Black start path searching method, device and system considering maximum load carrying capacity

Abstract

The application discloses a black start path searching method, device and system considering maximum load carrying capacity, the method comprises the following steps: determining the capacity, ramping rate and unit state of the to-be-restored units in the black start partition, comprehensively evaluating the load carrying capacity of each to-be-restored unit, and sequentially sorting the to-be-restored units according to the load carrying capacity from large to small; according to the sorting result, sequentially searching the restoration path of the to-be-restored units to the black start power source or the restored units, simulating and checking the obtained restoration path, and finally obtaining the black start path meeting the electrical quantity requirement in the black start process of the power grid. The application can improve the load restoration rate of the power grid, reduce the power outage time of the power grid, and reduce the power outage loss of the power grid.

Description

Technical Field

[0001] This invention belongs to the field of power system and its automation technology, specifically relating to a black start path search method, device and system that considers maximum load capacity. Background Technology

[0002] With the development of power grid interconnection and long-distance AC / DC transmission technologies, the scale of power systems is expanding, and power grids at all levels are continuously interconnected. The reliability and stability of system operation are also constantly improving. However, due to the continuous introduction of new energy power generation technologies, increasingly complex operating environments, and the unavoidable nature of various natural disasters, the network structure and dynamic characteristics of power systems are becoming more complex, with more stringent and unpredictable operating conditions. The risk of large-scale power outages still exists. Currently, during black start-up, the power grid prioritizes restoring the nearest electrically connected generating unit, without considering the unit's load-carrying capacity. When the unit's load-carrying capacity is weak, it affects the subsequent load and the grid's recovery speed, prolonging the grid's recovery time.

[0003] The load-carrying capacity of a power grid is determined by the generating units, which in turn is determined by the unit's capacity, ramp-up rate, and pre-start condition. Therefore, a reasonable assessment of the unit's load-carrying capacity and prioritizing the restoration of units with strong load-carrying capacity during the black start phase can, to some extent, accelerate the grid's recovery and reduce grid losses. Summary of the Invention

[0004] To address the aforementioned issues, this invention proposes a black start path search method, apparatus, and system that considers maximum load-carrying capacity. By establishing comprehensive evaluation indicators, it compares the load-carrying capacity of generating units with different capacities and ramp rates. Under the premise of ensuring that all electrical indicators during the black start process of the power grid meet operational requirements, it prioritizes the restoration of generating units with strong load-carrying capacity, thereby improving the load-carrying capacity of the power grid during the black start process, accelerating the recovery speed of subsequent loads and the power grid, and shortening the total power grid recovery time.

[0005] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a black-start path search method considering maximum load-bearing capacity, comprising:

[0007] Determine the capacity, ramp rate, and status of the units to be restored within the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity.

[0008] Based on the sorting results, the recovery path from the unit to be restored to the black start power source or the restored unit is searched sequentially. The obtained recovery path is simulated and verified, and finally the black start path that meets the electrical quantity requirements of the power grid black start process is obtained.

[0009] Optionally, the load-carrying capacity of each unit to be restored is calculated using the following evaluation formula:

[0010]

[0011] in:

[0012] w1 + w2 + w3 = 1

[0013]

[0014] C max =Max(C i ), i = 1, 2, 3... N

[0015] S max =Max(S) i ), i = 1, 2, 3... N

[0016] Where: R is the load-carrying capacity of the unit to be restored, w1, w2, and w3 are evaluation coefficients, and C... max S represents the maximum capacity of the units to be restored. max S represents the maximum ramp rate among the units to be restored, N represents the number of units to be restored, C represents the unit capacity, S represents the unit ramp rate, and I represents the unit status.

[0017] Optionally, the step of sequentially searching the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting results, and performing simulation verification on the obtained recovery path, includes the following sub-steps:

[0018] For the unit to be restored, numbered i, where i = 1, 2, ..., N, search for all restoration paths from the black start power supply to the restored unit;

[0019] Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers;

[0020] If the total recovery time of the paths is the same, calculate the total reactive power of the charging through the unrecovered lines of the recovered path, and sort them by the total reactive power of the unrecovered lines passed by the recovered path, with the smaller total reactive power ranked first.

