CN116823020A - Comprehensive evaluation method for low-carbon operation of transformer area considering load side carbon reduction potential - Google Patents

Abstract

The invention relates to a comprehensive evaluation method for low-carbon operation in a station area that considers the carbon reduction potential of the load side. The method includes the following steps: Step 1: Calculate the node carbon potential of the node where the station area is located; Step 2: Calculate the load side of the station area. Maximum carbon emission reduction; Step 3: Construct low-carbon platform area evaluation indicators; Step 4: Indicator preprocessing; Step 5: Use the indicator comprehensive weighting method to determine the comprehensive weight; Step 6: Use the superior and inferior solution distance method to calculate the evaluation results; This invention has the advantages of incorporating the load-side carbon reduction potential into the evaluation system, establishing low-carbon platform evaluation indicators, and establishing a comprehensive evaluation method.

Description

A comprehensive assessment method for low-carbon operation in Taiwan area considering load-side carbon reduction potential

Technical field

The invention belongs to the technical field of low-carbon operation in low-voltage distribution network stations of electric power systems, and specifically relates to a comprehensive evaluation method for low-carbon operation in stations that considers the load-side carbon reduction potential.

Background technique

When conducting low-carbon assessments in Taiwan, the key is to measure the carbon emissions of energy usage on the user side and clarify the sources of carbon emissions from various loads; the traditional method of calculating carbon emissions from the power system mainly considers the macro-level and cannot achieve user-level analysis. Accurate calculation of carbon emissions caused by electricity use, such as Carbon Emission Flow (CEF) theory. Carbon emission flow can be regarded as a virtual flow accompanying the active power flow in the power network, transferring the carbon emissions generated on the power generation side to On the power consumption side, the node carbon potential of the system node can be obtained based on the system power flow distribution at a certain time node, thereby calculating the carbon emissions of the system; another example is to use low-carbon demand response to guide users' power consumption behavior and consider users from the user side. The impact of electricity consumption behavior on carbon emissions; another example is the low-carbon effect evaluation system and quantitative calculation method of smart distribution network; the above method provides a meaningful reference for the calculation of carbon emissions and carbon reduction potential in Taiwan, but does not propose Taiwan The specific calculation method of the district carbon emission flow; as the power grid gradually transitions to low-carbonization, the low-carbon assessment of the power grid has gradually become a research hotspot. Traditional methods such as using the combined evaluation method of balanced principal component analysis to analyze the environmental benefits of the distribution network; another example is The superior and inferior solution distance method with improved connection degree is used to evaluate the proposed regional electric energy substitution potential. The evaluation method based on cloud model and possibility is used for the comprehensive evaluation of urban distribution network. Another example is to establish a system that considers economy, energy consumption, The evaluation index system of three aspects of the environment comprehensively evaluates the advantages and disadvantages of distributed energy system solutions; the above methods evaluate the low-carbon characteristics of the power grid from different aspects, but do not involve the measurement of carbon emissions, and lack of analysis of the carbon emissions in Taiwan from the perspective of the load side. Therefore, a comprehensive assessment of low-carbon operation in the station area that considers the load-side carbon reduction potential is provided. Method is very necessary.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a platform that considers the load-side carbon reduction potential by incorporating the load-side carbon reduction potential into the evaluation system, establishing low-carbon platform area evaluation indicators, and establishing a comprehensive evaluation method. Comprehensive assessment method for district low-carbon operations.

The object of the present invention is achieved as follows: a comprehensive assessment method for low-carbon operation in a station area that considers the load-side carbon reduction potential. The method includes the following steps:

Step 1: Calculate the node carbon potential of the node where the platform area is located;

Step 2: Calculate the maximum carbon emission reduction on the load side of the station area;

Step 3: Construct low-carbon platform area evaluation indicators;

Step 4: Indicator preprocessing;

Step 5: Use the indicator comprehensive weighting method to determine the comprehensive weight;

Step 6: Use the distance method between superior and inferior solutions to calculate the evaluation results.

The specific step 1 is: compared with the transmission network, most distribution networks have a radial topology and are in an open-loop operation state, which causes no circulation in the network; the direct algorithm of carbon emission flow is used for calculation, specifically Includes the following steps:

Step 1.1: According to the direct solution of carbon emissions, it is assumed that the main network system where the Taiwan area is located has a total of N nodes, of which M nodes have loads and K nodes have generator sets;

Step 1.2: First solve the power flow distribution of the entire network in a certain time period, and then generate the following types of matrices to obtain the carbon potential of each node of the system;

Step 1.3: Among them, the branch power flow distribution matrix P _B = (P _Bij ) _{N × N} describes the active power flow distribution on the branches connecting each node in the system; the unit injection distribution matrix P _G = (P _Gkj ) _{K × N} describes The connection relationship between the generator set and the node and the active power output of the unit; the load distribution matrix P _L = (P _Lmj ) _M×N , describing the connection relationship between the load and the node and the amount of active load; the node active flux matrix P _N = (P _Nij ) _N×N , describes the active power flow inflow of the node, and does not consider the outflow of the node;

Step 1.4: From this, the carbon potential of the nodes in the system can be obtained. The carbon potential of each node of the main network can be calculated from the above. Combined with the active power flow flowing through each node during this time period, the carbon emissions of each node can be obtained;

Step 1.5: The entire distribution network can be regarded as a load node in the main network. Therefore, by calculating the carbon potential of the nodes connecting the distribution network and the main network, the carbon potential of each node in the distribution network can be calculated; similarly, The station area can also be regarded as a load node in the distribution network. The carbon emissions of the station area can be obtained based on the load of the station area and the carbon potential of the node;

