Method for generating power allocation factor of distributed generation node and grid-connected control method

Abstract

The present invention belongs to the field of electric power equipment, and specifically relates to a method for generating a power allocation factor of a distributed power generation node, and a method and system for grid-connected control of distributed power generation nodes in a substation. In the power allocation factor generation stage, the index items that affect the grid-connected power of each node are first selected, and then the influence of each index item is calculated using the ordered graph method; then each index item of each node is quantified or assigned a corresponding standardized value, and finally the standardized value of each index item is weighted using the influence to obtain the power allocation factor of the node. In the process of grid-connected control, the power allocation factor is further used as a weight, and the total power to be allocated is allocated to each node according to the weight. The solution of the present invention comprehensively considers all factors of the substation, so that the control strategy has both fairness and reliability, meets the needs of grid peak regulation and demand-side response, and helps to improve the power regulation and safe and stable operation capabilities of large power grids.

Description

Technical Field

[0001] The present invention belongs to the field of electric power equipment, and specifically relates to a method for generating a power allocation factor of a distributed power generation node, and a method and system for grid-connected control of distributed power generation nodes in a substation. Background Art

[0002] As the energy transition process accelerates, more and more distributed power stations or power plants such as photovoltaic and wind power are connected to the grid, which improves the cleanliness and environmental protection of electricity. However, the stability of photovoltaic and wind power generation methods is easily affected by disasters and extreme climate, which leads to the random volatility of new energy and renewable energy output, posing severe challenges to the safe supply of electricity.

[0003] Behind the booming development of household distributed photovoltaics, the problems caused by the grid-connected operation of distributed photovoltaics are becoming increasingly prominent. Due to the lack of active sensing equipment and control-related devices, the power grid is facing an unknown, uncontrollable, and dared not control situation. Taking household photovoltaics as an example, during the daytime and other periods, the power generation capacity of the equipment is the strongest, but the power demand in the substation is relatively weak. If the equipment generates electricity at maximum power and goes online, it will not only cause a waste of resources, but also affect the normal operation of the power grid. In order to solve this problem, the technicians proposed that the substation side issue corresponding control instructions to each low-voltage photovoltaic user node based on the demand and supply of electricity, so that the supply and demand of the power grid is balanced.

[0004] In the existing scheme, when the substation side regulates the low-voltage photovoltaic power on the user side, it adopts an equal-amount regulation strategy, that is, it requires each node in the substation to adjust the power at the same amplitude. This regulation method ignores the differences in different low-voltage photovoltaic user types and equipment performance, which may not only lead to unreasonable distribution of benefits for grid-connected users, but also cause response delays in the regulation process and poor regulation effects. Therefore, how to ensure differentiated power distribution for different types of users and avoid the unstable operation of the power grid and unreasonable distribution of benefits caused by the increasing number of distributed photovoltaics on the substation side is becoming a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0005] In order to solve the problem that the existing power control strategy for photovoltaic users on the substation side cannot meet the needs of grid peak regulation and demand-side response, which in turn leads to a decrease in the safe and stable operation capacity of the grid, the present invention provides a method for generating a power allocation factor of a distributed power generation node, a grid-connected control method and a system.

[0006] The solution provided by the present invention includes:

[0007] A method for generating a power allocation factor of a distributed generation node is used to generate a power allocation factor for guiding power regulation, wherein the power allocation factor is a weight coefficient for guiding power allocation when power is reduced for each distributed generation node in the substation. Specifically, the method for generating a power allocation factor in the present invention comprises the following steps:

[0008] S1: Analyze the scenarios of distributed power nodes connected to the grid, and select several indicators U that affect the proportion of grid-connected power allowed for each node i ; i = 1…n, where n represents the number of selected index items.

[0009] S2: Use the priority diagram method to calculate the influence score A corresponding to each indicator item according to the degree of influence of any two indicators on the grid-connected power. i ; and calculate the influence of each indicator item α through the following formula i :

[0010]

[0011] S3: Divide the indicator items into quantifiable indicators and non-quantitative indicators, and use the assignment method to assign values ​​to the non-quantitative indicators of each node.

