Disclosure of Invention
The invention aims to provide a multi-stage power grid nested decomposition coordination active and reactive power joint scheduling method, which is used for performing active and reactive power joint scheduling on a multi-stage power grid, wherein the power grid in each stage of each region only needs to calculate the internal active and reactive power joint scheduling problem and exchange boundary information with the adjacent power grid, so that an active and reactive power joint scheduling strategy for ensuring the safety of the overall power grid can be obtained.
The invention provides a multi-stage power grid nesting decomposition coordination active and reactive power combined dispatching method which comprises the following steps:
(1) establishing an active and reactive power combined dispatching optimization model with multi-stage power grid cooperation:
(1.1) setting M levels of power grids in a multi-level power grid, N (M) regional power grids in the level power grid M, and establishing an optimization objective function of an active and reactive power combined dispatching optimization model for cooperation of the multi-level power grids, wherein the optimization objective function is the minimum of the sum of the power generation cost of each regional power grid in each level, and for the regional power grids numbered n in the level M, the expression of the power generation cost is as follows:
in the above formula, G is the number set of the generator set in the power grid, Pi GFor generating active power of generator set i, Ci(Pi G) For the power generation cost function of the generator set i, the power generation cost function is expressed as a quadratic function as follows:
Ci(Pi G)=a0,i+a1,iPi G+a2,i(Pi G)2
in the above formula, a0,i、a1,i、a2,iRespectively obtaining the power generation cost constant term, the primary term and the secondary term coefficient of the generator set i from a power grid dispatching center;
(1.2) establishing the constraint conditions of the active and reactive power combined dispatching optimization model of the multi-stage power grid cooperation as follows: for the regional power grid numbered n in level m, the following two cases are distinguished:
(1.2.1) if the regional power grid numbered n in the hierarchy m is a ring power grid, the constraint condition includes:
(1.2.1.1) branch flow equation constraint:
in the above formula, P
ijAnd Q
ijRespectively the active power flow and the reactive power flow of a node i to a node j in the power grid, which are variables to be solved, P
jiAnd Q
jiRespectively an active power flow and a reactive power flow flowing to a node i from a node j, wherein the active power flow and the reactive power flow are variables to be solved, namely tau
ijThe transformer transformation ratio of the branch ij between the node i and the node j is obtained by a transformer factory nameplate,
and
respectively the conductance and susceptance of the branch ij, obtained from a power grid dispatching center,
for charging susceptance of branch ij, obtained from the grid dispatching centre, V
iAnd V
jThe voltage amplitudes of the node i and the node j are respectively used as variables to be solved, theta
iAnd theta
jThe voltage phase angles of the node i and the node j are respectively the variables to be solved, phi
ijThe phase-shifting phase angle of the transformer as branch ij is obtained by the delivery nameplate of the transformerL is a number set of branches in the power grid;
(1.2.1.2) node injection balance constraints:
in the above formula, G
iAnd D
iRespectively, the serial numbers of the generator set and the load connected with the node i,
and
the active power and the reactive power of the generator set y are respectively used as variables to be solved,
and
respectively the active power demand and the reactive power demand of the load z, are obtained from a power grid dispatching center,
and
respectively obtaining the parallel conductance and the parallel susceptance of the node i from a power grid dispatching center, wherein B is a serial number set of the nodes in the system;
(1.2.1.3) Voltage safety constraints:
in the above formula, the first and second carbon atoms are,
and
iVrespectively obtaining the upper limit and the lower limit of the voltage safety amplitude of the node i from a power grid dispatching center;
(1.2.1.4) unit output constraint:
in the above formula, the first and second carbon atoms are,
