CN113314739B - Transient modeling method for hydrogen circulating pump in fuel cell system - Google Patents
Transient modeling method for hydrogen circulating pump in fuel cell system Download PDFInfo
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- 239000001257 hydrogen Substances 0.000 title claims abstract description 141
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 141
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 133
- 239000000446 fuel Substances 0.000 title claims abstract description 28
- 230000001052 transient effect Effects 0.000 title claims abstract description 21
- 238000000034 method Methods 0.000 title claims abstract description 18
- 239000007789 gas Substances 0.000 claims abstract description 33
- 238000004364 calculation method Methods 0.000 claims abstract description 22
- 230000004044 response Effects 0.000 claims abstract description 8
- 230000008878 coupling Effects 0.000 claims abstract description 4
- 238000010168 coupling process Methods 0.000 claims abstract description 4
- 238000005859 coupling reaction Methods 0.000 claims abstract description 4
- 238000011084 recovery Methods 0.000 claims abstract description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 26
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 150000002431 hydrogen Chemical class 0.000 claims description 9
- 238000013459 approach Methods 0.000 claims description 5
- 238000010606 normalization Methods 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 4
- 238000004088 simulation Methods 0.000 abstract description 6
- 238000011217 control strategy Methods 0.000 abstract description 5
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- 239000012528 membrane Substances 0.000 description 3
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- 238000011161 development Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/04305—Modeling, demonstration models of fuel cells, e.g. for training purposes
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The invention discloses a transient modeling method of a hydrogen circulating pump in a fuel cell system, which comprises the steps of fitting a model based on a polynomial regression method to obtain a relation function of the flow rate, the rotating speed and the outlet pressure of the hydrogen circulating pump, then coupling an inertia link of a driving motor to construct a complete transient centrifugal hydrogen circulating pump model, finally carrying out PID control on the control voltage of the driving motor, coupling and calculating the three models to obtain the transient response of the hydrogen circulating pump, and controlling the hydrogen circulating pump to meet the tail gas recovery requirement of a fuel cell stack, thereby achieving the purpose of controlling the hydrogen circulating pump. The model obviously improves the calculation rate on the premise of ensuring the simulation accuracy, can be used for calculating the working condition of the fuel cell stack under a steady state, can simulate and calculate the real-time transient response of the stack under the actual road working condition when the load is changed, can better perform linkage simulation with a fuel cell system, and has important significance for optimizing the control strategy of the fuel cell system.
Description
Technical Field
The invention belongs to the field of fuel cells, and particularly relates to a transient modeling method for a hydrogen circulating pump in a proton exchange membrane fuel cell.
Background
The negative impact of air quality has been an international urgent problem for decades, with motor vehicle exhaust pollution representing a significant proportion. In order to improve the air quality of cities, proton exchange membrane fuel cells attract the attention of many countries, and have the remarkable characteristics of zero greenhouse gas emission, fast load response, high energy conversion efficiency, silence, low working temperature and the like, so that fuel cell automobiles become an important direction for the development of new energy automobiles.
The fuel used by the fuel cell vehicle is derived from hydrogen stored in a high-pressure hydrogen tank. If the amount of hydrogen supplied by the vehicle fuel cell is reduced or even short of the amount of hydrogen supplied, irreversible damage and performance degradation may occur to the stack. Thus, a certain inventory of hydrogen must be maintained to maintain stack operation, but if a hydrogen recovery subsystem is not provided, unreacted hydrogen is vented directly to the environment. Besides increasing the use cost and reducing the endurance mileage, the fuel waste is critical to safety issues. In addition, for better performance, the hydrogen gas at the anode inlet of the stack often needs to be humidified, while the humidifier increases the volume and cost of the system, and the liquid water remaining in the humidifier freezes below zero, which affects the cold start speed of the fuel cell. If a hydrogen circulation pump is used in the fuel cell system, the above two problems can be effectively solved. The hydrogen circulating pump can send unreacted hydrogen at the anode outlet and steam back to the manifold of the supply system, and the unreacted hydrogen and the steam are mixed with the hydrogen supplied by the hydrogen tank and enter the cell stack again, so that the utilization rate of fuel is improved, and the function of humidifying the hydrogen is also realized.
