A method and device for calculating active-reactive operation envelope of energy storage power station

Abstract

The application provides an active-reactive operation envelope calculation method and device for energy storage power stations, and relates to the field of power system control and optimization.The method comprises the following steps: establishing a network linear flow model based on a network topology; constructing an energy storage power station operation envelope rectangular model based on power grid safety constraints; and constructing an energy storage power station operation envelope expansion model based on energy storage output requirements.The application maps the voltage constraints of a power system to the output limits of an energy storage power station by establishing an operation envelope of the energy storage power station.The application firstly constructs an active-reactive power operation envelope rectangular model of the energy storage power station, which is used to provide greater flexibility for the control of the energy storage power station under the condition of meeting the voltage constraints, and then generates a pentagonal expansion operation envelope by finding a new vertex on the p-q plane, so that the active power output limit of the energy storage power station is improved.

Description

Technical Field

[0001] This invention relates to the field of power system control and optimization, specifically to a method and apparatus for calculating the active-reactive operating envelope of an energy storage power station. Background Technology

[0002] With the large-scale application of energy storage systems in power systems, arbitrary adjustment of their power output may cause voltage over-limit problems, increasing the operational risks of the power system. Traditional operation control methods mainly rely on directly controlling the active and reactive power output of energy storage power stations to meet the system's safe operation requirements. However, direct control requires the system operator to have a comprehensive grasp and control of the energy storage power station's information and operating modes, which is difficult to achieve in practical applications.

[0003] To address this, the Operating Envelope (OE) technique has been proposed to provide an allowable power output range to energy storage power stations while meeting system safety constraints, thereby decoupling the regulation responsibilities between operators and users. However, current research largely focuses on calculating the active power operating envelope, neglecting the role of reactive power, resulting in a lack of flexibility in regulation by energy storage power stations. Furthermore, existing active-reactive power operating envelope models mostly employ fixed power factors or fair allocation principles, leading to a small envelope coverage area that is insufficient to meet the flexible control requirements of energy storage power stations.

[0004] Therefore, it is necessary to propose a new method for calculating the active-reactive power operating envelope, which increases the coverage of the operating envelope in the pq plane, provides a more flexible control space for energy storage power stations, ensures the safe operation of the power system, and supports the flexible adjustment needs of energy storage users. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides a method and apparatus for calculating the active-reactive operating envelope of an energy storage power station.

[0006] This invention is achieved through the following technical solutions.

[0007] According to one aspect of the present invention, a method for calculating the active-reactive operating envelope of an energy storage power station is provided, comprising the following steps:

[0008] Based on network topology, establish a linear power flow model for the network.

[0009] Based on the linear power flow model of the network, a rectangular envelope model of the energy storage power station operation is constructed.

[0010] Based on the rectangular model of the operating envelope of the energy storage power station and the energy storage output demand, an extended model of the operating envelope of the energy storage power station is constructed.

[0011] Preferably, the network linear power flow model includes:

[0012] Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, and columns represent buses. The direction of a branch is from the upstream bus to its connected downstream bus, as detailed below: Element a ij =1 indicates that bus i is the upstream bus of branch j, and element a ij =-1 indicates that bus i is the downstream bus of branch j, and element a ij =0 indicates that bus i and branch j are independent. Let the first column of the matrix be a0, and the rest be denoted as the simplified branch-bus incidence matrix A:

[0013]

[0014] F = -A -1

[0015] The linear power flow equations of the transmission network are as follows:

[0016]

[0017] In the formula, p and q are the active and reactive power vectors of all buses, respectively, and P and Q are the active and reactive power vectors of all branches, respectively. V0 is the voltage of the reference bus, and V is the voltage vector of each bus except the first bus. D r and D x These represent the resistance and reactance of the branch, respectively. From this, the formula for calculating the node voltage can be derived:

[0018] V = Rp + Xq + V0

[0019] In the formula, R and X are respectively:

[0020] R = 2FD r F T

[0021] X = 2FD x F T .

