Fuel cell based communication backup power system and control method thereof

Abstract

The application provides a fuel cell-based communication backup power supply system and a control method thereof. The communication backup power supply system comprises: a temperature control module including an air cooling fan and a low-temperature preheating heater; an auxiliary power supply unit connected with the low-temperature preheating heater for supplying power to the low-temperature preheating heater in a starting stage of the communication backup power supply system; a power conversion module with an input end connected with an output end of a fuel cell stack and an output end used for connecting a communication load as a power consumption device; a commercial power monitoring unit used for connecting external commercial power and outputting a signal representing a commercial power on-off state; a gas path control module including a proportional valve arranged in a hydrogen supply pipeline and a tail exhaust valve arranged at an exhaust end of the fuel cell stack; and a multi-dimensional sensing network including an environment sensor, a system sensor and a temperature sensor used for detecting a single piece temperature. Therefore, the communication backup power supply system can solve the problems in the prior art.

Description

Technical Field

[0001] This invention relates to the field of communication backup power technology, and more specifically to a communication backup power system based on a fuel cell and its control method. Background Technology

[0002] In communication network infrastructure, backup power systems are crucial for ensuring the continuous and stable operation of communication equipment during power outages. Currently, the main backup power sources for communication systems include diesel generators and lead-acid batteries; however, both have significant technical bottlenecks in terms of environmental friendliness, energy conversion efficiency, and environmental adaptability.

[0003] Diesel generators produce large amounts of pollutants such as carbon dioxide, nitrogen oxides, and particulate matter during operation, which is seriously inconsistent with the current global "dual carbon" goals and the needs of the communications industry's green transformation. Furthermore, their energy conversion efficiency is typically only 30%-40%, resulting in inefficient energy utilization, high operating noise, and frequent maintenance.

[0004] While lead-acid batteries offer advantages such as zero emissions and fast response, they pose a risk of lead pollution throughout their entire lifecycle. More importantly, their performance is highly sensitive to temperature, especially at low temperatures (e.g., -20°C), where capacity can decrease by more than 40%, making it difficult to guarantee reliable power supply for communication base stations in diverse climates, such as the frigid north and the scorching south. Furthermore, their low energy density and large size and weight make them unsuitable for emerging scenarios such as space-constrained edge computing nodes.

[0005] Therefore, existing technologies are no longer sufficient to meet the development needs of the communications industry in terms of environmental friendliness, efficiency, and wide temperature range adaptability, hindering the construction of a zero-carbon, efficient, and reliable backup power supply system. Hydrogen fuel cells, with their outstanding advantages of zero carbon emissions (reaction products are only water), high theoretical energy conversion efficiency (over 60%), and operation within a wide temperature range of -30°C to 50°C, have become an ideal choice for overcoming these technological bottlenecks. However, the core key to realizing the practical application of this technology lies in how to efficiently, reliably, and intelligently integrate fuel cell systems into the specific scenario of communication backup power supply, and design a matching control system and methodology. Summary of the Invention

[0006] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a communication backup power system based on fuel cells and its control method, which aims to solve the technical problems in the related technology to a certain extent.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This application provides a communication backup power system based on fuel cells, including: a fuel cell stack, a temperature control module, an auxiliary power supply unit, a power conversion module, a mains power monitoring unit, a gas path control module, a multi-dimensional sensor network, and a core controller;

[0009] The temperature control module includes an air-cooled fan and a low-temperature preheating heater. The air-cooled fan is located in the air intake path of the fuel cell stack, and the low-temperature preheating heater is used to preheat the fuel cell stack when the ambient temperature is lower than a set threshold.

[0010] The auxiliary power supply unit is connected to the low-temperature preheating heater and is used to supply power to the low-temperature preheating heater during the startup phase of the communication backup power system.

[0011] The input terminal of the power conversion module is connected to the output terminal of the fuel cell stack, and the output terminal of the power conversion module is used to connect to the communication load, which is an electrical device.

[0012] The mains power monitoring unit is used to connect to external mains power and output a signal representing the on / off state of the mains power.

[0013] The gas path control module includes a proportional valve installed in the hydrogen supply pipeline and a tail valve installed at the exhaust end of the fuel cell stack.

[0014] The multi-dimensional sensor network includes an environmental sensor for detecting ambient temperature and humidity, a system sensor for detecting internal temperature and humidity, and a temperature sensor installed on the fuel cell stack for detecting the temperature of its individual components.

