Metering-dependent power distribution system fault recovery and fault voltage regulation method

Abstract

The application discloses a kind of power distribution system fault recovery and fault voltage regulation method based on measurement dependence, comprising:1 constructs the emergency communication model based on unmanned aerial vehicle and small base station, the optimal route of each unmanned aerial vehicle to communication failure is determined by solving the model, and then all communication failure components are recovered;2 a power distribution system fault recovery model considering voltage safety is established, the sequential action of controllable switch, the power output of reconfigurable intelligent soft switch and the reactive power output strategy of controllable resource are determined by solving the model.The application can restore the observability and controllability of power distribution system, thereby improving the fault recovery capability of power distribution system and ensuring the real-time voltage safety during recovery process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of integrated energy system, in particular to a power distribution system fault recovery and fault voltage regulation method based on measurement dependence. BACKGROUND

[0002] With the richness of controllable resources in the power distribution system and the promotion of power distribution automation system, the coupling relationship between the power physical layer and the information layer is increasingly close. However, under extreme disasters, the information-physical deep coupling characteristics increase the vulnerability of the system, bringing more complex problems to the power distribution system. For example, natural disasters will also cause different degrees of damage to the communication network supporting power distribution automation, thereby affecting the effectiveness of the physical layer recovery decision. And in recent years, extreme events such as natural disasters have occurred frequently, causing many power outages, thereby causing significant economic losses and adverse social impacts. Among them, more than 90% of power outages are caused by faults in the power distribution layer. Therefore, it is necessary to study the coupling characteristics and evolution mechanism between the information layer and the physical layer recovery, and to cooperatively use the flexible resources on the information layer and the physical layer to improve the fault recovery capability of the power distribution system under extreme disasters.

[0003] The current fault recovery research mainly focuses on the physical layer power distribution system. Related research focuses on promoting power supply continuity in the power distribution system by coordinating flexible resources and topology reconstruction within the system. On the other hand, it focuses on the coordination of fault repair and fault recovery to restore power loss loads. However, the interdependence of power grid physical systems and information-physical systems is not considered, and the impact of communication system failure caused by disaster events on the power distribution system is ignored. In addition, the high proportion of distributed renewable energy sources within the system has strong randomness, which can also cause frequent voltage fluctuations or even over-limit problems during the recovery process, thereby affecting the system recovery performance. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the present application provides a power distribution system fault recovery and fault voltage regulation method based on measurement dependence, in order to restore the observability and controllability of the power distribution system, thereby improving the fault recovery capability of the power distribution system and ensuring real-time voltage safety during the recovery process.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] The power distribution system fault recovery and fault voltage regulation method based on measurement dependence provided by the present application is characterized in that it comprises the following steps:

[0007] S1: Construct an emergency communication model based on unmanned aerial vehicles and small base stations, including path constraints and time constraints of unmanned aerial vehicles;

[0008] S2: judging the observability and controllability of each node according to the state of the data transmission channel and the communication line of each node in the power distribution system:

[0009] If the data transmission channel of the node and the communication line between the nodes are not damaged by the fault, it indicates that the corresponding node has observability and controllability;

[0010] If the data transmission channel of the node is not damaged by the fault, but the communication line between the nodes is damaged by the fault, it indicates that the corresponding node has observability, but does not have controllability;

[0011] If the data transmission channel of the node is damaged by the fault, it indicates that the corresponding node does not have observability and controllability;

[0012] S3: constructing the operation constraints of the reconfigurable intelligent soft switch R-SOP and the fault flow constraints of the power distribution system according to the observability and controllability of each node;

[0013] S4: constructing the fault recovery model of the power distribution system based on the emergency communication model, the operation constraints of the reconfigurable intelligent soft switch R-SOP and the fault flow constraints of the power distribution system, and solving the fault recovery model by using a mixed integer nonlinear programming solver to obtain the fault recovery scheme and the voltage of the power distribution system during the fault recovery period, and outputting the fault recovery scheme, including: the unmanned aerial vehicle scheduling scheme during the entire fault recovery period, the active power scheduling scheme of the reconfigurable intelligent soft switch R-SOP, and the action of the controllable switch;

[0014] S5: based on the voltage of the power distribution system during the fault recovery period, establishing a centralized droop control voltage regulation model under time scale reduction, and solving the centralized droop control voltage regulation model by using a mixed integer nonlinear programming solver, so as to obtain the reactive power output of the reconfigurable intelligent soft switch R-SOP and photovoltaic, and used for regulating the real-time voltage of the power distribution system.

