CN2713654Y

CN2713654Y - Controller area network bus distributed type control device for fuel battery

Info

Publication number: CN2713654Y
Application number: CNU2004200210567U
Authority: CN
Inventors: 傅明竹; 胡里清
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2004-03-19
Filing date: 2004-03-19
Publication date: 2005-07-27
Anticipated expiration: 2014-03-19

Abstract

The utility model relates to a controller area network bus distributed type controlling device for fuel batteries which comprises a plurality of sensors provided with controller area network bus (CAN bus) interfaces, a plurality of mono-cell voltage detector for fuel batteries provided with the CAN bus interfaces, a plurality of executors provided with the CAN bus interfaces, a plurality of monitoring controllers provided with the CAN bus interfaces, a plurality of fault encoding protective controllers provided with the CAN bus interfaces and a plurality of operation parameter controllers for the fuel batteries provided with the CAN bus interfaces. The utility model has advantages of simple circuits, high anti-interference capability and low cost, etc.

Description

Fuel cell controller area bus distributed control device

Technical Field

The utility model relates to a fuel cell especially relates to a fuel cell controller regional bus distributed control device.

Background

An electrochemicalfuel cell is a device capable of converting hydrogen and an oxidant into electrical energy and reaction products. The inner core component of the device is a Membrane Electrode (MEA), which is composed of a proton exchange Membrane and two porous conductive materials sandwiched between two surfaces of the Membrane, such as carbon paper. The membrane contains a uniform and finely dispersed catalyst, such as a platinum metal catalyst, for initiating an electrochemical reaction at the interface between the membrane and the carbon paper. The electrons generated in the electrochemical reaction process can be led out by conductive objects at two sides of the membrane electrode through an external circuit to form a current loop.

At the anode end of the membrane electrode, fuel can permeate through a porous diffusion material (carbon paper) and undergo electrochemical reaction on the surface of a catalyst to lose electrons to form positive ions, and the positive ions can pass through a proton exchange membrane through migration to reach the cathode end at the other end of the membrane electrode. At the cathode end of the membrane electrode, a gas containing an oxidant (e.g., oxygen), such as air, forms negative ions by permeating through a porous diffusion material (carbon paper) and electrochemically reacting on the surface of the catalyst to give electrons. The anions formed at the cathode end react with the positive ions transferred from the anode end to form reaction products.

In a pem fuel cell using hydrogen as the fuel and oxygen-containing air as the oxidant (or pure oxygen as the oxidant), the catalytic electrochemical reaction of the fuel hydrogen in the anode region produces hydrogen cations (or protons). The proton exchange membrane assists the migration of positive hydrogen ions from the anode region to the cathode region. In addition, the proton exchange membrane separates the hydrogen-containing fuel gas stream from the oxygen-containing gasstream so that they do not mix with each other to cause explosive reactions.

In the cathode region, oxygen gains electrons on the catalyst surface, forming negative ions, which react with the hydrogen positive ions transported from the anode region to produce water as a reaction product. In a proton exchange membrane fuel cell using hydrogen, air (oxygen), the anode reaction and the cathode reaction can be expressed by the following equations:

and (3) anode reaction:

and (3) cathode reaction:

in a typical pem fuel cell, a Membrane Electrode (MEA) is generally placed between two conductive plates, and the surface of each guide plate in contact with the MEA is die-cast, stamped, or mechanically milled to form at least one or more channels. The flow guide polar plates can be polar plates made of metal materials or polar plates made of graphite materials. The fluid pore channels and the diversion trenches on the diversion polar plates respectively guide the fuel and the oxidant into the anode area and the cathode area on two sides of the membrane electrode. In the structure of a single proton exchange membrane fuel cell, only one membrane electrode is present, and a guide plate of anode fuel and a guide plate of cathode oxidant are respectively arranged on two sides of the membrane electrode. The guide plates are used as current collector plates and mechanical supports at two sides of the membrane electrode, and the guide grooves on the guide plates are also used as channels for fuel and oxidant to enter the surfaces of the anode and the cathode and as channels for taking away water generated in the operation process of the fuel cell.