The performance and the service life of the fuel cell can be improved by using the hydrogen circulating pump, but various complex problems occur in the specific using process, if the experiment research result is obtained by adopting a mathematical modeling method, the result is undoubtedly required by the industry, the research and development cost can be greatly reduced, and the actual problems can be predicted.
Disclosure of Invention
The invention aims to provide a transient modeling method of a centrifugal hydrogen circulating pump in a proton exchange membrane fuel cell system. The relation among the flow rate, the rotating speed and the outlet pressure of the centrifugal hydrogen circulating pump is fitted by adopting a polynomial regression method, then the inertia link of the driving motor is coupled, a transient centrifugal hydrogen circulating pump model is constructed, and finally the control voltage of the driving motor is subjected to proportional-integral-derivative control (PID) control, so that the aim of controlling the hydrogen circulating pump is fulfilled.
The technical scheme of the method is as follows: and establishing a relation model comprising the volume flow, the rotating speed and the outlet pressure of the hydrogen circulating pump, an inertia link model of the driving motor and a PID control model for controlling the voltage of the driving motor, coupling and calculating the three models to obtain the transient response of the hydrogen circulating pump, and controlling the hydrogen circulating pump to meet the tail gas recovery requirement of the fuel cell stack. The specific steps for establishing each model are as follows:
(1) establishing a relation model of volume flow, rotating speed and outlet pressure of the hydrogen circulating pump
Firstly, fitting a characteristic curve of a hydrogen circulating pump, and correcting the volume flow of gas at an inlet of the hydrogen circulating pump and the angular speed and the rotating speed of a rotor according to the following temperature and pressure:
wherein, Wbc、ωbcAnd NbcRespectively, the corrected volume flow, angular velocity and rotational speed, Wbl、ωblAnd NblRepresenting the actual volume flow, angular velocity and rotational speed, TinAnd PinIndicating the temperature and pressure, T, of the inlet gasrefAnd PrefRepresenting a reference temperature and pressure.
In order to improve the accuracy of data fitting, data normalization processing is performed on sample points in the characteristic curve of the disclosed (literature) hydrogen circulation pump as follows:
wherein x and y represent the rotational speed and the volume flow rate after data normalization processing, muNAnd muWRepresenting the mean value, σ, of the rotational speed and the volume flow of the sample pointNAnd σWThe standard deviation of the rotational speed and the volume flow at the sample point is indicated.
Based on sample points in a characteristic curve of the hydrogen circulating pump, fitting the relationship among the volume flow, the rotating speed and the outlet pressure of the hydrogen circulating pump by using a binary quadratic polynomial, wherein the relationship is as follows:
Pout＝a0+a1x+a2y+a3x2+a4xy+a5y2 (1-3)
wherein, PoutRepresents the outlet pressure of the hydrogen circulation pump, a0,a1,a2,a3,a4,a5Respectively, represent polynomial fitting coefficients.
(2) Constructing an inertia link model of a driving motor
The inertia link calculation expression of the hydrogen circulating pump is as follows:
wherein, ω isblRepresenting the angular velocity of the rotor, t representing time, JblRepresenting the moment of inertia, tau, of the rotor part of the hydrogen circulation pumpbmRepresenting the driving torque, tau, of the driving motorblThe load torque of the hydrogen circulation pump is indicated.
The drive torque calculation expression of the drive motor is as follows:
wherein eta isbmIndicating the efficiency of the drive motor, RbmDenotes the drive motor resistance, κtDenotes the moment constant, κ, of the drive motorvRepresenting the voltage constant, v, of the drive motorbmIndicating the control voltage, omega, of the drive motorblRepresenting the angular velocity of the rotor.
The calculation expression of the load moment of the hydrogen circulating pump is as follows:
wherein p isblRepresents the power of the hydrogen circulation pump, cp,inDenotes the specific heat capacity at constant pressure, T, of the inlet gasinIndicating the temperature, η, of the intake airblIndicates the efficiency of the hydrogen circulation pump, Pout、PinRespectively representing the pressure at the outlet and inlet of the hydrogen circulation pump, gammag,inDenotes the specific heat ratio coefficient of the inlet gas, minRepresenting the mass flow of the inlet gas.
