High and low carbon region division method based on carbon emission flow

Abstract

The invention relates to a high and low carbon region division method based on carbon emission flow, which belongs to the field of electrical engineering and comprises the following steps of: calculating direct current power flow in a system to obtain active power of each branch; counting the carbon emission intensity of each generator; calculating and generating a branch power flow distribution matrix, a unit injection distribution matrix and a node active flux matrix; node carbon potential, branch carbon flow rate and generator injection carbon flow rate are calculated; generating a node incidence matrix and a node susceptance matrix, and counting a known quantity generator bearing coefficient; the variable quantity of the branch carbon flow rate is obtained; and obtaining the conversion quantity of the carbon flow rate of each branch, comparing the conversion quantity with the carbon flow rate of each branch to obtain the fluctuation ratio of the carbon flow rate of each branch, selecting a standard branch, determining the branch with the fluctuation ratio higher than that of the standard branch as a high-carbon area, and otherwise, determining the branch as a low-carbon area. The problems that actual operation of a power system is separated and the calculation period is long when the carbon emission flow is calculated are solved; and low-carbon planning of the power system is completed from the load side.

Description

Technical Field

[0001] The present invention belongs to the field of electrical engineering, and specifically relates to a high / low carbon area division method based on carbon emission flow. Background Art

[0002] Clean power sources are gradually becoming the main source of electricity. Specifying a demand response mechanism that is conducive to carbon reduction from the load side can activate the load side power balance potential and promote the consumption of clean energy. In the future, demand-side response will pay more attention to electricity prices and carbon prices, and it is necessary to reasonably plan carbon quota indicators, carbon penalty prices, and carbon responsibility identification. However, at this stage, it is not possible to accurately monitor the carbon consumption on the load side. Therefore, effective carbon emission tracking is of great significance to the establishment of load demand response.

[0003] In traditional power systems, the load side does not pay attention to the power source and high / low attributes, but in low-carbon new power systems, the high / low carbon attributes of electricity consumption on the load side should be divided, that is, it is clear which areas are high-carbon currents and which areas are low-carbon currents. The original carbon emission flow calculation is divorced from the actual operation of the power system and only starts from the power supply side. The calculation cycle is long and it is difficult to divide the carbon emission areas of the power system. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention adopts the theory of carbon emission flow and conducts in-depth research on the calculation of carbon emission flow, and provides a high / low carbon area division method based on carbon emission flow, which solves the problem in the prior art that the calculation of carbon emission flow is detached from the actual operation of the power system and has a long calculation cycle.

[0005] The technical solution of the present invention is as follows:

[0006] A method for dividing high / low carbon areas based on carbon emission flow comprises the following steps:

[0007] Step 1: Calculate the DC power flow in the system and obtain the active power P of each branch L ;

[0008] Step 2: Calculate the carbon emission intensity of each generator G ;

[0009] Step 3: Calculate and generate branch power flow distribution matrix P B , unit injection distribution matrix P G , node active flux matrix P N ;

[0010] Step 4: According to Calculation node carbon potential E N ;

[0011] Step 5: Calculate the branch carbon flow rate R based on the branch carbon flow rate conceptB , generator injection carbon flow rate R G ;

[0012] Step 6: Generate node association matrix M K , node susceptance matrix B0, statistical known quantity generator bearing coefficient α G ;

[0013] Step 7: Obtain the change in branch carbon flow rate ΔR according to the carbon emission distribution factor calculation formula L-l ;

[0014] Step 8: Obtain the change in the carbon flow rate of each branch, and compare it with the branch carbon flow rate in step 5 to obtain the branch carbon flow rate volatility of each branch. Select a standard branch. The branch with a volatility higher than the standard branch is a high-carbon area, otherwise it is a low-carbon area.

[0015] In step 5, the branch carbon flow rate R B The formula is R B =P B diag(E N ).

