Method, apparatus, controller for controlling a hydrogen circulation pump, and fuel cell

Abstract

The present disclosure relates to a method, an apparatus, a controller and a fuel cell system for controlling a hydrogen circulation pump in a fuel cell system. The method comprises determining that the hydrogen circulation pump is blocked by ice. The method further comprises setting a start-up current of the hydrogen circulation pump to a predetermined current value, the predetermined current value being greater than a normal current value for starting up the hydrogen circulation pump in a case where the hydrogen circulation pump is not blocked by ice. Furthermore, the method further comprises restarting the hydrogen circulation pump in response to a phase current of the hydrogen circulation pump satisfying a predetermined condition. In this way, the time required for the ice breaking process can be reduced, the cold start-up speed of the hydrogen circulation pump can be accelerated, the duration of the ice breaking process can be reduced, and the wear and tear on various components due to an increase in self-heating can be reduced.

Description

Technical Field

[0001] This disclosure relates to fuel cell systems, and more specifically, to methods, apparatus, controllers, and fuel cell systems for controlling hydrogen circulation pumps. Background Technology

[0002] In a fuel cell system, the primary function of the hydrogen recirculation pump is to recirculate unreacted hydrogen from the stack outlet to the stack inlet. During power generation, hydrogen is supplied to the stack to participate in the electrochemical reaction, but in practice, the hydrogen supply is usually excessive to ensure the reaction proceeds fully. After unreacted hydrogen is discharged from the stack outlet, the hydrogen recirculation pump can return it to the inlet to participate in the reaction again.

[0003] In addition, the fuel cell system also includes a water vapor separator. Water (e.g., water vapor) discharged from the anode passes through the water vapor separator, a portion of which can be captured by the water vapor separator, while the other portion passes through the water vapor separator and is circulated back to the anode by the action of the hydrogen circulation pump. Summary of the Invention

[0004] In a first aspect of the embodiments of this disclosure, a method for controlling a hydrogen recirculation pump in a fuel cell system is provided. The method includes determining that the hydrogen recirculation pump is blocked by ice. The method further includes setting a starting current of the hydrogen recirculation pump to a predetermined current value, which is greater than a normal current value used to start the hydrogen recirculation pump when it is not blocked by ice. Furthermore, the method includes restarting the hydrogen recirculation pump in response to a predetermined condition being met by a phase current of the hydrogen recirculation pump.

[0005] In a second aspect of the embodiments of this disclosure, an apparatus for controlling a hydrogen circulation pump in a fuel cell system is provided. The apparatus includes a blockage determination unit configured to determine that the hydrogen circulation pump is blocked by ice. The apparatus also includes a current setting unit configured to set the starting current of the hydrogen circulation pump to a predetermined current value greater than a normal current value for starting the hydrogen circulation pump when it is not blocked by ice. Furthermore, the apparatus includes a current monitoring unit configured to restart the hydrogen circulation pump in response to a predetermined condition being met by the phase current of the hydrogen circulation pump.

[0006] In a third aspect of embodiments of this disclosure, a controller is provided. The controller includes one or more processors; and a storage device for storing one or more programs that, when executed by the one or more processors, cause the one or more processors to implement a method for controlling a hydrogen circulation pump in a fuel cell system. The method includes determining that the hydrogen circulation pump is blocked by ice. The method further includes setting a starting current of the hydrogen circulation pump to a predetermined current value greater than a normal current value used to start the hydrogen circulation pump when it is not blocked by ice. Furthermore, the method includes restarting the hydrogen circulation pump in response to a predetermined condition being met by a phase current of the hydrogen circulation pump.

[0007] In a fourth aspect of the embodiments of this disclosure, a fuel cell system is provided. The fuel cell system includes a fuel cell stack; a hydrogen recirculation pump located in a passage between the anode outlet and anode inlet of the fuel cell stack; and a controller provided according to a third aspect of the embodiments of this disclosure.

[0008] In a fifth aspect of the embodiments of this disclosure, a vehicle is provided. The vehicle includes a fuel cell system provided according to a fourth aspect of this disclosure.

[0009] In a sixth aspect of embodiments of this disclosure, a computer-readable storage medium is provided. The computer-readable storage medium stores computer-executable instructions, which are executed by a processor to implement the method provided according to a first aspect of this disclosure.

[0010] It should be understood that the description in the Summary of the Invention section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0011] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0012] Figure 1 A schematic diagram of an example fuel cell system in which several embodiments of the present disclosure may be implemented is shown;

[0013] Figure 2 A flowchart is shown of a method for controlling a hydrogen circulation pump in a fuel cell system according to some embodiments of the present disclosure;

[0014] Figure 3 A flowchart illustrating an example process for determining the initiation of an icebreaking process according to some embodiments of the present disclosure is shown;

[0015] Figure 4 A flowchart illustrating an example process for ice breaking according to some embodiments of this disclosure is shown;

[0016] Figure 5 A schematic diagram showing an example of the waveforms of the phase current before and after the ice melts, according to some embodiments of the present disclosure;

[0017] Figure 6 A schematic diagram illustrates an example of determining whether to restart a hydrogen circulation pump based on the degree of change in phase current amplitude over multiple cycles, according to some embodiments of the present disclosure.

[0018] Figure 7 A block diagram of an apparatus for controlling a hydrogen circulation pump in a fuel cell system, according to some embodiments of the present disclosure, is shown; and

[0019] Figure 8 A block diagram of a controller that can implement several embodiments of the present disclosure is shown. Detailed Implementation

[0020] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure. The embodiments of this disclosure described below with reference to the accompanying drawings are for illustrative purposes only.