[0015] The core controller is communicatively connected to the temperature control module, the auxiliary power supply unit, the power conversion module, the mains power monitoring unit, the gas path control module, and the multi-dimensional sensor network. It is used to control the start and stop of the communication backup power system according to the signal from the mains power monitoring unit, and to control the speed of the air-cooled fan, the start and stop of the low-temperature preheating heater, the opening degree of the proportional valve, and the opening and closing of the tail valve according to the detection data from the multi-dimensional sensor network.

[0016] Preferably, the power conversion module is a step-down DC / DC converter used to convert the voltage output by the fuel cell stack into a 220V AC power frequency voltage.

[0017] Preferably, the mains power monitoring unit is a room power detection relay.

[0018] Preferably, the core controller is configured as follows:

[0019] The opening of the proportional valve is adjusted according to the input current at the input terminal of the power conversion module to maintain the hydrogen pressure of the fuel cell stack; and,

[0020] During the startup phase of the communication backup power system, the tail valve is controlled to open and close periodically in a first cycle. After the communication backup power system enters a stable operation phase, the tail valve is controlled to open and close periodically in a second cycle, where the second cycle is longer than the first cycle.

[0021] Preferably, the core controller is configured as follows:

[0022] When the input current of the power conversion module is less than or equal to 3A, the opening of the proportional valve is controlled to maintain the hydrogen pressure of the fuel cell stack at 0.3±0.02 bar.

[0023] When the input current of the power conversion module is greater than 3A, the opening of the proportional valve is controlled to maintain the hydrogen pressure of the fuel cell stack at 0.5±0.02 bar.

[0024] Preferably, the first cycle is specifically: every 200 milliseconds of activation followed by 2 seconds of deactivation;

[0025] The second cycle is specifically: it is turned off for 6 seconds after being turned on for 200 milliseconds.

[0026] Preferably, the multi-dimensional sensing network further includes a hydrogen leakage sensor for detecting hydrogen leakage status of the communication backup power system.

[0027] Preferably, the communication backup power system further includes a discharge relay, which is connected to the fuel cell stack for power supply and to the core controller for communication. During the shutdown phase of the communication backup power system, the discharge relay is used to consume the residual power of the fuel cell stack under the control of the core controller.

[0028] This application provides a control method for a communication backup power system, including the following stages:

[0029] S1. System self-test: The core controller controls each module to perform a functional self-test;

[0030] S2, Standby State: After all modules pass the self-test, the signal from the mains power monitoring unit is obtained. If the signal indicates that the mains power supply is normal, the communication backup power system is controlled to enter the standby state of S2; if the signal indicates that the mains power supply is off, the system enters the startup activation state of S3.

[0031] S3. Start-up and activation: Sequentially turn on the gas path control module and temperature control module, and adjust the hydrogen pressure to control the fuel cell stack to start up and enter the operating state;

[0032] S4. Stable operation: The opening and closing cycle of the tail valve is switched to the second cycle, and the power conversion module is started to supply power to the communication load, and the speed of the air-cooled fan is dynamically adjusted according to the data of the multi-dimensional sensor network.

[0033] S5. Shutdown and Reset: When the mains power monitoring unit indicates that the mains power supply status is normal or the system detects a fault, the power conversion module is controlled to reduce load and shut down, and the gas path control module and temperature control module are shut down in sequence. The residual power of the fuel cell stack is consumed through the discharge relay, so that the communication backup power system returns to the standby state of S2.

[0034] Preferably, during the stable operation phase of S4, the core controller calculates the initial speed of the air-cooled fan using the following formula:

[0035] ;

[0036] Where DC is the output voltage at the input terminal of the power conversion module; P is the output power at the input terminal of the power conversion module; F is an empirical proportionality coefficient greater than 1; and T1 is the ambient temperature detected by the environmental sensor.