The calculation expression of the constant pressure specific heat capacity and specific heat ratio coefficient of the inlet gas is as follows:
wherein,
cp,vand
respectively represent the specific heat capacity at constant pressure of hydrogen, water vapor and nitrogen,
γvand
respectively represent specific heat ratio coefficients of hydrogen, water vapor and nitrogen,
yv,inand
respectively representing the mass fractions of hydrogen, water vapor and nitrogen in the inlet gas.
The calculation expression of the outlet gas temperature after being compressed by the hydrogen circulating pump is as follows:
wherein, ToutIndicating the temperature of the outlet gas.
(3) PID control model for constructing control voltage of driving motor
When the rotating speed of the hydrogen circulating pump is stable, the driving torque is equal to the load torque of the hydrogen circulating pump, then the stable control voltage of the driving motor is solved, and the calculation expression is as follows:
and comparing the actual outlet pressure with the target outlet pressure, and taking the difference value of the actual outlet pressure and the target outlet pressure as the deviation amount of PID control, thereby calculating the variation of the control voltage:
e(t)＝Ptar-Pout (3-2)
vbm,new＝vbm+u(t) (3-4)
wherein, PtarAnd PoutRespectively representing target and actual outlet pressures, e (t) representing the deviation, Kp、KI、KDRespectively representing proportional, integral and differential coefficients, u (t) representing the variation of the control voltage, vbm,newAnd represents the control voltage of the driving motor after PID control.
Correcting the volume flow of the inlet of the hydrogen circulating pump and the rotating speed at the current moment, matching with a characteristic curve of the hydrogen circulating pump to obtain the current outlet pressure, comparing the current outlet pressure with the target outlet pressure, taking the difference value of the current outlet pressure and the target outlet pressure as the deviation value of PID control, calculating the variation of the control voltage, obtaining a new rotating speed according to an inertia link model, and finally recalculating in combination with the volume flow of the inlet in such a reciprocating cycle manner to enable the actual outlet pressure to gradually approach or even be equal to the target outlet pressure.
The outlet pressure of the hydrogen circulating pump is determined by the volume flow of the inlet of the hydrogen circulating pump and the rotating speed of the rotor, the rotor of the hydrogen circulating pump is driven by a driving motor, and the rotating speed of the driving motor is determined by control voltage. Therefore, the hydrogen circulation pump transient model needs to be constructed by the three models.
And combining the model (1) and the model (2) to construct a steady-state model of the complete centrifugal hydrogen circulating pump, and then combining the model (3) to construct a transient model of the centrifugal hydrogen circulating pump, wherein the transient model can automatically adjust the rotating speed and control the outlet pressure. The former can calculate the actual stable outlet pressure of the hydrogen circulating pump under the condition of given rotating speed and volume flow, and the latter can automatically update the control voltage of the driving motor through PID control under the condition of given target outlet pressure, so as to adjust the rotating speed of the rotor, and ensure that the actual outlet pressure gradually approaches or even equals to the target outlet pressure.
The invention has the characteristics and beneficial effects that: compared with the traditional three-dimensional complex fluid mechanics analysis model, the constructed transient model of the centrifugal hydrogen circulating pump has the advantages of obvious calculation rate on the premise of ensuring the simulation accuracy, and overcomes the defects that the three-dimensional model has excessive parameters and can not be coupled into a reactor system to perform multi-component multi-subsystem combined simulation and real-time simulation. The constructed model can be used for calculating the working condition of the fuel cell stack under a steady state, and can simulate and calculate the real-time transient response of the stack under the actual road working condition when the load is changed, so that the authenticity of system level simulation is improved, and the model has wide applicability. The model can also respond to different electric pile control strategies, further optimize the control strategy of the fuel supply subsystem, effectively reduce the bench test cost in the electric pile research and development process, and has important scientific significance and economic value.
Drawings
Fig. 1 is a characteristic diagram of a centrifugal hydrogen circulation pump disclosed in the literature.
Fig. 2 is a flow diagram of a centrifugal hydrogen circulation pump control of the present invention.
FIG. 3 is the result of a binary quadratic polynomial fit of the present invention.
FIG. 4 is a performance representation of the hydrogen circulation pump model of the present invention under a PID control strategy.
FIG. 5 is a graph of the performance of the hydrogen circulation pump model of the present invention under the optimized PID control strategy.
Detailed Description
The modeling process of the present invention is further described by the following specific examples, which should be noted that the present calculation examples are illustrative and not limiting, and the scope of the present invention is not limited thereby.
