Fuel cell system for unmanned aerial vehicle and start-stop control method

Abstract

The invention discloses a fuel cell system for an unmanned aerial vehicle, which is characterized in that the fuel cell system comprises a fuel cell (2) and a lithium ion battery (3) which are installed on the unmanned aerial vehicle (1), the fuel cell (2) is connected with a power supply circuit of the unmanned aerial vehicle (1) through a DCDC converter (4), and the fuel cell system also comprises an FCU controller (5), a safety switch (6) and a current sensor (7), the current sensor (7) is arranged on one of an output positive electrode and an output negative electrode of the lithium ion battery (3), and meanwhile, the FCU controller (5) is electrically connected with the fuel cell (2), the DCDC converter (4), the safety switch (6) and the current sensor (7). The invention also discloses a start-stop control method of the fuel cell system.

Description

Technical Field

[0001] This invention relates to the application of hydrogen fuel cells in unmanned aerial vehicles (UAVs), and in particular to a fuel cell system for UAVs, as well as a start-stop control method for the system. Background Technology

[0002] Hydrogen-powered drones, as an emerging aviation technology, possess numerous advantages, including high energy conversion efficiency, strong temperature adaptability, zero carbon emissions, and extreme environmental friendliness. Furthermore, their endurance far surpasses that of traditional battery-powered drones, enabling long-duration continuous operations. This makes them particularly suitable for extended missions such as large-scale mapping, border patrol, disaster monitoring, and logistics transportation. Simultaneously, hydrogen-powered drones exhibit lower noise levels and better stealth capabilities, giving them unique value in military and ecological monitoring fields.

[0003] However, since most existing drones still rely primarily on lithium-ion batteries for power, their battery management systems (BMS) and flight control systems (flight controllers) are designed based on a pure battery-powered architecture, making them incompatible with hydrogen fuel cell systems. Especially for models already designed or in mass production, introducing a hydrogen power system to improve range requires modifications to the existing lithium-ion battery packs, BMS, and flight control systems to achieve synergy with the fuel cell system's start-stop control logic. This incurs significant manpower and material costs and may also interfere with the drone's native control logic due to adjustments to the flight control system, leading to extended verification and testing cycles and impacting actual deployment efficiency.

[0004] Therefore, a method or apparatus is needed to solve the above problems. Summary of the Invention

[0005] This invention addresses the aforementioned shortcomings of existing technologies by proposing a fuel cell system and start-stop control method for drones that enables autonomous start-stop control of the fuel cell system without altering the original architecture of the drone, thereby rapidly transforming the hydrogen power system to improve its range.

[0006] The technical solution of the present invention is: a fuel cell system for unmanned aerial vehicles (UAVs), characterized in that: the fuel cell system includes a fuel cell 2 and a lithium-ion battery 3 installed on the UAV 1, the fuel cell 2 is connected to the power supply circuit of the UAV 1 through a DC-DC converter 4, and the fuel cell system also includes an FCU controller 5, a safety switch 6 and a current sensor 7, the current sensor 7 is disposed on one of the positive and negative output terminals of the lithium-ion battery 3, and the FCU controller 5 is electrically connected to the fuel cell 2, the DC-DC converter 4, the safety switch 6 and the current sensor 7.

[0007] The current sensor 7 is a Hall sensor or a shunt.

[0008] The safety switch is a manual relay or contactor.

[0009] A start-stop control method for a fuel cell system for unmanned aerial vehicles (UAVs), characterized in that the method is performed according to the following steps: A. First, confirm that drone 1 is in standby mode and check if safety switch 6 is in the open position. If manual switch 6 is in the open position, proceed to the next step. B. Using Δt as the sampling period, the lithium battery current I is detected in real time. 锂 and voltage U 锂 That is, I is detected once every interval Δt. 锂 and U 锂 And calculate the time period t according to the following formula. 开 Average output power P within 平，

