Power supply device for fuel cell and power supply method thereof

Abstract

A power supply device for a fuel cell and a power supply method thereof. The power supply device is configured on an aircraft. The power supply device includes a secondary battery, a transformer, a fuel cell, and a bypass switch. The transformer is electrically connected between the secondary battery and the aircraft. The fuel cell is electrically connected to the aircraft and adapted to provide a first output current to the aircraft. The bypass switch is electrically connected between an output terminal of the secondary battery and an output terminal of the fuel cell, and the bypass switch is in parallel with the transformer. The transformer has a first output voltage set value. When a first output terminal voltage of the fuel cell is lower than the first output voltage set value, and the bypass switch is in a non-conducting state, a second output current of the secondary battery is provided to the aircraft through the transformer; when the first output terminal voltage of the fuel cell is lower than the first output voltage set value, and the bypass switch is in a conducting state, the second output current of the secondary battery is provided to the aircraft through the bypass switch.

Description

Technical Field

[0001] This disclosure relates to a power supply device for a fuel cell and a power supply method thereof. Background Technology

[0002] Traditional drones typically use secondary batteries (such as lithium batteries) to provide the power needed for flight. However, given the limited space and weight, the power provided by secondary batteries is only sufficient for a few tens of minutes of flight time. Therefore, in recent years, hybrid electric architectures that combine fuel cells and secondary batteries in drones have emerged, providing the power needed for extended flights.

[0003] However, a decrease in the power supply capacity of the fuel cell or its self-maintenance process can cause a sudden and significant change in the load voltage, leading to a deterioration in power quality. Furthermore, excessive load power demand causing secondary battery failure or exceeding the transformer's rated power will also degrade power quality. Summary of the Invention

[0004] This disclosure relates to a power supply device and a power supply method thereof, which can maintain the load voltage within a predetermined range and avoid large fluctuations in the load voltage.

[0005] According to one aspect of this disclosure, a power supply device is provided, configured on an aircraft having an average required power value. The power supply device includes a secondary battery, a transformer, a fuel cell, and a bypass switch. The transformer is electrically connected between the secondary battery and the aircraft. The fuel cell is electrically connected to the aircraft and adapted to provide a first output current to the aircraft. The bypass switch is electrically connected between an output terminal of the secondary battery and an output terminal of the fuel cell, and is connected in parallel with the transformer. The transformer has a first output voltage setting value. When the voltage at the first output terminal of the fuel cell is lower than the first output voltage setting value, and the bypass switch is in a non-conducting state, a second output current from the secondary battery is provided to the aircraft via the transformer; when the voltage at the first output terminal of the fuel cell is lower than the first output voltage setting value, and the bypass switch is in a conducting state, the second output current from the secondary battery is provided to the aircraft via the bypass switch, wherein the first output voltage setting value is a voltage value corresponding to any power within the range between a maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft.

[0006] According to one aspect of this disclosure, a power supply device is provided, configured on an aircraft having an average required power value. The power supply device includes a secondary battery, a transformer, a fuel cell, and a self-maintenance switch. The transformer is electrically connected between the secondary battery and the aircraft. The fuel cell is electrically connected to the aircraft and adapted to provide a first output current to the aircraft. The self-maintenance switch is electrically connected to the fuel cell and the aircraft, and is adapted to shut off power to a portion of the fuel cell stack, causing the fuel cell to perform a self-maintenance procedure. The transformer has a first output voltage setting value and a second output voltage setting value, the second output voltage setting value being greater than the first output voltage setting value. When a first output terminal voltage of the fuel cell is lower than the first output voltage setting value, a second output current from the secondary battery is provided to the aircraft via the transformer. When a decrease in the first output terminal voltage of the fuel cell is anticipated, the first output voltage setting value is dynamically adjusted to the second output voltage setting value, and the second output current from the secondary battery is provided to the aircraft via the transformer. The first output voltage setting value is a voltage value corresponding to any two power values ​​within the range between a maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft.

[0007] According to one aspect of this disclosure, a power supply method for a power supply device is proposed. The power supply device is configured on an aircraft and includes a secondary battery, a transformer, a fuel cell, and a bypass switch. The transformer is electrically connected between the secondary battery and the aircraft, the fuel cell is electrically connected to the aircraft, and the bypass switch is electrically connected between the secondary battery and the fuel cell, and is connected in parallel with the transformer. The transformer has a first output voltage setting value. The power supply method includes the following steps: the fuel cell provides a first output current to the aircraft. When a first output terminal voltage of the fuel cell is lower than the first output voltage setting value, the transformer provides a second output current from the secondary battery to the aircraft. Under a specific condition, the bypass switch is controlled to conduct, so that the second output current from the secondary battery is supplied to the aircraft via the bypass switch, instead of via the transformer. The specific condition is that the rated output power of the transformer is insufficient to supply the electrical energy required by the aircraft, the transformer is in an abnormal state, or the fuel cell is undergoing self-maintenance.

