CN1632976A

CN1632976A - Method for configurating dynamic series-parallel connection fuel cell system and fuel cell system

Info

Publication number: CN1632976A
Application number: CNA2003101230549A
Authority: CN
Inventors: 邓丰毅
Original assignee: ANTIG TECHNOLOGY Inc
Current assignee: ANTIG TECHNOLOGY Inc; Antig Technology Co Ltd
Priority date: 2003-12-23
Filing date: 2003-12-23
Publication date: 2005-06-29

Abstract

This invention relates to an aligning method by use of intelligent control dynamic series and parallel fuel battery system, which comprises the following steps: to provide at least one multi-switch transfer; to electrically connect two fuel batteries in the transfer; to control the switch to make it connect to at least two fuel batteries. The fuel batteries system comprises one multi-path switch transfer, at least two fuel batteries and one microprocessor.

Description

Configuration method for dynamically configuring fuel cell system in series-parallel connection and fuel cell system

Technical Field

The present invention relates to a method for configuring fuel cell units in a fuel cell system and a fuel cell system, and more particularly, to a method for configuring a fuel cell system by using an intelligent controllable dynamic series-parallel configuration and a fuel cell system.

Background

In general, a fuel cell refers to a power generation device that directly uses oxygen in fuel process air containing hydrogen to directly generate electric power without combustion through an electrochemical reaction process. The fuel cell is not discarded as it is when it is used up as a general primary battery, and is not charged to recover electric power as a general secondary battery, and the fuel cell can maintain its electric power by only continuing to add fuel.

Taking a Proton Exchange Membrane Fuel Cell (PEMFC) as an example, hydrogen is used as fuel, and the reaction mechanism thereof can be regarded as the reverse reaction of electrolyzed water, in the anode reaction, hydrogen enters through a diffusion layer, and is decomposed into hydrogen protons and electrons by the catalytic action of a catalyst such as platinum metal in a catalyst layer, the former enters into a cathode reaction zone through a proton exchange membrane, and the latter is transported to an external load for use through a current collector. The chemical reaction formula is shown as follows:

and (3) anode reaction:

and (3) cathode reaction:

and (3) total reaction:

taking a direct methanol fuel cell system (DMFC) as an example, an electrolyte membrane which is positioned in the middle layer and causes a mass transfer effect is respectively arranged at the upper side and the lower side of the electrolyte membrane, the catalyst layers are the electrochemical reaction sites of an anode and a cathode, the upper ends of the two sides of the catalyst layers are diffusion layers, reactant methanol of the anode diffuses into the catalyst layers through the diffusionlayers to react, carbon dioxide which is a product of a chemical reaction is discharged through the diffusion layers at the anode end, hydrogen protons transmit through the electrolyte layers to carry out mass transfer, electrons flow through a load after collecting current through an anode current collecting layer and then return to the cathode to combine with the hydrogen protons after mass transfer, oxygen which enters through the diffusion layers at the cathode end reacts on the catalyst layers, and generated water is discharged through the diffusion layers at the cathode end, so that a power generation reaction is completed. The chemical reaction formula is shown as follows:

and (3) anode reaction:

cathode reaction：

And (3) total reaction:

a fuel cell generally includes an innermost proton exchange membrane, catalyst layers on both sides, and gas diffusion layers on both sides, and the above-described reaction is the most basic principle of the operation of a fuel cell (cell). For Proton Exchange Membrane Fuel Cells (PEMFCs), the ideal potential generated by one fuel cell unit is 1.2V, and for direct methanol fuel cell systems, the ideal potential generated by one fuel cell unit is 1.2V, and analyzing the operation of the pem fuel cell, it can be seen that at least four power losses occur: anode activation loss, cell impedance loss, cathode activation loss, and mass transport loss. Observing the operation of the direct methanol fuel cell system, there are similar power losses, except that in addition to the above four power losses, it further includes the potential loss caused by methanol crossover. The power loss can cause potential drop of different degrees dueto ideal potential, so that the power generation efficiency of the fuel cell unit is poor, and the voltage drop loss can cause the voltage of a single fuel cell unit to drop by 0.4V-0.8V or even lower, so that the power generation output power of the fuel cell is unstable.