[0015] The power distribution system fault recovery and fault voltage regulation method based on measurement dependence has the characteristics that the S1 includes:

[0016] S1-1: constructing the path constraints of the unmanned aerial vehicle by using formula (1)-(4):

[0017] (1)

[0018] (2)

[0019] (3)

[0020] (4)

[0021] In formula (1)-(4), and respectively represent a set of communication failure points and a set of UAVs in a power distribution system; represents whether the rth UAV arrives at a communication failure point from a starting point ; ; represents whether the rth UAV arrives at an ending point from a communication failure point ; ; represents whether the rth UAV arrives at a communication failure point from a communication failure point ; ; and represent a starting point and an ending point of a small base station;

[0022] S1-2: Constructing time constraints of DSCs using formula (5)-(8)

[0023] (5)

[0024] (6)

[0025] (7)

[0026] (8)

[0027] In formula (5)-(8), is a time point at which the rth UAV leaves a communication failure point ; is a time point at which the rth UAV leaves a communication failure point ; is a time point at which the rth UAV leaves a communication failure point ; is a time spent by the rth UAV in repairing a communication failure point ; is a time spent by the rth UAV in moving between communication failure points and ; is a constant;

[0028] S1-3: Constructing a correspondence formula between time points and scheduled times using formula (9)-(11)

[0029] (9)

[0030] (10)

[0031] (11)

[0032] in formula (9) - formula (11), is an indicator variable, indicating the communication failure point whether in the dispatch period resumes communication, if is 1, indicating the communication failure point in the dispatch time resumes communication; if is 0, indicating the communication failure point not in the dispatch time resumes communication; is a constant; is a failure duration period; is an optimization time interval;

[0033] S1-4: constraints between the indicator variable and the line state are constructed using formula (12) - formula (13):

[0034] (12)

[0035] (13)

[0036] in formula (12) - formula (13), is the communication failure point in the dispatch period is the state, if is 1, indicating the communication failure point in the dispatch period has resumed communication, if is 0, indicating the communication failure point in the dispatch period is in a failure state; indicates a line set affected by the communication failure point; indicates a line in the dispatch period connectivity state; indicates the communication failure point whether in the period resumes communication.

[0037] The S3 includes:

[0038] S3-1: the running constraints of the R-SOP are constructed:

[0039] S3-1-1: feeder selection constraints are constructed using formula (14) - formula (15):

[0040] (14)

[0041] (15)

[0042] in formula (14) - formula (15), is the node The voltage source inverters at the feeder where the node Reside have a total capacity at the dispatch period is a binary variable representing whether the nth voltage source inverter is connected to the feeder where the node Resides; is the capacity of the nth voltage source inverter; is the set of voltage source inverters; is the set of feeders to which the voltage source inverters are selected to be connected;

[0043] S3-1-2: Construct the power dispatch constraints using formula (16) - formula (20):

[0044] (16)

[0045] (17)

[0046] (18)

[0047] (19)

[0048] (20)

[0049] in formula (16) - formula (20), and is the active power and reactive power of the nth voltage source inverter DC side at the dispatch period ; and is the active power and reactive power transmitted by the voltage source inverters connected to the node at the dispatch period ; is the active power loss of the voltage source inverters connected to the node at the dispatch period ; is the loss coefficient of the voltage source inverters; is the communication status of the voltage source inverters connected to the node at the dispatch period t; is the maximum output reactive power of the voltage source inverters connected to the node ;

[0050] S3-1-3: When the voltage When the control is in effect, the voltage constraint of the faulty side VSC is constructed by using equation (21) to provide voltage support for the fault area.

[0051] (21)

[0052] In equation (21), is the voltage source inverter connected to node the port voltage of the voltage source inverter connected to node is the lower limit of the voltage of the preset faulty side voltage source inverter;

[0053] S3-2: Construct the fault flow constraint:

[0054] S3-2-1: Construct the line state constraint containing controllable switches by using equation (22):

[0055] (22)

[0056] In equation (22), is the line between node and node j; is the on-off state of line at the scheduling period t; and are the nodes and node at both ends of line ; is the communication control signal state of node at the scheduling period t,

[0057] S3-2-2: Construct the on-off state constraint of the voltage source inverter by using equation (23):

[0058] (23)

[0059] In equation (23), is the communication state of the voltage source inverter connected to node k at the scheduling period t;

[0060] S3-2-3: Construct the fault flow constraint of the R-SOP distribution system by using equations (24)-(33):

[0061] (24)

[0062] (25)

[0063] (26)

[0064] (27)

[0065] (28)

[0066] (29)

[0067] (30)

[0068] (31)

[0069] (32)

[0070] (33)

[0071] in formula (24) - formula (33), and are the active power and the reactive power transmitted by the line in the scheduling period t; and are the active power and the reactive power transmitted by the line in the scheduling period t; and denote the active power and the reactive power injected into the node in the scheduling period t; is the current transmitted by the line in the scheduling period t; and are the resistance and the reactance of the branch ; and are the active power and the reactive power forecast of the photovoltaic at the node in the scheduling period t; and are the active power and the reactive power of the node in the scheduling period ; denotes the energized state of the node in the scheduling period t; and are the de-energized active power and the de-energized reactive power of the node in the scheduling period t; is the voltage of the node in the scheduling period t; is the voltage of the node in the scheduling period t; and are the upper and lower limits of the voltage of the power distribution system; For nodes The capacity of the photovoltaic system connected to the location; branch road The transmission power capacity; It is a set of nodes in the power distribution system; A collection of power distribution system lines; For photovoltaic arrays;

[0072] S3-2-4: Construct the actual power constraints of each node during the recovery process using equations (34)-(35):

[0073] (34)

[0074] (35)

[0075] The fault recovery model for the power distribution system in S4 includes:

[0076] S4-1: Objective function for constructing the fault recovery model of the power distribution system using equation (36) :

[0077] (36)

[0078] In equation (36), , , These represent the active power lost due to power failure, the network power loss, and the cost coefficient of the drone, respectively.