[0016] The step 7 comprises the following steps:

[0017] (1) Calculate the generator output power and pay attention to the distribution factor, using the formula

[0018] Get the generator output power transfer distribution factor G k-i ;

[0019] (2) To meet the actual situation of the power system, the matrix Rewrite the generator output transfer distribution factor into the quasi-steady-state generator output power transfer distribution factor

[0020]

[0021] (3) Based on the interdependence between carbon emission flow and power system flow and the carbon flow rate R injected by the generator set into the power system G-i =E G-i P G-i , the carbon emission rate corresponds to the active power in the power flow, and the formula can be obtained It is the carbon emission flow distribution factor;

[0022] Where X is the inverse matrix of the B0 susceptance matrix in the DC power flow; X i is the i-th column vector in X; X k is the impedance of the kth branch; M k is the column vector of the i-th branch in the incidence matrix of the topological structure.G n G ×n G The identity matrix (n G is the number of generators); 1 G n G ×1-dimensional column vector of all 1s. G-i The carbon injection rate of the generator at node i, E G-i is the carbon potential of the generator set at node i, P G-i is the active output of the generator set at node i. ΔR L-l The change in carbon flow rate injected into the generator ΔR G-i The change in carbon flow rate of branch l caused by is the carbon emission flow distribution factor.

[0023] In step 7, the expression of the branch carbon flow rate fluctuation rate is:

[0024] Where: l It is the ratio of the change of the carbon flow rate of the lth branch to the carbon flow rate of the branch, which is called the branch carbon flow rate fluctuation rate of the branch.

[0025] The advantages and effects of the present invention are as follows:

[0026] Track the carbon flow from the load side to the power side, calculate the carbon emission flow in dependence on the power system flow, and give the carbon emission flow a clearer physical meaning in the power system. Based on this theory, a comparison is made between the load side and the power side: the load side is a consumer of electricity, and the power side is a producer of electricity and also a carbon emitter. However, the power plant has already paid a huge grid-connected fee, so the power side should not bear the additional carbon price. Instead, the power consumption attributes of the load side should be determined by tracking from the load side to the power side, and users of high-carbon or low-carbon electricity should be treated differently. Typical areas of high-carbon and low-carbon electricity should be divided, and carbon taxes should be levied on high-carbon electricity. The electricity consumption habits of the load side should be changed to achieve effective demand response, and the low-carbon planning of the power system should be completed from the load side. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart for calculating carbon emission distribution factor.

[0028] Figure 2 This is the high / low carbon area division map under scenario 1.

[0029] Figure 3 This is the high / low carbon area division map under scenario 2. DETAILED DESCRIPTION

[0030] Example

[0031] Through the basic concepts of carbon emission flow: branch carbon flow F, branch carbon flow rate R, branch carbon flow density ρ, node carbon potential E N , the formula is as follows

[0032] e b is the node carbon potential, where are the set of generators connected to node b and the set of branches that provide active output kW to node b. g is the active power output of the generator set to node b, P l is the active power of branch l in kW, is the carbon emission intensity of generator set g, kgCO2 (kw·h) -1 , is the branch carbon flow density kgCO2 (kw·h) of branch l associated with node n -1 .

[0033] The specific steps for calculating carbon emission flow are as follows

[0034] (1) Generate branch power flow distribution matrix P based on the existing DC power flow B ; The distributed power flow P has been injected into the unit G ; Combination can get auxiliary matrix Node active flux matrix P N =diag(ζ N+K P Z ).

[0035] (2) Through the formula The node carbon potential E is calculated N

[0036] (3) Through the formula R B =P B diag(E N ), and obtain the branch carbon flow rate R B

[0037] where ξ N+K is an N+K-order row vector, where N is P B The order of K is the number parameter determined by the distribution network parameters, and all elements in the vector are 1.

[0038] After the above preparations are completed, the carbon emission flow distribution is rewritten by the generator output power transfer distribution factor. The generator output power transfer distribution factor is defined as the change in branch power flow caused by the change in generator output power. The calculation formula is as follows

[0039] (4) Calculate the generator output power and pay attention to the distribution factor, using the formula

[0040] Get the generator output power transfer distribution factor G k-i .

