Stability analysis methods, systems, electronic devices and storage media for wind and fire bundling.

Abstract

This application provides a method, system, electronic device, and storage medium for wind-fired power angle stability analysis, belonging to the field of power system technology. The scheme calculates the power loss on the collector line based on the voltage difference between adjacent units on the collector line, obtaining a wind farm output model considering power distribution. It then performs an equivalent transformation on the wind farm output model to obtain a wind-fired power angle equivalent model. Based on the wind-fired power angle equivalent model, it establishes an electromagnetic torque model and establishes rotor motion models for three time periods: before a fault occurs, during fault occurrence and recovery, and after fault recovery, obtaining a wind-fired power angle model. The scheme determines the generator operating power angle and the maximum stable power angle using the wind-fired power angle model. Finally, it performs stability judgment based on the generator operating power angle and the maximum stable power angle to determine the power angle stability analysis result. This scheme can consider the power distribution of each unit in a large-scale wind farm as well as the fault control and recovery process, improving the accuracy of wind-fired power angle stability analysis.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a method, system, electronic device and storage medium for analyzing the power angle stability of wind-fired power systems. Background Technology

[0002] In recent years, wind power technology has developed rapidly, and the scale of wind power grid connection has increased year by year. On the one hand, the large-scale integration of new energy sources reduces the start-up of synchronous turbine units; on the other hand, the rapid control and response characteristics of power electronic equipment have a significant impact on the transient stability of the power grid. Bundling wind and thermal power for transmission is currently a common method for large-scale new energy transmission, which can improve the absorption of new energy and reduce wind curtailment.

[0003] Currently, when performing power angle stability modeling for wind-thermal bundled systems, in order to simplify the analysis model and speed up the simulation, relevant technologies often treat a wind farm as one or more units operating in completely identical states. However, this simplification ignores the power distribution within the wind farm, resulting in the model failing to accurately reflect the actual situation when the power distribution of the units within the wind farm changes or a fault occurs. This, in turn, affects the power angle stability analysis results of the wind-thermal bundled system, posing a potential risk to the safe and stable operation of the power grid. Summary of the Invention

[0004] The main objective of this application is to propose a method, system, electronic device, and storage medium for wind-fired power angle stability analysis of large-scale wind-fired power ...

[0005] To achieve the above objectives, one aspect of this application proposes a method for analyzing the stability of the power angle of a combined wind and fire system, 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, resulting in a wind farm output model that considers power distribution.

[0007] The wind farm output model is transformed into an equivalent model to obtain a wind-fire bundled equivalent model.

[0008] An electromagnetic torque model is established based on the equivalent model of wind and fire bundling, and a rotor motion model is established for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the power angle model of wind and fire bundling.

[0009] The generator's operating power angle and maximum stable power angle are determined using the aforementioned wind-fire bundled power angle model.

[0010] Stability is determined based on the generator operating power angle and the maximum stable power angle, and the power angle stability analysis result is determined.

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

[0012] Based on the unit's output characteristics before and after a fault occurs, the unit's output characteristics during fault occurrence and recovery are determined according to a preset proportional coefficient.

[0013] The step of determining the unit's output characteristics during fault occurrence and recovery based on a preset proportional coefficient, according to the unit's output characteristics before and after a fault, includes the following steps:

[0014] Based on the active power of the first unit before the fault occurred, the active power of the second unit of the unit when the fault occurred is determined according to the preset active power coefficient.

[0015] 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 power coefficient.

[0016] Determine the recovery type of the fault recovery. If the recovery type is slope recovery, then based on the active power of the second unit, determine the active power of the third unit of the unit during the recovery process according to the preset slope coefficient; or, if the recovery type is immediate recovery, then 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 during the fault recovery.

[0017] The output characteristics of the generator set during fault occurrence and recovery are obtained based on the active power of the second generator set, the reactive power of the first generator set, and the active power of the third generator set.

[0018] In some embodiments, the step of calculating the power loss on the collector line based on the voltage difference between adjacent units on the collector line to obtain a wind farm output model considering power distribution includes the following steps:

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

[0020] The voltage difference model is transformed to obtain the power loss model between adjacent units;

[0021] The power loss on the collector wire is calculated based on the power loss model to obtain the collector wire power model;

[0022] Based on the power model of the collector line, the output characteristics of the wind farm under the condition of multiple collector lines are derived, and the output model of the wind farm considering the power distribution is obtained.

[0023] In some embodiments, the process of performing an equivalent transformation on the wind farm output model to obtain a wind-thermal bundled equivalent model includes the following steps:

[0024] The wind farm output model is equivalent to the wind farm negative impedance model.

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

[0026] A trigonometric transformation is performed on the Y-type equivalent impedance model to obtain the wind-fire bundling equivalent model, wherein the three sides of the wind-fire bundling equivalent model represent the electromagnetic impedance, the first grounding impedance, and the second grounding impedance. The expression for the trigonometric transformation is:

[0027]

[0028]

[0029]

[0030] In the formula, Z 电磁 For electromagnetic impedance, Z 接地1 Z is the first grounding impedance. 接地2 Z represents the second grounding impedance, Z represents the thermal power impedance, Z represents the transmission line impedance, and Z represents the wind power negative impedance.

