Verification method and system for energy management of DC / DC converter of fuel cell

Abstract

The invention provides a verification method and system for energy management of a DC / DC converter of a fuel cell stack. The verification method comprises the following steps: electrifying all components of the verification system; the controller controls the DC / DC converter and the verification battery to form an access, and detects the input voltage of the DC / DC converter; when it is detected that the input voltage of the DC / DC converter is within a first preset range, the controller sends a starting command to the DC / DC converter; detecting the current receiving and releasing condition of the electronic load, and detecting and verifying the current output condition of the battery; when it is detected that the output voltage of the DC / DC converter is within a second preset range, the controller sends an instruction to the high-voltage part, and the high-voltage part starts to operate; detecting an electronic load and verifying the operation condition of the battery; and repeating the steps until the verification result meets the expectation. Therefore, the fuel cell is prevented from being damaged, the test efficiency and the test accuracy are improved, and the test cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell technology, and in particular to a verification method and system for energy management of a DC / DC converter of a fuel cell stack. Background Art

[0002] The power output characteristics of the fuel cell system itself are relatively soft, and the power responsiveness is relatively weak. At the same time, the frequent load changes in electric vehicle operating conditions have a significant impact on the performance of the fuel cell stack, which is not conducive to its life. The operating conditions of electric vehicles are complex, and the road conditions are complex and changeable, especially the two conditions of emergency braking and emergency acceleration, which have high requirements for the responsiveness of the electric vehicle power system. These have brought many challenges to the fuel cell DC / DC converter. Therefore, a fuel cell DC / DC converter energy management system is needed, which can enable the power source to work efficiently, stably and reliably while meeting the vehicle performance requirements and ensuring the service life of each power source.

[0003] The previous verification method refers to directly using the fuel cell stack for real testing, which may cause the following adverse consequences: During the test, if the wrong management algorithm is used, it may cause the fuel cell to overcharge or over-discharge, thereby damaging the fuel cell itself, and it may also cause the fuel cell output power to be unstable, thereby affecting the performance of the fuel cell, or even causing the fuel cell to fail completely. Fuel cells are high-voltage devices. If a failure occurs during the test, risk safety issues may occur. And if the test is conducted directly on the actual fuel cell without going through the simulation system, there may be some adverse consequences in terms of test efficiency and test accuracy. For example, testing on the actual fuel cell requires a lot of time and resources, which may lead to low test efficiency. In actual testing, there may also be some difficult-to-control factors, such as temperature, humidity, etc., which may affect the accuracy of the test data. Actual testing requires a lot of manpower, material and financial resources, and the test difficulty and cost are high.

[0004] Therefore, in order to improve test efficiency and test accuracy and reduce test costs and safety risks, we designed a verification method and system for fuel cell stack DC / DC converter energy management. Summary of the invention

[0005] In order to overcome the above technical defects, the object of the present invention is to provide a verification method and system for the energy management of a DC / DC converter of a fuel cell stack.

[0006] The present invention discloses a verification method for energy management of a DC / DC converter of a fuel cell stack, comprising: powering on all components of a verification system; a controller controlling a DC / DC converter to form a path with a verification battery, and detecting an input voltage of the DC / DC converter; when it is detected that the DC / DC converter input voltage is within a first preset range, the controller sends a start command to the DC / DC converter; the current collection and release conditions of an electronic load are detected, and the current output conditions of the verification battery are detected; when it is detected that the output voltage of the DC / DC converter is within a second preset range, the controller sends an instruction to a high-voltage component, and the high-voltage component starts to operate; the electronic load and the operation conditions of the verification battery are detected; and the above steps are repeated until the verification result meets expectations.

[0007] Preferably, during the verification process, the electronic load is used to replace the battery management system; the verification battery is used to replace the fuel cell stack, and the parameter performance of the verification battery is consistent with that of the fuel cell stack.

[0008] Preferably, the controller is communicatively connected with the DC / DC converter and the high-voltage component; and circuit connections are verified between the battery and the DC / DC converter, the DC / DC converter and the electronic load, and the DC / DC converter and the high-voltage component.