A transient modeling method for hydrogen circulating pump in fuel cell system includes correcting volume flow at inlet of hydrogen circulating pump and rotation speed at current time, matching with characteristic curve of hydrogen circulating pump to obtain current outlet pressure, comparing with target outlet pressure, using difference value of two as deviation value of PID control to calculate variation of control voltage, obtaining new rotation speed according to inertial link model, and recalculating by combining with volume flow at inlet so as to make actual outlet pressure gradually approach or even equal to target outlet pressure.
The hydrogen circulating pump is a centrifugal hydrogen circulating pump. The PID control refers to proportional integral derivative control.
The examples relate to the following main parameters:
parameters of the centrifugal hydrogen circulating pump: the moment of inertia is 2.6 multiplied by 10-3kg m2Constant of driving motor kt、κv0.15N/mA and 0.15V/(rad/s) respectively, and the efficiency eta of the driving motorbmIs 0.9, the hydrogen circulation pump efficiency etablIs 0.8, motor armature resistance RbmIs 0.82 omega.
The inlet temperature of the hydrogen circulating pump is 343.15K, the inlet pressure is 0.9bar, and the inlet flow is 7.59m3H, hydrogen concentration, water vapor concentration and nitrogen concentration of the feed gas were 44.26mol/m, respectively3、9.00mol/m3And 0, the mass fraction of hydrogen, the mass fraction of water vapor and the mass fraction of nitrogen of the feed gas were 0.3551, 0.6449 and 0, respectively.
The specific heat capacity at constant pressure of hydrogen was 14283J/kg/K, the specific heat capacity at constant pressure of steam was 1867J/kg/K, and the specific heat capacity at constant pressure of nitrogen was 1038J/kg/K.
The specific heat ratio coefficient of hydrogen was 1.4378, that of water vapor was 1.3519, and that of nitrogen was 1.4008.
The current rotational speed of the drive motor is 4000 RPM.
The response process of the steady-state model of the hydrogen circulation pump in a time step when the target outlet pressure of the hydrogen circulation pump is changed from 1bar to 1.5bar is taken as an example.
Firstly, temperature and pressure correction needs to be carried out on the volume flow of gas at the inlet of the hydrogen circulating pump and the angular speed and the rotating speed of the rotor:
Wbc(m3 h-1) And Wbl(m3 h-1) Indicating the corrected and actual volume flow, ωbc(rad s-1) And ωbl(rad s-1) Representing corrected and actual angular velocity, Nbc(RPM) and Nbl(RPM) represents the corrected and actual volumetric flow rate speed, Tin(K) And Pin(bar) represents the temperature and pressure of the inlet gas, reference temperature Tref288K, reference pressure Pref＝1bar。
And then calculating the outlet pressure of the hydrogen circulation pump at the current moment, fitting a characteristic curve graph of the hydrogen circulation pump before the outlet pressure, extracting sample points in the graph 1, constructing a model in a Python 3.7.9 programming environment, and fitting by using a scimit-learn library, wherein the fitting result is shown in FIG. 3. First, data normalization processing is performed on sample points as follows:
a characteristic diagram of the hydrogen circulation pump can be obtained from the published article, as shown in fig. 1. x and y represent the rotation speed and volume flow after data normalization, and the average value mu of the rotation speed of the sample pointN3714.285PRM, mean value of sample point volume flow, μW＝7.032m3H, standard deviation σ of sample point rotational speedN1030.158, standard deviation σ of sample point volume flowW＝4.394。
Fitting the relationship among the volume flow, the rotating speed and the outlet pressure of the hydrogen circulating pump by using a binary quadratic polynomial, wherein the relationship is as follows:
Pout＝a0+a1x+a2y+a3x2+a4xy+a5y2
wherein, Pout(bar) represents the outlet pressure of the hydrogen circulation pump, a0,a1,a2,a3,a4,a5Respectively, the polynomial fitting coefficients are shown, and the values of the coefficients are shown in the following table. The coefficient of certainty of the fit results is 0.9923, which indicates that the fit between the fit results and the sample points is better (as shown in fig. 3).
| Parameter(s) | a0 | a1 | a2 | a3 | a4 | a5 |
| Numerical value | 1.4271 | 0.3671 | 0.4356 | 0.0588 | 0.1272 | 0.0745 |
(2) Inertia link of driving motor
Calculated by a correction formula, the corrected volume flow Wbc＝9.21m3H, corrected angular velocity ωbc383.74rad/s, corrected speed Nbc3664.50 RPM. And then, substituting the pressure into a polynomial equation to obtain the outlet pressure of the hydrogen circulation pump at the current moment as 1.215 bar.