[0079] S4-2: Constraints for constructing the fault recovery model of the power distribution system, including: emergency communication constraints, R-SOP operation constraints, fault power flow constraints, fault reconfiguration constraints, and energy-saving voltage reduction load constraints.

[0080] Construct CVR load constraints using equations (38)-(41):

[0081] P t , k L = P ¯ t , k L ⋅ [ β p 1 ( U t , k U ref ) 2 + β p 2 ( U t , k U ref ) + β p 3 ] , ∀ t , k (37)

[0082] Q t , k L = Q ¯ t , k L ⋅ [ β q 1 ( U t , k U ref ) 2 + β q 2 ( U t , k U ref ) + β q 3 ] , ∀ t , k (38)

[0083] (39)

[0084] (40)

[0085] In equations (37)-(40), and They are nodes During the scheduling period The preset active and reactive power; Vn is the voltage of node n; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vref is the voltage reference of the power distribution system; , , Pf, Qf, and Ppf are the constant impedance, constant current, and constant power percentage of active power, respectively; , , Pf, Qf, and Ppf are the constant impedance, constant current, and constant power percentage of active power, respectively.

[0086] The centralized droop control voltage regulation model in S5 includes:

[0087] S5-1: Reduce the time scale, and use formula (41) to construct the objective function of the centralized droop control voltage regulation model :

[0088] (41)

[0089] In formula (41), and are the weighted coefficients of network loss and voltage deviation, respectively; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period;

[0090] S5-2: Use formula (42) to construct the centralized droop control constraints of voltage source inverters and photovoltaics:

[0091] (42)

[0092] In formula (42), are the six voltage values corresponding to the six points on the droop control curve, where , ; Qinv is the reactive power output of the voltage source inverter and photovoltaic in the fault recovery stage; Qmax is the upper limit of the reactive power output of the voltage source inverter and photovoltaic; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period; Vn is the voltage of node n at dispatch period;

[0093] The electronic equipment comprises a memory and a processor, and is characterized in that the memory is used for storing a program supporting the processor to execute the power distribution system fault recovery and fault voltage regulation method, and the processor is configured to execute the program stored in the memory.

[0094] The computer readable storage medium stores a computer program, and the computer program is executed by a processor to execute the steps of the power distribution system fault recovery and fault voltage regulation method.

[0095] Compared with the prior art, the power distribution system recovery framework considering the measurement dependence based on information layer and physical layer information quantity has the beneficial effects that:

[0096] 1、The power distribution system recovery framework considering the measurement dependence based on information layer and physical layer information quantity is proposed, which considers the serious influence of communication layer failure on the observability and controllability of the power distribution system, establishes an emergency communication model based on a UAV base station, provides reliable communication guarantee for the development of the optimal recovery strategy of the power distribution system, and thus improves the rationality of the optimal recovery strategy applied to the post-disaster power distribution system.

[0097] 2、The power distribution system fault recovery model based on CVR and coordinated with R-SOP and dynamic reconstruction is established, which firstly proposes to promote the rapid recovery of the power outage load of the power distribution system by coordinating R-SOP, CVR and fault reconstruction, and thus effectively improves the fault recovery level of the power distribution system.

[0098] 3、The real-time voltage regulation strategy based on droop control real-time adjustment of system reactive power is proposed, which considers the voltage problems caused by system uncertainty, frequent changes of system topology and CVR, and thus establishes a real-time voltage regulation model based on droop control in a more fine time granularity, adjusts the reactive power resources in the system in real time, reduces the voltage fluctuation in the recovery process, and guarantees the real-time voltage safety performance in the recovery process. BRIEF DESCRIPTION OF DRAWINGS

[0099] Figure 1 is a schematic diagram of the power distribution system resilience improvement strategy framework based on measurement dependence;

[0100] Figure 2 is a schematic diagram of the cyber-physical power distribution system structure;

[0101] Figure 3 is a schematic diagram of the R-SOP topology structure;

[0102] Figure 4 is a droop control curve of the VSC and PV inverter;

[0103] Figure 5This is a diagram showing the establishment and dynamic reconfiguration results of emergency communication in the IEEE 33-node system.

[0104] Figure 6 This is a schematic diagram showing the results of power loss load restoration;

[0105] Figure 7 It is a controllable resource control diagram within the power distribution system, including: (a) R-SOP active power; (b) R-SOP reactive power; (c) VSCs port capacity; (d) PVs reactive power diagram;

[0106] Figure 8 It is a voltage diagram of the power distribution system, including: (a) the voltage extreme values ​​of each node; (b) the probability distribution diagram of the voltage deviation of each node;

[0107] Figure 9 This is a schematic diagram of the control modes of each port of the R-SOP;

[0108] Figure 10 This represents the load recovery rate for each case. Detailed Implementation

[0109] In this embodiment, to dynamically complete the power distribution system fault recovery and ensure voltage safety during the recovery process, a measurement-dependent power distribution system fault recovery and fault voltage regulation method is proposed, such as... Figure 1 As shown, the method includes the following steps:

[0110] S1: Construct an emergency communication model based on UAVs and small base stations, including: path constraints and time constraints for UAVs;

[0111] S1-1: Constructing path constraints for the UAV using equations (1)-(4):

[0112] (1)

[0113] (2)

[0114] (3)

[0115] (4)

[0116] In equations (1)-(4), and These are, respectively, a set of communication fault points in the power distribution system and a set of unmanned aerial vehicles (UAVs); Indicates whether the r-th drone started from the starting point. Arrival at the communication failure point ; Indicates whether the r-th drone has escaped from the communication failure point. Reach the finish line ; denotes whether the rth UAV reaches the communication failure point from the communication failure point ; and denote the start point and the end point of the small base station.

