CN114243750A - Photovoltaic absorption capacity assessment method and device considering time-space correlation and active management - Google Patents
Photovoltaic absorption capacity assessment method and device considering time-space correlation and active management Download PDFInfo
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Abstract
The invention discloses a photovoltaic absorption capacity evaluation method and device considering time-space correlation and active management, wherein the method comprises the steps of determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space; calculating the empirical distribution of uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids; and establishing a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation, and solving to obtain the maximum installed capacity of the renewable energy. According to the photovoltaic absorption capacity evaluation method, the influence of the correlation between active management and the distributed power supply on the absorption capacity can be quantized by considering the time-space correlation and the photovoltaic absorption capacity evaluation method of the active management, and the power distribution network is stimulated to improve the self absorption level.
Description
Technical Field
The invention belongs to the technical field of distributed energy consumption, and particularly relates to a photovoltaic consumption capacity evaluation method and device considering time-space correlation and active management.
Background
The distribution of distributed photovoltaics in a power distribution grid is generally more intensive. Under the influence of the same type of microclimate conditions, the output of distributed photovoltaic in the same power distribution network generally has stronger correlation, and the correlation can obviously reduce the fluctuation of the output of distributed photovoltaic clusters, so that the consumption level of the distributed photovoltaic of the power distribution network is influenced. The existing photovoltaic absorption capacity evaluation method does not consider the time-space correlation characteristic of photovoltaic output when calculating the maximum installation capacity of distributed photovoltaic in a distribution network, the calculated maximum installation amount of photovoltaic is conservative, the actual installation amount of photovoltaic is difficult to reflect, and solar energy resources in the distribution network are wasted.
Disclosure of Invention
The invention aims to provide a photovoltaic absorption capacity evaluation method and device considering time-space correlation and active management.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the invention provides a photovoltaic absorption capacity evaluation method considering time-space correlation and active management, which comprises the following steps of:
determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space;
calculating the empirical distribution of uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids;
establishing a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation; the model takes the maximum installed capacity of renewable energy sources on the node to be selected as a target function, and takes OLTC constraint, PV output constraint, reactive power output constraint of reactive power elements, tie line power constraint, branch power flow constraint, network topology constraint and safety constraint as constraint conditions;
and solving the robust photovoltaic consumption capability evaluation model to obtain the maximum installed capacity of the renewable energy source and the maximum photovoltaic consumption capability.
Further, in the above-mentioned case,
the ellipsoid uncertain set of the photovoltaic output time uncertainty and the ellipsoid uncertain set of the photovoltaic output space uncertainty are expressed as follows:
wherein, COVSAnd COVTIs a photovoltaic output spatial covariance matrix and a temporal covariance matrix,representing node j at time tPVThe average photovoltaic power generation amount of (a),represents the photovoltaic power generation amount of the node j at the time t,for the purpose of the spatial uncertainty budget,for the purpose of the time uncertainty budget,the covariance matrix of the output of any two photovoltaic power stations at time T and T +1 is shown, wherein T is 1,2, …, and T represent the number of time segments; sigmaPVn,PVn+1N is 1,2, …, N is the covariance matrix between the nth photovoltaic power plant and the (N + 1) th photovoltaic power plant, N is the number of photovoltaic power plants,σPVn、σPVn+1is the standard deviation, pPVn,PVn+1Andis the Pearson correlation coefficient.
Further, the empirical distribution of the uncertainty budget values of the time and space of the uncertainty set of the photovoltaic output ellipsoids is calculated as follows:
calculating the average photovoltaic output value of each time period according to historical photovoltaic output dataSum covarianceMatrix COVT;
Obtaining the gamma-shapedT(ii) an empirical distribution of;
deriving Γ from empirical distributionTAlpha percentile of (a);
and the number of the first and second groups,
obtaining an empirical relation of photovoltaic output correlation and geographic distance according to historical photovoltaic output data of a known geographic position;
calculating a distance matrix between target photovoltaic power stations according to the installation site of the target photovoltaic power station, and calculating a correlation coefficient matrix of a target photovoltaic power station group according to the obtained empirical relational expression;
sampling from N-dimensional Gaussian distribution according to the obtained correlation coefficient matrix to obtain the probability value of each sample;
calculating an actual sample value of the photovoltaic output according to the sample probability value and the inverse marginal distribution of the photovoltaic output;
Γ is calculated fromS(ii) an empirical distribution of;
deriving the parameter Γ from an empirical distributionSAlpha percentile of (c).
Further, a reference area with the same climate type as the target photovoltaic power station installation site is selected, and historical photovoltaic output data are obtained.
