CN2867720Y

CN2867720Y - Fan speed stabilizing control circuit for fuel cell engine air delivery device

Info

Publication number: CN2867720Y
Application number: CNU200520047311XU
Authority: CN
Inventors: 付明竹; 鲍军辉; 郭磊; 胡里清
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2005-12-08
Filing date: 2005-12-08
Publication date: 2007-02-07
Anticipated expiration: 2015-12-08

Abstract

The utility model relates to a wind turbine speed stabilization and control circuit of air feeding device of fuel battery motor. The wind turbine speed stabilization and control circuit comprises a single-chip, a wind turbine motor drive circuit, a speed control circuit, and a CAN interface circuit, wherein the wind turbine motor drive circuit is connected with the wind turbine motor at one end for acquiring rotation speed pulse signal of the wind turbine motor so as to control the rotation of wind turbine motor, and is connected with the single-chip and the output end of the speed control circuit at the other end. The single-chip is connected with the CAN interface circuit for receiving the predetermined rotation speed of the wind turbine motor from CAN bus and comparing it with the rotation speed signal obtained by the wind turbine motor drive circuit. The utility model can ensure long-time and stable speed of wind turbine motor of fuel battery motor so as to feed air with constant flow rate to the fuel battery motor. Accordingly, fault of the wind turbine motor can be identified effectively and its rotation speed is improved.

Description

Fan speed stabilizing control circuit of air conveying device of fuel cell engine

Technical Field

The utility model relates to a fuel cell especially relates to a fuel cell engine air conveyor fan speed stabilizing control circuit.

Background

A fuel cell is a device that can convert chemical energy generated when a fuel and an oxidant electrochemically react into electrical energy. The core component of the device is a Membrane Electrode (MEA), which consists of a proton exchange Membrane and two conductive porous diffusion materials (such as carbon paper) sandwiched between two surfaces of the Membrane, and finely dispersed catalysts (such as platinum) capable of initiating electrochemical reaction are uniformly distributed on the two side interfaces of the proton exchange Membrane contacting with the conductive materials. The electrons generated in the electrochemical reaction process are led out by conductive objects at two sides of the membrane electrode through an external circuit, thus forming acurrent loop.

At the anode end of the membrane electrode, fuel can permeate through a porous diffusion material (such as carbon paper) and perform electrochemical reaction on the surface of a catalyst, electrons are lost to form positive ions, and the positive ions can pass through a proton exchange membrane through migration to reach the other end of the membrane electrode, namely the cathode end. At the cathode end of the membrane electrode, a gas (e.g., air) containing an oxidant (e.g., oxygen) permeates through a porous diffusion material (e.g., carbon paper) and electrochemically reacts at the surface of the catalyst to give electrons that form negative ions that further combine with positive ions migrating from the anode end to form a reaction product.

In the presence of hydrogen as fuelIn a proton exchange membrane fuel cell using air containing oxygen as an oxidant (or pure oxygen as the oxidant), fuel hydrogen gas undergoes a catalytic electrochemical reaction in an anode region without electrons to form hydrogen positive ions (protons), and the electrochemical reaction equation is as follows: the oxygen gas undergoes a catalyzed electrochemical reaction in the cathode region to produce electrons, forming negative ions which further combine with the positive hydrogen ions migrating from the anode side to form water as a reaction product. The electrochemical reaction equation is as follows: 。

the function of the proton exchange membrane in a fuel cell, in addition to serving to carry out the electrochemical reaction and to transport the protons produced in the exchange reaction, is to separate the gas flow containing the fuel hydrogen from the gas flow containing the oxidant (oxygen) so that they do not mix with each other and produce an explosive reaction.