[0022] Based on the linear power flow model of the network, the expression for the node voltage can be derived, which provides the basis for constructing node voltage constraints.

[0023] Preferably, the operating envelope rectangular model of the energy storage power station includes:

[0024] The active-reactive operating envelope is the set of active and reactive power that satisfies all bus and branch voltage constraints. Typically, the operating envelope is defined as a rectangle, with its length and width representing the active and reactive power of the active bus, respectively. For simplicity, the rectangular operating envelope is defined as a vector. Let x = [pq]T Where p and q are the column vectors of active and reactive power injected into the nodes, respectively. The portion of x corresponding to the active node (the node configured with energy storage) 7) is defined as x. var The part corresponding to the passive node is defined as x. const The rectangular running envelope is defined as follows:

[0025]

[0026] In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes,

[0027] To reduce the constraints in subsequent derivations, the runtime envelope is represented as:

[0028]

[0029] It is a diagonal matrix, N act For the set of active nodes, |N act | represents the set dimension.

[0030]

[0031] To maximize the coverage of the operating envelope on the pq plane and thus provide the greatest flexibility for energy storage regulation, we set the objective function for operating envelope calculation as follows:

[0032]

[0033] In the formula, tr(E) is the trace of matrix E.

[0034] Energy storage regulation must comply with the following safety constraints:

[0035] 1) Node voltage constraints:

[0036]

[0037] and These are the upper and lower limits of the square of the voltage amplitude, respectively.

[0038] 2) Baseline operating point constraints:

[0039] The runtime envelope should include the baseline runtime point of the active node. For active node k, its baseline runtime point is:

[0040] By merging the baseline running points of all active nodes into a vector form, we obtain:

[0041]

[0042] The baseline operating point constraints are as follows:

[0043]

[0044] In the formula: c d c is the deviation coefficient. d ∈[0,1 / 2]; Let be the column vector formed by the diagonal elements of matrix E.

[0045] 3) Constraints on regulatory flexibility:

[0046] To ensure the flexibility of energy storage regulation, i.e., to ensure that the operating envelope can cover all four quadrants of the pq plane, the following constraints are applied:

[0047]

[0048] 4) Aspect Ratio Constraints:

[0049] To avoid an imbalance in the aspect ratio of the rotating rectangle model, which would lead to a loss of flexibility in energy storage regulation, the following constraints are applied:

[0050]

[0051] In the formula: c r c is the aspect ratio coefficient. r ∈(0,1];E n It is the nth diagonal element of E, corresponding to the length of the rotated rectangle; It is E of the |Nth act |+n diagonal elements, corresponding to the width of the rotated rectangle.

[0052] 5) Fairness constraints

[0053] Because distributed energy resources occupy different locations within the distribution network, the sensitivity of node voltage and line power flow to their injected power varies. The operating envelope of the first-end node may be much larger than that of the last-end node, leading to fairness issues. To address this, fairness constraints are added:

[0054]

[0055] In the formula: c f c is the fairness coefficient. f ≥1; E1, It is the 1st and |Nth of E act |+1 diagonal element.

[0056] Preferably, the operating envelope extension model of the energy storage power station includes:

[0057] Based on the rectangular operating envelope model, an extended operating envelope for the energy storage power station is constructed to maximize the active power output range of the energy storage.

[0058] Node voltage constraints are divided into:

[0059]

[0060] In the formula, C = [RX], and is decomposed into active node components C. var and passive node component C const x = [pq] T .get:

[0061]

[0062] In the formula, x var =[p var q var ] T ,x const =[p const q const ] T .

[0063] The extended vertices of the running envelope are represented as x. e =[q e q e ] T The extended runtime envelope is then represented as:

[0064]

[0065] In the formula, Gx≤b represents the constraint condition of the line connecting the extended vertex and two adjacent vertices. Matrices G and b satisfy:

[0066]

[0067] In the formula, e i It is the identity matrix The i-th row. The remaining elements satisfy the following condition, (g) i For the i-th row of a matrix or vector:

[0068]

[0069] The extended runtime envelope model is transformed into the following form:

[0070] Jy≤j

[0071] In the formula:

[0072]

[0073] The voltage constraint can then be transformed into the following dual form:

[0074]

[0075]

[0076] In the formula: Γ and Δ are matrices composed of dual variables.

