Wind-fire bundling power angle stability analysis method and system, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a wind-thermal bundling power angle stability analysis method and system, electronic equipment and a storage medium, and belongs to the technical field of power systems. According to the scheme, the power loss on the current collection line is calculated according to the voltage difference between adjacent units on the current collection line, and a wind power plant output model considering power distribution is obtained; carrying out equivalent transformation on the wind power plant output model to obtain a wind-thermal bundled equivalent model; establishing an electromagnetic torque model based on the wind-fire bundling equivalent model, and respectively establishing a rotor motion model from three times before fault occurrence, during fault occurrence and recovery and after fault recovery to obtain a wind-fire bundling power angle model; determining an operation power angle and a maximum stable power angle of the generator through a wind-fire bundling power angle model; and stability judgment is carried out according to the generator operation power angle and the maximum stable power angle, and a power angle stability analysis result is determined. According to the scheme, the power distribution and fault control and recovery process of each unit of a large-scale wind power plant can be considered, and the accuracy of wind-fire bundling power angle stability analysis is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method, system, electronic device and storage medium for analyzing the stability of wind-fire bundled power angles. Background Art

[0002] In recent years, wind power technology has developed rapidly, and the scale of wind power grid connection has increased year by year. The access of large-scale renewable energy has reduced the startup of synchronous units on the one hand, and the rapid control and response characteristics of power electronic equipment on the other hand will have an important impact on the transient stability of the power grid. The wind-fire bundling method is currently a common large-scale renewable energy transmission method, which can improve the consumption of renewable energy and reduce wind abandonment.

[0003] At present, in order to simplify the analysis model and speed up the simulation, relevant technologies usually equate the wind farm to one or more units with exactly the same operating status when modeling the power angle stability of wind-fire bundling. However, this simplification ignores the power distribution within the wind farm, resulting in the model being unable to accurately reflect the actual situation when the power distribution of the units within the wind farm changes or fails, which in turn affects the power angle stability analysis results of the wind-fire bundling system and brings potential risks to the safe and stable operation of the power grid. Summary of the invention

[0004] The main purpose of the embodiments of the present application is to propose a method, system, electronic device and storage medium for analyzing the power angle stability of a wind-fire bundle, aiming at a large-scale wind-fire bundle system, taking into account the power distribution of each wind turbine in a large-scale wind farm and the fault control and recovery process, to improve the accuracy of the wind-fire bundle power angle stability analysis.

[0005] To achieve the above purpose, one aspect of an embodiment of the present application provides a method for analyzing the stability of wind-fire bundling power angle, the method comprising:

[0006] The power loss on the collector line is calculated based on the voltage difference between adjacent units on the collector line, and the wind farm output model considering power distribution is obtained;

[0007] Performing an equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model;

[0008] An electromagnetic torque model is established based on the wind-fire bundling equivalent model, and rotor motion models are established at three times: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model;

[0009] Determine the generator operating power angle and maximum stable power angle through the wind-fire bundle power angle model;

[0010] A stability judgment is performed based on the generator operating power angle and the maximum stable power angle to determine a power angle stability analysis result.

[0011] In some embodiments, before the step of calculating the power loss on the collector line according to the voltage difference between adjacent units on the collector line to obtain a wind farm output model that considers power distribution, the wind-fire bundle power angle stability analysis method further includes the following steps:

[0012] Based on the output characteristics of the unit before the fault occurs and after the fault is recovered, the output characteristics of the unit during the fault occurrence and recovery are determined according to the preset proportional coefficient;

[0013] Wherein, the step of determining the output characteristics of the unit during the occurrence and recovery of a fault according to a preset proportionality coefficient based on the output characteristics of the unit before the fault occurs and after the fault is recovered comprises the following steps:

[0014] Based on the active power of the first unit of the unit before the fault occurs, determine the active power of the second unit of the unit when the fault occurs according to a preset active coefficient;

[0015] Based on the unit port voltage and the preset fault voltage reference value, determining the reactive power of the first unit of the unit when the fault occurs according to the preset reactive coefficient;

[0016] Determine the recovery type of the fault recovery, when the recovery type is slope recovery, determine the active power of the third unit of the unit in the recovery process based on the active power of the second unit according to a preset slope coefficient; or, when the recovery type is immediate recovery, determine the active power of the fourth unit of the unit after the fault recovery as the active power of the third unit of the unit in the fault recovery process;

[0017] The output characteristics of the units during fault occurrence and recovery are obtained according to the active power of the second unit, the reactive power of the first unit and the active power of the third unit.

[0018] In some embodiments, the step of calculating the power loss on the collector line according to the voltage difference between adjacent units on the collector line to obtain a wind farm output model that takes power distribution into consideration comprises the following steps:

[0019] A voltage difference model is established according to the voltage difference between adjacent units on the collector line;

[0020] Transforming the voltage difference model to obtain a power loss model between adjacent units;

[0021] Calculate the power loss on the collector line according to the power loss model to obtain a collector line power model;

[0022] The output characteristics of a wind farm with multiple collectors are derived according to the collector power model, and a wind farm output model considering power distribution is obtained.

[0023] In some embodiments, performing equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model comprises the following steps:

[0024] The wind farm output model is equivalent to a wind farm negative impedance model;

[0025] A Y-type equivalent impedance model of the wind-fire bundling system is established based on the negative impedance model of the wind farm, wherein the three sides of the Y-type equivalent model are the thermal impedance, the negative impedance of the wind farm and the transmission line impedance;

[0026] The Y-type equivalent impedance model is subjected to trigonometric transformation to obtain a wind-fire bundling equivalent model, wherein the three sides of the wind-fire bundling equivalent model are electromagnetic impedance, the first ground impedance and the second ground impedance, and the expression of the trigonometric transformation is:

[0027]

[0028]

[0029]

[0030] In the formula, Z 电磁 is the electromagnetic impedance, Z 接地1 is the first grounding impedance, Z 接地2 is the second grounding impedance, Z 火电 is the fire resistance, Z 线路 is the output line impedance, Z 风电 is the negative impedance of the wind farm.