In a typical pem fuel cell, the membrane electrode is generally placed between two conductive plates, and the two plates are both provided with channels, so the membrane electrode is also called as a current-guiding plate. The diversion grooves are arranged on the surface contacted with the membrane electrode and formed by die casting, stamping or mechanical milling and carving, and the number of the diversion grooves is more than one. The flow guide polar plate can be made of metal materials or graphite materials. The diversion trench on the diversion polar plate is used for respectively guiding fuel or oxidant into the anode region or the cathode region at two sides of the membrane electrode. In the structure of a single proton exchange membrane fuel cell, only one membrane electrode and two flow guide polar plates are arranged on two sides of the membrane electrode, one is used as the flow guide polar plate of anode fuel, and the other is used as the flow guide polar plate of cathode oxidant. The two flow guide polar plates are used as current collecting plates and mechanical supports at two sides of the membrane electrode. The diversion trench on the diversion polar plate is a channel for fuel or oxidant to enter the surface of the anode or the cathode, and is a water outlet channel for taking away water generated in the operation process of the battery.

In order to increase the power of the pem fuel cell, two or more single cells are connected together in a stacked or tiled manner to form a stack, or referred to as a cell stack. Such a battery pack is generally fastened together into one body by a front end plate, a rear end plate, and tie rods. In the battery pack, flow guide grooves, called bipolar plates, are arranged on both sides of a polar plate positioned between two proton exchange membranes. One side of the bipolar plate is used as an anode diversion surface of one membrane electrode, and the other side is used as a cathode diversion surface of the other adjacent membrane electrode. A typical battery pack also generally includes: 1) inlet and flow guide channels for fuel and oxidant gases. The fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas and gasoline) and oxidant (mainly oxygen or air) are uniformly distributed in the diversion trenches of the anode and cathode surfaces; 2) an inlet and an outlet for cooling fluid (such as water) and a flow guide channel. The cooling fluid is uniformly distributed in the cooling channels in each battery pack to absorb the reaction heat generated in the fuel cell and carry the reaction heat out of the battery pack for heat dissipation; 3) the outlets of the fuel and oxidant gases and the flow guide channel. The function of the device is to discharge the excessive fuel gas and oxidant which do not participate in the reaction, and simultaneously carry out the liquid or gaseous water generated by the reaction. The fuel inlet/outlet, the oxidant inlet/outlet, and the cooling fluid inlet/outlet are typically provided on one end plate or on both end plates of the fuel cell stack.

The proton exchange membrane fuel cell can be used as a power system of vehicles, ships and other vehicles and can also be manufactured into a movable or fixed power generation system.

In a fuel cell power generation system, when the power of a fuel cell engine changes, the required air supply amount also changes correspondingly. The method is characterized in that a certain amount of air is required to be provided by a fan corresponding to one power output, stable air volume must be ensured to be delivered to a fuel cell engine in order to ensure the long-time stable operation of the fuel cell engine, and the stable air volume is realized by adjusting the rotating speed of a fan motor. The speed control of the fan motor of the existing fuel cell engine adopts PWM pulse width voltage regulation control, a voltage of 0-12V is generated after PWM signals are filtered, and the rotating speed of the fan motor is controlled by regulating the voltage so as to achieve the purpose of regulating the air supply quantity of the fuel cell. The control method has large control precision deviation and poor consistency performance, the parameters of the controller need to be readjusted when the controller is replaced, long-time stable operation is difficult to ensure due to the absence of a speed feedback link, and the failure of the fan motor cannot be identified.

Disclosure of Invention

The utility model aims at providing a fuel cell engine air conveyor fan speed stabilizing control circuit which aims at overcoming the defects existing in the prior art.

The purpose of the utility model is realized like this: the utility model provides a fuel cell engine air conveyor fan speed stabilizing control circuit, its characterized in that, including singlechip U1, fan motor drive circuit U2, speed control circuit U3, CAN interface circuit U5, fan motor drive circuit U2 one end is connected with fan motor M1, acquires fan motor rotational speed pulse signal, control and drive fan motor and rotate, and the other end links to each other with the output of singlechip U1 and speed control circuit U3 respectively, and singlechip U1 is connected with CAN interface circuit, receives the given rotational speed of fan motor from the CAN bus to compare with the fan motor rotational speed signal that acquires from fan motor drive circuit U2, singlechip U1 links to each other with speed control circuit U3's input, sends control adjustment parameter, adjusts the motor speed.

