Disclosure of Invention
The purpose is as follows: in order to overcome the defects in the prior art, the invention provides an electric vehicle ordered charging control method based on an artificial fish swarm algorithm, so as to realize safe and stable operation of a power grid and minimum charging cost of a user.
The technical scheme is as follows: in order to solve the technical problems, the technical scheme adopted by the invention is as follows:
an electric automobile ordered charging control method based on an artificial fish swarm algorithm comprises the following steps:
step 1: construction of a scene optimization model G (t)opt),G(topt) The formula is as follows:
wherein, F1Representing the charge of the user during disordered charging, F2Representing the grid peak-to-valley difference during disordered charging, F1optRepresenting the charge of the user during the ordered charging, F2optRepresenting the grid peak-to-valley difference, λ, during ordered charging1And λ2Weighting coefficients representing the respective objective functions;
step 2: using minG (t)
opt) As an optimization target of the scene optimization model, the optimized charging period to is solved
ptOf (2) an optimal solution t
bestCombined with charging period t
cOptimizing by using an artificial fish swarm algorithm to obtain a final charging time interval
And step 3: according to the final charging period
And arranging the electric automobile to be charged in order.
Preferably, the charging period tcThe calculation formula is as follows:
tback<tc<tstart
wherein, tcDenotes a chargeable period, tcWhen the time is 1, the electric vehicle is charging at the moment, tcWhen the time is equal to 0, the electric automobile is not charged at the moment; t is tcShould be in the range of tstartAnd tbackT isstartAt the time of trip, tbackIs the return time; t is t0Represents the starting time of the charging in stages; t ischargeIndicating a periodic charging period.
Preferably, the user charging fee F in the disordered charging1The calculation formula is as follows:
wherein N is the total number of electric vehicles in the region; t is tbackTo return to time, tstartAt the time of trip, tcDenotes a chargeable period, PevTo charging power, ccRepresents the electricity price at the charging time;
the power grid peak-valley difference F during the disordered charging2The calculation formula is as follows:
F2=Lmax-Lmin
wherein ltRepresenting the basic load of residents at the time t;
user charging fee F during ordered charging1optThe calculation formula is as follows:
wherein N is the total number of electric vehicles in the region; t is tbackTo return to time, tstartAt the time of trip, toptRepresents an optimized charging period, PevTo charging power, ccRepresents the electricity price at the charging time;
the difference F between the peak and the valley of the power grid during the orderly charging2optThe calculation formula is as follows:
F2=Lmax-Lmin
wherein ltRepresenting the resident base load at time t.
As a preferred scheme, the optimization of the artificial fish swarm algorithm comprises the following specific steps:
2.1 pairs of t
cPerforming a random action RB to obtain an initial one
The RB calculation formula is as follows:
wherein step represents the moving step length, rand represents the random variable, and step-rand represents the randomly extracted moving step length;
2.2 after the above-mentioned operations
Executing the FB of foraging behavior to obtain
The FB calculation formula is as follows:
G(t
c)、
is G (to)
pt) To in
ptBy t
c、
Alternative calculation is carried out;
2.3 after the above-mentioned operations
Value to t'
cAnd to new t'
cPerforming clustering action SB to obtain
The SB calculation is as follows:
wherein R isvFor a dispatching range, m is the number of cars being charged in the dispatching range, tiCharging an ith automobile, wherein N is the total number of electric automobiles in the area; sigma is a self-defined crowding factor; g (t)k)、G(t′c) Respectively combine G (t)opt) T in (1)optBy tk、t‘cAlternative calculation is carried out;
2.4 after the above-mentioned operations
Assigned value to t'
cAnd for new t "
cExecuting the rear-end collision behavior REB to obtain
REB calculation formula is as follows:
wherein, tbestRepresenting an optimized target minG (t) within a scheduling scopeopt) Middle toptOf G (t)best)、G(t″c) Respectively combine G (t)opt) T in (1)optBy tbest、t”cAnd alternative calculation.
Preferably, λ is1+λ2=1。
Preferably, P isev·tcThe constraints of (2) are as follows:
wherein ltRepresenting the basic load of the residents at time t, t being tstartAnd tbackAll time in between; pMTo representThe maximum capacity of the transformer; mu represents the maximum capacity threshold multiple which can be carried by the transformer; t is tcDenotes a chargeable period, PevIs the charging power; and N is the total number of electric automobiles in the region.
Preferably, t isstartThe calculation formula of (a) is as follows:
wherein, tstartTo the time of trip, musExpected value, σ, of trip timesVariance of time of trip, fs(tstart) Is a probability density function of the travel time distribution.