Further, the objective function of the robust photovoltaic absorption capability evaluation model considering the photovoltaic output and the time-space correlation is as follows:
wherein,representing PV mounting node jPVUpper mounted photovoltaic capacity, psiPVRepresenting a set of PV installation nodes to be selected;
the constraint conditions are as follows:
A. the OLTC constraint:
wherein,indicating access node j at time tOLTCAn integer variable for a tap position, 0 for no at this tap position, 1 for at this tap position,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access node j at time tOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, M and M0Representing parameters in a Big-M calculation method;
B. PV output constraint:
wherein,andrepresenting PV mounting node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting PV mounting node jPVThe photovoltaic active and photovoltaic reactive power output of the photovoltaic,represents PV installation node j at time tPVZeta represents the minimum photovoltaic output level,installing node j for PV at time tPVThe angle of the power factor of (a),andinstalling node j for PV at time tPVMinimum and maximum power factor angle of (d);
C. reactive power output constraint of reactive power element:
wherein,installing node j for time tCONThe continuously variable VAR device of (a) reactive power,andrespectively represent installation nodes jCONThe minimum value and the maximum value of the reactive power,to install node jDISThe reactive power of the discrete adjustable VAR device of (a),for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing the installation of node j at time tDISIn discrete adjustable VAR deviceThe number of the drops is reduced,represents the adjustment range of a discrete adjustable VAR device,represents an installation node jDISAt the maximum number of adjustments of the discrete adjustable VAR apparatus,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISRepresenting a set of discrete adjustable VAR device installation nodes to be selected;
D. tie line power constraint:
wherein,andrepresents the installation of node j at time tTRThe active power and the reactive power of the transformer are obtained,andrepresents the installation of node j at time tTRThe minimum and maximum active power of the transformer,andrepresents the installation of node j at time tTRMinimum and maximum reactive power of the transformer, psisubRepresenting a set of transformer installation nodes to be selected;
E. branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,tAnd Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tFor the active and reactive power of line ij at time t, rijAnd xijAs resistance and reactance values of the line ij, bjIs the value of the conductance of the node j,andactive and reactive powers of node j, ΨEFor all line sets, ΨnFor all line node sets, eijIs a binary auxiliary variable representing whether line ij is connected or not, if line ijAre connected, then e ij1, and vice versa, | · | | non-woven phosphor2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively;
F. and (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE;
wherein N isbusIs the number of nodes of the distribution network, FijIs a non-negative variable representing the virtual power flow transmitted on line ij in the virtual power flow, Wj1Is the power provided by the source point in the virtual network;
G. safety restraint:
H. photovoltaic output time uncertainty and photovoltaic output space uncertainty represent:
further, in the above-mentioned case,
converting the robust photovoltaic absorption capacity evaluation model of the photovoltaic output and time-space correlation into a robust optimization form, and taking the efficiency factor of the photovoltaic systemTaking the minimum absorption capacity as a target for decision variables, adopting a CPLEX solver to calculate in an iterative mode until the calculation is finished when the line current error obtained by iteration is smaller than a preset threshold value, outputting the maximum photovoltaic installed capacity which is the photovoltaic absorption capacity of the power distribution network,
Furthermore, in the solving process, the second-order cone constraint of the power grid flow is dynamically tightened by adopting a secant plane method,
the cut plane in the τ +1 th iteration is:
wherein,representing the square of the current of line ij during time t in the # 1 th iteration,andrespectively representing the active power, the reactive power and the square of the node voltage in tau iterations.
The invention also provides a photovoltaic absorption capacity evaluation device considering time-space correlation and active management, which comprises:
the first calculation module is used for determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space;
the second calculation module is used for calculating the empirical distribution of the uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids;
the building module is used for building a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation; the model takes the maximum installed capacity of renewable energy sources on the node to be selected as a target function, and takes OLTC constraint, PV output constraint, reactive power output constraint of reactive power elements, tie line power constraint, branch power flow constraint, network topology constraint and safety constraint as constraint conditions;
and the number of the first and second groups,
and the output module is used for solving the robust photovoltaic consumption capability evaluation model to obtain the maximum installed capacity of the renewable energy source and the maximum photovoltaic consumption capability.
Further, the first calculation module is specifically configured to,
the ellipsoid uncertain set of the photovoltaic output time uncertainty and the ellipsoid uncertain set of the photovoltaic output space uncertainty are determined as follows:
wherein, COVSAnd COVTIs a photovoltaic output spatial covariance matrix and a temporal covariance matrix,representing node j at time tPVThe average photovoltaic power generation amount of (a),represents the photovoltaic power generation amount of the node j at the time t,for the purpose of the spatial uncertainty budget,for the purpose of the time uncertainty budget,the covariance matrix of the output of any two photovoltaic power stations at time T and T +1 is shown, wherein T is 1,2, …, and T represent the number of time segments; sigmaPVn,PVn+1N is 1,2, …, N is the covariance matrix between the nth photovoltaic power plant and the (N + 1) th photovoltaic power plant, N is the number of photovoltaic power plants,σPVn、σPVn+1is the standard deviation, pPVn,PVn+1Andis Pearson correlation coefficients.
Further, the building block is specifically configured to,
an objective function of a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation is established as follows:
wherein,representing PV mounting node jPVUpper mounted photovoltaic capacity, psiPVRepresenting a set of PV installation nodes to be selected;
the constraints are as follows:
A. the OLTC constraint:
wherein,indicating access node j at time tOLTCAn integer variable for a tap position, 0 for no at this tap position, 1 for at this tap position,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access node j at time tOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, M and M0Representing parameters in a Big-M calculation method;
B. PV output constraint:
wherein,andrepresenting PV mounting node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting PV mounting node jPVThe photovoltaic active and photovoltaic reactive power output of the photovoltaic,represents PV installation node j at time tPVZeta represents the minimum photovoltaic output level,installing node j for PV at time tPVThe angle of the power factor of (a),andinstalling node j for PV at time tPVMinimum sum of power factor angle ofA maximum value;
C. reactive power output constraint of reactive power element:
wherein,installing node j for time tCONThe continuously variable VAR device of (a) reactive power,andrespectively represent installation nodes jCONThe minimum value and the maximum value of the reactive power,to install node jDISThe reactive power of the discrete adjustable VAR device of (a),for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing the installation of node j at time tDISThe discrete adjustable VAR apparatus of (a) adjusts the state of increase and decrease,represents the adjustment range of a discrete adjustable VAR device,represents an installation node jDISAt the maximum number of adjustments of the discrete adjustable VAR apparatus,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISRepresenting a set of discrete adjustable VAR device installation nodes to be selected;
D. tie line power constraint:
wherein,andrepresents the installation of node j at time tTRThe active power and the reactive power of the transformer are obtained,andrepresents the installation of node j at time tTRThe minimum and maximum active power of the transformer,andrepresents the installation of node j at time tTRMinimum and maximum reactive power of the transformer, psisubRepresenting a set of transformer installation nodes to be selected;
E. branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,tAnd Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tFor the active and reactive power of line ij at time t, rijAnd xijAs resistance and reactance values of the line ij, bjIs the value of the conductance of the node j,andactive and reactive powers of node j, ΨEFor all line sets, ΨnFor all line node sets, eijIs a binary auxiliary variable representing whether line ij is connected, if line ij is connected, e ij1, and vice versa, | · | | non-woven phosphor2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively;
F. and (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE;
wherein N isbusIs the number of nodes of the distribution network, FijIs a non-negative variable representing the virtual power flow transmitted on line ij in the virtual power flow, Wj1Is the power provided by the source point in the virtual network;
G. safety restraint:
H. photovoltaic output time uncertainty and photovoltaic output space uncertainty represent:
compared with the prior art, the invention has the following advantages:
according to the photovoltaic power distribution network photovoltaic power generation and absorption capacity calculation method, the photovoltaic output time-space correlation and the power distribution network active management are considered when the power distribution network photovoltaic absorption capacity is calculated, and the photovoltaic fluctuation is utilized to the maximum extent to improve the power distribution network photovoltaic absorption capacity by fully considering the time and space correlation among a plurality of photovoltaic power stations. Meanwhile, active management strategies such as on-load tap changer regulation, network reconstruction, photovoltaic inverter reactive power output control and reactive compensation which are common in operation are comprehensively considered, and the photovoltaic consumption level of the active power distribution network can be calculated more accurately.
