Voltage control method and device for black start recovery process

Abstract

The application provides a voltage control method and device for a black start recovery process, and relates to the technical field of power system safety defense. The method comprises the following steps: in the black start recovery process, every interval of a first recovery period, a global objective function is established and solved to obtain node voltage planning values and reactive power output planning values of each regional subsystem, with the aim of minimizing network loss in each regional subsystem; every interval of a second recovery period, based on the node voltage planning values and the reactive power output planning values, a middle-layer objective function is established and solved to obtain terminal voltage adjustment values and reactive power output adjustment values of each local station, with the aim of minimizing node voltage offset and reactive power output deviation of the local station; and every interval of a third recovery period, the reactive power equipment in each local station is controlled to operate according to the terminal voltage adjustment values and the reactive power output adjustment values. The application can accurately control the voltage and the reactive power output in the black start recovery process, and ensure the safety of the black start recovery process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system security defense, and in particular to a voltage control method and device for a black start recovery process. BACKGROUND

[0002] With the continuous expansion of the scale of the power system and the increasing complexity, the power grid faces more potential risks. Natural disasters (such as earthquakes, typhoons, ice disasters, etc.), equipment failures, human operation errors or network attacks, etc. can all cause local or even large-scale power outage accidents, thereby causing serious economic losses and social impacts.

[0003] The black start recovery of the power system can be used to recover the power system that is out of power. The black start recovery process of the power system usually includes three stages: a black start stage, a network reconstruction stage and a load recovery stage. Among them, the network reconstruction stage involves the closing and energizing operation of a large number of no-load and light-load lines. In this stage, the input of capacitive lines will cause the excess of reactive power output of the recovered system, and then cause the overvoltage problem of the nodes to be recovered, resulting in the paralysis of the recovered system again.

[0004] In related technologies, a decentralized control strategy is mostly used in the black start recovery process, and most of them focus on equipment overvoltage suppression, lack of global optimization at the system level, and are difficult to adapt to the dynamic changes and complexity in the system recovery process, resulting in poor control effect.

[0005] In addition, with the rapid advancement of the construction of new power systems, large-scale grid connection of new energy (such as wind power and photovoltaic power), the recovery process of the power system becomes more complex. The volatility and uncertainty of new energy generation further increase the difficulty of voltage and reactive power output control. Therefore, in the black start recovery process of the new power system, how to realize the accurate control of voltage and reactive power output and ensure the safety of the power system recovery process has become a technical problem to be solved. SUMMARY

[0006] The embodiments of the present application provide a voltage control method and device for a black start recovery process to solve the problem of accurate control of voltage and reactive power output in the black start recovery process of the power system.

[0007] In a first aspect, the embodiments of the present application provide a voltage control method for a black start recovery process, wherein the power system includes a plurality of regional subsystems, and each regional subsystem includes a plurality of local stations.

[0008] The method comprises:

[0009] In the black start recovery process, every interval first recovery period, a global objective function is established and solved to minimize the network loss in each regional subsystem, to obtain the node voltage plan value and the reactive power output plan value of each regional subsystem;

[0010] Every interval second recovery period, based on the node voltage plan value and the reactive power output plan value, a middle layer objective function is established and solved to minimize the node voltage offset and the reactive power output deviation of the local station, to obtain the machine terminal voltage adjustment and the reactive power output adjustment of each local station; the length of the first recovery period is greater than the length of the second recovery period;

[0011] Every interval third recovery period, according to the machine terminal voltage adjustment and the reactive power output adjustment, the reactive power equipment in each local station is controlled; the length of the second recovery period is greater than the length of the third recovery period.

[0012] In a second aspect, an embodiment of the present application provides a control device of a black start recovery process, the power system comprising a plurality of regional subsystems, and each regional subsystem comprising a plurality of local stations;

[0013] The device comprises:

[0014] A global prediction module is configured to, in the black start recovery process, every interval first recovery period, establish and solve a global objective function to minimize the network loss in each regional subsystem, to obtain the node voltage plan value and the reactive power output plan value of each regional subsystem;

[0015] A middle layer adjustment module is configured to, every interval second recovery period, based on the node voltage plan value and the reactive power output plan value, establish and solve a middle layer objective function to minimize the node voltage offset and the reactive power output deviation of the local station, to obtain the machine terminal voltage adjustment and the reactive power output adjustment of each local station; the length of the first recovery period is greater than the length of the second recovery period;

[0016] A lower layer control module is configured to, every interval third recovery period, according to the machine terminal voltage adjustment and the reactive power output adjustment, control the reactive power equipment in each local station; the length of the second recovery period is greater than the length of the third recovery period.

[0017] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory and a processor, the memory storing a computer program, and the processor implementing the method in the first aspect or any possible implementation manner of the first aspect when executing the computer program.

[0018] In the black-start recovery process of a power system, this invention forms a centralized and decentralized voltage control system with global, intermediate, and local multi-regional cooperation through information transmission and coordination among the global, intermediate, and local layers. This hierarchical control structure can simultaneously take into account the optimized cooperation of multiple levels, including the global, intermediate, and local layers, thereby better adapting to the dynamic changes and complexities in the power system recovery process. Furthermore, this invention also employs different time scales for optimization solutions at different layers, thereby simultaneously taking into account the needs of global long-cycle prediction, intermediate-cycle adjustment, and lower-layer short-cycle correction, ultimately achieving the goal of accurately controlling voltage and reactive power output during the black-start recovery process. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the control framework of the voltage control method for the black start recovery process provided in an embodiment of the present invention;

[0020] Figure 2 This is a flowchart illustrating the implementation of the voltage control method for the black start recovery process provided in this embodiment of the invention.

[0021] Figure 3(a) is a heat map of node voltages under the two-layer control method;

[0022] Figure 3(b) is a node voltage heatmap under the control method provided in the embodiment of the present invention;

[0023] Figure 4(a) is a comparison diagram of network loss in the regional subsystem 1 provided in an embodiment of the present invention;

[0024] Figure 4(b) is a comparison diagram of network loss in the regional subsystem 2 provided in an embodiment of the present invention;

[0025] Figure 4(c) is a comparison diagram of network loss in the regional subsystem 3 provided in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the voltage control device for the black start recovery process provided in an embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] During the black start recovery process of a power system, the activation of capacitive lines can lead to excessive reactive power output in the already restored system, which in turn can cause overvoltage problems at the nodes to be restored, resulting in the restored system failing again. Therefore, precise control of voltage and reactive power output is required during the black start recovery process.

[0030] In order to precisely control the voltage and reactive power output in the black start recovery process, the embodiment of the present application forms a hierarchical control structure of global planning, middle layer adjustment and lower layer control through step-by-step information transmission and cooperation among the global, middle layer and local, so as to better adapt to the dynamic changes and complexity in the power system recovery process. Meanwhile, the embodiment of the present application also adopts different time scales for optimization of the objective function at different layers, so as to simultaneously meet the needs of global long-period prediction, middle layer medium-period adjustment and lower layer short-period correction, and finally achieve the purpose of precisely controlling the voltage and reactive power output in the black start recovery process.

