Converter for fuel cell of unmanned aerial vehicle

Abstract

The utility model relates to the field of unmanned aerial vehicles, and provides a converter for a fuel cell of an unmanned aerial vehicle, which comprises a boost chopper circuit and a half-bridge resonant circuit, the boost chopper circuit is connected with the half-bridge resonant circuit in parallel, and the boost chopper circuit comprises a direct current power supply a, a fly-wheel diode a, a full-control device a, an inductor a, a capacitor a and a resistor a, the positive electrode of the direct-current power supply a is connected with the inductor a, the inductor a is respectively connected with the fly-wheel diode a and the full-control device a, the fly-wheel diode a is respectively connected with the capacitor a and the resistor a, and the full-control device a, the capacitor a and the resistor a are connected with the negative electrode of the direct-current power supply a. When in use, the unmanned aerial vehicle has the advantages of high efficiency, stability, small size, energy conservation, environmental protection and the like, the space and the weight of the unmanned aerial vehicle are saved, the stability and the control precision of the unmanned aerial vehicle are enhanced, and stable flight of the unmanned aerial vehicle and normal operation of equipment are ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to unmanned plane field, more specifically, relate to a kind of converter for unmanned plane fuel cell. BACKGROUND

[0002] With the rapid development of civil aviation industry, unmanned plane field as a branch of civil aviation field, also more and more people favour, and widely used in various fields, expand unmanned plane market.Hydrogen fuel cell unmanned plane can effectively improve the endurance time of unmanned plane and reduce the volume of unmanned plane, but due to the output voltage fluctuation of hydrogen fuel cell is larger, extremely unstable, and the complex electrical application environment of unmanned plane, the DC (Direct Current) direct current of fuel cell output cannot be directly used for unmanned plane.

[0003] In hydrogen fuel cell unmanned plane, the design and optimization of DC-DC converter need to be carried out according to the characteristics of hydrogen fuel cell, to realize higher efficiency, stable conversion effect.

[0004] Therefore, we propose a kind of converter for unmanned plane fuel cell to solve the above problems. Utility model content

[0005] Technical problem to be solved

[0006] In view of the problems existing in the prior art, the purpose of the utility model is to provide a kind of converter for unmanned plane fuel cell, solve the problem of large output voltage fluctuation of hydrogen fuel cell, instability.

[0007] Technical scheme

[0008] To solve the above problems, the utility model adopts the following technical scheme.

[0009] A kind of converter for unmanned plane fuel cell, including boost chopper circuit, half-bridge resonant circuit, the boost chopper circuit with the half-bridge resonant circuit is parallelly connected, wherein:

[0010] The boost chopper circuit includes DC power supply a, freewheeling diode a, fully controlled device a, inductance a, capacitance a and resistance a, the positive pole of DC power supply a is connected with inductance a, inductance a is connected with freewheeling diode a and fully controlled device a respectively, freewheeling diode a is connected with capacitance a and resistance a respectively, the fully controlled device a, the capacitance a and the resistance a are connected with the negative pole of DC power supply a;

[0011] The half-bridge resonant circuit includes half-bridge square wave generator, transformer and full-bridge rectifier circuit, the left side of the transformer is connected with the half-bridge square wave generator, the right side of the transformer is connected with the full-bridge rectifier circuit.

[0012] In a new embodiment, the half-bridge square wave generator includes a DC power supply b and two fully controlled devices b. The DC power supply b and the two fully controlled devices b form a circuit. An inductor b1 is connected between the two fully controlled devices b. A capacitor b3 is connected to the inductor b1. The capacitor b3 is connected to one end of a transformer and the inductor b2 respectively. The other end of the transformer is connected to the inductor b2 and to the negative terminal of the DC power supply b.