[0031] In some embodiments, the electromagnetic torque model is established based on the wind-fire bundling equivalent model, and the rotor motion model is established from three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain the wind-fire bundling power angle model, including the following steps:

[0032] Based on the wind-fire bundling equivalent model, the relationship between electromagnetic power and generator power angle is established to obtain the electromagnetic torque model, wherein the expression of the electromagnetic torque model is:

[0033]

[0034] Where P 电磁 is the electromagnetic power, E′ is the generator electromotive force, δ is the generator power angle, and U is the collector bus voltage;

[0035] According to the balance relationship between the mechanical power of the generator and the electromagnetic power of the generator before the fault occurs, the first rotor motion equation before the fault occurs is established, wherein the expression of the first rotor motion equation is:

[0036]

[0037] Where, T J is the generator inertia time constant, dω / dt represents the rate of change of the rotor electrical angular velocity, P 前_m is the mechanical power of the generator before the fault occurs, P 前_e is the electromagnetic power of the generator before the fault occurs;

[0038] According to the power difference between the mechanical power of the generator and the electromagnetic power of the generator during the fault occurrence and recovery, a second rotor motion equation with increased power angle during the fault occurrence and recovery is established, wherein the expression of the second rotor motion equation is:

[0039]

[0040] Where dδ / dt represents the rate of change of the generator power angle, ω is the per unit value of the rotor electrical angular velocity, ω0 is a constant 2*π*50, and P 故障 _ m is the mechanical power of the generator during fault occurrence and recovery, P 故障 _ e It is the electromagnetic power of the generator during fault occurrence and recovery;

[0041] According to the power difference between the mechanical power of the generator and the electromagnetic power of the generator after the fault is restored, a third rotor motion equation with a reduced power angle after the fault is restored is established, wherein the expression of the third rotor motion equation is:

[0042]

[0043] Where P 后 _m is the mechanical power of the generator after fault recovery, P 后 _e is the electromagnetic power of the generator after fault recovery;

[0044] Obtaining a rotor motion model according to the first rotor motion equation, the second rotor motion equation and the third rotor motion equation;

[0045] The wind-fire bundling power angle model is obtained according to the electromagnetic torque model and the rotor motion model.

[0046] In some embodiments, the determining the generator operating power angle and the maximum stable power angle by using the wind-fire bundling power angle model comprises the following steps:

[0047] According to the first rotor motion equation, the initial generator power angle and initial speed of the wind-fire bundling system in steady-state operation before the fault occurs are obtained;

[0048] Substituting the initial generator power angle and the initial speed into the second rotor motion equation to obtain the generator operating power angle;

[0049] The maximum stable power angle at which the wind-fire bundling system reaches a new equilibrium point after fault recovery is obtained according to the third rotor motion equation.

[0050] In some embodiments, the step of performing stability judgment based on the generator operating power angle and the maximum stable power angle to determine a power angle stability analysis result includes the following steps:

[0051] Determining whether the generator operating power angle is greater than the maximum stable power angle;

[0052] When the operating power angle of the generator is greater than the maximum stable power angle, determining that the power angle stability analysis result is power angle instability;

[0053] When the generator operating power angle is less than or equal to the maximum stable power angle, it is determined whether the current system state of the wind-fire bundling system is in a steady state;

[0054] If the current system state is in a steady state, determining that the power angle stability analysis result is a power angle stability;

[0055] If the current system state is not in a steady state, the process returns to the step of substituting the initial generator power angle and the initial speed into the second rotor motion equation to obtain the generator operating power angle to calculate the generator operating power angle at the next moment.

[0056] To achieve the above purpose, another aspect of the embodiment of the present application provides a wind-fire bundling power angle stability analysis system, the system comprising:

[0057] The first module is used to calculate the power loss on the collector line according to the voltage difference between adjacent units on the collector line, and obtain a wind farm output model considering power distribution;

[0058] The second module is used to perform an equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model;

[0059] The third module is used to establish an electromagnetic torque model based on the wind-fire bundling equivalent model, and to establish a rotor motion model from three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model;

[0060] The fourth module is used to determine the operating power angle and the maximum stable power angle of the generator through the wind-fire bundle power angle model;

[0061] The fifth module is used to make a stability judgment based on the operating power angle of the generator and the maximum stable power angle, and determine a power angle stability analysis result.

[0062] To achieve the above objective, another aspect of an embodiment of the present application provides an electronic device, the electronic device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the above method when executing the computer program.

[0063] To achieve the above objective, another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0064] The embodiments of the present application include at least the following beneficial effects: The present application provides a method, system, electronic device and storage medium for analyzing the power angle stability of a wind-fire bundle. The scheme calculates the power loss on the collector line according to the voltage difference between adjacent units on the collector line to obtain a wind farm output model that considers the power distribution. It can consider the power distribution of each wind turbine unit in a large-scale wind farm as well as the fault control and recovery process, and refine the impact of each wind turbine unit on the wind farm model.

[0065] The wind-fire bundling equivalent model is obtained by performing an equivalent transformation on the wind farm output model; an electromagnetic torque model is established based on the wind-fire bundling equivalent model, and a rotor motion model is established at three times: before the fault occurs, during the fault occurs and recovery, and after the fault is recovered, to obtain a wind-fire bundling power angle model; the generator operating power angle and the maximum stable power angle are determined by the wind-fire bundling power angle model; a stability judgment is made based on the generator operating power angle and the maximum stable power angle, and the power angle stability analysis result is determined, which can improve the accuracy of the wind-fire bundling power angle stability analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a flow chart of the wind-fire bundling power angle stability analysis method provided in the embodiment of the present application;

[0067] Figure 2 It is a structural schematic diagram of the wind-fire bundling triangle equivalent model provided in the embodiment of the present application;

[0068] Figure 3 is a flow chart of the power angle stability analysis provided by an embodiment of the present application;

[0069] Figure 4 is a flow chart of a method for analyzing the stability of wind and fire bundling power angle provided by another embodiment of the present application;

[0070] Figure 5 It is a structural schematic diagram of the wind-fire bundling power angle stability analysis system provided in an embodiment of the present application;

[0071] Figure 6 It is a schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0073] It is understood that the terms "first", "second", etc. used in this application can be used to describe various concepts in this article, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiment of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein can be interpreted as "at the time of" or "when" or "in response to determination".

[0074] The terms "at least one", "multiple", "each", "any", etc. used in this application, at least one includes one, two or more, multiple includes two or more, each refers to each of the corresponding multiple, and any refers to any one of the multiple.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0076] Before describing the embodiments of the present application in detail, some related technologies involved in the embodiments of the present application are first described.