[0041] (5) To meet the actual situation of the power system, the matrix Rewrite the generator output transfer distribution factor into the quasi-steady-state generator output power transfer distribution factor

[0042]

[0043] (6) Based on the interdependence between carbon emission flow and power system flow and the carbon flow rate R injected by the generator set into the power system G-i =E G-i P G-i , the carbon emission rate corresponds to the active power in the power flow, and the formula can be obtained It is the carbon emission flow distribution factor.

[0044] Where X is the inverse matrix of the B0 susceptance matrix in the DC power flow; X i is the i-th column vector in X; X k is the impedance of the kth branch; M k is the column vector of the i-th branch in the incidence matrix of the topological structure. G n G ×n G The identity matrix (n G is the number of generators); 1 G n G ×1-dimensional column vector of all 1s. G-i The carbon injection rate of the generator at node i, E G-i is the carbon potential of the generator set at node i, P G-i is the active output of the generator set at node i. ΔR L-l The change in carbon flow rate injected into the generator ΔR G-i The change in carbon flow rate of branch l caused by is the carbon emission flow distribution factor.

[0045] In the process of calculating the change in branch carbon flow rate, each branch has its own carbon emission sensitivity factor, and the data shows nonlinear and irregular changes. It is impossible to directly divide the region into carbon attributes. Considering the actual operation of the power grid, there should be standard areas that meet the carbon emission indicators to divide the high-carbon and low-carbon areas. The concept of branch carbon flow rate fluctuation rate λ is introduced. The branch carbon flow rate change is not used directly for comparison, but converted into a unitless dimension, and a branch is selected as the standard fluctuation rate of the area. If it is higher than the standard fluctuation rate, it is a high-carbon branch at that moment, otherwise it is a low-carbon branch at that moment. The branches within the region are only provided with carbon emission flows by high-carbon or low-carbon power sources, and the branch carbon emission attributes only change with the power source. For the selection standard of branch carbon flow rate fluctuation rate, branches where both high-carbon and low-carbon power sources carry out carbon emission output should be selected.

[0046] The expression of the branch carbon flow rate fluctuation rate is:

[0047] Where: l It is the ratio of the change of the carbon flow rate of the lth branch to the carbon flow rate of the branch, which is called the branch carbon flow rate fluctuation rate of the branch.

[0048] pass Figure 1 The calculation steps are as follows to obtain the generator carbon emission distribution factor and calculate the change in branch carbon flow rate:

[0049] Step 1: Calculate the DC power flow in the system. For branch (i, j), ignoring parallel branches (such as line charging capacitors or equivalent parallel branches of non-standard ratio transformer branches), the active power flow formula of the branch can be written as: Get the power flow distribution of each branch P ij .

[0050] where g ij is the branch conductance, b ij is the branch susceptance. To calculate the DC power flow, the following simplified assumptions can be made: V i =V j =1, sinθ ij =θ ij , cosθ ij =1, r ij =0. The simplified formula is Where b′ ij =-1 / x ij , x ij is the branch reactance.

[0051] Step 2: Generate the branch power distribution matrix P based on the power distribution of each branch obtained in the previous step B , unit injection distribution matrix P G , the auxiliary matrix Node active flux matrix P N =diag(ζ N+K P Z ).

[0052] Step 3: Calculate the carbon emission intensity of each generator G

[0053] Step 4: According to Calculation node carbon potential E N .

[0054] Step 5: According to the branch carbon flow rate formula R B =E N P L Branch carbon flow rate R B , the carbon flow rate injected by the generator set into the power system R G-i =E G-i P G-i The carbon injection potential R G-i .

[0055] Step 6: Generate node association matrix M based on network topology K , node susceptance matrix B0, statistical known quantity generator bearing coefficient α G .

[0056] The node susceptance matrix B0 is 1 / x ij The N×N order node admittance matrix established for branch admittance.