The reason why the power generation efficiency of the fuel cell is unstable is that, in addition to the above-mentioned situation, the environment in which the fuel cell operates is also affected, the operating temperature, the operating pressure, and the flow rate of the oxygen supply are different, and the power generation efficiency of the fuel cell is different, and in addition, the methanol concentration and the methanol crossover rate are significant factors affecting the power generation output power in the case of the direct methanol fuel cell system. These factors and their interaction result in a large floating range of the voltage drop and current density of the fuel cell, and a relatively unstable voltage and current output of the fuel cell, and thus an unstable power output of the fuel cell.

In addition, the current forms of manufacturing fuel cells are roughly classified into the following types: stack fuel cells, planar expanded fuel cells and hybrid fuel cells. The assembly method of the stack type fuel cell is as follows: the individual cells (cells) are stacked in a vertical direction along their planes, with the thickness increasing for each additional stack. The planar expansion fuel cell is as follows: each cell (cell) is assembled in a horizontal direction along its plane. The composite fuel cell is formed by combining the two assembling modes. In any fuel cell, the required power is achieved by connecting the cells in series and in parallel, increasing the output voltage in series and increasing the available current in parallel. In the stack type fuel cell, the most direct operation is to connect the fuel cells in series by using the assembly method of the stack, and conversely, the fuel cells need to be connected in parallel. In the case of the planar expansion type fuel cell, the parallel connection is more convenient than the series connection. The hybrid fuel cell is more cumbersome. In any manufacturing method, after the connection method is fixed, the series connection and the parallel connection of the fuel cells are not changed.

Fig. 1 is a schematic diagram of a conventional fuel cell structure. In fig. 1, each fuel cell unit may have unstable power output, and in terms of the operation efficiency of the battery, if the power output by the fuel cell units is inconsistent, the service life of the fuel cell units is shortened, the power difference is increased, and the speed of the service life is shortened. In fig. 1, a total of six fuel cell units are provided, and assuming that the standard voltage of each fuel cell unit is 0.6V, three fuel cell units are connected in series, and two fuel cell units are connected in parallel, however, when the power output of the fuel cell unit 10A is unstable, for example, the voltage of the fuel cell unit is reduced to 0.2V, due to the influence of the fuel cell unit 10A, the efficiency of the fuel cell unit 10 is rapidly reduced, and the output power of the entire fuel cell unit 10 is suddenly reduced. Furthermore, if any one of the cells fails or is damaged, the entire fuel cell 10 may be completely disabled. Since the fuel cell 10 is assembled by using a conventional fixed assembly method, the failed fuel cell 10A cannot be individually disconnected, so that the whole fuel cell 10 is scrapped.

Furthermore, although the fuel cell 10 includes six fuel cell units therein, the six fuel cell units cannot be changed to another voltage for power supply because the six fuel cell units are connected by a fixed assembly method.

In view of the disadvantages of the conventional fixed-stack fuel cell assembly and the uncertainty of the rated voltage of the assembled fuel cell due to the difficulty of the fuel cell unit to reach the ideal potential of 1.2V due to the power loss caused by the fuel cell unit, the present inventors have earnestly invented an arrangement method of an intelligent controllable dynamic series-parallel arrangement fuel cell system and a fuel cell system thereof.

Disclosure of Invention

It is a first objective of the present invention to provide a configuration method for intelligently and dynamically configuring a fuel cell system in series-parallel connection and a fuel cell system implementing the method, which can easily dynamically connect each fuel cell in the fuel cell system to different voltages and electric quantities.

A second objective of the present invention is to provide a configuration method for an intelligent and controllable fuel cell system with dynamic serial-parallel configuration, and a fuel cell system implementing the method, which can isolate individual bad fuel cells in the fuel cell system, so that the fuel cell system can be more effectively utilized.

