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CN-121983619-A - Fuel cell system and control method thereof

CN121983619ACN 121983619 ACN121983619 ACN 121983619ACN-121983619-A

Abstract

The invention provides a fuel cell system and a control method thereof, wherein the control method comprises the steps of obtaining a current fluctuation value and a cooling liquid temperature of a fuel cell, and a stack anode inlet and outlet pressure difference and a hydrogen circulating pump running current, controlling a drain valve to drain water according to a preset drainage strategy when the obtained current fluctuation value, cooling liquid temperature, stack anode inlet and outlet pressure difference and the hydrogen circulating pump running current meet a first preset condition, continuously obtaining the current fluctuation value and the cooling liquid temperature after the drain valve drains water, and continuously obtaining the stack anode inlet and outlet pressure difference and the hydrogen circulating pump running current, and repeating the steps when the continuously obtained stack anode inlet and outlet pressure difference and the hydrogen circulating pump running current meet a second preset condition, and judging that a nitrogen removal valve fails when the repetition times of the steps are not lower than a preset time threshold value. The invention can realize the on-line diagnosis of the fault of the nitrogen discharge valve, and is beneficial to improving the use quality of the fuel cell system.

Inventors

  • FAN XUDONG
  • HE QIANG

Assignees

  • 未势能源科技有限公司

Dates

Publication Date
20260505
Application Date
20241030

Claims (10)

  1. 1. A control method of a fuel cell system, characterized by comprising: In the operation process of the fuel cell system, acquiring a current fluctuation value and a cooling liquid temperature of the fuel cell, and an anode-to-anode pressure difference of a galvanic pile (1) and an operation current of a hydrogen circulating pump (4); When the obtained current fluctuation value, the obtained cooling liquid temperature, the anode inlet and outlet pressure difference of the electric pile (1) and the operation current of the hydrogen circulating pump (4) meet a first preset condition, controlling a drain valve (5) to drain according to a preset drain strategy, and continuously obtaining the current fluctuation value and the cooling liquid temperature, and the anode inlet and outlet pressure difference of the electric pile (1) and the operation current of the hydrogen circulating pump (4) after the drain valve (5) drains water; And repeating the steps when the continuously acquired current fluctuation value, the cooling liquid temperature, the anode inlet and outlet pressure difference of the electric pile (1) and the running current of the hydrogen circulating pump (4) meet a second preset condition, and judging that the nitrogen discharge valve (6) fails when the repetition times of the steps are not lower than a preset time threshold.
  2. 2. The control method of a fuel cell system according to claim 1, characterized in that: The current fluctuation value of the fuel cell is the fluctuation value of the input current of the DC/DC converter; the cooling liquid temperature of the fuel cell is the average value of the cooling liquid in-pile temperature and the cooling liquid out-pile temperature.
  3. 3. The control method of a fuel cell system according to claim 1, characterized in that: The first preset condition comprises that the current fluctuation value is in a first preset current interval, the temperature of the cooling liquid is larger than a first preset temperature threshold, the anode inlet and outlet pressure difference of the electric pile (1) is larger than the first preset pressure difference threshold and lasts for a first preset time, and the running current of the hydrogen circulating pump (4) is larger than the first preset current threshold and lasts for a second preset time.
  4. 4. The control method of a fuel cell system according to claim 1, characterized in that: The second preset condition comprises that the current fluctuation value is in a second preset current interval, the temperature of the cooling liquid is larger than a second preset temperature threshold, the anode inlet and outlet pressure difference of the electric pile (1) is larger than a second preset pressure difference threshold, and the running current of the hydrogen circulating pump (4) is larger than the second preset current threshold.
  5. 5. The control method of the fuel cell system according to any one of claims 1 to 4, characterized in that the control method further comprises: and when the nitrogen discharge valve (6) is judged to be in fault, controlling the water discharge valve (5) to discharge water and nitrogen.
  6. 6. The control method of a fuel cell system according to claim 5, characterized in that: The preset drainage strategy comprises that the drainage valve (5) drains water according to a preset opening frequency and lasts for a third preset time.
  7. 7. The control method of a fuel cell system according to claim 6, characterized in that: the preset opening frequency and the opening frequency of the drain valve (5) during drainage and nitrogen removal are both larger than the opening frequency of the drain valve (5) during normal operation.
  8. 8. The control method of a fuel cell system according to claim 7, characterized in that: the opening frequency of the drain valve (5) for draining water and nitrogen is not larger than the preset opening frequency.
  9. 9. A fuel cell system characterized in that: the fuel cell system is provided with a memory (100) and a processor (200); The memory (100) has stored thereon computer readable instructions which, when executed by the processor (200), implement the control method of any of claims 1 to 8.
  10. 10. A vehicle, characterized in that: the fuel cell system according to claim 9 is provided in the vehicle.

