CN114696443A - Power supply device for fuel cell and power supply method thereof - Google Patents

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 comprises 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 is adapted to provide a first output current to the aircraft. The bypass switch is electrically connected between an output end of the secondary battery and an output end 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 of a first output end of the fuel cell is lower than the set value of the first output voltage, and the bypass switch is in a non-conducting state, a second output current of the secondary battery is provided for 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 supplied to the aircraft via the bypass switch.

Description

Power supply device for fuel cell and power supply method thereof

technical field

The present disclosure relates to a power supply device for a fuel cell and a power supply method thereof.

Background technique

General drones usually use secondary batteries (eg, lithium batteries) to provide power required during flight. However, under the limited space and weight, the power provided by the secondary battery is only enough to provide tens of minutes of flight time. Therefore, in recent years, the hybrid power architecture of fuel cells and secondary batteries has been deployed on UAVs, which can provide Electricity required for long flights.

However, when the power supply capacity of the fuel cell is reduced or the self-maintenance is performed, the load voltage may change instantaneously and greatly, resulting in the deterioration of the power supply quality. In addition, when the power demand of the load is too high, the power supply of the secondary battery fails or the rated power of the transformer is exceeded, and the quality of the power supply is also deteriorated.

SUMMARY OF THE INVENTION

The present 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 changes in the load voltage.

According to an aspect of the present disclosure, a power supply device is provided, which is configured on an aircraft, and the aircraft has 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 is 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 connected in parallel with the transformer. The transformer has a first output voltage setting. When the voltage of a first output terminal of the fuel cell is lower than the set value of the first output voltage and the bypass switch is in a non-conducting state, a second output current of the secondary battery is supplied to the aircraft through the transformer; When the voltage of the first output terminal is lower than the set value of the first output voltage, 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, wherein the set value of the first output voltage is The voltage value corresponding to any power in the range between a maximum power value of the characteristic curve of the fuel cell and the average required power value of the aircraft.

According to an aspect of the present disclosure, a power supply device is provided, which is configured on an aircraft, and the aircraft has 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 is 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 the self-maintenance switch is adapted to turn off the power of a part of the fuel cell stack, so that the fuel cell can perform a self-maintenance procedure. The transformer has a first output voltage setting value and a second output voltage setting value, and the second output voltage setting value is greater than the first output voltage setting value. When the voltage of a first output terminal of the fuel cell is lower than the set value of the first output voltage, a second output current of the secondary battery is supplied to the aircraft through the transformer. When it is expected that the voltage of the first output terminal of the fuel cell is about to decrease, the first output voltage setting value is dynamically adjusted to the second output voltage setting value, and the second output current of the secondary battery is provided to the aircraft through the transformer. The first output voltage setting value is a voltage value corresponding to any two powers within a range between a maximum power value of the characteristic curve of the fuel cell and an average required power value of the aircraft.

According to an aspect of the present disclosure, a power supply method of a power supply device is provided. 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, and the fuel cell is electrically connected In the aircraft, the bypass switch is electrically connected between the secondary battery and the fuel cell, and the bypass switch is connected in parallel with the transformer, and 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 the voltage of a first output terminal of the fuel cell is lower than the set value of the first output voltage, the transformer provides a second output current of the secondary battery to the aircraft. Under a specific condition, 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 without supplying the second output current through the transformer. Wherein, the specific condition is that an output rated power of the transformer is insufficient to supply the electric power required by the aircraft, the state of the transformer is abnormal, or the fuel cell is in self-maintenance period.

According to an aspect of the present disclosure, a power supply method of a power supply device is provided. 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 a self-maintenance switch is electrically connected to the fuel cell and the aircraft, and the self-maintenance switch is suitable for turning off a part of the power of the fuel cell stack , to make the fuel cell perform a self-maintenance procedure, the transformer has a first output voltage setting value and a second output voltage setting value, and the second output voltage setting value is 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 the voltage of a first output terminal of the fuel cell is lower than the set value of the first output voltage, the transformer provides a second output current of the secondary battery to the aircraft. When the voltage of the first output terminal 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 of the secondary battery is supplied to the aircraft through the transformer. The first output voltage setting value is a voltage value corresponding to any two powers within a range between a maximum power value of the characteristic curve of the fuel cell and an average required power value of the aircraft.