[0031] Figure 1 The control framework of the control method of the black start recovery process provided by the embodiment of the present application is shown in the figure. Figure 1 As shown in the figure, the embodiment of the present application proposes a centralized and decentralized control framework, which includes a global voltage / reactive power planning layer, a middle layer regional voltage / reactive power adjustment layer and a lower layer local voltage / reactive power control layer. The layers cooperate with each other to jointly ensure the safety and stability of the power system in the black start recovery process.

[0032] The global voltage / reactive power planning layer is the upper layer of the entire centralized and decentralized control framework, and its main task is to formulate the node voltage planning value and reactive power output planning value of each regional subsystem in each recovery period. Here, the reactive power output planning value mainly includes the reactive power output planning value of each local station.

[0033] Based on the system partition planning and regional subsystem recovery scheme in the black start recovery process, the global voltage / reactive power planning layer needs to cooperatively optimize and set the node voltage planning value and reactive power output planning value of the regional subsystem in each recovery period according to the predicted values of the regional subsystem for new energy and load in each recovery period, so as to provide global reference values for the middle layer control.

[0034] The regional voltage / reactive power adjustment layer is the middle layer of the entire centralized and decentralized control framework, which focuses on the voltage control of the node to minimize the voltage deviation of the node in the regional subsystem, while ensuring sufficient reactive power reserve in the regional subsystem. The output results of the middle layer regional voltage / reactive power adjustment layer provide the voltage / reactive power adjustment target for the lower layer local voltage / reactive power control layer as the reference benchmark for real-time adjustment.

[0035] The local voltage / reactive power control layer is the lower layer of the framework, which combines system measurement data to perform real-time adjustment according to the terminal voltage adjustment amount and reactive power output adjustment amount output by the regional voltage / reactive power adjustment layer, so as to ensure that the reactive power equipment can quickly respond to the voltage deviation caused by the random fluctuations of load and renewable energy.

[0036] Referring to Figure 2It shows the implementation flowchart of the voltage control method of the black start recovery process provided by the embodiment of the application, and is described in detail as follows:

[0037] In the black start recovery process, every interval of the first recovery period, a global objective function is established and solved to obtain the node voltage plan value and the reactive power output plan value of each regional subsystem, with the target of minimizing the network loss in each regional subsystem.

[0038] In the black start recovery process, the power system is divided into multiple regional subsystems, and the entire power system is eventually restored to normal operation by gradually restoring each regional subsystem and the electrical connection between the regional subsystems. The regional subsystems contain multiple local stations. In the embodiment of the application, the local stations mainly include conventional units, new energy stations and continuous reactive power compensation devices.

[0039] In the black start recovery process, the global voltage / reactive power planning layer establishes a global objective function with the target of minimizing the network loss in each regional subsystem.

[0040] On this basis, the global voltage / reactive power planning layer optimizes and solves the global objective function based on the system partition plan and the system active power recovery result in the black start recovery process, in combination with the short-term prediction of load demand and renewable energy output, with the first recovery period as the optimization step, so as to obtain the node voltage plan value and the reactive power output plan value of each regional subsystem in each first recovery period.

[0041] Here, the length of the first recovery period can be set according to actual conditions, and the embodiment of the application does not make specific limitations on this. Exemplarily, the length of the first recovery period can be any value between 15 min and 60 min.

[0042] It can be understood that, with the continuous progress of the black start recovery, the electrical connection between different regional subsystems is continuously restored, and when the electrical connection between any two regional subsystems is restored, the any two regional subsystems can be merged into one regional subsystem.

[0043] On this basis, before the embodiment of the application performs, every interval of the first recovery period, the establishment and solution of the global objective function with the target of minimizing the network loss in each regional subsystem, the embodiment of the application can also:

[0044] Real-time acquisition of the electrical connection state between the regional subsystems, if there is an electrical connection between any two regional subsystems, the any two regional subsystems are merged to obtain the merged regional subsystem.

[0045] Correspondingly, the above establishment and solution of the global objective function every interval of the first recovery period with the target of minimizing the network loss in each regional subsystem can be changed to:

[0046] Every interval of the first recovery period, based on the merged regional subsystem, a global objective function is established and solved to minimize the network loss in each regional subsystem.

[0047] The global voltage / reactive power planning layer adopts a regional independent optimization mode before the regional subsystems are electrically connected, each regional subsystem independently optimizes and solves the global objective function based on its own information to ensure independent operation of each sub-region; after the regional subsystems are electrically connected, a regional collaborative optimization mode is adopted, and through inter-regional communication, collaborative optimization between regions is realized. The global objective function of the collaborative optimization mode adopted by the present application under the inter-regional comprehensive communication mode remains consistent in mathematical essence with the global objective function under the regional independent optimization mode, that is, the regional collaborative optimization regards the two merged regional subsystems m1 and m2 as a new merged large system m={m1, m2} to optimize and solve the global objective function. When all regional subsystems are electrically connected, the power system is restored to a complete interconnected power grid and enters a normal operating state, and the global voltage / reactive power planning layer can be based on the overall network information for unified optimization and dispatching.

[0048] During the system recovery process, the global voltage / reactive power planning layer dynamically switches between the regional independent optimization mode and the regional collaborative optimization mode according to the electrical connection state of the regional subsystems.

[0049] At step 202, every interval of the second recovery period, based on the node voltage plan value and the reactive power output plan value, a middle-layer objective function is established and solved to minimize the node voltage deviation and the local station reactive power output deviation, to obtain the machine terminal voltage adjustment and the reactive power output adjustment of each local station.

[0050] The regional voltage / reactive power adjustment layer establishes a middle-layer objective function based on the node voltage plan value and the reactive power output plan value output by the global voltage / reactive power planning layer. The middle-layer objective function aims to minimize the node voltage deviation and the local station reactive power output deviation, focuses on the voltage control of the node to maintain the minimum voltage deviation of the node in the regional subsystem, and ensures sufficient reactive power reserve in the control regional subsystem.

[0051] The machine terminal voltage adjustment and the reactive power output adjustment obtained by solving the middle-layer objective function provide the voltage / reactive power adjustment target for the lower-layer local voltage / reactive power control layer, serving as a reference benchmark for real-time adjustment.

[0052] Here, the length of the first recovery period is greater than the length of the second recovery period. The specific value of the length of the second recovery period can be determined according to the actual situation, and exemplarily, the length of the second recovery period can be any value between 3min and 5min.

[0053] At step 203, every third recovery period, the voltage adjustment amount and the reactive power adjustment amount are used to control the operation of the reactive power equipment in each local station.

[0054] Here, the voltage adjustment amount refers to the voltage adjustment amount of each reactive power equipment in the local station. The reactive power adjustment amount refers to the reactive power adjustment amount of each reactive power equipment in the local station.

[0055] The reactive power equipment includes, but is not limited to, a generator, a static var compensator (SVC), a static var generator (SVG), and a capacitor and a reactor with automatic switching function, etc. capable of providing reactive power. Exemplarily, the reactive power equipment in the continuous reactive power compensation device mainly includes a static var compensator and a static synchronous compensator, etc.