Step 1.6: When there are no distributed power supplies and energy storage equipment in the station area, the power source of any node in the station area is the flow of power from the distribution network, and its carbon potential is equal to the carbon potential of the node connecting the distribution network and the main grid. ;

Step 1.7: When there are distributed power supplies and energy storage equipment in the Taiwan area, the carbon potential of its nodes will be affected by the output of new energy and energy storage discharge, so the carbon emission flow model of the energy storage equipment needs to be considered;

Step 1.8: When the energy storage is in the charging state, it can be regarded as a load, and the accumulated electricity and carbon flow can be calculated through the carbon potential of the node in the station area and its charging power;

Step 1.9: When the energy storage is in a discharge state, it can be regarded as a generating unit. The calculation method of the carbon emission flow in the Taiwan area transfers the carbon emissions generated on the power generation side to the load side through the flow of active power flow. According to the node carbon emissions in the Taiwan area The potential and load can be used to obtain the carbon emissions of the station area within a period of time.

The specific step 2 is: Based on the calculation method of carbon emission flow in Taiwan in step 1, for the load side, different electricity consumption behaviors of users will produce different carbon emissions; based on this, the low-carbon demand response mechanism can Allow users to effectively perceive different carbon emission information generated by different electricity consumption behaviors. The Taiwan District guides users to reasonably change their own electricity consumption behavior by releasing this information to users, thereby achieving low-carbon operation in the Taiwan District; use the information before and after users respond. By comparing the carbon emissions generated by electricity consumption, the effect of low-carbon demand response can be quantified. Within a period of time, by optimizing the user's electricity behavior with the maximum amount of carbon reduction in the Taiwan area as the objective function, we can obtain the load-side carbon reduction in the Taiwan area. potential.

The specific step 3 is: Selecting appropriate indicators is the basis and key for low-carbon assessment of the Taiwan District. In order to improve the applicability and feasibility of the low-carbon assessment method in the Taiwan District, combined with the maximum carbon reduction in the Taiwan District in step 2 The amount calculation method selects easy-to-obtain basic data of the Taiwan District to reflect the low-carbon operation level of the Taiwan District, considers the carbon reduction potential of the Taiwan District as a direct indicator, and considers the proportion of new energy output, comprehensive line loss rate, load rate, and electric energy replacement amount. as an indirect indicator.

The specific step 4 is: the low-carbon assessment indicators in Taiwan are divided into forward indicators and reverse indicators. The forward indicators have benefit attributes, and the larger their values are, the better; the reverse indicators have cost attributes, and the smaller their values are, the better; it is necessary To perform forward processing on reverse indicators and convert them into forward indicators to eliminate the impact of the indicator dimension on the evaluation results, it is necessary to perform dimensionless processing on the indicator values, and use the extreme value processing method to normalize each indicator value to [ 0, 1] interval.

The specific step 5 described is: in order to comprehensively reflect the impact of expert experience and the index data value itself on the weight, first use the analytic hierarchy process to determine the subjective weight, then use the entropy weight method to determine the objective weight, and finally linearly combine the two to determine the comprehensive Weights.

The analytical hierarchy process (AHP) in step 6 described above combines qualitative judgment with quantitative analysis through hierarchical structure and ratio analysis to improve the effectiveness of decision-making; among them, the target layer is the low-carbon level assessment of the Taiwan area, and the criterion layer is the evaluation Indicators, the program layer is typical Taiwan areas in different regions; according to the definition of information entropy, the smaller the entropy value of an indicator, the more information it provides, the greater the role it plays in the evaluation, and the greater the weight should be ,vice versa.

The entropy weight method in step 6 is to use the entropy value of the index information to determine its weight; the comprehensive weighting method linearly combines the weights determined by the analytic hierarchy process and the entropy weight method to set the weight of each indicator. It is more objective and reasonable and can take into account expert experience and data itself.

Described step 6 is specifically: the distance method of superior and inferior solutions calculates the distance between each solution and the optimal solution and the worst solution to obtain the evaluation result, and incorporates the comprehensive weight determined above into the distance method of superior and inferior solutions, that is, the TOPSIS method. Determine the final score for each scenario.

Beneficial effects of the present invention: The present invention is a comprehensive assessment method for low-carbon operation in the station area that considers the carbon reduction potential of the load side. In use, the purpose of the invention is to incorporate the carbon reduction potential of the load side of the low-voltage distribution station area into the station area. In the district low-carbonization evaluation index system, the evaluation indicators and comprehensive evaluation methods of the low-carbon station area are established; the comprehensive evaluation method of low-carbon operation of the low-voltage distribution station area considering the load-side carbon reduction potential of the present invention includes the following steps: Calculate the location of the station area The node carbon potential of the node; calculate the maximum carbon emission reduction on the load side of the station area; construct low-carbon station area evaluation indicators; index preprocessing; use the indicator comprehensive weighting method to determine the comprehensive weight; use the superior and inferior solution distance method to calculate the evaluation results; this The invention can effectively evaluate the low-carbon operation level of the Taiwan District, and provides a direction for the low-carbon transformation of the planning, construction and operation and maintenance of the Taiwan District; in terms of planning and construction, the planning capacity and construction scale of renewable generating units and energy storage can be increased, Guide distributed energy sources to be connected to the grid for power generation, build electric vehicle charging piles, and unleash the potential of electric vehicles for peak shaving and carbon reduction; in terms of operation and maintenance, reduce system line loss rates, guide users to actively participate in demand-side response and electric energy substitution, and aggregate controllable resources. , to improve the low-carbon operation level of the station area; this invention has the advantages of incorporating the load-side carbon reduction potential into the evaluation system, establishing low-carbon station area evaluation indicators, and establishing a comprehensive evaluation method.