[0021] The hydrogen recirculation pump is a key component in a proton exchange membrane fuel cell system, its main function being to provide a stable hydrogen circulation to the anode system. This process not only improves the purity and dryness of the hydrogen but also ensures stable hydrogen circulation, contributing to uniform gas distribution across different regions of the fuel cell anode. Furthermore, water discharged from the anode passes through a water-gas separator, with a portion of it being recycled back to the anode by the hydrogen recirculation pump. Therefore, accumulated moisture may exist in the hydrogen recirculation pump, which can freeze at low ambient temperatures, causing the pump to malfunction and become clogged. Cold start performance is one of the core indicators of a fuel cell system, and the cold start performance of multiple components directly affects the overall system efficiency. A successful cold start of the hydrogen recirculation pump promotes effective water circulation within the fuel cell stack, thus preventing water accumulation and freezing within the system.

[0022] However, hydrogen circulation pumps face numerous challenges in low-temperature environments. During cold starts, the interaction between hydrogen and water within the pump can easily cause moisture to freeze at low temperatures, obstructing pipes and the rotor, and ultimately leading to motor stall. In such cases, de-icing is typically required to ensure a successful cold start. Some technologies utilize high-frequency vibrations of the pump body by periodically changing the phase of the operating current to remove ice. However, this approach is often ineffective when dealing with large amounts of ice, and the high-frequency vibrations can cause wear on the pump body.

[0023] In other related technologies, an external heater can be used to heat the hydrogen recirculation pump. For example, hot air generated by an air compressor can be introduced into the pump body to melt ice. However, adding an external device increases system costs. Therefore, utilizing the heating characteristics of the hydrogen recirculation pump itself to melt ice is a lower-cost solution that avoids modifications to the overall structure of the fuel cell system, thus preventing additional costs.

[0024] However, self-heating solutions face two main challenges. First, since the heat generated by the hydrogen circulation pump motor is relatively small during normal operation, how to increase the heat generation during the ice-breaking process is a problem that needs to be solved. Second, the fuel cell system needs to detect in a timely manner that ice-breaking is complete and stop increasing heat generation. If the motor remains at a high temperature for an extended period, it will not only prolong the ice-breaking time, leading to a longer start-up time for the entire system, but may also damage some components of the motor due to overheating. In some related technologies, the time required for ice-breaking can be roughly estimated, thereby stopping the ice-breaking process after a predetermined time; however, this method has low real-time performance and accuracy.

[0025] Therefore, embodiments of this disclosure propose a scheme for controlling a hydrogen circulation pump in a fuel cell system. In embodiments of this disclosure, the controller can determine whether the hydrogen circulation pump is blocked by ice. If it is determined that the hydrogen circulation pump is blocked by ice, the controller can set the starting current of the hydrogen circulation pump to a predetermined current value to initiate the ice-breaking process. This predetermined current value is greater than the normal current value used to start the hydrogen circulation pump when it is not blocked by ice. During the ice-breaking process, the controller can monitor the phase current of the hydrogen circulation pump. If the phase current meets a predetermined condition, the controller can stop the ice-breaking process and restart the hydrogen circulation pump to perform a normal cold start process.

[0026] In this way, the increased starting current enhances the heat generation of the hydrogen circulation pump, thereby reducing the time required for the ice-breaking process and accelerating the cold start speed of the hydrogen circulation pump. Furthermore, monitoring the phase current allows for timely cessation of the increased current supply to the hydrogen circulation pump after the ice melts, thus reducing wear and tear on various components caused by the increased heat generation.

[0027] Figure 1 A schematic diagram of an example fuel cell system 100 in which several embodiments of the present disclosure may be implemented is shown. (See diagram for reference.) Figure 1 As shown, the fuel cell system 100 includes a control unit 102, a fuel cell stack 104, a water-gas separator 106, and a hydrogen recirculation pump 108. The control unit 102 can be any control unit within the fuel cell system 100, such as the control unit of the hydrogen recirculation pump 108, the fuel cell control unit (i.e., FCCU), or the control unit of a fuel cell subsystem. In the fuel cell system 100, the fuel cell stack 104 includes an anode 110, a cathode 112, and a proton exchange membrane 114.

[0028] Hydrogen gas can enter the anode 110 of the fuel cell stack 104 through inlet 116, and oxygen gas can enter the cathode 112 of the fuel cell stack 104. Hydrogen and oxygen can undergo an electrochemical reaction to produce water at the cathode 112. Normally, most of the water produced can be discharged from the cathode 112 through the air outlet. However, due to the higher water concentration at the cathode 112, a water concentration gradient is formed across the proton exchange membrane 114, allowing some water to diffuse through the proton exchange membrane 114 to the anode 110. This water diffused to the anode 110 is called permeate. After the permeate is discharged from the outlet 118 of the anode 110, it can enter the water-gas separator 106. The water-gas separator 106 can successfully capture a portion of the permeate, which can be stored in the water-gas separator 106 and discharged from the water-gas separator 106 at an appropriate time. The remaining uncaptured water is blown to the hydrogen circulation pump 108 and circulated back to the anode 110 of the fuel cell stack 104 by the action of the hydrogen circulation pump 108. Water passing through the hydrogen circulation pump 108 may accumulate in the hydrogen circulation pump 108 and freeze when the ambient temperature is low, causing the hydrogen circulation pump 108 to become blocked.