[0056] The local voltage / reactive power control layer performs measurement-based correction control on the voltage deviation of the node where the reactive power equipment is located, so that the voltage adjustment amount is as close as possible to the target value transmitted by the regional voltage / reactive power adjustment layer. According to the voltage adjustment amount and the reactive power adjustment amount provided by the regional voltage / reactive power adjustment layer, the layer combines the system measurement data to perform real-time adjustment, and ensures that the local reactive power equipment can quickly respond to the voltage deviation caused by the random fluctuations of the load and the renewable energy.

[0057] As the last link in the system recovery process, the local voltage / reactive power control layer relies on mature control strategies and loop designs. Through various reactive power equipment (such as conventional unit automatic excitation regulator, wind power / photovoltaic grid-connected inverter, static var compensator, on-load tap changer, etc.), the layer quickly responds to and compensates for voltage deviation and reactive power. Its core task is to ensure that the local reactive power equipment can quickly respond to load fluctuations and the uncertainty of renewable energy output according to the voltage adjustment amount and the reactive power adjustment amount provided by the regional voltage / reactive power adjustment layer, combined with real-time measurement data, so as to maintain the stability of the system voltage and the smooth progress of the black start recovery process.

[0058] Here, the length of the second recovery period is greater than the length of the third recovery period. The specific value of the length of the third recovery period can be determined according to the actual situation. Exemplarily, the length of the third recovery period can be any value between 1-10 seconds.

[0059] The centralized and decentralized control framework provided by the embodiment of the application is composed of a global voltage / reactive power planning layer, a regional voltage / reactive power adjustment layer and a local voltage / reactive power control layer. The global voltage / reactive power planning layer adopts a prediction-based advanced control strategy to make unified optimization decisions for the control period of the whole black-start recovery process and the node voltage and reactive power output in each regional subsystem. The regional voltage / reactive power adjustment layer dynamically optimizes and adjusts the node voltage and reactive power output in the regional subsystem recovery process. The lower layer quickly corrects the real-time voltage deviation of the reactive power equipment. The three-layer control framework realizes the decoupling and collaborative optimization control of the global, regional and local voltage / reactive power optimization control in the time dimension and the space dimension in the system black-start recovery process.

[0060] In the time dimension, the embodiment of the application adopts a multi-time scale collaborative optimization strategy to realize long-period advanced optimization based on load demand and renewable energy output prediction, medium-period dynamic adjustment based on real-time measurement data in the recovery period and short-period correction control based on real-time feedback. In the space dimension, a hierarchical control framework of the global layer, the regional layer and the local layer is constructed, the global layer is responsible for the global optimization decision, the regional layer dynamically adjusts the sub-regional, and the local layer realizes the rapid response of the equipment. Therefore, the voltage / reactive power centralized hierarchical control structure of the system recovery process from the time and space dimensions not only takes into account the economy and safety of the regional subsystem recovery process, but also switches the regional independent optimization mode and the regional collaborative optimization mode according to the recovery process and the interconnection state of each regional subsystem in the upper layer, ensuring the safety and economy of the system recovery in different stages and promoting the system recovery process and the recovery success rate.

[0061] Compared with the decentralized control strategy in the prior art, the embodiment of the application forms a global-intermediate-local multi-regional coordinated centralized and decentralized voltage control through information transmission and collaboration among the global layer, the intermediate layer and the local layer. This hierarchical control structure can simultaneously take into account the optimization and cooperation of multiple levels such as the global, the intermediate and the local, thereby better adapting to the dynamic changes and complexity in the power system recovery process. Meanwhile, the embodiment of the application also adopts different time scales for optimization and solution for different layers, thereby simultaneously taking into account the global long-period prediction, the intermediate medium-period adjustment and the lower short-period correction, and finally realizing the precise control of the voltage and reactive power output in the black-start recovery process.

[0062] The establishment of the global objective function and the solution method are introduced below.

[0063] In some embodiments, the network loss of each regional subsystem in the whole recovery period can be minimized The global objective function is established;

[0064] wherein, represents the global objective function corresponding to the mth regional subsystem, N T represents the total number of first recovery periods, I(m) represents the set of node numbers in the mth regional subsystem, P i,j,t represents the planned active power flow from node i to node j within the tth first recovery period in the mth regional subsystem, P j,i,t represents the planned active power flow from node j to node i within the tth first recovery period in the mth regional subsystem.

[0065] The constraint conditions corresponding to the global objective function mainly include:

[0066] (1) Node power balance equation constraint:

[0067]

[0068] wherein, G(i), R(i), S(i), C(i) and D(i) represent the set of numbers of the conventional units g, new energy stations r, continuous reactive power compensation devices s, discrete reactive power compensation devices c and loads d connected to node i; P g,t , P r,t and P d,t respectively represent the planned active power output values of the recovered conventional units g and new energy stations r, and the planned active power demand values of the loads d within the tth first recovery period, which are determined by the system active power recovery plan; J(i,m) represents the set of numbers of nodes j connected to node i in the mth regional subsystem; Q g,t , Q r,t , Q s,t , Q c,t and Q d,t respectively represent the planned reactive power output values of the recovered conventional units g, new energy stations r, continuous reactive power compensation devices s, discrete reactive power compensation devices c, and the planned reactive power demand values of the loads d within the tth first recovery period, wherein the planned reactive power demand values of the loads are determined according to a fixed proportional coefficient of their planned active power demand values.

[0069] (2) Reactive power constraints of conventional units, continuous reactive power compensation devices, discrete reactive power compensation devices, new energy stations and loads

[0070]

[0071] wherein, u g,t represents the state variable of whether the conventional unit g has been recovered in the tth first recovery period, which is determined by the system recovery plan, and respectively represent the minimum reactive power output value and the maximum reactive power output value of the conventional unit g, u s,tis a state variable representing whether the continuous reactive power compensation device s has been recovered in the tth first recovery period, the value of which is determined by the system recovery plan, and are the maximum reactive power output value and the minimum reactive power output value of the continuous reactive power compensation device s, respectively, u c,t is a state variable representing whether the discrete reactive power compensation device c has been recovered in the tth first recovery period, the value of which is determined by the system recovery plan, is the planned value of the number of capacitor / reactor groups put into operation by the discrete reactive power compensation device c in the tth first recovery period, is the maximum number of capacitor / reactor groups that can be put into operation by the discrete reactive power compensation device c; is the reactive power compensation amount of a single group of capacitors / reactors put into operation by the discrete reactive power compensation device c, G(m), S(m), C(m), R(m), and D(m) represent the number set of all conventional units g, continuous reactive power compensation devices s, discrete reactive power compensation devices c, new energy stations r, and loads d in the mth regional subsystem, respectively, the set being determined by the system partition plan; represents the power factor angle of the new energy station r, represents the power factor angle of the load d.

[0072] (3) System reactive power reserve constraint

[0073]

[0074]

[0075] wherein, and represent the planned value of the positive reactive power reserve and the planned value of the negative reactive power reserve of the conventional unit g in the tth first recovery period, respectively; and are the planned value of the positive reactive power reserve and the planned value of the negative reactive power reserve of the new energy station r in the tth first recovery period, respectively; and represent the minimum reactive power output value and the maximum reactive power output value of the new energy station r, respectively; and represent the total positive reactive power reserve demand and the total negative reactive power reserve demand of the mth regional subsystem, respectively.