[0077] The security constraints can be changed to:

[0078]

[0079] The expanded running envelope is a pentagon, and the objective is to maximize the height of the expanded triangle.

[0080]

[0081] In addition to the node voltage constraints and safety constraints as described above, the constraints also include:

[0082]

[0083] This led to the construction of an extended operating envelope for energy storage power stations.

[0084] As a further aspect of the present invention, the present invention also provides an active-reactive power storage power station active-reactive power envelope calculation device, comprising:

[0085] The model building module is used to build a linear power flow model of the network based on the network topology; to construct a rectangular operating envelope model of the energy storage power station based on the linear power flow model of the network; and to construct an extended operating envelope model of the energy storage power station based on the rectangular operating envelope model of the energy storage power station and the energy storage output demand.

[0086] The calculation module is used to calculate the active-reactive operating envelope of the energy storage power station based on the extended operating envelope model of the energy storage power station.

[0087] The model building module is specifically used to build a linear power flow model of the network according to the following steps:

[0088] Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, columns represent buses, and the direction of a branch is from the upstream bus to the downstream bus it connects to, as detailed below: Element a ij =1 indicates that bus i is the upstream bus of branch j, and element a ij =-1 indicates that bus i is the downstream bus of branch j, and element a ij =0 indicates that bus i and branch j are independent. Let the first column of the matrix be a0, and the rest be denoted as the simplified branch-bus incidence matrix A:

[0089]

[0090] F = -A -1

[0091] The linear power flow equations of the transmission network are as follows:

[0092]

[0093] In the formula, p and q are the active and reactive power vectors of all buses, P and Q are the active and reactive power vectors of all branches, V0 is the voltage of the reference bus, V is the voltage vector of each bus except the first bus, and D... r and D x Let the resistance and reactance of the branch be the values, respectively. From this, we can derive the formula for calculating the node voltage:

[0094] V = Rp + Xq + V0

[0095] In the formula, R and X are respectively:

[0096] R = 2FD r F T

[0097] X = 2FD x F T .

[0098] The method for constructing the rectangular envelope model of an energy storage power station operation includes the following steps:

[0099] Define the rectangular running envelope in vector form, let x = [pq] T Where p and q are the column vectors of active and reactive power injected into the nodes, respectively, and the portion of x corresponding to the active nodes is defined as x. var The part corresponding to the passive node is defined as x. const The rectangular running envelope is defined as follows:

[0100]

[0101] In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes,

[0102] The running envelope is represented in the following form to reduce the expression of constraints in subsequent derivations:

[0103]

[0104] It is a diagonal matrix, N act For the set of active nodes, |N act | represents the set dimension.

[0105] The objective function for calculating the envelope is set as follows:

[0106]

[0107] In the formula, tr(E) is the trace of matrix E;

[0108] Energy storage regulation must comply with the following safety constraints:

[0109] 1) Node voltage constraints:

[0110]

[0111] and These are the upper and lower limits of the square of the voltage amplitude, respectively;

[0112] 2) Baseline operating point constraints:

[0113] The runtime envelope contains the baseline runtime point of the active node. For active node k, its baseline runtime point is:

[0114] By merging the baseline running points of all active nodes into a vector form, we obtain:

[0115]

[0116] The baseline operating point constraints are as follows:

[0117]

[0118] In the formula: c d c is the deviation coefficient. d ∈[0,1 / 2]; Let be the column vector formed by the diagonal elements of matrix E;

[0119] 3) Constraints on regulatory flexibility:

[0120]

[0121] 4) Aspect Ratio Constraints:

[0122]

[0123] In the formula: c r c is the aspect ratio coefficient. r ∈(0,1];E n It is the nth diagonal element of E, corresponding to the length of the rotated rectangle; It is E of the |Nth act |+n diagonal elements, corresponding to the width of the rotated rectangle;

[0124] 5) Fairness constraints

[0125]

[0126] In the formula: c f c is the fairness coefficient. f ≥1; E1, It is the 1st and |Nth of E act |+1 diagonal element.