[0012] S4: Obtain the standardized values ​​of all index items of each node in the current substation in real time; and calculate the power allocation factor W of each node by the following formula j :

[0013]

[0014] In the above formula, represents the standardized value of the i-th indicator item of the j-th user; j=1…m, m represents the number of distributed generation nodes in the current area.

[0015] As a further improvement of the present invention, the preferred index items include user type, phase line type, Internet access mode, rated power, number of times participating in regulation and cumulative regulation power of the corresponding node.

[0016] As a further improvement of the present invention, among the six optimal index items, the relationship between the influence degrees between the two is:

[0017] User type>Phase line type, Internet access method, rated power, number of times involved in regulation, and cumulative regulated power;

[0018] Phase line type > rated power;

[0019] Internet access method > phase line type, number of times involved in regulation;

[0020] Rated power>on-grid mode and number of times involved in regulation;

[0021] Number of times involved in regulation>phase line type;

[0022] The accumulated regulated power is greater than the phase line type, access mode, rated power and number of times involved in regulation.

[0023] As a further improvement of the present invention, the influence degrees of user type, phase line type, Internet access method, rated power, number of times participating in regulation and cumulative regulated power calculated by the priority diagram method are 0.31, 0.08, 0.14, 0.14, 0.08 and 0.25 respectively.

[0024] As a further improvement of the present invention, in step S2, the method for calculating the influence score of each indicator item based on the priority diagram method is:

[0025] (1) According to the number of indicator items n, an n×n chessboard diagram is constructed, and the row number and column number of each grid in the chessboard diagram correspond one-to-one to an indicator item.

[0026] (2) Assign values ​​to each grid according to the following strategy:

[0027] ⅰ. If the importance of the indicator item corresponding to the row number of the current grid is higher than the indicator item corresponding to the column number, the grid is assigned a value of 1.

[0028] ⅱ. If the importance of the indicator item corresponding to the row number of the current grid is lower than the indicator item corresponding to the column number, the grid is assigned a value of 0.

[0029] ⅲ. If the indicator item corresponding to the row number of the current grid and the indicator item corresponding to the column number are the same indicator, the grid is assigned a value of 0.5.

[0030] (3) The values ​​of each grid in the chessboard are summed row by row, that is, the index item U corresponding to each row number is obtained. i Impact score of A i .

[0031] As a further improvement of the present invention, in step S3, the non-quantitative indicators in the selected indicator items include user type, phase line type and Internet access mode; the assignment method for the three is:

[0032] If the user type is a non-natural person user, the value is assigned to 8; if the user type is a natural person user, the value is assigned to 2; if the user type is other users, the value is assigned to 0.

[0033] If the phase line type is single-phase two-wire, the value is 3; if the phase line type is three-phase four-wire, the value is 7.

[0034] If the Internet access method is full payment, the value is assigned to 8; if the Internet access method is balance payment, the value is assigned to 2.

[0035] As a further improvement of the present invention, in step S4, if the i-th indicator item is a non-quantitative indicator, the result after its assignment is directly recorded as the standardized value If the i-th indicator item is a quantitative indicator, the actual value of the indicator corresponding to all nodes in the current area is scaled proportionally so that the magnitude of the scaled result is the same as the value space of the non-quantitative indicator when assigned. The scaled value is the standardized value.

[0036] The present invention also includes a grid-connected control method for distributed power generation nodes in a substation, which is used to control the grid-connected power of each node according to the attributes of each node and its historical grid-connected data; the grid-connected control method includes:

[0037] The power allocation factor W of each node in the area is updated in real time using the generation method of the distributed generation node power allocation factor as mentioned above. j .

[0038] The following strategy is used to generate the control power P for each distributed generation node: c , and issued regulatory instructions:

[0039] (I) During peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c :

[0040]

[0041] In the above formula, P t Indicates the total active power of the current area; C r It indicates the total power control target ratio of the substation side issued by the master station. This value is calculated by the master station based on the power supply and demand status of the substation predicted in the current period.