[0010] The sampling period Δt ranges from 0.1 to 1 second, and the time interval t... 开 The value range is 5-60 seconds, where t is the instantaneous moment at the time of detection. C. The average output power P obtained through calculation 平 With the set value P 设 Compare, if P 平 >P 设 Then start fuel cell 2 and monitor the output current I of fuel cell 2 in real time. 燃 Simultaneously, the system status of fuel cell 2 is set to running, completing the system startup of fuel cell 2. D. Calculate the net output current I of the lithium-ion battery and fuel cell in real time according to the following formula. 净 , when I 净 Less than the set value I 设 And the duration t 关 At that time, perform the shutdown operation. I 净 = I 锂 +I 燃 , When a lithium battery discharges, I 锂 When I is positive, it is during charging. 锂 For negative values, the time period t 关 The value range is 5-60 seconds. Alternatively, the status of safety switch 6 can be detected; when safety switch 6 is closed, a shutdown operation can be performed. E. When the current of fuel cell 2 is reduced to zero, fuel cell 2 is purged for a set time t. 吹 Then stop the purging and put drone 1 into standby mode. t 吹 The value range is 10-120 seconds.

[0011] The set value P 设 The value is the larger of two values: twice the standby power of UAV 1 and 0.2 times the startup power, and does not exceed 0.5 times the flight power.

[0012] The set value I 设 It is 1-3 times the standby current of fuel cell 2.

[0013] Compared with the prior art, the present invention has the following advantages: This type of fuel cell system for UAVs, along with its matching start-stop control method, can achieve automatic start-up by monitoring lithium battery power without modifying the UAV flight control or lithium battery. It can also determine whether the UAV system has landed by comparing the net output current, thereby achieving automatic start-stop. The entire control system requires no modification to the UAV, facilitating rapid adaptation to various UAVs and shortening the development cycle. This control method eliminates the need for additional flight controller control and eliminates the need for the lithium battery to send real-time status information via a BMS, reducing control loops and wiring harnesses, resulting in a more streamlined system and lower system costs. Furthermore, it employs a combination of safety switches and state variables (voltage, current) for control. Startup is confirmed via a safety switch to prevent malfunctions; simultaneously, a one-button stop function via the safety switch ensures automatic shutdown in case of sensor failures or other unforeseen circumstances, guaranteeing system reliability and safety.

[0014] It can be said that this fuel cell system and its start-stop control method have many advantages, making it particularly suitable for application in the field of traditional drone retrofitting, and its market prospects are very broad. Attached Figure Description

[0015] Figure 1 This is a system composition diagram of the fuel cell system in this invention. Detailed Implementation

[0016] Specific embodiments of the present invention will now be described in conjunction with the accompanying drawings. Figure 1 As shown: A fuel cell system for a drone includes a fuel cell 2 and a lithium-ion battery 3 installed on the drone 1. The fuel cell 2 is connected to the power supply circuit of the drone 1 through a DC-DC converter 4. The fuel cell system also includes an FCU controller 5, a safety switch 6, and a current sensor 7. The current sensor 7 is located on one of the positive and negative output terminals of the lithium-ion battery 3. The FCU controller 5 is electrically connected to the fuel cell 2, the DC-DC converter 4, the safety switch 6, and the current sensor 7.

[0017] The current sensor 7 is a Hall sensor or a shunt.

[0018] The safety switch is a manual relay or contactor.

[0019] A start-stop control method for a fuel cell system for unmanned aerial vehicles (UAVs) is performed according to the following steps: A. First, confirm that drone 1 is in standby mode and check if safety switch 6 is in the open position. If manual switch 6 is in the open position, proceed to the next step. B. Using Δt as the sampling period, the lithium battery current I is detected in real time. 锂 and voltage U 锂 That is, I is detected once every interval Δt. 锂 and U 锂 And calculate the time period t according to the following formula. 开 Average output power P within 平，

[0020] The sampling period Δt ranges from 0.1 to 1 second, and the time interval t... 开 The value range is 5-60 seconds, where t is the instantaneous moment at the time of detection. C. The average output power P obtained through calculation 平 With the set value P 设 Compare, if P 平 >P 设 Then start fuel cell 2 and monitor the output current I of fuel cell 2 in real time. 燃 Simultaneously, the system status of fuel cell 2 is set to running, completing the system startup of fuel cell 2. D. Calculate the net output current I of the lithium-ion battery and fuel cell in real time according to the following formula. 净 , when I 净 Less than the set value I 设 And the duration t 关 At that time, perform the shutdown operation. I 净 = I 锂 +I 燃 , When a lithium battery discharges, I 锂 When I is positive, it is during charging. 锂 For negative values, the time period t 关 The value range is 5-60 seconds. Alternatively, the status of safety switch 6 can be detected; when safety switch 6 is closed, a shutdown operation can be performed. E. When the current of fuel cell 2 is reduced to zero, fuel cell 2 is purged for a set time t. 吹Then stop the purging and put drone 1 into standby mode. t 吹 The value range is 10-120 seconds.