Description of the drawings

Figure 1 is a structural diagram of the low-carbon platform area of the present invention.

Figure 2 is a flow chart of the low-carbon platform comprehensive assessment process of the present invention.

Figure 3 is a topological structure diagram of the distribution network of the present invention.

Figure 4 is a graph of the main network node carbon potential and the photovoltaic and energy storage output of the station area according to the present invention.

Figure 5 is a table load curve diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Example 1

As shown in Figure 1-5, a comprehensive assessment method for low-carbon operation in Taiwan that considers load-side carbon reduction potential. The method includes the following steps:

Step 1: Calculate the node carbon potential of the node where the platform area is located;

Step 2: Calculate the maximum carbon emission reduction on the load side of the station area;

Step 3: Construct low-carbon platform area evaluation indicators;

Step 4: Indicator preprocessing;

Step 5: Use the indicator comprehensive weighting method to determine the comprehensive weight;

Step 6: Use the distance method between superior and inferior solutions to calculate the evaluation results.

The specific step 1 is: compared with the transmission network, most distribution networks have a radial topology and are in an open-loop operation state, which causes no circulation in the network; the direct algorithm of carbon emission flow is used for calculation, specifically Includes the following steps:

Step 1.1: According to the direct solution of carbon emissions, it is assumed that the main network system where the Taiwan area is located has a total of N nodes, of which M nodes have loads and K nodes have generator sets;

Step 1.2: First solve the power flow distribution of the entire network in a certain time period, and then generate the following types of matrices to obtain the carbon potential of each node of the system;

Step 1.3: Among them, the branch power flow distribution matrix P _B = (P _Bij ) _{N × N} describes the active power flow distribution on the branches connecting each node in the system; the unit injection distribution matrix P _G = (P _Gkj ) _{K × N} describes The connection relationship between the generator set and the node and the active power output of the unit; the load distribution matrix P _L = (P _Lmj ) _M×N , describing the connection relationship between the load and the node and the amount of active load; the node active flux matrix P _N = (P _Nij ) _N×N , describes the active power flow inflow of the node, and does not consider the outflow of the node;

Step 1.4: From this, the carbon potential of the nodes in the system can be obtained. The carbon potential of each node of the main network can be calculated from the above. Combined with the active power flow flowing through each node during this time period, the carbon emissions of each node can be obtained;

Step 1.5: The entire distribution network can be regarded as a load node in the main network. Therefore, by calculating the carbon potential of the nodes connecting the distribution network and the main network, the carbon potential of each node in the distribution network can be calculated; similarly, The station area can also be regarded as a load node in the distribution network. The carbon emissions of the station area can be obtained based on the load of the station area and the carbon potential of the node;

Step 1.6: When there are no distributed power supplies and energy storage equipment in the station area, the power source of any node in the station area is the flow of power from the distribution network, and its carbon potential is equal to the carbon potential of the node connecting the distribution network and the main grid. ;

Step 1.7: When there are distributed power supplies and energy storage equipment in the Taiwan area, the carbon potential of its nodes will be affected by the output of new energy and energy storage discharge, so the carbon emission flow model of the energy storage equipment needs to be considered;

Step 1.8: When the energy storage is in the charging state, it can be regarded as a load, and the accumulated electricity and carbon flow can be calculated through the carbon potential of the node in the station area and its charging power;

Step 1.9: When the energy storage is in a discharge state, it can be regarded as a generating unit. The calculation method of the carbon emission flow in the Taiwan area transfers the carbon emissions generated on the power generation side to the load side through the flow of active power flow. According to the node carbon emissions in the Taiwan area The potential and load can be used to obtain the carbon emissions of the station area within a period of time.

In this embodiment, ① Low-carbon station area architecture design: In the power system, due to the large number of power users, power companies generally use the power supply station as the smallest unit to manage the power users within the power supply range. The station area topology The architecture is the basis for analyzing the low-carbon characteristics of the station area. The low-carbon station area including renewable energy, energy storage and load-side flexibility resources is shown in Figure 1; on the power supply side, in addition to the electric energy transmitted from the main network to the distribution network , there are also photovoltaic, wind power, energy storage and other distributed power sources installed on the low-voltage side of the distribution transformer to provide electric energy. The Taiwan District collects real-time data from photovoltaic inverters, smart IoT energy meters, etc., to realize the analysis of new photovoltaic, energy storage and other new technologies. Access management of energy devices; on the load side, the proportion of flexible loads with control capabilities, such as electric vehicles and air conditioners, namely FL, is also growing simultaneously. Taiwan District uses information communication, power electronics and automatic control technology to improve load-side flexibility. Implement overall management of resources; in summary, by coordinating and controlling the operating status of source-grid-load-storage in Taiwan, we can effectively improve system operating efficiency, promote the utilization of clean energy, and achieve low-carbon operation in Taiwan;