In order to have a better understanding of the above-mentioned and other aspects of the present disclosure, the following specific embodiments are given and described in detail with the accompanying drawings as follows:

Description of drawings

FIG. 1A is a schematic diagram of a power supply device according to an embodiment of the present disclosure;

FIG. 1B is a graph showing the relationship between time and required power when the aircraft of FIG. 1A is in flight;

FIG. 1C depicts a characteristic curve of a fuel cell; and

1D is a schematic diagram of a power supply device according to another embodiment of the present disclosure;

2A is a schematic diagram of a power supply device according to an embodiment of the present disclosure;

FIG. 2B is a schematic diagram illustrating a characteristic curve of the fuel cell of FIG. 2A;

2C is a schematic diagram of a power supply device according to another embodiment of the present disclosure;

FIG. 3 is a graph showing the voltage change of the output point voltage during the period when the fuel cell stack temporarily stops outputting or reduces the output power.

【Symbol Description】

10: Aircraft

100-103: Power supply unit

110: Fuel Cells

110a, 120a: output terminal

115: Diode

120: Secondary battery

130: Transformer

140: Controller

c:node

C1: Curve

I ₁ : the first output current

I ₂ : The second output current

R1: Bypass switch

R2: Self-maintenance switch

V _S1 : The first output voltage setting value

V _S2 : The second input voltage setting value

Va: the voltage of the first output terminal

Vb: The second output terminal voltage

ΔP: range

T: for a while

Vc: node voltage

P _av : Average required power value

P _max : maximum power value

P _S1 : Power value

P _U : Maximum required power value

Detailed ways

The following examples are provided for detailed description, and the examples are only used as examples, and are not intended to limit the scope of protection of the present disclosure. In the following, the same/similar symbols are used to represent the same/similar elements for description. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or rear, etc., are only referring to the directions of the drawings. Accordingly, the directional terms used are illustrative and not limiting of the present disclosure.

first embodiment

Please refer to FIGS. 1A and 1B , wherein FIG. 1A is a schematic diagram of a power supply device according to an embodiment of the present disclosure, and FIG. 1B is a diagram illustrating the relationship between flight time and required power of the aircraft 10 of FIG. 1A . The power supply device 100 is, for example, configured on the aircraft 10 to supply power to the aircraft 10 . The aircraft 10 is, for example, a drone.

According to an embodiment of the present 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 the first output current I ₁ to the aircraft 10 . The aircraft 10 has an average required power value P _av , and the average required power value P _av is determined according to the flight mode of the aircraft 10 , which is not limited in this embodiment.

Referring to FIG. 1A , the transformer 130 has a first output voltage setting value V _S1 . When the first output terminal voltage Va of the output terminal 110a of the fuel cell 110 is lower than the first output voltage setting value V _S1 and the bypass switch R1 is in a non-conducting state, the second output current of the secondary battery 120 is at this time. I ₂ is provided to aircraft 10 via transformer 130 . In addition, when the first output terminal voltage Va of the output terminal 110a of the fuel cell 110 is lower than the first output voltage setting value V _S1 and the bypass switch R1 is in the conducting state, the second output current of the secondary battery 120 is switched to I ₂ is provided to the aircraft 10 via the turned on bypass switch R1, at this time, the transformer 130 is in a closed state (ie, the second output current I ₂ is not provided to the aircraft 10 by the transformer 130).

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. In addition, the controller 140 is electrically connected to the bypass switch R1, and is adapted to control the conduction state (conducting or non-conducting) of the bypass switch R1. In addition, the controller 140 is electrically connected to the transformer 130 and is adapted to detect the state of the transformer 130 and set the first output voltage setting value V _S1 of the transformer 130 .

In addition, the diode 115 is electrically connected between the fuel cell 110 and the bypass switch R1, the anode of the diode 115 is connected to the fuel cell 110, and the cathode is connected to the bypass switch R1, which can block the second output current _I2 of the secondary battery 120 from returning to the fuel battery 110.

In one embodiment, the maximum second output terminal voltage Vb that the output terminal 120a of the secondary battery 120 can provide is higher than the maximum first output terminal voltage Va that the output terminal 110a of the fuel cell 110 can provide, and the transformer 130 , for example, is a voltage reducer. In this way, when the second output terminal voltage Vb of the secondary battery 120 is higher than the first output voltage setting value V _S1 , the first transformer 130 can step down the second output terminal voltage Vb of the secondary battery 120 to the first output Voltage setting value V _S1 . The transformer 130 is, for example, a direct current to direct current (DC/DC) type transformer.