[0008] According to one aspect of this disclosure, a power supply method for a power supply device is proposed. The power supply device is configured on an aircraft. The power supply device includes a secondary battery, a transformer, a fuel cell, and a self-maintenance switch. The transformer is electrically connected between the secondary battery and the aircraft, the fuel cell is electrically connected to the aircraft, and the self-maintenance switch is electrically connected between the fuel cell and the aircraft. The self-maintenance switch is adapted to shut off power to a portion of the fuel cell stack, causing the fuel cell to perform a self-maintenance procedure. The transformer has a first output voltage setting value and a second output voltage setting value, the second output voltage setting value being greater than the first output voltage setting value. The power supply method includes the following steps: The fuel cell provides a first output current to the aircraft. When a first output terminal voltage of the fuel cell is lower than the first output voltage setting value, the transformer provides a second output current from the secondary battery to the aircraft. When the first output terminal voltage of the fuel cell is expected to decrease, the transformer is dynamically adjusted from the first output voltage setting value to the second output voltage setting value, and the second output current from the secondary battery is provided to the aircraft via the transformer. The first output voltage setting value is a voltage value corresponding to any two power values ​​within the range between a maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft.

[0009] To provide a better understanding of the above and other aspects of this disclosure, specific embodiments are described below in conjunction with the accompanying drawings: Attached Figure Description

[0010] Figure 1A A schematic diagram illustrating a power supply device according to an embodiment of the present disclosure;

[0011] Figure 1B Draw Figure 1A A graph showing the relationship between flight time and power required for an aircraft;

[0012] Figure 1C Plot the characteristic curves of the fuel cell; and

[0013] Figure 1D A schematic diagram illustrating a power supply device according to another embodiment of the present disclosure;

[0014] Figure 2A A schematic diagram illustrating a power supply device according to an embodiment of the present disclosure;

[0015] Figure 2B Draw Figure 2A A schematic diagram of the characteristic curves of a fuel cell;

[0016] Figure 2C A schematic diagram illustrating a power supply device according to another embodiment of the present disclosure;

[0017] Figure 3The diagram illustrates the voltage change at the output point during periods when the fuel cell stack temporarily stops outputting power or reduces its output power.

[0018] [Symbol Explanation]

[0019] 10: Aircraft

[0020] 100-103: Power supply device

[0021] 110: Fuel Cell

[0022] 110a, 120a: Output terminals

[0023] 115: Diode

[0024] 120: Secondary battery

[0025] 130: Transformer

[0026] 140: Controller

[0027] c: node

[0028] C1: Curve

[0029] I1: First output current

[0030] I2: Second output current

[0031] R1: Bypass switch

[0032] R2: Self-maintenance switch

[0033] V S1 First output voltage setting value

[0034] V S2 Second input voltage setting value

[0035] Va: Voltage at the first output terminal

[0036] Vb: Voltage at the second output terminal

[0037] ΔP: Range

[0038] T: a period of time

[0039] Vc: Node voltage

[0040] P av Average required power value

[0041] P max Maximum power value

[0042] P S1 Power value

[0043] P U Maximum required power value Detailed Implementation

[0044] The following embodiments are provided for detailed description. These embodiments are merely illustrative and are not intended to limit the scope of protection of this disclosure. The same / similar symbols are used to denote the same / similar elements in the following description. Directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are only for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the scope of this disclosure.

[0045] First Embodiment

[0046] Please refer to Figure 1A and 1B ,in Figure 1A A schematic diagram of a power supply device according to an embodiment of the present disclosure is shown. Figure 1B Draw Figure 1A The graph shows the relationship between flight time and power required for aircraft 10. A power supply unit 100 is, for example, mounted on aircraft 10 to supply power to it. Aircraft 10 is, for example, a drone.

[0047] According to one embodiment of this disclosure, the power supply device 100 includes a fuel cell 110, a diode 115, a secondary battery 120, a transformer 130, a controller 140, and a bypass switch R1. The transformer 130 is electrically connected between the secondary battery 120 and the aircraft 10. The fuel cell 110 is electrically connected to the aircraft 10 and can provide a first output current I1 to the aircraft 10. The aircraft 10 has an average required power value P. av Average required power value P av Depending on the flight mode of the aircraft 10, this embodiment is not limited.

[0048] Please refer to Figure 1A Transformer 130 has a first output voltage setting value V S1 When the voltage Va at the first output terminal of the fuel cell 110 is lower than the first output voltage setting value V... S1 When the bypass switch R1 is in a non-conducting state, the second output current I2 of the secondary battery 120 will be supplied to the aircraft 10 via the transformer 130. Furthermore, when the first output voltage Va of the output terminal 110a of the fuel cell 110 is lower than the first output voltage setting value V... S1 When the bypass switch R1 is in the on state, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 through the on bypass switch R1. At this time, the transformer 130 is in the off state (that is, the second output current I2 is not supplied to the aircraft 10 by the transformer 130).