[0031] In some embodiments, the step of establishing an electromagnetic torque model based on the equivalent model of the wind and fire bundling, and establishing rotor motion models for three time periods—before the fault occurs, during the fault occurrence and recovery, and after the fault recovery—to obtain the wind and fire bundling power angle model includes the following steps:

[0032] Based on the aforementioned equivalent model of wind and fire bundling, the relationship between electromagnetic power and generator power angle is established, resulting in an electromagnetic torque model. The expression for this electromagnetic torque model is:

[0033]

[0034] In the formula, P_electromagnetic is the electromagnetic power, E′ is the generator electromotive force, δ is the generator power angle, and U is the collector bus voltage.

[0035] Based on the balance between the generator's mechanical power and electromagnetic power before the fault occurred, the first rotor motion equation before the fault occurred is established, where the expression of the first rotor motion equation is:

[0036]

[0037] In the formula, T JLet P be the generator's inertial time constant, dω / dt represent the rate of change of the rotor's electrical angular velocity, and P be the generator's inertial time constant. 前_m P represents the mechanical power of the generator before the fault occurred. 前_e The electromagnetic power of the generator before the fault occurred;

[0038] Based on the power difference between the generator's mechanical power and electromagnetic power during fault occurrence and recovery, a second rotor motion equation is established to account for the increase in power angle during fault occurrence and recovery. The expression for this second rotor motion equation is as follows:

[0039]

[0040] In the formula, dδ / dt represents the generator power angle change rate, ω is the per-unit value of the rotor electric angular velocity, ω0 is a constant 2*π*50, and P 故 Fault_m represents the generator mechanical power during fault occurrence and recovery, P 故 The fault_e represents the electromagnetic power of the generator during fault occurrence and recovery.

[0041] Based on the power difference between the generator's mechanical power and electromagnetic power after fault recovery, a third rotor motion equation is established to account for the reduction in the power angle after fault recovery. The expression for this third rotor motion equation is as follows:

[0042]

[0043] In the formula, P 后 _m represents the generator's mechanical power after fault recovery, P 后 _e represents the electromagnetic power of the generator after the fault is recovered;

[0044] The rotor motion model is obtained based on 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 based on the electromagnetic torque model and the rotor motion model.

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

[0047] The initial generator power angle and initial speed of the wind-fire bundling system before the fault occurred are obtained based on the first rotor motion equation.

[0048] Substituting the initial generator power angle and the initial rotational speed into the second rotor motion equation, the generator operating power angle is obtained;

[0049] The maximum stable power angle of the wind-fire bundling system after fault recovery is obtained based on the third rotor motion equation.

[0050] In some embodiments, determining the power angle stability analysis result based on the generator operating power angle and the maximum stable power angle includes the following steps:

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

[0052] If the generator's operating power angle is greater than the maximum stable power angle, then the power angle stability analysis result is determined to be power angle instability.

[0053] If the generator operating power angle is less than or equal to the maximum stable power angle, then 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, then the power angle stability analysis result is determined to be power angle stable;

[0055] If the current system state is not in a steady state, then 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 at the next moment to calculate the generator operating power angle.

[0056] To achieve the above objectives, another aspect of this application proposes a wind-fire bundled power angle stability analysis system, the system comprising:

[0057] The first module is used to calculate the power loss on the collector line based on the voltage difference between adjacent units on the collector line, and to obtain the wind farm output model that takes power distribution into account.

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

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

[0060] The fourth module is used to determine the generator's operating power angle and maximum stable power angle using the aforementioned wind-fire bundled power angle model;

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

[0062] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0063] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0064] The embodiments of this application include at least the following beneficial effects: This application provides a method, system, electronic device and storage medium for wind and thermal bundled power angle stability analysis. This scheme calculates the power loss on the collector line based on the voltage difference between adjacent units on the collector line, and obtains a wind farm output model that considers power distribution. It can take into account the power distribution of each wind turbine in a large-scale wind farm as well as the fault control and recovery process, and refine the impact of each wind turbine on the wind farm model.

[0065] An equivalent model for wind farm power generation is obtained by performing an equivalent transformation on the wind farm output model. An electromagnetic torque model is established based on the equivalent model, and rotor motion models are established for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the power angle model for wind farm power generation. The generator operating power angle and the maximum stable power angle are determined through the power angle model for wind farm power generation. Stability is judged based on the generator operating power angle and the maximum stable power angle, and the power angle stability analysis results are determined, which can improve the accuracy of the power angle stability analysis for wind farm power generation. Attached Figure Description

[0066] Figure 1 This is a flowchart of the wind and fire bundling power angle stability analysis method provided in the embodiments of this application;

[0067] Figure 2 This is a schematic diagram of the structure of the wind and fire bundling triangle equivalent model provided in the embodiments of this application;

[0068] Figure 3 This is a flowchart of the power angle stability analysis provided in the embodiments of this application;

[0069] Figure 4 This is a flowchart of a wind-fire bundling power angle stability analysis method provided in another embodiment of this application;

[0070] Figure 5 This is a schematic diagram of the structure of the wind and fire bundling power angle stability analysis system provided in the embodiments of this application;

[0071] Figure 6 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying 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 those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

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

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

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

[0076] Before providing a detailed description of the embodiments of this application, some related technologies involved in the embodiments of this application will be described first.