In order to increase the total power of the whole proton exchange membrane fuel cell, two or more single cells can be connected in series to form a battery pack in a straight-stacked manner or connected in a flat-laid manner to form a battery pack. In the direct-stacking and serial-type battery pack, two surfaces of one polar plate can be provided with flow guide grooves, wherein one surface can be used as an anode flow guide surface of one membrane electrode, and the other surface can be used as a cathode flow guide surface of another adjacent membrane electrode, and the polar plate is called a bipolar plate. A series of cells are connected together in a manner to form a battery pack. The battery pack is generally fastened together into one body by a front end plate, a rear end plate and a tie rod.

A typical battery pack generally includes: (1) the fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas and gasoline) and the oxidant (mainly oxygen or air) are uniformly distributed in the diversion trenches of the anode surface and the cathode surface; (2) the inlet and outlet of cooling fluid (such as water) and the flow guide channel uniformly distribute the cooling fluid into the cooling channels in each battery pack, and the heat generated by the electrochemical exothermic reaction of hydrogen and oxygen in the fuel cell is absorbed and taken out of the battery pack for heat dissipation; (3) the outlets of the fuel gas and the oxidant gas and the corresponding flow guide channels can carry out liquid and vapor water generated in the fuel cell when the fuel gas and the oxidant gas are discharged. Typically, all fuel, oxidant, and cooling fluid inlets and outlets are provided in one or both end plates of the fuel cell stack.

The proton exchange membrane fuel cell can be used as a power system of vehicles such as vehicles and ships, and can also be used as a mobile or fixed power station.

A fuelcell power generation system generally consists of the following parts: 1. a fuel cell stack; 2. a fuel hydrogen supply subsystem; 3. an air supply subsystem; 4. and the cooling and heat dissipation subsystem 5 is an automatic control and electric energy output subsystem.

Fig. 1 shows a fuel cell power generation system in which a fuel cell engine controller implements dynamic control operation in "a fuel cell with a dynamic control device" (patent application No. 200410016609.4, utility model patent application No. 200420020471.0) of shanghai mystery science and technology ltd. The figure includes a fuel cell stack 1, a hydrogen cylinder 2, a pressure reducing valve 3, an air filter 4, an air compression supply device 5, a water-vapor separator 6, a water tank 7, a water pump 8, a radiator 9, a hydrogen circulating pump 10, a hydrogen path rotary type humidifier 11 capable of dynamically controlling humidification, an air path rotary type humidifier 12 capable of dynamically controlling humidification, rotary type humidifier adjustable speed motors 13, 13', a hydrogen path inlet fuel cell stack hydrogen relative humidity sensor 14, a hydrogen path inlet fuel cell stack hydrogen temperature sensor 15, an air path inlet fuel cell stack air relative humidity sensor 16, an air path inlet fuel cell stack air temperature sensor 17, a cooling fluid path inlet fuel cell stack cooling fluid temperature sensor 18, a hydrogen path inlet fuel cell stack pressure sensor 19, an air path inlet fuel cell stack pressure 20 sensor, a cooling fluid path inlet fuel cell stack pressure sensor 21, an air path outlet fuel cell stack air temperature sensor 22, a hydrogen path outlet fuel cell stack hydrogen pressure sensor 23, a cooling fluid path outlet fuel cell stack cooling fluid temperature sensor 24, a cooling fluid path outlet fuel cell stack cooling fluid pressure sensor 25, an air path outlet fuel cell stack air temperature sensor 26, an air path outlet fuel cell stack air pressure sensor 27,an SVM fuel cell stack operating voltage and operating voltage monitoring 28 of each single cell, a fuel cell stack operating current monitoring 29, an automatic load cut-off switch 30, and an automatic hydrogen cut-off solenoid valve 31.