[0077] Related technologies usually treat the wind farm as a whole when modeling the power angle stability analysis of wind-fire bundled power. This will result in the inability to accurately reflect the actual changes when the overall output power of the wind farm remains unchanged but the power distribution of the internal units changes. At the same time, when a fault occurs in the wind farm, due to the impedance of the collector line, the fault voltage sensed by each unit is not consistent, and during the fault recovery process, the fault recovery process is also inconsistent due to the inconsistency of the initial operating state of each unit. These problems cannot be effectively solved in the current power angle stability analysis modeling.

[0078] In view of this, a method, system, electronic device and storage medium for analyzing the power angle stability of a wind-fire bundle are provided in an embodiment of the present application. The scheme calculates the power loss on the collector line according to the voltage difference between adjacent units on the collector line, and obtains a wind farm output model that takes power distribution into consideration. It can consider the power distribution of each wind turbine unit in a large-scale wind farm as well as the fault control and recovery process, and refine the impact of each wind turbine unit on the wind farm model.

[0079] The wind-fire bundling equivalent model is obtained by performing an equivalent transformation on the wind farm output model; an electromagnetic torque model is established based on the wind-fire bundling equivalent model, and a rotor motion model is established at three times: before the fault occurs, during the fault occurs and recovery, and after the fault is recovered, to obtain a wind-fire bundling power angle model; the generator operating power angle and the maximum stable power angle are determined by the wind-fire bundling power angle model; a stability judgment is made based on the generator operating power angle and the maximum stable power angle, and the power angle stability analysis result is determined, which can improve the accuracy of the wind-fire bundling power angle stability analysis.

[0080] The wind-fire bundling power angle stability analysis method provided in the embodiment of the present application relates to the technical field of power systems. The wind-fire bundling power angle stability analysis method provided in the embodiment of the present application can be applied to a terminal, can also be applied to a server, and can also be software running in a terminal or a server. In some embodiments, the terminal can be a smart phone, a tablet computer, a laptop computer, a desktop computer, and a vehicle-mounted terminal, etc., but is not limited to this; the server side can be configured as an independent physical server, or it can be configured as a server cluster or a distributed system composed of multiple physical servers, and can also be configured as a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network; the software can be an application that implements the wind-fire bundling power angle stability analysis method, etc., but is not limited to the above forms.

[0081] The present application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc. The present application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0082] Figure 1 is an optional flow chart of the wind-fire bundling power angle stability analysis method provided in the embodiment of the present application, Figure 1 The method may include but is not limited to steps S101 to S105.

[0083] Step S101, calculating the power loss on the collector line according to the voltage difference between adjacent units on the collector line, and obtaining a wind farm output model considering power distribution.

[0084] Specifically, the power loss on the collector line is calculated according to the voltage difference between adjacent units on the collector line, and the wind farm output model considering power distribution is obtained. First, the power loss on the collector line segment is calculated according to the voltage difference between adjacent units on the collector line, and then the power loss on the entire collector line is calculated by superimposing the losses of each collector line segment, and the wind farm output model considering power distribution is obtained.

[0085] Step S102, performing equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model.

[0086] It should be noted that after obtaining the wind farm output model, it is also necessary to consider the interaction and influence between the wind farm and the thermal power system, regard the wind farm as a whole, and perform an equivalent transformation on the wind farm output model to obtain the wind-thermal bundling equivalent model.

[0087] Step S103, establishing an electromagnetic torque model based on the wind-fire bundling equivalent model, and establishing rotor motion models from three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model.

[0088] Specifically, an electromagnetic torque model is established based on the wind-fire bundling equivalent model, and rotor motion models are established at three times: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain the wind-fire bundling power angle model. After obtaining the wind-fire bundling equivalent model, the parameters in the model are used to establish an electromagnetic torque model that describes the relationship between electromagnetic power and generator power angle.

[0089] Then, the rotor motion model is established at three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers. Before the fault occurs, a rotor motion model is established to describe the speed, power angle, and balance between mechanical power and electromagnetic power in the steady state of the generator. During the fault occurs and recovers, a rotor motion model is established in which the balance between mechanical power and electromagnetic power is broken and the power angle changes dynamically. After the fault is recovered, a rotor motion model is established in which the power angle decreases after the fault is removed until a new balance point is reached again.

[0090] The electromagnetic torque model and the rotor motion models corresponding to different time periods together constitute the wind-fire bundling power angle model. This model can comprehensively describe the dynamic response of the wind-fire bundling system before a fault occurs, during a fault occurs and recovers, and after a fault recovers, so as to evaluate whether the wind-fire bundling system can maintain stable operation.

[0091] Step S104, determining the generator operating power angle and the maximum stable power angle through the wind-fire bundled power angle model.

[0092] Specifically, the operating power angle and maximum stable power angle of the generator are determined by the wind-fire bundling power angle model. The data of the wind-fire bundling system in steady-state operation before the failure occurs are used to calculate the speed and generator power angle of the system in steady state through the wind-fire bundling power angle model, and the speed and generator power angle in steady state are used as initial conditions to calculate the operating power angle of the generator at any time during the failure and recovery. At the same time, the maximum stable power angle allowed by the wind-fire bundling system is calculated through the wind-fire bundling power angle model.

[0093] Step S105, performing stability judgment according to the generator operating power angle and the maximum stable power angle, and determining a power angle stability analysis result.

[0094] Specifically, a stability judgment is made based on the generator operating power angle and the maximum stable power angle to determine the power angle stability analysis result. Compare whether the engine operating power angle exceeds the maximum stable power angle. If there is a moment when the engine operating power angle is greater than the maximum stable power angle, it means that the wind and fire baling system has power angle instability, and corresponding control measures need to be taken to maintain system stability. If the generator operating power angle is always less than the maximum stable power angle until the wind and fire baling system resumes stable operation, it means that the wind and fire baling system is stable.

[0095] In some embodiments, before step S101, the wind-fire bundling power angle stability analysis method further includes step S201.

[0096] Step S201, based on the output characteristics of the unit before the fault occurs and after the fault is recovered, the output characteristics of the unit during the fault occurrence and recovery are determined according to a preset proportionality coefficient.

[0097] It should be noted that, in general, the output power of wind turbines before and after a fault is mainly active power, and reactive power is basically zero. When a fault occurs, the wind farm needs to maintain connection with the grid for a period of time, during which the wind farm provides reactive power to support the grid voltage. The low voltage ride-through control strategy is designed to cope with this situation of grid voltage reduction, ensuring that wind turbines can maintain a certain output power during the fault, or can smoothly return to normal operation after the fault is removed.