[0049] The controller 140 is electrically connected to the output terminal 110a of the fuel cell 110 and the output terminal 120a of the secondary battery 120 to detect the first output voltage Va and the second output voltage Vb. Furthermore, the controller 140 is electrically connected to a bypass switch R1 and is adapted to control the conduction state (on or off) of the bypass switch R1. Additionally, the controller 140 is electrically connected to a transformer 130 and is adapted to detect the state of the transformer 130 and set the first output voltage setpoint V of the transformer 130. S1 .

[0050] In addition, diode 115 is electrically connected between fuel cell 110 and bypass switch R1. The anode of diode 115 is connected to fuel cell 110 and the cathode is connected to bypass switch R1, which can prevent the second output current I2 of secondary battery 120 from flowing back to fuel cell 110.

[0051] In one embodiment, the maximum second output voltage Vb that the output terminal 120a of the secondary battery 120 can provide is higher than the maximum first output voltage Va that the output terminal 110a of the fuel cell 110 can provide, and the transformer 130 is, for example, a step-down transformer. Thus, when the second output voltage Vb of the secondary battery 120 is higher than the first output voltage set value V... S1 At this time, the first transformer 130 can step down the voltage Vb at the second output terminal of the secondary battery 120 to the first output voltage set value V. S1 Transformer 130 is, for example, a DC-to-DC (DC / DC) type transformer.

[0052] In one embodiment, the bypass switch R1 is, for example, a transistor or other relay switch. The bypass switch R1 is connected in parallel with the transformer 130 and is electrically connected between the output terminal 110a of the fuel cell 110 and the output terminal 120a of the secondary battery 120. When the first output terminal voltage Va of the fuel cell 110 is lower than the first output voltage set value V... S1 When the bypass switch R1 is in the on state, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10. After the bypass switch R1 is turned on, a bypass path is formed, so the second output current I2 of the secondary battery 120 will not flow through the transformer 130.

[0053] Since the secondary battery 120 can provide a large second output current I2 after the bypass switch R1 is turned on, it is not limited by the rated output power of the transformer 130. Therefore, it can quickly make up for the power supply shortage caused by the fuel cell 110 and achieve the purpose of stable power supply.

[0054] Please refer to Figure 1AThe transformer 130 can detect the node voltage Vc at node c of the connection between the fuel cell 110 and the aircraft 10. Since the voltage drop between the output terminal 110a of the fuel cell 110 and node c is negligible, the node voltage Vc detected by the transformer 130 is approximately equal to the first output terminal voltage Va of the output terminal 110a of the fuel cell 110. In other words, when the node voltage Vc detected by the transformer 130 is lower than the first output voltage set value V... S1 This means that the first output voltage Va of the fuel cell 110 is lower than the first output voltage setting value V. S1 At that time, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130 or the bypass switch R1.

[0055] Because the voltage Va at the first output terminal of the fuel cell 110 is lower than the first output voltage setting value V S1 In this case, the secondary battery 120 provides the second output current I2 to the aircraft 10 through the transformer 130 or the bypass switch R1, while the first output voltage Va of the fuel cell 110 is higher than or equal to the first output voltage setting value V. S1 When the fuel cell 110 is in operation, the secondary battery 120 does not supply current to the aircraft 10, thus reducing the current loss through the transformer 130 and also reducing the power consumption of the secondary battery 120.

[0056] Please refer to Figure 1B Curve C1 represents the relationship between time and power during the operation of aircraft 10 (such as takeoff, flight, and descent), where P av P represents the average power required, while P represents the average power required. U This represents the maximum required power value. The average required power value P during the time period T during which aircraft 10 operates is also shown. av Power is supplied by fuel cell 110, while the average required power value P av With the highest required power value P U The instantaneous power demand is provided by the secondary battery 120. In other words, the secondary battery 120 makes up for the instantaneous high power required by the aircraft 10 (such as when the aircraft is turning or resisting gusts of wind).

[0057] Because of its high energy density, fuel cell 110 can serve as the primary power source to meet the power needs of the basic load. However, fuel cell 110 has the disadvantage of not being able to instantly increase its power supply. When the load demand increases instantaneously, the secondary battery 120, which has a high power density, provides the additional power.

[0058] Figure 1CThe characteristic curves of fuel cell 110 are plotted, including the relationship between current and voltage (as shown in the voltage curve) and the power curve. Figure 1C As shown, the first output voltage setting value V S1 This represents a value at one point on the voltage curve within the characteristic curve. The first output voltage setpoint V. S1 For example, the maximum power value P between the characteristic curve of fuel cell 110 and the maximum power value P. max The average power required by aircraft 10, P av Any power P within the range ΔP S1 The corresponding voltage value.