[0076] (4) Branch power flow equation constraint

[0077]

[0078] wherein, G ij and B ij represent the real part and the complex part of the element in the i-th row and the j-th column of the system node admittance matrix, respectively, V i,tand V j,t respectively represent the voltage amplitude planned value of node i and node j in the tth first recovery period, and i,j,t respectively represent the voltage amplitude planned value of node i and node j in the tth first recovery period, and

[0079] (5) Node voltage amplitude constraint

[0080] u i,t V i min ≤V i,t ≤u i,t V i max ,i=I(m),t=1,2,…,N T

[0081] wherein u i,t represents the state variable of whether node i is powered on in the tth first recovery period, and the value is determined by the system active power recovery plan, V i min and V i max respectively represent the minimum voltage amplitude limit value and the maximum voltage amplitude limit value of node i.

[0082] (6) Branch transmission power constraint

[0083]

[0084] wherein u l ( i,j ) represents the state variable of whether the branch l(i,j) between node i and node j is powered on in the tth first recovery period, and the value is determined by the system active power recovery plan; represents the transmission power limit of the branch l(i,j), and L(m) represents the branch number set of the mth regional subsystem, and the set is determined by the system partition plan.

[0085] On the basis of the above constraints, the embodiment of the application optimizes the global objective function to obtain the node voltage planned value (i.e. the voltage amplitude planned value of each node in each first recovery period) and the reactive power output planned value (i.e. the reactive power output planned value of the conventional unit, the new energy station and the continuous reactive power compensation device in each first recovery period) for guiding the middle-layer voltage / reactive power adjustment layer to establish and solve the middle-layer objective function.

[0086] The establishment and solving process of the middle-layer objective function will be specifically introduced below.

[0087] In some embodiments, when establishing the middle-layer objective function, the node voltage offset can be calculated based on the node voltage planning value first; then, the reactive power output deviation of the conventional unit and the new energy station can be calculated based on the reactive power output planning value; finally, the middle-layer objective function is established by taking the weighted combination value of the node voltage offset and the reactive power output deviation as the target for minimization.

[0088] In some embodiments, the node voltage offset can be calculated based on

[0089] the node voltage offset;

[0090] wherein ΔV represents the node voltage offset, I(m) represents the number set of node i in the mth regional subsystem, V i * represents the node voltage planning value of node i, which comes from the calculation result of the global layer in the corresponding time period V i,t , Visamp represents the node voltage sampling value of node i, G(m) represents the number set of all conventional units g in the mth regional subsystem, represents the sensitivity of the voltage change of node i to the terminal voltage change of conventional unit g, ΔV g represents the terminal voltage adjustment amount of conventional unit g, R(m) represents the number set of all new energy stations r in the mth regional subsystem, represents the sensitivity of the voltage change of node i to the point of interconnection voltage change of new energy station r, ΔV r represents the point of interconnection voltage adjustment amount of new energy station r, S(m) represents the number set of all continuous reactive power compensation devices in the mth regional subsystem, represents the sensitivity of the voltage change of node i to the point of interconnection voltage change of continuous reactive power compensation device s, ΔV s represents the point of interconnection voltage adjustment amount of continuous reactive power compensation device s.

[0091] In some embodiments, the reactive power output deviation of the conventional unit can be calculated based on

[0092]

[0093] the reactive power output deviation of the conventional unit;

[0094] wherein ΔQ G represents the reactive power output deviation of the conventional unit, G(m) represents the number set of all conventional units g in the mth regional subsystem, represents the reactive power output planning value of conventional unit g', represents the reactive power output sampling value of conventional unit g', represents the sensitivity of the reactive power output change of conventional unit g' to the terminal voltage change of conventional unit g, ΔVg represents the voltage adjustment amount of the grid-connected point of the new energy plant r, S(m) represents the number set of all continuous reactive power compensation devices in the mth regional subsystem, represents the sensitivity of the reactive power output change of the conventional unit g' to the voltage change of the grid-connected point of the new energy plant r, ΔV r represents the voltage adjustment amount of the grid-connected point of the new energy plant r, S(m) represents the number set of all continuous reactive power compensation devices in the mth regional subsystem, represents the sensitivity of the reactive power output change of the conventional unit g' to the voltage change of the grid-connected point of the continuous reactive power compensation device s, ΔV s represents the voltage adjustment amount of the grid-connected point of the continuous reactive power compensation device s.

[0095] In some embodiments, the reactive power output deviation amount of the new energy plant can be calculated based on

[0096]

[0097] the reactive power output deviation amount of the new energy plant,

[0098] wherein ΔQ R represents the reactive power output deviation amount of the new energy plant, R(m) represents the number set of all new energy plants in the mth regional subsystem, represents the planned value of the reactive power output of the new energy plant r', represents the sampled value of the reactive power output of the new energy plant r', G(m) represents the number set of all conventional units in the mth regional subsystem, represents the sensitivity of the reactive power output change of the new energy plant r' to the voltage change of the grid-connected point of the conventional unit g, ΔV g represents the voltage adjustment amount of the grid-connected point of the conventional unit g, represents the sensitivity of the reactive power output change of the new energy plant r' to the voltage change of the grid-connected point of the new energy plant r, ΔV r represents the voltage adjustment amount of the grid-connected point of the new energy plant, S(m) represents the number set of all continuous reactive power compensation devices in the mth regional subsystem, represents the sensitivity of the reactive power output change of the new energy plant r' to the voltage change of the grid-connected point of the continuous reactive power compensation device s, ΔV s represents the voltage adjustment amount of the grid-connected point of the continuous reactive power compensation device s.

[0099] In some embodiments, the reactive power output deviation amount of the continuous reactive power compensation device can be calculated based on

[0100] the reactive power output deviation amount of the continuous reactive power compensation device,

[0101] wherein ΔQ Srepresents reactive power output deviation of the continuous reactive power compensation device, S(m) represents a number set of all continuous reactive power compensation devices in the mth regional subsystem, represents a reactive power output planning value of the continuous reactive power compensation device s', represents a reactive power output planning value of the continuous reactive power compensation device s', represents a reactive power output planning value of the continuous reactive power compensation device s', g represents a reactive power output planning value of the continuous reactive power compensation device s', represents a reactive power output planning value of the continuous reactive power compensation device s', r represents a reactive power output planning value of the continuous reactive power compensation device s', represents a reactive power output planning value of the continuous reactive power compensation device s', s represents a reactive power output planning value of the continuous reactive power compensation device s'.

[0102] In some embodiments, the middle-layer target function can be established according to

[0103] wherein, represents a middle-layer target function corresponding to the mth regional subsystem, β1 represents a weight factor corresponding to the node voltage deviation, ΔV represents the node voltage deviation, β2 represents a weight factor corresponding to reactive power output deviations of the conventional unit and the new energy station, ΔQ G represents a reactive power output deviation of the conventional unit, ΔQ R represents a reactive power output deviation of the new energy station, ΔQ S represents a reactive power output deviation of the continuous reactive power compensation device; β1>β2.

[0104] By setting β1>β2, the embodiment of the application can preferentially ensure voltage safety of the power system, and on this basis, further pursue optimal economic distribution of reactive power output.