[0098] When a fault occurs, the fault voltage sensed by each unit is not consistent due to the impedance of the collector line. At the same time, during the fault recovery process, the fault recovery process is also different due to the inconsistency of the initial operating state of each unit.

[0099] When a fault occurs, the unit outputs active and reactive power according to the proportional coefficient set by the low voltage ride through control strategy. During the fault recovery process, the fault recovery is divided into two modes: slope recovery and immediate recovery. In the slope recovery mode, the unit output power is restored according to the proportional coefficient set by the low voltage ride through control strategy until it reaches stability; in the immediate recovery mode, the recovery process can be ignored.

[0100] Therefore, in order to accurately understand the behavior of the unit under fault conditions, the output characteristics of the unit before and after the fault is restored are determined according to the preset proportional coefficient. According to the active coefficient, reactive coefficient and slope coefficient set by the low voltage ride-through control strategy, combined with the fault voltage reference value and unit port voltage of each unit, the active and reactive output of the unit before and after the fault is restored are determined according to the active and reactive output.

[0101] Further, step S201 may include but is not limited to steps S301 to S304.

[0102] Step S301, based on the active power of the first unit of the unit before the fault occurs, the active power of the second unit of the unit when the fault occurs is determined according to a preset active coefficient.

[0103] Exemplarily, based on the active power of the first unit of the unit before the fault occurs, the active power of the second unit of the unit when the fault occurs is determined according to the preset active power coefficient. After the active power coefficient of the active output ratio change of the unit when the fault occurs is pre-set according to the low voltage ride-through control strategy, the active power of the first unit of the unit before the fault occurs is multiplied by the active power coefficient to obtain the active power of the second unit of the unit after power control when the fault occurs, wherein the calculation formula of the active power of the second unit is:

[0104] P 中 =k LVET_p P 前 (1)

[0105] Where P 中 is the active power of the second unit of the unit when the fault occurs, k LVET_p is the active power coefficient, P 前 It is the active power of the first unit before the fault occurs.

[0106] Step S302, based on the unit port voltage and the preset fault voltage reference value, the reactive power of the first unit of the unit when the fault occurs is determined according to the preset reactive coefficient.

[0107] Exemplarily, based on the unit port voltage and the preset fault voltage reference value, the first unit reactive power of the unit when the fault occurs is determined according to the preset reactive coefficient. After the reactive coefficient of the reactive output ratio change of the unit when the fault occurs is pre-set according to the low voltage ride-through control strategy, the voltage difference between the unit port voltage and the voltage fault reference value is calculated, and the calculated voltage difference is multiplied by the reactive coefficient to obtain the first reactive power of the unit after power control when the fault occurs, wherein the calculation formula of the first reactive power is:

[0108] Q 中 =k LVET_q (U LVET - U 机 ) (2),

[0109] In the formula, Q 中 is the active power of the first unit of the unit when the fault occurs, k LVET_q is the reactive power coefficient, U LVET is the fault voltage reference value, U 机 is the unit port voltage.

[0110] Step S303, determine the recovery type of fault recovery. When the recovery type is slope recovery, the active power of the third unit of the unit in the recovery process is determined based on the active power of the second unit according to a preset slope coefficient; or, when the recovery type is immediate recovery, the active power of the fourth unit of the unit after the fault recovery is determined as the active power of the third unit of the unit in the fault recovery process.

[0111] Specifically, the recovery type of the unit fault recovery is determined. When the recovery type is slope recovery, the active power of the third unit of the unit in the recovery process is determined based on the active power of the second unit according to the preset slope coefficient. Alternatively, when the recovery type is immediate recovery, the active power of the fourth unit of the unit after the fault recovery is determined as the active power of the third unit of the unit in the fault recovery. First, the respective recovery types of different units in the fault recovery stage are determined according to the initial operating state of each unit. Then, the output power of the computer group is calculated according to the recovery type.

[0112] When the recovery type of the unit is determined to be slope recovery based on the initial state of the unit, and the slope coefficient of the unit's active power recovery during fault recovery is pre-set according to the low voltage ride-through control strategy, the slope coefficient is multiplied by the recovery time and added to the active power of the second unit calculated in step S301 to obtain the active power of the third unit during the fault recovery process.

[0113] When the recovery type of the unit is determined to be immediate recovery based on the initial state of the unit, it means that the output power of the unit can be quickly restored after the fault is eliminated, and the time required for recovery can be ignored. Therefore, in the immediate recovery mode, the active power of the third unit in the unit fault recovery can be approximately considered to be the same as the active power of the fourth unit after the fault recovery. Among them, the calculation formula for the active power of the third unit is:

[0114]

[0115] Where P 恢复 is the active power of the third unit of the unit being restored from failure, P 后 is the active power of the fourth unit after fault recovery, P k is the preset slope coefficient, and t is the recovery time.

[0116] Step S304, obtaining the output characteristics of the units during fault occurrence and recovery according to the active power of the second unit, the reactive power of the first unit and the active power of the third unit.

[0117] It can be understood that the active power of the second unit reflects the change in the active power output of the unit at the moment of the fault, the reactive power of the first unit reflects the change in the reactive power output of the unit at the moment of the fault, and the active power of the third unit reflects the change in the active power output of the unit during fault recovery. By summarizing the power change characteristics of the unit at the key time point of the fault, the output characteristics of the unit during fault occurrence and recovery are obtained based on the active power of the second unit, the reactive power of the first unit and the active power of the third unit.

[0118] In some embodiments, step S101 may include but is not limited to steps S401 to S404.

[0119] Step S401, establishing a voltage difference model according to the voltage difference between adjacent units on the collector line.

[0120] Specifically, a voltage difference model is established based on the voltage difference between adjacent units on the collector line. First, the voltage difference equation between each wind turbine access point and the common point on the collector line is established, the voltage of each unit on the collector line node is calculated, and then the voltage difference model is established based on the voltage difference between adjacent units at the collector line node. The expression of the voltage difference model is:

[0121]

[0122] In the formula, ΔU 机_k represents the collector node voltage difference between the kth unit and the k+1th unit, Z 集电线_k is the impedance of the collector, P 机_j is the active power output of the jth unit, and U is the collector bus voltage.

[0123] Step S402: transform the voltage difference model to obtain a power loss model between adjacent units.

