A method and system for evaluating distributed energy acceptance capacity of distribution network

Abstract

The present invention belongs to the technical field of power grid evaluation. The present invention provides a method and system for evaluating the distributed energy acceptance capacity of a distribution network, including: monitoring whether the distribution network violates safety constraints after accessing distributed energy within an evaluation period, obtaining violation data after the distribution network accesses distributed energy within the evaluation period, judging whether the distribution network can accept the connected distributed energy, obtaining an influence coefficient based on the fact that the distribution network cannot accept the connected distributed energy, determining whether the distributed energy capacity has an impact on the distribution network's inability to accept the connected distributed energy based on the influence coefficient, if an impact is produced, obtaining a capacity regulation coefficient, regulating the capacity of the distributed energy based on the capacity regulation coefficient, so that the distribution network can accept the access of the distributed energy, and at the same time, obtaining the maximum capacity of the distributed energy that can be accessed by the distribution network, so as to realize the evaluation of the maximum capacity of the distributed energy that can be accessed by the distribution network.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid evaluation, and in particular to a method and system for evaluating the distributed energy acceptance capacity of a distribution network. Background Art

[0002] With the transformation of the global energy structure and the rapid development of clean energy, the proportion of distributed energy in the power system is increasing. However, the access of distributed energy poses severe challenges to the safe and stable operation of the distribution network, such as voltage fluctuations, line overload and other issues. Therefore, how to accurately evaluate the distribution network's ability to accept distributed energy has become an important issue that needs to be solved urgently in the current power industry.

[0003] In the prior art, after the distributed energy is connected, the distribution network is judged whether it has a certain acceptance capacity for the access of the distributed energy by analyzing whether the operating parameters of the distribution network exceed the safety constraints. However, there is a lack of specific analysis of its violation of the safety constraints, and it is impossible to guarantee an accurate assessment of its distribution network's acceptance capacity. Secondly, there is also a lack of analysis of the reasons why it cannot accept the access of the distributed energy, resulting in the inability to adjust and optimize according to the influencing reasons and to evaluate the maximum capacity of the distributed energy that the distribution network can access.

[0004] To this end, the present invention provides a method and system for evaluating the distributed energy acceptance capacity of a distribution network. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for evaluating the distributed energy acceptance capacity of a distribution network, comprising:

[0007] Monitor whether the distribution network violates safety constraints after connecting to distributed energy within the evaluation period, and generate an acceptance signal based on the monitoring results;

[0008] Wherein, accepting signals includes accepting normal signals and accepting analysis signals;

[0009] Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data after the distribution network is connected to the distributed energy within the evaluation period, wherein the violation data includes the violation performance value, and whether the distribution network can accept the connected distributed energy is determined according to the violation performance value;

[0010] Based on the inability of the distribution network to accept the connected distributed energy, an impact coefficient is obtained, and based on the impact coefficient, whether the capacity of the distributed energy has an impact on the inability of the distribution network to accept the connected distributed energy is determined, and a signal is generated, wherein the signal includes an impact signal and a non-impact signal;

[0011] Based on the generated influence signal, the capacity control coefficient is obtained, and the capacity of the distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of the distributed energy that can be accessed by the distribution network is obtained, and the maximum capacity of the distributed energy that can be accessed by the distribution network is evaluated.

[0012] As a further technical solution of the present invention, the distribution network is monitored by using a monitoring device, and the monitored operating parameters are compared with the safety constraints, so as to monitor and identify whether the distribution network violates the safety constraints after connecting to the distributed energy within the evaluation period;

[0013] If the distribution network does not violate the safety constraints after connecting to the distributed energy within the evaluation period, a normal acceptance signal is generated;

[0014] If the distribution network violates the safety constraints after connecting to distributed energy within the evaluation period, an acceptance analysis signal is generated.

[0015] As a further technical solution of the present invention, during the evaluation period, when the distribution network violates the safety constraint condition, a violation signal is generated, and when the distribution network does not violate the safety constraint condition, a non-violation signal is generated;

[0016] During the evaluation period, the time period when the violation signal appears is marked as the violation period. Based on the analysis of the violation period, the violation degree data is obtained, wherein the violation degree data includes the total violation time T, the number of constraint violation CS and the mean violation deviation PC;

[0017] After the total violation time T, the number of constraint violation CS and the mean violation deviation PC are dimensionless, they are substituted into the formula: Obtain a violation performance value BX, where s1, s2 and s3 are all preset proportional coefficients;

[0018] The violation degree data is obtained in the following way:

[0019] The total violation time T represents the length of time corresponding to the violation period;

[0020] The number of constraint violations CS represents the sum of the number of security constraints violated by the distribution network during the evaluation period;

[0021] The safety constraints violated by the distribution network during the evaluation period are marked as violation constraints. The detected operating parameters of the distribution network are subjected to difference processing with the maximum value of the violation constraints to obtain the violation deviation value. All the violation deviation values ​​are summed and averaged to obtain the violation deviation mean PC.