② Calculation of carbon reduction potential in Taiwan area: Node active flux matrix P _N = (P _Nij ) _N×N , describing the active power flow inflow of the node, without considering the outflow of the node; for node i: In the formula, I ⁺ is the set of branches with active power flow flowing into node i; P _Bs is the active power of branch s; P _Gi is the output of the generator unit at node i; thus the carbon potential of the nodes in the system can be obtained:/> In the formula, ρ _s is the carbon flow density of branch s, unit kgCO ₂ /(kW·h); e _Gi is the carbon emission intensity of the generating unit at node i, kgCO ₂ /(kW·h); when the energy storage is When the energy storage is in the charging state, it can be regarded as a load, and the accumulated electricity and carbon flow can be calculated through the carbon potential of the node in the station area and its charging power; when the energy storage is in the discharging state, it can be regarded as a generating unit. This The discharge carbon potential of energy storage can be calculated by the following formula: In the formula, _es (T) is the node carbon potential when the energy storage is discharging after T charging periods; F ₀ and Q ₀ are respectively the remaining carbon flow and electricity when the energy storage was switched to the charging state last time; eta is the storage Energy charge and discharge efficiency; P _t and e _t are the charging power and carbon potential of the t-th charging time period respectively; Δt is the length of the period;

Assume that there are G distributed renewable energy generating units in the Taiwan area, the carbon emission intensity of the units can be regarded as 0, and S energy storage devices are in the discharge state, then the node carbon potential of the Taiwan area is: In the formula, e _l,t is the node carbon potential of the l-th station area in the t-th period; P _n,t , P _g,t , P _s,t are the active power injected by the power grid in the t-th period, and the g-th station respectively. The active power output of the distributed generation unit and the active power output of the s-th energy storage device in the discharge state; _en,t and e _s,t are the carbon potential of the main network node and the discharge carbon potential of the energy storage device in the t-th period respectively;

The carbon reduction potential of the Taiwan area is calculated in units of days. The objective function is: In the formula, ΔE _D is the carbon emission reduction in the Taiwan area in one day; Ω is the set of power users in the Taiwan area; T _d is the total number of time periods in a day;/> are respectively the load reduction and load increase of users in period t after implementing low-carbon demand response;

In addition, the following constraints must be met. Formulas (1)-(2) represent the maximum and minimum constraints on user load adjustment; Formula (3) represents that the user's load increase in a certain period cannot exceed the ratio of the maximum rated load and the baseline load in that period. Difference; Formula (4) means that the user's load reduction in a certain period cannot exceed the baseline load in that period; Formula (5) means that the user cannot be in a load increase and load decrease state at the same time in a certain period; Formula (6) means that the user's load The total load change constraints within a day before and after the electrical behavior adjustment;

In the formula,/> They are 0-1 variables representing the increase and decrease of user load in the t period respectively;/> is the maximum rated load in the tth period; P _L,t is the baseline load in the tth period; They are the upper limit of the load increase and decrease that the user can adjust in each period;/> It is the maximum value of the total load change within a day;

After obtaining the maximum carbon reduction amount of the station area in one day, add it up to get the total maximum carbon reduction amount of the station area in one year: In the formula, ΔE _Y is the maximum carbon reduction amount in the Taiwan area throughout the year; T _Y is the total number of periods in a year.

The specific step 2 is: Based on the calculation method of carbon emission flow in Taiwan in step 1, for the load side, different electricity consumption behaviors of users will produce different carbon emissions; based on this, the low-carbon demand response mechanism can Allow users to effectively perceive different carbon emission information generated by different electricity consumption behaviors. The Taiwan District guides users to reasonably change their own electricity consumption behavior by releasing this information to users, thereby achieving low-carbon operation in the Taiwan District; use the information before and after users respond. By comparing the carbon emissions generated by electricity consumption, the effect of low-carbon demand response can be quantified. Within a period of time, by optimizing the user's electricity behavior with the maximum amount of carbon reduction in the Taiwan area as the objective function, we can obtain the load-side carbon reduction in the Taiwan area. potential.

The specific step 3 is: Selecting appropriate indicators is the basis and key for low-carbon assessment of the Taiwan District. In order to improve the applicability and feasibility of the low-carbon assessment method in the Taiwan District, combined with the maximum carbon reduction in the Taiwan District in step 2 The amount calculation method selects easy-to-obtain basic data of the Taiwan District to reflect the low-carbon operation level of the Taiwan District, considers the carbon reduction potential of the Taiwan District as a direct indicator, and considers the proportion of new energy output, comprehensive line loss rate, load rate, and electric energy replacement amount. as an indirect indicator.

In this embodiment, the comprehensive evaluation method of low-carbon Taiwan area: first, the low-carbon indicators of Taiwan area are explained as follows:

The first is the carbon reduction potential of Taiwan District (X ₁ ): Taiwan District can guide users to adjust their electricity consumption behavior to reduce carbon emissions through low-carbon demand response strategies and tap the regulatory potential of various controllable resources on the load side, so the carbon reduction potential of Taiwan District is selected ΔE _Y serves as an indicator that intuitively reflects the low-carbon level on the user side in Taiwan;

The second is the proportion of new energy output (X ₂ ): The installed capacity and consumption rate of grid-connected distributed new energy are key factors affecting low-carbon operation in Taiwan. The carbon emission intensity of distributed new energy units is zero. In order to improve the Energy utilization efficiency and reduction of carbon emissions in Taiwan should give priority to the output of new energy units; the proportion of new energy output in Taiwan indicates the ratio of photovoltaic, wind turbine and other output to the total power supply in Taiwan, which can reflect the low-carbon level of the power supply side of Taiwan. ;The proportion of new energy output can be expressed by the following formula: In the formula, P _pv,t and P _w,t are the photovoltaic and wind turbine output in the station area during the t period respectively;

The _third is the line loss rate ( During the transmission process, the ratio of the power loss of the Taiwan area line to the total power supply in the Taiwan area is used to reflect the economical and low-carbon nature of the Taiwan area operation; the line loss rate eta in the Taiwan area can be expressed as: In the formula, P ₁ is the total power supply in the Taiwan area; P ₂ is the total electricity consumption of users in the Taiwan area;