The above fuel cell power generation system follows the following principles and principles:

a. the allowable magnitude of power output from the fuel cell stack 1 is related to the magnitude of the fuel cell operating temperature sensor 18, and generally, a relationship between the allowable magnitude of power output and the value of the sensor 18 can be found, and the closer the value of the sensor 18 is to the rated operating temperature, the greater or closer the allowable output power is to the rated output power (see fig. 2);

b. the matching relation of the power output by the fuel cell stack 1, the hydrogen flow and the air flow of the fuel supplied to the fuel cell is calculated according to the hydrogen metering ratio 1.2 and the air metering ratio 2.0;

c. the hydrogen relative humidity sensor 14 and the air relative humidity sensor 16 are respectively related to the flow rate of hydrogen and air, the temperature sensors 15 and 17 and the pressure of hydrogen and air (fig. 3), and generally the gas flow rate can be found, and a certain relative humidity relation curve is achieved under certain pressure and temperature conditions, generally, the higher the gas flow rate is, the higher the temperature is, the lower the pressure is, and the more difficult the gas high relative humidity value is to be achieved; conversely, the lower the gas flow, the lower the temperature, and the higher the pressure, the easier it is for the gas to reach high relative humidity values (see FIG. 3).

d. The faster the rotary humidifier rotates, the higher the temperature and relative humidity of the hydrogen or air entering the fuel cell.

According to the principle or principle of the operation of the fuel cell power generation system, the fuel cell power generation system controller is adopted, the rotating speed setting control of the rotating motor of the rotary humidifier is determined by monitoring and calculating the working temperature and the output power requirement of the fuel cell and the values of the sensor 14, the sensor 16, the sensor 15, the sensor 17 and the sensor 18, and the control of the hydrogen flow and the air flow is determined at the same time, so that the fuel cell stack can realize the following functions under any power output requirement: 1. the output power is controlled in relation to the working temperature; 2. the output power, the hydrogen flow and the air flow are controlled in a correlation manner, wherein the hydrogen flow and the air flow are respectively controlled to be 1.2 and 2.0 according to the metering ratio required by the output power so as to realize the control of the rotating speed of a hydrogen circulating pump motor and the rotating speed of an air pump motor; 3. the hydrogen flow and the air flow are respectively in parallel dynamic control with the motor speed in a corresponding humidifying device which can realize dynamic humidifying regulation control, so that the hydrogen and the air at any flow entering the fuel cell stack keep the optimal relative humidity (a certain value between 70% and 95%); 4. and adjusting and controlling the method according to the conditions of the outside weather temperature and the outside weather humidity as in the point 3, and achieving the same purpose as the point 3. The final purpose is to make the fuel cell stack realize high-efficiency operation and operation under the optimal working condition under the working condition of any power output requirement, and the fuel cell stack not only has the optimal fuel efficiency, but also can greatly prolong the service life.

The control subsystem in the overall fuel cell engine or overall power generation system is critical to achieving safe, efficient, and long-lived operation of the fuel cell engine or power generation system.

In the aspect of safety guarantee, when a control subsystem in a fuel cell engine or a power generation system detects certain working parameters, such as temperature, pressure, humidity, current and voltage, an alarm can be given in time, and self-protection of the fuel cell engine is executed at the same time, such as load cut-off and fuel hydrogen supply cut-off.

The conventional prior art usually uses a central controller for controlling and monitoring the fuel cell engine or the power generation system, and the central controller has the functions of data storage, operation, processing and display, and control execution, wherein all monitoring points and control points of the fuel cell engine or the power generation system are respectively connected with the central controller through separate signal lines, as shown in fig. 4. The traditional integrated controller is respectively connected with a plurality of monitoring points and control points of a fuel cell engine to realize the purposes of monitoring and controlling, and the technology has the following defects:

1. because the physical quantity needing to be monitored and controlled in the fuel cell engine is too much (as shown in figure 1), the centralized controller is separately connected with the sensors point to point, so that the connecting wires are too much and the wiring is too complex.

2. The integrated controller and the sensor in the fuel cell engine generally carry out analog signal-digital communication with the integrated controller through weak current or weak voltage signals, so that the anti-interference capability is poor, communication and control errors are easyto occur, and even the fuel cell engine is halted.

3. The controller is connected with the actuating mechanism, most of the controller is high-current switching value, and therefore electromagnetic waves are radiated outwards inevitably, and the controller interferes with other equipment.

4. Because the data processing amount of the centralized controller in the fuel cell engine is too large, too many IO interfaces of the centralized controller are required, and the requirements on other data operation, storage and processing functions are high, the software overhead is huge, so that the price of the controller is too high.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a fuel cell controller regional bus distributed control device with simple circuit, strong anti-interference ability and low cost in order to overcome the defects existing in the prior art.

