Power system carbon flow calculation method based on extended incidence matrix

Abstract

The invention discloses an extended incidence matrix-based power system carbon flow calculation method, which comprises the following steps of: 1) acquiring a power grid topological structure and parameters of a power system, and generating a current tracking model; and 2) performing power calculation based on an extended incidence matrix on the current tracking model to obtain a power supply side-line side power distribution model and a power supply side-load side power distribution model. And 3) performing electric carbon coupling calculation on the power distribution model of the power supply side-line side and the power distribution model of the power supply side-load side to obtain a carbon flow calculation result of the power system. The method is not based on any subjectively set proportion distribution principle, but based on the power flow result or the state estimation result, unit-line-load carbon tracking and carbon calculation are achieved, and the calculation efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-carbon power, and in particular to a method for calculating carbon flow in a power system based on an extended incidence matrix. Background Art

[0002] As the main force in energy conservation and emission reduction, the power industry urgently needs to analyze and measure the carbon emissions of the power system. Therefore, the method for calculating the carbon emission flow of the power system has been rapidly developed and applied. At present, for the calculation of the carbon emission flow of the power system, the carbon flow analysis is mainly carried out based on the power flow calculation and the equal proportion principle to obtain the relevant carbon flow quantities such as the carbon potential of each node and the carbon flow density of the line. However, these methods are based on the principle of proportional sharing, which has a certain subjectivity, and this principle is not applicable when the load power factors vary greatly. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a method for calculating carbon flow in a power system based on an extended incidence matrix, which does not rely on any subjectively set proportional distribution principle, but is based on the power flow result or the state estimation result to achieve carbon tracking and carbon calculation for the unit-line-load, and effectively improve the calculation efficiency.

[0004] To achieve the above purpose, the technical solution provided by the present invention is: A method for calculating carbon flow in a power system based on an extended incidence matrix, comprising the following steps:

[0005] 1) Obtain the grid topology structure and parameters of the power system, and generate a current tracking model;

[0006] 2) Perform power calculation based on the extended incidence matrix on the current tracking model to obtain a power distribution model from the power source side to the line side and a power distribution model from the power source side to the load side;

[0007] 3) Perform electro-carbon coupling calculation on the power distribution model from the power source side to the line side and the power distribution model from the power source side to the load side to obtain the calculation result of the carbon flow in the power system.

[0008] Further, in step 1), the grid topology structure and parameters of the power system include: the grid topology structure and line admittance parameters, the output power and voltage of each generator node in the power system, the load power and voltage of each load node, and the carbon emission intensity factor of each generator. Based on the above topology structure and parameters, an extended incidence matrix-based current tracking model is generated, including:

[0009] ① The equivalent susceptance matrix to the ground, and the formula is:

[0010]

[0011] In the formula, j·(·) is the imaginary part, YX is the equivalent susceptance matrix to the ground, B(q) is the susceptance to the ground of line q, i and j′ are node numbers, and N i is the set of all lines connected to node i;

[0012] ② The equivalent susceptance injection current, and the formula is:

[0013]

[0014] In the formula, is the equivalent susceptance injection current, is the node voltage, is the equivalent susceptance to the ground of node m;

[0015] ③ The generator injection current vector and the load outflow current vector of the power system, and the formula is:

[0016]

[0017] In the formula, is the generator injection current column vector, is the load outflow current column vector, are the injected complex power vector and the generator node voltage vector of the unit respectively, are the load outflow power vector and the load node voltage vector respectively;

[0018] ④ The node equivalent injection current and the node equivalent injection power, and the formula is:

[0019]

[0020] In the formula, is the node equivalent injection current, which is the sum of the currents caused by the unit and the susceptance to the ground, is the node equivalent injection power.