[0105] Taking the length of the first recovery period as 15 minutes and the length of the second recovery period as 3 minutes as an example, in a 15-minute cycle of the upper-layer global voltage / reactive power planning layer, the middle-layer regional voltage / reactive power adjustment layer performs 5 times of optimization calculation. Each time of middle-layer calculation uses the voltage planning value and the reactive power output planning value calculated by the upper layer in the current 15-minute cycle.

[0106] The constraint conditions corresponding to the middle-layer target function mainly include: ​

[0107] (1) Node voltage constraint

[0108]

[0109] wherein, and respectively represent the minimum voltage limit and the maximum voltage limit of the terminal voltage of the conventional unit g, represents the sampling value of the node voltage of the conventional unit g, and respectively represent the minimum voltage limit and the maximum voltage limit of the node voltage of the new energy station r, r represents the sampling value of the node voltage of the new energy station r, and respectively represent the minimum voltage limit and the maximum voltage limit of the node voltage of the continuous reactive power compensation device s, represents the sampling value of the node voltage of the continuous reactive power compensation device s.

[0110] (2) Reactive power output constraint

[0111]

[0112] wherein, and respectively represent the minimum reactive power output value and the maximum reactive power output value of the conventional unit g, and respectively represent the minimum reactive power output value and the maximum reactive power output value of the new energy station r, and respectively represent the maximum reactive power output value and the minimum reactive power output value of the continuous reactive power compensation device s.

[0113] (3) Voltage single-step maximum adjustment amount constraint

[0114]

[0115] in the formula, and respectively represent the single-step maximum adjustment amount of the terminal voltage of the conventional unit g, the single-step maximum adjustment amount of the node voltage of the new energy station r, and the single-step maximum adjustment amount of the node voltage of the continuous reactive power compensation device s.

[0116] On the basis of the above constraint conditions, the middle-layer target function is solved to obtain the terminal voltage adjustment amount and the reactive power output adjustment amount of the conventional unit and the local station. The reactive power equipment in the conventional unit and the local station collects real-time measurement data according to the above terminal voltage adjustment amount and the reactive power output adjustment amount, and controls the adjustment of the voltage and the reactive power output in real time, so as to maintain the stability of the system voltage and ensure the smooth progress of the black start recovery process.

[0117] The voltage control method of the black-start recovery process is verified according to actual data of a provincial power grid in North China in the embodiments of the present application. The power grid includes 280 transformer substations, 34 thermal power plants, 1 pumped storage power station, 37 centralized wind power plants and 174 centralized photovoltaic power plants, 419 220kV and above nodes, and 559 branches. The example is developed and implemented based on C++ language, and is used to solve the global objective function and the middle-layer objective function. The lower-layer simulation environment is built on the power system analysis software platform independently developed by the China Electric Power Research Institute.

[0118] 1. System partition and active power recovery plan

[0119] In the black-start recovery process, the system partition and active power recovery plan is divided into three regional subsystems, and each region is configured with one black-start unit. The recovery plan adopts 30 minutes as a single time period step, and the total recovery time is 6 hours. According to the generated system partition recovery scheme, the three regional subsystems cover 111, 147 and 161 220kV and above nodes respectively. Table 1 lists the planned recovery node number and planned recovery load percentage of each regional subsystem in each recovery period.

[0120] Table 1 Overview of system partition recovery scheme

[0121]

[0122] As can be seen from Table 1, the three regional subsystems complete the black-start recovery of their respective regional subsystems in the 10th, 10th and 11th periods respectively. The system parallel (i.e., system merging) of regional subsystem 1 and regional subsystem 2 is completed in the 11th period, and the system parallel of regional subsystem 3 and the parallel system of regional subsystem 1 and regional subsystem 2 is completed in the 12th period. The system completes the black-start recovery in the 12th period.

[0123] 2. Effectiveness verification of the voltage control method of the black-start recovery process

[0124] To verify the effectiveness of the voltage control method provided by the embodiment of the present application, a two-layer voltage control method is compared with the three-layer voltage control method provided by the embodiment of the present application. The two-layer voltage control method is obtained by removing the middle-layer regional voltage / reactive power adjustment layer on the basis of the three-layer voltage control method provided by the embodiment of the present application. This comparison aims to comprehensively evaluate the overall performance of the centralized and decentralized control framework provided by the embodiment of the present application, especially the key role of the middle-layer regional voltage / reactive power adjustment layer in bridging the global voltage / reactive power planning layer and the local voltage / reactive power control layer. FIG. 3(a) and FIG. 3(b) are node voltage thermal maps under the two-layer voltage control and three-layer voltage control methods, which are used to show the node voltage of each node in the three regional subsystems at different time periods under the two-layer voltage control and three-layer voltage control methods.

[0125] In the thermal maps shown in FIG. 3(a) and FIG. 3(b), each color block represents the voltage per unit of a node at a specific time period. The darker the color block, the greater the voltage per unit of the node; while the white color block indicates that the node has not been restored at that time period. By comparing FIG. 3(a) and FIG. 3(b), we can intuitively observe that the dark color blocks in FIG. 3(a) are significantly more than in FIG. 3(b), which indicates that the degree of node voltage deviation from the standard node voltage under the two-layer voltage control method is significantly higher than that under the three-layer voltage control method. For example, in the last time period, the proportion of nodes with voltage deviation exceeding 0.05 p.u. in the three regions under the two-layer voltage control method is 11.12%, 23.9% and 31.67% respectively. In contrast, the proportion of nodes with voltage deviation exceeding 0.05 p.u. in the three regions under the three-layer voltage control method is all 0.

[0126] The results verify the superiority of the three-layer voltage control method provided by the embodiment of the present application and the effectiveness of the middle-layer regional voltage / reactive power adjustment layer method. Compared with the two-layer voltage control method, the introduction of the regional voltage / reactive power adjustment layer can better adapt to the rapid access of a large number of devices and the rapid change of network topology during the restoration process through dynamic monitoring and adjustment, ensuring voltage stability. At the same time, the regional voltage / reactive power adjustment layer also has the advantage of coordinated optimization between regional power sources, which optimizes the overall voltage distribution by coordinating the output of different power sources in the region, reduces voltage deviation, and improves system reliability and restoration speed. In addition, the three-layer voltage control method forms a complete control closed loop through hierarchical control and coordination, further improving the control efficiency and accuracy. These advantages work together to make the three-layer voltage control method perform better in voltage stability and system reliability.

[0127] Fig. 4(a), Fig. 4(b) and Fig. 4(c) show the network loss of the three regional subsystems in different periods under the two-layer voltage control and three-layer voltage control methods. The points on the curves in the figures represent the proportion of the network loss in the restored load in the corresponding period. It can be observed from the figures that in the three regional subsystems, the system network loss under the three-layer voltage control method is always lower than that under the two-layer voltage control method, and the average network loss is reduced by 9.67%. This result fully verifies the superiority of the three-layer voltage control method, especially the effectiveness of the regional voltage / reactive power adjustment layer in the second layer. The adjustment layer optimizes the overall reactive power distribution of the system through dynamic coordination, significantly reduces the system network loss, and further improves the economy of system restoration.