[0021] If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time.

[0022] Based on the sorting results, all recovery paths are simulated and verified sequentially until the simulation results meet the preset requirements. The unit to be recovered and the path are recorded and the recovery sequence number is assigned.

[0023] Optionally, the formula for calculating the total time required for path recovery is:

[0024]

[0025] Where: t 总 The total time required to restore this path, where n is the number of unrestored lines in the restored path, and t is the total time required. li The time required to restore power to the i-th unrestored line in the restoration path, where m is the number of unrestored substations in the restoration path, and t is the time required. tj The time required to restore power to the j-th unrestored substation in the recovery path.

[0026] Optionally, the formula for calculating the total charging reactive power is:

[0027]

[0028] Among them: Q 总 The total reactive power of charging is given by n, where n is the number of unrestored lines in the recovery path, and Q is the total reactive power. i The reactive power generated after restoring power to the i-th unrestored line in the restoration path.

[0029] Optionally, the preset requirements include:

[0030] p <p max

[0031] f min <f<f max

[0032] U 工min 工 工max

[0033] U 操 操max

[0034] Where: p is the line power, p max f is the maximum line power, and f is the system frequency. min For the minimum system frequency, f max For the maximum system frequency, U 工 For power frequency voltage, U 工min For the minimum power frequency voltage, U 工max For the maximum power frequency voltage, U 操 U is the operating voltage. 操max This is the maximum operating voltage. ​​​

[0035] Secondly, the present invention provides a black-start path search device that considers maximum load-bearing capacity, comprising:

[0036] The evaluation module is used to determine the capacity C, ramp rate S, and unit status I of the units to be restored in the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity.

[0037] The black start path search module is used to sequentially search for the recovery path from the unit to be restored to the black start power source or the restored unit according to the sorting results, perform simulation verification on the obtained recovery path, and finally obtain the black start path that meets the electrical quantity requirements of the power grid black start process.

[0038] Optionally, the load-carrying capacity of each unit to be restored is calculated using the following evaluation formula:

[0039]

[0040] in:

[0041] w1 + w2 + w3 = 1

[0042]

[0043] C max =Max(C i ), i = 1, 2, 3... N

[0044] S max =Max(S) i ), i = 1, 2, 3... N

[0045] Where: R is the load-carrying capacity of the unit to be restored, w1, w2, and w3 are evaluation coefficients, and C... max S represents the maximum capacity of the units to be restored. max S represents the maximum ramp rate among the units to be restored, N represents the number of units to be restored, C represents the unit capacity, S represents the unit ramp rate, and I represents the unit status.

[0046] Optionally, the step of sequentially searching the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting results, and performing simulation verification on the obtained path, includes the following sub-steps:

[0047] For the unit to be restored, numbered i, where i = 1, 2, ..., N, search for all restoration paths from the black start power supply to the restored unit;

[0048] Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers;

[0049] If the total recovery time of the paths is the same, calculate the total reactive power of the charging through the unrecovered lines of the recovered path, and sort them by the total reactive power of the unrecovered lines passed by the recovered path, with the smaller total reactive power ranked first.

[0050] If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time.

[0051] Based on the sorting results, all recovery paths are simulated and verified sequentially until the simulation results meet the preset requirements. The unit to be recovered and the path are recorded and the recovery sequence number is assigned.

[0052] Thirdly, the present invention provides a black boot path search system that considers maximum load capacity, comprising: a storage medium and a processor;

[0053] The storage medium is used to store instructions;

[0054] The processor is configured to operate according to the instructions to perform the steps of the method according to any one of the first aspects.