[0117] S1-2: Time constraints for constructing DSCs using formula (5)-(8):

[0118] (5)

[0119] (6)

[0120] (7)

[0121] (8)

[0122] In formula (5)-(8), is the time point at which the rth UAV leaves the communication failure point ; is the time point at which the rth UAV leaves the communication failure point ; is the time point at which the rth UAV leaves the communication failure point ; is the time spent by the rth UAV in repairing the communication failure point ; is the time spent by the rth UAV in moving between the communication failure point and ; is a constant.

[0123] S1-3: Corresponding relationship between time points and scheduling time using formula (9)-(11):

[0124] (9)

[0125] (10)

[0126] (11)

[0127] In formula (9)-(11), is an indicator variable, which denotes whether the communication failure point restores communication at the scheduling time period , if is 1, it indicates that the communication failure point restores communication at the scheduling time ; if 0, indicating the communication fault point not in the scheduling time resumes communication; is a constant; is a fault duration period; is an optimization time interval.

[0128] S1-4: constraints between the indicator variables and the line states are constructed using formula (12)-(13):

[0129] (12)

[0130] (13)

[0131] In formula (12)-(13), 0, indicating the communication fault point in the scheduling period , if 1, indicating the communication fault point in the scheduling period , if 0, indicating the communication fault point in the scheduling period is in a fault state; represents a set of lines affected by the communication fault point; represents the connectivity state of the line in the scheduling period between node k and node j; 0, indicating the communication fault point whether the communication has been restored in the period .

[0132] S2: according to the data transmission channel of each node in the power distribution system and the state of the communication line, the observability and controllability of each node are determined:

[0133] As shown in Figure 2 , after the fault occurs, the nodes of the power distribution system have three operating states:

[0134] If the data transmission channel of the node and the communication line between the nodes are not damaged by the fault, it indicates that the corresponding node has observability and controllability;

[0135] If the data transmission channel of the node is not damaged by the fault, but the communication line between the nodes is damaged by the fault, it indicates that the corresponding node has observability, but does not have controllability;

[0136] If the data transmission channel of the node is damaged by the fault, it indicates that the corresponding node does not have observability and controllability.

[0137] S3: Based on the observable and controllable state of each node, construct the operation constraints of the reconfigurable intelligent soft switch R-SOP and the fault flow constraints of the power distribution system.

[0138] S3-1: Combination Figure 3 As shown, the operational constraints for constructing R-SOP are:

[0139] S3-1-1: Construct feeder selection constraints using equations (14) and (15):

[0140] (14)

[0141] (15)

[0142] In equations (14)-(15), For nodes The voltage source inverter at the feeder location is during the dispatch period. Total capacity; To indicate the first Is the voltage source inverter connected to the node? The binary variable of the feeder in which it is located; For the first The capacity of the voltage source inverter; A collection of voltage source inverters; The set of feeders selected for connection to the voltage source inverter.

[0143] S3-1-2: Constructing power scheduling constraints using equations (16)-(20):

[0144] (16)

[0145] (17)

[0146] (18)

[0147] (19)

[0148] (20)

[0149] In equations (16)-(20), and For the DC side of the nth voltage source inverter during the dispatch period Active power and reactive power; and For nodes The connected voltage source inverter during the dispatch period Transmitted active and reactive power; For nodes The connected voltage source inverter during the dispatch period Active power loss; The loss factor of the voltage source inverter; For nodes The communication status of the connected voltage source inverter during scheduling period t; For nodes The maximum output reactive power of the connected voltage source inverter.

[0150] S3-1-3: When using voltage During control, the voltage constraint of the fault-side VSC is constructed using equation (21) to provide voltage support for the fault area;

[0151] (twenty one)

[0152] In equation (21), For nodes The port voltage of the connected voltage source inverter during the scheduling period t; This is to preset the lower voltage limit of the fault-side voltage source inverter.

[0153] S3-2: Constructing fault flow constraints:

[0154] S3-2-1: Constructing line state constraints with controllable switches using equation (22):

[0155] (twenty two)

[0156] In equation (22), Represents a node The line between node j The on / off status during scheduling period t; Indicates the line The on / off state during the initial period; and They represent the lines respectively. Nodes at both ends and nodes The status of communication control signals during scheduling period t. A collection containing controllable switch circuits; Representation and operation.