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 the bypass switch R1 is electrically connected between the output terminal 110 a of the fuel cell 110 and the output terminal 120 a of the secondary battery 120 . When the first output terminal voltage Va of the fuel cell 110 is lower than the first output voltage setting value V _S1 and the bypass switch R1 is in the conducting state, the second output current I ₂ of the secondary battery 120 is supplied to the aircraft at this time 10, and the bypass switch R1 is turned on to form a bypass path, so the second output current I ₂ of the secondary battery 120 does not flow through the transformer 130 .

Also, after the bypass switch R1 is turned on, the secondary battery 120 can provide a larger second output current I ₂ , which is not limited by the rated output power of the transformer 130 , so the shortage of power supply caused by the fuel cell 110 can be filled as soon as possible to achieve The purpose of stable power supply.

Referring to FIG. 1A , the transformer 130 can detect the node voltage Vc of the node c connecting the fuel cell 110 and the aircraft 10 . Since the voltage loss between the output terminal 110a of the fuel cell 110 and the node c is negligible, the node voltage Vc detected by the transformer 130 is substantially 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 setting value V _S1 , it means that the first output terminal voltage Va of the fuel cell 110 is lower than the first output voltage setting value V At _S1 , the second output current I ₂ of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130 or the bypass switch R1 .

Since the first output terminal voltage Va of the fuel cell 110 is lower than the first output voltage setting value V _S1 , the secondary battery 120 only provides the second output current I ₂ to the aircraft through the transformer 130 or the bypass switch R1 10, and when the first output terminal voltage Va of the fuel cell 110 is higher than or equal to the first output voltage setting value V _S1 , the fuel cell 110 is directly powered, and the secondary battery 120 does not provide current to the aircraft 10, so it can be Reducing the loss of current passing through the transformer 130 can also reduce the power consumption of the secondary battery 120 .

Please refer to FIG. 1B , the curve C1 represents the relationship between time and power during the operation of the aircraft 10 (such as the take-off process, the flight process in the air, the descent process), wherein P _av represents the average required power value, and _PU represents the highest required power value. During a period T of operation of the aircraft 10, the average required power value P _av is provided by the fuel cell 110, and the instantaneous power demand between the average required power value P _av and the highest required power value _PU is provided by the secondary battery 120 offers. In other words, the secondary battery 120 supplements the instantaneous high power required by the aircraft 10 (such as when the aircraft is turning or resisting gusts of wind that require high power).

Because the fuel cell 110 has the advantage of high energy density, it can be used as the main power supplier to provide the power supply demand of the basic load. However, the fuel cell 110 has the disadvantage of being unable to instantly increase the power supply. When the load demand increases instantaneously, the fuel cell 110 has the The power density secondary battery 120 provides additional power requirements.

FIG. 1C shows a characteristic curve of the fuel cell 110, which includes the relationship between current and voltage (as shown in the voltage curve) and a power curve. As shown in FIG. 1C , the first output voltage setting value V _S1 is a value at one point of the voltage curve in the characteristic curve. The first output voltage setting value V _S1 is, for example, corresponding to any power P _S1 in the range ΔP between the maximum power value P _max of the characteristic curve of the fuel cell 110 and the average required power value P _av of the aircraft 10 . voltage value.

The power supply method of the power supply device 100 is described below: when the aircraft 10 starts to operate, the secondary battery 120 can provide the second output current I ₂ to the aircraft 10 via the transformer 130 for the needs of the aircraft 10 in the early stage of operation (such as starting to rotate the blades, etc.). power (load), at this time, the node voltage Vc of the input terminal of the aircraft 10 is close to the first output voltage setting value V _S1 . When the first output terminal voltage Va of the fuel cell 110 continues to rise to a value greater than or equal to the first output voltage setting value V _S1 , the transformer 130 stops providing the second output current I ₂ to the aircraft 10 to stop the secondary battery 120 from supplying the aircraft to the aircraft. 10 current output. At this time, the fuel cell 110 serves as the main power source to provide the first output current I ₁ to the aircraft 10 . When the required electric power of the aircraft 10 increases (eg rises, so the blades rotate rapidly), the first output current _I1 provided by the fuel cell 110 to the aircraft 10 increases, which in turn causes the first output terminal voltage Va of the fuel cell 110 to drop. When the first output terminal voltage Va of the fuel cell 110 is lower than the first output voltage setting value V _S1 , the transformer 130 provides the second output current I ₂ of the secondary battery 120 to the aircraft as an auxiliary power source. However, under a certain condition, for example, the rated power output of the transformer 130 is insufficient to supply the electrical energy required by the aircraft 10, the transformer 130 is in an abnormal state, or during the self-maintenance of the fuel cell 110 (described in detail later), the bypass switch can be controlled. R1 is turned on, so that the secondary battery 120 provides power beyond the output rating of the transformer 130 to the aircraft 10 via the bypass switch R1 . In this embodiment, under the condition that the output rated power of the transformer 130 is not sufficient to supplement the auxiliary power required by the aircraft 10 , the controller 140 can control the bypass switch R1 to be turned on, so that the secondary battery 120 can provide more power than the transformer 130 The output rated power is supplied to the aircraft 10 , and the secondary battery 120 does not provide the second output current I ₂ via the transformer 130 at this time.