Drawings
FIG. 1 is a flow chart of a photovoltaic absorption capacity evaluation method considering time-space correlation and active management according to the present invention;
FIG. 2 is a diagram of a 59-node power distribution system in Suzhou, Jiangsu province in accordance with an embodiment of the present invention;
FIG. 3 is a typical time-of-day load and photovoltaic output curve for a 59-node power distribution system in an embodiment of the present invention;
fig. 4 illustrates photovoltaic absorption capability of each node in a 59-node power distribution system before and after active management (ANM) enabled by using a DC-PV-HCAM model according to an embodiment of the present invention.
Detailed Description
The invention is further described below. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
The invention provides a photovoltaic absorption capacity evaluation method considering time-space correlation and active management, which specifically comprises the following steps:
a reference area is selected that has sufficient historical photovoltaic output data and a similar climate type as the target photovoltaic installation site. In addition, the latitude and longitude should be as close as possible to the target photovoltaic installation site to be consistent with the actual photovoltaic parameters.
And (4) inspecting the correlation of the distributed photovoltaic power generation capacity with time and geographical distribution through historical photovoltaic output data. The separate spatial and temporal correlations further configure the uncertain set of photovoltaic exit ellipsoids to reduce overall conservation.
And calculating parameters of the photovoltaic output ellipsoid uncertainty set, corresponding uncertainty budgets and observation probabilities one to one, and respectively obtaining the empirical distribution of uncertainty budget values from two aspects of time and space.
And establishing a robust photovoltaic absorption capacity evaluation model (RC-PV-HCAM) considering the time-space correlation.
And converting the original problem into a problem of solving a single maximum value by using a robust equivalent model of RC-PV-HCAM to solve to obtain the maximum absorption capacity of the active power distribution network, and dynamically tightening second-order cone constraints by using a secant plane method in the solving process.
In the invention, the uncertain set of photovoltaic output ellipsoids is expressed as:
in the formula,represents a power distribution network node j at the moment tPVThe average photovoltaic power generation amount is obtained from long-term historical photovoltaic power generation amount data or a predicted value,representing the photovoltaic power generation amount of a power distribution network node j at the moment t; Σ denotes a covariance matrix obtained from historical data; gamma-shapedαCommonly referred to as uncertainty budget, represents the coverage of observations over the total samples.
Equation (1) can be decomposed into:
in the formula,andis the inverse of the historical photovoltaic output space and time covariance matrix;commonly referred to as spatial uncertainty budget, the specific calculation method is shown by equation (8);referred to as the time uncertainty budget, the specific calculation method is shown by equation (9).
Wherein the historical photovoltaic output time and spatial covariance matrix is expressed as:
in the formula,the method is characterized in that the method is a covariance matrix of output of any two photovoltaic power stations at time T and T +1, wherein T is 1,2 and …, T comprises time correlation among different time periods, and T represents the number of the time periods; sigmaPVn,PVn+1N is 1,2, …, where N is a covariance matrix between the nth photovoltaic power station and the (N + 1) th photovoltaic power station, where spatial correlation between different photovoltaic power stations is included, and N is the number of photovoltaic power stations;σPVn,σPVn+1is the corresponding standard deviation; rhoPVn,PVn+1Andis the Pearson correlation coefficient. The correlation coefficient is equal to 1 if a pair of photovoltaic power stations can always observe the same output at the same moment. Conversely, a correlation coefficient equal to zero means that the photovoltaic contribution is linearly independent. Equation (7) is a calculation equation of the Pearson correlation coefficient.
In the invention, the uncertainty of the time-space correlation is described by an ellipsoid-type uncertainty set defined by covariance. The uncertainty budget controls the conservatism of the uncertain set. A higher uncertainty budget usually means that the uncertainty set contains more observations, but it is also possible that a large number of invalid regions are thus covered, making the uncertainty set too conservative. An ideal uncertainty set should be well balanced between the volume and coverage of the uncertainty set, and shrinking the volume of the uncertainty set may result in a more ideal uncertainty set.
In the invention, the generation steps of the ellipsoid uncertainty set with time uncertainty are as follows:
(A1) calculating the average photovoltaic output value of each time period according to the historical photovoltaic outputSum covariance matrix COVT;
(A2) Obtaining gamma from formula (1)T(ii) an empirical distribution of;
(A3) deriving Γ from empirical distributionTAlpha percentile of (c).
In the invention, the generation steps of the ellipsoid uncertainty set with the space uncertainty are as follows:
(B1) obtaining an empirical relation of photovoltaic output correlation and geographic distance by using historical photovoltaic output data of a known geographic position;
(B2) calculating a distance matrix between the photovoltaic power stations to be selected by using the positions of the photovoltaic power stations to be selected, and calculating a correlation coefficient matrix of the target photovoltaic station group according to the empirical relational expression obtained in the step (B1);
(B3) sampling from N-dimensional Gaussian distribution by using the correlation coefficient matrix obtained in the step (B2) to obtain a probability value of each sample;
(B4) inverse marginal distribution F-1X by sample probability value and photovoltaic outputi(xi) Calculating an actual sample value of photovoltaic output;
(B5) Γ is calculated fromS(ii) an empirical distribution of;
(B6) deriving the parameter Γ from an empirical distributionSAlpha percentile of (c).
In the invention, a robust photovoltaic absorption capability evaluation model (RC-PV-HCAM) considering time-space correlation is established as follows:
the selected objective function is that the installed capacity of the renewable energy sources on the node to be selected is maximum:
in the formula,represents an installation node jPVTop mounted photovoltaic capacity psiPVRepresenting a set of installation nodes to be selected.