[0077] Current technologies for power angle stability analysis modeling of bundled wind and thermal power plants typically treat the wind farm as a single entity. This leads to inaccurate representation of changes in the power distribution of individual turbines while the overall output power of the wind farm remains constant. Furthermore, when a fault occurs in the wind farm, the fault voltage sensed by each turbine is inconsistent due to the impedance of the collector lines. Moreover, the fault recovery process also varies because the initial operating states of each turbine are different. These problems cannot be effectively addressed in current power angle stability analysis modeling.

[0078] In view of this, this application provides a method, system, electronic device and storage medium for wind and thermal bundled power angle stability analysis. This scheme calculates the power loss on the collector line based on the voltage difference between adjacent units on the collector line, and obtains a wind farm output model that considers power distribution. It can take into account the power distribution of each wind turbine in a large-scale wind farm as well as the fault control and recovery process, and refine the impact of each wind turbine on the wind farm model.

[0079] An equivalent model for wind farm power generation is obtained by performing an equivalent transformation on the wind farm output model. An electromagnetic torque model is established based on the equivalent model, and rotor motion models are established for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the power angle model for wind farm power generation. The generator operating power angle and the maximum stable power angle are determined through the power angle model for wind farm power generation. Stability is judged based on the generator operating power angle and the maximum stable power angle, and the power angle stability analysis results are determined, which can improve the accuracy of the power angle stability analysis for wind farm power generation.

[0080] The wind-thermal power angle stability analysis method provided in this application relates to the field of power system technology. This method can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, or vehicle-mounted terminal, but is not limited thereto. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, 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 implementing the wind-thermal power angle stability analysis method, but is not limited to the above forms.

[0081] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: 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, and distributed computing environments including any of the above systems or devices. This 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. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0082] Figure 1 This is an optional flowchart of the wind and fire bundling power angle stability analysis method provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S105.

[0083] Step S101: Calculate the power loss on the collector line based on the voltage difference between adjacent units on the collector line to obtain the wind farm output model considering power distribution.

[0084] Specifically, the power loss on the collector line is calculated based on the voltage difference between adjacent turbines on the collector line, resulting in a wind farm output model that considers power distribution. First, the power loss on the collector line segment is calculated based on the voltage difference between adjacent turbines on the collector line. Then, the power loss on the entire collector line is calculated by superimposing the losses of each collector line segment, thus obtaining a wind farm output model that considers power distribution.

[0085] Step S102: Perform an equivalent transformation on the wind farm output model to obtain an equivalent model of wind-thermal bundling.

[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. The wind farm is regarded as a whole, and the wind farm output model is transformed into an equivalent model of wind-thermal bundling.

[0087] Step S103: Based on the equivalent model of wind and fire bundling, establish an electromagnetic torque model, and establish rotor motion models for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the wind and fire bundling power angle model.

[0088] Specifically, an electromagnetic torque model is established based on the equivalent model of the wind-fire bundling system, and rotor motion models are established for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the wind-fire bundling power angle model. After obtaining the equivalent model of the wind-fire bundling system, an electromagnetic torque model describing the relationship between electromagnetic power and generator power angle is established using the parameters in this model.

[0089] Then, rotor motion models were established for three time periods: before the fault, during the fault and its recovery, and after the fault recovery. Before the fault, a rotor motion model was established to describe the generator's steady-state speed, power angle, and the balance between mechanical and electromagnetic power. During the fault and its recovery, a rotor motion model was established to show the dynamic changes in the power angle as the balance between mechanical and electromagnetic power was disrupted. After the fault was recovered, a rotor motion model was established to show the decrease in power angle after the fault was cleared until a new balance point was reached.

[0090] The electromagnetic torque model and the rotor motion model 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, during, and after a fault occurs, so as to evaluate whether the wind-fire bundling system can maintain stable operation.

[0091] Step S104: Determine the generator's operating power angle and maximum stable power angle using the wind-fire bundled power angle model.

[0092] Specifically, the generator operating power angle and maximum stable power angle are determined using a wind-fire bundled power angle model. Utilizing steady-state operating data before the wind-fire bundled system failure, the system's steady-state speed and generator power angle are calculated using the wind-fire bundled power angle model. Using the steady-state speed and generator power angle as initial conditions, the generator operating power angle at any moment during failure occurrence and recovery is calculated. Simultaneously, the maximum allowable stable power angle of the wind-fire bundled system is calculated using the wind-fire bundled power angle model.

[0093] Step S105: Based on the generator's operating power angle and maximum stable power angle, a stability judgment is made to determine the power angle stability analysis result.

[0094] Specifically, stability is determined based on the generator's operating power angle and the maximum stable power angle, thus establishing the power angle stability analysis results. The generator's operating power angle is compared to the maximum stable power angle. If, at any given moment, the generator's operating power angle exceeds the maximum stable power angle, it indicates that the power angle of the wind-fire bundling system has become unstable, requiring appropriate control measures to maintain system stability. If, until the wind-fire bundling system returns to stable operation, the generator's operating power angle remains below the maximum stable power angle, then the wind-fire bundling system is considered stable.