The calculation expression of the constant pressure specific heat capacity and specific heat ratio coefficient of the inlet gas is as follows:
wherein,
cp,v(J kg-1K-1) And
respectively represent the specific heat capacity at constant pressure of hydrogen, water vapor and nitrogen,
γvand
respectively represent specific heat ratio coefficients of hydrogen, water vapor and nitrogen,
yv,inand
respectively representing the mass fractions of hydrogen, water vapor and nitrogen in the inlet gas.
The constant pressure specific heat capacity c of the inlet gas can be calculated through known conditionsp,in6275.93J/kg/K, specific heat ratio coefficient gamma of inlet gasg,in＝1.3824。
The calculation expression of the hydrogen circulation pump power is as follows:
pbl(W) represents the power of the hydrogen circulation pump, cp,in(J kg-1K-1) Denotes the specific heat capacity at constant pressure, T, of the inlet gasin(K) Indicating the temperature, η, of the intake airblIndicates the efficiency of the hydrogen circulation pump, Pout(bar)、Pin(bar) represents the pressure at the outlet and inlet of the hydrogen circulation pump, respectively, gammag,inDenotes the specific heat ratio coefficient of the inlet gas, min(kg s-1) represents the mass flow rate of the inlet gas.
When the rotating speed of the hydrogen circulating pump is stable, the driving torque is equal to the load torque of the hydrogen circulating pump, then the stable control voltage of the driving motor is solved, and the calculation expression is as follows:
the mass flow m of the inlet gas can be calculated by knowing the conditionsin＝5.30×10-4kg/s, power p of the hydrogen circulation pumpbl123.57W, control voltage v of the drive motorbm＝64.62V。
(3) PID control and transient response
A schematic diagram of the hydrogen circulation pump control scheme is shown in fig. 2. And comparing the actual outlet pressure with the target outlet pressure, and taking the difference value of the actual outlet pressure and the target outlet pressure as the deviation amount of PID control, thereby calculating the variation of the control voltage:
e(t)＝Ptar-Pout
vbm,new＝vbm+u(t)
Ptar(bar) and Pout(bar) represents the target outlet pressure and the actual outlet pressure, respectively, e (t), (t) represents the deviation, u (t) (V) represents the variation of the control voltage, v (v) represents the variation of the control voltagebm,newAnd (V) represents the drive motor control voltage after PID control. In this example, the proportionality coefficient Kp2.842, integral coefficient KI232.770, the differential coefficient KD＝1.854。
The set of coefficients is optimized. If a default value is used, e.g. Kp＝KI＝KDThe control effect is shown in fig. 4 as 1. It can be seen that under the condition of using the set of coefficients, the time for the outlet pressure of the hydrogen circulating pump to reach the target pressure is long, and the fluctuation is large, so that the use of the hydrogen circulating pump is not facilitated. The control effect of the optimized coefficient on the hydrogen circulating pump is shown in figure 5, compared with figure 4, the time for the outlet pressure of the hydrogen circulating pump to reach the target pressure is greatly shortened, and the vibration is hardly generated, so that the aim of efficiently controlling the hydrogen circulating pump is fulfilled.
The deviation e (t) is 0.285V, the change u (t) of the control voltage is +12.72V, and the drive motor control voltage V after PID control can be calculated under known conditionsbm,new＝77.34V。
The drive torque calculation expression of the drive motor is as follows:
τbm(N m) represents a driving torque, η, of the driving motorbmIndicating the efficiency of the drive motor, Rbm(Ω) represents a drive motor resistance, κtDenotes the moment constant, κ, of the drive motorvRepresenting the voltage constant, v, of the drive motorbm(V) represents driveControl voltage, omega, of the motorbl(rad s-1) Representing the angular velocity of the rotor.
The calculation expression of the load moment of the hydrogen circulating pump is as follows:
τbl(N m) represents the load moment, p, of the hydrogen circulation pumpbl(W) represents the power of the hydrogen circulation pump, ωbl(rad s-1) denotes the actual angular velocity.
