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Method and process for hydrogen storage management of fuel cell commercial vehicles

发布日期:2020-01-18 03:51 Document serial number: 19730119 Publication date: 2020-01-18 03:51
Method and process for hydrogen storage management of fuel cell commercial vehicles

The invention relates to the technical field of hydrogen protection station safety protection, in particular to a hydrogen storage management method for a fuel cell commercial vehicle.



Background technique:

Compared with lithium battery electric vehicles, the body weight of hydrogen fuel cell vehicles is lighter and the energy replenishment time is greatly shortened, so it is almost free from the limitation of battery life. The large-scale application of emission vehicles has laid the foundation. The plan points out the development direction from the technical route of hydrogen fuel cell development, key technology research, industrialization breakthrough of the entire industry chain, and demonstration of commercialization of fuel cell vehicles.

Due to the use of hydrogen in hydrogen fuel cell vehicles, hydrogen has the characteristics of flammability, explosion, and hydrogen embrittlement. Therefore, the control and safety protection requirements for the hydrogen storage control system are particularly prominent. The quality of the control will directly affect the safety of the entire vehicle. At the same time, due to the characteristics of the fuel cell, if the supplied hydrogen has overpressure, overcurrent, and underpressure during operation, it will directly affect the life of the fuel cell.



Technical realization elements:

The purpose of the present invention is to provide a hydrogen storage management method for a fuel cell commercial vehicle, which aims to automatically perform bottle valve driving and hydrogen pressure detection, and the controller can timely detect the presence of overpressure, overcurrent, and underpressure of hydrogen during work. problem.

To achieve the above object, the present invention provides a hydrogen storage management method for a fuel cell commercial vehicle, the method includes:

Sensor power supply voltage collection, wherein the sensor includes a bottle valve temperature sensor, a pipeline pressure sensor, and a hydrogen concentration sensor;

And determine whether the sensor is faulty according to the collected power supply voltage of the sensor, and if so, determine the current fault level and code;

Collect the bottle valve pressure value and pipeline pressure value, and judge whether the pressure is normal according to the collected pressure value. If it is, determine the fault level and code according to the current pressure value;

Detect the temperature of the bottle valve, and determine whether the pipeline is faulty according to the collected valve temperature value. If so, determine the fault level and code according to the current valve temperature value;

Detect the hydrogen concentration value, and determine whether the pipeline has a fault according to the collected hydrogen concentration value of the bottle; if so, determine the fault action according to the current hydrogen concentration value;

Determine whether to close the bottle valve according to the bottle valve temperature, the hydrogen bottle pressure, the current hydrogen concentration, and the temperature difference between any two bottle valves;

According to the pressure value of the pipeline, the fuel cell system is shut down, the bottle valve is closed in sequence, and the machine is stopped.

In an optional implementation manner, the steps of performing shutdown of the fuel cell system, closing bottle valves in sequence, and stopping the vehicle according to the magnitude of the pipeline pressure value include:

According to the pressure value of the pipeline, execute:

When the medium pressure is: medium pressure is higher than tbdbarg for 5s, or medium pressure is lower than tbdbarg for 5s, or the sensor is faulty, the fuel cell system is shut down;

The high pressure is: when the high pressure exceeds 720barg, or the high pressure is less than 20barg, or when the sensor fails, the bottle valve is closed in order, and the machine is stopped.

In an optional implementation manner, the step of detecting the hydrogen concentration value and judging whether the pipeline fails according to the collected hydrogen concentration value of the bottle, and if so, determining the fault action according to the current hydrogen concentration value, including:

Detect the hydrogen concentration value. According to the hydrogen concentration value, execute: when the 3000ppm <hydrogen concentration value == 8000ppm for 5s, the meter starts to alarm; when the 8000ppm <hydrogen concentration value == 10000ppm for 5s, the fuel cell system is shut down. Close the bottle valve and stop; if the 10000ppm <hydrogen concentration value lasts for 5s, close the bottle valve and stop it; in the case of sensor failure, shut down the bottle valve in order and shut down.