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

[0096] Step S201: Based on the unit's output characteristics before and after the fault occurs, determine the unit's output characteristics during fault occurrence and recovery according to a preset proportional coefficient.

[0097] It should be noted that, under normal circumstances, the output power of wind turbines before and after a fault is mainly active power, with reactive power essentially zero. However, during a fault, the wind farm needs to maintain its connection to the grid for a period of time, during which the wind farm provides reactive power to support the grid voltage. Low-voltage ride-through control strategies are designed to address this grid voltage drop, ensuring that wind turbines can maintain a certain output power during a fault, or smoothly return to normal operation after the fault is cleared.

[0098] When a fault occurs, the fault voltage sensed by each unit is not consistent due to the impedance of the collector lines. Furthermore, the fault recovery process also differs because the initial operating conditions of each unit are different.

[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, to accurately understand the unit's behavior under fault conditions, the unit's output characteristics during fault occurrence and recovery are determined based on the unit's output characteristics before and after fault occurrence and recovery, according to a preset proportional coefficient. Based on the active power coefficient, reactive power coefficient, and slope coefficient set by the low-voltage ride-through control strategy, and combined with the fault voltage reference values ​​and unit port voltages for each unit, the active and reactive power outputs of the unit during fault occurrence and recovery are determined based on the active and reactive power outputs before and after fault occurrence and recovery.

[0101] Furthermore, 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 occurred, determine the active power of the second unit of the unit when the fault occurred according to the preset active power coefficient.

[0103] For example, based on the active power of the first unit of the generator before the fault occurred, the active power of the second unit of the generator at the time of the fault is determined according to a preset active power coefficient. After the active power coefficient for the change in the active power output ratio of the generator at the time of the fault is preset according to the low voltage ride-through control strategy, the active power of the first unit of the generator before the fault occurred is multiplied by the active power coefficient to obtain the active power of the second unit of the generator after power control at the time of the fault. The formula for calculating the active power of the second unit is:

[0104] P 中 =k LVET_p P 前 (1),

[0105] In the formula, P 中 k represents the active power of the second unit of the generator set at the time of the fault. LVET_p P is the active power coefficient. 前 This represents the unit's first active power before the fault occurred.

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

[0107] For example, based on the unit port voltage and a preset fault voltage reference value, the first reactive power of the unit when a fault occurs is determined according to a preset reactive power coefficient. After the reactive power coefficient for the proportional change of the unit's reactive power output when a fault occurs is preset 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. The calculated voltage difference is multiplied by the reactive power coefficient to obtain the first reactive power of the unit after power control when a fault occurs. The formula for calculating the first reactive power is:

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

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

[0110] Step S303: Determine the recovery type of the fault recovery. If the recovery type is slope recovery, then the active power of the third unit of the unit during the recovery process is determined based on the active power of the second unit and the preset slope coefficient; or, if the recovery type is immediate recovery, then 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 during the fault recovery.

[0111] Specifically, the recovery type of the unit fault recovery is determined. If the recovery type is slope recovery, the active power of the third unit during the recovery process is determined based on the active power of the second unit and a preset slope coefficient. Alternatively, if the recovery type is immediate recovery, the active power of the fourth unit after fault recovery is determined as the active power of the third unit during fault recovery. First, the recovery type of each unit during the fault recovery phase is determined based on its initial operating state. Then, the output power of the unit is calculated based on the recovery type.

[0112] When the unit recovery type 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 preset according to the low voltage ride-through control strategy, the slope coefficient is multiplied by the recovery time and added to the second unit active power calculated in step S301 to obtain the third unit active power during the fault recovery process.

[0113] When the unit's recovery type is determined to be immediate recovery based on its initial state, it means that the unit's output power can be quickly restored after the fault is cleared, and the recovery time is negligible. Therefore, under the immediate recovery method, the active power of the third unit during fault recovery can be approximately considered to be the same as the active power of the fourth unit after fault recovery. The formula for calculating the active power of the third unit is:

[0114]

[0115] In the formula, P 恢复 P represents the active power of the third unit during fault recovery. 后 P represents the active power of the fourth generating unit after the fault was repaired. k t is the preset slope coefficient, and t is the recovery time.

[0116] Step S304: Based on the active power of the second unit, the reactive power of the first unit, and the active power of the third unit, obtain the output characteristics of the unit during fault occurrence and recovery.

[0117] Understandably, the active power of the second unit reflects the change in the unit's output active power at the instant the fault occurs, the reactive power of the first unit reflects the change in the unit's output reactive power at the instant the fault occurs, and the active power of the third unit reflects the change in the unit's output active power during fault recovery. By summarizing the power change characteristics of the units at the critical time points of the fault, the output characteristics of the units during fault occurrence and recovery can be 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: Establish a voltage difference model based on 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 equations between the connection point of each wind turbine and the common point on the collector line are established, and the voltage of each unit at the collector line node is calculated. Then, a voltage difference model is established based on the voltage difference between adjacent units at the collector line node. The expression for the voltage difference model is as follows:

[0121]

[0122] In the formula, ΔU 机_k Z represents the voltage difference between the collector nodes of the k-th unit and the (k+1)-th unit. 集电线_k P is the impedance of the collector wire. 机_j U represents the active power output of the j-th generating unit, and U is the voltage of the collector bus.

