A kind of electric automobile power battery for considering battery life participates in power system frequency modulation and builds
Mould method
Technical field
The present invention relates to electric automobile power battery participates in power system frequency modulation modeling method.
Background technology
Electric automobile is with electrical network interaction technique (V2G technologies) as the important step of intelligent grid, and its technological subject is electronic
Automobile is because quick response and charge and discharge mode and the characteristic deposited, the effect is significant in power system frequency is adjusted.And participate in adjusting
It is taken in small doses at short intervals during business, frequently discharge and recharge can cause irreversible infringement to the physical arrangement of electric automobile power battery, and then
Reduce its service life.Battery life is the principal element for restricting Development of Electric Vehicles.Therefore, battery is being considered
Under the premise of, to set up electric automobile power battery and participate in power system frequency modulation model, analysis electric automobile power battery participates in electric power
System frequency modulation effect and the impact to its battery life, the development to promoting ev industry is significant.
Existing battery loss model does not account for influence factor and the rule of batteries of electric automobile cycle life, it is impossible to complete
Face describes battery in the different phase for participating in power system frequency modulation, the infringement suffered by battery life;Existing frequency modulation model is only
Comprising conventional power units such as steam turbine, the hydraulic turbines, do not consider under the overall situation of V2G technologies development, electric powered motor electricity
Pond participates in the effect of power system frequency modulation.
The content of the invention
The present invention is not account for the impact of batteries of electric automobile cycle life and electronic vapour to solve prior art
Car trip state it is participated in power system frequency modulation impact problem, and propose a kind of consideration battery life electric automobile
Electrokinetic cell participates in power system frequency modulation modeling method.
A kind of electric automobile power battery for considering battery life participates in power system frequency modulation modeling method according to the following steps
Realize:
Step one:The power system frequency modulation model containing electric automobile power battery module is set up, electric powered motor is exported
Battery power curve;
Step 2:Determine electric automobile networking ratio;
Step 3:The frequency modulation frequency modulation channel power perunit pole of power system frequency modulation model in step one is determined according to step 2
Limit value;
Step 4:Electric automobile power battery life consumption model is set up, and calculates electric automobile power battery and participate in adjusting
Capacitance loss and ceiling capacity skew after frequency.
Invention effect:
The present invention considers electric automobile trip state and participates in power system frequency modulation effect to electric automobile power battery
Affect, and participate in impact of the power system frequency modulation to the electric automobile power battery life-span, establish the electricity for considering battery life
Electrical automobile electrokinetic cell participates in power system frequency modulation model, and power system frequency modulation is participated in electric automobile from system end and battery-end
Effect is estimated.Power system chirping strategies are participated in by modeling method of the present invention to electric automobile to select, can be with
Battery capacity loss is dropped to into 0.0113% by 0.0158%, i.e. most senior general's battery capacity loss reduces by 28.5%.
Description of the drawings
Fig. 1 is single regional power system frequency modulation illustraton of model;
Fig. 2 is electric automobile power battery frequency modulation frequency modulation channel pattern figure;
Fig. 3 is private car trip proportion moment scattergram;
Fig. 4 is private car trip distance ratio scattergram;
Fig. 5 is private car trip average speed moment scattergram;
Fig. 6 is electric automobile trip proportion overview logic diagram;
Fig. 7 is electric automobile networking ratio scattergram;
Fig. 8 is electric automobile frequency modulation frequency modulation channel power ultimate value curve chart;
Fig. 9 is actual daily load curve figure certain electrical network one day;
Figure 10 predicts daily load curve figure one day for certain electrical network;
Figure 11 is electric automobile power battery primary frequency modulation strategy implementation method figure;
Figure 12 is the energy curves figure of power battery module group 1;
Figure 13 is the energy curves figure of power battery module group 2;
Figure 14 is system frequency deviation curve chart;
Figure 15 is electric automobile power battery frequency modulation frequency modulation passage limit value figure;
Figure 16 is that electrokinetic cell participates in frequency modulation frequency modulation system frequency difference curve chart;
Figure 17 is electrokinetic cell energy excursion curve chart.
