Dual sequencing control machine trip method combined with multi-region unit coordination

Abstract

The application belongs to the technical field of electric power automation, and particularly discloses a dual-order sequencing and control machine tripping method combined with multi-region unit cooperation. The application quantitatively analyzes the correlation coefficient from two aspects of power grid safety and stability and line thermal stability, and respectively formulates the machine tripping priority order of each unit group. After a large disturbance occurs in the power grid, the two kinds of machine tripping priority orders are combined to control the fault line near-zone line power flow to the thermal stability threshold range while ensuring the safety and stability of the power grid, and then precise safety control machine tripping is realized.

Description

Technical Field

[0001] This invention belongs to the field of power automation technology and is used to achieve precise safety control and generator tripping. Specifically, it is a dual-sequencing safety control and generator tripping method that combines multi-regional unit coordination. Background Technology

[0002] With the continuous advancement of power systems, various new technologies have emerged to ensure the safe and stable operation of the power grid.

[0003] When a large disturbance occurs in the power grid, existing technologies mainly employ a "three-line defense" approach to achieve grid safety management. Automatic safety devices, as the second line of defense, often use strategies such as disconnecting generating units or shelving loads to maintain grid stability. For the unit disconnection strategy, its primary task is to ensure that the power grid does not experience transient or dynamic instability.

[0004] Currently, some regional power grids face risks of dynamic and transient instability during actual operation. When a fault occurs in a power grid connection line, it is necessary to disconnect generating units that are electrically distant from the faulty line, taking into account the grid's stability characteristics, thereby reducing the overall transmission capacity. However, lines near the faulty line often exceed the thermal stability threshold. In this case, disconnecting generating units that are electrically distant from the faulty element often only solves the grid stability problem, but cannot solve the problem of the nearby lines exceeding the thermal stability threshold. If even more generating units with greater electrical distances are disconnected to overcome the above problems, it often leads to over-disconnection of generating units, resulting in problems such as excessive grid frequency drops. Therefore, disconnecting generating units that are electrically close to the faulty line is the most effective way to solve the problem of the nearby lines exceeding the thermal stability threshold.

[0005] Therefore, if we can combine the safety and stability of the power grid with the thermal stability of the lines, and formulate the priority order of each generator group from two perspectives after a major disturbance to the power grid, while ensuring the safety and stability of the power grid, we can implement precise safety control and generator switching, which will solve the problem of overheating and stability threshold of the near-field lines of the faulty lines. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-sequencing safety control tripping method that combines multi-regional unit coordination. From the perspectives of power grid safety and stability and line thermal stability, the method quantitatively analyzes the correlation coefficients and formulates the tripping priority order for each unit group. After a major disturbance occurs in the power grid, the two tripping priority orders are combined to ensure the safety and stability of the power grid while controlling the power flow of the faulty line in the vicinity to within the thermal stability threshold range, thereby achieving precise safety control tripping.

[0007] To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0008] A dual-sequencing safety control method for switching units, combining multi-regional unit coordination, is performed in the following steps:

[0009] S1. Establish a power grid data model and generate power flow files based on the power grid data model and operating mode;

[0010] S2. After a critical channel fails and is cleared, perform the following three operations.

[0011] ① Calculate the power flow transfer ratio of the critical channel that experienced the fault to the monitored line;

[0012] ② For critical channels that have experienced faults, disconnect units of equal capacity in each group separately, calculate the unit transfer ratio of the monitored lines, and prioritize the corresponding groups according to the unit transfer ratio from largest to smallest to obtain sequence A;

[0013] ③ In order to achieve the same grid stability characteristics, the capacity required to cut off each generator group individually is obtained through simulation analysis. The generator group with the smallest cut-off amount is set as the benchmark generator group. The stability sensitivity coefficient of each generator group is calculated. The generator groups are prioritized according to the stability sensitivity coefficient from largest to smallest to obtain sequence B.

[0014] According to the priority order of sequence B, the actual scalable unit capacity of each group after being multiplied by the stability sensitivity coefficient is gradually accumulated until the accumulated result is greater than or equal to the number of units to be scalped in the actual security control measures. The accumulated result at this time is recorded as the actual equivalent number of units to be scalped, and the actual scalable unit capacity of each group participating in the accumulation calculation is recorded as the scalable unit capacity of each group.

[0015] S3. Combine the power flow transfer ratio, unit transfer ratio and the capacity of the disconnected units of each group of units obtained in step S2 to calculate the equivalent power flow value of the monitoring line.