[0009] Preferably, the verification system further includes a low-voltage component, and the controller is communicatively connected to the high-voltage component and the low-voltage component; the high-voltage component and the low-voltage component do not include a fuel cell stack.

[0010] Preferably, the controller controls the DC / DC converter to form a path with the verification battery and detects the input voltage of the DC / DC converter, including: the controller controls the DC / DC converter to attract the positive relay and the negative relay.

[0011] Preferably, when it is detected that the DC / DC converter input voltage is within the first preset range, the controller sends a start command to the DC / DC converter, which includes: when it is detected that the DC / DC converter input voltage is within the first preset range, the controller sends an output current instruction to the DC / DC converter, and the DC / DC converter starts to output current.

[0012] Preferably, the detection of the current collection and release of the electronic load, and the detection of the current output of the verification battery include: a first current sensor is provided between the verification battery and the DC / DC converter, the first current sensor is used to detect the output current of the verification battery in real time, and compare it with the preset current in real time to see if it is consistent; a second current sensor is provided between the DC / DC converter and the electronic load, the second current sensor is used to detect the positive current and negative current of the electronic load in real time to obtain the current and voltage required during the startup process, thereby obtaining the power required for startup; wherein: when the fuel cell needs a first amount of electricity but the DC / DC converter only outputs a second amount of electricity less than the first amount of electricity, the difference between the first amount of electricity and the second amount of electricity is given by the electronic load, which is a negative current at this time; as the DC / DC converter outputs gradually more electricity, the electronic load gives less and less electricity until it is zero; when the DC / DC converter outputs more electricity than the fuel cell requires, the excess electricity is absorbed by the electronic load, which is a positive current at this time.

[0013] The present invention also discloses a verification system for energy management of a DC / DC converter of a fuel cell stack, comprising a DC / DC converter, a verification battery, a controller, an electronic load and a high-voltage component, wherein the controller is respectively connected to the DC / DC converter and the high-voltage component for communication; the controller also comprises a first current sensor and a second current sensor; all components of the verification system are powered on; the controller controls the formation of a path between the DC / DC converter and the verification battery, and detects the input voltage of the DC / DC converter; when it is detected that the DC / DC converter input voltage is within a first preset range, the controller sends a start command to the DC / DC converter; the electronic load's current collection and release conditions are detected by the first current sensor and the second current sensor, and the verification battery current output conditions are detected; when it is detected that the output voltage of the DC / DC converter is within a second preset range, the controller sends an instruction to the high-voltage component, and the high-voltage component starts to operate; the operation of the electronic load and the verification battery is detected; and the above steps are repeated until the verification result meets expectations.

[0014] Preferably, it also includes a first current sensor and a second current sensor, the first current sensor is used to detect and verify the output current of the battery in real time, and compare it with the preset current in real time to see if it is consistent; the second current sensor is used to detect the collection and release current of the electronic load in real time.

[0015] Compared with the prior art, the above technical solution has the following beneficial effects:

[0016] 1. The present invention can verify the actual logic of the operation of the fuel cell DC / DC converter energy management system. Through continuous modification and verification, when the control logic reaches maturity, it can be tested in the real system, which effectively increases the speed of research and development and the stability of the control logic.

[0017] 2. The verification system avoids damaging the fuel cell, affecting the fuel cell performance, and avoiding risk safety issues, thereby improving test efficiency and test accuracy and reducing test costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A simplified flow chart of a method for verifying energy management of a DC / DC converter of a fuel cell stack provided by the present invention;

[0019] Figure 2 A module diagram of a verification system for energy management of a DC / DC converter of a fuel cell stack provided by the present invention. DETAILED DESCRIPTION

[0020] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0022] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0023] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0024] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0026] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0027] See attached Figure 1 The present invention discloses a verification method for energy management of a DC / DC converter of a fuel cell stack, comprising:

[0028] S100, power on all components of the verification system;