The fourth is the load rate (X ₄ ): The load rate is the ratio of the average load to the peak load in the Taiwan area, which is used to measure the load changes in the Taiwan area throughout the year. The higher the load rate, the higher the load rate, the load is relatively flat throughout the year, and vice versa. The load fluctuates obviously; according to research, for every one percentage point increase in load rate, the coal consumption of coal-fired units is reduced by approximately 2.3g/(kW·h); the annual load rate calculation formula in Taiwan is as follows: In the formula, P _avg is the average monthly electricity consumption of the station area load; P _max is the maximum monthly electricity consumption of the station area load;

The fifth is the amount of electric energy substitution (X ₅ ): Electric energy substitution refers to the use of electric energy to replace other energy consumption forms such as coal and fuel oil in heating, transportation and other fields, which has positive significance for reducing carbon emissions and environmental pollution; the definition of electric energy substitution amount is the increment of the electric energy consumption in year τ compared to the electric energy consumption in the base year, which can be expressed as: In the formula, D _e,τ is the amount of electric energy replacement in year τ; Y _e,τ is the actual electric energy consumption in year τ; Y _τ is the total terminal energy consumption in year τ; T _B is the base year;/> is the total energy consumption in the base year;/> is the electricity consumption in the base year.

The specific step 4 is: the low-carbon assessment indicators in Taiwan are divided into forward indicators and reverse indicators. The forward indicators have benefit attributes, and the larger their values are, the better; the reverse indicators have cost attributes, and the smaller their values are, the better; it is necessary To perform forward processing on reverse indicators and convert them into forward indicators to eliminate the impact of the indicator dimension on the evaluation results, it is necessary to perform dimensionless processing on the indicator values, and use the extreme value processing method to normalize each indicator value to [ 0, 1] interval.

In this embodiment, the index data is preprocessed: Forward processing: x ^* =Mx, where x ^* is the reverse index value after forwarding; M is the maximum value of the index; x is Original inverse indicator value; dimensionless processing: In the formula, x _uv is the element in the original matrix X; M _v and m _v are the maximum and minimum values in x _uv respectively, M _v =max{x _uv },m _v =min{x _uv } ; z _uv is the element in the normalized matrix Z.

The specific step 5 described is: in order to comprehensively reflect the impact of expert experience and the index data value itself on the weight, first use the analytic hierarchy process to determine the subjective weight, then use the entropy weight method to determine the objective weight, and finally linearly combine the two to determine the comprehensive Weights.

The analytical hierarchy process (AHP) in step 6 described above combines qualitative judgment with quantitative analysis through hierarchical structure and ratio analysis to improve the effectiveness of decision-making; among them, the target layer is the low-carbon level assessment of the Taiwan area, and the criterion layer is the evaluation Indicators, the program layer is typical Taiwan areas in different regions; according to the definition of information entropy, the smaller the entropy value of an indicator, the more information it provides, the greater the role it plays in the evaluation, and the greater the weight should be ,vice versa.

The entropy weight method in step 6 is to use the entropy value of the index information to determine its weight; the comprehensive weighting method linearly combines the weights determined by the analytic hierarchy process and the entropy weight method to set the weight of each indicator. It is more objective and reasonable and can take into account expert experience and data itself.

Described step 6 is specifically: the distance method of superior and inferior solutions calculates the distance between each solution and the optimal solution and the worst solution to obtain the evaluation result, and incorporates the comprehensive weight determined above into the distance method of superior and inferior solutions, that is, the TOPSIS method. Determine the final score for each scenario.

In this embodiment, it is assumed that there are U evaluation schemes (station areas) and V evaluation indicators. After index preprocessing, the original matrix X = (x _uv ) _U×V is converted into a standardized matrix Z = (z _uv ) _{U ×V} , and then calculate the comprehensive weight of the indicator; the steps to determine the subjective weight are as follows:

① Construct a judgment matrix: Compare each indicator in pairs at the same level, and construct a judgment matrix based on importance: A = (a _ef ) _{V × V} , where a _ef represents the degree of importance between pairs of indicators, using a scale Method value, a _ef = 1a _ef > 0, a _ee = 1;

②Consistency test: In order to eliminate the decision-making errors caused by expert experience as much as possible, it is necessary to conduct a consistency test on the judgment matrix: In the formula, CI is the consistency index; λ _max is the maximum eigenvalue of the judgment matrix; CR is the consistency ratio; RI is the average random consistency index; value reference: when CR <0.1, it is considered valid, otherwise it should be modified it meets the requirements;

③ Calculate the subjective weight: Use the geometric mean method to calculate the subjective weight of the indicator:

The steps for determining objective weights are as follows:

① Calculate the probability matrix: The elements in the probability matrix P = (p _uv ) _U×V represent the proportion of the u-th station area under the v-th indicator:

② Calculate information entropy: For the v-th indicator, its information entropy is:

③Calculate objective weight: Linearly combine the subjective weight and objective weight to obtain the comprehensive weight:/> In the formula, ω _v is the comprehensive weight of the vth indicator; α is the subjective weight coefficient, α = 0.5;

④ Calculate the comprehensive evaluation results of each station area: For the standardized matrix Z = (z _uv ) _{U × V} , define the maximum and minimum values as: In the formula, v=1,2,...,V;

⑤ Calculate the distance between each evaluation scheme and the maximum value and minimum value:

⑥ Calculate the final score of each plan:

In summary, a comprehensive assessment method for low-carbon platform areas has been established. The specific process is shown in Figure 2.