[0059] The following describes the power supply method of the power supply device 100: When the aircraft 10 starts to operate, the secondary battery 120 can provide a second output current I2 to the aircraft 10 via the transformer 130 to supply the electrical energy (load) required by the aircraft 10 in the initial stage of operation (such as when the blades start to rotate). At this time, the node voltage Vc at the input terminal of the aircraft 10 is close to the first output voltage setting value V. S1 When the voltage Va at the first output terminal of the fuel cell 110 continues to rise to a value greater than or equal to the first output voltage set value V... S1 When the transformer 130 stops supplying the second output current I2 to the aircraft 10, the secondary battery 120 stops supplying current to the aircraft 10. At this time, the fuel cell 110 acts as the main power source, providing the first output current I1 to the aircraft 10. The first output voltage Va of the fuel cell 110 can change according to the required electrical energy of the aircraft 10. When the required electrical energy of the aircraft 10 increases (e.g., rising, thus causing the blades to rotate rapidly), the first output current I1 supplied by the fuel cell 110 to the aircraft 10 increases, which in turn causes the first output voltage Va of the fuel cell 110 to decrease. When the first output voltage Va of the fuel cell 110 is lower than the first output voltage set value V... S1 At this time, transformer 130 provides the second output current I2 of secondary battery 120 to the aircraft as an auxiliary power source. However, under certain specific conditions, such as when the rated output power of transformer 130 is insufficient to supply the electrical energy required by aircraft 10, when transformer 130 is in an abnormal state, or when fuel cell 110 is undergoing self-maintenance (described in detail later), bypass switch R1 can be controlled to be turned on, so that secondary battery 120 provides more than the rated output power of transformer 130 to aircraft 10 via bypass switch R1. In this embodiment, when the rated output power of transformer 130 is insufficient to supplement the auxiliary electrical energy required by aircraft 10, controller 140 can control bypass switch R1 to be turned on, so that secondary battery 120 can provide more than the rated output power of transformer 130 to aircraft 10. At this time, secondary battery 120 does not provide the second output current I2 via transformer 130.

[0060] In another embodiment, when the controller 140 detects an abnormal state of the transformer 130, such as the internal temperature of the transformer 130 reaching a predetermined value or the output power reaching a predetermined value, making it impossible for the transformer 130 to provide the auxiliary power required by the aircraft 10, the controller 140 may also control the bypass switch R1 to be turned on, so that the secondary battery 120 can provide more than the rated output power of the transformer 130 to the aircraft 10.

[0061] Please refer to Figure 1D The diagram illustrates a power supply device 101 according to another embodiment of the present disclosure. The power supply device 101 of this embodiment is similar to... Figure 1A Similar to the power supply device 100, but notably, the power supply device 101 also includes a self-maintenance switch R2, which is electrically connected to the fuel cell 110 and the aircraft 10. The self-maintenance switch R2 is adapted to shut off power to a portion of the fuel cell stack, allowing the fuel cell 110 to perform a self-maintenance procedure. For example, the fuel cell 110 must stop the power output of a portion of the fuel cell stack every certain period of time (e.g., 10 seconds), for approximately 0.05 to 0.5 seconds, to perform internal wetting operations. Specifically, the fuel cell 110 has one or more fuel cell stacks connected in parallel and has individual self-maintenance switches R2 to facilitate shutting off the output of some or all of the fuel cell stacks. In this embodiment, before the fuel cell 110 prepares to perform a self-maintenance procedure, the controller 140 first turns on the bypass switch R1, allowing the second output current I2 of the secondary battery 110 to be supplied to the aircraft 10 via the bypass switch R1, and then turns off the self-maintenance switch R2 to allow the fuel cell 110 to enter the self-maintenance procedure. This avoids a sudden drop in the voltage of the aircraft 10 during the self-maintenance procedure of the fuel cell 110. After the self-maintenance procedure ends, the controller 140 turns on the self-maintenance switch R2 to restore the first output voltage Va of the fuel cell 110 to normal, and then turns off the bypass switch R1, switching to a system where the first output voltage Va of the fuel cell 110 is lower than the first output voltage set value V. S1 At that time, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130.

[0062] Second Embodiment

[0063] Please refer to Figure 2A The diagram illustrates a power supply device 102 according to another embodiment of the present disclosure, which is, for example, disposed on an aircraft 10 to supply power to the aircraft 10. The aircraft 10 is, for example, a drone.