On-load tap changers (OLTC) can adjust the voltage on the secondary side of the transformer by changing the position of a tap. The active management of the OLTC implementation can be implemented by OLTC constraints, which are:
in the formula,is an access node j representing time tOLTCAn integer variable for a tap position, 0 for no at this tap position, 1 for at this tap position,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access node j at time tOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, NOLTCThe representation refers to the length of the OLTC tap at different positions, M and M0The parameters in the calculation method of Big-M are shown, and equations (13), (14), (16) and (17) are relaxation constraints for making substitution equivalent.
PV output constraint:
equations (24) - (26) represent the expected output of photovoltaic power generation at time t,andrepresents node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting the photovoltaic active and photovoltaic reactive power output,representing the equivalent power output coefficient, and zeta represents the minimum photovoltaic output level;is node jPVThe angle of the power factor of (c) or (c),andthe minimum and maximum power factor angle values.
Reactive power output constraint of reactive power element:
in the formula,in order to continuously adjust the reactive power of the VAR device,andrespectively represent the minimum value and the maximum value thereof,for the reactive power of a discrete adjustable VAR device,for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing node j at time tDISThe increase and decrease of the adjustment state of the discrete adjustable reactive power device,the adjustment range of the discrete adjustable reactive device is shown,a maximum number of adjustments is indicated,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISAnd representing a set of discrete tunable VAR device installation nodes to be selected. Equations (27), (28) represent continuously adjustable and continuously discrete VAR device constraints; equations (29) - (32) represent the daily switching operating constraints of the discrete tunable reactive device.
Tie line power constraint:
in the formula,andthe active and the reactive power of the transformer are represented,andrepresenting the minimum and maximum active power of the transformer,andrepresenting minimum and maximum reactive power, Ψ, of the transformersubAnd representing a set of transformer installation nodes to be selected.
Branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,t、Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tActive power, reactive power, r, for line ij at time tij、xijIs the resistance value, reactance value, b of line ijjIs the value of the conductance of the node j,is a node j hasPower, reactive power, psiEFor all line sets, ΨnIs a collection of all nodes. e.g. of the typeijIs a binary auxiliary variable representing whether line ij is connected, if line ij is connected, e ij1 and vice versa; i | · | purple wind2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively.
And (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE (42)
in the formula, NbusIs the number of nodes of the distribution network, FijIs a non-negative variable representing the virtual power flow transmitted on line ij in the virtual power flow,is the power provided by the "source" point in the virtual network (the transformer node in the distribution network). Equation (39) is a radial constraint and equations (40) - (43) are connectivity constraints.
Safety restraint:
safety constraints include line thermal constraints and node voltage constraints.Is the maximum value of the current of line ij,the minimum and maximum voltage values at node j.
Converting the comprehensive consumption capacity evaluation model into a robust optimization form by using the efficiency factor of the photovoltaic systemAnd determining the photovoltaic output efficiency by taking the minimum consumption capacity as a decision variable.
The decision variables are other continuous variables such as photovoltaic installed capacity and the like
At this time, the RC-PV-HCAM can be represented by a vector as:
in the formula, pi represents the weight of the parameter.
In the present invention, the robust peer-to-peer model of the RC-PV-HCAM described above is rewritten into matrix-vector form as equations (47) - (55):
s.t.ax=b (48)
ey=g (50)
hy≤k (51)
mx+ny=u (52)
x∈X (54)
Ω={δ|δTΣ-1δ≤Γ} (55)
wherein a, b, c, d, e, g, h, k, m, n, u, w, η and X are the corresponding parameter vectors and sets;representing the mean value, δ, of the uncertainty parameter ηRepresents a small perturbation of the uncertain parameter, Σ being the covariance matrix of the uncertain parameter. Equation (55) is an ellipsoid uncertainty set representation of the uncertainty variable. Equation (48) represents an equation relationship of continuous variables including equations (13), (16), (28), (35), (36), (40), (41); equation (49) includes the temporal coupling relationship between successive variables, and between uncertain photovoltaic outputs, including equations (14), (23), (24), (25), (26), (27), (33), (34), (37), (38), (42), (43), (44), (45); equations (50) and (51) represent equations and inequalities of discrete variables, respectively, including equations (39) and (19), (20), (21), (22), (29), (30), (31), (32); equation (52) represents the power flow balance constraint and the relationship between the continuous and discrete variables; equation (53) represents all second order cone constraints; equation (54) represents the value range of the continuous variable.
The model adopts a second-order cone equation to describe the power flow of the power distribution network. In the actual calculation process, because the problem that the original power flow variable is difficult to be tightly wrapped by the second-order cone exists when the maximum photovoltaic loading capacity target is described in the second-order cone power flow, the second-order cone equation needs to be further dynamically tightened by a secant plane method during iterative solution.
Further, the cutting plane method is as follows:
the cut plane in the τ +1 th iteration can be written as:
in the formula,representing the square of the current of line ij during time t in the # 1 th iteration,andrespectively representing the active power, the reactive power and the node voltage squared in tau iterations, and are considered as known parameters in tau +1 iterations. At this moment, above-mentioned distribution network photovoltaic absorption ability aassessment mouldThe model can be calculated in an iterative mode by using a CPLEX and other common commercial solvers until the line current error obtained by iteration is smaller than a preset threshold epsilon, and the calculation is finished, and the output maximum photovoltaic installed capacity is the photovoltaic absorption capacity of the power distribution network.
Examples
The RC-PV-HCAM model provided by the invention is verified by adopting a rural power distribution network with Jiangsu 59 nodes. The analysis considers the following two scenarios:
case A: and calculating the absorption capacity of the power distribution network by using a deterministic comprehensive PV horizontal absorption capacity assessment model (DC-PV-HCAM). Examine the effect of active management (ANM) on PV absorption capacity.
Case B: and calculating the consumption capacity of the power distribution network by using the RC-PV-HCAM. Case B takes into account the uncertainty and relevance of multiple PV contributions based on Case a. The effect of randomness and dependence of the photovoltaic contribution on the photovoltaic absorption capacity is illustrated by a comparison of Case a and Case B.