[0022] As a further technical solution of the present invention, the violation performance value BX is compared with the violation performance threshold value. The specific comparison process is as follows:

[0023] The default violation performance threshold is BY;

[0024] If the violation performance value BX is greater than the violation performance threshold BY, it means that the distribution network cannot accept the connected distributed energy;

[0025] If the violation performance value BX is less than or equal to the violation performance threshold BY, it means that the distribution network can accept the connected distributed energy.

[0026] As a further technical solution of the present invention, the time when the distribution network violates the voltage stability constraint within the violation period is obtained, and it is marked as the voltage violation time, and the voltage violation time is processed by ratio with the time corresponding to the violation period to obtain the voltage violation time ratio;

[0027] The detected voltage value of the distribution network within the voltage violation time is obtained, and all detected voltage values ​​are summed and averaged to obtain the voltage mean value, the voltage mean value is subjected to difference processing with the maximum value in the voltage stability constraint to obtain the over-limit voltage value, and the over-limit voltage value is subjected to ratio processing with the maximum value in the voltage stability constraint to obtain the voltage violation over-limit ratio;

[0028] The voltage violation time ratio and the voltage violation over-limit ratio are summed to obtain the first impact value DYy;

[0029] The second impact value DRy is obtained, and the obtained first impact value DYy and second impact value DRy are processed by the formula: The influence coefficient is obtained, where a1 and a2 are both preset proportional coefficients;

[0030] The influence coefficient Yx is compared with the influence coefficient threshold. The specific comparison process is as follows:

[0031] The preset impact coefficient threshold is Yxy;

[0032] If the influence coefficient Yx is greater than the influence coefficient threshold Yxy, it means that the distributed energy capacity affects the distribution network and cannot accept the connected distributed energy, and an influence signal is generated;

[0033] If the influence coefficient Yx is less than or equal to the influence coefficient threshold Yxy, it means that the distributed energy capacity does not affect the distribution network's inability to accept the connected distributed energy, and a non-influence signal is generated.

[0034] As a further technical solution of the present invention, the second impact value DRy is obtained in the following manner:

[0035] The capacity data of distributed energy connected to the distribution network in multiple historical evaluation cycles and the current evaluation cycle are obtained, wherein the capacity data includes the capacity value. The capacity value is marked and connected with the violation performance value of the distribution network in the historical evaluation cycle in the XY coordinate system to obtain a violation change curve, and the violation change curve is analyzed to obtain the percentage of the number of normal change sub-curves and the percentage of the number of normal synchronous change sub-curves. The percentage of the number of normal change sub-curves and the percentage of the number of normal synchronous change sub-curves are summed to obtain a second impact value DRy.

[0036] As a further technical solution of the present invention, the method for obtaining the quantity ratio of the normal change sub-curve is as follows:

[0037] Divide the violation change curve into a number of violation change sub-curves of equal length, connect the endpoints of the violation change sub-curves with straight lines, and measure the slope of the connected straight line to obtain the change slope value of the violation change sub-curve, and mark the violation change sub-curve based on comparative analysis of the slope values ​​of the violation change sub-curves, and mark the violation change sub-curves as normal violation change sub-curves and abnormal violation change sub-curves;

[0038] The number of normal violation change sub-curves in the violation change sub-curve is counted, and the ratio is processed with the number of violation change sub-curves to obtain the ratio of the number of normal change sub-curves;

[0039] The process of marking the sub-curve that violates the change is as follows:

[0040] The slope of the violation change sub-curve is compared with 0. If the slope value of the violation change sub-curve is greater than 0, the violation change sub-curve is marked as a normal violation change sub-curve. If the slope value of the violation change sub-curve is less than or equal to 0, the violation change sub-curve is marked as an abnormal violation change sub-curve.

[0041] As a further technical solution of the present invention, the method for obtaining the proportion of the number of the normal synchronous change sub-curves is as follows:

[0042] Draw perpendicular lines to the X-axis and Y-axis through the two end points of the normal violation change sub-curve, measure the distance between the two perpendicular lines drawn to the X-axis, and obtain the horizontal length of the normal violation change sub-curve; measure the distance between the two perpendicular lines drawn to the Y-axis, and obtain the vertical length of the normal violation change sub-curve; perform ratio processing on the vertical length and the horizontal length of the normal violation change sub-curve, and obtain the relevant change ratio;

[0043] Obtain the relevant change ratios corresponding to all normal violation change sub-curves, and sum and average them to obtain the relevant change ratio mean, perform difference processing on the relevant change ratio corresponding to the normal violation change sub-curve and the relevant change ratio mean, and take the absolute value of the difference to obtain the relevant change ratio deviation, sum and average all the obtained relevant change ratio deviations to obtain the relevant change ratio deviation mean, compare and analyze the relevant change ratio deviation with the relevant change ratio deviation mean, mark the normal violation change sub-curve, and mark it as a normal synchronous change sub-curve and a normal asynchronous change sub-curve;

[0044] The number of normal synchronous change sub-curves is obtained, and the ratio is processed with the number of normal violation change sub-curves to obtain the ratio of the number of normal synchronous change sub-curves;

[0045] The process of marking the normal violation change sub-curve is as follows:

[0046] If the correlation change ratio deviation is greater than the correlation change ratio deviation mean, it is marked as a normal asynchronous change sub-curve;

[0047] If the correlation change ratio deviation is less than or equal to the correlation change ratio deviation mean, it is marked as a normal synchronous change sub-curve.