[0157] S3-2-2: Constructing the on / off state constraints of the voltage source inverter using equation (23):

[0158] (twenty three)

[0159] In equation (23), communication state of the voltage source inverter connected to node k at dispatch period t;

[0160] S3-2-3: Construct the fault flow constraints of the R-SOP containing power distribution system by using formula (24)-(33):

[0161] (24)

[0162] (25)

[0163] (26)

[0164] (27)

[0165] (28)

[0166] (29)

[0167] (30)

[0168] (31)

[0169] (32)

[0170] (33)

[0171] In formula (24)-(33), and are the active power and reactive power transmitted by line at dispatch period t; and are the active power and reactive power transmitted by line at dispatch period t; and represent the active power and reactive power injected into node at dispatch period t; is the current transmitted by line at dispatch period t; and are the resistance and reactance of branch ; and are the active power and reactive power prediction values of photovoltaic at node at dispatch period t; and are the active power and reactive power of node at dispatch period ; representing nodes on-off status on scheduling period t; and representing nodes active power and reactive power of off on scheduling period t; representing nodes voltage on scheduling period t; representing nodes voltage on scheduling period t; and representing voltage upper and lower limits of power distribution system, respectively; representing nodes capacity of photovoltaic connected at representing transmission power capacity of branch representing a set of nodes of power distribution system; representing a set of lines of power distribution system; representing a set of photovoltaics.

[0172] S3-2-4: constructing actual power constraints of each node in the restoration process by using formula (34) - formula (35):

[0173] (34)

[0174] (35).

[0175] S4: constructing a fault restoration model of power distribution system based on emergency communication model, operating constraints of reconfigurable intelligent soft switch (R-SOP), and fault flow constraints of power distribution system, and solving the model by using a mixed integer nonlinear programming solver to obtain unmanned aerial vehicle (UAV) scheduling, R-SOP active power scheduling, action of controllable switch, and power distribution system voltage during the entire fault restoration period;

[0176] S4-1: constructing an objective function of the fault restoration model of power distribution system by using formula (36) :

[0177] (36)

[0178] in formula (36), , , representing off active power, network power loss, and cost coefficient of UAV, respectively.

[0179] S4-2: constructing constraint conditions of the fault restoration model of power distribution system, including: emergency communication constraints, R-SOP operating constraints, fault flow constraints, fault reconstruction constraints, and energy-saving voltage reduction load constraints: ​

[0180] S4-2-1: Construct the CVR load constraint by using formula (38) - formula (41):

[0181] P t , k L = P ¯ t , k L ⋅ [ β p 1 ( U t , k U ref ) 2 + β p 2 ( U t , k U ref ) + β p 3 ] , ∀ t , k (37)

[0182] Q t , k L = Q ¯ t , k L ⋅ [ β q 1 ( U t , k U ref ) 2 + β q 2 ( U t , k U ref ) + β q 3 ] , ∀ t , k (38)

[0183] (39)

[0184] (40)

[0185] In formula (37) - formula (40), and are the preset active power and reactive power of node in the dispatching period ; is the voltage of node in the dispatching period ; is the voltage reference value of the power distribution system; , , are the constant impedance, constant current and constant power percentage of active power, respectively; , , are the constant impedance, constant current and constant power percentage of reactive power, respectively.

[0186] S5: Based on the voltage of the power distribution system during fault recovery, reduce the time scale, construct a voltage regulation model based on centralized droop control, and solve the model by using a mixed integer nonlinear programming solver to obtain the reconfigurable intelligent soft switch R-SOP and the reactive power output of the photovoltaic and the real-time voltage of the power distribution system;

[0187] S5-1: Reduce the time scale, and construct the objective function of the voltage regulation model based on centralized droop control by using formula (41) :

[0188] (41)

[0189] In formula (41), and are the weighted coefficients of network loss and voltage deviation, respectively; is the voltage of line in the dispatching period after reducing the time scale; is the voltage of node in the dispatching period The voltage.

[0190] S5-2: Construct centralized droop control constraints for voltage source inverters and photovoltaics using equation (42):

[0191] (42)

[0192] In equation (42), These are the six voltage values ​​corresponding to six points on the droop control curve, where... , ; This refers to the reactive power output of the voltage source inverter and photovoltaic system during the fault recovery phase. This represents the upper limit of reactive power output for voltage source inverters and photovoltaic systems. For nodes Voltage source inverters and photovoltaics during dispatch periods The reactive power output.

[0193] In this embodiment, an electronic device includes a memory and a processor. The memory stores a program that supports the processor in executing the above-described method, and the processor is configured to execute the program stored in the memory.

[0194] In this embodiment, a computer-readable storage medium stores a computer program, which is executed by a processor to perform the steps of the above method.

[0195] I. Example Description and Simulation Result Analysis;

[0196] 1. Simulation scenario setup:

[0197] To verify the correctness and effectiveness of the fault recovery strategy and model proposed in this invention, a simulation test was conducted using an IEEE 33-node system with a 4-port R-SOP as the test object. The system's reference voltage is 12.66 kV, and the voltage safety range is 0.95-1.05 pu. The system contains one 4-port R-SOP with a total capacity of 2 MVA. The capacity ratio of each VSC port is determined using the golden ratio allocation method set in the invention. In the example, six photovoltaic power generation devices are connected, and their connection locations and capacity settings are shown in Table 1.

[0198] The fault occurs at 8:00, the time interval is set to 15 minutes, and the fault duration is 3 hours. The power distribution system has 4 line faults and 4 communication faults. The devices affected by the communication faults are: sectional switches 14-15, 20-21, and 30-31; tie switches: 9-15, 8-21, and 25-29; PV 30 and VSCs 18, 22, and 33 of R-SOP. The time for establishing emergency communication at the 3 base stations is 21 minutes, 7 minutes, and 12 minutes, respectively.