The driving torque tau of the driving motor after PID control can be calculated through known conditionsbm2.388N m, hydrogen circulation pump load torque τ at the present timebl＝0.295N m。
The inertia link calculation expression of the hydrogen circulating pump is as follows:
ωbl(rad s-1) Representing the angular velocity of the rotor, t(s) representing time, Jbl(kg m2) The moment of inertia of the rotor part of the hydrogen circulation pump is shown.
Through the above formula and known conditions, the new rotor angular velocity ω after PID control can be calculatedbl,new499.38rad/s new rotor speed Nbl＝4768.71RPM。
And finally, substituting the rotor rotating speed and the air inlet flow at the current moment into a correction expression and a relational expression of volume flow, rotating speed and outlet pressure, so that the outlet pressure of the hydrogen circulating pump at the current moment is 1.447bar, the difference between the outlet pressure and the target pressure is 1.5bar and 0.053bar, the outlet pressure at the previous moment is 1.215bar, and the difference between the outlet pressure and the target pressure is 0.285 bar. Therefore, after the optimization control of the PID, the difference between the outlet pressure of the hydrogen circulating pump and the target pressure is rapidly reduced.
After that, the above steps are continuously circulated, so that the outlet pressure of the hydrogen circulating pump gradually approaches or even equals to the target pressure.
Claims (3)
1. The transient modeling method of the hydrogen circulating pump in the fuel cell system is characterized in that: establishing a relation model comprising the volume flow, the rotating speed and the outlet pressure of the hydrogen circulating pump, an inertia link model of the driving motor and a PID control model for controlling the voltage of the driving motor, performing coupling calculation on the three models to obtain the transient response of the hydrogen circulating pump, and controlling the hydrogen circulating pump to meet the tail gas recovery requirement of the fuel cell stack, wherein the specific steps of establishing each model are as follows:
(1) establishing a relation model of volume flow, rotating speed and outlet pressure of the hydrogen circulating pump
Firstly, fitting a characteristic curve of a hydrogen circulating pump, and correcting the volume flow of gas at an inlet of the hydrogen circulating pump and the angular speed and the rotating speed of a rotor according to the following temperature and pressure:
wherein, Wbc、ωbcAnd NbcRespectively, the corrected volume flow, angular velocity and rotational speed, Wbl、ωblAnd NblRepresenting the actual volume flow, angular velocity and rotational speed, TinAnd PinIndicating the temperature and pressure, T, of the inlet gasrefAnd PrefWhich represents a reference temperature and pressure,
in order to improve the accuracy of data fitting, the data standardization process is performed on the sample points in the characteristic curve of the disclosed hydrogen circulation pump, as follows:
wherein x and y represent the rotational speed and the volume flow rate after data normalization processing, muNAnd muWRepresenting the mean value, σ, of the rotational speed and the volume flow of the sample pointNAnd σWRepresenting a sampleThe standard deviation of the rotational speed and the volume flow of a point,
based on sample points in a characteristic curve of the hydrogen circulating pump, fitting the relationship among the volume flow, the rotating speed and the outlet pressure of the hydrogen circulating pump by using a binary quadratic polynomial, wherein the relationship is as follows:
Pout＝a0+a1x+a2y+a3x2+a4xy+a5y2 (1-3)
wherein, PoutRepresents the outlet pressure of the hydrogen circulation pump, a0,a1,a2,a3,a4,a5Respectively representing polynomial fitting coefficients;
(2) constructing an inertia link model of a driving motor
The inertia link calculation expression of the hydrogen circulating pump is as follows:
wherein, ω isblRepresenting the angular velocity of the rotor, t representing time, JblRepresenting the moment of inertia, tau, of the rotor part of the hydrogen circulation pumpbmRepresenting the driving torque, tau, of the driving motorblThe load torque of the hydrogen circulation pump is indicated,
the drive torque calculation expression of the drive motor is as follows:
wherein eta isbmIndicating the efficiency of the drive motor, RbmDenotes the drive motor resistance, κtDenotes the moment constant, κ, of the drive motorvRepresenting the voltage constant, v, of the drive motorbmIndicating the control voltage, omega, of the drive motorblWhich is indicative of the angular velocity of the rotor,