The present invention is a comprehensive evaluation method for low-carbon operation in a station area that considers the carbon reduction potential of the load side. In use, the purpose of the invention is to incorporate the carbon reduction potential of the load side of the low-voltage distribution station area into the low-carbon evaluation index system of the station area. , establish evaluation indicators and comprehensive evaluation methods for low-carbon station areas; the comprehensive evaluation method for low-carbon operation of low-voltage distribution station areas that considers the load-side carbon reduction potential of the present invention includes the following steps: calculate the node carbon potential of the node where the station area is located; Calculate the maximum carbon emission reduction on the load side of the platform area; construct low-carbon platform area evaluation indicators; index preprocessing; use the indicator comprehensive weighting method to determine the comprehensive weight; use the superior and inferior solution distance method to calculate the evaluation results; this invention can effectively evaluate the platform area The low-carbon operation level provides a direction for the low-carbon transformation of Taiwan's planning, construction and operation and maintenance; in terms of planning and construction, the planned capacity and construction scale of renewable generating units and energy storage can be increased to guide the integration of distributed energy resources into the grid. Generate electricity, build electric vehicle charging piles, and unleash the potential of electric vehicles for peak shaving and carbon reduction; in terms of operation and maintenance, reduce system line loss rates, guide users to actively participate in demand-side response and electric energy substitution, aggregate controllable resources, and improve the low-carbon environment in Taiwan. Carbon operation level; this invention has the advantages of incorporating the load-side carbon reduction potential into the evaluation system, establishing low-carbon platform evaluation indicators, and establishing a comprehensive evaluation method.

Example 2

As shown in Figure 1-5, a comprehensive assessment method for low-carbon operation in Taiwan that considers load-side carbon reduction potential. The method includes the following steps:

Step 1: Calculate the node carbon potential of the node where the platform area is located;

Step 2: Calculate the maximum carbon emission reduction on the load side of the station area;

Step 3: Construct low-carbon platform area evaluation indicators;

Step 4: Indicator preprocessing;

Step 5: Use the indicator comprehensive weighting method to determine the comprehensive weight;

Step 6: Use the distance method between superior and inferior solutions to calculate the evaluation results.

In this embodiment, example analysis: In order to verify the rationality and applicability of the method proposed in the article, six typical Taiwan areas in three different regions of urban, suburban, and rural areas in a certain area of Henan were selected for carbon reduction potential analysis and low-carbon Level assessment, named A1, A2, B1, B2, C1, C2 respectively; obtain the basic data and information of each station area based on the assessment indicators;

Taking a typical day in the urban Taiwan area A1 as an example to analyze its carbon reduction potential: the network structure of the distribution network where the Taiwan area is located is shown in Figure 3. Among them, node 1 is connected to the superior main network, and its node carbon potential in each period is taken as The value has been given, and the station area A1 is connected to node 7. The carbon potential of the main network node of node 1 and the photovoltaic and energy storage output of the station area are shown in Figure 4; first, it is calculated based on the carbon potential of the main network node and the output of photovoltaic and energy storage equipment. The node carbon potential of the station area. The station area sends this information to the user as a low-carbon demand response signal. Assume that 10% of the load can participate in the low-carbon demand response. Calculate the background load change curve and carbon emission reduction before and after the response. Finally, The results are shown in Figure 5;

It can be seen from the figure that on the power supply side, during the period when the carbon potential of the main network node is low, the power in the Taiwan area is mainly transmitted by the distribution network, and the energy storage equipment is in a charging state; during the period when the carbon potential of the main network node is high, The energy storage equipment is in a discharge state, and at the same time, the carbon potential of the station area has decreased relative to the carbon potential of the main network; on the load side, after receiving the low-carbon demand response signal, in order to reduce the carbon emissions generated by its own electricity consumption, the carbon potential of the node is reduced. The power consumption behavior during high periods shifts the flexible power-consuming equipment to work during periods when the node's carbon potential is low. The carbon emission reduction in this station area during this typical day is 47kgCO ₂ ;

Conduct low-carbon assessment on six typical Taiwan areas: First, collect the basic data and relevant information of the Taiwan areas based on the established Taiwan area assessment indicators, and perform corresponding calculations and preprocessing; the preprocessed index data values are as shown in the table As shown in 1; from the data in Table 1, it can be seen that compared with suburban and rural Taiwan areas, urban Taiwan areas are located in a more developed regional economy, and residents on the user side have more flexible control resources such as electric vehicles and temperature control loads. It is more able to actively participate in low-carbon demand response and has great potential for low-carbon regulation; the load along the rural Taiwan area is relatively scattered, and the aggregation of controllable resources is difficult and the aggregation potential is low. In addition, the power supply distance in rural Taiwan areas is long and the line loss rate is large; new Indicators such as energy output ratio, load factor, and electric energy replacement amount have different numerical characteristics due to different actual conditions in the Taiwan area;

Table 1 Various index values after preprocessing

Secondly, the subjective weight and objective weight of each indicator are calculated, and the comprehensive weight is obtained, as shown in Table 2; the weight results show that the carbon reduction potential of the Taiwan District is a key indicator for evaluating the low-carbon level of the Taiwan District, indicating that it can be adjusted with the user side of the Taiwan District The regulation potential of resources has a greater correlation; secondly, the proportion of distributed new energy output has a larger weight, indicating the impact of the power supply side on the low-carbon level of the Taiwan area; while the line loss rate of the Taiwan area has a smaller proportion, indicating that this indicator is mainly It is related to the power grid structure and power supply distance, and its adjustability is small, so it is not used as the main evaluation index; in addition, the comprehensive weight comprehensively reflects the differences in expert experience judgment and the data of each evaluation object, and the indicators X ₁ , X ₂ , and X ₅ Compared with the subjective method, the weight of X ₃ and X ₄ has increased, which can eliminate the error caused by expert experience to a certain extent and make the setting of indicators more scientific and objective;