[0127] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0128] The active-reactive power operation envelope calculation method for energy storage power stations provided by this invention provides the operating range of energy storage power stations while ensuring grid security.

[0129] The present invention provides a method for calculating the active-reactive operating envelope of energy storage power stations, which expands the traditional rectangular model, improves the flexibility of energy storage power station regulation, and thus provides reliable support for the regulation and planning of energy storage power stations.

[0130] This invention provides a method for calculating the active-reactive power storage (ERS) operating envelope of an energy storage power station. Based on network topology, a linear power flow model is established; based on grid security constraints, a rectangular model of the ERS operating envelope is constructed; and based on energy storage output demand, an extended model of the ERS operating envelope is constructed. Compared with traditional design methods, this invention expands the range of the ERS operating envelope and improves the flexibility of ERS regulation.

[0131] The active-reactive power operation envelope calculation method for energy storage power stations provided by this invention has great practical engineering value. Attached Figure Description

[0132] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0133] Figure 1 This is a flowchart of the active-reactive operating envelope calculation method for an energy storage power station in a preferred embodiment of the present invention. Detailed Implementation

[0134] The embodiments of the present invention are described in detail below: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0135] This invention provides a method for calculating the active-reactive power supply envelope of an energy storage power station. Based on network topology, a linear power flow model is established; based on grid security constraints, a rectangular model of the energy storage power station's operating envelope is constructed; and based on energy storage output demand, an extended model of the energy storage power station's operating envelope is constructed. This method has practical theoretical significance and widespread application value for the scheduling and planning of energy storage power stations.

[0136] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0137] Please refer to the following first. Figure 1 , Figure 1 This is a flowchart of the active-reactive power storage power station active-reactive power operation envelope calculation method provided in this embodiment of the invention. As shown in the figure, the active-reactive power storage power station active-reactive power operation envelope calculation method provided in this embodiment of the invention includes the following steps:

[0138] Step 1) Establish a linear power flow model of the network based on the network topology.

[0139] As a preferred embodiment, the method of step 1) is as follows:

[0140] Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, and columns represent buses. The direction of a branch is from the upstream bus to its connected downstream bus, as detailed below: Element a ij =1 indicates that bus i is the upstream bus of branch j, and element a ij =-1 indicates that bus i is the downstream bus of branch j, and element a ij =0 indicates that bus i and branch j are independent. Let the first column of the matrix be a0, and the rest be denoted as the simplified branch-bus incidence matrix A:

[0141]

[0142] F = -A -1

[0143] The linear power flow equations of the transmission network are as follows:

[0144]

[0145] In the formula, p and q are the active and reactive power vectors of all buses, respectively, and P and Q are the active and reactive power vectors of all branches, respectively. V0 is the voltage of the reference bus, and V is the voltage vector of each bus except the first bus. Dr and D x These represent the resistance and reactance of the branch, respectively. From this, the formula for calculating the node voltage can be derived:

[0146] V = Rp + Xq + V0

[0147] In the formula, R and X are respectively:

[0148] R = 2FD r F T

[0149] X = 2FD x F T

[0150] Step 2) Based on the linear power flow model of the network, construct the rectangular envelope model of the energy storage power station operation;

[0151] As a preferred embodiment, the method of step 2) is as follows:

[0152] The active-reactive operating envelope is the set of active and reactive power that satisfies all bus and branch voltage constraints. Typically, the operating envelope is defined as a rectangle, with its length and width representing the active and reactive power of the active bus, respectively. For simplicity, the rectangular operating envelope is defined as a vector. Let x = [pq] T Where p and q are the column vectors of active and reactive power injected into the nodes, respectively. The portion of x corresponding to the active node (the node configured with energy storage) 7) is defined as x. var The part corresponding to the passive node is defined as x. const The rectangular running envelope is defined as follows:

[0153]

[0154] In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes,

[0155]

[0156] To reduce the constraints in subsequent derivations, the runtime envelope is represented as:

[0157]

[0158] It is a diagonal matrix, N act For the set of active nodes, |N act | represents the set dimension.