[0013] In a new embodiment, the full-bridge rectifier circuit includes parallel freewheeling diode group b1, freewheeling diode group b2, capacitor b4 and resistor b;

[0014] The freewheeling diode group b1 includes freewheeling diodes b11 and b12 connected in series, and the freewheeling diode group b2 includes freewheeling diodes b21 and b22 connected in series. One end of the transformer is connected between freewheeling diodes b11 and b12, and the other end of the transformer is connected between freewheeling diodes b21 and b22.

[0015] In a new embodiment, a sampling circuit is also included, which is used to convert the voltage signal at the measurement point into a current signal, and amplify and process it to obtain the desired voltage value;

[0016] The sampling circuit includes an operational amplifier.

[0017] In a new embodiment, an optocoupler driving circuit is also included, which is used to convert the electrical signal at the input end into the optical signal at the output end to achieve electrical isolation;

[0018] The optocoupler driving circuit includes an inverter and a driving chip.

[0019] In a new embodiment, a power module is also included, which is used to provide a power supply voltage.

[0020] In a new embodiment, a microcontroller is also included, wherein the microcontroller is an STM32-bit microcontroller.

[0021] In a new embodiment, it also includes an organic light-emitting semiconductor, four copper pillars, pin ports, and button circuitry.

[0022] Beneficial effects: Compared with the prior art, the advantages of this utility model are:

[0023] DC-DC converters not only convert the DC voltage of the input power supply into different output voltages, but also have advantages such as high efficiency, stability, small size, and energy saving and environmental protection. Using DC-DC converters can improve the energy utilization efficiency of drones using hydrogen fuel cells, save space and weight for drones, enhance the stability and control precision of drones, and ensure stable flight and normal operation of equipment. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main circuit of this utility model;

[0025] Figure 2 This is a schematic diagram of the DC voltage sampling circuit of this utility model;

[0026] Figure 3 This is a schematic diagram of the optocoupler driving circuit of this utility model;

[0027] Figure 4 This is the SMT32 circuit schematic diagram of this utility model;

[0028] Figure 5 This is a power supply schematic diagram of the power module of this utility model;

[0029] Figure 6 The schematic diagram of the boost chopper circuit proposed in this utility model is shown below.

[0030] Figure 7 This is a schematic diagram of the half-bridge resonant circuit proposed in this utility model;

[0031] Figure 8 This is a schematic diagram of the main circuit diagram of the converter proposed in this utility model;

[0032] Figure 9 This is a circuit diagram of the power supply module proposed in this utility model;

[0033] Figure 10 This is a schematic diagram of the overall structure of the converter main circuit proposed in this utility model. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0035] Reference Figures 1-10A converter for fuel cells in unmanned aerial vehicles. The main circuit of the DC-DC converter is constructed by connecting a Boost chopper circuit and a half-bridge LLC resonant circuit in parallel.

[0036] The DC voltage sampling circuit designed in this utility model is based on an operational amplifier of model LM358 and designed in accordance with the datasheet. Its main function is to convert the DC voltage signal at the measurement point into a current proportional to it. Under the action of the operational amplifier, the signal is amplified and processed to obtain the required voltage value.

[0037] The TLP250H optocoupler driver chip and Ai P74H inverter are used as the core components of the drive circuit. Combined with typical application circuit diagrams in the datasheet, the optocoupler drive circuit aims to provide the necessary signals to the MOSFETs in the main circuit, and then use internal components of the integrated circuit to provide electrical isolation control to external devices. Its main function is to ensure the stability and safety of current or voltage in harsh environments such as high voltage, high current, and high / low temperatures.

[0038] The power device power supply module provides drive voltage, ensuring a stable and reliable power supply for the power devices in the entire converter system, and providing the necessary operating power for control circuits, drive circuits, etc.; a 32-bit microcontroller developed by STMicroelectronics; organic light-emitting semiconductors; four copper pillars, mainly used for external circuit connection; pin ports; and button circuits, mainly used for control of circuit board circuits.