[0021] Furthermore, in step 2), a power distribution calculation based on the extended incidence matrix is performed on the current tracing model, including the following steps:

[0022] 2.1) For Equation (3), according to the conservation relationship of node currents and the power grid topology, construct an extended incidence matrix, and obtain the mathematical relationship between the real and imaginary parts of the injection current and the load outflow current:

[0023]

[0024] In the formula, A r is the real part extended incidence matrix, A i is the imaginary part extended incidence matrix, Re(·) represents taking the real part, Im(·) represents taking the imaginary part, represents the real part of the load outflow current, represents the real part of the injected current of the generator, represents the imaginary part of the current flowing out of the load, represents the imaginary part of the injected current of the generator, 1 T represents the unit column vector; among them, the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i The sub-elements are:

[0025]

[0026] In the formula, a r (·) and a i (·) respectively represent the sub-elements of the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i The sub-elements of, represents the current flowing from node s to node t through branch s-t, represents the current flowing from node f to node s through branch f-s, represents the injected current of node s;

[0027] 2.2) Calculate the current tracking coefficients of the power source side-network side-load side, take the inverse of Equation (5) and Equation (6), and obtain the relationship between the injected current and the real and imaginary parts of the current flowing out of the load as:

[0028]

[0029] In the formula, is the diagonal matrix of the injected current;

[0030] 2.3) In Equation (9), and are respectively the real part current distribution coefficient matrix K of the injected current with respect to the current flowing out of the load r and the imaginary part current distribution coefficient matrix K of the injected current with respect to the current flowing out of the load i :

[0031]

[0032] In the formula, k r (i,j′) is the real part current distribution coefficient of the injected current of node i with respect to the load current of node j′, and k i (i,j′) is the imaginary part current distribution coefficient of the injected current of node i with respect to the load current of node j′;

[0033] 2.4) Combine the imaginary and real part current distribution coefficients obtained from Equation (10) to form a complete current distribution coefficient. The formula is:

[0034]

[0035] In the formula, is the current distribution value of the injected current at node i to the load current at node j';

[0036] 2.5) Calculate the complex current distribution coefficient matrix of the injected current at node i to the load current at node j' and the matrix expression of the distribution of each injected current to each load current:

[0037]

[0038] In the formula, K = [k(i,j')] m×m is the complex current distribution coefficient matrix, and k(i,j') is the complex current distribution coefficient. is the distribution current matrix, is the load current at node j';

[0039] 2.6) Calculate the matrix expression of the power distribution from the power source side to the load side, which is called the power distribution model from the power source side to the load side:

[0040]

[0041] In the formula, is the node voltage vector, and its sub-element is the node voltage at node i. S in-L represents the complex power distribution matrix of each equivalent injected current to each load;

[0042] 2.7) Calculate the matrix expression of the power distribution from the power source side to the line side, which is called the power distribution model from the power source side to the line side:

[0043]

[0044] In the formula, is the diagonal matrix of the line start node voltage, is the diagonal matrix of the line end node voltage, represents the complex power matrix of each injected current to the injected power at the start of each line; represents the complex power matrix of each injected current to the injected power at the end of each line; is the distribution current of node i to line q;

[0045] So far, the power calculation of the current tracing model of the power system has been carried out based on the extended incidence matrix, and the power distribution model from the power source side to the line side and the power distribution model from the power source side to the load side have been obtained.

[0046] Further, in step 3), an electro-carbon coupling calculation is performed on the power distribution model between the power supply side and the line side and the power distribution model between the power supply side and the load side to obtain the calculation results of the carbon flow in the power system, that is, the carbon emission rates of the power supply side - load side and the power supply side - line side of the carbon flow, specifically as follows:

[0047] Calculate the carbon emission rate of the power supply side - load side of the carbon flow:

[0048] E L = Re(S in-L )Δe G (16)

[0049] In the formula, E L is the load carbon emission rate matrix, and e G is the matrix of carbon emissions generated per unit of electricity generated by each power source;

[0050] Calculate the carbon emission rate of the power supply side - line side of the carbon flow:

[0051]

[0052] In the formula, Ε Δ is the carbon emission rate of line network loss;

[0053] So far, the electro-carbon coupling calculation is completed, and the calculation results of the carbon flow in the power system are obtained.

[0054] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0055] 1. According to the power usage requirements, the present invention divides the carbon emission responsibility, enabling users to recognize the carbon emissions caused by their electricity consumption behaviors and stimulating users' enthusiasm for actively participating in energy conservation and consumption reduction. At the same time, the carbon emissions on the user side mainly come from the units at the same node or nearby units. Therefore, relevant green certificate enterprises can use this as a basis for site selection.