[0159]

[0160] To maximize the coverage of the operating envelope on the pq plane and thus provide the greatest flexibility for energy storage regulation, we set the objective function for operating envelope calculation as follows:

[0161]

[0162] In the formula, tr(E) is the trace of matrix E.

[0163] Energy storage regulation must comply with the following safety constraints:

[0164] 1) Node voltage constraints:

[0165]

[0166] and These are the upper and lower limits of the square of the voltage amplitude, respectively.

[0167] 2) Baseline operating point constraints:

[0168] The runtime envelope should include the baseline runtime point of the active node. For active node k, its baseline runtime point is:

[0169] By merging the baseline running points of all active nodes into a vector form, we obtain:

[0170]

[0171] The baseline operating point constraints are as follows:

[0172]

[0173] In the formula: c d c is the deviation coefficient. d ∈[0,1 / 2]; Let be the column vector formed by the diagonal elements of matrix E.

[0174] 3) Constraints on regulatory flexibility:

[0175] To ensure the flexibility of energy storage regulation, i.e., to ensure that the operating envelope can cover all four quadrants of the pq plane, the following constraints are applied:

[0176]

[0177] 4) Aspect Ratio Constraints:

[0178] To avoid an imbalance in the aspect ratio of the rotating rectangle model, which would lead to a loss of flexibility in energy storage regulation, the following constraints are applied:

[0179]

[0180] In the formula: cr c is the aspect ratio coefficient. r ∈(0,1];E n It is the nth diagonal element of E, corresponding to the length of the rotated rectangle; It is E of the |Nth act |+n diagonal elements, corresponding to the width of the rotated rectangle.

[0181] 5) Fairness constraints

[0182] Because distributed energy resources occupy different locations within the distribution network, the sensitivity of node voltage and line power flow to their injected power varies. The operating envelope of the first-end node may be much larger than that of the last-end node, leading to fairness issues. To address this, fairness constraints are added:

[0183]

[0184] In the formula: c f c is the fairness coefficient. f ≥1; E1, It is the 1st and |Nth of E act |+1 diagonal element.

[0185] Step 3): Based on the rectangular model of the energy storage power station's operating envelope and the energy storage output demand, construct an extended model of the energy storage power station's operating envelope.

[0186] As a preferred embodiment, the method of step 3) is as follows:

[0187] Based on the rectangular operating envelope model, an extended operating envelope for the energy storage power station is constructed to maximize the active power output range of the energy storage.

[0188] Node voltage constraints are divided into:

[0189]

[0190]

[0191] In the formula, C = [RX], and is decomposed into active node components C. var and passive node component C const x = [pq] T .get:

[0192]

[0193] In the formula, x var =[p var q var ] T ,x const =[p const q const ] T.

[0194] The extended vertices of the running envelope are represented as x. e =[q e q e ] T The extended runtime envelope is then represented as:

[0195]

[0196] In the formula, Gx≤b represents the constraint condition of the line connecting the extended vertex and two adjacent vertices. Matrices G and b satisfy:

[0197]

[0198] In the formula, e i It is the identity matrix The i-th row. The remaining elements satisfy the following condition, (g) i For the i-th row of a matrix or vector:

[0199]

[0200] The extended runtime envelope model is transformed into the following form:

[0201] Jy≤j

[0202] In the formula:

[0203]

[0204] The voltage constraint can then be transformed into the following dual form:

[0205]

[0206] In the formula: Γ and Δ are matrices composed of dual variables.