[0029] In the fuel cell system 100, the hydrogen circulation pump 108 can perform a cold start process after receiving a start command. During the cold start process, the hydrogen circulation pump 108 can start in an open loop based on a pre-set small start current, and then slowly switch to closed-loop start. Open-loop start and closed-loop start are two different control strategies, and their main difference lies in whether the operating parameters of the hydrogen circulation pump 108 are fed back in real time. During the open-loop start process, the pump's operation does not depend on the feedback control system. The operator or control system can start the hydrogen circulation pump 108 according to preset parameters (e.g., a fixed speed or power) without monitoring or adjusting the actual operating conditions. Closed-loop start is a start-up method based on real-time feedback control. The system can monitor key parameters (e.g., pressure, flow rate, speed, etc.) and adjust them according to feedback to ensure that the hydrogen circulation pump 108 operates stably according to the target parameters.

[0030] During open-loop startup, control unit 102 can monitor whether hydrogen circulation pump 108 is blocked by ice. For example, control unit 102 can determine that hydrogen circulation pump 108 is blocked by monitoring parameters associated with hydrogen circulation pump 108, and then determine that the blockage is caused by the freezing of water inside hydrogen circulation pump 108. If control unit 102 determines that hydrogen circulation pump 108 is blocked by ice, control unit 102 can initiate the ice-breaking process.

[0031] During the ice-breaking process, the control unit 102 can set the current of the hydrogen circulation pump 108 to a predetermined current value 120, which is greater than the normal current value during normal open-loop startup. Since the normal current value during normal open-loop startup is typically small, the heat generated by the hydrogen circulation pump 108 when blocked is also small, resulting in a longer ice-breaking process duration. By increasing the current value of the hydrogen circulation pump 108, its heat generation can be increased, thereby reducing the duration of the ice-breaking process. In some embodiments, the predetermined current value 120 can be the maximum value allowed by the hardware of the hydrogen circulation pump 108, thus maximizing the heat generation of the hydrogen circulation pump 108 and minimizing the duration of the ice-breaking process.

[0032] In the fuel cell system 100, because the current value of the hydrogen circulation pump 108 is set to a relatively large value during the ice-breaking process, failure to stop the ice-breaking process in time after the ice melts may cause additional wear and tear on the components of the hydrogen circulation pump 108. Therefore, during the ice-breaking process, the control unit 102 can monitor the phase current 122 of the hydrogen circulation pump 108 in real time. Phase current refers to the current intensity of a single phase (e.g., U phase, V phase, and W phase) in a three-phase motor or drive system. In a three-phase motor, the current fluctuates periodically over time, with each phase current phase differing by 120 degrees. By analyzing the phase current, it can be found that, with a constant current value, there is a difference between the waveform of the phase current of the hydrogen circulation pump 108 during the ice-breaking process and the waveform of the phase current of the hydrogen circulation pump 108 after successful ice-breaking. Therefore, the control unit 102 can determine whether the phase current 122 of the hydrogen circulation pump 108 meets the predetermined conditions. If the phase current 122 meets the predetermined condition, it indicates that the ice has melted, thus stopping the ice-breaking process and restarting the hydrogen circulation pump 108. When restarting the hydrogen circulation pump 108, an open-loop start can be performed based on the normal current value during normal startup. In this way, the control unit 102 can promptly detect that the ice has melted and stop the ice-breaking process, thereby reducing not only the duration of the ice-breaking process but also the wear and tear on the components of the hydrogen circulation pump 108.

[0033] In this way, the increased starting current can increase the heat generation of the hydrogen circulation pump 108 itself, thereby reducing the time required for the ice-breaking process and accelerating the cold start speed of the hydrogen circulation pump 108. In addition, monitoring the phase current can promptly stop supplying the increased current to the hydrogen circulation pump 108 after the ice melts, thereby reducing the wear and tear on various components caused by the increased heat generation.

[0034] Figure 2 A flowchart of a method 200 for controlling a hydrogen circulation pump in a fuel cell system according to some embodiments of the present disclosure is shown. Method 200 can be executed by any control unit in the fuel cell system; for example, method 200 can be performed by… Figure 1 The control unit 102 in the middle performs the operation. For example... Figure 2 As shown, in box 202, the controller can determine that the hydrogen circulation pump is blocked by ice. For example, in... Figure 1In the fuel cell system 100 shown, the hydrogen circulation pump 108 can perform a cold start process after receiving a start command. During the cold start process, the hydrogen circulation pump 108 can start in open loop according to a pre-set small start current, and then slowly switch to closed loop start. During the open loop start process, the control unit 102 can monitor whether the hydrogen circulation pump 108 is blocked by ice. For example, the control unit 102 can determine that the hydrogen circulation pump 108 is blocked by monitoring parameters associated with the hydrogen circulation pump 108, and then determine that the blockage is caused by the freezing of water inside the hydrogen circulation pump 108. If the control unit 102 determines that the hydrogen circulation pump 108 is blocked by ice, the control unit 102 can initiate an ice-breaking process.