[0056] 2. Compared with the widely used methods of active carbon flow tracking and complex power carbon flow tracking based on the proportional sharing principle, the algorithm of the present invention has a wider applicable scenario, is more in line with the actual situation, and the tracking results of carbon emissions are more reasonable.

[0057] 3. The matrix invertibility effectively reduces the calculation time and basically meets the actual engineering requirements, indicating the practicality of the algorithm of the present invention in actual engineering. Description of the Drawings

[0058] Figure 1 is the flowchart of the method of the present invention. Detailed Embodiments

[0059] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0060] As Figure 1 shown, this embodiment discloses a method for calculating carbon flow in a power system based on an extended incidence matrix, including the following steps:

[0061] 1) Obtain the grid topology structure and parameters of the power system, including: the grid topology structure and line admittance parameters, the output power and voltage of each generator node in the power system, the load power and voltage of each load node, and the carbon emission intensity factor of each generator. Generate a current tracing model based on the extended incidence matrix according to the above topology structure and parameters, including:

[0062] ① The shunt susceptance matrix to ground, with the formula:

[0063]

[0064] where jΔ(Δ) is the imaginary part, Y X is the shunt susceptance matrix to ground, B(q) is the shunt susceptance of line q to ground, i and j′ are node numbers, and N i is the set of all lines connected to node i;

[0065] ② The injected current of equivalent susceptance, with the formula:

[0066]

[0067] where is the injected current of equivalent susceptance, is the node voltage, is the shunt susceptance of node m to ground;

[0068] ③ The injected current vector of generators and the out-flowing current vector of loads in the power system, with the formula:

[0069]

[0070] where is the column vector of injected current of generators, is the column vector of out-flowing current of loads, are the injected complex power vector and the generator node voltage vector of the unit respectively, are the out-flowing power vector of the load and the load node voltage vector respectively;

[0071] ④ The equivalent injected current of the node and the equivalent injected power of the node, with the formula:

[0072]

[0073] where is the equivalent injected current of the node, which is the sum of the current caused by the unit and the shunt susceptance to ground, is the equivalent injection power of the node.

[0074] 2) Perform power calculation on the current tracking model based on the extended incidence matrix to obtain the power distribution models of the power source side-line side and the power source side-load side, including the following steps:

[0075] 2.1) For Equation (3), construct an extended incidence matrix according to the conservation relationship of node currents and the power grid topology structure, and obtain the mathematical relationships between the injection current and the real and imaginary parts of the load outflow current:

[0076]

[0077] In the formula, A r is the real part extended incidence matrix, A i is the imaginary part extended incidence matrix, Re(·) represents taking the real part, Im(·) represents taking the imaginary part, represents the real part of the load outflow current, represents the real part of the generator injection current, represents the imaginary part of the load outflow current, represents the imaginary part of the generator injection current, 1 T represents the unit column vector; among them, the sub-elements of the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i are:

[0078]

[0079] In the formula, a r (·) and a i (·) respectively represent the sub-elements of the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i , represents the current flowing from node s to node t through branch s-t, represents the current flowing from node f to node s through branch f-s, represents the injection current of node s;

[0080] 2.2) Calculate the current tracking coefficients of the power source side-network side-load side, take the inverse of Equation (5) and Equation (6), and obtain the relationships between the injection current and the real and imaginary parts of the load outflow current as:

[0081]

[0082] In the formula, is the injection current diagonal matrix;

[0083] 2.3) In Equation (9), and They are the real - part current distribution coefficient matrix \(K\) of the injection current with respect to the load outflow current r and the imaginary - part current distribution coefficient matrix \(K\) of the injection current with respect to the load outflow current i :

[0084]

[0085] In the formula, \(k\) r (i, j′) is the real - part current distribution coefficient of the injection current at node \(i\) with respect to the load current at node \(j′\), and \(k\) i (i, j′) is the imaginary - part current distribution coefficient of the injection current at node \(i\) with respect to the load current at node \(j′\);

[0086] 2.4) Combine the imaginary - part and real - part current distribution coefficients obtained from Equation (10) to form a complete current distribution coefficient. The formula is:

[0087]

[0088] In the formula, is the current distribution value of the injection current at node \(i\) with respect to the load current at node \(j′\);