[0207] The security constraints can be changed to:

[0208]

[0209] The expanded running envelope is a pentagon, and the objective is to maximize the height of the expanded triangle.

[0210]

[0211] In addition to the node voltage constraints and safety constraints as described above, the constraints also include:

[0212]

[0213] This led to the construction of an extended operating envelope for energy storage power stations.

[0214] Preferably, the present invention also provides an active-reactive operating envelope calculation device for an energy storage power station, comprising:

[0215] The model building module is used to build a linear power flow model of the network based on the network topology; to construct a rectangular operating envelope model of the energy storage power station based on the linear power flow model of the network; and to construct an extended operating envelope model of the energy storage power station based on the rectangular operating envelope model of the energy storage power station and the energy storage output demand.

[0216] The calculation module is used to calculate the active-reactive operating envelope of the energy storage power station based on the extended operating envelope model of the energy storage power station.

[0217] The model building module is specifically used to build a linear power flow model of the network according to the following steps:

[0218] Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, columns represent buses, and the direction of a branch is from the upstream bus to the downstream bus it connects to, as detailed below: Element a ij =1 indicates that bus i is the upstream bus of branch j, and element a ij =-1 indicates that bus i is the downstream bus of branch j, and element a ij =0 indicates that bus i and branch j are independent. Let the first column of the matrix be a0, and the rest be denoted as the simplified branch-bus incidence matrix A:

[0219]

[0220] F = -A -1

[0221] The linear power flow equations of the transmission network are as follows:

[0222]

[0223] In the formula, p and q are the active and reactive power vectors of all buses, P and Q are the active and reactive power vectors of all branches, V0 is the voltage of the reference bus, V is the voltage vector of each bus except the first bus, and D... r and D x Let the resistance and reactance of the branch be the values, respectively. From this, we can derive the formula for calculating the node voltage:

[0224] V = Rp + Xq + V0

[0225] In the formula, R and X are respectively:

[0226] R = 2FD r F T

[0227] X = 2FD x F T .

[0228] The method for constructing a rectangular envelope model of an energy storage power station based on grid security constraints includes the following steps:

[0229] Define the rectangular running envelope in vector form, let x = [pq] T Where p and q are the column vectors of active and reactive power injected into the nodes, respectively, and the portion of x corresponding to the active nodes is defined as x. var The part corresponding to the passive node is defined as x. const The rectangular running envelope is defined as follows:

[0230]

[0231] In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes,

[0232] The running envelope is represented in the following form to reduce the expression of constraints in subsequent derivations:

[0233]

[0234] It is a diagonal matrix, N act For the set of active nodes, |N act | represents the set dimension.

[0235] The objective function for calculating the envelope is set as follows:

[0236]

[0237] In the formula, tr(E) is the trace of matrix E;

[0238] Energy storage regulation must comply with the following safety constraints:

[0239] 1) Node voltage constraints:

[0240]

[0241] and These are the upper and lower limits of the square of the voltage amplitude, respectively;

[0242] 2) Baseline operating point constraints:

[0243] The runtime envelope contains the baseline runtime point of the active node. For active node k, its baseline runtime point is:

[0244] By merging the baseline running points of all active nodes into a vector form, we obtain:

[0245]

[0246] The baseline operating point constraints are as follows:

[0247]

[0248] In the formula: c d c is the deviation coefficient. d ∈[0,1 / 2]; Let be the column vector formed by the diagonal elements of matrix E;

[0249] 3) Constraints on regulatory flexibility:

[0250]

[0251] 4) Aspect Ratio Constraints:

[0252]

[0253] In the formula: c r c is the aspect ratio coefficient. r ∈(0,1];E n It is the nth diagonal element of E, corresponding to the length of the rotated rectangle; It is E of the |Nth act |+n diagonal elements, corresponding to the width of the rotated rectangle;

[0254] 5) Fairness constraints

[0255]

[0256] In the formula: c f c is the fairness coefficient. f ≥1; E1, It is the 1st and |Nth of E act |+1 diagonal element.