[0016] S4. Determine whether the equivalent power flow value of the monitored line exceeds the thermal stability threshold. If the equivalent power flow value of the monitored line exceeds the thermal stability threshold, proceed to step S5; if the equivalent power flow value of the monitored line does not exceed the thermal stability threshold, proceed directly to step S6.

[0017] S5. Based on the capacity of each generator group that has been disconnected obtained in step ③, the generator groups are disconnected in order of priority in sequence A. The sum of the disconnected capacity of each generator group and the capacity of each generator group that has been disconnected is used as the correction value of the capacity of each generator group that has been disconnected. Combining the power flow transfer ratio, generator transfer ratio and the correction value of the capacity of each generator group that has been disconnected obtained in step S2, the equivalent power flow value of the monitoring line is recalculated in real time according to the method in step S3 until the equivalent power flow value of the monitoring line is less than or equal to the thermal stability threshold. Then, step S7 is executed.

[0018] S6. Set the sum of the cut-off capacity of each group of units calculated in step ③ as the final cut-off amount, and perform the cut-off processing of each group of units according to the group priority order in sequence B.

[0019] S7, End.

[0020] As a limitation, the power flow transfer ratio of the monitored line in step ① is calculated according to formula I:

[0021]

[0022] Where m represents the power flow transfer ratio of the monitored line, P l-before P represents the active power of the monitored line before a critical channel failure. l-after P represents the active power of the monitored line after a critical channel failure. line This indicates the active power before a critical channel failure.

[0023] As a second limitation, the unit transfer ratio in step ② is calculated according to formula II:

[0024]

[0025] Where n represents the unit transfer ratio, P g-before P represents the active power of the monitoring line before each generator group is disconnected. g-after P represents the active power of the monitoring line after each generator group is disconnected. group This indicates the corresponding cut-off amount for each aircraft group.

[0026] As a third limitation, the stability sensitivity coefficient in step ③ is calculated according to formula III:

[0027]

[0028] Where k represents the stability sensitivity coefficient, P others P represents the number of other generating units that achieve the same grid stability performance as the benchmark generating unit. base This indicates the baseline number of generators to be switched off to ensure grid stability.

[0029] As a fourth limitation, the actual equivalent cutting quantity in step ③ is calculated according to formula IV:

[0030]

[0031] Where G represents the actual equivalent switching capacity, A i Indicates that the capacity of the i-th cluster has been cut, k i Let A1 represent the stability sensitivity coefficient of the i-th cluster, and let A1 represent the capacity of the reference cluster that has been switched off, and k1 represent the stability sensitivity coefficient of the reference cluster.

[0032] As a fifth limitation, the equivalent power flow value of the monitored line in step S3 is calculated according to Equation V:

[0033]

[0034] Among them, P sj P represents the equivalent power flow value of the monitored line. before-sj P represents the actual active power of the monitored line before a critical channel failure, m represents the power flow transfer ratio of the monitored line, and P represents the active power of the monitored line before a critical channel failure. line-sj n represents the actual active power before the critical channel failure. i A represents the unit transfer ratio of the i-th cluster. i B represents the capacity of the units that have been switched off in the i-th cluster; i This represents the capacity to be added to the i-th cluster, with an initial value of 0.

[0035] The present invention, by adopting the above-described technical solution, achieves the following technical advancements compared to existing technologies:

[0036] (1) This invention starts from the safety and stability of the power grid and the thermal stability of the line, quantitatively analyzes and formulates two types of generator group tripping priorities, and through the coordinated operation of the two tripping sequences, it ensures the safe and stable operation of the power grid while controlling the faulty line near the line to not exceed the thermal stability threshold.

[0037] (2) The present invention first obtains the number of generators that meet the safe operation of the power grid based on the generator tripping sequence obtained from the power grid stability characteristics, and then further optimizes the number of generators based on the generator tripping sequence obtained from the line thermal stability characteristics. The number of generators can be dynamically adjusted according to the actual power flow of the monitored line, thereby achieving precise safety control generator tripping.

[0038] (3) Since this method adopts two different switching sequences, each group will not have the problem of over-switching after the switching strategy is implemented. This ensures that the remaining capacity of each group is evenly distributed, thereby achieving reliable power supply to the area near each group.