Specific embodiment
Specific embodiment one:A kind of electric automobile power battery for considering battery life participates in the modeling of power system frequency modulation
Method is comprised the following steps:
Step one:The power system frequency modulation model containing electric automobile power battery module is set up, electric powered motor is exported
Battery power curve;
Step 2:Determine electric automobile networking ratio;
Step 3:The frequency modulation frequency modulation channel power perunit pole of power system frequency modulation model in step one is determined according to step 2
Limit value;
Step 4:Electric automobile power battery life consumption model is set up, and calculates electric automobile power battery and participate in adjusting
Capacitance loss and ceiling capacity skew after frequency.
Specific embodiment two:Present embodiment from unlike specific embodiment one:Set up in the step one and contain
The detailed process of the power system frequency modulation model of electric automobile power battery module is:
Step is one by one:Frequency modulation frequency modulation principle is unified based on power train, single regional power system frequency modulation model, such as Fig. 1 is set up
It is shown;
Containing primary frequency modulation passage and frequency modulation frequency modulation passage in power system, the transmission function of primary frequency modulation passage isGiS () is the transmission function of each unit, aiFor each power of the assembling unit share coefficient, δiFor each unit difference coefficient;Two
The transmission function of secondary FM channel is K (s), and K (s) is PI control functions;System is output as the frequency departure △ of current system
f;RiTo participate in the power partition coefficient of the unit of frequency modulation frequency modulation, Ta∑For regional power grid equivalent time constant, β∑For regional power grid
Equivalent self-balancing coefficient, τ is zero-order holder time delay.
Step one two:Electric automobile power battery module is added into single regional power system frequency modulation model;
Power battery module is described using first order inertial loop, and its transmission function is:
Wherein described KEVFor electric automobile work(frequency characteristic coefficient, TEVFor power battery module time constant, s is La Pula
This operator, GEVS () is the transmission function of power battery module;
It is a that electric automobile power battery participates in the transmission function of primary frequency modulation passage during power system frequency modulation modelEVGEV
(s), aEVThe power fraction coefficient shared by power battery module;Frequency modulation frequency modulation passage is secondary in single regional power system frequency modulation model
Power perunit ultimate value is increased on the basis of FM channel.Electric automobile power battery participates in power system frequency modulation frequency modulation passage
Logic diagram is as shown in Figure 2.
Other steps and parameter are identical with specific embodiment one.
Specific embodiment three:Present embodiment from unlike specific embodiment one or two:In the step 2 really
The detailed process for determining electric automobile networking ratio is:
The present invention considers the trip feature of electric automobile cluster determining electric automobile power battery frequency modulation frequency modulation passage
Perunit limit value.Private car trip proportion moment, distance and velocity distribution curve are obtained according to statistical result.In the five rings of Beijing
The statistical result of floating vehicle data survey is respectively as shown in Fig. 3, Fig. 4, Fig. 5.
For a certain moment t, automobile user trip proportion is designated as P (t).Any time, electric automobile trip
Range distribution is as shown in Figure 4.When electric automobile trip distance is longer, restricted by travel speed, it is impossible in a hour
Complete corresponding mileage.Therefore, at subsequent time (t+1), it is still in transport condition, it is impossible to be connected with electrical network.But just when (t+1)
For quarter, its operating range changes.And still moment t subsequent time run electric automobile in trip distance, OK
After sailing the renewal of the states such as speed, will be superimposed with the electric automobile at (t+1) moment trip state and ratio, it is electronic so as to obtain
The overview that automobile continuously runs.Specific procedure logic diagram is as shown in Figure 6.
Wherein s (t) refers to (1h) in unit interval, and at a time under average speed, electric automobile can be travelled
Ultimate range.And according to Fig. 4, d (t) refers to that electric automobile inscribes the row drawn up row distance and draw up this distance of row at this
Car ratio.For example, when electric automobile is when being 40km at moment t maximum displacements s (t), electricity of d (t) the middle rolling cars distance less than 40km
Electrical automobile is believed that within this period can switch to halted state by transport condition, network operation in parallel participates in system frequency modulation.And go
Electric automobile of the car distance more than 40km will be continued to run with subsequent time, and it is also needed in the distance for travelling and shared automobile group
Ratio will be updated in the state parameter of subsequent time.
On the basis of the above, by the way that to whole day 24 hours, electric automobile group use state carried out rolling renewal, you can obtain
Whole day not in the same time under, access electrical network electric automobile ratio change curve, as shown in Figure 7.