and
i GPrespectively obtaining the upper limit of the generating active power and the lower limit of the generating active power of the generator set i from a power grid dispatching center,
and
respectively acquiring the upper limit of the generating reactive power and the lower limit of the generating reactive power of the generator set i from a power grid dispatching center;
(1.2.1.5) line capacity constraint:
in the above formula, the first and second carbon atoms are,
obtaining the apparent power capacity of the branch circuit ij from a power grid dispatching center;
(1.2.2) if the regional power grid numbered n in the hierarchy m is a radial power grid, the constraint conditions include:
(1.2.2.1) relaxed branch flow equation constraints:
in the above formula, PijAnd QijRespectively the active power flow and the reactive power flow of the node i flowing to the node j, as variables to be solved, viIs the square of the voltage amplitude of node i, which is the variable to be solved, lijThe square of the current amplitude of the branch ij is used as a variable to be solved, and L is a serial number set of the branch in the system;
(1.2.2.2) node injection balance constraints:
in the above formula, G
iAnd D
iRespectively, the serial numbers of the generator set and the load connected with the node i,
and
the active power and the reactive power of the generator set y are respectively the variables to be solved, P
jiAnd Q
jiRespectively the active power flow and the reactive power flow of the node j flowing to the node i, and is a variable to be solved, i
jiThe square of the current amplitude of branch ji, the variable to be solved,
and
respectively the active power and reactive power requirements of the load z, are obtained from a power grid dispatching center,
and
the parallel conductance and the parallel susceptance of the node i are respectively obtained from a power grid dispatching center r
jiAnd x
jiRespectively obtaining the resistance and reactance of the branch ji from a power grid dispatching center, wherein B is a numbering set of nodes in the system;
(1.2.2.3) branch voltage drop constraint:
in the above formula, vjIs the square of the voltage amplitude of node j, is the variable to be solved, rijAnd xijRespectively obtaining the resistance and reactance of the branch ij from a power grid dispatching center;
(1.2.2.4) Voltage safety constraints:
in the above formula, the first and second carbon atoms are,
and
ivrespectively obtaining the upper limit and the lower limit of the square of the voltage safety amplitude of the node i from a power grid dispatching center;
(1.2.2.5) unit output constraint:
in the above formula, the first and second carbon atoms are,
and
i GPrespectively obtaining the upper limit of the generating active power and the lower limit of the generating active power of the generator set i from a power grid dispatching center,
and
respectively acquiring the upper limit of the generating reactive power and the lower limit of the generating reactive power of the generator set i from a power grid dispatching center;
(1.2.2.6) line capacity constraint:
in the above formula, the first and second carbon atoms are,
obtaining the upper limit of the square of the current amplitude of the branch ij from a power grid dispatching center;
(1.3) forming an active and reactive power combined dispatching optimization model with cooperation of the multilevel power grid by the optimization objective function in the step (1.1) and the constraint condition in the step (1.2), and expressing the following steps:
satisfies the following conditions:
in the above formula, m is the number of the hierarchy in the multi-level power grid, n is the number of the regional power grid in the same hierarchy, and x
m,nFor the internal optimization variable of the regional power grid numbered n in the hierarchy m, if the regional power grid is a ring power grid, x
m,nIncluding P
ij、Q
ij、P
ji、Q
ji、V
i、V
j、θ
i、θ
j、
And
if the regional grid is a radial grid, x
m,nIncluding P
ij、Q
ij、v
i、l
ij、
And
u
m,nfor the optimization variable of the coupling of the regional power grid numbered n in the hierarchy m and the superior power grid, if the regional power grid is a ring power grid, u
m,nIncluded
And
if the regional grid is a radial grid, u
m,nIncluding v
i、
And
l
m,nfor the optimization variable of the coupling of the regional power grid numbered n in the hierarchy m and the lower-level power grid, if the regional power grid is a ring-shaped power grid, l