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

[0124] Specifically, after establishing the voltage difference model, the voltage difference model is transformed to obtain the power loss model between adjacent units. Equation (4) is transformed according to Ohm's law and the power calculation formula. This transformation involves complex operations on voltage and impedance. After the voltage difference model transformation, a power loss model considering active and reactive power losses on the collector line is obtained. The expression for the power loss model is:

[0125]

[0126] In the formula, ΔPc is the active power loss of the collector line between the k-th unit and the (k+1)-th unit, and ΔQc is the active power loss of the collector line. 集电线 R represents the reactive power loss of the collector wires between the k-th unit and the (k+1)-th unit. 集电线_k Let X be the collector resistance of the k-th unit and the (k+1)-th unit. 集电线_k Let be the collector reactance of the k-th unit and the (k+1)-th unit.

[0127] Step S403: Calculate the power loss on the collector wire according to the power loss model to obtain the collector wire power model.

[0128] Specifically, the power loss on the collector line is calculated based on the power loss model to obtain the collector line power model. Assuming there are n1 generating units on the collector line, after obtaining the power loss models between adjacent units, the active power loss and reactive power loss between adjacent units are superimposed, summed from k=1 to k=n1, to obtain the collector line power models considering both the active power and reactive power delivered by the collector line. The expression for the collector line power model is:

[0129]

[0130] In the formula, P 输出_集电线 To account for losses, the active power delivered by the collector wire is Q. 输出_集电线 The reactive power delivered by the collector wire is taken into account for losses.

[0131] Step S404: Based on the collector power model, derive the output characteristics of the wind farm under the condition of multiple collectors to obtain the wind farm output model considering power distribution.

[0132] Specifically, based on the collector power model, the output characteristics of a wind farm with multiple collectors are derived, resulting in a wind farm output model considering power distribution. Considering the presence of multiple collectors in a wind farm, assuming there are m collectors, formula (6) can be generalized by deriving the output characteristics of the wind farm with multiple collectors, yielding a wind farm output model considering power distribution. The expression for the wind farm output model is:

[0133]

[0134]

[0135] In the formula, P output is the active power output model of the wind farm considering power distribution, and Q output is the reactive power output model of the wind farm considering power distribution. 计划 P contributed to the wind farm project. 机 _j,h represents the active power output of the h-th generator in the j-th collector line, Q 机 _j,h represents the reactive power output of the h-th generator unit in the j-th 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 the wind farm negative impedance model.

[0138] Specifically, the wind farm output model is equivalent to the wind farm negative impedance model. Treating the wind farm as a whole, the U, P, and Q outputs obtained from the wind farm output model established in step S101 are used to convert the wind farm into a wind farm load impedance model.

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

[0140] Specifically, a Y-type equivalent impedance model for the wind-thermal power plant bundled system is established based on the wind farm negative impedance model. The three sides of the Y-type equivalent model represent the thermal power impedance, the wind farm negative impedance, and the transmission line impedance. Using the wind farm negative impedance model and the thermal power plant negative impedance model as inputs, and the transmission line as the output, the wind-thermal power plant bundled system is merged and transformed using an equivalent transformation method, integrating it into an equivalent Y-type equivalent impedance model.

[0141] Step S503: Perform trigonometric transformation on the Y-type equivalent impedance model to obtain the wind and fire bundled equivalent model, wherein the three sides of the wind and fire bundled equivalent model are the electromagnetic impedance, the first grounding impedance, and the second grounding impedance.

[0142] Specifically, refer to Figure 2 A trigonometric transformation is performed on the Y-type equivalent impedance model to obtain the wind-fire bundled equivalent model, where the three sides of the wind-fire bundled equivalent model represent the electromagnetic impedance, the first grounding impedance, and the second grounding impedance. Using the thermal resistance impedance, wind farm negative impedance, and transmission line impedance obtained from the Y-type equivalent model, a trigonometric transformation is performed to calculate the electromagnetic impedance, the first grounding impedance, and the second grounding impedance, thus obtaining the wind-fire bundled equivalent model. The expression for the trigonometric transformation is:

[0143]

[0144]

[0145] In the formula, Z 电磁 For electromagnetic impedance, Z 接地1 Z is the first grounding impedance. 接地2 Z is the second grounding impedance. 火电 For the resistance impedance, Z 线路 For the output line impedance, Z 风电 It represents 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 equivalent model of wind and fire bundling, establish the relationship between electromagnetic power and generator power angle to obtain the electromagnetic torque model.

[0148] Specifically, based on the equivalent model of wind and fire bundling, the relationship between electromagnetic power and generator power angle is established, resulting in an electromagnetic torque model. Using the electromagnetic impedance calculated from the equivalent model of wind and fire bundling, and based on the generator electromotive force, the relationship between electromagnetic power and generator power angle is established, resulting in an electromagnetic torque model. The expression for the electromagnetic torque model is as follows:

[0149]

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

[0151] Step S602: Based on the balance between the mechanical power and electromagnetic power of the generator before the fault occurred, establish the first rotor motion equation before the fault occurred.