[0048] As a further technical solution of the present invention, the capacity regulation coefficient includes a capacity regulation value;

[0049] The normal synchronous change sub-curves are numbered in sequence, and the relevant change ratios corresponding to the normal synchronous change sub-curves are obtained, and the relevant change ratios are marked as Xgb;

[0050] By formula: Get capacity control value , where N represents the normal synchronous change sub-curve number, BX represents the violation performance value, and BY represents the violation performance threshold;

[0051] By formula: Get the maximum capacity of distributed energy that can be connected to the distribution network ,in, It represents the initial capacity of distributed energy.

[0052] A distributed energy acceptance capacity assessment system for a distribution network, comprising:

[0053] Admission analysis module: monitors whether the distribution network violates safety constraints after connecting to distributed energy within the evaluation period, and generates an admission signal based on the monitoring results;

[0054] Wherein, accepting signals includes accepting normal signals and accepting analysis signals;

[0055] Admission judgment module: Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data of the distribution network after the distributed energy is connected within the evaluation period, wherein the violation data includes the violation performance value, and the distribution network is judged whether it can accept the connected distributed energy according to the violation performance value;

[0056] Impact analysis module: based on the inability of the distribution network to accept the connected distributed energy, obtain the impact coefficient, determine whether the distributed energy capacity has an impact on the inability of the distribution network to accept the connected distributed energy based on the impact coefficient, and generate a signal, wherein the signal includes an impact signal and a non-impact signal;

[0057] Acceptance optimization evaluation module: Based on the generated impact signal, the capacity control coefficient is obtained, and the capacity of distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of distributed energy that can be accessed by the distribution network is obtained, and the maximum capacity of distributed energy that can be accessed by the distribution network is evaluated.

[0058] The beneficial effects of the present invention are as follows:

[0059] 1. The present invention monitors whether the distribution network violates the safety constraints after connecting to the distributed energy within the evaluation period, and generates an acceptance signal according to the monitoring result, wherein the acceptance signal includes an acceptance normal signal and an acceptance analysis signal. Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data of the distribution network after connecting to the distributed energy within the evaluation period, wherein the violation data includes a violation performance value, and whether the distribution network can accept the connected distributed energy is judged according to the violation performance value. The present invention judges whether the distributed energy can be accepted according to whether the distribution network violates the safety constraints. Secondly, when the distribution network violates the safety constraints, the specific degree of violation is analyzed to prevent the distribution network from violating the safety constraints only in a very short time and violating the safety constraints with a relatively small planning difficulty, thereby preventing the distribution network from violating the safety constraints only in a very short time and violating the safety constraints with a relatively small planning difficulty, thereby improving the accuracy of the distribution network distributed energy acceptance capacity evaluation.

[0060] 2. The present invention obtains an influence coefficient based on the inability of the distribution network to accept the connected distributed energy, determines whether the distributed energy capacity has an impact on the inability of the distribution network to accept the connected distributed energy based on the influence coefficient, and generates a signal, wherein the signal includes an influence signal and a non-influence signal, and obtains a capacity control coefficient based on the generation of the influence signal, and controls the capacity of the distributed energy based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of the distributed energy that can be connected to the distribution network is obtained, and the maximum capacity of the distributed energy that can be connected to the distribution network is evaluated. The present invention determines the influencing reasons why the distribution network cannot accept the connected distributed energy, which is beneficial to the distribution optimization of the energy access of the distribution network, optimizes the energy access of the distribution network according to the influencing reasons, which is beneficial to the access of distributed energy, and after the optimization, the maximum capacity of the distributed energy that can be connected to the distribution network is obtained, and the maximum energy capacity acceptance capacity of the distribution network is evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The present invention will be further described below in conjunction with the accompanying drawings.

[0062] Figure 1 is a flow chart of a method for evaluating the distributed energy acceptance capacity of a distribution network according to Embodiment 1 of the present invention;

[0063] Figure 2 is a flow chart of a method for evaluating the distributed energy acceptance capacity of a distribution network according to Embodiment 2 of the present invention;

[0064] Figure 3 It is a flowchart of a distribution network distributed energy acceptance capacity assessment system described in Example 3 of the present invention. DETAILED DESCRIPTION

[0065] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. Example 1

[0066] like Figure 1 As shown, a method for evaluating the distributed energy acceptance capacity of a distribution network according to an embodiment of the present invention includes:

[0067] Step 1: Monitor whether the distribution network violates the safety constraints after connecting to distributed energy within the evaluation period, and generate an acceptance signal based on the monitoring results;

[0068] Wherein, accepting signals includes accepting normal signals and accepting analysis signals;

[0069] It should be noted that the safety constraints include, but are not limited to, voltage stability constraints, current stability constraints, and power balance constraints;

[0070] It should also be noted that the evaluation period represents the length of time that the distribution network needs to be monitored and evaluated based on the operation and use requirements of the distribution network;

[0071] In some embodiments, the distribution network is monitored using a monitoring device, and the monitored operating parameters are compared with the safety constraints to monitor and identify whether the distribution network violates the safety constraints after the distributed energy is connected within the evaluation period;

[0072] The operating parameters include but are not limited to voltage, current, and power. It should be noted that the operating parameters correspond to the parameter types of the safety constraints, for example, voltage corresponds to voltage stability constraints, and current corresponds to current stability constraints.