[0128] 3. Effectiveness verification of dynamic switching strategy of global layer optimization mode

[0129] To verify the effectiveness of the global voltage / reactive power planning layer in the regional independent optimization and regional collaborative optimization modes proposed in the embodiments of the present application, the control method supporting mode switching is compared with the control method not supporting mode switching. The control method not supporting mode switching is based on the centralized and decentralized control framework proposed in the present application, but the switching function of the global voltage / reactive power planning layer between the regional independent optimization and regional collaborative optimization modes is cancelled, so that the global voltage / reactive power planning layer of each regional subsystem always maintains decoupled operation before and after the regional subsystems are parallel, and does not communicate with each other. By comparing the voltage restoration effect and optimization ability of the two before and after the system is parallel, the advantages of the control method supporting mode switching in adapting to the needs of different restoration stages of the system are analyzed. Here, the parallel of regional subsystems can be simply understood as the merging of regional subsystems.

[0130] Table 2 shows the control effect of the three regional subsystems in the system parallel period under the control method not supporting mode switching and the control method supporting mode switching. Among them, method 1 and method 2 respectively refer to the control method not supporting mode switching and the control method supporting mode switching. The overvoltage node ratio refers to the proportion of the number of nodes with voltage deviation exceeding 0.05 p.u. in the corresponding period to the number of restored nodes, and the network loss ratio refers to the proportion of the network loss in the corresponding period to the restored load.

[0131] Table 2 Comparison of control effects of supporting mode switching and supporting mode switching

[0132]

[0133] In terms of overvoltage node ratio, under method 1, the overvoltage node ratios of the regional subsystem 1 in time periods 11 and 12 are both 1.80%, the overvoltage node ratios of the regional subsystem 2 are 0.68% and 1.36% respectively, and the overvoltage node ratio of the regional subsystem 3 rises to 0.62% in time period 12. Under method 2, the overvoltage node ratios of all regional subsystems in time periods 11 and 12 are both 0%, indicating that the voltage deviation is effectively inhibited through inter-regional collaborative optimization.

[0134] In terms of network loss ratio, under method 1, the network loss ratios of the regional subsystem 1 in time periods 11 and 12 are 0.55% and 0.66% respectively, the network loss ratios of the regional subsystem 2 are 0.42% and 0.83% respectively, and the network loss ratios of the regional subsystem 3 are 0.13% and 0.22% respectively. Under method 2, the network loss ratios of the regional subsystem 1 are 0.53% and 0.60% respectively, the network loss ratios of the regional subsystem 2 are 0.35% and 0.72% respectively, and the network loss ratios of the regional subsystem 3 are 0.13% and 0.18% respectively. The network loss ratios of all regional subsystems under method 2 are lower than or equal to those under method 1, especially in the regional subsystem 1 and the regional subsystem 2, the network loss ratios are reduced by about 3.6% and 13.3% respectively, effectively improving the economic operation efficiency.

[0135] In summary, under the control method supporting mode switching, the global voltage / reactive power planning layer is significantly superior to the control method not supporting mode switching in terms of voltage stability and economic operation efficiency. The flexible switching function effectively avoids overvoltage problems and reduces network loss through global collaborative optimization after the parallel of regional subsystems, thereby comprehensively improving the recovery effect of the system. This result verifies the superiority of the control method supporting mode switching in adapting to the needs of different stages of system recovery, and provides a more efficient solution for voltage control in the process of black start recovery of power systems.

[0136] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0137] The following is a device embodiment of the present application. For details not described in detail, please refer to the corresponding method embodiments described above.

[0138] Figure 5 The structure of the voltage control device for the black start recovery process provided by the embodiment of the present application is shown. For the convenience of description, only the parts related to the embodiment of the present application are shown, and the details are as follows:

[0139] As shown in Figure 5 The voltage control device 5 for the black start recovery process includes a global prediction module 51, a middle layer adjustment module 52 and a lower layer control module 53.

[0140] The global prediction module 51 is configured to, during the black start recovery process, establish and solve a global objective function every first recovery period to obtain node voltage plan values and reactive power output plan values of the regional subsystems, with the aim of minimizing network loss in the regional subsystems;

[0141] The middle layer adjustment module 52 is configured to, every second recovery period, establish and solve a middle layer objective function based on the node voltage plan values and the reactive power output plan values, with the aim of minimizing node voltage deviation and local station reactive power output deviation, to obtain generator terminal voltage adjustment and reactive power output adjustment of each local station; the length of the first recovery period is greater than the length of the second recovery period;

[0142] The lower layer control module 53 is configured to, every third recovery period, control the operation of the reactive power equipment in each local station according to the generator terminal voltage adjustment and the reactive power output adjustment; the length of the second recovery period is greater than the length of the third recovery period.

[0143] In a possible implementation, the global prediction module 51 is specifically configured to:

[0144] According to establish a global objective function;

[0145] wherein, denotes the global objective function corresponding to the mth regional subsystem, N T denotes the total number of the first recovery periods, I(m) denotes a node i number set in the mth regional subsystem, P i,j,t denotes a planned active power value from the node i to the node j in the mth regional subsystem within the tth first recovery period, P j,i,t denotes a planned active power value from the node j to the node i in the mth regional subsystem within the tth first recovery period.

[0146] In a possible implementation, the local station includes a conventional generator unit, a new energy station and a continuous reactive power compensation device;

[0147] The middle layer adjustment module 52 is specifically configured to:

[0148] based on the node voltage plan values, calculate the node voltage deviation;

[0149] based on the reactive power output plan values, calculate the reactive power output deviation of the conventional generator unit, the new energy station and the continuous reactive power compensation device;

[0150] establish a middle layer objective function with the aim of minimizing a weighted combination value of the node voltage deviation and the reactive power output deviation.

[0151] In a possible implementation, the middle layer adjustment module 52 is specifically configured to:

[0152] based on

[0153] calculating the node voltage offset amount;

[0154] wherein ΔV represents the node voltage offset amount, I(m) represents a number set of nodes i in the mth regional subsystem, V i * represents a node voltage planned value of node i, V i samp represents a node voltage sampled value of node i, G(m) represents a number set of all conventional units in the mth regional subsystem, represents a sensitivity of a voltage change of node i to a terminal voltage change of conventional unit g, ΔV g represents a terminal voltage adjustment amount of conventional unit g, R(m) represents a number set of all new energy stations in the mth regional subsystem, represents a sensitivity of a voltage change of node i to a point of common coupling voltage change of new energy station r, ΔV r represents a point of common coupling voltage adjustment amount of new energy station r, S(m) represents a number set of all continuous reactive power compensation devices in the mth regional subsystem, represents a sensitivity of a voltage change of node i to a point of common coupling voltage change of continuous reactive power compensation device s, ΔV s represents a point of common coupling voltage adjustment amount of continuous reactive power compensation device s.