[0152] For example, based on the balance between the generator's mechanical power and electromagnetic power before the fault, the first rotor motion equation before the fault is established. Before the fault, the wind-fire bundling system is in a steady state, at which point the generator's mechanical power and electromagnetic power are in equilibrium. Equations are established based on the fundamental principles of rotor motion, and the balance between the generator's mechanical power and electromagnetic power before the fault is substituted into these equations to obtain the first rotor motion equation before the fault. The expression for the first rotor motion equation is:

[0153]

[0154] In the formula, T J Let P be the generator's inertial time constant, dω / dt represent the rate of change of the rotor's electrical angular velocity, and P be the generator's inertial time constant. 前_m P represents the mechanical power of the generator before the fault occurred. 前_e This represents the generator's electromagnetic power before the fault occurred.

[0155] Step S603: Based on the power difference between the mechanical power and electromagnetic power of the generator during fault occurrence and recovery, establish the second rotor motion equation that increases the power angle during fault occurrence and recovery.

[0156] For example, during a fault, the generator's mechanical power exceeds its electromagnetic power, causing the generator to accelerate and its power angle to increase. During fault recovery, although the generator's acceleration decreases, its power angle still increases. Therefore, based on the power difference between the generator's mechanical and electromagnetic power during fault occurrence and recovery, a second rotor motion equation is established to reflect the increase in power angle during both fault occurrence and recovery. The expression for the second rotor motion equation is:

[0157]

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

[0159] Step S604: Based on the power difference between the mechanical power and electromagnetic power of the generator after fault recovery, establish the third rotor motion equation with reduced power angle after fault recovery.

[0160] For example, after a fault is cleared and the fault is restored, the generator's electromagnetic power will exceed its mechanical power, and the power angle will decrease until a new equilibrium point is reached. Therefore, based on the power difference between the generator's mechanical power and electromagnetic power after fault restoration, a third rotor motion equation is established to account for the decrease in the power angle after fault restoration. The expression for the third rotor motion equation is:

[0161]

[0162] In the formula, P 后_m P represents the mechanical power of the generator after the fault is repaired. 后_e This represents the electromagnetic power of the generator after the fault is recovered.

[0163] Step S605: Obtain the rotor motion model based on the first rotor motion equation, the second rotor motion equation, and the third rotor motion equation.

[0164] Specifically, the rotor motion model is obtained based on the first, second, and third rotor motion equations. By integrating the rotor motion equations obtained from the generator's operating states in three different stages—before a fault occurs, during fault occurrence and recovery, and after fault recovery—a complete rotor motion model is obtained.

[0165] Step S606: Obtain the wind-fire bundling power angle model based on the electromagnetic torque model and the rotor motion model.

[0166] Specifically, the power angle model for the air-fire bundling system is obtained based on the electromagnetic torque model and the rotor motion model. This power angle model, established by combining the electromagnetic torque model and the rotor motion model, reflects the power angle changes of the air-fire bundling system before, during, and after a fault, providing a foundation for subsequent analysis of the system's power angle stability.

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

[0168] Step S701: Obtain the initial generator power angle and initial speed of the wind-fire bundling system in steady-state operation before the fault occurs, based on 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 occurred are obtained based on the first rotor motion equation. (Refer to...) Figure 3 The generator's steady-state operation is analyzed using formula (12) established in step S602. Under steady-state conditions, the first rotor motion equation can be simplified to mechanical power equal to electromagnetic power. Then, the initial generator power angle before the fault can be solved using the electromagnetic torque model. Simultaneously, the initial rotational speed can be obtained by converting the rotor's angular velocity under steady-state conditions into rotational 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] For example, 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 fault occurrence and recovery.

[0172] Step S703: Based on the third rotor motion equation, obtain the maximum stable power angle at which the wind-fire bundling system reaches a new equilibrium point after fault recovery.

[0173] For example, the maximum stable power angle of the wind-fire bundling system to reach a new equilibrium point after fault recovery is obtained according to the third rotor motion equation. The maximum allowable stable power angle when the wind-fire bundling 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: Determine 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. It is used to help determine whether the system can maintain stable operation after a fault. (Refer to...) Figure 3 By comparing the generator's operating power angle with its maximum stable power angle, it can be determined whether the generator's operating power angle is greater than the maximum stable power angle, so as to perform a stability analysis of the system.

[0177] Step S802: 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.

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

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

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

[0181] Step S804: If the current system state is in a steady state, then the power angle stability analysis result is determined to be power angle stable.

[0182] Specifically, if the current system state is in a steady state, the power angle stability analysis result is determined to be power angle stable. Provided 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 combined system will not undergo significant changes in the short term, and the system will operate stably under the current operating conditions. Therefore, the power angle stability analysis result is determined to be power angle stable.

[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 initial speed into the second rotor motion equation to obtain the generator operating power angle and 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, if the generator operating power angle of the wind-fire combined system at time t is less than the maximum stable power angle, but the current system state is not in a steady state, then the generator operating power angle at time t+1 is calculated and compared with the maximum stable power angle.

[0185] The following is a detailed introduction and explanation of the solutions in the embodiments of the present invention, with reference to specific application examples.