[0035] In box 204, the control unit can set the starting current of the hydrogen circulation pump to a predetermined current value, which is greater than the normal current value used to start the hydrogen circulation pump when it is not blocked by ice. For example, in... Figure 1 In the fuel cell system 100 shown, the control unit 102 can set the current of the hydrogen recirculation pump 108 to a predetermined current value 120, which is greater than the normal current value during normal open-loop startup. Since the normal current value during normal open-loop startup is typically small, the heat generated by the hydrogen recirculation pump 108 when it is blocked is also small, resulting in a longer ice-breaking process. By increasing the current value of the hydrogen recirculation pump 108, its heat generation can be increased, thereby reducing the duration of the ice-breaking process.

[0036] In block 206, the control unit can restart the hydrogen circulation pump in response to a predetermined condition being met by the phase current of the hydrogen circulation pump. For example, in... Figure 1 In the fuel cell system 100 shown, the control unit 102 can monitor the phase current 122 of the hydrogen circulation pump 108 in real time and determine whether the phase current 122 meets predetermined conditions. If the phase current 122 meets the predetermined conditions, it indicates that the ice has melted, thus the ice-breaking process can be stopped and the hydrogen circulation pump 108 can be restarted. When restarting the hydrogen circulation pump 108, the hydrogen circulation pump 108 can be started in open loop according to the normal current value during normal startup.

[0037] In this way, the increased starting current enhances the heat generation of the hydrogen circulation pump, thereby reducing the time required for the ice-breaking process and accelerating the cold start speed of the hydrogen circulation pump. Furthermore, monitoring the phase current allows for timely cessation of the increased current supply to the hydrogen circulation pump after the ice melts, further reducing the duration of the ice-breaking process and minimizing wear and tear on various components due to the increased heat generation.

[0038] In some embodiments, to determine whether the hydrogen circulation pump is blocked by ice, the rotational speed of the hydrogen circulation pump and the ambient temperature can be acquired, and the blockage can be determined based on the rotational speed and the ambient temperature. In some embodiments, in response to determining that the rotational speed of the hydrogen circulation pump is less than a predetermined rotational speed threshold or a requested rotational speed, and that the ambient temperature is less than a predetermined temperature threshold, the control unit can determine that the hydrogen circulation pump is blocked by ice.

[0039] Figure 3 A flowchart illustrating an example process 300 for determining the initiation of an icebreaking process according to some embodiments of the present disclosure is shown. As shown in FIG300, at block 302, the control unit may receive a request to start the hydrogen circulation pump. In some embodiments, the control unit may be a control unit of the hydrogen circulation pump. In these embodiments, the start request may, for example, come from another control unit (e.g., a fuel cell control unit, or a control unit of a fuel cell subsystem). In some embodiments, the control unit may be a fuel cell control unit or a control unit of a subsystem. In these embodiments, the start request may, for example, come from user input or an automatic control system. The start request may include control parameters required to start the hydrogen circulation pump, such as current values, frequency values, start-up modes (e.g., open-loop start), etc. In some embodiments, the start request may also not include control parameters, which are determined by the control unit. After receiving the start request, the control unit typically starts the hydrogen circulation pump in an open-loop manner with a small current value.

[0040] In block 304, the control unit can determine whether the motor of the hydrogen circulation pump is blocked, which can be due to various reasons, not limited to freezing of moisture in the hydrogen circulation pump. In some embodiments, the control unit can monitor the phase current of the motor in real time after the hydrogen circulation pump starts. Under normal circumstances, the motor should consume a specific current during startup. If the current suddenly rises to an abnormal level during startup, it may indicate that the motor is blocked. In other embodiments, the control unit can monitor the motor speed in real time (e.g., by a speed sensor or by using an algorithm to estimate it). If the speed is lower than an expected level corresponding to the startup current (e.g., less than a predetermined speed threshold or requested speed), it can be determined that the motor is blocked.

[0041] If the control unit determines that the motor is not blocked, process 300 can proceed to box 306. In box 306, the control unit can start the hydrogen circulation pump based on the normal starting current value. If the control unit determines that the motor is blocked, the process can proceed to box 308.

[0042] In box 308, the control unit can determine whether the ambient temperature is lower than a predetermined temperature threshold. For example, the control unit can obtain the current ambient temperature from a temperature sensor installed near the hydrogen circulation pump. Furthermore, the control unit can also obtain a pre-stored predetermined temperature threshold, which can be a pre-defined calibration value indicating a risk of icing in the hydrogen circulation pump. For example, the predetermined temperature threshold could be 0 degrees Celsius, -5 degrees Celsius, -10 degrees Celsius, etc.

[0043] If the ambient temperature is not lower than the predetermined temperature threshold, indicating that the motor blockage is not caused by water freezing, process 300 can proceed to box 310. In box 310, the control unit can send a fault message indicating a malfunction in the hydrogen circulation pump to prompt the system administrator or automatic control system to address the motor blockage promptly. If the ambient temperature is lower than the predetermined temperature threshold, indicating that the motor blockage is caused by water freezing, process 300 can proceed to box 312. In box 312, the control unit can initiate the de-icing process. During the de-icing process, the control unit can set the starting current of the hydrogen circulation pump to a larger value to increase the heat generated by the hydrogen circulation pump itself.

[0044] Real-time monitoring and data analysis can promptly detect blockages in the hydrogen circulation pump caused by ice, allowing for timely initiation of the ice-breaking process and improving the reliability, safety, and efficiency of the hydrogen circulation pump.