[0155] In a possible implementation, the middle-layer adjustment module 52 is specifically configured to:

[0156] based on

[0157]

[0158] calculating the reactive power output deviation amount of the conventional unit;

[0159] wherein ΔQ G represents the reactive power output deviation amount of the conventional unit, G(m) represents a number set of all conventional units in the mth regional subsystem, represents a reactive power planned value of conventional unit g', represents a reactive power sampled value of conventional unit g', represents a sensitivity of a reactive power change of conventional unit g' to a terminal voltage change of conventional unit g, ΔV g represents a terminal voltage adjustment amount of conventional unit g, R(m) represents a number set of all new energy stations in the mth regional subsystem, a sensitivity of reactive power output change of the conventional generating unit g' to voltage change at the grid connection point of the new energy plant r, ΔV r a voltage adjustment amount at the grid connection point of the new energy plant r, S(m) represents a number set of all continuous reactive power compensation devices in the mth regional subsystem, a sensitivity of reactive power output change of the conventional generating unit g' to voltage change at the grid connection point of the continuous reactive power compensation device s, ΔV s a voltage adjustment amount at the grid connection point of the continuous reactive power compensation device s.

[0160] In a possible implementation, the middle-layer adjustment module 52 is specifically configured to:

[0161] based on

[0162]

[0163] calculate a reactive power output deviation amount of the new energy plant;

[0164] wherein ΔQ R represents the reactive power output deviation amount of the new energy plant, R(m) represents a number set of all new energy plants in the mth regional subsystem, represents a planned value of reactive power output of the new energy plant r', represents a sampled value of reactive power output of the new energy plant r', G(m) represents a number set of all conventional generating units in the mth regional subsystem, a sensitivity of reactive power output change of the new energy plant r' to voltage change at the terminal of the conventional generating unit g, ΔV g represents a voltage adjustment amount at the terminal of the conventional generating unit g, a sensitivity of reactive power output change of the new energy plant r' to voltage change at the grid connection point of the new energy plant r, ΔV r represents a voltage adjustment amount at the grid connection point of the new energy plant, S(m) represents a number set of all continuous reactive power compensation devices in the mth regional subsystem, a sensitivity of reactive power output change of the new energy plant r' to voltage change at the grid connection point of the continuous reactive power compensation device s, ΔV s represents a voltage adjustment amount at the grid connection point of the continuous reactive power compensation device s.

[0165] In a possible implementation, the middle-layer adjustment module 52 is specifically configured to:

[0166] based on

[0167]

[0168] calculate a reactive power output deviation amount of the continuous reactive power compensation device;

[0169] wherein, AQ S represents the reactive power output deviation amount of the continuous reactive power compensation device, S(m) represents the number set of all continuous reactive power compensation devices in the mth regional subsystem, represents the reactive power output planned value of the continuous reactive power compensation device s', represents the reactive power output sample value of the continuous reactive power compensation device s', G(m) represents the number set of all conventional units in the mth regional subsystem, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device s' to the terminal voltage change of the conventional unit g, AV g represents the terminal voltage adjustment amount of the conventional unit g, R(m) represents the number set of all new energy stations in the mth regional subsystem, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device s' to the point of interconnection voltage change of the new energy station r, AV r represents the point of interconnection voltage adjustment amount of the new energy station, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device s' to the point of interconnection voltage change of the continuous reactive power compensation device s, AV s represents the point of interconnection voltage adjustment amount of the continuous reactive power compensation device s.

[0170] In a possible implementation, the middle-layer adjustment module 52 is specifically configured to:

[0171] According to establish the middle-layer target function;

[0172] wherein, represents the middle-layer target function corresponding to the mth regional subsystem, β1 represents the weight factor corresponding to the node voltage deviation amount, AV represents the node voltage deviation amount, β2 represents the weight factor corresponding to the reactive power output deviation amount of the conventional unit and the new energy station, AQ G represents the reactive power output deviation amount of the conventional unit, AQ R represents the reactive power output deviation amount of the new energy station, AQ S represents the reactive power output deviation amount of the continuous reactive power compensation device; β1>β2.

[0173] In a possible implementation, the global prediction module 51 is further configured to:

[0174] acquire the electrical connection state between each regional subsystem in real time;

[0175] if there is electrical connection between any two regional subsystems, merge any two regional subsystems to obtain a merged regional subsystem;

[0176] On this basis, the global prediction module 51 is specifically configured to:

[0177] Every interval first recovery period, based on the merged regional subsystem, to minimize the network loss in each regional subsystem, to establish and solve the global objective function.

[0178] The device embodiment is used to realize the method embodiment, and the technical principle and implementation effect are the same as those of the above method embodiment, which will not be repeated here.

[0179] Figure 6 is a schematic diagram of an electronic device provided by an embodiment of the application. As shown in Figure 6 The electronic device 6 of this embodiment includes a processor 60 and a memory 61. The memory 61 stores a computer program 62. The processor 60 implements the steps in each of the above method embodiments when executing the computer program 62. Alternatively, the processor 60 implements the functions of each module / unit in each of the above device embodiments when executing the computer program 62.

[0180] For example, the computer program 62 can be divided into one or more modules / units, which are stored in the memory 61 and executed by the processor 60 to complete the application. The one or more modules / units can be a series of computer program instruction segments that can complete a specific function, which are used to describe the execution process of the computer program 62 in the electronic device 6.

[0181] The electronic device 6 can include, but is not limited to, the processor 60, the memory 61. Those skilled in the art can understand, Figure 6 The electronic device 6 is only an example and does not constitute a limitation on the electronic device 6, and can include more or fewer components than the diagram, or combine certain components, or different components, for example, the electronic device 6 can also include an input / output device, a network access device, a bus, etc.

[0182] For the convenience and brevity of description, only the above-mentioned division of functional modules / units is exemplified, and in actual application, the above-mentioned functions can be completed by different functional modules / units according to needs. The above-mentioned modules / units can be realized in the form of hardware, software, or a combination of hardware and software.

[0183] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in a certain embodiment can be referred to the related description of other embodiments. If there is no special description and no logical conflict, the terms and / or descriptions of different embodiments are consistent and can be mutually referenced. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0184] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those ordinarily skilled in the art should understand: the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A voltage control method for a black start restoration procedure, characterized by, The power system comprises a plurality of regional subsystems, and each regional subsystem comprises a plurality of local stations; The method comprises: During the black start recovery process, a global objective function is established and solved every first recovery period to obtain node voltage plan values and reactive power output plan values of each regional subsystem, with the aim of minimizing network loss in each regional subsystem; Every second recovery period, a middle-layer objective function is established and solved based on the node voltage plan values and the reactive power output plan values, with the aim of minimizing node voltage deviation and reactive power output deviation of each local station, to obtain terminal voltage adjustment values and reactive power output adjustment values of each local station; the first recovery period is longer than the second recovery period; Every third recovery period, the reactive power equipment in each local station is controlled according to the terminal voltage adjustment values and the reactive power output adjustment values; the second recovery period is longer than the third recovery period; The global objective function is established with the aim of minimizing network loss in each regional subsystem, comprising: According to establishing a global objective function; wherein, represents a global objective function corresponding to the m th regional subsystem, represents the total number of first recovery periods, represents a set of node m numbers in the i th regional subsystem, represents the active power planning value from node m to node t within the i th first recovery period in the j th regional subsystem, represents the active power planning value from node m to node t within the j th first recovery period in the i th regional subsystem.

