Electric vehicle charging station management method using blockchain
An electric vehicle charging station management method using a blockchain includes the following steps: obtaining a maximum charging and a discharging electric power of each electric vehicle in each to-be-planned pane; obtaining a charging and discharging electric power of each electric vehicle in each to-be-planned pane according to electric vehicle information corresponding to the electric vehicle, at least one purchase price, at least one winning bid price, and at least one maximum charging and discharging electric power; determining whether at least one overloaded pane is provided according to a total consumed electric power of a charging station in each time pane; and adjusting the purchase price of each overloaded pane when it is determined that at least one overloaded pane is provided and re-planning the charging and discharging electric power of the electric vehicle in each to-be-planned pane until it is determined that no overloaded pane is provided.
1 . An electric vehicle charging station management method using a blockchain, wherein charging and discharging management of a plurality of electric vehicles parked at a charging station is implemented by using a blockchain system, the blockchain system comprises a server and a plurality of charging piles disposed in the charging station and in communication with the server, each electric vehicle corresponds to a piece of electric vehicle information stored in a distributed ledger of the blockchain system and is electrically connected to a corresponding one of the plurality of charging piles, and the electric vehicle information comprises entry time, departure time, a battery state of charge at a time of entry, a current battery state of charge, an expected departure battery state of charge, a minimum battery state of charge, a maximum battery state of charge, and a full charge capacity of the electric vehicle,
the electric vehicle charging station management method using the blockchain specifically comprises the following steps:
(A) mapping the entry time and departure time of each electric vehicle to a corresponding time pane in a scheduling cycle, obtaining at least one time pane corresponding to the electric vehicle, obtaining at least one to-be-planned pane of the electric vehicle from the at least one time pane, and writing the at least one to-be-planned pane into the distributed ledger of the blockchain system, wherein the at least one to-be-planned pane comprises each time pane from a current time pane to a last time pane corresponding to the electric vehicle;
(B) obtaining a charging priority weight and a discharging priority weight of each electric vehicle in each to-be-planned pane according to a current time, the departure time of the electric vehicle, the current battery state of charge, the departure battery state of charge, the full charge capacity, and a maximum charging and discharging electric power provided by one of the plurality of the charging piles corresponding to the electric vehicle;
(C) obtaining and writing a maximum charging electric power and a maximum discharging electric power of each electric vehicle in each to-be-planned pane into the distributed ledger in the blockchain system according to a maximum power of a transformer of the charging station and the charging priority weight and the discharging priority weight of the electric vehicle in each to-be-planned pane;
(D) obtaining and writing, by using a nonlinear programming model, a charging electric power or discharging electric power of each electric vehicle in each to-be-planned pane into the distributed ledger of the blockchain system according to the electric vehicle information of the electric vehicle, at least one purchase price per unit electric power purchased by the charging station in each to-be-planned pane, at least one winning bid price paid by the charging station for participating in demand bidding in each to-be-planned pane, a payment price per unit electric power paid by the charging station in each to-be-planned pane, a penalty price per unit electric power paid by the charging station when the electric vehicle is not fully charged, and the maximum charging electric power and the maximum discharging electric power of the electric vehicle in each to-be-planned pane;
(E) obtaining a total consumed electric power of the charging station in each time pane from the current time pane to the last time pane of the scheduling cycle according to the charging electric power or discharging electric power of each electric vehicle in each to-be-planned pane;
(F) determining whether at least one overloaded pane is provided from the current time pane to the last time pane of the scheduling cycle according to the total consumed electric power of each time pane obtained in step (E) and a maximum supplied electric power of the charging station, wherein the total consumed electric power of the at least one overloaded pane is greater than the maximum supplied electric power of the charging station; and
(G) adjusting the purchase price of each of the at least one overloaded pane when it is determined that the at least one overloaded pane is provided, repeating steps (D) to (F) and at least part of step (G) until it is determined that no overloaded pane is provided, and writing a currently obtained charging electric power or discharging electric power of each electric vehicle in each to-be-planned pane into the distributed ledger of the blockchain system, and controlling the charging station to charge or discharge each electric vehicle in the current time pane according to the currently obtained charging electric power or discharging electric power corresponding to each electric vehicle in the current time pane.