In an optional implementation manner, the step of determining whether to close the bottle valve according to the bottle valve temperature, the hydrogen bottle pressure, the current hydrogen concentration, and the temperature difference between any two bottle valves includes:

When any bottle valve generates an over-temperature alarm or a short circuit, close the bottle valve;

When the temperature of the bottle valve is between 75 ° C <temperature <= 85 ° C, start the instrument alarm. When the temperature of the bottle valve> 85 ° C, close the bottle valve and stop it. When the temperature of the bottle valve is <-40 ° C, close Bottle valve; when the bottle valve sensor fails, close the bottle valve;

When the temperature difference between any two hydrogen cylinders is greater than 20 ° C, the instrument will start an alarm.

In an optional implementation manner, the method further includes:

The vehicle controller vcu sends a mode request signal to the hydrogen system management unit hms and receives the work mode selection. The work mode is divided into automatic mode, manual mode, and maintenance mode;

Among them, in automatic mode, the vehicle controller vcu sends a start command to the hydrogen system management unit hms. After receiving the "start" command, the hydrogen system management unit hms opens the bottle valve in sequence after the start condition is met, and the opening interval is 200ms. And feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve shape;

In manual mode, the vehicle controller vcu directly controls the opening of the bottle valve. The vehicle controller vcu sends a hydrogen bottle valve request command to the hydrogen system management unit hms. After receiving the valve opening command, the hydrogen system management unit hms meets the opening Under the conditions, open the bottle valve, and feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve status;

In maintenance mode, the vehicle controller vcu directly controls the opening of the bottle valve. The vehicle controller vcu sends the hydrogen bottle valve request command to the hydrogen system management unit hms. After receiving the valve opening command, the hydrogen system management unit hms directly opens the bottle. Valve, and feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve status.

An optional implementation manner further includes processing of the startup instruction: the can input processing module converts the bus value of the startup instruction to an actual physical value; and when there is a transient failure, the startup instruction outputs the value of the previous cycle; When there is a confirmation failure in the can message transmission of the vehicle controller vcu, the startup instruction outputs a preset failure code;

The processing of the hydrogen cylinder valve request includes: the can input processing module converts the bus value requested by the hydrogen cylinder valve into the actual physical value; when there is a transient failure, the hydrogen cylinder valve requests the output to the value of the previous cycle; when the vehicle controller vcu When a can message transmission exists to confirm the fault, the hydrogen cylinder valve requests to output a preset fault code;

The processing of the HMS mode request of the hydrogen system management unit includes: the can input processing module converts the bus value requested by the HMS mode into the actual physical value; when there is a transient failure, the HMS mode request output is the value of the previous cycle; when the vehicle controller When there is a confirmation failure in the can message transmission of vcu, the hms mode requests to output a failure code;

The processing process of the fuel cell working state includes: the can input processing module converts the bus value of the fuel cell working state into the actual physical value; when there is a transient failure, the fuel cell working state output is the value of the previous cycle; when the vehicle controller When there is a confirmed fault in the can message transmission of the vcu, the fuel cell operating status request is output as a preset fault code.

Applying a method for hydrogen storage management of a fuel cell commercial vehicle provided by an embodiment of the present invention, the valve of the bottle is automatically driven, and the pressure of hydrogen is detected, and the controller can timely detect the over-voltage, over-current, and under-pressure of the hydrogen that occurs during work. .

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of a hydrogen storage management method for a fuel cell commercial vehicle according to an embodiment of the present invention.

detailed description

The following describes the embodiments of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementations, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to FIG. 1. It should be noted that the illustration provided in this embodiment only illustrates the basic idea of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagram instead of the actual implementation. The number, shape, and size of components are drawn. In actual implementation, the type, quantity, and proportion of each component can be changed at will, and the component layout may be more complicated.

As shown in FIG. 1, an embodiment of the present invention provides a hydrogen storage management method for a fuel cell commercial vehicle. The method includes the following steps:

s101, the power supply voltage collection of the sensor, wherein the sensor includes a bottle valve temperature sensor, a pipeline pressure sensor, and a hydrogen concentration sensor; judging whether the sensor is faulty according to the power supply voltage of the collected sensor, and if so, determining the current fault level and Code.