In another embodiment, when the controller 140 detects that the state of the transformer 130 is abnormal, for example, the internal temperature of the transformer 130 reaches a predetermined value or the output power reaches a predetermined value, so that the transformer 130 cannot provide the auxiliary power required by the aircraft 10 , the controller 140 can also control the bypass switch R1 to be turned on, so that the secondary battery 120 can provide the output rated power exceeding the transformer 130 to the aircraft 10 .

Please refer to FIG. 1D , which is a schematic diagram of a power supply device 101 according to another embodiment of the present disclosure. The power supply device 101 of this embodiment is similar to the power supply device 100 in FIG. 1A , but it should be noted that the power supply device 101 further includes a self-maintenance switch R2 that electrically connects the fuel cell 110 and the aircraft 10 . The self-maintenance switch R2 is adapted to turn off the power of a part of the fuel cell stack, so that the fuel cell 110 performs a self-maintenance procedure. For example, the fuel cell 110 must stop the power output of a part of the fuel cell stack every time period (for example, 10 seconds), approximately stop 0.05 seconds to 0.5 seconds for internal wetting operation. In detail, the fuel cell 110 has one or more cell stacks connected in parallel, and has an individual self-maintenance switch R2 to turn off the output of some or all of the cell stacks. In this embodiment, before the fuel cell 110 is ready to perform the self-maintenance procedure, the controller 140 turns on the bypass switch R1 first, so that the second output current _I2 of the secondary battery 110 is supplied to the aircraft 10 via the bypass switch R1, and then The self-maintenance switch R2 is then turned off to allow the fuel cell 110 to enter the self-maintenance procedure. In this way, a situation in which the voltage of the aircraft 10 suddenly drops during the self-maintenance procedure of the fuel cell 110 can be avoided. After the self-maintenance procedure ends, the controller 140 turns on the self-maintenance switch R2 to restore the voltage Va of the first output terminal of the fuel cell 110 to normal, and then turns off the bypass switch R1 to change the voltage Va of the first output terminal of the fuel cell 110 to the normal state. When Va is lower than the first output voltage setting value V _S1 , the second output current I ₂ of the secondary battery 120 is supplied to the aircraft 10 via the transformer 130 .

Second Embodiment

Please refer to FIG. 2A , which is a schematic diagram of a power supply device 102 according to another embodiment of the present disclosure. The power supply device 102 is, for example, disposed on the aircraft 10 to supply power to the aircraft 10 . The aircraft 10 is, for example, a drone.

The power supply device 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 a second output voltage setting value V _S2 , the second output voltage setting value V _S2 is greater than the first output voltage setting value V _S1 , and the second output voltage setting value V S2 The value V _S2 is approximately but slightly less than the first output terminal voltage Va (or node voltage Vc) of the fuel cell 110 output terminal 110a. 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 terminal voltage Va of the fuel cell 110 is lower than the first output voltage setting value V _S1 The second output current I ₂ is provided to the aircraft 10 via the transformer 130; when the first output terminal voltage Va of the output terminal 110a of the fuel cell 110 is expected to decrease, for example, the fuel cell 110 is in a self-maintenance stage or the fuel cell 110 needs to be shut down At this time, the controller 140 can dynamically adjust the transformer 130 from the first output voltage setting value V _S1 to the larger second output voltage setting value V _S2 to reduce the power output by the secondary battery 120 , etc. The threshold value of the auxiliary power supply is such that during the period when the first output terminal voltage Va of the output terminal 110a of the fuel cell 110 stops outputting or reduces the outputting of the first output current _I1 , the second output current _I2 of the secondary battery 120 passes through the transformer. 130 is provided to the aircraft 10 to avoid the problem of control of the aircraft 10 caused by the large fluctuation of the power of the load terminal caused by the stop of the output of the first output terminal voltage Va or the reduction of the output first output current I ₁ . When the first output terminal voltage Va of the output terminal 110a of the fuel cell 110 is higher than the second output voltage setting value V _S2 again, the transformer 130 is adjusted to the smaller first output voltage setting value V _S1 , so that The first output terminal voltage Va of the output terminal 110a of the fuel cell 110 resumes to output the first output current I ₁ .