[0186] Reference Figure 4In this embodiment, 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 access point is established by using the voltage difference between each wind turbine access point and the common point on the collector line. The power loss model on the collector line is calculated by using the voltage difference between adjacent units on the collector line. The power loss of each section of the collector line is superimposed to obtain the power model of the collector line. Finally, the power on all collector lines in the wind farm is accumulated to obtain the wind farm model considering the power distribution.

[0188] Then, the wind farm is considered as a whole, and the output model of the wind farm 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 from the three time periods before, during and after the fault to obtain the wind-fire bundled power angle model.

[0189] Finally, the power angle stability analysis was performed using the wind-fire bundled power angle model 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 bundled power angle stability analysis method considering the power distribution of the wind farm and the low-voltage control parameters is proposed. First, a wind farm output model is established using the voltage difference between the collector lines. The model considers the power distribution of each unit and refines the impact of inconsistent operating states of each wind turbine on the wind farm model. Then, through equivalent transformation of the wind-fire bundled system and combined with the wind farm model, an electromagnetic torque model and a rotor motion model are established to obtain the wind-fire bundled power angle model. This model considers the power distribution of each wind turbine, as well as the power control and fault recovery process under fault conditions, making the calculation results of the model closer to the actual model.

[0191] Please refer to Figure 5 This application also provides a system for analyzing the stability of the power angle of a bundled wind and fire system, which can implement the above-mentioned method for analyzing the stability of the power angle of a bundled wind and fire system. The system includes:

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

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

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

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

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

[0197] It is understood that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0198] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described wind-fire bundling power angle stability analysis method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0199] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment 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 according to another embodiment is illustrated. The electronic device includes:

[0201] The processor 901 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, 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 this application.

[0202] The memory 902 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 902 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 902 and is called and executed by the processor 901 using the wind-fire bundling power angle stability analysis method of the embodiments 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 enable communication and interaction between this device and other devices. Communication can be achieved via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

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

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

[0207] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for analyzing the stability of the wind-fire bundling angle.

[0208] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

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

[0210] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

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

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

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

[0214] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0215] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for analyzing the stability of the working angle of a wind-fire bundled device, characterized in that, The method includes the following steps: The power loss on the collector line is calculated based on the voltage difference between adjacent units on the collector line, resulting in a wind farm output model that considers power distribution. The wind farm output model is transformed into an equivalent model to obtain a wind-fire bundled equivalent model. An electromagnetic torque model is established based on the equivalent model of wind and fire bundling, and a rotor motion model is established for three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the power angle model of wind and fire bundling. The generator's operating power angle and maximum stable power angle are determined using the aforementioned wind-fire bundled power angle model. Based on the generator operating power angle and the maximum stable power angle, a stability judgment is made to determine the power angle stability analysis result. The process of establishing an electromagnetic torque model based on the equivalent model of the wind and fire bundling, and establishing rotor motion models for three time periods—before the fault occurs, during the fault occurrence and recovery, and after the fault recovery—to obtain the wind and fire bundling power angle model includes the following steps: Based on the aforementioned equivalent model of wind and fire bundling, the relationship between electromagnetic power and generator power angle is established, resulting in an electromagnetic torque model. The expression for this electromagnetic torque model is: ； In the formula, P 电磁 Electromagnetic power, E ′ represents the electromotive force of the generator. δ The generator power angle, U For collector bus voltage, Z 电磁 Electromagnetic impedance; Based on the balance between the generator's mechanical power and electromagnetic power before the fault occurred, the first rotor motion equation before the fault occurred is established, where the expression of the first rotor motion equation is: ； In the formula, T J The generator's inertial time constant, dω / dt Indicates the rate of change of rotor electrical angular velocity. P 前_m This represents the generator's mechanical power before the fault occurred. P 前_e The electromagnetic power of the generator before the fault occurred; Based on the power difference between the generator's mechanical power and electromagnetic power during fault occurrence and recovery, a second rotor motion equation is established to account for the increase in power angle during fault occurrence and recovery. The expression for this second rotor motion equation is as follows: ； In the formula, dδ / dt Indicates the rate of change of the generator's power angle. ω This is the per-unit value of the rotor's electrical angular velocity. ω 0 is a constant 2*π*50. P 故障_m The mechanical power of the generator during fault occurrence and recovery. P 故障_e This refers to the electromagnetic power of the generator during fault occurrence and recovery. Based on the power difference between the generator's mechanical power and electromagnetic power after fault recovery, a third rotor motion equation is established to account for the reduction in the power angle after fault recovery. The expression for this third rotor motion equation is as follows: ； In the formula, P 后_m This represents the mechanical power of the generator after the fault is repaired. P 后_e This refers to the electromagnetic power of the generator after the fault is recovered. The rotor motion model is obtained based on 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 based on the electromagnetic torque model and the rotor motion model.