Step 2 one, setting initial time value t=1, according to electric automobile trip speed v (t), trip proportion P of statistics
T the statistical result of () and trip distance d (t) obtains the speed in electric automobile 1 hour;
Step 2 two, speed of service v (t) for obtaining electric automobile;
Step 2 three, maximum displacement s (t) calculated in electric automobile 1 hour;
Step 2 four, as t=1 electric automobile operation ratio be P (t);When t is more than 1, the operating ratio of electric automobile
Example is P (t)+Pa.sum. (t);
Step 2 five, two to the step 2 four of iteration execution step 2, until t terminates to obtain electric automobile operation when being more than 24
Proportional curve figure, networking ratio=1-operation ratio.
Other steps and parameter are identical with specific embodiment one or two.
Specific embodiment four:Unlike one of present embodiment and specific embodiment one to three:The step 2
The process of asking for of Pa.sum. (t) is specially in four:
Ratio Ps.d. (t) of step (1), trip distance d (t) of counting statistics data acquisition more than s (t);
Driving ratio Pa.d. (t+1) outside step (2), counting statistics data, Pa.d. (t+1)=P (t) Ps.d. (t);
Step (3), renewal d (t+1) are d (t)-s (t);D (t+1) is brought in step (1) again, iteration execution step
(1) and step (2), Pa.d. (t+2) is obtained;Until d (t+m) terminates less than s (t+m);
Step (4), t hours, total driving ratio is outside statistical data
Other steps and parameter are identical with one of specific embodiment one to three.
Specific embodiment five:Unlike one of present embodiment and specific embodiment one to four:The step 3
The middle frequency modulation frequency modulation channel power perunit ultimate value for determining power system frequency modulation model in step one is specially:
Due to electric automobile power battery itself capacity limit, there is maximum output limit in it to the frequency modulation power that electrical network is provided
Value, according to the electric automobile networking ratio distribution curve obtained in step 2, with reference to battery types and electric automobile scale,
The output limit that electrokinetic cell is reached in electrical network provided auxiliary frequency modulation service can be calculated, as shown in Figure 8.
The mark of frequency modulation frequency modulation channel power perunit ultimate value=electric automobile networking ratio × batteries of electric automobile total capacity
One value.
Other steps and parameter are identical with one of specific embodiment one to four.
Specific embodiment six:Unlike one of present embodiment and specific embodiment one to five:The step 4
It is middle set up electric automobile power battery life consumption model detailed process be:
By taking lithium iron phosphate dynamic battery as an example, for cycle-index, ambient temperature, charge-discharge magnification and discharge and recharge depth
The factor of four aspects of degree is analyzed, and battery capacity is lost as the Main Basiss for weighing battery life decay, sets up and uses
In the battery module of electric vehicle Cycle life prediction model of frequency modulation service;
If the parameter of energy variation is A in cyclic processh;
Ah=DOD × n × Cap (2)
Cap is the capacity (AH) of set of cells in formula, and DOD is the depth of discharge (%) of set of cells, and n is electrokinetic cell circulation time
Number;
Based on Arrhenius formula, obtain battery capacity and lose with the relation of each electric stress factor:
In formula B be the preceding paragraph factor, EaFor reaction activity, its value is 31500Jmol-1, T is set of cells place environment
Thermodynamic temperature (K), R is gas constant, and its value is 8.314J (mol × K)-1, z is energy equation factor, and value is 0.55-
0.56;
When at set of cells place, thermodynamic temperature T of environment is 298K, preceding paragraph factor B is between discharge-rate C_Rate
Relational expression:
Other steps and parameter are identical with one of specific embodiment one to five.
Specific embodiment seven:Unlike one of present embodiment and specific embodiment one to six:The step 4
The middle capacitance loss calculated after electric automobile power battery participation frequency modulation and the detailed process of ceiling capacity skew are:
The electric automobile power battery power curve obtained in step one is integrated through integrator, electronic vapour is obtained
Car electrokinetic cell energy curves, according to energy curves ceiling capacity skew is obtained;Energy curves are input to
Battery life loss model, calculates electric automobile power battery and participates in after power system frequency modulation according to formula (2) to formula (4)
Capacitance loss.
Other steps and parameter are identical with one of specific embodiment one to six.
Embodiment one:
Emulated with the service data that certain electrical network is actual a day, load data is as shown in Figure 9 and Figure 10.With model
As a example by the electric automobile parameter of " Roewe E50 ", its parameter is as shown in table 1.