The purpose of the utility model can be realized through the following technical scheme: a fuel cell controller area bus distributed control device is characterized by comprising a plurality of sensors with controller area bus (CAN bus) interfaces, a plurality of fuel cell voltage detectors with CAN bus interfaces, a plurality of actuators with CAN bus interfaces, a plurality of monitoring controllers with CAN bus interfaces, a plurality of fault coding protection controllers with CAN bus interfaces and a plurality of fuel cell operation parameter controllers with CAN bus interfaces.

The sensor with the Controller Area (CAN) bus interface CAN also be a sensor with a combination of the sensor and the CAN bus interface.

The actuator with the CAN bus interface CAN also be an actuator with a combination of the actuator and the CAN bus interface.

Most state parameter values in the operation process of the fuel cell are transmitted on the CAN bus, so that data sharing of all equipment of the system is facilitated.

The sensors all have a uniform CAN bus interface protocol or an adapter for converting the CAN bus by using the sensor with analog quantity output as CAN bus parameter sampling nodes.

The control equipment is provided with a uniform CAN bus interface protocol or uses a CAN bus interface adapter.

The sensors, the actuators and the controllers all use CAN buses to transmit information in a long distance, other information transmission modes with lower reliability only transmit information in a short distance from the adapters to the sensors, the actuators and the controllers, and even a metal shielding box CAN be installed, so that the information transmission reliability of the system is ensured.

On the basis of the Cyclic Redundancy Check (CRC) of the CAN bus interface protocol, a secondary check code is added to a data byte, so that error data of power-on starting and watchdog actions CAN be effectively eliminated, and the reliability of the system is further improved.

The utility model discloses a fuel cell engine or power generation system CAN bus distributed control's method solves above-mentioned traditional control method's many technical defects. Compared with the prior art, the utility model has the advantages of the circuit is simple, the interference killing feature is strong, with low costs.

Drawings

FIG. 1 is a schematic diagram of a prior art fuel cell power generation system that can implement dynamically controlled operation;

FIG. 2 is a graph of fuel cell stack output power versus fuel cell operating temperature of FIG. 1, where PN is the rated output power and T is the operating temperature (sensor 18);

FIG. 3 is a graph of 100% RH air moisture versus temperature and pressure for the fuel cell stack of FIG. 1;

FIG. 4 is a view showing how many monitoring points and control points of the fuel cell stack integrated controller shown in FIG. 1 are respectively connected to a plurality of fuel cell engines to implement monitoring and control;

fig. 5 is a system diagram of the fuel cell power generation CAN bus controller of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

A CAN bus distributed control device of a fuel cell power generation system or a fuel cell engine comprises a plurality of sensors (mainly comprising temperature, pressure, humidity, flow, current, voltage and the like) with CAN bus interfaces or a combination of the sensors and the CAN bus interfaces, a plurality of fuel cell voltage detectors with the CAN bus interfaces, a plurality of actuators (or a combination of the actuators and the CAN bus interfaces) with the CAN bus interfaces, a plurality of monitoring controllers with the CAN bus interfaces, a plurality of fault coding protection controllers with the CAN bus interfaces and a plurality of fuel cell operation parameter controllers with the CAN bus interfaces.

The control device in the fuel cell power generation system adopts CAN bus distributed network control. Divided into various units of the following sizes:

a. temperaturesensor node

The temperature sensors such as the inlet and outlet temperatures of the concentrated hydrogen, the air and the cooling fluid are converted into digital quantities, and the digital quantities are sent to other nodes on the CAN bus through the CAN bus to be used.

b. Battery current/voltage sensor node

The current and voltage sensors of the battery pack measure and convert the measured values into digital values to be sent through the CAN bus.

c. Pressure sensor node

And voltage signals of pressure sensors such as hydrogen pressure, air pressure, cooling fluid inlet and outlet pressure and the like are converted into digital quantities, and the digital quantities are sent to the CAN bus.

d. Control node of heat radiation fan

The command control node sends a control command through the CAN bus according to the temperature of the cooling fluid, and the control node of the cooling fan 1 receives the command to control the operation or stop of the cooling fan. Rather than the master directly driving the fan to run or stop.