[0064] The power supply unit 102 includes a fuel cell 110, a diode 115, a secondary battery 120, a transformer 130, a controller 140, and a self-maintenance switch R2. The transformer 130 has a first output voltage setting value V. S1 and the second output voltage setting value V S2 Second output voltage setting value V S2 Greater than the first output voltage setting value V S1 And the second output voltage setting value V S2 Approximately, but slightly less than, the first output voltage Va (or node voltage Vc) at the output terminal 110a of the fuel cell 110. The power supply method of the power supply device 102 is basically similar to that of the power supply device 101, but it should be noted that when the first output voltage Va of the fuel cell 110 is lower than the first output voltage setting value Vc... S1 At this time, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130; when the first output voltage Va of the output terminal 110a of the fuel cell 110 is expected to decrease, for example, during the self-maintenance phase of the fuel cell 110 or when the fuel cell 110 needs to shut down the power output of part of the fuel cell stack, the controller 140 can dynamically adjust the transformer 130 from the first output voltage set value V S1 Up to the larger value of the second output voltage setting V S2 To lower the threshold of auxiliary power supply from the secondary battery 120, during the period when the first output voltage Va at the output terminal 110a of the fuel cell 110 stops outputting or reduces the output of the first output current I1, the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130. This avoids control problems of the aircraft 10 caused by large fluctuations in load power due to the first output voltage Va stopping outputting or reducing the output of the first output current I1. Once the first output voltage Va at the output terminal 110a of the fuel cell 110 returns to above the second output voltage set value V... S2 Then, adjust transformer 130 to the smaller first output voltage setting value V. S1 This restores the first output voltage Va at the output terminal 110a of the fuel cell 110 to the first output current I1.

[0065] The controller 140 is electrically connected to the output terminal 110a of the fuel cell 110 and the output terminal 120a of the secondary battery 120 to detect the first output terminal voltage Va and the second output terminal voltage Vb. Furthermore, the controller 140 is electrically connected to the transformer 130, adapted to detect the state of the transformer 130, and to set the output voltage setpoint of the transformer 130, so that the transformer 130 has a dynamically adjustable first output voltage setpoint V. S1 Or the second output voltage setting value V S2 .

[0066] In addition, the diode 115 is electrically connected between the fuel cell 110 and the transformer 130, which can prevent the second output current I2 of the secondary battery 120 from flowing back to the fuel cell 110.

[0067] The self-maintenance switch R2 is electrically connected to the fuel cell 110 and the aircraft 10. The self-maintenance switch R2 is adapted to shut off power to a portion of the fuel cell stack, enabling the fuel cell 110 to perform a self-maintenance procedure. The controller 140 is adapted to control the on / off state of the self-maintenance switch R2.

[0068] In detail, before the fuel cell 110 performs its self-maintenance procedure, the controller 140 obtains the node voltage Vc and adjusts the transformer 130 to the second output voltage setpoint V based on the node voltage Vc. S2 When the self-maintenance procedure is performed, the self-maintenance switch R2 is opened, and at this time, the voltage of the aircraft 10 is maintained at the expected second output voltage setting value V by the transformer 130. S2 It also provides the second output current I2 of the secondary battery 120 to the aircraft 10, thus preventing a sudden voltage drop in the aircraft 10 due to insufficient power supply during the self-maintenance process of the fuel cell 110. Once the self-maintenance process is complete, the self-maintenance switch R2 is turned on, and the output of the transformer 130 is set to the second output voltage setting value V. S2 Revert to the first output voltage setting value V S1 This restores the voltage Va at the first output terminal of the fuel cell 110 to power the aircraft 10.

[0069] In one embodiment, the fuel cell 110 is, for example, composed of 72 fuel cell units connected in series, each fuel cell unit having an operating voltage between 0.608V and 0.692V. Therefore, the fuel cell 110 can provide an operating voltage between 43.8V and 49.8V, but this disclosure is not limited thereto. In one embodiment, the first output voltage setting value V... S1 and the second output voltage setting value V S2 For example, within the operating voltage range of the fuel cell 110. First output voltage setting value V S1 For example, 43.8V, the second output voltage setting value V S1 For example, 46.8V.

[0070] Furthermore, the secondary battery 120 may be composed of, for example, 12 secondary battery cells connected in series, each with an operating voltage between 3.65V and 4.15V. Therefore, the secondary battery 120 can provide an operating voltage between 43.8V and 49.8V, but this disclosure is not limited thereto.