m,nIncluded
And
if the regional grid is a radial grid, then l
m,nIncluding v
i、
And
f
m,n(x
m,n) Optimizing the active and reactive power joint dispatching objective of the regional power grid n in the hierarchy m, and the step (1.1)
Corresponding to, G
m,n(x
m,n,u
m,n,l
m,n) The constraint condition of active and reactive power combined dispatching of the regional power grid n in the hierarchy m is less than or equal to 0, and if the regional power grid n in the hierarchy m is an annular power grid, G
m,n(x
m,n,u
m,n,l
m,n) The constraint condition from step (1.2.1.1) to step (1.2.1.5) is not more than 0, and if the regional power grid n in the hierarchy m is a radial power grid, G is
m,n(x
m,n,u
m,n,l
m,n) The constraint conditions from the step (1.2.2.1) to the step (1.2.2.6) are less than or equal to 0, M is the total level of the multilevel power grid, N (M) is the total number of the power grid areas in the level M, U (M, n) is the number in the level M-1 of the upper level regional power grid connected with the regional power grid n in the level M, and the constraint U
m,n=I
m, nl
m-1,U(m,n)Representing boundary coupling constraints of connected upper and lower level grids, I
m,nA mapping matrix for boundary coupling constraint of regional power grid n and upper power grid in hierarchy m, a mapping matrix I
m,nIn each row of (2), vector u
m,nEach element in l
m-1,U(m,n)In the corresponding row of I
m,nIs an identity matrix in I
m,nNo corresponding other behavior 0;
(2) a nested decomposition coordination method is adopted among all levels of power grids, an active and reactive power combined dispatching optimization model of the multi-level power grid cooperation in the step (1) is solved, and a dispatching method of the nested decomposition coordination active and reactive power combined dispatching of the multi-level power grids is obtained, and the method comprises the following steps:
(2.1) obtaining a power grid, wherein the number m of a middle hierarchy is 1, and the number n of a regional power grid is 1;
(2.2) calculating an optimal solution of the cooperative active and reactive power joint dispatching of the regional power grid numbered n in the hierarchy m and each regional power grid subordinate to the regional power grid by adopting a decomposition coordination method, wherein the process is as follows:
initializing regional grids and phases numbered n in hierarchy mIteration number k of adjacent lower regional power gridm,n1, solving an internal active and reactive power combined scheduling model by using a regional power grid numbered n in the hierarchy m, and judging m:
(2.2.1) if m is 1, the internal active and reactive power joint scheduling model is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
solving the model to obtain an optimal solution, and recording the optimal solution as
And
and constraining the optimal solution to G
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
(2.2.2) if m is not equal to 1, the internal active and reactive power joint scheduling model is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
solving the model to obtain an optimal solution, and recording the optimal solution as
And
and constraining the optimal solution to G
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
(2.3) judging m: if M ≠ M, taking n as the first entry in L (M, n), where L (M, n) is the number set of regional grids connected in the hierarchical grid M +1 by the regional grid numbered n in the hierarchical M, taking M equal to M +1, returning to step (2.2); if M ═ M, performing step (2.4);
(2.4) calculating an optimal cutting plane and an approximate projection function of the regional power grid numbered n in the hierarchy m, and comprising the following steps:
(2.4.1) judging m:
if M ═ M, then define
Is x
m,nDefinition of
Is f
m,n(x
m,n) Definition of
Is G
m,n(x
m,n,u
m,n,l
m,n) Definition of
Is composed of
If M ≠ M, then define
Is [ x ]
m,n l
m,n obj
m+1,n*]
TDefinition of
Is composed of
Definition of
Is composed of
Definition of
Is composed of
(2.4.2) obtaining the optimal cutting plane of the regional power grid with the number n in the hierarchy m according to the step (2.4.1)
Comprises the following steps:
approximating a projection function
Comprises the following steps:
in the above formula, item
Can be calculated by the following formula:
in the above equation, diag () is a diagonal matrix constructor.