[0089] 2.5) Calculate the complex - current distribution coefficient matrix of the injection current at node \(i\) with respect to the load current at node \(j′\) and the matrix expression of the distribution of each injection current to each load current:

[0090]

[0091] In the formula, \(K = [k(i, j′)] m×m is the complex - current distribution coefficient matrix, \(k(i, j′)\) is the complex - current distribution coefficient, is the distribution current matrix, is the load current at node \(j′\);

[0092] 2.6) Calculate the matrix expression of the power distribution from the power - source side to the load side, which is called the power - source - side to load - side power distribution model:

[0093]

[0094] In the formula, is the node - voltage vector, and its sub - element is the node voltage of node \(i\), \(S in-L represents the complex - power distribution matrix of each equivalent injection current to each load;

[0095] 2.7) Calculate the matrix expression of the power distribution from the power - source side to the line side, which is called the power - source - side to line - side power distribution model:

[0096]

[0097] Wherein, is the diagonal matrix of the node voltage at the head of the line, is the diagonal matrix of the node voltage at the end of the line, represents the complex power matrix of the injection power of each injection current into the head of each line; represents the complex power matrix of the injection power of each injection current into the end of each line; is the distribution current of node i to line q;

[0098] So far, the power calculation of the current tracking model of the power system has been carried out based on the extended incidence matrix, and the power distribution models of the power source side-line side and the power source side-load side have been obtained.

[0099] 3) Perform the electro-carbon coupling calculation on the power distribution models of the power source side-line side and the power source side-load side to obtain the carbon flow calculation results of the power system, that is, the carbon emission rates of the power source side-load side and the power source side-line side of the carbon flow, as follows:

[0100] Calculate the carbon emission rate of the power source side-load side of the carbon flow:

[0101] E L = Re(S in-L )·e G (16)

[0102] Wherein, E L is the load carbon emission rate matrix, and e G is the matrix of the carbon emissions generated by each power source per unit of power generation;

[0103] Calculate the carbon emission rate of the power source side-line side of the carbon flow:

[0104]

[0105] Wherein, Ε Δ is the carbon emission rate of line network loss;

[0106] So far, the electro-carbon coupling calculation has been completed, and the carbon flow calculation results of the power system have been obtained.

[0107] In summary, after adopting the above scheme, the present invention provides a pioneering method for the field of carbon flow calculation of power systems. Compared with the existing methods, the present invention does not rely on any subjectively set proportional distribution principle, and based on the power flow results or state estimation results, it realizes the power source side-line side and the power source side-line side. Its calculation time can meet the requirements of actual applications, plays an important role in the carbon calculation and carbon accounting of power systems, has a wide application prospect, and is worthy of promotion.

[0108] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for calculating carbon flow in a power system based on an extended incidence matrix, characterized in that Including the following steps: 1) Obtain the grid topology structure and parameters of the power system to generate a current tracking model; 2) Conduct power calculation based on the extended incidence matrix for the current tracking model to obtain the power distribution models of the power source side - line side and the power source side - load side; 3) Conduct electro - carbon coupling calculation on the power distribution models of the power source side - line side and the power source side - load side to obtain the carbon flow calculation results of the power system.

2. The carbon flow calculation method for a power system based on an extended incidence matrix according to claim 1, wherein, In step 1), the grid topology structure and parameters of the power system include: the grid topology structure and line admittance parameters, the output power and voltage of each generator node in the power system, the load power and voltage of each load node, and the carbon emission intensity factor of each generator. Based on the above topology structure and parameters, a current tracking model based on the extended incidence matrix is generated, including: ① The equivalent susceptance matrix to the ground, with the formula: where j·(·) is the imaginary part, Y X is the equivalent susceptance matrix to the ground, B(q) is the susceptance to the ground of line q, i and j′ are node numbers, N i is the set of all lines connected to node i; ② The equivalent susceptance injected current, with the formula: wherein, is the equivalent susceptance injection current, is the node voltage, is the equivalent susceptance to ground of node m; ③ The generator injected current vector and load outflow current vector of the power system, with the formula: In the formula, is the column vector of the injected current of the generator, is the column vector of the out-flowing current of the load, are respectively the complex power injection vector of the unit and the node voltage vector of the unit, are respectively the out-flowing power vector of the load and the load node voltage vector; ④ The node equivalent injected current and node equivalent injected power, with the formula: Wherein, is the equivalent injected current of the node, which is the sum of the currents caused by the unit and the shunt susceptance to the ground, is the equivalent injected power of the node.