The data are as follows: the structure of a 59-node rural power distribution system is shown in fig. 2. Two 300kVar SVCs are respectively arranged at nodes 18 and 42; there are 5 150kVar CBs at nodes 7, 24, 33, 38, and 59, and the capacitor tap is 50 kVar. The OLTC is located at node 1, with a total of 20 equally spaced taps, limited to adjustment only once per day. The voltage range of each node is set to [0.93, 1.07] p.u. The total load of the distribution network is 3.85MW and 0.97MVar, and the total electric quantity of the load of the distribution network in the daytime is 11.13 MWh. The test system comprises 15 candidate PV installation nodes, the minimum photovoltaic capacity of each candidate node is set to be 100kW, and the maximum photovoltaic power limiting rate of a distribution network is set to be 10%. The threshold epsilon of the secant plane method during the optimization solution is set to be 1%, and the relative clearance of the CPLEX is set to be 5%.
To be as close as practical, three types of loads are considered: industrial, commercial and residential loads. Figure 3 gives a typical daily load curve for three loads and the historical average and per unit value of the maximum solar photovoltaic power generation. In consideration of the power characteristics of the photovoltaic power generation output, the load and photovoltaic output values for 32 periods (15-minute intervals) in total from 8 am to 4 pm are used in the present embodiment. And obtaining a time-space covariance matrix of the photovoltaic output, uncertain budget and corresponding coverage rate of the uncertain budget according to the data.
Firstly, calculating the absorption capacity of the active power distribution network by using the DC-PV-HCAM, and comparing the absorption capacity of the power distribution network under the condition of existence of the ANM under the condition of average photovoltaic output scene and the maximum photovoltaic output scene.
The calculation results of the DC-PV-HCAM absorption capacity are shown in table 1, and fig. 4 shows the comparison of the installed photovoltaic capacity of each node before and after the ANM is enabled.
TABLE 1 distribution network photovoltaic absorption capability obtained by DC-PV-HCAM under different scenes
As can be seen from table 1, the absorption capacity of the power distribution network is significantly increased after the ANM is used, and the photovoltaic absorption capacity is significantly lower than the average photovoltaic output under the maximum photovoltaic output scene.
Table 2 shows the network reconstruction results calculated by the DC-PV-HCAM in different scenarios, and in the scenario where the ANM is not enabled, the disconnected line is the line shown by the dotted line in fig. 2. After the ANM is enabled, the network structure is also changed in order to maximize the photovoltaic efficiency, with the lines disconnected being 30-31, 40-59 and 14-15, 38-39, respectively.
TABLE 2 distribution network topology obtained from DC-PV-HCAM under different scenarios
And (4) on the basis of ANM, based on the evaluation result after the randomness and the correlation of the photovoltaic output are considered under different uncertain budgets of RC-PV-HCAM test.
First, assuming that the correlation coefficient is 1, the uncertainty ellipse is degenerated into a straight line. The photovoltaic absorption capacity after considering the photovoltaic output randomness is shown in table 3. Where the uncertainty budget has been translated into a corresponding uncertainty coverage. As can be seen from table 3, the photovoltaic absorption capacity increases with decreasing uncertainty coverage. In fact, a larger uncertainty budget means that more scenes deviating from the average photovoltaic contribution need to be considered, and an ellipsoid uncertainty set with a larger variance is selected for decision making. Therefore, the capacity evaluation result is more conservative.
The results in table 3 are based on the fully correlated photovoltaic contribution assumption, in fact only taking into account the fluctuations of a single photovoltaic contribution. The solution for RC-PV-HCAM will converge to the solution at the maximum photovoltaic output scenario in DC-PV-HCAM when the risk level is large enough. And as the uncertainty level is reduced, the worst scene gradually deviates to the original average photovoltaic output scene, and the solution of the RC-PV-HCAM also gradually converges to the solution in the DC-PV-HCAM under the average photovoltaic output scene.
TABLE 3 photovoltaic absorption Capacity (MW) of each node at different uncertainty levels without regard to relevance
The above results do not account for the influence of the correlation on the photovoltaic absorption capacity, and only account for the randomness of the photovoltaic output. In consideration of the smoothing effect brought by the correlation, the photovoltaic cluster output with the correlation can reduce the fluctuation of the total photovoltaic output, and the photovoltaic absorption capacity is possibly improved. Therefore, the correlation is taken into consideration, and the RC-PV-HCAM calculation is used for calculating the photovoltaic absorption capacity under different uncertain levels after the correlation is considered. The calculation results are shown in table 4.
TABLE 4 photovoltaic absorption Capacity (MW) of each node considering relevance at different uncertainty levels
It can be seen from table 4 that the photovoltaic absorption capacity can be improved indeed in consideration of the spatio-temporal correlation. Under the same uncertain level, the photovoltaic consumption of each node is improved to different degrees after the correlation is considered. The magnitude of the increase in absorptive capacity decreases with decreasing uncertainty level. Unlike the scenario where correlation is not considered in table 3, the results in table 4 consider the correlation of photovoltaic output, which has the most significant impact on the output of the photovoltaic cluster in the scenario of maximum photovoltaic output uncertainty. The sum of the output of the photovoltaic power generation system is more gentle than that of a single photovoltaic power generation system after being directly amplified, or the photovoltaic power generation system has the correlation of less than 1, so that the photovoltaic power generation system plays a role of 1+1<2, and the photovoltaic power generation system is more beneficial to photovoltaic consumption.
In terms of calculation performance, the DC-PV-HCAM calculation time is about 60min, and the secant plane method converges after 2-3 iterations. The RC-PV-HCAM calculation time is about 80-100min, and the secant plane method can be converged after 2-3 times of iteration. Considering that the estimation of the absorption capability is part of the planning process, and generally takes off-line calculation as the main part, the calculation efficiency is acceptable.