[0042] (II) During off-peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c :

[0043]

[0044] In the above formula, T N Indicates the actual reverse load rate of the current area; T T Indicates the preset maximum reverse load rate of the station area.

[0045] As a further improvement of the present invention, the grid-connected control method also issues a recovery instruction to each distributed power generation node after completing the control target, so as to allow the inverter of each distributed power generation node to resume output.

[0046] The timing for issuing a recovery command is:

[0047] (1) If a control order is issued due to peak electricity consumption, a recovery order shall be issued at the end of the effective period of the control order.

[0048] (2) If a control command is issued due to the reverse load rate exceeding the limit during non-peak hours, the real-time reverse load rate in the substation area is lower than the preset minimum reverse load rate T S When the real-time reverse load rate in the station area is lower than the preset maximum reverse load rate T T When the duration exceeds the preset time T, a recovery instruction is issued.

[0049] The present invention also includes a grid-connected control system for distributed power generation nodes in a substation area, which includes a master station and a concentrator.

[0050] The master station is used to send the first power control instruction to the substation during the peak power consumption period. The first power adjustment instruction includes the total power control target ratio C of the substation side. r The master station is also used to issue a reverse heavy overload control threshold during off-peak hours; and to issue a second power regulation instruction after receiving an over-limit event in which the real-time reverse load rate in the substation is higher than the preset maximum reverse load rate and the duration exceeds the preset time.

[0051] The concentrator is used to monitor the real-time reverse load rate in the substation area in real time during non-peak hours. When the real-time reverse load rate is higher than the preset maximum reverse load rate and the duration exceeds the preset time, an over-limit event is generated and reported to the master station. The concentrator also uses the aforementioned distributed generation node power allocation factor generation method to update the power allocation factor of each node in the substation area in real time. j After receiving the first power adjustment instruction and the second power adjustment instruction, the control power P of each node in the area is calculated by using the grid-connected control method of the distributed generation node in the area as mentioned above. c ; Then it is sent to each distributed power generation node in the substation area.

[0052] The technical solution provided by the present invention has the following beneficial effects:

[0053] This embodiment optimizes several key factors that affect the photovoltaic control power in the substation, and designs a new mechanism for dynamically allocating power control based on various factors. Under the mechanism of the present invention, with the execution of each control demand on the substation side, the photovoltaic control power allocation weights of different nodes will also be continuously adjusted. This mechanism can ensure that large-scale, high-power, non-natural person users are regulated and controlled first, and reduce the frequency of regulation for special users to ensure fairness. At the same time, the mechanism can also give priority to those who have participated in the regulation execution effect in the historical process, so as to reduce the delay of the regulation process and ensure the safety and stability of the power system. The mechanism of the present invention is used to assist in the reasonable allocation of photovoltaic control needs on the substation side, which can significantly improve the effect of power regulation.

[0054] The present invention divides the power regulation cycle into peak period and off-peak period, and designs new regulation strategies for different periods. During the peak period, the master station mainly obtains the total power share to be allocated based on the prediction of power demand and supply, while during the off-peak period, the concentrator calculates the total power share to be allocated based on the real-time reverse load rate on the power grid. At the same time, the present invention also stipulates the best time to restore the inverter output for different regulation scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a flowchart of the steps of a method for generating a power allocation factor of a distributed generation node provided in Example 1 of the present invention.

[0056] Figure 2 This is a flowchart of the steps of the method for calculating the influence score of each indicator item based on the priority diagram method adopted by the present invention. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0058] Example 1

[0059] This embodiment provides a method for generating a power allocation factor of a distributed generation node, which is used to generate a power allocation factor for guiding power regulation, and the power allocation factor is a weight coefficient for guiding power allocation when the power of each distributed generation node in the substation is reduced. When the power allocation factor of a distributed generation node is larger, when the power generation power needs to be reduced in the substation, the reduction share allocated to the node is larger, and vice versa, the reduction share allocated to the node is smaller.

[0060] Specifically, the method for generating the power allocation factor in this embodiment includes the following steps:

[0061] S1: Analyze the scenarios of distributed power nodes connected to the grid, and select several indicators U that affect the proportion of grid-connected power allowed for each node i ; i = 1…n, where n represents the number of selected index items.