[0037] Based on the above technical solution, the advantages of the present invention compared with the prior art are as follows:

[0038] A fuel cell-based communication backup power system provided in this application includes a fuel cell stack, a temperature control module, an auxiliary power supply unit, a power conversion module, a mains power monitoring unit, a gas path control module, a multi-dimensional sensor network, and a core controller. The temperature control module includes a cooling fan and a low-temperature preheating heater. The cooling fan is positioned in the air inlet path of the fuel cell stack, and the low-temperature preheating heater preheats the fuel cell stack when the ambient temperature is below a set threshold. The auxiliary power supply unit is connected to the low-temperature preheating heater and supplies power to it during the startup phase of the communication backup power system. The input of the power conversion module is connected to the output of the fuel cell stack, and the output of the power conversion module is connected to the communication load, which is used as an electrical device. The mains power monitoring unit connects to the external mains power and outputs power to the fuel cell stack. The system outputs a signal indicating the on / off state of the mains power; the gas path control module includes a proportional valve installed in the hydrogen supply pipeline and a tailpipe valve installed at the exhaust end of the fuel cell stack; the multi-dimensional sensor network includes an environmental sensor for detecting ambient temperature and humidity, a system sensor for detecting internal system temperature and humidity, and a temperature sensor installed on the fuel cell stack for detecting the temperature of its individual components; the core controller is communicatively connected to the temperature control module, auxiliary power supply unit, power conversion module, mains power monitoring unit, gas path control module, and multi-dimensional sensor network, respectively, thereby enabling it to control the start and stop of the communication backup power system based on the signal from the mains power monitoring unit, and to control the speed of the air-cooled fan, the start and stop of the low-temperature preheating heater, the opening degree of the proportional valve, and the opening and closing of the tailpipe valve based on the detection data from the multi-dimensional sensor network, thereby solving the problems of the prior art. Attached Figure Description

[0039] Figure 1 A schematic diagram of the specific structure of a fuel cell-based communication backup power system provided for this application;

[0040] Figure 2 A schematic diagram illustrating the specific flow of the control method for the communication backup power system provided in this application. Detailed Implementation

[0041] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0043] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or a power connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] As mentioned earlier, the core key to realizing the practical application of this technology lies in how to efficiently, reliably, and intelligently integrate fuel cell systems into the specific scenario of communication backup power supply, and design a matching control system and method.

[0045] In view of this, this application provides a fuel cell-based communication backup power system and its control method, which can be used to solve the problems in the prior art. For example... Figure 1 The diagram shows the specific structure of the communication backup power system, which includes: a fuel cell stack 10, a temperature control module 20, an auxiliary power supply unit 30, a power conversion module 40, a mains power monitoring unit 50, a gas path control module 60, a multi-dimensional sensor network 70, and a core controller 80.

[0046] The core controller 80 is connected to the temperature control module 20, the auxiliary power supply unit 30, the power conversion module 40, the mains power monitoring unit 50, the gas path control module 60, and the multi-dimensional sensor network 70. It can control the start and stop of the communication backup power system according to the signal of the mains power monitoring unit 50, and control the speed of the air-cooled fan in the temperature control module 20, the start and stop of the low-temperature preheating heater, the opening degree of the proportional valve in the gas path control module 60, and the opening and closing of the tail valve according to the detection data of the multi-dimensional sensor network 70.

[0047] The fuel cell stack 10, as the core of this communication backup power system, generates electricity through the redox reaction of hydrogen and oxygen. Specifically, the fuel cell stack 10 can be an air-cooled fuel cell stack, and its type can be either an open-cathode stack or a closed-cathode stack. In practical applications, hydrogen can be introduced into the anode channel of the fuel cell stack 10, whereby the hydrogen in the anode channel reacts with the oxygen (oxygen from the air) in the cathode channel. Of course, the fuel cell stack 10 can also be a water-cooled fuel cell stack; this is not specifically limited here.

[0048] Considering that communication backup power systems are usually used as backup power for outdoor base stations, and that outdoor temperature conditions are much harsher than indoor conditions, it is usually necessary to cool down when the temperature is too high and heat up when the temperature is too low. Therefore, the temperature control module 20 may include an air-cooled fan and a low-temperature preheating heater. The air-cooled fan is located in the air intake path of the fuel cell stack 10, so that the air in the air intake path of the stack can be cooled down. In this way, after the air flows into the interior of the fuel cell stack 10, it cools down the interior.

[0049] The cryogenic preheating heater is used to preheat the fuel cell stack 10 when the ambient temperature is below a set threshold. This set threshold is the limit of the stack's tolerance to ambient temperature, and is therefore typically related to the performance of the membrane electrode assembly (MEA) in the stack. Thus, the value of the set threshold can usually be set based on the performance of the MEA itself. Generally, the set threshold can be between 0 and 10 degrees Celsius, such as 0 degrees Celsius, 3 degrees Celsius, 8 degrees Celsius, or 10 degrees Celsius. This allows the cryogenic preheating heater to be activated when the ambient temperature is below the set threshold to preheat the fuel cell stack 10 and improve its performance.