[0045] In some embodiments, during the ice-breaking process, in addition to setting the starting current of the hydrogen circulation pump to a larger predetermined current, the starting frequency of the hydrogen circulation pump can also be set to a predetermined frequency value, which is greater than the normal frequency value for starting the hydrogen circulation pump when it is not blocked by ice. In some embodiments, the first cross-axis current value for the hydrogen circulation pump can be set to the maximum current value allowed by the hardware capabilities of the hydrogen circulation pump. In some embodiments, the predetermined frequency value can be the maximum frequency value allowed by the hardware capabilities of the hydrogen circulation pump.

[0046] In some embodiments, when setting the starting current of the hydrogen circulation pump, a first current value for the quadrature axis and a second current value for the direct axis of the hydrogen circulation pump can be determined based on a predetermined current value, wherein the ratio of the first current value to the second current value is greater than a predetermined ratio. In some embodiments, after setting the starting current of the hydrogen circulation pump to the predetermined current value, the control unit can obtain the duration for which the hydrogen circulation pump is started at the predetermined current value. In response to the duration exceeding a predetermined duration threshold, the control unit can stop starting the hydrogen circulation pump.

[0047] Figure 4 A flowchart of an example process 400 for ice breaking according to some embodiments of the present disclosure is shown. Figure 4As shown, in block 402, the control unit can initiate the ice-breaking process and start timing. In block 404, the control unit can set the open-loop starting current of the hydrogen circulation pump to a predetermined current value and the open-loop starting frequency to a predetermined frequency value. Both the predetermined current and frequency values ​​are greater than the normal current and frequency values ​​when the hydrogen circulation pump is started normally. The open-loop starting frequency refers to the motor's drive frequency, i.e., the frequency of the current applied to the motor windings. If the motor is blocked by ice and cannot rotate normally, increasing the frequency can lead to an increase in current, thereby increasing heat generation and reducing the duration of the ice-breaking process. The predetermined current and frequency values ​​can be the maximum current value (e.g., 22A) and maximum frequency value (e.g., 550kHz) allowed by the hardware capabilities of the hydrogen circulation pump, which can be determined through calibration.

[0048] When setting the current of a hydrogen circulation pump, the heat generation of the pump can be further increased by limiting the direction of iron losses in the stator and rotor of the motor. Iron losses refer to the energy loss generated in the stator and rotor due to changes in magnetic flux density during motor operation. In motor control, a three-phase AC motor includes a quadrature axis (i.e., the Q-axis) and a direct axis (i.e., the D-axis), which are defined in a rotating coordinate system to simplify motor control and analysis. The direct axis is the axis aligned with the direction of the motor's magnetic field and is primarily responsible for generating and controlling the motor's magnetic field. The quadrature axis is the axis rotated 90 degrees around the direct axis (i.e., perpendicular to the direct axis). The quadrature axis current is responsible for generating the motor's torque; increasing the quadrature axis current can increase the motor's output torque and affect the motor's power performance. When setting the current of the hydrogen circulation pump, all (or a large portion) of the current can be set to the quadrature axis current, and the direct axis current can be set to zero (or a small portion of the current). In this way, the rotor can achieve maximum heat generation even when blocked at any angle, thereby improving ice-breaking efficiency. In some embodiments, the motor components can be dually protected by simultaneously setting hardware overcurrent protection and software overcurrent fault reporting.

[0049] In block 408, the control unit can determine whether the ice-breaking duration exceeds a predetermined time threshold. If the ice-breaking duration has exceeded the predetermined time threshold, process 400 can proceed to block 410. In block 410, the control unit can stop the ice-breaking process and send a fault message indicating a malfunction in the hydrogen circulation pump. In this way, even if no ice melt is detected after the hydrogen circulation pump has been generating significant heat for a period of time, heating can be stopped in time, thereby reducing wear and tear on the components of the hydrogen circulation pump and improving safety.

[0050] Returning to box 408, if the ice-breaking duration does not exceed a predetermined time threshold, process 400 can proceed to box 412. In box 412, the control unit can determine whether the phase current of the hydrogen circulation pump meets a predetermined condition. Since the waveform of the phase current differs before and after successful ice breaking, a suitable predetermined condition can be predetermined. If the phase current meets the predetermined condition, it indicates that the ice has melted, and process 400 can proceed to box 414. In box 414, the control unit can stop the ice-breaking process and restart the hydrogen circulation pump according to the normal open-loop start-up current to allow the hydrogen circulation pump to operate normally. If the phase current does not meet the predetermined condition, process 400 can return to box 408 to continue the ice-breaking process.

[0051] In this way, the control unit can increase the heat generation of the hydrogen circulation pump from various aspects, such as increasing the current, increasing the frequency, and adjusting the direction of iron loss, thereby accelerating the ice-breaking speed. Furthermore, monitoring the duration of ice breaking reduces wear on the hydrogen circulation pump components and improves safety. In addition, monitoring the phase current allows for timely detection of ice melting, further reducing the duration of the ice-breaking process and minimizing wear on various components due to increased heat generation.

[0052] In some embodiments, the starting current of the hydrogen circulation pump includes multiple phases, and the phase current is a first phase current corresponding to a first phase among the multiple phases. When determining whether the phase current meets a predetermined condition, the control unit can determine the degree of change of the amplitude of the first phase current over multiple cycles. In response to the degree of change of the amplitude of the first phase current over multiple cycles being greater than a predetermined degree of change threshold, the control unit can determine that the phase current meets the predetermined condition, thereby stopping the ice-breaking process and restarting the hydrogen circulation pump.