Description

Fuel cell system and control method thereof Technical Field The present invention relates to the field of fuel cell fault diagnosis technology, and in particular, to a fuel cell system and a control method thereof. Background In the current fuel cell system, nitrogen on the cathode side of the stack permeates to the anode through the proton exchange membrane due to concentration difference diffusion effect along with the operation of the system, so that the nitrogen on the anode side needs to be periodically discharged through a nitrogen discharge valve, if the nitrogen discharge valve fails, the hydrogen concentration on the anode side can be reduced, the performance of the fuel cell is reduced, and even the phenomenon that the cell voltage is too low due to hydrogen starvation can occur in severe cases. In the prior art, in order to judge whether the nitrogen discharge valve is faulty, after the fuel cell system is stopped, the anode is used for maintaining pressure, the nitrogen discharge valve is manually controlled to discharge air, and whether the anode pressure can be normally discharged is checked, so that whether the nitrogen discharge valve is faulty is checked. The off-line fault detection mode can only be carried out after the shutdown of the fuel cell system, can not realize the timely discovery of the fault of the nitrogen discharge valve, has larger hysteresis, is easy to influence the normal operation of the system due to the fault of the nitrogen discharge valve in the operation process of the fuel cell system, and is not beneficial to the improvement of the use quality of the fuel cell system. Disclosure of Invention In view of the above, the present invention is directed to a control method of a fuel cell system, so as to overcome the defect of the existing fault determination method of the nitrogen exhaust valve, and facilitate improving the quality of the fuel cell system. In order to achieve the above purpose, the technical scheme of the invention is realized as follows: a control method of a fuel cell system, the control method comprising: In the operation process of the fuel cell system, acquiring a current fluctuation value and a cooling liquid temperature of the fuel cell, and an anode-to-anode pressure difference of a galvanic pile and an operation current of a hydrogen circulating pump; When the obtained current fluctuation value, the obtained cooling liquid temperature, the difference between the anode inlet and outlet of the electric pile and the operation current of the hydrogen circulating pump meet a first preset condition, controlling a drain valve to drain according to a preset drain strategy, and continuously obtaining the current fluctuation value and the cooling liquid temperature, the difference between the anode inlet and outlet of the electric pile and the operation current of the hydrogen circulating pump after the drain valve drains water; And repeating the steps when the continuously acquired current fluctuation value, the cooling liquid temperature, the anode inlet and outlet pressure difference of the electric pile and the running current of the hydrogen circulating pump meet a second preset condition, and judging that the nitrogen discharge valve fails when the repetition times of the steps are not lower than a preset time threshold. Further, the current fluctuation value of the fuel cell is the fluctuation value of the input current of the DC/DC converter; the cooling liquid temperature of the fuel cell is the average value of the cooling liquid in-pile temperature and the cooling liquid out-pile temperature. Further, the first preset condition includes that the current fluctuation value is in a first preset current interval, the temperature of the cooling liquid is greater than a first preset temperature threshold, the pressure difference between an anode and an inlet of the electric pile is greater than the first preset pressure difference threshold and lasts for a first preset time, and the running current of the hydrogen circulating pump is greater than the first preset current threshold and lasts for a second preset time. Further, the second preset condition includes that the current fluctuation value is in a second preset current interval, the temperature of the cooling liquid is greater than a second preset temperature threshold, the pressure difference between the anode and the inlet of the electric pile is greater than a second preset pressure difference threshold, and the running current of the hydrogen circulating pump is greater than a second preset current threshold. Further, the control method further includes: And when judging that the nitrogen discharge valve fails, controlling the drain valve to discharge water and nitrogen. Further, the preset draining strategy includes that the draining valve drains water according to a preset opening frequency and lasts for a third preset time. Further, the preset opening frequency and the opening frequency