[0050] The auxiliary power supply unit 30 is connected to the cryogenic preheating heater and is used to supply power to the cryogenic preheating heater during the startup phase of the communication backup power system. Typically, the auxiliary power supply unit 30 can be a small-capacity lithium battery or other types of battery. During the startup phase of the communication backup power system, its temperature is relatively low, and the membrane electrode assembly (MEA) is difficult to reach its optimal operating temperature (usually above 50 degrees Celsius). At this time, the auxiliary power supply unit 30 can supply power to the cryogenic preheating heater to support its operation and generate a certain amount of heat to preheat the fuel cell stack.

[0051] The input terminal of the power conversion module 40 is connected to the output terminal of the fuel cell stack 10. The output terminal of the power conversion module is used to connect to the communication load, which is an electrical device. In practical applications, the power conversion module 40 can be a DC / DC converter or a DC-AC converter. Thus, the output terminal of the fuel cell stack 10 can, through the power conversion module 40, adjust (possibly by boosting or bucking) the voltage of the stack to the voltage corresponding to the communication load (usually 220V or 380V), and convert the DC power generated by the fuel cell stack 10 into AC power to support the normal operation of the communication load. For example, for a high-power fuel cell stack 10, its output voltage may reach over 500V, while the voltage corresponding to the communication load is usually 220V. In this case, the power conversion module 40 can specifically be a buck DC / DC converter, capable of converting the voltage output by the fuel cell stack 10 (i.e., 500V) into a 220V power frequency AC voltage to support the normal operation of the communication load. The communication load can typically be a communication base station or other communication equipment, and the number of communication loads in this application can be one or more.

[0052] The mains power monitoring unit 50 is used to connect to external mains power and output a signal representing the on / off state of the mains power. In practical applications, the mains power monitoring unit 50 can be a room power detection relay, with its input terminal connected to external mains power and its output terminal connected to the core controller 80. Thus, it can send a signal representing the on / off state of the mains power to the core controller 80. For example, when the external mains power is off, the mains power monitoring unit 50 can send a signal representing the mains power is off to the core controller 80. For example, when the external mains power is normally supplied, the mains power monitoring unit 50 can send a signal representing the mains power is normally supplied to the core controller 80.

[0053] The gas path control module 60 includes a proportional valve disposed in the hydrogen supply pipeline and a tail valve disposed at the exhaust end of the fuel cell stack 10. In this embodiment, the opening degree of the proportional valve can be used to adjust the hydrogen supply to the fuel cell stack 10. For example, increasing the opening degree of the proportional valve can increase the hydrogen supply to the fuel cell stack 10, and decreasing the opening degree of the proportional valve can decrease the hydrogen supply to the fuel cell stack 10. The tail valve is disposed at the exhaust end of the fuel cell stack 10. Typically, the tail valve can be controlled to regulate the exhaust of the fuel cell stack 10, thereby removing inert gases and water produced by the reaction inside the stack to maintain the air and humidity balance inside the stack. In this embodiment, the core controller 80 is communicatively connected to the gas path control module 60, thereby controlling the opening degree of the proportional valve and the tail valve in the gas path control module 60.

[0054] It is important to note that, in this application, considering the characteristics of the fuel cell stack 10, especially the stack of an air-cooled fuel cell, a certain hydrogen pressure needs to be maintained to provide sufficient hydrogen (maintaining a hydrogen excess coefficient) to support the operation of the stack. The hydrogen excess coefficient is typically greater than 1, and theoretically, the larger the excess coefficient, the more stable the stack operation. However, an excessively large excess coefficient can easily lead to increased hydrogen consumption, affecting hydrogen utilization efficiency. The inventors of this application, through analysis of the power generation characteristics of fuel cells, found that hydrogen consumption is mainly affected by the power generation current. Generally speaking, a higher current indicates more moles of electron migration, thus requiring and consuming more hydrogen; conversely, a lower current indicates fewer moles of electron migration, thus requiring and consuming less hydrogen.