Table 2 Weight of various indicators

Finally, the final scores and rankings for evaluating the low-carbon level of each station area were calculated, as shown in Table 3; the results showed that station areas A1 and A2 had good low-carbon operation levels, while station areas B2 and C1 had poor low-carbon operation levels; among them , the load rate of B2 in Taiwan District is small, and the use time of electrical equipment needs to be reasonably adjusted to reduce the peak-valley difference; the carbon reduction potential, line loss rate and electric energy replacement amount of C1 in Taiwan District are small, and the power supply structure needs to be optimized to reduce the power supply radius to improve load-side demand response potential;

Table 3 Low carbon assessment results of each district

In order to further examine the effectiveness of the method proposed in this article and verify the low-carbon level of the Taiwan area under different time dimensions, taking the urban Taiwan area A1 as an example, it is assumed that the area has carbon reduction potential, new energy output proportion, and electric energy substitution in different periods. Measure the changes in the values of the three indicators and calculate the evaluation scores under different scenarios. The specific data and calculation results are shown in Table 4; the results show that with the development of the economy and society, the proportion of new energy installed capacity is increasing year by year, and the penetration rate of new energy is increasing year by year. , load-side electric vehicles are becoming more and more popular, and the potential of flexible resources to participate in demand response is increasing. With the development of science and technology and the low-carbon concept taking root in the hearts of the people, the amount of electric energy substitution will also increase year by year; therefore, the low-carbon assessment of Taiwan District The score also shows a gradually increasing trend;

Table 4 Values of various indicators in different periods

Based on the above analysis, the low-carbon operation level of the station area can be effectively evaluated through the index system and evaluation method proposed by the present invention, which provides a direction for the low-carbon transformation of the planning and construction and operation and maintenance of the station area; in terms of planning and construction, it can increase the available The planned capacity and construction scale of regenerative generating units and energy storage will guide distributed energy grid-connected power generation and the construction of electric vehicle charging piles to maximize the potential of electric vehicles for peak shaving and carbon reduction; in terms of operation and maintenance, reduce system line loss rates and guide users Actively participate in demand-side response and electric energy substitution, aggregate controllable resources, and improve the low-carbon operation level of the Taiwan region.

The present invention is a comprehensive evaluation method for low-carbon operation in a station area that considers the carbon reduction potential of the load side. In use, the purpose of the invention is to incorporate the carbon reduction potential of the load side of the low-voltage distribution station area into the low-carbon evaluation index system of the station area. , establish evaluation indicators and comprehensive evaluation methods for low-carbon station areas; the comprehensive evaluation method for low-carbon operation of low-voltage distribution station areas that considers the load-side carbon reduction potential of the present invention includes the following steps: calculate the node carbon potential of the node where the station area is located; Calculate the maximum carbon emission reduction on the load side of the platform area; construct low-carbon platform area evaluation indicators; index preprocessing; use the indicator comprehensive weighting method to determine the comprehensive weight; use the superior and inferior solution distance method to calculate the evaluation results; this invention can effectively evaluate the platform area The low-carbon operation level provides a direction for the low-carbon transformation of Taiwan's planning, construction and operation and maintenance; in terms of planning and construction, the planned capacity and construction scale of renewable generating units and energy storage can be increased to guide the integration of distributed energy resources into the grid. Generate electricity, build electric vehicle charging piles, and unleash the potential of electric vehicles for peak shaving and carbon reduction; in terms of operation and maintenance, reduce system line loss rates, guide users to actively participate in demand-side response and electric energy substitution, aggregate controllable resources, and improve the low-carbon environment in Taiwan. Carbon operation level; this invention has the advantages of incorporating the load-side carbon reduction potential into the evaluation system, establishing low-carbon platform evaluation indicators, and establishing a comprehensive evaluation method.

Claims (9)