[0053] Figure 5 A schematic diagram of example 500 showing the waveforms of phase currents before and after ice melts, according to some embodiments of the present disclosure. Example 500 includes waveforms of DC current 502, phase current 504 (e.g., U-phase), and phase current 506 (e.g., V-phase). Figure 5 As shown, in the waveforms of phase currents 504 and 506, the left part is the phase current waveform when the ice has not yet melted, and the right part is the phase current waveform after the ice has melted. Taking the waveform of phase current 504 as an example, the waveform in window 508 is the phase current waveform when the ice has not yet melted, and the waveform in window 510 is the phase current waveform after the ice has melted. The width of both window 508 and window 510 is N cycles.

[0054] like Figure 5As shown, within window 508, the waveform of phase current 504 is relatively flat, indicating that the amplitude variation of phase current 504 is small within the N periods contained in window 508. Within window 510, the waveform of phase current 504 exhibits a series of rising and falling peaks, indicating that the amplitude variation of phase current 504 is larger within the N periods contained in window 510. For example, window 510 includes amplitudes 512 and 514, where amplitude 512 is larger and amplitude 514 is smaller.

[0055] Based on the above observations, the control unit can determine the degree of change in the phase current amplitude over the past N cycles (i.e., the window duration). If the degree of change is small (e.g., less than a predetermined degree of change threshold), the control unit can determine that the ice has not yet melted and continue the ice-breaking process. If the degree of change is large (e.g., greater than the predetermined degree of change threshold), the control unit can determine that the ice has melted and promptly stop the ice-breaking process, and restart the hydrogen circulation pump according to the normal starting current (and normal starting frequency).

[0056] In this way, the difference in phase current waveform before and after successful ice breaking can be used to effectively determine whether the ice blocking the hydrogen circulation pump has melted and to stop the ice breaking process in time, thereby reducing the duration of the ice breaking process and reducing wear and tear on components.

[0057] In some embodiments, to determine the degree of variation of the amplitude of the first phase current over multiple cycles, the control unit may determine multiple amplitudes of the first phase current over multiple cycles, and then determine the standard deviation of the multiple amplitudes as the degree of variation of the first phase current over the multiple cycles. In some embodiments, the control unit may determine multiple degrees of variation of multiple amplitudes of multiple phase currents corresponding to multiple phases of the current over multiple cycles. In response to all of the multiple degrees of variation of the multiple amplitudes of the multiple phase currents over multiple cycles being greater than a predetermined degree of variation threshold, the control unit may stop the ice-breaking process and restart the hydrogen circulation pump.

[0058] Figure 6 A schematic diagram of example 600 is shown, illustrating how the degree of change in phase current amplitude over multiple cycles, according to some embodiments of the present disclosure, determines whether to restart the hydrogen circulation pump. Figure 6As shown, Example 600 includes a phase current of one phase (e.g., U phase) with multiple amplitudes (e.g., amplitudes 604-1, 604-2, ..., and 604-N, collectively referred to as amplitude 604) within multiple periods (e.g., periods 602-1, 602-2, ..., and 602-N, collectively referred to as period 602), wherein amplitude 604-1 corresponds to period 602-1, amplitude 604-2 corresponds to period 602-2, and amplitude 604-N corresponds to period 602-N.

[0059] In Example 600, the control unit can calculate the average of multiple amplitudes 604 to obtain an average amplitude 606. Then, the control unit can calculate the standard deviation 608 of the phase current amplitude based on the multiple amplitudes 604 and the average amplitude 606. The standard deviation 608 indicates the degree of amplitude variation of the phase current within periods 602-1 to 602-N. This calculation process can be represented by the following equation (1):

[0060]

[0061] Where x i This represents the phase current amplitude during period i. σ represents the average amplitude over N cycles, and σ represents the standard deviation of the phase current amplitude over N cycles.

[0062] The control unit can then compare the standard deviation 608 with a predetermined threshold 610. If the standard deviation 608 is greater than the predetermined threshold 610, it indicates that the amplitude variation of the phase current within the period 602-1 to 602-N is relatively large (e.g., reference). Figure 5 The waveform within window 510 indicates that the ice has melted, at which point the control unit can stop the ice-breaking process and restart the hydrogen circulation pump. If the standard deviation 608 is not greater than the predetermined threshold 610, it indicates that the amplitude variation of the phase current within the period 602-1 to 602-N is small (e.g., reference...). Figure 5 The waveform in window 508 can indicate that the ice has not yet melted, so the control unit can continue to perform the ice-breaking process.

[0063] In Example 600, in addition to calculating the standard deviation 608, the control unit can also additionally calculate the standard deviations of the phase currents of two other phases within periods 602-1 to 602-N. When all three standard deviations corresponding to these three phase currents are less than a predetermined threshold 610, it is determined that the ice has melted, thus stopping the ice-breaking process. This method improves the accuracy of ice state estimation and reduces additional ice-breaking processes caused by erroneous estimations.

[0064] In Example 600, the phase current amplitudes of the U, V, and W phases when the ice is not yet melted and when the ice has already melted can be collected through testing, and the standard deviation of the phase current amplitudes can be calculated. A predetermined threshold 610 can then be determined based on the calculated standard deviation of the phase currents. For example, Table 1 below shows the standard deviations calculated based on the phase current amplitudes collected from the two tests.