[0062] The indicator items in this embodiment can be manually designed by technical personnel. Taking a substation containing several low-voltage photovoltaic user nodes as an example, considering the timely response and effect of regulation, the factors affecting the regulation allocation weights are selected, including the user type of photovoltaic users, the phase line type of the inverter in the photovoltaic power generation equipment installed by the user, the access method, the rated power of the inverter; and the number of times each user has participated in regulation and the cumulative regulation power in the historical records, etc.

[0063] Among the above indicators, there are three types of users, namely, non-natural person users, natural person users, and other users. Non-natural person users refer to small photovoltaic power generation equipment that is not owned by individuals, such as photovoltaic power generation equipment installed on roofs or small waters by enterprises, governments, or factory units. Natural person users are small power stations built by private individuals, such as photovoltaic equipment installed on roofs. Other users refer to small photovoltaic power stations built with the help of the government. The phase line types of inverters are divided into single-phase two-wire and three-phase four-wire. The access to the Internet is divided into full access to the Internet and balance access to the Internet. The former means that the power generation of photovoltaic equipment is fully connected to the grid, and users draw and use electricity through the power grid; balance access to the Internet means that the power generation of photovoltaic equipment is used by users themselves first, and the remaining part is connected to the grid.

[0064] S2: Use the priority diagram method to calculate the influence score A corresponding to each indicator item according to the degree of influence of any two indicators on the grid-connected power. i ; and calculate the influence of each indicator item α through the following formula i :

[0065]

[0066] like Figure 2 As shown, this embodiment uses the priority diagram method to calculate the influence score A of each indicator item. i The method is:

[0067] (1) According to the number of indicator items n, an n×n chessboard diagram is constructed, and the row number and column number of each grid in the chessboard diagram correspond one-to-one to an indicator item.

[0068] (2) Assign values ​​to each grid according to the following strategy:

[0069] ⅰ. If the importance of the indicator item corresponding to the row number of the current grid is higher than the indicator item corresponding to the column number, the grid is assigned a value of 1.

[0070] ⅱ. If the importance of the indicator item corresponding to the row number of the current grid is lower than the indicator item corresponding to the column number, the grid is assigned a value of 0.

[0071] ⅲ. If the indicator item corresponding to the row number of the current grid and the indicator item corresponding to the column number are the same indicator, the grid is assigned a value of 0.5.

[0072] (3) The values ​​of each grid in the chessboard are summed row by row, that is, the index item U corresponding to each row number is obtained. i Impact score of A i .

[0073] Among the six indicator items selected in this embodiment, the relationship between the influence degrees of each other is as follows:

[0074] User type>Phase line type, Internet access method, rated power, number of times involved in regulation, and cumulative regulated power;

[0075] Phase line type > rated power;

[0076] Internet access method > phase line type, number of times involved in regulation;

[0077] Rated power>on-grid mode and number of times involved in regulation;

[0078] Number of times involved in regulation>phase line type;

[0079] The accumulated regulated power is greater than the phase line type, access mode, rated power and number of times involved in regulation.

[0080] According to the above importance comparison results, the chessboard diagram in the priority diagram method is shown in the following table:

[0081] Table 1: Calculation table of the weights of the priority graph of the six indicators in this embodiment

[0082]

[0083]

[0084] Finally, according to the influence score A of user type, phase line type, Internet access method, rated power, number of times of participation in regulation and cumulative regulation power calculated by the priority diagram method, i ,Further calculation shows that the influences of the six indicators are 0.31, 0.08, 0.14, 0.14, 0.08, and 0.25 respectively.

[0085] S3: Divide the indicator items into quantifiable indicators and non-quantitative indicators, and use the assignment method to assign values ​​to the non-quantitative indicators of each node.

[0086] Among the selected indicators, some are quantifiable indicators, and the evaluation results of such indicators are a numerical value, and the size of the numerical value represents the strength of the evaluation object in the current indicator item. Other indicators may be non-quantitative indicators, and the evaluation results of these indicators are not a numerical value, so the strength of the evaluation object in the current indicator item cannot be quantified through the evaluation results.