[0055] Taking into account both hydrogen conservation and the need to support stable operation, the core controller 80 of this application can be configured to adjust the opening of the proportional valve in the gas path control module 60 according to the input current at the input terminal of the power conversion module 40 (which is the current directly output by the fuel cell stack 10) to maintain the hydrogen pressure of the fuel cell stack 10. For example, as the input current at the input terminal of the power conversion module 40 gradually increases, the opening of the proportional valve in the gas path control module 60 needs to be gradually increased to maintain the hydrogen pressure of the fuel cell stack 10, thereby maintaining a sufficient hydrogen excess coefficient to support the normal operation of the fuel cell stack 10.

[0056] Specifically, for example, when the input current at the input terminal of the power conversion module 40 is less than or equal to 3A, the opening of the proportional valve can be controlled to maintain the hydrogen pressure of the fuel cell stack 10 at 0.3±0.02 bar. When the input current of the power conversion module is greater than 3A, the opening of the proportional valve can be controlled to maintain the hydrogen pressure of the fuel cell stack 10 at 0.5±0.02 bar. Thus, under the two operating conditions of less than or equal to 3A and greater than 3A, the opening of the proportional valve is controlled to maintain the hydrogen pressure of the fuel cell stack 10 within an appropriate range to maintain a sufficient excess hydrogen coefficient.

[0057] Of course, considering that the communication backup power system uses the fuel cell stack 10 to generate electricity, and that it is not typically used as a backup power source for extended periods, but only temporarily replaces the mains power for a certain period when there is a power outage (i.e., the mains monitoring unit 50 outputs a signal indicating a mains power failure), the communication backup power system may also face the problem of frequent restarts. For example, when the communication backup power system is used as a backup power source for multiple communication loads, any communication load experiencing a mains power outage (possibly due to a circuit problem) may require restarting the communication backup power system.

[0058] Considering that the hydrogen demand of the fuel cell stack 10 differs during startup and stable operation, and that during startup, a certain amount of impurity gases (such as air) may have entered the hydrogen path due to previous shutdowns, the venting requirements through the tailpipe valve also differ at different stages. Generally, the startup phase is characterized by the presence of impurity gases due to previous shutdowns, and a relatively low hydrogen demand, requiring less maintenance of high hydrogen pressure (allowing for relatively larger fluctuations in hydrogen pressure). However, during stable operation, there are fewer impurity gases in the hydrogen path, and the hydrogen demand is relatively higher, thus requiring a higher level of maintenance of hydrogen pressure.

[0059] Therefore, in this embodiment, during the startup phase of the communication backup power system, since the hydrogen path of the fuel cell stack 10 contains a certain amount of impurity gas and the demand for hydrogen is relatively low, the core controller 80 can be configured to control the tail valve to open and close periodically with a relatively short first cycle, thereby increasing the opening and closing frequency of the tail valve and quickly discharging the impurity gas. After the communication backup power system enters the stable operation phase, the impurity gas in the hydrogen path is less, and the demand for hydrogen is relatively higher. The core controller 80 can then be configured to control the tail valve to open and close periodically with a relatively long second cycle, which is longer than the first cycle, thereby reducing the opening and closing frequency of the tail valve to maintain stable hydrogen pressure. This startup phase can be the period from the start of operation of the fuel cell stack 10 to within one minute of operation. Of course, the duration of this startup phase can be configured according to the characteristics of the fuel cell stack 10 itself. Generally speaking, in order to adapt to the different needs of the startup phase and the stable operation phase, the first cycle can be turned off for 2 seconds after every 200 milliseconds of startup; the second cycle can be turned off for 6 seconds after every 200 milliseconds of startup.

[0060] It should be further explained that the multi-dimensional sensor network 70 may include an environmental sensor for detecting ambient temperature and humidity, a system sensor for detecting internal system temperature and humidity, and a temperature sensor installed on the fuel cell stack 10 for detecting the temperature of each individual cell. Thus, the core controller 80 can control the speed of the air-cooled fan based on the difference between the individual cell temperature (T) of the fuel cell stack 10 detected by the temperature sensor and the ambient temperature (T1) detected by the environmental sensor. Typically, during the operation of the fuel cell stack 10, its individual cell temperature T will be higher than the ambient temperature T1. The greater the difference between the two, the greater the speed of the air-cooled fan should be. Especially when the difference exceeds a preset threshold, it indicates that the individual cell temperature T of the fuel cell stack 10 is too high. To prevent the fuel cell stack 10 from burning out, the core controller 80 can control the fuel cell stack 10 to shut down and issue a warning message.