Monitoring the sensor supply voltage is normal. During the monitoring process, a transient fault and a certain fault will be generated. The supply voltage is obtained through the conversion of the sensor supply voltage signal adc value, so monitoring the sensor supply voltage signal adc value has the same effect. The sensor supply voltage signal adc value range is 500-530, of course, these two values are scalar. When any of the following conditions are met, the sensor power supply voltage transient fault will occur: the sensor power supply voltage signal adc value is less than a threshold value; the sensor power supply voltage signal adc value is greater than a threshold value; when the sensor power supply voltage transient fault occurs continuously for a period of time , There will be a fault determined by the sensor supply voltage.

s102: Collect the bottle valve pressure value and the pipeline pressure value, and determine whether the pressure is normal according to the collected pressure value. If it is, determine the fault level and code according to the current pressure value.

The coil used on the bv700 bottle valve has a low impedance of approximately 3ω and is designed for pulse width modulation (pwm) control. By adjusting the coil current to maximize performance and reduce power consumption. At present, the bottle valve is controlled by the hms using the pwm signal. When the bottle valve opening conditions are met, the hms opens the bottle valve with a current of 2a. When the bottle valve is opened, the current is reduced to a maintenance current of 1a. After the bottle valve is opened, the bottle valve will be closed when any of the following conditions are met: the bottle valve closing instruction is received, the bottle valve temperature is ≥85 ° C, the bottle valve temperature is ≤-40 ° C, the hydrogen bottle pressure is ≥72mpa, and the hydrogen concentration is ≥ 10000ppm, bottle valve temperature difference ≥20 ℃, can communication loss failure ≥2s.

Check whether the pressure signal has a short circuit / open circuit fault; by judging the current voltage value of the pressure signal. Calculate the current pressure; by the formula y = kx + b, the formula is provided by the sensor manufacturer.

Short-circuit / open-circuit transient faults occur when any of the following conditions are met:

The pressure signal voltage value is less than a threshold value;

The pressure signal voltage value is greater than a threshold.

When the following conditions are met at the same time, a fault identified by the pressure signal short circuit / open circuit will occur:

Pressure signal short-circuit / open-circuit transient fault occurs continuously for a period of time;

No transient failure of the sensor supply voltage;

No fault determined by the sensor supply voltage;

When no instantaneous and definite fault occurs, the conversion formula between pressure value and pressure voltage value is: p = (u + offset) * scaling. The formula is the relationship between the pressure sensor output voltage characteristics and actual physical characteristics. The specific scaling and offset parameters are provided by the sensor manufacturer. Different types of sensors have different two parameters. Where p is pressure in kpa; u is pressure signal voltage in v.

When any of the following conditions are met, the value of the current pressure is equal to the value of the previous cycle:

Transient failure of sensor supply voltage occurred;

Short-circuit / open-circuit transient fault of pressure signal occurs;

When any of the following conditions are met, the current pressure value is equal to 0;

Short-circuit / open-circuit transient fault of pressure signal in the first cycle of software operation;

A fault identified by the pressure signal short circuit / open circuit occurred.

S103: Detect the temperature of the bottle valve, and determine whether the pipeline has a fault according to the collected valve temperature value. If so, determine the fault level and code according to the current bottle valve temperature value.

When the bottle valve temperature signal adc value is converted into the bottle valve temperature, a look-up table is used, and the temperature value after the look-up table is subjected to a first-order lag filtering, and the filtering time constant is a standard amount. At the same time, it can also detect the bottle valve temperature sensor failure. The valve temperature of the bottle is obtained by checking the adc value of the bottle valve temperature signal. First-order filtering is performed on the temperature value obtained from the look-up table, and the filtering time constant can be calibrated. Currently, it is set to 200ms. A bottle valve temperature sensor failure occurs when any of the following conditions are met: the bottle valve temperature signal adc value is less than a threshold value; the bottle valve temperature signal adc value is greater than a threshold value; when the bottle valve temperature sensor transient failure continues for a period of time After that, a fault determined by the bottle valve temperature sensor will occur. When a fault determined by the bottle valve temperature sensor occurs, the bottle valve temperature is overwritten by 0 ° C.

S104: Detect the hydrogen concentration value, and determine whether the pipeline has a fault according to the collected hydrogen concentration value of the bottle, and if so, determine the fault action according to the current hydrogen concentration value.