[0199] Table 1: Location and parameters of devices

[0200]

[0201] 2. Emergency communication establishment and switch action strategy:

[0202] After the fault occurs, the power loss areas 23-25 and 8-18 of the power distribution system are formed, as well as the communication loss areas 20-22, 15-18, and 29-33. Based on the above fault conditions, the power supply recovery of the power loss load is carried out using the fault recovery method proposed in the application, and the emergency communication establishment process and results are shown in Figure 5 Specifically, the two drones prefer to go to the communication faults 28-29 and 15-16 because their communication conditions control the on-off state of the tie switches 9-15 and 25-29, and after the two switches are closed, the power loss nodes can be connected to the main power distribution line. The drone finally goes to the communication fault 19-20 because the on-off state of the tie switch 8-21 controlled by it has a lower effect on fault recovery than the above two tie switches.

[0203] During the recovery process, the communication line recovery and dynamic reconstruction schedule are shown in Table 2. The recovery process of the power loss load and the change of the load recovery rate are shown in Figure 6 Table 4 shows that at the 3rd time, after the control signals of the tie switches 9-15 and 25-29 are recovered, the two tie switches act and coordinate VSCs 12, 18, and 33 to realize power transmission and achieve the recovery of most of the power loss loads, effectively improving the load recovery rate. Among them, the VSC connected with feeder 18 becomes the only source node of the power loss area nodes 16-18, which runs in control mode, acts as a virtual power source for the fault area, and provides voltage support, which cooperates with dynamic reconstruction to promote the recovery of power loss loads.

[0204] Table 2: Communication line recovery and dynamic reconstruction results

[0205]

[0206] The power output of the controllable resources during the recovery process is shown in Figure 7As shown. And combined with Figure 6 As can be seen, after establishing emergency communication to restore the communication signals of some components of the power distribution system at the third moment, and combining the CVR with the VSC and tie switch that coordinate the restoration of communication for fault reconstruction, the power loss load of the power distribution system was quickly restored, and the load recovery rate was greatly improved, which fully demonstrates the effectiveness of the recovery strategy proposed in this invention.

[0207] 3. Voltage conditions:

[0208] During the recovery process, the voltage extreme values ​​and voltage deviation probability distribution of each node in the system are as follows: Figure 8 As shown. By Figure 8 It can be seen that by adjusting the reactive power regulation voltage of PVs and R-SOP in real time through droop control, the voltage during fault recovery can be kept within the safe range of [0.95, 1.05] pu. Furthermore, the voltage amplitude of most nodes is within 1.0 pu during the real-time phase. It can be concluded that real-time voltage regulation can effectively solve the problem of low voltage caused by CVR and the problem of voltage exceeding limits caused by system uncertainties.

[0209] 4. R-SOP support function:

[0210] During the recovery process, the control modes of each port of R-SOP are as follows: Figure 9 As shown. And combined with Figure 7 Part (c) shows that R-SOP can dynamically allocate the total capacity of VSCs connected to each feeder according to the actual power transmission demand of the feeders during operation. In the first two fault periods, all ports of R-SOP lose communication signals and emergency communication is not established; therefore, the capacity of each port of R-SOP is 0. In the third and fourth time periods, VSC33 is connected to the main grid, and node 33 is located at the end of the system with low voltage and high reactive power demand; therefore, the port capacity of VSC is large. VSC12 and VSC18 become the only source nodes in their respective power outage areas, operating in... Control mode. VSC33 transmits power to ports VSC12 and VSC18. Due to the different load demands of each node, and the presence of multiple PVs in the power outage area where VSC12 is located, VSC18 has a greater power transmission demand; therefore, its port capacity level is greater than that of VSC12. During times 5-12, port VSC22 resumes communication and connects to the main network through fault reconfiguration. Its power outage area also connects to the main network; therefore, VSC12 no longer operates in... Control mode. However, power-depleted nodes 16-18 consistently cannot connect to the main network, and VSC18 remains the sole source node in that area, always operating in [control mode]. Control mode. Each port dynamically allocates total capacity based on the load demand of nodes in its connected areas.

[0211] 5. Comparative cases:

[0212] To verify the superiority of the recovery strategy proposed in the present application, four cases are additionally set for comparative study:

[0213] Case 1: Without considering the establishment of emergency communication, the power supply system is restored, which is used as a control group for other cases;

[0214] Case 2: On the basis of the establishment of emergency communication, the optimal restoration of the power supply system is coordinated by symmetrical SOP and network reconstruction;

[0215] Case 3: On the basis of the establishment of emergency communication, the optimal restoration of the power supply system is coordinated by R-SOP and network reconstruction;

[0216] Case 4: On the basis of the establishment of emergency communication, the optimal restoration of the power supply system is coordinated by R-SOP and network reconstruction based on CVR technology;

[0217] Case 5: The measurement-dependent fault restoration method proposed in the present application.