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. In addition, the controller 140 is electrically connected to the transformer 130 and is adapted to detect the state of the transformer 130 and set the output voltage setting value of the transformer 130, so that the transformer 130 has a dynamically adjusted first output voltage setting value V _S1 or a second output voltage setting value V S1 Output voltage setting value V _S2 .

In addition, the diode 115 is electrically connected between the fuel cell 110 and the transformer 130 to block the second output current I ₂ of the secondary battery 120 from flowing back to the fuel cell 110 .

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 turn off the power of a part of the fuel cell stack, so that the fuel cell 110 performs a self-maintenance procedure. The controller 140 is adapted to control the conduction state (on or off) of the self-maintenance switch R2.

Specifically, before the fuel cell 110 performs the self-maintenance procedure, the controller 140 obtains the node voltage Vc, and adjusts the transformer 130 to the second output voltage setting value V _S2 according to the node voltage Vc. When the self-maintenance procedure is performed, the self-maintenance switch R2 is turned off. At this time, the voltage of the aircraft 10 is maintained at the expected second output voltage setting value V _S2 by the transformer 130 , and the second output current I ₂ of the secondary battery 120 is provided. For the aircraft 10, in this way, the situation where the voltage of the aircraft 10 suddenly drops due to insufficient power supply of the fuel cell 110 during the self-maintenance procedure can be avoided. After the self-maintenance procedure ends, turn on the self-maintenance switch R2 and change the output setting of the transformer 130 from the second output voltage setting value V _S2 back to the first output voltage setting value V _S1 , so that the first output voltage of the fuel cell 110 is set. The output terminal voltage Va restores power to the aircraft 10 .

In one embodiment, the fuel cell 110 is formed by, for example, 72 fuel cell units connected in series, and the operating voltage of each fuel cell unit is between 0.608V and 0.692V. Therefore, the fuel cell 110 can provide an operating voltage between 43.8V and 49.8V, but the present 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 are, for example, within the range of the operating voltage of the fuel cell 110 . The first output voltage setting value V _S1 is, for example, 43.8V, and the second output voltage setting value V _S1 is, for example, 46.8V.

In addition, the secondary battery 120 is formed by, for example, 12 secondary battery cells connected in series, and the operating voltage of each secondary battery cell is between 3.65V and 4.15V. Therefore, the secondary battery 120 can provide an operating voltage between 43.8V˜49.8V, but the present disclosure is not limited thereto.

FIG. 2B shows a characteristic curve of the fuel cell 110 of FIG. 2A , which includes a relationship between current and voltage (as shown by the voltage curve) and a power curve. As shown in FIG. 2B , the first output voltage setting value V _S1 and the second output voltage setting value V _S2 are the values of two points in the voltage curve in the characteristic curve. The first output voltage setting value V _S1 and the second output voltage setting value V _S2 are, for example, ranges between the maximum power value P _max of the characteristic curve of the fuel cell 110 and the average required power value P _av of the aircraft 10 . The voltage value corresponding to any two powers within ΔP. However, in other embodiments, the second output voltage setting value V _S2 does not necessarily need to be lower than the voltage value corresponding to the average power value P _av of the aircraft 10 , and the second output voltage setting value V _S2 only needs to be higher than the first output voltage setting value V S2 The output voltage setting value V _S1 is sufficient. In one embodiment, the first output voltage setting value V _S1 is, for example, the voltage value corresponding to the maximum power value P _max of the characteristic curve of the fuel cell 110 , and the second output voltage setting value V _S2 is, for example, the average value of the aircraft 10 . The voltage value corresponding to the required power value P _av .

In this embodiment, when the voltage Va of the first output terminal 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 setting value V _S1 to the second output voltage setting value V S1 can be dynamically adjusted. The fixed value V _S2 is used to lower the threshold value of auxiliary power supply by the secondary battery 120 , so that the second output current I ₂ generated by the secondary battery 120 can be provided to the aircraft 10 for use in advance, so as to prevent the possible power supply shortage caused by the fuel cell 110 .