[0055] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0056] This invention proposes a black start path search method, device, and system that considers maximum load-carrying capacity. By formulating comprehensive evaluation indicators, it realizes the comparison of the load-carrying capacity of units with different capacities and different ramp rates. Under the premise of ensuring that all electrical indicators of the power grid meet the operational requirements during the black start process, it prioritizes the restoration of units with strong load-carrying capacity, improves the load-carrying capacity of the power grid during the black start process, accelerates the recovery speed of subsequent loads and the power grid, and shortens the total power grid recovery time. Attached Figure Description

[0057] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0058] Figure 1 This is a flowchart of a black-start path search method considering maximum load capacity according to an embodiment of the present invention;

[0059] Figure 2 A schematic diagram of the power grid structure in a certain region during black start-up zones.

[0060] Figure 3 A schematic diagram of the power frequency overvoltage simulation results from BPA simulation software;

[0061] Figure 4 This invention provides a schematic diagram comparing the load-bearing capacity of the black start process of the searched black start path with that of the existing black start path. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of protection of the invention.

[0063] The application principle of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] Example 1

[0065] This invention provides a black-start path search method considering maximum load-carrying capacity. First, the black-start power source and the units to be restored within the black-start zone are identified. The load-carrying capacity of the units to be restored is assessed based on a comprehensive evaluation index, and then sorted from strongest to weakest load-carrying capacity. All paths from the unit to be restored to the black-start power source or already restored units are searched, and then sorted according to the restoration time required for each path. Simulation verification is performed on each path sequentially until the electrical requirements of the black-start process are met. Finally, the restoration path with the maximum load-carrying capacity is determined, maximizing the speed of grid load restoration and minimizing economic losses to the grid. Specifically, the method includes the following steps:

[0066] (1) Determine the capacity C, ramp rate S, and unit status I of the units to be restored within the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity; In the specific implementation process, when performing step (1), it is first necessary to determine the black start power supply and the units to be restored within the black start zone, and obtain the grid parameters of the black start zone, including: line restoration time t1, substation restoration time t t Unit recovery time t g Unit capacity C, unit ramp rate S, unit status I, line charging reactive power Q;

[0067] (2) Search the recovery path from the unit to be restored to the black start power source or the restored unit in sequence according to the sorting results, perform simulation verification on the obtained path, and finally obtain the black start path that meets the electrical quantity requirements of the power grid black start process.

[0068] In one specific embodiment of the present invention, the load-carrying capacity of each unit to be restored is calculated using the following evaluation formula:

[0069]

[0070] in:

[0071] w1 + w2 + w3 = 1

[0072]

[0073] Cmax =Max(C i ), i = 1, 2, 3... N

[0074] S max =Max(S) i ), i = 1, 2, 3... N

[0075] Where: R is the load-carrying capacity of the unit to be restored, w1, w2, and w3 are evaluation coefficients, and C... max S represents the maximum capacity of the units to be restored. max S represents the maximum ramp rate among the units to be restored, N represents the number of units to be restored, C represents the unit capacity, S represents the unit ramp rate, and I represents the unit status.

[0076] In one specific embodiment of the present invention, the step of sequentially searching the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting result, and performing simulation verification on the obtained path, includes the following sub-steps:

[0077] For the unit to be restored, numbered i, where i = 1, 2, ..., N, search for all restoration paths from the black start power supply to the restored unit;

[0078] Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers;

[0079] If the total recovery time of the paths is the same, calculate the total reactive power of the charging through the unrecovered lines of the recovered path, and sort them by the total reactive power of the unrecovered lines passed by the recovered path, with the smaller total reactive power ranked first.

[0080] If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time.

[0081] Based on the sorting results, perform simulation verifications of power flow, frequency, power frequency overvoltage, switching overvoltage, and self-excitation on all recovery paths in sequence until the simulation results meet the preset requirements. Record the unit to be restored and the path, and assign a recovery sequence number.

[0082] The formula for calculating the total time required for path recovery is as follows:

[0083]

[0084] Where: t 总 The total time required to restore this path, where n is the number of unrestored lines in the restored path, and t is the total time required. li The time required to restore power to the i-th unrestored line in the restoration path, where m is the number of unrestored substations in the restoration path, and t is the time required. tjThe time required to restore power to the j-th unrestored substation in the recovery path.