e. Hydrogen and air pump, cooling fluid pump and hydrogen and air humidification adjusting motor control node

And the instruction control node calculates the rotating frequency of the corresponding air pump driving motor according to the output power or the output total current of the galvanic pile, sends a control command through the CAN bus, and the air pump node receives the command and controls the running speed of the air pump frequency converter (comprising a CAN/RS485 adapter).

f. Main switching value control node

And the instruction control node sends a switching value electromagnetic valve control command throughthe CAN bus according to the running condition of the pile, and the main switching value control node receives the command and operates the electromagnetic valve, the contactor, the PWM speed regulating motor and the like.

g. Pile operation instruction control node

The pile operation instruction control node integrates all operation parameters of the pile, determines the operation conditions of the pile, and comprises the following steps: power, current/air pump frequency curves, control temperature, humidification motor operating conditions, etc. And (3) receiving a stop command of an upper-layer control (a double-port RAM node), closing the electromagnetic valve current contactor and stopping.

h. Control communication node with upper layer

The node is mainly used for communicating a fuel cell power generation system with an upper layer power demand controller and receiving power demands and startup and shutdown commands of the upper layer controller. Transmitting a fuel cell engine operation state code, a fault code and the like, transmitting a fuel cell engine operation state quantity: current, voltage, pressure, temperature, etc. for the upper controller to control.

The system is favorable for standardized design, can be used for building any control device through different node combinations, can greatly expand various sensor nodes and switching value control nodes, and is favorable for wiring. The sensor leads with poor interference rejection can be as short as possible. The exchange information between the components at a longer distance is transmitted through the CAN bus. And after the products of all nodes are standardized, the products can be produced in batches. The fuel cell power generation system, the engine controller and the like can be quickly assembled, and each node is convenient to maintain like a screw nut (as shown in figure 5).

In addition, if some sensors and devices in the system do not have CAN bus interfaces or CAN protocols are different (such as a single chip microcomputer of RS485 and the like), an interface adapter (such as an RS485/CAN adapter) is adopted to connect all monitoring nodes in the whole fuel cell power generation system by using the CAN bus and realize CAN bus control.

Examples

A fuel cell power generation system using the prior art utility model, as shown in fig. 5. Wherein the rated output power of the fuel cell power generation system is 60KW, and the peak output is 72 KW; the rated output power of the fuel cell stack 1 is 72KW, and the peak output is 82 KW. The air conveying device 5 is a super flat air compressor driven by a brushless motor capable of adjusting frequency and speed, the air flow can be controlled by adjusting the frequency and speed of the brushless motor, the rated power of the motor is about 8KW, the control rotating speed is between 0 and 8000 rpm, and the air flow is between 0 and 7 cubic/minute.

The hydrogen circulating device 10 is a circulating compression pump driven by a brushless motor capable of adjusting frequency and speed, and the hydrogen circulating flow can also be controlled by the frequency and speed adjustment of the brushless motor. The rotary humidifier 11 which is arranged in the hydrogen gas path and can dynamically control the humidification degree can drive the inner container of the humidifier to rotate through a brushless motor with speed regulation and frequency modulation, so as to achieve the purpose of adjusting the humidification degree of the hydrogen gas.

The rotary humidifier 12 which is arranged in an air path and can dynamically control the humidification degree drives the inner container of the humidifier to rotate through a brushless motor which canadjust the frequency and the speed, so as to achieve the purpose of adjusting the humidification degree of the air, and the rotating speed of the inner containers of the two humidifiers is about 1-70 r/min.

Various operating parameters in the entire fuel cell power generation system CAN be controlled using a CAN bus distribution, such as: collecting data of pressure, temperature and humidity of hydrogen, air and cooling fluid entering the fuel cell stack and pressure, temperature and humidity of hydrogen, air and cooling fluid exiting the fuel cell stack, collecting and monitoring working voltage and current of the fuel cell stack, and obtaining a relation curve (figure 2) between output power and working temperature of the fuel cell stack; the relationship curve of the output power of the fuel cell stack and the flow rate of the hydrogen and the air is respectively calculated according to the metering ratio of the air flow of 2.0 and the metering ratio of the hydrogen of 1.2; the relationship curve of the output power of the fuel cell stack and the temperature and the flow of the cooling fluid; and the relationship curves of the hydrogen gas, the air flow rate and the temperature (including the outside temperature) (fig. 3) and the rotation speeds of the rotary-

type humidifiers

11 and 12, and the relationship curves are programmed in advance to carry out PID adaptive demodulation control.