[0087] In view of the above differences in the index items, this embodiment assigns values ​​to the non-quantitative index of each node, and then converts it into a quantitative index. Specifically, still taking the six index items selected above as an example, this embodiment assigns values ​​to different user types, phase line types and Internet access methods according to Table 2, Table 3 and Table 4:

[0088] Table 2: Assignment table for different user types in this embodiment

[0089] User Type Value Non-natural person users 8 Natural person users 2 Other users 0

[0090] Table 3: Value assignment table for different phase line types in this embodiment

[0091] Phase line type Value Single-phase two-wire 3 Three-phase four-wire 7

[0092] Table 4: Value assignment table for different Internet access modes in this embodiment

[0093] How to access the Internet Value Full Internet Access 8 Balance online 2

[0094] S4: Obtain the standardized values ​​of all index items of each node in the current substation in real time; and calculate the power allocation factor W of each node by the following formula j :

[0095]

[0096] In the above formula, represents the standardized value of the i-th indicator item of the j-th user; j=1…m, m represents the number of distributed generation nodes in the current area.

[0097] In the solution of this embodiment, the non-quantitative indicators of user type, phase line type and Internet access mode in the selected indicator items are assigned values ​​and recorded as standardized values. The values ​​of the quantitative indicators rated power, number of times of participation in regulation and cumulative regulated power are directly used as the corresponding standardized values.

[0098] In the solutions of other embodiments of the present invention, in order to prevent the value of a certain quantitative index item of a certain node from being too large and thus affecting the fairness of the final power allocation factor, the standard value of the non-quantitative index may be specified as follows.

[0099] If the i-th indicator item is a non-quantitative indicator, the actual value of the indicator item corresponding to all nodes in the current area is scaled proportionally so that the magnitude of the scaled result is the same as the value space of the non-quantitative indicator when it is assigned. The scaled value is the standardized value.

[0100] For example, in this embodiment, the values ​​of the non-quantitative indicators after assignment are all within the range of 0-10, so the rated power, number of times of participation in regulation and cumulative regulation power of different indicators can be scaled proportionally, so that the maximum value of the relevant indicators of each node does not exceed 10, and the scaled result is used as the standardized value of the indicator item.

[0101] Example 2

[0102] On the basis of the scheme in Example 1, this embodiment further provides a method for grid-connected control of distributed power generation nodes in a substation, which is used to control the grid-connected power of each node according to the attributes of each node and its historical grid-connected data. The grid-connected control method provided in this embodiment includes two types, one of which is used to control the grid-connected power of each node according to the power demand and supply forecast results of the master station on the power grid during the peak period of the substation to meet the peak load demand of the power grid. The other is to timely control the grid-connected power during non-peak hours, combined with the reverse load rate on the power grid monitored in real time, to meet the requirements of power grid operation safety and stability and achieve supply and demand matching. Specifically, the grid-connected control method provided in this embodiment includes:

[0103] 1. Use the method for generating the power allocation factor of the distributed generation node in Example 1 to update the power allocation factor W of each node in the area in real time. j .

[0104] 2. Use the following strategy to generate the control power P for each distributed generation node c , and issued regulatory instructions:

[0105] (I) During peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c :

[0106]

[0107] In the above formula, P t Indicates the total active power of the current area; C r It indicates the total power control target ratio of the substation side issued by the master station. This value is calculated by the master station based on the power supply and demand status of the substation predicted in the current period.

[0108] (II) During off-peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c :

[0109]

[0110] In the above formula, T N Indicates the actual reverse load rate of the current area; T TIndicates the preset maximum reverse load rate of the station area.

[0111] The idea of ​​the control strategy provided in this embodiment is: first, combine the user type, phase line type, Internet access method, rated power, number of times participating in control and cumulative control power of each node in the substation to generate a power allocation factor for each node; then calculate the power value that needs to be reduced in the current substation, and finally use the power allocation factor of each node as the allocation weight to allocate the total power value to be allocated to each node in proportion as the reduction share of the inverter in the node.