The speed control circuit U3 includes optoelectronic coupler N2 and field effect transistor V3, the input of optoelectronic coupler N2 is connected with the singlechip, the output is connected with field effect transistor V3, field effect transistor V3 is connected with fan motor drive circuit U2, optoelectronic coupler N2 and field effect transistor V3 constitute PWM pulse width modulation signal isolation transmission circuit, produce 0 ~ 12V direct current speed regulation signal.

The fan motor drive circuit U2 and the singlechip U1 are connected through a photoelectric coupler N1, the input end of the photoelectric coupler N1 is connected with the fan motor drive circuit U2, and the output end of the photoelectric coupler N1 is connected with the singlechip U1, so that pulse speed output signals of the fan motor driver U2 are isolated from signals of the singlechip and converted.

One end of the CAN interface circuit U5 is connected with the singlechip, and the other end is connected with the CAN bus.

The single chip microcomputer U1 CAN be a Philips LPC2119-ARM chip, and the chip comprises a PWM pulse width modulation circuit and a CAN bus communication interface circuit.

The field effect transistor V3 may be IRFP 150N.

The photoelectric coupler N1 can be a PC 817.

The utility model discloses owing to adopted above technical scheme, overcome prior art's defect. Compared with the prior art, the utility model has the advantages of guarantee that fuel cell engine fan motor is stable for a long time speed, can effective discernment during fan motor trouble, the rotational speed precision is high.

Drawings

FIG. 1 is a block diagram of a fan speed stabilizing control circuit of the air delivery device of the fuel cell engine of the present invention;

fig. 2 is acircuit diagram of the fan speed stabilizing control of the fuel cell engine air conveying device of the present invention.

Detailed Description

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

Referring to fig. 2, fig. 2 is a schematic diagram of an embodiment of the present invention for controlling the rotational speed of an air supply fan in a 50 kw fuel cell power generation system. The rotating speed control circuit U3 comprises a photoelectric coupler N2 and a field effect transistor V3, five resistors, a capacitor and a diode, a pin corresponding to the cathode of an input end light emitting diode of the photoelectric coupler N2 is connected with a port POT2 of the singlechip U1, a pin corresponding to the anode of the light emitting diode is connected with a power supply VCC through a current limiting resistor R2, a pin corresponding to the emitter of an output end transistor is connected with the grid of the field effect transistor V3, a pin corresponding to the collector of the transistor is connected with a direct current power supply +24V through a current limiting resistor R4, the source of the field effect transistor V3 is grounded, a bridging resistor R5 is arranged between the grid and the source, two branches are arranged on a drain node and are respectively connected with the port POT2 of the fan motor driving circuit U2 and the anode of the diode V2, and the cathode of the diode V2. Two ends of the diode V2 are connected with a resistor R6 in parallel, a resistor R7 and a capacitor C1 are connected between the drain electrode of the field-effect tube V3 and the ground in parallel, and the photoelectric coupler N2 and the field-effect tube V3 form a PWM (pulse width modulation) signal isolation transmission circuit to generate a 0-12V direct-current speed adjusting signal. The fan motor driving circuit U2 is connected with the single chip microcomputer U1 through a photoelectric coupler N1, a pin corresponding to an anode of a light emitting diode at an input end of the photoelectric coupler N1 is connected with an output port POT1 of the fan motor driving circuit U2 through a resistor R3, a pin corresponding to a cathode is grounded, a pin corresponding to a collector of a transistor at the output end is connected with a power supply VCC, a pin corresponding to an emitter output of the transistor is connected with an output port POT1 of the single chip microcomputer U1, a resistor R1 is connected between an output port POT1 of the single chip microcomputer U1 and the ground, and the photoelectric coupler N1 is used for isolating and converting a pulse speed output signal of the fan motor driver U2 and a signal of the single.