The Roewe E50 vehicle relevant parameters of table 1
Step 1:The power system frequency modulation model that module containing electric automobile power battery is participated in is set up, wherein battery module is passed
Delivery function is:
Step 2:Determine that electric automobile participates in power system chirping strategies.
In the present embodiment, electric automobile power battery is only involved in power system primary frequency modulation.Electric automobile participates in power train
Unified time chirping strategies are as follows:Electric automobile power battery module is divided into two groups, and group 1 is participating in system primary frequency modulation process
In, first in charged state, group 2 is in discharge condition.Often through 60 minutes, two groups of charging and discharging states are exchanged.
In Matlab/Simulink emulation platforms, by measure battery module of electric vehicle is divided into into two groups, sets arteries and veins
The cycle for rushing generator is 3600s, when pulse signal is more than zero, to the electrokinetic cell of group 1 positive signal is input into, and now organizes 1
Electrokinetic cell be in charged state, to the negative signal of the electrokinetic cell input of group 2, now the electrokinetic cell of group 2 is in electric discharge
State;Conversely, when pulse signal is less than zero, group 1 is in discharge condition, and input signal is negative value, group 2 is in charged state,
Input signal be on the occasion of.With comparator determination frequency deviation signal whether zero passage.When frequency departure signal is for just and set of cells is defeated
The set of cells for entering signal for timing in charged state is started to charge up, when frequency departure signal is less than zero and is input into the letter of set of cells
Number for it is negative when, the set of cells in discharge condition is started working, and the conversion of two Battery pack charging and discharging states is realized with this, only with
Pulse signal is illustrated in case of being more than zero to model, and concrete steps are as shown in figure 11.
Step 3:Set up electric automobile power battery life consumption model.By taking lithium iron phosphate dynamic battery as an example, for following
Ring number of times, ambient temperature, the factor of four aspects of charge-discharge magnification and depth of discharge are analyzed, and battery capacity is damaged
Lose as the Main Basiss for weighing battery life decay, set up pre- for the battery module of electric vehicle cycle life of frequency modulation service
Survey model;
Being introduced into can reflect the parameter A of energy variation in cyclic processh, provide definition:
Ah=DOD × n × Cap (2)
Cap is the capacity (AH) of set of cells in formula, and DOD is the depth of discharge (%) of set of cells, and n is electrokinetic cell circulation time
Number;
It is to provide battery capacity to lose with the relation of each electric stress factor with Arrhenius formula:
In formula B be the preceding paragraph factor, EaFor reaction activity, its value is 31500Jmol-1, T is set of cells place environment
Thermodynamic temperature (K), R is gas constant, and its value is 8.314J (mol × K)-1, z is energy equation factor, and value is 0.55-
0.56;
When ambient temperature T is 298K, preceding paragraph factor B is with the relational expression between discharge-rate C_Rate
Emulated on Matlab/Simulink platforms, as a result as shown in Figure 12, Figure 13 and Figure 14.
Under calculating the strategy, the loss of electric automobile power battery module capacity is 0.0119%, and ceiling capacity skew is
1.85%.
Embodiment two:
Emulated with the service data that certain electrical network is actual a day, load data is as shown in Figure 9 and Figure 10.With model
As a example by the electric automobile parameter of " Roewe E50 ", its parameter is as shown in table 1.
The Roewe E50 vehicle relevant parameters of table 1
Step 1:The power system frequency modulation model that module containing electric automobile power battery is participated in is set up, wherein battery module is passed
Delivery function is:
Step 2:Determine that electric automobile participates in power system chirping strategies.
Electric automobile participation power system frequency modulation frequency modulation strategy is as follows in this strategy:System frequency deviation signal, first via
PID control link, generates corresponding power control signal.When power control signal exceedes setting signal marginal value, electronic vapour
In the presence of power control signal, the frequency modulation power needed for output system reaches power system frequency modulation to car power battery module
Purpose.
Wherein battery capacity share is 0.02, and zero-order holder time delay is set to 15s, electric automobile power battery
PID channel parameters are set to 0.15/0.6/0, and PID signal response marginal value is set to 0.002, the electricity according to determined by step 3
Electrical automobile electrokinetic cell frequency modulation frequency modulation limit value is as shown in figure 15.