2. The method according to claim 1, characterized in that, Before the step of calculating the power loss on the collector line based on the voltage difference between adjacent units on the collector line to obtain the wind farm output model considering power distribution, the wind-thermal bundled power angle stability analysis method also includes the following steps: Based on the unit's output characteristics before and after a fault occurs, the unit's output characteristics during fault occurrence and recovery are determined according to a preset proportional coefficient. The step of determining the unit's output characteristics during fault occurrence and recovery based on a preset proportional coefficient, according to the unit's output characteristics before and after a fault, includes the following steps: Based on the active power of the first unit before the fault occurred, the active power of the second unit of the unit when the fault occurred is determined according to the preset active power coefficient. 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 power coefficient. Determine the recovery type of the fault recovery. If the recovery type is slope recovery, then based on the active power of the second unit, determine the active power of the third unit of the unit during the recovery process according to the preset slope coefficient; or, if the recovery type is immediate recovery, then 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 during the fault recovery. The output characteristics of the generator set during fault occurrence and recovery are obtained based on the active power of the second generator set, the reactive power of the first generator set, and the active power of the third generator set.

3. The method according to claim 2, characterized in that, The process of calculating the power loss on the collector line based on the voltage difference between adjacent units on the collector line to obtain the wind farm output model considering power distribution includes the following steps: A voltage difference model is established based on the voltage difference between adjacent units on the collector line; The voltage difference model is transformed to obtain the power loss model between adjacent units; The power loss on the collector wire is calculated based on the power loss model to obtain the collector wire power model; Based on the power model of the collector line, the output characteristics of the wind farm under the condition of multiple collector lines are derived, and the output model of the wind farm considering the power distribution is obtained.

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

5. The method according to claim 1, characterized in that, The process of determining the generator operating power angle and maximum stable power angle using the wind-fire bundled power angle model includes the following steps: The initial generator power angle and initial speed of the wind-fire bundling system before the fault occurred are obtained based on the first rotor motion equation. Substituting the initial generator power angle and the initial rotational speed into the second rotor motion equation, the generator operating power angle is obtained; The maximum stable power angle of the wind-fire bundling system after fault recovery is obtained based on the third rotor motion equation.

6. The method according to claim 5, characterized in that, The process of determining the stability analysis result based on the generator operating power angle and the maximum stable power angle includes the following steps: Determine whether the generator operating angle is greater than the maximum stable angle; When the generator's operating power angle is greater than the maximum stable power angle, the power angle stability analysis result is determined to be power angle instability; If the generator operating power angle is less than or equal to the maximum stable power angle, then 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, then the power angle stability analysis result is determined to be power angle stable; If the current system state is not in a steady state, then 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 at the next moment to calculate the generator operating power angle.

7. A system for analyzing the stability of the working angle of a wind-fire bundled device, characterized in that, The system includes: The first module is used to calculate the power loss on the collector line based on the voltage difference between adjacent units on the collector line, and to obtain the wind farm output model that takes power distribution into account. The second module is used to perform an equivalent transformation on the wind farm output model to obtain an equivalent model of wind-fire bundling. The third module is used to establish an electromagnetic torque model based on the equivalent model of wind and fire bundling, and to establish rotor motion models from three time periods: before the fault occurs, during the fault occurrence and recovery, and after the fault recovery, to obtain the power angle model of wind and fire bundling. The fourth module is used to determine the generator's operating power angle and maximum stable power angle using the aforementioned wind-fire bundled power angle model; The fifth module is used to make a stability judgment based on the generator operating power angle and the maximum stable power angle, and to determine the power angle stability analysis result; The process of establishing an electromagnetic torque model based on the equivalent model of the wind and fire bundling, and establishing rotor motion models for three time periods—before the fault occurs, during the fault occurrence and recovery, and after the fault recovery—to obtain the wind and fire bundling power angle model includes the following steps: Based on the aforementioned equivalent model of wind and fire bundling, the relationship between electromagnetic power and generator power angle is established, resulting in an electromagnetic torque model. The expression for this electromagnetic torque model is: ； In the formula, P 电磁 Electromagnetic power, E ′ represents the electromotive force of the generator. δ The generator power angle, U For collector bus voltage, Z 电磁 Electromagnetic impedance; Based on the balance between the generator's mechanical power and electromagnetic power before the fault occurred, the first rotor motion equation before the fault occurred is established, where the expression of the first rotor motion equation is: ； In the formula, T J The generator's inertial time constant, dω / dt Indicates the rate of change of rotor electrical angular velocity. P 前_m This represents the generator's mechanical power before the fault occurred. P 前_e The electromagnetic power of the generator before the fault occurred; Based on the power difference between the generator's mechanical power and electromagnetic power during fault occurrence and recovery, a second rotor motion equation is established to account for the increase in power angle during fault occurrence and recovery. The expression for this second rotor motion equation is as follows: ； In the formula, dδ / dt Indicates the rate of change of the generator's power angle. ω This is the per-unit value of the rotor's electrical angular velocity. ω 0 is a constant 2*π*50. P 故障_m The mechanical power of the generator during fault occurrence and recovery. P 故障_e This refers to the electromagnetic power of the generator during fault occurrence and recovery. Based on the power difference between the generator's mechanical power and electromagnetic power after fault recovery, a third rotor motion equation is established to account for the reduction in the power angle after fault recovery. The expression for this third rotor motion equation is as follows: ； In the formula, P 后_m This represents the mechanical power of the generator after the fault is repaired. P 后_e This refers to the electromagnetic power of the generator after the fault is recovered. The rotor motion model is obtained based on 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 based on the electromagnetic torque model and the rotor motion model.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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