[0085] The formula for calculating the total charging reactive power is as follows:

[0086]

[0087] Among them: Q 总 The total reactive power of charging is given by n, where n is the number of unrestored lines in the recovery path, and Q is the total reactive power. i The reactive power generated after restoring power to the i-th unrestored line in the restoration path.

[0088] The preset requirements include:

[0089] p <p max

[0090] f min <f<f max

[0091] U 工min 工 工max

[0092] U 操 操max

[0093] Where: p is the line power, p max f is the maximum line power, and f is the system frequency. min For the minimum system frequency, f max For the maximum system frequency, U 工 For power frequency voltage, U 工min For the minimum power frequency voltage, U 工max For the maximum power frequency voltage, U 操 U is the operating voltage. 操max This is the maximum operating voltage.

[0094] The following is combined with Figure 1 The methods in the embodiments of the present invention will be described in detail.

[0095] Step 1: Identify the black-start power supply and the unit to be restored within the black-start zone, and obtain the network parameters of the black-start zone, including: line restoration time t1, substation restoration time t t Unit recovery time t g Unit capacity C, unit ramp rate S, unit status I, line charging reactive power Q, proceed to step two;

[0096] ​​​Step 2: Based on the unit capacity C, unit ramp rate S, and unit status I, calculate the comprehensive evaluation index value R of each unit to be restored using formula (1). Sort and number the units to be restored according to the comprehensive evaluation value from largest to smallest, and proceed to step 3.

[0097]

[0098] w1+w2+w3=1 (2)

[0099]

[0100] C max =Max(C i ), i = 1, 2, 3...N (4)

[0101] S max =Max(S) i ), i = 1, 2, 3...N (5)

[0102] Where: w1, w2, w3 are evaluation coefficients, C max S represents the maximum capacity of the units to be restored. max S represents the maximum ramp rate among the units awaiting restoration. max This represents the number of units to be restored.

[0103] Step 3: For unit number 1 to be restored, search for all paths from it to the black start power supply or the restored unit, and proceed to step 4;

[0104] Step 4: Based on the unrestored lines and substations along each path, calculate the total time t required to restore the path according to equation (6). 总 The total recovery time t is based on the recovery path. 总 Sort the data from smallest to largest and number them accordingly. If the total recovery time t for the recovery path is... 总 Similarly, according to equation (7), the total reactive power Q of the charging path through the unrestored line is calculated. 总 The total charging reactive power Q of the unrestored lines traversed by the comparison path 总 Sort by size, with the smallest total reactive power charging first, then proceed to step five;

[0105]

[0106] Where: t 总 The total time required to restore this path, where n is the number of unrestored lines in the restored path, and t is the total time required. li The time required to restore power to the i-th unrestored line in the restoration path, where m is the number of unrestored substations in the restoration path, and t is the time required. tj The time required to restore power to the j-th unrestored substation in the recovery path.

[0107]

[0108] Among them: Q 总 The total reactive power of charging is given by n, where n is the number of unrestored lines in the recovery path, and Q is the total reactive power. i The reactive power generated after restoring power to the i-th unrestored line in the restoration path.

[0109] Step 5: Perform simulation verification on recovery path number 1, simulate the black start recovery process, and monitor the line power p, system frequency f, and power frequency voltage U during the recovery process. 工 Operating voltage U 操 1. Check if self-excitation occurs, then proceed to step six;

[0110] Step 6: Determine whether the simulation result of the recovery path numbered 1 meets the requirements of equations (8)-(11). If it does, record the unit to be recovered and the path, and assign a recovery sequence number. Remove the unit to be recovered from the recovery unit set. Determine whether the recovery set is empty. If it is empty, the step ends. If it is not empty, proceed to step 2. If it does not meet the requirements, decrement all recovery path numbers by 1 and determine whether the path number is greater than 0. If it exists, proceed to step 5. If it does not exist, proceed to step 7.