[0065]

[0066] Table 1

[0067] As shown in Table 1, in the first test, when the ice was still hot, the standard deviations of the phase current amplitudes for phases U, V, and W were all less than 0.001. However, after the ice melted, the standard deviations of the phase current amplitudes for all three phases increased to over 0.04, indicating a significant difference in the degree of change in phase current amplitude before and after the ice melted. In the second test, the standard deviations of the phase current amplitudes for the three phases showed a similar pattern to the first test. Based on the data in Table 1, the value of the predetermined threshold 610 can be determined; for example, the predetermined threshold 610 could be 0.02. In this way, it is possible to effectively determine whether the ice has melted based on the degree of change in phase current amplitude, thereby reducing the duration of the ice-breaking process.

[0068] Figure 7 A block diagram of an apparatus 700 for controlling a hydrogen circulation pump in a fuel cell system, according to some embodiments of the present disclosure, is shown. Figure 7 As shown, the device 700 includes a blockage determination unit 702 configured to determine that the hydrogen circulation pump is blocked by ice. The device 700 also includes a current setting unit 704 configured to set the starting current of the hydrogen circulation pump to a predetermined current value, which is greater than the normal current value used to start the hydrogen circulation pump when it is not blocked by ice. Furthermore, the device 700 includes a current monitoring unit 706 configured to restart the hydrogen circulation pump in response to the phase current of the hydrogen circulation pump meeting a predetermined condition.

[0069] In some embodiments, the current setting unit 704 includes a frequency setting unit configured to set the starting current to the predetermined current value and the starting frequency to a predetermined frequency value, the predetermined frequency value being greater than the normal frequency value for starting the hydrogen circulation pump when it is not blocked by ice.

[0070] In some embodiments, the current setting unit 704 includes: a current value determining unit configured to determine a first current value for the quadrature axis of the hydrogen circulation pump and a second current value for the direct axis of the hydrogen circulation pump based on the predetermined current value, wherein the ratio of the first current value to the second current value is greater than a predetermined ratio; a quadrature axis setting unit configured to set the current of the quadrature axis of the hydrogen circulation pump to the first current value; and a direct axis setting unit configured to set the current of the direct axis of the hydrogen circulation pump to the second current value.

[0071] In some embodiments, the first cross-axis current value for the hydrogen circulation pump is the maximum current value allowed by the hardware capabilities of the hydrogen circulation pump.

[0072] In some embodiments, the starting current of the hydrogen circulation pump includes multiple phases, the phase current is a first phase current corresponding to a first phase among the multiple phases, and the current monitoring unit 706 includes: a degree of change determination unit configured to determine the degree of change of the amplitude of the first phase current over multiple periods; and a degree of change comparison unit configured to restart the hydrogen circulation pump in response to the degree of change of the amplitude of the first phase current over the multiple periods being greater than a predetermined degree of change threshold.

[0073] In some embodiments, the degree of variation determination unit includes: a first phase current amplitude determination unit configured to determine a plurality of amplitudes of the first phase current within the plurality of cycles; and a first phase current standard deviation determination unit configured to determine the standard deviation of the plurality of amplitudes as the degree of variation of the first phase current within the plurality of cycles.

[0074] In some embodiments, the starting current of the hydrogen circulation pump includes multiple phases, the phase current is a phase current corresponding to one of the multiple phases, and the current monitoring unit 706 includes: a multiple variation degree determination unit configured to determine multiple variation degrees of multiple amplitudes of the multiple phase currents corresponding to the multiple phases over multiple periods; and a multiple variation degree comparison unit configured to restart the hydrogen circulation pump in response to all of the multiple variation degrees of the multiple amplitudes of the multiple phase currents over the multiple periods being greater than a predetermined variation degree threshold.

[0075] In some embodiments, the apparatus 700 further includes: a duration acquisition unit configured to acquire the duration for which the hydrogen circulation pump is started at the predetermined current value after the starting current is set to the predetermined current value; and a duration comparison unit configured to stop starting the hydrogen circulation pump in response to the duration being greater than a predetermined duration threshold.

[0076] In some embodiments, the blockage determination unit 702 includes: a data acquisition unit configured to acquire the rotational speed and ambient temperature of the hydrogen circulation pump; and a data usage unit configured to determine, based on the rotational speed and the ambient temperature, that the hydrogen circulation pump is blocked by ice.

[0077] In some embodiments, determining that the hydrogen circulation pump is blocked by ice based on the rotational speed and the ambient temperature includes: a data comparison unit configured to determine that the hydrogen circulation pump is blocked by ice in response to determining that the rotational speed is less than a predetermined rotational speed threshold or a requested rotational speed, and that the ambient temperature is less than a predetermined temperature threshold.

[0078] It is understood that by using the apparatus 700 of this disclosure, at least one of the many advantages that can be achieved by the method or process described above can be realized. For example, it can reduce the time required for the ice-breaking process, accelerate the cold start speed of the hydrogen circulation pump, reduce the duration of the ice-breaking process, and reduce the wear and tear on various components due to increased heat generation.

[0079] Figure 8 A block diagram of a controller 800 that can implement various embodiments of the present disclosure is shown. The controller 800 may be, for example, as shown below. Figure 1 The control unit 102 is shown. As shown, the controller 800 includes a processor 801, which can perform various appropriate actions and processes based on computer program instructions loaded into random access memory (RAM) 803 according to computer program instructions stored in read-only memory (ROM) 802. The RAM 803 may also store various programs and data required for the operation of the controller 800. The processor 801, ROM 802, and RAM 803 are interconnected via bus 804. An input / output (I / O) interface 805 is also connected to bus 804.