(2.5) judging n: if n is not the last item in L (m-1, U (m, n)), taking n as the next item in L (m-1, U (m, n)), and returning to the step (2.2); if n is the last of L (m-1, U (m, n)), taking n as U (m, n) and m as m-1, carrying out step (2.6);
(2.6) solving an active and reactive power combined dispatching model considering a lower projection function in the regional power grid with the number of n in the hierarchy m, wherein the active and reactive power combined dispatching model comprises the following steps:
and (5) judging m:
(2.6.1) if m is 1, the active and reactive joint scheduling model internally considering the lower projection function is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
in the above formula, obj
m+1,n*As an auxiliary variable, the physical meaning is numbered n in the hierarchy m +1
*The number of iterations k of the grid numbered n in the hierarchy m
m,nIncrement by 1, the optimal solution calculated by the above equation is recorded
Constraint G at optimal solution
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
Constraining
Is recorded as a dual multiplier
Constraining
Is recorded as a dual multiplier
(2.6.2) if m is not equal to 1, an active and reactive power joint scheduling model internally considering the lower projection function is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
in the above formula, obj
m+1,n*As an auxiliary variable, the physical meaning is numbered n in the hierarchy m +1
*The number of iterations k of the grid numbered n in the hierarchy m
m,nIncrement by 1, the optimal solution calculated by the above equation is recorded
Constraint G with optimal solution
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
Constraining
Is recorded as a dual multiplier
Constraining
Is recorded as a dual multiplier
(2.7) carrying out convergence judgment on the calculation of the regional power grid with the number of n in the hierarchy m, and setting the convergence condition as
If the convergence condition is not met, returning to the step (2.3); if the convergence condition is met and m is not equal to 1, returning to the step (2.4); if the convergence condition is met and m is 1, performing step (3);
(3) according to the optimal solution obtained by calculation in the steps (2.2.2), (2.6.1) and (2.6.2)
Active power of each generator included in (1)
And reactive power
And dispatching the multi-stage power grid to realize the nested decomposition and coordination active and reactive power combined dispatching of the multi-stage power grid.
The invention provides a multi-stage power grid nesting decomposition coordination active and reactive power combined dispatching method which has the characteristics and advantages that:
the invention discloses a multilevel power grid nested decomposition coordination active and reactive power joint scheduling method. Secondly, an active and reactive power joint scheduling model of all levels of power grid cooperation is solved in a nested decomposition coordination mode among all levels of power grids, and active and reactive power joint scheduling is carried out on all regional power grids of all levels based on an optimal solution. The process of solving the cooperative active and reactive power joint dispatching model of each level of power grid in a nested decomposition and coordination mode comprises two key steps: the method comprises the steps of respectively calculating the optimal solution of the active and reactive power combined dispatching of a certain regional power grid and a subordinate power grid in a certain level in a decomposition coordination manner, and calculating the optimal secant plane and the approximate projection function of the certain regional power grid in the certain level, wherein the two steps are called recursively, so that the decomposition coordination calculation of the active and reactive power combined dispatching model of the cooperation of the power grids in all levels is realized. The method establishes an active and reactive power combined dispatching model of multi-level power grid cooperation, solves the active and reactive power combined dispatching model of each level power grid cooperation in a nested decomposition coordination mode among all levels of power grids, and performs active and reactive power combined dispatching on all regional power grids of all levels based on an optimal solution. The method has high convergence speed, can ensure the operation safety of each level of power grid, and avoids the operation risks of local overload, voltage out-of-limit and the like.