[0111] p <p max (8)

[0112] f min <f<f max (9)

[0113] U 工min 工 工max (10)

[0114] U 操 操max (11)

[0115] p is the line power, p max f is the maximum line power, and f is the system frequency. min For the minimum system frequency, f max For the maximum system frequency, U 工 For power frequency voltage, U 工min For the minimum power frequency voltage, U 工max For the maximum power frequency voltage, U 操 U is the operating voltage. 操max Maximum operating voltage;

[0116] Step 7: Decrement the number of all units to be restored by 1, and check if there is a number greater than 0. If there is, proceed to step 3; otherwise, the process ends. ​​​

[0117] The following is based on a 220kV grid structure of a black start zone in a certain regional power grid. The black start power source in this zone is the unit of Hanas Thermal Power Plant No. 2. The units to be restored are Dawukou Thermal Power Plant, Shiyi Power Plant, Shier Power Plant, and Western Thermal Power Plant connected to Fuxiang Station at 110kV.

[0118] The black-start path search method described in this invention is used to search for a search path, and the obtained path is compared with the original path.

[0119] The parameters of the units to be restored are shown in Table 1. The comprehensive evaluation index of the load-carrying capacity of each unit is calculated based on the parameters in the table, where w1, w2, and w3 are all taken as 0.33.

[0120] Table 1. Parameters of Black Start Power Supply and Units to be Restored

[0121]

[0122] Based on the comprehensive evaluation indicators of the units in Table 1, the recovery order of the units with recovery functions is: Shier Power Plant, Shier Power Plant, Dawukou Power Plant, and Western Thermal Power Plant.

[0123] Taking the search for the route from Hanas Thermal Power Plant No. 2 to Shijiazhuang No. 2 Plant as an example, all feasible routes are shown in Table 2. Based on Tables 3 and 4, the recovery time and total reactive power of each route are obtained, and the recovery routes are sorted.

[0124] Table 2. Route from Hanas Thermal Power Plant No. 2 to Shijiazhuang No. 2 Plant

[0125]

[0126] Table 3 Recovery Time

[0127]

[0128]

[0129] Table 4 Reactive Power of Line Charging

[0130]

[0131] Then, the path numbered 1 is verified, and during the simulation, all electrical quantities meet the following requirements:

[0132] Frequency: 49.5Hz ≤ f ≤ 50.5Hz

[0133] Power frequency voltage: 0.9pu≤U 工 ≤1.1pu

[0134] Operating voltage: U 操 ≤3.0pu

[0135] First, the power frequency voltage of the black start process of path number 1 was verified using BPA simulation software. The voltage of Hanas Thermal Power Plant No. 2 was the rated voltage. In order to absorb the reactive power generated by the transmission line, a 60Mvar reactor was put into the Jinfeng Station. The voltage of each node is shown in Table 5. No power frequency overvoltage occurred at any node.

[0136] Table 5. Power frequency voltage at nodes during black start-up (kV)

[0137]

[0138] Then, PSCAD simulation software was used to build a model suitable for operating voltage simulation, with the Hanas Thermal Power Plant No. 2 as the rated voltage. Through simulation of the closing process, the operating overvoltage of the empty charging transmission line is shown in Table 6. It can be seen that the operating overvoltage of each node meets the requirement of being lower than 3.0 pu.

[0139] Table 6. Node operating overvoltage (pu) during black start-up process

[0140] Factory Station Golden Phoenix Zhenshuo pedestrian bridge Lanshan Righteousness Shier Factory Voltage 1.73 1.87 1.42 1.51 1.62 1.23

[0141] No line overload or self-excitation occurred during the path restoration process, therefore the path is valid.