[0073] If the distribution network does not violate the safety constraints after connecting to the distributed energy within the evaluation period, a normal acceptance signal is generated;

[0074] If the distribution network violates the safety constraints after connecting to the distributed energy within the evaluation period, an acceptance analysis signal is generated;

[0075] It should be noted that the monitoring equipment includes but is not limited to voltmeters, ammeters and other related power detection equipment;

[0076] It should also be noted that the acceptance of normal signals means that after the distribution network is connected to distributed energy, the operation of the distribution network will not violate various safety constraints and can accept the access of distributed energy. The acceptance of analytical signals means that after the distribution network is connected to distributed energy, the operation of the distribution network violates the safety constraints, but the degree of violation needs to be specifically judged to prevent the distribution network from violating the safety constraints only in a very short period of time and violating the safety constraints with a relatively small planning difficulty, thereby leading to inaccurate assessment of the distribution network's acceptance capacity for the access of distributed energy.

[0077] Step 2: Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data after the distribution network is connected to the distributed energy within the evaluation period, wherein the violation data includes the violation performance value, and whether the distribution network can accept the connected distributed energy is determined according to the violation performance value;

[0078] In some embodiments, during the evaluation period, when the power distribution network violates the safety constraint condition, a violation signal is generated, and when the power distribution network does not violate the safety constraint condition, a non-violation signal is generated;

[0079] During the evaluation period, the time period when the violation signal appears is marked as the violation period. Based on the analysis of the violation period, the violation degree data is obtained, wherein the violation degree data includes the total violation time T, the number of constraint violation CS and the mean violation deviation PC;

[0080] After the total violation time T, the number of constraint violation CS and the mean violation deviation PC are dimensionless, they are substituted into the formula: Obtain a violation performance value BX, where s1, s2 and s3 are all preset proportional coefficients;

[0081] It should be noted that a person skilled in the art collects multiple groups of sample data and sets a corresponding preset proportional coefficient for each group of sample data; substitutes the preset proportional coefficient and the collected sample data into the formula, any three formulas constitute a three-variable linear equation system, and the calculated coefficients are screened and averaged to obtain the values ​​of s1, s2 and s3;

[0082] In some embodiments, the violation performance value BX is compared with the violation performance threshold, and the specific comparison process is as follows:

[0083] The default violation performance threshold is BY;

[0084] If the violation performance value BX is greater than the violation performance threshold BY, it means that the distribution network cannot accept the connected distributed energy;

[0085] If the violation performance value BX is less than or equal to the violation performance threshold BY, it means that the distribution network can accept the connected distributed energy;

[0086] Exemplary, the violation degree data is obtained in the following manner:

[0087] The total violation time T represents the length of time corresponding to the violation period;

[0088] The number of constraint violations CS represents the sum of the number of security constraints violated by the distribution network during the evaluation period;

[0089] The safety constraints violated by the distribution network during the evaluation period are marked as violation constraints, the detected operating parameters of the distribution network are subjected to difference processing with the maximum value of the violation constraints to obtain the violation deviation value, and all the violation deviation values ​​are summed and averaged to obtain the violation deviation mean PC;

[0090] The technical solution of the embodiment of the present invention is: monitoring whether the distribution network violates the safety constraints after connecting to the distributed energy within the evaluation period, generating an acceptance signal according to the monitoring result, wherein the acceptance signal includes an acceptance normal signal and an acceptance analysis signal, and analyzing the distribution network based on the acceptance analysis signal to obtain the violation data of the distribution network after connecting to the distributed energy within the evaluation period, wherein the violation data includes a violation performance value, and judging whether the distribution network can accept the connected distributed energy according to the violation performance value. The present invention judges whether the distributed energy can be accepted according to whether the distribution network violates the safety constraints. Secondly, when the distribution network violates the safety constraints, the specific degree of violation is analyzed to prevent the distribution network from violating the safety constraints only in a very short time and violating the safety constraints with a relatively small planning difficulty, thereby preventing the distribution network from violating the safety constraints only in a very short time and violating the safety constraints with a relatively small planning difficulty, thereby improving the accuracy of the distribution network's distributed energy acceptance capacity evaluation. Example 2

[0091] like Figure 2 As shown, based on Example 1, a method for evaluating the distributed energy acceptance capacity of a distribution network according to an embodiment of the present invention includes:

[0092] Step 3: based on the inability of the distribution network to accept the connected distributed energy, an impact coefficient is obtained, and based on the impact coefficient, whether the capacity of the distributed energy has an impact on the inability of the distribution network to accept the connected distributed energy is determined, and a signal is generated, wherein the signal includes an impact signal and a non-impact signal;

[0093] In some embodiments, the time when the distribution network violates the voltage stability constraint within the violation period is obtained and marked as the voltage violation time, and the voltage violation time is ratio-processed with the time corresponding to the violation period to obtain the voltage violation time ratio;

[0094] The detected voltage value of the distribution network within the voltage violation time is obtained, and all detected voltage values ​​are summed and averaged to obtain the voltage mean value, the voltage mean value is subjected to difference processing with the maximum value in the voltage stability constraint to obtain the over-limit voltage value, and the over-limit voltage value is subjected to ratio processing with the maximum value in the voltage stability constraint to obtain the voltage violation over-limit ratio;

[0095] The voltage violation time ratio and the voltage violation over-limit ratio are summed to obtain the first impact value DYy;

[0096] In some embodiments, the capacity data of the distributed energy connected to the distribution network in multiple historical evaluation cycles and the current evaluation cycle are obtained, wherein the capacity data includes a capacity value, and the capacity value is marked and connected with the violation performance value of the distribution network in the historical evaluation cycle in an XY coordinate system to obtain a violation change curve, wherein the X-axis represents the capacity value and the Y-axis represents the violation performance value;

[0097] Divide the violation change curve into a number of violation change sub-curves of equal length, connect the endpoints of the violation change sub-curves with straight lines, and measure the slope of the connected straight line to obtain the change slope value of the violation change sub-curve, and mark the violation change sub-curve based on comparative analysis of the slope values ​​of the violation change sub-curves, and mark the violation change sub-curves as normal violation change sub-curves and abnormal violation change sub-curves;

[0098] The number of normal violation change sub-curves in the violation change sub-curve is counted, and the ratio is processed with the number of violation change sub-curves to obtain the ratio of the number of normal change sub-curves;

[0099] The process of marking the sub-curve that violates the change is as follows:

[0100] Compare the slope of the violation change sub-curve with 0. If the slope value of the violation change sub-curve is greater than 0, mark the violation change sub-curve as a normal violation change sub-curve. If the slope value of the violation change sub-curve is less than or equal to 0, mark the violation change sub-curve as an abnormal violation change sub-curve.

[0101] Draw perpendicular lines to the X-axis and Y-axis through the two end points of the normal violation change sub-curve, measure the distance between the two perpendicular lines drawn to the X-axis, and obtain the horizontal length of the normal violation change sub-curve; measure the distance between the two perpendicular lines drawn to the Y-axis, and obtain the vertical length of the normal violation change sub-curve; perform ratio processing on the vertical length and the horizontal length of the normal violation change sub-curve, and obtain the relevant change ratio;

[0102] It should be noted that the horizontal length of the normal violation change sub-curve reflects the capacity change of distributed energy, and the vertical length of the normal violation change sub-curve reflects the change in the violation performance value. The ratios are processed to obtain the relevant change ratios.

[0103] Obtain the relevant change ratios corresponding to all normal violation change sub-curves, and sum and average them to obtain the relevant change ratio mean, perform difference processing on the relevant change ratio corresponding to the normal violation change sub-curve and the relevant change ratio mean, and take the absolute value of the difference to obtain the relevant change ratio deviation, sum and average all the obtained relevant change ratio deviations to obtain the relevant change ratio deviation mean, compare and analyze the relevant change ratio deviation with the relevant change ratio deviation mean, mark the normal violation change sub-curve, and mark it as a normal synchronous change sub-curve and a normal asynchronous change sub-curve;

[0104] The number of normal synchronous change sub-curves is obtained, and the ratio is processed with the number of normal violation change sub-curves to obtain the ratio of the number of normal synchronous change sub-curves;

[0105] The process of marking the normal violation change sub-curve is as follows:

[0106] If the correlation change ratio deviation is greater than the correlation change ratio deviation mean, it is marked as a normal asynchronous change sub-curve;

[0107] If the correlation change ratio deviation is less than or equal to the correlation change ratio deviation mean, it is marked as a normal synchronous change sub-curve;

[0108] The proportion of the number of the normal change sub-curve and the proportion of the number of the normal synchronous change sub-curve are summed to obtain a second impact value DRy;

[0109] The obtained first impact value DYy and second impact value DRy are processed by the formula: The influence coefficient is obtained, where a1 and a2 are both preset proportional coefficients;

[0110] It should be noted that a person skilled in the art collects multiple groups of sample data and sets a corresponding preset proportional coefficient for each group of sample data; substitutes the preset proportional coefficient and the collected sample data into the formula, any two formulas constitute a set of two-variable linear equations, and the calculated coefficients are screened and averaged to obtain the values ​​of a1 and a2;

[0111] In some embodiments, the influence coefficient Yx is compared with the influence coefficient threshold, and the specific comparison process is as follows:

[0112] The preset impact coefficient threshold is Yxy;