[0039] This invention belongs to the field of power automation technology. It overcomes the problem of over-switching of units caused by conventional safety control and generator tripping methods after a large disturbance in the power grid in order to ensure the safe and stable operation of the power grid and that the faulty line and the nearby lines do not exceed the thermal stability threshold. It has the characteristics of precise generator tripping according to different power grid problems, and small number of generator trips and small amount of calculation. Attached Figure Description

[0040] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0041] In the attached diagram:

[0042] Figure 1 This is a flowchart of an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the power grid structure according to an embodiment of the present invention;

[0044] Figure 3 This is a diagram illustrating the power flow changes of a monitored line, as shown in an embodiment of the present invention. Detailed Implementation

[0045] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0046] An embodiment of a dual-sequencing safety control method for unit switching that combines multi-regional unit coordination.

[0047] like Figure 1 As shown, this embodiment is performed in the following order:

[0048] S1. Establish a power grid data model and generate power flow files based on the power grid data model and operating mode;

[0049] S2. After a critical channel fails and is cleared, perform the following three operations.

[0050] ① Calculate the power flow transfer ratio of the critical channel that has failed to the monitored line according to Formula I;

[0051]

[0052] Where m represents the power flow transfer ratio of the monitored line, P l-before P represents the active power of the monitored line before a critical channel failure. l-after P represents the active power of the monitored line after a critical channel failure. line Indicates the active power before the critical channel fails;

[0053] ② For critical channels that have experienced faults, disconnect units of equal capacity in each group separately, calculate the unit transfer ratio of the monitoring line according to Formula II, and sort the corresponding groups in order of priority from largest to smallest according to the unit transfer ratio to obtain sequence A;

[0054]

[0055] Where n represents the unit transfer ratio, P g-before P represents the active power of the monitoring line before each generator group is disconnected. g-after P represents the active power of the monitoring line after each generator group is disconnected. group This indicates the corresponding cut-off quantity for each aircraft group;

[0056] ③ In order to achieve the same grid stability characteristics, the capacity required to cut off each generator group individually is obtained through simulation analysis. The generator group with the smallest cut-off amount is set as the benchmark generator group. The stability sensitivity coefficient of each generator group is calculated according to Equation III. The generator groups are prioritized and sorted according to the stability sensitivity coefficient from largest to smallest to obtain sequence B.

[0057]

[0058] Where k represents the stability sensitivity coefficient, P others P represents the number of other generating units that achieve the same grid stability performance as the benchmark generating unit. base This represents the baseline number of generating units to be switched off to ensure grid stability.

[0059] Based on the required number of units to be switched in the actual security control measures, and following the priority order of sequence B, the actual switchable unit capacity of each group, multiplied by the stability sensitivity coefficient, is gradually accumulated until the accumulated result is greater than or equal to the required number of units to be switched in the actual security control measures. This accumulated result is recorded as the actual equivalent number of units to be switched, and the actual switchable unit capacity of each group involved in the accumulation calculation is recorded as the switched unit capacity of each group. The actual equivalent number of units to be switched is calculated according to formula IV:

[0060]

[0061] Where G represents the actual equivalent switching capacity, A i Indicates that the capacity of the i-th cluster has been cut, k i Let A1 represent the stability sensitivity coefficient of the i-th cluster, and let A1 represent the capacity of the cut-off units in the reference cluster, and k1 represent the stability sensitivity coefficient of the reference cluster.

[0062] Steps ①②③ have no specific order;

[0063] S3. Combine the power flow transfer ratio m, unit transfer ratio n, and the disconnected unit capacity A of each unit group obtained in step S2. i Calculate the equivalent power flow value of the monitoring line according to Equation V;

[0064]

[0065] Among them, P sj P represents the equivalent power flow value of the monitored line. before-sj P represents the actual active power of the monitored line before a critical channel failure, m represents the power flow transfer ratio of the monitored line, and P represents the active power of the monitored line before a critical channel failure. line-sj n represents the actual active power before the critical channel failure. i A represents the unit transfer ratio of the i-th cluster. i Indicates that the capacity of the i-th cluster has been cut; B i This represents the capacity to be added to the i-th cluster, with an initial value of 0;

[0066] S4. Determine whether the equivalent power flow value of the monitored line exceeds the thermal stability threshold. If the equivalent power flow value of the monitored line exceeds the thermal stability threshold, proceed to step S5; if the equivalent power flow value of the monitored line does not exceed the thermal stability threshold, proceed directly to step S6.