[0142] The black boot path obtained using the method of this invention is as follows:

[0143] Hanas Thermal Power Plant No. 2 - Jinfeng - Zhenshuo - Buqiao - Lanshan - Zhengyi - Shier Plant - Hebin - Shiyi Plant - Chaohu - Changsheng - Dawukou Power Plant - Fuxiang - Western Thermal Power

[0144] The original black boot path of this black boot partition is as follows:

[0145] Hanas Thermal Power Plant No. 2 - Jinfeng - Zhenshuo - Buqiao - Chaohu - Changsheng - Dawukou Power Plant - Lanshan - Zhengyi - Hebin - Shiyi Power Plant - Fuxiang - Western Thermal Power - Yuxiang - Shahu - Chengguan - Huinong - Jing'an - Shier Power Plant

[0146] pass Figure 4 The comparison shows that the black start path searched by the method of the present invention has a stronger load-bearing capacity than the original black start path.

[0147] Example 2

[0148] This invention provides a black-start path search device that considers maximum load capacity, comprising:

[0149] The evaluation module is used to determine the capacity C, ramp rate S, and unit status I of the units to be restored in the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity.

[0150] The black start path search module is used to sequentially search for the recovery path from the unit to be restored to the black start power source or the restored unit according to the sorting results, perform simulation verification on the obtained path, and finally obtain the black start path that meets the electrical quantity requirements of the power grid black start process.

[0151] In one specific embodiment of the present invention, the load-carrying capacity of each unit to be restored is calculated using the following evaluation formula:

[0152]

[0153] in:

[0154] w1 + w2 + w3 = 1

[0155]

[0156] C max =Max(C i ), i = 1, 2, 3... N

[0157] S max =Max(S) i ), i = 1, 2, 3... N

[0158] Where: R is the load-carrying capacity of the unit to be restored, w1, w2, and w3 are evaluation coefficients, and C... max S represents the maximum capacity of the units to be restored. max S represents the maximum ramp rate among the units to be restored, N represents the number of units to be restored, C represents the unit capacity, S represents the unit ramp rate, and I represents the unit status.

[0159] In one specific embodiment of the present invention, the step of sequentially searching the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting result, and performing simulation verification on the obtained path, includes the following sub-steps:

[0160] For the unit to be restored, numbered i, where i = 1, 2, ..., N, search for all restoration paths from the black start power supply to the restored unit;

[0161] Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers;

[0162] If the total recovery time of the paths is the same, calculate the total reactive power of the charging through the unrecovered lines of the recovered path, and sort them by the total reactive power of the unrecovered lines passed by the recovered path, with the smaller total reactive power ranked first.

[0163] If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time.

[0164] Based on the sorting results, perform simulation verifications of power flow, frequency, power frequency overvoltage, switching overvoltage, and self-excitation on all recovery paths in sequence until the simulation results meet the preset requirements. Record the unit to be restored and the path, and assign a recovery sequence number.

[0165] Example 3

[0166] Based on Embodiment 1, this embodiment of the invention provides a black boot path search system that considers maximum load capacity, including: a storage medium and a processor;

[0167] The storage medium is used to store instructions;

[0168] The processor is configured to operate according to the instructions to perform the steps of the method according to any one of Embodiment 1.