[0112] In addition, the grid-connected control method provided in this embodiment also issues a recovery instruction to each distributed power generation node after completing the control target, so as to allow the inverter of each distributed power generation node to resume output.

[0113] According to different scenarios, the timing of issuing the recovery instruction in this embodiment is:

[0114] (1) If a control order is issued due to peak electricity consumption, a recovery order shall be issued at the end of the effective period of the control order.

[0115] (2) If a control command is issued due to the reverse load rate exceeding the limit during non-peak hours, the real-time reverse load rate in the substation area is lower than the preset minimum reverse load rate T S When the real-time reverse load rate in the station area is lower than the preset maximum reverse load rate T T When the duration exceeds the preset time T, a recovery instruction is issued.

[0116] In order to make the solution of the present invention clearer, the strategy of grid-connected regulation of the solution of the present invention is described in detail below in conjunction with a certain area including 8 photovoltaic grid-connected users:

[0117] According to the solution of Example 1, this embodiment still selects user type, phase line type, Internet access mode, rated power, number of times of participating in regulation and cumulative regulated power as index items. The influence of the six index items is calculated as shown in the following table:

[0118] Table 5: The influence of different indicators calculated based on the priority diagram method

[0119] User Type Phase line type How to access the Internet Rated Power Number of times of participating in regulation Cumulative control power 0.31 0.08 0.14 0.14 0.08 0.25

[0120] Furthermore, the basic information of each indicator item of the eight users in this embodiment is shown in the following table:

[0121] Table 6: Basic information of each user in the area

[0122]

[0123]

[0124] After obtaining the standard values ​​of each indicator item based on the above basic content, the power allocation factor of each user is calculated as shown in the following table:

[0125] Table 7: Power allocation factors for each user in the area

[0126] user Power allocation factor 1 19.00 2 9.43 3 4.39 4 3.96 5 6.51 6 2.20 7 4.97 8 9.92

[0127] Based on the above power allocation factors, if the current period is a non-peak period, the regulated power allocated to each user is calculated as shown in Table 8 below:

[0128] Table 8: Controlled power allocated to each user during off-peak hours

[0129] user Power regulation 1 <![CDATA[0.31*P T (T N -T T )]]> 2 <![CDATA[0.16*P T (T N -T T )]]> 3 <![CDATA[0.07*P T (T N -T T )]]> 4 <![CDATA[0.07*P T (T N -T T )]]> 5 <![CDATA[0.11*P T (T N -T T )]]> 6 <![CDATA[0.04*P T (T N -T T )]]> 7 <![CDATA[0.08*P T (T N -T T )]]> 8 <![CDATA[0.16*P T (T N -T T )]]>

[0130] If the current period is a peak period, the control power allocated to each user is calculated as shown in Table 9 below:

[0131] Table 9: Control power allocated to each user during peak hours

[0132] user Power regulation 1 <![CDATA[0.31*P T (1-C R )]]> 2 <![CDATA[0.16*P T (1-C R )]]> 3 <![CDATA[0.07*P T (1-C R )]]> 4 <![CDATA[0.07*P T (1-C R )]]> 5 <![CDATA[0.11*P T (1-C R )]]> 6 <![CDATA[0.04*P T (1-C R )]]> 7 <![CDATA[0.08*P T (1-C R )]]> 8 <![CDATA[0.16*P T (1-C R )]]>

[0133] Example 3

[0134] Based on the solutions of Example 1 and Example 2, this embodiment further provides a grid-connected control system for distributed power generation nodes in a substation. The system is implemented based on the existing master station and concentrator in the power grid. Corresponding functional modules are newly configured in the master station and concentrator. The newly added functional modules in the master station and concentrator adopt the methods of Examples 1 and 2 to realize dynamic update of power allocation factors and calculate the control power sent to each distributed power generation node.