[0039] Reference Figure 6 The Boost converter circuit consists of a DC power supply U, a freewheeling diode D, a fully controllable device Q, an inductor L, a capacitor C, and a resistor R. The fully controllable device Q is a MOSFET because MOSFET control is relatively simple, and it features high input impedance, good high-frequency characteristics, simple drive circuitry, good thermal stability, strong noise immunity, and low power consumption.

[0040] Reference Figure 7 The half-bridge LLC resonant circuit mainly consists of a DC power supply U0, fully controllable devices Q, a high-frequency transformer T, a freewheeling diode D, an inductor L, a capacitor C, and a resistor R. MOSFETs are used for the fully controllable devices Q1 and Q2 because MOSFETs offer advantages such as good thermal stability, simple control, simple drive circuitry, and low power consumption.

[0041] This design uses a half-bridge LLC resonant circuit. On the left is a half-bridge square wave generator composed of an N-type MOSFET and a P-type MOSFET, controlled by two pins for on / off switching. The middle section is the resonant network, which limits the amplitude of the waveform pulses from the switching transistors, optimizing the system's linearity and significantly improving its efficiency, stability, and reliability. Following the resonant circuit is a transformer; the transformer used in this design is a VPT87DB high-frequency isolation transformer. This transformer isolates the input and output voltages in the LLC circuit, achieving resonance, and also performs DC-DC power conversion and matching, improving the efficiency and stability of the resonant circuit. The rectifier section on the right is a full-bridge rectifier circuit composed of four diodes.

[0042] Reference Figure 8 The main circuit of the DC-DC converter is mainly composed of a boost circuit and a half-bridge LLC resonant circuit connected in parallel. The boost circuit is responsible for increasing the voltage, while the half-bridge LLC resonant circuit is responsible for electrical isolation and voltage stabilization.

[0043] The output voltage of a hydrogen fuel cell first enters the Boost circuit section of the main circuit for voltage boosting. After boosting, the voltage fluctuates significantly and requires filtering. The half-bridge LLC circuit designed in this paper incorporates a high-frequency transformer to achieve electrical isolation, isolating the input and output voltages and preventing power flow between power sources or between the power source and the load. Furthermore, the half-bridge LLC resonant circuit also includes a full-bridge rectifier circuit, which reduces the amplitude of the output voltage ripple after passing through the Boost circuit, converting the fluctuating input voltage into a smooth DC voltage for voltage stabilization. Therefore, a half-bridge LLC resonant circuit is connected in parallel after the Boost boost circuit to form the main circuit of the DC-DC converter.

[0044] Reference Figure 3 Optocoupler drive circuit is a device commonly used for isolation and protection circuits. It consists of an inverter and a driver chip, which can convert the electrical signal at the input end into the optical signal at the output end to achieve electrical isolation. In addition to electrical isolation and prevention of grounding interference, this circuit can also achieve low-pass filtering, phase change control and other features, thus greatly improving the reliability of the entire system, reducing crosstalk and noise, and playing a very important role in circuit performance

[27] . Common applications include controlling high voltage, protecting power transistors or other high-frequency switching devices.

[0045] This paper uses the TLP250H optocoupler driver chip and the Ai P74H inverter as the core components of the drive circuit. The optocoupler driver circuit designed in this paper is driven by the TLP250H chip, which aims to provide the required signal to the MOSFET in the main circuit, and then use the internal components of the integrated circuit to provide electrical isolation control to external devices. Its main function is to ensure the stability and safety of current or voltage in harsh environments such as high voltage, high current, and high and low temperatures.

[0046] Reference Figure 9 The power module for power devices provides the drive voltage, ensuring a stable and reliable power supply for the power devices throughout the converter system, and providing the necessary operating power for the control circuits, drive circuits, and other components. Typically, in a DC-DC converter, multiple modules need to coordinate their operation; therefore, each module requires a corresponding power module to provide the necessary voltage and current.