The single chip U1 adopts Philips LPC2119-ARM chip, which contains PWM pulse width modulation circuit and CAN bus communication interface circuit. In the example, a brushless motor controller is adopted by a motor in an air supply subsystem of a 50-kilowatt fuel cell power generation system, the internal speed stabilizing function is poor, a speed pulse signal output which has a linear relation with the actual rotating speed is provided, and the speed regulation control input signal of the brushless motor controller is 0-12 VDC. The photoelectric coupler N1 is used as the pulse speed output signal of the fan motor driver and is isolated and converted with the signal of the single chip microcomputer. The photoelectric coupler N2 and the field-effect tube V3 form a PWM (pulse-width modulation) signal isolation transmission circuit, and a speed adjusting signal of 0-12 VDC is generated. The single chip microcomputer receives the given speed of the fan from the CAN bus, the single chip microcomputer U1 measures the actual speed of the fan according to the pulse of the POT1 port, and the single chip microcomputer adjusts the pulse duty ratio of the PWM signal according to the deviation amount of the given speed and the actual speed to enable the given speed to be the same as the actual speed. When the given speed changes, the single chip microcomputer is adjusted to be the same as the given speed at the fastest speed, and the process control algorithm can be realized by adopting a proportional-integral-derivative (PID) control algorithm or a fuzzy control algorithm and the like.

Claims

1. The utility model provides a fuel cell engine air conveyor fan speed stabilizing control circuit, a serial communication port, including singlechip (U1), fan motor drive circuit (U2), speed control circuit (U3), CAN interface circuit (U5), fan motor drive circuit (U2) one end is connected with fan motor (M1), acquires fan motor rotational speed pulse signal, control and drive fan motor rotation, the other end links to each other with the output of singlechip (U1) and speed control circuit (U3) respectively, singlechip (U1) and CAN interface circuit are connected, receive fan motor's given rotational speed from the CAN bus to compare with the fan motor rotational speed signal that acquires from fan motor drive circuit (U2), singlechip (U1) links to each other with the input of speed control circuit (U3), send control adjustment parameter, adjust motor speed.

2. The fan speed stabilizing control circuit of the air conveying device of the fuel cell engine as claimed in claim 1, wherein the speed control circuit (U3) comprises a photoelectric coupler (N2) and a field effect transistor (V3), the input end of the photoelectric coupler (N2) is connected with the single chip microcomputer, the output end of the photoelectric coupler (N2) is connected with the field effect transistor (V3),the field effect transistor (V3) is connected with the fan motor driving circuit (U2), and the photoelectric coupler (N2) and the field effect transistor (V3) form a PWM pulse width modulation signal isolation transmission circuit to generate a 0-12V direct current speed adjusting signal.

3. The fan speed stabilizing control circuit of the air conveying device of the fuel cell engine as claimed in claim 1, wherein the fan motor driving circuit (U2) is connected with the single chip microcomputer (U1) through a photoelectric coupler (N1), the input end of the photoelectric coupler (N1) is connected with the fan motor driving circuit (U2), the output end of the photoelectric coupler is connected with the single chip microcomputer (U1), and the fan speed stabilizing control circuit is used for isolating and converting pulse speed output signals of the fan motor driver (U2) and signals of the single chip microcomputer.

4. The fan speed stabilizing control circuit of the fuel cell engine air conveying device according to claim 1, wherein one end of the CAN interface circuit (U5) is connected with the single chip microcomputer, and the other end is connected with a CAN bus.

5. The fan speed stabilizing control circuit of the air delivery device of the fuel cell engine as claimed in claim 1, wherein the single chip microcomputer (U1) is a philips LPC2119-ARM chip, and the chip comprises a PWM pulse width modulation circuit and a CAN bus communication interface circuit.

6. The fan speed stabilizing control circuit of the air delivery device of the fuel cell engine as claimed in claim 2, wherein the fet (V3) is IRFP 150N.

7. The fan speed stabilizing control circuit of the air delivery device of the fuel cell engine as claimed in claim 3, wherein the photoelectric coupler (N1) can be PC 817.