When the fuel cell power generation system is just started, and the distributed controller detects that the external temperature is lower (0 ℃) and the working temperature of the fuel cell stack is lower (5 ℃), the output power of the fuel cell stack is controlled to be about 20KW, at the moment, the distributed controller controls the air pump and the hydrogen pump, drives the motor to rotate at a speed, so that the air flow is about 1.0 cubic meter/minute, the total hydrogen flow is about 200 liters/minute, and the hydrogen circulation flow is about 40 liters/minute. The distributed controller controls the motors of the two

rotary humidifiers

11 and 12 to drive the inner containers to rotate at 50 r/min according to the parameter values of the air and hydrogen flow, the temperature and the outside temperature, the relative humidity of the air and the hydrogen entering the fuel cell stack is 80%, and the stable operation of the fuel cell stack is ensured.

When the fuel cell power generation system enters a rated working state, the working temperature is 70 ℃, and the distributed controller detects that the external temperature is higher (35 ℃); when the working temperature of the fuel cell stack is 70 ℃, the output power of the fuel cell stack is allowed to be 68KW by the distributed controller, and at the moment, the distributed controller controls the air pump and the hydrogen pump to drive the motor to rotate, so that the air flow is about 3.5 cubic meters per minute, the total flow of hydrogen is 700 liters per minute, and the circulation flow of hydrogen is 140 liters per minute. The distributed controller controls the motors of the two

rotary humidifiers

11 and 12 to drive the inner containers to rotate at a speed of 10 r/min according to the parameter values of the air and hydrogen flow, the temperature and the outside temperature.

The relative humidity of the air and the hydrogen entering the fuel cell stack is still 80%, the fuel cell stack works stably, and the whole system runs stably for a long time.

Claims

1. A fuel cell controller area bus distributed control device is characterized by comprising a plurality of sensors with controller area bus (CAN bus) interfaces, a plurality of fuel cell voltage detectors with CAN bus interfaces, a plurality of actuators with CAN bus interfaces, a plurality of monitoring controllerswith CAN bus interfaces, a plurality of fault coding protection controllers with CAN bus interfaces and a plurality of fuel cell operation parameter controllers with CAN bus interfaces.

2. The fuel cell controller area bus distributed control apparatus of claim 1, wherein said sensor with Controller Area (CAN) bus interface is a sensor with a combination of a sensor and a CAN bus interface.

3. The fuel cell controller area bus distributed control apparatus of claim 1, wherein the actuator with CAN bus interface is also an actuator with a combination of an actuator and a CAN bus interface.

4. The fuel cell controller area bus distributed control apparatus of claim 1, wherein most of the status parameter values during the operation of the fuel cell are transmitted on the CAN bus, so as to facilitate data sharing among the devices of the system.

5. The fuel cell controller local bus distributed control apparatus according to claim 1, wherein said sensors all have a uniform CAN bus interface protocol or an adapter for converting CAN bus using analog output sensors as CAN bus parameter sampling nodes.

6. The fuel cell controller area bus distributed control apparatus of claim 1, wherein said control devices are all equipped with a unified CAN bus interface protocol or use CAN bus interface adapters.

7. The fuel cell controller area bus distributed control device of claim 1, wherein the sensors, the actuators and the controllers all use CAN bus for long distance information transmission, other less reliable information transmission modes only carry out short distance information transmission from the adapter to the sensors, the actuators and the controllers, and even a metal shielding box CAN be installed to ensure the information transmission reliability of the system.

8. The distributed control device of fuel cell controller area bus according to claim 4, wherein a secondary check code is added to the data byte on the basis of the Cyclic Redundancy Check (CRC) of the CAN bus interface protocol itself, so that the error data of power-on start and watchdog action CAN be effectively eliminated, and the reliability of the system is further improved.