Check whether the concentration signal has short-circuit / open-circuit fault; by judging the current duty cycle value of the concentration signal.

Calculate the current concentration; use the formula y = kx + b, which is provided by the sensor manufacturer.

Short-circuit / open-circuit transient faults in concentration signals occur when any of the following conditions are met:

The duty cycle of the concentration signal is less than a threshold;

The duty cycle of the concentration signal is greater than a threshold;

When the following conditions are met at the same time, a failure of the concentration signal short circuit / open circuit determination will occur:

The concentration signal short-circuit / open-circuit transient fault occurs continuously for a period of time; when there is no instantaneous and definite fault, the conversion formula between the concentration value and the concentration duty cycle value is: c = (u + offset) * scaling.

The formula is the relationship between the sensor's output voltage characteristics and the actual physical characteristics. The specific scaling and offset parameters are provided by the sensor manufacturer. The two parameters are different for different types of sensors. Where c is the concentration in ppm; u is the duty cycle of the concentration signal in%.

When any of the following conditions is met, the current value is equal to the concentration value of the previous cycle: a short-circuit / open-circuit instantaneous failure of the concentration signal occurs.

When any of the following conditions is met, the current pressure value is equal to 10000 ppm, and the first cycle of the software operation has a pressure signal short-circuit / open-circuit instantaneous fault; a concentration signal short-circuit / open-circuit-determined fault occurs.

Specifically, to detect the hydrogen concentration value, according to the hydrogen concentration value, execute: when 3000ppm <hydrogen concentration value == 8000ppm for 5s, the meter starts an alarm; when 8000ppm <hydrogen concentration value == 10000ppm for 5s, the fuel cell The system shuts down, closes the bottle valve and shuts down; when the 10000ppm <hydrogen concentration value continues for 5s, closes the bottle valve and shuts down; when the sensor fails, the fuel cell system shuts down and closes the bottle valve in turn.

Control the opening and closing of the hydrogen cylinder valve according to the current hydrogen concentration. Therefore, when the hydrogen concentration sensor malfunctions, it should work as far as possible without releasing hydrogen, and the given 10000ppm is exactly the highest concentration fault value, so This will ensure that the subsequent control strategy will always close the hydrogen cylinder valve. As shown in Table 1.

Table 1

s105. Determine whether to close the bottle valve according to the bottle valve temperature, the hydrogen bottle pressure, the current hydrogen concentration, and the temperature difference between any two bottle valves.

When any bottle valve generates an over-temperature alarm or a short circuit, close the bottle valve;

When the temperature of the bottle valve is between 75 ° C <temperature <= 85 ° C, start the instrument alarm. When the temperature of the bottle valve> 85 ° C, close the bottle valve and stop it. When the temperature of the bottle valve is <-40 ° C, close Bottle valve; when the bottle valve sensor fails, close the bottle valve;

When the temperature difference between any two hydrogen cylinders is greater than 20 ° C, the instrument will start an alarm.

Exemplarily, as shown in Table 2, when two bottle valves are included, the corresponding operation of the bottle valve temperature and the display of the fault code and level are performed.

Table 2

s106: According to the pressure value of the pipeline, the fuel cell system is shut down, the valve of the bottle is closed in sequence, and the machine is stopped.

Specifically, according to the pressure value of the pipeline, the following judgment process is performed:

When the medium pressure is: medium pressure is higher than tbdbarg for 5s, or medium pressure is lower than tbdbarg for 5s, or the sensor is faulty, the fuel cell system is shutdown;

The high pressure is: when the high pressure exceeds 720barg, or the high pressure is less than 20barg, or when the sensor fails, the bottle valve is closed in order, and the machine is stopped. Exemplarily, as shown in Table 3, corresponding operations are performed according to different pipeline pressures, and corresponding fault codes and fault levels are displayed.

table 3

In the embodiment of the present invention, steps s101 to s104 are used to collect the current working state voltage of the sensor and the values of each sensor. After the collection, the pipeline working state, bottle valve working state, and sensor work are performed according to the current sensor value. State judgment to improve the safety and reliability of hydrogen storage control.

In an optional implementation manner, the method further includes: performing code level and fault classification based on CAN communication faults, as shown in Table 4.