Detailed Description
The invention provides a multi-stage power grid nesting decomposition coordination active and reactive power combined dispatching method which comprises the following steps:
(1) establishing an active and reactive power combined dispatching optimization model with multi-stage power grid cooperation:
(1.1) setting M levels of power grids in a multi-level power grid, N (M) regional power grids in the level power grid M, and establishing an optimization objective function of an active and reactive power combined dispatching optimization model for cooperation of the multi-level power grids, wherein the optimization objective function is the minimum of the sum of the power generation cost of each regional power grid in each level, and for the regional power grids numbered n in the level M, the expression of the power generation cost is as follows:
in the above formula, G is the number set of the generator set in the power grid,
for generating active power of generator set i, C
i(P
i G) For the power generation cost function of the generator set i, the power generation cost function is expressed as a quadratic function as follows:
Ci(Pi G)=a0,i+a1,iPi G+a2,i(Pi G)2
in the above formula, a0,i、a1,i、a2,iRespectively obtaining the power generation cost constant term, the primary term and the secondary term coefficient of the generator set i from a power grid dispatching center;
(1.2) establishing the constraint conditions of the active and reactive power combined dispatching optimization model of the multi-stage power grid cooperation as follows: for the regional power grid numbered n in level m, the following two cases are distinguished:
(1.2.1) if the regional power grid numbered n in the hierarchy m is a ring power grid, the constraint condition includes:
(1.2.1.1) branch flow equation constraint:
in the above formula, P
ijAnd Q
ijRespectively the active power flow and the reactive power flow of a node i to a node j in the power grid, which are variables to be solved, P
jiAnd Q
jiRespectively an active power flow and a reactive power flow flowing to a node i from a node j, wherein the active power flow and the reactive power flow are variables to be solved, namely tau
ijThe transformer transformation ratio of the branch ij between the node i and the node j is obtained by a transformer factory nameplate,
and
respectively the conductance and susceptance of the branch ij, obtained from a power grid dispatching center,
for charging susceptance of branch ij, obtained from the grid dispatching centre, V
iAnd V
jThe voltage amplitudes of the node i and the node j are respectively used as variables to be solved, theta
iAnd theta
jThe voltage phase angles of the node i and the node j are respectively the variables to be solved, phi
ijThe phase-shifting phase angle of the transformer which is the branch ij is obtained by a transformer delivery nameplate, and L is a serial number set of the branch in the power grid;
(1.2.1.2) node injection balance constraints:
in the above formula, G
iAnd D
iRespectively, the serial numbers of the generator set and the load connected with the node i,
and
the active power and the reactive power of the generator set y are respectively used as variables to be solved,
and
respectively the active power demand and the reactive power demand of the load z, are obtained from a power grid dispatching center,
and
respectively obtaining the parallel conductance and the parallel susceptance of the node i from a power grid dispatching center, wherein B is a serial number set of the nodes in the system;
(1.2.1.3) Voltage safety constraints:
in the above formula, the first and second carbon atoms are,
and
iVrespectively obtaining the upper limit and the lower limit of the voltage safety amplitude of the node i from a power grid dispatching center;
(1.2.1.4) unit output constraint:
in the above formula, the first and second carbon atoms are,
and
i GPrespectively obtaining the upper limit of the generating active power and the lower limit of the generating active power of the generator set i from a power grid dispatching center,
and
respectively acquiring the upper limit of the generating reactive power and the lower limit of the generating reactive power of the generator set i from a power grid dispatching center;
(1.2.1.5) line capacity constraint:
in the above formula, the first and second carbon atoms are,
obtaining the apparent power capacity of the branch circuit ij from a power grid dispatching center;
(1.2.2) if the regional power grid numbered n in the hierarchy m is a radial power grid, the constraint conditions include:
(1.2.2.1) relaxed branch flow equation constraints:
in the above formula, PijAnd QijRespectively the active power flow and the reactive power flow of the node i flowing to the node j, as variables to be solved, viIs the square of the voltage amplitude of node i, which is the variable to be solved, lijThe square of the current amplitude of the branch ij is used as a variable to be solved, and L is a serial number set of the branch in the system;
(1.2.2.2) node injection balance constraints:
in the above formula, G
iAnd D