[0057] Step 7: Calculate the carbon emission distribution factor formula The change of branch carbon flow rate ΔR is obtained L-l , the calculation ends.

[0058] Obtain the change in the carbon flow rate of each branch, and compare it with the branch carbon flow rate in step 5 to obtain the branch carbon flow rate volatility of each branch. Select a standard branch. The branch with a higher volatility than the standard branch is a high-carbon area, and vice versa, a low-carbon area. Figure 2 and Figure 3 The high- and low-carbon area division diagram of the IEEE 30-node system under two scenarios can flexibly divide the high and low carbon attributes of the area at different times, and then levy carbon taxes on high-carbon areas and identify carbon responsibilities, change users' electricity usage habits, reduce the use of high-carbon electricity, and achieve effective demand response from the load side to reduce carbon emissions. It can also increase low-carbon power sources and energy storage power stations in high-carbon areas and reduce carbon emissions through low-carbon planning methods.

[0059] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for dividing high-carbon and low-carbon regions based on carbon emission flow, characterized in that The steps include: Step 1: Calculate the DC power flow in the system and obtain the active power P of each branch L ; Step 2: Calculate the carbon emission intensity of each generator G ; Step 3: Calculate and generate branch power flow distribution matrix P B , unit injection distribution matrix P G , node active flux matrix P N ; Step 4: According to Calculation node carbon potential E N ; Step 5: Calculate the branch carbon flow rate R based on the branch carbon flow rate concept B , generator injection carbon flow rate R G ; Step 6: Generate node association matrix M K , node susceptance matrix B0, statistical known quantity generator bearing coefficient α G ; Step 7: Obtain the change in branch carbon flow rate ΔR according to the carbon emission distribution factor calculation formula L-l ; Step 8: Obtain the change in the carbon flow rate of each branch, and compare it with the branch carbon flow rate in step 5 to obtain the branch carbon flow rate volatility of each branch. Select a standard branch. The branch with a volatility higher than the standard branch is a high-carbon area, otherwise it is a low-carbon area.

2. A method for dividing high-carbon and low-carbon areas based on carbon emission flow according to claim 1, characterized in that: In step 5, the branch carbon flow rate R B The formula is R B =P B diag(E N ).

3. The method for dividing high-carbon and low-carbon regions based on carbon emission flow according to claim 1 is characterized in that: The step 7 comprises the following steps: (1) Calculate the generator output power and pay attention to the distribution factor, using the formula Get the generator output power transfer distribution factor G k-i ; (2) To meet the actual situation of the power system, the matrix Rewrite the generator output transfer distribution factor into the quasi-steady-state generator output power transfer distribution factor (3) Based on the interdependence between carbon emission flow and power system flow and the carbon flow rate R injected by the generator set into the power system G-i =E G-i P G-i , the carbon emission rate corresponds to the active power in the power flow, and the formula can be obtained It is the carbon emission flow distribution factor; Where X is the inverse matrix of the B0 susceptance matrix in the DC power flow; X i is the i-th column vector in X; X k is the impedance of the kth branch; M k is the column vector of the i-th branch in the incidence matrix of the topological structure; I G n G ×n G The identity matrix (n G is the number of generators); 1 G n G ×1-dimensional column vector of all 1s; R G-i is the carbon injection rate of the generator at node i, E G-i is the carbon potential of the generator set at node i, P G-i is the active output of the generator set at node i; ΔR L-l The change in carbon flow rate injected into the generator ΔR G-i The change in carbon flow rate of branch l caused by is the carbon emission flow distribution factor.

4. The method for dividing high-carbon and low-carbon areas based on carbon emission flow according to claim 1 is characterized in that: In step 7, the expression of the branch carbon flow rate fluctuation rate is: Where: l It is the ratio of the change of the carbon flow rate of the lth branch to the carbon flow rate of the branch, which is called the branch carbon flow rate fluctuation rate of the branch.

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