To achieve the above object, the present invention provides a configuration method for configuring a fuel cell system by using an intelligent controllable dynamic series-parallel configuration, comprising the following steps: providing at least one multi-way switch; electrically connecting at least two fuel cells to the multiway switch; controlling the switching of the multiswitch switch such that at least two fuel cells connected to the multiswitch switch are arranged in a series, parallel, open, partial-pass electrical connection configuration.

In order to achieve the above object, the present invention provides an intelligent controllable dynamic series-parallel fuel cell system, comprising: at least one multi-way switch; at least two fuel cells electrically connected to the multiway switch; the microcontroller is used for monitoring the power generation condition of the fuel cells and controlling the switching of the multi-way switch so that at least two fuel cells connected to the multi-way switch are configured into an electrical connection configuration of series connection, parallel connection, open circuit and partial access.

Drawings

Fig. 1 is a schematic diagram of a conventional fuel cell.

Fig. 2 shows a flow chart of a configuration method of the present invention for configuring a fuel cell system using an intelligent steerable dynamic series-parallel configuration.

Fig. 3 shows a schematic diagram of a fuel cell system implemented according to the method of the present invention.

FIG. 4 is a schematic diagram of a multiway switch according to the invention.

FIG. 5 illustrates an electrical connection configuration for controlling the switching of the multi-way switch according to the present invention.

FIG. 6A shows the switching states of the multi-way switch, which is arranged in a series electrical connection configuration.

Fig. 6B shows the switching states of the multi-way switch, which is configured in a parallel electrical connection configuration.

Fig. 6C shows the switching state of the multi-way switch, which is configured in an open electrical connection configuration.

Fig. 6D shows the switching states of the multi-way switch, which is configured in a partially-routed electrical connection configuration.

FIG. 6E shows the switching state of the multi-way switch, which is configured in another partial-path electrical connection configuration.

Fig. 7 shows an embodiment according to fig. 3.

FIG. 8 shows an electrical connection configuration corresponding to FIG. 7 for controlling the switching of the multi-way switch.

In the drawings

10 fuel cell

10A fuel cell unit

20 configuration method

30 fuel cell system

40 load

50 handover

201. 203, 205 step

301 fuel cell

303 multiway switch switcher

303a, 303b control signal input pin

303c, 303d output pins

303e, 303f pins

307a, 307b control signals

307c, 307d, 307e control signals

305 microcontroller

3031 first multiway switch switcher

3033 second multiway switch switcher

3035 third multiway switch switcher

3037 fourth multiway switch switcher

3039 fifth multiway switch switcher

To enable those skilled in the art to understand the objects, features and effects of the present invention, the present invention is described in detail by the following embodiments, in conjunction with the accompanying drawings, wherein:

Detailed Description

Fig. 2 shows a flow chart of a configuration method of the present invention for configuring a fuel cell system using an intelligent steerable dynamic series-parallel configuration, and fig. 3 shows an architecture diagram of a fuel cell system implemented according to the method of the present invention. The present invention utilizes the configuration method 20 of the intelligent controllable dynamic serial-parallel configuration fuel cell system, which is mainly applied to the fuel cell system, so that the fuel cell system 30 implementing the method 20 of the present invention can easily control all the fuel cells 301 therein, and according to the electrical specification requirement of the load 40 and the good state of the fuel cells 301, configure all the fuel cells 301 in parallel, or configure all the fuel cells 301 in series, or disconnect all the fuel cells 301 without connecting with the load 40, or connect only the good fuel cells 301 with the load 40, and configure the partial passage where the damaged fuel cells 301 are not connected with the load 40.