[0047] Reference Figure 2 A DC voltage sampling circuit is an analog circuit used to measure voltage values ​​in a circuit. It typically consists of components such as resistors and operational amplifiers to convert voltage signals at specific locations in the circuit into current signals. The operational amplifier then amplifies and processes the signals to obtain the desired voltage value. The DC voltage sampling circuit designed in this paper uses an LM358 operational amplifier as its core. Table 1 shows the component parameters of the main circuit of the DC-DC converter.

[0048] Table 1

[0049]

[0050]

[0051] Through converter design, the main circuit design parameters of the converter were calculated. A V-D150 heating station was used to solder surface-mount components onto the PCB experimental board. Then, a soldering station was used to solder through-hole components onto the PCB experimental board. Finally, the required DC-DC converter PCB experimental board was obtained, and the converter was experimentally verified. Table 2 shows the actual test results of the DC-DC converter.

[0052] Table 2

[0053]

[0054] The output voltage tested on the test platform was within the range of 23.5-24.1V with an error of less than 2.08%, which is within the allowable error range. The efficiency of the converter was stable at around 92%, which met the requirements of the converter design and verified the feasibility of the fuel cell UAV DC-DC converter designed in this paper.

[0055] The above description is merely a preferred embodiment of this utility model; however, the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and its improved concept, should be included within the protection scope of this utility model.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A converter for a fuel cell in an unmanned aerial vehicle (UAV), characterized in that, It includes a boost chopper circuit and a half-bridge resonant circuit, wherein the boost chopper circuit and the half-bridge resonant circuit are connected in parallel, wherein: The boost chopper circuit includes a DC power supply a, a freewheeling diode a, a fully controllable device a, an inductor a, a capacitor a, and a resistor a. The positive terminal of the DC power supply a is connected to the inductor a. The inductor a is connected to both the freewheeling diode a and the fully controllable device a. The freewheeling diode a is connected to both the capacitor a and the resistor a. The fully controllable device a, the capacitor a, and the resistor a are connected to the negative terminal of the DC power supply a. The half-bridge resonant circuit includes a half-bridge square wave generator, a transformer, and a full-bridge rectifier circuit. The left side of the transformer is connected to the half-bridge square wave generator, and the right side of the transformer is connected to the full-bridge rectifier circuit.

2. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 1, characterized in that, The half-bridge square wave generator includes a DC power supply b and two fully controlled devices b. The DC power supply b and the two fully controlled devices b form a circuit. An inductor b1 is connected between the two fully controlled devices b. A capacitor b3 is connected to the inductor b1. The capacitor b3 is connected to one end of a transformer and the inductor b2 respectively. The other end of the transformer is connected to the inductor b2 and to the negative terminal of the DC power supply b.

3. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 2, characterized in that, The full-bridge rectifier circuit includes parallel freewheeling diode group b1, freewheeling diode group b2, capacitor b4 and resistor b; The freewheeling diode group b1 includes freewheeling diodes b11 and b12 connected in series, and the freewheeling diode group b2 includes freewheeling diodes b21 and b22 connected in series. One end of the transformer is connected between freewheeling diodes b11 and b12, and the other end of the transformer is connected between freewheeling diodes b21 and b22.

4. The converter for a UAV fuel cell as described in claim 1, characterized in that, It also includes a sampling circuit, which is used to convert the voltage signal at the measurement point into a current signal, and amplify and process it to obtain the desired voltage value; The sampling circuit includes an operational amplifier.

5. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 1, characterized in that, It also includes an optocoupler driving circuit, which is used to convert the electrical signal at the input end into the optical signal at the output end to achieve electrical isolation; The optocoupler driving circuit includes an inverter and a driving chip.

6. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 1, characterized in that, It also includes a power module for providing power voltage.

7. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 1, characterized in that, It also includes a microcontroller, which is an STM32-bit microcontroller.

8. The converter for a fuel cell in an unmanned aerial vehicle as described in claim 1, characterized in that, It also includes organic light-emitting semiconductors, four-corner copper pillars, pin ports, and button circuits.

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