[0071] Figure 2B Draw Figure 2A The characteristic curves of the fuel cell 110 include the relationship between current and voltage (as shown in the voltage curve) and the power curve. Figure 2B As shown, the first output voltage setting value V S1 and the second output voltage setting value V S2 These are the values ​​of two points on the voltage curve in the characteristic curve. First output voltage setpoint V S1 and the second output voltage setting value V S2 For example, the maximum power value P between the characteristic curve of fuel cell 110 and the maximum power value P. max The average power required by aircraft 10, P av The voltage value corresponding to any two power levels within the range ΔP. However, in other embodiments, the second output voltage setting value V... S2 It is not necessarily required to have an average power value P of less than 10 times that of the aircraft. av The corresponding voltage value, the second output voltage setting value V S2 Only requires a voltage higher than the first output voltage setting value V S1 That is, in one embodiment, the first output voltage setting value V S1 For example, the maximum power value P of the characteristic curve of fuel cell 110. max The corresponding voltage value, the second output voltage setting value V S2 For example, the average power required for aircraft 10 is P. av The corresponding voltage value.

[0072] In this embodiment, when the first output voltage Va of the fuel cell 110 is expected to drop significantly or the electrical energy required by the aircraft 10 is expected to increase significantly, the first output voltage setpoint V can be dynamically adjusted. S1 To the second output voltage setting value V S2 This is to lower the threshold of auxiliary power supply from the secondary battery 120, so that the second output current I2 generated by the secondary battery 120 can be provided to the aircraft 10 earlier, in order to prevent insufficient power supply that may be caused by the fuel cell 110.

[0073] In other words, in this embodiment, the output setting of the transformer 130 can be dynamically adjusted to an appropriate first output voltage setting value V based on the first output terminal voltage Va of the fuel cell 110. S1 Or the second output voltage setting value V S2 This ensures that the voltage required by the aircraft 10 will not fluctuate significantly due to a decrease in the output power of the fuel cell 110 or a change in the first output current I1. The second output voltage setting value V S2(For example, 46.8V) can be set to a first output voltage Va (for example, 47V) close to the voltage before the self-maintenance procedure, so that when entering the self-maintenance operation, the fuel cell 110 stops outputting the first output current I1, and the transformer 130 provides the second output voltage setting value V. S2 This is to prevent significant fluctuations in the voltage of the aircraft 10.

[0074] In the first and second embodiments described above, the bypass switch R1 in the first embodiment and the output voltage setting of the dynamically adjusting transformer 130 in the second embodiment can also be used in combination. Please refer to... Figure 2C The diagram illustrates a power supply device 103 according to another embodiment of this disclosure. Specifically, before the fuel cell 110 performs a self-maintenance procedure, if it is anticipated that the first output voltage Va of the fuel cell 110 will decrease, for example, during the self-maintenance phase of the fuel cell 110 or when the fuel cell 110 needs to shut down the power output of part of the fuel cell stack, the controller 140 can dynamically adjust the transformer 130 from the first output voltage set value V. S1 Up to the larger value of the second output voltage setting V S2 To lower the threshold of auxiliary power supply from the secondary battery 120, during periods when the fuel cell 110 stops outputting or reduces its output of the first output current I1, the second output current I2 from the secondary battery 120 will be supplied to the aircraft 10 via the transformer 130. Once the self-maintenance procedure ends, the self-maintenance switch R2 is activated, and the output of the transformer 130 is set to the second output voltage setting value V. S2 Revert to the first output voltage setting value V S1 This restores the first output voltage Va of the fuel cell 110 to power the aircraft 10, preventing significant voltage fluctuations in the aircraft 10. In one embodiment, the second output current I2 of the secondary battery 120 can also be supplied to the aircraft 10 via a bypass switch R1. That is, before the self-maintenance procedure, the bypass switch R1 is turned on, and the second output current I2 of the secondary battery 120 is supplied to the aircraft 10 via the bypass switch R1. After the self-maintenance procedure ends, the bypass switch R1 is turned off to restore the power supply from the first output current I1 of the fuel cell 110. In addition, if the controller 140 detects an abnormal state of the transformer 130, such as the internal temperature of the transformer 130 reaching a predetermined value or the output power reaching a predetermined value, making it unable to provide the auxiliary power required by the aircraft 10, the controller 140 can control the bypass switch R1 to turn on, allowing the secondary battery 120 to directly drive the load via the bypass, providing power to the aircraft 10 exceeding the rated output power of the transformer 130, avoiding power failure to supply the load due to the rated limitations or abnormal failure of the transformer 130.