[0021] The set value P 设 The value is the larger of two values: twice the standby power of UAV 1 and 0.2 times the startup power, and does not exceed 0.5 times the flight power.

[0022] The set value I 设 It is 1-3 times the standby current of fuel cell 2.

[0023] Example 1: First, confirm that drone 1 is in standby mode and check if safety switch 6 is in the open position. If safety switch 6 is in the open position, proceed to the next step. Then, with a sampling period of Δt = 0.1 seconds, the lithium battery current I is detected in real time. 锂 and voltage U 锂 That is, I is detected every 0.1 seconds. 锂 and U 锂 And calculate the time period t according to the following formula. 开 =Average output power P over 5 seconds 平 ,

[0024] It should be noted that t represents the instantaneous time at the time of detection, and tt 开 That is, t before the detection time. 开 seconds, for example, when t 开 When the time interval is 5 seconds, the above formula calculates the average output power from 5 seconds before the detection time to the detection time.

[0025] C. Determine the average output power P calculated using the above formula. 平 Is it greater than 200W (i.e., the set value P)? 设 If P 平 If the current exceeds 200W, fuel cell 2 will be activated, and the output current I of fuel cell 2 will be monitored in real time. 燃 Simultaneously, the system status of fuel cell 2 is set to running, completing the system startup of fuel cell 2. D. Calculate the net output current I of the lithium-ion battery and fuel cell in real time according to the following formula. 净 , when I 净 Less than 2A (i.e., set value I) 设 When, and lasts for 5 seconds (i.e., t) 关 When ), perform a shutdown operation. I 净 = I 锂 +I燃 , Alternatively, the status of safety switch 6 can be detected; when safety switch 6 is closed, a shutdown operation can be performed. When fuel cell 2 is deloaded to zero current, fuel cell 2 is purged for a set time of 30 seconds (i.e., t). 吹 After that, stop the purging and put drone 1 into standby mode. In this embodiment, the standby power of drone 1 is 50W, twice that is 100W, while the startup power of drone 1 is 1000W, 0.2 times that is 200W. Since 200W > 100W and does not exceed 0.5 times the flight power of drone 1, the set value P is... 设 The value is 200W.

[0026] The standby current of fuel cell 2 is 2A, and the set value I is... 设 The value is 1 times the standby current, i.e., I 设 =2A.

[0027] In this embodiment, the current sensor 7 is located on the positive terminal of the lithium battery 3, and the current sensor 7 is a Hall sensor, while the safety switch 6 is a manual relay.

[0028] Example 2: First, confirm that drone 1 is in standby mode and check if safety switch 6 is in the open position. If safety switch 6 is in the open position, proceed to the next step. Then, with a sampling period of Δt = 1 second, the lithium battery current I is detected in real time. 锂 and voltage U 锂 That is, I is detected once every 1 second. 锂 and U 锂 And calculate the time period t according to the following formula. 开 =Average output power P over 60 seconds 平 ,

[0029] It should be noted that t represents the instantaneous time at the time of detection, and tt 开 That is, t before the detection time. 开 seconds, for example, when t 开 When the time interval is 60 seconds, the above formula calculates the average output power from 60 seconds before the detection time to the detection time.