The invention also provides a photovoltaic absorption capacity evaluation device considering time-space correlation and active management, which comprises:
the first calculation module is used for determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space;
the second calculation module is used for calculating the empirical distribution of the uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids;
the building module is used for building a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation; the model takes the maximum installed capacity of renewable energy sources on the node to be selected as a target function, and takes OLTC constraint, PV output constraint, reactive power output constraint of reactive power elements, tie line power constraint, branch power flow constraint, network topology constraint and safety constraint as constraint conditions;
and the number of the first and second groups,
and the output module is used for solving the robust photovoltaic consumption capability evaluation model to obtain the maximum installed capacity of the renewable energy source and the maximum photovoltaic consumption capability.
In the present invention, the first calculation module is specifically configured to,
the ellipsoid uncertain set of the photovoltaic output time uncertainty and the ellipsoid uncertain set of the photovoltaic output space uncertainty are determined as follows:
wherein, COVSAnd COVTIs a photovoltaic output spatial covariance matrix and a temporal covariance matrix,representing node j at time tPVThe average photovoltaic power generation amount of (a),represents the photovoltaic power generation amount of the node j at the time t,for the purpose of the spatial uncertainty budget,for the purpose of the time uncertainty budget,the covariance matrix of the output of any two photovoltaic power stations at time T and T +1 is shown, wherein T is 1,2, …, and T represent the number of time segments; sigmaPVn,PVn+1N is 1,2, …, N is the covariance matrix between the nth photovoltaic power plant and the (N + 1) th photovoltaic power plant, N is the number of photovoltaic power plants,σPVn、σPVn+1is the standard deviation, pPVn,PVn+1Andis the Pearson correlation coefficient.
In the present invention, the building blocks are used in particular,
an objective function of a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation is established as follows:
wherein,representing PV mounting node jPVUpper mounted photovoltaic capacity, psiPVRepresenting a set of PV installation nodes to be selected;
the constraints are as follows:
A. the OLTC constraint:
wherein,indicating access node j at time tOLTCInteger variable for tap position, 0 for not at this tap position, 1 forIn the position of this tap it is possible to,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access node j at time tOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, M and M0Representing parameters in a Big-M calculation method;
B. PV output constraint:
wherein,andrepresenting PV mounting node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting PV mounting node jPVThe photovoltaic active and photovoltaic reactive power output of the photovoltaic,represents PV installation node j at time tPVZeta represents the minimum photovoltaic output level,installing node j for PV at time tPVThe angle of the power factor of (a),andinstalling node j for PV at time tPVMinimum and maximum power factor angle of (d);
C. reactive power output constraint of reactive power element:
wherein,installing node j for time tCONThe continuously variable VAR device of (a) reactive power,andrespectively represent installation nodes jCONThe minimum value and the maximum value of the reactive power,to install node jDISThe reactive power of the discrete adjustable VAR device of (a),for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing the installation of node j at time tDISThe discrete adjustable VAR apparatus of (a) adjusts the state of increase and decrease,represents the adjustment range of a discrete adjustable VAR device,represents an installation node jDISAt the maximum number of adjustments of the discrete adjustable VAR apparatus,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISRepresenting a set of discrete adjustable VAR device installation nodes to be selected;
D. tie line power constraint:
wherein,andrepresents the installation of node j at time tTRThe active power and the reactive power of the transformer are obtained,andrepresents the installation of node j at time tTRThe minimum and maximum active power of the transformer,andrepresents the installation of node j at time tTRMinimum and maximum reactive power of the transformer, psisubRepresenting a set of transformer installation nodes to be selected;
E. branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,tAnd Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tFor the active and reactive power of line ij at time t, rijAnd xijAs resistance and reactance values of the line ij, bjIs the value of the conductance of the node j,andactive and reactive powers of node j, ΨEFor all line sets, ΨnFor all line node sets, eijIs a binary auxiliary variable representing whether line ij is connected, if line ij is connected, e ij1, and vice versa, | · | | non-woven phosphor2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively;
F. and (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE;
wherein N isbusIs the number of nodes of the distribution network, FijIs a non-negative variable representing the virtual power flow transmitted on line ij in the virtual power flow, Wj1Is the power provided by the source point in the virtual network;
G. safety restraint:
H. photovoltaic output time uncertainty and photovoltaic output space uncertainty represent:
it is to be noted that the apparatus embodiment corresponds to the method embodiment, and the implementation manners of the method embodiment are all applicable to the apparatus embodiment and can achieve the same or similar technical effects, so that the details are not described herein.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. A photovoltaic absorption capacity evaluation method considering time-space correlation and active management is characterized by comprising the following steps:
determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space;
calculating the empirical distribution of uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids;
establishing a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation; the model takes the maximum installed capacity of renewable energy sources on the node to be selected as a target function, and takes OLTC constraint, PV output constraint, reactive power output constraint of reactive power elements, tie line power constraint, branch power flow constraint, network topology constraint and safety constraint as constraint conditions;
and solving the robust photovoltaic consumption capability evaluation model to obtain the maximum installed capacity of the renewable energy source and the maximum photovoltaic consumption capability.
2. The method for photovoltaic absorption capacity evaluation considering time-space correlation and active management according to claim 1,
the ellipsoid uncertain set of the photovoltaic output time uncertainty and the ellipsoid uncertain set of the photovoltaic output space uncertainty are expressed as follows:
wherein, COVSAnd COVTIs a photovoltaic output spatial covariance matrix and a temporal covariance matrix,representing node j at time tPVThe average photovoltaic power generation amount of (a),represents the photovoltaic power generation amount of the node j at the time t,for the purpose of the spatial uncertainty budget,for the purpose of the time uncertainty budget,the covariance matrix of the output of any two photovoltaic power stations at time T and T +1 is shown, wherein T is 1,2, …, and T represent the number of time segments; sigmaPVn,PVn+1N is 1,2, …, N is the covariance matrix between the nth photovoltaic power plant and the (N + 1) th photovoltaic power plant, N is the number of photovoltaic power plants,σPVn、σPVn+1is the standard deviation, pPVn,PVn+1Andis the Pearson correlation coefficient.