Preferably, t isbackThe calculation formula of (a) is as follows:
wherein, tbackTo return to time, μeTo return the expected value of the time of day, σeAs variance of the return time, fe(tback) Is a probability density function of the distribution of the return moments.
Preferably, T ischargeThe calculation formula of (a) is as follows:
therein, SOC0Is the initial state of charge rate of the electric vehicle, Q is the battery capacity, PevIs the charging power.
Preferably, T ischargeThe constraints of (2) are as follows:
wherein, Tn,chargeRepresenting the charging time of the nth electric vehicle; pevRepresenting the charging power of the electric vehicle; qnRepresenting the battery capacity of the nth electric vehicle; η represents the charging efficiency; SOCn,eIndicates that the nth electric vehicle is at tstartUser desired SOC value at time; SOCn,0Indicates that the nth electric vehicle is at tbackInitial SOC value at time.
Has the advantages that: the invention provides an electric vehicle ordered charging control method based on an artificial fish swarm algorithm, which optimizes the charging behavior of electric vehicles in residential communities. The basic idea is that firstly, a disordered charging model is established based on a Monte Carlo method; secondly, establishing a charging constraint model according to a charging scene of the electric automobile; then, the problems of safe and stable operation of a power grid and the charging cost of a user are comprehensively considered, and an ordered charging optimization scheduling scheme is provided; and finally, constructing a residential community scene optimization model, and finishing scheduling optimization of the electric automobile by using an artificial fish swarm algorithm. The method can scientifically guide the charging behavior of the electric automobile, has important significance for optimizing and scheduling the large-scale charging behavior of the electric automobile, and has strong universality and practicability.
Detailed Description
The present invention will be further described with reference to the following examples.
As shown in fig. 1, an electric vehicle ordered charging control method based on an artificial fish swarm algorithm includes the following steps:
step 1, establishing a disordered charging model based on a Monte Carlo method. The chaotic charging model is as follows,
1.1 electric automobile travel time model
Wherein, tstartTo the time of trip, musExpected value, σ, of trip timesVariance of time of trip, fs(tstart) Is a probability density function of the travel time distribution.
1.2 electric vehicle Return time model
Wherein, tbackTo return to time, μeTo return the expected value of the time of day, σeAs variance of the return time, fe(tback) Is a probability density function of the distribution of the return moments.
1.3 electric automobile is long model during charging
Therein, SOC0Is the initial state of charge rate of the electric vehicle, Q is the battery capacity, PevFor charging power, TchargeIs the charging period.
1.4 relationship between electric vehicle return time and charging start time
The charging start time and the return time of the vehicle are considered to be approximately the same
tstchar=tback (4)
Wherein, tstcharTo the charging start time, tbackIs the return time.
And 2, establishing a charging constraint model according to the charging scene of the electric automobile. The charging constraint model is as follows,
2.1 Total Charge constraint
The charging load distributed by the charging pile to the electric vehicle should satisfy the State of Charge (SOC) of the battery expected by the user when charging is completed.
Therein, SOCn,eIndicates that the nth electric vehicle is at tstartUser desired SOC value at time, tstartExtracting by the travel time model in the step 1.1; SOCn,0Indicates that the nth electric vehicle is at tbackInitial SOC value at time, i.e. tstcharInitial SOC value at time, tbackExtracted from the return time model of step 1.2; t isn,chargeThe charging time length of the nth electric automobile is represented and determined by the charging time length model in the step 1.3; η represents the charging efficiency; pevIs the charging power; qnThe battery capacity of the nth electric vehicle.
2.2 electric vehicle charging duration constraint
Wherein, Tn,chargeThe charging time length of the nth electric automobile is represented and determined by the charging time length model in the step 1.3; pevRepresenting the charging power of the electric vehicle; qnThe battery capacity of the nth electric vehicle is shown.
2.3 electric vehicle chargeable time period constraint
The chargeable period of the electric automobile is distributed in any period between the return time and the departure time of the electric automobile.
tback<tc<tstart (8)
Wherein, tcDenotes a chargeable period, tcWhen the time is 1, the electric vehicle is charging at the moment, tcWhen the value is 0, the electric vehicle is not charged at that time. t is tcShould be in the range of tstartAnd tbackT isstartAnd tbackThe determination is carried out by steps 1.1 and 1.2 respectively; t is t0Indicating the start of the staged charging, the initial value of which is the start of charging t in step 1.4stchar;TchargeThe representative periodic charge period is determined by the charge period model of step 1.3.
2.4 Charge continuity constraints
Frequent opening and stopping fills the life-span that electric pile can loss car battery and fill electric pile components and parts, consequently need set for and fill the minimum interval time that stops of electric pile.