2 . The electric vehicle charging station management method using the blockchain according to claim 1 , wherein in step (D), the objective function of the nonlinear programming model is expressed as:
min
Σ
t
K
n
(
C
EV
,
t
,
n
+
C
EV
,
t
,
n
feedback
-
I
t
,
n
DR
+
C
EV
,
n
deficiency
)
,
t∈K n ,
C EV,t,n =
-
p
n
,
t
EV
×
C
t
TOU
×Δt, where
p
n
,
t
EV
<0,
C
E
,
V
,
t
,
n
feedback
=
p
n
,
t
EV
×C feedback,t ×Δt, where
p
n
,
t
EV
>0,
I
t
,
n
DR
=
p
n
,
t
EV
×C DR,t ×Δt, where
p
n
,
t
EV
>0, and
C
EV
,
n
deficiency
=
C
EV
penalty
×
(
E
charge
,
n
EV
+
Σ
t
T
n
p
n
,
t
EV
×
Δ
t
)
,
where
E
charge
,
n
EV
+
Σ
t
T
n
p
n
,
t
EV
×Δt>0,
objective function constraints are as follows:
restriction condition 1:
❘
"\[LeftBracketingBar]"
p
n
,
t
EV
❘
"\[RightBracketingBar]"
≤
P
n
max
,
restriction condition 2:
p
EV
,
n
,
t
ch_max
≤
p
n
,
t
EV
≤
p
EV
,
n
,
t
disch_max
,
restriction condition 3:
SOC
EV
,
n
min
≤
SOC
n
,
t
+
1
EV
≤
SOC
EV
,
n
max
,
restriction condition 4:
SOC
n
,
t
+
1
E
V
=
SOC
n
,
t
E
V
-
P
n
,
t
E
V
×
Δ
t
B
Ev
,
n
c
a
p
,
where
P
n
,
t
E
V
≠
0
and
restriction condition 5:
SOC
n
,
max
(
T
n
)
EV
=
SOC
n
,
EV
final
,
where K n is a serial number set of all the to-be-planned panes for a n th electric vehicle, C EV,t,n is the cost to be paid by the charging station when the n th electric vehicle is charged in a t th time pane,
C
t
TOU
is a purchase price per unit electric power purchased by the charging station in the t th time pane,
p
n
,
t
EV
is a charging electric power or discharging electric power of the n th electric vehicle in the t th time pane when
p
n
,
t
EV
<0, or
p
n
,
t
EV
is a discharging electric power of the n th electric vehicle in the t th time pane when
p
n
,
t
EV
<0,
I
t
,
n
DR
is the electricity saving profit obtained by the charging station when the n th electric vehicle participates in the demand response in the t th time pane, C DR,t is a winning bid price at which the charging station participates in the demand bidding in the t th time pane,
C
EV
,
t
,
n
feedback
is a compensation fee to be paid by the charging station to the n th electric vehicle when the electric vehicle is discharged in the t th time pane, C feedback,t is a payment price per unit electric power that the charging station pays in the t th time pane,
C
EV
,
n
deficiency
is the penalty fee when the n th electric vehicle does not meet the expected departure penalty battery state of charge,
C
EV
penalty
is the penalty price per unit electric power for not fully charging,
E
charge
,
n
EV
is a total amount of electricity that the n th electric vehicle needs to obtain when the expected departure battery state of charge is met,
p
n
max
is a maximum charging and discharging electric power that can be provided by the charging pile corresponding to the n th electric vehicle,
p
EV
,
n
,
t
ch
_
max
is a maximum charging electric power of the n th electric vehicle,
p
EV
,
n
,
t
disch
_
max
is a maximum discharging electric power of the n th electric vehicle, T n is a serial number set of all time panes corresponding to the n th electric vehicle,
SOC
EV
,
n
min
is a minimum battery state of charge of the n th electric vehicle,
SOC
EV
,
n
max
is a maximum battery state of charge of the n th electric vehicle,
SOC
n
,
t
+
1
EV
is a battery state of charge of the n th electric vehicle in a t+1 th time pane,
SOC
n
,
max
(
T
n
)
EV
is a battery state of charge of the n th electric vehicle in a max (T n ) th time pane,
B
Ev
,
n
cap
is a full charge capacity of the battery of the n th electric vehicle,
SOC
n
,
EV
final
is a departure battery state of charge of the n th electric vehicle, and Δt is a time pane time.
3 . The electric vehicle charging station management method using the blockchain according to claim 1 , further comprising: (H) writing a demand response event comprising a demand response period and a corresponding winning bid price thereof into the distributed ledger of the blockchain system, wherein step (H) is performed before step (D).