The steps of the configuration method 20 of the present invention are described below: step (201) provides the multiplexer 303. The multiplexer 303 of the present invention may be an electronic multiplexer, such as the multiplexer 303 formed by a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). Step (203) is to electrically connect at least two fuel cells 301 to the multiway switch 303. In step (203), the positive and negative poles of each fuel cell 301 are electrically connected to the multiswitch switch 303, respectively, and two of the output pins 303c, 303d of the multiswitch switch 303 are used as the positive and negative poles to which the load 40 is connected. Step 205 controls the switching 50 of the multiswitch switch 303 such that at least two fuel cells 301 connected to the multiswitchswitch 303 are arranged in a series, parallel, open, partial-pass electrical connection configuration. In step 205, the control signal input pins 303a and 303b of the multi-way switch 303 receive the

control signals

307a and 307b, and the multi-way switch 303 switches to the corresponding electrical connection configuration according to the received

control signals

307a and 307b, so that each fuel cell 301 is switched by the multi-way switch 303 to be connected in the electrical connection configuration of series, parallel, open, and partial pass.

The fuel cell system 30 of fig. 3 includes: a multiplexer 303, at least two fuel cells 301, and a microcontroller 305. Wherein at least two fuel cells 301 are electrically connected to the multiswitch switch 303, and the microcontroller 305 is configured to control the switch 50 of the multiswitch switch 303 such that the at least two fuel cells 301 connected to the multiswitch switch 303 are arranged in a series, parallel, open, partially-pass electrical connection configuration.

FIG. 4 is a schematic diagram of a multiway switch according to the invention. The control signal input pins 303a, 303b of the multiplexer 303 are used to connect to the microcontroller 305 for receiving the

control signals

307a, 307b, and the two output pins 303c, 303d are used to connect to the positive and negative poles of the load 40. The anode and cathode of each fuel cell 301 may be connected by pins 303e and 303f and output pins 303c and 303d of the multiplexer 303. The internal A, B, C, D, E, F, and G terminals of the multiplexer 303 are controlled by the control signals 307a, 307B, and are controlled to connect or disconnect each other.

FIG. 5 illustrates an electrical connection configuration for controlling the switching of the multi-way switch according to the present invention. When the microcontroller 305 outputs the control signal 307a of "0" (low voltage level) and the control signal 307b of "0" (low voltage level), it is configured in a series electrical connection configuration in cooperation with the switching state of the multi-way switch 303 shown in fig. 6A. When the microcontroller 305 outputs the control signal 307a of "1" (high voltage level) and the control signal 307B of "1" (high voltage level), it is configured in parallel electrical connection configuration in cooperation with the switching state of the multi-way switch 303 shown in fig. 6B. When the microcontroller 305 outputs the control signal 307a of "1" (high voltage level) and the control signal 307b of "0" (low voltage level), it is configured to be in an open electrical connection configuration in cooperation with the switching state of the multi-way switch 303 shown in fig. 6C. When the microcontroller 305 outputs the control signal 307a of "0" (low voltage level) and the control signal 307b of "1" (high voltage level), please refer to the switching state of the multi-way switch 303 shown in fig. 6D, which is configured to be a partially-pass electrical connection configuration, i.e. the fuel cell 301 on the right side of fig. 2 is good and supplies power to the load 40, while the fuel cell 301 on the left side is damaged and has been configured to be a partially-pass state, so that the damaged fuel cell stops operating and is connected to other available fuel cells. Furthermore, when the microcontroller 305 outputs the control signal 307a of "0" (low voltage level) and the control signal 307b of "1" (high voltage level), please refer to the switching state of the multi-way switch 303 shown in fig. 6E, which is configured to another partial-path electrical connection configuration, i.e. the fuel cell 301 on the left side of fig. 2 is good and supplies power to the load 40, while the fuel cell 301 on the right side is damaged and has been configured to a partial-path state, so that the damaged fuel cell stops operating and is connected to other available fuel cells.