iRespectively, the serial numbers of the generator set and the load connected with the node i,
and
the active power and the reactive power of the generator set y are respectively the variables to be solved, P
jiAnd Q
jiRespectively the active power flow and the reactive power flow of the node j flowing to the node i, and is a variable to be solved, i
jiThe square of the current amplitude of branch ji, the variable to be solved,
and
respectively the active power and reactive power requirements of the load z, are obtained from a power grid dispatching center,
and
the parallel conductance and the parallel susceptance of the node i are respectively obtained from a power grid dispatching center r
jiAnd x
jiRespectively obtaining the resistance and reactance of the branch ji from a power grid dispatching center, wherein B is a numbering set of nodes in the system;
(1.2.2.3) branch voltage drop constraint:
in the above formula, vjIs the square of the voltage amplitude of node j, is the variable to be solved, rijAnd xijRespectively obtaining the resistance and reactance of the branch ij from a power grid dispatching center;
(1.2.2.4) Voltage safety constraints:
in the above formula, the first and second carbon atoms are,
and
ivrespectively obtaining the upper limit and the lower limit of the square of the voltage safety amplitude of the node i from a power grid dispatching center;
(1.2.2.5) unit output constraint:
in the above formula, the first and second carbon atoms are,
and P
i GRespectively obtaining the upper limit of the generating active power and the lower limit of the generating active power of the generator set i from a power grid dispatching center,
and
respectively acquiring the upper limit of the generating reactive power and the lower limit of the generating reactive power of the generator set i from a power grid dispatching center;
(1.2.2.6) line capacity constraint:
in the above formula, the first and second carbon atoms are,
obtaining the upper limit of the square of the current amplitude of the branch ij from a power grid dispatching center;
(1.3) forming an active and reactive power combined dispatching optimization model with cooperation of the multilevel power grid by the optimization objective function in the step (1.1) and the constraint condition in the step (1.2), and expressing the following steps:
satisfies the following conditions:
in the above formula, m is the number of the hierarchy in the multi-level power grid, n is the number of the regional power grid in the same hierarchy, and x
m,nFor the internal optimization variable of the regional power grid numbered n in the hierarchy m, if the regional power grid is a ring power grid, x
m,nIncluding P
ij、Q
ij、P
ji、Q
ji、V
i、V
j、θ
i、θ
j、
And
if the regional grid is a radial grid, x
m,nIncluding P
ij、Q
ij、v
i、l
ij、
And
u
m,nfor the optimization variable of the coupling of the regional power grid numbered n in the hierarchy m and the superior power grid, if the regional power grid is a ring power grid, u
m,nIncluded
And
if the regional grid is a radial grid, u
m,nIncluding v
i、
And
l
m,nfor the optimization variable of the coupling of the regional power grid numbered n in the hierarchy m and the lower-level power grid, if the regional power grid is a ring-shaped power grid, l
m,nIncluded
And
if the regional grid is a radial grid, then l
m,nIncluding v
i、
And
f
m,n(x
m,n) Optimizing the active and reactive power joint dispatching objective of the regional power grid n in the hierarchy m, and the step (1.1)
Corresponding to, G
m,n(x
m,n,u
m,n,l
m,n) The constraint condition of active and reactive power combined dispatching of the regional power grid n in the hierarchy m is less than or equal to 0, and if the regional power grid n in the hierarchy m is an annular power grid, G
m,n(x
m,n,u
m,n,l
m,n) The constraint condition from step (1.2.1.1) to step (1.2.1.5) is not more than 0, and if the regional power grid n in the hierarchy m is a radial power grid, G is
m,n(x
m,n,u
m,n,l
m,n) The constraint condition from the step (1.2.2.1) to the step (1.2.2.6) is less than or equal to 0, M is the total level of the multilevel power grid, N (M) is the total number of power grid areas in the level M, and U (M, n) is the area power grid in the level Mn number in level m-1 of the upper level regional power grid connected with the upper level regional power grid, and constraint u
m,n=I
m, nl
m-1,U(m,n)Representing boundary coupling constraints of connected upper and lower level grids, I
m,nA mapping matrix for boundary coupling constraint of regional power grid n and upper power grid in hierarchy m, a mapping matrix I
m,nIn each row of (2), vector u
m,nEach element in l
m-1,U(m,n)In the corresponding row of I
m,nIs an identity matrix in I
m,nNo corresponding other behavior 0;
(2) a nested decomposition coordination method is adopted among all levels of power grids, an active and reactive power combined dispatching optimization model of the multi-level power grid cooperation in the step (1) is solved, and a dispatching method of the nested decomposition coordination active and reactive power combined dispatching of the multi-level power grids is obtained, and the method comprises the following steps:
(2.1) obtaining a power grid, wherein the number m of a middle hierarchy is 1, and the number n of a regional power grid is 1;
(2.2) calculating an optimal solution of the cooperative active and reactive power joint dispatching of the regional power grid numbered n in the hierarchy m and each regional power grid subordinate to the regional power grid by adopting a decomposition coordination method, wherein the process is as follows:
initializing iteration times k of a regional power grid numbered n in a hierarchy m and an adjacent lower-level regional power gridm,n1, solving an internal active and reactive power combined scheduling model by using a regional power grid numbered n in the hierarchy m, and judging m:
(2.2.1) if m is 1, the internal active and reactive power joint scheduling model is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
solving the model to obtain an optimal solution, and recording the optimal solution as
And
and constraining the optimal solution to G
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
(2.2.2) if m is not equal to 1, the internal active and reactive power joint scheduling model is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
solving the model to obtain an optimal solution, and recording the optimal solution as
And
and constraining the optimal solution to G
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
(2.3) judging m: if M ≠ M, taking n as the first entry in L (M, n), where L (M, n) is the number set of regional grids connected in the hierarchical grid M +1 by the regional grid numbered n in the hierarchical M, taking M equal to M +1, returning to step (2.2); if M ═ M, performing step (2.4);
(2.4) calculating an optimal cutting plane and an approximate projection function of the regional power grid numbered n in the hierarchy m, and comprising the following steps:
(2.4.1) judging m:
if M is equal to M, then decideYi (Chinese character)
Is x
m,nDefinition of
Is f
m,n(x
m,n) Definition of
Is G
m,n(x
m,n,u
m,n,l
m,n) Definition of
Is composed of
If M ≠ M, then define
Is [ x ]
m,n l
m,n obj
m+1,n*]
TDefinition of
Is composed of
Definition of
Is composed of
Definition of
Is composed of
(2.4.2) obtaining the optimal cutting plane of the regional power grid with the number n in the hierarchy m according to the step (2.4.1)
Comprises the following steps:
approximating a projection function
Comprises the following steps:
in the above formula, item
Can be calculated by the following formula:
in the above equation, diag () is a diagonal matrix constructor.
(2.5) judging n: if n is not the last item in L (m-1, U (m, n)), taking n as the next item in L (m-1, U (m, n)), and returning to the step (2.2); if n is the last of L (m-1, U (m, n)), taking n as U (m, n) and m as m-1, carrying out step (2.6);
(2.6) solving an active and reactive power combined dispatching model considering a lower projection function in the regional power grid with the number of n in the hierarchy m, wherein the active and reactive power combined dispatching model comprises the following steps:
and (5) judging m:
(2.6.1) if m is 1, the active and reactive joint scheduling model internally considering the lower projection function is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
in the above formula, obj
m+1,n*As an auxiliary variable, the physical meaning is numbered n in the hierarchy m +1
*The number of iterations k of the grid numbered n in the hierarchy m
m,nIncrement by 1, the optimal solution calculated by the above equation is recorded
Constraint G at optimal solution
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
Constraining
Is recorded as a dual multiplier
Constraining
Is recorded as a dual multiplier
(2.6.2) if m is not equal to 1, an active and reactive power joint scheduling model internally considering the lower projection function is as follows:
s.t.Gm,n(xm,n,um,n,lm,n)≤0
in the above formula, obj
m+1n*As an auxiliary variable, the physical meaning is numbered n in the hierarchy m +1
*The number of iterations k of the grid numbered n in the hierarchy m
m,nIncrement by 1, the optimal solution calculated by the above equation is recorded
Constraint G with optimal solution
m,n(x
m,n,u
m,n,l
m,n) Notation of dual multiplier not greater than 0
Constraining
Is recorded as a dual multiplier
Constraining
Is recorded as a dual multiplier
(2.7) carrying out convergence judgment on the calculation of the regional power grid with the number of n in the hierarchy m, and setting the convergence condition as
If the convergence condition is not met, returning to the step (2.3); if the convergence condition is met and m is not equal to 1, returning to the step (2.4); if the convergence condition is met and m is 1, performing step (3);
(3) according to the optimal solution obtained by calculation in the steps (2.2.2), (2.6.1) and (2.6.2)
Active power of each generator included in (1)
And reactive power
And dispatching the multi-stage power grid to realize the nested decomposition and coordination active and reactive power combined dispatching of the multi-stage power grid.