[0257] This invention provides a method for calculating the active-reactive power storage (ERS) operating envelope of an energy storage power station. Based on network topology, a linear power flow model is established; based on grid security constraints, a rectangular model of the ERS operating envelope is constructed; and based on energy storage output demand, an extended model of the ERS operating envelope is constructed. Compared with traditional design methods, this invention expands the range of the ERS operating envelope and improves the flexibility of ERS regulation.

[0258] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the active-reactive operating envelope of an energy storage power station, characterized in that, Includes the following steps: Based on network topology, establish a linear power flow model for the network. Based on the linear power flow model of the network, a rectangular envelope model of the energy storage power station operation is constructed. Based on the rectangular model of the operating envelope of the energy storage power station and the energy storage output demand, an extended model of the operating envelope of the energy storage power station is constructed. The active-reactive operating envelope of the energy storage power station is calculated based on the extended operating envelope model of the energy storage power station. The method for constructing an extended operating envelope model of an energy storage power station based on energy storage output demand includes the following steps: Based on the rectangular operating envelope model, an extended operating envelope for the energy storage power station is constructed. Node voltage constraints are divided into: In the formula, And decomposed into active node components. and passive node components , ,get: In the formula, , ; To represent the voltage of the reference bus, and These are the upper and lower limits of the square of the voltage amplitude, respectively. p and q These are the active and reactive power vectors of all buses, respectively. The extended vertices of the running envelope are represented as The extended runtime envelope is then represented as: In the formula, Let G and b represent the constraints of the line connecting the extended vertex and two adjacent vertices, and let matrices G and b satisfy: In the formula, It is the identity matrix In the i-th row, the remaining elements satisfy the following condition. For the i-th row of a matrix or vector: The extended runtime envelope model is transformed into the following form: In the formula: The voltage constraint can then be transformed into the following dual form: In the formula: and It is a matrix composed of dual variables; The security constraints become: In the formula, It is a fairness coefficient. ; The expanded running envelope is a pentagon, and the objective is to maximize the height of the expanded triangle. In addition to the transformed node voltage constraints and safety constraints, the constraints also include: This led to the construction of an extended operating envelope for energy storage power stations.

2. The method for calculating the active-reactive operating envelope of an energy storage power station according to claim 1, characterized in that, The method for establishing a linear power flow model of a network includes the following steps: Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, columns represent buses, and the direction of a branch is from the upstream bus to its connected downstream bus, as detailed below: Elements Indicates busbar i It is a side road j The upstream busbar, element Indicates busbar i It is a side road j Downstream busbar, element Indicates busbar i and branch roads j Irrelevant, let the first column of the matrix be a 0, the rest is denoted as the simplified branch-bus correlation matrix. A : The linear power flow equations of the transmission network are as follows: In the formula, p and q These are the active and reactive power vectors for all buses, respectively. P and Q These are the active and reactive power vectors for all branches, respectively. V 0 is the voltage of the reference bus. V It is the voltage vector of all buses except the first bus. D r and D x Let the resistance and reactance of the branch be the values, respectively. From this, we can derive the formula for calculating the node voltage: In the formula, R and X They are respectively: 。 3. The method for calculating the active-reactive operating envelope of an energy storage power station according to claim 1 or 2, characterized in that, The method for constructing the rectangular envelope model of an energy storage power station based on a linear power flow model includes the following steps: Define the rectangular running envelope in vector form, let ,in p and q Inject active and reactive power column vectors into the nodes respectively. x The part corresponding to the active node is defined as follows: x var The part corresponding to the passive node is defined as follows: x const The rectangular running envelope is defined as follows: In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes, ; The running envelope is represented in the following form to reduce the expression of constraints in subsequent derivations: It is a diagonal matrix. N act For the set of active nodes, For the set dimension, ; The objective function for calculating the envelope is set as follows: In the formula, For matrix E traces; Energy storage regulation must comply with the following safety constraints: 1) Node voltage constraints: 2) Baseline operating point constraints: The runtime envelope contains the baseline runtime point of the active node, for the active node. Its reference operating point is By merging the baseline running points of all active nodes into a vector form, we obtain: The baseline operating point constraints are as follows: In the formula: This is the deviation coefficient. ; For matrix A column vector consisting of the diagonal elements; 3) Constraints on regulatory flexibility: 4) Aspect Ratio Constraints: In the formula: The aspect ratio coefficient. ; yes No. Each diagonal element corresponds to the length of the rotated rectangle; yes No. Each diagonal element corresponds to the width of the rotated rectangle; 5) Fairness constraints In the formula: For fairness coefficient, ; yes The first and the One diagonal element.