[0124] Specifically, after the voltage difference model is established, the voltage difference model is transformed to obtain the power loss model between adjacent units. According to Ohm's law and the power calculation formula, equation (4) is transformed. This transformation involves complex operations on voltage and impedance. After the voltage difference model is transformed, a power loss model that considers active power loss and reactive power loss on the collector line is obtained. Among them, the expression of the power loss model is:

[0125]

[0126] Where ΔP 集电线 is the active power loss of the collector between the kth unit and the k+1th unit, ΔQ 集电线 is the reactive power loss of the collector between the kth unit and the k+1th unit, R 集电线_k is the collector resistance between the kth unit and the k+1th unit, X 集电线_k is the collector reactance between the kth unit and the k+1th unit.

[0127] Step S403, calculating the power loss on the collector line according to the power loss model to obtain the collector line power model.

[0128] Specifically, the power loss on the collector line is calculated according to the power loss model to obtain the collector line power model. Assuming that there are n1 units on the collector line, after obtaining the power loss model between adjacent units, the active power loss and reactive power loss between adjacent units are superimposed respectively, and the sum is taken from k=1 to k=n1 to obtain the collector line power model of the active power sent by the collector line after the loss is considered and the reactive power sent by the collector line after the loss is considered. Among them, the expression of the collector line power model is:

[0129]

[0130] Where P 输出_集电线 Q is the active power delivered by the collector after losses are taken into account. 输出_集电线 The reactive power delivered by the collector is taken into account after losses.

[0131] Step S404, deriving the output characteristics of a wind farm with multiple collectors according to the collector power model, and obtaining a wind farm output model that takes power distribution into consideration.

[0132] Specifically, the output characteristics of the wind farm with multiple collectors are derived according to the collector power model, and the wind farm output model considering power distribution is obtained. Considering the situation where there are multiple collectors in the wind farm, assuming that there are m collectors in the wind farm, the output characteristics of the wind farm with multiple collectors can be derived to generalize formula (6) to obtain the wind farm output model considering power distribution, where the expression of the wind farm output model is:

[0133]

[0134]

[0135] Where P 输出 is the wind farm output active power model considering power distribution, Q 输出 P is the wind farm output reactive power model considering power distribution. 计划 The wind farm plans to send active power, P 机 _ j,h is the active power output of the hth unit in the jth collector line, Q 机 _ j,h The reactive power output of the hth generator in the jth collector line.

[0136] In some embodiments, step S102 may include but is not limited to steps S501 to S503.

[0137] Step S501: Equivalent the wind farm output model to a wind farm negative impedance model.

[0138] Specifically, the wind farm output model is equivalent to the wind farm negative impedance model. The wind farm is regarded as a whole, and the wind farm is equivalent to the wind farm load impedance model using the U, P output and Q output obtained by the wind farm output model established in step S101.

[0139] Step S502: establishing a Y-type equivalent impedance model of the wind-fire bundling system based on the negative impedance model of the wind farm, wherein the three sides of the Y-type equivalent model are the thermal impedance, the negative impedance of the wind farm and the transmission line impedance.

[0140] Specifically, a Y-type equivalent impedance model of the wind-fire bundling system is established based on the negative impedance model of the wind farm, where the three sides of the Y-type equivalent model are the thermal impedance, the negative impedance of the wind farm and the impedance of the transmission line. The negative impedance model of the wind farm and the negative impedance model of the thermal power plant are taken as input, and the transmission line is taken as output. The wind-fire bundling system is integrated into an equivalent Y-type equivalent impedance model by merging and converting them through the equivalent transformation method.

[0141] Step S503, performing triangular transformation on the Y-type equivalent impedance model to obtain a wind-fire bundling equivalent model, wherein the three sides of the wind-fire bundling equivalent model are electromagnetic impedance, a first grounding impedance and a second grounding impedance.

[0142] Specifically, refer to Figure 2 , perform trigonometric transformation on the Y-type equivalent impedance model to obtain the wind-fire bundle equivalent model, where the three sides of the wind-fire bundle equivalent model are electromagnetic impedance, the first ground impedance and the second ground impedance. Use the Y-type equivalent model to obtain the thermal impedance, the negative impedance of the wind farm and the transmission line impedance to perform trigonometric transformation, calculate the electromagnetic impedance, the first ground impedance and the second ground impedance, and obtain the wind-fire bundle equivalent model. The expression of trigonometric transformation is:

[0143]

[0144]

[0145] In the formula, Z 电磁 is the electromagnetic impedance, Z 接地1 is the first grounding impedance, Z 接地2 is the second grounding impedance, Z 火电 is the fire resistance, Z 线路 is the output line impedance, Z 风电 is the negative impedance of the wind farm.

[0146] In some embodiments, step S103 may include but is not limited to steps S601 to S606.

[0147] Step S601, based on the wind-fire bundling equivalent model, the relationship between the electromagnetic power and the generator power angle is established to obtain the electromagnetic torque model.

[0148] Specifically, the relationship between electromagnetic power and generator power angle is established based on the wind-fire bundling equivalent model to obtain the electromagnetic torque model. The electromagnetic impedance calculated by the wind-fire bundling equivalent model is used to establish the relationship between electromagnetic power and generator power angle according to the generator electromotive force to obtain the electromagnetic torque model, where the expression of the electromagnetic torque model is:

[0149]

[0150] Where P 电磁 is the electromagnetic power, E′ is the generator electromotive force, and δ is the generator power angle.

[0151] Step S602: establishing a first rotor motion equation before the fault occurs according to the balance relationship between the generator mechanical power and the generator electromagnetic power before the fault occurs.

[0152] Exemplarily, the first rotor motion equation before the fault occurs is established based on the balance relationship between the mechanical power of the generator and the electromagnetic power of the generator before the fault occurs. Before the fault occurs, the wind-fire bundling system is in a steady state, at which time the mechanical power of the generator and the electromagnetic power are in a balanced state. The equation is established based on the basic principle of rotor motion, and the balance relationship between the mechanical power of the generator and the electromagnetic power of the generator before the fault occurs is substituted to obtain the first rotor motion equation before the fault occurs. Among them, the expression of the first rotor motion equation is:

[0153]

[0154] Where, T J is the generator inertia time constant, dω / dt represents the rate of change of the rotor electrical angular velocity, P 前_m is the mechanical power of the generator before the fault occurs, P 前_e is the electromagnetic power of the generator before the fault occurs.