FIG. 7 shows the embodiment of FIG. 3, and FIG. 8 shows an electrical connection configuration corresponding to FIG. 7 controlling the switching of the multiway switch. The first to fifth multi-way switching devices 3031 to 3039 of fig. 7 are electronic multi-way switching devices, such as MOSFET electronic components, and when the gates of the multi-way switching devices 3031 to 3039 are "1" (high voltage level), the sources are electrically connected to the drains, and conversely, when the gates of the multi-way switching devices 3031 to 3039 are "0" (low voltage level), the sources are electrically disconnected from the drains. The microcontroller 305

outputs control signals

307a, 307b, 307c, 307d, 307e to the first to fifth multi-way switch 3031 to 3039, respectively, so as to obtain the electrical connection configuration of series, parallel, open, partial path as disclosed in fig. 8.

The microcontroller 305 of the present invention can further be used to monitor the power generation status of each fuel cell 301 to determine the quality of each fuel cell 301, so as to achieve the optimal configuration of the intelligent controllable dynamic series-parallel fuel cells 301.

The fuel cell 301 of the present invention may be a fuel cell unit, or may be a stacked fuel cell, a flat-open fuel cell, a hybrid fuel cell, or the like. Further, the fuel cell 301 of the present invention may be a Proton Exchange Membrane Fuel Cell (PEMFC), a Direct Methanol Fuel Cell (DMFC), other fuel cell, or the like.

The configuration method 20 and the fuel cell system 30 of the present invention are not limited to for the two numbers of fuel cells 301 disclosed above, and those skilled in the art can deduce that the configuration method 20 and the fuel cell system 30 can be implemented on more than two numbers of fuel cells 301 according to the principle spirit of the present invention, and these equivalent scope changes still fall within the scope of the present invention.

Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A configuration method for configuring a fuel cell system by using intelligent controllable dynamic series-parallel connection comprises the following steps:

providing a multi-way switch switcher;

electrically connecting at least two fuel cells to the multiway switch;

controlling the switching of the multiswitch switch such that at least two fuel cells connected to the multiswitch switch are arranged in a series, parallel, open, partially closed electrical connection configuration.

2. The method of claim 1, wherein the multi-way switch is an electronic multi-way switch.

3. The method of claim 1, wherein the step of electrically connecting at least two fuel cells to the multiswitch switch electrically connects an anode and a cathode of each fuel cell to the multiswitch switch, respectively.

4. The method of claim 1, wherein the step of controlling the switching of the multi-way switch comprises outputting a control signal to the multi-way switch by a microcontroller, so that the multi-way switch changes the switching according to the control signal.

5. The method of claim 1, wherein the fuel cell is one of a fuel cell unit, a stacked fuel cell, a flat-bed fuel cell, a hybrid fuel cell, and the like.

6. The method of claim 1, wherein the fuel cell is one of a Proton Exchange Membrane Fuel Cell (PEMFC), a Direct Methanol Fuel Cell (DMFC), and the like.

7. The method of claim 4, wherein said microcontroller is further configured to monitor power generation of said fuel cell.

8. An intelligent steerable dynamic series-parallel fuel cell system comprising:

a multi-way switch switcher;

at least two fuel cells electrically connected to the multiway switch;

a microcontroller for controlling the switching of the multi-way switch such that at least two fuel cells connected to the multi-way switch are arranged in a series, parallel, open, partial-pass electrical connection configuration.

9. The fuel cell system of claim 8, wherein the multi-way switch is an electronic multi-way switch.

10. The fuel cell system of claim 8, wherein the at least two fuel cells are each electrically connected to the multiway switch at a positive pole and a negative pole of the fuel cell.

11. The fuel cell system of claim 8, wherein the microcontroller is configured to output a control signal to the multi-way switch to cause the multi-way switch to vary the switching according to the control signal.

12. The fuel cell system of claim 8, wherein the fuel cell is one of a fuel cell unit, a stacked fuel cell, a flat-open fuel cell, a hybrid fuel cell, and the like.

13. The fuel cell system of claim 8, wherein the fuel cell is one of a Proton Exchange Membrane Fuel Cell (PEMFC), a Direct Methanol Fuel Cell (DMFC), and the like.

14. The fuel cell system of claim 8, wherein the microcontroller is further configured to monitor a power generation condition of the fuel cell.