4. A device for calculating the active-reactive operating envelope of an energy storage power station using the method described in any one of claims 1-3, characterized in that, include: The model building module is used to build linear power flow models of a network based on its topology. Based on the linear power flow model of the network, a rectangular envelope model of the energy storage power station operation is constructed. Based on the rectangular model of the operating envelope of the energy storage power station and the energy storage output demand, an extended model of the operating envelope of the energy storage power station is constructed. The calculation module is used to calculate the active-reactive operating envelope of the energy storage power station based on the extended operating envelope model of the energy storage power station.

5. The active-reactive power storage power station active-reactive power envelope calculation device according to claim 4, characterized in that, The model building module is specifically used to build a linear power flow model of the network according to the following steps: Generate the branch-bus correlation matrix of the power transmission network In this matrix, rows represent branches, columns represent buses, and the direction of a branch is from the upstream bus to its connected downstream bus, as detailed below: Elements Indicates busbar i It is a side road j The upstream busbar, element Indicates busbar i It is a side road j Downstream busbar, element Indicates busbar i and branch roads j Irrelevant, let the first column of the matrix be a 0, the rest is denoted as the simplified branch-bus correlation matrix. A : The linear power flow equations of the transmission network are as follows: In the formula, p and q These are the active and reactive power vectors for all buses, respectively. P and Q These are the active and reactive power vectors for all branches, respectively. V 0 is the voltage of the reference bus. V It is the voltage vector of all buses except the first bus. D r and D x Let the resistance and reactance of the branch be the values, respectively. From this, we can derive the formula for calculating the node voltage: In the formula, R and X They are respectively: 。 6. The active-reactive power storage power station active-reactive power envelope calculation device according to claim 5, characterized in that, The method for constructing the rectangular envelope model of an energy storage power station operation includes the following steps: Define the rectangular running envelope in vector form, let ,in p and q Inject active and reactive power column vectors into the nodes respectively. x The part corresponding to the active node is defined as follows: x var The part corresponding to the passive node is defined as follows: x const The rectangular running envelope is defined as follows: In the formula: and These are the upper and lower bounds of the rectangular running envelope, respectively. For passive nodes, ; The running envelope is represented in the following form to reduce the expression of constraints in subsequent derivations: It is a diagonal matrix. N act For the set of active nodes, For the set dimension, ; The objective function for calculating the envelope is set as follows: In the formula, For matrix E traces; Energy storage regulation must comply with the following safety constraints: 1) Node voltage constraints: and These are the upper and lower limits of the square of the voltage amplitude, respectively; 2) Baseline operating point constraints: The runtime envelope contains the baseline runtime point of the active node, for the active node. Its reference operating point is By merging the baseline running points of all active nodes into a vector form, we obtain: The baseline operating point constraints are as follows: In the formula: This is the deviation coefficient. ; For matrix A column vector consisting of the diagonal elements; 3) Constraints on regulatory flexibility: 4) Aspect Ratio Constraints: In the formula: The aspect ratio coefficient. ; yes No. Each diagonal element corresponds to the length of the rotated rectangle; yes No. Each diagonal element corresponds to the width of the rotated rectangle; 5) Fairness constraints In the formula: yes The first and the One diagonal element.

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