[0155] Step S603, establishing a second rotor motion equation with increased power angle during fault occurrence and recovery according to the power difference between the generator mechanical power and the generator electromagnetic power during fault occurrence and recovery.

[0156] For example, when a fault occurs, the mechanical power of the generator will be greater than the electromagnetic power, causing the generator to accelerate and the power angle to increase; and during the fault recovery process, although the generator acceleration decreases, the power angle still increases. Therefore, according to the power difference between the mechanical power of the generator and the electromagnetic power of the generator during the fault occurrence and recovery, the second rotor motion equation with increased power angle during the fault occurrence and recovery is established. The expression of the second rotor motion equation is:

[0157]

[0158] Where dδ / dt represents the rate of change of the generator power angle, ω is the per unit value of the rotor electrical angular velocity, ω0 is a constant 2*π*50, and P 故障_m is the mechanical power of the generator during fault occurrence and recovery, P 故障_e It is the electromagnetic power of the generator during fault occurrence and recovery.

[0159] Step S604: establishing a third rotor motion equation with a reduced power angle after fault recovery according to the power difference between the mechanical power of the generator and the electromagnetic power of the generator after fault recovery.

[0160] For example, after the fault is restored, the fault is removed, the electromagnetic power of the generator will be greater than the mechanical power, and the power angle will decrease until a new equilibrium point is reached. Therefore, according to the power difference between the mechanical power of the generator and the electromagnetic power of the generator after the fault is restored, the third rotor motion equation with reduced power angle after the fault is restored is established. Among them, the expression of the third rotor motion equation is:

[0161]

[0162] Where P 后_m is the mechanical power of the generator after fault recovery, P 后_e It is the electromagnetic power of the generator after fault recovery.

[0163] Step S605, obtaining a rotor motion model according to the first rotor motion equation, the second rotor motion equation and the third rotor motion equation.

[0164] Specifically, the rotor motion model is obtained according to the first rotor motion equation, the second rotor motion equation and the third rotor motion equation. A complete rotor motion model is obtained by integrating the rotor motion equations obtained from the operating states of the generator in three different stages: before the fault occurs, during the fault occurs and recovers, and after the fault recovers.

[0165] Step S606, obtaining the wind-fire bundling power angle model according to the electromagnetic torque model and the rotor motion model.

[0166] Specifically, the wind-fire bundling power angle model is obtained based on the electromagnetic torque model and the rotor motion model. The wind-fire bundling power angle model established by combining the electromagnetic torque model and the rotor motion model can reflect the power angle changes of the wind-fire bundling system before, during and after a fault, providing a basis for the subsequent analysis of the power angle stability of the system.

[0167] In some embodiments, step S104 may include but is not limited to steps S701 to S703.

[0168] Step S701, obtaining the initial generator power angle and initial speed of the wind-fire bundling system in steady-state operation before a fault occurs according to the first rotor motion equation.

[0169] Specifically, the initial generator power angle and initial speed of the wind-fire bundling system in steady-state operation before the fault occurs are obtained according to the first rotor motion equation. Figure 3 , the operating state of the generator in steady state is analyzed by formula (12) established in step S602. In steady state, the first rotor motion equation can be simplified to mechanical power equal to electromagnetic power. Then, the electromagnetic torque model can be used to inversely solve the initial generator power angle before the fault occurs. At the same time, the initial speed can be obtained by converting the angular velocity of the rotor in steady state into the speed.

[0170] Step S702: Substitute the initial generator power angle and initial speed into the second rotor motion equation to obtain the generator operating power angle.

[0171] Exemplarily, the initial generator power angle and initial speed are substituted into the second rotor motion equation to obtain the generator operating power angle. The initial generator power angle and initial speed calculated in step S701 are used as initial conditions and substituted into formula (13) to obtain the generator operating power angle at any time during the occurrence and recovery of the fault.

[0172] Step S703, obtaining the maximum stable power angle for the wind-fire bundling system to reach a new equilibrium point after the fault is restored according to the third rotor motion equation.

[0173] Exemplarily, the maximum stable power angle of the wind-fire baling system to reach a new equilibrium point after fault recovery is obtained according to the third rotor motion equation. The maximum stable power angle allowed when the wind-fire baling system reaches a new equilibrium point after fault recovery is analyzed by formula (14) established in step S604.

[0174] In some embodiments, step S105 may include but is not limited to steps S801 to S805.

[0175] Step S801, determining whether the generator operating power angle is greater than the maximum stable power angle.

[0176] Specifically, the maximum stable power angle is the maximum power angle value at which the wind-fire bundling system can maintain stable operation after a fault occurs, and is used to help determine whether the system can maintain stable operation after a fault occurs. Figure 3 , compare the generator operating power angle and the maximum stable power angle, and determine whether the generator operating power angle is greater than the maximum stable power angle, so as to perform stability analysis on the system.

[0177] Step S802: When the operating power angle of the generator is greater than the maximum stable power angle, the power angle stability analysis result is determined to be power angle instability.

[0178] Specifically, when the generator operating power angle is greater than the maximum stable power angle, the power angle stability analysis result is determined to be power angle instability. When the generator operating power angle is greater than the maximum stable power angle at any time, it means that the wind-fire bundling system has power angle instability, and the power angle stability analysis result is determined to be power angle instability.

[0179] Step S803, when the operating power angle of the generator is less than or equal to the maximum stable power angle, it is determined whether the current system state of the wind-fire bundling system is in a steady state.

[0180] Specifically, when the generator operating power angle is less than or equal to the maximum stable power angle, it is determined whether the current system state of the wind and fire bundling system is in a steady state. Considering that it is not sufficient to determine whether the wind and fire bundling system is unstable only by the generator operating power angle being less than or equal to the maximum stable power angle, even if the generator operating power angle does not exceed it at the current moment, because the system is in a dynamic change process, it may still exceed the maximum stable power angle at some point in the future. Therefore, it is necessary to further determine whether the current system state of the wind and fire bundling system is in a steady state.

[0181] Step S804: if the current system state is in a steady state, determine that the power angle stability analysis result is a power angle stability.

[0182] Specifically, if the current system state is in a steady state, the power angle stability analysis result is determined to be power angle stability. Under the premise that the generator operating power angle does not exceed the maximum stable power angle, if the current system state is in a steady state, it means that the wind-fire bundling system will not change significantly in a short time, and the system will operate stably under the current operating conditions. Therefore, the power angle stability analysis result is determined to be power angle stability.