[0135] Specifically, in the grid-connected control system of the distributed generation nodes in the substation provided in this embodiment, the master station is used to send a first power control instruction to the substation during the peak power consumption period. The first power adjustment instruction includes the total power control target ratio C of the substation side. r The master station is also used to issue reverse overload control thresholds during off-peak hours, and to issue a second power regulation command after receiving an over-limit event in which the real-time reverse load rate in the substation exceeds the preset maximum reverse load rate and lasts for a preset time (usually set to 5 minutes).

[0136] The concentrator is used to monitor the real-time reverse load rate in the substation area in real time during non-peak hours, and when the real-time reverse load rate is higher than the preset maximum reverse load rate and the duration exceeds the preset time, an over-limit event is generated and reported to the master station. The concentrator also uses the method for generating the power allocation factor of the distributed generation node as in Example 1 to update the power allocation factor of each node in the substation area in real time. j After receiving the first power adjustment instruction and the second power adjustment instruction, the grid-connected control method of the distributed generation node in the substation area as in Example 2 is used to calculate the control power P of each node in the substation area. c ; Then it is sent to each distributed power generation node in the substation area.

[0137] In addition, after completing the control target, the master station also issues a release command of the control command to each node through the concentrator, so that each inverter in the substation can resume output. Specifically, the power control command corresponding to the peak period includes a command validity period, and such control command is automatically released after the validity period (i.e., the corresponding peak period) ends. The control command corresponding to the non-peak period is decided by the master station based on the real-time reverse load rate on the substation power grid monitored by the concentrator. The master station can choose to release the control command when the real-time reverse load rate after control is less than a preset lower limit value, or it can choose to release the control command when the real-time reverse load rate after control is lower than a preset upper limit value and the duration reaches a preset time.

[0138] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for generating a power allocation factor of a distributed generation node, which is used to generate a power allocation factor for guiding power regulation; characterized in that: The method for generating the power allocation factor comprises the following steps: S1: Analyze the scenarios of distributed power nodes connected to the grid, and select several indicators U that affect the proportion of grid-connected power allowed for each node i ; i = 1…n, where n represents the number of selected index items; The selected indicators include the user type, phase line type, access mode, rated power, number of times of participation in regulation and cumulative regulation power of the corresponding node. S2: Use the priority diagram method to calculate the influence score A corresponding to each indicator item according to the degree of influence of any two indicators on the grid-connected power. i ; and calculate the influence of each indicator item α through the following formula i ; S3: Divide the indicator items into quantifiable indicators and non-quantifiable indicators, and use the assignment method to assign values ​​to the non-quantifiable indicators of each node; S4: Obtain the standardized values ​​of all index items of each node in the current substation in real time; and calculate the power allocation factor W of each node by the following formula j : In the above formula, represents the standardized value of the i-th indicator item of the j-th user; j=1…m, m represents the number of distributed generation nodes in the current area.

2. The method for generating a distributed generation node power allocation factor according to claim 1, characterized in that: Among the six selected indicators, the relationship between the influence degree between them is: User type>Phase line type, Internet access method, rated power, number of times involved in regulation, and cumulative regulated power; Phase line type > rated power; Internet access method > phase line type, number of times involved in regulation; Rated power>on-grid mode and number of times involved in regulation; Number of times involved in regulation>phase line type; The accumulated regulated power is greater than the phase line type, access mode, rated power and number of times involved in regulation.

3. The method for generating a distributed generation node power allocation factor according to claim 2, characterized in that: The influence degrees of user type, phase line type, access mode, rated power, number of times participating in regulation and cumulative regulated power calculated by the priority diagram method are 0.31, 0.08, 0.14, 0.14, 0.08 and 0.25 respectively.

4. The method for generating a power allocation factor of a distributed generation node according to claim 1, characterized in that: In step S2, the method for calculating the influence score of each indicator item based on the priority diagram method is: (1) According to the number of indicator items n, an n×n chessboard is constructed, and the row number and column number of each grid in the chessboard correspond to an indicator item one by one; (2) Assign values ​​to each grid according to the following strategy: ⅰ. If the importance of the indicator item corresponding to the row number of the current grid is higher than the indicator item corresponding to the column number, the grid is assigned a value of 1; ii. If the importance of the indicator item corresponding to the row number of the current grid is lower than the indicator item corresponding to the column number, the grid is assigned a value of 0; ⅲ. If the indicator item corresponding to the row number of the current grid and the indicator item corresponding to the column number are the same indicator, the grid is assigned a value of 0.5; (3) The values ​​of each grid in the chessboard are summed row by row, that is, the index item U corresponding to each row number is obtained. i Impact score of A i .

