Fuel cell system power control method

Abstract

The invention relates to the technical field of new energy, and discloses a fuel cell system power control method, which comprises the following steps: setting limited power judgment of a plurality of levels according to different limited power faults, setting a corresponding trigger condition for each limited power judgment layer, enabling the priority of the previous level to be greater than that of the next level, and when the trigger conditions are met, controlling the power of the fuel cell system. Adjusting the output power of the fuel cell step by step; according to the invention, multi-level limited power control is carried out on the fuel cell system, and a better system protection effect is achieved.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and specifically to a power control method for a fuel cell system. Background Art

[0002] Fuel cells are devices that convert the chemical energy of fuel directly into electrical energy. Due to their high efficiency and pollution-free characteristics, they have great development potential and application prospects. There are many types of fuel cells. The most mature and widely used one is the proton exchange membrane fuel cell, which works by converting chemical energy into electrical energy by generating water and electrons through electrochemical reactions between hydrogen and oxygen.

[0003] A fuel cell system usually includes several major parts, including a stack module, a hydrogen path module, an air path module, a water path module, and an electrical module. The normal operation of the fuel-electric system requires the cooperation of various modules. When an abnormality occurs in one of the modules, the fuel-electric system must first be power-limited. If the abnormality can be restored in a short time, the fuel-electric system can continue to operate and carry the load. If the abnormality cannot be restored for a long time, the fuel-electric system will be shut down and restarted after the problem is found and solved.

[0004] Currently, the more common power limiting control method for fuel cell systems is to set power limiting faults with different triggering conditions in the fault diagnosis module. When the fuel-electric system triggers the power limiting fault during operation, the power of the fuel-electric system is directly limited, and the general limit is 50% of the rated power. When the fuel-electric system does not meet the power limiting fault triggering threshold, the power limiting fault is cured and the system can continue to load power. However, if the power limiting fault is triggered again during the re-loading process, power limitation will continue.

[0005] However, the existing fuel cell system power limit control method adopts a one-level power limit method, that is, only one power limit is set, which is prone to frequent load increases and decreases, and the fuel-electric system cannot be applied in complex application scenarios.

[0006] Application Contents

[0007] The purpose of the present application is to provide a fuel cell system power control method that performs multi-level power limiting control on the fuel cell system to achieve better system protection.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The fuel cell system power control method of the present invention includes setting multiple levels of power limit judgment according to different power limit faults, each power limit judgment layer sets a corresponding trigger condition, the priority of the previous layer is greater than the priority of the next layer, and when the trigger condition is met, the output power of the fuel cell is adjusted step by step.

[0010] Furthermore, when an abnormality occurs in the operation of the fuel-electric system, the triggering condition of the first-level power limit judgment is triggered, and the current power request value and the first power limit value are taken as the smaller value to obtain the first-level power limit value, wherein the first power limit value is 50% of the rated power;

[0011] Set the abnormal delay time. When the abnormal duration exceeds the set abnormal delay time, the trigger condition of the second-level power limit judgment is triggered. The power limit value of the first level and the second power limit value are taken as the smaller one to obtain the power limit value of the second level, where the second power limit value is the idle power.

[0012] Compared with the prior art, the beneficial effects of this application are:

[0013] Use multiple Switch modules for logical nesting. Set as many levels of power limiting as needed to use as many Switch modules. The power limit values ​​are arranged from high to low in order from front to back. The judgment condition of each Switch module can be set as a trigger flag for different power limiting fault levels as required, thereby achieving the purpose of multi-level power limiting control in complex scenarios. Use multiple Switch modules for logical nesting, and the power limit values ​​are arranged from high to low. This application performs multi-level power limiting control on the fuel cell system to provide better system protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a flow chart of the method of this application. DETAILED DESCRIPTION

[0016] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0017] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show the layers related to the present invention rather than being drawn according to the number, shape and size of the layers in actual implementation. In actual implementation, the type, quantity and proportion of each layer may be changed arbitrarily, and the layer layout may also be more complicated.

[0018] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present invention; however, it is apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0019] See also Figure 1 The fuel cell system power control method includes a fuel cell system power control method, which is characterized in that: according to different power limit faults, multiple levels of power limit judgment are set, each power limit judgment layer sets a corresponding trigger condition, the priority of the previous level is greater than the priority of the next level, and when the trigger condition is met, the output power of the fuel cell is adjusted step by step.