Table 4

The vehicle controller vcu sends a mode request signal to the hydrogen system management unit hms and receives the work mode selection. The work mode is divided into automatic mode, manual mode, and maintenance mode;

Among them, in automatic mode, the vehicle controller vcu sends a start command to the hydrogen system management unit hms. After receiving the "start" command, the hydrogen system management unit hms opens the bottle valve in sequence after the start condition is met, and the opening interval is 200ms. And feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve shape;

In manual mode, the vehicle controller vcu directly controls the opening of the bottle valve. The vehicle controller vcu sends a hydrogen bottle valve request command to the hydrogen system management unit hms. After receiving the valve opening command, the hydrogen system management unit hms meets the opening Under the conditions, open the bottle valve, and feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve status;

In maintenance mode, the vehicle controller vcu directly controls the opening of the bottle valve. The vehicle controller vcu sends the hydrogen bottle valve request command to the hydrogen system management unit hms. After receiving the valve opening command, the hydrogen system management unit hms directly opens the bottle. Valve, and feedback the working mode to the vehicle controller vcu, and at the same time feedback the bottle valve status.

The embodiment of the present invention further includes control of the hydrogenation process, including: when the HMS receives an external hydrogenation signal, the HMS is activated, and at this time the HMS detects whether the hydrogen concentration, the temperature of the hydrogen cylinder, and the pressure of the hydrogen cylinder are satisfied, and the HMS passes after the conditions are met. A hard-wired enable signal to the infrared communication module activates the infrared module.

HMS handshake with infrared communication module, HMS sends protocol type proto_type, vehicle infrared module system version ver_irm, hydrogen tank capacity tank_volh, vehicle filling type acceptacle_type to infrared communication module. At this time, the infrared module will return the protocol type proto_typefb, the vehicle infrared module system version ver_irmfb, and the infrared module system program version ver_irsfbh. After the handshake is successful, when the infrared communication module has no fault information feedback, hms will open the bottle valve in turn.

HMS sends a "filling" command to the infrared communication module through the fueling instruction fueling_cmd, and simultaneously sends the filling pressure p_tankh and the temperature and temperature of the hydrogen cylinder to the infrared communication module in real time. After receiving the instruction, the hydrogenation machine performs the hydrogenation action, and simultaneously The hydrogenation status fuelling_state feedback "Hydrogenation"; after the hydrogenation is completed, hms sends a "Stop" command to the infrared communication module via the hydrogenation instruction fueling_cmd, at the same time closes the bottle valve, and at the same time, the fuelling_state feedback "Stop hydrogenation"; When the hydrogenation gun is unplugged, it enters the powerlatch delayed power-down mode. At this time, the infrared communication module enable signal is disconnected, and after recording the number of fillings and fault information, it enters the sleep mode.

An optional implementation manner further includes processing of the startup instruction: the can input processing module converts the bus value of the startup instruction to an actual physical value; and when there is a transient failure, the startup instruction outputs the value of the previous cycle; When there is a confirmation failure in the can message transmission of the vehicle controller vcu, the startup instruction outputs a preset failure code;

The processing of the hydrogen cylinder valve request includes: the can input processing module converts the bus value requested by the hydrogen cylinder valve into the actual physical value; when there is a transient failure, the hydrogen cylinder valve requests the output to the value of the previous cycle; when the vehicle controller vcu When a can message transmission exists to confirm the fault, the hydrogen cylinder valve requests to output a preset fault code;

The processing of the HMS mode request of the hydrogen system management unit includes: the can input processing module converts the bus value requested by the HMS mode into the actual physical value; when there is a transient failure, the HMS mode request output is the value of the previous cycle; when the vehicle controller When there is a confirmation failure in the can message transmission of vcu, the hms mode requests to output a failure code;

The processing process of the fuel cell working state includes: the can input processing module converts the bus value of the fuel cell working state into the actual physical value; when there is a transient failure, the fuel cell working state output is the value of the previous cycle; when the vehicle controller When there is a confirmed fault in the can message transmission of the vcu, the fuel cell operating status request is output as a preset fault code.

The above-mentioned embodiments merely illustrate the principle of the present invention and its effects, but are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field to which they belong without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

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