5. The method for generating a power allocation factor of a distributed generation node according to claim 1, characterized in that: In step S3, the non-quantitative indicators in the selected indicator items include user type, phase line type and Internet access method, and the method of assigning values ​​to the three is: If the user type is a non-natural person user, the value is 8; if the user type is a natural person user, the value is 2; if the user type is other users, the value is 0; If the phase line type is single-phase two-wire, the value is 3; if the phase line type is three-phase four-wire, the value is 7; If the Internet access method is full payment, the value is assigned to 8; if the Internet access method is balance payment, the value is assigned to 2.

6. The method for generating a power allocation factor of a distributed generation node according to claim 1, characterized in that: In step S4, if the i-th indicator item is a non-quantitative indicator, the result after its assignment is directly recorded as the standardized value If the i-th indicator item is a quantitative indicator, the actual value of the indicator corresponding to all nodes in the current area is scaled proportionally so that the magnitude of the scaled result is the same as the value space of the non-quantitative indicator when assigned. The scaled value is the standardized value.

7. A method for controlling the grid connection of distributed power generation nodes in a substation, characterized in that: It is used to regulate the grid-connected power of each node according to the properties of the node and its historical grid-connected data; The grid-connected control method comprises: The power allocation factor W of each node in the area is updated in real time by using the method for generating the power allocation factor of the distributed generation node as described in any one of claims 1 to 6. j ; The following strategy is used to generate the control power P for each distributed generation node: c , and issued regulatory instructions: (I) During peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c : In the above formula, P t Indicates the total active power of the current area; C r Indicates the total power control target ratio of the substation side issued by the master station; (II) During off-peak hours, the control power P allocated to each distributed generation node is calculated by the following formula: c : In the above formula, T N Indicates the actual reverse load rate of the current area; T T Indicates the preset maximum reverse load rate of the station area.

8. The method for controlling the grid connection of distributed power generation nodes in a substation area as claimed in claim 7, characterized in that: The grid-connected control method also issues a recovery instruction to each distributed generation node after completing the control target, so as to allow the inverter of each distributed generation node to recover output; The timing for issuing a recovery command is: (1) If a control order is issued due to peak electricity consumption, a recovery order will be issued at the end of the effective period of the control order; (2) If a control command is issued due to the reverse load rate exceeding the limit during non-peak hours, the real-time reverse load rate in the substation area is lower than the preset minimum reverse load rate T S When the real-time reverse load rate in the station area is lower than the preset maximum reverse load rate T T When the duration exceeds the preset time T, a recovery instruction is issued.

9. A grid-connected control system for distributed power generation nodes in a substation, characterized in that: It includes: The master station is used to send a first power adjustment instruction to the substation during the peak power consumption period. The first power adjustment instruction includes a total power control target ratio C of the substation side. r ; The master station is also used to issue a reverse heavy overload control threshold during non-peak hours; and issue a second power adjustment instruction after an over-limit event occurs in the area where the real-time reverse load rate is higher than the preset maximum reverse load rate and the duration exceeds the preset duration; A concentrator, which is used to monitor the real-time reverse load rate in the substation area in real time during non-peak hours, and generate an over-limit event when the real-time reverse load rate is higher than the preset maximum reverse load rate and the duration exceeds the preset time, and report it to the main station; the concentrator also uses the method for generating the power allocation factor of the distributed generation node according to any one of claims 1 to 6 to update the power allocation factor of each node in the substation area in real time. j After receiving the first power adjustment instruction and the second power adjustment instruction, the grid-connected control method of the distributed generation node in the substation as described in claim 7 or 8 is used to calculate the control power P of each node in the substation c ; Then it is sent to each distributed power generation node in the substation area.

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