[0061] In practical applications, considering that the fuel cell stack 10 uses hydrogen as fuel to generate electricity, in order to increase the safety of the communication backup power system, the multi-dimensional sensor network 70 may also include a hydrogen leak sensor to detect the hydrogen leak status of the communication backup power system. Generally speaking, the hydrogen leak sensor can be set on the inner wall of the outer shell of the communication backup power system, such as on the inner wall of the top of the outer shell, to detect the hydrogen concentration in the communication backup power system and determine the hydrogen leak status of the fuel cell stack 10.

[0062] It should be further explained that, since the communication backup power system in this embodiment uses the fuel cell stack 10 to generate electricity, during the shutdown phase of the communication backup power system, the fuel cell stack 10 gradually stops working, but a certain amount of hydrogen will remain in its hydrogen path (including hydrogen pipelines and hydrogen flow channels inside the stack, etc.). Considering that air will also remain in the air path of the fuel cell stack 10, these residual hydrogen and air will cause the fuel cell stack to maintain a certain amount of residual power, which may pose certain safety risks and damage the membrane electrode assembly of the fuel cell stack 10. Therefore, the communication backup power system may also include a venting relay, which is connected to the fuel cell stack 10 for power supply and communicates with the core controller 80. During the shutdown phase of the communication backup power system, the core controller 80 controls the consumption of the residual power of the fuel cell stack 10.

[0063] A fuel cell-based communication backup power system provided in this application includes a fuel cell stack 10, a temperature control module 20, an auxiliary power supply unit 30, a power conversion module 40, a mains power monitoring unit 50, a gas path control module 60, a multi-dimensional sensor network 70, and a core controller 80. The temperature control module 20 includes a cooling fan and a low-temperature preheating heater. The cooling fan is located in the air inlet path of the fuel cell stack, and the low-temperature preheating heater is used to preheat the fuel cell stack 10 when the ambient temperature is below a set threshold. The auxiliary power supply unit 30 is connected to the low-temperature preheating heater and supplies power to it during the startup phase of the communication backup power system. The input terminal of the power conversion module 40 is connected to the output terminal of the fuel cell stack, and the output terminal is used to connect to the communication load, which is an electrical device. The mains power monitoring unit 50 is used to connect to external mains power and output... The system outputs a signal indicating the on / off state of the mains power; the gas path control module 60 includes a proportional valve installed in the hydrogen supply pipeline and a tail exhaust valve installed at the exhaust end of the fuel cell stack 10; the multi-dimensional sensor network 70 includes an environmental sensor for detecting ambient temperature and humidity, a system sensor for detecting internal temperature and humidity, and a temperature sensor installed on the fuel cell stack 10 for detecting the temperature of its individual components; the core controller 80 is communicatively connected to the temperature control module 20, the auxiliary power supply unit 30, the power conversion module 40, the mains power monitoring unit 50, the gas path control module 60, and the multi-dimensional sensor network 70, thereby enabling it to control the start and stop of the communication backup power system based on the signal from the mains power monitoring unit 50, and to control the speed of the air-cooled fan, the start and stop of the low-temperature preheating heater, the opening degree of the proportional valve, and the opening and closing of the tail exhaust valve based on the detection data from the multi-dimensional sensor network 70, thereby solving the problems of the prior art.

[0064] Based on the communication backup power system provided in the embodiments of this application, the embodiments of this application also provide its control method. For any unclear aspects of this method embodiment, please refer to other parts of the specification. Figure 2 The diagram shown illustrates the specific flow of this control method, which includes the following stages:

[0065] S11, System Self-Check: The core controller performs a self-check of the functions of each module.

[0066] The communication backup power system can perform periodic self-tests, such as every 24 hours, to determine if any of its modules are faulty, preparing for subsequent startup. During the system's self-test phase, the core controller 80 can control the multi-dimensional sensor network 70, temperature control module 20, power conversion module 40, and air path control module 60 to perform functional self-tests. If a module fails to return a successful self-test message within 2 minutes, the core controller 80 determines that the module has a level 3 fault and sends a fault signal to the host computer. The host computer then generates a fault record and issues a warning message. Conversely, if all modules return a successful self-test message within 2 minutes, a fault-free signal is sent to the host computer.

[0067] S2, Standby State: After all modules pass the self-test, the signal from the mains power monitoring unit is obtained. If the signal indicates that the mains power supply is normal, the communication backup power system is controlled to enter the standby state of S2; if the signal indicates that the mains power supply is off, the system enters the startup activation state of S3.