3. A carbon flow calculation method for a power system based on an extended incidence matrix according to claim 2, characterized in that, In step 2), conducting power distribution calculation based on the extended incidence matrix for the current tracking model includes the following steps: 2.1) For equation (3), according to the conservation relationship of node currents and the grid topology structure, construct an extended incidence matrix, and obtain the mathematical relationship between the imaginary part and real part of the injected current and the load outflow current: Where, A r is the real part extended incidence matrix, A i is the imaginary part extended incidence matrix, Re(·) represents taking the real part, Im(·) represents taking the imaginary part, represents the real part of the load out - flowing current, represents the real part of the generator injected current, represents the imaginary part of the load out - flowing current, represents the imaginary part of the generator injected current, 1 T represents the unit column vector; among them, the sub - elements of the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i are: where a r (·) and a i (·) respectively represent the sub-elements of the real part extended incidence matrix A r and the imaginary part extended incidence matrix A i ; represents the current flowing from node s to node t through branch s-t, represents the current flowing from node f to node s through branch f-s, represents the injected current at node s; 2.2) Calculate the current tracking coefficients of the power source side - grid side - load side. Take the inverse of equations (5) and (6) to obtain the relationship between the real part and imaginary part of the injected current and the load outflow current as: In the formula, is the diagonal matrix of the injection current; 2.3) In Equation (9), and are the real - part current distribution coefficient matrix \(K_{re}\) of the injection current with respect to the load outflow current r and the imaginary - part current distribution coefficient matrix \(K_{im}\) of the injection current with respect to the load outflow current i : where k r (i, j′) is the real - part current distribution coefficient of the injection current of node i to the load current of node j′, and k i (i, j′) is the imaginary - part current distribution coefficient of the injection current of node i to the load current of node j′; 2.4) Combine the imaginary part and real part current distribution coefficients obtained from equation (10) to form a complete current distribution coefficient, with the formula: In the formula, is the current distribution value of the injected current of node i to the load current of node j'; 2.5) Calculate the complex current distribution coefficient matrix of the injected current at node i to the load current at node j′ and the matrix expression of the distribution of each injected current to each load current: Wherein, K = [k(i,j′)] m×m is a complex current distribution coefficient matrix, and k(i,j′) is a complex current distribution coefficient, is a distributed current matrix, is the load current of node j′; 2.6) Calculate the matrix expression of the power distribution of the power source side - load side, which is called the power distribution model of the power source side - load side: In the formula, is the node voltage vector, and its sub-element is the node voltage of node i. S in-L represents the complex power distribution matrix of each equivalent injection current to each load; 2.7) Calculate the matrix expression of the power distribution of the power source side - line side, which is called the power distribution model of the power source side - line side: In the formula, is the diagonal matrix of the line's head node voltage, is the diagonal matrix of the line's tail node voltage, represents the complex power matrix of the injection power of each injection current into the head of each line; represents the complex power matrix of the injection power of each injection current into the tail of each line; is the distribution current of node i to line q. So far, power calculation based on the extended incidence matrix has been conducted on the current tracking model of the power system, and the power distribution models of the power source side - line side and the power source side - load side have been obtained.

4. The carbon flow calculation method for a power system based on an extended incidence matrix according to claim 3, characterized in that In step 3), conduct electro - carbon coupling calculation on the power distribution models of the power source side - line side and the power source side - load side to obtain the carbon flow calculation results of the power system, that is, the carbon emission rates of the power source side - load side and the power source side - line side of the carbon flow, specifically as follows: Calculate the carbon emission rate of the power source side - load side of the carbon flow: E L = Re(S in-L )·e G (16) where, E L is the load carbon emission rate matrix, and e G is the carbon emission matrix generated by each power source per unit of electricity generated; Calculate the carbon emission rate of the power source side - line side of the carbon flow: where Ε Δ is the carbon emission rate of line network loss; So far, the electro - carbon coupling calculation has been completed, and the carbon flow calculation results of the power system have been obtained.

Images