reference voltage source circuit are respectively connected to an external central control circuit to receive the hydrogen fuel cell stack current signal, lithium battery group current signal and load current of the central control circuit.

5. The intelligent charging system according to claim 4, characterized in that: The hydrogen fuel cell stack current sampling circuit includes a first integrated circuit and resistors R201 to R203; The first integrated circuit is grounded via a resistor R201, connected to a voltage terminal VB- and a voltage terminal Vref via resistors R202 and R203 respectively, and an output terminal is connected to a voltage terminal Uip.

6. The intelligent charging system according to claim 4, characterized in that: The lithium battery pack current sampling circuit includes a second integrated circuit and resistors R205 to R207; The second integrated circuit is grounded via a resistor R205, and is connected to the negative electrode BAT- and the Vref voltage terminal of the lithium battery pack via resistors R206 and R207, respectively, and the output terminal is connected to the voltage terminal Uob.

7. The intelligent charging system according to claim 4, characterized in that: The load current sampling circuit includes a third integrated circuit and resistors R209 to R211; The third integrated circuit is grounded via a resistor R209, connected to a load terminal LOAD- and a Vref voltage terminal via resistors R210 and R211, respectively, and an output terminal is connected to a voltage terminal Uol.

8. The intelligent charging system according to claim 4, characterized in that: The reference voltage source circuit includes a fourth integrated circuit; The fourth integrated circuit is connected to the 3.3V voltage terminal and the ground.

9. The intelligent charging system according to claim 1, characterized in that: The constant current control circuit includes a comparator group and resistors R223-R232; The comparator group compares the second voltage threshold preset at the first input terminal and the output voltage received at the second input terminal, and when the second voltage threshold is greater than the output voltage, reduces the voltage at the output terminal, so that the boost charging circuit enters an input constant current mode.

Images