[0183] Step S805, if the current system state is not in a steady state, return to the step of substituting the initial generator power angle and the initial speed into the second rotor motion equation to obtain the generator operating power angle to calculate the generator operating power angle at the next moment.

[0184] Specifically, if the current system state is not in a steady state, the process returns to step S702 to calculate the generator operating power angle at the next moment. For example, when the generator operating power angle of the wind-fire bundling system at moment t is less than the maximum stable power angle, but the current system state is not in a steady state, the generator operating power angle at moment t+1 is calculated and compared with the maximum stable power angle.

[0185] The following is a detailed introduction and description of the solution of the embodiment of the present invention in conjunction with a specific application example.

[0186] Reference Figure 4In the embodiment of the present application, the unit output power is first set according to the low voltage ride-through control strategy. The unit output power includes the active and reactive power of the unit before the fault, the active and reactive power of the unit during the fault, the active and reactive power of the unit during the fault recovery process, and the active and reactive power of the unit after the fault recovery.

[0187] Next, a voltage difference model between each wind turbine access point and the common point on the collector line is established. The power loss model on this section of the collector line is calculated by the voltage difference between adjacent units on the collector line. The collector line power model is obtained by superimposing the power losses of each section on the collector line. The power on all collector lines in the wind farm is accumulated to obtain a wind farm model that takes power distribution into account.

[0188] Then, the wind farm is regarded as a whole, and the wind farm output model is equivalent to the equivalent impedance model. Based on the electromagnetic impedance calculated by the equivalent impedance model, the electronic torque model and rotor motion model are established at three times before, during and after the fault to obtain the wind-fire bundling power angle model.

[0189] Finally, the wind-fire bundled power angle model is used to perform power angle stability analysis based on the generator power angle and the maximum stable power angle to determine whether the power angle is stable.

[0190] In this embodiment, a wind-fire bundling power angle stability analysis method considering the power distribution of the wind farm and the low-throughput control parameters is proposed. First, the wind farm output model is established using the collector line voltage difference. The power distribution of each unit is considered in the model, and the impact of the inconsistent operating status of each wind turbine on the wind farm model is refined. Then, the wind-fire bundling system is transformed into an equivalent value, and an electromagnetic torque model and a rotor motion model are established in combination with the wind farm model to obtain a wind-fire bundling power angle model. This model considers the power distribution of each wind turbine as well as the power control and fault recovery process under faults, so that the calculation results of the model are closer to the actual model.

[0191] Please refer to Figure 5 The embodiment of the present application further provides a wind-fire bundling power angle stability analysis system, which can implement the wind-fire bundling power angle stability analysis method described above, and the system includes:

[0192] The first module is used to calculate the power loss on the collector line according to the voltage difference between adjacent units on the collector line, and obtain a wind farm output model that takes power distribution into consideration.

[0193] The second module is used to perform equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model.

[0194] The third module is used to establish an electromagnetic torque model based on the wind-fire bundling equivalent model, and to establish a rotor motion model from three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model.

[0195] The fourth module is used to determine the generator operating power angle and maximum stable power angle through the wind-fire bundled power angle model.

[0196] The fifth module is used to make stability judgment based on the generator operating power angle and the maximum stable power angle, and determine the power angle stability analysis result.

[0197] It can be understood that the contents of the above method embodiments are all applicable to the present system embodiments, the functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0198] The embodiment of the present application also provides an electronic device, the electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the above-mentioned wind-fire bundling power angle stability analysis method when executing the computer program. The electronic device can be any intelligent terminal including a tablet computer, a vehicle-mounted computer, etc.

[0199] It can be understood that the contents of the above method embodiments are all applicable to the present device embodiments, the functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0200] Please refer to Figure 6 , Figure 6 The hardware structure of an electronic device of another embodiment is illustrated, and the electronic device includes:

[0201] The processor 901 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0202] The memory 902 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 902 can store an operating system and other application programs. When the technical solution provided in the embodiment of this specification is implemented by software or firmware, the relevant program code is stored in the memory 902, and the processor 901 calls and executes the wind-fire bundling power angle stability analysis method of the embodiment of this application.

[0203] The input / output interface 903 is used to implement information input and output.

[0204] The communication interface 904 is used to realize the communication interaction between this device and other devices. Communication can be realized through wired methods (such as USB, network cable, etc.) or wireless methods (such as mobile network, WIFI, Bluetooth, etc.).

[0205] The bus 905 transmits information between various components of the device (eg, the processor 901 , the memory 902 , the input / output interface 903 , and the communication interface 904 ).

[0206] The processor 901 , the memory 902 , the input / output interface 903 and the communication interface 904 are connected to each other in communication within the device via a bus 905 .

[0207] The embodiment of the present application further provides a computer-readable storage medium storing a computer program, which implements the above-mentioned wind-fire bundling power angle stability analysis method when executed by a processor.

[0208] It can be understood that the contents of the above method embodiments are all applicable to the present storage medium embodiments, the functions specifically implemented by the present storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0209] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0210] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0211] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0212] The system embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0213] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0214] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0215] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A method for analyzing the stability of wind and fire bundling angle, characterized in that: The method comprises the following steps: The power loss on the collector line is calculated based on the voltage difference between adjacent units on the collector line, and the wind farm output model considering power distribution is obtained; Performing an equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model; An electromagnetic torque model is established based on the wind-fire bundling equivalent model, and rotor motion models are established at three times: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model; Determine the generator operating power angle and maximum stable power angle through the wind-fire bundle power angle model; A stability judgment is performed based on the generator operating power angle and the maximum stable power angle to determine a power angle stability analysis result.

2. The method according to claim 1, characterized in that Before the step of calculating the power loss on the collector line according to the voltage difference between adjacent units on the collector line to obtain the wind farm output model considering the power distribution, the wind-fire bundled power angle stability analysis method further includes the following steps: Based on the output characteristics of the unit before the fault occurs and after the fault is recovered, the output characteristics of the unit during the fault occurrence and recovery are determined according to the preset proportional coefficient; Wherein, the step of determining the output characteristics of the unit during the occurrence and recovery of a fault according to a preset proportionality coefficient based on the output characteristics of the unit before the fault occurs and after the fault is recovered comprises the following steps: Based on the active power of the first unit of the unit before the fault occurs, determine the active power of the second unit of the unit when the fault occurs according to a preset active coefficient; Based on the unit port voltage and the preset fault voltage reference value, determining the reactive power of the first unit of the unit when the fault occurs according to the preset reactive coefficient; Determine the recovery type of the fault recovery, when the recovery type is slope recovery, determine the active power of the third unit of the unit in the recovery process based on the active power of the second unit according to a preset slope coefficient; or, when the recovery type is immediate recovery, determine the active power of the fourth unit of the unit after the fault recovery as the active power of the third unit of the unit in the fault recovery process; The output characteristics of the units during fault occurrence and recovery are obtained according to the active power of the second unit, the reactive power of the first unit and the active power of the third unit.

