CN111169328A

CN111169328A - Fuel cell control method for passenger car

Info

Publication number: CN111169328A
Application number: CN201811331214.1A
Authority: CN
Inventors: 云大笑; 顾春豪; 韦潘林
Original assignee: Shanghai Shenlong Bus Co Ltd
Current assignee: Shanghai Shenlong Bus Co Ltd
Priority date: 2018-11-09
Filing date: 2018-11-09
Publication date: 2020-05-19
Anticipated expiration: 2038-11-09
Also published as: CN111169328B

Abstract

The invention relates to a control method of a fuel cell for a passenger car, which comprises the following steps: 1) starting the vehicle; 2) receiving a stack starting command; 3) acquiring the SOC value of the current power battery, judging whether the SOC value is not greater than a threshold value a, if so, sending an FC ON command, and if not, stopping the power battery; 4) comparing the SOC value with a threshold value b, 41) when b < SOC is less than or equal to a, sending a target power x by the vehicle-mounted VCU, and carrying out step 5); 42) when the SOC is less than or equal to b, the vehicle-mounted VCU sends out target power y, and the step 7) is carried out; 5) comparing the SOC value with a threshold value c, when a is smaller than or equal to C, sending out target power z, and performing the step 6), otherwise, returning to the step 4); 6) when the SOC is more than or equal to c, the FCU responds to shutdown; 7) and comparing with a threshold value d, when the SOC is larger than or equal to d, sending out target power x by the vehicle-mounted VCU, and performing the step 5), otherwise, returning to the step 42). Compared with the prior art, the invention has the advantages of safe operation, high safety performance, improved fuel utilization rate, quick energy charging and the like.

Description

Fuel cell control method for passenger car

Technical Field

The invention relates to the field of motor vehicle fuel cell control, in particular to a fuel cell control method for a passenger car.

Background

The national requirements on the emission standards of motor vehicles are higher and higher, the waste pollution of the diesel internal combustion engine used in the passenger car industry is greater, and a sustainable development energy with zero emission, zero pollution, lower carbon and environmental protection is needed to solve the problem of environmental pollution.

The development of new energy vehicles is guided by a series of national good policies, the technical development becomes mature day by day, the endurance mileage of the vehicles is continuously improved due to the repeated improvement of the energy density of the power battery, but the pure electric vehicles can only cover urban public transport and short-distance travel lines at present, the long-distance transportation needs are mainly the traditional diesel vehicles at present, and the market is blank.

Since the first fuel cell automobile in the world was introduced by general-purpose automobiles in 1966, with the rapid improvement of fuel cell technology, the improvement of hydrogen energy storage and hydrogen station construction, the comprehensive synthesis of fuel cells and other conditions which are favorable for the industrial development of fuel cell automobiles, the development of third fuel cell automobiles has come. Fuel cell vehicles of various international vehicle factories including Toyota, Honda, Benz, general, modern, Ford, BMW and the like are intensively listed in 2016-2018, and energy-saving and new energy vehicles are proposed in 'China manufacturing 2025' as a key development field and indicate directions for the development of fuel cell vehicles in China. The working reaction rate of the fuel cell engine cannot achieve invalid power response like an internal combustion engine and a pure electric motor, and certain hysteresis exists, so that a control strategy is needed to meet the coupling of the fuel cell engine and a power battery so as to meet the operation of a driving motor, and the smooth operation of a vehicle is achieved.

Disclosure of Invention

The present invention is directed to a method for controlling a fuel cell for a passenger vehicle to overcome the above-mentioned drawbacks of the prior art.

The purpose of the invention can be realized by the following technical scheme:

a fuel cell control method for passenger cars is used for realizing the uninterrupted parallel coupling work of a fuel cell and a pure electric battery, and comprises the following steps:

1) starting the vehicle, starting the vehicle-mounted VCU to be powered on and sending a preparation signal;

2) the vehicle-mounted VCU receives a stack starting command of opening a fuel cell stack switch;

3) the vehicle-mounted VCU acquires the SOC value of the current power battery and judges whether the SOC value is not greater than a first threshold value a, if so, an FC ON command is sent out, the step 4) is carried out, and if not, the fuel battery is in a shutdown state;

4) the vehicle-mounted FCU (fuel cell controller) sends a loading-allowable power instruction after self-checking, and compares the SOC value with a second threshold b, specifically:

41) when b is less than or equal to a, the vehicle-mounted VCU sends a first target power x to the FCU, and the FCU carries out step 5 after responding;

42) when the SOC is less than or equal to b, the vehicle-mounted VCU sends a second target power y to the FCU, and the FCU carries out step 7 after responding;

5) comparing the SOC value with a third threshold value c, when the SOC is more than or equal to a and less than or equal to c, the vehicle-mounted VCU sends a third target power z to the FCU, and after the FCU responds, the step 6) is carried out, otherwise, the step 4) is returned;

6) when the SOC is larger than or equal to c, the vehicle-mounted VCU sends an FC OFF command, the FCU responds to shutdown, and the fuel cell is in a shutdown state;

7) and comparing the SOC value with a fourth threshold value d, when the SOC is larger than or equal to d, sending a first target power x to the FCU by the vehicle-mounted VCU, and performing the step 5) after the FCU responds, otherwise, returning to the step 42).

In the step 4), if the self-checking of the vehicle-mounted FCU finds a fault, the vehicle-mounted VCU receives fault alarm information of the FCU and then carries out grading processing according to fault grades.

The size relationship of the first threshold value a, the second threshold value b, the third threshold value c and the fourth threshold value d is that b is more than d and less than a and more than c.

The value of the first threshold value a is 86%, the value of the second threshold value b is 60%, the value of the third threshold value c is 90%, and the value of the fourth threshold value d is 65%.

The first target power x, the second target power y and the third target power z have the size relation that z is more than x and less than y.

The first target power x is 10kW, the second target power y is 30kW, and the third target power z is 3 kW.

The front side of the fuel cell stack switch is provided with H₂Typeface, and be equipped with anti-reset mechanism.

Compared with the prior art, the invention has the following advantages:

1) the operation is safe: the invention adoptsThe size of the conventional rocker switch is convenient for a driver to use, and the front surface of the switch adopts a striking' H₂The word is that the lock is used to prevent the false closing;

2) the safety performance is high: the low-voltage electrification is carried out firstly, then the high-voltage electrification is carried out, and the high-voltage electrification is carried out after the detection of the hydrogen concentration is finished, so that the safety performance of the whole vehicle is effectively protected;

3) improving the fuel utilization rate: under the condition of different power battery SOC values, the fuel battery system is required to output corresponding power, and energy waste of the fuel battery system is avoided;

4) and (3) quick energy charging: the charging time of the hydrogen used as an energy source is shorter than that of a conventional power battery, and the pure electric vehicle can run again only by filling the hydrogen in more than ten minutes, so that the endurance mileage of the pure electric vehicle is greatly improved.

Drawings

FIG. 1 is a flow chart of the method of the present invention.

Fig. 2 is a schematic diagram of a fuel cell stack switch.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Examples

As shown in fig. 1, the present invention provides a fuel cell control method for a passenger car, which is used for how a fuel cell and a pure electric battery are coupled in parallel to work, so that the vehicle can run smoothly without power interruption, and a series of faults such as overcharge of a fuel cell engine and the like cannot be caused in an energy recovery process.

The invention specifically comprises the following steps:

3) the vehicle-mounted VCU acquires the SOC value of the current power battery, judges whether the SOC value is not greater than a first threshold value a (86% in the embodiment), if so, sends an FC ON command, and performs the step 4), and if not, the fuel battery is in a shutdown state;

4) the vehicle-mounted FCU sends a power loading permission instruction after self-checking, and compares the SOC value with a second threshold b (in this example, 60%), specifically:

41) when the SOC of b is less than or equal to a, the vehicle-mounted VCU sends a first target power of 10kW to the FCU, and the FCU carries out step 5 after responding;

42) when the SOC is less than or equal to b, the vehicle-mounted VCU sends a second target power of 30kW to the FCU, and the FCU carries out step 7 after responding;

5) comparing the SOC value with a third threshold value c (the value is 90% in the example), when the SOC is more than or equal to a and less than or equal to c, the vehicle-mounted VCU sends a third target power of 3kW to the FCU, and the FCU carries out step 6 after responding, otherwise, returning to step 4);

7) and (3) comparing the SOC value with a fourth threshold value d (taking a value of 65% in the example), when the SOC is larger than or equal to d, sending a first target power of 10kW to the FCU by the vehicle-mounted VCU, and after the FCU responds, performing the step 5), otherwise, returning to the step 42).