[0218] In combination with Table 3 and Figure 10 Analysis shows that Case 1 cannot realize the power supply restoration of the outage load. Because Case 1 does not consider the establishment of emergency communication, the tie switches and the VSC ports cannot accept the communication signals, the tie switches cannot be actuated for dynamic reconstruction, and the VSCs cannot output power for the outage nodes, so the outage load cannot be restored for power supply, which shows the necessity of considering the establishment of emergency communication. By comparing Case 2 and Case 3, it can be seen that Case 3 realizes the flexible allocation of VSC capacity by virtue of the reconfigurable design of R-SOP, improves the transmission power of SOP, and the amount of lost load is 0.2993 MWh less than that of Case 2, and the load restoration rate is also higher than that of Case 2 after the communication is restored. In addition, the voltage deviation of Case 3 is also smaller than that of Case 2, which shows that R-SOP has more accurate and flexible power flow control capability and can reduce the voltage deviation of the system.

[0219] Table 3 Restoration results of each case

[0220]

[0221] Compared with Case 3, Case 4 effectively reduces the load outage by using CVR technology, but also causes the problem of increasing the system voltage out-of-limit rate and voltage deviation. Compared with the above cases, Case 4 adopts the restoration strategy of power distribution system based on emergency communication establishment considering R-SOP and CVR, which effectively promotes the power supply recovery of outage load by coordinating controllable switches and R-SOP for dynamic reconfiguration. And considering the uncertainty in the recovery process and the problem of low node voltage caused by CVR, Case 4 carries out real-time voltage regulation based on droop control, greatly reduces the system voltage deviation by adjusting the output power of R-SOP and PVs, and achieves zero voltage out-of-limit of nodes, ensuring the voltage safety performance in the recovery process.

Claims

1. A method for measurement-dependent based power distribution system fault restoration and fault voltage regulation, comprising: The method comprises the following steps: S1: constructing an emergency communication model based on a UAV and a small base station, including path constraints and time constraints of the UAV; S2: judging the observability and controllability of each node according to the state of the data transmission channel of each node in the power distribution system and the communication line, wherein if the data transmission channel of the node and the communication line between the nodes are not damaged by the fault, the corresponding node has observability and controllability; if the data transmission channel of the node is not damaged by the fault, but the communication line between the nodes is damaged by the fault, the corresponding node has observability but does not have controllability; and if the data transmission channel of the node is damaged by the fault, the corresponding node does not have observability and controllability; S3: constructing operation constraints of a reconfigurable intelligent soft switch R-SOP and fault flow constraints of the power distribution system according to the observability and controllability of each node; S4: constructing a fault recovery model of the power distribution system based on the emergency communication model, the operation constraints of the reconfigurable intelligent soft switch R-SOP and the fault flow constraints of the power distribution system, and solving the fault recovery model by using a mixed integer nonlinear programming solver to obtain a fault recovery scheme and a voltage of the power distribution system during the fault recovery, and outputting the fault recovery scheme, including a UAV scheduling scheme during the entire fault recovery period, an active power scheduling scheme of the reconfigurable intelligent soft switch R-SOP, and an action of a controllable switch; S4-2: constructing constraint conditions of the fault recovery model of the power distribution system, including emergency communication constraints, R-SOP operation constraints, fault flow constraints, fault reconstruction constraints and energy-saving voltage reduction load constraints: CVR load constraints are constructed by using formulas (38)-(41): S5: establishing a centralized droop control voltage regulation model in a time scale reduction based on the voltage of the power distribution system during the fault recovery, and solving the centralized droop control voltage regulation model by using a mixed integer nonlinear programming solver, so as to obtain reactive power output of the reconfigurable intelligent soft switch R-SOP and photovoltaic, and regulate real-time voltage of the power distribution system; S4-1 : Constructing an objective function of a fault restoration model of a power distribution system using Equation (36) : (36) in formula (36), , , Pd, Pn, and C represent the loss of active power, the network power loss, and the cost coefficient of the UAV, respectively; tr represents the time spent by the rth UAV moving between the communication failure points and ; and are the set of communication failure points in the distribution system and the set of UAVs, respectively; is the set of feeder lines to which the voltage source inverters are connected; Pn represents the active power loss of the nth voltage source inverter in the scheduling period ; is the loss coefficient of the voltage source inverter; Pd represents the loss of active power at node in the scheduling period t; is the set of nodes in the distribution system; is the set of lines in the distribution system; is the duration of the fault; is the optimization time interval; is the current transmitted by the line in the scheduling period t; is the resistance of the branch ; S5-2: constructing centralized droop control constraints of the voltage source inverter and the photovoltaic by using formula (42): The S1 comprises: (37) (38) (39) (40) in formulas (37) - (40), and are the active power and the reactive power of the line at the scheduling period t; are the preset active power and the preset reactive power of the node at the scheduling period t; are the voltage of the node at the scheduling period t; is the voltage reference of the power distribution system; , , are the constant impedance, the constant current and the constant power percentage of the active power, respectively; , , are the constant impedance, the constant current and the constant power percentage of the reactive power, respectively; is the voltage of the node at the scheduling period t; and are the active power and the reactive power of the line transmitted at the scheduling period t; S1-1: constructing path constraints of the UAV by using formulas (1)-(4): S5-1: Reduce the time scale, and construct the objective function of the centralized droop control voltage regulation model using equation (41) : (41) In equation (41), and These are the weighting factors for network loss and voltage deviation, respectively. For the line Scheduling period after narrowing the time scale The voltage; For nodes During the scheduling period The voltage; S1-2: constructing time constraints of the DSCs by using formulas (5)-(8) (42) In formula (42), are six voltage values corresponding to the six points on the droop control curve, wherein, , ; is the reactive power output of the voltage source inverter and the photovoltaic in the fault recovery phase; is the upper limit of the reactive power output of the voltage source inverter and the photovoltaic; is the reactive power output of the voltage source inverter and the photovoltaic at the node in the dispatching period .