3. The method of claim 2, wherein the empirical distribution of the temporal and spatial uncertainty estimates for the uncertain set of photovoltaic output ellipsoids is calculated as follows:
calculating the average photovoltaic output value of each time period according to historical photovoltaic output dataSum covariance matrix COVT;
Obtaining the gamma-shapedT(ii) an empirical distribution of;
deriving Γ from empirical distributionTAlpha percentile of (a);
and the number of the first and second groups,
obtaining an empirical relation of photovoltaic output correlation and geographic distance according to historical photovoltaic output data of a known geographic position;
calculating a distance matrix between target photovoltaic power stations according to the installation site of the target photovoltaic power station, and calculating a correlation coefficient matrix of a target photovoltaic power station group according to the obtained empirical relational expression;
sampling from N-dimensional Gaussian distribution according to the obtained correlation coefficient matrix to obtain the probability value of each sample;
calculating an actual sample value of the photovoltaic output according to the sample probability value and the inverse marginal distribution of the photovoltaic output;
Γ is calculated fromS(ii) an empirical distribution of;
from the warpObtaining parameter gamma in the distributionSAlpha percentile of (c).
4. The method of claim 3, wherein a reference area having the same climate type as the target photovoltaic power plant installation site is selected and historical photovoltaic output data is obtained.
5. The photovoltaic absorptive capacity evaluation method considering the spatio-temporal correlation and the active management according to claim 3, wherein the objective function of the robust photovoltaic absorptive capacity evaluation model considering the photovoltaic output and the spatio-temporal correlation is as follows:
wherein,representing PV mounting node jPVUpper mounted photovoltaic capacity, psiPVRepresenting a set of PV installation nodes to be selected;
the constraint conditions are as follows:
A. the OLTC constraint:
wherein,indicating access node j at time tOLTCInteger variable for tap position, 0 for not at this tap position, 1 tableShown in this position of the tap,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access node j at time tOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, M and M0Representing parameters in a Big-M calculation method;
B. PV output constraint:
wherein,andrepresenting PV mounting node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting PV mounting node jPVThe photovoltaic active and photovoltaic reactive power output of the photovoltaic,represents PV installation node j at time tPVZeta represents the minimum photovoltaic output level,installing node j for PV at time tPVThe angle of the power factor of (a),andinstalling node j for PV at time tPVMinimum and maximum power factor angle of (d);
C. reactive power output constraint of reactive power element:
wherein,installing node j for time tCONThe continuously variable VAR device of (a) reactive power,andrespectively represent installation nodes jCONThe minimum value and the maximum value of the reactive power,to install node jDISThe reactive power of the discrete adjustable VAR device of (a),for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing the installation of node j at time tDISThe discrete adjustable VAR apparatus of (a) adjusts the state of increase and decrease,represents the adjustment range of a discrete adjustable VAR device,represents an installation node jDISAt the maximum number of adjustments of the discrete adjustable VAR apparatus,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISRepresenting a set of discrete adjustable VAR device installation nodes to be selected;
D. tie line power constraint:
wherein,andrepresents the installation of node j at time tTRThe active power and the reactive power of the transformer are obtained,andrepresents the installation of node j at time tTRThe minimum and maximum active power of the transformer,andrepresents the installation of node j at time tTRMinimum and maximum reactive power of the transformer, psisubRepresenting a set of transformer installation nodes to be selected;
E. branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,tAnd Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tFor the active and reactive power of line ij at time t, rijAnd xijAs resistance and reactance values of the line ij, bjIs the value of the conductance of the node j,andactive and reactive powers of node j, ΨEFor all line sets, ΨnFor all line node sets, eijIs a binary auxiliary variable representing whether line ij is connected, if line ij is connected, eij=1,Vice versa, | · purple sweet2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively;
F. and (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE;
wherein N isbusIs the number of nodes of the distribution network, FijIs a non-negative variable, representing the virtual power flow transmitted on line ij in the virtual power flow,is the power provided by the source point in the virtual network;
G. safety restraint:
H. photovoltaic output time uncertainty and photovoltaic output space uncertainty represent:
6. the method for photovoltaic absorption capacity evaluation considering time-space correlation and active management according to claim 5,
converting the robust photovoltaic absorption capacity evaluation model of the photovoltaic output and time-space correlation into a robust optimization form, and taking the efficiency factor of the photovoltaic systemTaking the minimum absorption capacity as a target for decision variables, adopting a CPLEX solver to calculate in an iterative mode until the calculation is finished when the line current error obtained by iteration is smaller than a preset threshold value, outputting the maximum photovoltaic installed capacity which is the photovoltaic absorption capacity of the power distribution network,
7. The method for evaluating the photovoltaic absorption capacity by considering the time-space correlation and the active management as claimed in claim 6, wherein in the solving process, a secant plane method is adopted to dynamically tighten the second-order cone constraint of the power flow of the power grid,
the cut plane in the τ +1 th iteration is:
8. A photovoltaic absorption capacity evaluation apparatus considering a time-space correlation and an active management, comprising:
the first calculation module is used for determining an ellipsoid uncertain set of photovoltaic output time uncertainty and an ellipsoid uncertain set of photovoltaic output space uncertainty based on the correlation of photovoltaic output with time and space;
the second calculation module is used for calculating the empirical distribution of the uncertainty precalculated values of the time and space of the uncertain set of the photovoltaic output ellipsoids;
the building module is used for building a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation; the model takes the maximum installed capacity of renewable energy sources on the node to be selected as a target function, and takes OLTC constraint, PV output constraint, reactive power output constraint of reactive power elements, tie line power constraint, branch power flow constraint, network topology constraint and safety constraint as constraint conditions;
and the number of the first and second groups,
and the output module is used for solving the robust photovoltaic consumption capability evaluation model to obtain the maximum installed capacity of the renewable energy source and the maximum photovoltaic consumption capability.
9. The photovoltaic absorption capability assessment apparatus according to claim 8, wherein said first calculation module is specifically configured to,
the ellipsoid uncertain set of the photovoltaic output time uncertainty and the ellipsoid uncertain set of the photovoltaic output space uncertainty are determined as follows:
wherein, COVSAnd COVTIs a photovoltaic output spatial covariance matrix and a temporal covariance matrix,representing node j at time tPVThe average photovoltaic power generation amount of (a),represents the photovoltaic power generation amount of the node j at the time t,for the purpose of the spatial uncertainty budget,for the purpose of the time uncertainty budget,the covariance matrix of the output of any two photovoltaic power stations at time T and T +1 is shown, wherein T is 1,2, …, and T represent the number of time segments; sigmaPVn,PVn+1N is 1,2, …, N is the covariance matrix between the nth photovoltaic power plant and the (N + 1) th photovoltaic power plant, N is the number of photovoltaic power plants,σPVn、σPVn+1is the standard deviation, pPVn,PVn+1Andis the Pearson correlation coefficient.