That is to say, in this embodiment, the output setting of the transformer 130 can be dynamically adjusted to an appropriate first output voltage setting value V _S1 or a second output voltage setting value according to the first output terminal voltage Va of the fuel cell 110 V _S2 , so that the voltage required by the aircraft 10 does not greatly change due to the drop of the output power of the fuel cell 110 or the change of the first output current I ₁ . The second output voltage setting value V _S2 (for example, 46.8V) can be set close to the first output terminal voltage Va (for example, 47V) before the self-maintenance procedure, so that the fuel cell 110 stops the first output when entering the self-maintenance operation. The output of the current I ₁ is provided by the transformer 130 to provide the second output voltage setting value V _S2 , so as to keep the voltage of the aircraft 10 from changing significantly.

In the above-mentioned first embodiment and the second embodiment, the bypass switch R1 of the first embodiment and the method of dynamically adjusting the output voltage setting value of the transformer 130 of the second embodiment can also be used in combination. Please refer to FIG. 2C , which is a schematic diagram of a power supply device 103 according to another embodiment of the present disclosure. That is, before the fuel cell 110 performs the self-maintenance procedure, if it is expected that the first output terminal voltage Va of the fuel cell 110 is about to decrease, for example, the fuel cell 110 is in the self-maintenance stage or the fuel cell 110 needs to shut down part of the fuel cell stack. At this time, the controller 140 can dynamically adjust the transformer 130 from the first output voltage setting value V _S1 to the larger second output voltage setting value V _S2 to reduce the threshold value of the auxiliary power supply by the secondary battery 120 , The second output current I ₂ from the secondary battery 120 is supplied to the aircraft 10 via the transformer 130 during the period in which the fuel cell 110 stops outputting or reduces the output first output current I ₁ . After the self-maintenance procedure ends, turn on the self-maintenance switch R2 and change the output setting of the transformer 130 from the second output voltage setting value V _S2 back to the first output voltage setting value V _S1 , so that the first output voltage of the fuel cell 110 is set. The output terminal voltage Va restores power to the aircraft 10 to prevent the voltage of the aircraft 10 from fluctuating greatly. In one embodiment, the second output current I ₂ of the secondary battery 120 can also be provided to the aircraft 10 via the bypass switch R1, that is, before the self-maintenance procedure is performed, the bypass switch R1 is turned on first, and the secondary battery 120 is turned on. The second output current I ₂ is provided to the aircraft 10 via the bypass switch R1 , and after the self-maintenance procedure ends, the bypass switch R1 is turned off to restore the power supply from the fuel cell 110 outputting the first output current I ₁ . In addition, if the controller 140 detects that the state of the transformer 130 is abnormal, for example, the internal temperature of the transformer 130 reaches a predetermined value or the output power reaches a predetermined value, so that the transformer 130 cannot provide the auxiliary power required by the aircraft 10 , the controller 140 may The bypass switch R1 is controlled to be turned on, so that the secondary battery 120 can directly drive the load through the bypass, which can provide the output power exceeding the rated power of the transformer 130 to the aircraft 10, and avoid the failure of the power supplying the load due to the rated limit or abnormal failure of the transformer 130. .

Please refer to FIG. 3 , which shows a voltage change diagram for the output point voltage (ie, the node voltage Vc) during the period when the fuel cell stack temporarily stops outputting or reduces the output power. It should be noted that, in general use, the fuel cell 110 is the main power supply, so the node voltage curve is basically the same as that of the fuel cell, so the voltage curve of the fuel cell is not shown in FIG. 3 . The first mode in the figure is that when the output voltage is set at a fixed value, during the period when the fuel cell stack temporarily stops outputting or reduces the output power, the voltage of the fuel cell 110 may be instantaneously affected by the power required by the aircraft 10 to continuously pull the load. drop to the fixed output voltage setting value (eg 43.8V) set by the transformer 130, so it can be seen that in the first mode, the node voltage curve drops sharply; the second mode is to use the above-mentioned embodiment of FIG. 1D to turn on By bypassing the switch R1, during the period when the fuel cell 110 stack temporarily stops outputting or reduces the output power, the power is supplied directly via the secondary battery 120, so that the node voltage curve suddenly jumps to the voltage close to the secondary battery 120 (for example, 49V), It shows that if the voltage of the secondary battery 120 is much higher than the current node voltage, the voltage of the load point will suddenly rise; Before the stack 110 stops outputting or reduces the output power, the output setting of the transformer 130 is dynamically adjusted to be close to the current output point voltage (for example, 47V), so that when the fuel cell stack temporarily stops outputting or reduces the output power, the output point voltage can be maintained at the first voltage. Two output battery settings (for example, 46.8V), without sudden drop or sudden rise, can provide a stable node voltage at the load end.