[0068] In step S2, after all modules pass their self-tests, the signal from the mains power monitoring unit can be acquired. If the signal indicates that the mains power supply is normal, the communication backup power system does not need to be started. Instead, the communication backup power system can be controlled to enter a low-power standby state. Conversely, if the signal indicates that the mains power supply is off, the subsequent step S13 can be executed to activate the communication backup power system.

[0069] S13. Start-up and activation: Sequentially turn on the gas path control module and temperature control module, and adjust the hydrogen pressure to control the fuel cell stack to start up and enter the operating state.

[0070] During the startup and activation phase of this communication backup power system, its function is to control the fuel cell stack to start up and enter the operating state. Therefore, the gas path control module and temperature control module can be turned on sequentially through the control of the core controller. This includes opening the proportional valve in the hydrogen supply pipeline to supply hydrogen to the fuel cell stack, and controlling the tail valve at the exhaust end of the fuel cell stack to exhaust (for example, opening and closing in the first cycle). Through these two, the hydrogen pressure of the fuel cell stack can be adjusted. In addition, the system can also control the start-up of the air-cooled fan and the low-temperature preheating heater to regulate the temperature, and finally control the fuel cell stack to start up and enter the operating state.

[0071] S14. Stable operation: Control the opening and closing cycle of the tail valve to switch to the second cycle, start the power conversion module to supply power to the communication load, and dynamically adjust the speed of the air-cooled fan according to the data of the multi-dimensional sensor network.

[0072] After the fuel cell stack enters the operating state, the communication backup power system also enters the stable operation stage. In this stable operation stage, it is necessary to further control the opening and closing cycle of the tail valve to switch to the second cycle (for example, switch from the first cycle mentioned above to the second cycle), start the power conversion module to supply power to the communication load, and dynamically adjust the speed of the air-cooled fan according to the data of the multi-dimensional sensor network.

[0073] It is important to note that during the stable operation phase of S14, the core controller calculates the initial speed of the air-cooled fan using the following formula: In this formula, DC is the output voltage at the input terminal of the power conversion module, P is the output power at the input terminal of the power conversion module, and F is an empirical proportionality coefficient greater than 1. Its specific value can be set based on parameters such as the air pressure and airflow of the air-cooled fan itself, and it is typically a value between 3.5 and 5, for example, 3.9. Furthermore, in the subsequent control of the air-cooled fan speed, the initial speed of the air-cooled fan can be dynamically adjusted based on the imbalance of the individual cell voltages of the fuel cell stack (usually reflected by the extreme values ​​between the individual cell voltages; the larger the extreme value, the greater the imbalance), as well as the cell temperature T and the ambient temperature T1. For example, when the extreme value is larger or the difference between the cell temperature T and the ambient temperature T1 is larger, the speed of the air-cooled fan can be increased using a PID algorithm; conversely, when the extreme value is smaller or the difference between the cell temperature T and the ambient temperature T1 is smaller, the speed of the air-cooled fan can be decreased using a PID algorithm. The range of voltages of each individual cell in a fuel cell can be calculated by first obtaining the voltage of each individual cell, then obtaining the maximum and minimum voltages of each individual cell, and finally calculating the difference between the maximum and minimum voltages.

[0074] S5. Shutdown Reset: When the mains power monitoring unit indicates that the mains power supply status is normal or a fault is detected in the system, the control power conversion module is reduced and shut down, and the gas circuit control module and temperature control module are shut down in sequence. The residual power of the fuel cell stack is consumed through the discharge relay, so that the communication backup power system returns to the standby state of S2.