2. The voltage control method of black start restoration procedure according to claim 1, characterized in that, The local station comprises a conventional unit, a new energy station and a continuous reactive power compensation device; The middle-layer objective function is established based on the node voltage plan values and the reactive power output plan values, with the aim of minimizing node voltage deviation and reactive power output deviation of each local station, comprising: Based on the node voltage plan values, node voltage deviation is calculated; Based on the reactive power output plan values, reactive power output deviation of the conventional unit, the new energy station and the continuous reactive power compensation device is calculated; The middle-layer objective function is established with the aim of minimizing the weighted combination value of the node voltage deviation and the reactive power output deviation.

3. The voltage control method of black-start restoration procedure according to claim 2, characterized in that, The node voltage deviation is calculated based on The reactive power output deviation of the conventional unit is calculated based on The reactive power output deviation of the new energy station is calculated based on in, This represents the node voltage offset. Indicates the first m Nodes in a regional subsystem i The set of numbers, Represents a node i The planned value of the node voltage. Represents a node i The node voltage sampling value, Indicates the first m The set of unit numbers for all conventional units within a regional subsystem. Represents a node i Voltage changes affect conventional units g The sensitivity to changes in terminal voltage. Indicates conventional units g The amount of voltage adjustment at the generator terminal. Indicates the first m A set of numbers for all new energy power stations within a regional subsystem. Represents a node i Voltage changes affect new energy power plants r The sensitivity of the grid connection point voltage change Indicates new energy power station r The voltage adjustment at the grid connection point, Indicates the first The set of serial numbers of all continuous reactive power compensation devices within a regional subsystem. Represents a node Voltage changes affect continuous reactive power compensation devices The sensitivity of the grid connection point voltage change Indicates continuous reactive power compensation device The voltage adjustment at the grid connection point.

4. The voltage control method of black start restoration procedure according to claim 2, characterized in that, The reactive power output deviation of the continuous reactive power compensation device is calculated based on The middle-layer objective function is established with the aim of minimizing the weighted combination value of the node voltage deviation and the reactive power output deviation, comprising: calculating reactive power output deviation amount of the conventional unit; wherein, represents the reactive power output deviation amount of the conventional generating unit, represents the number set of all conventional generating units in the m th regional subsystem, represents the reactive power output planned value of the conventional generating unit , represents the reactive power output sampled value of the conventional generating unit , represents the sensitivity of the reactive power output change of the conventional generating unit to the terminal voltage change of the conventional generating unit g , represents the terminal voltage adjustment amount of the conventional generating unit g , represents the number set of all new energy stations in the m th regional subsystem, represents the sensitivity of the reactive power output change of the conventional generating unit to the point of common coupling voltage change of the new energy station r , represents the point of common coupling voltage adjustment amount of the new energy station r , represents the number set of all continuous reactive power compensation devices in the th regional subsystem, represents the sensitivity of the reactive power output change of the conventional generating unit to the point of common coupling voltage change of the continuous reactive power compensation device , represents the point of common coupling voltage adjustment amount of the continuous reactive power compensation device .

5. The voltage control method of black start restoration procedure as claimed in claim 2, wherein, Before the global objective function is established and solved every first recovery period with the aim of minimizing network loss in each regional subsystem, the method further comprises: based on calculate a reactive power output deviation amount of the new energy station; wherein, represents reactive power output deviation amount of the new energy station, represents a number set of all new energy stations in the m th regional subsystem, represents the reactive power output planning value of the new energy station , represents the reactive power output sampling value of the new energy station , represents a number set of all conventional units in the m th regional subsystem, represents the sensitivity of the reactive power output change of the new energy station to the terminal voltage change of the conventional unit g , represents the terminal voltage adjustment amount of the conventional unit g , represents the sensitivity of the reactive power output change of the new energy station to the point of common coupling voltage change of the new energy station r , represents the point of common coupling voltage adjustment amount of the new energy station, represents a number set of all continuous reactive power compensation devices in the th regional subsystem, represents the sensitivity of the reactive power output change of the new energy station to the point of common coupling voltage change of the continuous reactive power compensation device , represents the point of common coupling voltage adjustment amount of the continuous reactive power compensation device, .

6. The voltage control method of black start restoration procedure as claimed in claim 2, wherein, Real-time acquisition of electrical connection states between regional subsystems; based on calculating a reactive power output deviation amount of the continuous reactive power compensation device; wherein, represents the reactive power output deviation amount of the continuous reactive power compensation device, represents the number set of all continuous reactive power compensation devices in the th regional subsystem, represents the reactive power output planned value of the continuous reactive power compensation device , represents the reactive power output sampled value of the continuous reactive power compensation device , represents the number set of all conventional generating units in the m th regional subsystem, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device to the terminal voltage change of the conventional generating unit g , represents the terminal voltage adjustment amount of the conventional generating unit g , represents the number set of all new energy stations in the m th regional subsystem, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device to the grid-connected point voltage change of the new energy station r , represents the grid-connected point voltage adjustment amount of the new energy station, represents the sensitivity of the reactive power output change of the continuous reactive power compensation device to the grid-connected point voltage change of the continuous reactive power compensation device , represents the grid-connected point voltage adjustment amount of the continuous reactive power compensation device .

7. The voltage control method of black start restoration procedure as claimed in claim 2, wherein, If there is electrical connection between any two regional subsystems, the any two regional subsystems are merged to obtain a merged regional subsystem; According to establishing the middle-layer objective function; wherein, represents the middle layer objective function corresponding to the m represents the weight factor corresponding to the node voltage offset, represents the node voltage offset, represents the weight factor corresponding to the reactive power output deviation of the conventional generating unit and the new energy station, represents the reactive power output deviation of the conventional generating unit, represents the reactive power output deviation of the new energy station, represents the reactive power output deviation of the continuous reactive power compensation device. .​​ 8. The voltage control method of black start restoration procedure as claimed in claim 1 wherein, The global objective function is established and solved every first recovery period based on the merged regional subsystem with the aim of minimizing network loss in each regional subsystem. The power system comprises a plurality of regional subsystems, and each regional subsystem comprises a plurality of local stations; The device comprises: ​ ​ 9. A voltage control device for a black start restoration procedure, characterized by ​ ​ The global prediction module is configured to, during the black-start recovery process, establish and solve a global objective function every first recovery period, so as to obtain node voltage plan values and reactive power output plan values of the regional subsystems, and the target of minimizing network loss in the regional subsystems is achieved. The middle-layer adjustment module is configured to, every second recovery period, based on the node voltage plan values and the reactive power output plan values, establish and solve a middle-layer objective function, so as to obtain terminal voltage adjustment values and reactive power output adjustment values of the local stations, and the target of minimizing node voltage offset and reactive power output deviation of the local stations is achieved; the first recovery period is longer than the second recovery period. The lower-layer control module is configured to, every third recovery period, control the reactive power equipment in the local stations according to the terminal voltage adjustment values and the reactive power output adjustment values; the second recovery period is longer than the third recovery period. The global objective function is established with the target of minimizing network loss in the regional subsystems, and the global objective function comprises: According to establishing a global objective function; wherein, denotes the global objective function corresponding to the m th regional subsystem, denotes the total number of first recovery periods, denotes the set of node m numbers in the i th regional subsystem, denotes the active power schedule value from node m to node t within the i th first recovery period in the j th regional subsystem, denotes the active power schedule value from node m to node t within the j th first recovery period in the i th regional subsystem.

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