Step 3:Set up electric automobile power battery life consumption model.By taking lithium iron phosphate dynamic battery as an example, for following
Ring number of times, ambient temperature, the factor of four aspects of charge-discharge magnification and depth of discharge are analyzed, and battery capacity is damaged
Lose as the Main Basiss for weighing battery life decay, set up pre- for the battery module of electric vehicle cycle life of frequency modulation service
Survey model;
Being introduced into can reflect the parameter A of energy variation in cyclic processh, provide definition:
Ah=DOD × n × Cap (2)
Cap is the capacity (AH) of set of cells in formula, and DOD is the depth of discharge (%) of set of cells, and n is electrokinetic cell circulation time
Number;
It is to provide battery capacity to lose with the relation of each electric stress factor with Arrhenius formula:
In formula B be the preceding paragraph factor, EaFor reaction activity, its value is 31500Jmol-1, T is set of cells place environment
Thermodynamic temperature (K), R is gas constant, and its value is 8.314J (mol × K)-1, z is energy equation factor, and value is 0.55-
0.56;
When ambient temperature T is 298K, preceding paragraph factor B is with the relational expression between discharge-rate C_Rate
Emulated on Matlab/Simulink platforms, as a result as shown in Figure 16 and Figure 17.
Through calculating, electrical automobile power battery module life loss is 0.0215% under the strategy, and ceiling capacity skew is
14.62%.
Embodiment three:
Emulated with the service data that certain electrical network is actual a day, load data is as shown in Figure 9 and Figure 10.With model
As a example by the electric automobile parameter of " Roewe E50 ", its parameter is as shown in table 1.
The Roewe E50 vehicle relevant parameters of table 1
In the present embodiment, there are four kinds of discharge and recharge strategies:
Strategy 1:During system primary frequency modulation is participated in, power battery module can freely turn between charge and discharge state
Change;
Strategy 2:Electric automobile power battery module is divided into three groups, and group 1 is first during system primary frequency modulation is participated in
In charged state, when energy content of battery change exceedes gross energy 1.85%, switch to discharge condition.Group 2 is similar to group 1, but first
In discharge condition.Group 3 will participate in system frequency modulation when will be in identical charging and discharging state with group 2 organizing 1.Wherein, group 1 and group 2
Battery capacity is the 40% of electrokinetic cell total capacity, organizes 3 capacity for the 20% of electrokinetic cell total capacity;
Strategy 3:Electric automobile power battery module is divided into two groups, and group 1 is first during system primary frequency modulation is participated in
In charged state, group 2 is in discharge condition.Often through 60 minutes, two groups of charging and discharging states are exchanged;
Strategy 4:Electric automobile power battery module is divided into two groups, organizes 1 during system primary frequency modulation is participated in, only
It is charged, group 2 is only discharged.
Step 1:The power system frequency modulation model that module containing electric automobile power battery is participated in is set up, wherein battery module is passed
Delivery function is:
Step 2:Set up electric automobile power battery life consumption model.By taking lithium iron phosphate dynamic battery as an example, for following
Ring number of times, ambient temperature, the factor of four aspects of charge-discharge magnification and depth of discharge are analyzed, and battery capacity is damaged
Lose as the Main Basiss for weighing battery life decay, set up pre- for the battery module of electric vehicle cycle life of frequency modulation service
Survey model;
Being introduced into can reflect the parameter A of energy variation in cyclic processh, provide definition:
Ah=DOD × n × Cap (2)
Cap is the capacity (AH) of set of cells in formula, and DOD is the depth of discharge (%) of set of cells, and n is electrokinetic cell circulation time
Number;
It is to provide battery capacity to lose with the relation of each electric stress factor with Arrhenius formula:
In formula B be the preceding paragraph factor, EaFor reaction activity, its value is 31500Jmol-1, T is set of cells place environment
Thermodynamic temperature (K), R is gas constant, and its value is 8.314J (mol × K)-1, z is energy equation factor, and value is 0.55-
0.56;
When ambient temperature T is 298K, preceding paragraph factor B is with the relational expression between discharge-rate C_Rate
Power battery module capacity and energy variation numerical value are as shown in table 2 under through calculating Different Strategies.
Power battery module capacity and energy variation under the Different Strategies of table 2
Analyze by the method for the invention, pay the utmost attention to the capacitance loss of battery, selection strategy 2 is used as electric powered motor
Battery participates in power system chirping strategies, battery capacity loss can be dropped to into 0.0113% by 0.0158%, i.e. most senior general
Battery capacity loss reduces by 28.5%.