[0067] S5. Based on the capacity of each generator group that has been disconnected obtained in step ③, the generator groups are disconnected in order of priority in sequence A. The sum of the disconnected capacity of each generator group and the capacity of each generator group that has been disconnected is used as the correction value of the capacity of each generator group that has been disconnected. Combining the power flow transfer ratio, generator transfer ratio and the correction value of the capacity of each generator group that has been disconnected obtained in step S2, the equivalent power flow value of the monitoring line is recalculated in real time according to the method in step S3 until the equivalent power flow value of the monitoring line is less than or equal to the thermal stability threshold. Then, step S7 is executed.

[0068] In Equation V, Ai represents the capacity of the i-th cluster that has been scrambled; Bi represents the additional capacity of the i-th cluster, with an initial value of 0. Obviously, the additional capacity of each cluster will only be generated when step S5 is executed, and the value of Bi will be greater than 0. At this time, it is necessary to add the additional capacity of each cluster to the capacity of the scrambled cluster to correct the capacity of the scrambled cluster. If step S5 is not executed, the additional capacity of each cluster will not be generated, and there is no need to correct the capacity of the scrambled cluster. Therefore, when step S3 is executed initially, Bi = 0.

[0069] S6. Set the sum of the cut-off capacity of each group of units calculated in step ③ as the final cut-off amount, and perform the cut-off processing of each group of units according to the group priority order in sequence B.

[0070] S7, End.

[0071] The following is combined with Figure 2 The power grid structure diagram shown illustrates an embodiment of the present invention. This embodiment is used to solve the dynamic stability problem of the power grid after the N-2 severe fault occurs in the FQ-WQ double-circuit line and the problem that the JBZ-QY single-circuit line is prone to exceeding the thermal stability threshold. Figure 2 In this system, Unit 1 includes three thermal power plants: HDBT, DQ51, and DQ52; Unit 2 includes three thermal power plants: JT, ZC, and MG; and Unit 3 includes three thermal power plants: JH, FZ, and BFHL. When the FQ-WQ double-circuit line is disconnected due to an N-2 fault, the JBZ-QY single-circuit line is prone to exceeding the thermal stability threshold. Therefore, the JBZ-QY single-circuit line is designated as the primary monitoring line.

[0072] After inputting the power grid parameters using PSD-BPA simulation software, a power grid data model is established. Then, based on the power grid data model and the operating mode, a power flow file is generated. Combined with the power flow transfer data obtained in step ①, the power flow transfer of the FQ-WQ double-circuit line to the monitored single-circuit line JBZ-QY after the N-2 fault is cleared is shown in Table 1.

[0073] Table 1 Calculation of Power Flow Transfer Ratio

[0074]

[0075] As shown in step ②, after the N-2 fault occurs on the FQ-WQ double-circuit line, the 1000MW units of group 1, 2, and 3 are disconnected separately. The unit transfer ratio and group priority of each group to the monitored single-circuit line JBZ-QY are shown in Table 2 below.

[0076] Table 2 Unit Transfer Ratio and Unit Priority Table

[0077] Cutting capacity / MW JBZ-QY Single-Circuit Line / MW Unit transfer ratio Cluster Priority Uncut machine 0 3140 — — Resection Group 1 1000 2840 0.3 Low Resection Group 2 1000 2740 0.4 middle Resection Group 3 1000 2560 0.58 high

[0078] As shown in Table 2, to ensure that the monitored single-circuit line JBZ-QY experiences an N-2 fault on the FQ-WQ double-circuit line, Unit 1 disconnects 1000MW of its units, reducing the power flow on the JBZ-QY single-circuit line from 3140MW to 2800MW, with a unit transfer ratio of 0.3; Unit 2 disconnects 1000MW of its units, reducing the power flow on the JBZ-QY single-circuit line from 3140MW to 2740MW, with a unit transfer ratio of 0.4; and Unit 3 disconnects 1000MW of its units, reducing the power flow on the JBZ-QY single-circuit line from 3140MW to 2560MW, with a unit transfer ratio of 0.58. Based on the impact of each unit group on the power flow of the monitored single-circuit line JBZ-QY, the unit disconnection priority, ranked from highest to lowest unit transfer ratio, is: Unit 3, Unit 2, and Unit 1.