4 . The electric vehicle charging station management method using the blockchain according to claim 1 , wherein the charging station is provided with an electric energy storage device, the electric energy storage device corresponds to electric energy information stored in the distributed ledger of the blockchain system and is electrically connected to a corresponding one of the plurality of charging piles, the electric energy information comprises an entry battery state of charge, a current battery state of charge, a minimum state of charge, a maximum state of charge, a full charge capacity, and a maximum charging and discharging electric power of the electric energy storage device, and before step (E) is performed, the electric vehicle charging station management method using the blockchain further comprises the following steps:
(I) treating all the time panes of the scheduling cycle as the time panes corresponding to the electric energy storage device, obtaining at least one to-be-planned pane of the electric energy storage device from the time pane corresponding to the electric energy storage device, and writing the at least one to-be-planned pane into the distributed ledger of the blockchain system, wherein the at least one to-be-planned pane of the electric energy storage device comprises each time pane from the current time pane to the last time pane corresponding to the electric energy storage device; and
(J) obtaining and writing, by using a nonlinear programming model, a charging electric power or discharging electric power of the electric energy storage device in each to-be-planned pane into the distributed ledger of the blockchain system according to the electric energy information corresponding to the electric energy storage device, a purchase price per unit electric power purchased by the charging station in each to-be-planned pane of the electric energy storage device, a winning bid price participating in the demand bidding, and a degradation cost consumed per unit electric power to charge or discharge the electric energy storage device,
wherein in step (E), the total consumed electric power of the charging station in each time pane from the current time pane to the last time pane of the scheduling cycle is obtained not only according to the charging electric power or discharging electric power of each electric vehicle in each to-be-planned pane but also the charging electric power or discharging electric power of the electric energy storage device in each to-be-planned pane.
5 . The electric vehicle charging station management method using the blockchain according to claim 4 , wherein the charging station is also provided with a solar module for generating electricity and a plurality of loads, and before step (E) is performed, the electric vehicle charging station management method further comprises:
(K) predicting, by using a power generation prediction model, a predicted solar electric power corresponding to the solar module in each time pane of the scheduling cycle according to a solar electric power generated by the solar module in each time pane of a previous scheduling cycle of the scheduling cycle and weather information corresponding to the scheduling cycle; and
(L) predicting, by using an electricity consumption prediction model, a predicted load power consumption electric power corresponding to the loads of the charging station in each time pane of the scheduling cycle according to a load power consumption electric power correspondingly consumed by the loads of the charging station in each time pane of the previous scheduling cycle and the weather information corresponding to the scheduling cycle,
wherein in step (E), the total consumed electric power of the charging station in each time pane from the current time pane to the last time pane of the scheduling cycle is obtained not only according to the charging electric power or discharging electric power of each electric vehicle in each to-be-planned pane, the charging electric power or discharging electric power of the electric energy storage device in each to-be-planned pane, but also the predicted solar electric power and the predicted load power consumption electric power of each time pane of the scheduling cycle.
6 . The electric vehicle charging station management method using the blockchain according to claim 5 , wherein in step (C), the maximum charging electric power and the maximum discharging electric power of each electric vehicle in each to-be-planned pane are obtained not only according to the maximum power of the transformer of the charging station and the charging priority weight and the discharging priority weight of the electric vehicle but also the predicted solar electric power and the predicted load power consumption electric power corresponding to each time pane of the scheduling cycle.
7 . The electric vehicle charging station management method using the blockchain according to claim 6 , wherein in step (C), according to the charging priority weight
pri
t
,
n
ch
of the n th electric vehicle, the charging priority weight of all electric vehicles, the discharging priority weight
pri
t
,
n
disch
of the n th electric vehicle, the discharging priority weight of all electric vehicles, the maximum power
P
tr
max
of the transformer of the charging station, the predicted solar electric power p pv,t in the t th time pane, and the predicted load power consumption electric power p load,t in the t th time pane, the maximum charging electric power
p
EV
,
n
,
t
ch_max
and the maximum discharging electric power
p
EV
,
n
,
t
disch_max
of the n th electric vehicle in the t th time pane are obtained through the following formulas:
p
EV
,
n
,
t
ch_max
=
(
-
P
tr
max
+
p
load
,
t
-
p
pv
,
t
)
×
pri
t
,
n
ch
∑
n
N
pri
t
,
n
ch
and
p
EV
,
n
,
t
disch_max
=
(
P
tr
max
+
p
load
,
t
-
p
pv
,
t
)
×
pri
t
,
n
disch
∑
n
N
pri
t
,
n
disch
where N is a number of all electric vehicles.
8 . The electric vehicle charging station management method using the blockchain according to claim 4 , wherein in step (E), according to the charging electric power or the discharging electric power
p
n
,
t
EV
of the n th electric vehicle in a t th time pane, the charging electric power or the discharging electric power p ESS,t of the electric energy storage device in the t th time pane, a predicted load power consumption electric power p load,t of the charging station in the t th time pane, and the predicted solar electric power p pv,t in the t th time pane, the total consumed electric power P sum,t of the charging station in the t th time pane is obtained through the following formula:
P sum,t =p load,t −p ESS,t −p pv,t −
∑
n
N
p
n
,
t
EV
,
t∈K ESS ,
where N is a number of all electric vehicles, and K ESS is a serial number set of all to-be-planned panes of the electric energy storage device, and
in step (G), for each of the at least one overloaded pane, the purchase price of the at least one overloaded pane is adjusted according to an electricity price adjustment coefficient f t (x) corresponding to the at least one overloaded pane,
f
t
(
x
)
=
P
load
,
t
-
P
E
S
S
,
t
-
P
p
v
,
t
-
∑
n
N
P
n
,
t
E
V
P
tr
max
,
t
∈
T
overload
,
where
P
tr
max
is the maximum supplied electric power, and T overload is a serial number set of all overloaded panes.