To sum up, although the present disclosure has been disclosed above with examples, it is not intended to limit the present disclosure. Those skilled in the art to which the present disclosure pertains can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure should be determined by the scope defined by the appended claims.

Claims (22)

1. A power supply device configured on an aircraft, the aircraft having an average requested power value, the power supply device comprising:

a secondary battery;

a transformer electrically connected between the secondary battery and the aircraft; and

the fuel cell is electrically connected with the aircraft and is suitable for providing first output current for the aircraft; and

a bypass switch electrically connected between the output terminal of the secondary battery and the output terminal of the fuel battery, and connected in parallel with the transformer;

when the first output end voltage of the fuel cell is lower than the first output voltage set value and the bypass switch is in a non-conducting state, the second output current of the secondary battery is provided for 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 cell is provided to the aircraft through the bypass switch;

wherein the first output voltage setting value is a voltage value corresponding to any power within a range between a maximum power value of a characteristic curve of the fuel cell and the average required power value of the aircraft.

2. The power supply device according to claim 1, further comprising a diode electrically connected between the fuel cell and the bypass switch, an anode of the diode being connected to the fuel cell, and a cathode of the diode being connected to the bypass switch.

3. The power supply device according to claim 1, further comprising a self-maintenance switch electrically connecting 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 bypass switch being turned on before the fuel cell performs the self-maintenance procedure, and the bypass switch being turned off after the self-maintenance procedure is completed.

4. The power supply apparatus according to claim 1, further comprising a controller electrically connected to the bypass switch and the transformer, wherein the controller is adapted to control a conduction status of the bypass switch and detect a status of the transformer, and when the controller detects an abnormal status of the transformer, the controller controls the bypass switch to conduct, so that the secondary battery provides an output rated power exceeding the transformer.

5. The power supply apparatus according to claim 4, wherein the abnormal state of the transformer is that an internal temperature of the transformer reaches a predetermined value or an output power of the transformer reaches a predetermined value.

6. The power supply device according to claim 1, wherein the maximum second output terminal voltage that the secondary battery can provide is higher than the maximum first output terminal voltage that the fuel cell can provide.

7. A power supply device configured on an aircraft, the aircraft having an average requested power value, the power supply device comprising:

a secondary battery;

a transformer electrically connected between the secondary battery and the aircraft;

the fuel cell is electrically connected with the aircraft and is suitable for providing first output current for the aircraft; and

the self-maintenance switch is electrically connected with the fuel cell and the aircraft and is suitable for closing part of the electric power of the fuel cell stack so as to enable the fuel cell to carry out a self-maintenance program;

wherein the transformer has a first output voltage set value and a second output voltage set value, the second output voltage set value being greater than the first output voltage set value, a second output current of the secondary battery being supplied to the aircraft via the transformer when the first output voltage of the fuel cell is lower than the first output voltage set value; dynamically adjusting the transformer from the first output voltage setting to the second output voltage setting when a decrease in the first output voltage of the fuel cell is expected, the second output current of the secondary battery being provided to the aircraft via the transformer;

the first output voltage set value is a voltage value corresponding to any two powers within a range between the maximum power value of the characteristic curve of the fuel cell and the average required power value of the aircraft.

8. The power supply device according to claim 7, wherein the first output voltage setting is a voltage value corresponding to the maximum power value of a characteristic curve of the fuel cell, and the second output voltage setting is a voltage value corresponding to the average requested power value of the aircraft.

9. The power supply device according to claim 7, further comprising a bypass switch 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, and when the bypass switch is in a conducting state, the second output current of the secondary battery is supplied to the aircraft via the bypass switch.

10. The power supply apparatus according to claim 9, wherein the situation where the first output terminal voltage of the fuel cell is expected to decrease comprises a self-maintenance procedure of the fuel cell, wherein the bypass switch is turned on before the self-maintenance procedure is performed, and the bypass switch is turned off after the self-maintenance procedure is completed.

11. The power supply apparatus according to claim 9, further comprising a controller electrically connected to the bypass switch and the transformer, wherein the controller is adapted to control a conduction condition of the bypass switch and detect a state of the transformer, and when the controller detects that the state of the transformer is abnormal, the controller controls the bypass switch to conduct, so that the secondary battery provides an output rated power exceeding the output rated power of the transformer to the aircraft.

12. The power supply apparatus according to claim 11, further comprising a controller electrically connected to the fuel cell, the secondary battery and the transformer, the controller being adapted to detect a state of the transformer and control the output voltage of the transformer to be the first output voltage setting value or the second output voltage setting value.