[0029] S200, the controller controls the DC / DC converter to form a path between the verification battery and detects the DC / DC converter input voltage;

[0030] S300, when it is detected that the DC / DC converter input voltage is within a first preset range, the controller sends a start command to the DC / DC converter;

[0031] S400, detecting the current receiving and releasing status of the electronic load, and detecting and verifying the current output status of the battery;

[0032] S500, when it is detected that the output voltage of the DC / DC converter is within the second preset range, the controller sends an instruction to the high-voltage component, and the high-voltage component starts to operate;

[0033] S600, detect electronic load and verify battery operation;

[0034] S700. Repeat the above steps, adjusting and modifying the control logic as needed, until the verification result meets expectations.

[0035] During the verification process, the electronic load is used to replace the battery management system, the verification battery is used to replace the fuel cell stack, and the parameter performance of the verification battery is consistent with the fuel cell stack. In addition, not only the verification battery, but all the equipment used needs to be adjusted to the same working state when the real system is running.

[0036] The present invention enables all conceivable fault problems in real operating conditions to be solved in this verification method, simulating the faults that may occur in real operation, which is equivalent to artificially creating faults for the system, thereby solving the faults and avoiding direct damage to the life of the battery stack or direct damage to the battery stack when a fault occurs in the real system.

[0037] Furthermore, before S100, S000 is also included, all components are arranged as follows Figure 2 The verification system is constructed by connecting as shown. The controller is in communication connection with the DC / DC converter and the high-voltage component. The verification battery is in circuit connection with the DC / DC converter, the DC / DC converter is in circuit connection with the electronic load, and the DC / DC converter is in circuit connection with the high-voltage component. Preferably, the controller is 24V. The electronic load is 550V, constant voltage mode, the verification battery is 230V, the maximum current is 80A, 18.4kW.

[0038] Furthermore, the verification system also includes a low-voltage component. The controller is connected to the high-voltage component and the low-voltage component in communication. The high-voltage component and the low-voltage component here refer to other components in the fuel cell system except the fuel cell stack.

[0039] In step S200, the controller controls the DC / DC converter to form a path between the verification battery. Preferably, the controller controls the DC / DC converter to attract the positive relay and the negative relay. Detecting the input voltage of the DC / DC converter means that the DC / DC converter itself has the function of detecting the input voltage. When it detects the input voltage, it will send a feedback signal to the controller.

[0040] In step S300, when it is detected that the DC / DC converter input voltage is within the first preset range, the controller sends a start command to the DC / DC converter, specifically, the controller sends an output current instruction to the DC / DC converter, and the DC / DC converter starts to output current. Here, the DC / DC converter is set to have a start voltage, preferably, the start voltage range is 90V to 450V. When it is detected that the DC / DC converter input voltage is within the preset range, the DC / DC converter starts to work. The purpose of this setting is to ensure that the stack voltage is high enough before starting with load, to avoid damage to the fuel cell stack, thereby protecting the stack.

[0041] In step S400, the load current is detected, and the verification battery current output is detected. The purpose is to fully understand the current and voltage required during the startup of the verification system, so as to understand the power required for startup, and continuously adjust the power until it is appropriate. A first current sensor is provided between the verification battery and the DC / DC converter. The first current sensor is used to detect the output current of the verification battery (i.e., the input current of the DC / DC converter) in real time, and to compare whether it is consistent with the preset current in real time. A second current sensor is provided between the DC / DC converter and the electronic load, and the second current sensor is used to detect the current of the electronic load in real time. That is, positive current and negative current, that is, the direction of the current needs to be verified. Simulate when the fuel cell BOP (fuel cell BOP includes air supply system, hydrogen circulation system, water heat management system, control system, etc., and the core products are air compressor, circulation pump, humidifier and electronic water pump, etc.) and other components require 10kW of electricity, but the DC / DC converter only outputs 5kW of electricity. The 5kW of this time difference is given by the electronic load, which is a negative current. As the output power of the DC / DC converter gradually increases, the electronic load gives less and less power until it is zero. When the DC / DC converter output power exceeds the power required by the BOP, the excess power is absorbed by the electronic load, which is a positive current. From this, we can know the current and voltage required during the startup process, and thus understand the power required for startup.