9 . The electric vehicle charging station management method using the blockchain according to claim 4 , wherein in step (J), an objective function of the nonlinear programming model is expressed as:
min
∑
t
K
ESS
(C ESS,t +
C
ESS
,
t
deg
−I′ DR,t ),t∈K ESS ,
C ESS,t =−p ESS,t ×
C
t
T
O
U
×Δt, where p ESS,t <0,
C
E
S
S
,
t
deg
=
C
E
S
S
b
a
t
❘
"\[LeftBracketingBar]"
m
ESS
1
0
0
❘
"\[RightBracketingBar]"
❘
"\[LeftBracketingBar]"
P
ESS
,
t
❘
"\[RightBracketingBar]"
×
Δ
t
B
ESS
cap
,
and
I′ DR,t =p ESS,t ×C DR,t ×Δt, where p ESS,t >0,
objective function constraints are as follows:
restriction condition 1: |p ESS,t |≤
P
ESS
max
,
restriction condition 2:
SOC
ESS
min
≤SOC ESS,t+1 ≤
SOC
ESS
max
,
restriction condition 3:
S
O
C
ESS
,
t
+
1
=
S
O
C
ESS
,
t
-
P
ESS
,
t
×
Δ
t
B
ESS
cap
,
where
P
ESS
,
t
≠
0
, and
restriction condition 4:
SOC
ess
initial
=
SOC
ess
final
,
where K ESS is a serial number set of all to-be-planned panes of the electric energy storage device, C ESS,t is a cost to be paid by the charging station when the electric energy storage device is charged in a t th time pane, I′ DR,t is an electricity saving profit obtained by the charging station when the electric energy storage device participates in a demand response in the t th time pane,
C
t
TOU
is a purchase price per unit electric power purchased by the charging station in the t th time pane, p ESS,t is a charging electric power of a electric energy storage device in the t th time pane when p ESS,t <0, p ESS,t is a discharging electric power of the electric energy storage device in the t th time pane when p ESS,t >0,
C
ESS
,
t
deg
is a total degradation cost of charging or discharging the electric energy storage device in the t th time pane,
C
ESS
bat
is a total cost of the electric energy storage device, m ESS is a ratio of the battery capacity change of the electric energy storage device to a battery cycle number change,
B
ESS
cap
is the full charge capacity of the electric energy storage device,
C
ESS
bat
❘
"\[LeftBracketingBar]"
m
ESS
100
❘
"\[RightBracketingBar]"
1
B
ESS
cap
is the degradation cost consumed per unit electric power to charge or discharge the battery of the electric energy storage device, C DR,t is the winning bid price at which the charging station for participates in the demand bidding in the t th time pane,
P
ESS
max
is a maximum charging and discharging electric power of the electric energy storage device,
SOC
ESS
min
is a minimum battery state of charge of the electric energy storage device,
SOC
ESS
max
is a maximum battery state of charge of the electric energy storage device, SOC ESS,t+1 is a battery state of charge of the electric energy storage device in a t+1 th time pane,
SOC
ess
inital
is an entry battery state of charge of the electric energy storage device,
SOC
ess
final
is a departure battery state of charge of the electric energy storage device, and Δt is a time period corresponding to each time pane.
10 . The electric vehicle charging station management method using the blockchain according to claim 1 , wherein in step (B), according to the current time t current the departure time
t
n
dep
corresponding to the n th electric vehicle, the current battery state of charge
SOC
n
current
,
the departure battery state of charge
SOC
n
final
,
the full charge capacity
B
n
cap
,
and the maximum charging and discharging electric power
P
n
max
provided by the charging pile corresponding to the electric vehicle, the charging priority weight
pri
t
,
n
ch
and discharging priority weight
pri
t
,
n
disch
of the n th electric vehicle are obtained through the following formulas:
pri
t
,
n
ch
=
(
SOC
n
final
-
SOC
n
current
)
×
B
n
cap
(
t
n
dep
-
t
current
+
1
)
×
Δ
t
×
P
n
max
and
pri
t
,
n
disch
=
1
pri
t
,
n
ch
,
where Δt is a time period corresponding to each time pane.