2. The measurement-dependence based power distribution system fault restoration and fault voltage regulation method according to claim 1, wherein, S1-3: constructing a corresponding relationship between time points and scheduling times by using formulas (9)-(11): S1-4: constructing constraints between the indicator variables and the line states by using formulas (12)-(13): (1) (2) (3) (4) in formulas (1) - (4), denotes whether the rth drone reaches the communication failure point from the starting point ; denotes whether the rth drone reaches the end point from the communication failure point ; denotes whether the rth drone reaches the communication failure point from the communication failure point ; and denote the starting point and the end point of the small base station;​​​ The S3 comprises: (5) (6) (7) (8) in formulae (5) to (8), the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; the point in time at which the rth drone leaves the communication failure point; S3-1: constructing operation constraints of the R-SOP: (9) (10) (11) In formulas (9) - (11), is an indicator variable, indicating a communication failure point is 1, indicating a communication failure point is 0, indicating a communication failure point is 1, indicating a communication failure point is 0, indicating a communication failure point is 1, indicating a communication failure point is 0, indicating a communication failure point is 1, indicating a communication failure point is 0, indicating a communication failure point is a constant S3-1-1: constructing feeder selection constraints by using formulas (14)-(15): (12) (13) in formulas (12) - (13), is a communication failure point in the scheduling period is in a state of recovered communication in the scheduling period is 1, indicating that the communication failure point is in a state of recovered communication in the scheduling period is 0, indicating that the communication failure point is in a state of failure in the scheduling period is in a state of failure in the scheduling period ; represents a set of lines affected by the communication failure point; represents a line between node k and node j is in a state of communication in the scheduling period ; represents whether the communication failure point has recovered communication in the period .

3. The measurement-dependence based power distribution system fault restoration and fault voltage regulation method according to claim 2, wherein, S3-1-2: constructing power scheduling constraints by using formulas (16)-(20): S3-2: constructing fault flow constraints: S3-2-1: constructing line state constraints containing controllable switches by using formula (22): (14) (15) In equations (14)-(15), For nodes The voltage source inverter at the feeder location is during the dispatch period. Total capacity; To indicate the first Is the voltage source inverter connected to the node? The binary variable of the feeder in question; For the first The capacity of a voltage source inverter; A collection of voltage source inverters; S3-2-2: constructing on-off state constraints of the voltage source inverter by using formula (23): (16) (17) (18) (19) (20) in formulas (16)-(20), and is the active power and reactive power transmitted by the voltage source inverter connected to node at the dispatch period and is the active power and reactive power transmitted by the voltage source inverter connected to node at the dispatch period ; is the communication state of the voltage source inverter connected to node at the dispatch period t; is the maximum output reactive power of the voltage source inverter connected to node ; S3-1-3: When employing voltage control, the voltage constraint of the faulty side VSC is constructed using equation (21) to provide voltage support for the fault region; (21) In formula (21), is a node a voltage source inverter connected to the node is a voltage lower limit of the preset faulty side voltage source inverter; ​ ​ (22) in formula (22), representing a node and a line between node i and node j the on-off state at scheduling period t; representing a line the on-off state at an initial period; and representing a line between two nodes and node the communication control signal state at scheduling period t, a set containing controllable switch lines; representing an operation; ​ (23) In formula (23), is the communication state of the voltage source inverter connected to node k at dispatch period t; S3-2-3: Construct the fault flow constraints of the R-SOP containing power distribution system by using formula (24) - formula (33): (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) PQ(t) = PQ(t) + PQ(t) (24) - (33) and respectively represent the active power and the reactive power injected into the node at the dispatch period t; and respectively represent the active power and the reactive power injected into the node at the dispatch period t; is the reactance of the branch ; and are the active power and the reactive power prediction of the photovoltaic at the node at the dispatch period t; and are the active power and the reactive power of the node at the dispatch period ; represents the energized state of the node at the dispatch period t; is the de-energized reactive power of the node at the dispatch period t; is the voltage of the node at the dispatch period t; and are the upper and lower limits of the voltage of the power distribution system; is the capacity of the photovoltaic connected at the node ; is the transmission power capacity of the branch ; is the set of photovoltaics; S3-2-4: Construct the actual power constraints of each node in the recovery process by using formula (34) - formula (35): (34) (35)。 4. An electronic device comprising a memory and a processor, characterized in that The memory is configured to store a program supporting the processor to execute the power distribution system fault recovery and fault voltage regulation method of any one of claims 1-3, and the processor is configured to execute the program stored in the memory.

5. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to perform the steps of the power distribution system fault recovery and fault voltage regulation method of any one of claims 1-3.

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