[0042] In step S500, when it is detected that the output voltage of the DC / DC converter is within the second preset range, the controller sends an instruction to the high-voltage component, and the high-voltage component starts to operate. Specifically, the DC / DC converter itself has a function of detecting the output voltage. When it is detected that the output voltage of the DC / DC converter is within the preset range, the high-voltage component starts to operate, thereby avoiding damage to the high-voltage component.

[0043] In step S600, the electronic load is detected and the battery operation is verified. After the high-voltage components are running, the voltage and current of the electronic load and the verification battery will change, and it is necessary to verify whether they are still within the preset value range. What needs to be simulated here is the change of the current of the electronic load under various conditions such as loading, unloading, variable load, sudden power failure, etc., and the change of the output voltage of the verification battery. If it is not within the preset range, the above steps will be repeated until the verification result meets expectations.

[0044] Preferably, controlling the DC / DC converter to connect to the verification battery also includes: controlling the DC / DC converter to connect to the verification battery to perform pre-charging first, and then perform main charging after a third preset time period, thereby protecting the verification battery (fuel cell stack).

[0045] See attached Figure 2The present invention also discloses a verification system for energy management of a DC / DC converter of a fuel cell stack, including a DC / DC converter, a verification battery, a controller, an electronic load and a high-voltage component. The controller is communicatively connected to the DC / DC converter and the high-voltage component respectively. Circuit connections are made between the verification battery and the DC / DC converter, the DC / DC converter and the electronic load, and the DC / DC converter and the high-voltage component. During the verification process, the electronic load is used to replace the battery management system, and the verification battery is used to replace the fuel cell stack. Furthermore, the verification system may also include a low-voltage component. The controller communicates with the high-voltage component and the low-voltage component. The high-voltage component and the low-voltage component here refer to other components in the fuel cell system except the fuel cell stack.

[0046] It also includes a first current sensor and a second current sensor. The first current sensor is used to detect and verify the output current of the battery in real time, and compare it with the preset current in real time. The second current sensor is used to detect the collection and release current of the electronic load in real time.

[0047] Specifically, all components of the verification system are powered on, and the controller controls the DC / DC converter to attract the main positive relay and the main negative relay. At this time, the input voltage can be detected, and the first current sensor detects the input current of the DC / DC converter in real time; if the difference between the input current and the preset input current is within the first preset range, it is considered that its voltage is stable, and the controller sends an output current instruction to the DC / DC converter to control the DC / DC converter to connect the electronic load to output current to the electronic load. At this time, the second current sensor detects the output current between the verification battery and the DC / DC converter in real time; if the difference between the output current and the preset output current is within the second preset range, it is considered that its voltage is stable, and the controller controls the high-voltage component to connect the DC / DC converter, thereby controlling the high-voltage component to connect the verification battery, and detects the electronic load's retracted and released current in real time through the second current sensor to detect the load and voltage stabilization source conditions.

[0048] Preferably, a pre-charging resistor and a pre-charging relay are also included. The pre-charging resistor is connected in series with the pre-charging relay and then connected in parallel at both ends of the main positive relay and the main negative relay. The high voltage on the system requires the main relays (main positive and main negative) to be completely closed before it can be connected. In order to protect the main positive relay contacts, the present invention sets a pre-charging relay in series with a pre-charging resistor (the resistance value gradually decreases with the connection time, and the resistance is variable) to protect the circuit from sudden changes in high voltage and large current. At the same time, a pre-charging environment is also provided for high-voltage components. After the pre-charging is completed, the main relay is closed.