[0113] If the influence coefficient Yx is greater than the influence coefficient threshold Yxy, it means that the distributed energy capacity affects the distribution network and cannot accept the connected distributed energy, and an influence signal is generated;

[0114] If the influence coefficient Yx is less than or equal to the influence coefficient threshold Yxy, it means that the distributed energy capacity does not affect the distribution network's inability to accept the connected distributed energy, and a non-influence signal is generated;

[0115] It should be noted that the impact signal indicates that after the distribution network cannot accept the access of distributed energy, the distributed energy capacity is determined to have an impact on the distribution network's inability to accept the connected distributed energy, which is conducive to effectively evaluating the distribution network's acceptance capacity based on the influencing factors. Conversely, the non-influence signal indicates that after the distribution network cannot accept the access of distributed energy, the distributed energy capacity is determined to have no impact on the distribution network's inability to accept the connected distributed energy, which is conducive to effective and rapid investigation of the influencing factors, facilitating rapid determination of the influencing factors, and timely evaluating the distribution network's acceptance capacity.

[0116] Step 4: Based on the generated impact signal, the capacity control coefficient is obtained, and the capacity of the distributed energy is controlled based on the capacity control coefficient, so that the distribution network can accept the access of the distributed energy. At the same time, the maximum capacity of the distributed energy that can be connected to the distribution network is obtained, and the maximum capacity of the distributed energy that can be connected to the distribution network is evaluated;

[0117] Among them, the capacity control coefficient includes the capacity control value;

[0118] Specifically, the normal synchronous change sub-curves are numbered in sequence, for example: 1.2.3.4...N; and the relevant change ratios corresponding to the normal synchronous change sub-curves are obtained, and the relevant change ratios are marked as Xgb;

[0119] By formula: Get capacity control value , where N represents the normal synchronous change sub-curve number, BX represents the violation performance value, and BY represents the violation performance threshold;

[0120] By formula: Get the maximum capacity of distributed energy that can be connected to the distribution network ,in, It represents the initial capacity of distributed energy;

[0121] It should be noted that the amount by which the violation performance value represented by BX-BY exceeds the violation performance threshold is It represents the inverse of the mean value of the correlation change ratio corresponding to all normal synchronous change sub-curves. The amount of violation performance value exceeding the violation performance threshold is ratioed with the mean value of the correlation change ratio to obtain the capacity control value. The capacity control value is differenced with the initial capacity of the distributed energy to obtain the maximum capacity of the distributed energy that the distribution network can access. The maximum capacity of the distributed energy that the distribution network can access can be used to understand the maximum capacity of the distributed energy that the distribution network can currently access, thereby realizing the evaluation of the current distribution network's acceptance capacity.

[0122] The technical solution of the embodiment of the present invention is: based on the inability of the distribution network to accept the connected distributed energy, an impact coefficient is obtained, and based on the impact coefficient, it is determined whether the distributed energy capacity has an impact on the inability of the distribution network to accept the connected distributed energy, and a signal is generated, wherein the signal includes an impact signal and a non-impact signal, based on the generation of the impact signal, a capacity control coefficient is obtained, and the capacity of the distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of the distributed energy that can be connected to the distribution network is obtained, and the maximum capacity of the distributed energy that can be connected to the distribution network is evaluated. The present invention determines the influencing reasons why the distribution network cannot accept the connected distributed energy, which is beneficial to the distribution optimization of the energy access of the distribution network, and optimizes the energy access of the distribution network according to the influencing reasons, which is beneficial to the access of distributed energy, and after the optimization, the maximum capacity of the distributed energy that can be connected to the distribution network is obtained, and the maximum energy capacity acceptance capacity of the distribution network is evaluated. Example 3

[0123] like Figure 3 As shown, a system for evaluating distributed energy acceptance capacity of a distribution network according to an embodiment of the present invention includes:

[0124] Admission analysis module: monitors whether the distribution network violates safety constraints after connecting to distributed energy within the evaluation period, and generates an admission signal based on the monitoring results;

[0125] Wherein, accepting signals includes accepting normal signals and accepting analysis signals;

[0126] Admission judgment module: Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data of the distribution network after the distributed energy is connected within the evaluation period, wherein the violation data includes the violation performance value, and the distribution network is judged whether it can accept the connected distributed energy according to the violation performance value;

[0127] Impact analysis module: based on the inability of the distribution network to accept the connected distributed energy, obtain the impact coefficient, determine whether the distributed energy capacity has an impact on the inability of the distribution network to accept the connected distributed energy based on the impact coefficient, and generate a signal, wherein the signal includes an impact signal and a non-impact signal;

[0128] Acceptance optimization evaluation module: Based on the generated impact signal, the capacity control coefficient is obtained, and the capacity of distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of distributed energy that can be accessed by the distribution network is obtained, and the maximum capacity of distributed energy that can be accessed by the distribution network is evaluated.