[0020] Use multiple Switch modules for logical nesting. Set as many levels of power limiting as needed to use as many Switch modules. The power limit values ​​are arranged from high to low in order from front to back. The judgment condition of each Switch module can be set as a trigger flag for different power limiting fault levels as required, thereby achieving the purpose of multi-level power limiting control in complex scenarios. Use multiple Switch modules for logical nesting, and the power limit values ​​are arranged from high to low. This application performs multi-level power limiting control on the fuel cell system to provide better system protection.

[0021] See also Figure 1 When an abnormality occurs in the operation of the fuel-electric system, the triggering condition of the first-level power limit judgment is triggered, and the current power request value and the first power limit value are taken as the smaller value to obtain the first-level power limit value, wherein the first power limit value is 50% of the rated power;

[0022] Set the abnormal delay time. When the abnormal duration exceeds the set abnormal delay time, the trigger condition of the second-level power limit judgment is triggered. The power limit value of the first level and the second power limit value are taken as the smaller one to obtain the power limit value of the second level, where the second power limit value is the idle power.

[0023] When the fuel-fired power system does not have any abnormality during operation, the fuel-fired power system continues to output power according to the current power request. When the fuel-fired power system has an abnormality during operation, the triggering condition of the first-level power limit judgment is triggered, and the current power request value and the first power limit value are taken as the smaller value to obtain the first-level power limit value, thereby achieving the purpose of power limit, wherein the first power limit value is 50% of the rated power.

[0024] The abnormal delay time is set by the delay module. When the abnormal duration is less than the abnormal delay time, the fuel cell system output power is output according to the power limit of the first level. When the abnormal duration exceeds the set abnormal delay time, the trigger condition of the second level power limit judgment is triggered, and the power limit of the first level and the second power limit are taken as the smaller operation to obtain the power limit of the second level, so as to achieve the purpose of further power limitation, and the second power limit is the idle power. The present application adopts multi-level power limits, and the fuel cell system can limit power step by step according to specific judgment conditions, and there will be no problem of frequent load and load changes, which can extend the service life of the system.

[0025] The existing fuel cell system power limiting control strategy usually adopts a first-level power limiting method, that is, only one power limit is set. When an abnormality occurs during the operation of the fuel-electric system, the system power is limited to the set value. Although the limit can be set as a calibration value and calibrated during system testing or operation, there are still many problems.

[0026] First, the first-level power limit can easily cause the fuel-fired power system to frequently increase or decrease load due to triggering a power limit fault during operation. Since the power limit fault is generally a protective fault, the fault threshold setting will not be too strict, resulting in the system being more likely to trigger a power limit fault and easier to cure. Frequent increase or decrease load will affect the system service life and directly affect the life of the fuel cell stack.

[0027] Secondly, the first-level power limit is not flexible enough in use, and it is impossible to perform multi-level power limit control on the system according to the severity of the power limit fault or the duration of the power limit fault. As a result, the fuel-fired power system cannot be well applied in more complex application scenarios, and cannot provide better protection for the system when abnormalities occur in the fuel-fired power system.

[0028] The multi-level power limit control strategy can effectively solve the above two problems. Because of the multi-level power limit, the fuel cell system can limit the power step by step according to the specific judgment conditions, and there will be no problem of frequent load increase and decrease, which can extend the service life of the system and enable the fuel cell system to be better used in complex application scenarios.

[0029] In the above-mentioned embodiments, although the present invention has been described in conjunction with the specific embodiments of the present invention, many replacements, modifications and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description. The embodiments of the present invention are intended to cover all such replacements, modifications and variations falling within the broad scope of the appended claims.

[0030] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A fuel cell system power control method, characterized in that: It includes setting multiple levels of power limit judgment according to different power limit faults, setting corresponding trigger conditions for each power limit judgment layer, and the priority of the previous layer is greater than the priority of the next layer. When the trigger conditions are met, the output power of the fuel cell is adjusted step by step.

2. The fuel cell system power control method according to claim 1, characterized in that: When an abnormality occurs in the operation of the fuel-electric system, the trigger condition of the first-level power limit judgment is triggered, and the current power request value and the first power limit value are taken as the smaller value to obtain the first-level power limit value, wherein the first power limit value is 50% of the rated power; Set the abnormal delay time. When the abnormal duration exceeds the set abnormal delay time, the trigger condition of the second-level power limit judgment is triggered. The power limit value of the first level and the second power limit value are taken as the smaller one to obtain the power limit value of the second level, where the second power limit value is the idle power.

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