After the low-voltage power-on of the whole vehicle is finished, the whole vehicle controller carries out logic judgment on the whole vehicle and then carries out high-voltage power-on after no fault exists, the process is expected to wait for 5 seconds to enable the vehicle to normally run, and because the hydrogen concentration detection is needed when the fuel cell system is added, the detection time needs to be increased by 30 seconds to ensure that the fuel cell engine can normally run.

The hydrogen concentration sensor needs to be preheated, the detection time of the hydrogen concentration is about 30 seconds, and the vehicle cannot be electrified at high voltage in the process, so that safety accidents such as explosion and the like caused by hydrogen leakage in the electrifying process are prevented. And the whole vehicle controller is enabled to perform a high-voltage process after receiving the completion of the self-inspection of the fuel cell through a control strategy.

The whole vehicle can travel smoothly after 35 seconds, because the fuel cell vehicle is provided with the power battery of corresponding electric quantity, obtain through a large amount of experimental data and analysis policy under the different circumstances of power battery soc, the electric quantity of different power of fuel cell output is in order to satisfy the vehicle and stably to travel, increases the continuation of the journey mileage of vehicle.

As shown in FIG. 2, the fuel cell stack start switch of the present invention is turned onThe front side of the gate adopts striking' H₂The vehicle controller receives high level after the switch is pressed down, and then can communicate with the fuel cell system to execute the fuel cell working strategy to enable the fuel cell to intervene in the vehicle operation.

The invention can effectively protect the safety performance of the whole fuel cell system from starting to working, simultaneously reduce the energy consumption rate of the fuel cell system in the working process, and has higher safety by the active driving behavior of a driver.

Claims

1. A fuel cell control method for passenger car, in order to realize the uninterrupted parallel coupling work of fuel cell and pure electric battery, it is characterized in that, comprises the following steps:

1) When the vehicle starts, the on-board VCU starts to power on and sends a ready signal;

2) The on-board VCU receives the stack start command that the fuel cell stack switch is turned on;

3) The vehicle-mounted VCU obtains the SOC value of the current power battery, and judges whether it is not greater than the first threshold a, if so, issue an FC ON command, and go to step 4), if not, make the fuel cell in a shutdown state;

4) After the self-check, the on-board FCU issues a command to allow loading power, and compares the SOC value with the second threshold b, specifically:

41) When b<SOC≤a, the vehicle-mounted VCU sends the first target power x to the FCU, and the FCU responds and proceeds to step 5);

42) When SOC≤b, the vehicle-mounted VCU sends the second target power y to the FCU, and the FCU responds and proceeds to step 7);

5) Compare the SOC value with the third threshold value c, when a<SOC≤c, the vehicle-mounted VCU sends the third target power z to the FCU, and the FCU responds to step 6), otherwise, return to step 4);

6) When SOC≥c, the vehicle-mounted VCU issues an FC OFF command, the FCU responds to shutdown, and the fuel cell is in a shutdown state;

7) Compare the SOC value with the fourth threshold d, when SOC≥d, the on-board VCU sends the first target power x to the FCU, and the FCU responds to step 5), otherwise, return to step 42).

2. a kind of fuel cell control method for passenger car according to claim 1, is characterized in that, in described step 4), if vehicle-mounted FCU self-check is to find fault, then vehicle-mounted VCU receives the fault alarm information of FCU Afterwards, deal with them according to the fault level.

3 . The fuel cell control method for a passenger car according to claim 1 , wherein the magnitude relationship of the first threshold a, the second threshold b, the third threshold c and the fourth threshold d is b. 4 . <d<a<c.

4 . The fuel cell control method for a passenger car according to claim 3 , wherein the first threshold value a is 86%, the second threshold b is 60%, and the third threshold c is 60 . 5 . The value is 90%, and the fourth threshold d is 65%.

5 . The fuel cell control method for a passenger vehicle according to claim 1 , wherein the magnitude relationship between the first target power x, the second target power y and the third target power z is z<x. 6 . <y.

6 . The fuel cell control method for a passenger vehicle according to claim 5 , wherein the first target power x is 10kW, the second target power y is 30kW, and the third target power is 30kW 6 . The value of z is 3kW.

7 . The fuel cell control method for passenger cars according to claim 1 , wherein the front of the fuel cell stack switch is provided with the word H ₂ and an anti-reset mechanism. 8 .