[0075] Please refer to Figure 3This plot shows the voltage change of the output point voltage (i.e., node voltage Vc) during periods when the fuel cell stack temporarily stops outputting or reduces its output power. It's important to note that under normal operating conditions, fuel cell 110 is the primary power source; therefore, the node voltage curve is essentially the same as the fuel cell voltage curve. Figure 3 The voltage curve of the fuel cell is not shown in the figure. In the first mode, under a fixed output voltage setting, during a period when the fuel cell stack temporarily stops outputting or reduces its output power, the voltage of the fuel cell 110 may momentarily drop to the fixed output voltage setting (e.g., 43.8V) of the transformer 130 due to the influence of the electrical energy required for continuous load transport by the aircraft 10. Therefore, a sharp drop in the node voltage curve can be observed in the first mode. The second mode uses the method described above... Figure 1D In the embodiment, by turning on the bypass switch R1, during the period when the fuel cell 110 stack temporarily stops outputting or reduces its output power, it is directly powered by the secondary battery 120. This causes the node voltage curve to suddenly jump to a level close to that of the secondary battery 120 (e.g., 49V), demonstrating that if the secondary battery 120 is significantly higher than the current node voltage, it will cause a momentary surge in the load point voltage. The third mode employs the method described above. Figure 2A The method of dynamically adjusting the output voltage setting value shows that before the fuel cell stack 110 stops outputting or reduces output power, the output setting of the transformer 130 is dynamically adjusted to be close to the current output point voltage (e.g., 47V). This ensures that when the fuel cell stack temporarily stops outputting or reduces output power, the output point voltage can be maintained at the second output battery setting value (e.g., 46.8V) without sudden drops or rises, thus providing a stable node voltage at the load end.

[0076] In summary, although this disclosure has been presented above with reference to embodiments, it is not intended to limit the scope of this disclosure. Those skilled in the art to which this disclosure pertains can make various modifications and refinements without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the appended claims.

Claims

1. A power supply device disposed on an aircraft having an average required power value, the power supply device comprising: Secondary batteries; A transformer is electrically connected between the secondary battery and the aircraft. as well as A fuel cell, electrically connected to the aircraft, and adapted to provide a first output current to the aircraft; as well as A bypass switch is electrically connected between the output terminal of the secondary battery and the output terminal of the fuel cell, and the bypass switch is connected in parallel with the transformer; The transformer has a first output voltage setting value. When the voltage at the first output terminal of the fuel cell is lower than the first output voltage setting value and the bypass switch is in a non-conducting state, the second output current of the secondary battery is provided to the aircraft through the transformer. When the voltage at the first output terminal of the fuel cell is lower than the first output voltage setting value and the bypass switch is in a conducting state, the second output current of the secondary battery is provided to the aircraft through the bypass switch. The first output voltage setting value is a voltage value corresponding to any power within the range between the maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft. The power supply device also includes a self-maintenance switch, which is electrically connected to the fuel cell and the aircraft. The self-maintenance switch is adapted to shut off the power to part of the fuel cell stack, so that the fuel cell can perform a self-maintenance procedure. Before the fuel cell performs the self-maintenance procedure, the bypass switch is turned on and then the self-maintenance switch is turned off. After the self-maintenance procedure is completed, the self-maintenance switch is turned on and then the bypass switch is turned off.

2. The power supply device as claimed in claim 1 further includes a diode electrically connected between the fuel cell and the bypass switch, wherein the anode of the diode is connected to the fuel cell and the cathode of the diode is connected to the bypass switch.

3. The power supply device as claimed in claim 1 further includes a controller electrically connected to the bypass switch and the transformer. The controller is adapted to control the conduction state of the bypass switch and detect the state of the transformer. When the controller detects an abnormal state of the transformer, the controller controls the bypass switch to conduct, so that the secondary battery provides power exceeding the rated output power of the transformer.

4. The power supply device as claimed in claim 3, wherein the abnormal state of the transformer is that the internal temperature of the transformer reaches a predetermined value or the output power of the transformer reaches a predetermined value.

5. The power supply device as claimed in claim 1, wherein the maximum second output voltage that the secondary battery can provide is higher than the maximum first output voltage that the fuel cell can provide.

6. A power supply device disposed on an aircraft having an average required power value, the power supply device comprising: Secondary batteries; A transformer is electrically connected between the secondary battery and the aircraft. A fuel cell, electrically connected to the aircraft, and adapted to provide a first output current to the aircraft; as well as A self-maintenance switch is electrically connected to the fuel cell and the aircraft. The self-maintenance switch is adapted to shut off power to a portion of the fuel cell stack, enabling the fuel cell to perform a self-maintenance procedure. The transformer has a first output voltage setting value and a second output voltage setting value, the second output voltage setting value being greater than the first output voltage setting value. When the first output terminal voltage of the fuel cell is lower than the first output voltage setting value, the second output current of the secondary battery is supplied to the aircraft via the transformer. When it is expected that the first output terminal voltage of the fuel cell will decrease, the transformer is dynamically adjusted from the first output voltage setting value to the second output voltage setting value, and the second output current of the secondary battery is supplied to the aircraft via the transformer. The first output voltage setting value and the second output voltage setting value are voltage values ​​corresponding to any two power values ​​within the range between the maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft. The scenario in which the voltage at the first output terminal of the fuel cell is expected to decrease includes the fuel cell's self-maintenance procedure. Before the self-maintenance procedure is performed, the output setting of the transformer is adjusted to the second output voltage setting value, and then the self-maintenance switch is turned off. After the self-maintenance procedure is completed, the self-maintenance switch is turned on, and then the output setting of the transformer is changed back from the second output voltage setting value to the first output voltage setting value.