[0049] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for verifying energy management of a DC / DC converter of a fuel cell stack, characterized in that: include: Power on all components of the verification system; The controller controls the DC / DC converter to form a path with the verification battery and detects the input voltage of the DC / DC converter; When it is detected that the DC / DC converter input voltage is within a first preset range, the controller sends a start command to the DC / DC converter; Detect the current of the electronic load and verify the current output of the battery; When it is detected that the output voltage of the DC / DC converter is within the second preset range, the controller sends an instruction to the high-voltage component, and the high-voltage component starts to operate; Test electronic loads and verify battery operation; Repeat the above steps until the verification result meets your expectations.

2. The verification method for energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: During the verification process, the electronic load is used to replace the battery management system; the verification battery is used to replace the fuel cell stack, and the parameter performance of the verification battery is consistent with that of the fuel cell stack.

3. The verification method for energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: The controller is in communication connection with the DC / DC converter and the high voltage components; Verify circuit connections between battery and DC / DC converter, DC / DC converter and electronic load, DC / DC converter and high-voltage components.

4. The verification method for energy management of a DC / DC converter of a fuel cell stack according to claim 3, characterized in that: The verification system also includes a low voltage component, and the controller is communicatively connected between the high voltage component and the low voltage component; The high voltage components and the low voltage components do not include a fuel cell stack.

5. The verification method for energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: The controller controls the DC / DC converter to form a path with the verification battery and detects the input voltage of the DC / DC converter, including: The controller controls the DC / DC converter to attract the positive relay and the negative relay.

6. The verification method for energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: When it is detected that the DC / DC converter input voltage is within the first preset range, the controller sends a start command to the DC / DC converter, including: When it is detected that the input voltage of the DC / DC converter is within the first preset range, the controller sends an output current instruction to the DC / DC converter, and the DC / DC converter starts to output current.

7. The method for verifying energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: The detecting of the current receiving and releasing conditions of the electronic load and the detecting and verifying of the current output conditions of the battery include: A first current sensor is provided between the verification battery and the DC / DC converter, and the first current sensor is used to detect the output current of the verification battery in real time, and compare it with the preset current in real time to see whether it is consistent; A second current sensor is provided between the DC / DC converter and the electronic load, and the second current sensor is used to detect the positive current and negative current of the electronic load in real time to obtain the current and voltage required in the startup process, thereby obtaining the power required for startup; Among them: it is simulated that when the fuel cell needs a first amount of electricity but the DC / DC converter only outputs a second amount of electricity which is less than the first amount of electricity, the difference between the first amount of electricity and the second amount of electricity is given by the electronic load, and it is a negative current at this time; as the output electricity of the DC / DC converter gradually increases, the amount of electricity given by the electronic load becomes less and less until it is zero; when the output electricity of the DC / DC converter exceeds the electricity required by the fuel cell, the excess electricity is absorbed by the electronic load, and it is a positive current at this time.

8. The method for verifying energy management of a DC / DC converter of a fuel cell stack according to claim 1, characterized in that: The detecting electronic load and verifying the battery operation condition comprises: After the high-voltage components are running, verify the changes in the current of the electronic load and the changes in the output voltage of the battery.

9. A verification system for energy management of a DC / DC converter of a fuel cell stack, characterized in that: It includes a DC / DC converter, a verification battery, a controller, an electronic load and a high-voltage component, wherein the controller is respectively connected to the DC / DC converter and the high-voltage component in communication; Power on all components of the verification system; The controller controls the DC / DC converter to form a path with the verification battery and detects the input voltage of the DC / DC converter; When it is detected that the DC / DC converter input voltage is within a first preset range, the controller sends a start command to the DC / DC converter; Detect the current of the electronic load and verify the current output of the battery; When it is detected that the output voltage of the DC / DC converter is within the second preset range, the controller sends an instruction to the high-voltage component, and the high-voltage component starts to operate; Test electronic loads and verify battery operation; Repeat the above steps until the verification result meets your expectations.

10. The verification system for energy management of a DC / DC converter of a fuel cell stack according to claim 9, characterized in that: It also includes a first current sensor and a second current sensor. The first current sensor is used to detect and verify the output current of the battery in real time, and compare it with the preset current in real time to see if it is consistent; the second current sensor is used to detect the collection and release current of the electronic load in real time.

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