[0169] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A black-start path search method considering maximum load-bearing capacity, characterized in that, include: Determine the capacity C, ramp rate S, and unit status I of the units to be restored within the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity. Based on the sorting results, the recovery path from the unit to be restored to the black start power source or the restored unit is searched sequentially. The obtained recovery path is simulated and verified, and finally a black start path that meets the electrical quantity requirements of the power grid black start process is obtained. The step of sequentially searching for the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting results, and performing simulation verification on the obtained recovery path, includes the following sub-steps: For numbered Units awaiting restoration Search for all recovery paths to the black-start power supply or the recovered unit; Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers; If the total recovery time of the paths is the same, calculate the total reactive power of the recovered path through the unrecovered lines, compare the total reactive power of the unrecovered lines through the recovered path, and sort them, with the smaller total reactive power ranked first. If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time. Based on the sorting results, all recovery paths are simulated and verified sequentially until the simulation results meet the preset requirements. The unit to be recovered and the path are recorded and the recovery sequence number is assigned. The formula for calculating the total time required for path recovery is as follows: ； in: The total time required to restore this path. To restore the number of unrestored lines in the recovery path, For the first in this recovery path The time required to restore power to the unrestored lines This represents the number of substations that have not been restored in this recovery path. For the first in this recovery path The time required to restore power supply to a substation that has not yet been restored; The formula for calculating the total charging reactive power is as follows: ； in: The total charging power is unavailable. To restore the number of unrestored lines in the recovery path, For the first in this recovery path The reactive power generated after power is restored to a line that has not yet been restored; The preset requirements include: ； ； ； ； in: For line power, This represents the maximum line power. For system frequency, For the minimum system frequency, For the maximum system frequency, It is the power frequency voltage. The minimum power frequency voltage, This is the maximum power frequency voltage. Operating voltage, Maximum operating voltage; The load-carrying capacity of each unit to be restored is calculated using the following evaluation formula: ； in: ； ； ； ； in: To restore the load-carrying capacity of the units to be restored , , For evaluation coefficients, This represents the maximum capacity of the units awaiting restoration. This represents the maximum ramp rate among the units awaiting restoration. This represents the number of units to be restored. For unit capacity, This refers to the unit's ramp rate. This refers to the unit's status.

2. A black-start path search device considering maximum load-bearing capacity, characterized in that, include: The evaluation module is used to determine the capacity C, ramp rate S, and unit status I of the units to be restored in the black start zone, comprehensively evaluate the load-carrying capacity of each unit to be restored, and sort them in descending order of load-carrying capacity. The black start path search module is used to sequentially search for the recovery path from the unit to be restored to the black start power source or the restored unit according to the sorting results, perform simulation verification on the obtained recovery path, and finally obtain the black start path that meets the electrical quantity requirements of the power grid black start process. The step of sequentially searching for the recovery path from the unit to be restored to the black-start power supply or the restored unit according to the sorting results, and performing simulation verification on the obtained recovery path, includes the following sub-steps: For numbered Units awaiting restoration Search for all recovery paths to the black-start power supply or the recovered unit; Based on the unrestored lines and substations along each restoration path, calculate the total time required to restore the path, sort them in ascending order, and assign them numbers; If the total recovery time of the paths is the same, calculate the total reactive power of the recovered path through the unrecovered lines, compare the total reactive power of the unrecovered lines through the recovered path, and sort them, with the smaller total reactive power ranked first. If the total recovery time for the paths is different, the recovery paths are sorted from shortest to longest time. Based on the sorting results, all recovery paths are simulated and verified sequentially until the simulation results meet the preset requirements. The unit to be recovered and the path are recorded and the recovery sequence number is assigned. The formula for calculating the total time required for path recovery is as follows: ； in: The total time required to restore this path. To restore the number of unrestored lines in the recovery path, For the first in this recovery path The time required to restore power to the unrestored lines This represents the number of substations that have not been restored in this recovery path. For the first in this recovery path The time required to restore power supply to a substation that has not yet been restored; The formula for calculating the total charging reactive power is as follows: ； in: The total charging power is unavailable. To restore the number of unrestored lines in the recovery path, For the first in this recovery path The reactive power generated after power is restored to a line that has not yet been restored; The preset requirements include: ； ； ； ； in: For line power, This represents the maximum line power. For system frequency, For the minimum system frequency, For the maximum system frequency, It is the power frequency voltage. The minimum power frequency voltage, This is the maximum power frequency voltage. Operating voltage, Maximum operating voltage; The load-carrying capacity of each unit to be restored is calculated using the following evaluation formula: ； in: ； ； ； ； in: To restore the load-carrying capacity of the units to be restored , , For evaluation coefficients, This represents the maximum capacity of the units awaiting restoration. This represents the maximum ramp rate among the units awaiting restoration. The number of units to be restored. For unit capacity, This refers to the unit's ramp rate. This refers to the unit's status.

3. A black-start path search system considering maximum load capacity, characterized in that, include: Including storage media and processor; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to claim 1.

Images