7. The power supply device as claimed in claim 6, wherein, The first output voltage setting is the voltage value corresponding to the maximum power value of the characteristic curve of the fuel cell, and the second output voltage setting is the voltage value corresponding to the average required power value of the aircraft.

8. The power supply device of claim 6 further includes a controller electrically connected to the fuel cell, the secondary battery and the transformer, the controller being adapted to detect the state of the transformer and control the output voltage of the transformer to the first output voltage setting value or the second output voltage setting value.

9. A method for supplying power to a power supply device, the power supply device being disposed on an aircraft, the power supply device comprising a secondary battery, a transformer, a fuel cell, and a bypass switch, the transformer being electrically connected between the secondary battery and the aircraft, the fuel cell being electrically connected to the aircraft, the bypass switch being electrically connected between the secondary battery and the fuel cell, and the bypass switch being connected in parallel with the transformer, the transformer having a first output voltage setting value; the power supply method comprising: The fuel cell provides the initial output current to the aircraft; When the voltage at the first output terminal of the fuel cell is lower than the set value of the first output voltage, the transformer supplies the second output current of the secondary battery to the aircraft; and Under certain conditions, the bypass switch is controlled to be turned on, so that the second output current of the secondary battery is supplied to the aircraft through the bypass switch, instead of through the transformer. The specific conditions include: the transformer's rated output power is insufficient to supply the electrical energy required by the aircraft; the transformer is in an abnormal state; or the fuel cell is undergoing self-maintenance. The power supply device also includes a self-maintenance switch, which is electrically connected to the fuel cell and the aircraft. The self-maintenance switch is adapted to shut off the power to part of the fuel cell stack, so that the fuel cell can perform a self-maintenance procedure. Before the fuel cell performs the self-maintenance procedure, the bypass switch is turned on and then the self-maintenance switch is turned off. After the self-maintenance procedure is completed, the self-maintenance switch is turned on and then the bypass switch is turned off.

10. The power supply method of claim 9, wherein the aircraft has an average required power value, and the first output voltage setting value is a voltage value corresponding to any power within the range between the maximum power value of the characteristic curve of the fuel cell and the average required power value of the aircraft.

11. The power supply method of claim 9, wherein the maximum second output voltage that the secondary battery can provide is higher than the maximum first output voltage that the fuel cell can provide.

12. The power supply method as claimed in claim 9, wherein the abnormal state of the transformer is that the internal temperature of the transformer reaches a predetermined value or the output power of the transformer reaches a predetermined value.

13. A method for supplying power to a power supply device, the power supply device being disposed on an aircraft, the power supply device comprising a secondary battery, a transformer, a fuel cell, and a self-maintenance switch, the transformer being electrically connected between the secondary battery and the aircraft, the fuel cell being electrically connected to the aircraft, the self-maintenance switch being electrically connected between the fuel cell and the aircraft, the self-maintenance switch being adapted to shut off power to a portion of the fuel cell stack to enable the fuel cell to perform a self-maintenance procedure, the transformer having a first output voltage setting value and a second output voltage value, the second output voltage setting value being greater than the first output voltage setting value; the power supply method comprising: The fuel cell provides the initial output current to the aircraft; When the voltage at the first output terminal of the fuel cell is lower than the first output voltage setting value, the transformer provides the second output current of the secondary battery to the aircraft; as well as When it is anticipated that the first output voltage of the fuel cell will decrease, the transformer is dynamically adjusted from the first output voltage setting value to the second output voltage setting value, and the second output current of the secondary battery is supplied to the aircraft through the transformer; The first output voltage setting value and the second output voltage setting value are voltage values ​​corresponding to any two power values ​​within the range between the maximum power value of the fuel cell's characteristic curve and the average required power value of the aircraft. The scenario in which the voltage at the first output terminal of the fuel cell is expected to decrease includes the fuel cell's self-maintenance procedure. Before the self-maintenance procedure is performed, the output setting of the transformer is adjusted to the second output voltage setting value, and then the self-maintenance switch is turned off. After the self-maintenance procedure is completed, the self-maintenance switch is turned on, and then the output setting of the transformer is changed back from the second output voltage setting value to the first output voltage setting value.

14. The power supply method of claim 13, wherein the first output voltage setting is the voltage value corresponding to the maximum power value of the characteristic curve of the fuel cell, and the second output voltage setting is the voltage value corresponding to the average required power value of the aircraft.

15. The power supply method of claim 13, wherein the second output voltage setting value is approximately, but slightly less than, the first output terminal voltage of the fuel cell.

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