10. The method for photovoltaic absorption capacity assessment considering time-space correlation and active management according to claim 8, wherein said building block is specifically configured to,
an objective function of a robust photovoltaic absorption capacity evaluation model considering photovoltaic output and time-space correlation is established as follows:
wherein,representing PV mounting node jPVUpper mounted photovoltaic capacity, psiPVRepresenting a set of PV installation nodes to be selected;
the constraints are as follows:
A. the OLTC constraint:
wherein,indicating access node j at time tOLTCAn integer variable for a tap position, 0 for no at this tap position, 1 for at this tap position,the number of total taps is represented as,is a binary variable that is a function of the variable,is thatThe length of the binary expression of (a),indicating access node j at time tOLTCThe voltage of the secondary side of the transformer,is the access node j at time tOLTCThe ratio of the number of the phase-change material,indicating access at time tNode jOLTCThe change in the tap is such that,is the OLTC tap minimum turn ratio,andindicating access node j at time tOLTCThe increase or decrease of the adjustment state of (2),an increase is indicated by a value of 1,a value of 1 indicates a decrease in the number,representing an access node jOLTCThe regulation range of the on-load voltage regulator,representing an access node jOLTCMaximum regulation number of on-load voltage regulator, M and M0Representing parameters in a Big-M calculation method;
B. PV output constraint:
wherein,andrepresenting PV mounting node jPVThe minimum and maximum photovoltaic capacity of the installation,andrepresenting PV mounting node jPVThe photovoltaic active and photovoltaic reactive power output of the photovoltaic,represents PV installation node j at time tPVZeta represents the minimum photovoltaic output level,installing node j for PV at time tPVThe angle of the power factor of (a),andinstalling node j for PV at time tPVMinimum and maximum power factor angle of (d);
C. reactive power output constraint of reactive power element:
wherein,installing node j for time tCONThe continuously variable VAR device of (a) reactive power,andrespectively represent installation nodes jCONThe minimum value and the maximum value of the reactive power,to install node jDISThe reactive power of the discrete adjustable VAR device of (a),for each adjusted reactive power of a discrete adjustable VAR device,andis a binary auxiliary variable representing the installation of node j at time tDISThe discrete adjustable VAR apparatus of (a) adjusts the state of increase and decrease,represents the adjustment range of a discrete adjustable VAR device,represents an installation node jDISAt the maximum number of adjustments of the discrete adjustable VAR apparatus,for control-effective binary variables in discrete adjustable reactive devices, where the subscript s denotes the tap position, ΨCONRepresenting a set of mounted nodes of a candidate continuously variable VAR device, ΨDISRepresenting a set of discrete adjustable VAR device installation nodes to be selected;
D. tie line power constraint:
wherein,andrepresents the installation of node j at time tTRThe active power and the reactive power of the transformer are obtained,andrepresents the installation of node j at time tTRThe minimum and maximum active power of the transformer,andrepresents the installation of node j at time tTRMinimum and maximum reactive power of the transformer, psisubRepresenting a set of transformer installation nodes to be selected;
E. branch flow constraint:
where δ (j) is the set of all lines from node j, π (j) is the set of all lines connected to node j, Pjk,tAnd Qjk,tFor the active and reactive power of the line jk at time t, Pij,t、Qij,tFor the active and reactive power of line ij at time t, rijAnd xijAs resistance and reactance values of the line ij, bjIs the value of the conductance of the node j,andactive and reactive powers of node j, ΨEFor all line sets, ΨnFor all line node sets, eijIs a binary auxiliary variable representing whether line ij is connected, if line ij is connected, eij1, and vice versa, | · | | non-woven phosphor2Representing the euclidean norm.Representing the square of the line current and the node voltage, respectively;
F. and (3) network topology constraint:
-M·eij≤Fij≤M·eij ij∈ΨE;
wherein N isbusIs the number of nodes of the distribution network, FijIs a non-negative variable, representing the virtual power flow transmitted on line ij in the virtual power flow,is the power provided by the source point in the virtual network;
G. safety restraint:
H. photovoltaic output time uncertainty and photovoltaic output space uncertainty represent:
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Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109378861A (en) * | 2018-12-28 | 2019-02-22 | 东南大学 | The robust Optimization Scheduling of the active distribution network of meter and temporal correlation |
CN113241759A (en) * | 2021-05-13 | 2021-08-10 | 国网上海市电力公司 | Power distribution network and multi-microgrid robust scheduling method, electronic equipment and storage medium |
-
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- 2021-11-09 CN CN202111319231.5A patent/CN114243750B/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109378861A (en) * | 2018-12-28 | 2019-02-22 | 东南大学 | The robust Optimization Scheduling of the active distribution network of meter and temporal correlation |
CN113241759A (en) * | 2021-05-13 | 2021-08-10 | 国网上海市电力公司 | Power distribution network and multi-microgrid robust scheduling method, electronic equipment and storage medium |
Non-Patent Citations (2)
Title |
---|
MOSTAFA NAZEMI, ET AL: "Multivariate Uncertainty Characterization for Resilience Planning in Electric Power Systems", 2020 IEEE/IAS 56TH INDUSTRIAL AND COMMERCIAL POWER SYSTEMS TECHNICAL CONFERENCE (I&CPS), 25 August 2020 (2020-08-25), pages 1 - 8 * |
吴巍等: "考虑风电功率条件相关性的广义椭球不确定集合建模", 中国电机工程学报, vol. 37, no. 9, 5 May 2017 (2017-05-05), pages 2500 - 2507 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN117411086A (en) * | 2023-11-16 | 2024-01-16 | 南京工业大学 | Novel electric power system distribution robust optimal scheduling method and system containing fused magnesium |
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