[0079] As shown in step ③, in order to meet the grid stability requirements, after the N-2 fault occurs on the FQ-WQ double-circuit line, in order to achieve the same grid stability performance, the grid dynamic stability damping ratio is set to be greater than 0.015. The required capacity for individual shutdown of each generator group is obtained through simulation analysis. The generator group with the smallest shutdown amount is set as the benchmark generator group. The generator groups are prioritized according to the stability sensitivity coefficient from large to small, as shown in Table 3.

[0080] Table 3 Power Grid Stability Priority Table

[0081] Group 1 Group 2 Group 3 Cutting capacity / MW 2350 3500 5100 Stable sensitivity coefficient 1 0.67 0.46 Priority high middle Low Damping ratio 0.015 0.015 0.015

[0082] As shown in Table 3, in order to keep the power grid stable after the N-2 fault occurs on the FQ-WQ double-circuit line, it is necessary to disconnect 2350MW of units for unit 1, 3500MW of units for unit 2, and 5100MW of units for unit 3. Therefore, unit 1 is set as the baseline unit, and the unit disconnection priority from high to low is unit 1, unit 2, and unit 3.

[0083] Meanwhile, as shown in Tables 2 and 3, in this embodiment, the unit priorities obtained in steps ② and ③ are opposite, in order to simultaneously ensure the safety and stability of the power grid and that the faulty lines in the vicinity do not exceed the thermal stability threshold. If the unit priority obtained in step ③ is used for tripping according to the conventional tripping method, it is easy to cause over-tripping of units.

[0084] Assuming the FQ-WQ double-circuit line is 3000MW and the JBZ-QY single-circuit line is 1350MW, in the actual safety control measures, after the FQ-WQ double-circuit line experiences an N-2 fault, the required capacity to be cut off is 2500MW. According to the priority ranking of each group of units calculated in step ③, the capacity of the units cut off in group 1 is 2350MW and the capacity of the units cut off in group 2 is 224MW. That is, the equivalent capacity to be cut off is G=1×2350+0.67×224=2500MW.

[0085] According to step S3, after the fault in the FQ-WQ double-circuit line, and following step 4 (switching the machine), the equivalent power flow value of the JBZ-QY single-circuit line is monitored.

[0086] P=1350+3000×0.7-(2350×0.3+224×0.4)=2655.4MW

[0087] Assuming the thermal stability threshold for a single-circuit line JBZ-QY is 2300MW, the equivalent power flow of this single-circuit line is 2655.4MW, exceeding the thermal stability threshold. If the conventional generator tripping method is used, and generator group 1 is added according to the priority in Table 3, the added capacity is 1185MW, and the monitored equivalent power flow value for the single-circuit line JBZ-QY is 2300MW. However, if generator group 3, with the highest priority, is further added according to the generator group priority shown in Table 2, the added capacity is 612MW, and the monitored equivalent power flow value for the single-circuit line JBZ-QY is:

[0088] P=1350+3000×0.7-(2350×0.3+224×0.4+612×0.58)=2300MW

[0089] To simultaneously ensure grid safety and stability and prevent the JBZ-QY single-circuit line from exceeding the thermal stability threshold, the required capacity for each generating group in this embodiment is as follows: Group 1 requires 2350MW, Group 2 requires 224MW, and Group 3 requires 612MW. The method is simulated and analyzed using PSD-BPA, as follows... Figure 3 As shown, after a fault in the FQ-WQ double-circuit line, the actual power flow of the JBZ-QY single-circuit line can be reduced to below 2300MW after implementing this method.

[0090] In summary, the cutting volume of this embodiment and the conventional method are compared as shown in Table 4.

[0091] Table 4 Comparison between this embodiment and conventional methods

[0092]

[0093]

[0094] As shown in Table 4, in order to ensure both the safety and stability of the power grid and the thermal stability of the lines, the total amount of generators to be cut in this embodiment is 3186MW, while the total amount of generators to be cut in the conventional method is 3759MW. Compared with the conventional method, this embodiment can effectively reduce the amount of generators to be cut in the safety control system.