1. A comprehensive assessment method for low-carbon operation in Taiwan that considers load-side carbon reduction potential, characterized in that: the method includes the following steps: Step 1: Calculate the node carbon potential of the node where the platform area is located; Step 2: Calculate the maximum carbon emission reduction on the load side of the station area; Step 3: Construct low-carbon platform area evaluation indicators; Step 4: Indicator preprocessing; Step 5: Use the indicator comprehensive weighting method to determine the comprehensive weight; Step 6: Use the distance method between superior and inferior solutions to calculate the evaluation results. 2. A comprehensive assessment method for low-carbon operation in Taiwan that considers load-side carbon reduction potential as claimed in claim 1, characterized in that: the step 1 is specifically: compared with the transmission network, most distribution networks It is a radial topology and is in an open-loop operation state, which causes no circulation in the network; the direct algorithm of carbon emission flow is used for calculation, which specifically includes the following steps: Step 1.1: According to the direct solution of carbon emissions, it is assumed that the main network system where the Taiwan area is located has a total of N nodes, of which M nodes have loads and K nodes have generator sets; Step 1.2: First solve the power flow distribution of the entire network in a certain time period, and then generate the following types of matrices to obtain the carbon potential of each node of the system; Step 1.3: Among them, the branch power flow distribution matrix P _B = (P _Bij ) _{N × N} describes the active power flow distribution on the branches connecting each node in the system; the unit injection distribution matrix P _G = (P _Gkj ) _{K × N} describes The connection relationship between the generator set and the node and the active power output of the unit; the load distribution matrix P _L = (P _Lmj ) _M×N , describing the connection relationship between the load and the node and the amount of active load; the node active flux matrix P _N = (P _Nij ) _N×N , describes the active power flow inflow of the node, and does not consider the outflow of the node; Step 1.4: From this, the carbon potential of the nodes in the system can be obtained. The carbon potential of each node of the main network can be calculated from the above. Combined with the active power flow flowing through each node during this time period, the carbon emissions of each node can be obtained; Step 1.5: The entire distribution network can be regarded as a load node in the main network. Therefore, by calculating the carbon potential of the nodes connecting the distribution network and the main network, the carbon potential of each node in the distribution network can be calculated; similarly, The station area can also be regarded as a load node in the distribution network. The carbon emissions of the station area can be obtained based on the load of the station area and the carbon potential of the node; Step 1.6: When there are no distributed power supplies and energy storage equipment in the station area, the power source of any node in the station area is the flow of power from the distribution network, and its carbon potential is equal to the carbon potential of the node connecting the distribution network and the main grid. ; Step 1.7: When there are distributed power supplies and energy storage equipment in the Taiwan area, the carbon potential of its nodes will be affected by the output of new energy and energy storage discharge, so the carbon emission flow model of the energy storage equipment needs to be considered; Step 1.8: When the energy storage is in the charging state, it can be regarded as a load, and the accumulated electricity and carbon flow can be calculated through the carbon potential of the node in the station area and its charging power; Step 1.9: When the energy storage is in a discharge state, it can be regarded as a generating unit. The calculation method of the carbon emission flow in the Taiwan area transfers the carbon emissions generated on the power generation side to the load side through the flow of active power flow. According to the node carbon emissions in the Taiwan area The potential and load can be used to obtain the carbon emissions of the station area within a period of time. 3. A comprehensive assessment method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 2, characterized in that step 2 is specifically: calculation of carbon emission flow in the Taiwan area based on step 1. Method, for the load side, different electricity consumption behaviors of users will produce different carbon emissions; based on this, the low-carbon demand response mechanism can enable users to effectively perceive the different carbon emission information generated by different electricity consumption behaviors. The Taiwan District passed Release this information to users to guide them to reasonably change their electricity consumption behavior, thereby achieving low-carbon operation in the Taiwan area; comparing the carbon emissions generated by users' electricity consumption behavior before and after the response can quantify the effect of low-carbon demand response , within a period of time, the load-side carbon reduction potential of the station can be obtained by optimizing the user's electricity consumption behavior with the maximum carbon reduction amount in the station area as the objective function. 4. A comprehensive evaluation method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 3, characterized in that: the step 3 is specifically: selecting appropriate indicators is to carry out low-carbon operation in the Taiwan area. The basis and key of the assessment. In order to improve the applicability and feasibility of the Taiwan District's low-carbon assessment method, combined with the Taiwan District's maximum carbon reduction calculation method in step 2, easy-to-obtain basic data of the Taiwan District is selected to reflect the low-carbon operation of the Taiwan District. level, the carbon reduction potential of the Taiwan area will be considered as a direct indicator, and the proportion of new energy output, comprehensive line loss rate, load rate, and electric energy replacement amount will be used as indirect indicators. 5. A comprehensive evaluation method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 1, characterized in that: the step 4 is specifically: the low-carbon evaluation indicators in the Taiwan area are divided into positive indicators And reverse indicators, forward indicators have benefit attributes, the larger the value, the better; reverse indicators have cost attributes, the smaller the value, the better; reverse indicators need to be forwarded, converted into positive indicators, and eliminated The impact of dimensions on evaluation results requires dimensionless processing of index values, and the extreme value processing method is used to normalize each index value to the [0, 1] interval. 6. A comprehensive evaluation method for low-carbon operation in Taiwan that considers load-side carbon reduction potential as claimed in claim 1, characterized in that step 5 is specifically: in order to comprehensively reflect expert experience and the index data value itself Regarding the impact of weight, first the analytic hierarchy process is used to determine the subjective weight, then the entropy weight method is used to determine the objective weight, and finally the comprehensive weight is determined by a linear combination of the two. 7. A comprehensive evaluation method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 6, characterized in that: the analytic hierarchy process (AHP) in step 5 is based on hierarchical structure and ratio analysis. Combine qualitative judgment with quantitative analysis to improve the effectiveness of decision-making; among them, the target layer is the low-carbon level assessment of the Taiwan area, the criterion layer is the evaluation index, and the program layer is the typical Taiwan areas in different regions; according to the definition of information entropy, a certain The smaller the entropy value of an indicator, the more information it provides, the greater its role in the evaluation, and the greater its weight, and vice versa. 8. A comprehensive evaluation method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 7, characterized in that: the entropy weight method in step 5 is to obtain the index information entropy value, Determine its weight; the comprehensive weighting method described linearly combines the weights determined by the analytic hierarchy process and the entropy weight method, making the weight setting of each indicator more objective and reasonable, taking into account expert experience and the information of the data itself. 9. A comprehensive evaluation method for low-carbon operation in a Taiwan area that considers load-side carbon reduction potential as claimed in claim 1, characterized in that: the step 6 is specifically: the distance method of superior and inferior solutions is to calculate the relationship between each plan and The distance between the optimal solution and the worst solution is evaluated. The comprehensive weight determined above is incorporated into the distance method between the best and worst solutions, that is, the TOPSIS method to determine the final score of each solution.