13. A power supply method of a power supply device is provided, the power supply device is configured on an aircraft, the power supply device comprises 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, the bypass switch is electrically connected between the secondary battery and the fuel cell, the bypass switch is connected with the transformer in parallel, and the transformer has a first output voltage set value; the power supply method comprises the following steps:

the fuel cell providing a first output current to the aircraft;

the transformer supplying a second output current of the secondary battery to the aircraft when a first output terminal voltage of the fuel cell is lower than the first output voltage set value; and

under a specific condition, controlling the bypass switch to be conducted, so that the second output current of the secondary battery is provided to the aircraft through the bypass switch without the second output current being provided through the transformer;

wherein the specific condition is that the output rated power of the transformer is insufficient to supply the electric energy required by the aircraft, the state of the transformer is abnormal or the fuel cell is in self-maintenance period.

14. The power supply method according to claim 13, wherein the aircraft has an average requested power value, and the first output voltage setting value is a voltage value corresponding to any power within a range between a maximum power value of a characteristic curve of the fuel cell and the average requested power value of the aircraft.

15. The power supply method according to claim 13, wherein the maximum second output terminal voltage that the secondary battery can provide is higher than the maximum first output terminal voltage that the fuel cell can provide.

16. The power supply method according to claim 13, wherein the abnormal state of the transformer is that an internal temperature of the transformer reaches a predetermined value or an output power of the transformer reaches a predetermined value.

17. The power supply method according to claim 13, wherein the power supply device further comprises a self-maintenance switch electrically connecting the fuel cell and the aircraft, the self-maintenance switch is adapted to turn off a portion of the power of the fuel cell stack to enable the fuel cell to perform a self-maintenance procedure, the bypass switch is turned on before the fuel cell performs the self-maintenance procedure, and the bypass switch is turned off after the self-maintenance procedure is completed.

18. A power supply method of a power supply device, the power supply device is disposed on the aircraft, the power supply device includes secondary battery, voltage transformer, fuel cell and self-maintenance switch, the voltage transformer is connected between the secondary battery and the aircraft, the fuel cell is connected to the aircraft, the self-maintenance switch is connected to the fuel cell and the aircraft, the self-maintenance switch is suitable for closing part of the electric power of the fuel cell stack, make the fuel cell carry on the self-maintenance procedure, the voltage transformer has the first output voltage set value and the second output voltage value, the second output voltage set value is greater than the first output voltage set value; the power supply method comprises the following steps:

the fuel cell providing a first output current to the aircraft;

the transformer supplying a second output current of the secondary battery to the aircraft when a first output terminal voltage of the fuel cell is lower than the first output voltage set value; and

dynamically adjusting the transformer from the first output voltage setting to the second output voltage setting when the first output voltage of the fuel cell is expected to decrease, the second output current of the secondary cell being provided to the aircraft via the transformer;

the first output voltage set value is a voltage value corresponding to any two powers in a range between the maximum power value of the characteristic curve of the fuel cell and the average required power value of the aircraft.

19. The power supply method according to claim 18, wherein the first output voltage set value is a voltage value corresponding to the maximum power value of a characteristic curve of the fuel cell, and the second output voltage set value is a voltage value corresponding to the average required power value of the aircraft.

20. The power supply method of claim 18 wherein the second output voltage set point is approximately but slightly less than the first output voltage of the fuel cell.

21. The power supply method according to claim 18, wherein the power supply device further comprises a bypass switch electrically connected between the secondary battery and the fuel cell, and the bypass switch is connected in parallel with the transformer, wherein the situation in which the first output terminal voltage of the fuel cell is expected to decrease comprises a self-maintenance procedure of the fuel cell, the bypass switch is turned on before the self-maintenance procedure is performed, so that the second output current of the secondary battery is supplied to the aircraft through the bypass switch, and the bypass switch is turned off after the self-maintenance procedure is completed.

22. The power supply method according to claim 18, wherein the power supply device further comprises a bypass switch electrically connected between the secondary battery and the fuel cell, and the bypass switch is connected in parallel with the transformer, the power supply method further comprising: and under the specific condition, controlling the bypass switch to be conducted, so that the second output current of the secondary battery is provided to the aircraft through the bypass switch without providing the second output current through the transformer, wherein the specific condition is that the output rated power of the transformer is insufficient to supply the electric energy required by the aircraft, the state of the transformer is abnormal or the fuel cell is in a self-maintenance period.

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