Claims

1. A dual-sequencing safety control method for switching units that combines multi-regional unit coordination, characterized in that, Follow these steps in sequence: S1. Establish a power grid data model and generate power flow files based on the power grid data model and operating mode; S2. After a critical channel fails and is cleared, perform the following three operations. ① Calculate the power flow transfer ratio of the critical channel that experienced the fault to the monitored line; ② For critical channels that have experienced faults, disconnect units of equal capacity in each group separately, calculate the unit transfer ratio of the monitored lines, and prioritize the corresponding groups according to the unit transfer ratio from largest to smallest to obtain sequence A; ③ In order to achieve the same grid stability characteristics, the capacity required to cut off each generator group individually is obtained through simulation analysis. The generator group with the smallest cut-off amount is set as the benchmark generator group. The stability sensitivity coefficient of each generator group is calculated. The generator groups are prioritized according to the stability sensitivity coefficient from largest to smallest to obtain sequence B. According to the priority order of sequence B, the actual scalable unit capacity of each group after being multiplied by the stability sensitivity coefficient is gradually accumulated until the accumulated result is greater than or equal to the number of units to be scalped in the actual security control measures. The accumulated result at this time is recorded as the actual equivalent number of units to be scalped, and the actual scalable unit capacity of each group participating in the accumulation calculation is recorded as the scalable unit capacity of each group. S3. Combine the power flow transfer ratio, unit transfer ratio and the capacity of the disconnected units of each group of units obtained in step S2 to calculate the equivalent power flow value of the monitoring line. S4. Determine whether the equivalent power flow value of the monitored line exceeds the thermal stability threshold. If the equivalent power flow value of the monitored line exceeds the thermal stability threshold, proceed to step S5; if the equivalent power flow value of the monitored line does not exceed the thermal stability threshold, proceed directly to step S6. S5. Based on the capacity of each generator group that has been disconnected obtained in step ③, the generator groups are disconnected in order of priority in sequence A. The sum of the disconnected capacity of each generator group and the capacity of each generator group that has been disconnected is used as the correction value of the capacity of each generator group that has been disconnected. Combining the power flow transfer ratio, generator transfer ratio and the correction value of the capacity of each generator group that has been disconnected obtained in step S2, the equivalent power flow value of the monitoring line is recalculated in real time according to the method in step S3 until the equivalent power flow value of the monitoring line is less than or equal to the thermal stability threshold. Then, step S7 is executed. S6. Set the sum of the cut-off capacity of each group of units calculated in step ③ as the final cut-off amount, and perform the cut-off processing of each group of units according to the group priority order in sequence B. S7, End.

2. The dual-sequencing safety control and unit switching method combining multi-regional unit coordination as described in claim 1, characterized in that, The power flow transfer ratio of the monitored line in step ① is calculated according to formula I: Where m represents the power flow transfer ratio of the monitored line, P l-before P represents the active power of the monitored line before a critical channel failure. l-after P represents the active power of the monitored line after a critical channel failure. line This indicates the active power before a critical channel failure.

3. The dual-sequencing safety control and unit switching method combining multi-regional unit coordination as described in claim 1, characterized in that, In step ②, the unit transfer ratio is calculated according to formula II: Where n represents the unit transfer ratio, P g-before P represents the active power of the monitoring line before each generator group is disconnected. g-after P represents the active power of the monitoring line after each generator group is disconnected. group This indicates the corresponding cut-off amount for each aircraft group.

4. The dual-sequencing safety control and unit switching method combining multi-regional unit coordination as described in claim 1, characterized in that, In step ③, the stability sensitivity coefficient is calculated according to formula III: Where k represents the stability sensitivity coefficient, P others P represents the number of other generating units that achieve the same grid stability performance as the benchmark generating unit. base This indicates the baseline number of generators to be switched off to ensure grid stability.

5. The dual-sequencing safety control and switching method combining multi-regional unit coordination as described in claim 1, characterized in that, In step ③, the actual equivalent cutting quantity is calculated according to formula IV: Where G represents the actual equivalent switching capacity, A i Indicates that the capacity of the i-th cluster has been cut, k i Let A1 represent the stability sensitivity coefficient of the i-th cluster, and let A1 represent the capacity of the reference cluster that has been switched off, and k1 represent the stability sensitivity coefficient of the reference cluster.

6. The dual-sequencing safety control and unit switching method combining multi-regional unit coordination as described in claim 1, characterized in that, In step S3, the equivalent power flow value of the monitored line is calculated according to formula V: Among them, P sj P represents the equivalent power flow value of the monitored line. before-sj P represents the actual active power of the monitored line before a critical channel failure, m represents the power flow transfer ratio of the monitored line, and P represents the active power of the monitored line before a critical channel failure. line-sj n represents the actual active power before the critical channel failure. i A represents the unit transfer ratio of the i-th cluster. i Indicates that the capacity of the i-th cluster has been cut; B i This represents the capacity to be added to the i-th cluster, with an initial value of 0.

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