Wherein, tinterFor the set minimum interval time of starting and stopping the charging pile, the charging starting time needs to be reduced due to the calculation of the continuous working time, so the t is calculatedinterA subtraction of 1 is required.
2.5 Peak load constraint
The peak load requirement for electric vehicle charging is lower than the transformer capacity.
Wherein ltRepresenting the basic load of the residents at time t, t being tstartAnd tbackAll moments in between, tstartAnd tbackThe determination is carried out by steps 1.1 and 1.2 respectively; pMRepresents the maximum capacity of the transformer; mu represents the maximum capacity threshold multiple which can be carried by the transformer; pevIs the charging power; and N is the total number of electric automobiles in the region.
And step 3, comprehensively considering the problems of safe and stable operation of the power grid and the charging cost of a user, and providing an ordered charging optimization scheduling scheme. The specific ordered charging optimized scheduling scheme is as follows,
3.1 user Charge cost model
Wherein, Pev·tcThe constraint condition of the step 2.4 is satisfied; n is the total number of electric vehicles in the region; t is tbackTo return to time, tstartAt the time of trip, tstartAnd tbackThe determination is carried out by steps 1.1 and 1.2 respectively; c. CcRepresenting the electricity price at the moment of charging. Determining a user charge fee F based on this step1。
3.2 Power grid Peak-valley Difference model
F2=Lmax-Lmin (15)
Wherein, PevRepresenting the charging power of the electric vehicle, Pev·tcThe constraint condition of the step 2.4 is satisfied; l ismaxRepresents the highest peak load throughout the day; l isminRepresenting the lowest trough load throughout the day. Determining a grid peak-to-valley difference F based on the step2。
And 4, constructing a residential community scene optimization model, and finishing scheduling optimization of the electric automobile by using an artificial fish swarm algorithm.
4.1 scene optimization model
Wherein, G (to)pt) Optimizing the model for the scene; f1Representing the charge of the user during disordered charging, F2Representing the grid peak-to-valley difference during chaotic charging, the charging period t determined in step 2.3cDetermination of F by substitution into Steps 3.1 and 3.2, respectively1And F2,F1And F2The reference value used as the reference of the subsequent operation is fixed; f1optRepresenting the charge of the user during the ordered charging, F2optRepresenting the peak-valley difference of the power grid during ordered charging, and optimizing the charging time period t after each stepoptSubstituting into steps 3.1 and 3.2 respectively for tcDetermination of F1optAnd F2opt,F1optAnd F2optWill vary accordingly with the optimization process, toptDetermined by step 4.2; lambda [ alpha ]1And λ2Representing the weighting coefficients of the objective functions and satisfying lambda1+λ 21 is the requirement.
4.2 Charge period optimization
With G (t) in step 4.1opt) Min G (t)opt) As optimization objective of the model, the chargeable period t determined in step 2.3cOptimizing by using an artificial fish swarm algorithm, and taking a variable t as the optimized charging time periodoptDenotes, toptThe charge continuity constraint in step 2.5 should be met.
First for t
cPerforming a random action RB to obtain an initial one
The expression of RB is as follows,
wherein step represents the moving step length, rand represents the random variable, and step and rand describe the randomly extracted moving step length;
after the above operations are carried out
The foraging behaviour FB is executed,
G(t
opt) A scene optimization model, determined by step 4.1; g (t)
c)、
To step 4.1G (t)
opt) T in (1)
optBy t
c、
And alternative calculation.
After the above operations are carried out
Value to t'
cAnd to new t'
cThe clustering action SB is performed in such a way that,
wherein R isvFor a dispatching range, m is the number of cars being charged in the dispatching range, tiCharging an ith automobile, wherein N is the total number of electric automobiles in the area; sigma is a self-defined crowding factor; t is tkStoring the coordinates at the center of the primary scheduling range as temporary variables; g (t)opt) A scene optimization model, determined by step 4.1; g (t)k)、G(t′c) To respectively combine step 4.1G (t)opt) T in (1)optBy tk、t‘cAlternative calculation is carried out; RB stands for random behavior.
After the above operations are carried out
Assigned value to t'
cAnd for new t "
cThe rear-end collision action REB is executed,
wherein, tbestRepresenting an optimized target minG (t) within a scheduling scopeopt) Optimal solution, G (t)opt) A scene optimization model, determined by step 4.1; g (t)best)、G(t″c) To respectively combine step 4.1G (t)opt) T in (1)optBy tbest、t”cReplacing, and calculating; FB for foraging behavior.
The optimized charging time interval is obtained through the steps
Namely the ordered charging time period obtained by the ordered charging control method of the electric vehicle, the model optimization target realized by the ordered charging time period is stored in min G (t)
opt) In (1).
The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.