[0080] Processor 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 801 performs the various methods and processes described above, such as method 200. For example, in some embodiments, method 200 may be implemented as a computer software program tangibly contained in a machine-readable medium. In some embodiments, part or all of the computer program may be loaded and / or mounted to controller 800 via ROM 802. When the computer program is loaded into RAM 803 and executed by processor 801, one or more steps of method 200 described above may be performed. Alternatively, in other embodiments, processor 801 may be configured to perform method 200 by any other suitable means (e.g., by means of firmware).

[0081] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload programmable logic devices (CPLDs), and so on.

[0082] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0083] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. Furthermore, although operations are depicted in a specific order, this should be understood as requiring that such operations be performed in the specific order shown or in sequential order, or requiring that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0084] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A method (200) for controlling a hydrogen circulation pump in a fuel cell system, comprising: It was determined that the hydrogen circulation pump (202) was blocked by ice. The starting current of the hydrogen circulation pump is set (204) to a predetermined current value, which is greater than the normal current value for starting the hydrogen circulation pump when it is not blocked by ice. as well as In response to the phase current of the hydrogen circulation pump meeting a predetermined condition, the hydrogen circulation pump is restarted (206).

2. The method (200) according to claim 1, wherein setting the starting current (204) of the hydrogen circulation pump to the predetermined current value comprises: The starting current is set to the predetermined current value and the starting frequency is set to a predetermined frequency value, which is greater than the normal frequency value for starting the hydrogen circulation pump when it is not blocked by ice.

3. The method (200) according to claim 1, wherein setting the starting current (204) of the hydrogen circulation pump to the predetermined current value comprises: A first current value for the quadrature axis of the hydrogen circulation pump and a second current value for the direct axis of the hydrogen circulation pump are determined based on the predetermined current value, wherein the ratio of the first current value to the second current value is greater than a predetermined ratio. Set the current of the cross-axis of the hydrogen circulation pump to the first current value; as well as Set the current of the direct shaft of the hydrogen circulation pump to the second current value.

4. The method (200) according to claim 3, wherein the first current value of the cross-axis for the hydrogen circulation pump is the maximum current value allowed by the hardware capability of the hydrogen circulation pump.

5. The method (200) according to claim 1, wherein the starting current of the hydrogen circulation pump includes a plurality of phases, the phase current is a first phase current corresponding to a first phase among the plurality of phases, and restarting (206) the hydrogen circulation pump in response to the phase current of the hydrogen circulation pump satisfying the predetermined condition comprises: Determine the degree of variation of the amplitude of the first phase current over multiple cycles; as well as In response to the fact that the magnitude of the first phase current changes more than a predetermined threshold value over the plurality of cycles, the hydrogen circulation pump is restarted.

6. The method (200) of claim 5, wherein determining the degree of variation of the amplitude of the first phase current over the plurality of cycles comprises: Determine multiple amplitudes of the first phase current within the multiple cycles; as well as The standard deviation of the plurality of amplitudes is determined as the degree of variation of the first phase current within the plurality of cycles.

7. The method (200) of claim 1, wherein the starting current of the hydrogen circulation pump comprises a plurality of phases, the phase current being a phase current corresponding to one of the plurality of phases, and restarting (206) the hydrogen circulation pump in response to the phase current of the hydrogen circulation pump satisfying the predetermined condition comprises: Determine the degree of change of multiple amplitudes of multiple phase currents corresponding to the multiple phases over multiple periods; as well as In response to the fact that the magnitudes of the multiple phase currents within the multiple cycles all exceed a predetermined threshold for change, the hydrogen circulation pump is restarted.

8. The method (200) according to claim 1, further comprising: After setting the starting current to the predetermined current value, the duration for which the hydrogen circulation pump is started at the predetermined current value is obtained; as well as In response to the duration exceeding a predetermined duration threshold, the hydrogen circulation pump is stopped from starting.

9. The method (200) according to claim 1, wherein determining (202) that the hydrogen circulation pump is blocked by ice comprises: The rotational speed and ambient temperature of the hydrogen circulation pump were obtained; as well as The hydrogen circulation pump was determined to be blocked by ice based on the rotational speed and the ambient temperature.

10. The method (200) of claim 9, wherein determining that the hydrogen circulation pump is blocked by ice based on the rotational speed and the ambient temperature comprises: In response to determining that the rotational speed is less than a predetermined rotational speed threshold or a requested rotational speed, and that the ambient temperature is less than a predetermined temperature threshold, it is determined that the hydrogen circulation pump is blocked by ice.

11. An apparatus (700) for controlling a hydrogen circulation pump in a fuel cell system, comprising: The blockage determination unit (702) is configured to determine that the hydrogen circulation pump is blocked by ice. The current setting unit (704) is configured to set the starting current of the hydrogen circulation pump to a predetermined current value, which is greater than the normal current value for starting the hydrogen circulation pump when it is not blocked by ice. as well as The current monitoring unit (706) is configured to restart the hydrogen circulation pump in response to the phase current of the hydrogen circulation pump meeting a predetermined condition.

12. A controller (800), comprising: At least one processor (801); as well as A memory (802) coupled to the at least one processor and having instructions stored thereon, which, when executed by the at least one processor (801), cause the controller (800) to perform the method according to any one of claims 1-10.

13. A fuel cell system, comprising: fuel cell stack; A hydrogen circulation pump is located in the channel between the anode outlet and the anode inlet of the fuel cell stack; as well as The controller according to claims 1-10.

14. A vehicle comprising the fuel cell system according to claim 13.

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