the calculation expression of the load moment of the hydrogen circulating pump is as follows:
wherein p isblRepresents the power of the hydrogen circulation pump, cp,inDenotes the specific heat capacity at constant pressure, T, of the inlet gasinIndicating the temperature, η, of the intake airblIndicates the efficiency of the hydrogen circulation pump, Pout、PinRespectively representing the pressure at the outlet and inlet of the hydrogen circulation pump, gammag,inDenotes the specific heat ratio coefficient of the inlet gas, minWhich represents the mass flow rate of the inlet gas,
the calculation expression of the constant pressure specific heat capacity and specific heat ratio coefficient of the inlet gas is as follows:
wherein,
cp,vand
respectively represent the specific heat capacity at constant pressure of hydrogen, water vapor and nitrogen,
γvand
respectively represent hydrogen and waterThe specific heat ratio coefficient of the vapor and the nitrogen,
yv,inand
respectively represents the mass fractions of hydrogen, water vapor and nitrogen in the inlet gas,
the calculation expression of the outlet gas temperature after being compressed by the hydrogen circulating pump is as follows:
wherein, ToutWhich is indicative of the temperature of the outlet gas,
(3) PID control model for constructing control voltage of driving motor
When the rotating speed of the hydrogen circulating pump is stable, the driving torque is equal to the load torque of the hydrogen circulating pump, then the stable control voltage of the driving motor is solved, and the calculation expression is as follows:
and comparing the actual outlet pressure with the target outlet pressure, and taking the difference value of the actual outlet pressure and the target outlet pressure as the deviation amount of PID control, thereby calculating the variation of the control voltage:
e(t)＝Ptar-Pout (3-2)
vbm,new＝vbm+u(t) (3-4)
wherein, PtarAnd PoutAre respectively provided withRepresenting target and actual outlet pressures, e (t) representing the deviation, Kp、KI、KDRespectively representing proportional, integral and differential coefficients, u (t) representing the variation of the control voltage, vbm,newThe control voltage of the driving motor after PID control is represented;
correcting the volume flow of the inlet of the hydrogen circulating pump and the rotating speed at the current moment, matching with a characteristic curve of the hydrogen circulating pump to obtain the current outlet pressure, comparing the current outlet pressure with the target outlet pressure, taking the difference value of the current outlet pressure and the target outlet pressure as the deviation value of PID control, calculating the variation of the control voltage, obtaining a new rotating speed according to an inertia link model, and finally recalculating in combination with the volume flow of the inlet in such a reciprocating cycle manner to enable the actual outlet pressure to gradually approach or even be equal to the target outlet pressure.
2. The transient modeling method for a hydrogen circulation pump in a fuel cell system according to claim 1, characterized in that: the hydrogen circulating pump is a centrifugal hydrogen circulating pump.
3. The transient modeling method for a hydrogen circulation pump in a fuel cell system according to claim 1, characterized in that: the PID control refers to proportional integral derivative control.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106848351A (en) * | 2016-12-26 | 2017-06-13 | 天津大学 | The method that proton exchange film fuel battery performance forecast model is set up |
| CN106951677A (en) * | 2017-02-20 | 2017-07-14 | 天津大学 | The method that Proton Exchange Membrane Fuel Cells transient process model is set up |
| CN111613815A (en) * | 2020-05-26 | 2020-09-01 | 东风汽车集团有限公司 | Fuel cell hydrogen circulation system and control method thereof |
| CN112635802A (en) * | 2020-12-24 | 2021-04-09 | 海卓动力(青岛)能源科技有限公司 | Hydrogen control method for vehicle proton exchange membrane fuel cell system |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106848351A (en) * | 2016-12-26 | 2017-06-13 | 天津大学 | The method that proton exchange film fuel battery performance forecast model is set up |
| CN106951677A (en) * | 2017-02-20 | 2017-07-14 | 天津大学 | The method that Proton Exchange Membrane Fuel Cells transient process model is set up |
| CN111613815A (en) * | 2020-05-26 | 2020-09-01 | 东风汽车集团有限公司 | Fuel cell hydrogen circulation system and control method thereof |
| CN112635802A (en) * | 2020-12-24 | 2021-04-09 | 海卓动力(青岛)能源科技有限公司 | Hydrogen control method for vehicle proton exchange membrane fuel cell system |
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