[0129] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for evaluating the distributed energy acceptance capacity of a distribution network, characterized by: include: Monitor whether the distribution network violates the safety constraints after connecting to distributed energy within the evaluation period. If so, generate an acceptance analysis signal; The generation process of the admission analysis signal is as follows: The distribution network is monitored using monitoring equipment, and the monitored operating parameters are compared with the safety constraints to monitor and identify whether the distribution network violates the safety constraints after connecting to distributed energy within the assessment period; If the distribution network does not violate the safety constraints after connecting to the distributed energy within the evaluation period, a normal acceptance signal is generated; If the distribution network violates the safety constraints after connecting to the distributed energy within the evaluation period, an acceptance analysis signal is generated; Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data after the distribution network is connected to the distributed energy within the evaluation period, wherein the violation data includes the violation performance value, and whether the distribution network can accept the connected distributed energy is determined according to the violation performance value; The violation performance value is obtained in the following manner: During the evaluation period, when the distribution network violates the safety constraint condition, a violation signal is generated, and when the distribution network does not violate the safety constraint condition, a non-violation signal is generated; During the evaluation period, the time period when the violation signal appears is marked as the violation period. Based on the analysis of the violation period, the violation degree data is obtained, wherein the violation degree data includes the total violation time T, the number of constraint violation CS and the mean violation deviation PC; The violation degree data is obtained in the following manner: The safety constraints violated by the distribution network during the evaluation period are marked as violation constraints, the detected operating parameters of the distribution network are subjected to difference processing with the maximum value of the violation constraints to obtain the violation deviation value, and all the violation deviation values ​​are summed and averaged to obtain the violation deviation mean PC; The total violation time T represents the length of time corresponding to the violation period; The number of constraint violations CS represents the sum of the number of security constraints violated by the distribution network during the evaluation period; After the total violation time T, the number of constraint violation CS and the mean violation deviation PC are dimensionless, they are substituted into the formula: Obtain a violation performance value BX, where s1, s2 and s3 are all preset proportional coefficients; Based on the inability of the distribution network to accept the connected distributed energy, an impact coefficient is obtained, and based on the impact coefficient, it is determined whether the capacity of the distributed energy has an impact on the inability of the distribution network to accept the connected distributed energy. If an impact is produced, an impact signal is generated; Based on the influencing signal, the capacity control coefficient is obtained, and the capacity of the distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of the distributed energy that can be accessed by the distribution network is obtained, and the maximum capacity of the distributed energy that can be accessed by the distribution network is evaluated.

2. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 1, characterized in that: The process of judging whether the distribution network can accept the connected distributed energy according to the violation performance value is as follows: The violation performance value BX is compared with the violation performance threshold. The specific comparison process is as follows: The default violation performance threshold is BY; If the violation performance value BX is greater than the violation performance threshold BY, it means that the distribution network cannot accept the connected distributed energy; If the violation performance value BX is less than or equal to the violation performance threshold BY, it means that the distribution network can accept the connected distributed energy.

3. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 1, characterized in that: The generation process of the impact signal is as follows: The time when the distribution network violates the voltage stability constraint within the violation period is obtained, and it is marked as the voltage violation time. The voltage violation time is ratio-processed with the time corresponding to the violation period to obtain the voltage violation time ratio; The detected voltage value of the distribution network within the voltage violation time is obtained, and all detected voltage values ​​are summed and averaged to obtain the voltage mean value, the voltage mean value is subjected to difference processing with the maximum value in the voltage stability constraint to obtain the over-limit voltage value, and the over-limit voltage value is subjected to ratio processing with the maximum value in the voltage stability constraint to obtain the voltage violation over-limit ratio; The voltage violation time ratio and the voltage violation over-limit ratio are summed to obtain the first impact value DYy; The second impact value DRy is obtained, and the obtained first impact value DYy and second impact value DRy are processed by the formula: The influence coefficient is obtained, where a1 and a2 are both preset proportional coefficients; The influence coefficient Yx is compared with the influence coefficient threshold. The specific comparison process is as follows: The preset impact coefficient threshold is Yxy; If the influence coefficient Yx is greater than the influence coefficient threshold Yxy, it means that the distributed energy capacity affects the distribution network and cannot accept the connected distributed energy, and an influence signal is generated; If the influence coefficient Yx is less than or equal to the influence coefficient threshold Yxy, it means that the distributed energy capacity does not affect the distribution network's inability to accept the connected distributed energy, and a non-influence signal is generated.

4. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 3, characterized in that: The second impact value DRy is obtained in the following manner: The capacity data of distributed energy connected to the distribution network in multiple historical evaluation cycles and the current evaluation cycle are obtained, wherein the capacity data includes the capacity value. The capacity value is marked and connected with the violation performance value of the distribution network in the historical evaluation cycle in the XY coordinate system to obtain a violation change curve, and the violation change curve is analyzed to obtain the percentage of the number of normal change sub-curves and the percentage of the number of normal synchronous change sub-curves. The percentage of the number of normal change sub-curves and the percentage of the number of normal synchronous change sub-curves are summed to obtain a second impact value DRy.

5. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 4, characterized in that: The method for obtaining the proportion of the number of the normal change sub-curves is as follows: Divide the violation change curve into a number of violation change sub-curves of equal length, connect the endpoints of the violation change sub-curves with straight lines, and measure the slope of the connected straight line to obtain the change slope value of the violation change sub-curve, and mark the violation change sub-curve based on comparative analysis of the slope values ​​of the violation change sub-curves, and mark the violation change sub-curves as normal violation change sub-curves and abnormal violation change sub-curves; The number of normal violation change sub-curves in the violation change sub-curve is counted, and the ratio is processed with the number of violation change sub-curves to obtain the ratio of the number of normal change sub-curves; The process of marking the sub-curve that violates the change is as follows: The slope of the violation change sub-curve is compared with 0. If the slope value of the violation change sub-curve is greater than 0, the violation change sub-curve is marked as a normal violation change sub-curve. If the slope value of the violation change sub-curve is less than or equal to 0, the violation change sub-curve is marked as an abnormal violation change sub-curve.

6. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 4, characterized in that: The method for obtaining the proportion of the number of normal synchronously changing sub-curves is as follows: Draw perpendicular lines to the X-axis and Y-axis through the two end points of the normal violation change sub-curve, measure the distance between the two perpendicular lines drawn to the X-axis, and obtain the horizontal length of the normal violation change sub-curve; measure the distance between the two perpendicular lines drawn to the Y-axis, and obtain the vertical length of the normal violation change sub-curve; perform ratio processing on the vertical length and the horizontal length of the normal violation change sub-curve, and obtain the relevant change ratio; Obtain the relevant change ratios corresponding to all normal violation change sub-curves, and sum and average them to obtain the relevant change ratio mean, perform difference processing on the relevant change ratio corresponding to the normal violation change sub-curve and the relevant change ratio mean, and take the absolute value of the difference to obtain the relevant change ratio deviation, sum and average all the obtained relevant change ratio deviations to obtain the relevant change ratio deviation mean, compare and analyze the relevant change ratio deviation with the relevant change ratio deviation mean, mark the normal violation change sub-curve, and mark it as a normal synchronous change sub-curve and a normal asynchronous change sub-curve; The number of normal synchronous change sub-curves is obtained, and the ratio is processed with the number of normal violation change sub-curves to obtain the ratio of the number of normal synchronous change sub-curves; The process of marking the normal violation change sub-curve is as follows: If the correlation change ratio deviation is greater than the correlation change ratio deviation mean, it is marked as a normal asynchronous change sub-curve; If the correlation change ratio deviation is less than or equal to the correlation change ratio deviation mean, it is marked as a normal synchronous change sub-curve.

7. A method for evaluating the distributed energy acceptance capacity of a distribution network according to claim 4, characterized in that: The capacity control coefficient includes a capacity control value; The method for obtaining the capacity control value is as follows: The normal synchronous change sub-curves are numbered in sequence, and the relevant change ratios corresponding to the normal synchronous change sub-curves are obtained, and the relevant change ratios are marked as Xgb; By formula: Get capacity control value , where N represents the normal synchronous change sub-curve number, BX represents the violation performance value, and BY represents the violation performance threshold; By formula: Get the maximum capacity of distributed energy that can be connected to the distribution network ,in, It represents the initial capacity of distributed energy.

8. A system for evaluating the distributed energy acceptance capacity of a distribution network, the system being used to implement the monitoring method as described in any one of claims 1 to 7 above, characterized in that: include: Admission analysis module: monitors whether the distribution network violates the safety constraints after connecting to distributed energy within the evaluation period. If so, an admission analysis signal is generated; Admission judgment module: Based on the acceptance analysis signal, the distribution network is analyzed to obtain the violation data of the distribution network after the distributed energy is connected within the evaluation period, wherein the violation data includes the violation performance value, and the distribution network is judged whether it can accept the connected distributed energy according to the violation performance value; The violation performance value is obtained in the following manner: During the evaluation period, when the distribution network violates the safety constraint condition, a violation signal is generated, and when the distribution network does not violate the safety constraint condition, a non-violation signal is generated; During the evaluation period, the time period when the violation signal appears is marked as the violation period. Based on the analysis of the violation period, the violation degree data is obtained, wherein the violation degree data includes the total violation time T, the number of constraint violation CS and the mean violation deviation PC; After the total violation time T, the number of constraint violation CS and the mean violation deviation PC are dimensionless, they are substituted into the formula: Obtain a violation performance value BX, where s1, s2 and s3 are all preset proportional coefficients; Impact analysis module: based on the fact that the distribution network cannot accept the connected distributed energy, the impact coefficient is obtained, and based on the impact coefficient, it is determined whether the distributed energy capacity has an impact on the fact that the distribution network cannot accept the connected distributed energy. If an impact is produced, an impact signal is generated; Acceptance optimization evaluation module: Based on the influencing signal, the capacity control coefficient is obtained, and the capacity of distributed energy is regulated based on the capacity control coefficient, so that the distribution network can accept the access of distributed energy. At the same time, the maximum capacity of distributed energy that can be accessed by the distribution network is obtained, and the maximum capacity of distributed energy that can be accessed by the distribution network is evaluated.

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