[0075] This invention is not limited to the embodiments described above. Those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A communication backup power system based on fuel cells, characterized in that, include: Fuel cell stack, temperature control module, auxiliary power supply unit, power conversion module, mains power monitoring unit, gas path control module, multi-dimensional sensor network and core controller; The temperature control module includes an air-cooled fan and a low-temperature preheating heater. The air-cooled fan is located in the air intake path of the fuel cell stack, and the low-temperature preheating heater is used to preheat the fuel cell stack when the ambient temperature is lower than a set threshold. The auxiliary power supply unit is connected to the low-temperature preheating heater and is used to supply power to the low-temperature preheating heater during the startup phase of the communication backup power system. The input terminal of the power conversion module is connected to the output terminal of the fuel cell stack, and the output terminal of the power conversion module is used to connect to the communication load, which is an electrical device. The mains power monitoring unit is used to connect to external mains power and output a signal representing the on / off state of the mains power. The gas path control module includes a proportional valve installed in the hydrogen supply pipeline and a tail valve installed at the exhaust end of the fuel cell stack. The multi-dimensional sensor network includes an environmental sensor for detecting ambient temperature and humidity, a system sensor for detecting internal temperature and humidity, and a temperature sensor installed on the fuel cell stack for detecting the temperature of its individual components. The core controller is communicatively connected to the temperature control module, the auxiliary power supply unit, the power conversion module, the mains power monitoring unit, the gas path control module, and the multi-dimensional sensor network. It is used to control the start and stop of the communication backup power system according to the signal from the mains power monitoring unit, and to control the speed of the air-cooled fan, the start and stop of the low-temperature preheating heater, the opening degree of the proportional valve, and the opening and closing of the tail valve according to the detection data from the multi-dimensional sensor network.

2. The communication backup power system according to claim 1, characterized in that, The power conversion module is specifically a step-down DC / DC converter, used to convert the voltage output by the fuel cell stack into a 220V AC power frequency voltage.

3. The communication backup power system according to claim 1, characterized in that, The mains power monitoring unit is specifically a room power detection relay.

4. The communication backup power system according to claim 1, characterized in that, The core controller is configured as follows: The opening of the proportional valve is adjusted according to the input current at the input terminal of the power conversion module to maintain the hydrogen pressure of the fuel cell stack; and, During the startup phase of the communication backup power system, the tail valve is controlled to open and close periodically in a first cycle. After the communication backup power system enters a stable operation phase, the tail valve is controlled to open and close periodically in a second cycle, where the second cycle is longer than the first cycle.

5. The communication backup power system according to claim 4, characterized in that, The core controller is configured as follows: When the input current of the power conversion module is less than or equal to 3A, the opening of the proportional valve is controlled to maintain the hydrogen pressure of the fuel cell stack at 0.3±0.02 bar. When the input current of the power conversion module is greater than 3A, the opening of the proportional valve is controlled to maintain the hydrogen pressure of the fuel cell stack at 0.5±0.02 bar.

6. The communication backup power system according to claim 4, characterized in that, The first cycle is specifically: every 200 milliseconds of activation followed by 2 seconds of deactivation; The second cycle is specifically: it is turned off for 6 seconds after being turned on for 200 milliseconds.

7. The communication backup power system according to claim 1, characterized in that, The multi-dimensional sensing network also includes a hydrogen leakage sensor for detecting hydrogen leakage in the communication backup power system.

8. The communication backup power system according to claim 1, characterized in that, The communication backup power system also includes a venting relay, which is connected to the fuel cell stack for power supply and to the core controller for communication. During the shutdown phase of the communication backup power system, the core controller controls the consumption of the residual power of the fuel cell stack.

9. A control method for a communication backup power system as described in any one of claims 1 to 8, characterized in that, Includes the following stages: S1. System self-test: The core controller controls each module to perform a functional self-test; S2, Standby State: After all modules pass the self-test, the signal from the mains power monitoring unit is obtained. If the signal indicates that the mains power supply is normal, the communication backup power system is controlled to enter the standby state of S2; if the signal indicates that the mains power supply is off, the system enters the startup activation state of S3. S3. Start-up and activation: Sequentially turn on the gas path control module and temperature control module, and adjust the hydrogen pressure to control the fuel cell stack to start up and enter the operating state; S4. Stable operation: The opening and closing cycle of the tail valve is switched to the second cycle, and the power conversion module is started to supply power to the communication load, and the speed of the air-cooled fan is dynamically adjusted according to the data of the multi-dimensional sensor network. S5. Shutdown and Reset: When the mains power monitoring unit indicates that the mains power supply status is normal or the system detects a fault, the power conversion module is controlled to reduce load and shut down, and the gas path control module and temperature control module are shut down in sequence. The residual power of the fuel cell stack is consumed through the discharge relay, so that the communication backup power system returns to the standby state of S2.

10. The control method according to claim 9, characterized in that, During the stable operation phase of S4, the core controller calculates the initial speed of the air-cooled fan using the following formula: ； Where DC is the output voltage at the input terminal of the power conversion module; P is the output power at the input terminal of the power conversion module; F is an empirical proportionality coefficient greater than 1; and T1 is the ambient temperature detected by the environmental sensor.

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