3. The method according to claim 2, characterized in that The method of calculating the power loss on the collector line according to the voltage difference between adjacent units on the collector line to obtain a wind farm output model taking into account power distribution includes the following steps: A voltage difference model is established according to the voltage difference between adjacent units on the collector line; Transforming the voltage difference model to obtain a power loss model between adjacent units; Calculate the power loss on the collector line according to the power loss model to obtain a collector line power model; The output characteristics of a wind farm with multiple collectors are derived according to the collector power model, and a wind farm output model considering power distribution is obtained.

4. The method according to claim 2, characterized in that: The equivalent transformation of the wind farm output model to obtain the wind-fire bundling equivalent model comprises the following steps: The wind farm output model is equivalent to a wind farm negative impedance model; A Y-type equivalent impedance model of the wind-fire bundling system is established based on the negative impedance model of the wind farm, wherein the three sides of the Y-type equivalent model are the thermal impedance, the negative impedance of the wind farm and the transmission line impedance; The Y-type equivalent impedance model is subjected to trigonometric transformation to obtain a wind-fire bundling equivalent model, wherein the three sides of the wind-fire bundling equivalent model are electromagnetic impedance, the first ground impedance and the second ground impedance, and the expression of the trigonometric transformation is: In the formula, Z 电磁 is the electromagnetic impedance, Z 接地1 is the first grounding impedance, Z 接地2 is the second grounding impedance, Z 火电 is the fire resistance, Z 线路 is the output line impedance, Z 风电 is the negative impedance of the wind farm.

5. The method according to claim 4, characterized in that The method of establishing an electromagnetic torque model based on the wind-fire bundling equivalent model and establishing rotor motion models at three times, before a fault occurs, during a fault occurs and is recovered, and after the fault is recovered, to obtain a wind-fire bundling power angle model includes the following steps: Based on the wind-fire bundling equivalent model, the relationship between electromagnetic power and generator power angle is established to obtain the electromagnetic torque model, wherein the expression of the electromagnetic torque model is: Where P 电磁 is the electromagnetic power, E′ is the generator electromotive force, δ is the generator power angle, and U is the collector bus voltage; According to the balance relationship between the mechanical power of the generator and the electromagnetic power of the generator before the fault occurs, the first rotor motion equation before the fault occurs is established, wherein the expression of the first rotor motion equation is: Where, T J is the generator inertia time constant, dω / dt represents the rate of change of the rotor electrical angular velocity, P 前_m is the mechanical power of the generator before the fault occurs, P 前_e is the electromagnetic power of the generator before the fault occurs; According to the power difference between the mechanical power of the generator and the electromagnetic power of the generator during the fault occurrence and recovery, a second rotor motion equation with increased power angle during the fault occurrence and recovery is established, wherein the expression of the second rotor motion equation is: Where dδ / dt represents the rate of change of the generator power angle, ω is the per unit value of the rotor electrical angular velocity, ω0 is a constant 2*π*50, and P 故障_m is the mechanical power of the generator during fault occurrence and recovery, P 故障_e It is the electromagnetic power of the generator during fault occurrence and recovery; According to the power difference between the mechanical power of the generator and the electromagnetic power of the generator after the fault is restored, a third rotor motion equation with a reduced power angle after the fault is restored is established, wherein the expression of the third rotor motion equation is: Where P 后_m is the mechanical power of the generator after fault recovery, P 后_e is the electromagnetic power of the generator after fault recovery; Obtaining a rotor motion model according to the first rotor motion equation, the second rotor motion equation and the third rotor motion equation; The wind-fire bundling power angle model is obtained according to the electromagnetic torque model and the rotor motion model.

6. The method according to claim 5, characterized in that The method of determining the generator operating power angle and the maximum stable power angle by using the wind-fire bundled power angle model comprises the following steps: According to the first rotor motion equation, the initial generator power angle and initial speed of the wind-fire bundling system in steady-state operation before the fault occurs are obtained; Substituting the initial generator power angle and the initial speed into the second rotor motion equation to obtain the generator operating power angle; The maximum stable power angle at which the wind-fire bundling system reaches a new equilibrium point after fault recovery is obtained according to the third rotor motion equation.

7. The method according to claim 6, characterized in that The step of performing stability judgment according to the generator operating power angle and the maximum stable power angle to determine a power angle stability analysis result comprises the following steps: Determining whether the generator operating power angle is greater than the maximum stable power angle; When the operating power angle of the generator is greater than the maximum stable power angle, determining that the power angle stability analysis result is power angle instability; When the generator operating power angle is less than or equal to the maximum stable power angle, it is determined whether the current system state of the wind-fire bundling system is in a steady state; If the current system state is in a steady state, determining that the power angle stability analysis result is a power angle stability; If the current system state is not in a steady state, the process returns to the step of substituting the initial generator power angle and the initial speed into the second rotor motion equation to obtain the generator operating power angle to calculate the generator operating power angle at the next moment.

8. A wind and fire bundling power angle stability analysis system, characterized in that: The system comprises: The first module is used to calculate the power loss on the collector line according to the voltage difference between adjacent units on the collector line, and obtain a wind farm output model considering power distribution; The second module is used to perform an equivalent transformation on the wind farm output model to obtain a wind-fire bundling equivalent model; The third module is used to establish an electromagnetic torque model based on the wind-fire bundling equivalent model, and to establish a rotor motion model from three time periods: before the fault occurs, during the fault occurs and recovers, and after the fault recovers, to obtain a wind-fire bundling power angle model; The fourth module is used to determine the operating power angle and the maximum stable power angle of the generator through the wind-fire bundle power angle model; The fifth module is used to make a stability judgment based on the operating power angle of the generator and the maximum stable power angle, and determine a power angle stability analysis result.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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