[0030] C. Determine the average output power P calculated using the above formula. 平 Is it greater than 300W (i.e., the set value P)? 设 If P 平 If the current exceeds 300W, fuel cell 2 will start, and the output current I of fuel cell 2 will be monitored in real time.燃 Simultaneously, the system status of fuel cell 2 is set to running, completing the system startup of fuel cell 2. D. Calculate the net output current I of the lithium-ion battery and fuel cell in real time according to the following formula. 净 , when I 净 Less than 6A (i.e., set value I) 设 When, and lasts for 60 seconds (i.e., t) 关 When ), perform a shutdown operation. I 净 = I 锂 +I 燃 , Alternatively, the status of safety switch 6 can be detected; when safety switch 6 is closed, a shutdown operation can be performed. When fuel cell 2 is deloaded to zero current, fuel cell 2 is purged for a set time of 120 seconds (i.e., t). 吹 After that, stop the purging and put drone 1 into standby mode. In this embodiment, the standby power of drone 1 is 100W, twice that is 200W, while the startup power of drone 1 is 1500W, 0.2 times that is 300W. Since 300W > 200W and does not exceed 0.5 times the flight power of drone 1, the set value P is... 设 The value is 300W.

[0031] The standby current of fuel cell 2 is 2A, and the set value I is... 设 The value is 3 times the standby current, i.e., I 设 =6A.

[0032] In this embodiment, the current sensor 7 is located on the negative terminal of the lithium battery 3, and the current sensor 7 is a shunt. Meanwhile, the safety switch 6 is a manual relay.

Claims

1. A fuel cell system for unmanned aerial vehicles (UAVs), characterized in that: The fuel cell system includes a fuel cell (2) and a lithium-ion battery (3) installed on the drone (1). The fuel cell (2) is connected to the power supply circuit of the drone (1) through a DC-DC converter (4). The fuel cell system also includes an FCU controller (5), a safety switch (6) and a current sensor (7). The current sensor (7) is set on one of the positive and negative output terminals of the lithium-ion battery (3). The FCU controller (5) is electrically connected to the fuel cell (2), the DC-DC converter (4), the safety switch (6) and the current sensor (7).

2. The fuel cell system for unmanned aerial vehicles according to claim 1, characterized in that: The current sensor (7) is a Hall sensor or a shunt.

3. The fuel cell system for unmanned aerial vehicles according to claim 1, characterized in that: The safety switch is a manual relay or contactor.

4. A start-stop control method for a fuel cell system for unmanned aerial vehicles (UAVs), characterized in that: The method is performed according to the following steps: A. First, confirm that the drone (1) is in standby mode and check whether the safety switch (6) is in the open state. If the manual switch (6) is in the open state, proceed to the next step. B. Using Δt as the sampling period, the lithium battery current I is detected in real time. 锂 and voltage U 锂 That is, I is detected once every interval Δt. 锂 and U 锂 And calculate the time period t according to the following formula. 开 Average output power P within 平， ； The sampling period Δt ranges from 0.1 to 1 second, and the time interval t... 开 The value range is 5-60 seconds, where t is the instantaneous moment at the time of detection. C. The average output power P obtained through calculation 平 With the set value P 设 Compare, if P 平 >P 设 Then start the fuel cell (2) and monitor the output current I of the fuel cell (2) in real time. 燃 At the same time, the system state of the fuel cell (2) is set to the running state, and the system startup of the fuel cell (2) is completed. D. Calculate the net output current I of the lithium-ion battery and fuel cell in real time according to the following formula. 净 , when I 净 Less than the set value I 设 And the duration t 关 At that time, perform the shutdown operation. I 净 = I 锂 +I 燃 , When a lithium battery discharges, I 锂 When I is positive, it is during charging. 锂 For negative values, the time period t 关 The value range is 5-60 seconds. Alternatively, the status of the safety switch (6) can be detected. When the safety switch (6) is closed, a shutdown operation can be performed. E. When the fuel cell (2) is deloaded to zero current, the fuel cell (2) is purged for a set time t. 吹 Then stop purging and put the drone (1) into standby mode. t 吹 The value range is 10-120 seconds.

5. The start-stop control method for a fuel cell system for unmanned aerial vehicles according to claim 4, characterized in that: The set value P 设 The larger of the two values, which is twice the standby power and 0.2 times the startup power of the UAV (1), and not exceeding 0.5 times the flight power.

6. The start-stop control method for a fuel cell system for unmanned aerial vehicles according to claim 4, characterized in that: The set value I 设 It is 1-3 times the standby current of fuel cell (2).

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